沙果多酚的提取及组成分析

采用水浴振荡辅助乙醇提取法提取沙果果干中的总多酚,对提取工艺进行优化并分析了沙果果干中的多酚种类。通过正交试验优化出沙果青果的最佳提取工艺:乙醇体积分数50%,料液比1∶25(g∶mL),水浴振荡时间50 min,水浴振荡温度30℃,此条件下多酚得率可达(7.875±0.008)mg/g;沙果熟果的最佳提取工艺:乙醇体积分数60%,料液比1∶25(g∶mL),水浴振荡时间30 min,水浴振荡温度40℃,此条件下多酚得率可达(10.259±0.020)mg/g。液相色谱分析表明:沙果青果多酚主要含有4种多酚,分别为绿原酸22.033%、原花青素B_(2)8.875%、表儿茶素5.95%和根皮苷1.259%,这4种多酚占总多酚的38.117%;沙果熟果除含有上述4种多酚(分别为41.0758%、5.6413%、8.3252%、0.4998%),还含有(+)-儿茶素(7.2444%),这5种多酚占总多酚的62.7865%,沙果中仍有大部分未知多酚未检出。沙果熟果多酚种类及含量高于青果,营养价值更丰富。

Extraction and Composition Analysis of Polyphenols from Malus asiatica Nakai

The method of water bath oscillation assisted with ethanol extraction was used to optimize the extraction process of polyphenols from Malus asiatica Nakai, and the composition of polyphenols was analyzed. The optimal extraction conditions of unripe M. asiatica were the volume fraction of ethanol 50%, solid-liquid ratio of 1∶25(g∶mL), water bath oscillation time with 50 min, and water bath oscillation temperature of 30 ℃ via the orthogonal experiment. Under these conditions, the polyphenol yield could reach(7.875±0.008) mg/g. Similarly, the optimal extraction conditions of ripe M. asiatica were the volume fraction of ethanol 60%, solid-liquid ratio of 1∶25(g∶mL), water bath oscillation time with 30 min, and water bath oscillation temperature at 40 ℃, correspondingly, the polyphenol yield could reach(10.259±0.020) mg/g. The results of liquid chromatography showed that there were four kinds of polyphenols in the unripe M. asiatica, including chlorogenic acid(22.03%), proanthocyanidin B₂(8.875%), epicatechin(5.95%), and phloperidin(1.259%). These four kinds of polyphenols accounted for 38.117% of the total polyphenols. Meanwhile, the above four kinds of polyphenols in the ripe M.asiatica were 41.075%, 5.641 3%, 8.325 2%, and 0.499 8%, respectively. In addition, (+)-catechtin was also found with the fraction of 7.244 4%, and the above five kinds of polyphenols accounted for 62.786 5% of the toal polyphenols in the ripe M. asiatica. However most unknow polyphenols were not detected in the ripe M. asiatica. The ripe fruit had more polyphenol and nutrition than that in the unripe one.