Inhibition effects of typical antioxidants on the formation of glycidyl esters in rice oil and chemical model during high temperature exposure

Glycidyl esters (GEs) are heat-induced processing contaminants in refined oil. This study aimed to investigate the inhibition effects of seven typical antioxidants including quercetin (QU), astaxanthin (AS), tert -butylhydroquinone (TBHQ), propyl gallate (PG), L-ascorbyl palmitate (AP), puerarin (PU), and α-tocopherol (VE) on the generation of GEs in rice oil (RO) and chemical model systems during high-temperature exposure. The results showed that all selected antioxidants (0.06%, m/m) significantly inhibited the generation of GEs in both RO and chemical model systems heated at 240 °C for 1.5 h. The inhibitory effects in RO were ranked as: PG > AS > AP > PU > TBHQ > QU > VE. PG, AS and AP with different multiple antioxidant mechanisms exhibited the significantly better GEs-inhibition effects in RO (43.20%, 30.82%, and 27.72%, respectively). Further study found that increasing doses of PG led to a dose-dependent decrease in the inhibition rate of GEs in RO. Amazingly, AS could promote the formation of GEs in RO heated at 270 °C. The GEs inhibition of PG and AS in RO exhibited a remarkable time-dependent effect. These results may widen the knowledge for the chemical inhibition of GEs by blocking reaction path, and also provide new perspective on GEs inhibition in refined oil by natural compounds.