RVS AGRICULTURAL COLLEGE

(Affiliated to Tamil Nadu Agricultural University, Coimbatore - 3)

THANJAVUR – 613 402

FSN 111 – Principles of Food Science and Nutrition (1+1)

Theory Study Material
II - Semester

Course Teacher
Dr. B. KARPAGAVALLI, Ph. D
Assistant Professor (FSN)

2019
 FSN 111 Principles of Food Science and Nutrition (1+1)

Theory Schedule
1. Food Science – definition, scope and classification, food pyramid.
2. Methods, merits and demerits of moist heat, dry heat and microwave cooking of foods.
3. Importance and scope of nutrition and the relation of nutrition to health.
4. Carbohydrate – classification, functions, digestion and absorption, deficiency symptoms,
sources and requirements.
5. Protein – classification, functions, digestion and absorption, deficiency symptoms, sources
and requirements. Protein quality – supplementary value of protein.
6. Fat - classification, functions, digestion and absorption, deficiency symptoms, sources and
requirements. Rancidity – types. Determination of energy value of foods.
7. Fat soluble vitamins – A, D, E and K – functions, deficiency symptoms, sources and
requirements.
8. Water soluble vitamins - thiamine, riboflavin, niacin, pyridoxine, folic acid, cyanacobalamin,
biotin, pantothenic acid, ascorbic acid – functions, deficiency symptoms, sources and
requirements.
9. Mid Semester Examination
10. Minerals – calcium, iron, phosphorus, iodine, magnesium, zinc, sodium, potassium, fluorine
and chlorine – functions, sources, requirements and deficiency diseases.
11. Importance of water and maintenance of electrolyte balance. Health benefits of fibre.
12. Preservation of food by low and high temperature and food irradiation.
13. Processing of puffed, flaked and extruded products
14. Preservation by using sugar (jam, jelly, squash and marmalade), preservation by using salt
(brining and pickling) and use of preservatives in food preservation.
15. Food packaging – importance, types of packaging materials and nutrition labeling.
16. Common food adulterants and their detection.
17. Food laws and regulations and quality control standards - FSSAI, ISO, EU standards, FDA,
HACCP and Codex Alimentarius Commission.
 LECTURE - 1
INTRODUCTION TO FOOD SCIENCE – NEED AND SCOPE OF FOOD SCIENCE

Food is the basic necessity of man. It is a mixture of different nutrients such as

carbohydrate, protein, fat, vitamins and minerals. These nutrients are essential for growth,
development and maintenance of good health throughout life. The selection of foods best suited
for promoting health has been found out by trial and error by continued use. The knowledge of
nutrition has been built upon the observation by several pioneers. Lavoisier is referred as Father
of Nutrition due to his remarkable contribution in quantification of energy metabolism.
Food
Food is defined as any substance solid or liquid which when swallowed, digested and
assimilated nourishes our body.
Food science
Food Science can be defined as the application of the basic sciences and engineering to
study the fundamental physical, chemical and biochemical nature of foods and the principles of
food processing. It is a broad discipline which contains food chemistry, food analysis, food
microbiology, food processing and food engineering.
Nutrition
Nutrition is defined as “the science of foods and nutrients, their action, interaction and
balance in relationship to health and disease, the processes by which the organism ingests,
digests, absorbs, transports and utilizes nutrients and disposes of their end product” (Robinson
,1982).
Health
Health is defined by the World Health Organization (WHO) as the “State of complete
physical, mental and social well-being and not merely the absence of disease or infirmity”.
Malnutrition as defined by World Health Organization (WHO) is a pathological state
resulting from the intake of inadequate or excess quantity of food or nutrients.
Under-nutrition is the pathological state resulting from the intake of an inadequate
quantity of food over an extended period of time.
Over-nutrition is the pathological state resulting from the intake of an excess quantity of
food over an extended period of time.
Balanced diet
Balanced diet is a diet consisting of a variety of different types of food and providing
adequate amounts of the nutrients necessary for good health. A balanced diet should provide
around 60-70% of total calories from carbohydrate, 10-12% from protein and 20-25% of total
calories from fat.
Objectives of studying Food Science
 To understand the functions of foods
 To know how to select foods to meet our need for nutrients
 To understand the composition of food and the changes that occurs during preparation
 To learn the methods of food preparation
 The economic management of food budget to meet family’s needs efficiently.
 To increase variety and food availability through processing
 To avoid food borne diseases through sanitary handling and preparation.
Scope/Applications
 It is useful in developing palatable, nutritious, low cost foods.
 To develop new food products including those used in the space shuttle program.
 Food losses during storage and processing can be avoided by advanced methods of
preservation
 The nutrient content of foods can be altered to reduce or increase the nutritive value.
 Fruits and vegetables can be stored for long time by controlled atmospheric packaging.
 Food Scientists are making the foods as safe as possible. The judicious application of
food processing, storage and preservation methods helps to prevent outbreaks of food
poisoning by pathogenic microorganisms and toxic chemicals such as pesticides.
 Food Scientists work with nutritionists to develop standards for the optimal nutritional
content of the diet.
 Food Scientists are involved in establishing international food standards to promote and
facilitate world trade and to assure the wholesomeness of foods.
Classification of Foods
Man must eat to live and what he eats will affect to a high degree his ability to keep well,
to work and to live long. Food performs many vital functions in the body. There are different
food groups like cereals, pulses, fruits, vegetables, milk and meat products and nuts and oil seeds
etc. Foods are classified based on their functions and nutritive value.
Functional Classification of Foods
In functional classification foods are classified based on their function in our body.
1. Energy Yielding Foods
Foods rich in carbohydrates, fats and protein are called energy yielding foods. They
provide energy to carry out various professional, household and recreational activities. Each one
gram carbohydrate and protein gives 4 Kcal. While one gram of fat gives 9 Kcal.
 Cereals, pulses, nuts and oil seeds roots and tubers
 Pure carbohydrates like sugars and fats and oils.
2. Body Building Foods
Foods rich in protein are called body building foods. Protein helps in building and
repairing tissues. They are divided in to two groups.
 Plant source: Pulses, nuts and oil seeds
 Animal source: Egg, milk, meat, and fish etc.,
3. Protective and Regulatory Foods
Foods rich in protein, minerals and vitamins are known as protective and regulatory
foods. They are essential for health and regulate activities such as maintenance of body
temperature, muscle contraction, control of water balance, clotting of blood, removal of waste
products. Protective foods are classified into two groups.
 Foods rich in vitamins, minerals and protein - milk, egg, fish, liver
 Foods rich in vitamins and minerals only - green leafy vegetables, vegetables and
fruits
4. Health Maintaining Foods
Foods contain certain phytochemicals and antioxidants which help in preventing
degenerative diseases like cancer, heart disease etc. Whole grains, soy bean, green leafy
vegetables, fruits and vegetables and spices are rich in phytochemicals and antioxidants.
Food Groups / Nutritional Classification
Foods have been classified into different groups depending upon the nutritive value, for
the convenience of planning diets. Food groups like ‘Basic four’, ‘Basic five’, ‘Basic seven’ or
‘Basic eleven’ can be used for planning diets as per the convenience.
 1. Basic Four
Group Nutrients
Cereals, millets and pulses Energy, protein, B-vitamins, minerals
Vegetables and fruits Vitamins, minerals and fibre
Milk, milk products, and animal foods Protein, calcium, B-vitamins
Oils, fats, nuts and oilseeds Energy, protein, fat and fat soluble vitamins

2. Basic Five: ICMR Classification

Food Group Nutrients
1. Cereals, Grains and its Products: Rice, Wheat, Energy, protein, invisible fat,
Ragi, Bajra, Maize, Jowar, Barley, Rice Flakes, Wheat thiamine, folic acid, riboflavin, iron
Flour. and fibre
2. Pulses and legumes: Bengal gram, Black gram, Protein, invisible fat, thiamine,
Green gram, Red gram, Lentil (whole as well as dhals) riboflavin, folic acid, calcium, iron
Cowpea, Peas, Rajmah, Soya beans, Beans. and fibre
3. Milk and Meat products:
Protein, fat, riboflavin, calcium,
Milk, Curd, Skimmed milk, Cheese
iron, vit ‘A’
Chicken, Liver, Fish, Egg, Meat
4. Fruits and Vegetables: Carotenoids, vitamin C, riboflavin,
Fruits: Mango, Guava, Tomato Ripe, Papaya, Orange. folic acid, iron, potassium,
Sweet Lime, Watermelon. phosphorus and fibre.
Vegetables (Green Leafy): Amaranth, Spinach,
Drumstick leaves, Coriander leaves, Mustard leaves,
and fenugreek leaves.
Other Vegetables: Carrots, Brinjal, Ladies fingers,
Capsicum, Beans, Onion, Drumstick, Cauliflower.
5. Fats and Sugars: Energy, essential fatty acids, iron
Fats: Butter, Ghee, Hydrogenated oils, Cooking oils
like Groundnut, Mustard, Coconut.
Sugars : Sugar, Jaggery
 3. Basic Seven
Group Nutrients
1.Green and yellow vegetables Carotenoids, fibers
2. Oranges, grape fruit, tomatoes or raw cabbage Vitamin c, carotenoids
3. Potatoes, other vegetables Carbohydrate
4. Milk and milk products Protein, fat, calcium, phosphorus
5. Meat, poultry, fish and eggs Protein, fat, iron, vitamin A,
6. Bread, flour and cereals Protein, thiamine, riboflavin, iron and
fibre
7. Butter or fortified margarine Fat and fat soluble vitamins.

IV. Basic Eleven

Group Nutrients
1. Cereals Carbohydrate (starch), thiamine, riboflavin, and fibre
2. Pulses Protein, starch, fiber
3. Nuts and oil seeds Fat, protein and minerals
4. Vegetables Vitamins, minerals and fiber
5. Fruits Vitamins, minerals and fiber
6. Milk and milk products Protein, fat, calcium, phosphorus
7. Eggs Protein, fat, vitamin D, vitamin A
8. Flesh foods, fish Protein, iron, calcium, phosphorus, vitamin B6, vitamin
B12, ω-3 fatty acids
9. Fats and oils Fat and fat soluble vitamins
10. Sugar and jaggery Energy and iron
11. Spices and condiments Phytochemicals and antioxidants

In planning balanced diet food should be chosen from each group in sufficient quantity.
Cereals and pulses should be taken adequately; fruits and vegetables liberally; animal foods
moderately and oils and sugars sparingly
Food Pyramid
A food pyramid is a pyramid shaped diagram representing the amount and type of food to
be included in our diet. It is an outline of what to eat each day. The first pyramid was published
in Sweden in 1974. The USDA food guide pyramid was created in 1992 and divided into six
horizontal sections containing depictions of foods from each section's food group. It was updated
in 2005 with colorful vertical wedges replacing the horizontal sections and renamed My
Pyramid. My Pyramid was often displayed with the food images absent, creating a more abstract
design. In an effort to restructure food nutrition guidelines, the USDA rolled out its new My
Plate program in June 2011. My Plate is divided into four slightly different sized quadrants, with
fruits and vegetables taking up half the space, and grains and protein making up the other half.
The vegetables and grains portions are the largest of the four.

Food Guide Pyramid (USDA, 1992)

The USDA's updated Food Pyramid (2005)

My Plate (2011)
 LECTURE –2
METHODS OF COOKING

Food preparation is an important step in meeting the nutritional needs of the family. Food
has to be pleasing in appearance and taste in order to be consumed. Foods like fruits, vegetables
and nuts can be eaten raw but most foods are cooked to bring about desirable changes. The
process of subjecting food to the action of heat is termed as cooking.
Objectives / Merits of Cooking
 Improves the palatability, appearance, flavour, texture and taste of food quality
 Destruction of microorganisms
 Improves digestibility
 Increases variety
 Increase consumption of food
 Increase availability of nutrients
 Concentrates nutrients
Demerits of Cooking
 Heat sensitive nutrients (vitamins) may be lost during cooking.
 Water soluble vitamins are leached into the water during cooking.
 Vitamin A & C content may be reduced due to oxidation and heat.
 Quality of protein may be reduced due to destruction of certain amino acids during
cooking e.g. bread

COOKING METHODS
Heat may be transferred to the food during cooking by conduction, convection, radiation
or by the energy or microwaves – electronic heat transfer.
Water or steam and air or fat or combinations of these are used as cooking media. Moist
heat involves water and steam. Air or fat are used in dry heat. Foods can also be cooked by
microwaves.
Classification of cooking methods:
1. Moist heat methods
Boiling, simmering, stewing, poaching, steaming and pressure cooking
 2. Dry heat methods
Grilling or broiling, toasting, pan broiling or roasting, baking, sautéing and frying
3. Combination methods
Braising
I. MOIST HEAT METHODS
Boiling:
Boiling is a method of cooking foods by just immersing them in water at 100ºC and
maintaining the water at that temperature till the food is tender. Foods that are cooked by boiling
are rice, eggs, dhals, meat, roots and tubers.
Merits
 It is a simple method
 It does not require special skill and equipment.
 Uniform cooking can be done.
Demerits
 Continuous excessive boiling leads to damage in the structure and texture of food.
 Loss of heat labile nutrients and water soluble nutrients.
 Time consuming – Boiling takes more time to cook food and fuel may be wasted.
 Water soluble pigments may be lost.
Simmering
Foods are cooked in a pan with a well-fitting lid at temperature just below the
boiling point 82 – 92ºC of the liquid in which they are immersed. It is a useful method when
foods have to be cooked for a long time to make it tender as in the case of cheaper cuts of meat,
fish, cooking custard, kheer, vegetables and carrot halwa. This method is also employed in
making soups.
Merits
 Foods get cooked thoroughly
 Scorching or burning is prevented
 Losses due to leaching is minimum
Demerits
 There is loss of heat sensitive nutrients, due to long period of cooking.
 Takes more time and more fuel is required.
Stewing
Food is cooked in a pan with a tight fitting lid, using small quantities of liquid to
cover only half the food. The liquid is brought to a boiling point and the heat applied is reduced
to maintain the cooking at simmering temperature (82 - 90ºC). The food above the liquid is
cooked by the steam generated within the pan. Apple, meat along with some root vegetables and
legumes are sewed.
Merits
 Loss of nutrients by leaching does not takes place.
 Falvour is retained.
Demerits
 This process is time consuming and there is wastage of fuel.
Poaching
This involves cooking in the minimum amount of liquid at a temperature of 80-85°C
that is below the boiling point. Foods generally poached are eggs, fish and fruits.
Merits
 No special equipment is needed
 Very quick method of cooking and therefore saves fuel
 Easily digestible since no fat is used.
Demerits
 It is bland in taste.
 Food can be scorched if water evaporates due to careless monitoring.
 Water soluble nutrients may be leached into the water.
Steaming
Food is cooked in steam generated from vigorously boiling water or liquid in a pan
so that the food is completely surrounded by steam and not in contact with the water or liquid.
Foods prepared by steaming are idli, dhokla, rice (or) ragi puttu, idiappam, appam, kolukattai
and custards. There are two types of steaming
Wet steaming
The steam is in direct contact with the food e.g. idli.
Dry steaming
Double boiler is used for cooking the food. Double boiling is cooking in a container over
hot or boiling water. This process is used for such preparations as sauces and custards where
temperatures below boiling point are desirable. The food is placed in a utensil which is kept in
another utensil containing water. When the water is heated or boiled the food gets cooked.
Merits
 Cooking time is less and fuel wastage is less.
 Steamed foods are easily digestible contain less fat and are good for children, aged
people and therapeutic diets.
 There is less chance for burning and scorching.
 Texture of the food is better and becomes light and fluffy.
 Steamed foods have good flavour.
 Nutrient loss is minimised
Demerits
 Steaming equipment is required.
 Many foods cannot be prepared by this method
Pressure cooking
When steam under pressure is used the method is known as pressure cooking and the
equipment used is the pressure cooker. In pressures cooking, escaping steam is trapped and kept
under pressure so that the temperature of the boiling water and steam can be raised above 100ºC
and reduce cooking time. Rice, dhal, meat, roots and tubers are usually pressure cooked.
Merits
 It takes less time to cook.
 Different items may be cooked at the same time.
 Fuel is saved.
 Requires less attention.
 Nutrient and flavour loss may be less.
 Food is cooked thoroughly by this method.
 There is an indication for the completion of cooking.
 Less chances for scorching or burning.
Demerits
 Knowledge of the usage, care and maintenance of cooker is required to prevent accidents.
 Initial investment is not affordable to everybody
 Careful watch on the cooking time is required to prevent over cooking

II. DRY HEAT METHODS

In this method either air or fat is used as the medium of cooking.
Air as medium of cooking
Grilling (or) Broiling
Grilling or broiling refers to the cooking of foods by exposing it to direct heat. In this
method food is placed below (or) above (or) in between a red hot surface. When under the
heater, the food is heated by radiation only. Foods cooked by grilling are cob on the corn, papad,
brinjal, phulkas, sweet potato and chicken.
Merits
 Enhance flavor, appearance and taste of the product
 It requires less time to cook
 Minimum fat is used
Demerits
 Constant attention is required to prevent charring.
Toasting
This is a method where food is kept between the two heated elements to facilitate
browning on both sides. Bread slices are cooked by toasting.
Merits
 Quick method of cooking.
 Less or no fat is required.
 Flavour is improved.
Demerits
 Constant attention is required to prevent charring.
 Special equipment required
Pan broiling (or) Roasting:
In this method food is cooked in a heated metal or frying pan without covering it. Eg.
Groundnut.
Merits
 Improves the appearance, colour, flavour and texture of the food.
 Reduces the moisture content of the food and improves the keeping quality e.g. rava.
 It is easy to powder e.g. cumin seeds and coriander seeds after roasting.
 It is one of the quick methods of cooking foods.
Demerits
 Constant attention is required otherwise the foods can be scorched
 Losses of nutrients like amino acids occur when the food becomes brown.
Baking
In this method the food gets cooked in an oven by hot air. The principle involved in
baking is the air inside the oven is heated by a source of heat either electricity (or) gas and wood
in the case of tandoori. The temperatures that normally maintained in the oven are 120°C –
260°C. Foods prepared by baking are custards, pies, biscuits, pizzas, puffs, buns, bread, cakes,
tandoori chicken, meat and fish.
Merits
 Baking lends a unique baked flavor to foods
 Foods become light and fluffy - cakes
 Flavour and texture are improved.
 Variety of dishes can be made.
 Uniform and bulk cooking can be achieved e.g. bun and bread.
Demerits
 Special equipment and skill are required.
 Careful monitoring needed to prevent scorching
Fat as a medium of cooking
Sauteing:
Sautéing is a method in which food is tossed in just enough of oil to cover the base of
the pan (greasing the pan) e.g. dosa. Sometimes the pan is covered with lid, reducing the flame
and allowing the food to be cooked till tender in its own steam. The product obtained in cooking
by this method is slightly moist, tender but without any liquid or gravy. Foods cooked by
sauteing are generally vegetables used as side dishes in a menu. The heat is transferred to the
food mainly by conduction.
Merits
 Take less time
 Simple technique
 Minimum oil is used
Demerits
 Constant attention is needed to prevent scorching
Frying:
In this method, the food to be cooked is brought into contact with larger amount of
hot fat. Two types: Shallow fat frying and deep fat frying.
Shallow fat frying:
The food is cooked in only little fat and the food is turned in both sides in order to cook
on both sides. Heat is transferred to the food partially by conduction by contact with the heated
pan and partially by the convection currents of the foods. e.g. Paratha, Chaphti, Cashewnuts,
potatoes, fish, cutlets.
Deep fat frying:
Food is totally immersed in hot oil and cooked by vigorous convection currents and
cooking is uniform on all sides of the foods. Cooking can be rapidly completed in deep fat frying
because the temperature used is 180°C - 220°C. In most foods, this high temperature results in
rapid drying out of the surface and the production of a hard crisp surface, brown in colour.
Samosa, papad, chips, muruku, pakoda, bajji and bonda are made by deep fat frying.
Merits
 Taste is improved along with the texture.
 Increases the calorific value.
 Fastest method of cooking.
 In shallow fat frying the amount of oil consumption can be controlled.
Demerits
 Sometimes the food may become oily or soggy with too much absorption of oil.
 More attention is required as foods easily get charred and care should be taken to avoid
 accidents.
 Fried foods are not easily digested.
 Repeated use of heated oils may produce harmful substances (acrolein, which causes
irritation to the eyes and nose).
III. COMBINATION OF COOKING METHODS
Braising:
Braising is a combined method of roasting and stewing in a pan with a tight fitting
lid. Flavourings and seasoning are added and allowed to cook gently.
Many food preparations are made by not only single method but by a combination of
cooking methods.
Vermicelli payasam - Roasting and simmering
Vegetable curry - Sauteing and simmering
Uppma - Roasting and boiling
Meat cutlet - Boiling and deep frying
Vegetable pulav - Frying and simmering
Microwave cooking:
Microwaves are electromagnetic waves of radiant energy. These waves have penetrating
power and they excite the molecules of the food. The essential component of a microwave
oven is a magnetron which converts electrical energy into microwave energy. The
electromagnetic energy is transformed into heat energy, this heat, cooks the food. These waves
cannot pass through metal. They are reflected by metals and absorbed by food. The food is
placed on a rotating tray, and when the oven starts, microwaves are emitted which cook the food
the uniformly.
Merits
 Quick method – 10 times faster than conventional method.
 There is no wastage of energy.
 Loss of nutrients is minimized.
 Food gets cooked uniformly.
 Only the food gets heated and the oven does not get heated.
 Leftovers can be reheated without changing the flavour and texture of the product.
 It saves time in heating frozen foods. Thawing can be done in minutes or seconds.
  Preserves the natural colour of vegetables and fruits.
Demerits
 Due to short period of cooking, food does not become brown and crispness unless the
microwave has a browning unit.
 It is not possible to make chapathi or tandoori rotis
 It cannot cook soft or hard boiled eggs.
 Deep frying cannot be done
 The short cooking time may not give a chance of blending of flavours as in conventional
methods.
 The operator should be careful in operating the microwave oven since any exposure to
microwave oven causes physiological abnormalities.

