本文選題：五倍子 + 單寧酸��； 參考：《貴州大學(xué)》2017年碩士論文

【摘要】：單寧酸是一種以天然植物五倍子為原料,經(jīng)過(guò)物理化學(xué)提取純化工藝得到的產(chǎn)品。單寧酸是一種多酚類(lèi)化合物,具有獨(dú)特的化學(xué)性質(zhì)及特殊的生理和藥理功能,已被廣泛應(yīng)用于食品、醫(yī)藥、冶金、選礦、皮革等行業(yè),市場(chǎng)需求量較大。但是,現(xiàn)階段五倍子單寧酸產(chǎn)品的純度一般在90%~95%之間,其沒(méi)食子酸殘留量一般在2%~4%之間。因此,進(jìn)行反萃取降低沒(méi)食子酸殘留提純五倍子單寧酸的研究對(duì)開(kāi)發(fā)高純單寧酸的應(yīng)用具有重要意義。本文針對(duì)五倍子提取單寧酸工藝及提純五倍子單寧酸和反萃取降低其沒(méi)食子酸殘留量進(jìn)行了工藝優(yōu)化性試驗(yàn)研究,主要結(jié)果如下:1)采用乙酸乙酯作為萃取劑,使用有機(jī)溶劑萃取法和超聲輔助提取法結(jié)合的聯(lián)合提取法對(duì)五倍子進(jìn)行單寧酸提取,研究了提取溫度、提取時(shí)間、五倍子粉與乙酸乙酯固液比等因素對(duì)提取效果的影響。在單因素試驗(yàn)結(jié)果的基礎(chǔ)上,經(jīng)過(guò)響應(yīng)面優(yōu)化后的五倍子提取單寧酸的工藝為:提取溫度為30℃,提取時(shí)間為5 h,五倍子粉與乙酸乙酯固液比為1:5(g:mL)。在此條件下,可得到含量高達(dá)95%的五倍子單寧酸。2)根據(jù)單寧酸在有機(jī)溶劑和水相中的溶解度不同,研究了五倍子單寧酸與乙酸乙酯固液比、五倍子單寧酸與萃取液固液比、不同萃取劑等因素對(duì)提純效果的影響。在單因素試驗(yàn)結(jié)果的基礎(chǔ)上,得到了提純五倍子單寧酸的制備方法,經(jīng)過(guò)正交試驗(yàn)優(yōu)化后的五倍子單寧酸提純工藝為:單寧酸與乙酸乙酯固液比1:5(g:mL),單寧酸與萃取液固液比1:2.5(g:mL),選擇pH 6.8的磷酸鈉鹽溶液作為反萃劑。在此條件下,可得到含量高達(dá)98.5%的五倍子單寧酸。3)采用反萃取法,研究了反萃取降低高純五倍子單寧酸生產(chǎn)中沒(méi)食子酸殘留量的應(yīng)用,通過(guò)對(duì)五倍子單寧酸與乙酸乙酯固液比、五倍子單寧酸與萃取液固液比、不同萃取劑等因素的試驗(yàn),得出了最佳因素條件。在單因素試驗(yàn)結(jié)果的基礎(chǔ)上,反萃取降低高純五倍子單寧酸中沒(méi)食子酸殘留量的最佳工藝條件為:單寧酸與乙酸乙酯固液比1:5(g:m L),單寧酸與萃取液固液比1:2.5(g:mL),選擇pH 6.8的磷酸鈉鹽溶液作為反萃劑。在此條件下,可使得五倍子單寧酸中的沒(méi)食子酸殘留量降低到1%以?xún)?nèi)。
[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，

本文編號(hào)：2075554