Abstract

Microbial quality of Shawarma sold in Umuahia metropolis; Twenty(20) shawarma sandwiches comprising of two categories, Beef  Sharwama (B1-B10), and Chicken Sharwama (C1-C10), were analysed. From the study, the Total Heterotrophic Count (THC) has the highest count of 2.8x105 (cfu/g) (C2)  and lowest count of 9.0x104 (cfu/g) (B5), the Total Coliform Count (TCC) has the highest count of 2.5x 104 (cfu/g) (C10) while the lowest count is 6.5x103 (cfu/g) (B6), the Staphylococcal count (SC) has the highest count of 2.3x104 (cfu/g) (B3) and lowest count of 4.0x103 (cfu/g) (B8), the Salmonella Count (SAC) has the highest count of 1.9x104 (cfu/g) (C6) while the lowest count is 5.4x103 (cfu/g) (B4), the Shigella count (SHC)  has the highest count of 1.9x104 (cfu/g) (C1) and lowest count of 4.1x103 (cfu/g) (B4), the Escherichia coli count (EC) has the highest count of 1.7x104 (cfu/g) (C8) and lowest count of 4.0x103 (cfu/g) (B5), the Lactobacillus count (LC) has the highest count of 1.3x104 (C7) (cfu/g) while the lowest count is 2.6x103(cfu/g) (B3), the Total Fungal Count (TFC) has the highest of 1.0x104(cfu/g) (C2) while the lowest count is 3.9x103(cfu/g) (B5).The distribution of the isolates include; Salmonella spp 15 (75%), Escherichia  coli 14 (70%), Staphylococcus aureus 11 (55%), Shigella spp 9 (45%), Lactobacillus spp 8 (40%), Bacillus spp 6 (30%),  Rhizopus spp 7 (35%), Aspergillus spp. 2 (10%). The total heterotrophic count (THC) was further subjected to statistical analysis, and showed a significant difference (P< 0.05, P< 0.01) between the beef and chicken Sharwama varieties. Higher contamination rates were found in the chicken variety when compared with the meat variety. The presence of the isolated pathogens is of public health concern because some strains are capable of producing a heat-stable enterotoxin that causes food poisoning in humans, and should therefore be taken into account in risk assessment.

TABLE OF CONTENTS       PAGES

Title page       i

Certification                          ii

Dedication                     iii

Acknowledgement                  iv

Table of Contents                       v

List of Tables                 ix

List of Figures                               x

Abstract xi

CHAPTER ONE      

1.0 Introduction       1

1.1 Aims and objective               4

CHAPTER TWO                    

2.0 Literature Review     5

2.1 Definition of Shawarma               5

2.2 History and Nature of Shawarma     5

2.3 Ingredients and condiments used in the preparation of Shawarma     7

2.4 Preparation of Shawarma     7

2.5 Popular dressings used in Shawarma recipes     8

2.6 Serving and packaging     8

2.7 Health and Nutritional facts about Shawarma 9

2.8. Microbiological changes in Shawarma            9

2.8.1 Contamination of meat     10

2.8.2 Microbiological changes of meat               12

2.8.2.1 Contamination of chicken             15

2.8.2.2 Microbiological changes of Chicken     17

2.8.3 General methods of meat preservation     21

2.8.4. Contamination of vegetable     27

2.8.4.1 Microbiological changes of vegetable                                 29

2.8.4.2 Preservation of vegetables     31

CHAPTER THREE    

3.0 Materials and method     35

3.1 Study Area     35

3.2 Sample collection     35

3.3 Experimental design     35

3.4 Sterilization of Materials         36

3.5 Media used and their preparation   36

3.6 Microbiological analysis of samples             36

3.6.1 Serial dilution   36

3.6.2 Isolation and enumeration   37

3.6.3 Detection of Salmonella spp      37

3.7 Characterization and identification of Bacterial isolates   38

3.7.1 Purification and storage of isolates   38

3.7.2 Colonial morphology   38                                               

3.7.3 Motility test   38

3.7.4 Gram staining   39

3.7.5 Biochemical tests   40

3.7.5.1 Catalase test   40

3.7.5.2 Coagulase test   40

3.7.5.3 Indole test   40

3.7.5.4 Methyl red test   41

3.7.5.5 Voges proskauer   41

3.7.5.6 Citrate utilization test   42

3.7.5.7 Oxidase test   42

3.7.5.8 Urease test   42

3.7.5.9 Sugar fermentation test   43

3.8 Identification and characterization of fungal isolates   43

CHAPTER FOUR

4.1 Results 44

CHAPTER FIVE

5.1 Discussion 54

5.2 Conclusion 59

5.3 Recommendation 59

References   61

Appendices     70