Fatty glyceride preparation method

Abstract

The present invention provides a fatty glyceride preparation method, comprising converting fatty acid short-chain alcohol ester into fatty glyceride basic mixture by sequentially carrying out a normal-pressure reaction and a vacuum reaction in the nitrogen condition in the temperature of 80 C. to 150 C.; and meanwhile adding a basic catalyst and glycerin or adding a basic catalyst and a glycerin derivative into the fatty acid short-chain alcohol ester, so as to implement a conversion from the fatty acid short-chain alcohol ester to the fatty glyceride. Conditions of the preparation method are relatively moderate, and the structure of the fatty acid is not damaged in the reactions; the yield of the glyceride is high, compositions of the glyceride are stable and controllable, glyceride products having a high content of triacylglycerol can be obtained; the process is simple, costs are low, and the fatty glyceride is applicable to industrial production.

Claims

1. A fatty glyceride preparation method, comprising: converting fatty acid short-chain alcohol ester into fatty glyceride basic mixture by in sequence carrying out a normal-pressure reaction and a vacuum reaction in nitrogen condition at a temperature of 80 C. to 150 C., and meanwhile adding a basic catalyst and a glycerin derivative into the fatty acid short-chain alcohol ester, so as to implement a conversion from the fatty acid short-chain alcohol ester to the fatty glyceride, wherein the basic catalyst is potassium alkoxide or sodium alkoxide, wherein the glycerol derivative is glycerol triacetate, glycerin triformate, or glycerol tripropionate; adding an acid water into the fatty glyceride basic mixture, wherein the acid water is selected from the group consisting of phosphoric acid aqueous solution, acetic acid aqueous solution, and citric acid aqueous solution; washing an oil layer by water to pH=6-7 to obtain crude glyceride; and sequentially decolorizing and distilling the crude fatty acid glyceride to obtain the fatty acid glyceride product, wherein a content of triglyceride in the fatty acid glyceride product is more than 80%.

2. The fatty glyceride preparation method according to claim 1, wherein the fatty acid short-chain alcohol ester is C16-C22 fatty acid methyl ester or C16-C22 fatty acid ethyl ester.

3. The fatty glyceride preparation method according to claim 1, wherein a vacuum degree in the vacuum reaction is 50-10000 Pa.

4. The fatty glyceride preparation method according to claim 1, wherein the acid water has a concentration of 0.2-1.5 mol/L.

5. The fatty glyceride preparation method according to claim 1, wherein the potassium alkoxide is potassium methoxide or potassium ethoxide, and wherein the sodium alkoxide is sodium methoxide or sodium ethoxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) Hereafter, the present invention will be described specifically with reference to the examples. The examples are given only for illustration of the technical solution of the present invention and should not be construed to limit the present invention.

Example 1

(2) To add 100 g of a purified palmitic acid (C16:0) methyl ester to 11 g of glycerol to obtain a mixture, and then heat the mixture to 80 C., afterwards dropwise add 1 mL of sodium methoxide solution to carry out a normal-pressure reaction under nitrogen condition at a temperature of 80 C. for 1 h, and open the vacuum and continue to carry out a reaction under a pressure of 50 Pa for 2 h to obtain a fatty glyceride basic mixture.

(3) To add 100 ml of water and 1.2 g of acetic acid into the fatty glyceride basic mixture and carry out a neutralization reaction under stirring and keeping warm for 5 minutes, and then let stand for layered, remove a water layer, and wash a grease layer by water to pH=6-7, remove water by vacuum rotary steam to obtain a crude palmitic acid glyceride.

(4) To carry out a molecular distillation of the crude palmitic acid glyceride after decoloration of the crude palmitic acid glyceride, to remove unreacted impurities such as methyl ester to obtain a product with high content of palmitic acid glyceride, and the yield of palmitic acid glyceride in the product is 95.1%, the content of triglyceride is 80.8%, and the content of palmitic acid in the product is 90.6%.

Example 2

(5) To add 200 g of a purified linolenic acid (C18:3) methyl ester to 50 g of glycerol triacetate to obtain a mixture, and then heat the mixture to 120 C., afterwards dropwise add 4 mL of sodium methoxide solution to carry out a normal-pressure reaction under nitrogen condition at a temperature of 120 C. for 1 h, and open the vacuum and continue to carry out a reaction under a pressure of 1000 Pa for 3 h to obtain a linolenic acid glyceride basic mixture.

(6) To add 200 ml of water and 4 g of phosphoric acid into the linolenic acid glyceride basic mixture and carry out a neutralization reaction under stirring and keeping warm for 10 minutes, and then let stand for layered, remove a water layer, and wash a grease layer by water to pH=6-7, remove water by vacuum rotary steam to obtain a crude linolenic acid glyceride.

(7) To carry out a molecular distillation of the crude linolenic acid glyceride after decoloration of the crude linolenic acid glyceride, to remove unreacted impurities such as methyl ester to obtain a product with high content of linolenic acid glyceride, and the yield of linolenic acid glyceride in the product is 94.5%, the content of triglyceride is 83.6%, and the content of linolenic acid in the product is 81.2%.

