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.
TABLE OF CONTENTS
Abstract
CHAPTER ONE: INTRODUCTION
1.0
Introduction 1
1.1
Justification of study 2
1.2 Objectives 2
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
2.6 Spoilage 11
CHAPTER THREE: MATERIALS AND
METHOD
3.1 Study Area 13
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
CHAPTER FOUR
4.1 Result 18
CHAPTER FIVE: DISCUSSION, CONCLUSION AND RECOMMENDATION
5.1. Conclusion 27
5.2. Recommendation 27
References