摘要:
In the present study,the extraction efficiency of flavanones and methoxyflavones have been investigated on the solvent concentration,temperature,time,and solid-liquid ratio.Water precipitation method was used to enrich the total flavonoids of sweet orange peel extract and antioxidant activity of the extracts were evaluated.Results showed that the main flavonoids of citrus peel were flavanones and methoxyflavones.A significant difference of the flavanones and methoxyflavones content under different extracting parameters.The optimal extraction of flavanones were:70% ethanol concentration,solid-liquid ratio of 1 ∶ 20,90°C extraction 4 h,the content of total flavanones can reached (24.74 ± 0.42) mg/g;the optimum condition of methoxyflavones were:80% ethanol concentration,and solid-liquid ratio of 1∶ 10,60 °C extract 2 h,the yield of total methoxyflavones was (2.83 ±0.08) mg/g.Water precipitation method was used for enrichment sweet orange peel flavonoids extracts by removing sugars,organic acids,pigments and other impurities.After purification,the extraction yield of flavonoids was increased from 12.34% to 42.05%.The oxidation abilities by 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH),and 2,2'-azino-bis (3-ethylbenzthiozoline-6)-sulphonic acid (ABTS) methods demonstrated that the antioxidant capacity was highly correlated to the total content of flavonoids in the extracts.%以甜橙果皮为材料,采用加热浸提法,研究乙醇体积分数、时间、温度、以及料液比等提取参数对黄烷酮和多甲氧基黄酮含量的影响.利用水沉法精制甜橙果皮黄酮提取物,并研究了精制后甜橙总黄酮的体外抗氧化活性.结果表明,甜橙果皮中黄酮类物质主要为黄烷酮和多甲氧基黄酮,不同提取参数下,两者的变化趋势差异明显.其中黄烷酮的最佳提取工艺为:乙醇体积分数70%,料液比为1∶20,90°C提取4h,达到(24.74±0.42)mg/g;而多甲氧基黄酮提取的最佳条件为:乙醇体积分数80%,料液比为1∶10,60°C提取2h,可达(2.83±0.08)mg/g.水沉法能够有效地除去糖类、有机酸,脂溶性色素等杂质,可以用于精制甜橙果皮总黄酮提取物,精制后的提取物总黄酮纯度从12.34%提高到42.05%.采用自由基清除(2,2-diphenyl-1-picrylhydrazyl radicals,DPPH)和自由基抗氧化(2,2'-azino-bis(3-ethylbenzthiozoline-6)-sulphonicacid,ABTS)法研究提取物的抗氧化活性,发现抗氧化性与提取物中总黄酮含量呈极显著相关.