响应面优化龙胆多糖的提取工艺及抗氧化性研究

该研究优化了龙胆草多糖的提取工艺，并对其体外抗氧化活性进行了评价。在单因素试验的基础上，选择醇沉浓度，提取温度，提取时间，液料比为考察因素，以龙胆草多糖提取率为响应值，应用Box-Behnken试验进行四因素三水平设计，采用响应面法来优化龙胆草多糖的提取工艺。并评价龙胆草多糖清除DPPH·﹑ABTS+·﹑OH·﹑O2-·作用以及总还原能力。结果表明，龙胆草多糖的最佳提取工艺为醇沉体积分数为90%，提取时间为2 h，液料比为26∶1（mL∶g），提取温度为75 ℃；龙胆草多糖的实际提取率为（5.89±0.25）%，与预测值相比，偏差较小。龙胆草多糖有一定的抗氧化活性，但活性均小于同浓度的维生素C。

Extraction optimization and antioxidant activity of Gentian polysaccharides by response surface methodology

The extraction technology of polysaccharide from Gentiana scabra Bunge was optimized and the in vitro antioxidant activity was evaluated. On the basis of single factor experiments, using alcohol precipitation concentration, extraction temperature, time and liquid-solid ratio as affecting factors, Gentian polysaccharide extraction ratio as response value, four factors and three levels Box-Behnken experiments were designed, and then the extraction technology was optimized by response surface methodology. The scavenging effect of Gentian polysaccharide on DPPH·, ABTS·, OH·, O2-· was evaluated. Results showed that the optimum extraction conditions for Gentian polysaccharide was ethanol concentration 90%, extraction time 2 h, liquid-solid ratio 26∶1 (ml∶g), temperature 75 ℃. The actual extraction rate of polysaccharide from G. scabra was (5.89±0.25)%, and the deviation was quite small compared with the predicted values. Gentian polysaccharide had certain antioxidant activity, but it was less than vitamin C with the same concentration.