马齿苋多糖提取工艺优选及活性初筛

Optimization of polysoccharides extraction from Portulaca oleracea L. and its actirity prelinunary screening

以多糖提取得率为指标,采用正交试验对加酶超声辅助法提取马齿苋多糖的工艺条件进行了优化。方法:以未经酶解和未采用超声处理的传统水提醇沉法得到的多糖做对照,通过近红外光谱分析加酶超声处理对马齿苋多糖结构的影响并对马齿苋多糖的抗氧化活性进行分析。结果表明:在纤维素酶2.5%,超声温度60℃,超声功率70 W,超声时间20 min,多糖提取得率达到18.40%。结论:近红外光谱分析表明,加酶超声对多糖的结构没有显著影响,提高了多糖提取率。体外抗氧化性实验表明,所提取马齿苋多糖具有较强的总抗氧化能力,对.OH和DPPH均有较好的清除能力,活性大小与多糖的浓度呈明显的线性关系。

To optimize the extraction conditions of polysaccharides from Portulaca oleracea L.by ultrasound-assisted enzymolysis method and extraction yield as evaluation index.Methods： Effectiveness of enzymatic hydrolysis and ultrasonic treatment on the structure of Portulaca oleracea L.polysaccharides was evaluated through the near infrared spectral analysis,the non-enzymolysis and without ultrasound-assisted treatment was used as control.The results showed that the optimal extraction conditions of ultrasound-assisted enzymolysis method were as follows： cellulase 2.5%,ultrasonic temperature 60 ℃,ultrasonic power 70W,ultrasonic time 20min.Under these conditions,the yield of crude polysaccharide was up to 18.40%.The result of near infrared spectral analysis showed that enzymatic hydrolysis and ultrasonic assisted extraction technology improved the extraction yield of polysaccharides with no significant effect on the structure of Portulaca oleracea L.polysaccharides.Portulaca oleracea L.polysaccharides had remarkable total antioxidant capacity,and good scavenging activities on DPPH· and ·OH.Furthermore,the scavenging activity had a significant correlation with polysaccharides concentration.