Abstract: The purpose of this study was to investigate the antioxidant properties of soy lipophilic protein (SLP) and to analyze its amino acid and fatty acid profiles by amino acid automatic analyzer and gas chromatography (GC). The results showed that compared with soy protein isolate (SPI), 11S and 7S globulin, SLP was richer in branched-chained amino acids (16.44 g/100 g). A total of 27 fat acids were identified, mainly including palmitic acid, heptadecanoic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, and arachidic acid, with unsaturated fatty acids accounting for 66.55% of the total fatty acids. The in vitro antioxidant assay results showed that SLP had strong scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulphonate (ABTS) cation radicals, and ferric reducing-antioxidant power (FRAP), owing to the high content of Cys, Tyr and disulfide bonds, abundant phospholipids with good amphipathic property and a large hydrophobic core. The results provide theoretical support for the development and utilization of SLP as a functional protein in the fields of antioxidant and muscle building.

Key words: soy lipophilic protein; amino acid profile; fatty acid composition; antioxidant properties