Method for Synthesizing Diglyceride

Abstract

Disclosed is a method for synthesizing a diglyceride. The diglyceride is obtained by mixing a fatty acid donor with glycerol, partial glyceride lipase, and monoglyceride lipase by adding water, then subjecting the same to an esterification reaction, with a reaction time of 8 to 24 hours, and further separating and purifying the same. In the present invention, monoglyceride lipase is used to promote the reaction efficiency of partial glyceride lipase in the esterification reaction, so as to increase the synthesis rate of diglyceride. Compared with a single enzyme, the synthesis time is shortened by half or more, and 45.50% or more of diglyceride is obtained after the esterification reaction. Since substantially no triglyceride is generated in products, the content of DAG reaches 98% or more after the same has been purified by means of molecular distillation.

Claims

1. A method for synthesizing a diglyceride, characterized in that, it comprises mixing a fatty acid donor with a glycerol, a partial glyceride lipase, and a monoglyceride lipase by adding water, subjecting the mixture to an esterification reaction, and performing further separation and purification after reaction is ended, to obtain the diglyceride.

2. The method according to claim 1, characterized in that, the partial glyceride lipase is one or a mixture of two of partial glyceride lipases Lipase SMG1 derived from Malassezia and Lipase G50, and the monoglyceride lipase is Lipase GMGL derived from marine Bacillus licheniformis.

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

4. The method according to claim 1, characterized in that, a molar ratio of the fatty acid donor to the glycerol is 1:(0.3 to 10); and a mass ratio of the glycerol to the water is (10 to 30):1.

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

6. The method according to claim 4, characterized in that, the fatty acid donor is one or a mixture of two or more of a fatty acid, a low-carbon alkyl ester of fatty acid, or a raw material containing the fatty acid or the low-carbon alkyl ester of fatty acid.

7. The method according to claim 4, characterized in that, the fatty acid is one or a mixture of two or more of fatty acids having 6 to 22 carbon atoms; and the low-carbon alkyl ester of fatty acid is one or a mixture of two of methyl ester, ethyl ester, propyl ester, butyl ester, and pentyl ester.

8. The method according to claim 4, characterized in that, a temperature of the esterification reaction is 10 to 60° C., a time for the esterification reaction is 8 to 24 hours, and a pH is 4 to 10.

9. The method according to claim 8, characterized in that, the temperature of the esterification reaction is 20 to 50° C., the time for esterification reaction is 12±2 hours, and the pH is 6 to 8.

10. The method according to claim 9, characterized in that, the temperature of the esterification reaction is 30 to 40° C.

11. The method according to claim 2, characterized in that, a molar ratio of the fatty acid donor to the glycerol is 1:(0.3 to 10); and a mass ratio of the glycerol to the water is (10 to 30):1.

12. The method according to claim 3, characterized in that, a molar ratio of the fatty acid donor to the glycerol is 1:(0.3 to 10); and a mass ratio of the glycerol to the water is (10 to 30):1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a graph of effects of Lipase G.sub.50 and Lipase GMGL on the content of catalytically synthesized DAG in Example 1; and

[0022] FIG. 2 is a graph of effects of Lipase SMG1 and Lipase GMGL on the content of catalytically synthesized DAG in Example 2.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Example 1

[0023] 4.3210 g of fatty acid, 5.6790 g of glycerol (a molar ratio being 1:4), and 0.4 g of phosphoric acid buffer solution with a pH of 7.5 were taken, added into a conical flask with a stopper, and mixed uniformly, and the conical flask was placed on a thermostatic magnetic stirrer with a rotation speed of 500 rpm for preheating at 35° C. for 10 minutes; after preheating was ended, 240 U/g of partial glyceride lipase Lipase G.sub.50 (based on a total mass of reactants, commercially available from Amano Enzyme Inc., Japan) was added and 240 U/g of monoglyceride lipase GMGL was added at the same time; and the mixture was subjected to reaction at a reaction temperature controlled to 35° C. for 12 hours. The content of DAG in an esterification product was 49.50%, and the content of DAG was as high as 98.07% after further separation and purification by means of molecular distillation.

Example 2

[0024] 4.3210 g of fatty acid, 5.6790 g of glycerol (a molar ratio being 1:4), and 0.4 g of phosphoric acid buffer solution with a pH of 7.5 were taken, added into a conical flask with a stopper, and mixed uniformly, and the conical flask was placed on a thermostatic magnetic stirrer with a rotation speed of 500 rpm for preheating at 35° C. for 10 minutes; after preheating was ended, 240 U/g of partial glyceride lipase SMG1 (based on a total mass of reactants) was added and 240 U/g of monoglyceride lipase GMGL was added at the same time; and the mixture was subjected to reaction at a reaction temperature controlled to 35° C. for 12 hours. The content of DAG in an esterification product was 50.04%, and the content of DAG was as high as 98.30% after further separation and purification by means of molecular distillation.

