Diwash Ready To Print Thesis

PREPARATION AND QUALITY EVALUATION OF MALTED
SORGHUM INCORPORATED BREAD
by
Diwash Acharya
Department of Food Technology
Central Campus of Technology
Institute of Science and Technology
Tribhuvan University, Nepal
2021
Preparation and quality evaluation of malted sorghum incorporated
bread
A dissertation submitted to the Department of Food Technology, Central Campus of

Technology, Tribhuvan University, in partial fulfillment of the requirements for the
degree of B.Tech. in Food Technology
by
Diwash Acharya
Central Campus of Technology, Dharan
Tribhuvan University, Nepal
March, 2021
Tribhuvan University
ii
Central Campus of Technology, Dharan
Approval Letter
This dissertation entitled Preparation and Quality Evaluation of Malted Sorghum

Incorporated Bread presented by Diwash Acharya has been accepted as the partial
fulfillment of the requirement for the B. Tech. degree in Food Technology
Dissertation Committee
1. Head of the Department __________________________________
(Mr. Basanta Kumar Rai, Prof.)
2. External Examiner ______________________________________

(Mr. Raj Kumar Rijal, DFTQC Chief)
3. Supervisor _____________________________________________
(Mr. Dambar Bahadur Khadka, Asst.Prof.)
4. Internal Examiner ______________________________________

(Mrs. Babita Adhikari, Assoc. Prof.)
iii
March, 2021
Acknowledgements
I express my deep sense of gratitude to my supervisor Asst. prof. Mr. Dambar Bahadur
Khadka.
I am also indebted to Prof. Basanta K. Rai (Chairperson, Department of Food

Technology) and Prof. Dr. Dhan B. Karki (Campus Chief, Central Campus of Technology)
for providing requisite facilities and encouragement for the work. I also would like to
acknowledge all my teachers for their participation, encouragement and academic support
throughout my study.
I am also grateful to all the laboratory, library and administrative staffs for their
generous help. I am thankful to my friends, Subash Sigdel, Saphal Ghimire, Saroj Katwal,
Sharad Bhattrai, Archana Bhatta, Stuti Sapkota and my juniors Anup paudel, Trilochan
Pandey, Ranjan Shrestha, Prakash Sapkota for their co-operation during my dissertation
work.
March, 2021
iv
Diwash Acharya
Abstract
A study was conducted to optimize malted sorghum flour in bread. Malted sorghum flour
was obtained by germination the sorghum grains were followed by drying at 50°C for 24 h
till the constant weight obtained and finally processed into fine powder.
Different formulations were made by using Design Expert v 7.1.5. varying incorporation
of malted sorghum flour 2 to 20% with partial replacement of wheat flour and keeping all
other ingredients same.. The Statistical analysis showed that 5.04% malted sorghum flour
incorporated bread was superior to all bread formulations in terms of sensory
characteristics. Physical analysis of bread formulations showed that the specific loaf
volume and volume decreases while the weight increases with the incorporation of malted
sorghum flour. The proximate analysis for moisture (db), crude protein (db) , crude fat (db),
crude fiber (db), total ash (db), carbohydrate (db) and reducing sugar (db) of malted
sorghum flour was done and the values were found to be (5.5, 10.67, 6.59, 3.20, 0.57,
3.19, and 75.34%) respectively. The incorporation of malted sorghum flour significantly
improved nutritional attributes in terms of the protein, fat, and crude fiber. The proximate
composition of best bread according to which the moisture content, protein (db), fat (db),
fiber (db), ash content (db), and carbohydrate are found to be 19.34, 13.43, 5.36, 5.55, 1.13
and 73.63% respectively.
v
Contents
Approval Letter...................................................................................................................iii
Acknowledgements..............................................................................................................iv
Abstract.................................................................................................................................v
List of Tables.......................................................................................................................xii
List of Figures.....................................................................................................................xii
List of Plates.......................................................................................................................xiii
List of abbreviations .......................................................................................................... xv
1. Introduction .................................................................................................................. 1-4
1.1 General introduction ................................................................................................

1
1.2 Statement of the problem ........................................................................................ 2
1.3 Objectives ................................................................................................................

3
1.3.1 General objective ....................................................................................... 3
1.3.2 Specific objective ....................................................................................... 3
1.4 Significance of the study ......................................................................................... 3
vi
1.5 Hypothesis ...............................................................................................................
3
1.6 Limitation ................................................................................................................ 4
2. Literature review ........................................................................................................ 5-45
2.1 Sorghum .................................................................................................................. 5
2.1.1 Origin and historical background ............................................................... 5
2.1.2 Production of sorghum ............................................................................... 6

2.1.3 Structure of the sorghum grain ...................................................................
8
2.1.4 Utilization of sorghum ............................................................................. 11
2.1.5 Physical properties ................................................................................... 14
2.1.6 Chemical composition of sorghum .......................................................... 15
2.1.7 Health benefits of sorghum ...................................................................... 17
2.2 Malting .................................................................................................................. 19
2.2.1 History of malting .................................................................................... 21
2.2.2 Change on physical structure ................................................................... 22
2.2.3 Chemical changes during malting ............................................................

24
2.3 Composite bread ....................................................................................................

26
vii
2.3.1 Developments in Composite Flour Program ............................................
26
2.3.2 Composite flour program in Nepal .......................................................... 27
2.4 History of bread making in Nepal ......................................................................... 28
2.5 Modern bread making process .............................................................................. 28
2.6 Method of dough making process ......................................................................... 29
2.6.1 Traditional straight-dough process ...........................................................

30
2.7 Raw materials for bread making ........................................................................... 30
2.7.1 Wheat flour ...............................................................................................

31
2.7.2 Yeast .........................................................................................................

31
2.7.3 Salt ............................................................................................................

32
2.7.4 Water ........................................................................................................32

2.7.5 Sugar ........................................................................................................34
2.7.6 Fat .............................................................................................................34
2.7.7 Milk and milk products ............................................................................ 34
2.7.8 Malt products ........................................................................................... 35
2.7.9 Malt extract ............................................................................................... 36
viii
2.7.10 Custard powder ....................................................................................... 36
2.7.11 Other improvers ..................................................................................... 36
2.8 Bread making process ........................................................................................... 37
2.8.1 Dough mixing ...........................................................................................

37
2.8.2 Dough fermentation ................................................................................. 38
2.8.3 Knock back ...............................................................................................

38
2.8.4 Dividing ....................................................................................................

38
2.8.5 Proofing ....................................................................................................

39
2.8.6 Baking of dough .......................................................................................

39
2.8.7 Bread cooling ........................................................................................... 39
2.9 The technology involved in dough formation ....................................................... 40
2.10 Factors affecting the bread quality ...................................................................... 41
2.10.1 Flour ....................................................................................................... 41
2.10.2 Water ...................................................................................................... 41
2.10.3 Leavening agent ..................................................................................... 42

2.10.4 Salt ..........................................................................................................42
ix
2.10.5 Sugar ......................................................................................................42
2.10.6 Fat ...........................................................................................................42
2.11 Nutritional value of bread ................................................................................... 42
2.12 Wheat flour and bread standards in Nepal .......................................................... 44
3. Materials and methods ............................................................................................. 45-

54
3.1 Raw material ......................................................................................................... 45
3.1.1 Wheat flour ...............................................................................................

45
3.1.2 Sorghum (Junelo) ..................................................................................... 45
3.1.3 Butter ........................................................................................................

45
3.1.4 Baker’s Yeast ........................................................................................... 45
3.1.5 Sugar and salt ........................................................................................... 45
3.2 Apparatus required ................................................................................................ 45
3.3 Procedure for malting ............................................................................................

46
3.3.1 Cleaning ................................................................................................... 47
3.3.2 Steeping ....................................................................................................

47
x
3.3.3 Germination ..............................................................................................
47
3.3.4 Drying/ Malt kilning ................................................................................ 47
3.4 Method of experiment ........................................................................................... 48
3.4.1 Formulation of receipe ............................................................................. 49
3.5 Method of preparation of malted sorghum incorporated bread .............................

49
3.6 Analytical procedure .............................................................................................50

3.6.1 Physical analysis of raw materials and final product ...............................50
3.6.2 Chemical analysis .....................................................................................51
4. Results and discussion .............................................................................................. 53-

69
4.1 Chemical analysis of wheat flour .......................................................................... 53
4.2 Chemical analysis of unmalted and malted sorghum flour ................................... 54
4.3 Physical properties of sorghum grain and malt .....................................................

56
4.4 Physical properties of malted sorghum flour incorporated bread ......................... 57
4.5 Sensory properties of bread ...................................................................................

58
4.5.1 Color .........................................................................................................

58
4.5.2 Texture ..................................................................................................... 59

xi
4.5.3 Taste ......................................................................................................... 60
4.5.4 Crumb appearance ....................................................................................

62
4.5.5 Flavor ....................................................................................................... 63
4.5.6 Overall acceptability ................................................................................ 64
4.6 Composition of optimized bread ........................................................................... 65
5. Conclusions and recommendations ..............................................................................

67
5.1 Conclusions ........................................................................................................... 67
5.2 Recommendations .................................................................................................. 67
6. Summary ........................................................................................................................ 68
References ................................................................................................................. 70-83
Appendices ................................................................................................................ 81-94

Color plates .................................................................................................................... 92
xii
List of Tables
Table No. Title Page No.
2.1 Area, yield and production of sorghum by region 7
2.2 Chemical composition of sorghum whole grain and 17

its fractions
2.3 Typical composition of bread 43
2.4 Wheat flour & bread standard in Nepal 44
3.1 Recipe formulation for bread 48
4.1 Composition of wheat flour 53
4.2 Composition of unmalted and malted sorghum flour 54
4.3 Physical properties of sorghum grain and malt 56
4.4 Physical parameters of MSF incorporated bread 57
4.5 Composition of product 65
List of Figures
Figure No. Title Page No.
3.1 General flow chart of malting 21
3.2 Flow chart of bread making process 49

xiii
4.1 Mean sensory scores for color of bread samples of 58
different formulations
4.2 Mean sensory scores for texture of bread samples of 59

4.3 Mean sensory scores for taste of bread samples of 60

4.4 Mean sensory scores for crumb of bread samples of 62

4.5 63
Mean sensory scores for flavor of bread samples of
4.6 Mean sensory scores for overall acceptability of bread 64

samples of different formulations
List of Plates
Plate no. Title Page no.
P.1 Steeping of sorghum 93
P.2 Germination of sorghum 93
P.3 Semi trained panelist doing sensory analysis 93
P.4 Malted sorghum incorporated bread samples 93
xiv
List of abbreviation
Abbreviation Full form
ANOVA Analysis of Variance
ADP Adenosine Diphosphate
CO2 Carbon Dioxide
FAO Food and Agriculture Organization
KMS Potassium metabisulphite
RSM Response Surface Methodology
xv
Part I
Introduction
1.1 General introduction
Sorghum [Sorghum bicolor (L) Moench] is the fifth most important cereal crop in the
world; however, it has a wide range of other applications that are being explored with
worldwide interest in renewable resources (Dahlberg et al., 2011). Having been
domesticated for a variety of useful products and cultivated in a broad range of
environments, sorghum exhibits a great range of phenotypic diversity. Around the world,
sorghum is grown for the production of dense grain panicles (for food, feed, and/or
energy), tall, thick sweet stalks (for food, feed, and/or energy), and various forage types
(for feed and fuel) (Kimber et al., 2013). The sorghum kernel varies in color from white
through shades of red and pale yellow to deep purple-brown. The most common colors are
white, bronze and brown. Kernels are generally spherical but vary in size and shape. The
caryopsis can be rounded and bluntly pointed, 4 to 8 mm in diameter. The grain is partially
covered with glumes (FAO, 1995).
Large grains with carotene and xanthophyll increases the nutritive value of sorghum
(FAO 1995). The crop is rich in minerals but bioavailability vary from less than 1% for
some forms of iron to greater than 90% for sodium and potassium. The reasons for this are
varied and complex, since many factors interact to determine the ultimate bioavailability of
a nutrient. Like other grains, sorghum protein is generally low in the essential amino acids
such as lysine and threonine. Sorghum, like legume and oil seed meals has some
limitations, due to the presence of antinutritional factors, such as trypsin and amylase
inhibitors, phytic acid, and tannins. These compounds are known to interfere with protein,
carbohydrates and mineral metabolism (Mohammed et al., 2011).
Malting is a biotechnological technique which involves the controlled germination of a

cereal grain which aims at activating enzyme systems that catalyze the hydrolysis of
polymerized reserved food materials, notably, proteins, starches and cell-wall substances,
thus, extracting fermentable materials (Gautam et al., 2015). The goal of malting in
brewing is to transform the food reserves of the grain, such that they can be dissolved and
extracted by hot water during the mashing stage to produce wort, which is an aqueous
solution of fermentable carbohydrates and soluble protein. The extent of transformation or
modification of the grain during malting is influenced by the sprouting conditions to which
the grain is exposed. It has been established that malting conditions such as steeping
schedule, duration of germination, drying temperature (kilning) and sorghum cultivar
influence the quality characteristics of malt (Djameh et al., 2015).
Bread is baked aerated dough, the primary ingredients of which are wheat flour, yeast,
salt and water. The yeast ferments the sugar and thereby evolves carbon dioxide which
aerates dough. The purpose of bread making is to present cereals flour to the consumer in
an attractive and digestive form (Chamberlain, 1975). The first requirement in bread
making is formation of gluten network, the second is the aeration of mixture by
incorporation of gas, the third is coagulation of material by heating it in the oven so that
the gas is retained in and the structure of the material is stabilized. The advantage of
having an aerated, finely vesiculated crumb in the baked product is that it is easily
masticated (Kent, 1983). To make good bread, dough made by any process must be
extensible enough for it to relax and to expand while it is rising. Good dough is extensible
if it will stretch out when pulled. It also must be elastic, that is, have the strength to hold
the gases produced while rising, and stable enough to hold its shape and cell structure.
Two proteins (gliadin and glutenin) present in flour form gluten when mixed with water
and gives dough these special properties.
1.2 Statement of the problem
Bread is food for many people around the world. People are consuming bread made from
wheat flour or other sources. In this context, increasing interests in the study of products
which are health beneficial as well as nutritious have been in light for consumers. Several
studies have used blended flours or composite flours to produce breads. There have also
been a number of attempts to improve their nutritional characteristics by partially replacing
the wheat flour with non- wheat ingredients in the production of bread. So, the preparation
of malted sorghum composite bread quality can increase sensory properties as well as
nutritional value of bread may be increased.
1.3 Objectives
1.3.1 General objective
The general objective of this work was to incorporate malted sorghum flour for bread
making and its quality evaluation.
2
1.3.2 Specific objectives
The specific objectives of the work were:
1. To prepare bread from Malted-Sorghum flour partially replacing the wheat flour.
2. To perform physiochemical analysis of the prepared bread.
3. To perform sensory analysis as well.
4. To find best proportion of malted sorghum flour incorporated bread.
5. To evaluate the nutritional properties of the obtained best formulation of malted
sorghum incorporated bread.
1.4 Significance of the study
Sorghum is one of the gluten free product and contain less protein as compared to barley.
A major objective of malting is to promote the development of hydrolytic enzymes, which
are not present in the non-germinated grain (Taylor and Belton, 2002). The amount of
reducing sugar increases in the malted flour sorghum varieties. Sorghum in vitro digestion
studies show that malting caused an improvement in protein digestibility and other protein
quality characteristics, including percentage of protein and content of the first limiting
amino acid and lysine (Mella, 2011).
Also during malting, both starch and protein are partially degraded allowing for better
digestibility (Mella, 2011). Narsih et al. (2012) reported the increase in ash content due to
an increase in phytase enzyme activity during germination. Hence by incorporating malted
sorghum in bread could increase its nutritional quality.
1.5 Hypothesis
The null hypothesis of this study will be set up as:
Incorporation of malted sorghum may not affect the sensory characteristics and chemical
composition of bread.
The alternative hypothesis of this study will be set up as:

