Optimization of Extraction Process of RHIZOMA DIOSCOREAE Polysaccharide and Determination of Its Antioxidant Activity

[Objective] To optimize the extraction parameters of RHIZOMA DIOSCOREAE polysaccharide,and to determine its antioxidant activity.[Method] The extraction process was optimized with orthogonal test based on single factor test,and the hydroxyl radical scavenging rate of RHIZOMA DIOSCOREAE polysaccharide with different binding degree of protein was comparatively determined.[Result] The optimum extraction parameters were:extraction temperature of 60 ℃,extraction duration of 3.0 h,solid-to-liquid ratio of 1:8 and pH value of 8.Under the optimal conditions the mean extraction rate of RHIZOMA DIOSCOREAE polysaccharide was 15.1%.The antioxidant activity of RHIZOMA DIOSCOREAE polysaccharide hydrolyzed with protease,treated with Sevage method and untreated ranked the first,second and last,respectively.[Conclusion] The optimal extraction parameters were gained in this study,which provided technical support for the development of RHIZOMA DIOSCOREAE polysaccharide.