M-02 Injera Processingx

Cereal processing
Level III
Based on October 2021, Version 2 Occupational

standard
Module Title: Processing Injera

LG Code: IND CRP2 M02 LO (1-4) LG (5-8)
TTLM Code: IND CRP3 TTLM02 0121 v1
November, 2023
Bishoftu, Ethiopia
Table of Contents
Introduction ................................................................................................................... 1
LO#1- LO1 Prepare equipment ..................................................................................... 2

Instruction sheet ..................................................................................................... 2
Information Sheet 1 ................................................................................................ 3
Self-check 1 ................................................................................................... 32
Operation Sheet -1 ............................................................................................... 34
LAP TEST-1 ................................................................................................... 39
LO#2- Prepare dough .................................................................................................. 40

Instruction sheet ................................................................................................... 40
Information Sheet 2 ............................................................................................. 41
Self-Check – 2 ................................................................................................ 52
Operation Sheet -2 ............................................................................................... 53
LAP TEST-2 ................................................................................................... 55
LO 3- Prepare Absit ..................................................................................................... 56

Self-check 3 ................................................................................................... 61
Operation Sheet 3................................................................................................. 62
LAP TEST-3 ................................................................................................... 63
LO#4 - Baking Injera ............................................................................................... 64

Information Sheet 4 .............................................................................................. 65
Self - check 4 ................................................................................................. 87
Operation Sheet -4 ............................................................................................... 88
LAP TEST-4 ................................................................................................... 91
Reference Materials ....................................................................................... 92
I
Introduction
This module covers the skills and knowledge required to prepare dough, fermentation, Absit
preparation, baking and packaging in Injera processing
Page 1 of 98 Ministry of Labor and Cereal processing Level -III Version 1

Skills September 2021
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LO#1- LO1 Prepare equipment
LG #5
Instruction sheet
This learning guide is developed to provide you the necessary information regarding the
following content coverage and topics:
• Confirming materials.
• Identifying and confirming cleaning requirements.
• Confirming services.
• Entering processing/operation parameters.
• Checking cooling equipment.
• Carrying out pre-start checks.
This guide will also assist you to attain the learning outcomes stated in the cover page.
Specifically, upon completion of this learning guide, you will be able to:
• Confirm materials.
• Identify and confirming cleaning requirements.
• Confirm services.
• Enter processing/operation parameters.
• Check cooling equipment’s.
• Carry out pre-start checks.
Learning Instructions:
Page 2 of 98 Ministry of Labor and Cereal processing Version 1

Skills Level -III September 2021
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1. Read the specific objectives of this Learning Guide.
2. Follow the instructions described below.
3. Read the information written in the information Sheets
4. Accomplish the Self-checks
5. Perform Operation Sheets
6. Do the “LAP test”
Information Sheet 1
1.1 Confirming materials

Confirming materials in injera processing refers to the process of reviewing and verifying the
availability of all necessary ingredients, additives, flavorings, packaging materials, and
equipment required for the production and packaging of cereal products. This ensures that the
company has enough resources to meet its operational needs and fulfill customer demands. By
confirming the availability of these materials, the company can be confident in its ability to
continue production without any disruptions.
Conforming Material is Materials that meet all of the physical and/or chemical criteria or any
other criteria specifically identified by buyer or its design as outlined in standard.
In Ethiopia, injera is a thin, soft fermented baked food made from cereal flour that is fermented
for 24 to 96 hours, depending on the optimum temperature. Sorghum, teff, corn, wheat, and
barley are among the cereals used in its preparation.
Injera is thin, prepared from teff flour, water and starter (a fluid collected from previously
fermented mix) after successive fermentations. The best acceptable (sensory) injera should be
rich in eyes, softer, thin, rolable and sour taste due to the fermentation process
• The confirming raw material
Teff flour
Water
Ersho

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Wheat
Barley
sorghum
Teff flour
Teff grain was first cleaned and milled to whole flour to fineness level traditionally used for injera
making. Samples for laboratory analysis were kept in an air–tight, sealed plastic bag at room temperature
until it is used.
Teff is a small cereal grain that derives from the plant “Agrostis teff”. These grains have a mild
nutty and molasses flavor. Teff flour is a popular substitute for wheat flour because it is naturally
gluten free and has a favorable nutrient profile. It is naturally high in protein, dietary fiber, and
calcium.
Teff tops the charts for calcium content among ancient grains, containing 123 mg/1 cup cooked
which is five times as much as whole wheat. Most grains don't contain significant amounts of
calcium, but teff does it is very beneficial for the immune system as well as healthy bones and
tissues.
Figure 1.1 Process flow diagram for the preparation of Teff flour

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Figure 1.2 teff flour
Ersho | Starter
The process of making this is similar to the process of making a sour dough starter. It is made by
combining water and teff flour in a 2:1 ratio. The mixture is left to ferment undisturbed in a
warm dark place for up to three days to ferment before using for making injera
Figure 1.3 Teff ersho
Water
It is best to use distilled, filtered, or purified water for the most consistent results. Different
minerals like chlorine found in tap water can sometimes offset the fermentation process. If you
do not have access to purified water, and your starter is not reacting properly you can leave a
glass container filled with tap water on the counter for about 24 hours days to oxidize and try
again. This helps to evaporate chlorine from the water

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Water, a substance composed of the chemical elements’ hydrogen and oxygen and existing in
gaseous, liquid, and solid states. It is one of the most plentiful and essential of compounds. A
tasteless and odorless liquid at room temperature, it has the important ability to dissolve many
other substances.
1.1.1.Criteria of confirming raw material for injera

A. Quality of teff
Injera quality is believed to be influenced by teff grain quality (white-color) and its growing
environments. The white-colored injera which comes from the white-colored teff grain is the
most preferred type compared to the darker grain injera
Figure 1.4 Teff

B. Gluten free nutritional content
High in Protein, Calcium, Iron, Magnesium and Copper.
Not only is a source of B vitamins, Teff the only grain known to contain
significant amounts of vitamin C.
Teff is high in probiotic fiber (a key benefit for IBS sufferers)
Whole grain, with high resistant starch (low GI)
C. Superior nutritional quality.
Teff’s nutritional content can be different, depending on the variety you use. Whole grain teff is
packed with nutrients, including:
It contains 11% protein, 80% complex carbohydrate and 3% fat. It is an excellent source of
essential amino acids, especially lysine, the amino acid that is most often deficient in grain foods.

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Protein. Whole grain teff is 11% protein. This is similar to wheat, maize,
barley, and pearl millet.
The protein in whole grain teff is higher than rye, sorghum, and brown rice.
Amino acids. Since teff is high in protein, it has lots of essential amino
acids. Protein and amino acids are important as the building blocks of your
tissues.
Fiber. Teff is higher in fiber than other grains. This is because the bran and
the germ are usually intact. Getting lots of fiber can help prevent chronic
diseases like heart disease, bowel disease, kidney disease, and type 2
diabetes.
D. The shelf life of injera
Injera has a high nutritional value, as it is rich in calcium and iron. Unfortunately, injera has a
shelf life of only 3-4 days essentially due to mould spoilage. The use of weak organic acid as
preservative is allowed in acidic foods, primarily as mould inhibitors.
E. Mineral content:
Compared with other cereals, teff flour has the highest calcium and iron content. Gluten-free
grain: Teff flour is gluten free, making it suitable for people following a gluten-free diet. This
includes individuals with celiac disease, non-celiac gluten sensitivity, and wheat allergy
F. The characteristics of injera
Teff seeds are graded according to color, used to make different kinds of injera: nech (white),
key or quey (red), and sergegna (mixed). When teff is not available, usually because of location
or financial limitations, injera is made by fermenting a variety of different grains, including
barley, millet, and sorghum.
https://www.hindawi.com/journals/ijfs/2022/4419955/ Access date: 14/11/ 2023)
https://www.sciencedirect.com/science/article/abs/pii/S0973082617300261 Access date: 14/11/

2023)

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1.2.Identifying and confirming cleaning requirements.
Identifying and confirming cleaning requirements in injera processing, producers can maintain a
clean and safe processing environment, minimizing the risk of contamination and ensuring the
production of high-quality injera.
Identifying and confirming cleaning the operation in industry through different techniques. those
are: -
• Visual inspection. Microbial testing, any potable water used in the process,
• Cleaning validation protocols
• Cleaning verification
• Analytical verification, after taking surface swabs or rinses, and is carried out and
facility switches products.
• Determine with a certain system to need cleaning.
• Accurately identify the most effective cleaning methodology.
• Confirm with confidence that the system was cleaned to your requirements.
• Clear, sharp, edge of processing systems equipment/machine by system can be
included in handover documentation.
• Powerful magnets enable effective inspection of vertical surfaces
Identifying and confirming cleaning requirements in injera processing involves:

• Identifying areas and equipment that require cleaning: This includes all surfaces,
utensils, and equipment used in the processing of injera.
• Determining the frequency of cleaning: Depending on the production volume and
processing schedule, the frequency of cleaning may vary. It is important to establish
a regular cleaning schedule to maintain cleanliness and prevent contamination.
• Selecting appropriate cleaning agents and methods: Different surfaces and
equipment may require different cleaning agents and methods. It is important to
select the appropriate cleaning agents and methods to effectively remove dirt, debris,
and potential contaminants.
• Establishing sanitation procedures: Clearly outlining the procedures for cleaning and
sanitizing equipment and work areas is essential to ensure that all necessary steps are
followed consistently.

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• Training personnel: Proper training of staff on the importance of cleaning and
sanitation, as well as the correct procedures for cleaning, is crucial to maintaining a
clean and safe processing environment.
• Monitoring and verifying cleanliness: Regular monitoring and verification of
cleanliness through visual inspections, microbial testing, or other methods can
confirm that cleaning requirements are being met
1.2.1.Cleaning of equipment
The term 'cleaning equipment' is very broad. True bakery like injera is grains supplement that
can be used in versatile ways around the house.
• Types of cleaning equipment:
pressure cleaners
Sweepers
Polishers and Vacuum cleaners.
It is important to choose the right equipment for a certain cleaning job.
Figure 1.5 cleaning equipment
1.2.1.1.Cleaning Out of Place (COP)

COP equipment is taken to a designated decontamination for cleaning. COP requires
dismantling/disassembling, washing, checking/inspecting, validating, and reassembling.

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Figure 1.6 Cleaning Out of Place (COP)
1.2.1.2.Clean In Place (CIP)

Clean-in-place (CIP) is a cleaning method widely used in the food, dairy, pharmaceutical,
brewing and winemaking industries that require the highest standards of plant hygiene. CIP
implies cleaning equipment and its parts without disassembling them. CIP methods can include:
Soaking/agitation systems solvent refluxing High-impact spray-cleaning turbulent flow. Cleaning
in place (CIP) cleaning of equipment by circulation of flowing cleaning solutions, with water
rinsing into and over surfaces in equipment or systems without dismantling them. CIP implies
cleaning equipment and its parts without disassembling them. CIP methods can include:
The output of handmade injera is low and the efficiency is slow, but as more and more people
choose the injera making machine to produce injera and the output has been greatly improved.
Whether it is a injera making machine or other food machinery, food safety is the most important
issue for every food manufacturer and consumer, and the maintenance of food machinery.

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Figure 1.6. Clean In Place (CIP)
https://www.orbitcleaning.com.au/clean-in-place-cip-vs-clean-out-of-place-cop/
Access date: 12/11/ 2023)
https://www.kersia.uk/divisions/food-processing/technique/cleaning-in-place/
1.2.2.Main part of continuous injera baking machine

The whole set machines include: batter mixing machine, feeding system, main machine, heating
cylinder, conveying device, dusting device, cooling system, stacking device, counting system.
Each machine is made of stainless steel, make sure the food production is healthy. We design
continuous injera machine with two heating methods, electric heating and gas heating; the
temperature is generally controlled at 110~140, depending on the thickness of the finished
product, the surface temperature of the baking wheel is controlled by thermocouple and
temperature control instrument.
Advantages of Injera Making Machine
• This machine is made of food grade stainless steel. The heating mode of the
roasting wheel can be gas type of electric type.
• The thickness of the end product can be 0.3-4.0 mm, capacity is 500-4000pcs/h.
Both the diameter and capacity can be customized.
• It is the intelligent model machine, which has the high output, low energy
consumption.

