铁皮石斛叶多糖提取工艺优化及其抗氧化活性

Optimization of extraction process of polysaccharides from Dendrobium officinale leaves and its antioxidant activity

在单因素试验的基础上,采用响应面试验法优化铁皮石斛叶多糖超声波-微波协同提取工艺。同时,通过测定清除DPPH自由基和ABTS自由基能力,考察铁皮石斛叶多糖的抗氧化活性。结果表明:铁皮石斛叶多糖的最优提取工艺条件为:提取时间30min、微波功率350W、超声波功率50W、液料比35∶1(mL/g)、提取2次。在此条件下,铁皮石斛叶多糖得率为14.03%。抗氧化实验结果表明:铁皮石斛叶多糖和VC对DPPH自由基半数清除率(IC_(50))分别为0.639mg/mL、0.358mg/mL,对ABTS自由基半数清除率(IC_(50))分别为0.608mg/mL、0.293mg/mL,清除率与多糖质量浓度呈正比例关系。超声波-微波协同提取铁皮石斛叶多糖具有提取得率高、时间短的优点,铁皮石斛叶多糖具有一定的抗氧化活性,但弱于VC。

Response surface methodology was used to optimize ultrasonic-microwave assisted extraction of polysaccharides from Dendrobium officinale leaves.Meanwhile,the antioxidant activities of polysaccharides from Dendrobium officinale leaves were investigated by scavenging free radicals of DPPH and ABTS.The results showed that the optimal extraction conditions were:extraction time 30min,microwave power 350W,ultrasonic power 50W,liquid-solid ratio 35∶1(mL/g),and extraction times twice.Under these conditions,polysaccharides yield of polysaccharide from Dendrobium officinale leaves was 14.03%.The results showed DPPH radical half scavenging rates of polysaccharide and VC were 0.639mg/mL and 0.358mg/mL,respectively.The ABTS radical half scavenging rates of the polysaccharide and VC were 0.608 mg/mL and 0.293 mg/mL,respectively.The scavenging rates had positive correlation to the polysaccharide mass concentration.The ultrasonic-microwave assisted extraction had the advantages of high extraction yield and short extraction time.Polysaccharide from Dendrobium officinale leaves had some antioxidant activity,but were weaker than VC.