Behavior of Yersinia enterocolitica and Salmonella typhimurium in Crottin goat´s cheese.

L.M.TAMAGNINI, G.B. DE SOUSA, R.D. GONZÁLEZ, J. REVELLI C.E. BUDDE

INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY

Elsevier B.V

Año: 2005 vol. 99 p. 129 - 134

0168-1605

In order to evaluate the behavior of Yersinia enterocolitica and Salmonella typhimorium in Crottin goat´s cheese, inoculated products stored at 5, 15 and 25 C were analyzed together with chemical and microbiological characteristics of the cheese. In general low counts of microorganisms were detected. None of the samples showed the presence of Escheritchia coll, 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. The primary mathematical models used to analyze the behavior of Y. enterocolitica and S. Typhimurium were the Vitalistic, Gompertz´s empirical and Churchill´s 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 analyze their behavior in specific foods.