Survival of Yersinia enterocolitica in Yogurt and Ice-cream

Document Type : Original Articles

Author

Department of Food Hygiene and Control, Faculty of Veterinary medicine, Cairo University

Abstract

Yersinia enterocolitica has a public health and food hygiene concern as a food contaminant due to its ability to grow in raw milk and viability at refrigeration temperatures for long time. Y. enterocolitica infection causes yersiniosis disease.  In this study yogurt was inoculated with Y. enterocolitica strain during its manufacture, then part stored at refrigerated temperature and the other part stored at room temperature. Acidity % and pH were measured as well as enumeration of Yersinia. Results showed that Y. enterocolitica could be detected in refrigerated stored yogurt but not in yogurt stored at room temperature by the end of the week. The same strain was inoculated during manufacture of vanilla as well as lemon flavor ice-cream and enumeration of the microorganism was done for 2 months. Results revealed that Y. enterocolitica survived in vanilla ice-cream but can’t survive in lemon flavor ice-cream for 2 months. It was concluded that strict hygienic measures must be applied to prevent infections associated with Y. enterocolitica contamination.

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