ABSTRACT

Assessment of the microbial fermentation of mixed fruit juices was investigated. The study was carried out to determine the microbial and chemical characteristics of fermented juices and their safety for human consumption. Pineapple (Ananas comosus) and watermelon (Citrullus lanatus) were processed to produce mixed fruit juice which was left to ferment for 5days. Marginal changes in pH and titratible acidity were recorded. The titratible acidity (0.45-2.25) increased and the pH value (3.80-3.30) decreased progressively during fermentation period. Total viable and fungal counts as well as the total lactic acid bacteria were monitored during the fermentation period. The total lactic acid bacteria increased steadily for (1.9 x 104Cfuml) to 9.0 x 1011Cfuml) during the fermentation period. Salmonella and Shigella species were not detected. The percentage occurance in bacteria count showed that Micrococcus had the lowest count of (11.4%) while Lactobacillus had the highest count of (57.1%) during fermentation. This study indicated that once a hygienic practice of mixed fermented juice is applied it could be safe for human consumption.

TABLE OF CONTENTS

Title Page i

Certification ii

Dedication iii

Acknowledgements iv

Table of Contents v

List of Tables viii

Abstract ix

CHAPTER ONE: INTRODUCTION

1.1 Objective of study 2

CHAPTER TWO: LITERATURE REVIEW

2.1 Mixed fruit juice and products 4

2.2 Pineapple and pineapple products 4

2.3 Nutritional content of pineapple 5

2.4 Watermelon and Watermelon products 6

2.5 Nutritional value of watermelon 7

2.6 Economic Importance and uses of watermelon 8

CHAPTER THREE: MATERIALS AND METHODS

3.1 Collection of samples 9

3.2 Washing and peeling of the samples 9

3.3 Preparation of the mixed fruit juice 9

3.4 Juice extraction 9

3.5 Fermentation 9

3.6 Sampling 10

3.7 Isolation and enumeration of bacteria and fungi 10

3.7.1 Sugar Fermentation 12

3.8 Biochemical Analysis 12

3.9 Flowchart for watermelon and pineapple

CHAPTER FOUR: RESULTS

CHAPTER FIVE: DISCUSSION AND CONCLUSION:

5.1 Discussion 19

5.2 Conclusion 20

REFERENCES 22

APPENDIX 2