ABSTRACT
African breadfruit (Treculia africana) seeds were processed into whole, dehulled, malted and defatted flours. Flours from African breadfruit and maize, and coconut grits were blended with the following combinations: 0:95:5 (control), 20:75:5, 25:70:5, 30:65:5, 35:60:5 and 95:0:5% for African breadfruit, maize and coconut respectively. The flour combinations were mixed with other ingredients to form dough, placed in pans, baked, cut to 5cm length and packaged. Developed snack bars from whole, dehulled, malted and defatted African breadfruit were analysed for proximate composition, anti-nutrient factors, dietary fibre content, digestible, resistant and total starch, in vitro protein and starch digestibilities and in vitro glycemic indices. A two factor factorial experiment in a completely randomized block design was used to study the effects of processing, levels of African breadfruit seed flour and the interaction of the two variables on the responses analysed. Crude protein content of snack bars ranged from 16.16 to 27.15%, crude fibre content of the snack bars ranged from 10.12 to 18.13 %, ash content was from 2.66 to 4.57%, fat content ranged from 6.03 to 8.93% and energy content was from 324.01 to 371.30 kcal/100g. Processing significantly (p<0.05) reduced the anti-nutrient contents of the African breadfruit seed flours and consequently the snack bars. Up to 51.72% reduction of tannin was obtained by dehulling. Defatting, malting and dehulling resulted in 18.75, 34.37 and 65.62% reduction respectively in oxalate content. Highest reduction was obtained by dehulling, and was 70.69% in phytate, 79.95% in saponin, and 48.17% in trypsin inhibitor activity. Dehulling reduced the fibre content, while malting and defatting processes increased the fibre content of the snack bars. High fibre content was recorded in snack bars, which ranged from 10.72 to 30.41%. Snack bar formulated with 20% African breadfruit showed the highest in vitro starch and protein digestibilities irrespective of the processing method involved. In vitro digestibilities decreased with increasing amount of African breadfruit in the blend. Processing African breadfruit significantly increased the in vitro nutrient digestibilties investigated. An increase of 3.00 to 24.10% by defatting, 5.90 to 29.09% by malting and 9.70 to 31 80% by dehulling was recorded in in vitro starch digestibility. Improvement, up to 9.97% by dehulling, 9.86% by malting and 8.64% by defatting, was recorded in in vitro protein digestibility. In vitro glycemic index of the snack bars ranged from 43.62 to 55.83%, which qualifies their classification as low or medium glycemic index (GI) foods. Malted African breadfruit based snacks recorded the highest values of essential amino acids. Sensory evaluation revealed that 20:75:5 formulation was preferred and most accepted above all other African breadfruit supplemented snack bars. Effect of processing on the sensory scores showed snack bars from dehulled African breadfruit was most preferred probably because of its high hedonic score in appearance and aroma. All snack bar formulations had good sensory acceptance.
