STUDIES ON THE COMPOSITION AND SENSORY PROPERTIES OF CHIN-CHIN FROM WHEAT, AFRICAN BREADFRUIT, SOYBEAN AND SORGHUM COMPOSITE FLOUR BLENDS

1

STUDIES ON THE COMPOSITION AND SENSORY
PROPERTIES OF CHIN-CHIN FROM WHEAT, AFRICAN
BREADFRUIT, SOYBEAN AND SORGHUM
COMPOSITE FLOUR BLENDS

BY
RUTH GINIKA UGWUANYI
PG/PGD/15/78560

DEPARTMENT OF FOOD SCIENCE AND TECHNOLOGY
FACULTY OF AGRICULTURE
UNIVERSITY OF NIGERIA, NSUKKA

FEBRUARY, 2017


i

STUDIES ON THE COMPOSITION AND SENSORY PROPERTIES OF
CHIN-CHIN FROM WHEAT, AFRICAN BREADFRUIT, SOYBEAN
AND SORGHUM COMPOSITE FLOUR BLENDS

A THESIS SUBMITTED TO THE DEPARTMENT OF FOOD SCIENCE AND
TECHNOLOGY, FACULTY OF AGRICULTURE, UNIVERSITY OF NIGERIA,
NSUKKA IN PARTIAL FULFILMENT FOR THE REQUIREMENTS FOR THE
AWARD OF POSTGRADUATE DIPLOMA OF SCIENCE IN FOOD SCIENCE AND
TECHNOLOGY

BY

RUTH GINIKA UGWUANYI
PG/PGD/15/78560

SUPERVISOR: PROF. EZE J.I.,

FEBRUARY, 2017


ii

CERTIFICATION PAGE
Ruth

Ginika

Ugwuanyi

an postgraduate of the Department of

Technology, Faculty of Agriculture, University of

Food Science and

Nigeria, Nsukka has satisfactorily

completed the requirements for the award of the degree of Diploma (PGD) in Food
Science and Technology. The work embodied in this project is original and has not been
submitted in part or full for any other degree of this or other university.

By

_____________________
Prof. Eze J.I.,
Project Supervisor

____________________

___________________
Prof. Okonkwo T. M.
Head of Department

_____________________
Date

Date


iii
DEDICATION
This research work is dedicated to God and my Family, Kingsley, Chimdindu and Chibuikem.


iv

ACKNOWLEDGEMENT
To my wonderful project supervisor, Prof. Eze J.I., this research could not have been
successful without your effort to bringing it to accomplishment. Sir, your help has been
invaluable. The time you patiently spent on picking my countless calls, replying my messages
and even on sitting down to tell me where I did not get it right, made me a better student. I
say thank you so much sir.

My husband has been a great pillar. Your passion for excellence can`t be neglected. Thank
you for your love, encouragement and financial support. Your type is rare.
I won`t fail to appreciate my family members. My Kids, Chimdindu and Chibuikem
Ugwuanyi Mumy loves you. Sunday Onah you were there, thank you. To my mother and my
mother in-law, God will keep you both for me. You people were my strength. When the kids
needed attention, my presence wasn’t felt that much because you were there. Thank you so
much!
My immense gratitude goes to all my lecturers, I can`t mention names. Thank you.
To my friends, Ekene Umego, Ebere Okoye, Chigozie Okoyezu ... your support and advice
were so helpful. I am proud to have you. Thank you so much.
Finally I will not fail to acknowledge the spiritual support from my pastor Evang Ebenezer
Okechukwu, the senior pastor of city of purpose ministry international. Sir, you are a man of
excellence. Thank you for advice and prayer.


