Sviluppo di innovazioni tecnologiche per l’aumento della sostenibilità della filiera lattiero casearia attraverso il miglioramento della produzione, del trasporto, dello stoccaggio della materia prima e dei sottoprodotti della lavorazione

Raw sheep milk is a key resource for the Sardinian economy, but its management along the supply chain raises important food safety concerns. In the first part of the study, the impact of transport on the microbiological profile of raw sheep milk was evaluated, assessing the effect of distance and travel time on microbial proliferation. A total of 213 raw milk samples were collected along three routes with different distances and travel times. Total bacterial count, Enterobacteriaceae, Pseudomonas spp., coagulase-positive staphylococci (CPS), and non-aureus staphylococci (CNS) were analyzed by comparing farm (MF) and dairy plant (TT) values. Results showed high variability, often exceeding the limits established by Regulation (EC) No 853/2004, whereas the impact of transport was generally limited. The main variations were observed for Enterobacteriaceae, Pseudomonas spp., and CNS, and were more closely associated with farm management practices than with transport duration. In the second part, the presence and phenotypic characteristics of contaminating microbial species commonly found in milk storage and processing environments were investigated. A total of 78 strains were isolated, including 25 Pseudomonas fluorescens strains characterized by biofilm-forming ability. Biofilm formation, particularly under low-temperature and prolonged storage conditions, highlighted the persistence potential of this microorganism along the dairy chain. Biocide tests confirmed the effectiveness of alkaline detergents, although partially tolerant strains were detected. The third part focused on sampling in a sheep dairy processing plant to assess the microbiological profile of milk, whey, and scotta, with particular attention to pathogenic and spore-forming microorganisms. Overall, the results highlight the need for an integrated food safety approach considering farm practices, hygiene conditions, transport, and by-product management across the entire production chain.