TABLE OF CONTENTS
Title Page i
Declaration ii
Certification iii
Dedication iv
Acknowledgements v
Table of Contents vi
List of Tables xvi
List of Figures xxiv
List of Plates xxv
Abstract xxvi
CHAPTER
1: INTRODUCTION 1
1.1 Background
of the Study 1
1.2 Statement
of Problem 3
1.3 Objectives
of the study 4
1.4 Justification
of the study 4
CHAPTER
2: LITERAURE REVIEW 5
2.1 Food
Fibre 5
2.1.1 Distinction
between dietary fibre and crude fibre 5
2.1.2 Meaning
and composition of dietary fibre 6
2.1.3 Components
of dietary fibre 7
2.1.4 Sources
of dietary fibre 8
2.1.5 Classes
of dietary fibre 8
2.1.5.1 Soluble and insoluble dietary fibre 8
2.1.6 Detergent
fibre components 8
2.1.6.1 Neutral detergent fibre 9
2.1.6.2 Acid detergent lignin 9
2.1.6.3 Acid detergent fibre 9
2.1.7 Role
of dietary fibre to consumers
10
2.2 Cereal
Bars as Convenient Foods 11
2.2.1 Classes
of cereal bars 11
2.2.2 Consumption
of cereal bars 12
2.3 Functional
Food 13
2.3.1 Definition
of functional foods 13
2.3.2 Classes
of functional foods 14
2.3.3 Role
of Cereals in Functional Foods 14
2.4 Enhancing
the Quality of Food Through Processing 14
2.4.1 Drying 15
2.4.2 Malting 16
2.5 Species,
Cultivation and Distribution of African Breadfruit 18
2.5.1 Nutritional
composition of African breadfruit seeds 18
2.6 Maize
Utilization 19
2.6.1
Nutritional value of maize 19
2.7 Nutritional
Value of Coconut 20
2.7.1 Coconut
flour 21
2.7.2 Coconut
as a source of dietary fibre in foods 21
2.8 Digestibility
of Food 22
2.8.1 In vitro digestibility 23
2.8.2 Starch
digestibility 23
2.8.2.1 Classes of starch 24
2.8.2.2 Kinetics of starch digestibility 25
2.8.2.3 Effect of food processing on
starch digestibility 26
2.8.2.4 Effect of proteins on starch
digestibility 28
2.8.2.5 Effect of dietary fibre on
starch digestibility 29
2.8.2.6 Effect of anti-nutrients on
starch digestibility 29
2.8.3 Protein
digestibility 30
2.9 Slowly
digestible starch 31
CHAPTER
3: MATERIALS AND METHODS 33
3.1 Materials 33
3.2 Methods 33
3.2.1 Production
of African breadfruit seed flours 33
3.2.1.1 Production of whole African breadfruit seed flour 33
3.2.1.2 Production of dehulled African breadfruit seed flour 33
3.2.1.3 Production of malted African breadfruit seed flour 35
3.2.1.4 Production of defatted African breadfruit seed flour 35
3.2.2 Production
of maize flour 36
3.2.3 Production
of full fat coconut grits 38
3.3 Characterization
of Flours 40
3.4 Flour
Blend Formulation 40
3.5 Snack
Bar Recipe 40
3.6 Production
of Snack Bars 40
3.7 Preparation
of Samples for Analyses 42
3.8 Proximate
Analyses 42
3.8.1 Determination
of moisture content 42
3.8.2 Determination
of crude fat content 43
3.8.3 Determination
of crude protein content 43
3.8.4 Determination
of total ash 44
3.8.5 Determination
of crude fibre 44
3.8.6 Determination
of carbohydrate content (by difference) 45
3.8.7 Determination
of total energy content 45
3.9 Determination
of Anti-Nutritional Factors 45
3.9.1 Determination
of tannin content 45
3.9.2 Determination
of oxalate content 46
3.9.3 Determination
of phytate content 47
3.9.4 Determination
of saponin content 48
3.9.5 Determination
of trypsin inhibitor activity content 49
3.10 Determination
of Detergent Fibre Fractions 49
3.10.1 Determination of neutral detergent fibre (NDF) 49
3.10.2 Determination of acid detergent fibre (ADF) 50
3.10.3 Determination of acid detergent lignin (ADL) 50
3.10.4 Determination of hemicellulose content 51
3.10.5 Determination of cellulose content 51
3.11 Determination of Soluble, Insoluble and
Total Dietary Fibre of the Raw
Materials
and Snack Bars 51
3.12 Determination
of Total Starch, Resistant Starch and Digestible Starch 52
3.12.1 Total starch (TS) and resistant starch (RS) 52
3.12.2 Rapidly digestible starch (RDS) and slowly digestible starch (SDS) 53
3.13 Determination
of In Vitro Starch Digestibility 53
3.14 Determination
of In Vitro Protein Digestibility 54
3.15 In Vitro Glycemic Index Analysis 54
3.16 Determination
of Amino-Acid Profile 56
3.16.1 Determination of tryptophan 57
3.17 Microbiological
Analysis 59
3.18 Sensory
Evaluation 60
3.19 Experimental
Design 60
3.20 Analysis
of Data 61
CHAPTER
4: RESULTS AND DISCUSSIONS 62
4.1 Characterization
of Flours 62
