Effect of different salting technologies on the chemical and microbiological characteristics of PDO Pecorino Siciliano cheese

The present work was carried out to evaluatethe effect of two salting technologies [dry salting (DS) andthe combined dry-brine salting (DBS)] on the chemicophysicaland microbiological characteristics of PDO PecorinoSiciliano cheeses of different final weight (6 and12 kg). Dry matter was significantly influenced by bothsalting process and final size. Twelve kilogram cheesestreated by DBS showed higher protein content with highersoluble nitrogen per cent than 6 kg cheeses. Salt contentwas in the range 3.1–4.0% on dry matter. The colour didnot show significant differences for any of the factors, but12 kg cheeses subjected to DS showed higher yellow indexthan the other cheeses. The resistance at 30% of strain wasinfluenced by cheese size, with 6 kg cheeses showinghigher resistances than 12 kg cheeses. All cheeses weredominated by coccus LAB, but pseudomonads and Enterobacteriaceaeshowed comparable levels of about 105 cfu/g.Significant microbiological differences were evidencedonly for enterococci and yeasts concerning the final cheesesize. Thirteen species of LAB, belonging to five genera(Enterococcus, Lactobacillus, Lactococcus, Pediococcusand Streptococcus), were identified, but several spoilage/pathogenic species were also identified, especially Pseudomonasputida, Citrobacter freundii and Stenotrophomonasmaltophilia. LAB isolates were preliminaryevaluated for their physiological characteristics in view of developing autochthonous starters to improve the microbiologicalquality of PDO Pecorino Siciliano cheese.