Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019 Aug 29;29(3):339-350.
doi: 10.1007/s10068-019-00670-0. eCollection 2020 Mar.

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

Mi Jin Kwon  1 , Min Suk Rhee  2 , Ki Sun Yoon  1
Affiliations

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

Mi Jin Kwon et al. Food Sci Biotechnol. .

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.

PubMed Disclaimer

Conflict of interest statement

Conflict of interestThe authors declare that they have no conflict of interest regarding the publication of this paper.

Figures

Fig. 1
Fig. 1
Conceptual model for conducting QMRA on B. cereus in packaged tofu
Fig. 2
Fig. 2
Probabilistic distribution of initial contamination level of B. cereus in tofu
Fig. 3
Fig. 3
Primary predictive models of B. cereus in tofu. (A) 4 °C, (B) 9 °C, (C) 11 °C, (D) 17 °C, (E) 30 °C, (F) 40 °C, (G) 45 °C. Unit: Delta (d), LT(h), SGR(log cfu/h)
Fig. 4
Fig. 4
Cumulative distribution for comparing the contamination level of B. cereus in tofu from the initial contamination level to home IC, Initial contamination level; C1, Market storage; C2, Transportation; C3, Before consumption
Fig. 5
Fig. 5
The correlation coefficient for sensitivity analysis affecting illness by B. cereus with consumption of tofu numbers in the bars represent coefficient value
See this image and copyright information in PMC

References

    1. Acai P, Valik L, Liptakova D. Quantitative risk assessment of Bacillus cereus in pasteurized milk produced in the Slovak Republic. Czech J. Food Sci. 2014;2:122–131. doi: 10.17221/106/2013-CJFS. - DOI
    1. Albert I, Mafart P. A modified Weibull model for bacterial inactivation. Int. J. Food Microbiol. 2005;100:197–211. doi: 10.1016/j.ijfoodmicro.2004.10.016. - DOI - PubMed
    1. Ananchaipattana C, Hosotani Y, Kawasaki S, Pongswat S, Latiful BM, Isobe S, Inatsu Y. Bacterial contamination of soybean curd (tofu) sold in Thailand. Food Sci. Technol. Res. 2012;18:843–848. doi: 10.3136/fstr.18.843. - DOI
    1. Bahk GJ. Statistical probability analysis of storage temperatures of domestic refrigerator as a risk factor of foodborne illness outbreak. Korean J. Food Sci. Technol. 2010;42:373–376.
    1. CAC (Codex Alimentarius Commission). Principles and guidelines for the conduct of a microbiological risk assessment. CAC/GL-30, Rome, Italy: FAO/WHO (1999)

LinkOut - more resources