Microbial quality, aflatoxin content and nutrient degradation of silver cyprinid stored at landing sites and in markets in Uganda

Abstract

Silver cyprinid (Rastrineobola argentea) is a nutritious and low-cost source of proteins for food and feed. Processing and storage of silver cyprinid are still sub-optimal and may therefore impact on its quality and safety. In this study, we evaluated markers of microbial quality, nutrient degradation and aflatoxin content in stored dry silver cyprinid from four landing sites on Lake Victoria and five markets in Kampala district. The moisture content of fish samples from both landing sites and markets was higher than 12% which is the recommended by East African standards. The microbial quality of the silver cyprinid from landing sites met the national standards (total coliform count, 3.6 (3.0, 4.6) log cfu/g) while that of market samples (total coliform count 4.2 (3.0, 5.0) log cfu/g). Silver cyprinid from the landing sites and markets contained aflatoxins (14.5 ± 0.9 ppb; 15.5 ± 2.2 ppb, respectively) above the standard specification. Additionally, fat degradation of the landing site samples was higher than the maximum allowable limit: free fatty acid content 3.6 (3.1, 4.3) mgKOH/g. Fat degradation of the market site samples was higher than the maximum allowable limit: free fatty acid content 7.4 ± 1.4 mgKOH/g. Stored, dry silver cyprinid fish may pose a health risk, and may have slightly less healthy fats than fresh fish.

Keywords

• small-scale fisheries
• silver cyprinid
• rastrineobola argentea
• nutritional quality
• microbial quality
• aflatoxin
• food storage