阅读说明：本技术 一种合成甘油二酯的方法 (Method for synthesizing diglyceride ) 是由 王永华 刘萱 杨博 王卫飞 蓝东明 罗日明 于 2019-11-06 设计创作，主要内容包括：本发明公开了一种合成甘油二酯的方法,将脂肪酸供体与甘油、偏甘油酯脂肪酶、单甘油酯脂肪酶加水混合后,进行酯化反应,反应时间8-24h,进一步分离纯化,得到甘油二酯。本发明利用单甘油酯脂肪酶在酯化反应中促进偏甘油酯脂肪酶的反应效率,以提高合成甘油二酯的速率,相比于单酶,合成时间缩短了一半以上,而且酯化反应后得到45.50％以上的甘油二酯,因产物基本没有甘油三酯的生成,经分子蒸馏纯化后,DAG含量高达98％以上。本发明是一种快速、高效、绿色、便于工业化生产的合成方法。(The invention discloses a method for synthesizing diglyceride, which comprises the steps of mixing a fatty acid donor with glycerol, partial glyceride lipase and monoglyceride lipase by adding water, carrying out esterification reaction for 8-24h, and further separating and purifying to obtain the diglyceride. The method utilizes the reaction efficiency of the partial glyceride lipase in the esterification reaction to improve the rate of synthesizing the diglyceride, shortens the synthesis time by more than half compared with the single enzyme, obtains the diglyceride with the content of more than 45.50 percent after the esterification reaction, and has DAG content of more than 98 percent after molecular distillation and purification because the product basically has no triglyceride. The invention is a synthesis method which is rapid, efficient, green and convenient for industrial production.)

1. A method for synthesizing diglycerides, comprising: and (3) mixing the fatty acid donor, glycerol, partial glyceride lipase and monoglyceride lipase with water, carrying out esterification reaction, and further separating and purifying after the reaction is finished to obtain diglyceride.

2. The method of claim 1, wherein the partial glyceride Lipase is a partial glyceride Lipase derived from the malassezia spp SMG1 and spp G ₅₀One or two of the above-mentioned materials are mixed, and the described monoglyceride lipase is Lipase GMG derived from marine bacillus licheniformisL。

3. The method according to claim 2, wherein the partial glyceride lipase is added in an amount of 120 to 240U/g based on the total mass of the reaction mixture; the addition amount of the monoglyceride lipase is 60-240U/g based on the total mass of the reaction mixture.

4. The method according to any one of claims 1 to 3, wherein the molar ratio of the fatty acid donor to glycerin is 1 (0.3 to 10); the mass ratio of the glycerol to the water is (10-30) to 1.

5. The method according to claim 4, wherein the molar ratio of the fatty acid donor to glycerin is 1 (3-4); the mass ratio of the glycerol to the water is (14.2-28.4): 1.

6. The method according to claim 4, wherein the fatty acid donor is one or a mixture of two or more of fatty acid, fatty acid lower alkyl ester, and raw material containing fatty acid, fatty acid lower alkyl ester.

7. The production method according to claim 4,

the fatty acid is one or a mixture of more than two of fatty acids with 6-22 carbon atoms;

the fatty acid lower alkyl ester is one or a mixture of two of methyl ester, ethyl ester, propyl ester, butyl ester and amyl ester.

8. The method according to claim 4, wherein the esterification reaction is carried out at a temperature of 10-60 ℃, for a reaction time of 8-24 hours and at a pH of 4-10.

9. The method according to claim 8, wherein the temperature of the esterification reaction is 20-50 ℃, the time of the esterification reaction is 12 +/-2 hours, and the pH is 6-8.

10. The method according to claim 9, wherein the temperature of the esterification reaction is 30 to 40 ℃.

Technical Field

The invention relates to a method for synthesizing diglyceride.

Background

Diglyceride (DAG) is the product of esterification of two hydroxyl groups on glycerol with fatty acids, a natural component of fats and oils, and also an intermediate product of fat metabolism. There are two naturally occurring DAGs, which are classified into two isomers, 1,2-DAG and 1,3-DAG, depending on the position of the vacant hydroxyl group. Because the metabolic pathway of diglyceride is completely different from that of triglyceride, DAG has the functions of reducing blood fat, relieving diabetes and complications thereof and inhibiting the accumulation of fat, and is healthy and safe functional grease.

