Modified Chinese quince oligomeric proanthocyanidin protects deep-frying oil quality by inhibiting oxidation.

Chinese quince (Chaenomeles sinensis) fruit is an underutilized resource, rich in proanthocyanidins with antioxidant ability but poor lipid solubility. In this study, a novel modified oligomeric proanthocyanidin (MOPA) was prepared, which exhibited favorable lipid solubility (354.52 mg/100 g). It showed higher radical scavenging abilities than commercial antioxidant-BHA (butylated hydroxyanisole), both at 0.4-0.5 mg/mL. The addition of MOPA (0.04 %wt.) significantly increased the oxidative stability index of the soybean oil from 5.52 to 8.03 h, which was slightly lower than that of BHA (8.35 h). Analysis of the physicochemical properties and composition of oil during deep-frying showed that MOPA demonstrated significant antioxidant effects and effectively restricted the oil oxidation. This inhibition also delays the formation of heterocyclic amines (HAs) in fried food, thereby reducing the migration of HAs from food to deep-frying oil. Therefore, MOPA is a promising novel liposoluble antioxidant for protecting the quality of deep-frying oil.