Comparison of Deproteinization Methods for Onion Crude Polysaccharide

In order to explore the best deproteinizaion method of onion polysaccharide,the deproteinization effects of four methods were compared based on the indexes of deproteinization percentage,polysaccharide loss rate,capacity of polysaccharide solutions scavenging hydroxyl radicals and its reducing power. The results showed that when the Sevag method was repeated four times,the deproteinization percentage was 79. 44%,the polysaccharide loss rate was 22. 30% and the IC50 of polysaccharide solutions scavenging hydroxyl radicals was 16. 00 μg/m L,the deproteinization polysaccharide also had higher reductive capability. The effective order of four methods is Sevag method,then lead acetate method and HCl method,and finally trichloroaceticacid method.