银杏外种皮多酚提取工艺及抗氧化性能研究
Study on extract process and antioxidant activities of polyphenol from the Ginkgo biloba exocarp
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摘要: 以银杏外种皮为原料,用乙醇为溶剂提取其中的酚类化合物,研究银杏外种皮多酚(polyphenol exocarp of ginkgo biloba,PEGB)粗提物的乙醇提取工艺条件及抗氧化性能。选择乙醇体积分数、浸提时间、浸提温度、料液比四个因素进行单因素实验,通过响应面法进一步优化提取条件。结果表明,最佳提取工艺条件为乙醇浓度70%,浸提时间2.6h,浸提温度90℃,料液比1∶30,此条件下多酚的提取率为5.33mg GAE/g。PEGB粗提物对DPPH自由基和羟基自由基的清除能力随浓度升高而增强。当PEGB粗提物浓度为0.5mg/mL时,对DPPH的清除率为84.25%,对羟基自由基的清除率为78.89%,表明高浓度的PEGB粗提物具有较强的抗氧化性能。Abstract: Ginkgo biloba exocarp being material and ethanol being solution to extract phenolic compounds, the ethanol extraction conditions and oxidation resistance of crude extract from the ginkgo biloba exocarp (PEGB) were studied. Taking ethanol volume fraction, extracting time and temperature as well as ratio of solid to liquid to conduct single factor experiment, the extraction conditions were further optimized with response surface methodology. The results showed that the optimal extraction conditions were as follows:ethanol concentration70%, extracting time 2.6h, temperature 90℃ and ratio of solid to liquid 1∶30. The extracting rate of crude extract was 5.33 mg GAE/g under such conditions. The scavenging effect of PEGB crude extract on DPPH and hydroxyl radicals was enhanced with increased concentration. When the concentration of PEGB crude extract was 0.5mg/mL, the clearance rate for DPPH was 84.25% and 78.89% for hydroxyl radicals. It showed that high concentrations of PEGB crude extract had strong antioxidant properties.
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