ABSTRACT

The contribution of yeast in maize fermentation for ogi production was studied. Maize seeds were fermented for 72hrs and sub-samples were collected and analyzed every six hours. Quality characteristics of the fermenting liquor was determined including microbial load and flora. Obtained results shows that the bacterial load was in the range from 1.13×106 cfu/ml to 2.05×106 cfu/ml while the fungal load ranged from 2.3×103 cfu/ml to a maximum of 5.41×103 cfu/ml. The bacterial load reduced to 1.59×106 cfu/ml while the fungal load reduced to 2.1×103 cfu/ml. Bacterial flora of the fermenting liquor consisted of Lactobacillus sp, Staphylococcus sp, Streptococcus sp, Bacillus sp, Pseudomonas sp, while the fungal load consisted of Yeasts sp, Aspergillus sp, Fusarium sp, and Rhizopus sp. The contribution of yeast was assessed by test on the ability to produce enzymes. Obtained results also show that the yeast isolates demonstrated enzyme acttivties in the form of amylase, lipase, and protease activity. Amylase activity was in the range of 3.3 enzyme units to 20.81 enzyme units from the first day to the third day. Lipase activity was in the range of 1.43 to 2.87 enzyme units of the same period while protease activity was in the range of 6.20 to 7.53 enzyme units of the same period. It was concluded that major contribution of yeast in the fermentation, lies with the enzymatic hydrolysis of the carbohydrate during the fermentation with the accompanied by-products including organic acids, alcohol etc. 

TABLE OF CONTENTS

Tile page

Certification

Dedication

Acknowledgement

Table of contents

List of Tables

List of Bar Charts

Abstract

CHAPTER ONE

 1.0 Introduction

1.1 Background of Study

1.2 Aims and Objectives

CHAPTER TWO

2.0 Literature Review

2.1 Yeast

2.2 Fermented Maize

2.3 Yeast and Indigenous Fermented Foods

2.4 Prospect of Yeast in Fermented Foods

CHAPTER THREE

3.0 Materials and Methods

3.1 Sample collection

3.2 Sample and Media Preparation

3.2.1 Sample Preparation

3.2.2 Media Preparation

3.3 Fermentation of Maize

3.4 Determination of Microbial Load of Fermenting Maize Liquor

3.5 Isolation and identification of Microbes

3.6 Characterization of Isolates

3.6.1 Characterization of Fungi Isolates

3.6.1.1 Colony features

3.6.1.2 Structural features

3.6.2 Characterization of Bacteria Isolation

3.6.2.1 Colony features

3.6.2.2 Structural features

3.6.2.3 Biochemical Tests

3.6.2.4 Sugar Utilization Test

3.7   Identification of Isolates

3.8   Evaluation of Yeast Contribution

CHAPTER FOUR

4.0 Results and Discussion

4.1  Results

4.2 Discussion

CHAPTER FIVE

5.0 Conclusion and Recommendation

5.1 Conclusion

5.2 Recommendation

References

Appendix