Incorporation of malted sorghum may affect the sensory characteristics and chemical
composition of bread.
1.6 Limitation
1. Only one variety of sorghum will be used for the study.
2. Germination of sorghum couldn’t be done at controlled condition.
4
Part II
Literature review
2.1 Sorghum
Globally, sorghum is the dietary staple of more than 500 million people in more than 30
countries. Only rice, wheat, maize, and potatoes surpass it in the quantity eaten. For all
that, however, it produces merely a fraction of what it could. Indeed, if the 20 th century has
been the century of wheat, rice, and maize, the 21 st could become the century of sorghum
(Sorghum bicolor) (NRC, 1996). It belongs to family Poaceae family, tribe
Andropogoneae, subtribe Sorghinae, genus Sorghum (Smith and Frederiksen, 2000).
2.1.1 Origin and historical background
Sorghum was originated in north east Africa. Domestication of sorghum started in Ethiopia
and Egypt around 3000 years back. It progenitor races of durra, guinea and caffra were
found to grow wild in different parts of Eastern, Western and Central Africa. In India, it
might have been introduced through early sailors well before the Christian era but not
earlier to 1500 BC. It was introduced to America and Australia about 125 years back, and
Mediterranean/Middle Eastern countries started sorghum cultivation 300 years back (Joshi,
2015).
Sorghum (Holcus) saccharatum (Halapense andropogon), a variety of S. vulgare, or of

the Durrha, is the sugarcane of Northern China and by the Zulu Kaffirs called Imphee. The
Japanese cultivate it only for the sugar and the alcohol, and for the same purpose it is now
cultivated in the United States (Collier, 1884).
The common sorghum (vulgare) is the principle grain food in Africa. It is used to make
bread, or eaten as musb. It is the principle nutriment in many parts of India, where it is
called Jovari, and in the dry regions of Arabia, in Syria, where it has been cultivated since
time immemorial. Sorghum bicolor is cultivated in Abyssinia at 8000 feet above the sea
(Collier, 1884).
Sorghum has not yet attracted the same amount of research as the other major cereals,
wheat, rice and corn. However, with rapidly increasing interest in its food and industrial
properties, cultivation of this crop, ranking fourth amongst cereals in world production, is
likely to expand (Nesbitt, 2012).
2.1.2 Production of sorghum
The total production of sorghum in the world in 1990 was 58 million tonnes, a decrease
from 60 million tonnes in the year 1989 and 62 million tonnes in 1988. A decrease in yield
from 1340 kg/ha in 1989 to 1312 kg/ha in 1990 was reported, while the area remained
around 44 million hectares in both years. Table 2.1 provides data on area, yield and
production of sorghum in various regions of the world (FAO, 1995). In 2007, the world
planted 43.8 million hectares of sorghum, with over 80% of the area devoted to the crop
being found in Africa and Asia (FAO, 2008).
In statistics collected from 1992-1994 about general millet, Nepal had an area of 0.21
million ha , with an yield rate of 1.14 (t/ha), and produced about 0.24 million tons of
sorghum.
An estimation of the world-wide tonnage produced in 2007-2008 is shown in Table 2.1.
6
Table 2.1 Area, yield and production of sorghum by region
Countries Production (tones x 1000) % of total
United states 12,827 20
Nigeria 10,000 16
India 7,780 12
Mexico 6,100 10
Sudan 4,500 7
Ethiopia 3,230 5
Argentina 2,900 5
Australia 2,691 4
China 1,900 3
Burkina faso 1,800 3
Brazil 1,700 3
Other countries 6,800 12
Total 62,308 100

Source: U.S. Grain Council (2008)
The five largest producers of sorghum in the world are the United States (25%), India
(21 .5%), Mexico (almost 11%), China (9%) and Nigeria (almost 7%). Together these five
countries account for 73% of total world production (FAO, 1995).
2.1.3 Structure of the sorghum grain
Examination of microscopic view of a section through a mature sorghum kernel helps to

divide the kernel between the outer seed cover or pericarp, the embryo or germ, and the
endosperm (Wall and Blessin, 1969). The structure of sorghum is shown in Fig. 2.1.
7
Aleurone layer
Horny
Sub-aluerone
Testa
Starchy endosperm
Scutellem
Floury endosperm
Plumule
Germ
Radicle
Pericarp
Fig. 2.1 Structure of Sorghum grain .
Source: Sautier and O'Deye (1989)
2.1.3.1 Pericarp
The pericarp constitutes 4.3% to 8.7% of the sorghum caryopsis (Waniska and Rooney,
2000). It has a thickness of 8 to 160 μm varying within individual mature caryopses (Earp,
McDonough, and Rooney, 2004).It is subdivided into three tissues: epicarp, mesocarp and
endocarp. The epicarp is covered with a thin layer of wax and is usually pigmented. The sorghum
mesocarp contains starch granules, a characteristic unique to sorghum (SernaSaldivar et al., 1994).
The tube cells, which are part of the pericarp, conduct water during germination while, the cross
cells form a layer that impedes moisture loss. The pericarp contains approximately 5% to 8% of
the grain protein (Waniska and Rooney, 2000).
8
2.1.3.2 Testa
Some sorghum cultivars have pigmented sub-coat (testa) located between the pericarp and
the endosperm as shown in Fig. 2.1 (Earp, et al., 2004) . The pigmented testa contains
tannins (proanthocyanidins) (Waniska and Rooney, 2000). Tannins protect the grain against
insects, birds and fungal attack but condensed tannins are associated with nutritional
disadvantages and reduced food quality (Serna-Saldivar and Rooney, 1995). The nutritional
disadvantages of sorghum tannins lie primarily in their ability to form poorly digestible
complexes with dietary protein (Butler et al., 1984).
2.1.3.3 Aluerone layer
The endosperm consists of an outer single-cell layer of aleurone tissue. Aleurone cells are rich
in oil, protein, and ash (Wall and Blessin, 1970).
2.1.3.4 Endosperm
The endosperm constitutes 82% to 87% of the sorghum grain (Waniska and Rooney, 2000).
It is composed of peripheral, and floury and corneous (horny, vitreous, glassy) areas as
shown in Fig. 2.1 (Serna-Saldivar et al., 1994). The peripheral region has several layers of
dense cells containing more protein bodies and smaller starch granules than the corneous
area. The peripheral and corneous areas affect processing and nutrient digestibility
(Waniska and Rooney, 2000). In a review of the composition of the sorghum endosperm
cells, Taylor et al. (2006) noted that both the floury and corneous endosperm cells are
composed of starch granules, protein matrix, protein bodies and the cell walls are
predominated by water insoluble glucuronoarabinoxylans (GAX). The endosperm contains
approximately 81% of sorghum protein (Waniska and Rooney, 2000). In normal sorghum
cultivars, most of the proteins in the endosperm are prolamin (soluble in alcohol-water
mixtures) as well as some limited amounts of glutelins (soluble in dilute acid and dilute
alkali) (Taylor and Schussler, 1986).
To understand the phenomenon of sorghum endosperm hardness and factors responsible

for it, Shull et al. (1990) observed the differences in developing sorghums of varying
hardness. They found that corneous sorghum endosperm had more and evenly distributed
9
proteins. Similarly, in a review of biochemical basis and implications of hardness and grain
strength in sorghum and maize, Chandrashekar and Mazhar (1999) noted that the protein
bodies in the corneous endosperm contained more γ-prolamin, which seemed to be
crosslinked by disulphide bonds, than in soft grains. These authors suggested that the
amounts of α- and γ- prolamin relative to the total prolamin content may be essential for
corneous texture, in which these prolamin are usually higher in hard grains than in soft
grains. Furthermore, Ioerger et al. (2007) investigated the role of cross-linking of sorghum
storage proteins (kafirins) into larger polymeric groups in influencing grain hardness. They
used a number of protein analytical techniques to study the protein composition of isolated
corneous and floury endosperm. These authors found that corneous endosperm had a
greater level of kafirin crosslinking than did floury endosperm and that the cross-linking
produced a larger molecular weight distribution than in the floury endosperm. These
workers also reiterated that the γ-kafirins in the corneous endosperm may have the most
obvious relationships to indicators of kafirin cross-linking in the corneous endosperm
(Ioerger et al., 2007).
Reviewing the traditional food applications of sorghum, Murty and Kumar (1995)
reported that sorghum endosperm texture determines the food making properties of
sorghum. However, there are differing reports on the preferences for traditional sorghum
foods based on the endosperm hardness. For example, Bello et al. (1990) and Da et al.
(1982)found that to (a West African thick porridge) prepared using corneous endosperm
sorghum produced desirable firmer texture than floury endosperm sorghum. On the other
hand, Fliedel (1995), working on tuwo and Aboubacar et al. (1999) using tuwo (a sorghum
porridge consumed in Niger) did not find any correlation between thick porridge firmness
and endosperm texture. However, there is a consensus that corneous endosperm sorghum is
not suitable for preparation of fermented and unfermented flatbreads as it produces
undesirable stiffer bread (Rooney et al., 1988; Yetneberk et al., 2004).
2.1.3.5 Germ
The germ is the living part of the sorghum grain. It consists of two main parts: embryonic
axis and scutellum as shown in Fig. 2.1. The embryonic axis contains the new plant. During
germination and development the radicle forms the primary roots while the plumule forms
10
the shoot (Evers and Millar, 2002). The scutellum is the cotyledon and has reserve
nutrients: moderate quantity of oil, protein, enzymes, and minerals, doubling up as a link
between endosperm and germ (Waniska and Rooney, 2000). The germ contains
approximately 15% of the protein in sorghum. It is rich in albumin (water-soluble) and
globulins (soluble in dilute salt solution) which are rich in lysine and other essential amino
acids (Taylor and Schussler, 1986).
2.1.4 Utilization of sorghum
The traditional method of consumption as a food grain staple (roti, porridge, or mixed with
rice) continue to dominate sorghum use for some time, particularly in India, Pakistan, and
Burma. But more importantly, sorghum use (and its perception) as a source of feed for
livestock and poultry has developed rapidly during recent times. Presently, a little less than
20% of the sorghum produced in Asia goes for animal feed (Kelley et al., 1992).
Grain sorghum has long been a potential source of industrial raw material. The grits
obtained from the endosperm can be used in brewing, just as corn grits and broken rice are
now used. Until methods of milling that permitted a satisfactory separation of the germ
from the endosperm were developed in 1947, sorghum grits were too high in oil for the best
use in fermentation industries. Most of the oil of the grain is in the germ. The oil is suitable
for salad oils. The starch from grain sorghum can be used for food products, adhesives, and
sizing for paper and fabrics (Martin and Macmasters, 1950-1951).
2.1.4.1 Human food
While total food consumption of all cereals has risen considerably during the past 35 years, world
food consumption of sorghum has remained stagnant, mainly because, although nutritionally
sorghum compares well with other grains, it is regarded in many countries as an inferior grain.
Per caput consumption of sorghum is high in countries or areas where climate does not allow the
economic production of other cereals and where per caput incomes are relatively low. These
include especially the countries bordering the southern fringes of the Sahara, including Ethiopia
and Somalia, where the national average per caput consumption of sorghum can reach up to 100
kg per year. Other countries with significant per caput consumption include Botswana, Lesotho,
11
Yemen and certain provinces in China and states in India. In most other countries, food
consumption of sorghum is relatively small or negligible compared to that of other cereals (FAO,
1989).
More than 95% of total food use of sorghum occurs in countries of Africa and Asia. In
Africa, human consumption accounts for almost three-quarters of total utilization and
sorghum represents a large portion of the total calorie intake in many countries. For
example, in Burkina Faso about 45% of the total annual calorie intake from cereals comes
from sorghum, although its share has declined from 55% in the early 1960s. China and
India account for about 90 % of total food use in Asia (FAO, 1989).
Available data from Africa indicate that despite an increase in total food use between the
early 1960s and the mid-1980s, the average per caput consumption declined from 20 to 15
kg per year. Decreases were concentrated in Kenya, Mozambique, Nigeria and Somalia but
occurred also in Botswana, Ethiopia, Lesotho and Zimbabwe. In Asia, both total and per
caput food use of sorghum declined (FAO, 1989).
This decline in per caput consumption in many countries was due in part to shifts in
consumer habits brought about by a number of factors: the rapid rate of urbanization, the
time and energy required to prepare food based on sorghum, inadequate domestic structure,
poor marketing facilities and processing techniques, unstable supplies and relative
unavailability of sorghum products, including flour, compared with other foodstuffs.
Changes in consumption habits were concentrated in urban areas. Per capita food
consumption of sorghum in rural producing areas remained considerably higher than in the
towns. In addition, national policies in a number of countries had a negative influence on
sorghum utilization as food. For instance, large imports of cheap wheat and rice and
policies to subsidize production of those crops in some countries had considerable negative
impact on the production of sorghum (FAO, 1989).
2.1.4.2 Alcohol distilleries
Although the quantity of sorghum grain presently used by the alcohol sector is
comparatively low, it seems to be the most "enthusiastic" user of the crop as an industrial
12
raw material. With recent changes in government policies on licensing alcohol production
and trade, the use of grains to produce potable alcohol is being promoted, thereby providing
an opportunity for sorghum to gain greater acceptability as a raw material in the industry
(Kleih et al., 2007).
There are few complaints about sorghum, although some distillers indicated a preference
for varieties with a higher starch content and less protein. Distilleries had no objection to
using severely blackened grain as long as the starch content was acceptable (Kleih et al.,
2007).
In general, like most other industrial users, distilleries purchase rainy-season sorghum
through traders or brokers in main producing centers. Though there were few complaints
about this system, some distillers felt that brokers sometimes abused their position to
"control" the market. In this context, contract farming may be an option providing better
linkages between producers and industrial users (Kleih et al., 2007).
2.1.4.3 Animal feed sector
While discussing sorghum utilization for animal feed in India, one has to distinguish
between poultry and dairy production. Although the latter has a solid foundation in the co-
operative sector, the poultry industry appears to be more dynamic. According to poultry
producers and feed millers, very little sorghum was used in poultry feed in 1998/99 due to
the availability of maize and its price advantage. Nevertheless, it was acknowledged that in
the past, when maize was expensive, sorghum had been used at an inclusion rate of up to
10% in the case of broilers and up to 15% in the case of layers. The demand for sorghum
in poultry feed largely depends on the price of maize, which is the energy source preferred
by poultry producers. According to industry sources, to make sorghum competitive, its
price should be 20 - 30% lower than that of maize (Kleih et al., 2007).
2.1.4.4 Starch industries
Some of the India's main starch manufacturers, who are primarily based in Ahmedabad,
have used up to 50000 MT of sorghum in the past when maize was in short supply. Starch
producers have even undertaken their own research into sorghum-based starch
13
manufacturing technologies, and their conclusion was that sorghum was not a preferred raw
material and would only be used if there were no alternatives (Kleih et al., 2007).
2.1.4.5 Other industries
Although brewers are aware of sorghum-based beer production in Africa, they prefer barley
malt as the principal raw material. In addition, broken rice or flaked maize are used as
adjuncts. However, one brewery (i.e., Hindustan Breweries in Mumbai) expressed interest
in undertaking trials using sorghum as an adjunct (Kleih et al., 2007).
With the exception of a small market for speciality breads in urban centers, sorghum is
not accepted as a raw material for industrial food processing. Wheat flour or maize starch
are the preferred ingredients. Composite flours do not currently appear to be an option in
bread baking or biscuit manufacturing (Kleih et al., 2007).
Export of sorghum does not appear to be an option for the time being. Moreover, Indian
sorghum at present is not globally competitive and export quotas for coarse grains are
usually taken up by maize (Kleih et al., 2007).
2.1.5 Physical properties
Sorghum is a naked kernel, free from hull. In terms of size and shape, sorghum varieties
differ widely. The average dimensions of a sorghum caryopsis (grain) are length 4 mm,
width 2 mm and weigh about 25 to 35 mg (Haussmann et al., 1999). The shape varies from
obovoid to ellipsoid with 1000 kernel weight varying from 20 to 80 g (Serna-Saldivar and
Rooney, 1995). The mean particle and bulk density of sorghum grain obtained were 1.02
g/cm3 and 568.5 g/cm3 respectively. The particle density of sorghum grain decreased with
increasing moisture within the moisture range of 8.89-16.50% wb (Simonyan et al., 2007).
The value of sphericity, 1000 kernel wt., bulk density, particle density (specific gravity),
and porosity as 0.67, 32.41 g, 69.9 kg/HL, 1.18 g/cm 3 and 40.80% of sorghum grain
(Ndirika and Mohammed, 2005).
14
Botanically, the sorghum kernel is dry, indehiscent, single seeded fruit. The caryopsis is
composed of three major portions: the outer covering (pericarp), the storage tissue
(endosperm), and the germ (Johnson and Peterson, 1974).
2.1.6 Chemical composition of sorghum
The sorghum grain has the composition as that of the corn which are as follows.
2.1.6.1 Protein
A typical mature sorghum seed of one of the common hybrids might contain about 15%
protein, of which around half would be prolamines, or alcohol soluble proteins, about a
third would be glutelin type proteins, 7-9% would be globulins, and the remainder, usually
near 5-6%, would be albumin. The tissues differ in their percentage contents of protein, and
in the types of proteins which make up the total. There is very little prolamine in the germ
and hull, while they predominate in the endosperm. The aleurone layer is rich in albumin
and globulins. A major factor affecting the amino acid composition of the proteins is the
cultivar, variety and hybrid. During germination, starch and protein were degraded to
soluble sugars and amino acids, respectively. Their degradations indicated the metabolic
system interference to reserve starch and protein by amylases and proteases (Elbaloula et
al., 2014). Amino acids found in malted sorghum are threonine, methionine, phenylalanine,
lysine and tryptophan (Matz, 1991) whereas aspartic, serine, glycine, alanine, arginine,
tyrosine, cystine, proline, threonine, histidine are found in wheat (Yetneberk et al., 2004).
2.1.6.2 Carbohydrate
Carbohydrates other than starch are present only in small amounts. Both waxy and regular
types average 1.20% sugars composed of approximately 0.85% sucrose, 0.09% glucose,
0.09% D-fructose and 0.11% raffinose. Sweet variety contain about 2.8% of these sugars
(Matz, 1991).
Starch content of sorghum ranges from 61 to 74%. Gelatinization temperature of sorghum

