Ruolo della microflora lattica mesofila sulla proteolisi dei formaggi tipo Grana

In addition to natural whey starter microflora, non-starter mesophilic lactic acid bacteria (NSLAB) take part in the proteolytic process in cooked body, long ageing type cheese such as Parmigiano-Reggiano. Some cheese making processes, connected to different experimental profiles, were carried out through the variation of the microbiological composition of milk, in order to identify the role of NSLAB in cheese ripening. The results highlighted the fact that the effect of NSLAB was more intense than that of traditional starters, particularly at the β-casein level with increased production of hydrophobe oligopeptids from hydrolysis of the casein fraction. Though αs1 casein does not appear to undergo the action of these microflora, nonetheless αs1l, the product of this degradation, is proteolised more quickly in NSLAB cheese than in traditional cheese. This result could lead to the conclusion that the use of NSLAB in the production of cooked body, long ageing cheese, where the use of selected starters is permitted, is a useful tool for speeding up the ageing process.