Study of the development of Listeria monocytogenes in raw milk butter

Currently, Listeria monocytogenes is considered one of the most important foodborne pathogens. It is often implicated in epidemics of human listeriosis that represents a real health risk, given the high mortality rate (over 25%) of infected persons. Listeria monocytogenes can directly or indirectly contaminate products and the environment, which makes Listeria a worrying pathogen for the dairy industry.
The Commission Regulation (EC) 2073/2005 on microbiological criteria for foodstuffs, imposes an absence of this pathogen in 25g of the products able to support the growth of Listeria monocytogenes.
This criterion is applicable to products before they leave the immediate control of the food business operator, unless the manufacturer is able to demonstrate, to the satisfaction of the competent authority, that the product will comply with the limit of 100 cfu/g throughout the shelf life.
As butter is a product with a wide variation in the production process, more information and data on the growth and survival of Listeria monocytogenes in relation to formulation and butter structure are therefore needed.