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• It can also save manpower, and reduce the production cost, improve market
competitiveness, seize business opportunities
Fig 1.7 injera making full plant
https://www.longer-machinery.com/product/noodle-plant/injera-baking- machine.html
1.2.3.Injera Making Machine Maintenance

Maintenance including; -
check injera making machine for each transmission pipe interface where there
is no leakage. After each use, notice that the switch in the working state should
be cut off, otherwise it will affect the use of spring roll sheet machine
regularly check and maintain parts of injera maker machine, wipe and add
lubricating oil, so as to avoid dirt accumulation and affect work efficiency.
Try to avoid scratching in daily use and affect the beauty of the machine.
1.2.4. Types of injera making maintenance
• Operation maintenance: operate the injera making machine correctly, clean,
lubricate and adjust according to the operating regulations, and execute by the
operator.

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• Routine inspection and maintenance: check the machine parts as normal every
day according to the inspection standard, find out the problem in time, and
eliminate the failure in the initial state.
• Prevention and maintenance: establish weekly, monthly, quarterly and annual
maintenance plans according to the condition of the equipment, working
environment, and technical maintenance points, and carry out regularly
Requirements of the production environment: the use of machines to make injera requires the
environment to be closed and humid, and the wind hood is installed above the roast wheel The
gear in the gear pump is cleaned after every use and thoroughly cleaned with water. It prevents
the gluten from sticking to the gear and affects the gear rotation, causing the motor load to be too
large.
If the machine is electrically heated, it is often turned on to heat the tide. The produced injera
should be sealed and kept well, sealed with plastic bags or put into foam insulation box
The output of handmade injera is low and the efficiency is slow, but as more and more
people choose the injera making machine to produce injera, the output has been greatly
improved.
Figure 1.8 A) injera baking machine
https://www.noodle-plant.com/blog/injera-making-machine-maintenance.html Access date:

14/11/ 2023)
https://noodlemachinery.wordpress.com/2018/03/20/ethiopian-injera-maker-maintenance/

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1.3.Confirming services
Confirming service is the Identity' of a raw material and service refers to fulfill the standard of
accepted for function to be purported. 'Purity' of a raw material refers to freedom from
adulteration or contamination. The confirmation of a raw material's identity and purity are
established through testing.
1.3.1. Common services required to mixing and blending operation
• water supply
• Electrical panel
• Temperature control
• Power
• Steam
• Fuel
• Vacuum
Adequate supply of potable water shall be available. This potable water shall be able to meet the
standards of ISO: 10500 and shall be tested semi-annually through a recognized laboratory.
Potable water shall be used for cooking, handling food, cleaning equipment & container which
come in contact with food, premises in food handling area. Only potable water shall be used for
processing/cooking, preparing ice & steam which is used as an ingredient; handling raw food or
cleaning food contact surfaces/equipment/plant cleaning. If water is recycled, it shall meet the
standards of potable water, if used for the activities mentioned above.
Non potable water shall have a separate system. Non potable water shall be identified & shall not
connect with or allow reflux into potable water system. Color coding of pipes is recommended.
Storage of water & transferring pipes shall be made of food grade material. Storage
containers shall be cleaned periodically. Water tanks should be suitably covered to prevent
access by animals, birds, pests & other extraneous matters. Water filters shall be regularly
changed or effectively maintained.
• Compressed air & other gases

Compressed air, carbon dioxide, nitrogen & other gas systems wherever required used in
manufacturing &/or packaging shall be constructed & maintained so as to prevent contamination
Gases intended for direct or incidental product contact (including those used for transporting,

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blowing or drying materials, products or equipment) shall be from a source approved for food
contact use, filtered to remove dust, oil & water. Where oil is used for compressors and there is
potential for the air to come into contact with the product, the oil used shall be food grade. Use
of oil free compressors is recommended. Requirements for filtration, humidity (RH %) and
microbiology shall be specified. Filtration of the air should be as close to the point of use as is
practicable.
• Temperature control
Adequate facilities shall be available for achieving & maintaining temperatures required for
heating, cooling, chilling, cooking, refrigerating & freezing food. There shall be facility for
monitoring &controlling temperatures.
• Electrical Panel
In new plants, all socket circuits for hand-held machines must be equipped with additional
protection in the form safety switch with a tripping current of 30 mA. The electrical panels
should have rubber mats/shockproof paint flooring below to prevent from any electric shock to
any employee working at the station.

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1.4.Entering processing/operation parameters
Entering processing/operation parameters in the cereal processing industry refers to setting and
adjusting the various factors and conditions that affect the production process. This includes
parameters such as temperature, pressure, moisture content, cooking time, mixing speed, and
other variables that are critical to achieving the desired quality and consistency of the cereal
products. These parameters are carefully monitored and controlled to ensure that the production
process runs smoothly and efficiently, resulting in high-quality cereal products that meet the
company's standards and customer expectations.
Entering processing/operation parameters in processing injera to meet safety and production
requirements may include setting and adjusting factors such as temperature of the cooking
surface, fermentation time, moisture content of the batter, thickness of the injera, and cooking
time. These parameters are critical to ensuring that the injera is produced safely and meets the
required quality standards. Additionally, parameters related to hygiene and sanitation practices,
as well as equipment maintenance and cleaning schedules, are also important to ensure the safety
and quality of the injera production process. Monitoring and controlling these parameters is
essential to producing high-quality injera that meets safety and production requirements.
Process Parameters (also called a process variable) are certain measures that refer to status of the
process (their values indicate whether the process meets the plan or it needs adjustment). In order
to obtain effective execution of the process its parameters should stay under continuous control.
Process parameters are the variables that affect the quality, efficiency, and cost of your
production, such as
• temperature,
• pressure,
• speed, and
• Time.
• PH fermentation
Outcomes are the results that you measure to evaluate your performance, such as yield, defect
rate, customer satisfaction, and profitability.
1.4.1. Temperature for making injera

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In the preparation of injera, teff flour undergoes fermentation by lactic acid bacteria and yeast.
This review was lead to deductions that increasing fermentation temperature was brought in
increased titratable acidity and reduced pH of the dough during injera making. The optimum
temperature for fermentation is between 75-80°F.
Temperature is the driving force in fermentation, and fermentation impacts sourdough bread
volume, flavor, and texture. Warmer bread dough will ferment faster than colder dough, and
strong fermentation will result in better bread.
1.4.1. Fermentation temperature and time

Fermentation temperature has an effect on the physicochemical quality of spontaneous teff
fermentations and the quality of injera. Temperature control is important in sour dough
production as changes in fermentation temperature may cause variation in the micro flora of sour
dough and affects the final bread quality and flavor.
Temperature in the highlands of Ethiopia is generally between 17 and 25°C, hence, injera made
at these temperatures should still have the desired quality characteristics. Fermentation is a time-
dependent and known to cause changes in the physicochemical and sensory quality of the food
products.
During the fermentation process in order to observe whether there are any significant changes in
pH, titratable acidity, viscosity, elasticity, eye formation and moisture of injera, it was necessary
to monitor fermentation at different temperature and time. Teff flour was fermented for different
fermentation time starting from 0 and 72 hrs for the primary fermentation process at ambient
temperature (22-25°C).
The researcher observed that different primary fermentation time (0, 24, 48 and 72 hrs) made
difference on injera quality indicators such as viscosity of batter, moisture content, elasticity, eye
numbers, pH and titratable acidity. It was concluded that fermentation time would have a
significant effect on the physicochemical and sensory quality of injera.

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Figure 1.9 injera fermentation process
A dough thermometer helps you ensure that you're bulk rising and proofing at optimal
temperatures, and if not it gives you the opportunity to make any necessary adjustments to get
premium results
Fig1.10 Thermometer of dough
1.4.2.1 Baking temperature and time

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During the baking process of injera, heat is transferred from the hot pan to the surface of the
food material, while moisture is transferred from the interior to the surface of the product and
then evaporates. As a result, changes in temperature and moisture conditions develop as cooking
proceeds and bring about the desirable characteristics (color, texture, and flavor) of the food.
During baking of teff injera, starch is completely gelatinized and forms a steam leavened spongy
matrix in which bubbles of gas, microorganisms, and fragments of bran and the outer layer of
endosperm are surrounded.
Teff starch is the major contributor to the texture and keeping other properties of bread injera
quality. The water absorption index (WAI) of teff starches has been reported to be considerably
higher when compared to other starchy cereals. This can be related to the small teff starch
granule size and narrower granule diameter ranges and teff starch granule is - 2-6µm; maize- 5-
30µm; wheat- 2-55µm; barley- 0.9-44.9µm. The smaller the granule size and the larger surface
area will result in the higher the water absorption capacity of the grains.
Figure 1.10 effect of temperature in fermentation of dough making injera
1.4.2.2.The PH of fermentation

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The pH of the initial batter was within the extend of 5.7–6.2 with an average of 5.9 Æ 0.2. In
batter obtained after 1st stage fermentation, the pH ranged from 3.5 to 4.4 with an average of 3.8
Æ 0.3. In batter obtained after 2nd stage fermentation, the pH ranged from 3.4 to 4.1 with an
average of 3.6 Æ 0.2.
PH is defined as the logarithm of the reciprocal of the hydrogen ion concentration. In modern
food analysis. PH is usually determined instrumentally with a pH meter, but chemical pH
indicators also exist. Cereal mashes with a pH of 5-6.2, which are rich in fermentable 14
carbohydrates, that has been preferentially fermented by LAB, at least to a pH below four, and
below this point, acid-tolerant yeasts dominate the fermentation.
Good quality injera is a slightly sour taste due to acidic or low PH nature. If the batter is over
fermented, the acidity of injera will increase due to the secretion of acid by bacteria during
fermentation time. Even though the more acidic injera is less exposed to microbial growth, the
more acidic it is less acceptable in its taste by consumers. Different kinds of the pH values in teff
injera are recorded different ranges. determined the pH of teff injera 3.4 recorded the pH values
of teff injera samples were between 3.65 and 4.02. However, the optimum amount of pH was not
determined and it should be determined in this study. It is critical to maintain a pH range of 4.0 to
5.0, but if it exceeds this range, the production of by-products such as acetic and butyric acid may
have eaten part of the substrates, lowering ethanol fermentation efficiency.

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Figure 1.2 The effect of PH on dough making injera
1.4.2.2.Aeration
Aeration is an important component that affects the fermentation process of many components.
The effects could be the Custer effect, which inhibits growth in anaerobic conditions, or the
Pasteur effect, which inhibits fermentation in aerobic conditions. In aerobic conditions, D.
bruxellensis is severely suppressed by S. cerevisiae in batch fermentations [59]. The presence of
high aeration causes a decrease in the final ethanol yield. In the process, yeast creates acetic acid
instead of alcohol, yeast destroys ethanol in the presence of air, or ethanol evaporates when gas
exchange is not controlled [60]. Aeration induces acetic acid production and if it affects the total
ethanol yield, so limited air is a better fermentation condition to get a good product [60] as
shown in (Figure 3). The oxygen supply should be adequate for cell development and
maintenance but restricted to avoid excessive cell growth and ethanol absorption. For ethanol
production, the amount of oxygen transfer coefficient, oxygen transfer rate, and dissolved
oxygen tension should all be restricted. KLa values in the range of 2.3 to 5.9 h1 were regarded as
having the optimum balance between productivity and yield. In terms of DOT, S.
stipitis produced more ethanol when the saturation level was less than 1% [61]
Fig 1.13PH meter batter

https://www.hindawi.com/journals/ijfs/2022/4419955/ Access date: 14/11/ 2023)
https://www.fao.org/3/W1544E/W1544E06.ht Access date: 14/11/ 2023)
1.4.3.Effect of entering processing/operation parameters in processing injera

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Entering processing/operation parameters in processing injera to meet safety and production
requirements may include setting and adjusting factors such as temperature of the cooking
surface, fermentation time, moisture content of the batter, thickness of the injera, and cooking
time. These parameters are critical to ensuring that the injera is produced safely and meets the
required quality standards. Additionally, parameters related to hygiene and sanitation practices,
as well as equipment maintenance and cleaning schedules, are also important to ensure the safety
and quality of the injera production process. Monitoring and controlling these parameters is
essential to producing high-quality injera that meets safety and production requirements.
Entering processing/operation parameters in the cereal processing industry refers to setting and
adjusting the various factors and conditions that affect the production process. This includes
parameters such as temperature, pressure, moisture content, cooking time, mixing speed, and
other variables that are critical to achieving the desired quality and consistency of the cereal
products.
The effect of entering processing/operation parameters in processing injera can have a significant
impact on the safety and quality of the final product. By setting and adjusting factors such as
temperature, fermentation time, moisture content, thickness, and cooking time, the following
effects can be achieved:
• Safety: Properly controlled processing parameters can help ensure that the injera is
produced in a safe manner, minimizing the risk of contamination and foodborne illness.
• Quality: By controlling parameters such as moisture content, thickness, and cooking
time, the quality of the injera can be optimized, resulting in a consistent texture, taste, and
appearance.
• Efficiency: Setting and adjusting processing parameters can help optimize production
efficiency, leading to higher output and reduced waste.
• Consistency: Controlled parameters can help ensure that each batch of injera is consistent
in terms of quality and safety, meeting the required standards. Compliance: By
monitoring and controlling processing parameters, producers can ensure that they are in
compliance with food safety regulations and quality standards.
Overall, entering processing/operation parameters in processing injera is essential for achieving
safe and high-quality production, while also ensuring compliance with regulations and standards.

