Effect of Some Potentially Synergistic Treatments in Combination with 100 Krad Irradiation on the Iced Shelf Life of Cod Fillets

Irradiation of cod fillets with a maximum absorbed dose of 100 Krad extended iced storage life by about 9 days. Further extension of several days resulted when irradiation was combined concurrently with either 60% CO2 packaging atmosphere or sorbate additive. Packaging at low oxygen tension did not provide any additional benefit for irradiated fish. No important difference in storage life of treated fish was observed due to one vs three day postmortem age. The 100 Krad treatment extended grade B quality market life as opposed to grade A (prime quality) market life. Certain physical/chemical tests were evaluated for their efficacy in estimating spoilage. Concentrations of TMA, DMA, hypoxanthine, APC and pH at spoilage were comparable in control and air-irradiated samples, but were less in sorbate-irradiated fillets.