Purpose: This study aimed to evaluate temperature requirements in handling areas by developing a risk assessment of Bacillus cereus associated with ready-to-eat rice balls produced and consumed in Taiwan and suggest temperature requirements and effective intervention steps to control the risks.
Methods: Data on the prevalence, concentration and growth of B. cereus in ready-to-eat rice balls were collected through literature and sample analysis. Actual questionnaires were sent to chilled food distribution centers and retail shops by mail to obtain actual temperatures and time related information in different operational steps in summer seasons. Probability distributions were then selected to describe these data. A Monte Carlo simulation model was created using @risk.
Results: Preliminary results indicated prevalence and initial concentration of B. cereus in ready-to-eat rice balls during food factory were 2.5 log cfu/g. By soliciting 100 food distribution centers, we received 7 responses by 1 March 2016. Average actual handling temperatures and time spent at chilled distribution centers for chilled foods were 7.79 ℃ and 5.41 hours. As for retailers, actual handling temperatures and time were 24℃ and 0.29 hours. Predictive microbiology models simulated that final number of B. cereus at 6.59 log cfu/g, and we also found that by controlling handling temperatures at 15 ℃ both at distribution center and retail, B. cereus can be reduced one log cfu/g. The most influential interventions on the risk of illness were handling temperature and storage temperatures in distribution centers.
Significance: The findings could be used by the food regulatory agencies in Taiwan to establish food safety policies and develop risk management strategies to reduce food safety risk associated with the consumption of ready-to-eat foods.