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1.5.Checking cooling equipment
An equipment check for inspection is used to assess whether the equipment meets safety and
quality standards before being used. This type of checklist is often used in the manufacturing.
The purpose of an inspection is to identify whether work equipment can be operated, adjusted
and maintained safely, with any deterioration detected and remedied before it results in a health
and safety risk. A hydrometer allows you to draw a small amount of coolant from your system
and shows you the freezing point of your coolant. There are a few different types of hydrometers,
including float and ball hydrometers.
A hydrometer or aerometer is an instrument that measures the specific gravity (relative density)
of liquids—the ratio of the density of the liquid to the density of water. A hydrometer is usually
made of glass, and consists of a cylindrical stem and a bulb weighted with mercury or lead shot
to make it float upright
Fig1.14 Hydrometer
1.5.1 Cooling equipment

Cooling Equipment means equipment or machinery designed to regulate the temperature of the
interior of Equipment. Its working principle is that the machine automatically adsorbs the batter
to the baking pan. Then the baking pan heats the batter to form and mature. After the baking pan
turns around, the shovel on the machine automatically shoveled down Injera and cooled on the
conveyor belt.
1.5.2. Types of cooling equipment.

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• Fans
• Sefied/Mentekia
• Stirrer
• air conditioners and
• industrial coolers
• Once-Through Cooling System.
• Closed Recirculating System / Dry Cooling Tower:
• Open Recirculating System / Wet Cooling Tower / Evaporative Cooling Tower:
• Cooling Tower Water Quality.

https://patents.google.com/patent/CA2689420A1/en / Access date 14/11/2023
1.5.3. Component of injera making production line:
Roll sheet making machine is the automatic injera making machine can be used to make different
shapes of injera or spring roll sheets, lump wrappers, samosa sheet, like round and quadrate
shapes, etc. Cutting machine → rotating cutter; the final part (Tightly arrange and cut spring roll
sheet). → batter pump, spray nozzle, baking wheel; cooling conveyor . Cutting machine →
rotating cutter; cut spring roll sheet.
Fig1.15 mixing cooling and delivering
Mixing the teff flour with the water, and then cover it with a cloth and let the dough rest until it
ferments and bubbles appear on the surface. It should be similar in consistency to the semi-liquid
batter used to make crepes.

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Fig1.16 mixing machine
Modern Injera making machines can automatically grout, baking, form, and cool. Its working
principle is that the machine automatically adsorbs the batter to the baking pan. Then the baking
pan heats the batter to form and mature. After the baking pan turns around, the shovel on the
machine automatically shoveled down Injera and cooled on the conveyor belt. And the heating
method of this machine is various. There are electric heating, resistance wire heating,
electromagnetic heating, gas heating, and other heating methods.
Fig 1.17.Full plant injera machine

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Fig 1.18 injera

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1.6.Carrying out pre-start checks
Pre-start checks are safety checks conducted on equipment before using the item. Pre starts often
involve routine inspections conducted by the machine or equipment operator. Checking for
damage or faults before starting equipment is important for safety. Pre-start checks on mobile
plant and production equipment can assist companies to identity and repair minor problems
before they cause more serious problems or accident e.g. brakes, lights and steering operate
correctly, and checking oil or water levels to ensure the plant operators correctly. A checklist
helps the operator conduct the pre-start check in a standardized way. The contents of the pre-start
checklist differ for each type of equipment. Decreased likelihood or severity of injury from
catastrophic equipment failure. All the proposed injera baking machines operate either with
electricity or gas.
Checking for damage or faults before starting equipment is important for safety. Pre-start checks
on mobile plant and production equipment can assist companies to identity and repair minor
problems before they cause more serious problems or accident e.g. brakes, lights and steering
operate correctly, and checking oil or water levels to ensure the plant operates correctly. Pre-start
checks should also confirm that the operator has the required licence or training to use the
equipment.
In an industry, there are many types of works to be operated. For example, machine and
laboratory operation. So, before we are going to operate machine/lab equipment we have to
inspect/check whether it was in a good operating condition or not. Checking conditions of
operating equipment has a vital role for the operator’s safety, quality of a product and also for
equipment safety.
Operators always have to check the following just before going to manipulate operations
Parameter setting (pressure, temperature, flow...),
Identify faulty conditions,
Analyze maintenance requirements, and
Identify hazards.
All these can be accomplished by investigating.
Use a non-reactive storage container, for example a food safe plastic or glass container. Metals
such as aluminum, cast iron, and copper can cause reactions to occur during fermentation and

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make the process more difficult sometimes resulting in discoloration of your injera or batter It is
also best to have a container with a wide enough opening for easy access for cleaning and
replacing water, as necessary. Having it be clear, especially when making injera for the first
time, is helpful. It needs to have a tight-fitting lid or the ability to be sealed to keep the bacteria
and moisture contained.
1.6.2. Types equipment to check: -
Production machinery- Emergency stop buttons are accessible and working, all
machine guards are in place.
Portable electrical equipment- electrical cord is not causing trip hazard or damaged,
and inspection tag is within date, no physical damage to equipment, guards secured
in place, any attachments are compatible and correctly attached.
Mobile plant- brakes, warning lights etc.
During pre-start checking Activity’s including: -

• Operation maintenance: Operate the injera making machine correctly, clean,
lubricate and adjust according to the operating regulations, and execute by the
operator.
• Routine inspection and maintenance: Check the machine parts as normal every day
according to the inspection standard and find out the problem in time, and eliminate
the failure in the initial state.
• Prevention and maintenance: establish weekly, monthly, quarterly and annual
maintenance plans according to the condition of the equipment, working
environment, and technical maintenance points, and carry out regularly.
• Requirements of the production environment: the use of machines to make injera
requires the environment to be closed and humid and the wind hood is installed above
the roast wheel.
• The produced injera should be sealed and kept well, sealed with plastic bags or put
into foam insulation box.
• If the equipment is not used for a long time, pay attention to the rust prevention of the
baking wheel. If it rusts, use the 80 or 100 mesh sand paper to grind the rust on the

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surface of the baking wheel, smear the oil and wrap it on the film. If the machine is
electrically heated, it is often turned on to heat the tide.
• The gear in the gear pump is cleaned after every use and thoroughly cleaned with
water. It prevents the gluten from sticking to the gear and affects the gear rotation,
causing the motor load to be too large. The motor is regularly installed with inorganic
deceleration oil. Fasten the chain and screw on the equipment regularly to prevent the
use of loosening.
1.6.3. Important of Carrying out pre-start checks

In many industries involving the use of potentially dangerous equipment, it is standard procedure
to conduct pre-start inspections. A pre-start inspection involves a routine examination of a piece
of equipment by its operator, that is standardized via a checklist. Whether it be a light vehicle,
heavy vehicle, mobile plant or tools, pre-start inspections are an important task with financial,
and more importantly, safety implications. Pre-start inspection can potentially be the difference
between life and death. Despite the fact that most companies that require pre-start inspections
use a customized pre-start checklist, most aspects of a pre-start inspection are common across
different industries and companies. Even amongst different types of equipment there are
similarities.
in order to ensure that the task or equipment is used safely, certain things should be included in a
pre-start inspection, such as:
• Reviewing Safe Work Procedures or other instructions

• Ensuring that workers understand the task to be performed
• Inspecting equipment for mechanical faults or damage
• And reviewing existing safety controls (e.g., protective equipment or
guards
The reason why they are carried out include the following
• Worker’s safety (no injury involved)
• Working/fitted probably
• Electrical equipment is suitable

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• Electrical equipment is in good condition
Figure 1.20 pre start check list
1.6.4. The pre- and post-operation equipment inspection checklist

• Clear any accumulated debris from the equipment’s: It’s important to check and
remove any material from the jobsite
• Check signs of damage in mitad or oven
• Check for tearing, breaking or pooled fluid around and under the mitad or oven
machine: This is an easy Indicator that something isn’t right and the source of
that fluid should be identified and addressed/fixed before operation.
• Check for new signs of structural damage, scratches or dents on the machine:
This is almost more important post-operation than it is pre-operation.
• Inspect the operator compartment and clear away any debris or obstructions and
waters.
• Familiarize yourself with the control style and change as needed: Most of
today’s machines come with rather simple pattern selectors that allow the
operator to use the control pattern that they are most familiar with. This will
lead to greater productivity and greater operator satisfaction.
• Identify auxiliary/attachment controls: Each type and style of machine controls
attachments differently operators should identify how to properly work their
attachment prior to attempting to use it.

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• Start the power and review console indicators and warnings: Today’s machines
are built to give the operator more feedback on the workings of internal systems
than ever previously available.
Review all external surroundings: Know your work site, and the people and
structures that exist inside your working envelope. This will ensure optimal
jobsite safety and productivity.
1.6.5. monitor equipment and tools used in injera processing

The equipment and tools used for effectively start, operate, monitor, and adjust ovens/Mitad
equipment for measuring of energy consumption for electrical stoves in the injera processing
are e.g.: -
• Digital energy meter
• model. Energy meter can register energy use (Wh), voltage (V), current (A),
time (sec), power (W) - Temperature meters thermocouples
• Non-metallic holder fixture for thermocouple
• Digital scale (for weighing)
• Air pressure meter
• Cookware
• saucepan diameter 22 cm for pre-test
• Non-metallic mixer
By following these steps and using the appropriate equipment and tools, you can effectively start,
operate, monitor, and adjust ovens/Mitad to achieve the required quality outcomes.

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Self-check 1 Written test
Name…………………………………………… ID………………………… Date…….

Test I: Writ true if statement is correct or write false if the statement is incorrect (5 point each)
1. Fermentation temperature has an effect on the physicochemical quality of

spontaneous teff fermentations and the quality of injera.
2. The white-colored injera which comes from the white-colored teff grain is the most
preferred type compared to the darker grain injera
Test II: choose the correct answer from the given alternative
1. What is the optimum temperature for fermentation?

A) 80- 100 C0
B) 22-25°C
C) 17 - 25°C
D) 75-80°F
2. What is it affecting the process parameters/variables
A) Quality
B) Efficiency
C) cost of your production
D) All
3. From the following process parameter, one is no affect the quality of the final injera
A) Temperature
B) Pressure
C) Time
D) PH fermentation
E) None of the above
4. Which one of the following is true about pre start check of the equipment
A) Routine inspection and maintenance:

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B) Operation maintenance
C) Prevention and maintenance
III. Short answer
1. What is equipment performance measurement?

2. Write the importance of checking performances?
3. List the stages of pre-start check?
4. Describe the two equipment cleaning methods?

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Operation Sheet -1
1.1.Techniques in pre-start checks for injera processing machines
A) Tools and equipment’s
• Stirrer
• Mitad (traditional Ethiopian clay oven) or electric griddle
• Injera batter
• Ladle or measuring cup for pouring the batter onto the Mitad
• Spatula for flipping the injera
• Thermometer to check the temperature of the Mitad
• Timer to monitor cooking time
• Oven mitts or heat-resistant gloves for handling hot equipment
• Cleaning supplies to ensure the Mitad is clean and free from debris before
use
• Safety guards and shields to ensure safe operation of the Mita
• Sefied/Mentekia
B) Procedures
1. Inspect the machine for any visible damage or wear and tear.
2. Check all moving parts and mechanisms for proper functionality.
3. Ensure that all safety guards and shields are in place and functioning
properly.
4. Verify that all electrical connections and components are secure and in
good condition.
5. Check the cleanliness of the machine and ensure that it is free from any
debris or foreign objects.
6. Test the machine's operation by running it without any ingredients to
ensure that it is functioning smoothly.
7. Calibrate and adjust any settings or controls as necessary for the specific
production requirements.