Microwave Oven
 LECTURE 3
IMPORTANCE AND SCOPE OF NUTRITION AND THE RELATION OF NUTRITION
TO HEALTH
Nature has provided a variety of foods for man to consume and be healthy. We consume
food for maintenance of health, growth and to develop greater resistance against infections.
Foods contain substances called nutrients in varying proportions, which are needed for proper
growth and maintenance of life processes. Knowledge of the functions of these nutrients and
major food sources is necessary for man to formulate a nutritious diet.
NUTRITION
Nutrition is defined as a science concerned with the role of food and nutrients in the
maintenance of health.
Nutrition as defined by Robinson (1982) is “ the science of foods and nutrients, their
action, interaction and balance in relationship to health and disease, the processes by which the
organism ingests, digests, absorbs, transports and utilizes nutrients and disposes of their end
product”.
NUTRIENTS
Nutrients are the constituents in food that must be supplied to the body in adequate
amounts. These include Carbohydrates, Proteins, Fats, Minerals and Vitamins. Nutritional status
is the condition of health of the individual as influenced by the utilization of the nutrients..
HEALTH
Health is defined by the World Health Organization (WHO) as the “State of complete
physical, mental and social well-being and not merely the absence of disease or infirmity”. To
maintain good health and nutritional status one must eat a balanced food, which contains all the
nutrients in the correct proportion.
RELATION BETWEEN GOOD NUTRITION AND HEALTH
 Nutrition is a process in which the food that is consumed is used for nourishing the body.
Good nutrition is essential for good health.
 Nutrition is very important for a person to grow and develop normally and to remain
healthy throughout life.
  When a person does not eat proper food, there are chances of his not developing
normally- the likelihood that some organ of his body may start malfunctioning, or that he
may get some disease?
 Poor nutrition may also influence his mental and social well-being.
 Thus, generally, the health of a person depends on the kind and amount of food he eats.
 The right kind of food eaten in the right quantity is necessary for good health.
The essential requisites of health would include the following:
 Achievement of optimal growth and development, reflecting the full expression of one’ s
genetic potential.
 Maintenance of the structural integrity and functional efficiency of body tissues
necessary for an active and productive use.
 Mental well-being
 Ability to withstand the inevitable process of aging with minimal disability and
functional impairment.
 Ability to combat diseases such as
– resisting infections (immunocompetence)
– preventing the onset of degenerative diseases
– resisting the effect of environmental toxins/ pollutants
Till three decades ago the role of nutrition in growth and development and tissue integrity
alone was clear, but now the persuasive role nutrition plays in the other dimensions of health is
implicit. Hence an optimal nutritional status is an indication of good health. This recent advance
has brought about a large-scale change in dietary habits and practices of the population.
CONCEPTS OF MALNUTRITION – UNDER NUTRITION AND OVER NUTRITION
Malnutrition as defined by World Health Organisation (WHO) is a pathological state
resulting from a relative or absolute deficiency or excess of one or more essential nutrients, this
state being clinically manifested or detected only by biochemical, anthropometric or
physiological tests.
Four forms can be distinguished:
1. Undernutrition – the pathological state resulting from the consumption of an inadequate
quantity of food over an extended period of time.
 2. Marasmus is synonymous with severe undernutrition. Starvation implies total elimination
of food and hence the rapid development of under nutrition and marasmus.
3. Specific deficiency – the pathological state resulting from a relative or absolute lack of an
individual nutrient.
4. Over nutrition – the pathological state resulting from a disproportion of essential nutrients
with or without the absolute deficiency of any nutrient as determined by the requirement
of a balanced diet.
IMPORTANCE OF NUTRITION
 Eating a balanced diet is vital for good health and wellbeing. Food provides our bodies
with the energy, protein, essential fats, vitamins and minerals to live, grow and function
properly. We need a wide variety of different foods to provide the right amounts of
nutrients for good health.
 Nutrition, nourishment, or aliment, is the supply of materials - food - required by
organisms and cells to stay alive. In science and human medicine, nutrition is the science
or practice of consuming and utilizing foods.
 In hospitals, nutrition may refer to the food requirements of patients, including nutritional
solutions delivered via an IV (intravenous) or IG (intragastric) tube.
 Nutritional science studies how the body breaks food down (catabolism) and repairs and
creates cells and tissue (anabolism) - catabolism and anabolism = metabolism. Nutritional
science also examines how the body responds to food.
 Nutrition also focuses on how diseases, conditions and problems can be prevented or
lessened with a healthy diet.
 In addition, nutrition involves identifying how certain diseases, conditions or problems
may be caused by dietary factors, such as poor diet (malnutrition), food allergies,
metabolic diseases, etc.,
CLINICAL SIGNS OF NUTRITIONAL DEFICIENCY DISORDERS
Clinical examination is an important practical method for assessing the nutritional status
of a community. Essentially, the method is based on examination for changes, believed to be
related to inadequate nutrition that can be seen or felt in the superficial epithelial tissues
especially the skin, eyes, hair and buccal mucosa or in organs near the surface of the body such
as the parotid and thyroid glands.
 Clinical assessment must always be carried out by individuals with adequate training.
The following simple guide is employed to interpret the following deficiencies.
Guide for the interpretation of deficiencies and identifying the clinical signs.
Condition Clinical Signs
(i)Protein Energy Odema, depigmentation, sparseness and easy pluckability
Malnutrition : of hair, moon face, enlarged liver, muscle wasting
(ii) Vitamin A deficiency : Night blindness, Bitot’ s spots in the eye, Xerosis of skin.
(iii) Riboflavin deficiency : Angular stomatitis, cheilosis.
(iv) Thiamine deficiency : Oedema, sensory loss, calf muscle tenderness.
(v) Niacin deficiency : Raw tongue, pigmentation of the skin
(vi) Vitamin C deficiency : Spongy and bleeding gum.
(vii) Vitamin D deficiency : Rickets, beading of ribs, Knock – knees, bowed legs.
(viii) Iron deficiency : Pale conjunctiva, spoon – shaped nails.
(ix) Iodine deficiency : Enlargement of thyroid gland.

Dietitian’s physicians can observe physical signs that suggest good or poor nutrition as listed in
the table
GOOD NUTRITION BAD NUTRITION
Body size Normal weight for height body Recessive obesity or thinness,
frame and age, normal rate of sudden loss or gain in weight failure
growth to grow in stature to gain weight.
Behaviour Alert ,good attention span, Apathetic, short attention span,
regular attendance, cooperative, frequent absence. Irritable, easily
cheerful, interested ,has fatigue, inability to concentrate, poor
endurance work capacity
Skin Firm, clear, slightly moist, Dry, pale scaly around ears and
healthy, pink mucous nose, bed sores, brittle ridged nails
membrane, firm pink nails
Hair Soft, glossy, healthy scalp Dry, brittle then easily pulled out,
change in pigmentation
Eyes Clear bright not unduly Red, swollen or dry, itching or
sensitive to light burning. Poor vision in dim light,
excessive, sensitivity to bright light.
Mouth Moist smooth, pink tongue with Chopped tissues at corners of lips.
 surface papillae, pink firm Swollen tongue – scarlet or magenta
gums. Even teeth, well-formed smooth in appearance. Bleeding
jaw. gums, receding from tooth line.
Decayed or missing teeth. Inability
to chew
Skeleton Erect posture, arms and legs Poor posture, deformities of long
straight abdomen in, chest chin bones, spines, pelvis, hump back,
in bow legs or knock ness
Neuromuscular Firm, strong muscles with Flabby under developed muscles,
system moderate padding of fat good lack of fat padding or excessive fat;
muscular co-ordination. poor muscle coordination reduced
knee and ankle reflexes, burning and
tingling of hands and feet.
Gastro intestinal Good appetite & digestion, Poor appetite, in digestion, diarrhea
system regular elimination or constipation
Glands No enlargement of thyroid Enlarged thyroid
Immune system Resistance to infections Frequent colds & other infections,
longer covalence from illness slower
wound healing
 LECTURE 4
CARBOHYDRATES
Energy that is needed to move, perform work and live is chiefly consumed in the form of
carbohydrates. Carbohydrates, primarily starches, are least expensive, easily obtained and readily
digested form of fuel.
COMPOSITION
Carbohydrates are organic compounds composed of carbon, hydrogen and oxygen, with
the later elements in the ratio of 2:1. The general formula is (CH2O)n. They are viewed as
hydrated carbon atoms.
CLASSIFICATION – SIMPLE AND COMPLEX:
Carbohydrates are classified, depending on the number of sugar units they contain, as
simple carbohydrate and complex carbohydrates.
SIMPLE CARBOHYDRATES
Monosaccharides and disaccharides are called simple sugars containing one and two
sugar units respectively.
Monosaccharides
There are two main classes of monosaccharides based on the carbonyl group present in
them. They are aldoses and ketoses, aldoses (eg; glucose) containing the aldehyde group (CHO)
and ketoses, (eg;- fructose) containing the ketone group (C=O). Aldoses are further divided into
trioses, tetroses, pentoses and hexoses based on the number of carbon atoms.
Glucose (Dextrose, Blood Sugar)
Glucose serves as the main source of energy in the body. Normal human blood contains
about 80-120 mg of glucose per 100ml of blood. This level is maintained constantly in healthy
subjects.
Fructose (Levulose, Fruit sugar)
Fructose occurs in the free state along with glucose in many fruits (2-5 per cent) and in
honey 30-40 per cent). It is utilised by the body as a source of energy.
Galactose
It does not occur in the free state but occurs as a constitute of lactose present in milk.
Disaccharides
Disaccharides are formed by the combination of two monosaccharides by the elimination
of one molecule of water.
Sucrose (Table sugar/Cane sugar/Beet sugar)
Sucrose occurs in sugar cane (10-12 per cent) and beet root (12-18 per cent). It is
manufactured on a large scale from sugar cane or beet root. Sucrose is hydrolysed to glucose and
fructose by dilute mineral acids or by the enzyme sucrase present in intestinal juice.
Maltose (Malt sugar)
Maltose is present in malt. It is formed in cereals grains (barley, jowar, ragi etc) during
germination by the hydrolysis of starch by the enzyme diastase (Amylase)

Starch Amylase Maltose Maltase Glucose (2 molecules)

Lactose (Milk sugar)

Lactose occurs in the milk of all mammals but has not so far been found in plant foods.
Lactose is hydrolysed to glucose and galactose by the enzyme lactase present in the intestinal
juice.

Lactose + H2O Lactase Glucose + Galactose

COMPLEX CARBOHYDRATES
Oligosaccharides and Polysaccharides are called Complex Carbohydrates.
Oligosaccharides
Oligosaccharides are short carbohydrate chains of 3 – 10 monosaccharides, which cannot
be broken down by human enzymes, though can be digested by colonic bacteria. Found in
legumes and human milk Examples: Raffinose and Stachyose.
Polysaccharides
Polysaccharides are structurally larger and more complex than simple sugars.
Polysaccharides have high molecular weight and are insoluble in water. They are in the form of
long chains either branched or unbranched. Examples include storage polysaccharides such as
starch and glycogen, and structural polysaccharides such as cellulose and chitin.
Storage Polysaccharides
Starch (Plant storage form of carbohydrate)
Starch is a glucose polymer in which glucopyranose units are bonded by alpha-linkages.
It is made up of a mixture of amylose (15–20%) and amylopectin (80–85%). Amylose is a
polysaccharide made of α-D-glucose units, bonded to each other through α (1→4) glycosidic
bond. It consists of a linear chain of several hundred glucose molecules. In amylopectin, glucose
units are linked in a linear way with α (1→4) glycosidic bond. Branching takes place with α
(1→6) bonds occurring every 24 to 30 glucose units. Starches are insoluble in water. They can
be digested by breaking the alpha-linkages (glycosidic bonds). Both humans and animals have
amylases, so they can digest starches. Potato, rice, wheat, and maize are major sources of starch
in the human diet.
Glycogen (Animal storage form of carbohydrate)
Glycogen is analogous to starch, referred to as animal starch having a similar structure to
amylopectin but more extensively branched and compact than starch. Glycogen is a polymer of α
(1→4) glycosidic bonds linked, with α (1→6)-linked branches. Glycogen forms an energy
reserve in liver and the muscles that can be quickly mobilized to meet a sudden need for glucose.
Structural polysaccharides
Cellulose
Cellulose is a polysaccharide consisting of a linear chain of several hundred to many
thousands of β(1→4) linked D-glucose units. It is a polymer made with repeated glucose units
bonded together by beta-linkages. Cellulose is an important structural component of plants is
formed primarily from cellulose. Humans and many animals lack an enzyme to break the beta-
linkages, so they do not digest cellulose.
Chitin
Chitin is one of many naturally occurring polymers. It forms a structural component of
many animals, such as exoskeletons. Its breakdown may be catalyzed by enzymes called
chitinases, secreted by microorganisms such as bacteria and fungi, and produced by some plants.

The polysaccharides are further classified into groups depending upon the products they
yield on hydrolysis. Homopolysaccharides yield only one type of monosaccharide units on
hydrolysis eg:- starch, dextrin, cellulose, glycogen. Heteropolysaccharides yield more than one
type of monosaccharide units on hydrolysis eg:- Heparin, Hyaluronic acid. Heparin is an
anticoagulant found in the liver, spleen, lungs and blood. Hyaluronic acid is found in the
umbilical cord, synovial fluid and vitreous humour. It has a lubricating action. In tissues it forms
an important part of the cementing ground substance.

FUNCTIONS OF CARBOHYDRATES
Carbohydrates have a variety of functions in the animal and human body.
i. They supply energy for body functions and for doing work.
ii. They are essential for the oxidation of fats
iii. They have a sparing action on proteins.
 iv. They provide the carbon skeleton for the synthesis of some non-essential amino
acids, glycoproteins and glycolipids.
v. Some carbohydrates are present in some tissue constitutents.
vi. They add flavour to the diet.
vii. composite carbohydrates can absorb water and give bulk to the intestinal contents
which aids in the elimination of waste products
Protein Sparing Action:
Carbohydrates exert a protein sparing action. If sufficient amounts of carbohydrates are
not available in the diet, the body will convert protein to glucose in order to supply energy.
Hence to spare proteins for tissue building, carbohydrates must be supplied in optimum amounts
in the diet. This is called the protein sparing action of carbohydrates.
DIGESTION AND ABSORPTION OF CARBOHYDRATES
The first stage in the digestion of carbohydrates takes place in the mouth when the food is
chewed. The saliva contains an alpha amylase called ptyalin. This enzyme acts on starch
spliting it into dextrin and maltose amylase acts best at neutral pH. As soon as the food reaches
the stomach it mixes with the acidic gastric juice and amylase activity is inhibited. The digestion
of carbohydrates is mainly accomplished in the small intestines where they are subjected to the
action of pancreatic amylases and intestinal amylase, sucrase, lactase, maltase and isomaltase
present in the intestinal juice.

Amylase from saliva

Starch Maltose + Isomaltose
and pancreatic & intestinal
juice

Maltose Maltase glucose

Isomaltose Isomaltase Glucose

Sucrose Sucrase Glucose + Fructose
Lactose Lactase Glucose + Galactose

The ultimate products of digestion of carbohydrate are glucose, fructose and galactose.
These are absorbed in the small intestine (brush border of the epithelium covering the villi -
small hair-like structure). Only monosaccharaides are absorbed. The rate of absorption is
Galactose > Glucose > Fructose. The non-digestible carbohydrates present in the food. Viz.,
cellulose, hemicellulose, pentosans, galactans. Fructosane etc., are not acted upon by the
digestive juices. They add bulk to the contents of large intestines is excreted in the faeces. Some
of these are fermented by bacteria present in the large intestine.

Metabolism of carbohydrates
Glucose, galactose and fructose absorbed in the intestines pass through the portal
circulation to the liver. In the liver a part of the glucose and the entire galactose and fructose are
converted into glucose and enter into the general circulation and to the various tissues for being
oxidized and used as energy. A small part of glucose is stored in liver and muscle as glycogen
and some portion of the glucose is converted into fat stored in adipose tissue. The oxidation of
glucose in the issues occurs into 2 stages as indicated below:-
i. Glycogen glucose pyruvic acid lactic acid
Oxidation
ii. Pyruvic acid CO2 + H2O

The first stage is called glycolysis. The oxidation of pyruvic acid takes place through a
series of reactions known as tricarboxylic acid cycle (krebs cycle)
Regulation of Blood Glucose
The body needs glucose to make ATP (via cell respiration), however the amount required
will fluctuate according to demand. Normal Blood Glucose level 80 - 120 mg/100 ml. High
levels of glucose in the blood can damage cells (creates hypertonicity) and hence glucose levels
must be regulated. Two antagonistic hormones are responsible for regulating blood glucose
concentrations – insulin and glucagon. These hormones are released from pancreatic pits (called
the islets of Langerhans) and act principally on the liver.
When blood glucose levels are high (e.g. after feeding):
 Insulin is released from beta (β) cells of the pancreas and cause a decrease in blood
glucose concentration
 This may involve stimulating glycogen synthesis in the liver (glycogenesis), promoting
glucose uptake by the liver and adipose tissue, or increasing the rate of glucose
breakdown (by increasing cell respiration rates)
When blood glucose levels are low (e.g. after exercise):
  Glucagon is released from alpha (α) cells of the pancreas and cause an increase in blood
glucose concentration
 This may involve stimulating glycogen breakdown in the liver (glycogenolysis),
promoting glucose release by the liver and adipose tissue, or decreasing the rate of
glucose breakdown (by reducing cell respiration rates).

DIABETES MELLITUS
Diabetes mellitus is a metabolic disorder that results from a high blood glucose concentration
over prolonged period results in hyperglycemia. It is a chronic disease in which blood glucose
level is raised above 180 per 100 ml of blood and glucose is excreted in urine.
Causes
1. Insufficient production of insulin (Type I or Juvenile diabetes or insulin-dependent
diabetes)
2. Failing to respond to insulin production (Type II or non - insulin-dependent diabetes)
Symptoms
• Acute - increased thirst, urine production, hunger
• Chronic - risk of heart disease, kidney disease, blindness, neural damage

DEFICIENCY SYMPTOMS OF CARBOHYDRATES

Acidosis:
In carbohydrate starvation, there is shift from glycolysis (breakdown of glucose) to
lipolysis (breakdown of lipids) and ketogenesis for energy needs. The resultant production of
ketoacids increases acidity in the blood and other body tissues. These changes in the pH of
arterial blood outside 7.35 pH - 7.45 pH result in irreversible cell damage.
Ketosis:
During prolonged carbohydrate fasting or starvation, acetyl-CoA in the liver is used to
produce ketone bodies formed by the breakdown of fatty acids and by the deamination of amino
acids, leading to a state of ketosis.
Hypoglycemia:
The non availability of glucose due to severe lack of carbohydrate causes drop in the
blood sugar levels. Hypoglycemia occurs when blood glucose, levels drop under 70 mg/dL with
typical symptoms like giddiness, fatigue, distress and delirium.
Fatigue and decreased energy levels:
The immediate non availability of glucose in the blood for energy production, result in
dip in the energy levels and fatigue.
Muscle wasting:
As the fat reserves and amino acids are getting used up for energy production, there will
be general loss of muscle mass and impairment of growth.
Unhealthy weight loss:
The loss of fat and muscle mass leads to emaciation and weight loss.
Dehydration and reduced body secretions:
As there is loss of fluids from the body due to ketosis, a state of chronic dehydration is
reached. This results in reduction in mucus secretion, dry eyes and compromised mucus
production in tear glands, salivary glands, sinuses, airways, and gastrointestinal tract.
Loss of sodium:
Excess of ketone in the blood leads to fluid loss and excretion of sodium ions(Na+) from
the body. This may lead to muscle cramps, exhaustion and lassitude.
Weakened immune system:
With increased fluid loss and degradation, vitamin C loss from the body is increased.
Adding to this, the chronically dehydrated condition leads to weakened immune system and
susceptibility to infections.
Constipation:
Dietary fiber is an essential component of carbohydrate food, which is known to prevent
recto-colon cancer and help digestion. The absence of dietary fiber can cause constipation.
Mood swing:
Dietary carbohydrate exclusion causes the brain to stop regulating serotonin hormone.
Low serotonin supply causes mood swing and depression.
FOOD SOURCES OF CARBOHYDRATES
Cereal grains, roots and tubers are the major sources of starch. Fruits and vegetables
contain varying amounts of monosaccharides and dissaccharides. Sugar is obtained from
sugarcane. Types and sources of Carbohydrates are given in the table
Types and Sources of Carbohydrates
Carbohydrate Food Source
Monosaccharides
Glucose Fruits, honey, corn-syrup.
Fructose Fruits and honey.
Galactose, Maltose These do not occur in free form in foods.
Dissaccharides
Sucrose Cane and beet sugar.
Lactose Milk and milk products.
Maltose Malt and Cereal products.
Polysaccharides
Digestible:
Starch & Dextin Grains, vegetables especially roots& tubers
and legumes
Glycogen Meat products and sea foods
Indigestible:
Cellulose Stalks and leaves of vegetables, outer coat of
seeds
Pectins, Gums Fruits, Plant secretions and seeds.

REQUIREMENTS
As carbohydrate is utilized as main source of energy, at least 40 percent of the total
energy in the food should come from Carbohydrates. In our country 60 – 80 percent of a day’s
energy needs are met from carbohydrates in the form of starch furnished by cereals and pulses.
In developed countries only 30 – 40 percent of days energy needs are met from carbohydrates.
The percentage of total energy intake for adults and Adolescents (50 - 70%), Pregnant and
lactating women (40 -60 %), Infants and Preschool children (40 -50 %).
 LECTURE 5
PROTEIN
The name protein was suggested by Mulder in 1838. One fifth of an adults total body
weight is protein. Protein is found in every cell of our body. All the tissues in our body such as
muscle, blood, bone, skin and hair are made up of proteins. Many hormones and enzymes are
either protein or protein derivatives. The nucleic acids in the cell nucleus occur in combination
with proteins as nucleoproteins.
COMPOSITION
Proteins contain carbon, hydrogen, oxygen and nitrogen. They are distinguished from
carbohydrates and fats by the presence of nitrogen. Protein is synthesized from basic units
called amino acids. Protein molecules, which contain up to hundred amino acids, are much
larger than carbohydrates or lipid molecule.
Amino acid
Amino acids are organic compounds containing amine (-NH2) and carboxyl (-COOH)
functional groups, along with a side chain (R group) specific to each amino acid
CLASSIFICATION OF AMINO ACIDS
Amino acids are classified based on a variety of features, including whether people can
acquire them through diet. Three amino acid types:
1. Essential
2. Nonessential
Essential Amino acids
An essential amino acid is one that cannot be synthesized by the body to meet the
physiological needs. So it should be supplied by the diet. Eight of these amino acids are
essential (or indispensable) and cannot be produced by the body. Eight amino acids (Leucine,
Isoleucine, Valine, Threonine, Methionine, Phenylalanine, Tryptophan and Lysine) are
considered essential for adults and nine (those mentioned above plus Histidine) for children.
Nonessential amino acids
Nonessential amino acids are produced by the human body either from essential amino
acids or from normal protein breakdowns. Nonessential amino acids include:
1. Asparagine 7. Glutamine
2. Alanine 8. Proline
 3. Arginine 9. Glycine
4. Aspartic acid 10. Tyrosine
5. Cysteine 11. Serine
6. Glutamic acid
Amino acids' classification depends upon the side chain structure
• Sulfur containing amino acids - Cysteine and Methionine
• Neutral amino acids - Asparagine, Serine, Threonine, and Glutamine
• Acidic amino acids - Glutamic acid and Aspartic acid
• Basic amino acids - Arginine and Lysine
• Aliphatic amino acids - Leucine, Isoleucine, Glycine, Valine, and Alanine
• Aromatic amino acids - Phenylalanine, Tryptophan, and Tyrosine
CLASSIFICATION OF PROTEINS
I. BASED ON THE SOURCE OF PROTEIN MOLECULE
Proteins have been traditionally divided into two well defined groups animal proteins and
plant proteins
Animal proteins are the proteins derived from animal sources such as eggs, milk, meat
and fish. They are usually called higher quality proteins because they contain adequate
amounts of all the essential amino acids.
Plant proteins are the proteins derived from plant sources. They are called lower quality
proteins since they have a low content (limiting amount) of one or more of the essential amino
acids. The four most common limiting amino acids are methionine, lysine, threonine and
tryptophan. Although plant proteins have limiting amounts of some (but not all) amino acids, it
should not be construed that they are poor protein sources. Most plant foods tend to have too
little of one or more particular essential (indispensable) amino acids.
Table 1: Limiting amino acid in some plant proteins
Food Amino acids
Cereal grains and millets Lysine , Threonine
Rice and soy bean Methionine
Legumes Methionine, Tryptophan
Groundnuts Methionine, Lysine, Threonine
Sunflower seeds Lysine
Green leafy vegetables Methionine
II. BASED ON THE COMPOSITION
Simple protein
Proteins containing only amino acids are called simple proteins. On hydrolysis they
yield only amino acids.
Example: albumins, globulins, glutelins, prolamins, histones, protamins and fibrous protein
Conjugated or complex proteins
The protein which combined with non-protein substances like carbohydrate, lipid,
phosphorus, nucleic acid are called as conjugated protein.
Example: glycoprotein, lipoprotein, nucleoprotein, haemoglobins
 Glycoprotein - Carbohydrate & Protein
 Lipoprotein - Lipid & Protein
 Phosphoprotein - Phosphorus & Protein
 Haemoglobin - Haem & Protein
Derived proteins
These proteins are derived by partial to complete hydrolysis of simple or conjugated
proteins by the action of acids, alkalies or enzymes.
Types of derived proteins
 Primary derived proteins are derivatives of proteins in which the size of protein
molecule is not altered materially - Proteans, Metaprotein, Coagulated Protein (boiled
egg)
 Secondary derived proteins are derivatives of proteins in which the hydrolysis has
certainly occurred - Proteoses, Peptones, Peptides
BASED ON THE NUTRITIONAL VALUE
Complete Protein
A complete protein (or whole protein) is a source of protein that contains an adequate
proportion of all nine of the essential amino acids necessary for the dietary needs of humans.
Sources of complete proteins are mostly foods of animal origin such as milk, yogurt, cheese,
eggs, meat, fish, and poultry. The exceptions are gelatin, which is of animal origin but does not
have the indispensable amino acid tryptophan, and soy protein, which is of plant origin but is a
complete protein.
Partially Complete Protein
It is partially lacking in one or more essential amino acids, e.g., Wheat protein
(gluten).
Incomplete Protein
It is any protein that lacks one or more essential amino acids in correct proportions.
Incomplete proteins or low-quality proteins are derived from plant foods such as legumes,
vegetables, cereals, and grain products. Examples, Zein, gelatin. Incomplete protein containing
foods and their limiting amino acid(s) are listed in Table 1.
Complementary proteins
To ensure that the body receives all the essential amino acids, certain proteins can be
ingested together or combined so that their amino acid patterns become complementary. This
practice or strategy is called mutual supplementation. For example, legumes, with their high
content of lysine but low content of sulfur-containing amino acids, complement the grains, which
are more than adequate in methionine and cysteine but limited in lysine.
FUNCTIONS/IMPORTANCE OF PROTEIN
1. It helps in growth and repairs the body tissues.
2. Enzymes pepsin, trypsin, amylase etc., are made up of proteins.
3. It act the as catalyze in digestion of foods and other biochemical reactions.
4. Hormones such as insulin, growth hormones etc are also made up of protein. It regulates
metabolic functions of cells.
5. It aids in transmitting nerve signals from one nerve cell to another.
6. It aids in transporting nutrients from intestinal wall to blood.
7. Contractile protein, myosin and actin regulate muscle contraction.
8. It helps in the regulation of water balance in our body. Low blood protein level causes
oedema.
9. Proteins act as buffers in blood and maintain the optimum pH.
10. Antibodies are made up of proteins. It helps to fight against the infection.
11. Protein also a good source of energy. It provides 4 Kcal per gram of protein.
DIGESTION OF PROTEIN
Stomach
Pepsin is present in gastric juice and hydrolyses the peptide bonds in protein molecules. It
hydrolyses the dietary protein into polypeptides.
Pepsin
Dietary protein large Polypeptides
Small intestine
The polypeptides formed in stomach are digested in small intestine by trypsin,
chymotrypsin secreted in the pancreatic juice. Polypeptides are peptides, dipeptides or
tripeptides.
Polypeptide Trypsin & Chymotrypsin Peptides + Amino acids

The carboxypeptidase hydrolyses the peptides in to amino acid.