v

TABLE OF CONTENTS
Title page -

-

-

-

-

-

-

-

-

-

-

i

Certification page-

-

-

-

-

-

-

-

-

-

ii

Dedication-

-

-

-

-

-

-

-

-

-

iii

Acknowledgement-

-

-

-

-

-

-

-

-

-

iv

Table of contents--

-

-

-

-

-

-

-

-

-

v

List of tables- -

-

-

-

-

-

-

-

-

-

viii

List of figures--

-

-

-

-

-

-

-

-

-

ix

Abstract-

-

-

-

-

-

-

-

-

-

x

-

-

-

-

-

-

-

-

1

-

-

-

-

-

-

-

-

3
4

1.4 Objectives of the study - -

-

-

-

-

-

-

-

4

-

-

CHAPTER ONE: INTRODUCTION
1.1 Background-

-

1.2 Statement of Problem 1.3 Justification of Study -

CHAPTER TWO: LITERATURE REVIEW
2.1 Snack-

-

-

-

-

-

-

-

-

-

-

5

-

-

-

-

-

-

-

-

-

5

2.2.1 Food and Oil Interaction under Heat- -

-

-

-

-

-

6

2.3 Chin-chin -

-

-

--

-

-

-

-

-

-

6

2.4 Cereals - -

-

-

-

-

-

-

-

-

-

7

2.4.1 Wheat (Triticum aestivum L.) - -

-

-

-

-

-

-

7

2.4.1.1 Nutritional Composition of Wheat - -

-

-

-

-

-

8

2.5 Sorghum (Sorghum bicolor)-

-

-

-

-

-

-

-

8

2.5.1 World use of Sorghum- -

-

-

-

-

-

-

-

8

2.5.2 Nutritional composition of sorghum-

-

-

-

-

-

-

8

2.5.3 Anti-nutritional factors in sorghum-

--

-

-

-

-

-

10

2.5.4 Food uses of soybeans- -

-

-

-

-

-

-

11

2.2 Deep Frying-

-


vi

2.6 Legumes- -

-

-

-

-

-

-

-

-

-

11

2.6.1 Soybeans (Glycine max)-

-

-

-

-

-

-

-

13

2.6.2 Nutritional Composition of soybean-

-

-

-

-

-

-

14

2.6.3 Anti-nutritional factors in soybean-

-

-

-

-

-

-

16

2.6.4 Food uses of soybeans- -

-

-

-

-

-

-

17

2.7 African Breadfruit (Treculia africana)- -

-

-

-

-

-

17

2.7.1 Nutritional composition of african breadfruit- -

-

-

-

-

18

2.7.2 Uses of African breadfruit-

-

-

-

-

-

18

2.7.3 Anti-nutritional factors of African breadfruit- -

-

-

-

-

18

-

-

-

CHAPTER THREE: MATERIALS AND METHODS
3.1 Materials - -

-

-

-

-

-

-

-

-

-

19

3.1.1 Source of raw materials -

-

-

-

-

-

-

-

19

3.1.2 Sample preparation-

-

-

-

-

-

-

-

19

-

3.2

Methods of Analyses -

-

-

-

-

-

-

-

25

3.2.1

Proximate analysis - -

-

-

-

-

-

-

-

25

3.2.1.1 Determination of moisture content - -

-

-

-

-

-

25

3.2.1.2 Determination of Ash Content -

-

-

-

-

-

-

25

3.2.1.3. Crude Protein Determination -

-

-

-

-

-

-

27

3.2.1.4 Fat determination-

-

-

-

-

-

-

-

27

-

-

-

-

-

-

-

28

3.2.6 Carbohydrate determination- -

-

-

-

-

-

-

28

3.3 Sensory Evaluation-

-

-

-

-

-

-

28

-

-

-

-

-

29

-

3.2.1.5 Crude fibre determination-

-

-

3.4 Experimental Design and Statistical AnalysisCHAPTER FOUR: RESULT AND DISCUSSION
4.1 Proximate Composition of Chin-chin-

-

-

-

-

-

-

30

4.1.1 Protein- -

-

-

-

-

-

-

30

-

-

-


vii

4.1.2 Ash-

-

-

-

-

-

-

-

-

-

-

32

4.1.3 Fibre-

-

-

-

-

-

-

-

-

-

-

32

4.1.4 Fat-

-

-

-

-

-

-

-

-

-

-

33

4.1.5 Moisture-

-

-

-

-

-

-

-

-

-

33

4.1.6 Carbohydrate- -

-

-

-

-

-

-

-

-

34

4.2 Sensory Properties of the Chin-chin Samples.- -

-

-

-

-

34

4.2.1 Colour- -

-

-

-

-

-

-

-

-

-

34

4.2.2 Texture- -

-

-

-

-

-

-

-

-

-

34

4.2.3 Flavour -

-

-

-

-

-

-

-

-

-

37

4.2.4 Taste-

-

-

-

-

-

-

-

-

-

37

-

-

-

-

-

-

-

-

-

37

4.2.6 Overall acceptability- -

-

-

-

-

-

-

-

38

-

4.2.5 After taste-

CHAPTER FIVE: CONCLUSION AND RECOMMENDATIONS
5.1 Conclusion -

-

-

-

-

-

-

-

-

-

39

5.2 Recommendation -

-

-

-

-

-

-

-

-

39

REFERENCES


viii

LIST OF TABLES
Table 1: Nutrient Composition of Some Selected Legumes- -

-

-

-

12

Table 2: Proportion of composite flour with sorghum, soybean,
breadfruit and wheat flour.- -

-

-

-

23

Table 3: ingredients and their quantities for the production of chin chin-

-

-

24

Table 4: Proximate composition of chin-chin produced from wheat,
sorghum, soybean- -

-

-

31

Table 5: Sensory scores of chin chin produced from wheat, breadfruit,
soybean and sorghum flours-

