Quantitative microbial risk assessment and control effects of clostridium perfringens and bacillus cereus in ready-to-eat lunch box

Quantitative risk assessment of Clostridium perfringens and diarrheal Bacillus cereus in RTE lunch boxes from convenience stores was performed. The efficacy of control measures using a microwave for B. cereus in RTE lunch boxes was also evaluated using the stochastic food safety objective (FSO) tool. The risk of C. perfringens and B. cereus due to consumption of RTE lunch boxes was estimated with @RISK. The results of the worst-case exposure assessment indicate that the probability of foodborne illness caused by C. perfringens was 1.22×10^-10per one serving per day from a vacuum-packaged lunch box, while the probability of foodborne illness caused by B. cereus was zero. Storage time for lunch boxes could be extended up to 6 h at 20°C, 4 h at 25°C, and 2 h at 30°C with microwave heating for 3 min.