Fatty acid composition of Murazzano PDO cheese as affected by pasture vegetation types

The present study investigated the influence of botanically diverse pastures grazed by dairy ewes on the fatty acid (FA) composition of Protected Designation of Origin (PDO) Murazzano cheese. Twelve multiparous Delle Langhe ewes beyond peak of lactation were blocked according to stage of lactation, parity, milk yield, gross composition, and FA profile of milk fat, and randomly assigned to two groups. The groups were allowed to graze for three weeks on two different mountain vegetation types, either dominated by Lolium perenne L. and Trifolium repens L. (LT) or by Bromus erectus Huds., Festuca gr. rubra L. and Thymus serpyllum L. (BFT); both groups were also supplemented with 0.4 kg head-1 day-1 of concentrate during milking. Each week, bulk milk obtained from the two groups was separately used on three consecutive days to produce a total of eighteen Murazzano PDO cheeses. The FA profile of cheese was significantly influenced by the pasture vegetation type. Murazzano cheese manufactured with LT milk showed higher concentrations of total polyunsaturated FA, n3 FA, n6 FA, trans-C18:2 and -C18:1 biohydrogenation intermediates of dietary unsaturated FA, while cheese manufactured with BFT milk was significantly richer in branched-chain FA. The botanical composition of grazed pastures, significantly influencing the FA composition and nutritional quality of cheese, appears to be a key factor in the assessment of dairy products traceability.