“Produzione di “Casu Marzu” in condizioni controllate: valutazione dell’effetto della colonizzazione da Piophila casei sulle caratteristiche microbiologiche e chimiche dei formaggi”

The aim of the present study was to evaluate the effect of the Piophila casei colonization under controlled conditions on “casu marzu”, a typical Sardinian sheep milk cheese. Three batches of two different kind of cheese (PO, holed paste and PC, firm paste) were produced in duplicate (test and control). Test cheeses were exposed to the Piophila casei colonization in a conditioned store room, while control cheeses were suitably protected. All the samples were analyzed at 0, 10, 30, 60 and 90 days from the production. The pH and aw, the chemical composition and the microbiological parameters (food safety and process hygiene criteria) were determined. The colonization was unhomogeneous between the batches: PO cheeses were more easily colonized and showed more intense proteolysis and lipolysis respect to PC cheeses. The microbiological parameters were strongly affected by the experimental process conditions. The authors discuss about the opportunity of a controlled production of “casu marzu” and the implications to the health of consumers.