Effect of Gamma Irradiation on the Shelf Life and Quality of Mutton

The present study was undertaken to assay the effects of gamma irradiation on fresh mutton compared with non-irradiated mutton. For this purpose the meat samples were divided into four treatments. The experiment was conducted on fresh mutton treated with 60Co gamma irradiation having dose of 0 (T0), 1.5 (T1), 2 (T2) and 4 kGy (T3) and stored in 0, 30 and 60 days at -20ºC to estimate the effect on proximate, sensory, physicochemical, biochemical and microbial changes in mutton. Proximate analysis (DM, CP, EE, and Ash), physicochemical and bio-chemical tests (pH value, cooking loss, PV, TBARS and FFA), sensory tests (color, flavor, tenderness, juiciness, overall acceptability) and microbial test (TVC, TCC and TYMC) were done to evaluate the effect of irradiation on shelf life and quality of mutton during preservation. The mutton samples were stored up to 2 months and evaluated at 0, 30 and 60th day. Irradiation increased DM, EE and decreased ash of mutton. CP was decreased with treatment. The PV, TBARS, FFA values and Cooking loss were increased with treatment. But raw pH was decreased with irradiation. There were significant differences in color and flavor with treatment. There were no significant differences in tenderness, juiciness and overall acceptability with treatment. The TVC (logCFU/g), TCC (logCFU/g) and TYMC (logCFU/g) were decreased with treatment. As a result, it can be concluded that irradiation increased shelf life of mutton to maintain nutritional quality of meat. Among the treatments, the highest irradiation dose (4.0 KGy) found the best results in terms of overall acceptability, microorganism control and for shelf life extension of mutton.