EVALUATION AND OPTIMIZATION OF PHYSICOCHEMICAL PROPERTIES OF WHEAT FLOUR AND CHEMICALLY MODIFIED STARCHES FROM AFRICAN YAM BEANS AND CASSAVA

  • 0 Review(s)

Product Category: Projects

Product Code: 00007222

No of Pages: 120

No of Chapters: 1-5

File Format: Microsoft Word

Price :

₦5000

  • $

ABSTRACT

 

 

Composite breads were made by supplementing wheat flour (WF) with chemically modified African yam bean starch (AYBS) and Cassava starch (CS) after the starch were produced from the cleaned seeds and roots using hammer milling system. The blends (WF/AYBS/CS 80/10/10, 80.83/10.83/8.33, 85/10/5, 82.5/10/7.5, 82.5/12.5/5, 80/13.5/6.5, 80.83/13.33/5.83, 82.50/12.5/5, 81.67/11.67/6.67, 80/12.5/7.5, 81/13.5/5.5, 83.33/10.83/5.83, 80/15/5, 84.5/10/5.5) was obtained from the D-Optimal Mixture Design of Response Surface Methodology. The Functional properties of the flour/ starch blends, Physical and Sensory evaluation of the bread was determined and subjected to Statistical Analysis of Variance (ANOVA) using models comprising the Mean, Linear mixtures, Quadratic, Special cubic and Cubic and the general acceptability determined using spider plot design of Microsoft Excel System. The models and the model terms (interactions) were judged for significance at 95% confidence intervals (p<0.05). The flour/ samples had functional properties ranging from 5.66 to 7.44 pH, 6 to 8.85%w/n Least gelation concentration, 60 to 72 0C Gelation temperature, 3.86 to 4.84 % Moisture content, 0.43 to 0.52 g/cm3 Bulk density, 61 to 74.42 ml/g Water absorption capacity, 66 to 77.5 ml/g Oil absorption capacity, 2 to 5.75 % Swelling power, 1.15 to 8.1 % Swelling volume, 28.51 to 62.5 % Solubility and 15.55 to 26.25 cp Viscosity. The physical properties of the bread samples range from 0.7 to 3.2 cm Oven spring, 3.5 to 6.4 cm Height, 266.7 to 442.05 g Weight, 254.71 to 764.14 cm3 Loaf volume, 0.74 to 2.34 cm3/g Specific volume and 0.43 to 1.36 g/cm3 Bulk density. The sensory evaluation results showed that all the bread samples had high rating for all the parameters evaluated except 85/10/5% of AYBS and CS supplementation. The 84.5/10/5.5% and 80/12.50/7.5% of AYBS and CS supplementation compared better than other substitution levels which were generally acceptable as they were neither liked nor disliked by the judges. The result for the optimization of all the attributes evaluated for adequate models and model terms suggested that the blend 82.00/10.88/7.13 of AYBS and CS supplementation will satisfy all the desirable goals for optimization with the desirability value of 0.68. 






TABLE OF CONTENTS

 

Title page                                                                                                                                i

Declaration                                                                                                                              ii

Certification                                                                                                                            iii

Dedication                                                                                                                              iv

Acknowledgments                                                                                                                 v

Table of contents                                                                                                                   vi

List of tables                                                                                                                          ix

List of figures                                                                                                                        x

List of plates                                                                                                                          xii

Abstract                                                                                                                                  xiii

CHAPTER 1: INTRODUCTION

1.1       Background of the Study                                                                                           1

1.2       Statement of The Problem                                                                                          3

1.3       Justification                                                                                                                 4

1.4       Objectives                                                                                                                   5

CHAPTER 2: LITERATURE REVIEW

2.1       Wheat (Triticum aestivum)                                                                                          6

2.1.1    Utilization and nutritional quality of wheat                                                               6

2.2       The African yam bean                                                                                                 7

2.2.1    Nutritional value of African yam bean                                                                       8

2.2.2    Economic importance of African yam bean                                                               10

2.2.3    Factors militating the utilization of African yam bean                                               10

2.2.4    Detoxification of African yam bean                                                                           12

2.2.5    African yam bean products and utilization                                                                 13

2.3       Cassava (Manihot esculenta Muell)                                                                            15

