Assessments And Bacteriological Examination Of Ice-Cream Offered For Public Consumption In Umuahia

ABSTRACT

Ice-cream is a nutritionally enriched diary products consumed by all age groups most especially children particularly in summer as well as throughout the year. Its microbial quality has always been crucially important to the public health. The present study was constructed to assess the bacteriological quality of ice cream sold in Umuahia. A total of 14 samples were randomly purchased from the fast food joint, supermarket, school, market and street hawkers differentiated in 2 categories: industrially produced ice cream (IND1-IND7) and locally produced ice cream (LP1-LP7). The total heterotrophic count range from 3.0x10³-2.0x106 (cfu/g) with industrially variety (IND3-IND4) recording no bacterial growth and also some lowest count while locally produced ice-cream has the highest count. The total staphylococcus ranged from 1.0x10² (cfu/g) in the industrially produced variety (IND4) to 3.0x10³ (cfu/g) in the locally produced variety (LP5). For E. coli count, the range was from 1.0x10² (IND2)-2.0X105 (LP5) (cfu/g) in both industrially produced and locally produced. The Lactobacillus count range from 1.0x10² (LP1)-1.0X104 (LP4) (cf/g). Total isolates were eight bacteria (Staphylococcus aureus, Lactobacillus spp., Streptococcus spp., Proteus spp.,Escherichia coli, Klebsiellae and Pseudomonas aeroginosa). Lactobacillus has the highest incidence (7) with the percentage of 50% while Proteus spp, Klebsiella, Pseudomonas aeroginosa had the least incidence and percentage of (1) 7.1%, (2) 14.2% and (2) 14.2% respectively. The total heterotrophic count was further subjected to a t- test statistical analysis which showed no significant difference (p<0.05;) between comparing the bacteriological quality of locally produced ice cream and industrially produced ice cream fall into the same categories. Since in the bacteriological count of ice cream industrially produced, 2 out of 7 products show no bacteria growth which implies that if adequate preparation that is standard process are used it is possible for industrially produced ice cream to be safe to health and better than locally produced ice cream. The presence of pathogenic organism in the ice cream  sample should be viewed with concern by the consumes, producers, ice cream manufacturing industries and the government since food poisoning by Staphuyloccocus Aureus, Bacillus spp, is possible through consumption of contaminated ice cream.

TABLE OF CONTENTS

Title page              ﾿ i

Certification                                        ﾿ ii

Dedication ﾿ iii

Acknowledgement ﾿ iv

List of tables ﾿ v

CHAPTER ONE

1.0 ﾿ Introduction ﾿ 1

1.1 Aims and objectives ﾿ 4

CHAPTER TWO

2.0 Literature review ﾿ 5

2.1 Location of microbes ﾿ 6

2.2 Manufacture of ice-cream ﾿ 7

2.3 Microorganisms in ice-cream ﾿ 7

2.3.1 Bacteria ﾿ 8

2.3.2 Mould ﾿ 8

2.3.3 Yeast ﾿ 8

2.4 Microbial community of ice-cream ﾿ 8

2.5 Hygienic and microbial aspects ﾿ 9

2.6 Major diseases transmitted through ice-cream ﾿ 13

2.7 Microbiology of ice-cream ﾿ 15

CHAPTER THREE

3.0 Materials and method ﾿ 17

3.1 Study area ﾿ 17

3.2 Experimental design ﾿ 17

3.3 Sample collection ﾿ 17

3.4 Sterilization of materials ﾿ 18

3.5 Media ﾿ 18

3.6 Preparation of serial dilution ﾿ 19

3.7 Bacteriological examination ﾿ 19

3.8 Characterisation and identification of bacteria isolates ﾿ 20

3.9 Gram staining ﾿ 20

3.9.1 Catalase test ﾿ 21

3.9.2 Coagulase test ﾿ 21

3.9.3 Oxidase test ﾿ 21

3.9.4 Citrate test ﾿ 22

3.9.5 Motility test ﾿ 22

3.9.6 Indole test ﾿ 22

3.9.7 Statistical analysis ﾿ 23

CHAPTER FOUR

4.0 Results ﾿ 24

CHAPTER FIVE

5.0 Discussion ﾿ 33

5.1 Conclusion ﾿ 36

5.2 Recommendation ﾿ 37

References

Appendix