ABSTRACT

Flours prepared from D. alata and D. rotundata were evaluated for their fufu and cake making potentials. Chips were also prepared from the two species of yam and their attributes compared. Proximate analysis and starch analysis were carried out on the two yam species. Also functional properties determination were carried out on the flours made from the yam. The moisture, ash, fibre, protein and fat content were higher in the D. alata while carbohydrate was higher in D. rotundata. The starch content was also higher in D. rotundata. The amylose fraction of the D. alata was higher (24.77) while the D. rotundata was 20.03. The amylopectin of the D. rotundata was higher than the D. alata. The total soluble sugar of the D. alata was 4.27 while the D. rotundata was 3.81. The D. rotundata scored higher in most of the functional properties of the flour apart from whippability, emulsion capacity and wettability. The chips from D. Alata were highly acceptable than chips from D. rotundata. The cake from the wheat flour was more acceptable than the cake from the composite flour although all the cake samples were acceptable. The yam fufu made from thç fresh D. rotundata and D. alata were better than those made form the flour samples.

TABLE OF CONTENTS

PAGE

Title

Certification ii

Dedication iii

Acknowledgement iv

Abstract Vi

Table of Ccintents vii

List of Tables... xi

List of Figures xii

CHAPTER ONE

1.0 INTRODUCTION 1

1.5 Aim and Objectives 3

CHAPTER TWO

2.0 LITERATURE REVIEW ... 4

2.1 Chemical composition of yam 4

2.1.1 Moisture ... 5

2.1.2 Carbohydrates 5

2.1.3 Proteins 6

2.1.4 Yam lipids 7

2.l5Minerals .. 8

2.1.6 Vitamins 9

2.2 Antinutritional Compounds of Yams 10

2.3 Functional properties of Yam Starch ... 11

2.4 Methods of preparing and rocessing yam for food ... 14

2.4.1 Boiled yam ... ...

2.4.2 Baked yam ... ... 15

2.4.3 Fried yam ... 15

2.4.4 Pounded yam 15

2.4.5 Special delicacy 16

2.4.6 Dehydrated yam flaskes 16

2.4.7 Yam flour 17

CHAPTER 3

3.0 MATERIALS AND METHODS ... 19

3.1 Materials 19

3.2. Methods 19

3.2.1 Preparation of yam flours 19

3.2.2 Preparation of yam fufu 21

3.2.3 Preparation of yam cake 21

3.2.4 Preparation of yam chips / 22

3.2.5 Test Panel Evaluation of Products...

3.3 Chemical analysis of yam sample 1 24

3.3.1 Moisture determination 24

3.3.2 Crude protein determination 25

3.3.3 Ash content determination ... 26

3.3.4 Fat determination 26

3.3.5 Crude fibre determination .. 27

3.3.6 Carbohydrate determination 28

3.4 Starch Analysis 28

3.4.1 Estimate of starch 29

3.4.2 Fractionation of Amylose and Amylopectin 29

3.4.3 Estimate of total soluble sugar... 29

3.5 Functional properties of flour sample 30

3.5.1 Geletinization Temperature... 30

3.5.2 Water absorption capacity ... 30

3.5.3 Oil absorption capacity ..• 31

3.5.4 Swelling index 31

3.5.5 Foam stability ... ... 31