ABSTRACT

Fresh fruits may harbour a wide range of microbial contaminants due to several factors which may be of public health significance. This study was conducted to evaluate the microbial quality of sliced watermelon and pineapple sold in Umudike, MOUAU. Evaluation of the possible bacteria and fungi on the fruit samples was carried out based on standard microbiological methods. A total of seven species of bacteria and five species of fungi were isolated from twenty samples of fresh cut pineapple and water melon fruits analyzed. This work revealed the Total Viable Count (TVC) and Total Fungal Count (TFC) for both Pineapple and Watermelon collected from different locations. 5.2×108 and 1.1×107 (CFU/ml) represented the highest and lowest Total Viable Count (TVC) respectively while 2.4×107 and 0.2×107 represented the highest and lowest Total Fungal Count (TFC) respectively for Pineapple. The Total Viable Count (TVC) and Total Fungal Count (TFC) for Watermelon collected from different locations were 5.2×107 and 1.0×107 (CFU/ml) representing the highest and lowest Total Viable Count (TVC) respectively while 5.5×107 and 0.1×107 represented the highest and lowest Total Fungal Count (TFC) respectively. It was observed that almost all the fruits examined had bacterial counts above the acceptable limit and is therefore microbiologically unacceptable. Pineapple appeared to have the highest bacterial count which may be due to its high carbohydrate content needed for the growth of bacteria. From this, the percentage occurrence of the different bacterial isolates for both Pineapple and Watermelon, S. epidermidis had the highest percentage occurrence (31.9%) followed by Staphylococcus aureus 19.1%, Bacillus sp 17%. Pseudomonas aeruginosa 14.9%, Enterobacter 8.5%, Proteus 6.4% while E. coli had the lowest percentage occurrence (2.1%). The percentage occurrence of fungal isolates revealed that Aspergillus sp had the highest percentage occurrence (40%) followed by Mucor sp 25%, Botrypdiplodia sp 15%, while Fusarium sp and Penincillum sp had the lowest percentage occurrence (10%) respectively. The commonest genera of fungi that were isolated and identified included Aspergillus sp, Mucor, Penicillum sp, Fusarium sp, and Botrypdiplodia sp. There is need for urgent improvement in the hygienic condition of preparation and handling of fresh cut fruits, especially when organisms like S. aureus, E. coli, and Bacillus species occur in high numbers. E. coli count in fruits is widely used and accepted as indicators of feacal contamination.

TABLE OF CONTENT

Title Page i

Certification ii

Dedication iii

Acknowledgement iv

Table of Contents v

List of Table viii

Abstract ix

CHAPTER ONE

1.0 Introduction 1

1.1 Aim and Objectives of the Study 3

1.1.1 Aim of the Study 3

1.1.2 Objectives of the Study 3

CHAPTER TWO

2.0 Literature Review 5

2.1 Water Melon (Citrullus Lanatus) 5

2.2 Pineapple (Ananas Comosus) 9

2.2.1 Nutritional Value 11

2.3 Pathogens of Greatest Concern in Fruits 13

2.3.1 Shigella Species 13

2.3.2 Escherichia Coli 14

2.3.3 Campylobacter Species 15

2.3.4 Yersinia Enterocolitica 15

CHAPTER THREE

3.0 Materials and Methods 17

3.1 Sample Collection 17

3.2 Media Used 17

3.3 Sterilization 17

3.4 Enumeration of Bacteria 17

3.5 Identification and Characterization of Isolates 18

3.5.1 Gram Staining 18

3.5.2 Spore Staining Technique 18

3.5.3 Motility Test 19

3.6 Biochemical Cultural Characteristics 19

3.6.1 Catalase Test 19

3.6.2 Coagulase Test 19

3.6.3 Citrate Test 19

3.6.4 Indole Test 20

3.6.5 Oxidase Test 20

3.6.6 Urease Test 20

3.6.7 Methyl Red Test 21

3.6.8 Voges-Proskaeur Test 21

3.7 Sugar Fermentation Test 22

3.8 Identification of Fungi 22

CHAPTER FOUR

4.0 Results 23

CHAPTER FIVE

5.0 Discussion, Conclusion Recommendation 30

5.1 Discussion 30

5.2 Conclusion 33

5.3 Recommendations 34

REFERENCES

Table Title Page

4.1 Total Viable Count (TVC) and Total Fungal Count (TFC) of Pineapple from different location in CFU/ml 24     

4.2 Total Viable Count (TVC) and Total Fungal Count (TFC) of Water from different location in CFU/ml 25

4.3 Percentage occurrence of bacteria isolates from Pineapple and Watermelon 26

4.4 Percentage occurrence of Fungi isolated from Water melon and Pineapple 27

4.5 Cultural Characteristics of Fungal Isolates 28

4.6 Morphological and Biochemical Identification of Isolates 29

LIST OF TABLES