Evolution of the Microbiological Profile of Vacuum-Packed Cheese During Shelf-Life.

cheese is a salted variety of traditionally made in Sardinia (Italy) from the whey remaining after the production of protected designation of origin or other sheep milk cheeses. cheese is very critical for the possible growth of pathogenic and spoilage microorganisms. Sporadic cases of listeriosis associated with cheese have been reported over recent years. The objective of the present study was to assess the evolution of spoilage and pathogen microorganism of vacuum-packed cheese during the entire product shelf-life. The durability study was conducted on 18 vacuum-packed cheese samples analysed at the beginning of the shelf-life and after 60 and 90 days of refrigerated storage. Pathogens as and were never detected. During shelf-life total bacterial counts ranged between 7.90±0.64 and 9.19±0.58 CFU g on the rind and between 2.95±0.68 and 4.27±1.10 CFU g in the inner paste, while ranged between 4.22±0.66 and 5.30±0.73 CFU g on the rind and 3.13±1.80 and 2.80±0.88 CFU g in the inner paste. By considering the technology used, the intrinsic properties and the almost total absence of competing microflora, cheese can support the growth of spoilage and pathogen microorganisms originating from the processing environment. The high level of total bacterial counts and observed both on the rind and in the inner paste suggests contamination of the product from the processing environment. Therefore, a strict implementation of hygiene during processing is essential in order to reduce the load of environmental contaminants that may grow during refrigerated storage.