TABLE OF CONTENTS
PAGE
Title Page i
Certification ii
Dedication iii
Acknowledgements iv
Abstract v
Table of Contents vi
List of Figures ix
CHAPTER ONE: INTRODUCTION
11 Introduction
1
12 Biology of Cassava and Maize
2
121 Cassava
2
122 Maize
6
13 Starch
8
131 Starch properties
8
132 Test for starch
10
133 Cassava starch
11
134 Starch synthesis
12
135 General biosynthesis of polysaccharides
12
136 Biosynthesis of a glycosidic bond
14
137 Structural alterations to sugar nucleotide before polysaccharide assembly
16
138 Starch hydrolysis (degradation)
17
139 Acid hydrolysis
17
1310 Enzyme hydrolysis of starch
19
14 Amylases
19
141 General properties of amylases
19
142 Sources of amylases
20
143 Plant amylases
20
144 Amylases production in germinating cereals
21
145 Maize amylases
22
15 Aims and objectives of research
23
CHAPTER TWO: MATERIALS AND METHODS
21 Materials
24
211 Sample collection and location(s)
24
2111 Cassava varieties
24
2112 Maize varieties
24
212 Chemicals/Reagents/Samples
25
213 Apparatus
26
22 Methods
26
221 Preparation of buffers
26
222 Extraction of cassava starch
27
223 Glucose calibration curve
27
224 Enzyme extraction
27
225 Method of enzyme assay
27
226 Effect of germination on maize amylase activity
27
227 Effect of pH on maize amylase activity
28
228 Germination of maize
28
229 Determination of activity in 20 varieties of hydrid maize
28
2210 Assay of amylase activity in maize
28
2211 Effect of Ca
2+
ions on amylase activity
29
2212 Determination of protein concentration in all enzyme extracts
29
2213 Protein determination
29
2214 Maize amylase specific activity
30
2215 Activity of maize amylase on cassava starch
30
2216 Effect of pH on amylase activity using cassava starch as substrate
30
2217 Effect of substrate concentration on enzyme activity
30
23 Statistical Analysis
31
CHAPTER THREE: RESULTS
31 Effect of germination on amylase activity
32
32 Effect of pH on amylase activity
32
33 Amylase activity before imbibition at pH 55, 75 and 95
33
34 Amylase activity on day 3 after imbibition at pH 55, 75 and 95
34
35 Amylase activity on day 5 after imbibition at pH 55, 75 and 95
35
36 Protein determination
39
37 Maize amylase specific activity
41
38 Determination of maize variety with the highest amylase activity
45
39 Hydrolysis of cassava starch by enzyme extract from VARIF2
45
310 Effect of Ca
2+
on enzyme activity
45
311 Effect of substrate (starch) concentration on maize enzyme activity
45
312 Effect of pH on amylase activity using 1% cassava starch
46
CHAPTER FOUR: DISCUSSION AND CONCLUSION
41 DISCUSSION
50
42 CONCLUSION
55
REFERENCES
57
APPENDICES
62