Branched-Chain Fatty Acids: a Potential Parameter for Assessing Authenticity of PDO Mountain Cheeses.

During the last decades several analytical approaches have been developed for assessing typicalness and authenticity of PDO mountain cheeses. As milk fat composition is very sensitive to changes in cow feeding, the study of fatty acid profile can give information about cow farming. In particular presence of branched-chain fatty acids (BCFAs) has been associated with the activity of rumen bacteria, especially under certain feeding practices. On this basis the levels of different BCFAs were investigated in four PDO mountain cheeses (Toma, Raschera, Bitto, Formai de Mut) and PDO Grana Padano cheese. The results demonstrated that the highest levels of 13-methyl-tridecanoic acid (i- C14) were recorded in fat of cheeses produced with milk from cows grazed or fed forage. Similar levels were found in cheese also during winter if cows were fed hay and haylage. Use of maize silage in cow diet significantly (about 60 %) reduced the amount of i-C14 in cheese fat. Overall, level of BCFAs and particularly of i-C14 allowed to distinguish