Shelf-life of blue molded cheeses packaged in polylactic acid trays

The shelf-life of hard and semi-hard cheeses is usually prolonged by means modified atmosphere packaging in very high barrier materials, in order to prevent as long as possible the interactions between cheese and oxygen, responsible for microbiological and oxidative decay. However, the complete exclusion of oxygen into the headspace of packages containing "respiring cheeses" may be detrimental for their right and prolonged preservation. In this work the possible use of poly(lactic acid) (PLA) for the packaging of Gorgonzola cheese will be discussed. A predictive simple model was used to foresee the atmosphere evolution inside the PLA trays, as a function of the cheese respiration rates and the package OTR. According to the result obtained, slices of Gorgonzola were packaged in the selected PLA trays and stored at 4° C for a month. The analytical controls performed at fixed interval of time (headspace composition, pH, color, weight loss) demonstrated that the use of PLA allows a good refrigerated shelf-life of Gorgonzola up to 4 weeks.