荷叶多糖的酵母菌发酵提取及体外抗氧化活性研究OA

Objective To optimize the fermentation conditions for extracting polysaccharides from lotus leaf powder and to evaluate the antioxidant activity of the obtained polysaccharides.Methods Using the yield of lotus leaf polysaccharide as the response value,the opti-mum fermentation conditions were determined by single factor experiments and response surface methodology.The scavenging rate of lotus leaf polysaccharide against 2,2-diphenyl-1-picrylhydrazyl(DPPH·)and hydroxyl radical(·OH)were determined by ultraviolet spectro-photometry.Results The optimal conditions for the extraction of lotus leaf polysaccharide by yeast fermentation were as follows:fermentation temperature 27.6℃,fermentation time 48 h,yeast addition 2.6%,and liquid-solid ratio 26mL/g.Under these conditions,the extraction rate of crude polysaccharide was 4.19%,with a polysaccharide content of 19.30%.The scavenging rates of DPPH·and·OH were 73.3%and 93.4%,respectively.Conclusion The yeast fermentation method can not only improve the extraction rate of lotus leaf polysac-charide,but also enhance its antioxidant activity,providing a reference for the industrial extraction of lotus leaf polysaccharide.