Salting-out extraction system composed of ethanol and ammonium sulfate was used to separate total phenolics

flavonoid

and proanthocyanidin from wine grape seed. The experimental results showed that components were extracted into the top ethanol-rich phase (the system consisted of 30% (mass) ethanol/18% (mass) ammonium sulfate) to give the yield of total phenolics

flavonoid

and proanthocyanidin in 64.54

42.45

and 23.16 mg·g-1

and corresponding recovery rates in 97.31%

98.19%

and 97.92%

respectively. The antioxidant activity of seed extracts were assayed with radical-scavenging ability (IC50) of 2

2-diphenyl-1-picrylhydrazyl and 2

2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) at room temperature. The seed extracts by salting-out extraction showed lower IC50 (61.85 and 71.76 mg·L-1) than that by heat reflux extraction (78.73 and 90.34 mg·L-1).