Mitigation mechanism of resveratrol on thermally induced trans-α-linolenic acid of trilinolenin

Investigations in the control of the thermal isomerization of trans fatty acids (TFAs) in edible oils are of great significance in effectively improving the safety of edible oil. The mitigation mechanism of resveratrol (Res) on thermally induced trans-α-linolenic acids (TALAs) of trilinolenin was delved by gas chromatography and density functional theory. The results revealed that the mitigative rate of Res on TALAs in trilinolenin increased with the heating temperature and time, and C18-3:9c,12c,15t (3.82–13.90%) > C18-3:9t,12c,15c (3.47–11.50%) > C18-3:9c,12t,15c (3.82–4.22%). After heating at 180 °C and 200 °C for 4 h and 8 h without oxygen, the mitigation of TALAs by Res was mainly exerted by the hydrogen extraction and proton transfer isomerism mechanism. Both mitigation mechanisms were that Res firstly bound to the Ln allyl position to increase molecular steric hindrance, thereby preventing the bond rotation and proton transfer to inhibit the formation of TALAs; Res was preferentially bound to the di-allyl sites (Ln-11 site > Ln-14 site), followed by the mono-allyl sites (Ln-17 site > Ln-8 site). The study provides a theoretical foundation for the precise control of TALAs in edible oil systems.