Quality assessment of fresh Lake Malawi Tilapia (Chambo) collected from selected local and super markets in Malawi

Abstract

The aim of this study was to assess quality of Lake Malawi Tilapia (local name: Chambo) from local and super markets in Malawi. Fish from local markets had significantly higher numbers of viable bacteria counts (9.5× 10 8 CFU/g, cm 2) (P<0.01) which were above acceptable limits compared to fish from super markets (2.7× 10 5 CFU/g, cm 2). Most isolated bacteria species were Corynebacterium, Micrococcus, Pseudomonas, Bacillus, Flavobacterium and Escherichia coli. Mean total volatile basic nitrogen (TVB-N), trimethylamine nitrogen (TMA-N) (g/100mg) and pH of fish from local and super markets were 15.40±0.00, 0.10±0.01, 6.11±0.12 and 14.90±0.58, 0.13±0.02, 6.20±0.07, respectively. Fish collected from local markets had significantly higher levels of TVB-N (P<0.05) compared to those from super markets. Fish from both local and super markets were contaminated generally due to poor handling by sellers but not necessarily at the selling points. The study nevertheless observed that despite being microbiologically contaminated, fish were not wholly spoiled. This suggests that product declared unfit for consumption through sensory evaluation may still be nutritionally good hence need for validating such results with other methods.