微生物发酵法制备铁皮石斛多糖及抗氧化活性的研究

采用微生物发酵法提取铁皮石斛中的多糖,探讨料液比和pH对多糖提取率的影响,并评价多糖的体外抗氧化活性。2因素3水平正交法优化的铁皮石斛多糖提取,料液比为1∶90(g/mL),pH为5,在此条件下的多糖提取率为42.86%;探究微生物发酵铁皮石斛多糖对羟自由基和DPPH自由基的清除作用,结果显示,微生物发酵法制备的铁皮石斛粗多糖具有一定的抗氧化性,且自由基清除率在一定范围内随浓度增加而增强。

Study on the Extraction and Antioxidant Activity of Dendrobium candidum Polysaccharides Obtained by Microbial Fermentation

Using microbial fermentation method to extract polysaccharides from Dendrobium candidum,solid-liquid ratio and fermentation pH were selected as single factors for polysaccharides extraction,and to evaluate the antioxidant activity of polysaccharides in vitro. The optimum conditions obtained by two factors and three levels orthogonal method of Dendrobium candidum polysaccharides extraction were as follows:the solid-liquid ratio was 1:90,the pH value was 5,the polysaccharides extraction ratio in this condition was 42.86%;experiments were operated on scavenging the hydroxyl radical,DPPH radical and superoxide anion radical of the polysaccharides extract by microbial fermentation, results showed that crude Dendrobium can-didum polysaccharides had certain antioxidant activity and the antioxidant activity showed dose-effect relationship at selected concentrations.