Effect of non-thermal pasteurization on minced chicken meat based pet food and its quality attributes through gamma ray and electron beam irradiation

The potential of non-thermal pasteurization was evaluated for elimination of hazardous pathogenic microorganisms in feed ingredients for pet food. Salmonella and Escherichia coli were inoculated into minced chicken based feed ingredients at 6.05±0.75 and 6.80±0.14 log CFU/g, respectively. Feed ingredients were irradiated at a dose of 3, 5, 7 and 10 kGy of gamma ray and electron beam irradiation. In the gamma ray irradiation, the microbial population of both Salmonella and E. coli was reduced to the limit of detection (LOD) level from the lowest dose of 3 kGy. Electron beam irradiation also inactivated both microorganisms under the LOD at 3 kGy. The lowest dose level of 3 kGy was sufficient to provide a pasteurization effect for both Salmonella and E. coli. For the quality attributes, gamma ray and electron beam irradiation did not show any detrimental effect on pH and color of minced chicken meat. Electronic nose analysis indicated an off flavor in irradiated chicken meat. With gamma ray irradiation, the off flavor was detected from the 3 kGy dose, showed similar levels up to 7 kGy, and then increased markedly after 10 kGy irradiation. Electron beam irradiation also induced the off flavor from 3 kGy, and this gradually increased in accordance with rises in the dose level.