starch is quite high compared to those from other cereals. Most sorghum starches start to
gelatinize at c. 70-75°C and reach maximum gelatinization far above these temperatures until
about 90-97°C (Verbruggen, 1996).
15
On a 1 kg basis, sorghum starch contain 200–300 g of amylose and 700–800 g of
amylopectin, with waxy varieties containing 0–150 g of amylose and 850–1000 g of
amylopectin (Li et al., 2015).
2.1.6.3 Lipids
Average oil content of the whole grain is 3.6%, with oil contents of the endosperm, germ,
and bran, 0.6, 28.1, and 4.9%, respectively. The endosperm contains 13% of the total oil in
the kernel; the germ, 76%; and the bran, 11%. The petroleum ether extract from sorghum
bran consists mostly of wax rather than oil (Wall and Blessin, 1970).
Free lipids make up 2-4% of the grain and bound lipids 0.1-0.5%. The oil's properties
are similar to those of maize oil. In other words, the fatty acids are highly unsaturated.
Oleic and linoleic acids account for 76% of the total (NRC, 1996).
2.1.6.4 Vitamin and minerals
Compared to maize, sorghum contains higher levels of the B vitamin pantothenic acid,
niacin, folate, and biotin; similar levels of riboflavin and pyridoxine; and lower levels of
vitamin A (carotene). Most B-vitamin are located in the germ.
The grain's ash content ranges from about 1-2%. As in most cereals, potassium and
phosphorus are the major minerals. The calcium and zinc levels tend to be low. Sorghum
has been reported to be a good source of more than 20 micronutrients (NRC, 1996).
Table 2.2 Chemical composition of sorghum whole grain and its fractions
16
Kernel fraction %of kernel weight Protein (%) Ash (%) Oil (%) Starch (%)
Whole kernel 100 12.3 1.67 3.6 73.8
Endosperm 82.3 12.3 0.37 0.6 82.5
Germ 9.8 18.9 10.4 28.1 13.4
Bran 79 6.7 2 4.9 34.6

Source: FAO (1995)
2.1.7 Health benefits of sorghum
2.1.7.1 Good source of vitamin, minerals and fibers
Sorghum, like other cereals, is an excellent source of the fat-soluble and B-complex
vitamin. Amongst the B vitamin, concentrations of thiamine, riboflavin and niacin in
sorghum were comparable to those in maize. The detectable fat-soluble vitamin are vitamin
B, E and K. It is also an important source of mineral and amongst them, phosphorus is the
most abundant. Minerals and vitamin are located at the pericarp and germ; therefore,
refined sorghum products lose part of these important nutrients. Sorghum is also one of the
best sources of dietary fiber. Sorghum does not have an inedible hull so that the whole
grain could be eaten. This means it supplies even more fiber, in addition to many other
crucial nutrients. One serving of sorghum grain contains 12 g of dietary fiber which is 48%
of your daily recommended intake. High-fiber content of sorghum is important for
digestion, hormone production and cardiovascular health (Anon., 2017b).
2.1.7.2 Sorghum may inhibit cancer tumor growth
Compounds in sorghum called 3-Deoxyanthoxyanins (3-DXA) are present in darker-

colored sorgums, and to a lesser extent in white sorghum. Scientists at the University of
Missouri tested extracts of black, red, and white sorghums and found that all three extracts
had strong antiproliferative activity against human colon cancer cells (Yang et al., 2009).
17
2.1.7.3 Rich in antioxidant
Sorghum contains polyphenol compounds in its pericarp which have the health-protective
effect that is superior to many of the more popular consumed grains, fruits and vegetables.
The antioxidant activity of sorghum was even 3-4 time higher than some of other whole
grains. Black sorghum is especially rich in antioxidants because of its high content of
anthocyanins. The antioxidants found in sorghum has anti-inflammatory, anti-cancer,
antidiabetic effects (Anon., 2017b).
2.1.7.4 Protect against diabetes and insulin resistance
Advanced glycation end products (AGEs) are increasingly implicated in the complications
of diabetes. A study from the University of Georgia Neutraceutical Research Libraries
showed that sorghum brans with a high phenolic content and high anti-oxidant properties
inhibit protein glycation, whereas wheat, rice or oat bran, and low-phenolic sorghum bran
did not. These results suggest that “certain varieties of sorghum bran may a ect critical
biological processes that are important in diabetes and insulin resistance” (Farrar et al.,
2008).
2.1.7.5 Sorghum is safe for people with celiac disease
Up to one % of the U.S. population (and about 0.5% worldwide) is believed to have Celiac
Disease, an autoimmune reaction to gluten proteins found in wheat, barley and rye. While
sorghum has long been thought safe for celiacs, no clinical testing had been done until
researchers in Italy made a study. First, they conducted laboratory tests; after those tests
established the likely safety, they fed celiac patients sorghum-derived food products for
five days. The patients experienced no symptoms and the level of disease markers
(antitransglutaminase antibodies) was unchanged at the end of the five day period (Ciacci
et al., 2007).
2.1.7.6 Sorghum may help to manage cholesterol
Scientists at the University of Nebraska observed that sorghum is a rich source of

phytochemicals, and decided to study sorghum’s potential for managing cholesterol. They
18
fed di erent levels of sorghum lipids to hamsters for four weeks, and found that the healthy
fats in sorghum significantly reduced “bad” (non-HDL) cholesterol. Reductions ranged
from 18% in hamsters fed a diet including 0.5% sorghum lipids, to 69% in hamsters fed a
diet including 5% sorghum lipids. “Good” (HDL) cholesterol was not affected.
Researchers concluded that “grain sorghum contains beneficial components that could be
used as food ingredients or dietary supplements to manage cholesterol levels in humans”
(Carr et al., 2005).
2.1.7.7 Sorghum may help to treat human melanoma
Scientists in Madrid studied the e ect of three di erent components from wine and one
from sorghum, to gauge their e ects on the growth of human melanoma cells. While results
were mixed, they concluded that all four components (phenolic fractions) “have potential as
therapeutic agents in the treatments of human melanoma” although the way in which each
slowed cancer growth may di er (Gomez-Cordoves et al., 2001).
2.2 Malting
Malted barley, or 'Malt' as it is most commonly known, is a wonderful package of starch,

enzymes, protein, vitamin, and minerals plus many other minor constituents that provide
the brewer and distiller with their main raw material. 60-65% of the weight of malt is
undegraded starch and malt contains all the key enzymes for starch degradation during the
mashing stage of both the brewing and distilling process. These enzymes produce
fermentable sugars to supplement the other key nutrients for yeast growth that malt
provides. These include amino acids, vitamin, and minerals (Anon., 2017a).
The Malting Process consists of 4 stages which are steeping, germination, kilning and roasting.
a) Steeping
The purpose of steeping is to increase the moisture in the grain from around 12% to
approximately 45%. This is achieved through successive immersions and air rests over a
period of 2-3 days. During this process, the grain begins to germinate and therefore
produces heat and carbon dioxide. In the immersion cycles, the grain is immersed in water
19
and air is blown through the wet grain to keep the level of dissolved oxygen in the water
high enough so as to not stifle the developing embryos. In the air rests, the carbon dioxide
is removed (Anon., 2017a).
Due to the varying degree of moisture tolerance of the different grains, steeping is a
crucial step in the malting process. When the steeping process is complete, all of the grain
should be evenly hydrated and show signs of germination (Anon., 2017a).
b) Germination
The Germination phase is the 'control' phase of malting. Germination continues for a
further 4-5 days depending on the product type being made. The germinating grain bed is
kept at temperature and oxygenated by providing a constant flow of humidified air through
the bed at specific temperatures. The grain is turned regularly to prevent rootlets matting
and to maintain a loosely packed grain bed. The maltster manipulates the germination
conditions to vary the type of malt being manufactured (Anon., 2017a).
c) Kilning
Kilning, the third phase of malting, dries the grain down to 3-5% moisture and arrests
germination. Large volumes of hot air are blown through the grain bed. By varying air
flows and kiln temperatures, malts of different colors can be produced with varying flavor
profiles. At the end of kilning the malt is cooled and the tiny rootlets removed before
analysis and storage. The final malt is analyzed extensively according to malt type and
customer profile.
The malt may be dispatched in bags, in containers or in bulk (Anon., 2017a).
d) Roasting
Roasting is done in 4 distinct stages: steeping, germinating, roasting and cooling. At GWM
Malt, grain spends 34-46 h in steep tanks where we aim for a target moisture of 42-44%.
The grain is transferred to germination which lasts for around 4 days in Wanderhaufen style
streets. This is a semi continuous moving batch germination process. Once germination is
complete, the green malt is then transferred to the roasting drum (Anon., 2017a).
20
The roasting takes place in two roasting drums. The average roasting time is 2.5-3 h with
an air on temperatures of up to 460°C. Our roasters take a batch size of 2.4–3.5 tonnes. The
roasted malt is then transferred to the cooler and spends 35-60 min there in order to drop the
temperature to <15°C and fix the color and flavor compounds. The malt is analyzed before
storage and thereafter awaits dispatch to our customers (Anon., 2017a).
The general flow chart for malting is shown in Fig. 2.1.
Sorghum grain
Cleaning
Steeping
Germination
Drying/ Kilning (50°C for 6 h)
Removal of acrospires
Milling
Malt flour
Fig. 2.1 General flow chart of malting
Source: Ratnavati and Chavan (2016) 2.2.1

History of malting
Malt, in substantially the same form as we know it today, was an important product long
before the days of recorded history. Although its actual origin is buried in antiquity, there is
a legend that early Egyptians manufactured malt by placing it in a wicker basket, which
was then lowered into the open wells of that time. It was first lowered into the water for
steeping, after which it was raised above the water level for germination (Anon., 2018 ).
21
The rate of germination was controlled by adjusting the height of the basket within the
well. As germination progressed and heat developed, the basket would be lowered to a
lower temperature level thus retarding growth and dissipating heat. To accelerate
germination, the basket was simply raised to a higher level (Anon., 2018 ).
The malt was kept from matting by raising it to the top of the well and agitating the
basket. Drying was by natural means, probably a simple process of spreading on the
ground, and subjecting it to the direct rays of the sun. The use of malt at this time was
thought to be exclusively for beverage purposes (Anon., 2018 ).
The making and selling of malts was often controlled, in Nurnberg in 1290 only barley
was allowed to be malted, while in Augsberg between 1433 and 1550 beer was only to be
made from malted oats. In England malt carried a tax for many years until 1880. By 1588,
European settlers in North America were trying to make beer from malted maize. Beer can
be brewed from a range of cereals, but by the 17th century beers brewed from barley malt
predominated in Europe. By the 17th century floor malting was the method being used to
malt larger quantities. Floor malting was the only method of malting in use until the 1850’s.
In floor malting, steeped barley is laid in piles on tiled or concrete floors and allowed to
build up some heat and begin growth. The malt is turned manually with wooden shovels to
reduce heat buildup and aerate the grain. This method is very labor intensive and time
consuming (Briggs, 1998).
By the 19th century the development of large breweries led to the industrialization of
malting and an increase in the size of production units. Pneumatic malting was developed
and reached commercial success in the late 1800s. Two Belgian malting engineers; Galland
and Saladin are considered to be the fathers of the modern malting equipment. Galland
introduced the first aerated rectangular boxes in 1873 and Saladin introduced turning
machines in 1880s. Saladin boxes are in common use today (Briggs, 1998).
With the expansion of trade and the discovery of the New World, making beer from
barley malt spread across the globe. Currently, approximately 1,400 million hectolitres of
beer are brewed annually around the world (Mallett, 2014).
22
2.2.2 Change on physical structure
During germination enzymes migrate from the germ and partially break down the endosperm
starch granules and protein bodies and matrix (Hough, 1985).
During steeping, the grain swells and increases its volume by about a quarter. Space is
allowed in the steep tanks to accommodate the swollen grain. The first microscopic
indication of germination after casting is the appearance of the ‘chit’. The white coleorhizae
or root – sheath that breaks through the pericarp and testa and produces from the base of the
corn. In time seminal roots also called rootlets, culms, cooms, or malt sprouts bursts,
through root sheath and form a tough at end of the grain, at the same time the first ‘leaf-
seat’ or coleoptiles. Variously called by maltsters the ‘acrospires’, ‘spire’, ‘blade’,
penetrates the apex between pericarp and the husk. In conventional malting practice, the
malt is kilned and growth terminated before the acrospires grows beyond the end of the
grain (Hough, 1985).
Starch appears in small amounts in the embryonic structures after the onset of
germination. Coincident with the appearance of this starch the first sign of the breakdown
of the starchy endosperm are seen as an enzymes partial dissolution of some cell walls.
This process, cytolysis, begins in the compressed layer, adjacent to the scutellum and
progressively spreads through the starchy endosperm towards the apex of the grains
(Hough, 1985).
As these hydrolytic breakdown processes precede alterations may be detected in