-

-

35

ix

LIST OF FIGURES
Figure 1: Flow chart for sorghum flour production- -

-

-

-

-

20

Figure 2: Soybean flour production-

-

-

-

-

-

21

Figure 3: Flow chart for soybean flour production- -

-

-

-

-

22

Figure 4: Production of chin chin-

-

-

-

-

26

--

-

-

x

ABSTRACT
This work was done to produce chin-chin from composite flours of wheat, breadfruit,
soybean and sorghum. The grains were processed and used to prepare wheat: bread fruit,
wheat: soybean and wheat: sorghum (80:20, 70:30 and 60:40 respectively) composite flour
blends. Chin-chin was produced from the various ratios of composite flour blends and 100%
wheat flour chin-chin was used as the control. The chin-chin samples were evaluated for
proximate composition and sensory properties. Proximate composition result showed that
substitution of wheat flour with breadfruit, soybean and sorghum significantly (p<0.05)
affected the chin-chin samples. There was increase in the crude protein, ash and crude fiber
contents of wheat: breadfruit chin-chin samples from 15.73 to 19.34%, 0.68 to 1.27% and
0.42 to 0.91%, wheat: soybean chin-chin samples from 19.2 to 24.62%, 0.95 to 2.16% and
0.68 to 0.83% and wheat: sorghum chin-chin samples from 9.11 to 10.73%, 1.06 to 1.26%
and 3.73 to 0.92% respectively. The sensory properties of the chin-chin samples significantly
(p<0.05) decreased with increase in the level of substitution. The overall acceptability score
of the control sample was higher than the chin-chin samples from the composite flour blends.
In as much as the substituted samples had higher nutrients than the control sample, panelists
preferred the control sample which is the 100% wheat chin-chin sample.


1

CHAPTER ONE
INTRODUCTION
1.1 Background
Snack food have been part of human diet for a long time and has contributed
tremendously to economy of every nation (Lasekan and Akintola, 2002). The demand for
snacks is attributed to the rapid population and urbanization of both developed and
developing countries. In the past, toasting, flaking, frying and all sorts of local processing

methods have been used in making local snacks such as popcorn, toasted African breadfruit
(ukwa), akara buns (fried bean paste), bole (roasted plantain), potato chips, plantain chips,
owuna (fried bambara nut), African yam bean (ijiriji), coconut flake, and many others. Snacks
are enjoyed by large groups of people, both the young and the elders.
In Nigeria most snack foods are either fried or baked. Fried products are center of attraction
for many consumers due to the aroma, feel and taste they give. Snacks foods are easy to eat
product, cheap and readily available on the streets, shops, high ways (carried about by
vendors) schools, churches and during parties. These qualities make the circulation of snacks
food easy. It is generally regarded as convenience food.
The modern day snacks involves the use of frying, baking

and its customary

ingredients for the manipulation of cereal based products, after which different products of
related properties emerges Chin-chin is a fried snack popular in West African countries
especially Nigeria. It is a sweet hard donut like fried product which is sometimes a baked
dough of wheat flour, with eggs and other ingredients (Akubor, 2004). The flour is mixed to
form elastic dough b d0which is properly kneaded, rolled and cut into desired shapes. The
shaped flat dough is then deep fried in hot oil and when it is slightly gold brown, it is scooped
out to let oil drain (Mepba et al., 2007). This is usually served to visitors during parties and
ceremony.
Deep fat frying (DFF) or immersion frying is a cooking and drying process using a
hot oil medium and is widely used in food preparation (Opara et al., 2013). In this method
oil is used for immersion at higher temperature above the boiling point of water. The
temperature of the oil usually ranges from 130-200 oC (Tangduangde et al., 2003). During
frying, heat that is used to cook foods attacks the moisture and as the heat penetrates the food,
moisture evaporates from the surface of the food and it dries. Food with high moisture
content such as starch repels oil absorption. The increased temperature of the oil and the
decreased moisture content of the fried food cause many physical, nutritional and chemical
changes such as browning, which is as a result of reaction between the sugar present in food

2

and amino acid under high temperature (Millard reaction), gelatinization (swollen of starch
under high temperature) and even de-naturation of protein present in the fried product. All
these changes are dependent on the frying conditions: oil temperature, frying time, the oil
type and the nature of the food to be fried (Cheevasanthianchioporn and Tangdaungdee,
2009).
Cereals are the fruits of cultivated grasses belonging to the monocotyledononous
family Graminae (Okaka, 1997). They are high in carbohydrate, low in fat and contain fair
amount of protein. Cereal protein is known to be deficient .Their vitamins and minerals are
scattered on their hull. Some cereals such as millet, sorghum and acha are rich in β
carotenoid, niacin, selenium, magnesium and iron. The major constraint in the utilization of
cereals is the anti nutrients such as phytate present in sorghum, poly phenolic compounds,
tannin, oxalate, dhurin and many others which make some of the nutrients unavailable by
binding them. These anti-nutrients can be minimized or eliminated by different processing
methods such as malting, fermentation, soaking and de-hulling. Wheat flour has been the
basic raw material in the bakery industry.. In the past wheat has been used for snack products
such as bread, cakes, chin chin, cakes and biscuits (Opara et al, 2013). Nigerian climate is not
favorable for the production of wheat as only little quantity is being produced annually.
Between 2012 and 2013, 100,000 tones was produced (USDA, 2012) which is not enough to
meet demand. Thus, wheat importation is imminent as it is the only way to match the demand
for wheat for baking and other purposes which is not favorable for the country’s foreign
exchange. As a result, a lot of research has been ongoing on incorporation of non-wheat flour
for baking and other purposes such as in bread and snack products (Gomez et al., 1992). The
use of soybean flour as supplementation of wheat flour was studied by Olaoye et al. (2006)
while (Mepba et al., 2007) worked on the production of composite flours of wheat and
plantain, with 30% supplementation of plantain flour and (Omobuwajo, 2003) evaluated the
use of breadfruits for baking purposes.

