MICROBIOLOGICAL ANALYSIS OF COMMERCIALLY PREPARED YOGHURT

200%">ABSTRACT

. Microbial quality of
commercially prepared yoghurt sold in umuahia was evaluated. Ten(10) different
brands of Yoghurt was purchased randomly from hawkers and beverage stores in
Umuahia urban and analyzed in the laboratory. Six (6) of the samples where
registered by NAFDAC [ Sample A, B, C, D, E and F,] while four(4) others were
not registered [ Sample G, H, I, J.]. total viable count (TVC) of the samples
ranged from 3.25x10² (sample B) to 5.0x10⁴ (sample F) for
registered samples (A to F) and 8.2x10⁴ cfu/ml (sample A) to 2.12x10⁵
cfu/ml (sample J). staphylococcal count ranged  from 2.0x10² cfu/ml (sample B and F)
to 9.6x10⁴ cfu/ml (sample J). which is within the acceptable limit
for microbiological quality for readily to eat food samples. Sample B  was negative for taphylococcus aureus. TCC ranges from 1.0x10² cfu/ml
(sample B) to 5.0x10⁴ cfu/ml (sample E) for registered and non-registered
samples, sample C showed no growth of coliform. Total Fungal count ranged from
1.0x10² cfu/ml (sample A and D) to 4.0x10⁴ cfu/ml (sample
G). sample B,  and D showed  no growth of fungi. Organism isolated include

Escherichia coli, Staphylococcus aureus, Salmonella spp,  Citrobacter

spp  and Lactobacillus

spp . Aspergillous spp and candida
albicans was also isolated from the samples. Results shows that yoghurt sold
in Umuahia showed  presence of coliforms,
bacteria and fungi which poses great health risk to consumers. 

tab-stops:168.9pt center 3.25in">TABLE OF CONTENTS

Abstract                                                                                                                                       

200%">CHAPTER ONE: INTRODUCTION

1.0  
Introduction                                                                                                                            1

1.1  
Justification of study                                                                                                              2

text-indent:-.25in;line-height:200%;mso-list:l0 level2 lfo1;tab-stops:.5in right 6.4in">1.2    Objectives                                                                                                                              2

200%">CHATER TWO: LITERATURE REVIEW

2.1     History                                                                                                                                  3

2.2     Processing of yoghurt                                                                                                           4

2.2.1.   Modifying milk composition                                                                                             4

2.2.2   Pasteurization and Homogenization                                                                                   4

2.2.3   Fermentation                                                                                                                       6

2.2.4   Flavour                                                                                                                                6

2.3.  
Yoghurt preservation                                                                                                             7

2.4.  
Quality control of yoghurt                                                                                                    8

2.5.  
Nutritional health effect                                                                                                      10

2.5.1.    Probiotics                                                                                                                        10

text-indent:-.25in;line-height:200%;mso-list:l2 level2 lfo2;tab-stops:.5in right 6.4in">2.6     Spoilage                                                                                                                               11

200%">CHAPTER THREE:  MATERIALS AND
METHOD

text-indent:-.25in;line-height:200%;mso-list:l1 level2 lfo3;tab-stops:.5in right 6.4in">3.1   Study Area                                                                                                                             13

text-indent:-.25in;line-height:200%;mso-list:l1 level2 lfo3;tab-stops:.5in right 6.4in">3.2    Sample Collection                                                                                                                13

3.3   
preparing of Media                                                                                                              13

3.4   
Isolation and enumeration of microorganism                                                                     14

3.5   
Characterization and Identification of Isolates                                                                   14

3.5.1   Gram Staining                                                                                                                   14

3.5.1   Biochemical test                                                                                                                15

200%">CHAPTER FOUR

text-indent:-.25in;line-height:200%;mso-list:l3 level2 lfo4;tab-stops:.5in right 6.4in">4.1     Result                                                                                                                                  18

200%">CHAPTER FIVE: DISCUSSION, CONCLUSION AND RECOMMENDATION

5.1.    Conclusion                                                                                                                         27

5.2.    Recommendation                                                                                                               27

line-height:200%">References