Fate of Listeria monocytogenes during production and storage of artisan water buffalo mozzarella cheese

The study aim was to assess the behaviour of Listeria monocytogenes during the production and shelf life of artisan water buffalo mozzarella cheese (WBMC) under different storage conditions. Raw milk was deliberately contaminated by L. monocytogenes and the evolution of L. monocytogenes count during production and shelf life was monitored. In traditional WBMC production technology L. monocytogenes can multiply in the curd during ripening, but its growth rate expressed in log CFU/g/h is lower than the growth rate reported by theoretical predictions. Stretching proved to be a process with good repeatability and able to reduce L. monocytogenes contamination by about 2 Log CFU/g. The intrinsic characteristics of traditional WBMC proved to be able to obstacolate the growth of L. monocytogenes during storage even in the case of severe thermal abuse.