Conjugated linoleic acid and C18:1 isomers content in milk fat of sheep and their transfer to Pecorino Toscano cheese

The aim of the study was to evaluate the transfer of conjugated linoleic acid (CLA) and of C18:1 isomers from sheep milk to Pecorino Toscano protected denomination of origin cheese and to monitor the stability of these fatty acids during ripening. The total content of C18:1 fatty acids was not affected by milk treatment but there were changes in the isomers profile. In particular, the milk trans11 C18:1 decreased with pasteurization and after starter culture addition. In contrast, trans10 C18:1 and cis9, trans11 C18:2 were enhanced by the thermal treatment of milk. The fatty acid profile of cheese reflected that of milk used for cheese making with the exception of the C18:1 and CLA isomer profile. The cheese ripening affected the percentage of cis9, trans11 C18:2, which increased more than 10% on total content of CLA.