Effect of Storage Temperature on Sensory and Microbial Quality of Rastrelliger kanagurta (Cuvier, 1816) from Andaman Coast

The effect of storage temperature on the microbial and sensory quality of Indian Mackerel, Rastrelliger kanagurta (Cuvier, 1816) marketed in South Andaman was assessed during the present study. The fishes kept at room temperature (28°C) were monitored for 5 hours and found that the fishes were still acceptable with little signs of spoilage, a slightly alkaline pH of 7.2 and bacterial load at fish surface of 1.8×104 cfu/cm2 . At iced temperature (4°C), belly ruptured at 18th hour and at 24th hour, the eyes became shrunken and the odour became rancid with slight alkaline pH 7.5. The fish was still acceptable based on the sensory standards at 18th hour and the bacterial load of 6.9x 104 cfu/g of the fish tissue at 24th hour. At -5°C temperature, the belly became non-elastic during 4th day and the pressing impressions remained on the body. On the 5th day, the eyes became cloudy and the microbial load of the fish sample was as low as 6.1×104 cfu/g on the 5th day. The bacterial species isolated from the various parts of R. kanagurta during the study were Lactobacillus acidophilus, Bacillus subtilis, Bacillus cereus,Staphylococcus sp., Psuedomonas sp., Flavobacter sp., E.coli, Micrococcus sp., Streptococcus sp., Vibrio sp., Acinetobacter sp., Flavorbacter sp., Klebsiella sp., Proteus vulgaris, Vibrio cholerae, Vibrio parahaemolyticus, Aeromonas sp. and Shigella sp. The study have shown that the shelflife of R.kanagurta collected from South Andaman at ambient (28°C) and iced (4°C) temperatures was 5 hours and 24 hours respectively and the sensory and microbiological approaches in the analysis were all in agreement with the recommended international limits for acceptability. So the Indian Mackerel stored and marketed in Andaman at ambient temperature is best for consumption within the first five hours, 24 hours for iced (4°C) and at -5°C, acceptable even after 5 days.