Use of γ-irradiation to reduce Clostridium perfringens on ready-to-eat bovine tripe

The aim of this study was to determine the effect of gamma irradiation at a target dose of 9 kGy and storage at 5 and 15 °C on the safety of ready-to-eat (RTE) tripe with respect to Clostridium perfringens count (CC) and aerobic plate count (APC), and to determine the effect of boiling (1 h) and irradiation (9 kGy) on Cl. perfringens ATCC 13124 spore structure. Irradiation significantly reduced APC stored at 5 and 15 °C for 7 days. However, 0 kGy control samples increased in their APC to >7 log10 cfu/g throughout 7 days of storage. Irradiation eliminated the inoculated Cl. perfringens ATCC 13124 spores on RTE tripe throughout storage at 5 and 15 °C. Transmission electron microscopy of Cl. perfringens ATCC 13124 spores showed that boiling caused a reduction in spore material, irradiation caused elongation of the Cl. perfringens ATCC 13124 spores, and boiling in combination with gamma irradiation caused loss of spore material. Therefore, irradiation at 9 kGy, together with storage at 5 °C, can assure the microbiological safety of RTE bovine tripe, with respect to Cl. perfringens spores for at least 7 days at 5 and 15 °C.