响应面法优化核桃枝多酚的提取工艺及体外抗氧化活性研究

Optimization of Extraction Technology of Polyphenols from Juglans regia Branch by Response Surface Method and Study on Its Antioxidant Activity in vitro

目的:优化核桃枝多酚的提取工艺并评价其体外抗氧化活性。方法:以核桃枝多酚提取量为响应值,以料液比、提取温度和乙醇体积分数为响应因子,在单因素试验的基础上,采用响应面法优化核桃枝多酚的提取工艺;以维生素C为阳性对照,考察核桃枝多酚对羟自由基、1,1-二苯基-2-三硝基苯肼(DPPH)自由基的清除能力及总还原能力,评价其体外抗氧化活性。结果:优化的核桃枝多酚的提取条件为料液比1∶25(g/m L)、提取温度50℃、乙醇体积分数70%;验证试验中核桃枝多酚的提取量为9.30 mg/g(RSD=0.57%,n=3)。核桃枝多酚在质量浓度分别为12.0、3.0、3.0μg/m L时对羟自由基、DPPH自由基的清除率和总还原能力分别为50.24%、95.42%、1.118,同质量浓度下维生素C的相关数据分别为93.71%、46.17%、0.628(P<0.05)。结论:用响应面法优化得到的核桃枝多酚提取工艺稳定、可行;核桃枝多酚具有一定的体外抗氧化活性。

OBJECTIVE：To optimize the extraction technology of polyphenols from Juglans regia branch and evaluate its antioxidant activity in vitro. METHODS：Using extraction amount of polyphenols from J. regia branch as response value,solvent-solid ratio,extraction temperature and ethanol volume fraction as response factors,based on single factor test,response surface method was used to optimize the extraction technology of polyphenols from J. regia branch. Using vitamin C as positive control,scavenging on hydroxyl radicals and 1,1-diphenyl-2-picrylhydrazyl（DPPH）radicals and total reducing activities of polyphenols from J. regia branch were investigated. And its antioxidant activity in vitro was evaluated. RESULTS：Optimized extraction conditions for polyphenols from J. regia branch was as follow as solid-liquid ratio of 1 ∶ 25（g/m L）,extraction temperature of 50 ℃,ethanol volume fraction of 70%. The extraction amount of polyphenols from J. regia branch was 9.30 mg/g（RSD=0.57%,n=3）in the verification test. Clearance rate on hydroxyl radicals and DPPH radicals and total reducing activity of polyphenols from J. regia branch were respectively 50.24%,95.42%,1.118 when it was under the mass concentration of 12.0,3.0,3.0 μg/m L;and the related data of vitamin C was 93.71%,46.17%,0.628 under the same mass concentration（P〈0.05）. CONCLUSIONS：Extraction technology of polyphenols from J. regia branch optimized by response surface method is stable and feasible;polyphenols from J. regia branch shows certain antioxidant activity in vitro.