香菇多糖提取工艺的优化及其抗氧化活性研究

为了提高香菇多糖的得率和抗氧化活性,本文采用超声波辅助法提取香菇多糖,在单因素实验的基础上,利用响应曲面法对提取工艺进行优化,并对优化条件下提取的香菇多糖进行体外抗氧化活性测定和结构分析。优化后的最佳提取工艺为超声时间50min、超声温度62℃、超声功率640W。此优化条件下香菇多糖的得率为7.34%,氧自由基吸收能力(ORAC值)为821.35μmol Trolox/g,实验测得数据与预测值无显著性差异。测定产物香菇多糖的羟基自由基的清除能力、ABTS自由基清除能力和还原力,结果表明提取后的香菇多糖具有较高的抗氧化活性。进行红外光谱分析发现超声提取多糖具有多糖的特征吸收峰,说明化学结构没有明显改变。 

Optimization of ultrasonic extraction of polysaccharides from Lentinan and there bioactive activities

To improve the extraction yield and the antioxidant activity, the Lentinan polysaccharides were obtained by ultrasonic assisted water extraction in this study.And a Box-Behnken design was employed to optimize the ultrasound extraction based on single factor experiments.The polysaccharides extracted under the optimized condition were conducted to determinate the antioxidant activity in vitro and their structures.The optimal conditions were as follows: time 50min, temperature 62℃, ultrasound power 640W。Under optimal conditions, the extraction yield achieved 7.34%, and the Oxygen Radical Absorbance Capacity (ORAC value) was 821.35μmol Trolox /g, with no significant difference to the predictive values.The scavenging activity of ABST radicals, hydroxyl radicals and reducing power were employed to evaluate the antioxidant of polysaccharides.The results showed that the extraction polysaccharides possessed considerable higher antioxidant activity.The polysaccharides showed typical absorption peaks by infrared spectroscopy, indicating that the chemical structure did not change significantly compared with those of polysaccharides prepared by traditional hot water extraction.