2.3.1    Description of cassava                                                                                                16

2.3.2    Origin of cassava                                                                                                        16

2.3.3    Economic importance                                                                                                 18

2.3.4    Nutritional profile                                                                                                       19

2.3.5    Uses of cassava                                                                                                           20

2.4       Starch modification                                                                                                    21

2.4.1    Compositions of natural starch                                                                                   21

2.4.2    Reactions of natural starch under basic conditions                                                    23

2.4.3    Esterification of starch                                                                                                26

2.5       Composite flour                                                                                                          30

2.5.1    Baking                                                                                                                         31

2.6       Optimization                                                                                                               32

2.6.1    Statistical optimization; response surface methodology                                             35

2.6.2    Response surface functions                                                                                        37

CHAPTER 3: MATERIALS AND METHODS

3.1       Materials/ sources of materials                                                                                    38

3.2       Sample preparation                                                                                                     39

3.2.1    Preparation of modified starches                                                                                41

3.2.2    Production of wheat flour                                                                                          42

3.2.3    Experimental design                                                                                                   43

3.2.4    Determinant of adequacy (significance) of models                                                    44

3.2.5    Optimization process                                                                                                  45

3.2.6    Formulation                                                                                                                 46

3.3       Functional properties of the starch – flour samples                                                    46

3.3.1    Determination of pH                                                                                                   47

3.3.2    Determination of ash content                                                                                     47

3.3.3    Least gelation concentration                                                                                       47

3.3.4    Determination of moisture content                                                                             48

3.3.5    Bulk density (BD)                                                                                                      48

3.3.6    Water absorption capacity (WAC)                                                                             48

3.3.7    Oil absorption capacity (OAC)                                                                                   49

3.3.8    Determination of swelling volume, swelling power and solubility                             49

3.3.9    Determination of viscosity                                                                                          50

3.4       Physical characteristics of bread                                                                                 50

3.4.1    Height determination                                                                                                  50

3.4.2    Oven spring                                                                                                                 50

3.4.3    Loaf weight                                                                                                                50

3.4.4    Loaf volume                                                                                                                50

3.4.5    The specific volume                                                                                                    51

3.4.6    The bulk density                                                                                                         52

3.5       Sensory evaluation                                                                                                      52

3.6       Statistical analysis                                                                                                       52

CHAPTER 4: RESULTS AND DISCUSSIONS

4.1       Functional properties of the flour – starch samples                                                    53

4.1.1    pH of the starch samples                                                                                             53

4.1.2    Least gelation concentration (LGC)                                                                           57

4.1.3    Gelation temperature (GT)                                                                                          59

4.1.4    Moisture composition                                                                                                 62

4.1.5    Bulk density                                                                                                                65

4.1.6    Water absorption capacity (WAC)                                                                             68

4.1.7    Oil absorption capacity (OAC)                                                                                   70

4.1.8    Swelling power (SP), swelling volume (SV) and solubility (S)                                  73

4.1.9    Viscosity                                                                                                                     78

4.2       Physical characteristics of the bread samples produced from the flour –

            starch blends                                                                                                               82

4.2.1    Bread height                                                                                                               82

4.2.2    Oven spring                                                                                                                 85

4.2.3    Loaf weight                                                                                                                86

4.2.4    Loaf volume and specific volume                                                                               88

4.2.5    Bulk density                                                                                                                92

4.3       Sensory evaluation of the bread samples produced from the            

            flour – starch   blends                                                                                                  93

4.3.1    Appearance                                                                                                                 94

4.3.2    Crumb and crust                                                                                                         97

4.3.3    Taste                                                                                                                            99

4.3.4    Aroma                                                                                                                         101

4.3.5    Determination of general acceptability of the bread produced from

            flour – starch composite                                                                                              103

4.4       Optimization of the functional properties of the flour/ starch blends, sensory         

            and physical characteristics of its composite bread                                                    106

CHAPTER 5: CONCLUSION AND RECOMMENDATIONS

5.1       Conclusion                                                                                                                  109

5.2       Recommendations                                                                                                      109

            References                                                                                                                  110