4.1.1 Particle
size distribution of flours 62
4.1.2 Proximate
composition and energy values of whole, dehulled, malted and
defatted
African breadfruit seed flours, maize flour and coconut grits 64
4.1.3 Anti-nutrient
content of flours 69
4.1.4 Soluble
(SDF), insoluble (IDF) and total dietary fibre (TDF) of flours 73
4.2 Characterisation
of Snack Bars 75
4.2.1 Pictures
of snack bars produced with different levels of whole, dehulled,
malted and defatted
African breadfruit seed flour 75
4.3 Proximate
Composition and Energy Value of Snack Bars 80
4.3.1 Proximate
composition and energy values of snack bars produced with
different levels of whole
African breadfruit seed flour 80
4.3.2 Proximate
composition and energy value of snack bars produces with
different levels of
dehulled African breadfruit seed flour 84
4.3.3 Proximate
composition and energy value of snack bars produced with
different levels of
malted African breadfruit seed flour 90
4.3.4 Proximate composition and energy value of
snack bars produced with
different
levels of defatted African breadfruit seed flour 95
4.3.5 Effect
of premilling treatments and substitution of African breadfruit seed
flours on crude fibre
content of the snack bars 99
4.3.6 Effect
of premilling treatments and substitution of African breadfruit seed
flours on crude protein
content of the snack bars 102
4.3.7 Effect
of premilling treatments and substitution of African breadfruit seed
flours on energy value of
the snack bars 104
4.4 Anti-Nutrient
Contents of Raw Materials and Snack Bars 107
4.4.1 Effect
of premilling treatments and substitution of African breadfruit seed
flours on tannin content
of the snack bars 107
4.4.2 Effect
of premilling treatments and substitution of African breadfruit seed
flours on oxalate content
of the snack bars 110
4.4.3 Effect
of premilling treatments and substitution of African breadfruit seed
flours on phytate content
of the snack bars 112
4.4.4 Effect
of premilling treatments and substitution of African breadfruit seed
flours on saponin content
of the snack bars 115
4.4.5 Effect
of premilling treatments and substitution of African breadfruit seed
flours on trypsin inhibitor
activity (TIA) of the snack bars 117
4.5 Detergent
Dietary Fibre Fraction of the Snack Bars 119
4.5.1 Detergent
fibre fraction of snack bars produced with different levels of
whole African breadfruit
seed flour
119
4.5.2 Effect of added dehulled African breadfruit
seed flour on detergent
fibre
content of snack bars 122
4.5.3 Effect
of added malted African breadfruit seed flour on detergent
fibre content of snack
bars 124
4.5.4 Effect
of added defatted African breadfruit seed flour on detergent fibre
content of snack bars 126
4.6 Soluble,
Insoluble and Total Dietary Fibre Content of Snack Bars 128
4.6.1 Soluble
(SDF), insoluble (IDF) and total dietary fibre (TDF) content of
snack bars produced with different
levels of whole African breadfruit
seed flour 128
4.6.2 Soluble
(SDF), insoluble (IDF) and total dietary fibre (TDF) content of
snack bars produced with
different levels of dehulled African breadfruit
seed flour 130
4.6.3 Soluble
(SDF), insoluble (IDF) and total dietary fibre (TDF) content of
snack bars produced with
different levels of malted African breadfruit
seed flour 132
4.6.4 Soluble
(SDF), insoluble (IDF) and total dietary fibre (TDF) content of
snack bars produced with
different levels of defatted African breadfruit
seed flour 134
4.6.5 Effect
of premilling treatments and substitution of African breadfruit seed
flours on total dietary
fibre (TDF) content of snack bars 136
4.7 Starch
Fractions of Snack Bars Produced with Different Levels of African
Breadfruit Seed Flour 138
4.7.1 Starch
fractions of snack bars produced with different levels of whole
African breadfruit seed
flour 138
4.7.2 Starch
fractions of snack bars produced with different levels of dehulled
African breadfruit seed
flour 140
4.7.3 Starch
fractions of snack bars produced with different levels of malted
African breadfruit seed
flour 142
4.7.4 Starch
fractions of snack bars produced with different levels of defatted
African breadfruit seed
flour 144
4.7.5 Effect
of premilling treatments and substitution of African breadfruit seed