protoplasm of cells of the aleuronic layer of columnar cells between the compressed cells
endosperm and the scutellum. As germination proceeds, the cells of epithelium tend to
separate and elongate so forming a ‘pile’ which projects into the solubilized part of the
endosperm. This alteration in similar form greatly increases the surface area of the cells and
makes the epithelium a more efficient absorptive organ (Hough, 1985).
Partial dissolution of the cell walls and reduction of starch grains are both characteristics
of physical modification of sorghum. ‘Modification’ progresses form the embryo parallel to
the scutellum towards the apex of the grain advancing fastest on the dorsal side of the grain
beneath the aleuronic layer (Hough, 1985).
23
The softening of endosperm that occurs during malting is easily and conveniently
detected by ‘rubbing out’ the green malt by hand. Chewing grains to see that they are
‘crunchy’ and devoid of hard tips may check the degree of modification of finished malt
(Hough, 1985).
Kernel density decreased during malting. Density of malted sorghum correlated with
diastatic power and reduction in pasting viscosity (Beta et al., 1995). Physical and
biochemical properties such as kernel weight, diastatic properties, malt yield and
fermentable sugars are critical in the preliminary evaluation and selection of grain for
malting. However, further studies on the optimum modification conditions for the cultivars,
friability index of the malts, component fermentable sugars and free amino nitrogen (FAN)
need to be undertaken before final certification of the cultivars for malting purposes
(Makeri et al., 2013).
2.2.3 Chemical changes during malting
The chemical changes occurring during malting are complex. They can only be understood
by appreciating the range of, sometimes conflicting, processes that occur during steeping,
germination and kilning, and the effects of deculming and dressing the malt. Polymeric
reserve substances, such as starch and proteins, are partly hydrolysed in the endosperm; the
low molecular weight degradation products diffuse through the grain. Those reaching the
living tissues may be metabolized, together with the reserves of these tissues (e.g. sugars,
lipids). The aleurone may release some of its metabolic products. There is a net movement
of materials to the embryo where they may be respired, converted into new substances
and/or be incorporated into the growing tissues of the acrospire and the rootlets. Thus the
synthesis of new, complex molecules (proteins, polysaccharides) in the embryo partly
offsets the degradative changes that occur elsewhere in the grain chiefly in the starchy
endosperm (Briggs, 1998).
2.2.3.1 Proximate composition
The moisture content increased significantly by 37.13% which is a normal indication of rapid
water uptake by a viable grain expected during steeping. This hydration process activated a
wide array of enzyme systems which hydrolysed and solubilised food reserves during
24
germination. The moisture content of Sorghum malt was found to be 10.7% for tabat and
10.1% for faterita (Abbas, 2000). Elshewaya (2003) reported lower moisture content values
for tabat malt (3.72%) and faterita malt (4.17%). Bolarinwa et al. (2015) also reported the
very low moisture content of sorghum malt as 6.76%. While Wall and Blessin (1970)
obtained the moisture content and crude fiber content of sorghum grain as 12-14% and 2.7-
2.9% respectively.
The crude protein showed an initial significant decrease of 28.53% before a later
increase of 0.1%. This may be due to the fact that storage nitrogen reserves may have been
mobilized during sprouting after hydrolysis by proteolytic enzymes (which digest the
macromolecular proteins into the more easily assimilable peptides and amino acids) to play
a role in the synthesis of its cellular materials for the rapidly growing roots and shoots
during germination. The carbohydrate content of the malted samples decreased
significantly by 24.33%. This significant decrease could be attributed to metabolism
(Ogbonna et al., 2012). The carbohydrates may have been digested into simple sugars by
amylolytic enzymes which are rapidly taken up by the growing embryo to serve as its
energy source during germination (Elkhier and Hamid, 2008). The reducing sugar increase
with increase in time and relative humidity. It may be due to favorable condition
established for the breakdown of starch at high relative humidity. As the time increase more
starch will breakdown due to exposure of starch to amylase for long time (Tejinder, 2007).
The total ash content of the malted samples decreased significantly by 34.38% from that of
the control. This may be due to the incorporation of mineral elements into cell constituents
during the germination process (Ogbonna et al., 2012).
Mineral ions play vital roles in metabolism as enzyme stabilizers and transport
cofactors. The crude fibre content of the malted samples increased significantly by 72.5%
during the malting period compared to the control (Ogbonna et al., 2012). Crude fibre
consists mainly of cellulose, lignin and hemicellulose (Eggum et al., 1981). This increase
could be attributed to increased bran matter and the building of dry matter during the
growth and development (germination) of the plant. A highly significant increase of
111.82% in the crude fat levels of the malted samples was observed at first and later
decreased significantly by 22.75%. This suggests that there was a change in the crude fat
25
content during the malting stage which may be due to its proportional increase as a result of
decrease in the other food reserves like carbohydrates (Ogbonna et al., 2012). Lipase
activity increased during germination and the proportion of lipid bodies during germination
will decrease due to the synthesis of lipase (Narsih et al., 2012).
2.3 Composite bread
Composite bread is a baked product, the primary ingredients of which are composite flour,
yeast, salt and water. As discussed earlier, technically composite bread may be different
from the whole wheat flour bread in having composite flour, instead of wheat flour alone
and other ingredients remaining same. Composite flours are the mixture of flours from
tubers rich in starch (e.g., cassava, yam, sweet potato) and/or protein-rich flours (e.g. soy,
peanut) and/or cereals (e.g., maize, rice, millet, buckwheat), with or without wheat flour
(Popper et al., 2006). The use of composite flours with or without wheat gives rise to
technical problems in the production of baked goods, particularly composite bread. From
the baker’s point of view the most important component of wheat flour is the protein of the
gluten that plays a decisive role in dough formation, gas retention and the structure of the
crumb. So, in order to produce bread with its characteristic structure and firmness, wheat
containing gluten cannot be completely eliminated from bread.
According to Kent and Evers (2004), wheat flour can be substituted up to 30% with
nongluten millet flour in preparation of bread. The percentage of non-gluten millet flour
that can substitute wheat flour also depends upon the strength of the wheat flour. The
substitution can be increased further in case of other baked but unleavened goods like
biscuits, cookies, pastry, pasta, etc. Bread has been man’s food for at least 6000 years. The
purpose of bread making is to present the cereal flours to the consumer in an attractive,
palatable and digestive form (Chamberlain, 1975; Herringshaw, 1969). It was probably the
first processed food ever produced and remains the most widely acceptable. Bread is one of
the few universal staples which is complete in it and requires no additional preparation.
Though it is not perfect nutritional source of protein, it is however, a principal source of
both calories and protein for a lot of people because of unique structural properties of
hydrated wheat protein.
26
2.3.1 Developments in Composite Flour Program
The Composite Flour Program was established by the Food and Agriculture Organization in
1964 to find new ways of using flours other than wheat, particularly maize, millet and
sorghum, in bakery and pasta products, with the objective of stimulating local agricultural
production, and saving foreign exchange, in those countries heavily dependent on wheat 21
imports (Kent and Evers, 2004). Since, then several researches work and trails have already
proven the success of composite baked products. The ingredients used in composite flours
must take account of the raw materials available in the country concerned. The objective is
to save as much expensive imported wheat as possible when making bakery products. In
the late 1960s, tests were carried out in Brazil in which 75% wheat flour was mixed with
the relevant amounts of potato, maize or cassava flour. The baking tests were conducted on
the basis of the Chorleywood bread process. The same flours were used as raw materials
for biscuits, but the proportion of wheat flour was reduced to 50%. Most of the trails with
composite flours have been carried out in Africa because of its continually growing
population. Reports are available from Senegal, Niger and Sudan (Berghofer, 2000).
In the bread sector the task here was to produce typical French bread with composite
flour. The proportion of wheat flour in the different mixtures varied greatly, the maximum
being 70%. Europe and North America produce sufficient quantities of bread cereals, so
theoretically they have no need to market and use composite flours at all. But constantly
widening ranges of bread and small baked goods and the emergence of certain types of
bread as “functional food” have led to an interest in mixtures of wheat flour with other
agricultural raw materials. Composite flours are an ideal partner in programs to combat
celiac disease (Kader, 2000; Kim and de Ruiter, 1969). In Asia, traditionally, rice and
tapioca have been cultivated as carbohydrate sources. Flour from tapioca (tapioca starch) is
used to replace wheat flour in some applications, mainly in pastry (Popper et al., 2006).
2.3.2 Composite flour program in Nepal
Local initiatives for Biodiversity, Research and Development (LI-BIRD) in collaboration

with Nepal Agriculture Research Council (NARC) carried out research and development
work for 3 years (2002-2004) in finger millet with similar objectives in Kaski and Nuwakot
27
districts of Nepal. The various public awareness activities conducted by the project on
nutritional importance of finger millet through FM radio, print materials, food fairs and
festivals, workshops, school programs raised awareness among consumers and producers.
This resulted increase demand in millet products by conscious groups (intellectuals,
diabetics, young generation and foreigners) in Pokhara. According to entrepreneurs,
departmental stores and many shops requested for supplying millet bread, cookies and
namkin to sale in Pokhara. Several research works related to composite flour have been
carried out at Central Campus of Technology, Dharan. Composite breads and biscuits
incorporated with soya flour, millet, buckwheat, cassava, rapeseed, etc., have already been
tested and several other similar works are in progress.
2.4 History of bread making in Nepal
Before 2007 BS (1950 AD), production of bread loaf was started by Rana’s family. For
several years, bread for public was produced in small bakeries. The dough was made by
hand and baked in small wood charcoal heated bhatties. Bread is made in this manner still
in parts of Nepal. Upgrading this traditional method of bread making means using dough
mixer and several accessory machineries added in the unit. The ovens in many places are
fired by wood. In Kathmandu and some other big towns, several big scale bakeries with
electrical ovens and big scale machinery have come into operation. The quality of breads
produced by these bakeries is very standard and can be compared with developed countries.
Most of the big hotels in Kathmandu and Pokhara are having their own bakeries and
showrooms (Khanal, 1997).
The first professional bread industry in Nepal was Krishna Pauroti Bhandar, located in
Kathmandu is professionally still famous in Kathmandu valley. Many professional bakers
are not intended to improve the quality of bread. The concerned department should give 11
simple, hygienic and economic technologies to the bakers so that bakery industry can
flourish. Bread produced by such technology will be of better quality and cheap to
consumer (Khanal, 1997).
28
2.5 Modern bread making process
The main object of the bread making is to present cereal flours in an attractive palatable and
digestible form the actual baking process is really the last and most important steps in the
production of baking products. At its simplest this is achieved by baking portions of
kneaded mixtures of crushed grains and water, usually with salt added to enhance flavor
and wheat are still consumed in this form in many communities. Bread is fundamentally
foamed gluten. It was in 1962 that two research workers C.O. Swanson and E.B. working
of the Kansas state agricultural college designed a laboratory mixer, which combined a
pack squeeze pull tear action and demonstrated that intense mechanical working of dough
modified its structure in such a way that bulk fermentation could be omitted without loss of
bread quality (William, 1975).
In 1950, the British baking industrial research association laboratory in Chorleywood

led by Dr. Chamberlin researched in to the basic chemicals and physical principals of
mechanical dough development. Further discoveries followed which designed other
conditions which had to be fulfilled for the production of good quality bread and eventually
these are collected together in to a set of rules and published in 1961 under the name of
Chorley wood Bread Process (CBP) (Chamberlain, 1975). At the same time, mechanical
development was being quantified in Britain as the CBP, the second alternative to bulk
fermentation as means of developing dough made its appearance, in the USA as chemical
dough development although initially it was introduced by Hemika and Zenner as instant
dough development process and made use of a balanced blend of reducing and oxidizing
agents added as dough ingredients. This method later developed as a chemical dough
development process. The principal of chemical dough development was further explored
in Britain (Chamberlain, 1975) and modification made to suit local circumstance the
Chorley Wood workers christened the process.
2.6 Method of dough making process
The protein in wheat flour has the special property that when hydrated with water and
mixed in to dough, they form a 3-dimensional viscoelastic matrix known as gluten. This
matrix surrounds the small air cells which expand and form the basic characteristic of the
29
loaf contributing to the overall texture and structure. Similarly they lose their organized
granular characteristics during baking (Priestley, 1979). When the basic ingredients ae
mixed together the intermediate resultant coherent mixture is in elastic, and the desired
elastic and gas retaining properties are obtained by the process of dough development
(William, 1975). There are several procedures for achievements of this effect and
consequently bread making procedures have been developed on the basic of dough
development technique. Basically, there are three making process. Firstly, the fermentation
system which is the traditional method of bread making, secondly the mechanical dough
development (MDD) system which is generally known as Chorleywood bread making
process (CBP) and thirdly a chemical system called activated dough development system
(ADD).
2.6.1 Traditional straight-dough process
This process involves mixing of flour, yeast, salt and water, plus any other desired
ingredients, in bulk for up to 20 min. The dough in the bowl is put to one side, covered and
allowed to ferment for three hours at 27ºC. Thereafter, the dough is mechanically divided
and molded into ball-type shapes of the desired weight, which are allowed to stand for 15 to
20 min. This is known as the first proof. The process continues with remolding into the
final shaped dough piece, which is placed on a baking sheet or in a baking tin. The final
proof continues for 45 min to one hour in a proofer (or “prove”), which has humidity
controlled at up to 48ºC. The dough is then baked for up to 30 min at 225ºC in a travelling
oven. The total time of process, from flour mixing to the oven outlet, is about 5h.
The bread is cooled and then sliced and wrapped if required. Cooling on a large scale is
carried out industrially over times ranging from one hour to two hours, 30 min or more in a
large ambient air cooler, sometimes air conditioned. The interior crumb temperature is
reduced ideally to 27ºC or less to optimize slicing performance. Variants include the
spongeand-dough process, which extends the processing time by two hours or more. In this
method, fermentation is split into two stages: sponge and dough. The sponge stage mixes
part of the flour and water and often all of the yeast; the dough stage contains the remaining
ingredients. This process, which demands strong flour, was popular in the United States,
Canada and Scotland during the 1950s and 1960s.
30
2.7 Raw materials for bread making
Four basic ingredients are required for the manufacture of bread, namely, wheat flour,
yeast, salt and water. If anyone of these four is omitted, bread as we know it cannot be
made. Two other ingredients are often added, fat to improve softness and keeping quality
and sugar in many areas to increase sweetness. Nowadays, whole range of additives is
employed for various reasons, for example to improve fermentation, keeping properties,
moisture retention, volume, crumb structure and to prevent mould growth (Flynn and
James, 1981). Eggs, milk and milk products are also used in bread according to their
varieties. Eggs are excellent improver and they improve the handing properties by
stabilizing the dough, so that the result of increased volume and boldness are obtained
(Bennion, 1967).
2.7.1 Wheat flour
For normal bread making, flour from grist containing a large proportion of strong wheat is
required. Good bread making flour is characterized by having protein which is in quantity
and of satisfactory quality in respect of elasticity, strength and stability, satisfactory gassing
properties and amylase activity, satisfactory moisture content not higher than about 14% to
permit safe storage and satisfactory color. Starch is a major component of wheat flour
(69%) which is composed of amylase and amylopectin. It is the main factor imparting
softness in crumb. Some of the starch granules in flour become damaged during the milling
process. It is believed that flour amylases are able to attack only the damaged or available
starch to supply sugar during fermentation. Excessive starch damage however, has an
adverse effect on the quality of bread, loaf volume is decreased and the bread is less
attractive in appearance (Bennion, 1967; Kent, 1983). Flour contains small but important
amounts of various sugars such as sucrose, maltose and dextrose without which in the
presence of yeast there could be no fermentation. The bread making quality of freshly
milled flour tends to improve during storage for a period of 1-2 months (Kent (1983).
2.7.2 Yeast
Yeast or Saccharoromyces cerevisiae is group of minute fungi capable of fermenting a

