Microbial Quality Assessment Of Shawarma Sold In Umuahia Metropolis, Abia State

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