Peptides Carboxypeptidase Amino acids

The intestinal mucosa also contains dipeptidase and tripeptidase which hydrolyses
dipeptides and tripeptides, respectively into amino acids.
Dipeptides Dipeptidase Amino acids

Tripeptides Tripeptidase Amino acids

Absorption
The end product of digestion of protein is amino acids. The amino acids are absorbed in
small intestine and transported to the liver via hepatic portal vein.
DEFICIENCY DISEASES
Protein Energy Malnutrition (PEM) / Protein Calorie Malnutrition (PCM)
Protein Energy Malnutrition (PEM) is a form of malnutrition resulting from inadequate
protein and calorie intake. It is the primary nutritional problem in India. Due to the “food gap”
between the intake and requirement. It causes childhood morbidity and mortality.
 Kwashiorkor (deficiency in protein intake)
 Marasmus (deficiency in protein and calorie intake)
 Marasmic Kwashiorkor (both Kwashiorkor and Marasmus symptoms)
Kwashiorkor
The word Kwashiorkor was first introduced by Dr. Cicely Williams. The term
‘Kwashiorkor’ means ‘the disease which the child gets when the next baby is born’.
Signs and symptoms of Kwashiorkor
1. Growth failure and wasting of muscles.
2. Behavioural changes like irritability and apathy are common.
3. Oedema which is the accumulation of fluid in the tissues making them soft and spongy.
4. Scaly pigmentation of skin (crazy paveoment dermatosis)
5. Changes in hair (dry and sparse and red colour).
6. Loss of appetite, vomiting, diarrhoea
7. Enlargement of the liver.
8. Anaemia
9. Moon face (full well rounded face)
Marasmus
Nutritional Marasmus is due to the consumption of diet deficient in both protein and
energy.
Signs and symptoms
1. Growth retardation
2. Severe muscle wasting
3. Loss of subcutaneous fat
4. Child appear skin and bones
5. Irritability and apathy
6. Frequent diarrhoea
7. Dehydration
8. Oedema and fatty liver are absent
Marasmic Kwashiorkor
The child shows a mixture of the features of Marasmus and Kwashiorkor. The features
of kwashiorkor are severe oedema of feet and legs and also hands, lower arms, abdomen and
face. Pale skin and hair, and the child are unhappy. Signs of marasmus include wasting of the
muscles of the upper arms, shoulders and chest so that you can see the ribs.
Treatment
 Resolving life threatening conditions (Hospital Treatment)
Hypothermia, hypoglycemia, infection, dehydration, electrolyte imbalance,
anaemia and other vitamin and mineral deficiencies should be corrected
 Restoring nutritional status (Dietary Management)
Inexpensive, easily digestible, evenly distributed food throughout the day and
increased number of feedings to increase the quantity of food. Daily calorie intake should
be 140-150 Kcal/kg and protein intake 3-5 g/kg body weight.
 Ensuring nutritional rehabilitation (Rehabilitation)
Practical nutritional training for mothers
Prevention
1. Promotion of breast feeding
2. Development of low cost weaning
3. Nutrition education and promotion of correct feeding practices
4. Family planning and spacing of births
5. Immunization
6. Food fortification
7. Early diagnosis and treatment
FOOD SOURCE OF PROTEIN
 Pulses, oil seeds, nuts, soybeans, cereals and millets, bread, dry beans, peas, peanut butter
when combined with small amounts of egg, cheese, meat, fish and poultry give just as
good an assortment of amino acids as a large an amount of animal foods.
 Soya bean is the richest source with 40% protein followed by watermelon seeds (34%),
wheat germ (29%) and ground nuts (26%).
 Although cereals have low protein content, as they are being consumed in bulk, good
amount of protein is consumed. The quality of protein in rice is better than that of wheat.
 In vegetarian diets, a combination of cereal grains and legumes provide satisfactory
biological value.
Recommended dietary allowances (RDA) of protein
The Indian Council of Medical Research recommends 1.0 g/kg/day as the safe level of
intake in terms of dietary protein for Indians.
 Group Particulars Protein (g)
Men Sedentary work 60
Moderate work
Heavy work
Women Sedentary work 55
Moderate work
Heavy work
Pregnant women +23
Lactation
0-6 months +19
6-12 months +13
Infants 0-6 months 1.16 g/kg/d
6-12 months 1.16 g/kg/d
Children 1-3 years 16.7
(Preschool children)
4-6 years 20.1
7-9 years 29.5
Boys 10-12 years 39.9
Girls 10-12 years 40.4
Boys 13-15 years 54.3
Girls 13-15 years 51.9
Adolescents 16-17 (Boys) 61.5
16-17 (Girls) 55.5

Protein quality
The quality of a protein is determined by the kind and proportion of amino acid it
contains. Proteins that contain all essential amino acids in proportions capable of promoting
growth are described as complete protein, good quality protein, or proteins of high biological
value.
 A good quality protein is digested and utilized well. Egg protein is a complete protein and
is considered as a reference protein with the highest biological value. The quality of other
proteins is determined based on their comparison with egg protein.
The protein of animal foods like milk, meat, and fish generally compare well with egg in
the essential amino acid composition and are categorized as good quality proteins.
Plant proteins are of poor quality, since the essential amino acid composition is not well
balanced.
PER, NPR, NPU and amino acid score are most suitable methods of evaluation of quality of
protein.
Digestibility coefficient
It refers to the percentage of the ingested protein absorbed into the blood stream after the
digestion is completed.
Albino rats (28 days old)

I Group II Group

Fed protein diet Fed protein free diet

Determine faecal nitrogen Determine endogenous faecal nitrogen

Calculate the Digestibility coefficient

Digestibility coefficient = Nitrogen intake – Nitrogen loss in digestion X 100

Nitrogen intake
Biological value
Biological value of protein is the percentage of nitrogen that is absorbed and available for
use by the body for growth and maintenance. It measures the amount of dietary protein utilised
by body for maintenance and growth. The method is briefly as follows:
 Albino rats (28 days old)

I Group II Group

Fed test diet (10 % protein) Fed non-protein diet

Record the food intake

Collect urine and faeces

Determine the nitrogen content

Calculate the NPU

Biological value = Nitrogen digested – Nitrogen lost in metabolism X 100

Nitrogen digested

Protein efficiency ratio (PER)

Protein efficiency ratio is defined as the weight gain per gram of protein intake. This
method was developed by Osborne, Mendel and Ferry.

Gain in weight (g)

Protein intake (g)

Net protein utilization (NPU)

Miller and bender (1955) developed a direct method of estimating ‘Net Protein
Utilisation’. The method is briefly as follows:
 Albino rats (28 days old)

I Group II Group

Fed test diet (10 % protein) Fed non-protein diet

Killed after 10 days

Determine the body nitrogen content

Calculate the NPU

Nitrogen retained
Net protein Utilization = X100
Nitrogen intake

Net protein Ratio (NPR)

This method of assay was introduced by Bender and Doell in 1957. This method is the
modification of PER method. An allowance is made for the protein requirements and also for
maintenance.
Gain in weight (g) of the test group + loss in weight (g) of non-protein group
NPR =
Protein intake (g) of test group
Amino acid score / chemical score

The amino acid score is the ratio between the content of the most limiting amino acid in
the test protein to the content of the same amino acid in egg protein (reference protein).

Amino acid score = Limiting amino acid content in the test protein X 100

The same amino acid in egg protein

 Nutritional value of food protein

Protein PER BV NPU Chemical Score Limiting Amino Acid

Egg 4.5 96 90 100 Nil

Milk 3.0 84 75 65 Sulphur amino acids

Fish 3.0 85 70 60 Tryptophan

Meat 2.7 75 76 70 Sulphur amino acids

Rice 2.2 68 60 60 Lysine, Threonine

Wheat 1.5 58 47 42 Lysine, Threonine

Bengal gram 1.7 58 47 45 Sulphur amino acids

 LECTURE 6
LIPIDS/FATS
Introduction
The word lipid is derived from the Greek word ‘lipos’ meaning fat. Fat is one of the three
main macronutrients, along with carbohydrate and protein. Fats, also known as triglycerides, are
esters of three fatty acid chains and the alcohol glycerol. The terms "lipid", "oil" and "fat" are
often confused. "Lipid" is the general term, though a lipid is not necessarily a triglyceride. "Oil"
normally refers to a lipid with short or unsaturated fatty acid chains that is liquid at room
temperature, while "fat" refer to lipids that are solids at room temperature however, "fat" may be
used in food science as a synonym for lipid. Fats, like other lipids, are generally hydrophobic,
and are soluble in organic solvents and insoluble in water.
Fatty acids
Fatty acids are the main building blocks of fat. They joined together in groups of three,
forming a molecule called a triglyceride. A fatty acid is nothing more than a long C-H chain with
a carboxyl group (COOH) on the end. The COOH gives it an acid property.

CLASSIFICATION OF FATTY ACIDS

I. Based on the length of free fatty acid chains
Fatty acid chains differ by length, often categorized as short to very long.
1. Short-chain fatty acids (SCFA) are fatty acids with aliphatic tails of five or fewer
carbons (e.g. formic acid, Propionic acid, Isobutyric acid, Butyric acid, Isovaleric acid &
valeric acid).
2. Medium-chain fatty acids (MCFA) are fatty acids with aliphatic tails of 6 to 12
carbons, which can form medium-chain triglycerides (e.g. Caproic acid (C6), caprylic
acid(C8), capric acid (C10) and lauric acid (C12))
 3. Long-chain fatty acids (LCFA) are fatty acids with aliphatic tails of 13 to 21 carbons.
(e.g. α Linolenic acid (ALA), Linoleic acid (LA), Eicosapentaenoic acid (EPA),
Docosahexaenoic acid (DHA)
4. Very long chain fatty acids (VLCFA) are fatty acids with aliphatic tails of 22 or more
carbons
II. Based on degree of unsaturation
1. Saturated Fatty Acids
Saturated fatty acids have no double bonds. Saturated fatty acids have only single bonds;
each carbon atom within the chain has 2 hydrogen atoms. Eg. Butyric acid, Lauric acid, Myristic
acid, Palmitic acid, Stearic acid
2. Unsaturated Fatty Acids
Unsaturated fatty acids have one or more double bonds between carbon atoms. Eg. Oleic
acid, Palmitic acid, Erucic acid, Linoleic acid, Linolenic acid and Arachidonic acid.
 Mono Unsaturated Fatty Acid (MUFA) – one C=C double bond
Eg. Oleic acid, Palmitic acid, Erucic acid
 Poly Unsaturated Fatty Acid (PUFA) – more than one C=C double bond
Eg. Linoleic acid, Linolenic acid and Arachidonic acid

Cis and Trans fatty acids

The two carbon atoms in the chain that are bound next to either side of the double bond can
occur in a Cis or Trans configuration.
 Trans fatty acids - two hydrogen atoms near the double bonds
are on the opposite sides of the molecule - makes them
straight and more rigid and solid. Trans fats are not found in
nature and are the result of human processing (e.g.,
hydrogenation).
  Cis fatty acids - they are on the same side, which makes them more flexible and liquid.
III. Based on location of double bonds
1. Omega−3 fatty acids – (ω−3 fatty acids or n−3 fatty acids) - PUFAS with a double
bond (C=C) at the third carbon atom from the end of the carbon chain. Eg. α-linolenic
acid (ALA) (found in plant oils), Eicosapentaenoic acid (EPA) (found in marine oils) and
Docosahexaenoic acid (DHA) (found in marine oils)
2. Omega-6 fatty acids - (ω-6 fatty acids or n-6 fatty acids) - Omega-6 fatty acids are a
family of polyunsaturated fatty acids that have in common a final carbon-carbon double
bond in the 6 position. Eg. Linoleic acid and Arachidonic acid.
IV. Based on synthesis in body
 Essential fatty acid
Essential fatty acids (EFA) are those which cannot be synthesized by the body and need
to be supplied through diet. Linolenic acid, linoleic acid and arachidonic acid are essential fatty
acids.
 Non -essential fatty acids
Non-essential fatty acids are those which can be synthesized by the body and which need
not be supplied through the diet. Palmitic acid, oleic acid and butyric acid are examples of non –
essential fatty acids.
CLASSIFICATION OF FATS
I. Based on their chemical composition
1. Simple lipids or Homolipids - Esters of fatty acid with various alcohols.
 Fats and oils - Esters of fatty acids with glycerol. e.g., vegetable oil, ghee, butter
 Waxes - Esters of fatty acids and alcohols. In human body it is present in the form
of esters of cholesterol e.g., plant wax, insect wax (bees wax)
2. Compound lipids or Heterolipids - The compound lipids contain, in addition to fatty
acids and glycerol, some other organic compounds.
 Phospholipids - These contain phosphoric acid and nitrogenous base in addition
to fatty acids and glycerol. e.g., lecithin and cephalin
 Glycolipids - These lipids contain carbohydrates in combination with fatty acids
and glycerol. e.g., cerebrosides
 Lipoprotein - It contains protein subunits along with lipids.
 3. Derived lipids - Substances derived from simple and compound lipids by hydrolysis are
called as derived lipids. Fatty acids, alcohols and sterols are example for derived
lipids.
II. Based on degree of unsaturation
1. Saturated fats - A saturated fat is a fat in which the fatty acids all have single bonds.
Examples
• Butyric acid with 4 carbon atoms (contained in butter)
• Lauric acid with 12 carbon atoms (contained in coconut oil, palm kernel oil, and
breast milk)
• Myristic acid with 14 carbon atoms (contained in cow's milk and dairy products)
• Palmitic acid with 16 carbon atoms (contained in palm oil and meat)
• Stearic acid with 18 carbon atoms (also contained in meat and cocoa bean)
2. Unsaturated fats - An unsaturated fat is a fat or fatty acid in which there is at least one
double bond within the fatty acid chain.
a. Mono Unsaturated fat – one C=C double bond. Eg. Oleic acid, Palmitic acid,
Erucic acid (Olive oil, peanut oil, canola oil, avocados, nuts)
b. Poly Unsaturated fat– more than one C=C double bond. Eg. Linoleic acid,
Linolenic acid and Arachidonic acid (corn, safflower, soybean, sunflower oils and
fish oils).
FUNCTIONS OF FAT
 It is a concentrated source of energy. One gram of fat gives 9 Kcal.
 Fats are essential for the absorption of fat soluble vitamins like A, D, E, K.
 Fats contain essential fatty acids like linoleic, linolenic and arachidonic acids which are
essential for maintaining tissues in normal health.
 Vegetable oils are good source of vitamin E.
 Butter and fish liver oil are good source of vitamin A.
 Fats improve the palatability of the diet
 It gives satiety value, i.e., a feeling of fullness in the stomach
 Phospholipids and other compound lipids are essential constituents of nervous tissue.
 Fats are deposited in the adipose tissue and this deposit serves as the source of energy
during starvation.
  Fat deposited in adipose tissue functions like an insulating material against cold and
physical injury.
 Cholesterol is essential for maintaining the cell membrane in good condition.
 Cholesterol is act as a precursor for the formation of some steroid hormones
DIGESTION AND ABSORPTION OF FATS
Stomach
Lipase present in stomach is unable to digest fats due to high acidity of gastric juice. So
fat is not digested in stomach.
Small intestine
Bile salt is essential for the digestion and absorption of fat. It helps to emulsify fats before
digestion. Pancreatic lipase and intestinal lipase hydrolyze the fat into diglycerides,
monoglycerides and fatty acids. Phospholipase and cholesterol esterase hydrolyze phospholipids
and cholesterol
Fat (triglycerides)
Bile salt

Emulsification
Pancreatic lipase Intestinal lipase

Monoglycerides & diglycerides

Absorption of fats
The products of digestion pass into the cells of the intestinal wall, where synthesis of new
glycerides takes place. The lipids pass through the lacteals of the small intestine to thoracic duct
and then to the blood stream in the form of fine particles known as chylomicrons. A greater part
of the cholesterol present in the diet is absorbed while phytosterols present in vegetable fats and
oils are not absorbed.
The oxidation takes place through the tricarboxylic acid cycle. Fat is also synthesized in
the body from carbohydrates by a complex mechanism.
 LIPIDS IN BLOOD

DEFICIENCY OF FATS
Adult
‘Phrynoderma’ or ‘Toad skin’ is the essential fatty acid deficiency symptoms. It is
characterised by the presence of horny popular eruption on limbs, backs and buttocks.
Infant
Perianal irritation and changes in skin (dryness, thickening, desquamation).
Symptoms of dietary fat deficiency
 Cancer is a condition where the cells of the body start to grow in a rapid, uncontrollable
way. Monounsaturated fats and omega 3 essential fatty acids (EFAs) have been linked
with the prevention of breast cancer, colon cancer and prostate cancer.
 Diabetes is a condition where the body struggles to control blood glucose levels. This
causes damage to the blood vessels and a number of vital organs. Diet rich in omega 3
EFAs reduced risk of diabetes.
 Fat Soluble Vitamin Deficiency - Polyunsaturated fats support the absorption of fat
soluble vitamins. Reducing dietary fat intake significantly can cause to become deficient
in these essential vitamins which can lead to a number of unpleasant symptoms including
anemia (a low red blood cell count), vision problems, weak bones and skin problems
 Fatty Liver - Polyunsaturated fats reduce the deposit of fatty droplets on the liver.
 Growth Problems - Both saturated fats and omega 6 EFAs support the development of
strong healthy bones.
  Hair, Nail and Skin Problems - Polyunsaturated fats promote the formation of healthy
hair, nail and skin cells. Not getting enough can have an adverse effect on skin and lead
to problems such as acne, dermatitis (inflammation of the skin), psoriasis (a skin disease
which causes dry, red, scaly patches to develop) and wrinkles. It can also affect hair and
nails leading to dry hair, hair loss and impaired nail growth.
 Heart Disease – Reducing fats from diet leads to atherosclerosis (hardening of the
arteries), increases triglyceride levels and also reduces blood levels of high density
lipoprotein (HDL) cholesterol (a type of cholesterol which removes plaques from the
artery walls). Both atherosclerosis and low HDL cholesterol restrict the flow of blood to
heart whilst high triglyceride levels have also been linked with an increased heart disease
risk.
 High Blood Pressure - High blood pressure is a condition which can damage blood
vessels and vital organs. It also increases risk of a heart attack or a stroke. Regular
consumption of omega 3 EFAs can lower blood pressure whilst not getting enough can
have the opposite effect and lead to high blood pressure.
 Inflammation - Both monounsaturated fats and polyunsaturated fats reduce
inflammation in the body. Failing to eat enough of these fats can lead to a number of
inflammatory disorders including arthritis.
 Macular Degeneration - Omega 3 EFAs are used by body to create retinal tissue and
can combat age related macular degeneration.
 Mental Problems - Omega 3 EFAs support the production of signal pathways in brain
and also act in a protective capacity.
 Stroke - High blood pressure is one of the major contributors to a stroke and as
discussed above omega 3 EFA deficiencies cause an increase in blood pressure
FOOD SOURCES
Foods in general contain two types of fat namely “visible fats” and “invisible” or
“hidden” fats.
Visible fats - Visible fats are fats extracted from the following sources.
 Oil seeds: coconut, corn, cornseed, groundnut, mustard, palm, rice bran, safflower,
seasame, soyabean, sunflower and hydrogenated vegetable oils (vanaspathi).
 Animal fats: Butter and Ghee.
  Fish oils: Shark and cod liver oils.
Invisible or hidden fats:
Invisible or hidden fats are those which form an integral part of foods and are therefore
not visible. It includes the fats present in the cells and cell walls and cell membranes of both
plant and animal tissues. Almost everything we eat as listed below carries some invisible fats.
 Plant food – Cereals, millets, vegetables, spices, nuts and oil seeds, coconut, avacado.
 Animal food – Milk and milk products (curd, cream, cheese), flesh foods, (mutton, beef,
pork, chicken) organ meats (brain, liver, kidney), fish, shrimp, prawn.
REQUIREMENTS
The ICMR recommended allowances for fat for Indians is given in table
S. No Group Requirement Total calories from fat
(g/day) (%)
1 Infants (0-1 year) 19 25-30
2 children 25-30
3 Adolescents (13-17 year)
Boys 45-50 15-20
Girls 35-40
4 Man 25-40 10-20
5 Woman 20-30

RANCIDITY
The development of off-flavours or unpleasant odour in fats is known as rancidity.
There are three main types of rancidity. Rancidity is a term generally used to denote “a condition
of unpleasant odours and flavours in foods resulting from deterioration in the fat or oil portion of
a food”
 Hydrolytic rancidity
 Oxidative rancidity and
 Ketonic rancidity
Hydrolytic/ lipolytic rancidity
The fats and oils are hydrolysed by the enzyme lipase and yield free fatty acids and
glycerol. It results in off-odour development. This is known as hydrolytic rancidity. In case of
butter and coconut oil, butyric acid and other low molecular weight fatty acids are set free by
hydrolysis by lipase. The odours of these acids contribute to the smell of rancid butter.
Lipase
Fat/oil free fatty acids + glycerol
Hydrolysis (off- odour)
Oxidative rancidity
The fat and oil are contact with the atmospheric oxygen in the presence of lipoxygenase
enzyme. It results in the formation of hydroperoxides. Further, it breaks into aldehydes and
ketone which is responsible for off-flavour. This is called as oxidative rancidity.
This is the common type of rancidity observed in all fats and oils. The oxidation takes
place at the unsaturated linkage. Certain metals, e.g. copper, hasten the onset of oxidative
rancidity.
Fat/oil

O2 lipoxygenase

Hydroperoixdes

Decompose

Aldehydes Ketones
(Off-flavour)
Ketonic rancidity
This type is most frequently encountered as a result of action of fungi such as
Aspergillus niger, pencillium glaucum on coconut or other oil seeds. They tallowy odour
developed may be due to aldehydes and ketones formed by the action of the enzymes present in
the fungi on oils.
Prevention of rancidity
Fats can be protected against the rapid development of rancidity by controlling the
conditions of storage.
 Storage at refrigerator temperature prevents rancidity.
  Rays of light catalyse the oxidation of fats by the use of coloured glass containers that
absorb the active rays, fats can be protected against spoilage.
 Certain shades of green bottles and wrappers and yellow transparent cellophane wrappers
are effective in preventing rancidity.
 Vacuum packaging also helps to retard the development of rancidity by excluding
oxygen.
 Antioxidants naturally present in the food such as vitamin C, beta carotene and vitamin E
protect against rancidity.
 Antioxidants like Butylated Hydroxy Anisole (BHA), Butylated Hydroxy Toluene
(BHT), Tertiary Butyl Hydroquinone (TBHQ) and Propyl Gallate (PG) can also be added
to prevent rancidity.
 Substances like citric acid may be used along with antioxidants in foods as synergists. A
synergist increases the effectiveness of an antioxidant but is not as effective an agent
when used alone.
 Some Chelating agents are bind or chelate the metals and prevent the oxidation process.
Chelating agents are sometimes called sequestering agents.
Hydrogenation
Hydrogenation means adding hydrogen to a substance. Liquid vegetable oils that are
unsaturated will react with hydrogen at about 60 °C in the presence of a nickel catalyst. This is
an example of an addition reaction where hydrogen adds across the double bond leaving only
single bonds. Hydrogenation raises the melting point above room temperature and makes the
liquid oil become solid in a process called hardening. The solid product is used as a margarine or
vanaspathi. Unsaturated glycerides present in the plant oil can be converted to more saturated
glycerides.
The picture below shows hydrogenation of a double bond.

