2022 Volume 39 Issue 2 Pages 70-76
In recent years, the consumption of cooked rice produced in rice cooking factory has been increasing. To clarify the risk of food poisoning associated with cooked rice, we investigated the bacterial contamination in rice cooking factories, bacterial proliferation in cooked rice during storage tests, and the growth and enterotoxin production of Staphylococcus aureus spiked into cooked rice. Cooked rice was less contaminated during production, but the viable cell count increased remarkable with the storage test at 35℃. In the S. aureus spiked tests, high growth of S. aureus was observed and a sufficient amount of enterotoxin was produced after 24 to 48 hr at 35℃ storage. It suggests that staphylococcal food poisoning can be caused by improperly contaminated or stored cooked rice. The pH adjusters added to the cooked rice were shown to be insufficient bacteriostatic activity under the conditions of storage tests and S. aureus spiked tests in this study. These results indicate that mishandling of cooked rice can lead to a major food poisoning outbreak with or without pH adjusters.
