绿茶茶多酚超临界CO2提取及体外抗氧化活性检测

［目的］研究绿茶茶多酚超临界CO2提取工艺及茶多酚体外抗氧化活性。［方法］利用超临界CO2（SCFCO2）萃取绿茶中的茶多酚，以茶多酚提取率为响应值，采用响应面法对萃取工艺予以优化，对所得粗品茶多酚精制后进行体外抗氧化活性研究。［结果］萃取试验结果表明优化萃取工艺条件为：CO2压力25MPa、萃取温度80℃、萃取时间2.5h，在此条件下，SCFCO2可将绿茶中47.50%的茶多酚提取出来；抗氧化试验结果表明：SCFCO2萃取的茶多酚具有优异的清除DPPH自由基、羟自由基活性和较强的清除超氧负离子自由基活性，具有突出的还原能力（与VC基本相当）和抑制猪油氧化的能力，其抗氧化活性相当于或优于VC且明显高于乙酸维生素E。［结论］该研究提取的绿茶茶多酚具有较强的体外抗氧化活性。

The Extraction of Green Tea Polyphenols by Supercritical Carbon Dioxide Fluid and Determination of Its' Antioxidation Activity in vitro

Objective]The research aimed to study the optimal conditions of green tea polyphenols(GTP)extraction and the antioxidation activities of purified GTP in vitro.Method]Technological conditions of extracting green tea polyphenols from green tea by supercritical carbon dioxide fluid(SCF-CO2)were optimized by response surface methodology(RSM),in which the extraction rate of GTP was taken as response value.After the extracted crude TP was refined,the antioxidation activities of purified GTP in vitro were invest...