Diglyceride can be prepared by various processes, mainly including hydrolysis method, esterification method and glycerolysis method. The hydrolysis method is characterized in that refined animal and vegetable oil is used as a raw material, sn-1, 3-bit specific lipase is selected to carry out hydrolysis reaction on the animal and vegetable oil, and a DAG-rich sample is obtained by controlling the hydrolysis degree. However, the degree of hydrolysis is difficult to control, a large amount of by-produced fatty acids is produced, and the DAG content is low. The preparation of diglyceride by glycerolysis refers to the reaction of triglyceride and glycerol catalyzed by lipase to obtain DAG. The method is influenced by factors such as solvent and enzyme preparation type, and has the problem of low conversion rate.

The esterification method is a commonly used method for industrially preparing diglyceride at present, takes free fatty acid and glycerol as raw materials, and utilizes lipase to catalyze and synthesize the diglyceride. The purity of DAG prepared by adopting the partial glycerol lipase can reach more than 90 percent after separation and purification. The products are Diglycerides (DAG), Monoglycerides (MAG) and fatty acids (FFA). However, the efficiency of preparing diglyceride by catalyzing esterification reaction with partial glyceride lipase is low, generally longer reaction time is needed, and the industrial application prospect is severely restricted. Monoglyceride lipase generally has stronger hydrolytic activity, and patent CN102965404A discloses a method for preparing high-purity diglyceride, which utilizes esterification reaction of glycerol and fatty acid, then hydrolyzes monoglyceride from an esterification product by using monoglyceride lipase, and DAG content reaches 98% after separation and purification by molecular distillation. However, the esterification activity of monoglyceride lipase is generally weak, especially the esterification activity of long-chain fatty acid is very low, and at present, no report exists that the monoglyceride lipase can be used for catalyzing the esterification of long-chain fatty acid to prepare glyceride.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a method for quickly and efficiently synthesizing diglyceride, which adds a certain amount of monoglyceride lipase into a reaction system for preparing diglyceride by catalyzing long-chain fatty acid with partial glyceride lipase, and finds that the catalytic efficiency of the partial glyceride lipase can be improved and the time for the esterification reaction to reach balance can be obviously shortened while the balance point of the esterification reaction is not changed.

The purpose of the invention is realized by the following technical scheme:

a method for synthesizing diglyceride comprises mixing fatty acid donor with glycerol, partial glyceride lipase and monoglyceride lipase with water, performing esterification reaction, and further separating and purifying to obtain diglyceride.

Preferably, the partial glyceride Lipase is derived from Malassezia Lipase SMG1 and Lipase G ₅₀The monoglyceride lipase is LipaseGMGL derived from marine Bacillus licheniformis.

Preferably, the addition amount of the partial glyceride lipase is 120-240U/g based on the total mass of the reaction mixture; the addition amount of the monoglyceride lipase is 60-240U/g based on the total mass of the reaction mixture.

Preferably, the molar ratio of the fatty acid donor to the glycerol is 1 (0.3-10); the mass ratio of the glycerol to the water is (10-30) to 1.

Preferably, the molar ratio of the fatty acid donor to the glycerol is 1 (3-4); the mass ratio of the glycerol to the water is (14.2-28.4): 1.

Preferably, the fatty acid donor is one or a mixture of more than two of fatty acid, fatty acid lower alkyl ester or raw materials containing fatty acid and fatty acid lower alkyl ester.

Preferably, the fatty acid is one or a mixture of more than two of fatty acids with 6-22 carbon atoms.

The fatty acid lower alkyl ester is one or a mixture of two of methyl ester, ethyl ester, propyl ester, butyl ester and amyl ester.

Preferably, the esterification reaction time is 8-24h, more preferably, the esterification reaction time is 12. + -.2 h.

Preferably, the temperature of the esterification reaction is 10-60 ℃, and the pH is 4-10.

Preferably, the temperature of the esterification reaction is 20-50 ℃, and the pH value is 6-8.

Preferably, the temperature of the esterification reaction is 30-40 ℃.

Compared with the prior art, the invention has the following advantages:

the present invention relates to the use of partial glyceride lipase together with monoglyceride lipase in an enzymatic reaction to synthesize diglycerides. When two enzymes are used together, the synthesis rate of diglyceride is far higher than that of any one enzyme when the two enzymes are used alone, the synthesis time is shortened by more than half, and more than 45.50% of diglyceride is obtained after esterification reaction, and the DAG content is up to more than 98% after molecular distillation and purification because the product is basically free from triglyceride.

Drawings

FIG. 1 shows Lipase G in example 1 ₅₀And Lipase GMGL effect on DAG content in catalytic synthesis.

FIG. 2 is a graph of the effect of Lipase SMG1 and Lipase GMGL on the content of catalytically synthesized DAG in example 2.

Detailed Description