A risk assessment study of Bacillus cereus in packaged tofu at a retail market in Korea

Mi Jin Kwon; Min Suk Rhee; Ki Sun Yoon

doi:10.1007/s10068-019-00670-0

A risk assessment study of Bacillus cereus in packaged tofu at a retail market in Korea

Food Sci Biotechnol. 2019 Aug 29;29(3):339-350. doi: 10.1007/s10068-019-00670-0. eCollection 2020 Mar.

Authors

Mi Jin Kwon¹, Min Suk Rhee², Ki Sun Yoon¹

Affiliations

¹ 1Department of Food and Nutrition, College of Human Ecology, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447 Republic of Korea.
² 2Department of Food Bioscience and Technology, Korea University, Seoul, 02841 Republic of Korea.

Abstract

The objective of the study was to conduct a quantitative microbial risk assessment of Bacillus cereus for packaged tofu in Korea. Packaged tofu, including soft and firm tofu from six retail markets in Korea, were monitored to determine the initial contamination level of B. cereus. Predictive growth and survival models were developed to predict the change in B. cereus populations as a function of time and temperature (4-45 °C) from market to home. B. cereus was detected in 11 (12.9%) samples among 85 samples purchased at retail markets, and the average contamination level was 1.84 log CFU/g. Growth of B. cereus in tofu was observed at a temperature above 11 °C. The probability risk of B. cereus diarrheal illness due to packaged tofu consumption at the retail market is 1.0 × 10^-4 per person per day. Key risk factors at the retail market and home are storage temperature and time of packaged tofu.

Keywords: Bacillus cereus; Packaged tofu; Predictive model; Quantitative microbial risk assessment; Retail market.