Sorghum locally called guinea corn and “dawa” in Nigeria is a gluten free grain that
has the potential to be used as an alternative to wheat flour (Liu et al., 2011). Close to 50% of
the land is devoted to sorghum and this makes the crop to be extensively grown in the
country (Aba et al., 2004). In Northern Nigeria, sorghum is widely processed into several
food products (Opara et al., 2013). Some are used as snack, while others are used for
alcoholic and non-alcoholic beverages such burukutu and kunu. It is also used for animal
feed (Faddlah, 2010). Sorghum can grow under harsh weather conditions where other crops
do not thrive well.


3

Legumes are the edible seeds of leguminous plants belonging to the family
Leguminosae . They are known to contain doubled amount of protein compared to cereals
and this is usually added to the cereal based snacks to improve their protein content (Enwere,
1998). This is to provide the ideal dietary protein of vegetable origin for human consumption.
The common legume cultivated in Nigeria includes soybean, African yam bean, African
locust bean, bambara groundnut, cowpea groundnut, pigeon pea among others.
Soybean (Glycine max) is a rich source of protein, fat, carbohydrate, vitamins,
minerals, and water. It is regarded as poor man’s meat in the developing countries where
animal products are costly. It is used as a right substitute to mitigate the challenge of protein
energy malnutrition (Nath and Chattopadhyay, 2007).
African breadfruit (Trecullia African) belongs to the mulberry family Moraccae which
is of African origin, but now being grown in the most tropical and sub tropical countries
(Agu et al., 2007). African breadfruit is a wide jack fruit in some areas neglected and
underexploited tropical tree (Osuiji and Owei, 2010). It is a common forest tree in Nigeria
used as a low cost meat substitute to animal protein for poor families (Badifu and Akubor,
2001). The seeds can be baked, toasted, boiled or fried before consumption. They can also be
ground into flour which can be used as a substitute for wheat flour in bakery product (Ije et
al., 2010).

1.4 Statement of Problem


Lots of money is being spent on wheat importation. This is because Nigerian grown
wheat is not enough to meet demand so the baking and other allied industries depend
mainly on imported premium wheat to function effectively.



Post-harvest losses faced by developing countries to which Nigeria is not an exception
is a cause for concern. Farmers helplessly watch as their harvested crops such as
breadfruit rot away because routine methods of processing are inadequate to utilize all
the breadfruit harvested whereas this same crop can be ground into flour and utilized
for other purposes.



The sweet taste of snack foods and its convenience (readily available) make people to
reduce the intake of normal balanced diet. People rush to it and soft drink as savior to
quench their hunger. They sometimes use it for meal replacement and do not really
care if it is a balanced diet or not. Some children like biscuit, chin-chin, bread, buns,
donut etc. which are mainly prepared by cereal flour and other bakery ingredients.


4

This gives rise to protein energy malnutrition, obesity, and increase in death in most
developing and under developed countries. Therefore, there is the need to beef up the
nutrient adequacy of snack foods.
1.5 Justification of Study

Production of composite flour from nutrient rich sorghum, soybean and breadfruit will
help improve the nutrient content of snack foods.
The use of available food crops such as soybeans, sorghum and breadfruit will help to
increase versatility and minimize both importation of wheat flours and post harvest losses in
Nigeria. It will further create new business enterprise, enhance job creation, increase food
security, reduce environmental pollution and reduce unemployment.
1.4 Objectives of the study
The broad objective of this research was to prepare chin chin from wheat, breadfruit,
soybean and sorghum flour blends.
The specific objectives of this research were to:
1.
2.
3.

Prepare composite flour from wheat, sorghum, soybean and breadfruit.
Prepare chin chin from the composite flour blends.
Determine the proximate composition and sensory properties of the chin chin.

CHAPTER TWO


5

LITERATURE REVIEW
2.2 Snack
The term ‘snack’ is broad, it can not only be limited to traditional style items such as
popcorn, snacks-extruded products, potato chips, and similar products, but has a very much
wider connotation covering a large proportion of the foods that are (or have been)
customarily consumed as a component of or with main meals (Booth, 1990). Therefore, a
snack is a portion of food, often smaller than a regular meal, generally eaten between meals.

