Shelflife extension of fresh aquacultured channel catfish using X-ray irradiation

Consumer uncertainty of irradiated food products has slowed the implementation of food irradiation, even though it is a proven safe and effective technology. The present research was designed to determine if X-ray irradiation affects the sensory characteristics of fresh aquacultured channel catfish fillets during refrigerated storage and if treatment results in changes in selected quality and safety parameters (color, texture, microbial load, and Listeria monocytogenes incidence). Fillets were dosed to 0, 0.5, 1.0 and 1.5 kGy using an X-ray irradiator and held in refrigeration (3°C) for 17 days. TCC, APC, and PPC increased with time as expected. Overall, L. monocytogenes incidence was 40%, 27%, 0%, and 7% at 0, 0.5, 1.0, and 1.5 kGy, respectively. Color, texture, and oxidation values did not change over time or with irradiation dose. Aroma of irradiated catfish fillets was significantly different, with greater aroma differences recorded as storage time increased. Neither appearance nor texture was significantly different for any treatment throughout testing. X-ray irradiation maintained the quality and improved the safety of fresh catfish fillets without negatively affecting consumer purchase attributes. Shelflife extension (3 to 4 days) was also achieved.