Quality attributes and reduction in total microbial population of fresh Malawian Tilapia (Oreochromis species) treated with dried buffered vinegar and stored on ice

Abstract

Fish provide major nutritional and economic benefits to the people of Malawi. Unfortunately, fresh fish spoils rapidly because of limited availability of refrigeration and ice, and extensive distances traveled to market. This study was conducted to determine antimicrobial properties of dried buffered white vinegar (DV) on whole ungutted and gutted Malawian Tilapia, and ascertain the effects of DV treatments on quality attributes and pH. Whole fish were either gutted (GF) or left ungutted (UGF), treated with 0, 5, 8 or 10% (w/v) DV solutions, stored on ice and analyzed for pH, aerobic plate count (APC), total coliform (TCC), generic Escherichia coli (ECC), and quality attributes for 5 days. The pH values were similar (P > 0.05) for all treatments. At least 5% DV was necessary to achieve 2 log reductions (P <0.05) in APC and generic E. coli on day 5 when compared to controls. Gutting had no effect on APC, pH, and quality attributes, but resulted in reduced DV antimicrobial activity for ECC. The data suggested that at least 8% DV solutions should be used to treat fresh Tilapia to insure safety and maintain quality attributes for 5 days storage on ice.