sugar solution producing carbon dioxide and alcohol. Baker’s yeast is a different strain and
31
it must be fresh and active. The quantity used is related inversely to the time of
fermentation and to the temperature of the dough (Bennion, 1967; Kent, 1983). Yeast
action in fermentation has three main functions according to Bennion (1967).
1. To produce carbon dioxide, in sufficient quantities and at the right time to inflate the
dough and produce a light spongy texture which will result in palatable bread when
correctly baked.
2. To produce a complex mixture of chemical compounds of many types, which contribute to

the flavor of the bread.
3. To help bring about the essential changes in the gluten structure known ripening or
maturing of the dough.
The activity of yeast depends upon its enzymes, coenzymes and activator contents.
There is little or no growth during the first 2 h after the yeast is added to the dough, but
some growth in 2 to 4 h, if that time is allowed before baking and then a decline in growth
in 4 to 6 h. Fermentation by the yeast begins as soon as the dough is mixed and continues
until the temperature of the oven inactivates the yeast enzymes (Frazier and Westhoff,
2005).
2.7.3 Salt
Functions of salt in bread making are (Bennion, 1967).
1. Primarily to give flavor to the bread.
2. To confer bloom or wholesome appearance on the finished loaf.
3. To tighten up and give stability to the gluten of the flour and enable a bold loaf to be
produced with firm cutting crumb.
4. To prevent yeast working too fast in process dough and to control the action of acid
producing bacteria in dough.
32
5. To help to keep the loaf moist after with drawl from the oven.
Salt is largely responsible for crust color in bread made from normal flour because of its
controlling influence on fermentation. If the speed of fermentation is retarded by the use of
increased amount of salt there will be less sugar used by the yeast to produce gas. In
consequence, there will be more sugar caramelized on the crust producing a high crust
color. If there is too little salt used, the opposite happens and there is little crust color
(Fance, 1972).
2.7.4 Water
Water is an essential part of bread formulation and helps in the following manner.
1. The most important function of water is the formation of bread gluten from flour which
makes the dough flexible.
2. Helps in controlling the viscosity or toughness of dough.
3. Helps in making the starch digestible.
4. Helps in controlling the temperature of dough and also contributes towards proper mixing
of minor ingredients in flour.
5. Helps in the fermentation process.
The water to be used in for bread formulation should be fresh, clean, soft water and free
from any microorganism and limited mineral content. Dissolved mineral and organic matter
present in the water can affect the flavor, color and physical attributes of the finished baked
goods (Arora, 1980). Dough should have a pH value of 5-6, that is acidic. If sufficient
alkaline water were mixed in dough so as to give an alkaline condition, the activities of the
yeast, diastase and lactic acid bacteria would be restrained so that the production of gas and
acidity would be slow and the time necessary for ripening the dough greatly increased.
When flour is mixed with water at dough making both the gluten and starch absorb
water within the range of dough temperature which may be stated as 21-32°C. There is no
33
doubt that proteins of the flour take up the water much more readily then the starch.
Determination of the moisture percentage in a piece of wet gluten washed out at 21°C from
an average flour show that the dry gluten holds nearly twice its own weight of water,
whereas somewhat similar experiments with starch would indicate that at the same
temperature the dry starch does not hold more than 40% of its own weight of water
(Bennion, 1967). Njintang et al. (2008) and Olaoye et al. (2006) found that the moisture
content of the composite breads increased with the increase in the non-wheat flour
substitution. And this was attributed to the greater water holding capacity of the non-wheat
flour substitution (Tekle, 2009).
The flour from strong wheat (with higher protein content) and flour from hard wheat (with
a higher damaged starch grain) require more water than is needed by flour from weak
(lower protein) or soft (less damaged starch) wheat to make a dough of standard
consistency (Kent, 1983).
2.7.5 Sugar
Although sugar is not an essential ingredient of the bread formulation, yet it is added to
improve the texture, taste and flavor of the bread. In very small and cottage scale unit it is
added as crystallized sugar while mechanized units incorporate it as corn syrups, sucrose or
invert syrup (Arora, 1980). Ordinary cane sugar is used not so much to increase gas
production as to improve the color and bloom of the loaf, for there is naturally present in a
normal flour sufficient sugar for gas production. Cane sugar can be used at the rate 1 lb per
sac to supplement any deficiency in the natural product as in those flours obtained from
some of the white wheat. With dough lying for a long period especially in overnight dough
added sugar may prove a danger, for it is readily broken down by lactic acid bacteria, thus
increasing the acidity. Too much sucrose however will slow down fermentation. If very
sweet dough is prepared adding 10% or more of sucrose at once, the growth of the yeast
and the formation of carbon dioxide may be slow (Meyer, 1987).
Glucose can also be used. This will be fermented by the yeast directly; it can used in
quantities up to 1½ lb per sac to improve the bloom and color of the bread. Invert sugar at
the rate of 3 lb per sac is a very effective bread improver, bringing about the physical
34
modification of the gluten so that well-conditioned dough is produced and bread with a
more mature moist crumb and good crust color results (Bennion, 1967 ).
2.7.6 Fat
Shortenings are used in bread for increased calorific value longer preservation period,
better finish and taste and to improve its gas retaining characteristics. Generally,
hydrogenated oils are used. Research over many years has shown that fats are better
improvers than vegetable oils. Fats have power of preventing the toughness of gluten,
according to the methods and amount used. All fats are therefore shortening agents. Fats
confer flavor according to the type used (Arora, 1980; Bennion, 1967; Fance, 1972).
2.7.7 Milk and milk products
The advantages derived from the use of milk products are as follows.
1. They confer a delicate flavor on the crumb of the loaf.

2. They improve the bloom and color of the bread.
3. They assist in the production of a thin, biscuit like crust.
4. They improve the texture and sheen of the crumb.
5. Skimmed milk powder enables the flour to take up slightly more water and the softer
dough obtained can be worked more easily.
6. They increase the mineral content of the loaf and hence its value as a food especially for
children.
When any type milk product is used other than fresh whole milk, it should always be
used in conjunction with fat generally in the proportion half the weight. Skim milk powder
(SMP) alone will always tend to produce drier eating bread due to influence of the casein.
The milk sugar is not fermentable by yeast so that milk is essentially an enriching agent and
improver. When higher proportion of milk are used, attention must be paid to baking
35
temperature because of the amount of sugar in dough which readily caramelizes and can
cause excessive crust color (Bennion, 1967). The addition of milk to the dough raises the
pH because of the presence of butter salts in the milk. Milk consequently retards amylase
activity. However, in presence of acid salts such as calcium hydrogen phosphate or the
acetic acid of vinegar this retardation may be eliminated and gas formation may even be
increased by the milk through the improved nutrition of yeast. Raw or pasteurized milk
decreases the baking qualities of flour unless the milk is first heated. It is believed that milk
contains some substance which increase the activity of proteolytic enzyme and
consequently during fermentation period faster the formation of gluten which is too sticky
(Meyer, 1987).
2.7.8 Malt products
Malt products are available to the baker in three forms malt flour, malt extract (which is
thick, viscous and amber colored syrup) and dehydrated malt extracts which in the dry
crystal form . Some patents flours are low in amylase activity and this is rectified by the
addition of malted wheat flour or malted barley flour with the diastatic value of the malt
extract and malt extract greater proportion than the dried product (Meyer, 1987). Malt flour
is manufactured by passing the malted grain through fluted rollers, similar to the break
rollers used in the milling of wheat.
It is then sieved to remove the coarse particles. Malt being very dry and brittle the outer coating
breaks up into fine particles so that the resultant flour is reddish brown in color (Fance, 1972).
2.7.9 Malt extract
The malt is disintegrated and mixed with an equal volume of water and macerated for 6
hours. Four times the amount of water is then added and the mixture is digested for 1 hour
at a room temperature not exceeding 54.44°C so that the maximum conversion of starch to
sugar is obtained. The sweet liquors are separated and transferred to vacuum pans where
concentration is carried out at such a temperature that the diastase is not destroyed when the
correct consistency is obtained the syrup is transferred to drum. Ordinary malt extract may
be converted into a dry crystalline powder by removing the remaining water in travelling
band vacuum oven (Bennion, 1967).
36
2.7.10 Custard powder
Making of custard powder requires edible starch, corn flour, food colors and flavors. The
cook combines several tablespoons of the custard powder with sugar and enough milk to
form a paste. The paste is then slowly added to hot milk and stirred until completely
dissolved. The result is a thick custard sauce, not identical to traditional egg custard, but
still good over bread, cake, pudding or other desserts. The addition of custard makes the
bread pudding luscious and creamy in texture. Old fashioned custard bread puddings are
the ultimate in comfort foods.
2.7.11 Other improvers
Soya flour, lecithin, eggs, gelatinized starch or scalded flour are generally used as
improvers (Bennion, 1967). A rapid acting reducing agent, L-cysteine and a slow acting
oxidizing agent potassium bromate or a mixture of potassium bromate and ascorbic acid are
added at the dough mixing stage using convectional slow speed mixing equipment. The
reducing agent accelerates the uncoiling and reorientation of the protein molecules and the
oxidizing agent follows up by stimulating the formation of cross links stabilize the desired
elastic three dimensional gluten network (Kent, 1983).
Rao and Rao (1993) studied on the effect of potassium bromate or ascorbic acid on rheological
characteristics and bread making quality of commercial wheat flours. Ascorbic acid brought about
greater changes in the baking qualities as compared to the potassium bromate. Soft wheat flour
responded more than medium or hard wheat flours to improvers. The effect of potassium bromate
on rheological characteristics was more pronounced, when the pH of the dough was lowered to
less than 5.0, potassium bromate and ascorbic acid brought about greater improvement in the milk
bread as compared to other varieties such as plain sugar and fruit bread (Khanal, 1997).
2.8 Bread making process
There are three stages in the manufacture of bread, mixing and development of the dough, aeration
of the dough and oven baking of the dough (Kent, 1983).
37
2.8.1 Dough mixing
Main ingredients of bread are wheat flour, water, yeast and salt. Other ingredients may be
malt flour, soya flour, yeast food, milk and milk products, fats, fruits and gluten. When
these ingredients are mixed in correct proportions, the following phenomena take place.
1. The proteins in the flour begins to hydrate i.e., to combine with some of the water to
form a cohesive material called gluten which has peculiar extensible properties, it
can be stretched like elastic and possess a certain degree of recoil or spring. The
elastic properties which are developed during mixing appear to involve sulfhydryl
groups possibly their oxidation to disulphide bonds, possibly the formation of new
bonds.
2. Evolution of the carbon dioxide gas by action of the enzymes produced by the yeast
upon the sugars. These are mixed using water at temperature that will bring the
mixture to about 27°C (80°F). The yeast is dispersed in some of the water and the
salt dissolved in another portion, yeast suspension, the salt solution and the rest of
the water are then blended with the flour. Thorough mixing and correct dough
development demand correct absorption of water to produce ideal clear dough. Such
dough will produce a loaf with qualities superior to any loaf made from dough
which is badly mixed. Dough processed correctly gives even texture and uniform,
soft and moist crumb (Bennion, 1967; Kent, 1983).
2.8.2 Dough fermentation
Enzymes for panary fermentation are diastase (α and β amylase) in flour, maltase, invertase
and the zymase complex in the yeast. Starch in the flour is broken down into maltose by
amylase enzymes. Maltose is splitted to glucose by maltase. Cane sugar added is splitted to
glucose and fructose by invertase enzyme and these products are converted into carbon
dioxide and alcohol by zymase complex. Most of alcohol thus produced is driven off during
the baking process. Secondary product e.g., acids, carbonyls and esters may affect the
gluten or import flavor to the bread (Kent, 1983). During the fermentation, conditioning of
the dough takes place when the flour proteins (gluten) mature i.e., become elastic and
springy and therefore capable of retaining a maximum amount of carbon dioxide gas
38
produced by the yeasts. The conditioning results from action on the gluten by (1)
proteolytic enzymes from the yeast, from the malt or added otherwise and (2) the reduction
in pH by acids added and formed (Frazier and Westhoff, 2005). Adequate gas should be
produced during fermentation process; otherwise the loaf will not be inflated sufficiently.
Gas production depends upon quantity of soluble sugar present in flour, its diastatic power
and granulation (Kent, 1983).
2.8.3 Knock back
As the fermentation is going on, volume of fermenting dough increases continuously. As

