Ail the different kinds of grated cheeses offered by the supermarket s
tores in the area of Milan have been collected. Their quality has been
evaluated through sensorial, microbiological and chemical tests, part
icularly as lipid oxidation was concerned. From a packaging point of v
iew the samples could be divided into three categories: samples closed
under air into plastic pouches (namely aria), samples in flexible or
rigid containers under vacuum or in modified atmosphere (namely MAP-SV
) and samples in expanded polystyrene trays overwrapped by a cling fil
m (namely freschi). These last samples, certainly prepared for a very
short shelf-life, always appeared as the best in quality, followed by
the cheeses in MAP-SV which had longer shelf-lives; samples in air, fr
equently resulted to be dried cheeses, were the least appreciated by t
he panelists and showed the poorest chemical and microbiological index
es. The overall results of this screening underline the importance of
correct packaging choices and demonstrate that modified atmosphere or
under vacuum packaging guarantee high quality standards during the con
servation of these products.