The aim of the focus action "Listeria in blue cheese" was to determine the extent of contamination of blue cheese with Listeria monocytogenes. A total of 70 samples (origin EU) were tested.

• Not a single sample had to be rejected

Blue cheese belongs to the group of soft cheeses and is mainly produced from pasteurized milk. Special mold cultures (mostly Penicillium roqueforti) are responsible for the typical aroma and appearance of these cheeses. Like all soft cheeses, mold cheeses form a rind in the course of ripening, which differs from the cheese interior not only in the composition of the ripening flora but also in chemical parameters (e.g. pH). The increase in pH in the peripheral areas of the cheese offers any listeria present good conditions for multiplication and makes blue cheese, as well as other soft cheeses (lubricated soft cheeses, white mold cheeses), risk products with regard to listeria.