Assessment of the Safety of Some On-The-Shelf Canned Food Products Using PCR-Based Molecular Technique

Abstract

Study on the assessment of bacteria load of some on-the-shelf canned food  products bought from different shops in the open markets in Owerri, Imo State, Nigeria was undertaken. Eleven canned food products including 2 cans of tomato paste (TP), 2 of fish-in-tomato-sauce (FTS), 3 of sweet corn (SC), baked beans (BB), 1 of green peas (GP) and 2 kidney beans (KB) were collected randomly and used for the analysis. Culture-based identification depicts the presence of Bacillus sp., Staphylococcus sp., Vibrio parahaemolyticus, Salmonella sp., Klebsiella sp., Proteus sp., Pseudomonas sp. and Escherichia coli. Plasmid profiling of culture-dependent isolates showed visible bands except Staphylococcus sp., Klebsiella sp. and Bacillus sp. Randomly amplified polymorphism DNA [RAPD] profiling using varying oligonucleotide primers specific for identification of 16SrRNA genes of some organisms of public health concern, confirmed the presence of coliforms, Staphylococcus sp., Vibrio sp., S. typhi and S. enteritidis on gel electrophoresis field. In the context of possible risk of consuming contaminated canned food products, this study was designed to show that most onthe- shelf canned food products can possibly habour organisms of public health importance which can be ascertained through molecular characterization using PCR-based technique. There is also the possibility of these organisms posing food safety issues and pharmaceutical risks in case of possible out break, assayed through plasmid profiling of the culture-dependent isolates. A major concern in this study is the lack of adherence to food safety regulations. The products still been marketed on the shelves and analyzed in this study must have outlived the shelf stability period.

Keywords: RAPD, canned food, bacteria load, plasmid profiling, oligonucleotide primers.