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8. Verify that all necessary supplies, such as flour and water, are available and
ready for use.
9. Review the operating manual and any safety guidelines to ensure that all
procedures are being followed correctly.
Conduct a final inspection of the entire machine to confirm that it is ready for
use

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1.2.Techniques to start, operate, monitor, and adjust ovens/Mitad to achieve required quality
outcomes
• Digital energy meter
• model. Energy meter can
• Non-metallic holder fixture for thermocouple
• Digital scale (for weighing)
• Air pressure meter
• Cookware
• saucepan diameter 22 cm for pre-test
• Non-metallic mixer
B) Procedures
1. Start Preheat the oven/Mitad to the required temperature
2. Put Place the dough or ingredients onto the Mitad
3. Monitor the cooking process, periodically checking the progress of the
food to ensure even cooking and prevent burning.
4. Adjust the temperature and cooking time as necessary to achieve the
desired outcome
5. Use appropriate tools such as oven mitts or tongs to handle hot items
and make any necessary adjustments to the food during the cooking
process.
6. Keep the oven/Mitad clean and free from any debris or spills that
could affect the quality of the food being cooked.
7. Follow all safety guidelines and procedures when operating the
oven/Mitad, including using appropriate protective equipment and
ensuring that all safety guards and shields are in place and functioning
properly.

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8. Refer to the operating manual for the oven/Mitad to understand its
specific features and functions, and to ensure that you are using it
correctly.
Figure 1. Modern starting and operating injera ovens/Mitad
Figure 2. traditional starting and operating injera ovens/Mitad

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1.3.Procedure to prepare Ersho | Starter

• Mixing Bowl
• Measuring Cups and Spoons:
• Grinder or Blender:
• Fermentation Container:
• Cloth or Plastic Wrap:
• Warm Place:
• Ladle or Spoon
B) procedure
1. Combine amount of Teff flour with amount of room temperature water
in a container.
2. Combine flour and ingredients until it should observe a thin foam film
develop on the top
3. Seal the container store in a dark, dry room at around 70 F0. The warmer
the room, the faster your starter will ferment.
4. Observe fermentation throughout the next three days, but do not touch or
disturb the container.
5. open the container and see a foam film on the top as well as a layer of
murky water above the settled flour Approximately 3 days later
6. Discard the murky water layer and stir the starter making sure it is
thoroughly combined
7. starter is now ready to use.
8. add water (about 3/4 amount for this ratio) and store in the refrigerator

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LAP TEST-1 Performance Test
Name………………………………. ID……………………………..
Date…………………………………….
Time started: ________________________ Time finished: ________________
Instructions: Given necessary templates, tools and materials you are required to perform the
following tasks within 1h hour. The project is expected from each student to
do it.
Task-1 perform pre-start checks for in injera processing machines

Task-2 Perform Starting, operate, monitor, and adjust ovens/Mitad to achieve required
quality outcomes
Task-3 Perform prepare Ersho | Starter

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LO#2- Prepare dough
LG #6
Instruction sheet
• Mixing Weighed ingredients and additives.
• Applying fermentation process.
• Mix Weighed ingredients and additives.

• Apply fermentation process.
• Read the specific objectives of this Learning Guide.
• Follow the instructions described below.
• Read the information written in the information Sheets
• Accomplish the Self-checks
• Perform Operation Sheets
• Do the “LAP test”

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Information Sheet 2
2.1. Weighing,Mixing, ingredients and additives

2.1.1.Weighed ingredients of injera
Weighing ingredients for quality compliance is extremely important. This is because ingredients
must be weighed to fulfill product recipe specifications and quality requirements. Measuring
ingredients with extreme accuracy ensures they are distributed equally, and the product tastes the
same in every batch.
Mixing weighed ingredients and additives in injera processing involves:
• Weighing the ingredients: Accurately measuring and weighing the ingredients and
additives according to the recipe or formulation is essential to ensure consistency and
quality in the final product.
• Mixing the ingredients: Once the ingredients are weighed, they need to be thoroughly
mixed to ensure uniform distribution of all components. This may involve using
mixers, blenders, or other mixing equipment to achieve the desired consistency.
• Adding any necessary additives: If any additives or additional ingredients are
required, they should be added at the appropriate stage of the mixing process,
following the recipe or formulation guidelines.
• Monitoring mixing time and speed: It is important to monitor the mixing time and
speed to ensure that the ingredients are properly combined without overmixing, which
can affect the texture and quality of the injera.
• Ensuring hygiene and sanitation: During the mixing process, it is crucial to maintain a
clean and sanitized work environment and equipment to prevent contamination of the
ingredients.
• Following standard operating procedures: Adhering to standard operating procedures
for mixing ingredients and additives is essential to maintain consistency and quality
in the production of injera.

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By following these steps, producers can ensure that the weighed ingredients and additives are
properly mixed to produce high-quality injera products.
The best way to measure flour for baking is by using a portion scale. Flour compacts easily, so
dipping a measuring spoon into the flour will lead to inconsistent results. A portion scale will
allow you to measure accurately and replicate your recipe.
Follow the steps below to learn how to weigh flour on a scale:

Step1. Place a bowl on your food scale.
Step2. Zero out your scale with the bowl on top.
Step 3. Scoop the flour into the bowl until it reaches the amount called for in the recipe
Step4. Sift the measured flour into your recipe to avoid clumps.
Fig 2.1 A) Flour Fig 2.1.B) Mixing vole

The basic weighing and mixing ingredients are:
• Flour
• Water
• Sourdough starter/Ersho
• Benzoic acid
• Sodium benzoate
• Potassium sorbate
• Calcium propionate.

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2.1.2. The Starter preparation
The injera starter is also known as Ersho. When making injera, the starter is always where to
start which is called the starter.
• Characteristics of ready starter

The dough is at its highest level of activity; If you nudge your starter, little air
pockets should shoot up to the top.
The water has separated, and foam has gathered on the very top.
This recipe makes about 5-7 16” injera.
If you want to make less for your first time, the recipe works just as well when
halved.
Refrigeration slows down the microbes and lessens their need to be fed. However,
do not neglect your starter, if you do not make injera frequently make sure to be
adding teff flour periodically to maintain a healthy culture.
Visit our Tips & Tricks section on the webpage
Fig2. 2. Starter
2.1.1. Applying fermentation process

The fermentation stages of teff flour for injera making have two stages, which are independently
processed. The first fermentation stage is where the dough left to ferment for about 24 to 72hrs
or 48–72hrs depending on fermentation temperatures (Steinkraus, 2002; Mezemir, 2015). The
primary fermentation starts after adding the back slope or a clear yellow liquid that accumulates
on the surface of the dough towards the final stage of a previous fermentation. The initial 18 hrs

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of fermentation are characterized by a vigorous evolution of gas and maximum dough-rising
(Mezemir, 2015). This is followed by the appearance of an acidic yellowish liquid on the surface
of the dough at about 30-33 hrs of fermentation. fermentation process associated
with injera and concluded that both the yeast and bacteria have important roles in fermenting teff
for injera production.
the progression of microbial flora during the wild fermentation of teff (no starter culture)
determining that lactic acid bacteria were responsible for the acidic flavor and pH development.
Members of Enterobacteriaceae decrease the pH from 6.6 to 5.8 over the first 18 hrs after which
they are succeeded by Streptococcus faecalis andLeuconostoc mesenteroides. Pedi coccus
cerevisiae, Lactobacillus brevis, Lactobacillusfermentum, and Lactobacillus plantarum appear in
significant numbers (106 CFU/g) at 30 hrs(pH 4.7) and dominate the fermentation after 42 hrs.
Yeasts become the most widespread flora at60 hrs, after which there is little change in pH, but
high counts of lactic acid bacteria remain until the termination of fermentation at 72 hrs.
Dough making for primary fermentation undertaken by taking 1 Kg of teff flour, 2L tap water or
1:2 (w/w) as stated in Ashagrie and Abate (2012). About 60 mL (6% of culture from previous
spontaneous fermentation of dough by the weight of the dough) was added (Yoseph et al., 2019)
and it was kneaded in a bowl by hands with continuous addition of a measured amount of water
for each treatment. The dough was allowed to ferment in an oven at a specified temperature and
time as per treatment combination. After the specified time and temperature scheduled
completed, the supernatant (the slightly yellowish liquid) floated on the surface of the fermented
batter decanted before used at the next steps
2.1.2. Batter/dough making process

After primary fermentation, the yellowish liquid layer is discarded and about 10% of the
fermenting dough is mixed with three parts of water and boiled for 15 minutes to form the absit.
The hot cooked dough (absit) is cooled to about 450C before it is mixed into
the main part of the dough and sufficient potable water is added to make a batter (Dessalegn,
2018). The second fermentation time start after absit is added on the first fermented dough and
lasts for 2-4hrs.
However, the secondary fermentation time is affected by the altitude of the area, the amount of
the irsho, temperature of the environment and the container used (Mezemir, 2015).

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Different literature stated that, the amount of absit added to the batter for secondary fermentation
does varies.
The teff flour, water and Ersho are usually mixed in different proportions to make the dough.
Proper dough making is important for the quality of baked goods including injera. Injera is made
with just three ingredients – teff flour, starter and water. Teff flour is ground from the grains
of Eragrostis teff, also known as teff.
To make injera, teff flour is mixed with water. The fermentation process is started by adding
ersho, a clear, yellow liquid that accumulates on the surface of fermenting teff flour batter and is
collected from previous fermentations. The baking method for injera has changed since its origin
traditionally; the flour is mixed with water and fermented. It is baked by pouring the mixture
onto a large circular griddle, known as a mitad. Injera being cooked on a griddle and baked into
large, flat and round pieces. The dough's viscosity allows it to be poured onto the baking surface,
rather than rolled out.
The prepared absit mixes back to the primary fermented batter and allowed for secondary
fermentation for 2 hours. Finally batter is ready for injera preparations. Some researchers used
varying amounts of teff flour to water ratio in teff flour fermentation. The flour to water ratio
varies in literature from 1:1 to 2:3. Dough mixing is a process in which flour and water are
mixed until gluten is developed, a result of the enhanced interaction between dispersed and
hydrated gluten-forming proteins. "Injera" is bread similar to pancake, made usually from teff.
Injera is thin, prepared from teff flour, water and starter (a fluid collected from previously
fermented mix) after successive fermentations.

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Figure 2.3. injera dough making
Characteristics of dough
The dough will soak up a some of the top water over the course of the fermentation. This will
result in consistency changing from dough to a thick batter, because of this it keep dough as thick
as possible while mixing.
2.1.3. Injera making Machine

The Ethiopian injera maker machine manufactured by our factory is the special equipment for
processing various pasta wrappers, such as spring roll sheets, lump wrappers, etc. The main
structure of the injera machine includes a batter mixing barrel, a batter injection device, a baking
drum, a cooling fan, a mesh belt conveyor, an automatic sorting device, etc. The automatic injera
making machine can be used to make different shapes of injera or spring roll sheets, lump
wrappers, samosa sheet, like round and quadrate shapes, etc. This machine is:-
• Cutting machine → rotating cutter; The final part(Tightly arrange and cut spring roll
sheet)
• Roll sheet making machine → batter pump, spray nozzle, baking wheel;
• Cooling conveyor
• Cutting machine → rotating cutter;

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The dough is prepared according to the requirements of the dough making process. After the
dough is heated and baked by the round baking wheel, it becomes a fixed thickness spring roll or
other sheet-like food.
a mixing machine
a nonstick pan or cast-iron skillet
weighing machine/balance
cooling machine
Fig 2.4Automatic Injera making Machine
https://www.hwayihgin.com/hy-910-cl-a...
Fig2.4. B) Baking injera

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Fig2.4. A) Baking injera
Fig2.4. B) injera

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• Applying fermentation process
Teff flour production and dough making process to produce the flour teff grain is grind between
two stone-discs in the case of disc mill and the hammer mill and crush the grain repeatedly until
it passes through the sieve that is fitted inside the mill and the blade mill having rotary blades to
grind the grain. The teff flour, water and ersho are usually mixed in different proportions to make
the dough. Some of the flour to water ratio is proper dough making is important for the quality of
baked goods including injera.
Fermentation refers to any process in which the activity of microorganisms brings about a
desirable change to a foodstuff or beverage (Karovicova and Kohajdova, 2007). According to
Steinkraus (2002), the traditional fermentation of foods is used for the enhancement of diet
10
through the development of flavor, aroma, and texture in food substrates, preservation and shelf
life extension through lactic acid, alcohol, acetic acid and alkaline fermentation. Similarly,
improvements in the protein digestibility of fermented products are mainly associated with
enhanced proteolytic activity of the fermenting microflora. Fermentation has been shown to
improve the nutritional value of grains such as wheat, maize, teff and rice, by increasing the
content of the essential amino acids lysine, methionine and tryptophan (Zannini et al., 2012).
During fermentation time, Lactic Acid Bacteria (LAB) and yeasts are responsible micro floras in
starch/carbohydrates degradation and production of different exopolysaccharides (EPS) and CO2
gases (Assefa, 2017; Stewart and Getachew 1962). During fermentation process, microorganisms
and the enzymes found in teff flours involved in a biochemical modification of the flours prior
to process or bake for human consumption. This condition leads to changes in texture, taste,
aroma, nutritional value and digestibility of the food products. During fermentation, yeast and
mainly lactic acid bacteria play an important role because LAB produces lactic acid that lowers
the pH to 3.5-4. The lactic acid bacteria perform second proteolysis and this activity makes an
increase of amino acids that is associated with an improvement in protein digestibility
A. Primary fermentation process

• The fermentation stages of teff flour for injera making have two stages, which
are independently processed. The first fermentation stage is where the dough
left to ferment for about 24 to 72hrs or 48–72hrs depending on fermentation
temperatures.

