ABSTRACT

Gari, a product from cassava is widely consumed in many West African countries especially Nigeria, is known to contain toxic a compound which is detrimental to the health of the consumer. 1'his research study is carried out to investigate the dctoxihcatioin of cassava by three different stages of palm oil addition during the preparation of gari. The stages of addition are; addition of oil to the mash before fermentation, addition of oil during frying and non addition of oil to the fried gari. From the spectrophotornetric method used for the determination of the HCN content of gari, it is seen that the gari fried without oil has the highest HCN retention both in the high cyanide variety and low cyanide variety, while the addition of palm oil before fermentation has the highest reduction of the HCN level in gari than that added during frying. lt is seen that on high cyanide variety, oil addition on frying reduces the 1-ICN level by 8. 11% while addition of oil before fermentation reduces the HCN level by 13.5% ie. twice the effect of reduction on frying. The other major finding of the research study is that oil addition has no significant effect on the physical characteristics of the gari samples such as, swelling index and bulk density but has a significant effect on the reduction of the moisture content by prolonging garification time. Addition of oil to the mash before fermentation has the highest reduction 1 of HCN content of the gari.

TABLE OF CONTENT

TITLE PAGE ii

CERTIFICATION PAGE iii

DEDICATION iv

ACKNOLEDGEMENT v

TABLE OF C0NTENF vi

LIST OF TABLES viii

LIST OF HGURES ix

ABSTACT X

CHAPTER ONE

1.0 TNTRODCUTION

1. 1 Statement of Problem

1.2 Objective of Study

CHAPTER TWO

2.0 LITERATURE REVIEW

2. 1 Cassava Varities

2.2 Distribution of Toxic Cyanogens

2.3 Factors Influencing Glucoside Content of

Cassava 6

2.4 Traditional Method of Preparation oC.Gari 6

2.5 Effect of Processing on Cyanide Content of Cassava 9

2.6 Products From Cassava 10

2.7 Gari II

2.8 Particle and Pieces size 12

2.9 Nutritive value of gari ._- 12

2. 10 Mechanism of detoxification 13

2. 11 Effect of palm oil addition on garification 17

2. 10 Moisture Effect on Gari I S

CHAPTER THREE

3.0 MATERIALS AND METHODS

3. 1 Raw Materials Procurement 19

3.2 Preparation of The Samples 19

3.3 Cyanide Content Determination 21

3.4 Spectrophotometric Measurement 21

3.5 Moisture Content Determination 22

3.6 Swelling Index Determination 22

3.7 Bulk Density Determination 23

3.8 Kcn Standard Preparation 23

3.9 Determination of Percentage Reduction of Cyanide from

the Spectrophotometric Reading 2-I

CHAPTER FOUR

4.0 RESULTS AND DISCUSSION 25

4.1 Effects of Palm Oil Addition on the Cynade Level

of Gari 25

4.2 The Effect of Oil Addition on the Moisture Content of Gari,

Bulk Density and Swelling Index 27

CHAPTER FIVE

5.0 Conclusion and Recommendation 29

REFERENCES 30

APENDIX 34