Valutazione del profilo microbico dei formaggi Asiago DOP e Toma Piemontese in relazione alla formazione vegetazionale del pascolo.

The Asiago PDO cheese was produced in the upper Asiago highlands using milk from two homogeneous groups of animals. The 2 groups fed on rich and poor fescue grass, respectively. The Toma Piemontese PDO cheese was made in the Alpe Valcavera alpine pasture (Valle Stura di Demonte), from the milk of 2 groups of animals grazing on fescue and clover grass, respectively. For a preliminary characterization of the microflora of the cheeses, analyses were conducted to identify microflora useful for dairy processes (lactic acid bacteria homo and heterofermentative, cocci and rods, bacteria able to confer particular flavors peculiar to cheeses - like enterococci and propionibacteria) and microflora harmful to such processes (coliform, E. coli, yeasts, moulds and contaminant bacteria). According to the results, it was possible to individualize different microbial profiles for the 2 cheeses. The most important differences regard the content in propionibacteria (higher in Asiago PDO cheese) and heterofermentative lactic acid bacteria (higher in Toma Piemontese PDO cheese). Considering the cheese microflora in relation to the different pastures, significant differences were found only for the Toma Piemontese PDO cheese, where the content of propionibacteria was higher in the cheese produced from the milk of cows grazing on fescue grass, while the content of coagulase-positive staphylococci was higher in the cheese made from the milk the clover pasture group. On the contrary, no relevant differences were found in Asiago PDO cheese between the products derived from the 2 different vegetations of the pasture-lands