蒙古栎种壳多酚的超声辅助提取及抗氧化能力

采用超声辅助提取法对蒙古栎种壳多酚进行了提取。对超声提取过程中的各因素在单因素实验的基础上应用Box Behnken中心组合进行3因素3水平的实验设计法进行了得率与纯度双响应值的优化，得到蒙古栎种壳多酚最佳提取工艺条件为：乙醇体积分数为60.56%，液料比30.72∶1 mL·g^-1，提取时间42.39 min，在此条件下蒙古栎种壳多酚平均得率为0.38%，平均纯度为18.8%，该多酚清除DPPH自由基的EC₅₀值为176 μg·mL^-1，高于合成抗氧化剂BHA和BHT等。

Extraction Process and Antioxidant Activity of Polyphenols from Testa of Quercus mongolica Fischer

In this study, ultrasound assisted extraction was used to extract polyphenols from testa of Quercus mongolica Fischer. Response surface methodology (RSM) combined with Box-Behnken central composite design was applied for modeling and optimizing of three variables that influence the extraction, namely ethanol concentration, extraction time and ratio of liquid to solid. The yields and the contents of polyphenols were selected as responses to optimize the extraction process. The optimum conditions for the extraction of polyphenols were as follows: ethanol concentration 60.56%, ratio of liquid to solid 30.72∶1 mL·g^-1, ultrasound time 42.39 min. Under the optimum conditions, the yield and the purity of polyphenols were 0.38% and 18.8%, respectively and EC₅₀ of DPPH free-radical scavenging ability of these polyphenols is 176 μg·mL^-1, which is higher than BHA and BHT.