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• The primary fermentation starts after adding the back slope or a clear yellow
liquid that accumulates on the surface of the dough towards the final stage of a
previous fermentation. The initial 18 hrs. of fermentation are characterized by a
vigorous evolution of gas and maximum dough-rising. This is followed by the
appearance of an acidic yellowish liquid on the surface of the dough at about
30-33 hrs. of fermentation. Gas evolution decreases after the pH has fallen
below 5.8 (31 hrs) were the first to investigate the fermentation process
associated with injera and concluded that both the yeast and bacteria have
important roles in fermenting teff for injera production.
• The microbial flora during the wild fermentation of teff (no starter culture)
determining that lactic acid bacteria were responsible for the acidic flavor and
pH development.
• Members of Entero bactericide decrease the pH from 6.6 to 5.8 over the first 18
hrs after which they are succeeded by Streptococcus faecalis and Leuconostoc
mesenteroides. Pedicoccus cerevisiae, Lactobacillus brevis, Lactobacillus
fermentum, and Lactobacillus plantarum appear in significant numbers (106
CFU/g) at 30 hrs (pH 4.7) and dominate the fermentation after 42 hrs. Yeasts
become the most widespread flora at 60 hrs, after which there is little change in
pH, but high counts of lactic acid bacteria remain until the termination of
fermentation at 72 hrs. identified that Lactobacillus pontis is the dominant
species in teff sourdoughs that were spontaneously initiated and stabilized by
back slopping.
https://www.hindawi.com/journals/ijfs/2022/4419955/ Accessing date 15/11/2023

https://arccarticles.s3.amazonaws.com/arcc/Attachment-at-accept-article-R-193.pdf
Accessing date 15/11/2023

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Figure 2.5 Teff fermentation process

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Self-Check – 2 Written test
Name…………………………………………… ID………………………… Date…….
Test I: choose the correct answer from the given alternative

1. Which one of the following are not common ingredients in injera dough making process
A) water B) teff C) starter

2. ……………………is the gelatinization process, and one of the many steps that help
create the right texture, characteristics, and bubble formation (eyes) in injera.
A. Absit B. Starter C. Batter D. Ersho D) Non
3. …….is very similar to that of sour dough and requires a starter (ersho) to be created
approximately three days before mixing the batter.
A) injera fermentation B. Batter C. ersho D. Starter
4. Ersho is prepared after the teff flour mixed with water
A) True B. false
Give short answer (5pts each)

1. What is equipment performance measurement?
2. List equipment available in bakery processing?
3. Write the importance of checking performances?
4. List the stages of pre-start check?
5. Describe the two equipment cleaning methods?
Note: Satisfactory rating - 5 points Unsatisfactory - below 5 points

You can ask you teacher for the copy of the correct answers.

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Operation Sheet -2
2.1. procedure of injera making dough
• Mixing bowl
• Sifter
• Ladle
• Frying pan
• Clean tea towel
C) Procedures/Steps/Technique
1. mixes the starter with the flour then transfer to a sealable container a
large sealable container.
2. Gradually pour amount of water at a time of mixing either by hand or
with a mixer that you may not need more than as you want the dough to
be a thick consistency.
3. Knead the dough for about 3-5 minutes, until it is very thick and
smooth.
4. Press the doughy batter into the bottom of the container.
5. Use the remaining amount of water to clean off the container’s sides.
6. Be sure to not mix the water with the dough, as it is just meant to keep
mold from growing on the surface of the pressed dough.
7. There should be a thick layer of the dough and a layer of murky water
above when done.

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8. Put a tight lid on the container and store in a dry place at room
temperature for 1-3 days based on desired sourness (one day being less
sour and three days being very acidic).
9. discard the top water and place new water of the same amount daily to
reduce sourness as well.

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Name………………………………. ID……………………………..
Date…………………………………….
following tasks within 1 hour. The project is expected from each student to do
it.
Task-1 performing of injera making dough

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LO 3- Prepare Absit
LG #7
Instruction sheet
• Adding prepared Absit.

• Applying resting and cooling.
• Add prepared Absit.

• Apply resting and cooling.
• Read the specific objectives of this Learning Guide.

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Information Sheet 3
3.1.Adding prepared Absit

3.1.1. Absit
Absit is the gelatinization process, and one of the many steps that create the right texture,
characteristics, and bubble formation (eyes) in injera. In gelatinization, starches are hydrated to
produce a gel-like texture.
In the process, the teff flour is mixed with the water and a seed culture (Ersho) from the previous
batch. The mixture will be fermented from 2-3 days for primary fermentation. After the primary
fermentation a portion of the batter mixed and boiled to produce absit. The prepared absit mixes
back to the primary fermented batter and allowed for secondary fermentation for 2 hours.
Finally, batter is ready for injera preparations.
Effects of Absits in primary fermentation

After the primary fermentation a portion of the batter mixed and boiled to produce absit. The
primary mixture prepared to make injera is fermented and a portion of that batter boiled to
produce absit.
Absit is a portion of the fermented dough diluted to paste with water and then cooked and
gelatinizes the starch which enhances proper fermentation of the batter.
Absit making process and secondary fermentation after primary fermentation, the yellowish
liquid layer is discarded and the fermenting dough is mixed with three parts of water and boiled
for 15 minutes to form the absit (Ashenafi, 2006). The hot cooked dough (absit) is cooled to
about 450C before it is mixed into the main part of the dough and sufficient potable water is
added to make a batter.
The second fermentation time start after absit is added on the first fermented dough and lasts for
2-4hrs. However, the secondary fermentation time is affected by the altitude of the area, the
amount of the ersho, temperature of the environment and the container used. The amount of absit
added to the batter for secondary fermentation does varies.
Absit added to the fermented batter can be used as hydrocolloids in products which provide the
batter with a better gas-holding capacity by increasing its viscosity. Injera baked at 24hrs or less
is called aflegna and has sweet taste and such type of injera is recommended for

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people suffering from gastritis who do not tolerate acidic foods (Mezemir, 2015; Sahlin and Nair,
2012). The objective of starch gelatinization is primarily to bring about the cohesiveness of the
batter and secondly to provide easily fermentable carbohydrates to leave the injera (Yetneberk et
al., 2004). The researchers also reported that by cooking part of the fermented batter, the carbon
dioxide produced by the fermentation is trapped and leavens the injera during baking. Therefore,
11it can be concluded from the literature that the main role of absit is to enhance the quality of
injera as an enhancer of fermentation microorganism and improving texture and binding ability
of the dough.
• Absit | Gelatinization ration
2 cups (473g) water

1 cup (274g) batter
2-4 cups (473g-946g) of room temperature water
Materials
Saucepan
Whisk and Measuring cup or scale
• Characteristics of absit
If recipe is halved, after mixture has boiled, take off the burner and add 1-2
cups of cold water into the saucepan and stir well.
Set to the side and wait for the mixture cool enough to touch before adding it
back in to the batter.
Figure3.1 absit preparation

https://www.researchgate.net/publication/327838740_The_effect_of_mechanical_kneading_
and_absit_preparation_on_tef_injera_quality
https://www.hindawi.com/journals/jfq/2022/8972355/

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3.2.Applying resting and cooling
Resting and cooling are important steps in the injera processing to ensure the quality and texture
of the final product. Here's how to apply resting and cooling workplace requirements in injera
processing:
• Resting the batter:

After mixing the ingredients, the batter needs to rest for a certain period of time to allow the
fermentation process to take place. This can range from a few hours to overnight, depending on
the recipe and desired flavour. During this time, it is important to cover the batter and maintain a
consistent temperature to promote proper fermentation.
• Cooling the cooked injera:
Once the injera is cooked on a hot griddle, it needs to be cooled properly to prevent it from
becoming soggy or losing its texture. This can be done by laying the cooked injera flat on a clean
surface and allowing it to cool at room temperature. It is important to avoid stacking the injera
while it is still hot, as this can cause it to become moist and lose its characteristic texture.
• Monitoring temperature and humidity:
During both the resting and cooling processes, it is important to monitor the temperature and
humidity levels in the processing area to ensure that they are within the optimal range for
fermentation and cooling. This may involve using temperature and humidity monitoring
equipment and making adjustments as needed.
• Following food safety guidelines:
It is essential to follow food safety guidelines during the resting and cooling processes to
prevent contamination and ensure the safety of the final product. This includes maintaining a
clean and sanitized work environment, proper storage of ingredients and finished products, and
adhering to hygiene practices.
Injera is a perishable product and must be given extra care. Generally, Injera stays fresh at room
temperature 7-9 days but it's BEST kept in a refrigerator (can last up to 21 days). You can also
store Injera bread in a freezer (lasts up to 3 months).
Injera has a high nutritional value, as it is rich in calcium and iron. Unfortunately, injera has a
shelf life of only 3-4 days essentially due to mould spoilage. The use of weak organic acid as
preservative is allowed in acidic foods, primarily as mould inhibitors These researchers were

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confirmed that chemical preservatives (0.1 benzoic acid, 0.2% potassium sorbate, 0.1% sodium
benzoate and 0.2% of the three preservatives) have capacity to extent the shelf-life of injera up to
10 days at room temperature. While there are many kinds of teff available in Ethiopia, the two
most commonly found in the US are brown teff, and light ivory teff. The differences in teff
create differences in how the Injera looks. Purchasing Injera from a store or restaurant, may the
difference in coloring.
By applying these resting and cooling workplace requirements in injera processing, producers
can ensure that the final product meets quality standards and is safe for consumption. In the
preparation of injera, teff flour undergoes fermentation by lactic acid bacteria and yeast and
increasing fermentation temperature was brought in increased titratable acidity and reduced pH
of the dough during injera making.

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Self-check 3 Written test
Name…………………………………………… ID………………………… Date…….

Directions: Answer all the questions listed below.
Part I. True / False
1. Which of the following steps is NOT essential for preparing injera, a traditional
Ethiopian flatbread made from fermented batter, in order to achieve the best results
when studying for the ABSITE (American Board of Surgery In-Training Examination)?
A. Ensuring the batter has the right consistency and texture before
fermentation.
B. Allowing the batter to undergo a sufficient fermentation period for optimal
flavor and texture development.
C. Using teff flour, a staple in Ethiopian cuisine, as the primary ingredient for
the batter.
D. Adding yeast or a sourdough starter to the batter to facilitate fermentation
and leavening.
E. Cooking the injera on a hot, lightly greased pan or griddle until bubbles
form on the surface and the edges start to lift.
2. Which of the following grains require absit during the process of making injera?
A. Rice B. Wheat C. Teff D. Barley

Part II. Give short answer (5pts)
1. What is the baking temperature of injera?

2. How to rest injera after baked?
3. Write the roles of bacteria and yeast in injera making process?
4. Describe the baking condition of injera from place to place?
5. What is best chemical used to preserve injera during storage?

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Operation Sheet 3
3.1.Procedure of preparing absit

• A large saucepan
• A whisk
• Measuring cups
• A stove
B) procedure / step applying absit preparing

1. open the container and discard the water on the top After 1-3 days, The
dough will have become more like a thick batter than a dough, mix
thoroughly.
2. Bring amount of water to be a boil then turn the heat down to a medium-
low.
3. Add the required ratio of batter to the water while whisking to avoid
clumping. Then turn heat back to medium-high to bring mixture to a boil.
4. add the mixture into the batter and dilute with 1-2 additional cups of water
until desired consistency is reached before Once it has bubbled,
5. The batter should be thick enough to lightly coat the spoon but not so thick
that you cannot see the spoon.
6. Ensure the batter is the right consistency as no pure water can be added
after the final fermentation is complete.
7. Seal with the lid and leave in a dark and dry room until small bubbles form
towards the surface, anywhere from 1-4 hours. We have found 2 hours in
the fridge works well.