Snacks come in a variety of forms including packaged snack foods and other processed
foods, as well as items made from fresh ingredients at home (Department of Health, 2010).
Snacks are prepared from ingredients commonly available in the home. Often cold cuts, fruit,
leftovers, nuts, sandwiches, and the like are used as snacks. Snack foods are typically
designed to be portable, quick, and satisfying. Processed snack foods, as one form of
convenience food, are designed to be less perishable, more durable, and more portable than
prepared foods. They often contain substantial amounts of sweeteners, preservatives, and
appealing ingredients such as chocolate, peanuts, and specially-designed flavors (such as
flavored potato chips) (Macrae, 1993). Snack foods have become an integral part of eating
habits of the majority of the world`s population according to Thakur and Saxena (2000).
2.2 Deep Frying
One of the earliest known practices of deep frying came from the Egyptians in the 5th
millennium B.C Later developments included the Greeks deep frying food in olive oil in the
5th century B.C (Sumnu and Sahin, 2008). In the 1st century, a Roman cook book, Apicius,
appears to list the ancient Romans' first use of deep frying to prepare Pullum Frontonianum, a
chicken dish (Wei, 2013). The practice of deep frying spread to other parts of Europe and
Arabia in the following centuries: 19th, 18th and 20th century.
Modern deep frying began in the 19th century with the growing popularity of cast
iron, particularly around the American South which leads to the development of many
modern deep-fried dishes (Robert, 2015). French fries, invented in the late 18th century
became popular in the early 19th century Western Europe. Doughnuts were invented in the
mid-19th century, with foods such as onion rings deep-fried turkey and corn dogs all being
invented in the early 20th century. In recent years, the growth of fast food has expanded the
reach of deep-fried foods, especially French fries.
Deep frying food is defined as a process where food is completely submerged in hot
oil at temperatures typically between 177 and 191 °C at this temperature, the oil is ready, in


6

which the food is submerged in it. The surface of it begins to dehydrate and it undergoes
Maillard reactions which break down sugars and proteins, creating the golden brown exterior
of the food. Once the surface is dehydrated, it forms a crust which prevents further oil
absorption. The heat conducts throughout the food causing proteins to denature, starches to
undergo gelatinization, and dietary fiber to soften (Joachim and Andrew, 2015). Some foods
are coated for protection against shrinkage but most high starchy foods repel it, because they
contain high moisture (Cornelia et al., 2003).
2.2.1 Food and Oil Interaction under Heat
When moist food is dropped into oil, it behaves as if it is boiling, but those bubbles
are from hot water coming out of the food. This is because the heat of the oil is higher than
the boiling point of water present in the food. This expulsion of steam repels the oil and
keeps it from penetrating the inside of the food. It also cools the oil surrounding the food
which extends the cooking time to enable flavor develop and to allow the heat transfer to the
center of the food without case hardening. Steam keeps escaping until equilibrium is reached;
at this point the food surface dehydrates leaving a crispy crust. Once the food becomes
golden brown and less steam bubbles are seen, the food is cook at this point. During frying
it’s always necessary not to overcrowd the oil with so many foods at the same time. This is to
avoid bringing down the temperature of the oil to the point it start absorbing oil (Greene,
2013).
The oil food absorbs during deep fat frying contains large amounts of saturated and
trans-fats (Erikson, 2007), which when consumed in large quantity can lead to higher risk of
cancer including protease cancer. It also increases the cholesterol level as well as obesity,
heart attacks and diabetes (Robert 2015). Also when fat degrades during deep frying process
the nutritional value is lost. Frying with sunflower oil and olive oil has been proven healthy
(Bruso, 2015). Although excessive reuse of particular oil releases compounds to the oil which
can deposit into the body system to release carcinogens, affect the liver or even to inhibit the
absorption of vitamins.
2.3 Chin-chin
Chin-chin is referred to as snack common in the West African countries especially
Nigeria. It is made from the mixture of wheat flour with water, butter and other customary

baking items. It is usually deep fried in hot oil, after rolling and cutting of the paste thick
elastic dough. Sometimes pineapple juice is added to the flour mixture to improve the


7

vitamin content of the product. Nutmeg is also added as flavorings. The color of chin-chin
and its flavor attracts the attention of consumers, since chin-chin is a fried product, and frying
adds flavors to a product. It is taken by both adults and children. But the soft ones are usually
taken by kids especially during lunch period in school. Most children take snack in place of
food. This is as a result of the rapid love for the consumption of snack. Snack is one good
thing we can find in a street, in shopping mall, on high ways, in a school canteen, in the
church in fact everywhere. This is made easy by the packaging industry. Chin-chin is a
cereal based product which has carbohydrate as the major nutrient.
2.4 Cereals
Cereals belong to various tribes of the grass family. They are made up of important
food crops which serve both for industrial raw materials and as major staples all over the
world (Enwere, 1998). Ogbo (2007) also defines cereals as any graineous plant yielding an
edible farinaceous grain such as wheat, maize, etc. Cereals are cultivated in every part of
world. Some are common in the temperate region such as wheat, oat, rye and barley. While
some other ones are widely grown in the tropical region, such as sorghum, maize, and rice.
Cereals are rich in carbohydrate. The fat content of cereals are low and their protein content is
appreciable though it has limitation in essential amino acid lysine and sometimes tryptophan
depending on the type of cereals involved.
2.4.1 Wheat (Triticum aestivum L.)
Wheat is one of the most important cereal crop all over the world. It spread from the
Near East, where it first emerged in the nitrogen-poor soils of a semiarid Mediterranean
climate, to flourish in a wide range of environments – from the short summers of far northern
latitudes, to cool uplands, to irrigated regions of the tropics. Wheat is grown throughout the
temperate regions of the world, like Russia, France, India, The united State of America,

Australia, Pakistan, Turkey and China (Vaughan and Geissler, 2009). The colors of the grain
vary from yellow to red-brown but cultivars are usually referred to as white. Wheat flours
are said to be strong (a relatively high protein content) or weak. Hard wheat is used in bread
manufacture; soft for the production of cakes, cookies, biscuits and pastry (FAO, 1995).
Wheat flour has the ability to form elastic dough of which gluten protein present in it is
responsible. It has the ability to retain carbon dioxide produced during fermentation. It
produces high yield of food more than any other cereal crop all over the world. Because of its
use it is transported to other countries whose climatic factors are not favorable for its growth.


