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

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

Bacteria Species Associated with Ugba (Pentaclethra macrophylla) Produced Traditionally and in the Laboratory and the Effect of Fermentation on Product of Oligosaccharide Hydrolysis

Study on isolation of bacterial species associated with ugba fermentation was  carried out. Bacterial species including Bacillus licheniformis, Bacillus sphaericus, Bacillus subtilis, Bacillus pumilus, Bacillus firmus, Escherichia coli, Klebsiella and Staphylococcus were isolated from traditionally fermented ugba (TPU) obtained from the market, whereas laboratory produced ugba (LPU) indicated the presence of Bacillus licheniformis, Bacillus pumilus, Bacillus sphaericus, Bacillus subtilis and Staphylococcus before boiling and fermentation. The absence of Bacillus pumilus and Staphylococcus was evident in LPU during post fermentation assay.  Quantitative estimation of pentose and hexose sugars which are product of  hydrolysis of galacto-oligosaccharide content of the test legume reduced from 1158 ppm – 346.4 ppm and 588 ppm – 516 ppm respectively. Greater loss was observed after boiling of LPU (564 and 486 mg/l) on comparison to TPU (94 and 10 mg/l) for pentose and hexose respectively. Plasmid profile analysis carried out showed that Bacillus species from fermented and unfermented ugba had bands indicating the presence in the organism of the genes coding for enzymes responsible for hydrolysis of oligosaccharides in the substrate. This study elucidates the need for good manufacturing practices and adequate boiling before consumption of ugba with the view to prove that there are other Bacillus species aside B. subtilis which can ferment ugba (Pentaclethra macrophylla) to give it its characteristic flavour and taste. It also quantified the effect of fermentation process on some dietary carbohydrate content of the ugba.Keywords: Bacterial species, ugba, fermentation, galacto-oligosaccharide,  hydrolysis