大豆胚芽中异黄酮提取研究

【作者】 李珊珊；

【导师】 任其龙；

【作者基本信息】 浙江大学 ， 化学工艺， 2004， 硕士

【摘要】 本文研究了从大豆胚芽中提取和纯化总异黄酮的方法与工艺，包括总异黄酮的初步提取和异黄酮提取物的固体酸水解两个主要过程。 在大豆胚芽总异黄酮初步提取条件优化实验中，以单因素实验方法优化了四个影响因素：提取温度、提取时间、溶剂用量、溶剂浓度。以胚芽中总异黄酮提取率和提取的选择性为指标，确定60％乙醇为提取溶剂、提取温度50℃、提取次数三次、每次提取的液固比为6:1、三次的提取时间分别为60min、10min、10min，三次总提取率为92％。 在异黄酮固体酸水解实验中，选择南开大学化工厂的D72强酸性阳离子交换树脂作为固体酸催化剂。经过两次固定床水解反应，染料木素、大豆黄素和黄豆黄素等三种异黄酮转化率可达90％。实验研究了温度、甲醇水配比、进料配比以及接触时间对游离型异黄酮转化率的影响。结果表明，在实验温度范围内(60～70℃)，温度变化对genistein和glycitein影响较明显，温度升高转化率增大；温度变化对daidzein的转化率影响不大；接触时间越长，反应的转化率越高，并逐渐趋向平衡值；甲醇水配比为1:2有利于水解反应；溶剂比例增大，三种异黄酮转化率都增大，溶剂比例增大到一定程度转化率变化不明显。 异黄酮精制过程中，探索了柱层析、溶剂萃取、溶剂沉淀等方法，最终异黄酮含量可达40％，对胚芽异黄酮收率50％左右。 建立了总异黄酮的分析方法和游离态异黄酮的HPLC分析方法。更多还原

【Abstract】 A process for extracting and purifying isoflavones from soybean germ was studied in this paper. The process includes extraction of total isoflavones and hydrolyzation of soybean isoflavone by solid acid catalyst.In the experiments of extraction of total isoflavones, five factors were studied: temperature, extracting time, concentration of solvent and amount of solvent. With the extraction efficiency of total isoflavones and the selectivity of extraction as study targets, the optium extraction conditions were as followed: solvent 60% ethanol, temperature 50℃, solvent volume to sobean germ weight 6:1, extracting for 3times, 60min 10min , 10min respectively. Extraction efficiency of total isoflavones was about 92%.In the experiments of fixed bed process, soybean isoflavone glucoside can be hydrolyzed into isoflavone aglucone with methanol in a fixed bed filled with solid acid catalyst(Nankai Chemical Factory, D72). Conversion of isoflavones is about 90%. The effect of temperature, contact time, concentration of methanol and proportion of solvent to material on conversion was studied. The results show that enhancing temperature and prolonging the contact time are favor of the reaction, and the ratio of methanol to water is appropriately 1:2.During the process of refining of isoflavones from the extraction, methods such as chromatogram, extraction, deposition were researched. Content of isoflavone was as high as 40%, and recovery percent of isoflavone based on soybean germ was about 50%. Analytical method for total isoflavones and isoflavone aglucone was established.更多还原