核桃青皮多糖微波辅助提取工艺及抗氧化活性研究

Study on microwave-assisted extraction and antioxidant activity of polysaccharides from Walnut husks

采用响应面分析法优化微波辅助提取核桃青皮多糖工艺,并通过与抗坏血酸对比·OH、DPPH·、ABTS+·的清除能力和总抗氧化能力,评价核桃青皮多糖抗氧化活性。结果表明:微波辅助提取核桃青皮多糖的最佳条件为水料比251(m L/g)、微波功率750 W、提取时间8.5 min、提取次数2次,在该条件下核桃青皮多糖得率可达10.17%。抗氧化试验结果显示,核桃青皮多糖具有一定的抗氧化活性,但弱于抗坏血酸。核桃青皮多糖对·OH、DPPH·、ABTS^+·的IC50值分别为83 975.520,628.800,694.733μg/m L,总抗氧化能力的FRAP值为120.42μmol/m L。

The response surface methodology was used to optimize microwave-assisted extraction process of polysaccharides from walnut husks.Compared with the ascorbic acid,the preliminary antioxidant activities of the polysaccharides was evaluated by investigated the ·OH,DPPH ·,ABTS＋· free radical scavenging capacity and total antioxidant capacity.The results showed that the optimal conditions were water-feed ratio 25∶ 1（ m L/g）,microwave power 750 W,extraction time 8. 5 min,extract2 times. Under these conditions, the yield of polysaccharides was10. 17%. The results of anti-oxidation experiment showed that the walnut husks polysaccharides had some scavenging effects,but not as good as ascorbic acid. The walnut husks polysaccharides scavenged the ·OH,DPPH·,ABTS＋· free radical as IC50 values of 83 975. 520,628. 800 and694. 733 μg / m L,and the FRAP（ total antioxidant capacity） were 120. 42μmol /m L.