Gorgonzola, one of the most important Italian cheeses, awarded
with the “Protected Denomination of Origin” (PDO) from the European
Commission (EU Regulation, 1996), represents an optimal
food substrate for the growth of Listeria monocytogenes (Lomonaco,
Patti, Knabel, & Civera, 2012). Gorgonzola is a blue-veined, mouldripened
cheese, made with pasteurised cow's milk and characterised
by a final pH ranging from 4.5 to 6.5 and a sodium chloride
content of 2.3e7%. During ripening, biochemical changes due to the
proteolytic activity of Penicillium roqueforti, that develops as an
internal blue-green mould, cause an increase in pH, influencing the
microflora's evolution and favouring possible contamination by