Liquid fat addition of H2 Semisolid/solid fat

(more unsaturated fatty acids) Nickel (more saturated fatty acids)
Determination of Energy Value of Foods
The energy or calorific value of food depends on the quantity of carbohydrates, fats and
proteins present in them. Energy value of food can be determined by oxidizing a known weight
of food in an instrument called bomb calorimeter and measuring the heat produced in energy
unit. The energy value of food can be expressed in terms of kilocalories. One kilocalorie is the
quantity of heat required to raise the temperature of 1 kg of water through 1°C.
Bomb calorimeter – Principle
The energy value of food is usually determined using the instrument bomb caloriemeter.
It consists of a heavy steel bomb, with a platinum or gold plated copper lining and a cover held
tightly in place by means of a sample.
A bomb calorimeter is a type of constant – volume calorimeter used in measuring the
heat of combustion of a particular reaction. Bomb calorimeters have to withstand the large
pressure within the calorimeter as the reaction is being measured. Electrical energy is used to
ignite the fuel, as the fuel is burning, it will heat up the surrounding air, which expands and
escapes through a tube that leads the air out of the calorimeter. When the air escaping through
the copper tube it will also heat up the water outside the tube. The temperature of the water
allows for calculating calorie content of the fuel.
Procedure
A weighed amount of a sample is usually pressed into pellet forms and placed in a
capsule with in the bomb crucible which is then, closed except for the oxygen value charged with
oxygen to a pressure of about 25 pounds and immersed in a weighed amount of water. The water
is constantly stirred and its temperature taken at intervals of 1 minute by means of a differential
thermometer capable of being read to thousand with of a degree. After the temperature of water
has been determined, the sample is ignited by means of oxygen present. It undergoes rapid and
complete combustion. The heat liberated is absorbed by the water in which the burnt is immersed
and the result raise in temperature readings and also continued through an after period in older
that the radiation correction may be calculated and the absorbed raise multiplied by the total heat
capacity of the apparatus and the water which it is immersed gives the total heat liberated in the
bomb. Then this heat arising from accessory combustion must be detected to obtain the number
of calories arising from the combustion of the sample.
Calculation
Weight of sample taken = 2g
Weight of water in the outside vessel = 3000 g
Water Equivalent of the calorimeter = 500g
Initial temperature of water = 24° C
Final temperature of water = 26° C
Rise in temperature = (Final temperature of water – Initial temperature of water)
= 26 -24 = 2° C
Heat gained by water and calorimeter = (Weight of water + Equivalent weight of water
x Rise in temperature)
= 3000 + 500 X 2 = 7000
Energy value of given sample = 7000 Cal or 7 KCal
Energy value of given sample per g = Heat gained by water and calorimeter / weight
of the sample
= 3500 Cal or 3.5 KCal

Bomb Calorimeter
 LECTURE 7
VITAMINS

Vitamins may be defined as organic compounds occurring in small quantities in the

different natural foods and necessary for the growth and maintenance of good health in human
beings and certain experimental animals

Classification of vitamins
Vitamins are classified as follows:
Fat soluble vitamins Water soluble vitamins
1. Vitamin A  Vitamin B complex
2. Vitamin D 1. Thiamine (Vitamin B1)
3. Vitamin E and 2. Riboflavin (Vitamin B2)
4. Vitamins K 3. Niacin (Vitamin B3)
4. Panthothenic acid (Vitamin B5)
5. Pyridoxine (vitamin B6)
6. Biotin (Vitamin B7)
7. Folic acid (Vitamin B9)
8. Vitamin B12
 Vitamin C (Ascorbic acid)

FAT SOLUBLE VITAMINS

VITAMIN A
Vitamin A only present in foods of animal origin. Vitamin A activity is also possessed by
carotenoids present in plants. So carotenoids (β- carotene) are called as provitamin A or
precursor of vitamin A. Vitamin A – Antixerophthalmic vitamin
FUNCTIONS
1. Vitamin A is very important for good vision.
2. Maintaining the health of the epithelial tissues of eyes and skin.
3. Supports reproduction and growth.
4. It helps to strengthen immune system.
5. Beta carotene acts as antioxidant and protecting the body against cancer.
6. It is essential for normal bone formation.
Role of vitamin A in Visual cycle
In the retina, retinaldehyde functions as the prosthetic group of the light – sensitive opsin
proteins, forming rhodopsin (in rods) and iodopsin (in cones). Any one cone cell contains only
one type of opsin and is sensitive to only one colour. In the pigment epithelium of the retina, all
– trans – retinol is isomerized to 11-cis-retinol and oxidized to 11 – cis-retinaldehyde. This reacts
with a lysine residue in opsin forming the holoprotein rhodopsin.
As shown in the figure the absorption of light by rhodopsin causes isomerization of the
retinaldehyde from 11 cis to all trans and a conformational change in opsin. This results in the
release of retinaldehyde from the protein and the initiation of a nerve impulse. The formation of
the initial excited from of rhodopsin, bathorhodopsin occurs within picoseconds of illumination.
There is then a series of conformational changes leading to the formation of metarhodopsin II,
which initiates a guanine nucleotide amplification cascade and then a nerve impulse. The nerve
impulse generated by the optic nerve is conveyed to the brain where it can be interpreted as
vision. The final step is hydrolysis to release all – trans retinaldehyde and opsin. The key to
initiation of the visual cycle is the availability of 11 – cis – retinaldehyde, and hence Vitamin A.
by a series of reactions all trans retinol is converted to 11 cis – retinal which reassociates with
opsin to from Rhodopsin. In deficiency, both the time taken to adapt to darkness and the ability
to see in poo light are impaired.
Visual Cycle

DEFICIENCY:
The important deficiency status due to lack of vitamin A in the diet are
Night blindness
In early stages of vitamin A deficiency, the individual cannot see well in dim light.
Difficulty in reading or driving the car in dim light is experienced. In advanced deficiency, the
subject cannot see objects in dim light. Night blindness is fairly common in regions where the
vitamin A intake is inadequate.
Xerosis conjunctivae
The conjunctiva is dry, thickened, wrinkled and pigmented. This is due to the
keratinisation of the epithelial cells. The pigmentation gives the conjunctiva a smoky
appearance. This condition is extremely common among all age groups in India and other
developing countries where the vitamin A intake is inadequate.
Xerosis cornea
When dryness spreads to cornea, it takes on a dull, hazy, lusterless appearance. This is
due to the keratinisation of the epithelial tissue covering the cornea.
Bitots spots
Grayish glistening, white plaques formed of desquamated thickened conjunctiva
epithelium, usually triangular in shape and firmly adhering to the conjunctiva are frequently
found in children having other signs of vitamin A deficiency.
Keratomalacia
When xerosis of the conjunctiva and cornea is not treated, it may develop into the
condition known as ‘keratomalacia’. The corneal epithelium becomes opaque and ulceration and
bacterial invasion of the cornea bring about its destruction resulting in blindness.
DIETARY SOURCES
Sheep liver, butter, ghee, egg, milk, curds, liver oils of shark, green leafy vegetables,
carrots, mango and papaya are the rich source of vitamin A.
REQUIREMENTS
Table 11.1: Requirements/RDA of Vitamin A
Age Group Requirements (µg)
Children 400
Adolescents & adult 600
Pregnancy 800
Lactation 950
 VITAMIN D
Vitamin D can be synthesized in the body in adequate amounts by simple exposure to
sunlight, even for 5 minutes per day is sufficient. The 7-dehydrocholesterol is present in skin and
act as precursor of vitamin D. It is essential for bone growth and calcium metabolism. It acts as a
hormone in the body by facilitating calcium absorption and deposition in the bone.
FORMS
 Vitamin D2 – Erogcalciferol
 Vitamin D3 - Cholecalciferol
Vitamin D in the body
Vitamin D is a fat soluble vitamin that exists in
various forms. The animal form is vitamin D3
(cholecalciferol) and the plant form is vitamin D2
(ergocalciferol). Vitamin D2 and D3 are not biologically
active; they must be modified in the body to have any
effect. The active form of vitamin D is indeed a
hormone and is known as 1,25-dihydroxyvitamin D3
[1,25(OH)2D3] or calcitriol. Both vitamin D2 and D3
have been commercially synthesized and both forms
seem to be effective at maintaining blood levels of
vitamin D in the body.
Step 1: cholesterol to 7-dehydrocholesterol, which is a precursor of vitamin D3.
Step 2: When we are exposed to UVB radiation, 7-dehydrocholesterol in the skin is converted to
vitamin D3.
Step 3: Vitamin D3 must then be hydroxylated in the liver and the kidneys to become active. At
this point, it can exert its endocrine effect.
FUNCTIONS
1. Vitamin D helps in the absorption of calcium and phosphorous.
2. It helps in the formation of bone and teeth.
3. Vitamin D helps to maintain the calcium and phosphorous levels in the body by
stimulating absorption in the gastro intestinal tract, retention by the kidney.
DEFICIENCY
Vitamin D deficiency causes the disease rickets in children and osteomalacia in adults.
 Rickets (Children)
It is a disease in which there is weakness and abnormalities in bone formation. Rickets
primarily affects children. Box like head, bowed knee, swelled wrist, pigeon breast are the
symptoms of rickets.
 Osteomalacia (Adult rickets)
The unmineralised condition of bone (soft bone) is called Osteomalacia. It occurs in women
in Purdah, not exposed to sunshine. It causes pain in pelvis, lower back, legs and frequent bone
fractures.
 Osteoporosis (old age)
Osteoporosis is a medical condition in which the bones become brittle and fragile from
loss of tissue, typically as a result of hormonal changes, or deficiency of calcium or vitamin
D.
SOURCES
Sunlight, Cod liver oil, shrimp, liver, butter, yolk, cheese, milk, spinach and cabbage are
the rich source of vitamin D.
REQUIREMENTS
Requirements/RDA of Vitamin D
Age Group Requirements (mg)
Infant & preschool children 10
Older children & Adult 5
Expectant & Nursing mother 10

VITAMIN E
Vitamin E is essential for normal reproduction in several species of animals and also in
human beings. It is otherwise known as Tocopherol/Antisterility vitamin.
FUNCTIONS
The important functions of vitamin E are as follows :
 i. Prevents peroxidation of polyunsaturated fatty acids in tissues and cell membranes. In
vitamin E deficiency PUFA undergo peroxidation and yellow and brown pigments are
formed.
ii. It protects red blood cells from haemolysis by oxidising agents.
iii. In vitamine E deficiency, there is degeneration of cellular and sub-cellular membranes
which are known to be rich in PUFA.
iv. Vitamin E offers definite protection to liver injury due to carbon tetrachloride poisoning.
v. Vitamin E along with an activator present in microsomal supernatant is able to prevent
the respiratory decline in isolated mitochondria.
DEFICIENCY
Vitamin E deficiency in animals causes several disorders such as reproductive failure,
liver necrosis, muscular dystrophy etc. They are briefly discussed below.
Reproductive failure
In the female rat fed on vitamin E deficient diets, foetal death and resorption take place.
The primary metabolic defect which causes death and subsequent resorption of the embryo is
now known. There are degenerative changes in the uterus. However, the vascular system of the
embryo also undergoes degeneration. In the male rat, irreversible testicular degeneration occurs
in vitamin E deficiency.
Liver necrosis
Necrosis of the liver produced in rats fed on yeast is prevented by vitamin E
Erythrocyte haemolysis
In vitamin E deficient animals, the erythrocytes readily undergo haemolysis when treated
with hydrogen peroxide. This is prevented by vitamin E.
Anaemia
Monkeys fed on vitamin E deficient diets develop anaemia. This is due to lack of
haemotopoiesis in the bone marrow rather than from excessive red cell destruction.
Administration of vitamin E cures the anaemia.
Muscular dystrophy
Rabbits, guinea pigs, monkeys and chicks fed on vitamin E deficient diets develop
muscular dystrophy which is cured and prevented by vitamin E.
SOURCES
Wheat germ, Vegetable oils, sunflower seeds, almonds, safflower oil, Sesame oil and
mustard oil, eggs, butter are the rich source of vitamin E.
REQUIREMENTS
Requirements/RDA of Vitamin E
Age Group Requirements (mg)
Infant & preschool children 3-4
Adult 10
Pregnancy 12
Lactation 13

VITAMIN K
Dam and Schonhyder (1934) found that chicks fed on purified diets containing all
vitamins known at that time developed haemorrhagic condition which was cured by Lucerne
(alfalfa) and decayed fish meal. Vitamin K is recognized as the antihaemorrhagic factor due to
its vital role in blood clotting mechanism.
Forms
 Vitamin K1 – Phyloquinone
 Vitamin K2 - menaquinone
FUNCTION
Vitamin K is essential for blood coagulation. Vitamin K administration leads to an
increase in the prothrombin level. In vitamin K deficiency, prothrombin level is reduced.
Blood clotting mechanisms:
 When we get cut blood vessels around the wound immediately constrict to reduce blood
loss
 The platelets in the blood exposed to air become sticky and clump together to plug the
wound
 Thrombokinase & other clotting factors are released by platelets.
 In the presence of of calcium ions thrombokinase converts prothrombin into thrombin.
Prothrombin a plasma preotin synthesized in the liver and requires vitamin K.
 Thrombin converts soluble plasma protein fibrinogen into insoluble fibrin fibres which
forms ameshworks of threads over the wound
 As the blood flows out, erythrocytes & platelets are trapped in the fibrin fibres and blood
clot forms it dries to from scab.
Blood clotting mechanisms
DEFICIENCY
Vitamin K deficiency leads to a lowering of prothrombin level and increased clotting
time of blood. This may lead to haemorrhagic conditions. Vitamin K deficiency can occur in
the following ways:
i. Inadequate intake of vitamin K
ii. Inadequate intestinal absorption.
Inadequate intake of vitamin K
Inadequate intake of vitamin K by the mother may causes the haemorrhagic disease of the
new born. The infants have a low prothrombin level and they recover rapidly when vitamin K is
administered by injection.
Inadequate intestinal absorption
In adequate intestinal absorption of vitamin K may result from.
a) lack of bile in the intestine due to defective secretion of bile as in liver disorders
intestinal obstruction and
b) Poor absorption due to diarrhea or dysentery.
SOURCES
Vitamin K occurs in plant foods while vitamin K2 occurs in microganism. The best
sources of vitamin K, are the green leafy vegetables eg: alfalfa, spinach, cabbage, etc.
REQUIREMENTS

Requirements/RDA of Vitamin K
Age Group Requirements (mg)
Infant 12-20
Adult 70-140
Pregnancy 200
Lactation 150
Adolescents 50-100
 LECTURE 8
WATER SOLUBLE VITAMINS

The various members of the vitamin B complex are not related either chemically or
physiologically, yet they have many features in common:
(a) All of them except lipoic acid are water-soluble.
(b) Most of them, if not all, are components of coenzymes that play vital roles in metabolism
(c) Most of these can be obtained from the same source, i.e., liver and yeast.
(d) Most of them can be synthesized by the intestinal bacteria.
Coenzyme derivatives of water-soluble vitamins
Vitamin Coenzyme form
Vitamin B1 (Thiamine) Thiamine pyrophosphate (TPP)
Vitamin B2 (Riboflavin) Flavin mononucleotide (FMN)
Flavin adenine dinucleotide (FAD)
Vitamin B3 (Niacin) Nicotinamide adenine dinucleotide (NAD)
Nicotinamide adenine dinucleotide phosphate (NADP)
Vitamin B5 (Pantothenic acid) Coenzyme A (CoA)
Vitamin B6 (Pyridoxine) Pyridoxal phosphate (PALP),
Pyridoxamine phosphate (PAMP)
Vitamin B7 (Biotin) Biocytin
Vitamin B9 (Folic acid) Tetrahydrofolic acid (THFA)
Vitamin B12 (Cyanocobalamin) Deoxyadenosyl cobalamin
Vitamin C (Ascorbic acid) Not known

VITAMIN B1 (THIAMINE)
Thiamine was the first member of the vitamin B group to be identified and hence given
the name vitamin B1. Thiamine was first isolated by Jansen (1934) in Holland from rice
polishings. On account of its curing action against beriberi, it is commonly known as
antiberiberi factor. It is also known as antineuritic factor or heat-labile factor. In Europe, it is
also designated aneurin.
FUNCTIONS:
 Used in metabolism of carbohydrates for energy, electrolyte balance, muscle and nerve
function, and hydrochloric acid production in the stomach.
 Oxidation of pyruvic acid.
DEFICIENCY
Vitamin B1 deficiency leads to polyneuritis in animals and beriberi in human beings.
Polyneuritis in birds renders them unable to fly, walk or even stand. Rats develop, among other
symptoms, a brachycardia (slowing of the heart rate).
The major symptoms may follow
One of the following 3 courses (and accordingly beriberi is of 3 types) :
1. Wet beriberi
Oedema in the legs, enlargement of the heart and palpitation and breathlessness.
2. Dry beriberi
Loss of appetite, tingling and numbness of the legs and wasting of muscle and difficulty
in walking.
3. Infantile beriberi
The early symptoms are restlessness, sleeplessness and loss of appetite. Palpitation and
breathlessness and loss of appetite develop, as the disease advances, due to the
enlargement of the heart. Death may occur suddenly if treatment is delayed.
SOURCES
 Rich sources: dried yeast, rice polishing and wheat germ are rich sources.
 Good sources: whole cereals, legumes, oilseeds and nuts are good sources.
 Fair sources: milled cereals, vegetables, fruits, milk, meat and fish are fair
sources.
REQUIREMENTS
Requirements/RDA of Vitamin B1
Age Group Requirements (mg)
Infant 0.2-0.3
Preschool children 0.5
Adolescents & Adult 1.0-1.7
Pregnancy 1.6
Lactation 1.7
 VITAMIN B2 (RIBOFLAVIN)
Riboflavin or vitamin B2 was first isolated in 1879 from milk whey which is an essential
dietary factor for rats. Since it was first isolated from milk, vitamin B2 is also known as
lactoflavin. Originally, it was also known as ovoflavin (from eggs) and hepatoflavin (from liver).
Its synthesis was done by Richard Kuhn and Paul Karrer. It is popularly called as the “yellow
enzyme” because of its colour.
FUNCTIONS
 Riboflavin plays an important role in many enzyme system involved in the metabolism of
carbohydrates, fats and protein.
 Helps in energy production, making niacin, red blood cell formation, and human growth.
DEFICIENCY
 Angular Stomatitis: Lesions at the angles of the mouth is called Angular Stomatitis
 Glossitis: The inflammation of the tongue with magenta colour is called glossitis
 Cheilosis: Dry chapped appearance of the lip with ulcers is called cheilosis.
 Scrotal lesions: scrotal dermatitis – adults.
 Common - anemia, mouth sores, sore throat, swelled mucous membranes, and skin
disorders.
SOURCES
Liver, dried yeast, egg powder, milk, skim milk powder, dairy, eggs, green leafy vegeta-
bles, nuts, meat, legumes, and enriched flour.
REQUIREMENTS
Requirements/RDA of Vitamin B2
Age Group Requirements (mg)
Infant 0.3 - 0.4
Preschool children 0.6
Adolescents 1.2
Adult 1.4 - 2.1
Pregnancy 2.1
Lactation 2.0
 VITAMIN B3 (NIACIN)
Vitamin B3 refers to nicotinic acid and was named as pellagra preventive (PP) factor by
an Austrian- American physician of the U. S. Public Health Service, Joseph Goldberger (1920)
because of its curing action on pellagra (After Goldberger's death, vitamin B3 was sometimes
called vitamin G in his honour).
The vitamin role on nicotinic acid was first recognized by Conrad Elvehjem and D.
Wayne Woolley of Wisconsin University in 1937. As this vitamin has a curing action against
black tongue disease in dogs, it is also called as anti black tongue factor. It was first isolated by
Funk in 1911.
FUNCTIONS
 Nicotinic acid is essential for the normal functioning of the skin, intestinal tract and
nervous system.
 Nicotinamide is a component of two coenzymes (NAD and NADP) which are essential
for the metabolism of carbohydrates, fats and proteins.
DEFICIENCY
A deficiency of niacin causes pellagra in man and blacktongue in dogs. Pellagra (of
Italian origin, pellis = skin; agra = rough) is characterized by 3 “Ds”, namely dermatitis of the
exposed parts, diarrhea and dementia (mental symptoms).
• Glossitis (redness & soreness of tongue) and diarrhoea -loose stools a day with blood and
mucous.
• Dermatitis- skin is red and slightly swollen later the skin becomes dry, less red and the
surface desquamates.

• Delirium is the commonest severe mental disturbance is acute pellagra. Dementia more
frequently seen in the chronic cases.

Niacin equivalent of tryptophan present in dietary proteins

60 mg of tryptophan yield 1mg of niacin in addition to the preformed niacin present in

food stuff, the tryptophan present will also provide additional niacin.
SOURCES
Dried yeast, liver, rice polishing Pork, turkey, fish, beef, peanut butter, legumes,
enriched and fortified grains.
REQUIREMENTS
Requirements/RDA of Vitamin B3
Age Group Requirements (mg)
Infant 650-710 µg /Kg
Preschool children 8
Adolescents 14
Adult 16-21
Pregnancy 16
Lactation 20

VITAMIN B5 (PANTOTHENIC ACID)

This was first isolated by Roger J. Williams in 1938 from yeast and liver concentrates.
On account of its wide distribution, he named it as pantothenic acid (pantosG = everywhere).
The coenzyme form of this vitamin (coenzyme A or CoA-SH) was isolated and its structure
determined by Fritz A. Lipmann. The chemical synthesis of this coenzyme was, however,
described by Khorana in 1959. This vitamin is sometimes called as filtrate factor or the yeast
factor.
Functions
 Pantothenic acid in the form of coenzyme A takes part in the metabolisms of
carbohydrates and fats.
 •It is essential for the oxidation of pyruvic acid.
DEFICIENCY
In human beings, no definite deficiency syndrome has been ascribed to pantothenic acid,
probably because of the ubiquitous nature of this vitamin and because of the fact that a little
amount of this vitamin can perhaps be synthesized in the body. Its correlation with
achromotrichia (premature greying of the hair) has been described in the case of man,
sometimes. But it seems too much to hope that grey hair can be averted by attention to diet.
SOURCES
Although widespread in nature, yeast, liver and eggs are the richest sources of it. The
vegetables (potatoes, sweet potatoes, cabbage, cauliflower, broccoli) and fruits (tomatoes,
peanuts) and also the skimmed milk, wheat bran, whole milk and canned salmon are some of the
less important sources. In most animal tissues and microorganisms, it occurs as its coenzyme.
Requirements
 5—10 mg per day for children to adolescence.