flours on slowly
digestible starch (SDS) content of snack bars 146
4.7.6 Effect
of premilling treatments and substitution of African breadfruit seed
flours on total starch
(TS) content of snack bars 148
4.8 Effect
of Premilling Treatments and Levels of Substitution of African
Breadfruit Seed Flours on
In Vitro Starch Digestibility of
Snack Bars 150
4.9 Effect of Premilling Treatments and
Levels of Substitution of African
Breadfruit
Seed Flours on In Vitro Protein
Digestibility (IVPD) of
Snack
Bars 154
4.10 Effect of Premilling Treatments and Levels
of Substitution of African
Breadfruit
Seed Flours on In Vitro Glycemic
Index (IVGI) of the Snack
Bars 157
4.11 Amino-Acid
Profile of Snack Bars 160
4.11.1 Amino-acid
profile of snack bars produced with different levels of whole
African breadfruit seed
flour 160
4.11.2 Amino-acid
profile of snack bars produced with different levels of
dehulled African
breadfruit seed flour 162
4.11.3 Amino-acid
profile of snack bars produced with different levels of malted
African breadfruit seed
flour 165
4.11.4 Amino-acid
profile of snack bars produced with different levels of
defatted African
breadfruit seed flour 168
4.11.5 Effect of
premilling treatments and substituted African breadfruit seed
flours on total essential
amino-acid (TEAA) content of snack bars 170
4.11.6 Effect of
premilling treatments and substituted African breadfruit seed
flours on total
amino-acid (TAA) content of snack bars 173
4.12 Microbial
Quality of Snack Bars 175
4.12.1 Effect of
premilling treatments and substituted African breadfruit seed
flours on total viable
count (TVC) of the snack bars 175
4.12.2 Effect of
premilling treatments and substituted African breadfruit seed
flours on total mould
count (TMC) of the snack bars 177
4.13 Sensory
Properties of Snack Bars 180
4.13.1 Sensory
properties of snack bars produced with different levels of
substituted whole African
breadfruit seed flour 180
4.13.2 Sensory
properties of snack bars produced with different levels of
substituted dehulled
African breadfruit seed flour 183
4.13.3 Sensory
properties of snack bars produced with different levels of
substituted malted
African breadfruit seed flour 186
4.13.4 Sensory
properties of snack bars produced with different levels of
substituted defatted
African breadfruit seed flour 188
4.13.5 Effect of processing and levels of African
breadfruit seed flour on the
overall acceptability of
snack bars 191
CHAPTER 5: CONCLUSION AND
RECOMMENDATIONS
5.1 Conclusion 193
5.2 Recommendations 194
References 196
Appendices 221
LIST OF TABLES
4.1 Particle
size distributions of whole, dehulled, malted and defatted
African
breadfruit seed flours, maize flour and coconut grit 63
4.2 Proximate
composition and energy values of whole, dehulled, malted,
Defatted
African breadfruit seed flours, maize flour and coconut grit 68
4.3 Anti-nutrient
content of the samples 72
4.4 Soluble,
insoluble and total dietary fibre content of the samples 74
4.5 Proximate
composition and energy values of snack bars produced with
Different
levels of whole African breadfruit seed flour 82
4.6 Proximate
composition and energy values of snack bars produced with
Different
levels of dehulled African breadfruit seed flour 87
4.7 Proximate
composition and energy values of snack bars produced with
Different
levels of malted African breadfruit seed flour 93
4.8 Proximate
composition and energy values of snack bars produced with
Different
levels of defatted African breadfruit seed flour 96
4.9 Effect
of processing methods and levels of inclusion of African breadfruit
Seed
flour on crude fibre content of snack bars 101
4.10 Effect of processing methods and
composition (levels) of inclusion of
African breadfruit seed
flour on crude protein content of snack bars 103
4.11 Effect
of premilling treatments and substituted levels of African
Breadfruit
seed flours on the energy content of snack bars 106
4.12 Effect
of premilling treatments and substituted levels of African
Breadfruit
seed flours on the tannin content of snack bars 109
4.13 Effect
of premilling treatments and substituted levels of African breadfruit
seed flours on oxalate
content of snack bars 111
