MICROBIOLOGICAL QUALITY IMPROVEMENT OF DRIED FISH BY GAMMA IRRADIATION AND ASSESSMENT OF FOOD VALUE UPON IRRADIATION WITH RESPECT TO BIOCHEMICAL ASPECT

Abstract

A study was conducted to determine the effects of radiation on biochemical (moisture, protein, fat, ash, carbohydrate, calcium and phosphorus) and microbiological qualities (TVBC, TCC and TFC) of three different dried fishes (Chepa, Loitta and Chingri) collected from retails markets. Among the three non-irradiated dried fishes, the highest moisture content (40.85 ± 0.42) was found in Chepa compare to Loitta (19.48 ±0.40) and Chingri (17.09 ±0.77). Highest rate of total protein content was found in non-irradiated Chingri (60.39 ±0.75) and Loitta (55.85 ± 0.40) compare to Chepa (32.67 ± 0.06). Results revealed that radiation (3 and 5 kGy) has no significant effect on biochemical composition of three dried fishes. Results of microbiology showed that total viable bacterial count (TVBC) was estimated in non-irradiated Chepa (5.58 ± 0.14 log cfu/g), Loitta (3.72 ± 0.09 log cfu/g) and Chingri (5.34 ± 0.15 log cfu/g) respectively which was significantly reduced by 1 to 3 logs at 3 kGy and 3 to 5 logs at 5 kGy gamma radiation. Maximum Total coliform count (TCC) was found in non-irradiated Chepa (5.28 ± 0.02 log cfu/g) compare to Loitta (3.23± 0.09) and Chingri (4.56 ± 0.06). Total fungal count (TFC) was recorded as 3.60 ± 0.09 and 3.78 ± 0.05 log cfu/g in non-irradiated Chepa and Chingri respectively but there was no TFC in non-irradiated Loitta. At 3 and 5 kGy , no TCC and TFC were found in all dried fishes