8

2.4.1.1 Nutritional Composition of Wheat
Wheat is considered good source of protein, mineral, B-group vitamins and dietary
fiber, i.e. an excellent health building food (Kumar et al., 2011). Wheat provides nearly
78.10% of carbohydrate, 14.70% of protein, 2.10% of fat and 2.10% of minerals with
considerable amount of vitamins. Its protein content is higher than other cereals. Though, it is
low in some essential amino acids so supplementation with legume will increase its protein
value.
2.5 Sorghum (Sorghum bicolor)
Sorghum is an ancient crop which belongs to the grass family Graminae and
subfamily panicoideae, tribe Andropongonea. The name sorghum is an Italian term “sorgo”
which evolved from the latin word syricum (granum) meaning the grain of the Syria (Wang,
2015). It is believed that sorghum may have been originated from East central Africa,
Ethiopia or Sudan because of the diversities in these areas. Sorghum is known under a variety
of names- great millet and guinea corn in West Africa, kafir corn in South Africa, dura in
Sudan, mtama in East Africa, jowar in India, kaoliang in China and milo or milo-maize in the
United states (FAO, 1995).
2.5.1 World use of Sorghum
Sorghum is a unique crop produced for both domestic and export markets for different

uses as food, mainly in Africa, feed in the United States, fodder, fiber grown globally and
fuel. In the industries, sorghum is used as raw material for the production of potable alcoholic
beverages (Rooney and Waniska 2000) and this include transport grade ethanol malt, beer,
liquids, gruels, starch adhesives, core binders for metal casting ore, refining grits and
packaging material.(Wang, 2015). Sorghum is grown in 98 countries of Africa, Asia, Oceania
and the America. The major producers of sorghum are Nigeria, India, Mexico, Sudan, china
and Argentina. Sorghum is highly valued because of its ability to grow in areas with marginal
rainfall (400-600 mm) and high temperatures. Sorghum has short growing season (Smith and
Frederiksen, 2012). It is hardy and can even grow in areas under poor soil fertility condition.

2.5.2 Nutritional composition of sorghum


9

Sorghum grain has similar nutritional value to that of the maize though its mineral
content is higher (Balota, 2012). Sorghum grain has antioxidant properties (Green, 2012). Its
protein content is higher than the ones found in other grains usually between 11.5-16.5%. It
is also rich in calories (Adegbola, 2013). Sorghum contains 326 calories most of which come
from the carbohydrate. The average starch content of sorghum is 69.5%, other carbohydrates
are in small quantities. Glucose, sucrose, D-fructose and raffinose all combine to give about
1.2% total sugars (Enwere, 1998). It contains fair amount of iron (Thompson, 2010). It
consists of amylopectin, a branched- chain polymer of glucose, and amylase, a straight chain
polymer (FAO, 1995). About 70-80% of sorghum starch is amylopectin and 20-30%
remaining is amylase. The second major component of sorghum is protein (FAO, 1995). It is
present in the endosperm, germ and bran. Its protein content is higher than those found in
other grains usually between 11.5-16.5% (Adegbola, 2013). The quality of a protein is
primarily a function of its essential amino acid composition (Doggett, 1998). The limiting
factor in the amino acid composition of sorghum is that it lacks lysine, methionine and
threonine which is a common problem associated with cerealThe crude fat content of

sorghum is 3% which is higher than that of wheat and rice but lower than that of maize. The
fatty acid composition of dewaxed sorghum oil are as follows 0.2% myristic, 8.3% palmitic
acid, 58% stearic, 0.1% hexadcanoic, 36.2% oleic and 49.4% linoleic acids (Enwere, 1998).
The germ and aleurone layers are the main contributors to the lipid fraction. The germ itself
provides about 80 percent of the total fat (FAO, 1995).
Sorghum is a rich source of B-complex vitamins. Some yellow-endosperm varieties of
sorghum contain ß-carotene which can be converted to vitamin A by the human body.
Detectable amounts of other fat-soluble vitamins, namely D, E and K, have also been found
in sorghum grain. Sorghum as it is generally consumed is not a source of vitamin C. It’s a
rich source of niacin which can provide up to 35% of niacin requirement per day (Riggio,
2015). Though the niacin content is said to exist in bound form i.e. it is biologically
unavailable (FAO, 1995). The mineral composition of sorghum is highly variable. The
mineral matter is unevenly distributed in the kernel and is more concentrated in the germ.
Dehulling improves iron availability because the hull is rich in phytate, a compound that
binds iron and certain other minerals and makes them biologically unavailable. Mbofung and
Ndjouenkeu (1990) observed that the percentage of soluble and ionizable iron was higher in
gruels prepared from mechanically dehulled sorghum than in those prepared from grain
milled traditionally using mortar and pestle. The increase in iron availability was attributed
partly to the efficient removal of the phytate-rich hull in mechanical milling and partly to the