4.14 Effect
of premilling treatments and substituted levels of African breadfruit
seed flours on phytate
content of snack bars 114
4.15 Effect
of premilling treatments and substituted levels of African breadfruit
seed flour on saponin
content of snack bars 116
4.16 Effect of premilling treatments and
substituted levels of African
breadfruit
seed flours on trypsin inhibitor activity of snack bars 118
4.17 Detergent
fibre fractions of snack bars produced with different levels
of
whole African breadfruit seed flour 121
4.18 Effect of added dehulled African
breadfruit seed flour on detergent
Fibre fractions of snack
bars 123
4.19 Effect of added malted African breadfruit
seed flour on detergent
Fibre fractions of snack
bars 125
4.20 Effect of added defatted African
breadfruit seed flour on detergent
Fibre fractions of snack
bars 127
4.21 Soluble,
insoluble and total dietary fibre content of snack bars
produced
with different levels of whole African breadfruit seed flour 129
4.22 Soluble,
insoluble and total dietary fibre content of snack bars
produced with different
levels of dehulled African breadfruit
seed
flour 131
4.23 Soluble,
insoluble and total dietary fibre content of snack bars
produced
with different levels of malted African breadfruit seed flour 133
4.24 Soluble,
insoluble and total dietary fibre content of snack bars
produced
with different levels of defatted African breadfruit seed flour 135
4.25 Effect
of premilling treatments and substituted levels of African breadfruit
seed
flours on total dietary fibre (TDF)
content of snack bars 137
4.26 Starch
fractions of snack bars produced with different levels of
whole African breadfruit
seed flour 139
4.27 Starch
fractions of snack bars produced with different levels of
dehulled
African breadfruit seed flour 141
4.28 Starch
fractions of snack bars produced with different levels of
malted
African Breadfruit Seed Flour 143
4.29 Starch
fractions of snack bars produced with different levels of
defatted
African breadfruit seed flour 145
4.30 Effect
of premilling treatments and substituted levels of African breadfruit
seed
flours on slowly digestible starch (SDS) content of snack bars 147
4.31 Effect
of premilling treatments and substituted levels of African breadfruit
seed
flours on the total starch (TS) content of snack bars 149
4.32 Effect of premilling treatments and
substituted levels of African
breadfruit
seed flours on percentage in vitro starch digestibility (IVSD)
of
snack bars 151
4.33 Effect of premilling treatments and
substituted levels of African breadfruit
seed
flours on percentage in vitro protein digestibility (IVSD) of
snack
bars 155
4.34 Effect of premilling treatments and
substituted levels of African breadfruit
seed
flour on in vitro glycemic index
(IVGI) of snack bars 158
4.35 Amino-acid
profile of snack bars produced with different levels of added
whole African breadfruit
seed flour 161
4.36 Amino-acid
profile of snack bars produced with different levels of
dehulled African
breadfruit seed flour 164
4.37 Amino-acid
profile of snack bars produced with different levels of
malted African breadfruit
seed flour 167
4.38 Amino-acid
profile of snack bars produced with different levels of
defatted African
breadfruit seed flour 169
4.39 Effect of premilling treatments and
substituted levels of African breadfruit
seed
flour on total essential amino-acid (TEAA) content of snack bars 172
4.40 Effect of premilling treatments and
substituted levels of African breadfruit
seed
flour on total amino-acid (TAA) content of snack bars 174
4.41 Effect of premilling treatments and
substituted levels of African breadfruit
seed
flour on total viable count (TVC) of snack bars 176
4.42 Effect
of premilling treatments and substituted levels of African breadfruit
seed flour on total mould count (TMC) of snack
bars 179
4.43 Sensory
properties of snack bars produced with different levels of
whole African breadfruit
seed flour 182
4.44 Sensory
properties of snack bars produced with different levels of
dehulled
African breadfruit seed flour 185
4.45 Sensory
properties of snack bars produced with different levels of
malted
African breadfruit seed flour 187
4.46 Sensory
