The Applicability of Predictive Microbiology Tools for Analysing Listeria Monocytogenes Contamination in Butter Produced by the Traditional Batch Churning Method

The study was carried out on the assumption that raw materials for butter production by the traditional batch churning method can be contaminated with Listeria monocytogenes cells. Raw milk and cream used in butter making were experimentally contaminated with the pathogen, and two contamination scenarios were considered. In the first variant, it was assumed that cream for butter making is contaminated with L. monocytogenes. The second scenario relied on the assumption that butter is contaminated during packaging. The experimental material was divided into samples and stored at a temperature of 3, 6, 9,12 or 21 degrees C. The study demonstrated that L. monocytogenes cells proliferated twice as fast in butter produced from contaminated cream as in butter that was contaminated during packaging. Results of microbiological tests conducted on raw materials, products, and rinses during batch butter production can predict the direction and rate of L. monocytogenes cell growth/inactivation. (c) 2022 Elsevier Ltd. All rights reserved.