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Name………………………………. ID……………………………..
Date…………………………………….
Instructions: Given necessary templates, tools and materials you are required to
perform the following tasks within 1 hour. The project is expected from
each student to do it.
Task1. Perform procedures for absit preparation

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LG #8 LO#4 - Baking Injera
Instruction sheet
• Selecting baking parameters.

• Operating oven/ Mitad.
• Meeting legislative requirements for baked products.
• Identifying, rectifying, and/or reporting unacceptable baked product with workplace
information.
• Maintaining work area with housekeeping standards.
• Conducting work.
Operating the work with relevant policies and proceduresThis guide will also assist you to attain
the learning outcomes stated in the cover page. Specifically, upon completion of this learning
guide, you will be able to:
• Select baking parameters.

• Operate oven/ Mitad.
• Meet legislative requirements for baked products.
• Identify, rectifying, and/or reporting unacceptable baked product with workplace
information.
• Maintain work area with housekeeping standards.
• Conduct work.
• . Read the specific objectives of this Learning Guide.


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Information Sheet 4
4.1.Selecting baking parameters

4.1.1. Baking of injera
Baking of injera is the final process of the fermented teff batter and it is the process where heat is
transferred from the hot pan to the surface of the food baked on it and as a result, moisture
continuously removed out. After the batter is poured in a circular manner on the hot pan, the pan
will be covered and left for 2 to 3 minutes to be steam cooked.
A lid is used to cover the injera during baking process after eyes forming started on the surface.
This is to allow steam to cook the upper surface of the injera and prevent it from drying out. The
tested electric injera stove for different ranges of baking temperature, and the quality of injera in
the range of 135-220°C remains the same and a slightly baking time difference was observed.
The temperature range for baking crumpets is 200-230°C, and observed that baking temperature
increased the elasticity of the crumpets is stated injera baked on a mitad or griddle for about 2-3
min at a temperature of 180 to 220°C got the highest quality than other temperatures and time
tested and although were conducted on injera baking condition no one optimized the temperature
and time at which good quality injera could be baked.
Baking condition of injera (temperature and time) vary from optimum time and temperature.
Therefore, it is necessary to obtain an optimum temperature and time at which injera should be
baked in order to obtain proper physicochemical and sensory quality.

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Figure 4.1 Flow diagram of baking Injera
Procedure of injera dough

steps to produce dough: -
a. a large sealable container mixes the starter with the flour then transfer to a
sealable container.
b. Gradually pour amount of water at a time of mixing either by hand or with a
mixer that you may not need more than as you want the dough to be a thick
consistency.
c. Knead the dough for about 3-5 minutes, until it is very thick and smooth.
d. Press the doughy batter into the bottom of the container.
e. Use the remaining amount of water to clean off the container’s sides.

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f. Be sure to not mix the water with the dough, as it is just meant to keep mold
from growing on the surface of the pressed dough.
g. There should be a thick layer of the dough and a layer of murky water above
when done.
h. Put a tight lid on the container and store in a dry place at room temperature for
1-3 days based on desired sourness (one day being less sour and three days
being very acidic).
4.1.2.Quality parameters of baking injera

Carbon dioxide concentration
Carbon dioxide produced during the primary fermentation stage significantly affects the number
of eyes formed on the surface of injera. The small bubbles of CO2 resulting from fermentation
play an important role in nuclei or pore development and without these nuclei a porous structure
in the final product could not be formed. These nuclei are the source of dominant pore structure
in the final product, which results from the initial explosive release of water vapor from the
batter together with the desorption of CO2. The increase in gas bubbles at around 24 and 48 hrs
during primary fermentation could have caused an increase in the viscosity of the batter which
results in the high number of eyes and elasticity of injera.
• Number of „eyes‟ per square centimeter on injera
The number of eyes on the surface of injera has always been taken as a good indicator of injera
quality.
It was indicated that the gas bubbles formed during fermentation create nuclei like hole due to
the developing of CO2. These gas bubbles in the batters will try to find out a way to escape by
the temperature of baking which in turn leaves a hole like structure called the honeycomb-like
eye.
Injera with large unevenly spaced eyes or those with tiny eyes is both considered poor quality.
While the former signifies insufficient fermentation, the latter indicates too much absit in the
dough. Different factors affect the quality, size and number of eyes on injera.
According to different studies on injera, these factors are mentioned as fermentation process,
absit-making process, the viscosity of batter, fermentation temperature and time, baking
temperature and time. Therefore, these factors should be optimized in order to get good quality

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injera. The increasing as bubbles at around 24 and 48 hrs during primary fermentation could
have cause an increase in the viscosity of the batter which results in the high number of eyes and
elasticity of injera.
Figure 4.2 Number of „eyes‟ per square centimeter on injera
• Rollability of injera
The injera should be soft enough to cut piece easily with the fingers but resilient enough so that it
does not crack or crumble when folded or used to wrap around wot portions during eating. The
spongy and soft structure of teff injera is essential for its keeping freshness, flavor and better
keeping qualities and is soft, spongy, and resilient, and its texture should not be gluey or stick to
the fingers when handled. It becomes drier and more brittle as the number of days of storage
increases. Teff injera is preferred to other cereals since it can be stored for 3 days without losing
its pliability. Pliability is related to the ability of injera to roll or wrap around a 1-5 cm wooden
dowel without tearing or cracking and this is a mark of good quality injera.

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Figure 4.3 rollability of injera
• Tensile strength/ extensibility of injera
The texture is the overall experience of how a substance feels in hand and mouth. It contributes
to the overall eating experience. The malleability of injera makes it good for folding or rolling
and its eyes also good for picking up wot. A non-powdery, soft appearance is also characteristic
of good quality injera.
Lack of textural quality and the interaction of flavor and texture are more likely to cause
rejection of teff injera. Free sugars in fermented teff may also affect glass transition temperature
(TG) of injera. . The flexibility of injera is based on its glass transition temperature and an
important attribute as it relates to its elasticity. Instrumental texture measurement techniques are
mainly based on evaluation of mechanical properties. The amount of force required to produce a
given amount of deformation is used for quantitative evaluation of texture.
• PH
PH is defined as the logarithm of the reciprocal of the hydrogen ion concentration. In modern
food analysis, pH is usually determined instrumentally with a pH meter, but chemical pH
indicators also exist. Cereal mashes with a pH of 5-6.2, which are rich in fermentable 14
carbohydrates, that has been preferentially fermented by LAB, at least to a pH below four, and
below this point, acid-tolerant yeasts dominate the fermentation.
Good quality injera is a slightly sour taste due to acidic or low PH nature. If the batter is over
fermented, the acidity of injera will increase due to the secretion of acid by bacteria during
fermentation time. Even though the more acidic injera is less exposed to microbial growth, the
more acidic it is less acceptable in its taste by consumers.
• Titratable Acidity
Titratable Acidity (TA) refers to the total concentration of free protons and undissociated acids in
a solution that can react with a strong base and could be neutralized. It is dealing with a
measurement of the total acid concentration contained within a portion of food and called total
acidity.
It is a better predictor of acid impact on flavor than pH. Foods establish complex buffering
systems that dictate how hydrogen ions (H+), the fundamental unit of acidity, are expressed.
Even in the absence of buffering, less than 3% of any food acid is ionized into H+ and its anionic
parent species(it is conjugate base). The ability of microorganisms to grow in a specific food is

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an important example of a process that is more dependent on hydronium ion concentration than
on titratable acidity.
• Moisture content
One of the most important ingredients in any gluten-free formulation is water. Moisture in foods
is known to have an effect on quality both positively and negatively. The moisture content in the
product might affect the water activity level that is responsible for the microbial growth and
affects the shelf life of the product. Gelatinization of starch is strongly affected by water content.
Therefore, the moisture content of injera has an effect on its texture.
https://academicjournals.org/journal/AJFS/article-full-text-pdf/4CE3DC764095/ Access date:

16/11/ 2023)
https://academicjournals.org/journal/AJFS/article-full-text-pdf/4CE3DC764095/ Access date:
16/11/ 2023)
4.1.3. Parameters Effect in injera baking on injera quality

Baking temperature and time During the baking process of injera, heat is transferred from the hot
pan to the surface of the food material, while moisture is transferred from the interior to the
surface of the product and then evaporates. As a result, changes in temperature and moisture
conditions develop as cooking proceeds and bring about the desirable characteristics (color,
texture, and flavor) of the food. During baking of teff injera, starch is completely gelatinized and
forms a steam leavened spongy matrix in which bubbles of gas, microorganisms, and fragments
of branandthe outer layer of endosperm are surrounded. Teff starch is the major contributor to 12
the texture and keeping other properties of Ethiopian bread injera quality. The water absorption
index (WAI) of teff starches has been reported to be consider ably higher when compared to
other starchy cereals (Bultosa et al., 2002). This can be related to the small teff starch granule
size and narrower granule diameter ranges and teff starch granule is - 2-6µm; maize- 5-30µm;
wheat-2-55µm;barley-0.9-44.9µm.

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4.2. Operating oven/ Mitad
By following these guidelines for operating an oven or mitad in injera processing, producers can
ensure that the injera is cooked to the highest quality standards and meets customer expectations.
• Preheating the oven:

Before starting the injera processing, it is important to preheat the oven or mitad to the
appropriate temperature. This can vary depending on the specific recipe and equipment being
used, so it is important to follow the manufacturer's guidelines or recipe instructions.
• Ensuring even heat distribution:

When using an oven or mitad to cook injera, it is important to ensure that the heat is evenly
distributed across the cooking surface. This can be achieved by allowing the oven or mitad to
preheat thoroughly and checking for any hot spots before starting the cooking process.
• Maintaining the right temperature:

Throughout the injera cooking process, it is important to maintain a consistent temperature to
ensure that the injera cooks evenly and achieves the desired texture. This may involve making
adjustments to the heat source or cooking time as needed.
• Using proper cooking techniques:

When operating an oven or mitad for injera processing, it is important to use proper cooking
techniques to ensure that the injera cooks evenly and does not become burnt or undercooked.
This may involve flipping the injera at the right time and monitoring its progress closely.
• Cleaning and maintenance:

After each use, it is important to clean the oven or mitad thoroughly to remove any residue or
build-up that could affect the quality of the next batch of injera. Regular maintenance and
inspection of the equipment are also important to ensure that it continues to operate effectively.
Injera making machine working process:

• Stir wheat, water and other raw materials into batter with a mixer

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• The batter flows from the nozzle to the baking tray.
• Automatic baking mature.
• The mature injera is separated from the baking tray.Cut to a custom size (if
you want to produce a round injera, there is no this step)
The thickness of injera can be adjusted between 0.3-2.0 mm, depending on the formula ratio and
the customer’s needs . The output of the injera machine ranges from 800 to 28,000 pieces per
hour, and the specific output is related to the customer’s size requirement for the finished product
1
. The heating method can be electric heating or gas heating . an injera-making machine depend
on the specific model. However, most injera-making machines consist of the following
components:
• Batter mixer: This is where the teff flour and water are mixed to form the
batter.
• Batter pump: The batter is then pumped from the mixer to the baking chamber.
• Spray nozzle: The batter is sprayed onto the baking chamber through the
nozzle.
• Baking wheel: The baking wheel is responsible for baking the injera.
• Cooling conveyor: The injera is then cooled on a conveyor belt.
• Cutting machine: The injera is cut to the desired size using a rotating cutter

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Figure 4.5 operating injera /mitad machine A) & B
4.2.1.performance of conventional electric injera baking stove/ Mitad

The performance of conventional electric injera baking stove is low because of the poor thermal
conductivity of the backing plate material. This leads to a high energy consumption or high kilo
watt per hours for initial heating and observed uneven temperature distribution on the baking
surface. Electricity consumption of electric injera baking stoves depends on the power rating of
the set, voltage level, thickness of the batter to be baked, and experience of the baker.
The temperature range for baking crumpets is 200-230°C, and observed that baking temperature
increased the elasticity of the crumpets is stated injera baked on a mitad or griddle for about 2-3
min at a temperature of 180 to 220°C got the highest quality than other temperatures and time
tested and although were conducted on injera baking condition no one optimized the temperature
and time at which good quality injera could be baked.
Baking condition of injera (temperature and time) vary from optimum time and temperature.
Therefore, it is necessary to obtain an optimum temperature and time at which injera should be
baked in order to obtain proper physicochemical and sensory quality.
The process of making injera involves pouring the thin injera batter onto a pre-heated flat baking
surface so as to thinly cover the surface. The thinly spread batter bakes to its characteristic thin
soft honey comb appearance in about a minute or so.
In contrast to the preparation of pancakes, in which the patty is flipped during cooking, injera
sheets are baked on one side only during preparation.
• First, the hot baking surface upon which it is prepared is optionally polished with a
non-stick applicator, so as to prevent the baked injera from sticking to the baking
surface.
• Second, the batter is rapidly poured onto the flat baking surface, so that the baking
surface is fully covered with a thin layer of batter in a short amount of time.