properties of snack bars produced with different levels of
defatted
African breadfruit seed flour 190
4.47 Effect
of processing methods and levels of African breadfruit seed flour
on
overall acceptability (preference) of snack bars 192
LIST OF FIGURES
3.1 Flow
diagram for the processing of African breadfruit seeds to flour 34
3.2 Flow
diagram for the production of maize flour 37
3.3 Flow
diagram for the production of full fat coconut grits 39
3.4 Flow
diagram for the production of ABS-based snack bars. 41
LIST OF PLATES
4.1 Photographs of snack bars produced with
different Levels of
whole
African breadfruit seed flour 76
4.2 Photographs
of snack bars produced with different levels of
dehulled
African breadfruit seed flour 77
4.3 Photographs of snack bars produced with
different levels of
malted
African breadfruit seed flour 78
4.4 Photographs
of snack bars produced with different levels of
defatted
African breadfruit seed flour 79
CHAPTER 1
INTRODUCTION
1.1
BACKGROUND OF THE STUDY
Snack foods have become significant part of human diets due to
their availability, affordability and convenience, thereby attracting the
attention of consumers (Patil et al.,
2016; Nørgaard et al., 2014; Nor et al., 2013; Brennan et al., 2013). Mostly available in the
markets are snacks made with refined flours from cereals, and are usually rich fats,
salts and digestible carbohydrates (Struck et
al., 2014; Brennan et al., 2013).
The small nature of snacks makes them handy, easy to manage and distribute. In
developed countries, snacks are eaten in between meals to check hunger, provide
energy and tasty appeal, but in the developing countries, they are eaten as
main meal because of their readily availability and affordability (James and
Nwabueze, 2013). With the recent increase reported about the consumption of
snack foods, there has also been a corresponding increase in obesity and thus
an unhealthy population (Oliveira et al.,
2015; Struck et al., 2014; Brennan et al., 2013; Woolnough et al., 2008). Consequently, growing
interests has been observed in the recent time by the researchers on
health-promoting snack foods. The role of diets in disease conditions have been
extensively studied (Nagai et al., 2006).
Snack bars are commonly referred to
as cereal bars (Khouryieha and Aramouni, 2013). Cereal bars are standard, well-accepted
and convenient foods ideal to deliver fruit-derived phenolic antioxidants and
fibre (Foschia et al., 2010; Agbaje et al., 2014). They are often made of a
base of processed cereal grains and may contain different ingredients such as
nuts, seeds, fruits, raisins, and chocolate (Khouryieha and Aramouni, 2013). Among
fast foods, snack bars are known for their convenience and balanced nutritient
composition (Silva et al., 2013). Cereal
bars are generally made with a mixture of cereals and dried fruit, compressed
and shaped. Glucose or sugar syrup is usually the aggregator element for other
ingredients in the bars, providing quick absorption of energy (Silva et al., 2013). Cereal bars consumption,
according to Dutcosky et al. (2006), increased due to change of people’s
lifestyles and the desire for snack foods, fast and ready-to-eat meals and convenience.
High-fibre cereals and snacks has gained
more interest in the food industry. The dietary benefits of this type of food
are outstanding and well documented. According to recent researches, a high
fibre diet benefits the heart, prevents heart attack, lowers the risk of blocked
arteries and strokes, lowers sugar and insulin levels in the blood, and blood cholesterol.
In addition to reducing the risk of certain chronic diseases, high fibre diets
fill the stomach and thereby reduce the appetite. Thus, high fibre diets
protect against obesity (Schill and Munz, 2013). Therefore, the consumption of
dietary fibre plays is important in preventing some diseases, including colon
cancer, coronary heart disease, obesity, diabetes, and gastrointestinal
disorders. Insoluble fibre, which is often found in cereals, is mainly related
to intestinal regulations, whereas soluble fibre, mainly found in fruits and
vegetables, is involved in lowering blood cholesterol and glucose adsorption
(Leoro et al., 2010).