the dough rises, the interior contains intimate cell like structure in the form of very
network. Each cell is filled with carbon dioxide, knocking the dough removes carbon
dioxide and develops gluten, rendering it more elastic and capable of producing a better and
more even textured loaf, knock back should be carried out at the early stages of
fermentation, otherwise, it has little effect on the desired texture of finished product
(Bennion, 1967).
2.8.4 Dividing
The next step in bread making is the division of the dough into the sizes required for the
finished bread, either by hand or machine. Hand division is coupled with weighing of each
piece. Machine division is by volume and results in greater accuracy and hence uniformity
in size of product. The pieces of divided by unshaped dough are next rolled into a ball. This
has two fold objectives. Firstly, it expels the spent gas which has accumulated during the
fermentation stage and secondly it allows a regular shaped piece of dough to be presented
to the final shaper or molding machine (Flynn and James, 1981).
2.8.5 Proofing
The ball of dough is given an intermediate proofing, a resting period of about ten minutes
before final shaping to allow it to recover its extensibility and elasticity. The ball of dough
is then shaped as required. After shaping, there is final proofing period which is again a
continuation of fermentation, allowing the shaped dough piece to double its size prior to
baking. This period lasts from 45 min to 60 min (Flynn and James, 1981).
39
2.8.6 Baking of dough
When the dough is in fully expanded state (called “full proof”) baking is started. Once the
loaf is in oven, physical, chemical and biological changes become rapid (Fance, 1972). As
the temperature of loaf rises in oven, baking the yeast works faster and produces large
quantities of gases. This condition in oven is termed as oven spring. After attaining of
temperature 42.22°C, the yeast cells are inactivated and they are killed when loaf center
reaches 54.44°C. Gelatinization of starch and its degradation takes place as temperature
rises gradually to 76.67°C. Diastase enzyme becomes inactivated after the temperature
170ºF has reached. At a temperature of 50°C the process of denaturation and coagulation of
protein starts and proceed rapidly up to 80°C. Steam and alcohol escapes from the center of
the loaf, while its surface loses a large proportion of its moisture and the crust begins to
form. As baking proceeds, evaporation of water takes place and at 110-120°C, and yellow
dextrins are produced and these change into brown dextrins and caramel to form the red
brown color at 160°F. The dark brown color is produced at temperature beyond 200°C. It is
also interesting to note that yeast activity ceases after 20 min and diastatic activity after 26-
30 min according to temperature of the oven (Bennion, 1967). Humidity of the oven is also
of importance for the expansion of loaf to good shape. If the humidity is too great, the
bread has tough leathery crust and an excessive shine which is unattractive. Insufficient
humidity in oven causes rapid evaporation of moisture from skin of the loaf.
2.8.7 Bread cooling
After taking out bread loaves from oven it should be cooled rapidly so that it can be packed for
distribution. During cooling moisture moves from interior outward towards the crust and to
atmosphere, if the moisture content of the crust rises considerably during cooling, the texture of
the crust becomes leathery and tough and attractive crispness of freshly baked bread is lost.
Excessive drying during cooling results in weight loss and poor crumb characteristics. The aim of
cooling is to lower the temperature without much loss of moisture. Bread loaf can be cooled by
counter flow of air at 21.11°C and 80% relative humidity within 2-3 h. If bread is packed before
cooling, steam coming from loaf condensates on the crust surface called sweating (Fance, 1972;
Kent, 1983).
40
2.9 The technology involved in dough formation
Wheat gluten consists mainly of the storage protein of wheat endosperm, i.e., gliadin and
glutenin. Upon hydration and during processing, gliadin and glutenin interact to a unique
viscoelastic glutein network, envisaged as being necessary for holding the gases and for
producing light porous crumb textured bread. Recent work has confirmed that the elastic
properties of gluten are due to the glutenin fraction, whilst the viscous properties come
from the gliadin fraction. An appropriate balance in the amount of these two major protein
components of wheat gluten is required for achieving the desired bread quality (Khatkar
and Schofield, 1997). The glutenin polypeptides are joined head-to-tail via S-S (disulphide)
bonds in a linear chain. The glutenin polymerise into a linear chain by intermolecular S-S
bonds between the cysteine residues located in the α-helical regions near N- and C terminal
ends of high molecular glutenin subunits. The central domain is thought to be rich in
repetitive β-turns which form stable β-spiral structure. Under stress conditions, the β- spiral
structures undergo deformation and on release of stress, the β-spirals resume the
energetically more favorable original conformation. The presence of cysteine residues at
either end of glutenin molecules allows deformation/reformation to occur in the central
spiral region (Schofield and Booth, 1983; Shewry et al., 1992).
Wheat proteins favor hydrophobic interactions due to their low solubility; on the other
hand, soy proteins are more water soluble and they exhibit hydrophilic characteristics in a
soy-wheat composite dough system. An initial step towards improving the dough and
baking quality of soy-wheat composites has been reported; it involves the use of a heat
treatment that increases the size distribution of the soy protein and its hydrophobicity,
thereby increasing the contribution to the ‘‘unextractable polymeric protein’’ (UPP) of the
soy in the composite dough. A higher % UPP is reported to contribute to dough strength in
wheat dough (Maforimbo et al., 2008).
2.10 Factors affecting the bread quality
Good bread is made from good ingredient. Therefore, the selection of raw materials in
making of bread is very important to do to achieve expected quality of the final product.
Some of the factors that affect the quality of bread are as follows:
41
2.10.1 Flour
The main ingredient in making of bread is flour. The most suitable flour in making of good
bread is the flour. The most suitable flour in making of good bread is the flour that has
high protein content (> 12.5%). Eighty-five percent of proteins in the flour are glutenin and
gliadin, and the rest are globulin, albumin and protease. When flour is mixed with water, it
will make a gluten form which has a cohesive and extensive characteristic. This gluten will
have an influence in holding the forming of carbon dioxide gas in the dough during the
fermentation by yeast (Zr, 2010). Summer and M.A. (1976) concluded that the
incorporation of more than 10% sorghum flour in bread formulation darkened the internal
and external loaf color of the bread. (Munak, 1995). The corneous endosperm of sorghum
adversely affects the breads crumb and crust texture (Munak, 1995). Non wheat flour in
bread increases color darkness in baked product (Banks et al., 1997). Perten (1977)
reported that high levels of malted sorghum flour substation in wheat flour are detrimental
to bread characteristics and loaf volume. Abdelghafor et al., (2010) reported similar results
for taste of bread from composite flour of sorghum and hard white winter wheat.
2.10.2 Water
Water when mixed with flour will form gluten base. Besides that, the function of water is to
be a dissolve agent and distributes the other materials in dough to be well blended and also
controlling the structure of dough (Zr, 2010). loaf weight is directly proportional to
absorption of water as revealed by Rao and Hemamalini (1991). Incorporating high levels
of sorghum flour depresses the loaf volume (Fleming and Sosulski, 1978).
2.10.3 Leavening agent
Leaven is used in bread making to produce carbon dioxide and ethyl alcohol through sugar
fermentation. Bread leaven is a kind of yeast (Saccharomyces cerevisiae). Leaven could be
classified into two types of yeast. The first is wet yeast which contain 60-70% of water and
the second is dry yeast which contain 7-8% of water (Zr, 2010).
42
2.10.4 Salt
Salt is required in the manufacture of bread to give a taste. It helps controlling the rate of
fermentation and strengthens the gluten and improves dough extensibility and the ability of
holding the gas. Dough that does not have enough salt will be soft, the rate of fermentation
will be too fast, will produce bland bread and also will make a rough texture of bread (Zr,
2010).
2.10.5 Sugar
There are several types of sugar that can be used, which are sucrose, dextrose, fructose, and
maltose. Each has a different degree of sweetness. Sugar in bread making is used as a food
for yeast. The remaining sugar after being used by yeast is to provide sweetness and an
influence factor in the process of caramelization during roasting and also contribute in the
forming of brown color in the bread (Zr, 2010).
2.10.6 Fat
The use of fat in bread making will give an influence in gluten lubrication, increasing the
volume of the dough and in an easy way during cutting. Fat in the dough also could
increase the extensibility and elasticity of the dough. So the dough becomes more adaptive
to the machine and easy to handle. Fats also influence in good flavor and aroma and also
help to control water evaporation, so it can maintain the tenderness of bread during storage
(Zr, 2010).
2.11 Nutritional value of bread
Bread is one of the complete foods available for human consumption. Most lacking factor
in bread is fat which is generally compensated by the addition of butter, margarine. Typical
composition of bread is shown in the Table 2.3.
43
Table 2.3 Typical composition of bread
Constituents White bread Whole bread
Water (%) 40 45
Protein (%) 6.5 6.3
Fat (%) 1.0 1.2
Starch, sugar, etc (%) 51.2 44.8
Cellulose (%) 0.3 1.5
Mineral matters (%) 1.0 1.2
Source: Bennion (1967)
Normal bread contains all the amino acids but lysine is deficient in it. Enriched bread
e.g., composite bread, egg bread, milk bread, etc., supplement the deficiency (Fance, 1972).
The most important vitamins in bread are those of vitamin B 1 and B2. Vitamin C is absent
in bread. Vitamin D exists in two major forms D 2 and D3. Three main minerals in flour are
calcium, phosphorus and iron and in bread sodium is added in the form of sodium
chloride.Calcium content of whole meal bread is greater than white bread but is unavailable
to the body. All cereals are poor source of calcium so that chalk is added to all white flour
by statute (14 oz per sac), whole meal also has more iron content than wheat flour.Again,
less of it is absorbed in the body so that iron is added in white flour by statuate (1.65
mg/100 g flour).
Whole meal bread contains 287 mg of phosphorus per 100 g of meal as compared with
mg/100 g of white flour. Phosphorus in cereals antagonizes the absorption of calcium from
other sources e.g., cheese, milk and fish. Phosphorus in one pound of whole meal bread
would blanket the calcium in 9/10 pint of milk so that whole meal bread is eaten; milk
consumption must also be raised. In higher extraction flours, some of the phosphorus is
contained in phytic acid which combines with calcium and produces phytates which are not
utilized by digestive system. Bread provides about 26% of our total calcium and 30% of
44
total intake of iron. Phytic acid is hydrolyzed to phosphoric acid and inositol by the enzyme
phytase, optimum activity occurring at 55°C. Probably 60% of the phytic acid in flour is
hydrolyzed during bread making (Bennion, 1967; Fance, 1972; Kent, 1983).
2.12 Wheat flour and bread standards in Nepal
According to Nepal Rajpatra Standards (2057 B.S.), wheat flour and white bread should
possess the following criteria as shown in Table 2.4. Table 2.4 Wheat flour and bread
standards in Nepal
Parameters Wheat flour Bread
Moisture ≤ 14% (130-133ºC/2 h)
Total ash ≤ 0.70% (dry wt. basis)
Acid insoluble ash (in HCl) ≤0.1% (dry wt. basis) 0.1% a,≤ 0.2% b
Alcoholic acidity c (as H2SO4) ≤ 0.12% (dry wt. basis) ≤ eq. of 7.5 ml N
NaOH/100 g of dried
substance
Gluten ≥ 8.0% (dry wt. basis)
Guar gum ≤ 0.5%
Total soluble solids ≥ 60%
Improvers (e.g., CaPO4) ≤ 0.25%
Anti-mold agent (e.g., Ca-propionate) ≤ 0.5%
a= simple bread, b= spice/fruit bread and c= 90% alcohol

Source: Nepal Rajpatra Standards, (2057) B.S.
45
Part III
Materials and methods
3.1 Raw material
3.1.1 Wheat flour
Wheat flour in the form of maida was used for bread making. The maida was purchased
from local market of Dharan.
3.1.2 Sorghum (Junelo)
A common variety of sorghum were purchased from the local market of Kathmandu.
3.1.3 Butter
Butter (amul butter) was used as shortening agent. It was obtained from Bhatbhateni Super
Market of Dharan.
3.1.4 Baker’s Yeast
Yeast was obtained from the lab of Central Campus of Technology.
3.1.5 Sugar and salt
Sugar and salt were brought from local market of Dharan.
3.2 Apparatus required

➢ Soxhlet assembly
➢ Burette
➢ Dessicator
➢ Conical flask
➢ Heating arrangement
➢ Measuring cylinder
➢ Bunchner filter assembly
➢ Beaker
➢ Suction pump
➢ Pipette
➢ Crucible
➢ Cabinet dryer
➢ Whatman filter paper
➢ Weighing balance
➢ Muffle furnace
➢ Hot air oven
➢ Petridish
➢ Silica crucible
➢ Spectrophotometer
➢ Kjeldahl digestion and distillation
set
➢ Caliper
➢ Measuring scale
3.3 Procedure for malting
The malting procedure was adopted from Ratnavati and Chavan (2016) with slight
modification. The steeping period and drying period were increased to obtain the similar
condition that was described by Ratnavati and Chavan (2016). The modified process that
was adopted is shown in Fig. 3.1.
Sorghum grain
Cleaning
Steeping (24 h at 26ºC)
Germination
Drying/kilning (50ºC for 24 h)
47
Removal of acrospires
Milling
Malt flour
Fig. 3.1 Flowchart for malting process as (Ratnavati and Chavan, 2016).
3.3.1 Cleaning
Sorghum grain was first winnowed with woven bamboo trays (nanglo). In this step; husk,
immature grains and light particles was winnowed away and heavier particles such as
specks and stones was separated by gravity during winnowing.
3.3.2 Steeping
Cleaned seeds were transferred to the plastic containers and water was added 3 times that
of sorghum. Light materials present in the sample were skimmed off. Agitation was done
to clean the seed. The grain was steeped for 24 h at room temperature (28±3ºC) and
drained to remove the excess water. Then it was dipped in KMS solution for 10 min to
prevent the mold growth.
3.3.3 Germination
The steeped grain was first collected in a muslin cloth and swirled in order to drain excess
water. The grains were spread over another muslin cloth and left for germination.
3.3.4 Drying/ Malt kilning
Germinating sorghum were taken and were dried to stop further germination. Drying was
carried out in a cabinet drier at 50°C until the constant weight was obtained.
After drying, the rootlets were removed and the prepared malt was packed in airtight
containers.
48
3.4 Method of experiment
Design Expert v 7.1.5 software is used to create the recipe. D-optimal design is used to
formulate the recipe. The independent variable for the experiment is the concentration of
sorghum flour whereas concentration of fat, sugar, salt and yeast are kept constant.
3.4.1 Formulation of recipe
The recipe formulation for the sorghum flour incorporated bread was carried out as given
in Table 3.1.
Table 3.1 Recipe formulation for bread
A B C D E F G H
Wheat flour (parts) 100 97.48 94.95 92.45 90 85.04 82.52 80

Sorghum flour 0 2.52 5.04 7.54 10 14.95 17.48 20
(parts)
Fat (%) 4 4 4 4 4 4 4 4
Sugar (%) 8 8 8 8 8 8 8 8
Yeast (%) 2 2 2 2 2 2 2 2
Salt (%) 1 1 1 1 1 1 1 1
Water (parts) 65 65 65 65 65 65 65 65
The bread was made as per the recipe formulation done and coded name A, B, C, D, E, F,
G, and H were given to each recipe. Composite breads were prepared using the straight
dough development method as in Fig. 3.2.
49
3.5 Method of preparation of malted sorghum incorporated bread
The method of preparation of malted sorghum incorporated bread is given in Fig 3.2
Wheat flour + Malted sorghum flour
Activation of yeast with Addition of water + salt + sugar little flour and
water
Dough mixing (20 min)
Fermentation (1/2
-1 h)
Knock
-Back
Scaling and dividing by weighing
First proofing (20 min)
Moulding
Panning
Final proofing (1 h)
Baking in oven º(225

C for 30 min)
Depanning
Cooling
Slicing and packing
Fig. 3.2 Flowchart for bread making process as (Kent and Evers, 2004).
50
3.6 Analytical procedure
3.6.1 Physical analysis of raw materials and final product
3.6.1.1 1000 kernel weight
The 1000 kernel weight of raw materials and final products were determined by measuring
the weight of 1000 kernels of sorghum grains after selecting the appropriate sample size by
quartering method as stated in Buffo et al. (1998).
3.6.1.2 Bulk density
The bulk density was measured as mentioned in Clementson et al. (2010) by pouring the
grains into the funnel shaped hopper, the hopper was centered over the measuring bushel,
the hopper valve was opened quickly, and the grains were allowed to flow freely into the
measuring bushel. After the bushel was filled, the excess material was leveled off with
gentle zigzag strokes using the standard Seedburo striking stick. The filled measuring
bushel was then weighed, and the mass of grains in the bushel was determined by
subtracting the mass of the measuring bushel itself. The bulk density (ρ) of grain was then
calculated using the following expression:
Mass of grain
Bulk density =
Volume of bushel
3.6.1.3 Particle density
True density of grain was measured by turpentine displacement method as mentioned in

Simonyan et al. (2007).At first weight is measured and volume was determined by water
displacement method.
3.6.1.4 Porosity
Porisity of grain was measured as mentioned in Ndirika and Mohammed (2005).
51
Porosity = [1- Bulk density/ Particle density] × 100
3.6.1.5 Sphericity
Sphericity of grain was determined as mentioned in Simonyan et al. (2007).Each kernel

sample was measured for its length, breadth and thickness by using grain caliper and
sphericity is calculated.
Sphericity = (lbt) 1/3/ l
Where, l = length of grain
b = breadth of grain
t = thickness of grain
3.6.1.6 Volume
Volume of bread was determined by rapeseed displacement method as mentioned in white

bread.
3.6.1.7 Specific loaf volume of the bread
Specific loaf volume of bread is defined as the ratio of the volume of bread to the weight of
bread. The specific loaf volume of bread was determined as illustrated in Al-Saleh and
Brennan (2012).
Specific loaf volume =
3.6.2 Chemical analysis
3.6.2.1 Proximate analysis
3.6.2.1.1 Moisture content
The moisture content was determined by using hot air oven method. 5 g of sample was
weighted and heated in an insulated oven at 110°C to constant weight. The difference in
weight was the water that has evaporated as Ranganna (1986).
52
3.6.2.1.2 Crude fat
The fat content was determined by Soxhlet method. Solvent extraction of 10 g sample was
done by recycling hot solvent for number of times until complete extraction and fat was
recovered by evaporating away the solvent as standard method of Ranganna (1986).
3.6.2.1.3 Crude protein
The crude protein was determined by using Kjeldahl’s method. 2 g fatless sample was
digested, steam distillated after decomposing the former NaOH. Titration of entrapped
NH3 boric acid was done with standard acid as standard method of Ranganna (1986).
3.6.2.1.4 Crude fiber
Crude fiber was determined by using chemical process, the sample was treated with boiling
dilute Sulphuric acid, boiling sodium hydroxide and then with alcohol as standard method
of Ranganna (1986).
3.6.2.1.5 Total ash
Ash content was determined using muffle furnaces according to Ranganna (1986). 5 g of
weighed sample in silica crucible was charred in hot plate till no smoke raise from it and
finally, ashing was done in muffle furnace at 550°C to the constant weight. The difference
in weight was the total ash content remaining in crucible, under standardized condition
(Ranganna, 1986).
53
Part IV
Results and discussion
The malting of sorghum was done and malted sorghum incorporated bread was prepared.
Physical properties and chemical composition of wheat flour, malted sorghum flour and
bread was done.
4.1 Chemical analysis of wheat flour
The proximate composition of wheat flour was determined. The results obtained are
presented in Table 4.1
Table 4.1 Composition of wheat flour
Proximate Wheat flour

composition in % (db)
Moisture content 12.37 (0.15)