Example 3

[0025] 4.3210 g of fatty acid, 5.6790 g of glycerol (a molar ratio being 1:4), and 0.2 g of phosphoric acid buffer solution with a pH of 7.5 were taken, added into a conical flask with a stopper, and mixed uniformly, and the conical flask was placed on a thermostatic magnetic stirrer with a rotation speed of 500 rpm for preheating at 35° C. for 10 minutes; after preheating was ended, 240 U/g of partial glyceride lipase Lipase G.sub.50 (based on a total mass of reactants) was added and 240 U/g of monoglyceride lipase GMGL was added at the same time; and the mixture was subjected to reaction at a reaction temperature controlled to 35° C. for 12 hours. The content of DAG in an esterification product was 45.50%, and the esterification product was further separated and purified by means of molecular distillation.

Example 4

[0026] 4.3210 g of fatty acid, 5.6790 g of glycerol (a molar ratio being 1:4), and 0.2 g of phosphoric acid buffer solution with a pH of 7.5 were taken, added into a conical flask with a stopper, and mixed uniformly, and the conical flask was placed on a thermostatic magnetic stirrer with a rotation speed of 500 rpm for preheating at 35° C. for 10 minutes; after preheating was ended, 240 U/g of partial glyceride lipase SMG1 (based on a total mass of reactants) was added and 240 U/g of monoglyceride lipase GMGL was added at the same time; and the mixture was subjected to reaction at a reaction temperature controlled to 35° C. for 12 hours. The content of DAG in an esterification product was 46.01%, and the esterification product was further separated and purified by means of molecular distillation.

Example 5

[0027] 4.3210 g of fatty acid, 5.6790 g of glycerol (a molar ratio being 1:4), and 0.4 g of phosphoric acid buffer solution with a pH of 7.5 were taken, added into a conical flask with a stopper, and mixed uniformly, and the conical flask was placed on a thermostatic magnetic stirrer with a rotation speed of 500 rpm for preheating at 35° C. for 10 minutes; after preheating was ended, 240 U/g of partial glyceride lipase Lipase G.sub.50 (based on a total mass of reactants) was added and 60 U/g of monoglyceride lipase GMGL was added at the same time; and the mixture was subjected to reaction at a reaction temperature controlled to 35° C. for 12 hours. The content of DAG in an esterification product was 48.11%, and the esterification product was further separated and purified by means of molecular distillation.

Example 6

[0028] 4.3210 g of fatty acid, 5.6790 g of glycerol (a molar ratio being 1:4), and 0.4 g of phosphoric acid buffer solution with a pH of 7.5 were taken, added into a conical flask with a stopper, and mixed uniformly, and the conical flask was placed on a thermostatic magnetic stirrer with a rotation speed of 500 rpm for preheating at 35° C. for 10 minutes; after preheating was ended, 240 U/g of partial glyceride lipase SMG1 (based on a total mass of reactants) was added and 60 U/g of monoglyceride lipase GMGL was added at the same time; and the mixture was subjected to reaction at a reaction temperature controlled to 35° C. for 12 hours. The content of DAG in an esterification product was 49.01%, and the esterification product was further separated and purified by means of molecular distillation.

Example 7

[0029] 5.0360 g of fatty acid, 4.9640 g of glycerol (a molar ratio being 1:3), and 0.4 g of phosphoric acid buffer solution with a pH of 7.5 were taken, added into a conical flask with a stopper, and mixed uniformly, and the conical flask was placed on a thermostatic magnetic stirrer with a rotation speed of 500 rpm for preheating at 35° C. for 10 minutes; after preheating was ended, 240 U/g of partial glyceride lipase Lipase G.sub.50 (based on a total mass of reactants) was added and 240 U/g of monoglyceride lipase GMGL was added at the same time; and the mixture was subjected to reaction at a reaction temperature controlled to 35° C. for 12 hours. The content of DAG in an esterification product was 46.91%, and the esterification product was further separated and purified by means of molecular distillation.

Example 8

[0030] 5.0360 g of fatty acid, 4.9640 g of glycerol (a molar ratio being 1:3), and 0.4 g phosphoric acid buffer solution with a pH of 7.5 were taken, added into a conical flask with a stopper, and mixed uniformly, and the conical flask was placed on a thermostatic magnetic stirrer with a rotation speed of 500 rpm for preheating at 35° C. for 10 minutes; after preheating was ended, 240 U/g of partial glyceride lipase SMG1 (based on a total mass of reactants) was added and 240 U/g of monoglyceride lipase GMGL was added at the same time; and the mixture was subjected to reaction at a reaction temperature controlled to 35° C. for 12 hours. The content of DAG in an esterification product was 46.10%, and the esterification product was further separated and purified by means of molecular distillation.

