ABSTRACT

This research work aims at studying the nutritional value and biochemical properties of cocoyam (Xanthosoma Sagittifolium) and unripe plantain(musa paradisiaca) flour as a substitute to Yam (Dioscorea Spp) flour blends. Samples of the flour blends were analyzed using different analysis such as proximate analysis, phytochemical, vitamin composition, mineral nutrients and functional properties as well as anti oxidant activities of the flours were carried out using standard techniques. The aim is to check the flour blends with the highest glycemic index that can be used as a substitute to yam flour.Materials and reagents used for the analysis include petroleum ether, copper sulphate, sulphuric acid, phenol, ethanol, acetic acid etc.,and equipment include cliffton electric hot plate stirrer, USA, sohxlet apparatus, exello-England, carbolite , electric oven, England and hammer mill etc. and the samples are dried flour samples of cocoyam, unripe plantain and yam. Four respondents to observe the result of the experiment in terms of the properties experimental upon which include colour, texture and general acceptability were selected using purperine sampling techniques and the respondents are staff and students of college of food science and tourism. The result of the analysis shows that Xanthosoma spp showed significantly ( P<0.05) higher crude protein, crude lipids, carbohydrates and energy value than Musa spp and yam flour which contains significantly higher (P<0.05) moisture content, fiber and ash. In vitamins composition, sample musa spp flour has a higher value of A and C than that of Xanthosoma spp and Yam flour.But all contains vitamins B (B1, B2, B3) and there is no significant difference (P>0.05) among them. In addition, the Xanthosoma spp flours contains higher qualities of flavonoids, saponin, tannin, calcium (Ca), Zinc (Zn), Sodium (Na), Phosphorus (P) Crude Fiber as well as antioxidant activity but lower quantities of alkaloids than the musa spp flours. No functional and phytochemical properties was analysed for the yam flour. From the results of the sensory evaluation of the flours (colour, texture and general acceptability). The colour of Xanthosoma spp was not affected by heat or processing, and maintained its whitish colour, the same goes to the yam flour. Texture preference was only affected by particle size and coarse form of Xanthosoma unlike the Musa Paradisaca whose colour maintained the same colour as that of edible portion of the unripe plantain (Emperatriz Pacheli Delaheye 2002). The general acceptability was carried out by observational  techniques by four observers. The result showed that it was generally accepted. It was suggested that cocoyam and unripe plantain could be a close  substitute to yam flour in management of diabetic nephropathy via dietary practices using new meal alternatives. Diabetics is one of the most challenging diseases of the 21st century that affect essential biochemical pathways of the body (carbohydrate, protein and lipid metabolism) and whose prevalence is rising globally including the rural Nigeria population. Due to the inability of the modern therapy to control all the path physiological aspects of the disorder as well as enormous cost it poses on the economy of the developing nations of the world, alternative strategies are urgently needed, hence the use of medicinal plants in traditional management of diabetes mellitus. Cocoyam and unripe plantain flour blends could be used as a substitute for yam flour in assessment of diabetic meals.

TABLE OF CONTENT

Title page i

Approval page ii

Certification iii

Dedication iv

Acknowledgement v

Table of content vi

Abstract vii

List of tables

Table 4.1: Proximate Analysis 52

Table 4.2: Phytochemical Composition 54

Table 4.3: Vitamin Composition 56

Table 4.4: Mineral Contents 58

Table 4.5: Functional Properties 61

CHAPTER ONE

INTRODUCTION

1.1 BACKGROUND OF THE STUDY 1

1.2 STATEMENT OF PROBLEM 3

1.3 PURPOSE OR OBJECTIVE OF THE STUDY 3

1.4 RESEARCH QUESTIONS 4

1.5 SCOPE OF STUDY 4

1.6 SIGNIFICANCE OF STUDY 4

1.7 KEY DEFINITION OF TERMS 5

CHAPTER TWO

2.0 GUIDELINES FOR REVIEW 6

2.1 Conceptual Framework 6

2.1.1 Origin and distribution of cocoyam 7

2.1.2 Nutritional value of Cocoyam 8

2.1.3 Uses of cocoyam and its parts 8

2.1.4 General uses of cocoyam 9

2.1.5 Origin and Distribution of Plantain 9

2.1.6 Nutritional Value of Plantain 10

2.1.7 Uses of Plantain Parts 12

2.1.8 Processing Method of Plantain 14

2.1.9 Origin And Distribution Of Yam 16

2.1.10 PREVALENCE STUDY/PROBLEM OF DIABETES 18

2.1.11 SIGNIFICANCE/IMPORTANCE OF COCOYAM 20

2.1.12 SIGNIFICANCE/IMPORTANCE OF PLANTAIN 24

2.1.10 Economic Importance of Cocoyam 24

2.1.13 Economic Importance of Plantain 27

2.2 Theoretical framework 30

2.2.1 PHYSIOLOGICAL FUNCTION 33

2.2.2 PSYCHOLOGICAL FUNCTION 33

2.2.3 SOCIAL FUNCTION 33

2.2.4 FOOD CHOICES 34

2.3 SUMMARY OF RELATED LITERATURE 34

CHAPTER THREE

MATERIALS AND METHODS

3.0 MATERIALS 35

3.1 RESEARCH DESIGN 35

3.2 STUDY AREA 36

3.3 POPULATION OF THE STUDY 36

3.4 SAMPLE OF STUDY/SAMPLING TECHNIQUES 36

3.4.1 PLANTAIN FLOUR 37

3.4.2 COCOYAM FLOUR 37

3.5 INSTRUMENTATION 39

3.6 SENSORY EVALUATION 52

3.7STATISTICAL ANALYSIS 52 

CHAPTER FOUR

RESULTS AND DISCUSSION

4.1 PROXIMATE ANALYSIS 53

4.2 PHYTOCHEMICAL COMPOSITION 56

4.3 VITAMIN COMPOSITION 58

4.4 MINERAL CONTENT 60

4.5 FUNCTIONAL PROPERTIES 62

4.6 SENSORY EVALUATION 65

CHAPTER FIVE

SUMMARY, CONCLUSIONS AND RECOMMENDATION

5.1 SUMMARY 66

5.2 RESTATEMENT OF PROBLEM 67

5.3 CONCLUSION 67

5.4 RECOMMENDATION 68

5.5 CONTRIBUTION TO FURTHER STUDY 68

REFERENCES

APPENDIX