            Appendix                                                                                                                    129

           

 

 




 

LIST OF TABLES

 

3.1: Mixture formulations of wheat: AYB: cassava blends from D-optimal                         43

                 model of response surface methodology                                                              

3.2: Goals of optimization process                                                                                          45

4.1: Functional compositions of the flour – starch blend                                                       55

4.1a: Mixture linear model for pH                                                                                          56

4.1b: Mixture cubic model for least gelation concentration                                                   58

4.1c: Mixture linear model for gelation temperature                                                              61

4.1d: Mixture quadratic model for moisture composition                                                      64

4.1e: Mixture linear model for bulk density                                                                           67

4.1f: Mixture special cubic model for water absorption capacity                                           69

4.1g: Mixture special cubic model for oil absorption capacity                                               72

4.1h: Mixture linear model for swelling power                                                                       75

4.1i: Mixture linear model for swelling volume                                                                      75

4.1j: Mixture cubic model for solubility                                                                                 76

4.1k: Mixture linear model for viscosity                                                                                 79

4.2: The physical analyses of composite bread samples produced from                                 83

        flour – starch

4.2a: Mixture linear model for bread height                                                                           84

4.2b: Mixture linear model for oven spring                                                                            85

4.2c: Mixture cubic model for loaf weight                                                                             87

4.2d: Mixture special cubic model for specific volume                                                          89

4.2e: Mixture linear model for loaf volume                                                                            90

4.2f: Mixture quadratic model for bulk density                                                                     92

4.3: The sensory evaluation of composite bread samples produced from                              95

        flour – starch blends  

4.3a: Mixture cubic model for appearance                                                                              96

4.3b: Mixture cubic model for crumb and crust                                                                     98

4.3c: Mixture cubic model for taste                                                                                        100

4.3d: Mixture cubic model for aroma                                                                                     102

4.3e: General acceptability of the flour/ starch composite bread                                            104

 





 

LIST OF FIGURES

 

2.1: Chemical structures of amylose and amylopectin                                                            22

2.2: Nitration of starch                                                                                                            27

2.3: Acylation by carboxylic acid chloride                                                                             29

3.1: Flow chart for the production of native cassava starch                                                   39

3.2: Schematic diagram for the production of African yam bean starch                                40

3.3: Flow chart of modified starches                                                                                      41

3.4: Flow chart for the production of wheat flour                                                                  42

4.1: 3D Plot showing the effect of wheat flour, african yam bean starch and                       56

            cassava starch on pH

4.2: 3D Plot Showing the Effect of Wheat Flour, African Yam Bean Starch and               59

            Cassava Starch on Lgc

4.3: 3D plot showing the effect of wheat flour, African yam bean starch and                      62

            cassava starch on gelation temperature

4.4: 3D plot showing the effect of wheat flour, African yam bean starch and                      65

            cassava starch on moisture composition

4.5: 3D plot showing the effect of wheat flour, African yam bean starch and                      67

            cassava starch on bulk density

4.6: 3D plot showing the effect of wheat flour, African yam bean starch and                      70

            cassava starch on water absorption capacity

4.7: 3D plot showing the effect of wheat flour, African yam bean starch and                      72

            cassava starch on oil absorption capacity

4.8: 3D plot showing the effect of wheat flour, African yam bean starch and                      76

            cassava starch on swelling power

4.9: 3D plot showing the effect of wheat flour, African yam bean starch and                      77

            cassava starch on swelling volume

4.10: 3D plot showing the effect of wheat flour, African yam bean starch and                    77

            cassava starch on solubility

4.11: 3D plot showing the effect of wheat flour, African yam bean starch and                    80

            cassava starch on viscosity

4.12: 3D plot showing the effect of wheat flour, African yam bean starch and                    84

            cassava starch on bread height

4.13: 3D plot showing the effect of wheat flour, African yam bean starch and                    86

            cassava starch on oven spring

4.14: 3D plot showing the effect of wheat flour, African yam bean starch and                    88

            cassava starch on loaf weight

4.15: 3D plot showing the effect of wheat flour, African yam bean starch and                    91

            cassava starch on loaf volume

4.16: 3D plot showing the effect of wheat flour, African yam bean starch and                    91

