Effect of different dose gamma radiation and refrigeration on the chemical and sensory properties and microbiological status of aqua cultured sea bass (Dicentrarchus labrax)

Quality and shelf life of non-irradiated and irradiated (2.5 and 5 kGy) sea bass in ice conditions and stored at +4∘C were investigated by measurement in microbiological, chemical sensory analyses. Microbial counts for non-irradiated sea bass samples were higher than irradiated fish. Among chemical indicators of spoilage, total volatile base nitrogen (TVB-N) values increased to 36.44 mg/100 g for non-irradiated sea bass during iced storage, whereas for irradiated fish lower values of 25.26 mg/100 g and 23.61 mg/100 g were recorded at 2.5 and 5 kGy, respectively (day 17). Trimethylamine (TMA-N) values and thiobarbituric acid (TBA) values for irradiated samples were lower than that for non-irradiated samples. Acceptability scores for odour, taste and texture of cooked sea bass decreased with storage time. The sensory scores of sea bass stored in control and 2.5-5 kGy at +4∘C were 13 and 15 days, respectively. The results obtained from this study showed that the shelf life of sea bass stored in ice, as determined by overall acceptability of all data, is 13 days for non-irradiated sea bass and 15 days for 2.5 kGy irradiated and 17 days for 5 kGy irradiated sea bass.