核桃内种皮多酚提取工艺及其体外抗氧化活性的初步研究

Optimization of extraction technology and in vitro antioxidant activities of polyphenols from walnut kernel pellicle

采用单因素试验和正交试验优化核桃内种皮多酚的回流提取工艺条件,采用清除羟自由基(·OH)、超氧阴离子(·O2-)、过氧化氢(H2O2)评价核桃内种皮多酚的体外抗氧化活性。结果表明,核桃内种皮多酚提取工艺条件:乙醇体积分数45%、液固比60:1(mL∶g)、提取温度70℃、提取时间60 min。在此条件下,多酚得率为25.05%。核桃内种皮多酚具有显著的清除·OH、·O2-和H2O2的能力,其中,当质量浓度为160μg/mL时,对·OH的清除率达100%,优于维生素C。

Extraction technology ofpolyphenols from walnut kernel pellicle was optimized by single-factor and orthogonal experiments.Meanwhile,the in vitro antioxidant activities of polyphenols from walnut kernel pellicle were evaluated by detecting hydroxyl radical （· OH）,superoxide anion （· O2） and hydrogen peroxide （H2O2） scavenging rates.Results showed that the optimized extraction conditions were as follows：ethanol concentration 45％,liqnid-solid ratio 60：1,temperature 70 ℃,and extraction time 60 min.Under such condition,the polyphenol extraction yield was 25.05％.Antioxidant experiments showed that polyphenols of walnut kernel pellicle had significant scavenging effect on · OH,· O2 and H2O2.When the polyphone concentration was 160 μg/ml,the · OH scavenging rate of polyphenols from walnut kernel pellicle was 100％,which was higher than vitamin C.