10

greater destruction of phytate during soaking of the grain prior to dehulling (FAO, 1999). It is
very rich in selenium. It is rich in phosphorous, potassium, calcium and contains trace
amount of sodium (Thompson, 2010).
2.5.4 Anti-nutritional factors in sorghum
Phytate: Phytate is a compound that makes iron and other minerals biologically unavailable.
They are complex phosphorous compounds. In mature seeds di hydrogen phosphate is the
main phosphorous store. This phytic acid has a strong binding capacity, forming complexes

with multivalence cations and protein (FAO, 1995).
Dhurrin: The action of enzyme on dhurin releases chemicals known as hydrogen cyanide
(HCN). When hydrogen cyanide is taken in excess the central nervous system is affected and
the cytchrome oxidase in this system is inactivated which can result to death within few
seconds (Etuk et al., 2012).
Polyphenolic compounds: The role of polyphenolic compound is to protect the plant from
predatory attacks of herbivores, pathogenic fungi and parasitic weed. It offers protection
against mould growth, premature germination and attack from insects (FAO, 1999). Low
concentration in food does not have adverse effect to human beings (Axe, 2016).
Phenolic compounds: Phenolic compounds are located at the outer layers of the grain, they
are flavonoids, tannins and phenolic compounds. They inhibit the activity of microorganisms
and probably impart resistance against mould (FAO, 1995).
Flavonoids: Flavonoids in sorghum, derivatives of the monomeric polyphenol flavan-4-ol,
are called anthocyanidins. The two flavonoids identified to be abundant in sorghum grains are
luteoforol (FAO,1995).
Tannins: Tannin is low in unpigmented sorghum but usually very high in brown colored
type. It reduces feed intake in lower animal because of reduction in digestion, diminished
utilization of nutrients and its adverse effects on metabolism and toxicity. The nutritional
value of sorghum is influenced by the level of tannin present in it. Tannins are polymers
resulting from condensation of flavan-3-ols. Most brown color sorghum contains tannin.
During maturity this very brown colour develops astringency which causes resistance to the


11

bird.

Processing methods such as drying, soaking, grinding and pelleting reduce tannin

content (Etuk et al., 2012)

2.6 Legumes
The term legume originated from the Latin word legumen, meaning seed harvested in
pods. Legumes are important sources of foods in the developing countries. Soybeans,
groundnuts, dry beans, peas, breadfruit, broad beans, chickpeas and lentils are the common
legumes in most countries depending on their climatic conditions and food habits (Riahi and
Ramaswamy, 2013). Legumes are cheap sources of proteins for many low income earners in
developing countries. Legumes contain 17-27% protein, and are good sources of minerals
such as phosphorous and iron. Their high content in lysine make them good complements for
cereal protein which is low but high sulphur containing amino acids (Okaka, 1997).,
Methionine and Cystein (Enwere, 1998).
2.6.1 Soybeans (Glycine max)
Soybean is a leguminous vegetable of the pea family that grows in tropical,
subtropical, and temperate climates. Soybean was domesticated in the 11th century BC
around northeast of China. It is believed that it might have been introduced to Africa in the
19th century by Chinese traders along the east coast of Africa (IITA, 2015). The first
domestication of soybean has been traced to the eastern half of North China in the eleventh
century B.C. or perhaps a bit earlier. Soybean has been one of the five main plant foods of
China along with rice, soybeans, wheat, barley and millet. According to early authors,
soybean production was Soybean is prevalent in many parts of Africa as animal protein is too
expensive for most populations. Many leguminous crops provide some protein, but soybean
is the only available crop that provides an inexpensive and high quality source of protein
comparable to meat, poultry and eggs. A by-product from the oil production (soybean cake)
is used as a high-protein animal feed in many countries. Soybean also improves soil fertility
by adding nitrogen from the atmosphere. This is because of its ability to convert atmospheric
nitrogen to ammonia. Soybean contains nitrogen fixing bacteria Rhizobia symbiotic bacteria.
This is located within the nodule of the root system. These bacteria have the ability of fixing
nitrogen from atmospheric molecular nitrogen from atmospheric (N 2) into ammonia (NH3).
The chemical reactions are as follows: Ammonia is converted to another form ammonium
(NH4+) usable by some plants
Table 1: Nutrient Composition of Some Selected Legumes

12

Composition
Water (%)
Energy (kcal)
Protein(g)
Fat (g)
Carbohydrate (g)
Ash (g)
Calcium (g)
Iron (mg)
Thamine (mg)
Riboflavin (mg)
Nicotinic acid

