The antioxidant capacity of maca has been considered to be the basis for other bioactivities, and revealing the active antioxidant compounds would help to elucidate a variety of bioactive compounds. In this study, the correlation between the antioxidant activity of maca and secondary metabolites, including ferric reducing antioxidant potential (FRAP), hydroxyl radical scavenging ability (HRSA), lipid peroxidation inhibition ability (LPIA), total phenolic contents (TPCs), total alkaloid contents (TACs), and total sterol contents (TSCs), was investigated by measuring. Chloroform was selected to be an efficient extraction solvent for antioxidant compounds in maca by polarity fractions test. The results showed that TPC exhibited significant linear correlations (P<0.05) to FRAP and LPIA, while TAC had significant linear correlations (P<0.05) to FRAP, HRSA, and LPIA. These results suggested that alkaloids and phenols were the most important substances for the antioxidation of maca, of which the antioxidant effect of alkaloids seemed to be higher than that of phenols.

This study aimed to investigate the effect of processing methods on inhibiting lipid oxidation of deep fried crickets (Gryllus bimaculatus) during storage. Four antioxidants and two packaging methods were used. The effects of different antioxidants and packaging methods on composition of fatty acids, contents of free fatty acids (FFA), peroxide value (PV), and thiobarbituric acid reactive substances (TBARSs) value of deep fried Gryllus bimaculatus were analyzed during 150 days of storage. The composition of fatty acids changed and the content of FFA, PV, and TBARs value also increased with the extension of storage time, indicating that the lipid oxidation dominated by oxidation of unsaturated fatty acids could occur in deep fried Gryllus bimaculatus during storage. In the same storage period, the total content of FFA, PV, and TBARs value of samples treated with antioxidants and vacuum-filling nitrogen packaging were lower than those of controls, suggesting that antioxidants and vacuum-filling nitrogen packaging have noticeable effects on inhibiting lipid oxidation and improving the quality of deep fried crickets, and dibutyl hydroxyl toluene (BHT) was found as the most effective antioxidant in this study. The results may provide a reliable reference for processing of deep fried edible insects.