Antioxidant functions of quercetin in supramolecular oxidation of bulk oil: Role of polyglycerol polyricinoleate in the mass transfer network

Using surface-active agents in bulk oils is an emerging method to increase antioxidant activity. This research aimed to investigate the effect of adding polyglycerol-polyricinoleate (PGPR) - as an improvement agent of interfacial activity - on the antioxidant activity of quercetin in bulk oil. A kinetic regime was obtained using peroxide test data, and various kinetic parameters were calculated employing a sigmoid-linear model. The oxidation rate constant in the presence of quercetin (5.294 mmol L-1) and PGPR was 1.02 meq kg-1 min-1, which decreased by 17.7% compared to the basic state. The antioxidant activity of quercetin was enhanced to 38.82, while the synergistic effect of PGPR on the inhibitory function was 35.69%. The PGPR addition improved the interfacial action of quercetin and modified its mechanisms of hydrogen donating and electron transfer. This improvement was accompanied by a decrease in the participation of the quercetin molecule and its radical in the side reactions of oxidation.