A Comparative Quality Assessment of Five Types of Selected Fishes Collected from Retail Market in Sri Lanka

The chemical and microbiological quality and safety of fresh fish obtained from the retail and supermarkets of Sri Lanka were examined. Fresh fish samples (n = 155) of yellowfin tuna (Thunnus albacares), sailfish (Istiophorus platypterus), salaya/ sardine (Sardinella gibbosa, shrimp (Fenneropenaeus indicus) and squids sp (Loligo duvaucelii) were collected from 19 places around the country and evaluated in the laboratory. Samples were analysed for several chemical and microbial quality including total volatile base nitrogen, histamine, total mercury and total plate count. Furthermore, the presence of selected pathogens such as Escherichia coli and Salmonella spp. were detected. In microbiological analysis of samples total plate counts were obtained in the range of 7 x 103-1.2 x 108 cfu/g and 28% of the samples had 103 MPN/g of E. coli and 1 sample contained 500 MPN/g and rest of the samples had < 200 MPN/g with 33% of the samples without E. coli. Twelve percent of samples were positive for Salmonella spp. The range of total volatile base nitrogen (TVB-N) was 15-4883 mgN/100 g and 33% samples were exceeded the maximum acceptable levels. Further considering histamine and mercury level of yellowfin tuna and sailfish, 7% and 4% of samples exceeded the maximum acceptable levels respectively. When considering both microbiological and chemical results it can be seen that majority of the samples are not fit for the human consumption and that counted as; 35% of yellowfin tuna, 47% of sailfish, 35% of sardine, 100% of squids and 53% shrimp.