Bacterial and Fungal Quality of Oven-Dried African Catfish (Clarias gariepinus) Marinated with Extracts of Sweet Orange (Citrus sinensis)

Abstract

Citrus sinensis generates a lot of waste that needs to be put into beneficial use. The study was done to investigate the shelf life of smoked Clarias gariepinus marinated in extracts of Citrus sinensis. Samples were taken for microbial analysis after the 3rd, 5th, and 7th days and compared with the samples not marinated. Microbial isolates were identified by conventional methods. The mean Total Heterotrophic Bacterial Counts (mTHBC) and mean Total Fungal Counts (mTFC) for the marinated samples ranged from 1.30 ± 0.3 to 3.20 ± 0.3 (cfu/g) and 1.2 ± 0.3 to 2.83 ± 0.1 (cfu/g), respectively, while the unmarinated samples had mTHBC values from 5.0–5.4 cfu/g and mTFC values between 4.8–5.1 cfu/g. The microorganisms isolated include Escherichia, Salmonella, Shigella, Staphylococcus, and Vibrio. While Vibrio spp., Escherichia coli, Staphylococcus aureus, and Salmonella typhi were capable of proliferating in both samples at different stages, yeast and molds were the only isolated organisms in the unmarinated samples. This showed that marination of oven-dried Clarias gariepinus with the extract of Citrus sinensis has enabled it to possess less microbial load by eliminating most of the potential pathogens of significant public health concern as well as extending the shelf life.