1H NMR detection of cyclopropane fatty acids in yoghurt as molecular markers for haymilk authentication

Cyclopropane fatty acids (CPFAs) in dairy products are indicators of silage feeding in cows’ diet. Since Alpine haymilk production strictly prohibits silage feeding, CPFAs analysis provides a reliable approach to verify the authenticity of haymilk. In this study, commercial yoghurt samples − primarily from Italy and Austria − were analyzed for the detection of CPFAs molecular markers using 1 H NMR. The method was validated by GC-MS. The two methods showed a strong correlation in the quantitative detection of the CPFAs (R 2 = 9480). 1 H NMR detected the CPFAs in all non-haymilk yoghurt samples, as well as in one sample derived from haymilk, with concentrations ranging from 254 to 1174 mg kg −1 of total fat. Moreover, experimental yoghurt samples showed CPFAs contents consistent with those of the starting milk. Overall, 1 H NMR represents a rapid and reliable alternative to GC-MS for the detection of CPFAs markers to assess the authenticity of haymilk in yoghurt production and verify compliance with production regulations. • Cyclopropane fatty acids (CPFAs) are molecular markers for silage feeding in dairy. • 1 H NMR detected CPFAs in yoghurt products to verify haymilk authenticity. • 1 H NMR results were validated with GC-MS. • CPFAs content in yoghurt depends on the starting milk composition.