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• Third, after the injera has baked a sufficient amount of time, it is removed onto a
cooling pan. Cooling the injera makes somewhat it easier to handle without risk of a
tear and also makes it easier for the diner to enjoy (warm portions being preferable to
those which are prohibitively hot or unsatisfyingly cold). Thus, in almost any kitchen,
whether a personal kitchen serving a small family or a commercial one serving many
diners, each freshly baked injera wafer is frequently set aside to cool in succession in a
stack, while its successor cooks on the pan.
https://www.sciencedirect.com/science/article/abs/pii/S0973082622000485 Access date: 16/11/
2023)
https://www.sciencedirect.com/science/article/abs/pii/S2214785321064737 /Access date: 16/11/
2023)

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4.3. Meeting legislative requirements for baked products
4.3.1.Meeting legislative requirements
Legislative Requirements means the relevant legislation, regulations, rules and codes and other
associated documents applicable to the Services in the country where the Services are taking
place.
Ensuring food safety is a legal obligation for all businesses involved in food preparation and
handling.
• Food storage
• Food handling
• Food preparation
• Facility cleanliness
• Food safety management
4.3.2.Good manufacturing practices and prerequisite programs

Any food safety system starts with a solid foundation of programs that manage the basic
environment hygienic conditions where safe food can be produced. These programs set the stage
for the facility and its workers to comply with good manufacturing practices (GMPs).
Without GMPs, it would be challenging for bakeries to ensure a safe food processing
environment. Such principles and practices are implemented through a series of prerequisite
programs (e.g. cleaning and sanitation programs).
4.3.3. HACCP (food safety management system)

This food safety system is focused on critical control points and operational prerequisites
identified through hazard analysis as being essential to maintain food safety of the products and
food processing environment. To properly execute the principles of this system, a detailed
HACCP plan needs to be documented and implemented. This plan is the playbook for the bakery
to make sure the system is working properly.
4.3.4. FSMA (food safety management system)

The keystone of FSMA, like HACCP, is the development of riskbased preventive controls for
food facilities. Bakeries are required to develop and implement written plans for preventive
controls and for recall which involve:

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• Evaluating hazards that could affect food safety
• Specifying what preventive steps, or controls, will be put in place to
significantly minimize or prevent the hazards
• Specifying how the facility will monitor these controls to ensure they are
working
• Maintaining routine records of the monitoring
• Specifying what actions, the facility will take to correct problems that may arise
The Final Rule for Preventive Controls for Human Food implements FSMA requirements for
food manufacturers to establish. It also calls for implementing a food safety system that includes
sanitation programs, hazard analysis, and riskbased preventive controls. Specifically, the rule
establishes requirements for:
• A written food safety plan
• Hazard analysis
• Preventive controls
• Monitoring
• Corrective actions and corrections
• Verification
• Supply chain program
• Recall plan
• Associated records

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4.4.Identifying, rectifying, and/or reporting unacceptable baked product with workplace
information
The term out of specifications, are defined as those results of in process or finished product
testing, which falling out of specified limits, that are mentioned in compendia, drug master file, or
drug application. The OOS, may arise due to deviations in product manufacturing process, errors
in testing procedure, or due to malfunctioning of analytical equipment. When an OOS has arrived,
a root cause analysis has to be performed to investigate the cause for OOS. The reasons for OOS
can be classified as assignable and non-assignable. When the limits are not in specified limits,
called out of specifications.
During final fermentation the shape of the injera change. After mixing the dough goes through a
number of processing stages, these change the shape of the dough and re-orientate the bubbles. It
later moves to a sheeting stage, passes under a curling chain, then the pressure board and guide
bars may well determine the length of the dough piece coming from the end of the final round
injera.
4.4.1.Unacceptable dough structure

Faults in loaf scrap structure, such as dis colored, coarse patches, streaks and variation in softness
are not uncommon in modern cereal dough making. Many combinations of raw materials and
dough processing stages can influence the occurrence of such faults but they have a common
origin. They are the direct result of instability in the structure formed during mixing and/or
subsequent damage to the bubble structure during moulding. It is important to remember that
dough is more likely to be damaged during final moulding if the dough bubble structure is
vulnerable in the first place.
Areas that certainly need to be investigated if dough stability are:
• Flour protein levels and quality of flour.
• Grade colour (bran contamination)
• Oxidation
During the mixing of dough, oxidation causes bonds to form which increase the strength of the
gluten. Too much mixing or kneading (really only possible with a mixer) can lead to over
oxidation, causing the flour to become bleached and the finished loaf to lose flavour.
• Fat failure
• Tight doughs

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• Cold doughs.
• All of the above can influence how stable the dough is during processing and how much
pressure is required to change the shape of the dough at the final moulder stage.
• Dough sheets formed during final moulding were sampled and their density and
rheological properties measured. Evidence of loss of bubble structure and changed
rheological properties were found to coincide with the damage patterns identified using
the coloured dough. As a result of these studies, it is now possible to trace areas of
damage back to where they occurred during final moulding. We have also found that the
problems are affected by the direction of dough feed into the dough moulders
• Figure 4.6. Unacceptable dough structure

• https://www.thefreshloaf.com/node/44889/uneven-dough-structure-due-shaping Access
date: 16/1/ 2023)

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4.5.Maintaining work area with housekeeping standards
Good housekeeping practices in the laboratory have a number of benefits. For example, in terms
of safety, it can reduce the number of chemical hazards (health, physical, reactive, etc.) in the
laboratory and help control the risks from hazards that cannot be eliminated. Practices that
encourage the appropriate labeling and storage of chemicals can reduce the risks of mixing of
incompatible chemicals and assist with regulatory compliance. From a security standpoint, order
in the laboratory makes it easier to identify items out of place or missing. And finally, good
housekeeping can help reduce scientific error by, for example, reducing the chances of samples
becoming confused or contaminated and keeping equipment clean and in good working order.
Therefore, good housekeeping practices are essential for all workplaces, example
• Spills on floors should be cleaned up immediately
• walkways should be kept clear of obstructions
• work materials should be neatly stored
• Any waste should be regularly removed
• Suitable containers for waste should be conveniently located and regularly emptied.
Poor housekeeping can be a cause of incidents, such as:

• Tripping over loose objects on floors, stairs and platforms
• Being hit by falling objects
• Slipping on greasy, wet or dirty surfaces
• Striking against projecting, poorly stacked items or misplaced material
• Cutting, puncturing, or tearing the skin of hands or other parts of the body on
projecting nails, wire or steel strapping.
Food safety practices refer to specific food handling controls related to food handling and
preparation in business/industry. These include things such as the receipt, storage, processing,
display, packaging and transportation of food. As well as paying attention to the practices
specific to food handling and preparation in product handling business/Industry there are some
practices that support food safety. These are called Support programs and include things such as
cleaning and sanitizing, time and temperature controls, pest control, and Food recalls and waste
disposal.
In order to maintain the work place to its standards to keep food safety practices: there should be:

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• Appropriate storage area
• Processing area and display facilities
• Packaging and transportation facilities and also
• Cleaning and sanitizing facilities
• pests control mechanism
• waste disposal
• Temperature controls are maintained to its standards.
Routine maintenance tasks for the industry include system awareness and adjusting equipment
according to manufacturers' recommendations. It’s important to ensure your core system works
well, has regular inspections, and receives needed maintenance.
a. Daily Maintenance
Having an established daily routine that involves general equipment awareness and excellent
hygiene practices will go a long way in creating an effective preventive maintenance program.
b. Equipment Maintenance
Keeping the area and equipment clean will help extend the life of your assets and reduce costs of
corrective chemical usage or emergency repairs.
c. Regular Inspections
Whether other components of your milking system need to be inspected, replaced, or serviced
will really depend on your equipment usage. In the dairy industry, tasks should be based on run
time or observation of problems. For example, regularly check, clean and replace hoses as
needed.
Facilities required in the processing room should be:
• Separate handwashing facilities for staff, with soap, clean water, nail brushes and
clean towels.
• Toilets, which should be separated from the processing room by two doors or located
in a nearby building.
• First aid materials.
• Appropriate storage area
• Processing area and display facilities
• Packaging and transportation facilities and also
• Cleaning and sanitizing facilities

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• pests control mechanism
• Temperature controls are maintained to its standards.
• Cleaning chemicals, stored away from the processing room
• Clean the processing room, toilets, washing facilities and storerooms every day
• Use the correct chemicals to clean equipment, make sure there are no food residues
Following minimum requirements are laid down in the dairy product processing for hygienic
production and quality standards: Location and surroundings of the factory
Sanitary and hygienic conditions of premises
Personnel hygiene
Portability of water
Machinery & Equipment with installed capacity
Quality control facility & Technical staff Product Standards
Limits for preservatives & other additive.
Figure 4.7 Effective hand washing steps

https://www.gov.mb.ca/agriculture/food-safety/at-the-food-processor/housekeeping-in-
grain-processing-plants.htm Access date: 16/1/ 2023)

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4.6.Conducting work
While conducting work in food safety program the following are very important points to be
considered. Some of them are: include all those measures and conditions required to prevent and
control produce contamination hazards, mainly biological. GMP (at primary and post-harvest
stages) already includes all recommendations regarding hygiene practices to produce and handle
safe products. (Reference reading: Code of Hygienic Practices for Fresh Fruits and Vegetables).
Proclamation no. 513/2007 Sold waste management proclamation Food industries and
restaurants shall collect, store and dispose of the food related solid waste they generate in an
environmentally sound manner. Good Hygienic Practices: Include all those measures and
conditions required to prevent and control produce contamination hazards, mainly biological. In
practical terms, the implementation of GAP and GMP (at primary and post-harvest stages)
already includes all recommendations regarding hygiene practices to produce and handle safe
products. (Reference reading: Code of Hygienic Practices for Fresh Fruits and Vegetables).
4.6.1. Good Manufacturing Practice (GMP)

GMP Is that a part of quality assurance aimed at ensuring that products are consisting
manufactured to quality appropriate to their intended use. GMP is a term that is recognized
worldwide for the control management of manufacturing and quality control of food,
pharmaceutical products and medical devices.
• GMP covers following areas are.
Process control (including identification, verification and monitoring of critical control
points in a HACCP scheme, hygienic design of plant and layouts to minimize cross
contamination, cleaning schedules, recording of critical production data, sampling
procedures and contingency plans to cover safety issues)
Premises (including methods of construction to minimize contamination, maintenance,
waste disposal)
Quality control (including product specifications and quality standards for non -safety
quality issues, monitoring and verification of quality before distribution)
Personnel (including training, personal hygiene, clothing and medical screening)

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Final product (including types and levels of inspection to determine conformity with
quality specifications, isolating non -conforming products, packaging checks, inspection
records, complaints monitoring systems)
Distribution (to maintain the product integrity throughout the chain, batch traceability
and product recall systems).
4.6.1.1.Principles of GMP
• Design & construct the facilities & equipment's properly.
• Follow written procedures & instructions.
• Document work
• Validate work.
• Monitor facilities & equipment.
• Write step by step operating procedures & work on instructions.
• Design, develop & demonstrate job competence.
• Protect against contamination.
• Control components & product related process,
• Conduct plan & periodic audits.
Each workplace relies on the exchange of information to carry out its daily business. Information
is passed from employee to employee, customer to employee, supervisor to team member,
supplier to customer, and so on. Dealing effectively with information and records is necessary
and important for all organizations. The quantity and variety of information kept by an
organization can be huge. Information needs to be sorted into related groups so that it can be
stored easily and found when needed. An organization success depends largely on how well it
manages its information. You need to be familiar with the type of information used in your job
and the way records are organized so you can collect, file, store and find information quickly and
easily. Finding and using information is a large part of many jobs, so knowing how to deal with
it is an important workplace skill. Being confident and efficient in this skill helps you and your
organization succeed.
• Workplace safety procedures

