Discrimination between Slovenian cow, goat and sheep milk and cheese according to geographical origin using a combination of elemental content and stable isotope data

The presented work uses stable isotope ratios of major bioelements (13C/12C, 15N/14N, 18O/16O, 34S/32S) and elemental composition to determine the regional provenance of 124 Slovenian milk and 30 cheese samples collected during May, June and July in 2012 and 2013. The ability to discriminate between cow milk based on geographical origin was only possible in summer 2012, where discriminant analysis identified Cl, Zn, P, Ca and K as the most significant parameters. Both sheep milk and cheese could be distinguished according to their geographical origin based on P, S, K, Cl, Ca, Zn content and δ13C and δ15N values in casein and to refuse possible imitations with a correct classification in 97% of cases. Furthermore, stable isotopes of light elements in combination with elemental composition can distinguish sheep and goat milk and cheese from that produced from cow milk with a prediction ability of 95.2%. Such methodology can effectively contribute towards supporting the existence of the Protected Designated Origin of Bovški and Kraški sheep cheese and Tolminc cow cheese and could be incorporated into a traceability system.