MICROORGANISMS ASSOCIATED WITH CANNED TOMATO CONSUMED IN AGBARA, LAGOS STATE.

ABSTRACT

Canning is a process of hermetically sealing cooked food for future use. It is a preservation method in which prepared glass jars or metal cans that are hermetically sealed to keep out air and then heated to a specific temperature at specified time to destroy disease causing microorganisms and prevent spoilage. Tomato producers are committed to taking proactive steps to ensure and enhance the safety of the food they produce, in addition to providing consistency in product quality and wholesomeness. The aim of this research work is to identify microorganisms present in different canned tomatoes sample sold in Agbara, lagos state, Nigeria. Ten different brands of canned tomatoes samples which include (Chasito, Gino, Cito, Derica, Chuga, Strita, Taima, Day by Day, Read sarsa and Jacomo respectively were bought from Agbara market, Lagos state, Nigeria and brought to the laboratory for microbial load evaluation  and identification of the organisms at day zero, day 7 (1week) and day 14 (2weeks). The materials used for this study were sterilized by appropriate methods to free them from microbial contamination. At day zero, the canned tomatoes sample were swab with methylated spirit and opened with the aid of a sterile knife.  At day seven Serial dilution were carried out on the samples up to 10² and plated as done at day zero, while at day 14 serial dilutions were carried out up to 10³ and plate. Growth was recorded in colony forming units (cfu). This study shows that various types of microorganisms were encountered in canned tomato product analyzed in the laboratory. Bacillus species were seen to be associated with all the samples except for sample J, Streptococcus species were found associated with  Gino, Cito, Derica, Stita, Taima,Day by Day, Red sarsa, Jacomo tomato samples, but were not found in Chasito and Chuga tomato samples. Staphylococccus species were found with Gino, Strita, Taima, Day by Day, Red Sarsa, Jacomo tomato samples, but were not found in  Chasito, Cito, Derica and Chuga tomato samples.  E. coli were found to be associated with Taima, Day by day, Red sarsa and Jacomo tomato samples only. Aspergillus species were found in all the samples in exception Jacomo tomato samples, while Saccharomyces species were seen in all the samples of canned tomatoes used.

KEYWORDS: Canning, Tomatoes, Microorganisms, Bacillus species, Streptococcus species, Staphylococccus species, E. coli, Aspergillus species, Saccharomyces species.

TABLE OF CONTENTS

CHAPTER ONE: INTRODUCTION

CHAPTER TWO: LITERATURE REVIEW

2.1: TOMATO (Lycopersicum esculentus) AS A PLANT

2.2: SPOILAGE ORGANISMS

2.3: MODELLING SPOILAGE

CHAPTER THREE: MATERIALS AND METHODS

3.1: COLLECTION OF SAMPLES

3.2: SAMPLE PRESERVATION

3.3: STERILIZATION OF MATERIALS AND MEDIA PREPARATION

3.4: ISOLATION OF MICROBES FROM THE STUDY SAMPLES

3.5: SUB-CULTURING BY STREAK METHOD

3.6: LABORATORY IDENTIFICATION OF FUNGI

CHAPTER FOUR

RESULTS

CHAPTER FIVE                                                                                                                

DISCUSSION AND CONCLUSION

REFERENCES

LIST OF TABLES

1 MICROBIAL LOAD OF CANNED TOMATO SAMPLE AT DAY ZERO

2 MEAN MICROBIAL LOAD/ml OF CANNED TOMATOES SAMPLES EXPOSED AT DAY 7

3 MEAN MICROBIAL LOAD OF CANNED TOMATOES SAMPLES EXPOSED AT DAY 14

4 MICROBES ASSOCIATED WITH CANNED TOMATOES

LIST OF FIGURES

1 SOME BACILLUS SP COLONIES FROM SAMPLE F AT DAY 7

2 1cfu OF E.COLI  FROM  SAMPLE G AT DAY ZERO

3 LACTIC ACID BACTERIA FROM SAMPLE D AT DAY

4 FUNGI COLONY FROM SAMPLE C AT DAY 7

5 FUNGI COLONIES FROM SAMPLE E AT DAY 7

6 MIXED FUNGI COLONIES FROM SAMPLE G AT DAY 14