ABSTRACT 

Five samples of powdered milk collected from retailed shops in the market were analysed for microbial quality. The milks were tested for total aerobic count (TAC), coliform counts and various foodborne pathogens. TACs ranges from 2.98 x 103 to 3.64 x 103 cfu/ml. Escherichia coli were detected in 25% of the samples. Bacillus cereus was confirmed in 27% of the samples. Staphylococcus aureus was detected in 27% of the samples. Lactobacillus was detected in 15.5% of the samples. fumigatus, and mucor sp was observed for the fungi isolates. An apparent relationship between high aerobic count detection of coliforms and presence of food- borne pathogens was observed. These findings suggest that most of the powdered milk sold by retailers may constitute sources of bacterial food poising, consequently public health hazards. The need for improvement and maintenance of good hygienic practices by food handlers in this country is emphasized. 

TABLE OF CONTENTS

Title page i

Certification ii

Dedication iii

Acknowledgement iv

Table of contents v

List of Tables ix

Abstract

CHAPTER ONE

1.1  INTRODUCTION 1

1.2 Aims and Objectives 4

CHAPTER TWO 

LITERATURE REVIEW 

2.1 Milk 5

2.2 Factors Affecting Milk Production 5 

2.3 Breed 6

2.4 Dry period 6

2.5 Age and body weight at calving 6

2.6 Lactation number 7

2.7 Pregnancy 7

2.3 Milk Nutrition 9

2.3.1 Nutritional significance 10

2.4The quality of milk 10

2.5 Types of Milk 10

2.6 Powdered milk 11

2.6.1 Salting 11

2.6.2 Dehydrating 11

2.6.3 Freezing 12

2.6.4  Use of Dry milk 12

2.7 Determination of Microbial Quality of Liquid Milk 12

2.8 Milk Fermentation 13 

2.9 By Products of Milk 14

2.9.1 Cheese 14 

2.9.2 Ice Cream 16 

2.9.3 Buttermilk (Cultured) 17

2.9.4 Yogurt 17

2.10 Processing the Powdered Milk 18

2.11 Micro Flora of Dried Milks 19

 2.12 Contamination of Food 19

2.12.1 Sources of Milk Contamination 20

CHAPTER THREE

MATERIALS AND METHODS 25

3.1 Collection of Samples 25 

3.2. Preparation of Media 25

3.3 Sample Analysis and Identification 25

3.4 Viable count 26 

3.5 Characteristics of Bacterial Isolates 26 

3.5.1 Gram stain 26

3.6 Biochemical Test 26

 3.6.1 Oxidase test 26

3.6.2 Catalase test 27

3.6.3 Coagulase test 27

3.6.4 Citrate Test 27

3.6.5 Lysine test 27 

3.6.6 Indole test 28 

3.6.7 Hydrogen sulfide (H2S) 29

3.6.8 Motility test 29

3.6.9 Voges Proskauer Test 29

CHAPTER FOUR

CHAPTER FIVE

5.0 DISCUSSION, CONCLUSION AND RECOMMENDATION 

5.1 Discussion 36

5.2 Conclusion 38

5.3 Recommendations 38 

References