酶法雙甘酯的制備

化工論文編號:HG020  本論文字數:19829,頁數:36

目 錄
1  緒論 1
 1.1  前言 1
 1.2  雙甘酯的組成、結構與功能 1
 1.2.1  雙甘酯的組成與結構 1
 1.2.2  雙甘酯的生理功能 2
 1.3  雙甘酯的應用 3
 1.3.1  雙甘酯在食品添加劑中的應用 3
 1.3.2  雙甘酯在醫藥中的應用 4
 1.3.3  雙甘酯在化妝品中的應用 4
 1.3.4  其他應用 4
 1.4  雙甘酯的各種制備方法 5
 1.4.1  雙甘酯的化學制備方法 5
 1.4.2  雙甘酯的酶法制備 6
 1.4.3  雙甘酯各種制備方法的特點分析 8
 1.4.4  雙甘酯的分析方法 9
 1.5  超聲波及其在酶促反應中的應用 10
 1.5.1  超聲波 10
 1.5.2  超聲波工作原理 11
 1.5.3  超聲波在酶促反應中的應用 12
 1.6  課題研究內容 13
2  測定方法 14
 2.1  樣品制備 14
 2.2  羥基值的測定 14
 2.2.1  乙酰化試劑的配置 14
 2.2.2  測定步驟 14
 2.3  單甘酯的含量測定 14
 2.4  游離甘油含量測定 15
 2.5  游離脂肪酸的含量測定 15
 2.6  雙甘酯的含量 16
 2.7  甘三酯的含量 16
3  酶促棕櫚油甘油醇解、水解制備雙甘酯 17
 3.1  試驗材料與儀器 18
 3.1.1  試驗材料 18
 3.1.2  試驗儀器 18
 3.2  試驗方法 18
 3.2.1  酶促甘油醇解反應 18
 3.2.2  酶促水解反應 19
 3.3  結果與討論 19
 3.3.1  酶促甘油醇解反應影響因素 19
 3.3.2  酶促水解反應影響因素 20
 （1）反應時間對雙甘酯產率的影響 20
 （2）加酶量對雙甘酯產率的影響 20
 （3）反應溫度對雙甘酯產率的影響 21
 （4）底物摩爾比對雙甘酯產率的影響 22
 3.4  結論 23
4  超聲場中酶促水解制備雙甘酯 24
 4.1  試驗材料與儀器 24
 4.1.1  試驗材料 24
 4.1.2  試驗儀器 24
 4.2  試驗方法 25
 4.3  結果與討論 25
 4.3.1  超聲功率對雙甘酯產率的影響 25
 4.3.2  超聲場與機械攪拌條件對比 26
 4.4  結論 27
5  結論與展望 28
 5.1  結論 28
 5.2  存在的問題與展望 28
參考文獻  29
Abstract  31 
致    謝  32

摘        要
 雙甘酯（Diacylglycerol, DG）是甘三酯（Triacylglycerol, TG）中的一個脂肪酸被羥基取代的結構脂質。雙甘酯是天然植物油脂中的微量成分及體內脂肪代謝的內源中間產物，它是公認安全(GRAS)的食品成分。近年來的研究表明, 雙甘酯具有許多獨特的生理作用和物化性質, 可廣泛地應用于食品、醫藥、化妝品及其他化工產品, 是一類很有開發前景的新型化工原料。本論文主要對雙甘酯的酶促甘油醇解、水解以及超聲波外力場輔助酶促水解制備進行了研究。
 首先研究了酶促棕櫚油甘油醇解反應制備雙甘酯，研究表明：在攪拌、棕櫚油與甘油底物摩爾比為2：1、加酶量為油脂質量的8%、甘油加水量0%、反應溫度42℃的條件下，酶促甘油解制備雙甘酯反應較慢，反應30小時，DG的質量分數才達40%。試驗同時發現，體系中游離脂肪酸生成速率較快，尤其在前12小時。體系中沒有加入水，參與反應的水主要源于酶中以及油脂中已有的水分，這二者的水分含量均不高，在此情況下，水解反應卻較快，這說明，酶催化水解反應的能力很強。既然酶催化水解易于進行，因此，下文進行了酶促水解制備DG的研究。
 試驗顯示，在機械攪拌條件下，酶促水解的最優條件為：底物摩爾比（水∶棕櫚油）為1.1，加酶量為油脂質量的6%，反應溫度42℃，反應時間4h，產物中雙甘酯的含量達到42.6%。該試驗表明，酶促水解反應比甘油醇解反應快得多，且雙甘酯產率高。
 為了進一步加快反應速率，本文在超聲波作用下，對脂肪酶催化棕櫚油水解制備雙甘酯進行了試驗。試驗結果表明：在底物摩爾比（水∶棕櫚油）為1.1，加酶量為油脂質量的6%，反應溫度為37℃，超聲功率為50W，僅需反應2h，產物中雙甘酯的含量即達到50.72%。
關鍵詞：雙甘酯  脂肪酶  甘油醇解  水解  超聲波

The Preparation of Diglyceride catalized by Enzyme
 Abstract: Diglyceride (DG) is a kind of structured lipid that hydroxyl replace acyl in the sn-1, 2, 3 position of triglyceride (TG). DG is a natural minor component of various edible oils and the endogenetic intermediate metabolite of lipid. Moreover, it is generally recognized as safe (GRAS) by FDA. Recent investigations have shown that diglyceride can be extensively applied to food, pharmaceuticals, cosmetics and other chemical products due to its specific physiological actions and physico-chemical properties. Diglyceride is one kind of new and promising chemical product. In this paper, the preparation of DG in different conditions were studied.
 Firstly, the preparation of DG by enzymatic glycerine alcoholysis of palm oil was studied. The research indicated that the DG content in the yield was only about 40% under the following conditions: mechanical agitation, ratio of palm oil to glycerol 2：1，lipase content 8%, water content of glycerol 0%，reaction temperature 42℃ and reaction time 30h. At the same time，the results show that the ability of enzymatic hydrolysis reaction is strong compared to the enzymatic glycerine alcoholysis reaction.
 Secondly, the preparation of DG by enzymatic hydrolysis of palm oil under the mechanical agitation condition was studied. The optimum reaction conditions were got by single-factor experiments and they are as follows: ratio of palm oil to water 1∶1.1, lipase content 6%, reaction temperature 42℃, reaction time 4h. The DG content in the yield was 42.62% under the above conditions.
 Thirdly, the preparation of DG by enzymatic hydrolysis of palm oil in the ultrasonic field were studied. The optimum reaction conditions are as follows: ratio of palm oil to water 1∶1.1, Lipase content 6%, reaction temperature 37℃, Ultrasonic power 50W and the reaction time 2h. The DG content in the yield was 50.72% under the above conditions.
Key words: Diacylglycerol(DG);Lipase;Glycerine Alcoholysis;Hydrolysis;Ultrasound