Microbial Risk Assessment of Non-Enterohemorrhagic in Natural and Processed Cheeses in Korea.

This study assessed the quantitative microbial risk of non-enterohemorrhagic (EHEC). For hazard identification, hazards of non-EHEC in natural and processed cheeses were identified by research papers. Regarding exposure assessment, non-EHEC cell counts in cheese were enumerated, and the developed predictive models were used to describe the fates of non-EHEC strains in cheese during distribution and storage. In addition, data on the amounts and frequency of cheese consumption were collected from the research report of the Ministry of Food and Drug Safety. For hazard characterization, a dose-response model for non-EHEC was used. Using the collected data, simulation models were constructed, using software @RISK to calculate the risk of illness per person per day. Non-EHEC cells in natural- (n=90) and processed-cheese samples (n=308) from factories and markets were not detected. Thus, we estimated the initial levels of contamination by Uniform distribution × Beta distribution, and the levels were -2.35 and -2.73 Log CFU/g for natural and processed cheese, respectively. The proposed predictive models described properly the fates of non-EHEC during distribution and storage of cheese. For hazard characterization, we used the Beta-Poisson model (α=2.21×10, N=6.85×10). The results of risk characterization for non-EHEC in natural and processed cheese were 1.36×10 and 2.12×10 (the mean probability of illness per person per day), respectively. These results indicate that the risk of non-EHEC foodborne illness can be considered low in present conditions.