Inhibition mechanism of trans-resveratrol on thermally induced trans fatty acids in peanut oil

Abstract

The unanticipated inhibitory effect of trans-resveratrol (trans-Res) on the formation of trans fatty acids (TFAs) by thermal isomerization of peanut oil (PO) and its mechanism were investigated by experiment and density functional theory. Results showed that trans-Res inhibited the amount and formation rate of TFAs. trans-Res first inhibited the formation of C18:2, then C18:1, by the mechanism of proton transfer isomerism. The most active reaction site of trans-Res (4′-OH free radical) preferentially combined with the OOL-L-C11• (di-allyl) and then with OOL-O-C11• (mono-allyl) allyl groups in PO, resulting in the higher reaction energy barrier of speed control steps in OOL-L (transition state 1) and OOL-O (transition state 2), and the lower reaction rate of OOL-L and OOL-O (both decreased by 1–103 times), to reduce the formation of TFAs. Our study provided a theoretical foundation for the precise regulation of natural hydroxy compound to TFAs in oil.