VITAMIN B6 (PYRIDOXINE)
The name vitamin B6 was also named as adermin or antidermatitis factor. Vitamin B6
group includes 3 compounds : pyridoxine, pyridoxal and pyridoxamine. Pyridoxine was first
isolated, in 1938, from yeast and liver. Later, Snell (1942) discovered the other two compounds.
Pyridoxal (PAL) and pyridoxamine (PAM) also occur in nature as their coenzymes, namely,
pyridoxal phosphate (PALP) and pyridoxamine phosphate (PAMP), respectively.
FUNCTIONS
Pyridoxine plays major role in protein metabolism.
2. It is essential for the growth of infant.
3. It aids in the formation of synthesis of haemoglobin.
4. Pyridoxine is essential for deamination and decarboxylation.
5. Vitamin B6 is involved in the conversion of tryptophan into niacin.
6. It aids in the conversion of linoleic acid to arachidonic acid.
7. It aids in the release of glycogen from liver and muscle.
DEFICIENCY
 Vitamin B6 deficiency or apyridoxosis in rats leads to the development of acrodynia, a
disease of dermatitis on ears, mouth and tail and accompanied by edema and scaliness of
these structures.
 In human infants, vitamin B6 deficiency results in convulsions, anaemia, dermatitis and
gastrointestinal disorders such as nausea and vomiting. However, this deficiency is rare.
Moreover, tryptophan metabolism is also disturbed.
 In adults, the vitamin B6 deficiency is normally not found because the intestinal bacteria
are capable of synthesizing vitamin B6.
 In B6-deficient anaemia, the RBCs are microcytic and hyperchromic. There are increased
serum iron concentrations, saturation of iron-binding protein, hemosiderin deposits in
bone marrow and liver, and failure of iron utilization for hemoglobin synthesis.
 Diseases with malabsorption, such as celiac syndrome, may contribute to vitamin B6
deficiency
SOURCES
 Rich sources: Dried yeast, rice polishings, wheat germ and liver are rich sources.
 Good sources: Whole cereals, legumes (pulses), oilseeds and nuts, egg, milk, meat and
fish and green leafy vegetables are good sources. Pyridoxine is adequately available in
human and cow’s milk.
REQUIREMENTS
Requirements/RDA of Vitamin B6
Age Group Requirements (mg)
Infant 0.3-0.4
Preschool children 0.6
Adolescents 2.0
Adult 2.0
Pregnancy 2.5
Lactation 2.5

VITAMIN B7 (BIOTIN)
In 1927, Boas made an important observation that when raw egg white was incorporated as then
main source of protein in the diets of rats, they developed deficiency symptoms characterized by
dermatitis, loss of hair and muscular in coordination.
In 1935, Fritz Kögl, a Dutch biochemist, isolated in crystalline form from 250 kg of dried
egg yolks about 1 mg of a ‘bios’ factor (growth promoting factor) necessary for yeast and named
it as “biotin”. Four years later, Szent-Györgyi et al conclusively proved that biotin is
synonymous to the “antiegg white injury factor” which is responsible for the cure of egg white
injury, induced in rats and other animals by feeding them with raw egg white.
Anti-Egg white factor/ injury
The raw egg white contains a biotin-antagonist protein, avidin, which combines with
biotin in a firm linkage to form a compound that cannot be absorbed by the intestine and is
therefore, excreted. It is also called as coenzyme R because it is a growth factor for the nitrogen-
fixing bacterium, Rhizobium.
FUNCTIONS
 Biotin is essential for normal gestation and lactation in experimental animals.
 It helps to maintain the skin and the nervous system in sound condition.
  It is essential for the synthesis of malonyl COA from acetyl COA and oxaloacetic acid
from pyruvic acid.
DEFICIENCY
 In most animals including man, intestinal bacteria synthesize appreciable amounts of
biotin. It is because of this reason that biotin-deficiency in human beings, fed on
biotinfree diets, cannot be produced.
 However, biotin-deficiency may be induced by sterilization of intestine and by feeding
with raw egg white.
 Avidin, the egg white protein, inactivates biotin by eliminating it from an otherwise
complete diet. Such a deficiency in man leads to dermatitis, loss of hair, decrease in
weight and edema.
 The lesions on skin appear with changes in posture and gait. These disorders may lead to
death.
 Heating egg white destroys the avidin and prevents the so-called egg white injury.
SOURCES
Biotin has a wide range of distribution both in the animal and the vegetable kingdoms.
Yeast, liver, kidney, milk and molasses are among the richest sources; peanuts and eggs have
lesser amounts. Biotin occurs in nature usually in combined state as biocytin. It is a bound form
of biotin, linked as a peptide with the amino acid lysine.
Requirements
The intestinal bacteria synthesize biotin in such appreciable amounts that the amount
excreted in urine exceeds the intake. That is why the RDA for this vitamin has not been
established. However, about 10 mg per day of biotin is sufficient for an adult.

VITAMIN B9 (FOLIC ACID)

The potent factor was obtained from spinach leaf and this led to its nomenclature as folic
acid, FA (foliumL = leaf). The official name of this vitamin is folacin. This is also known as liver
Lactobacillus casei factor as it was isolated from liver and was shown as necessary for the
growth of lactic acid bacteria.
Functions
 It helps in the formation of haem group of haemoglobin.
  It is essential for the maturation of red blood cells.
 It is act as key compounds for the formation of Purines which are essential constituents of
living cells.
 It is essential for the formation Thymine which is essential compound of DNA.
 It is necessary for the conversion of phenylalanine into tyrosine.
DEFICIENCY
Megaloblastic anaemia
 Megaloblastic anaemia in infants and children.
 In man, the folic acid deficiency leads to megaloblastic anemia, glossitis and
gastrointestinal disorders. Pregnant women and infants are also particularly vulnerable.
Folic acid deficiency is a major feature of tropical sprue, in which there is a general
deficiency in absorption of many nutrients from the small intestine.
SOURCES
Important sources are liver, kidney, tuna fish, salmon, yeast, wheat, dates and spinach.
Root vegetables, sweet potatoes, rice, corn, tomatoes, bananas, pork and lamb contain little folid
acid. With improper cooking, folacin contents are destroyed, like thiamine.
REQUIREMENTS
Requirements/RDA of Folic acid
Age Group Requirements (mg)
Infant 25
Preschool children 80
Adolescents 200
Adult 200
Pregnancy 500
Lactation 300

VITAMIN B12 (CYANOCOBALAMNE)

In 1926, two American physicians, George Minot and George William Murphy
discovered that patients suffering from pernicious anemia could be cured by feeding them with
about half a pound of liver a day. This anti-pernicious anemia factor (APA factor) was, later,
isolated in crystalline form in 1948 independently by E. Lester Smith in England and by Edward
Rickes and Karl Folkers in the United States. It was then named as vitamin B12 or
cyanocobalamin. It is the last B-vitamin to be isolated and is also known as Factor X or L.L.D.
factor. The coenzyme form of this vitamin (deoxyadenosyl cobalamin or cobamide coenzyme)
was first isolated by Barker of California. It contains cobalt. It is sensitive to sun light.
FUNCTIONS
 Promotes the maturation of red blood cells.
 It acts on the narrow elements and is involved in the formation of white blood cells and
blood platelets.
 It cures the neurological symptoms of pernicious anaemia.
 It acts as a coenzyme in the synthesis of methionine.
 DNA synthesis
DEFICIENCY
Pernicious anaemia:
 Immature red blood cells with normal amounts of haemoglobin, soreness and
inflammation of tongue, numbness and tingling in fingers and toes.
 The rare disease juvenile (or congenital) pernicious anemia springs up due to an inability
to secrete gastric intrinsic factors.
 It is prominent at 9 months to 10 years of age. As the anemia becomes severe, irritability,
anorexia and listlessness occur.
 This typical deficiency disease, adult pernicious anemia (= anemia caused by failure of
erythrocyte formation), is characterized by R.B.Cs. becoming abnormally large and fewer
in number (1–3 million per cubic millimeter instead of the normal 4–5 million).
 The patient weakens, loses its weight and the nervous system is also gradually affected
because there occurs demyelinization of the large nerve fibres of the spinal cord.
 All these changes ultimately lead to death.
SOURCES
 Vitamin B12 has been found only in animals ; the chief source is liver, although it is also
present in milk, meat, eggs, fish, oysters and clams. Under certain dietary conditions,
vitamin B12 may be synthesized by the intestinal microorganisms.
 In general, cyanocobalamin is not present in plant foods except in Spirulina, a blue-green
algae.
REQUIREMENTS
Requirements/RDA of Vitamin B12
Age Group Requirements (mg)
Infant 0.2
Preschool children 0.2-1.0
Adolescents 1.0
Adult 1.0
Pregnancy 1.2
Lactation 1.5

VITAMIN C (ASCORBIC ACID)

The chemical name for Vitamin C is ascorbic acid. It was discovered in 1747 by the
British physician Lind and demonstrated that citrus fruit juices prevented and cured scurvy. It is
also called cevitamin. It has a curing action against scurvy and hence popularly called as
antiscorbutic factor.
FUNCTIONS
1. Ascorbic Acid is essential for formation of cement substances and collagen which is
found in blood vessels teeth and bones.
2. It helps in the biosynthesis of non-essential amino acids.
3. It is essential for the conversion of phenlalanine to tyrosine and for the oxidation of
tyrosine.
4. It is required for normal wound healing.
5. Vitamin C is an excellent anti-oxidant and prevents oxidation of cells.
6. Vitamin C is required for carnitine synthesis which helps in the transport of fatty acids in
the cell.
7. Vitamin C is essential for the synthesis of norepinephrine a neurotransmitter.
8. It activates hormones.
9. Drug detoxifying metabolic systems in the body requires Vitamin C for its optimal
activity
10. Ascorbic acid reduces the ferric iron to ferrous iron and thus helps in the absorption of
iron.
DEFICIENCY
Infantile scurvy: The early symptoms of the disease are : (i) loss of appetite and (ii)
listlessness. The infant cries when its legs and arms are moved. Swelling is observed at the ends
of long bones. Haemorrhages occur under the skin. Gums are swollen. Convulsions may occur
resulting in death of the infant.
Scurvy in adults: The disease is characterized by general weakness, spongy bleeding
gums, loose teeth with desorbed dentine, swollen tender joints and haemorrhages in various
tissues and under the skin.
SOURCES
Amla, drumstick leaves, guava, cashew fruit, agathi, cabbage, bitter gourd, oranges, and
tomatoes are the rich source of vitamin C.
REQUIREMENTS
Requirements/RDA of Vitamin C
Age Group Requirements (mg)
Infant 25
Preschool children 40
Adolescents & Adult 40
Pregnancy 60
Lactation 80
 LECTURE 10
MINERALS

Minerals are inorganic substances and the body contains about 24 minerals, all of which
must be provided by the diet. These include calcium, phosphorus, potassium, sodium, chlorine,
magnesium, iron, manganese, copper, iodine, cobalt, zinc, aluminium, arsenic, bromine, fluorine,
nickel, chromium, cadmium, selenium, silicon, vanadium, and molybdenum. These minerals are
necessary for the following different functions:
1. As constituents of bones and teeth, e.g., calcium, phosphorus and magnesium,
2. As constituents of body cells of soft tissues such as muscles, liver, etc., e.g., phosphorus.
3. As soluble salts which give to the body fluids and cell contents, their composition and
stability which are both essential for life, e.g.,
a) Iron and copper – formation of haemoglobin,
b) Iodine – formation of thyroxine,
c) Zinc – constitution of an enzyme, e.g., carbonic anhydrase and a hormone e.g.,
insulin,
d) Cobalt – constituents of a vitamin, e.g., vitamin B12

CALCIUM
Calcium is an essential element required for several life processes. The function and
requirement of Calcium and Phosphorous are closely linked. Over 99% of the Calcium and
Phosphorous is present in the bones and the remaining 1% in the body fluids. The Calcium and
Phosphorous are present in the ratio of 2:1 in our body. Adult body contains about 1000 to 1200
g of calcium. The diet should have calcium and phosphorous in ratio of 1:2. Vitamin D is
essential for the absorption calcium.
Functions
1. It is essential for the formation of bone.
2. It is essential for the formation of teeth.
3. Calcium is essential for the clotting of blood.
4. It is essential for the contraction of the heart and skeletal muscle.
5. It regulates the excitability of the nerve fibres.
Food Sources
Milk is the best natural source and skim milk powder is very rich source (1.37 per cent) of
calcium. Ragi is the cheapest natural source of calcium, containing about 0.3 to 0.36 per cent.
Though sesame seeds are rich in calcium (1.45 per cent) the calcium is present as calcium
oxalate mostly in the skin. Green leafy vegetables are one of the cheapest natural sources of
calcium containing about 0.44 to 1.13 per cent. Small fish eaten along with bones is an excellent
source of calcium.
Deficiency Diseases
Adults: Osteoporosis
Osteoporosis in adults is a condition in which decalcification of the bone occurs due to
calcium deficiency in the diet. Fractures of the brittle bones occur even after minor accidents.
Pain due to fractures of vertebrae may radiate round the trunk, to the buttocks or down the legs.
Healing of fractures is not impaired in osteoporosis and pain subsides as soon as the fractures are
healed.
Children:
1) decreased rate of growth; (2) negative calcium balance; (3) loss of calcium from bone
leading to the development of osteoporosis; (4) hyperplasia (a diffuse overgrowth) of parathyroid
glands; and (5) hypeirritability and tetancy leading to death
Requirements/RDA of Calcium
Age Group Requirements (mg)
Infant 500
Preschool children 600
Adolescents 800
Adult 600
Pregnancy 1200
Lactation 1200

PHOSPHORUS
Adult body contains about 400-700 g (approximately 1% of the body weight) of
phosphorus. The Calcium and Phosphorous are present in the ratio of 2:1 in our body.
Functions
1. Phosphorus is essential for the formation of bones and teeth.
2. It is essential for the formation of phospholipids. Phoshpolipids are major
components of cell membrane.
3. It is essential for carbohydrate metabolism as phosphorylation of glycogen.
4. Phosphates play an important role as buffers to prevent changes in acidity of the body
fluids.
5. In the DNA and RNA, phosphate is an essential part of the nucleic acids.
Food Sources
Phosphorus is widely distributed in both plants and animal foods. Diets rich in protein
and calcium provide sufficient phosphorus. Eggs, milk, meat, fish and flour are excellent sources
of phosphorus. Whole grain cereals are good source but fruits and vegetables as whole are low in
phosphorus content.
Deficiency
A deficiency of this element is very rare in human beings because diets having sufficient
cereals are seldom inadequate in this nutrient. The deficiency is common in animals and causes
stiff joints and bones become fragile and break easily.
Requirements/RDA of Phosphorus
Phosphorus requirements depend on the availability of calcium present in the diets. It
depends upon the calcium: Phosphorus ratio. The optimal calcium phosphorus ratio for infants
and children is 1:1 and or adults 2:1.

IRON
Those elements which are required in traces are known as trace element. Iron is a trace
element, as its presence in small amount is very significant. Most of the iron in the body is
present as hemoglobin. Most of the body’s iron is found in complex forms bound to proteins
either as porphyrin or heme compounds or as ferritin. Free inorganic iron occurs in small
amount. About 70% of iron is in circulating hemoglobin, 4% into myoglobin. 25% is stored in
liver, spleen, kidney and 1% in plasma and various oxidative enzymes.
Functions
1. Iron essential for the formation of haemoglobin.
2. It forms a part of the myoglobin in muscles which makes oxygen available for muscle
contraction.
3. Iron present in cytochrome oxidase enzyme. It is very essential of the respiratory
chain.
As part of enzymes iron catalyzes many important reactions in the body. Examples are
 Conversion of beta carotene to active form of Vitamin A.
 Synthesis of collagen and neurotransmitters.
 Detoxification of drugs in the liver.
 It is essential for the transport and storage of oxygen.
Food Sources
Vegetable sources are cereals, beans, bajra, letils, vegetable leaves, spinach, dried peach
and apricot, pomegranate, jaggary and mollasses. Non-vegetable sources are liver, kidney, brain,
egg yolk, meat and fish etc.
Deficiency diseases
Nutritional Anaemia
In healthy individual blood contains approximately 14gm of haemoglobin per 100 ml.
Sometimes the level goes down and a low level of haemoglobin in blood is called anaemia. This
can be due to deficiency of one or more essential nutrients (iron, calcium, copper, vitamin C,
folic acid vitamin B12 protein etc). Iron deficiency anaemia follows a specific sequence. The iron
reserves getting depleted and transferring (transport form of iron) level of blood goes on
increasing and plasma iron is reduced. The blood cells are pale, less in number and small in size.
Deficiency of iron may be caused in a number of ways. The diet may not provide enough or it
may be in unabsorbable form. This is usually by blood loss but occasionally iron may be
excreted in urine and cause haemosidernuria.
Signs and Symptoms of Nutritional Anaemia
1. Reduced Haemoglobin level (less than 12 g /dl).
2. Paleness of skin.
3. Inside of the lower eyelid is pale pink.
4. Finger nails becoming thin and flat (spoon shaped nails).
 5. Fatigue, breathlessness on exertion.
6. Sleeplessness, dimness of vision.
Requirements/RDA of Iron
Age group Requirements (mg)
Adult Men 17
Adult Women 21
Pregnant women 35
Lactating women 21
Adolescents: Boys 28
Girls 26

IODINE
Iodine is an essential constituent of the thyroid hormone produced by the thyroid glands.
It occurs as free iodide ions or as protein bound iodine in our body. About 15 – 23 mg of iodine
is present in the adult human body.
Functions
1) Iodine plays an important role as it is incorporated into thyroxine hormone. It is
responsible for the rate of oxidation with in the cells and in doing so determines the
rate of metabolism.
2) Thyroxine is related with the tissues of nerves and muscles.
3) It helps in increasing heart rate.
4) Iodine helps in converting glycogen to glucose. In this way it increase blood sugar
level. Liver is affected because there is a possibility of emptying of glucose stores.
Sources
Sea foods like fish, shellfish and fish liver oils are the richest sources. The iodine content
of vegetables, fruits and cereals depends upon the iodine of the soil. Iodized salt supplies
sufficient iodine intake as it is used by all.
DEFICIENCY DISEASES
Goitre
Deficiency of iodine results in a disease known as goiter. Goiter is an enlargement of the
thyroid gland. This is when due to the deficiency of iodine; the secretion of thyroxine hormone is
also reduced, so the gland cells try to produce iodine, in large quantity which leads to
multiplication of cells which results in the enlargement of the gland that forms goitre.
Cretinism
The retardation in physical and mental growth of children due to severe iodine deficiency is
known as cretinism. The symptoms of cretinism are:
1) Low basal metabolic rate.
2) Muscular flabbiness and weakness
3) Dry skin
4) Rough hair
5) Enlarge tongue
6) Thick lips retardation of skeletal development
7) Mental retardation
Myxedema
Iodine deficiency in adults results in Myxedema. Face becomes thick and looks puffy.
Facial expression is poor and person becomes inactive.
Hypothyroidism
This condition may be due to a tumor of thyroid gland which produces and excess of
thyroid hormone or it may be due to Grave’s disease (Toxic Goiter) an increased production of
the hormone due to over active thyroid gland. Hyperthyroidics shows hyper activity, tremors, a
rapid heart rate, high blood pressure, bulging eyes, accelerated growth with loss of weight and
emotional instability. If the symptoms do not subside with medicines surgery is required.
Requirements/RDA of Iodine
Age group Requirements (µg)
Adult 100-200
Pregnant women +25
Lactating women +50
Infant 40-50
Goitrogens
Goitrogens are substances present in foods which cause goitre. These substances react
with iodine present in the food and making it unavailable for absorption. Foods like cabbage,
cauliflower, raddish contain goitrogens.
 MAGNESIUM
The human body contains minute quantities of magnesium in the bones along with
calcium and phosphorus and the rest in soft tissue. An adult human body has about 25g, of
magnesium. Normal human serum contains about 2 to 3 mg/100ml.
Functions
1. It acts as activator of several enzymes, e.g., alkaline phosphatase.
2. It is required as a co-factor for oxidative phosphorilation.
3. Magnesium is present in certain enzyme, e.g., co-carboxylase
Effect of deficiency
 Vomiting and intestinal fistula.
 Diabetic acidosis is associated with raised serum level of magnesium.
 Neuromuscular irritability, tremors, cramps, twitching and convulsions
 Confusion, disorientation and visual hallucinations
Source
Cereals, pulses, almond, cashew, peanut, mik, pork etc.
Requirements/RDA of Magnesium
Age Group Requirements (mg)
Infant 30-45
Preschool children 50
Adolescents 235
Adult 310-340
Pregnancy 310
Lactation 310

POTASSIUM
Approximately 97% of the potassium in the body is available with in the cells and
remaining is distributed in the extracelluar fluid. Plasma contains very small amount of
potassium but large amount of it is present in red blood cells.
Functions
1. It plays important role in the regulation of the acid base balance in the cells.
2. It is essential for the muscular contraction.
 3. It is essential for the growth and builds up of tissues as it is required for the synthesis
of protein.
Deficiency
Less intake of food during starvation and surgery is responsible for the deficiency of
potassium. Excessive loss might occur during vomiting and diarrhea for long duration. In severe
burns and prolonged fever potassium deficiency occurs. Patient might complains of nausea,
vomiting, muscle weakness, low blood pressure and tachycardia.
Source
Meat, fish and poultry foodstuffs are good sources of potassium. Fruits, vegetables and
whole grain cereals are especially high in potassium. Banana, potatoes, tomato, carrots, grape
fruit juice contains potassium.
SODIUM
Sodium chloride or common salt is the taste-giver in our diet. Extracellular fluid contains
sodium for the maintenance of normal osmotic pressure and water balance. Approximately 50%
of the body’s sodium is present in the extracellular fluid, 40% in bones and 10% or less in
intracellular fluid.
Functions
1. It regulates acid-base balance of the body.
2. It regulates the osmotic pressure of plasma.
3. Na ions play an important part in the absorption of monosaccharide and amino acids
from small intestine.
4. Na ions play an important part in maintaining the heart beat.
Effect of Deficiency
Sodium deficiency occurs when the intake is poor or excessive amount is lost. Sodium
loss through excessive sweating causes sodium deficiency unless salt intake is not increased.
Vomiting, severe diarrhea ,.addison’s disease are also responsible for sodium deficiency there is
also giddiness, cramps in muscles, collapsed, veins, low blood pressure, dryness of mouth,
inelastic skin and oliguria.
Sources
Fresh meat, fish, poultry, egg and milk are the sources of sodium. Foods from plant
origin are poor in sodium. Salt used during cooking is the commonest source of sodium.
Requirements/RDA of Sodium
Age group Tropical (g) Temperate (g)
Adult : light work 10 5
Moderate work 15-20 8
Heavy work 25-30 15
Children 5 3-5
Adolescents 10-25 6-8

ZINC
In an adult 2 to 3 gms of zinc is present. It is present in certain parts of the eye, certain
glands and in their secretion. Liver, muscles, bone and hair contain some of the remaining zinc.
Blood, especially the RBC, has some zinc. In small amounts it is present in tissues and bone
cells.
Functions
1. Zinc is essential for the brain development of children
2. It is essential for the spermatogenesis and development of primary and secondary sex
organs
3. It is essential for quick wound healing.
4. It is essential for normal taste sensation.
5. Zinc is a constituent of enzymes such as carbonic anhydrase, alkaline phosphatase, and
lactic dehydrogenase.
6. It is a constituent of the hormone insulin.
7. It plays a major role in the synthesis of DNA and proteins.
Sources
Sea foods, meat, poultry and eggs are good sources of zinc. Cereals, legumes and nuts
contain considerable amounts. Fruits and vegetables are poor sources. On milling eighty per cent
of zinc is lost.
Deficiency Diseases
Acrodermatitis enteropathica (severe dermatitis in infants), emotional disorder, impaired
taste (hypogeusia) and smell, delayed genital development, immunological defects, impaired
glucose tolerance.
Requirements/RDA of Zinc
Infants require 3 to 5 mg. for children 10 to 15 mg and during pregnancy and lactation 20
to 25 mg of zinc are required.
FLUORINE
Fluorine occurs in the form of fluoride in nature. It is present in soils, water, plants and
animals.
Functions
1. Fluorine in the teeth helps to protect them from decay.
2. Fluoride gives stability to bone and enamel tissues.
Toxic effects of excess of fluorine
1. Skeletal Fluorosis
Intake of fluorine higher than the 10 mg/litre of drinking water leads to skeletal fluorosis
(genuvalgum- knock knees). In skeletal fluorosis there is hypercalcification of the bone of the
spine, pelvis, and limbs.
2. Dental Fluorosis (Mottled Enamel)
Intake of fluorine higher than the 3-5 mg/litre of drinking water leads to dental fluorosis.
Chalky white patches, brown staining are the symptoms of dental fluorosis.
Source
Soil and water are the major source of fluorine.
Requirements/RDA of Fluorine
Age group Requirements (mg)
Adult 1.5 – 4.0
Adolescents 1.5-2.5
Infant 0.1-1.0

