Disinfection of Bacillus Cereus in Different Food Matrix using Gamma Irradiation

Abstract

Bacillus cereus is gram positive facultative anaerobic bacterium. It is a foodborne pathogen responsible for human food poisoning. In this study, growth and disinfection of B. cereus KTCC-11204 and B. cereus KTCC-400935 were examined in different food matrix using gamma radiation. Both of these strains were inoculated separately into fried rice and pasta samples which were collected from Dhaka. After appropriate incubation fried rice and pasta were irradiated using gamma radiation at 1 kGy, 3 kGy, 5 kGy, 7 kGy, 8 kGy and 9 kGy. Results showed that when the radiation doses were increased in fried rice, the number of colonies of B. cereus were significantly decreased. Both of the strains in fried rice were completely eliminated at 8 kGy of gamma radiation dose. Meanwhile, pasta samples showed similar results and complete elimination was obtained at 8 kGy gamma radiation dose. In both fried rice and pasta showed higher growth of KTCC-11204 than KTCC-400935. This study indicates that B. cereus can grow in prepared foods that can be potentially disinfected using gamma radiation which might be helpful in improving food safety of prepared foods.