Purpose: To estimate the risk associated with consumption of ice cream contaminated with Listeria monocytogenes in Brazil.
Methods: The quantitative risk assessment model consisted of six modules considering the reception of raw materials, pasteurization of the milk, ice cream mixture, pasteurization of syrup, aging and the consumption scenarios. Data from literature were used to build the quantitative risk assessment model. The model was built in Microsoft Excel spreadsheet and simulated in @RISK 7 and a total of 10,000 iterations were performed using Monte Carlo method. The outputs considered the likelihood of infection per month and number of people who can be infected in a month after consuming ice cream only for elderly people and adults, due the lack of data of child and pregnant woman.
Results: The risk model predicted that the probability of infection per L. monocytogenes due to consumption of ice cream was 8.46 E-06, for elderly and 6.30 E-06, for adults in average. The risk of infection was 6.93 E-07 for the elderly and 5.15 E-08, for adults also in average. The model suggest that measures to ensure the microbial quality of raw materials and to avoid cross-contamination at post-pasteurization steps will result in the biggest impact on risk of infection of L. monocytogenes.
Significance: Data as level of contamination of raw material, the pathogen behavior during the syrup pasteurization step and refrigerated storage for all ice cream shelf life shall be generated to corroborate the assumptions used for the development of this model.