Determination of organic milk authenticity using carbon and nitrogen natural isotopes

- Organic milk authenticity was determined by using δ13C and δ15N.
- Mean carbon isotope ratio (δ13C) was higher in organic milk (OM) than in conventional milk (CM).
- Mean nitrogen isotope ratio (δ15N) was lower in the OM than in the CM.
- The combination of δ13C and δ15N was more effectively distinguished between OM and CM.