超声波处理对北五味子多糖抗氧化活性的影响

利用超声波对北五味子多糖进行改性，从而提高其抗氧化活性。以羟自由基（·OH）及1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl，DPPH）自由基清除率为指标，考察了超声波处理功率、超声波处理时间对北五味子多糖抗氧化活性的影响。结果表明：超声波处理功率、处理时间对北五味子多糖抗氧化活性有显著影响。最佳超声波处理功率为330 W、处理时间为20 min。经此条件处理后，·OH清除率由74.34%提高到87.05%，半抑制浓度（IC50）为10.7 mg/mL；DPPH自由基清除率由84.43%提高到95.05%，IC50＜2 mg/mL。适当的超声波处理可以提高北五味子多糖的抗氧化活性。

Effect of Ultrasonic Treatment on Antioxidant Activity of Polysaccharides from Mature Fruits of Schisandra chinensis

Ultrasonic treatment was employed to improve the antioxidant activity of polysaccharides from the mature fruits
of Schisandra chinensis. Based on hydroxyl and DPPH radical scavenging activity, the effects of ultrasonic power and
treatment time on antioxidant activity of polysaccharides were studied. The results showed that both ultrasonic power and
treatment time had significant effects on the antioxidant activity of polysaccharides. The optimal conditions of ultrasonic
treatment were 330 W of ultrasonic power, 20 min of treatment time. Under these conditions, the scavenging rates of
hydroxyl and DPPH radicals were increased from 74.34% to 87.05%, and from 84.43% to 95.05%, respectively. The IC50 of
the treated polysaccharides for scavenging of hydroxyl and DPPH radicals were 10.7 and less than 2 mg/mL, respectively.
In conclusion, appropriate ultrasonic treatment can improve the antioxidant activity of polysaccharides from Schisandra
chinensis fruits.