The effects of the traditional producing system on physicochemical, microbial and sensory properties of Caciocavallo Palermitano cheese

Abstract

Caciocavallo Palermitano (CP) is a traditional cheese made with raw milk from cows of Sicilian local breeds fed pasture-based diets in extensive farms (EXT), processed by an artisanal technology (ART) based on wooden tools and the action of native microflora. CP is obtained also in intensive farms (INT) where milk from cows of specialized breeds fed dry diets is transformed by advanced procedures (ADV) using a stainless steel equipment and lactic acid starter cultures. This research was planned to investigate the changes in cheese properties due to production system and ripening., Milk was collected 3 times from an EXT and an INT farm and processed in ART and ADV conditions. The 12 produced CP were evaluated at 30, 60 and 120d. EXT CP showed higher yield and protein, lower fat, NaCl and soluble N, a less yellow color, a smoother paste, and a sweeter, less bitter and salty, and more acidic taste than INT CP. The pasture led to EXT CP with a beneficial FA profile to human health, richer in PUFA, n-3 FA and CLA. ART CP showed lower yield, higher fat and color indexes, lower NaCl and soluble N, a harder and more compact paste, with less holes, and at taste was less bitter, salty and acidic, and more piquant than ADV CP. During ripening, the soluble N, the yellow color and the consistency of paste increased. In ART CP, the proteolysis was slower, and the increasing of yellow color was more intense. The microbial analysis of ART CP showed that the wooden vat is a reservoir of lactic acid bacteria (LAB) inoculating milk, among which strains of Streptococcus thermophilus were dominant and acted as a starter culture, while undesired microorganisms were absent or very low. During ripening, all LAB decreased except enterococci. The canonical discriminant analysis of physicochemical and microbial data was able to separate CP from different productions and ripening time. Among dominant LAB, 10 species were genetically identified at strain level and some of them showed antibacterial activity. In ART CP, the comparison of polymorphic profiles of LAB strains isolated from the wooden vat with those of strains collected during maturation showed the persistence of 3 Enterococcus spp. strains, among which E. faecalis was found at dominant level till 120d. The absence of these strains in ADV CP evidenced the contribution of the wooden vat LAB during ripening. EXT and ART CP showed the best features in terms of hygienic safety, health benefits and typical sensory properties.