CHLORINE
Chlorine in the body exists in the form of chloride, an essential electrolyte mineral. It is
best known as the other half of sodium-chloride or table salt. It makes up about 0.15% of body
weight (around 115 g for an average adult) and is found mainly in the fluid surrounding cells,
alongside sodium. A small percentage of about 15% of chloride in the body is located inside
cells, with the highest amounts in red blood cells. Chloride is also present in very small amounts
in bones. Most of our chloride intake is from table salt. It is easily absorbed by the intestines. It
is eliminated through the kidneys in a finely tuned mechanism that regulates acid-base balance
by either removing or retaining chloride.
Functions
This electrolyte mineral works with the other electrolytes potassium and sodium to
maintain the proper balance of body fluids, as well as their pH balance. Chloride is also an
essential component of digestive juices, as it is needed with hydrogen to form stomach
hydrochloric acid.
 keeps the amount of fluid within and around cells in balance
 helps regulate the pH (acid-alkali / acid-base) balance of body fluids
 maintains proper blood volume and pressure
 critical constituent of hydrochloric acid, a key component of gastric juice secreted
by the stomach that is vital for maintaining the normal acidic environment needed
by pepsin, and aids digestion and absorption of many nutrients including iron and
vitamin B12
 may help conserve potassium
Deficiency
Deficiency of chloride, or when blood levels of it drop too low, is known as
hypochloremia. It is rare, as chloride is part of table salt which is present in most foods. In fact,
people are prone to consuming more chloride than is really needed, due to salt-laden diets.
Hypochloremia can occur however, for a variety of reasons that include:
 heavy sweating, as large amounts of sodium and chloride can be lost in
perspiration
 excessive fluid loss due to prolonged diarrhea or vomiting, or overuse of coffee or
laxatives or diuretics
 over-hydration
 burns
 congestive heart failure
 certain kidney disorders
 Addison's disease
 most often seen in infants on chloride-deficient formulae
Chloride deficiency symptoms
 loss of appetite
 muscle weakness
 lethargy
 dehydration
 deficiency leads to alkalosis, a condition in which body fluids have excess base (alkali),
that can result in dangerously high blood pH and excessive loss of potassium in urine
(which in turn causes hypokalemic metabolic alkalosis with symptoms that include loss
of control of muscle function which might lead to breathing and swallowing difficulties).
Sources
Chloride is found in almost all foods in the salt that is added, often in large amounts,
during processing or cooking. Foods high in chloride are table salt or sea salt (sodium chloride),
salt substitutes such as potassium chloride, seaweed (such as dulse and kelp), olives, rye,
vegetables like celery, lettuce, tomatoes, preserved meats such as bacon, ham, sausages,
processed or canned or fast foods that are high in salt. Other chloride food sources include
cheese, vegetables, yeast extract as potassium chloride found in most foods.
Requirements/RDA of chlorine
Age group Requirements (g)
Adult 2.3
Adolescents 2.3
Infant 0.2-10.6
Children 1.5-2.0
 LECTURE 11
WATER

Water is vital for human existence. We can live without food for extended periods of
time, but without water will result in death. Water is colourless, calorie less compound of
hydrogen and oxygen that virtually every cell in the body needs to survive. Water is closer being
a universal solvent than any other compound.
Water is the largest constituent of the body, about 60-70 per cent of the total body weight
consisting of water. The water content of soft tissues ranges from 70-80 per cent while that of
bone about 20 per cent. Body water is distributed as follows:
 Inside the cells of tissue – intracellular water (50 per cent)
 Outside the tissue cells – extra cellular water (20 per cent).
The extracellular water is further subdivided into
 Water in blood plasma (about 4 per cent)
 Interstitial water – water in tissue space (9 per cent)
 Lymph in the lymphatic vessels (7 per cent).
Additional minor divisions of extracellular water are cerebrospinal fluid and aqueous humour
in the anterior chamber of the eye).
Functions of water
1. It is an essential constituent of all the cells of the body.
2. It helps in transporting nutrients into the cells and removes waste products.
3. Water is a medium for most biochemical reactions.
4. It is a valuable solvent for electrolytes, non-electrolytes, hormones, enzymes and
vitamins.
5. Plays a vital role in the maintenance of body temperature.
6. It is constituents of several enzymes and hormones. Saliva is about 99.5 percent water.
7. Water helps in maintaining the form and texture of the tissues.
8. Water is essential for the maintenance of acid base and electrolyte balance.
9. Water forms good source of minerals like Calcium, Magnesium, Fluoride, Iron and
Iodine.
Water intake
Water intake varies widely depending on the climate; As drinking water, about 1500-
5000 ml and in food 1000-2000 ml. Water is taken in food and also as drinking water. In
addition, water is formed in the tissues by the oxidation of hydrogen present in fats,
carbohydrates and proteins.
Water loss
Water is lost continuously from the body in the following ways:
(i) via kidney as urine (1000-1500 ml)
(ii) via the skin in the form of insensible perspiration and as sweet (800-5200 ml)
(iii) via the lungs in the expired air (400 ml)
(iv) via the large intestines in the faeces (100-200 ml)
(v) Lactating women in the milk.
In a normal individual, the water intake is approximately equal to water lost from the
body and the water content of the body is maintained fairly constant.
Requirements
Requirements of water vary with climate, activities and surface area of the body. Normal
intake of water ranges between 8-10 glasses (2500-3000 ml) per day.
Dehydration
Extra cellular and intra cellular fluid losses through vomiting, diarrhoea, excessive
sweating is called dehydration.
Oral Rehydration Therapy
It is the administration of fluid orally to prevent or correct dehydration.
Oral Rehydration Salt (WHO and UNICEF formula)
To be dissolved in one litre of potable drinking water.
Sodium chloride (NaCl) -3.5 g,
Sodium bicarbonate (NaHCO3) - 2.5 g,
Potassium chloride (KCl) -1.5 g and
Glucose - 20 g
 DIETARY FIBRE
Dietary fibre is defined as that portion of plant material ingested in the diet that is
resistant to digestion by gastro intestinal secretions. It consists of hemicellulose, cellulose,
lignins, oligosaccharides, pectins, gums and waxes.
TYPES OF FIBRE
Soluble Fibre
Soluble fibres are indigestible but soluble in water, e.g., Gums, pectins, mucilages.
Insoluble Fibre
Insoluble fibres are indigestible and insoluble in water e.g., Cellulose, hemicelluloses,
lignin.
Functions of Fibre
1. It control the blood glucose level by slows down the absorption of glucose from food.
2. Soluble dietary fibre reduces the serum cholesterol level.
3. Fibre intake reduces the blood pressure and reduces the risk of heart diseases.
4. Insoluble fibre helps to prevent constipation.
5. Insoluble fibre helps to prevent colon cancer and haemorrhoids.
6. It controls the appetite by giving feeling of fullness to stomach.
7. It helps in elimination of wastes.
8. Dietary fibre intake reduces the risk of atherosclerosis.
Sources
Types and Source of Fibre
Types of Fibre Major Food Sources
Soluble fibres
Gums, pectins, mucilages Citrus fruits, apple, oats, barley, legumes
Insoluble fibres Whole wheat products, wheat bran, whole grain
Cellulose, hemicelluloses, breads, cereals and vegetables like green peas,
beans, cabbage.
Lignin Skin of vegetable and fruits
Fibre Content of Foods
Cereals
 Whole cereal flours contain about 8 to 15% of total dietary fibre.
Pulses
 Whole pulses (with cuticle) contain about 32 to 40% of dietary fibre.
 Dhals (decuticled split pulses) contain from 8 to 10%.
Nuts
 Groundnut (without skin) contains about 9.3% of dietary fibre.
Vegetables
 The dietary fibre content of vegetables on fresh basis may vary from 1.3 to 7-8% and on
dry basis from 9.6 to 38.4%.
Fruits
 The dietary fibre content of fruits range from 1.4 to 3.6% on the fresh basis and 9.6 to
14.4% on dry basis.
RDA for Dietary Fibre
Recommended dietary allowances for fibre is 30 g/day or 12g/1000 Kcal for normal
healthy adult. American diabetic association recommends 25-38 g of dietary fibre per day per
persons suffering from diabetes.
 LECTURE 12
PRESERVATION OF FOOD BY TEMPERATURE

Preservation
Preservation are the measures employed to prevent (or) minimize all such undesirable
changes takes place due to spoilage which caused by both internal and external organisms.
Need for preservation of foods
Freshly harvested or prepared products are highly attractive in appearance and possess
good taste and aroma, but deteriorate rapidly if kept for sometimes.
This is due to
 Fermentation caused by moulds, yeasts and bacteria
 Enzymes present in the products may affect the colour and flavour adversely
 Chemicals present in the processed food react with one another and spoil its taste and
aroma
 Air coming in contact with the product, may react with the glucosidal materials present in
it and render the product bitter
 Traces of metal from the equipment may get into the product and spoil its taste and
aroma.
Importance / advantages of food preservation
 Prevention of wastage of fresh produce.
 To extent the shelf life of the produce.
 To develop value added products.
 Self employment opportunities.
 Provides convenient and preferable forms to the consumer (jam, jellies, RTS,
squash,etc.).
 Foreign exchange earnings from the export of processed foods and it will improve our
national economy.
 Available in the form of ready to serve and hence (fuel consumption) energy is saved.
I. Preservation of low temperature
Microbial growth and enzyme reactions are retarded in foods stored at low temperature.
The lower the temperature, the greater the retardation. Low temperature can be produced by
a. Cellar storage (about 15oC)
The temperature in cellar (underground rooms) where surplus food is stored in many villages
is usually not much below that of the outside air and is seldom lower than 15oC. It is not enough
to prevent the action of many spoilage organisms or of plant enzymes. Root crops, potatoes,
cabbage, apples, onions and similar foods can be stored for limited periods during the winter
months.
b. Refrigerated (or) chilling (0 to 5oC)
Chilling temperature are obtained and maintained by means of ice or mechanical
refrigeration. It may be used as the main preservative method for foods or for temporary
preservation until some other preservative process is applied. Most perishable foods, including
eggs, dairy products, meats, sea foods, vegetables and fruits, may be held in chilling storage for a
limited time with little change from their original condition. Enzymatic and microbial changes in
the foods are not prevented but are slowed considerably.
c. Freezing (18 to 40oC)
At temperature below the freezing point of water, growth of microorganisms and enzyme
activity are reduced to minimum. Most perishable foods can be preserved for several months.
Fruits, vegetables, juices and fleshy foods (meat poultry fish and sea foods) can be preserved in
this method.

II. Preservation by high temperature

Application of heat to the foods leads to the destruction of microorganisms. The specific
treatment varies with:
a. The organisms that has to be killed.
b. The nature of the food to be preserved and
c. Other means of preservation that may be used in addition to high temperature.

High temperatures used for preservation are usually:

(1) Pasteurization temperature – below 100oC
(2) Heating at about 100oC and
(3) Sterilization temperature above 100oC.
a. Pasteurization–below 100oC
Pasteurization is a heat treatment that kills part but not all the microorganisms present
and the temperature applied is below 100oC. The heating may be by means of steam, hot H2O,
dry heat or electric currents and the products are cooled promptly after the heat treatments.
Methods of pasteurization
 HTST method - High temperature and short time (above 70oC)
 LTH method - Low temperature and higher time (or) Holding method (60-70oC)
b. Heating at about 100oC
A temperature of approximately 100oC is obtained by boiling a liquid food, by immersion
of the container of food in boiling water or by exposure to flowing steam. Acid foods, e.g.,
sauerkraut may be preheated to a temperature somewhat below 100oC, packaged hot and not
further heat processed. Blanching fresh vegetables before freezing or drying involves heating
briefly at about 100oC.
c. Sterilization-above 100oC
By this method all microorganisms are completely destroyed due to high temperature.
The time and temperature, necessary for sterilization vary with the type of food. Temperatures
above 100oC can only be obtained by using steam pressure sterilizers such as pressure cookers
and autoclaves.
Vegetables like green peas, okra, beans, etc. being non acidic and containing more starch
than sugar, require higher temperature to kill the spore forming organisms. Continuous heating
for 30-90 min. at 116oC is essential for their sterilization. Before using, empty cans and bottles
should also be sterilized for about 30 min. by placing them in boiling water.
Difference between pasteurization and sterilization
Pasteurization Sterilization

1. Partial destruction of microorganism 1. Complete destruction of microorganism

2. Temperature below 100oC 2. Temperature 100oC and above
3. Normally used for fruits 3. Normally used for vegetables
Food Irradiation
Food irradiation (the application of ionizing radiation to food) is a technology that
improves the safety and extends the shelf life of foods by reducing or eliminating
microorganisms and insects. Irradiation is sometimes referred to as “cold pasteurization” since
the result achieved is similar to heat-based pasteurization but without the heat.
Purpose of Irradiation
Prevention of Foodborne Illness – irradiation can be used to effectively eliminate organisms
that cause foodborne illness, such as Salmonella and Escherichia coli (E. coli).
Preservation – irradiation can be used to destroy or inactivate organisms that cause spoilage and
decomposition and extend the shelf life of foods.
Control of Insects – irradiation can be used to destroy insects in or on tropical fruits
Delay of Sprouting and Ripening – irradiation can be used to inhibit sprouting (e.g., potatoes)
and delay ripening of fruit to increase longevity.
Sterilization – irradiation can be used to sterilize foods, which can then be stored for years
without refrigeration.
Sources of Irradiation
There are three sources of radiation approved for use on foods.
Gamma rays are emitted from radioactive forms of the element cobalt (Cobalt60) or of the
element Cesium (Cesium137).
X-rays are produced by reflecting a high-energy stream of electrons off a target substance
(usually one of the heavy metals) into food.
Electron beam (or e-beam) is similar to X-rays and is a stream of high-energy electrons
propelled from an electron accelerator into food.
Doses
 Radiation dose of upto 1 Mrad is not hazardous.
 Low doses (<1 kGy): control of insects and parasites, delay of ripening
 Medium doses (1 - 7 kGy): reduction of foodborne pathogens, extension of shelf life
 High dose (> 25 kGy): sterilization
Mode of action
Energy waves passing through the food break molecular bonds in the DNA of bacteria,
other pathogens, and insects. These organisms die or, unable to reproduce, their numbers are held
down. Food is left virtually unchanged, but the number of harmful bacteria, parasites and fungi is
reduced and may be eliminated.
Labeling of Irradiated Foods
Any irradiated food, or food containing an irradiated ingredient must
carry the word “Irradiated” in a prominent position either as part of the main
label or next to the ingredient that has been irradiated. It may also (optional)
show the international icon for irradiated food called the “Radura” symbol
along with the statement “Treated with radiation” or “Treated by irradiation”
on the food label.
Foods suitable for Irradiation
The main types of food that have been classified as safe to irradiate are meat, seafood,
fruit, vegetables, herbs and spices.
Effects of irradiation on the nutritional content and safety of food
The Food and Drug Administration has evaluated the safety of this technology and has
found irradiation to be safe under a variety of conditions and has approved its use for many
foods. Irradiation does not significantly reduce nutritional quality or significantly change food
taste, texture or appearance. Irradiated foods do not become radioactive. Irradiation can produce
changes in food, similar to changes caused by cooking, but in smaller amounts.
 LECTURE 13
PROCESSING OF PUFFED, FLAKED AND EXTRUDED PRODUCTS

The snack food is one of the most important areas of the food industry. Designing snack
foods today can be a complex process to meet changing consumers taste and expectations and
elusive search for something unique that also appeals to a wide variety of people. As a simplest,
inexpensive and quickest traditional method of dry heat application for preparation of weaning
food formulations and ready-to-eat snacks products, popping and puffing have been practiced
since hundreds of years.
Popping
Popping is a process in which kernels are heated until internal moisture expands and pops
out through the outer shell of the kernel. Popping is defined as direct heating of the moistened
grain (18 to 20 %) at a temperature of 190° C to 250°C in a closed container until moisture inside
the grain vaporizes and expands the kernel causing it to “pop” or explode. During the popping of
popcorn the pericarp acts as a pressure vessel and popping occurs at about 177°C, which is
equivalent to a pressure of 135psi inside the kernel. During popping the material practically gets
sterilized and most of the seed microflora is destroyed. Popping also improves the digestibility of
starch as it involves gelatinization of starch and degradation of dietary fibres.
A variety of popped cereals like popcorn, popped rice, popped sorghum, popped ragi and
popped pulses were marketed and consumed as snacks by all segments of population. While
popcorn is popular among urban elite, other popped cereals are more popular among middle and
lower income segments of the population in regions where the specific cereal is predominantly
grown. Popcorn is an important snack food made from corn and is growing popular day by day.
The microwave popcorns are becoming popular with the increasing availability of microwave
ovens at home scale. The popcorn coated with different ingredients such as butter, hydrogenated
oil, sugar syrup, salt, savors, etc., are sold in market in small packs.
 Flow chart for preparation of popping of millets
Millets (Samai/Varagu)

Soaking in water (1:1.5, 1-2hrs) (Moisture 19%)

Draining

Tempering (2-4hrs)

Popping in roasted fine sand (BS 60 mesh sieve) (270oC)

Popping

Puffing
Puffing is a popular Ready - to - eat snack product is obtained by puffing cereals and
pulses. Puffing is a process where, sudden release of water vapour and expansion of pre-
gelatinized kernel takes place. Superheated vapour is produced inside the grains by instantaneous
heating, which cooks the grain and expands the endosperm while escaping with great force
through the micropores of the grain structure. Most of the water in the kernel is superheated at
the moment of popping and provides driving force for expanding the kernel once pericarp
ruptures. It is defined as heating of the dry grain at a temperature of 250°c in hot sand. Puffed
rice and puffed bengal gram are more common in India.
Puffed Rice
Puffed rice is very popular in many countries as a cereal breakfast component or as a
light food. It is a whole grain puffed product from parboiled milled rice. It is prepared from
hydrothermally treated or pregelatinized milled rice by heating in high temperature air, oil and
sand or by gun puffing method. Puffed rice is ready for consumption and easily digestible. It is
commonly used in snacks, cereals drinks, Ready- to- Eat (RTE) breakfast cereals and infant
foods. During puffing, rice kernels increase their volume several times and a fully heat-treated
crisp, porous, ready-to-eat product is created. Regardless of the puffing process two important
parameters should be taken into account: the selection of an appropriate sort of rice, and the use
of a proper hydro-heat treatment of raw rice. The optimum moisture content for puffing of rice
for puffing expansion in most of the studies found to be 13-14%. Salt solution is invariably
added to milled rice before it is heat expanded in the industry.
Flow chart for preparation of puffed pulses (Bengal gram)
Bengalgram

Cleaning

Washing

Soaking (5% salt and 3% NaHCO3)

Draining

Puffing (250oC for 5 minutes)

Sieving

Puffed bean

Dehulling

Winnowing

Puffed dhal
Flaking
A popular form of ready-to-eat breakfast cereal is the crisp flake. Before flaking, grains
and pulses are softened by being partially cooked in steam. They are then pressed or rolled into
flakes which are subsequently dried. Such partially-cooked cereals may be used as quick-
cooking or ready-to-eat foods. Flaked grains are eaten crisp and need to be packaged in moisture-
proof containers. The moisture content must be below 7 per cent; otherwise the product becomes
soggy and tough.
Flow chart for preparation of flaking of millets
Dehulling

Soaking in water (3- 4 hrs)

Steaming/ pressure cooking
(to effect complete gelatinization of starch)

Drying (upto18% moisture)

Flaking (using machine)
(to requisite thickness between heavy duty roller)

Drying at 70o C for 1 hr

Packing

Extrusion
Extrusion is a process of partial gelatinization of the flour and extruding in small orifices
under high pressure and temperature. Extrusion is a process that combines several unit
operations, including mixing, kneading, shearing, heating, cooling, shaping and forming. It
involves compressing and working raw materials e.g. flours, starches, proteins, salt, sugar and
other minor ingredients, to form a semi-solid mass under a variety of controlled conditions and,
then forcing into to pass through a restricted opening such as a shaped hole or slot at a
predetermined rate. Heat is applied directly by steam injection or indirectly through a heated
barrel or the conversion of mechanical energy. The final process temperature in the cooking
extruder can be as high as 200oC but the residence time is relatively short i.e. 10-60 seconds.
Thus extrusion cooking is also called a high temperature short time (HTST) process. This
process of HTST, extrusion bring gelatinization of starch, denaturation of proteins, modification
of lipids and inactivation of enzymes, microbes and many antinutritional factors.
Flow chart for the preparation of noodles
Maida: Millet flour blend

100:0 90:10 80:20 70:30

Mixing with salt

Steaming for 10 minutes

Cooling

Kneading for 10 min (300 ml / 1 kg flour) water

Extruding

Sun drying (one day) / cabinet drying at 70 oC for 4 hrs

Packing

Storing
Examples of extruded foods
Types of product Examples
Cereal-based products Expanded snack foods
RTE and puffed breakfast cereals
Soup and beverage bases, instant drinks
Weaning foods
Pre-gelatinised and modified starches, dextrins
Crisp bread and croutons
Pasta products
Pre-cooked composite flours
Sugar-based products Chewing gum
Liquorice
Toffee, caramel, peanut brittle
Fruit gums
Protein-based products Texturised vegetable protein (TVP)
Semi-moist and expanded pet foods and animal feeds and
protein supplements
Sausage products, frankfurters, hot dogs Surimi
Caseinates
Processed cheese
 LECTURE 14
PRESERVATION OF FOOD BY SUGAR AND SALT