Maize (Zea mays L.) grains are
popular cereals, readily available and cheap in Nigeria. A grain of maize is
said to contain about 1.5 % minerals, 3 % crude fibre, 4 % crude fat, 11 %
protein, 65 % starch and some other forms of carbohydrate (Sivasankar, 2005;
Ihekoronye and Ngoddy, 1985).
Treculia
africana (African breadfruit) is a tropical
ever-green leguminous tree that has immense potentials as a source of nutrients
to man and other domestic animals. African breadfruit seeds are rich in
protein, minerals, and fibre, and is readily available in Nigeria. The seeds
are obtained from fruit head, boiled or roasted, dehulled and eaten with fresh
milky corn, coconut, palm kernel or eaten alone as snacks. In the rural areas,
they are sometimes made to porridage and used for weaning babies (Runsewe et al., 2001; Nwabueze et al., 2008; Nwabueze and Iwe, 2010).
Coconut is known as a very important
versatile economic crop. It is rich in minerals, vitamins and dietary fibre. Coconut
is considered as a "functional food" due to its ability to provide numerous
benefits to human health. Coconut flour has no gluten, contains low digestible
carbohydrates, and are cheaper than flours obtained from most other nuts. Coconut
flours are also contain important nutrients and dietary fibres that promote health,
and tastes great. Coconut dietary fibre is of particular importance has been
reported by researchers to produce butyric acid in the stomach, which helps to
inhibit formation of tumors. Coconut flour substituted snacks have low glycemic
index, and are recommended for management and control of diabetes mellitus and
in the maintenance of weight (Yalegama and Chavan, 2004). It can reduce serum
total cholesterol and triglycerides in moderately raised serum cholesterol
levels of human (Trinidad et al.,
2001). Fibre readily absorbs fluids. It
also appears to absorb harmful carcinogens and other toxic substances
(Ramaswamy, 2013).
1.2 STATEMENT OF THE PROBLEM
In
today’s world, the busy lifestyle and desire for convenience has caused many to
depend on convenient foods such as snacks, breakfast cereal, ready-to-eat foods
which can be eaten directly or reconstituted with warm or cold milk or water.
Snacks available in the market today are high in calorie and fat and low in
proteins, vitamins and micronutrients (Ranhotra and Vetter, 1991). The
awareness of the importance of food fibres has led to the demand and subsequent
development of a large market for fibre-rich products and ingredients
(Rodriguez et al., 2006). The raw
materials used for this research could be possible sources of these nutrients
which are the current snacks lack. African breadfruit is readily available in
Nigeria and there is no known snack bars with these nutritional balance
anticipated from this source. There is therefore need to develop and produce
snack bars that make a complete or near complete nutritious and healthy snacks.
1.3 OBJECTIVES OF THE STUDY
The
main objective of this study was to evaluate the quality characteristics of
high fibre and nutrient snack bars from blends of African breadfruit seed flour,
maize flour and coconut grits.
Specific
objectives include:
i.
To produce maize flour,
coconut grits and whole, dehulled, malted whole, and defatted whole African
breadfruit seed flours.
ii.
To produce snack bars
from blends of maize flour, coconut grits and whole, dehulled, malted and
defatted whole African breadfruit seed flours.
iii.
To evaluation nutrient
and phytochemical composition of the snack bars.
iv.
To determine the crude
fibre content and glycemic index of the snack bars.
v.
To determine the starch
fractions and starch digestibility of the snack bars.
vi.
To determine the protein
digestibility and amino-acid profile of the snack bars.
vii.
To evaluate the microbial
and sensory qualities of the snack bars.
1.4 JUSTIFICATION OF THE STUDY
The
study is necessary in the scaling up operations in processing and utilization
of local farm produce such as African breadfruit seeds, maize and coconut. This
will also create an alternative to the conventional wheat-corn snacks, such as
biscuits, cookies or short cakes, available in the market today. The high fibre
snack bars that are produced will provide cheap and convenient high fibre nutrition
to the ever busy public, and will also help combat/prevent various diseases
associated with lack or insufficient fibre in human diets.
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