EFFECT OF IRRADIATION ON SHELFLIFE AND MICROBIAL QUALITY OF COLD-STORED SOUS-VIDE MACKEREL FILLETS

Abstract

The combined effect of irradiation on microbial quality and shelflife of sous-vide mackerel fillets was investigated. Fillets were vacuum packaged, pasteurized (70C, 10 min) and rapidly cooled. Sous-vide fillets were separated into three groups as nonirradiated (control) and irradiated at the doses of 2.5 and 5.0 kGy, respectively. Samples were stored at 21C. Sensorial, physical, chemical and microbial analyses were carried out weekly. According to the sensory results, 5.0 kGy irradiated samples were acceptable until the eighth week of cold storage while control and 2.5 kGy irradiated samples were unacceptable by the seventh week. Total mesophilic and psychrophilic bacterial counts and TVB-N values of control samples exceeded the limits on the sixth week; however, irradiated samples never exceeded the limits. Irradiation of sous-vide fillets provides microbial safety and longer shelflife to consumers who prefer both safe and quick food.