Comparative Example 1

[0031] 4.3210 g of fatty acid, 5.6790 g of glycerol (a molar ratio being 1:4), and 0.4 g of phosphoric acid buffer solution with a pH of 7.5 were taken, added into a conical flask with a stopper, and mixed uniformly, and the conical flask was placed on a thermostatic magnetic stirrer with a rotation speed of 500 rpm for preheating at 35° C. for 10 minutes; after preheating was ended, 240 U/g of partial glyceride lipase Lipase G.sub.50 (based on a total mass of reactants) was added; and the mixture was subjected to reaction at a reaction temperature controlled to 35° C. for 12 hours. The content of DAG in an esterification product was 39.30%, and the esterification product was further separated and purified by means of molecular distillation.

Comparative Example 2

[0032] 4.3210 g of fatty acid, 5.6790 g of glycerol (a molar ratio being 1:4), and 0.4 g of phosphoric acid buffer solution with a pH of 7.5 were taken, added into a conical flask with a stopper, and mixed uniformly, and the conical flask was placed on a thermostatic magnetic stirrer with a rotation speed of 500 rpm for preheating at 35° C. for 10 minutes; after preheating was ended, 240 U/g of partial glyceride lipase GMGL (based on a total mass of reactants) was added, and the mixture was subjected to reaction at a reaction temperature controlled to 35° C. for 12 hours, and no DAG was substantially synthesized.

Comparative Example 3

[0033] 4.3210 g of fatty acid, 5.6790 g of glycerol (a molar ratio being 1:4), and 0.4 g of phosphoric acid buffer solution with a pH of 7.5 were taken, added into a conical flask with a stopper, and mixed uniformly, and the conical flask was placed on a thermostatic magnetic stirrer with a rotation speed of 500 rpm for preheating at 35° C. for 10 minutes; after preheating was ended, 240 U/g of partial glyceride lipase SMG1 (based on a total mass of reactants) was added; and the mixture was subjected to reaction at a reaction temperature controlled to 35° C. for 12 hours. The content of DAG in an esterification product was 37.42%, and the esterification product was further separated and purified by means of molecular distillation.

Comparative Example 4

[0034] 4.3210 g of fatty acid, 5.6790 g of glycerol (a molar ratio being 1:4), and 0.2 g of phosphoric acid buffer solution with a pH of 7.5 were taken, added into a conical flask with a stopper, and mixed uniformly, and the conical flask was placed on a thermostatic magnetic stirrer with a rotation speed of 500 rpm for preheating at 35° C. for 10 minutes; after preheating was ended, 240 U/g of partial glyceride lipase Lipase G.sub.50 (based on a total mass of reactants) was added; and the mixture was subjected to reaction at a reaction temperature controlled to 35° C. for 12 hours. The content of DAG in an esterification product was 35.20%, and the esterification product was further separated and purified by means of molecular distillation.

Comparative Example 5

[0035] 4.3210 g of fatty acid, 5.6790 g of glycerol (a molar ratio being 1:4), and 0.2 g of phosphoric acid buffer solution with a pH of 7.5 were taken, added into a conical flask with a stopper, and mixed uniformly, and the conical flask was placed on a thermostatic magnetic stirrer with a rotation speed of 500 rpm for preheating at 35° C. for 10 minutes; after preheating was ended, 240 U/g of partial glyceride lipase SMG1 (based on a total mass of reactants) was added; and the mixture was subjected to reaction at a reaction temperature controlled to 35° C. for 12 hours. The content of DAG in an esterification product was 35.02%, and the esterification product was further separated and purified by means of molecular distillation.

Comparative Example 6

[0036] 5.0360 g of fatty acid, 4.9640 g of glycerol (a molar ratio being 1:3), and 0.4 g of phosphoric acid buffer solution with a pH of 7.5 were taken, added into a conical flask with a stopper, and mixed uniformly, and the conical flask was placed on a thermostatic magnetic stirrer with a rotation speed of 500 rpm for preheating at 35° C. for 10 minutes; after preheating was ended, 240 U/g of partial glyceride lipase Lipase G.sub.50 (based on a total mass of reactants) was added; and the mixture was subjected to reaction at a reaction temperature controlled to 35° C. for 12 hours. The content of DAG in an esterification product was 36.30%, and the esterification product was further separated and purified by means of molecular distillation.

Comparative Example 7

[0037] 5.0360 g of fatty acid, 4.9640 g of glycerol (a molar ratio being 1:3), and 0.4 g of phosphoric acid buffer solution with a pH of 7.5 were taken, added into a conical flask with a stopper, and mixed uniformly, and the conical flask was placed on a thermostatic magnetic stirrer with a rotation speed of 500 rpm for preheating at 35° C. for 10 minutes; after preheating was ended, 240 U/g of partial glyceride lipase SMG1 (based on a total mass of reactants) was added; and the mixture was subjected to reaction at a reaction temperature controlled to 35° C. for 12 hours. The content of DAG in an esterification product was 35.42%, and the esterification product was further separated and purified by means of molecular distillation.