Identification of Lipid Biomarkers to Discriminate between the Different Production Systems for Asiago PDO Cheese

The lipid fraction of Asiago Protected Designation of Origin (PDO) cheese was analyzed to identify specific biomarkers of its main production systems through a canonical discriminant analysis. The three main production systems of the cheese were considered. Two were located in the upland (UL): pasture-based (P-UL) vs hay-based total mixed rations (H-UL). The third was located in the lowland (LL) and processed milk from cows fed maize silage-based rations (maize silage lowland: MS-LL). The discriminant analysis selected nine fatty acids and vitamin A as lipid biomarkers useful to separate the three production systems. High contents of conjugated linoleic acids, anteiso-C15:0, and vitamin A were discriminant factors for P-UL cheese. The separation between H-UL and MS-LL cheese was less marked with the former having the higher content of conjugated linoleic acids and some polyunsaturated n-6 fatty acids and with the latter being identified by cyclopropane fatty acid and C9:0.