I. Preservation by using sugar

Sugar absorbs most of the available water with the result that there is very little water for
the growth of microorganisms hence their multiplication is inhibited, and even those already
present die out gradually. Dry sugar does not ferment. Thus sugar acts as a preservative by
osmosis and not as a true poison for microorganisms. Fruit syrup, jam, jelly marmalade,
preserve, candy, crystallized fruit and glazed fruit are preserved by sugar.
Jam
Jam is a product made by boiling fruit pulp with sufficient quantity of sugar to a
reasonable thick consistency, firm enough to hold the fruit tissues in position. Apple, sapota,
papaya, plums, mango, grapes, jack, pine apple, banana, guava and pears are used for the
preparation of jam. It can be prepared from one kind of fruit or from two or more kind of fruits.
In its preparation about 45% of fruit pulp should be used for every 55% of sugar. The FPO or
FSSAI specification of jam is 68.5% TSS, 45% of fruit pulp and 0.5 – 0.6% acid (citric acid) per
100g of prepared product.
Preparation of jam
 Select matured and ripened fruits.
 To remove the dust and dirt.
 Remove the skins from the flush of the fruits.
 Cut the peeled fruits into small portions.
 Make it into pulp either by use of hand pulper (or) by mixie.
 Take the pulp and sugar (required amount) in a vessel and heat it over fire by stirring
continuously, till the final TSS reaches 68.5ͦ bx.
 Remove from the fire and allow cooling to room temperature.
 Pack it in a sterilized bottle and cover it with airtight cover.
 Label it with correct information.
Sheet or flake test
The end point of the jam is judged by sheet (or) flake test. A small portion of jam is taken
out during boiling in a spoon (or) wooden ladle and cooled slightly. It is then allowed to drop. If
the product falls off in the form of a sheet (or) flakes instead of flowing in a continuous stream
(or) syrup, it means that the end point has been reached and the product is ready. Otherwise,
boiling is continued till the sheet test is positive.
Problems in jam production
Crystallization
If the percentage of invert sugar is less than 30 % cane sugar may crystallize out on
storage and if it is more than 50% the jam will become a honey like mass duo to formation of
small crystals of glucose. Corn syrup or glucose may be added along with cane sugar to avoid
crystallization.
Sticky or gummy jam
Because of higher percentage of TSS, Jams tend to become gummy or sticky. This
problem can be solved by addition of pectin or citric acid or both.
Premature setting
This is due to low TSS and high pectin content in the jam and can be prevented by adding
more sugar.
Surface graining and shrinkage
This is caused by evaporation of moisture during storage of jam. Storing in cool place can
reduce it.
Microbial spoilage
Moulds may spoil the jam during storage. It is also advisable to add 40 ppm of SO2 in the
form of KMS or 200 ppm of benzoic acid.
Jelly
Jelly is prepared by boiling the fruit with or without water, straining, mixing the strained
and clear juice extract with sugar and boiling the mixture to a stage at which it will set to a clear
gel. A perfect jelly should be transparent, well set, but not too stiff and should have the original
flavour of the fruit. It should be of attractive colour and should keep its shape when removed
from the mould. When cut, it should retain its shape and show a clean-cut surface. It should be
tender enough to quiver, but not flow.
The FPO or FSSAI specification for jelly is 65% TSS, 45% of fruit extract and 0.5 –
0.75% acid (citric acid) per 100g of prepared product. Guava, sour apple, plum, karonda, wood
apple, papaya and jack fruit are rich in pectin and generally used for the preparation of jelly.
Preparation of jelly
 Select sound fully matured ripe fruit (not over ripened or under ripened).
 Wash thoroughly with water to remove any adhering dirt.
 Peel the skin and make it into pulp and add water at the rate of 1½ times and boil it for 30
min. with citric acid.
 Filter the boiled pulp through the muslin cloth.
 Check the pectin strength of the extracted pectin by using alcohol test method.
 Add required sugar to the extract and cook by stirring continuously till it reaches the TSS
of 65o bx.
 Remove from the fire and cool, it to room temperature.
 Pack it in a sterilized bottle and cover it airtight.
 Label with correct information.
Alcohol test
One teaspoonful of strained extract is taken in a beaker and 3 teaspoonful of methylated
spirit are poured gently down the side of the beaker, which is rotated for mixing and allowed to
stand for a few minutes. Observations are
a. If extract is rich in pectin, a single transparent lump or clot will form. An equal amount
of sugar is to be added to the extract for preparation of jelly.
b. If extract contains moderate amount of pectin, the clot will be less firm and fragmented.
Three-fourth, amount of sugar is to be added.
c. If extract is poor in pectin, numerous small granular clots will be seen. Half the amount
of sugar is added.
Add required sugar to the extract and cook by stirring continuously till it reaches the TSS
of 65o bx. Remove from the fire and cool, it to room temperature. Pack it in a sterilized bottle
and cover it airtight. Label with suitable information.
Problems in Jelly Making
Failure to set
This may be due to addition of too much sugar, lack of acid or pectin, cooking below or
beyond end point, prolonged cooking.
Cloudy or foggy jellies
This is due to the following reasons use of non-clarified juice or extract, use of immature
fruits, over cooking, over cooling, non-removal of scum.
Formation of crystals
It is due to excess of sugar
Syneresis or weeping of jelly
The phenomenon of spontaneous exudation of fluid from a gel is called syneresis or
weeping. This may due to excess of fluid, too low concentration of sugar, insufficient pectin,
premature gelation and fermentation.
Squash
Squash is a type of fruit beverage .The FPO or FSSAI specification for squash is fruit juice
25 per cent, TSS 45o brix, acidity 1.0 per cent, preservative 350 ppm of SO2 (or) 700 ppm of
potassium metabisulphite or 600 ppm of sodium benzoate. The dilution is 1:4. Lime, mango,
orange and pine apple are used for making squash commercially using KMS as preservative or
fruits viz. jamun, passion fruit, raspberry, strawberry, grape fruit with sodium benzoate as
preservative.
Preparation of squash
 Select ripe and firm fruits
 Washing and Peeling of outer skin
 Cut into small pieces
 Extraction of juice by crushing
 Strain the juice and Juice measuring
 Preparation of sugar syrup (Sugar + water + acid heating to dissolve)
 Strain and Cool the syrup
 Mix with juice
 Addition of preservative
 Bottling and Capping
Marmalade
Marmalade is a fruit jelly in which slices of the fruit or its peel are suspended. The term
is generally used for products made from citrus fruits like oranges and lemons in which shredded
peel is used as the suspended material. The FPO or FSSAI specification for marmalade is TSS –
65%, and fruit juice – 45 % of the prepared product. Citrus marmalades are classified into
 Jelly marmalade – it is prepared from the clarified pectin extract.
 Jam marmalade - The pectin extract is not clarified and whole pulp is used.
Preparation of marmalade
 Select ripe fruits
 Washing and peeling outer portion
 Cutting the peel in to fine shreds and boiled for 10 -15 mins
 Cutting the thick slices of peeled fruit or crushing into pulp
 Boiling (2-3 times its weight of water for 40 – 60 min)
 Straining extract
 Test for pectin content (alcohol test)
 Addition of sugar
 Cooking to 103 -1 05 o C
 Addition of prepared shreds
 Boiling till jellying point (test for end point - sheet / drop /temperature test)
 Cooling and add flavour
 Fill in sterilized bottles, seal and store at ambient temperature.
II. Preservation by using salt
Sodium chloride is an indispensible component of food. At lower concentrations it
contributes significantly to the flavour. At higher concentrations it exhibits an important
bacteriostatic action. Salt at a concentration of 15-25%, is sufficient to preserve most products. It
inhibits enzymatic browning and discolouration and also acts as an antioxidant, salt in the form
of brine is used for canning and pickling of vegetables and curing of meat. Salt has been reported
to have the following effects;
 It causes high osmotic pressure and hence plasmolysis of cells
 It dehydrates foods by drawing out and tying up moisture as it dehydrates microbial cells.
 It ionizes to yield the chloride ion, which is harmful to organisms
 It reduces the solubility of O2 in the moisture
 It sensitizes the cell against CO2
  It interferes with the action of proteolytic enzymes.
Pickling process
Pickling is the result of fermentation by lactic acid forming bacteria which are generally
present in large numbers on the surface of fresh vegetables and fruits. These bacteria can grow in
acid medium and in the presence of 8-10 % salt solution whereas the growth of a majority of
undesirable organisms is inhibited. There are two methods for pickling
Dry salting method
Alternate layers of vegetables and salt 20-30 g of dry salt /Kg vegetables are kept in a
vessel which is covered with a cloth and a wooden board and allowed to stand for about 2 hrs.
During this period due to osmosis sufficient juice comes out from the vegetables to form brine.
As soon as the brine is formed the fermentation process starts and CO2 begins to evolve. The salt
content is now increased gradually so that by the time pickle is ready, salt concentration reaches
15% when fermentation is over gas formation ceases.
Fermentation in brine
Steeping of the vegetable in a salt solution of predetermined concentration for a certain
length of time is called brining. This type of treatment is adopted in the case of cucumbers and
similar vegetables which do not contain sufficient juice to from brine with dry salt. Brine can be
prepared by dissolving in common salt in water and filtering it through the cloth to remove
insoluble impurities. The remaining process is similar to that of dry salting method.
III. Preservation by using chemicals
Preservative
A preservative is defined as any substance which is capable of inhibiting, retarding or
arresting the growth of microorganisms. Microbial spoilage of food products is also controlled
by using chemical preservatives. The inhibitory action of preservatives is due to their interfering
with the mechanism of cell division, permeability of cell membrane and activity of enzymes.
Two important chemical preservatives are permitted to beverages according to the FPO (1955).
 Sulphur dioxide
 Benzoic acid
Sulphur dioxide (SO2)
It is widely used throughout the world in the preservation of juice, pulp, nectar, squash,
crush, cordial and other products. It has good preserving action against bacteria and moulds and
inhibits enzymes, etc. in addition it acts as an antioxidant and bleaching agent. Potassium
metabisulphite ((K2S2O5) is commonly used as a stable source of SO2.
Benzoic acid
It is only partially soluble in water hence its salt, sodium benzoate is used. The bacterial
action of benzoic acid is increased in the presence of CO2 and acid. It is more effective against
yeasts tan against moulds. It does not stop lactic acid and acetic acid fermentation.
Permissible limits of preservatives in food products (FPO)
Sulphur dioxide Quantity (ppm)
Fruit pulp 2000-3000
Fruit juice concentrate 1500
Dried fruits 2000
squash 350
Jam, marmalade, preserve 40
RTS 70
Pickles 100
Dehydrated vegetables 2000
Benzoic acid Quantity (ppm)
squash 600
Jam, jelly, maramalde 200
Pickles 250
Tomato sauce 750
 LECTURE 15
FOOD PACKAGING AND NUTRITION LABELING

Food Packaging:
In today's society, packaging is pervasive and essential. It surrounds, enhances and
protects the goods we buy, from processing and manufacturing, through handling and storage, to
the final consumer. Without packaging, materials handling would be a messy, inefficient and
costly exercise and modem consumer marketing would be virtually impossible. The packaging
sector represents about 2% of Gross National Product (GNP) in developed countries and about
half of all packaging is used to package food.
Definition of packaging:
Packaging has been defined as a socio scientific discipline which operates in society to
ensure delivery of goods to the ultimate consumer of those goods in the best condition intended
for their use.
The Packaging Institute International (PII) defines packaging as the enclosure of
products, items or packages in a wrapped pouch, bag, box, cup, tray, can, tube, bottle or other
container form to perform one or more of the following functions: containment, protection,
preservation, communication, utility and performance. If the device or container performs one or
more of these functions, it is considered a package.
Other definitions of packaging include a co-ordinated system of preparing goods for
transport, distribution, storage, retailing and end-use, a means of ensuring safe delivery to the
ultimate consumer in sound condition at optimum cost, and a techno-commercial function aimed
at optimizing the costs of delivery while maximizing sales.
Package, Packaging, Packing:
It is important to distinguish between the words "package," "packaging" and "packing."
The package is the physical entity that contains the product. Packaging was defined above and in
addition, is also a discipline. The verb "packing" can be defined as the enclosing of an individual
item (or several items) in a package or container.
Levels of Packaging:
A primary package is the one which is in direct contact with the contained product. It
provides the initial, and usually the major protective barrier. Example: Metal cans, paperboard
cartons, glass bottles and plastic pouches, aerosal spray can, Beverage can, cushioning
envelopes, plastic bottles, skin pack.
A secondary package contains a number of primary packages. It is outside the primary
packaging perhaps used to group primary packages together. It is the physical distribution carrier
and is sometimes designed so that it can be used in retail outlets for the display of primary
packages. Ex. Corrugated case, Boxes
A tertiary package is made up of a number of secondary packages. It is used for bulk
handling. Example being a stretch-wrapped pallet of corrugated cases.
A quaternary package is frequently used to facilitate the handling of tertiary packages.
This is generally a metal container up to 40 m in length which can be transferred to or from
ships, trains, and flatbed trucks by giant cranes. Certain containers are also able to have their
temperature, humidity and gas atmosphere controlled. This is necessary in particular situations
such as the transportation of frozen foods, chilled meats and fresh fruits and vegetables.
Functions of packaging:
Contain
 portion control (profitability)
 consistency
 company reputation
 consumer expectation
 consumer convenience
Protect
 contamination
 maintain quality
 legislation (Codex, local legislation)
 product consistency
 company reputation
Inform (labelling)
 nature of the contents
 legislation, Codex, and other codes
 nutrition
 instructions for use
  elimination of fraud
 storage requirements
Attract
 advertise that this product is satisfying and fun and healthy
Classification of Packages:
Packages can be classified as 1) traditional or natural and 2) fabricated or modern
packaging materials based on the availability of the materials.
Traditional or natural packaging materials are – Bamboo basket, fiber or leaf mats, Leather
containers of animal skin, clay containers, gunny bags, cloth bags, Arecanut and teak leaves
sheath.
Modern packaging materials can be divided into rigid, semi rigid and flexible materials.
 Rigid containers are – metal drums, metal barrels, glass bottles, glass jars, wooden
boxes, wooden crates, plastic bottles, plastic drums, plastic crates, paper drums, plywood
containers.
 Semi rigid containers are – aluminium collapsible tube, plastic collapsible tube,
composite container, paper based cartons.
 Flexible container is plastic bags.
Types of Packaging Materials:
1. Paper based packaging materials
2. Metal packaging materials
3. Glass packaging materials
4. Plastic packaging materials
5. Edible and bio based packaging materials
Paper as Packaging Material:
Paper derives its name from the reedy plant “papyrus”, which the ancient Egyptians used
to produce the world's first writing material by beating and pressing together thin layers of the
plant stem. Paper is widely used as a packaging material because of its stiffness and printability.
The main advantages of paper as packaging material are – Good stiffness, good
absorbent, good creaseability, good printability, low density, not brittle, biodegradable, low cost.
The main disadvantages are – poor tensile strength, poor wet strength, tear easily, no barrier
property without coating.
Types of Paper:
 Kraft paper
 Bleached paper
 Greaseproof Paper
 Glassine paper
 Vegetable parchment
 Waxed paper
Paper is divided into two broad categories:
 Fine papers, generally made of bleached pulp, and typically used for writing paper, bond,
ledger, book, and cover papers, and
 Coarse papers, generally made of unbleached kraft softwood pulps and used for
packaging.
Paperboard Products:
Paper is generally termed board when its grammage exceeds 224 g m-2. Multiply boards
are produced by the consolidation of one or more web plies into a single sheet of paperboard,
which is then subsequently used to manufacture rigid boxes, folding cartons, beverage cartons
and similar products. One advantage of multi-ply forming is the ability to utilize inexpensive and
bulky low-grade waste materials (mostly old newspapers and other postconsumer waste papers)
in the inner plies of the board where low fiber strength and the presence of extraneous materials
(e.g., inks, coatings, etc.) have little effect on board properties. However, multi-ply boards
containing postconsumer waste papers are not used for food contact purposes.
Paperboard Grades:
 Linerboard
 Foodboard
 Folding Boxboard (Cartonboard)
 Chipboard
 Folding Cartons
 Beverage Cartons
 Molded pulp containers
Metal packaging materials
Four metals are commonly used for the packaging of foods: steel, aluminium, tin and
chromium. Today, materials like tinplate and aluminum have become universally adopted for the
manufacture of containers and closures for foods and beverages, largely due to several important
qualities of these metals. These include their mechanical strength and resistance to working, low
toxicity, superior barrier properties to gases, moisture and light, ability to withstand wide
extremes of temperature and ideal surfaces for decoration and lacquering.
Advantages
Metal cans have a number of advantages over other types of container, including the
following:
 They provide total protection of the contents
 They are convenient for ambient storage and presentation
 They are tamperproof.
Disadvantages
 The high cost of metal and the high manufacturing costs make cans expensive.
 They are heavier than other materials, except glass, and therefore have higher
transport costs
Protective and Decorative Coatings:
 They protect the metal from the contents
 They avoid contamination of the product by metal ions from the container
 They facilitate manufacture
 They provide a basis for decoration and product dentification
 They form a barrier to external corrosion or abrasion
Protective coatings:
For most containers, the enamel is applied to the metal in the flat before fabrication.
Many types of internal enamel are available for food containers including oleoresinous, vinyl,
vinyl organosol, acrylic, alkyd, polybutadiene, phenolic and epoxyphenolic
Decorative Coatings:
Although the primary purpose in decorating the external surface of a metal container is to
improve its appearance and assist its marketability, it also significantly improves the container's
external corrosion resistance.
Aluminum foils and containers:
Aluminum foil is a thin-rolled sheet of alloyed aluminum varying in thickness from about
4 to 150 μm. Foil can be produced by two methods: either by passing heated aluminium sheet
ingot between rollers in a mill under pressure and then rerolling on sheet and plate mills until the
desired gauge is obtained, or continuously casting and cold rolling. Aluminum foil is essentially
impermeable to gases and water vapor when it is thicker than 25.4 μm, but it is permeable at
lower thicknesses due to the presence of minute pinholes
Glass packaging materials
Glass has been defined by the American Society for Testing and Materials (ASTM) as
"an amorphous, inorganic product of fusion that has been cooled to a rigid condition without
crystallizing”. The two main types of glass container used in food packaging are bottles (which
have narrow necks) and jars (which have wide openings).
Advantages:
Glass containers have the following advantages:
 They are impervious to moisture, gases, odours and micro-organisms
 They are inert and do not react with or migrate into food products
 They are suitable for heat processing when hermetically sealed
 They are re-useable and recyclable
 They are resealable
 They are transparent to display the contents
 They are rigid, to allow stacking without container damage.
Disadvantages:
 Higher weight which incurs higher transport costs than other types of packaging
 Lower resistance than other materials to fractures, scratches and thermal shock
 More variable dimensions than metal or plastic containers
 Potentially serious hazards from glass splinters or fragments in foods.
Plastic packaging material:
Plastics are organic polymers which are long chain molecules obtained by addition or
condensation of one or more monomers. Polymerization of single repeating unit gives homo
polymers and addition of more than one monomer results in co-polymer.
Plastics have become a major packaging material, along with paper, metal and glass. Plastics are
used mainly for consumer packages in the form or wraps, pouches, cartons, bags, tubes, bottles,
jars and boxes. In transport, they are used in the form of sacks, stretch films for wrapping tray-
loads, containing unit packs or for entire pallet loads. The advent of snack foods, convenience
foods and prepared foods has been possible to a great extent due to the availability of plastic
packaging materials.
Advantages:
 Barrier to water vapour and gases
 Light weight
 Good strength
 Design flexibility
 Resistance to breakage
 Machinability-high speed filling using form fill and seal techniques
 Glossy and transparent
 Colouring is possible
 High tensile strength
 High tear strength
 High printability
 High level lamination
 Low cost
Disadvantage:
 The disadvantage of plastic is the disposability i.e. it is difficult to get it
disintegrated into soil.
Polyethylene:
It is the polymer of ethylene. It accounts for the biggest proportion of the plastics used in
packaging. It is good barrier to water vapour but less to oxygen; has high permeability to volatile
oils and swells in contact with fats and oil. It gives very good heat seals and easily coated to
other materials and serves as a laminated layer. It is used as bags, liners, bottles
1. Low Density Polyethylene (LDPE):
2. Linear Low Density Polyethylene (LLDPE):
3. High Density Polyethylene (HDPE):
Polypropylene (PP):
Polypropylene is a linear polymer containing little or no unsaturation. PP has low water
vapour transmission, medium gas permeability, good resistance to greases and chemicals, good
abrasion resistance, high temperature stability, good gloss and high clarity
Polystyrene (PS):
It is produced by the polymerization of styrene. It is transparent, but has low barrier
property. The material is used for packing vegetables and fresh meat on trays, yoghurt and other
milk products in cups, and for the over wrapping of fruits and vegetables.
Polycarbonate:
It is glass-like, heat resistant, and sterilisable upto 130°C and is available in the form of
film, beside the rigid containers, but has very few food packaging applications.
Polyvinyl Chloride (PVC):
There are two types – rigid and plasticized. The rigid form has good moisture and gas
barrier properties and resistance to fats. Hence, these are used for packing butter or margarine,
and for making transparent bottles for mineral water, edible oils, fruit juices, carbonated
beverages and beer, as these bottles can withstand pressure. The plasticised form is used for
packing meat, fruits and vegetables and for shrink wrapping. It is also used for the shrink
wrapping of pallets.
Polyvinylidene Chloride (PVdC):
PVDC has the lowest water vapour, oxygen and CO2 permeability amongst all
commercially used plastic films, besides having resistance to fats and chemicals. PVDC is used
as a coating material on polyethylene and other plastics, to improve the gas and moisture barrier
properties of the native plastics. It is used for packing dense materials like cheese, poultry etc.
Ethylenevinyl Alcohol (EVOH):
EVOH copolymers offer not only excellent processability but also superior barriers to
contaminants such as gases, odors, fragrances and solvents. It is widely used polymer in the
manufacture of high barrier containers, as in the manufacture of bulk bags used for aseptic
packaging, retort pouches and containers.
Polyethylene Terephthlate (PET):
PET is a linear, transparent thermoplastic polymer. It has low permeability to moisture
and gases, but has poor sealing property. Hence, it has to be laminated with PE. PET containers
are used widely for packing mineral water, carbonated and non-carbonated beverages, syrups,
edible oils and liquors.
Retort Pouch:
The retort pouch is a flexible package, hermetically sealed on three or four sides and
made from one or more layers of plastic or foil, each layer having a specific functionality. The
advantages include the ease of carrying, reheating and serving, as well as weight and space
saving. Finally, disposal of the used pouch is much simpler than for the metal can as it can be
easily flattened. Three-layer pouch structure would consist of an outer layer of 12 μm PET for
strength and toughness, a middle layer of 7 to 9 μm of aluminium foil as a moisture, light and
gas barrier and an inner layer of 70 to 100 μm of CPP for heat sealability, strength and
compatibility with all foods. An additional inner layer of 15 to 25 μm of PA is used when a
longer shelf life is required.
Edible and bio based packaging materials
Biodegradable polymers are a newly emerging field in food packaging. These are
biodegradable, ecofriendly and are produced from natural or renewable resources. Biodegradable
polymers (BDPs) or biodegradable plastics refer to polymeric materials that are ‘capable of
undergoing decomposition into carbon dioxide, methane, water, inorganic compounds, or
biomass in which the predominant mechanism is the enzymatic action of microorganisms, that
can be measured by standardized tests, in a specified period of time, reflecting available disposal
condition’.
Classification of Biodegradable Polymers
Biopolymers can be classified into two main groups, these two groups being
 The agropolymers obtained by biomass fragmentation processes (polysaccharides,
proteins…),
 The biopolyesters obtained
 by synthesis from bio-derived monomers (polylactic acid – PLA) or
 by extraction from micro-organisms (polyhydroxyalkanoate – PHA) or
 by synthesis from synthetic monomers (polycaprolactone – PCL, aromatic and
aliphatic copolyesters – PBAT, PBSA…)
Advantages of Biodegradable Polymers
The principal advantages of plastics are their cost, functionality, durability and weight.
The advantages of biodegradable plastic are numerous.
 Biodegradable plastics take less time to break down
 Biodegradable plastics are renewable
 Biodegradable plastics are good for the environment
 Biodegradable plastics require less energy to produce
 Biodegradable plastics are easier to recycle
 Biodegradable plastics are not toxic
 Biodegradable plastics reduce dependence on foreign oil
Controlled atmosphere Packaging:
Controlled atmosphere packaging (CAP) is the enclosure of food in a gas impermeable
package inside which the gaseous environment with respect to CO2, O2, N2, water vapor and
trace gases has been changed, and is selectively controlled to increase shelf life. In this
technology, the storage system consists of airtight storage chambers, O2 regulatory unit, CO2
absorbing unit equipment for monitoring as well as controlling the chambers and composition.
Liquid N2 generator is commonly installed to flush and chambers with liquid N2 as and when
required for maintaining optimum level of O2. For maintaining optimum level of CO2 in the
chambers, air in chambers is circulated through CO2 scrubber frequently. CO2 absorbing
materials such as hydrated lime, calcium or potassium hydroxides are generally used in scrubber.
Refrigeration unit is employed for maintaining storage temperature. The storage life of various
fruits and vegetables can be increased by 2 to 4 times the normal life by employing Controlled
Atmosphere storage technology.
Modified Atmosphere Packaging:
Modified Atmosphere Packaging (MAP) can be defined as the enclosure of food in a
package in which the atmosphere inside the package is modified or altered to provide an
optimum atmosphere for increasing shelf life and maintaining quality of the food. Modification
of the atmosphere may be achieved either actively or passively. Active modification involves
displacing the air with a controlled, desired mixture of gases, a procedure generally referred to as
gas flushing. Passive modification occurs as a consequence of the food's respiration or the
metabolism of micro-organisms associated with the food; the package structure normally
incorporates a polymeric film, and so the permeation of gases through the film (which varies
depending on the nature of the film and the storage temperature) influences the composition of
the atmosphere that develops.
Advantages:
 Shelf life will be increased by 50 to 400%.
 Reduced economic losses due to longer shelf life.
 Provides a high quality product.
 Centralized packaging and portion control.
 Improved presentation – clear view of product and all –around visibility.
 Little or no need for chemical preservatives.
 Sealed packages are barriers against product recontamination and drip from package.
 Odorless and convenient packages.
Disadvantages:
 Added costs for gases, packaging materials and machinery.
 Temperature control necessary.
 Different gas formulations for each product type.
 Special equipment and training required.
 Increased pack volume adversely affects transport costs and retail display space.
 Loss benefits once the pack is opened or leaks.
 CO2 dissolving into the food could lead to pack collapse and increased drip.
Gases used in MAP:
The three main gases used in MAP are CO2, O2, and N2, either singly or in combination.
Carbon dioxide: Carbon dioxide is the most important gas in the MAP of foods because of its
bacteriostatic and fungistatic properties. It inhibits the growth of any spoilage bacteria, the
degree of inhibition increasing with increasing concentration.
Oxygen: Oxygen promotes several types of deteriorative reactions in foods including fat
oxidation, browning reactions and pigment oxidation. Most of the common spoilage bacteria and
fungi require O2 for growth. For these reasons, O2 is either excluded or the level set as low as
possible. Exceptions occur where O2 is needed for fruit and vegetable respiration or the retention
of color in red meat.
Nitrogen: Nitrogen is an inert gas with no odor or taste. It has a lower density than air and a low
solubility in water and other food constituents, making it a useful filler gas in MAP to counteract
package collapse caused by CO2 dissolving in the food. Nitrogen indirectly influences the micro-
organisms in perishable foods by retarding the growth of aerobic spoilage microbes but it does
not prevent the growth of anaerobic bacteria.
Labelling
Labelling” includes any written, printed or graphic matter that is present on the label,
accompanies the food, or is displayed near the food, including that for the purpose of promoting
its sale or disposal
Nutrition labelling
Nutrition labelling is information found on the labels of prepackaged foods. The
legislated information includes:
 The Nutrition Facts table
 The ingredient list
 Some optional nutrition claims
These give information about the nutritional value of a food. The Nutrition Facts table gives
information about calories, 13 core nutrients and percentage daily value (% DV) of nutrients. All
of the information in the Nutrition Facts table is based on an amount of food. This amount is
always found at the top of the nutrition facts table.
Important functions of labelling:
(i) Describe the Product and Specify its Contents:
A label provides complete information regarding the product. It mainly includes
ingredients of the product, its usage, and caution in use, cares to be taken while using it, date of
manufacturing, batch number, etc.
(ii) Identification of the Product or Brand:
It is easier to identify a particular product among many with the help of labelling.
(iii) Grading of Product:
When a product has different qualities, labelling helps to find out which pack contains
what type of quality
(iv) Help in Promotion of Products:
 The fourth function of labeling is to promote sales. Sometimes a consumer gets
encouraged to buy a product simply due to attractive label. Nowadays labeling is used as an
effective sales promoting tool.
(v) Providing information required by Law:
Another important function performed by labeling is to provide statutory warning
required by law. To put ‘smoking is injurious to health’ on the package of cigarette and
‘Chewing Tobacco is Injurious to Health’ on the package of Pan Masala are the examples of
statutory warning? Similarly, in case of hazardous or poisonous products, appropriate statutory
warning need to be put on the label.
Mandatory Labelling of Prepackaged Foods
The following information shall appear on the label of prepackaged foods
The name of the food
The name shall indicate the true nature of the food and normally be specific and not
generic. A “coined”, “fanciful”, “brand” name, or “trade mark” may be used
List of ingredients
Except for single ingredient foods, a list of ingredients shall be declared on the label. The
list of ingredients shall be headed or preceded by an appropriate title which consists of or
includes the term ‘ingredient’. All ingredients shall be listed in descending order of ingoing
weight (m/m) at the time of the manufacture of the food. The following foods and ingredients are
known to cause hypersensitivity and shall always be declared:
 Cereals containing gluten; i.e., wheat, rye, barley, oats;
 Crustacea and products of these;
 Eggs and egg products;
 Fish and fish products;
 Peanuts, soybeans and products of these;
 Milk and milk products (lactose included);
 Tree nuts and nut products; and
 Sulphite in concentrations of 10 mg/kg or more.
Net contents and drained weight
The net contents shall be declared in the metric system (“Système International” units).
The net contents shall be declared in the following manner:
 (i) for liquid foods, by volume;
(ii) for solid foods, by weight;
(iii) for semi-solid or viscous foods, either by weight or volume.
Name and address
The name and address of the manufacturer, packer, distributor, importer, exporter or
vendor of the food shall be declared.
Country of origin
The country of origin of the food shall be declared if its omission would mislead or
deceive the consumer.
Lot identification
Each container shall be embossed or otherwise permanently marked in code or in clear to
identify the producing factory and the lot.
Date marking and storage instructions
If not otherwise determined in an individual Codex standard, the following date marking shall
apply:
(i) The “date of minimum durability” shall be declared.
(ii) This shall consist at least of:
 the day and the month for products with a minimum durability of not more than three
months;
 the month and the year for products with a minimum durability of more than three
months. If the month is December, it is sufficient to indicate the year.
(iii) The date shall be declared by the words:
• “Best before ...” where the day is indicated;
• “Best before end ...” in other cases.
(iv) The words referred to in paragraph (iii) shall be accompanied by:
• either the date itself; or
• a reference to where the date is given.
(v) The day, month and year shall be declared in uncoded numerical sequence except that the
month may be indicated by letters in those countries where such use will not confuse the
consumer.
 LECTURE 16
COMMON FOOD ADULTERANTS AND THEIR DETECTION

