Combined effect of gamma irradiation and cold temperature storage on the sensory properties of edible estuarine crab Scylla serrata

The present study evaluates the combined effect of dose-dependent gamma irradiation and cold storage on sensory characteristics of mud crab, Scylla serrata. The samples were irradiated at 0.5, 1.0 and 2.0 kGy and stored at 4 o C and -20 o C along with non-irradiated control. The sensory properties of the both irradiated and cold stored samples were assessed at weekly intervals up to maximum of 28 days. Though extended storage at 4 o C (up to 14 days) resulted reduction in sensory quality of both irradiated and non-irradiated control samples, irradiated samples scored significantly higher value which was concomitant with the irradiation doses applied. Gamma irradiation at any applied dosage (0.5, 1.0 and 2.0 kGy) has no significant advantage on sensory characteristics of crab during their storage at -20 o C until 14 days compared to control; further extended storage (up to 28 days), however, enhanced the degree of sensory quality in the samples received 1.0 and 2.0 kGy gamma irradiation compared to the samples irradiated with the low dose (0.5 kGy) and control. The overall experimental results indicated that gamma irradiation at the dose range of 1.0-2.0 kGy and the subsequent cold (4 o C) and frozen storage (-20 o C) would be helpful to extend the shelf life of Scylla serrata by maintaining fairly good sensory quality for maximum duration of 14 and 28 days respectively.