(g/100 g)
Crude protein 10.3 (0.21)
Crude fat 0.94 (0.51)
Crude fiber 0.36 (0.31)
Total ash 0.94 (1.23)
Carbohydrate 74.88 (0.45)
Gluten content 8.1 (0.41)
-
* The values are the means of triplicate samples and the values in the parenthesis are standard
deviation.
The moisture content of wheat flour was 12.37% which is common in commercial wheat
flour as previously reported by Kent and Evers (2004).The protein and fat content was found
to be 10.3% and 0.94% respectively which was similar to the findings by Kent and Evers
(2004).It was found that ash content was found to be 0.94% which is similar to the results
obtained by Adhikari et al. (2016).The carbohydrate and gluten content was found to be
74.88% and 8.1% respectively as reported by Kent and Evers (2004).
4.2 Chemical analysis of unmalted and malted sorghum flour
The proximate composition of unmalted and malted sorghum flour was determined. The results
obtained are presented in Table 4.2
Table 4.2 Composition of unmalted and malted sorghum flour
Proximate composition in % (db) Unmalted flour Malted flour
Moisture content (g/100 g) 12.2 5.5
Crude protein (%, db) 11.46a ±0.10 10.67b±0.05
Crude fat (%, db) 3.66a±0.08 3.72a±0.07
Crude fiber (%, db) 2.21a±0.03 3.20b±0.04
Total ash (%, db) 0.55a±0.07 0.57a±0.05
Carbohydrate (%, db) 80.36a±1.08 3.19b±0.87
Reducing sugar (%, db) 1.57a±0.51 75.86b±0.87
*values are the means of triplicate determinations ± S.D
*ab means with the different superscripts on the same row are significantly different
The moisture content increased initially during germination. But the moisture content of
malted flour is decreased significantly at p (≤0.05) by 54.91% which is due to enzyme
55
inactivation process during malting i.e. kilning. The hydration process during germination
activated a wide array of enzyme which hydrolyzed and solubilized food reserves. There
crude protein content of the malted flour sample decreased significantly at p (≤0.05). The
slight change in protein content may attributed to the fact that water soluble nitrogen was
lost during soaking of seeds and also, during seed germination, part of the protein was
utilized for the growth and development of the embryo. During germination, starch and
protein were degraded to soluble sugars and amino acids, respectively. Their degradations
indicated the metabolic system interference to reserve starch and protein by amylases and
proteases (Elbaloula et al., 2014). The crude fat content of the malted flour slightly
increased which may be due to its proportional increase as a result of decrease in other
food reserves like non-reducing carbohydrate.
The crude fiber content of the malted sample increased significantly p (≤0.05).This
increased could be attributed to increased bran matter and the building of dry matter during
the growth and development (germination) of plant. Narsih et al. (2012) reported the
increase in ash content of sorghum malt which is similar to the results of our study.
Germination would increase the mineral content due to an increase in fitase enzyme activity
during germination. The enzyme will hydrolyze the bond between the protein-enzyme
minerals become free, therefore increasing the availability of minerals (Narsih et al.,
2012).The carbohydrate content was also found to be decreased in malted flour this
significant decrease may be due to the activity of enzymes. The carbohydrate may have
been digested to simple sugar by amylolytic enzymes as a result there is significant increase
of reducing sugar on the malted sample at p (≤0.05).
56
4.3 Physical properties of sorghum grain and malt
The physical properties of sorghum grain and malt was determined. The results obtained are
presented in Table 4.3
Table 4.3 physical properties of sorghum grain and malt
Physical properties Sorghum grain Sorghum malt

Sphericity 0.65±0.52 0.75±0.39
1000 kernel wt. (g) 29.89±0.54 25.24±0.58
Bulk density (kg/HL) 81.30±0.59 72.33±0.53
Particle density 1.22±0.64 1.07±0.39
(g/ml)
Porosity 0.34±0.63 0.31±0.75
Ndirika and Mohammed (2005) reported the value of sphericity, 1000 kernel wt., bulk
density, particle density (specific gravity), and porosity as 0.67, 32.41 g, 69.9 kg/HL, 1.18
g/cm3 and 40.80% of sorghum grain (Farafara variety) which is similar to the mean values
of unmalted sorghum grain of our study. Similar values were obtained by Simonyan et al.
(2007) in their study.
The 1000 kernel wt., bulk density, and particle density decreased on malting. Similar
result was observed by Beta et al. (1995) during malting of different varieties of sorghum
grains. This decrease may due to hydrolysis of heavier starch molecules in lighter
disaccharides like maltose by high amylase activity. Also decrease in weight may results
due to the dry matter loss during malting and utilization of nutrients by growing shoots.
57
This decrease may also be due to respiration of growing shoots during germination Beta et
al. (1995). But Makeri et al. (2013) reported that there were not significant changes in most
of the physical properties of barley grain after malting.
4.4 Physical properties of malted sorghum flour incorporated bread
Physical parameters of bread such as loaf volume, weight and specific loaf volume were
affected by the substation increment of the level of malted sorghum flour which is
presented in the Table 4.4 The result indicated that the weight of the bread slightly
increased with increasing substitution percentage of MSF.20 parts MSF incorporated bread
revealed the maximum weight (92.15 g).Increase in loaf weight is due to increased
absorption of water as revealed by Rao and Hemamalini (1991).
Also, the results of loaf volume and specific loaf volume of bread revealed a reduction in
loaf volume from 211.70 to 184.52 cm3 and specific loaf volume from 2.91 to 2.00 cm 3/g. It
is clear that increased in MSF proportion results decrease in loaf volume and specific loaf
volume for different bread which may be due to decrease in gluten network in dough and
less ability of dough to rise, due to weaker cell structure (Maforimbo et al., 2008). The
physical parameters of bread are presented in Table 4.4
Table 4.4 physical parameters of malted sorghum flour incorporated bread
Samples Loaf volume Weight Specific loaf volume

(cm3) (g) (cm3/g)
A 211.70±0.34 72.68±0.48 2.91

B 206.62±0.18 75.45±0.67 2.73
C 204.79±0.38 78.67±0.34 2.60
D 203.13±0.45 80.35±0.18 2.52
E 198.38±0.48 83.29±0.38 2.38
F 193.68±0.86 87.23±0.76 2.22
G 188.35±0.64 89.16±0.43 2.11
58
H 184.52±0.84 92.15±0.68 2.00
4.5 Sensory properties of bread
Statistical analysis of the sensory scores was obtained from 12 semi-trained panelists using
9point hedonic rating scale (9=like extremely, 1= dislike extremely) for composite bread
formulations. Sensory analysis was performed with the aid of different panelists evaluating
color, flavor, appearance, mouth feel and overall acceptability of malted sorghum
incorporated bread against the blank.
4.5.1 Color
b b b
8 b
b
7
a a
Mean Scores a
6
1
A B C D E F G H
Sample Formulations
Fig. 4.1 Mean scores for color of bread samples of different formulations (where A is
control, B, C, D, E, F, G, and H contains 2.52%, 5.04%, 7.54%, 10%, 14.95%,17.48% and
20 % malted sorghum flour respectively). Means with different subscript are significantly
different at p< 0.05.
59
The average mean scores of colors are shown in Fig 4.4. Statistical analysis showed that
partial substitution of wheat flour with malted sorghum flour had significant effect (p< 0.05) on
the color. The mean sensory score for color of sample B was 7.50 and was the highest score
scored among the different formulations. Samples A (control), C, D, and E were not significantly
different to sample B. The lowest mean sensory score was of sample H. It can be also noticed
that samples F and G were not significantly different from sample H. The bread with the higher
amount of malted sorghum such as samples F, G, and H had low score which could be due to the
darker color of sorghum flour as compared to wheat flour.(Summer and M.A., 1976) concluded
that the incorporation of more than 10% sorghum flour in bread formulation darkened the
internal and external loaf color of the bread. The darker crust color may be because of the greater
amount of the milliard reaction between reducing sugars and proteins (Raidi and Klein, 1983).
Non wheat flour in bread formulation has been shown to increase color darkness in baked
product (Banks et al., 1997). 4.5.2 Texture
9 d d cd
c
8 b
b
7 a
Mean Scores a
6
1
A B C D E F G H
Sample Formulations
Fig. 4.2 Mean scores for texture of bread samples of different formulations (where A is
different at p<
60
0.05.
The mean sensory score for texture of bread samples of different formulations are
shown in Fig 4.6. The mean sensory score for texture of sample A (control) was found to
be 8.4 which was the highest score of all the bread formulations. Samples B and C were
not significantly different from sample A (control). Statistical analysis showed that partial
substitution of wheat flour with malted sorghum flour had significant effect (p< 0.05) on
the texture. Product G and H were not significantly different to each other and scored
lowest in texture because sorghum flour tend to give drier and gritty (sandy) texture to
sorghum and wheat composite breads (Munak, 1995).It was generally accepted that it was
the corneous endosperm of sorghum which adversely affects the breads crumb and crust
texture (Munak, 1995).It was reported that since wheat flours contain gluten protein which
by suitable development gives the bread its unique and most desired texture; the inclusion
of sorghum flour dilutes wheat gluten and consequently weakens its strength.
4.5.3 Taste
9
b b b b b
8
7
a
6 Scores
Mean a a
1
A B C D E F G H
Sample Formulations
Fig. 4.3 Mean scores for taste of bread samples of different formulations (where A is
61
different at p<
0.05.
The mean sensory score for taste of bread samples of different formulations are shown in
Fig 4.6 above. The mean sensory score for taste of sample A (control) was found to be 7.50
which was the highest score of all the bread formulations. Samples B, C, D, and E were not
significantly different from sample A (control). Statistical analysis showed that partial
substitution of wheat flour with malted sorghum flour had significant effect (p< 0.05) on
the taste. Samples F, G, and H were not significantly different and scored low in terms of
taste which are in accordance with the findings of Perten (1977) who reported that high
levels of malted sorghum flour substation in wheat flour were detrimental to bread
characteristics and loaf volume. Abdelghafor et al., (2010) reported similar results for taste
of bread from composite flour of sorghum and hard white winter wheat.
62
4.5.4 Crumb appearance
e de
9
cd c
8 c
b
b
7
Mean Scores a
6
1
A B C D E F G H
Sample Formulations
Fig. 4.4 Mean scores for crumb appearance of bread samples of different formulations
(where A is control, B, C, D, E, F, G, and H contains 2.52%, 5.04%, 7.54%, 10%,
14.95%,17.48% and 20 % malted sorghum flour respectively). Means with different
subscript are significantly different at p< 0.05.
The mean sensory score for taste of bread samples of different formulations are shown
in Fig 4.6. The mean sensory score for crumb appearance of sample A (control) was found
to be 8.50 which was the highest score of all the bread formulations. Sample B was found
similar to sample A (control). Similarly, as we can see sample C is not significantly
different from samples B, D, and F. Statistical analysis showed that partial substitution of
wheat flour with malted sorghum flour had significant effect (p< 0.05) on the crumb
appearance. Sample H has got lowest scores as compared to other samples score because
incorporating high levels of sorghum flour depresses the loaf volume, which gives poor
crumb characteristics and decreases acceptability (Fleming and Sosulski, 1978). An
63
appropriate balance in the amount of two major protein components (glutenin & gliadin) of
wheat gluten is required for achieving the desired bread quality. But malted sorghum flour
contains less gluten as compared to wheat flour and more incorporation of sorghum flour
dilutes gluten giving poor crumb characteristics. 4.5.5 Flavor
Sample Formulations
Fig. 4.5 Mean scores for flavor of bread samples of different formulations (where A is
different at p<
0.05.
Mean sensory score for flavor of bread samples of different formulations are shown in
Fig 4.6. Statistical analysis showed that partial substitution of wheat flour with malted
sorghum flour had significant effect (p< 0.05) on the flavor. The mean sensory score for
flavor of sample G and H was found to be 8.30 which was the highest score of all the bread
formulations. It means there is no any significant difference between sample G and H.
Samples A and B are similar in nature and has lower score than other samples. Sample E, F,
G, and H has got higher score as compared to others because typical malt flavor is produced
during malting of sorghum; flavoring compounds such as aldehyde and ketones may be
64
increased during malting. A similar increase in malt flavor with the supplement of sorghum
flour was noticed by (Briggs, 1998). 4.5.6 Overall acceptability
9 d
d d e
8
c
b
7
Mean Scores a a
6
0
A B C D E F G H
Sample Formulations
Fig. 4.6 Mean scores for overall acceptability of bread samples of different formulations
(where A is control, B, C, D, E, F, G, and H contains 2.52%, 5.04%, 7.54%, 10%,
14.95%,17.48% and 20 % malted sorghum flour respectively). Means with different
subscript are significantly different at p< 0.05.
Mean scores of overall acceptability of breads of different formulations are shown in Fig
4.9. Sample C scored highest in overall acceptability of the sensory conducted among the
panelists.It was found to be almost similar to the control sample A but it was found better in
maximum sensory attributes. Statistical analysis from the experimental data showed that the
partial substitution of malted sorghum flour in samples showed significant difference
(p<0.05) in overall acceptability of samples. Sample G showed lowest score in overall
acceptability which could be as a result of higher amount of malted sorghum flour
incorporated in it.. On the other hand, sample C scored highest in overall acceptability
which maybe as a result of optimum malted sorghum flour incorporated in it. The overall
65
acceptability mean showed that the product C with 5.04% of malted sorghum flour to be of
the highest score.
4.6 Composition of optimized bread
The composition of the best product and the control bread from chemical analysis was carried
out. The result of the analysis is given in the Table 4.5.
Table 4.5 Composition of product
Parameters Product A (wheat Product C (malted sorghum

bread)
bread
containing 5.04%
malted sorghum)
Moisture content 18.25 19.34
(g/100 g)
Crude protein (%, db) 12.96a ±0.54 13.43b±0.25
Crude fat (%, db) 5.13a±0.12 5.36b±0.42
Crude fiber (%, db) 5.43a±0.42 5.55b±0.45
Total ash (%, db) 1.23a±0.15 1.13b±0.13
Carbohydrate (%, db) 74.55a±0.99 73.63b±0.63
*ab means with the different superscripts on the same column are significantly different
Moisture content, protein, fat, crude fiber, ash, and carbohydrate of the product C were
found to be 19.34, 13.43, 5.36, 5.55, 1.13, and 73.63% respectively and that of product A
were found to be 18.25, 12.96, 5.13, 5.43, 1.23, and 74.55% respectively.
Moisture content increased in product C because Njintang et al. (2008) and Olaoye et al.
66
(2006) found that the moisture content of the composite breads increased with the increase in the
non-wheat flour substitution. And this was attributed to the greater water holding capacity of the
non-wheat flour substitution (Tekle, 2009).
Protein content of product A (control) is significantly different to the protein content of

