USE OF COLIFORM ORGANISMS AS INDICATORS OF QUALITY OF YOGHURT PRODUCTS SOLD IN MICHAEL OKPARA UNIVERSITY OF AGRICULTURE, UMUDIKE

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 ﾿