反萃取高纯单宁酸、降低没食子酸残留量的研究

发布时间：2018-06-27 22:48

  本文选题：五倍子 + 单宁酸　； 参考：《贵州大学》2017年硕士论文

【摘要】：单宁酸是一种以天然植物五倍子为原料,经过物理化学提取纯化工艺得到的产品。单宁酸是一种多酚类化合物,具有独特的化学性质及特殊的生理和药理功能,已被广泛应用于食品、医药、冶金、选矿、皮革等行业,市场需求量较大。但是,现阶段五倍子单宁酸产品的纯度一般在90%~95%之间,其没食子酸残留量一般在2%~4%之间。因此,进行反萃取降低没食子酸残留提纯五倍子单宁酸的研究对开发高纯单宁酸的应用具有重要意义。本文针对五倍子提取单宁酸工艺及提纯五倍子单宁酸和反萃取降低其没食子酸残留量进行了工艺优化性试验研究,主要结果如下:1)采用乙酸乙酯作为萃取剂,使用有机溶剂萃取法和超声辅助提取法结合的联合提取法对五倍子进行单宁酸提取,研究了提取温度、提取时间、五倍子粉与乙酸乙酯固液比等因素对提取效果的影响。在单因素试验结果的基础上,经过响应面优化后的五倍子提取单宁酸的工艺为:提取温度为30℃,提取时间为5 h,五倍子粉与乙酸乙酯固液比为1:5(g:mL)。在此条件下,可得到含量高达95%的五倍子单宁酸。2)根据单宁酸在有机溶剂和水相中的溶解度不同,研究了五倍子单宁酸与乙酸乙酯固液比、五倍子单宁酸与萃取液固液比、不同萃取剂等因素对提纯效果的影响。在单因素试验结果的基础上,得到了提纯五倍子单宁酸的制备方法,经过正交试验优化后的五倍子单宁酸提纯工艺为:单宁酸与乙酸乙酯固液比1:5(g:mL),单宁酸与萃取液固液比1:2.5(g:mL),选择pH 6.8的磷酸钠盐溶液作为反萃剂。在此条件下,可得到含量高达98.5%的五倍子单宁酸。3)采用反萃取法,研究了反萃取降低高纯五倍子单宁酸生产中没食子酸残留量的应用,通过对五倍子单宁酸与乙酸乙酯固液比、五倍子单宁酸与萃取液固液比、不同萃取剂等因素的试验,得出了最佳因素条件。在单因素试验结果的基础上,反萃取降低高纯五倍子单宁酸中没食子酸残留量的最佳工艺条件为:单宁酸与乙酸乙酯固液比1:5(g:m L),单宁酸与萃取液固液比1:2.5(g:mL),选择pH 6.8的磷酸钠盐溶液作为反萃剂。在此条件下,可使得五倍子单宁酸中的没食子酸残留量降低到1%以内。
[Abstract]:Tannic acid is a natural plant Galla chinensis as raw material, through physical and chemical extraction and purification of the product. Tannic acid is a polyphenolic compound with unique chemical properties and special physiological and pharmacological functions. It has been widely used in food, medicine, metallurgy, mineral dressing, leather and other industries, the market demand is large. However, at present, the purity of gallnut tannic acid is generally between 90% and 95%, and the residue of Gallic acid is generally between 2% and 4%. Therefore, it is of great significance for the development of high purity tannic acid to reduce the residue of gallnut tannic acid by reverse extraction. In this paper, the process of extracting tannic acid from Galla chinensis, purifying tannic acid and reducing the residue of Gallic acid by reverse extraction were studied. The main results are as follows: (1) Ethyl acetate was used as extractant. The effects of extraction temperature, extraction time and solid-liquid ratio of gallnut powder to ethyl acetate on the extraction of Galla chinensis were studied by using the combined extraction method of organic solvent extraction and ultrasonic assisted extraction. On the basis of the results of single factor test, the process of extracting tannic acid from Galla chinensis by response surface optimization is as follows: extraction temperature is 30 鈩，

本文编号：2075554