PHYSICAL AND CHEMICAL-CHANGES IN VACUUM-PACKAGED PARMIGIANO REGGIANO CHEESE DURING STORAGE AT 25, 2 AND -25C

Parmigiano Reggiano (PR) cheese, packed in single 20g portions under v acuum, was stored at three different temperatures (25C, 2C and -25C) t o evaluate chemical and physical changes in the product during 120 day s of storage, There was no increase in lipid oxidation, even though th e presence of pentane in the head space showed that the PR samples wer e already slightly oxidized following the 18 months of ripening proces s. Color and water activity determinations led to the hypothesis that the lipid fraction migrated to the sample surface when stored at 25C. Other changes observed by the authors influenced the modification of t he flavor and a decrease in the overall acceptance of the PR samples p acked under vacuum and stored at room temperature. However, they did n ot seem to be related to lipid oxidation.