摘要：以洋葱为原料，对洋葱多糖的提取、分离纯化及抗氧化活性进行了研究。脱蛋白的最佳方法为木瓜蛋白酶-Sevag法脱蛋白；AB-8为最佳脱色树脂，树脂用量25 g，0.5 mL/min的速度吸附，溶液pH 5.5脱色效果最好。对洋葱多糖提取液进行超滤实验，应采用10×103的超滤膜。洋葱对-OH的清除效果好，对O2--的清除效果弱，具有较强的还原能力，且随浓度的增大还原力逐渐增强。

关键词 洋葱；多糖；提取；分离纯化；抗氧化

Abstract：Onions were used as raw material in this paper, and its extraction, purification, monosaccharide and antioxidant activity were studied. The best way of deproteinization is the Papain-Sevag method; AB-8macroporous resin has the better adsorption abilities, the weight of AB-8 was 25 g. When the moving speed was 0.5 mL/min, the pH was 5.5 . Ultrafiltration experiment was used in the separation and purification of onion polysaccharide，the best was 10×103 of the membrane. The onion polysaccharides have strong scavenging effects on hydroxyl radicals, the scavenging effect on superoxide radical was not abvious. Moreover, onion polysaccharides have certain reductive capability, and its ability increased with the concentration gradually.

Keywords  Nion  Olysaccharide  Extraction  Reification  Ntioxidantactivity