            cassava starch on specific volume

4.17: 3D plot showing the effect of wheat flour, African yam bean starch and                    93

            cassava starch on bread density

4.18: 3D plot showing the effect of wheat flour, African yam bean starch and                    96

            cassava starch on appearance

4.19: 3D plot showing the effect of wheat flour, African yam bean starch and                    98

            cassava starch on crumb and crust

4.20: 3D plot showing the effect of wheat flour, African yam bean starch and                    100

            cassava starch on Taste

4.21: 3D plot showing the effect of wheat flour, African yam bean starch                           102

            and cassava starch on Aroma

4.22: Spider plot showing the general acceptability of bread samples                                   105

4.23: Plot of desirability of the optimized blend (Desirability = 0.68)                                   107

 

 

 

 

 

 

LIST OF PLATES

 

3.1: Wheat grain                                                                                                                      38

3.2: African yam bean                                                                                                             38

3.3: Cassava                                                                                                                            38

 

4.1: A: 80% Wheat: 10% AYB Starch: 10% Cassava Starch, B: 80.83% Wheat:                 81

            10.83% AYB Starch: 8.33% Cassava Starch, G: 80.83% Wheat: 13.33% AYB

            Starch: 5.83% Cassava Starch, H: 82.5% Wheat: 12.5% AYB Starch: 5%

            Cassava Starch, M: 80% Wheat: 15% AYB Starch: 5% Cassava Starch,

            N: 84.5% Wheat: 10% AYB Starch: 5.5% Cassava Starch

 

4.2: C: 85% Wheat: 10% AYB Starch: 5% Cassava Starch, D: 82.5% Wheat: 10%            81

            AYB Starch: 7.5% Cassava Starch, I: 81.67% Wheat: 11.67% AYB Starch:

            6.67% Cassava Starch, J: 80% Wheat: 12.5% AYB Starch: 7.5% Cassava Starch

 

4.3: E: 82.5% Wheat: 12.5% AYB Starch: 5% Cassava Starch, F: 80% Wheat:                  81

            13.5% AYB Starch: 6.5% Cassava Starch, K: 81% Wheat: 13.5% AYB Starch:

            5.5% Cassava Starch, L: 83.33% Wheat: 10.83% AYB Starch: 5.83% Cassava

            Starch

 

4.4: A: 80% Wheat: 10% AYB Starch: 10% Cassava Starch, B: 80.83% Wheat:                 108

            10.83% AYB Starch: 8.33% Cassava Starch, C: 85% Wheat: 10% AYB

            Starch: 5% Cassava Starch, D: 82.5% Wheat: 10% AYB Starch: 7.5% Cassava

            Starch, E: 82.5% Wheat: 12.5% AYB Starch: 5% Cassava Starch, F: 80%

            Wheat: 13.5% AYB Starch: 6.5% Cassava Starch

 

4.5: K: 81% Wheat: 13.5% AYB Starch: 5.5% Cassava Starch, L: 83.33%                         108

            Wheat: 10.83% AYB Starch: 5.83% Cassava Starch, M: 80% Wheat: 15% AYB

            Starch: 5% Cassava Starch, N: 84.5% Wheat: 10% AYB Cassava Starch:

            5.5% Starch

 

4.6: G: 80.83% Wheat: 13.33% AYB Starch: 5.83% Cassava Starch, H: 82.5%                  108

            Wheat: 12.5% AYB Starch: 5% Cassava Starch, I: 81.67% Wheat: 11.67%

            AYB Starch: 6.67% Cassava Starch, J: 80% Wheat: 12.5% AYB Starch: 7.5%

            Cassava Starch

 

 

 

 

 

 

 

CHAPTER 1

INTRODUCTION


1.1       BACKGROUND OF THE STUDY

It is paramount to understand the nutrient, functional, toxic substances and the anti-physiological substances composition and organoleptic properties of locally available foods in any community or country. Adequate background information and the usage of local foods can go a long way in aiding to solve the problem of food unavailability and eliminate malnutrition. Reports established that fighting against malnutrition in developing countries should likely be centered on the adequate use of mixtures of cereals, tubers and legumes indigenous to her (Nnam, 2003). Urbanization has been found to cause people to forget their traditional foods and patronize convenient foods which are most of the times nutritionally inadequate and unpurchaseable.