sample C at p (≤0.05). The protein content is significantly increased in malted sorghum
flour incorporated bread which is due to more protein in sorghum flour than that of wheat
flour (Matz, 1991).It was found that crude fat content of wheat bread was 5.13 and that of
malted sorghum flour bread was 5.36. Statistical analysis showed that there is significant
increase in fat content at p(≤0.05).It may be probably due to the fact that in which samples
fortified with malted sorghum flour requires more fat during kneading operation in order to
get dough of smooth consistency in addition to pleasant flavor and acceptable taste for the
bread samples.
It was observrd that crude fibre content is also significantly increased in malted
sorghum flour incorporated bread which was due to higher crude fibre content in sorghum
flour than that of wheat flour.Ash content of malted sorghum flour incorporated bread is
significanly drecased than that of wheat bread this may be because wheat as a cereal crops
are known to be very rich in minerals such as Ca, P, and K as a result substution of malted
sorghum flour results in decrease in ash content.
It was found that the amount of carbohydrate decreased significantly in malted sorghum
incorporated bread. It may be due to the carbohydrates may have been digested into simple
sugars by amylolytic enzymes which are rapidly taken up by the growing embryo to serve
as its energy source during germination (Elkhier and Hamid, 2008).
67
PART V
Conclusions and recommendations
5.1 Conclusions
Despite some limitations the research was completed and on the basis of research,
following conclusions can be drawn:
1. The proximate composition of malted sorghum is significantly different from the

unmalted sorghum at 5% level of significance. The malted sorghum is superior in
crude fibre, crude fat, crude ash as compared to the unmalted sorghum.Sphericity
is also increased in malted sorghum.
2. Preparation of malted sorghum flour incorporated bread can be carried out

successfully. The statistical analysis showed that formulation with 5.04% malted
sorghum flour was significantly superior in terms of color, texture, taste and overall
acceptability among formulations.
3. Cost of bread per 100 g was found to be Rs.6.95 that excludes processing,
packaging, manpower and profit margin.
4. Crude protein, crude fat, and crude fibre of the malted sorghum flour incorporated
bread was increased due to the supplementation of malted sorghum flour and was
higher than control bread.
5.2 Recommendations
On the basis of the study done here, following recommendations can be given from the
study of malted sorghum flour incorporated bread:
1. The 5.04% malted sorghum flour incorporated bread can be used for the
commercial production of composite bread.
2. Study on the effect of various parameters on the medicinal components on the

malted sorghum flour incorporated bread can be carried out.
Part VI
Summary
Raw material (sorghum) was obtained from the local market of Kathmandu and (wheat,fat
e.t.c.) were brought from local market of Dharan. . The sorghum grains were soaked for 24
h at 28°C, at last steeped in KMS solution for 10 min to prevent mold growth and
germinated at room temperature . After germination the sorghum grains were dried at 50°C
for 24 h to obtain the desired final moisture content and was processed into fine powders.
Response Surface Methodology was used for the formulation of recipe and for this,
Design Expert v7.1.5 software was used.
Eight different bread formulations, namely A (100% wheat flour), B (2.52% malted
sorghum flour), C (5.04% malted sorghum flour), D (7.54% malteds sorghum flour), E
(10% malted sorghum flour), F (14.95% malted sorghum flour), G (17.48% malted
sorghum flour), and H (20% malted sorghum flour) were prepared by straight dough
process with the incorporation of yeast 2%, salt 1%, fat 4%, water 65%, and sugar 8% per
100 parts of flour mixture. The proximate analysis for moisture, crude protein , crude fat,
crude fiber, total ash and carbohydrate, of wheat flour was done and the values were
found to be (12.37, 10.3, 0.94, 0.36, 0.94, and 74.88%) respectively. . The proximate
analysis for moisture (db), crude protein (db) , crude fat (db), crude fiber (db), total ash
(db) ,carbohydrate (db) and reducing sugar (db) of sorghum flour and malted sorghum
flour was done and the values were found to be ( (12.2, 11.46, 3.66, 2.21, 0.55, 80.36, and
1.57%), (5.5, 10.67, 6.59, 3.20, 0.57, 3.19, and 75.34%) respectively.
All the prepared products were subjected to sensory evaluation in terms of crumb
appearance, color, taste, flavor, texture, and overall acceptance as their sensory qualities
and all the experimental bread were evaluated on a nine-point hedonic rating (1=dislike
extremely, 9=like extremely) by different semi-trained panelists. The obtained data was
analyzed statistically by Genstat Discovery Edition 3 (DE3), for Analysis of Variance
(ANOVA) at 5% level of significance. The Statistical analysis showed that 5.04% malted
sorghum flour incorporated bread was superior to all bread formulations. Mean sensory
score of formulation C regarding color, taste, texture and overall acceptance was
69
significantly better from other formulations. So product C was selected as the best product.
The proximate composition of best bread according to which the moisture content, protein
(db), fat (db), fiber (db), ash content (db), and carbohydrate are found to be 19.34, 13.43,
5.36, 5.55, 1.13 and 73.63% respectively.
It was concluded from the present study that although substitution of MSF resulted
slight decrease in loaf volume of bread. Statistical analysis for the proximate composition
of bread samples showed that substitution of malted soghum flour significantly improved
most of the nutritional attributes compared to whole wheat bread. Substitution significantly
increased the protein, fat, and crude fiber. whereas significantly decreased ash and
carbohydrate content of bread.
71
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Appendices
Appendix A
Sensory evaluation score sheet for bread

Date:
83
Hedonic rating test
Name of the panelist: ………………………………….
Name of the product: Bread
Please test the following samples of Bread and check how much you prefer for each of the
samples. Give the points for your degree of preferences for each parameter for each sample
as shown below:
Judge the above characteristics on the 1-9 scale as below:
Like extremely – 9 Like Slightly – 6 Dislike moderately – 3

Like very much – 8 Neither like nor dislike -5 Dislike very much - 2
Like moderately – 7 Dislike slightly – 4 Dislike extremely – 1
Formulations A B C D E F G H
Attributes
Crumb
Color
Taste
Texture
Flavor
Overall acceptability
Any Comments:…………………….. Signature……………………..
Appendix B
Table B.1 Paired t test for two sample of means of crude protein content of raw and malted
sorghum
Variable 1 Variable 2
Mean 11.46666667 10.67
84
Variance 0.010833333 0.0031
Observations 3 3
Pearson Correlation 0.603957174
Hypothesized Mean Difference 0
Df 2
t Stat 16.57166836
P(T<=t) one-tail 0.001810812
t Critical one-tail 2.91998558
P(T<=t) two-tail 0.003621623
t Critical two-tail 4.30265273
Table B.2 Paired t test for two sample of means of crude fat content of raw and malted
sorghum
Mean 3.666666667 3.72
Variance 0.007433333 0.0036
Observations 3 3
Pearson Correlation -0.985886958
df 2
t Stat -0.633943081
P(T<=t) one-tail 0.295476003
P(T<=t) two-tail 0.590952006
Table B.3 Paired t test for two sample means of crude fiber content of raw and malted
sorghum
Mean 2.21 3.206667
Variance 0.0013 0.001633
85
Observations 3 3
Df 2
t Stat -68.5953
P(T<=t) one-tail 0.000106
P(T<=t) two-tail 0.000212
Table B.4 Paired t test for two sample of means of ash content of raw and malted sorghum
Mean 0.556666667 0.57
Variance 0.005233333 0.0004
Observations 3 3
df 2
t Stat -0.254513905
P(T<=t) one-tail 0.411438511
P(T<=t) two-tail 0.822877023
86
Table B.5 Paired t test for two sample of means of reducing sugar content of raw and
malted sorghum
Mean 1.573333333 75.34333333
Variance 0.268133333 0.416033333
Observations 3 3
df 2
t Stat -125.0099592
P(T<=t) one-tail 3.19918E-05
P(T<=t) two-tail 6.39837E-05
Table B.6 Paired t test for two sample of means of carbohydrate content of raw and malted
sorghum
Mean 80.36333333 3.196666667
Variance 1.171033333 0.770033333
Observations 3 3
df 2
t Stat 68.25049357
P(T<=t) one-tail 0.000107305
P(T<=t) two-tail 0.000214609
87
Appendix C
Table C.1 Paired t test for two sample of means of crude protein content of control and
best product.
Mean 12.96 13.43
Variance 0.2916 0.0625
Observations 3 3
Pearson Correlation -1
df 2
t Stat -1.030460607
P(T<=t) one-tail 0.205551389
P(T<=t) two-tail 0.411102779
Table C.2 Paired t test for two sample of means of crude fat content of control and best
product.
Mean 5.13 5.366666667
Variance 0.0144 0.180833333
Observations 3 3
Df 2
t Stat -0.751880749
P(T<=t) one-tail 0.26528124
P(T<=t) two-tail 0.530562481
88
Table C.3 Paired t test for two sample of means of crude fiber content of control and best
product.
Mean 5.43 5.55
Variance 0.1764 0.2025
Observations 3 3
Pearson Correlation 1
df 2
t Stat -6.92820323
P(T<=t) one-tail 0.010102051
P(T<=t) two-tail 0.020204103
Table C.4 Paired t test for two sample of means of ash content of control and best product.
Mean 1.233333333 1.133333333
Variance 0.023333333 0.015633333
Observations 3 3
Df 2
t Stat 4.803844614
P(T<=t) one-tail 0.02035289
P(T<=t) two-tail 0.040705781
89
Table C.5 Paired t test for two sample of means of carbohydrate content of control and
best product.
Mean 74.55 73.63
Variance 0.9801 0.3969
Observations 3 3
Pearson Correlation 1
df 2
t Stat 4.426352064
P(T<=t) one-tail 0.023718664
P(T<=t) two-tail 0.047437328
90
Appendix D
ANOVA for physical analysis of samples
Table D.1 Two-way ANOVA (No blocking) For color
Source of variation d.f. s.s. m.s. v.r. F pr.
sample 7 56.2000 8.0286 18.03 <.001
panelist 9 2.5500 0.2833 0.64 0.762
Residual 63 28.0500 0.4452
Total 79 86.8000
Table D.2 Two-way ANOVA (No blocking) For c mb

ru appearance
sample 7 57.2000 8.1714 18.35 <.001
panelist 9 5.7500 0.6389 1.43 0.193
Residual 63 28.0500 0.4452
Total 79 91.0000
Table D.3 Two-way ANOVA (No blocking) For

flav or
sample 7 94.0000 13.4286 30.49 <.001
panelist 9 4.2500 0.4722 1.07 0.396
Residual 63 27.7500 0.4405
Total 79 126.0000
Table D.4 Two-way ANOVA (No blocking) For taste

sample 7 60.5875 8.6554 19.11 <.001
panelist 9 5.3625 0.5958 1.32 0.247
91
Residual 63 28.5375 0.4530
Total 79 94.4875
Table D.5 Two-way ANOVA (No blocking) For

text ure
sample 7 86.8000 12.4000 36.42 <.001
panelist 9 5.9500 0.6611 1.94 0.062
Residual 63 21.4500 0.3405
Total 79 114.2000
Table D.6 Two-way ANOVA (No blocking) For overall acceptability

sample 7 97.1500 13.8786 50.39 <.001
panelist 9 1.0500 0.1167 0.42 0.918
Residual 63 17.3500 0.2754
Total 79 115.5500
Appendix E
Two-way ANOVA (no blocking) for sensory analysis of different bread

formulations.
Table E. 1 Mean sensory scores for different attributes
92
Quality Attributes
Sample Crumb Color Flavor Texture Taste Overall

Acceptability
A 8.5e 7.4b 5.4a 8.4d 7.5b 7.5d
B 8de 7.5b 5.6a 8.3d 7.4b 7.2d
C 7.7cd 7.2b 6.2b 8cd 7.2b 8.8e
D 7.4c 7.4b 6.9c 7.7c 7.1b 7.5d
E 6.8b 7.2b 7.6d 6.9b 7.3b 6.7e
F 7.4c 5.8a 7.7d 6.5b 5.8a 6.2b
G 6.6b 5.7a 8.3e 5.9a 5.4a 5.3a
H 5.6a 5.4a 8.3e 5.5a 5.4a 5.4a
LSD 0.5963 0.5936 0.5931 0.5215 0.0.6015 0.4690
The values are the mean of 12 panelist score. The values having same superscript in
column did not vary significantly at 5% level of significance.
F-ratio ≤ 0.05 indicate significant difference at 5% level of significance.
Cost calculation of malted sorghum incorporated bread
Materials Weight in lot (g) Cost per Kg (NRs) Cost (NRs)

Wheat flour 94.95 40 3.79
93
Sorghum flour 5.04 100 0.50
Fat 4 310 1.24
Sugar 8 65 0.52
Yeast 2 440 0.88
Salt 1 20 0.02
Cost of malted sorghum 6.95
bread (NRs/100g)
Note: The cost excludes processing, packaging, manpower cost and profit margin.
Color plates
94
P.1 Germination of sorghum P.2 Steeping of sorghum
P.4 Malted sorghum incorporated bread

P.3 semi trained panelist doing sensory samples
analysis
95

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PREPARATION AND QUALITY EVALUATION OF MALTED

SORGHUM INCORPORATED BREAD

Department of Food Technology

Central Campus of Technology

Institute of Science and Technology

Tribhuvan University, Nepal

A dissertation submitted to the Department of Food Technology, Central Campus of

Department of Food Technology

Central Campus of Technology, Dharan

Institute of Science and Technology

Tribhuvan University, Nepal

Department of Food Technology

Central Campus of Technology, Dharan

This dissertation entitled Preparation and Quality Evaluation of Malted Sorghum

(Mr. Basanta Kumar Rai, Prof.)

2. External Examiner ______________________________________

4. Internal Examiner ______________________________________

I am also indebted to Prof. Basanta K. Rai (Chairperson, Department of Food

List of abbreviations .......................................................................................................... xv

1. Introduction .................................................................................................................. 1-4

1.1 General introduction ................................................................................................

1.2 Statement of the problem ........................................................................................ 2

1.3 Objectives ................................................................................................................

1.3.1 General objective ....................................................................................... 3

1.3.2 Specific objective ....................................................................................... 3

1.4 Significance of the study ......................................................................................... 3

1.6 Limitation ................................................................................................................ 4

2. Literature review ........................................................................................................ 5-45

2.1 Sorghum .................................................................................................................. 5

2.1.1 Origin and historical background ............................................................... 5

2.1.2 Production of sorghum ............................................................................... 6

2.1.4 Utilization of sorghum ............................................................................. 11

2.1.5 Physical properties ................................................................................... 14

2.1.6 Chemical composition of sorghum .......................................................... 15

2.1.7 Health benefits of sorghum ...................................................................... 17

2.2 Malting .................................................................................................................. 19

2.2.1 History of malting .................................................................................... 21

2.2.2 Change on physical structure ................................................................... 22

2.2.3 Chemical changes during malting ............................................................

2.3 Composite bread ....................................................................................................

2.3.2 Composite flour program in Nepal .......................................................... 27

2.4 History of bread making in Nepal ......................................................................... 28

2.5 Modern bread making process .............................................................................. 28

2.6 Method of dough making process ......................................................................... 29

2.6.1 Traditional straight-dough process ...........................................................

2.7 Raw materials for bread making ........................................................................... 30

2.7.1 Wheat flour ...............................................................................................

2.7.2 Yeast .........................................................................................................

2.7.3 Salt ............................................................................................................

2.7.4 Water ........................................................................................................32

2.7.6 Fat .............................................................................................................34

2.7.7 Milk and milk products ............................................................................ 34

2.7.8 Malt products ........................................................................................... 35

2.7.9 Malt extract ............................................................................................... 36

2.7.11 Other improvers ..................................................................................... 36

2.8 Bread making process ........................................................................................... 37

2.8.1 Dough mixing ...........................................................................................

2.8.2 Dough fermentation ................................................................................. 38

2.8.3 Knock back ...............................................................................................