ABSTRACT

This study examined the quality of yoghurts sold in Michael Okpara University of Agriculture, Umudike using coliform as indicator of quality. Five different brands of yoghurt were bought from different outlets in Michael Okpara University of Agriculture Umudike. Pour plate method was used for the isolation of bacteria from the yoghurts. The isolates were identified using some standard microbiological techniques. 0nly two (2) bacterial sp were isolated namely; Klebsiella sp and Lactobacillus sp. Escherichia coli was not isolated from any of the samples examined while  Lactobacillus sp was isolated from all the samples. The highest bacteria count          (1.6x104 cfu/ml) was recorded against sample C (Pastures yoghurt). This study shows that the yoghurt samples’ quality conformed to the standard quality specifications by food regulators.  

TABLE OF CONTENTS

Certification i

Dedication ii

Acknowledgement iii

Table of Contents iv

List of Tables vi

Abstract vii

CHAPTER ONE -     INTRODUCTION

1.1 Aims and Objectives of Study 2

1.2  Main Objective of Study 2

1.3 Significance of Study 3

CHAPTER TWO -      LITERATURE REVIEW

2.1 Definition of Terms 4

2.1.1 Fermented Foods 4

2.1.2 Starter cultures 4

2.1.3   Protective Cultures 4

2.1.4 Probiotics 5

2.2 Significance of Enterobacteriaceae to Food industry 5

2.3 Coliforms as Indicator and Index Organisms 6

2.4 Coliforms as Food Borne Pathogens 11

2.5 The Lactic Acid Bacteria (LAB) 12

2.6. Lactobacillus acidophilus 14

CHAPTER THREE     -     MATERIALS AND METHODS

3.1   Sample Collection and Preparation 16

3.2   Preparation of Media 16

3.3    Inoculation of Samples 17

3.3.1 Total plate count 17

3.3.2 Coliform count 17

3.3.3 Isolation of Escherichia coli 18

3.3.4 Lactobacillus sp count 18

3.4   Characterisation and identification of bacteria isolates 18

3.4.1 Indole test 18

3.4.2   Methyl-red test 19

3.4.3   Voges proskauer test 19

3.4.4    Citrate utilization test 19

3.4.5 Gram Staining 20

CHAPTER FOUR   -   RESULTS 21

CHAPTER FIVE     -    DISCUSSIONS, CONCLUSION AND RECOMMENDATIONS

5.1 Discussions 24

5.2    Conclusion 25

5.3 Recommendations 25

References 26

Appendix