Starch is the mostly used biodegradable polymer whose usage has been found to be increasing geometrically in many branches of industry because of its respective physicochemical properties (Yu et al., 2010). It occurs naturally in grains, fruits, roots and tubers of most plants which also act as their major storage material. It can be found in potatoes, corn, wheat and rice using separation process method. Chemically, starch is made up of two polysaccharides of note: the linear amylose type, wherein the units of 𝛼-𝐷 glucopyranose are linked with 𝛼 (14)–glycosidic bonds, and the branched amylopectin whose additional 𝛼 (16) glycosidic bonds are contained in the carbon chain (Biliaderis, 1991; Kaur et al., 2012).

Report has it that native starches despite the fact that their sources are undesirable many applications in the industry because of the chemical compositions inherent in them are not able to withstand some condition of processing such as maximum temperature (causes inadequate thermal resistance), diverse pH, and higher shear rate (causes inadequate shear resistance) (Singh et al., 2007), loss of viscosity, high tendency of retrogradation, syneresis and thickening power during cooking and storage especially at low pH. Studies indicated that native starches produce pastes of poor stability which thereby decreases their shelf stability (stability during storage) which causes shrinkages and release of water from the matrices (Tester et al., 2004). To improve on the desirable functional properties and overcome its limitations, native starches are often modified. Modification (alteration of the chemical and physical components to improve structural characteristics) can be used to improve significantly the inherent poor physicochemical properties of native starches improving its utilization by specific industries (Cock, 1982; Miyazaki et al., 2006).

Starch modification can be classified into four major classes namely: physical, chemical, enzymic and biological modifications. Among these modification methodologies, the chemical type is the most used process (Daramola and Osanyinlusi, 2006). Chemical modification process of starch involves the treatment of native starch with specific chemical reagents. This definition includes acetylated, oxidized, pyrodextrinized, hydroxypropylated and cross-linked starches (Kaur et al., 2004).

The grain size of the starch also affects its reactivity. The larger the grains are, the higher the susceptibility to modification. This is because the larger the grains, the easier the external factors access to them (Lewandowicz and Mączynski, 1990).

Recently there is great shift of interest to the physical modifications of starch (like radiation as well as high and low temperature treatment conditions), on the industrial perspective, chemical modifications are still the most frequently used. Among the lists are three basic reactionswhich includes: oxidation, esterification, and etherification (Tomasik and Zaranyika, 1995; Tomasik and Gladkowski, 2001). One such legume and tuber of interest is African yam bean (Sphenostylis stenocarpa) (AYB) and cassava (Manihot palmata Muell).

African yam beans (AYB) are an herbaceous leguminous plant occurring throughout tropical Africa {United States Department of Agriculture (USDA), 2007}. It is widely grown as a minor crop coupled with yam and cassava. African Yam Bean can serve as a security crop; it has the capacity to supply year-round protein requirements if grown on a large amount {World Health Organization (WHO), 2002}. African yam beans (AYB) are highly nutritious with high amounts of protein, fibre, mineral and contents. Its protein content has been found to be similar to that of some major and commonly consumed legumes. Its amino acid profile compares, if not better than those of cowpeas, soy beans and pigeon peas (Obizoba and Souzey, 1989; Ene-Obong and Carnovale, 1992; Uguru and Madukaife, 2001). It contains high metabolic energy, low true protein digestibility (62.9%) and moderate mineral content. The amino and fatty acids contents are comparable to those of most edible pulses (Nwokolo, 1987; Uguru and Madukaife, 2001). It contains a higher water absorption capacity when compared to cowpeas (Achinewhu and Akah, 2003).