Adulteration
Food adulteration is an act of intentionally debasing the quality of food offered for sale
either by the admixture or substitution of inferior substances or by the removal of some valuable
ingredient. Food adulteration takes into the account not only the intentional addition or
substitution or abstraction of substances which adversely affect nature, substances and quality of
foods, but also their incidental contamination during the period of growth, harvesting, storage,
processing, transport and distribution.
Adulterant means any material which is or could be employed for making food unsafe or
sub-standard or mis-branded or containing extraneous matter.
Adulteration of food stuffs is commonly practiced in India by traders. In order to protect
the health of the consumer, the Government of India promulgated the prevention of food
adulteration act (P.F.A) in 1954 which prohibits the manufacture, sale and distribution of not
only adulterated foods but also foods contaminated with toxicants and misbranded foods.
Types of adulterants
Type Substances added
Intentional adulterants Sand, marble chips, stones, mud, other filth, talc, chalk powder,
water, mineral oil and harmful colour
Incidental adulterants Pesticide residues, droppings of rodents, larvae in foods
Metallic adulterants Arsenic from pesticides, lead from water, effluent from chemical
industries, tin from cans
Methods for detection of common adulterants in foods
S. No Food Adulterant Detection

1 Milk Water The presence of water can be by putting a drop of milk

on a polished slanting surface. The drop of pure milk
either stops or flows slowly leaving a white trail behind
it ,whereas milk adulterated with water will flow
immediately without leaving a mark
Starch Add a few drops of iodine solution. Formation of blue
colour indicates the presence of starch
2 Fat and oil Argemone oil Take small quantity of oil in a test tube. Add equal
quantity of concentrated nitric acid to a sample and
shake carefully. Red to reddish brown colour in acid
layer indicates the presence of argemone oil
3 Ghee or Mashed potato, Add a few drops of iodine solution, which is brownish
butter sweet potato & other in colour turns to blue if the starches are present
starches

Vanaspathi or Take about one teaspoon full of melted sample of ghee

margarine or butter with equal quantity of concentrated
hydrochloric acid in a stoppered test tube and add to it a
pinch of sugar shake for one minute and let it for five
minutes. Appearance of crimson colour in lower layer
shows presence of vanaspathi or margarine
4 Asafoetida Soap stone or earth Little portion of the sample is shaken with water and
matter allowed to settle. If stone of soap or earth matter
present will settle at the bottom

5 Chilly Red brick powder, To a little powder of chilli add small amount of conc.
powder soap stone HCl and ix to the consistency of paste dip the rear end
of the match stick into the paste and hold over the
flame brick red flame colour due to the presence of
calcium slats in brick powder.
6 Turmeric Metanil yellow Take a turmeric powder in a test tube. Add a few drops
powder of conc. HCl. Instant appearance of violet colour which
disappears on dilution with water. If the colour persists,
presence of metanil yellow indicated.
7 Pepper Dry papaya seeds Papaya seeds can be separated out from pepper as they
are shrunken , oval in shape and greenish brown or
brownish black in colour.

8 Powdered White powdered Take one gram of powdered spices in a test tube and
spices stone, chalk powder, add 5 ml of carbon tetra chloride solvent. Shake well
yellow soap and leave for some time. Impurities will settle at the
bottom while the spice powder will flat on the surface
9 Wheat Chalk powder Add few drops of hydrochloric acid, effervescence
flour (give off bubbles) indicate the presence of chalk
powder

10 Dal whole Khesari dal Add 50 ml of dilute Hydrochloric acid to dal and keep
and spilt on simmering water about 15 minutes. The pink colour
developed indicates the presence of khesri dal.

11. Pulses Lead chromate Shake 5 gram of pulse with 5 ml of HCl. Pink colour
indicates lead chromate.

12 Honey Molasses (sugar A cotton wick dipped in pure honey when lighted with
solution) match stick burns and shows the purity of honey. If
adulterated, the presence of water will not allow the
honey to burn. If it does it will produce cracking sound.

13 Sugar/ Chalk powder Stir a spoonful sample of sugar in a glass of water, the
Jaggery chalk powder settle down.
 Washing soda Add few drops of hydrochloric acid, effervescence
(give off bubbles) indicate the presence of washing
soda

14 Tea Exhausted tea Take a filter paper and spread a few tea leaves.
Sprinkle with water to wet the filter paper, if coal tar is
present it would immediately stain the filter paper.
Wash the filter paper under tap water and observe the
stains against light
15 Salt Chalk powder Stir a spoonful of sample of salt in a glass of water.
The presence of chalk will make solution white and
other insoluble impurities will settle down.
 LECTURE 17
FOOD LAWS AND REGULATIONS AND QUALITY CONTROL STANDARDS

Every country needs laws to encourage the production of safe and wholesome foods, and
to prohibit the sale of foods that are unsafe or fraudulent.
Food Safety and Standard Act 2006(FSSAI)
The Food Safety and Standards Authority of India (FSSAI) has been established under
Food Safety and Standards act, 2006 which consolidates various acts & orders that have hitherto
handled food related issues in various Ministries and Departments.
FSSAI has been created for laying down science based standards for articles of food and
to regulate their manufacture, storage, distribution, sale and import to ensure availability of safe
and wholesome food for human consumption.
Highlights of the Food Safety and Standard Act, 2006
 Various central Acts like Prevention of Food Adulteration Act (1954), Fruit Products
Order (1955), Meat Food Products Order (1973), Vegetable Oil Products (Control)
Order,(1947), Edible Oils Packaging (Regulation) Order (1988), Solvent Extracted Oil,
De- Oiled Meal and Edible Flour (Control) Order (1967), Milk and Milk Products Order,
(1992) was repealed after commencement of FSS Act, 2006.
 The Act also aims to establish a single reference point for all matters relating to food
safety and standards, by moving from multi- level, multi- departmental control to a single
line of command.
Salient Features of FSSAI Act, 2006
Some of the salient features of the Act are:
 FSSAI as a single reference point for all matters relating to Food Safety and Standards,
Regulations and Enforcement.
 Integrated response to strategic issues like Novel foods, Health Foods, Nutraceuticals,
GM foods, international trade etc.
 Adequate information dissemination on food to enable consumer to make informed
choices.
 Graded penalty depending upon the gravity of offences.
  Adequate representation of government, industry organizations, consumers, farmers,
technical experts, retailers etc.
 Enforcement of the legislation by the State Governments/ UTs through the state
Commissioner for Food Safety, his officers and Panchayati Raj/Municipal bodies.
Establishment of the Authority
Ministry of Health & Family Welfare, Government of India is the Administrative
Ministry for the implementation of FSSAI. The Chairperson and Chief Executive Officer of
Food Safety and Standards Authority of India (FSSAI) have already been appointed by
Government of India. The Chairperson is in the rank of Secretary to Government of India.
Functions performed by FSSAI
 Framing of Regulations to lay down the Standards and guidelines in relation to articles of
food and specifying appropriate system of enforcing various standards thus notified.
 Laying down mechanisms and guidelines for accreditation of certification bodies engaged
in certification of food safety management system for food businesses.
 Laying down procedure and guidelines for accreditation of laboratories and notification
of the accredited laboratories.
 To provide scientific advice and technical support to Central Government and State
Governments in the matters of framing the policy and rules in areas which have a direct
or indirect bearing of food safety and nutrition.
 Collect and collate data regarding food consumption, incidence and prevalence of
biological risk, contaminants in food, residues of various, contaminants in foods
products, identification of emerging risks and introduction of rapid alert system.
 Creating an information network across the country so that the public, consumers,
Panchayats etc receive rapid, reliable and objective information about food safety and
issues of concern.
 Provide training programmes for persons who are involved or intend to get involved in
food businesses.
 Contribute to the development of international technical standards for food, sanitary and
phyto-sanitary standards.
 Promote general awareness about food safety and food standards.
AGMARK

The word Agmark is derived from Agricultural Marketing. The DMI under the
Department of Agriculture and Co-operation in the Ministry of Agriculture enforces the
Agricultural Products (Grading and Marketing) Act 1937. Under this Act Grade standards are
prescribed for agricultural and allied commodities. Agmark grading means grading of an article
in accordance with grade/standards prescribed under the provisions of the act.
The quality of the product is determined based on the size, variety, weight, colour,
moisture, fat content and other factors. It covers quality assurances of unprocessed, semi
processed and processed agricultural commodities. The grades incorporated are grades 1, 2, 3
and 4 or special, good, fair and ordinary.
Salient features of Agmark standard
 Quality standards for Agricultural commodities are framed Food safety factors are being
incorporated in the standards to compete in world trade.
 Standards are being harmonized with international standards
 certified products through 23 laboratories and 43 offices spread all over the country
Products available under AGMARK are pulses, wheat products, vegetable oils, ground
spices, whole spices, milk products, honey, compounded asafoetida, rice, tapioca sago, seedless
tamarind and gram flour.
Grading of these commodities is voluntary. On the other hand grading of commodities like
tobacco, walnut, spices, basmati rice, essential oils, onion, potatoes are meant for export is
compulsory under AGMARK.
The Directorate of marketing and inspection of central government has 21 laboratories and
50 sub offices spread all over the country. The central AGMARK laboratory at Nagpur
continuously carries out research and development works in this field. In addition to the Central
AGMARK Laboratory (CAL) in Nagpur, there are Regional AGMARK Laboratories (RALs) in
11nodalcities(Mumbai, Newdelhi, Chennai, Kolkata, Kanpur, Kochi, Guntur, Amritsar, Jaipur,
Rajkot, Bhopal). Each of the regional laboratories is equipped with and specializes in the testing
of products of regional significance. Hence the product range that could be tested varies across
the centres.
Bureau of Indian Standards (BIS)/Indian standard institute (ISI)
BIS is the National Standards Organization established as Society in 1947 as Indian
Standards Institution and subsequently made its statutory body as BIS under Bureau of Indian
Standards Act 1986. It revoked Indian Standards Institutions (Certification Marks) Act 1952 but
incorporated all its provisions. The Bureau is a body corporate and responsible for laying down
policy guidelines for BIS. It comprises of members Representing Industry, Consumer
Organizations, Scientific and Research Institutions, Professional/technical institutes, Central
Ministries; State Government and Members of Parliament. The act is mandatory for milk
powders, sweetened condensed milk, infant formula etc. This act generally covers hygienic
conditions of manufacture, raw material quality and safety. It also ensures the quality to the
consumers by certification.

Salient Features of the BIS:

 Standard Formulation,
 Certification: Product Quality Management System, Eco Mark, Environment
 Management System, Hazard Analysis’ and Critical Control Points,
 Laboratory: Testing, Calibration and Management,
 Standards Promotion,
 Consumer Affairs and
 Awareness and Training Programs.
There are 14 different technical departments engaged in formulation of the standards. So far
17000 standards have been formulated in different technological areas depending upon the
national priority. These standards are evolved through the consensus from different sectors like
industry, consumers, testing and laboratory experts and committees / sub-committees of Govt
organization. The standards are reviewed time to time and continuously updated to match the
technological changes. The BIS has formulated 1133 standards pertaining to food products.
Powers and Functions of the Bureau
 Establishment, Publication and Promotion of Indian Standards
 Procedure for Establishment of Indian Standards
 Grant of License
 Inspection
 STOP Marking
Codex Alimentarius Commission (CAC)
The term Codex Alimentarius is taken from Latin and means food code. The Codex
Alimentarius Commission develops food standards, guidelines and related texts such as codes of
practice under the Joint FAO / WHO Food Standards Programme. About 170 countries were
member of the commission.
Purpose of Codex Alimentarius Commission
 It is to protect the health of consumers and to ensure fair practice in the food trade
 To promote coordination of all food standards work undertaken by international
governmental and non-governmental organizations
 To determine priorities and initiate and guide the preparation of draft standards through
and with the aid of appropriate organizations
 To finalize standards and after acceptance by Governments, publish them in a Codex
Alimentarius either regional or worldwide standards
It brings together all the interested parties viz. scientists, technical experts, governments,
consumers and industry representatives to help develop standards for food manufacturing and
trade. These standards, guidelines and recommendations are recognized worldwide for their vital
role in protecting the consumer and facilitating international trade. As Codex Alimentarius
represent a consensus of food and trade experts from around the world, these standards are more
and more being used in international trade negotiations and also for setting of disputes by WTO.
The Codex contract Point in India is the Directorate General of Health Services (DGHS) in the
Ministry of Health; however, the Ministry of Food processing Industries is closely associated
with the activities of Codex Alimentarius.
Codex can be divided in to three main groups
 The commodity standards committee work vertically dealing with food products such as
processed fruits and vegetables , fats and oil, fresh fruit and vegetables, natural mineral
 water, cocoa products and chocolates, fish and fishery products, sugar, milk, products,
cereal and meat products.
 The general subject committees work horizontally on standards such veterinary drug
residues, food additives and contaminants, pesticide residues, hygiene, labeling,
inspection and certification systems, analysis and sampling, nutrition and foods for
special dietary uses.
 The six regional coordinating committees are based in Africa, Asia, Europe, Latin
America and Caribbean, North America and South West Pacific and the near East.
Salient Features of Codex Alimentarius:
 Protecting health of the consumers and ensuring fair trade practices
 Promoting coordination of all food standards work undertaken by international
governmental and non-governmental organizations
 Determining priorities and initiating and guiding the preparation of draft standards.
 Finalizing standards
 Amending published standards
 Submission of a proposal for a standard
 A decision by the Commission or the executive committee
 Preparation of a proposed draft standard by subsidiary body
 Adoption of standard by the Commission
 Addition of Codex Standard in the Codex Alimentarius
Hazard Analysis Critical Control Point (HACCP):
The Hazard Analysis Critical Control Point (HACCP) is a scientific, rational and
systematic approach to identify, assess and control hazards during production, processing,
manufacturing and use of food. It ensures safety of the food. A systematic approach to the
identification, evaluation, and control of food safety hazards based on seven principles.
History of HACCP:
The application of HACCP to food production was pioneered by the Pillsbury Company
with the cooperation and participation of the National Aeronautic and Space Administration
(NASA), Natick Laboratories of the US Army, and the US Air Force Space Laboratory Project
Group. In the Indian food industry, HACCP is not compulsory practice but due to increase in the
cases of food poisoning in the country, HACCP has been recognized internationally as a science-
based logical tool for management of food safety. India as signatory to WTO, TBT & SPS
agreements along with TQM and ISO is committed to follow WTO regulations whose priority is
to protect health of consumer. Our food industry thus needs to install HACCP to avoid any
rejection of foods shipped to international market.
Seven principles of HACCP
1. Conduct hazard analysis: In this first step, the team assesses hazards associated with
growing, harvesting, raw materials and ingredients, processing, manufacturing, distribution,
marketing, preparation, and consumption of the food. They identify all significant hazards
(biological, chemical, and physical) that need to be controlled to assure food safety throughout
each step in the process.
2. Determine critical control points: After identifying the significant hazards, the team
establishes preventative measures to control the identified hazards. The team identifies areas or
points in the flow of a food product (flow chart) with their critical limits that must be met to
control the identified hazards. These are called critical control points (CCPs). A Critical Control
Point (CCP) is a point, step, or procedure in a food process at which control can be applied and
as a result, a food safety hazard can be prevented, eliminated, or reduced to an acceptable level.
3. Establishment of specification for critical limits: At each CCP, teams define boundaries or
limits of safety to assure that the CCP is in control. They establish upper limits for CCPs. CCP
limits are usually based on time, temperature, pH, and moisture content of a food.
4. Development of monitoring and testing system to control critical point: CCP and CCP
limits are only effective if they are monitored during food processing. Monitoring ensures that
the process is in control. Testing procedures have to be developed to ensure that each critical
control point is consistently monitored and the process is under control.
5. Establishment of corrective actions when particular CCP is not under control: Whenever
food companies note a deviation in the critical limits for a CCP, they must correct the deviation.
Corrective action may include changing the process, reprocessing, or discarding the product.
Corrective actions are intended to ensure that no product injurious to health.
6. Establish record keeping procedures: Food companies must keep records of the results of
monitoring critical control points. These records are the only proof for a company that process is
in control and that they are complying with the HACCP plan. Depending on the commodity,
records should be accessible for one to three years. Thus, a system must establish documentation
of procedures and records for all aspects of the HACCP programme and give evidence of its
functioning base on all data obtained from testing and analysis, deviation or correction actions.
7. Verification of HACCP system to confirm efficacy: The procedure need to be established to
verify and confirms that operating HACCP system is working effectively. Verification ensures
that HACCP plan is adequate and verification includes such activities as review of HACCP
plans. They may request an internal or external food safety audit to verify that the HACCP plan
is working.
Benefits of HACCP: There are numerous benefits for the food industry while applying HACCP
system as a management tool for food safety control. Some of the important benefits are as
follows:
1) Application of the HACCP concept is the cost effective approach to food safety.
2) Application of the HACCP concept is enough flexible.
3) Helps to maintain the global food quality and safety standards.
4) The HACCP approach is a systematic approach for all aspects of food safety and can be
applied to all stages of the food chain, including raw materials, growth, harvesting, purchase,
production, distribution, and storage to final product use.
5) Provides scientifically sound base for protections of a hazard from reaching the end consumer
products.
6) HACCP systems can promote international trade by increasing confidence in food safety.
7) HACCP system can facilitate the design and construction of new foodprocessing facilities and
equipment.
8) The HACCP system can be readily integrated in to quality management systems like (Total
Quality Management) TQM and ISO 9000 etc.
9) HACCP system focuses resources mainly on those parts of the process which are critical for
assuring safe products.
10) HACCP system can reduce product losses due to spoilage.

International Standards Organization (ISO): The product sell based on the product quality as
perceived by the customer is the major factor for sustained what makes a sales of a product. The
method of quality control consisted largely of physical inspection of the end product against the
product specification. However, technical specifications may not by themselves guarantee, that a
customer's requirements will be met, if there happens to be any deficiency in the specifications
or in the organizational system, to design and produce the products, or service. Consequently,
this has led to the development of quality system standards and guidelines that complement
relevant product, or service, requirements given in the technical specifications.
ISO 22000: 2005: It specifies requirements for a food safety management system where an
organization in the food chain needs to demonstrate it stability to control food safety hazards in
order to ensure that food is safe at\ the time of human consumption.
ISO 22000:2005 specifies following requirements to enable an organization:
 To plan, implement, operate, maintain and update a food safety management system
aimed at providing products that, according to their intended use, are safe for the
consumer
 To demonstrate compliance with applicable statutory and regulatory food safety
requirements
 To evaluate and assess customer requirements and demonstrate conformity with those
mutually agreed customer requirements that relate to food safety, in order to enhance
customer satisfaction
 To effectively communicate food safety issues to their suppliers, customers and relevant
interested parties in the food chain
 To ensure that the organization conforms to its stated food safety policy
To demonstrate such conformity to relevant interested parties and
 To seek certification or registration of its food safety management system by an external
organization, or make a self-assessment or self-declaration of conformity to ISO
22000:2005.
EU standards - European Standards
Each European Standard is identified by a unique reference code which contains the
letters 'EN'. A European Standard is a standard that has been adopted by one of the three
recognized European Standardization Organizations (ESOs): CEN, CENELEC or ETSI. It is
produced by all interested parties through a transparent, open and consensus based process.
European Standards are a key component of the Single European Market. Although
rather technical and mostly unknown to the public and media, they represent one of the most
important issues for businesses. Often perceived as boring and not particularly relevant to some
organizations, they are actually crucial in facilitating trade and hence have high visibility among
manufacturers inside and outside Europe. Standards provide individuals, businesses and all kinds
or organizations with a common basis for mutual understanding. A standard represents a model
specification, a technical solution against which a market can trade. It codifies best practice and
is usually state of the art.
In essence, European Standards relate to products, services or systems. Today, however,
standards are no longer created only for technical reasons but have also become enablers for
greater social inclusiveness and engagement with technology, as well as convergence and
interoperability within growing markets across industries.