茶条槭叶总酚的提取工艺优化及其抗氧化活性

Optimization of total phenol extraction from leaves of Acer ginnala and its antioxidant activity

【目的】研究茶条槭叶总酚的提取工艺,并对茶条槭叶总酚提取物的抗氧化活性进行评价,为茶条槭叶的开发利用提供依据。【方法】以乙醇为溶剂,以总酚提取率为考察指标,采用超声辅助提取法处理茶条槭叶,先通过单因素试验确定乙醇体积分数、超声提取时间和液固比的适宜范围,再应用中心组合设计和响应面分析相结合的方法筛选最佳提取条件;最后采用铁离子还原法、DPPH自由基清除法测定茶条槭叶提取物的抗氧化能力。【结果】超声波辅助提取茶条槭叶总酚的最佳工艺条件为:乙醇体积分数55%,超声提取时间46min,液固比246mL/g,在此条件下茶条槭叶总酚提取率为(10.95±0.22)%。茶条槭叶总酚提取液对铁离子还原的IC_(50)为(0.157±0.005)mg/mL,对DPPH自由基的IC_(50)为(0.073±0.003)mg/mL。【结论】超声提取法可以避免总酚在较高温度下的分解,且优化后提取率较高,可以用于茶条槭叶总酚的提取;茶条槭叶提取液具有较高的抗氧化活性。

[Objective] This paper investigated the extraction process of total phenol from Acer ginnala leaves and evaluated its antioxidant activity to provide basis for the development and utilization of A. gin- nala leaves. [Method] A. ginnala leaves were processed using ultrasonic assisted method with ethanol as the solvent and total phenol extraction yield as examining index. First, ethanol volume fraction, suitable range of ultrasonic extraction time, and solid-liquid ratio were determined by single factor experiments. Then,central composite design and response surface analysis method were applied for screening the best extraction conditions. At last, the iron reduction method and DPPH free radical scavenging assay were a- dopted to determine antioxidant capacity of A. ginnala leaves extract. [Result] The Optimum conditions for ultrasonic assisted extraction were ethanol volume fraction 55% ,extraction time 46 rain,and liquid-solid ra- tio 246 mL/g with the optimal total phenol yield of （10.95±0.22）%. The iron ions reduction ICs0 of ex- tract was （0. 157±0. 005） mg/mL and that for DPPH was （0. 073±0. 003） mg/mL. [Conclusion] Ultra- sonic extraction method can avoid the decomposition of total phenol under high temperature, and had highyield after optimization. Thus,it can be used for extraction of total phenol from A. ginnala leaves, which had high antioxidant activity.