Example 3

(8) To add 200 g of a purified conjugated linoleic acid (C18:2) ethyl ester to 38 g of glycerin triformate (that is, triformin) to obtain a mixture, and then heat the mixture to 90 C., afterwards dropwise add 2 mL of sodium ethoxide solution to carry out a normal-pressure reaction under nitrogen condition at a temperature of 90 C. for 2 h, and open the vacuum and continue to carry out a reaction under a pressure of 10000 Pa for 3 h to obtain a conjugated linoleic acid glyceride basic mixture.

(9) To add 100 ml of water and 5 g of citric acid into the conjugated linoleic acid glyceride basic mixture and carry out a neutralization reaction under stirring and keeping warm for 5 minutes, and then let stand for layered, remove a water layer, and wash a grease layer by water to pH=6-7, remove water by vacuum rotary steam to obtain a crude conjugated linoleic acid glyceride.

(10) To carry out a molecular distillation of the crude conjugated linoleic acid glyceride after decoloration of the crude conjugated linoleic acid glyceride, to remove unreacted impurities such as ethyl ester to obtain a product with high content of conjugated linoleic acid glyceride, and the yield of conjugated linoleic acid glyceride in the product is 95.5%, the content of triglyceride is 81.3%, and the content of conjugated linoleic acid in the product is 80.5%.

Example 4

(11) To add 500 g of a purified algal oil DHA (C22:6) ethyl ester to 124 g of glycerol tripropionate to obtain a mixture, and then heat the mixture to 100 C., afterwards dropwise add 10 mL of sodium ethoxide solution to carry out a normal-pressure reaction under nitrogen condition at a temperature of 150 C. for 1 h, and open the vacuum and continue to carry out a reaction under a pressure of 5000 Pa for 3 h to obtain an algal oil DHA glyceride basic mixture.

(12) To add 100 ml of water and 8 g of acetic acid into the algal oil DHA glyceride basic mixture and carry out a neutralization reaction under stirring and keeping warm for 10 minutes, and then let stand for layered, remove a water layer, and wash a grease layer by water to pH=6-7, remove water by vacuum rotary steam to obtain a crude algal oil DHA glyceride.

(13) To carry out a molecular distillation of the crude algal oil DHA glyceride after decoloration of the crude algal oil DHA glyceride, to remove unreacted impurities such as ethyl ester to obtain a product with high content of algal oil DHA glyceride, and the yield of algal oil DHA glyceride in the product is 92.1%, the content of triglyceride is 86.2%, and the content of DHA in the product is 72.3%.

Example 5

(14) The product of fatty glycerides obtained by Examples 1-4 are prepared for corresponding methyl ester or ethyl ester by alcoholysis. The content of a target component is determined by GC. The content after the reaction relative to the content before the reaction are shown in Table 1.

(15) TABLE-US-00001 TABLE 1 The target component Example 1 Example 2 Example 3 Example 4 and its content (C16:0) (C18:3) (C18:2) (C22:6) Before the reaction 90.5% 81.2% 80.8% 72.7% After the reaction 90.6% 81.2% 80.5% 72.3%

(16) It may be seen from the comparison of Table 1 that no content change of the target component before the reaction and after the reaction is obviously occurred. The process is suitable for both saturated fatty acids without double bonds and unsaturated fatty acids with multiple double bonds.

Example 6

(17) Control experiments of Examples 1-4 are carried out. The reactions of the control experiments are directly reacted under vacuum condition without previous normal-pressure reaction, and other process parameters are the same as the examples 1-4. In comparison with the yield of the fatty glyceride and the content of triglyceride of the control groups and the examples 1-4, the results are shown in Table 2.

(18) TABLE-US-00002 TABLE 2 Example Control Example Control Example Control Example Control Results 1 group 1 2 group 2 3 group 3 4 group 4 yield of 95.1 87.9 94.5 80.1 95.5 85.6 92.1 69.1 glyceride % content of 80.8 78.0 83.6 75.2 81.3 79.1 86.2 73.4 triglyceride %

(19) Compared with the examples 1-4 of the preset invention, both of the yield of glyceride and the content of triglyceride of the control groups are relatively low. Especially, the differences between the examples 1-4 and the control groups are more significant in the case of higher reaction temperature. The process of the present invention can significantly increase the yield of glyceride and the content of triglyceride.

(20) Although the present invention has been described in connection with the above embodiments, it should be understood that the present invention is not limited to such preferred embodiments and procedures set forth above. The embodiments and procedures were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention. It will be apparent to those skilled in the art that various substitution, modifications and changes may be thereto without departing from the scope and spirit of the invention. Therefore, the intention is intended to cover all alternative constructions and equivalents falling within the spirit and scope of the invention as defined only by the appended claims and equivalents thereto.