Studies on microbial load of Clarias gariepinus smoked with different parts and product of Parkia biglobosa

Abstract

This research aims to study the microbial load on Clarias gariepinus smoked using Parkia biglobosa parts and products. Forty (40) table-sized Clarias gariepinus, were smoked with ten pieces for each treatment, using P. biglobosa charcoal (PBC), bark (PBB), leaf (PBL), and wood (PBW). The smoked fish were stored for six (6) months to monitor the microbial load (bacteria and fungi). There was evidence of deterioration and increased microbial load as the storage time advanced. Fish with PBC had the highest Total Viable Count (TVC) of 1.01×105 cfu/g, whereas fish with PBW yielded the lowest value of 8.78×104 cfu/g. Also, the highest and lowest Total Coliform Counts (TCC) were observed in PBC-treated fish (4.10×104 cfu/g) and PBW-treated fish (2.13×104 cfu/g), respectively. Fish with PBL recorded the highest total fungi count of 9.59×105 cfu/g, while fish with PBW had the lowest count of 1.06×105 cfu/g. The culture-dependent approach of microorganism detection revealed the presence of Klebsiela spp and Micrococcus spp in PBC, Bacillus spp and Staphylococcus aureus in PBB, Escherichia coli and Micrococcus spp in PBL, and Staphylococcus aureus and Bacillus spp in PBW. The fungi species identified include Aspergillus niger, Penicillium sp., Aspergillus flavus, and Aspergillus fumigatus. The findings of this study suggest that PBW is better suited for smoking C. gariepinus due to its better resistance to bacterial and fungi load. Further research can be made to characterize the chemicals deposited by the smoke in different treatment of Parkia biglobosa (bark, leaf, wood, and charcoal).