Microbiological Quality of Traditionally Smoked Fish from Lake Victoria Crescent, Uganda

Abstract

Microbiological quality of traditionally smoked fish was assessed to ascertain the effectiveness of traditional smoking process and handling conditions for smoked fish shelf-life and safety. Fish smoking is a popular preservation method in Uganda. Although fish smoking is a widely used method of preservation, the presence of spoilage and pathogenic bacteria in smoked fish and food borne illnesses remain a threat in developing countries. However, little is known about microbial quality of fish smoked from Uganda. In light of this, the status of spoilage, hygiene and pathogenic indicator organisms in fish (Nile perch) was investigated. A total of 75 randomly selected fresh, freshly smoked, and on shelf smoked fish from landing sites and markets respectively, were obtained for microbial and moisture content analysis. Descriptive statistics was used to present the data, while ANOVA and Tukey tests were used to analyze the data. The study revealed that, the smoking process significantly (P<0.05) reduced microbial load in freshly fish to levels acceptable for consumption, despite the high levels of moisture content in the range of 59.2% to 66.5%. The mean microbial load (log of cfu/g) of indicator organisms for samples from different sites varied from; 9.97 to 10.18; 7.39 to 8.19 (aerobic mesophilic bacteria or TPC), 5.18 to 5.27; 0 to 4.28 (total coliforms), 2.73 to 5.55; 0 to 0.85 ( E. coli ), 4.97 to 7.32; 0 to 3.11 ( S. aureus ), and 2.21 to 4.56; 0 to 0.82 (Yeasts and molds), for fresh and smoked fish samples respectively. Additionally, mean microbial load for on shelf smoked fish from markets varied from; 8.2 to 10.57 (TPC), 2.8-6.63 (total coliforms), 0 to 6.11 ( E. coli ), 6.74 to 8.89 ( S. aureus ), and 0 to 5.51 (Yeasts and molds). Although findings showed that, traditional fish smoking was somewhat effective in reducing microbial load to acceptable levels, the microbial status of on shelf smoked fish indicated poor fish handling and storage. Therefore, proper fish handling during and post-smoking as well as cooking before consumption, are highly recommended for assured shelf-life and safety of smoked fish for consumption in Uganda.