The most common starchy food sources are wheat, corn, cassava/tapioca, rice and potato. Cassava has been reported as second only to sweet potato as one of the most important starchy root crops in the tropics (Grace, 1977). It is grown widely as food crop majorly for food and commercial purposes. In Nigeria, cassava is a staple food for both rural and urban areas and in recent years it has been transformed from being a subsistent crop to an industrial cash crop. The major use of cassava is the traditional food processing in the house or in small-scale cottage operations. Apart from the traditional foods, there is great demand for cassava products which include raw materials like modified starches for the food, beverages, pharmaceutical and textile industries amongst others. Currently, increased production of cassava chips is being advocated for export and incorporation of 10% cassava flour into wheat flour as composite for bread baking (Bertolini et al., 2001).


1.2       STATEMENT OF THE PROBLEM

Studies have shown that in spite of the good attributes of African yam bean, it is underutilized and rarely consumed in urban and rural areas in Nigeria. Its current status as a minor crop means that its potential is largely unexploited. Successful productions have been done with Wheat has been the most suitable flour for baking due to its gluten compositions, but it has been ascertained that wheat is not in relative abundance and hence partial replacement of some proportions of the wheat up to 30% is highly recommended. Modified African yam bean and cassava starches developed from native crops should serve as a better substitute.

Different authors have tried to understand what kind of modification is responsible for the baking properties of the cassava starch. Some attributed this property to the enzyme and the partial acid modifications of the starch as well as the presence of some bacterial exopolysaccharides produced during the fermentation (Camargo et al., 1988; Lacerda et al., 2005). However, these factors have not been proved to be responsible for the baking behaviour. Others stated that the UV wavelengths as well as the lactic acid fermentation are essential for the baking expansion ability of the starch (Bertolini et al., 2001; Vatanasuchart, 2005). However, in their study with cassava starch samples using native, fermented sun-dried and oxidized starches, Demiate et al. (2000) associated the high expansion of the baking characteristics to the carboxylate groups on the chemically treated starches. As the structural modification of sun-dried starch were made detectable by the oxidation, it may be possible to obtain other sensory and functional potentials of the fermented starch by some other form of modifications.


1.3       JUSTIFICATION

The study would provide information on the functional and sensory properties of chemically modified African yam bean (AYB) and cassava starches. The wheat/ starch bread made from African yam bean and cassava would be a form of dietary diversification, which will enhance African yam bean and cassava food use and contribute to ensuring food security and sustainability in Nigeria. It may also stimulate local production and create employment for rural population. It will also minimize the level of post-harvest losses, which may be useful to food industries, institutes and homes on improving the methods of processing and preservation of products made from indigenous food materials. The study would serve as baseline information for researchers in this area.


1.4       OBJECTIVES

The main objective of this study was to evaluate and optimize the physicochemical properties of wheat flour and chemically starches from modified African yam bean and cassava.

Specific objectives are to:

a.       Produce starches from African yam bean and cassava and to chemically modify the starches using esterification (acetylation) method to improve their qualities

b.      Formulate composite blends of African yam bean and cassava starches and wheat flour at different substitution levels obtained from optimal mixture model of response surface methodology (RSM)

c.       Determine the functional properties of the wheat – starch composite flour blends

d.      Produce bread from wheat – starch composite blends

e.       Determine the physical characteristics and the sensory properties of the breads produced from the formulated blends

f.       Optimization of the formulated blends

 

 

Click “DOWNLOAD NOW” below to get the complete Projects

FOR QUICK HELP CHAT WITH US NOW!

+(234) 0814 780 1594

Buyers has the right to create dispute within seven (7) days of purchase for 100% refund request when you experience issue with the file received. 

Dispute can only be created when you receive a corrupt file, a wrong file or irregularities in the table of contents and content of the file you received. 

ProjectShelve.com shall either provide the appropriate file within 48hrs or send refund excluding your bank transaction charges. Term and Conditions are applied.

Buyers are expected to confirm that the material you are paying for is available on our website ProjectShelve.com and you have selected the right material, you have also gone through the preliminary pages and it interests you before payment. DO NOT MAKE BANK PAYMENT IF YOUR TOPIC IS NOT ON THE WEBSITE.

In case of payment for a material not available on ProjectShelve.com, the management of ProjectShelve.com has the right to keep your money until you send a topic that is available on our website within 48 hours.

You cannot change topic after receiving material of the topic you ordered and paid for.

Ratings & Reviews

0.0

No Review Found.


To Review


To Comment