Food authenticity using natural carbon isotopes (12C, 13C, 14C) in grass-fed and grain-fed beef

Abstract

Natural carbon isotopes, 12C, 13C, and 14C, help to authenticate/trace foods and beverages. Levels of total carbon (TC), 13C (δ13C), and 14C in muscle and lipid tissues from grass-fed versus grain-fed steers are reported. The δ13C in muscle versus lipid of steaks were around 5‰ higher in grain over grass-fed (p<0.05). The δ13C and 14C levels were higher in muscle over lipid tissues while the opposite was true for TC (p<0.05). TC content was around 20% higher in lipid over muscle due to different elemental compositions, lipid versus muscle, not carbon isotopes discrimination.