Identification and quantification of synergetic antioxidants and their application in sunflower oil

Abstract

Combined antioxidants play indispensable roles in inhibiting lipid peroxidation and further preventing food deterioration. However, synergetic antioxidants are now identified stochastically and blindly. Herein, a reasonable and precise approach has been established for identification and quantitation of the binary antioxidants with synergistic interactions. Our results demonstrated that, among ascorbic acid (AA), α-tocopherol, ascorbyl palmitate (AP), rosemary extracts (RE), tea polyphenol palmitate (TP) and tea polyphenol (T), the combination of RE and TP was superior to scavenge DPPH and ABTS radicals, and the optimal ratio was theoretically 5:3. Intriguingly, the addition induction period (aIP) of sunflower oil with this combination at the ratio of 5:3 was 3.63 and 1.91 folds of individual RE and TP, respectively. Electron spin resonance (ESR) further confirmed that these binary antioxidants were effectively reduced alkyl, peroxyl and α-phenyl-N-tert-butylnitrone (PBN) like radicals. Therefore, this approach is feasible and effective to identify and quantify the synergistic antioxidants with the function of scavenging DPPH and ABTS radicals, and providing theoretical support for the implication of binary antioxidants in food industry.