Abstract: 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).

Key words: salting-out extraction, ethanol/ammonium sulfate, phenolic compounds, antioxidant activity, partitioning

摘要： 采用乙醇/（NH₄）₂SO₄两相盐析体系，从酿酒副产物葡萄籽中提取多酚、类黄酮和原花青素。实验结果表明，在室温下用组成（质量分数）为30%乙醇/18%（NH₄）₂SO₄的体系提取葡萄籽中多酚、类黄酮以及原花青素，得率分别为64.54、42.45、23.16 mg·g^-1；它们富集于上相乙醇相，萃取回收率分别为97.31%、98.19%、97.92%。室温条件下用2，2-二苯基-1-苦基肼（DPPH）法与2，2'-连氮基-双-（3-乙基苯并二氢噻唑啉-6-磺酸）（ABTS）法测定两相盐析萃取物抗氧化、清除自由基能力，IC₅₀分别为61.85、71.76 mg·L^-1，比传统的热回流提取物具有更强的抗氧化活性。

关键词: 盐析萃取, 乙醇/硫酸铵, 多酚, 抗氧化活性, 分配