Microbial quality evaluation of grated cheese samples collected at retail level in Calabria (Italy)

To evaluate the microbial quality of grated cheese sold in Southern Italy, a total of 47 samples were collected at retail. Enumeration of fungi performed by culture reveled concentration ranging between 1 and 5.56 Log10 CFU/g and between 1 and 4 Log10 CFU/g for yeasts and molds, respectively. Selected mold colonies (n = 95) available from 31 samples (65.96%) were further identified. In total, 27 different mold species were recorded. The top five strains were in descending order as follows: Moniliella suaveolens (21.05%, n = 20), Geotrichum candidum (9.47%, n = 9), Penicillium brevicompactum (7.36%, n = 7), Cladosporium cladosporioides (6.31%, n = 6) and Gliocladium album (5.26%, n = 5). Regarding bacterial growth, Staphylococcal cells were available from 19 out of 47 (40.42%) collected samples with a range from 1.30 to 5.15 Log10 CFU/g. Staphylococcus aureus-like colonies were not detected and similarly, pathogenic Listeria monocytogenes Salmonella and Escherichia coli was not isolated while two colonies were identified as Listeria innocua. To prevent any potential contamination and growth of pathogenic and spoilage microorganisms in dairy products including grated cheeses high hygiene standards need to be considered.