Cowpea
11.5
340
22.7
1.6
6.1
3.2
110
6.2
0.59
0.22
2.3

Groundnut
7.3
543
23.4
45.3
21.6
2.4
58
2.2
1.0
0.13
16.8

Bean
12.1
334
21.5
1.2
61.4
3.8
98
3.9
0.40
0.12
1.8

(mg)
Source: Ihekoronye and Ngoddy (1985)

Soybean

10.5
400
35.1
17.7
32.0
5.0
226
8.5
0.66
0.22
2.2


13

N2 + 8H+ + 8ē

→

2NH3+ H2

then converted to ammonium
NH3 + H+

→

NH4+

This arrangement means that the root nodules are sources of nitrogen in legumes,
making them relatively rich in protein (Jim, 2012). This is a major benefit in African farming

systems, where soils have become exhausted by the need to produce more food for increasing
populations, and where fertilizers are hardly available and are expensive for farmers. More
than 216 million tons of soybeans were produced worldwide in 2007, of which 1.5 million
were in Africa.
2.6.2 Nutritional Composition of soybean
High protein content is one of the main reasons why soybean is the broadest
cultivated legume (Duranti, 2006). Soybean oil and protein content account for about 60% of
dry soybeans by weight (protein at 40% and oil at 20%) The remainder consists of 35%
carbohydrate and about 5% ash. Most soy protein are relatively heat stable storage protein.
This heat stability enables soy food products requiring high temperature cooking. Such as soy
milk and textured vegetable protein soy (flour) to be made. The principal soluble
carbohydrates of mature soybeans are the disaccharide, sucrose (range 2.5-8.2%) The
trisaccharide sucrose raffinose (0.1-1.0%) composed of one sucrose molecule connected to
one molecule of galactose and the tetra saccharide starchyose (1.4 to 4.1%) composed of one
sucrose connected to two molecules of galactose, while the oligosaccharide raffinose and
stachyose protect the viability of the soy bean seed. They are not digestible sugars. So
contribute to flatulence and abdominal discomfort in humans and other monogastric animals,
comparable to the diasaccharide tretrose. Undigested oligosaccharides are broken down in the
intestine by native microbes producing gases such as carbon dioxide, hydrogen and methane.
The insoluble carbohydrate in soybeans consists of complex polysaccharides cellulose,
hemicelluloses and pectin. The majority of soybean carbohydrate can be classified as
belonging to dietary fibre. soybean oil or the lipid portion of the seed is contains the
phytosterols: stigmasterol 17 - 21%) sitasterol (53 - 56%) and campesterol 920 - 23%)
accounting for 2.5% of the lipid fractions (Jun et al., 2005).


14

2.6.3 Anti-nutritional factors in soybean
Compounds that interfere with the intake, availability, or metabolism of nutrients in

the animal are referred to as anti-nutritional factors. Their biological effects can range from a
mild reduction in animal performance to death, even at relatively small intakes. The subject is
complicated by the fact that different species and ages react in different ways to the presence
of anti-nutritional factors (Uni.Georgia, 2016). These are the major constraints associated
with the consumption of legumes. Soybean contains the following anti –nutrients: protease
inhibitors,

trypsin

inhibitors,

chemotrypsin,

elastin,

papain,

phytohaemagluttinins,

glucosinolates, phytic acid, saponins, estrogenic factors, flatulence factor, anti-vitamin E
factor, anti- vitamin A factor, anti-vitamin D factor, anti-vitamin B 12 factor and allergens
(Lorenzo and Marco, 2008).
Protease inhibitors: Protease inhibitors can inhibit the activity of proteolytic enzymes and
can cause a decrease in digestive efficiency, inadequacy in dietary sulfur amino acids. As a
consequence of inhibition of proteolytic enzymes the animals tend to react to the presence of
protease inhibitors by secreting more digestive enzymes, which results in pancreatic
hypertrophy. In poultry and swine, trypsin inhibitors significantly reduce the digestibility and
utilization of amino acids. At least five trypsin inhibitors have been identified. However, the
principal protease inhibitors present in raw or underpriceded soybeans are the Kunitz factor
and the Bowman-Birk factor; the latter is more resistant to the action of heat, alkali and acid.

Their average levels in raw soybeans are 1.4 and 0.6%, respectively (uni.Georgia, 2016). In
animal they cause the lowering of the nitrogen retention, decreasing the performance results
and increasing the metabolic nitrogen excretion. These inhibitors interfere with the digestion
of protein resulting in decreased growth in animal. The activity of these inhibitors may be
decreased by toasting or heat processes. The right heat treatment eliminates these inhibitors.
(Winiarska, 2007).
Lectins (hemaglutinins): They are protein that bind carbohydrates. They present in raw
soybean and can decrease growth and cause mortality rate in animals. Autoclaving is the best
method of removing this substance from soybean (Fasina et al., 2003).
Phyto estrogenes: Soybean contains isoflavones. And these compounds have biochemical
activity including estrogenic, anti estrogenic and hypocholesterllemic effects. This compound
has these content daidzein, genisttein and glycitein in three isomers and three forms. These