Behavior of Yersinia enterocolitica and Salmonella typhimurium in Crottin goatʹs cheese

In order to evaluate the behavior of Yersinia enterocolitica and Salmonella typhimurium in Crottin goatʹs cheese, inoculated products stored at 5, 15 and 25 °C were analysed together with chemical and microbiological characteristics of the cheese. eral, low counts of microorganisms were detected. None of the samples showed the presence of Escherichia coli, Salmonella spp. or Y. enterocolitica. In the inoculation tests, Y. enterocolitica and S. typhimurium were inhibited during storage; nevertheless, these bacteria survived for extensive periods. The counts at the end of the experiments at 5 and 15 °C were high, indicating that contamination with high bacterial numbers represents a potential health hazard. imary mathematical models used to analyse the behavior of Y. enterocolitica and S. typhimurium were the Vitalistic, Gompertzʹs empirical and Churchillʹs model. The mean square error was calculated for the three models in order to evaluate the goodness-of-fit of each one. For Y. enterocolitica, the Vitalistic model was the best at the three temperatures. For S. typhimurium, there was no significant difference between the three models at 5 and 15 °C; the Churchill model was clearly the best at 25 °C. These results confirm that, in order to predict the risk of transmission of pathogenic microorganisms in foods using mathematical models, it is essential to analyse their behavior in specific foods.