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The most important concept to remember is that you are responsible for your own safety and the
safety of others. Most safety practices are common sense. Unfortunately, they can be forgotten or
overlooked unless you make safe practices a habit or an instinct. General Safety By doing things
right, you and your co-workers will commit yourselves to safety on the job and everyone will
benefit. Accidents occur in many ways but most often can be traced back to one of two basic
factors: ignorance or carelessness. You must always be concerned with your own safety and with
the safety of others around you.
• Specification
A specification often refers to a set of documented requirements to be satisfied by a material,
design, product, or service. A specification is often a type of technical standard there is different
types of technical or engineering specifications and the term is used differently in different
technical contexts. They often refer to particular documents, and/or particular information within
them. The word specification is broadly defined as "to state explicitly or in detail" or "to be
specific.
https://nationalfoodinstitute.com.au/nfi/3-ways-to-improve-workplace-safety-in-food-processing/

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4.7.Operating the work with relevant policies and procedures
4.7.1. Policy and procedures
Policies and procedures are sets of principles and rules that provide structure and standardization
to processes carried out across an organization. The purpose of policies and procedures is to
bring uniformity to corporate operations and therefore reduce the risk of an unwanted event: -
There are five models for the whole series of automatic injera machine (if the standard model
cannot meet your needs, we can customize according to your requirement), each model produces
a different size, shape, thickness injera, so the price is also different. However, the working
principle and functions of each model are the same. If you want to produce spring roll sheet,
samosa pastry sheets and other small thickness products, there are 5 models to choose. If you
want to produce thicker products such as injera, there are 3 models to choose.
Organizations need to develop or improve work policies and procedures that reflect their vision,
values and culture as well as the needs of their employees. Once they are in place, enforcing
these guidelines is even more important. However, accomplishing these goals can be tougher
than it sounds.
4.7.2.The Importance of Policies and Procedures
Regardless of your organization's size, developing formal policies and procedures can make it
run much more smoothly and efficiently. They communicate the values and vision of the
organization, ensuring employees understand exactly what is expected of them in certain
situations.
Because both individual and team responsibilities are clearly documented, there is no need for
trial-and-error or micromanaging. Upon reading the workplace policies and procedures,
employees should clearly understand how to approach their jobs.
Formal policies and procedures save time and stress when handling HR issues. The absence of
written policies results in unnecessary time and effort spent trying to agree on a course of
action. With strict guidelines already in place, employees simply have to follow the procedures
and managers just have to enforce the policies.
Implementing these documents also improves the way an organization looks from the outside.
Formal policies and procedures help to ensure your company complies with relevant regulations.

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They also demonstrate that organizations are efficient, professional and stable. This can lead to
stronger business relationships and a better public reputation.
How to Develop Policies and Procedures in the Workplace

When creating a policy or procedure for your workplace, start by reviewing the mission
statement, vision and values. According to the New South Wales Government Industrial
Relations, "a workplace policy should:
• set out the aim of the policy
• explain why the policy was developed
• list who the policy applies to
• set out what is acceptable or unacceptable behavior
• set out the consequences of not complying with the policy
provide a date when the policy was developed or updated"
https://www.executivecompass.co.uk/blog/bid-management/writing-company-policies-and-
procedures/
https://www.powerdms.com/policy-learning-center/following-policies-and-procedures-and-why-
its-important

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Self - check 4 Written test
Name…………………………………………… ID………………………… Date…….

Directions: Answer all the questions listed below.
1. Gelatinization of starch is strongly affected by water content therefore, the

moisture content of injera has an effect on its texture.
2. The number of eyes on the surface of injera has always been taken as a good
indicator of injera quality.
3. Baking condition of injera (temperature and time) vary from optimum time and
temperature.
4. Carbon dioxide produced during the primary fermentation stage significantly
affects the number of eyes formed on the surface of injera.
Part 1. Give short answer (5pts)
1. write the process Flow diagram of baking Injera

2. write the Principles of GMP and its role in injera cooking process
3. What is the baking temperature of injera?
4. write the process Flow diagram of baking Injera
5. How to rest injera after baked?
6. Write the roles of bacteria and yeast in injera making process?
7. Describe the baking condition of injera from place to place?
8. What is best chemical used to preserve injera during storage?

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Operation Sheet -4
4.1.Procedure /methods of Cooking injera

• Prepared injera batter
• Mitad or flat frying pan (non-stick or add oil prior cooking and as
needed).
• Ladle
• Flat mat for lifting injera.
• A plastic or parchment paper covered placemat
B) Procedures/Steps/Techniques
2. The small bubbles develop then the batter is now ready to cook
3. Remove any water that has separated and set aside to add back if
needed for desired consistency.
4. Do not add pure water, as you will dilute the fermentation
5. Heat your non-stick cooking surface to medium-high. If using a 16″
Wass Mitad you have found 215°F work well.
6. Prefer 350°F so just test your cooking surface until you find the right
temperature for you.
7. use less batter to check the bubble formation aka “eyes”–about
500ml-600ml of the batter is equal to 1 large 16” injera.
8. cover with a lid Once about 80% of the eyes have formed,
9. Remove lid once steam starts to develop.
10. start lifting off the cooking surface when the edges of the injera
should
11. use it to lift the injera from the grill and slide a thin mat under the
injera and

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12. perform cool injera using parchment paper or a plastic surface
13. Wait for the injera to cool down entirely before stacking to avoid
sticking.
14. Top with desired injera
https://www.youtube.com/watch?v=AhLeuJ7Q09Y

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4.2. Procedure /methods of working process of an injera-making machine
• Prepared injera batter
• Mitad or flat frying pan (non-stick or add oil prior cooking and as
needed).
• Ladle
• Flat mat for lifting injera.
• A plastic or parchment paper covered placemat
B) Procedures/Steps/Techniques
a. Start to Stir wheat, water and other raw materials into batter with a
mixer
b. Set up the batter flows from the nozzle to the baking tray
c. Adjusting automatic baking mature
d. separate the baking tray from the mature injera is.
e. Cut to a custom size (if you want to produce a round injera, there is
no this step)
f. Set to Coole by a cooling fan
g. Stacking and grouping to required quantity automatically

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Name………………………………. ID……………………………..
Date…………………………………….
following tasks within 45 m. The project is expected from each student to do
it.
Task-1 doing Cooking of injera

Task-2 perform working process of an injera-making machine

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Reference Materials
Books:
Dasa, Fikiru, and Ly Nguyen Binh. "Variety and baking effects on injera making quality,
polyphenols content and antioxidant activity of millet flours and injera." African
Journal of Food Science 14, no. 5 (2020): 134-142.
Gebrekidan, B., & Gebrehiwot, B. (1981, October). Sorghum injera preparations and quality
parameters. In Proceedings of the International Symposium on Sorghum grain
quality (pp. 55-66).
Keyeta, G. T. (2021). The Fermentation Methods for Production of Injera and Dabo in Ethiopia:
A Review. Agricultural Reviews, 42(4), 440-444.
Mengesha, Y., Tebeje, A., & Tilahun, B. (2022). A review on factors influencing the
fermentation process of Teff (Eragrostis teff) and other cereal-based Ethiopian
injera. International Journal of Food Science, 2022.
Mengesha, Yizengaw, Alemu Tebeje, and Belay Tilahun. "A review on factors influencing the
fermentation process of Teff (Eragrostis teff) and other cereal-based Ethiopian
injera." International Journal of Food Science 2022 (2022).
Rashid, Muhammad Imran, et al. "Operational discipline in practice." Process Safety

Progress 40.2 (2021): e12207.
Shimelis Admassu (Associate Professor) Professor Felicidad Ronda Dr. Workineh Abeeba
(Senior Researcher).
Whitman WE. Quality Assurance and Control Operations. In Food Industries Manual 1993 (pp.
537-568). Boston, MA: Springer US.
Whitman, W. E. (1993). Quality Assurance and Control Operations. In Food Industries

Manual (pp. 537-568). Boston, MA: Springer US.

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Solomon, Alamrew B., Solomon W. Fanta, Mulugeta A. Delele, and Maarten Vanierschot.
"Modeling and simulation of heat and mass transfer in an Ethiopian fresh injera drying
process." Heliyon 7, no. 2 (2021).
Tafere, A. T. (2011). Experimental investigation on performance characteristics and efficiency of

electric injera baking pans (‘Mitad’). Energy Technology.
Zewdie, Senait, Kelbessa Urga, and Ayele Nigatu. "Co-fermentation of kocho with barley for an
improved injera." SINET: Ethiopian Journal of Science 20, no. 2 (1997): 261-270.
Web addresses
• https://www.alibaba.com/product-detail/Stainless-Widely-Use-Ethiopian-
Injera-Making_60507478905.html Asceses date: 14/11/ 2023)
• https://youtube.com/watch?v=StYfFAMEexA Asceses date: 14/11/ 2023
• https://www.youtube.com/watch?v=WniNDDn5d0I(Asceses:dat19/12023)
• https://www.internationaljournalssrg.org/IJME/2020/Volume7-
Issue1/IJME-V7I1P102.pdf Access date: 16/1/ 2023)
• https://www.researchgate.net/publication/327838740_The_effect_of_
mechanical_kneading_and_absit_preparation_on_tef_injera_quality
• https://www.hindawi.com/journals/jfq/2022/8972355/ Access date:
16/11/ 2023)
• https://pastrymachinery.com/how-to-make-injera-with-ethiopian-injera-
maker-machine/ Access date: 16/11/ 2023)
• https://www.youtube.com/watch?v=_UQ2Ae_2nUU
• https://www.youtube.com/watch?v=NwVSl3FQt78
• https://www.youtube.com/watch?v=FJqWBi2NeEo
• https://www.youtube.com/watch?v=Up16s87mCHs
• https://www.noodle-plant.com/blog/injera-making-machine-
video.html

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AKNOWLEDGEMENT
Ministry of Labor and Skills and Ministry of Healthwish to extend thanks and appreciation to
the many representatives of TVET instructors and respective industry experts who donated their
time and expertise to the development of this Teaching, Training and Learning Materials
(TTLM).

Author/Copyright
The trainers who developed the learning guide
No Name Qualification Educational Region Phone number E-mail

level
1 Tesfaye Mekuriyaw Food Science & A Addis Ababa 09 27 78 51 74 tesftegegn@gmail.com

Nutrition
2 Debre shewarega Food technology B Addis Abeba 0922944810 Henatu3@gmail.com

&process engineering
3 Yonatan Asrat Chemical engineering A Yirgalem 0915604465 yonimman@gmail.com
Page 95 of 98 Ministry of Labor and Cereal processing Level -III Version 1

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Cereal processing

Based on October 2021, Version 2 Occupational

Module Title: Processing Injera

LO#1- LO1 Prepare equipment ..................................................................................... 2

LO#2- Prepare dough .................................................................................................. 40

LO 3- Prepare Absit ..................................................................................................... 56

LO#4 - Baking Injera ............................................................................................... 64

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1.1 Confirming materials

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Figure 1.3 Teff ersho

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1.1.1.Criteria of confirming raw material for injera

Figure 1.4 Teff

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https://www.hindawi.com/journals/ijfs/2022/4419955/ Access date: 14/11/ 2023)

https://www.sciencedirect.com/science/article/abs/pii/S0973082617300261 Access date: 14/11/

Page 7 of 98 Ministry of Labor and Cereal processing Version 1

Identifying and confirming cleaning requirements in injera processing involves:

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Figure 1.5 cleaning equipment

1.2.1.1.Cleaning Out of Place (COP)

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1.2.1.2.Clean In Place (CIP)

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1.2.2.Main part of continuous injera baking machine

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Fig 1.7 injera making full plant

1.2.3.Injera Making Machine Maintenance

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Figure 1.8 A) injera baking machine

https://www.noodle-plant.com/blog/injera-making-machine-maintenance.html Access date:

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• Compressed air & other gases

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1.4.1. Temperature for making injera

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1.4.1. Fermentation temperature and time

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Fig1.10 Thermometer of dough

1.4.2.1 Baking temperature and time

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Figure 1.10 effect of temperature in fermentation of dough making injera

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Fig 1.13PH meter batter

https://www.fao.org/3/W1544E/W1544E06.ht Access date: 14/11/ 2023)

1.4.3.Effect of entering processing/operation parameters in processing injera

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1.5.1 Cooling equipment

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• Closed Recirculating System / Dry Cooling Tower:

• Open Recirculating System / Wet Cooling Tower / Evaporative Cooling Tower:

• Cooling Tower Water Quality.

Fig1.15 mixing cooling and delivering

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Time started: ________ Time finished:

Time started: ________ Time finished: