Irradiation for shelf-life extension and improvement of the hygienic quality of cold-smoked herrings and hot-smoked eels

ABSTRACT

A shelf-life extension and improving the hygienic quality of cold- smoked herrings and hot-smoked eels were done using gamma irradiation. The preparation of each product was described. Dose level of 5 kGy extended the shelf-life of cold-smoked herrings with 48% moisture and 8% salt up to 4 months at room temperature compared by one month for the unirradiated samples. This irradiation dose was also sufficient and efficient for eliminating the risk resulting from pathogenic bacteria and mycotoxigenic fungi, which may be present in smoked fish. Application of 7.5 kGy of gamma rays appeared to be effective and sufficient for eliminating the anaerobic and pathogenic bacteria in the hot-smoked eels [60% moisture and 1.5% salt] packed in polyamide- polyethylene bags under vacuum condition. It has remarkable effect in decreasing the total aerobic bacteria and hence extending the shelf- life of smoked eels to more than 60 days under cold storage [3 +/- 1C] compared by only 15 days for the unirradiated samples. This dose greatly affect the flavor of this product. Irradiation dose of 5.0 kGy appeared to be optimum for extending the shelf-life and improving the hygienic quality of hot-smoked eels without changing their attractive flavor