JPH01108990A - Production of oil and fat - Google Patents

Abstract

PURPOSE:To obtain oils and fats by a safe and simple method industrially advantageously, by treating a glyceride and a fatty acid (ester) with lipase in a supercritical carbon dioxide gas and carrying out ester interchange while removing a fatty acid (ester) prepared as a by-product with the supercritical carbon dioxide gas. CONSTITUTION:Oils and fats containing a glyceride (e.g., fish oil) and a fatty acid (e.g., eicosapentaenoic acid) are subjected to alcoholysis with a lower alcohol such as ethanol into a lower alcohol ester thereof, urea is added saturated acids are removed by urea addition reaction and eicosapentaenoic acid is concentrated and purified with a supercritical carbon dioxide gas. Then the eicosapentaenoic acid and the triglyceride are reacted with lipase, the supercritical carbon dioxide gas is introduced, a fatty acid prepared as a by- product or a lower alcohol ester thereof is dissolved in the supercritical carbon dioxide gas and removed to give the triglyceride subjected to ester exchange.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing fats and oils, and particularly to a method for producing glycerides containing high concentrations of eicosapentaenoic acid and docosahexaenoic acid.

[Conventional technology]

Wink ring, hydrogenation reaction, transesterification reaction, etc. are known as typical techniques for modifying fats and oils. Winkling crystallizes and removes glycerides that are rich in saturated fatty acids from fats and oils, and is used to remove high-melting-point substances from fats and oils. Moreover, if this method is carried out to the extreme, fats and oils with a high degree of unsaturation can be produced. The hydrogenation reaction can produce fats and oils with appropriate melting points. For example, it is used in the production of margarine, shortening, etc., and is known as a method for producing fats and oils called hydrogenated oils.

Furthermore, by extremely hydrogenating beef tallow, oleic acid can be converted to stearic acid, which can be used as a raw material for the production of stearic acid. Transesterification is a reaction between fats and oils and alcohol,
It is carried out between oils and fatty acids, and between oils and fats, and is used industrially in the field of edible oils and fats such as margarine and cacao substitutes, as well as the production of esters. Of course, these techniques are often used in combination.

The transesterification reaction is generally carried out using an acid or an alkali metal as a catalyst, but it is advantageous to use an alkali metal because the reaction is faster and the reaction proceeds even at low temperatures.

However, there is a drawback that the reaction is difficult to proceed in the presence of water or fatty acids.

Therefore, acid catalysts are often used when transesterifying fats and oils with fatty acids.

In addition to these acid and alkali catalysts, transesterification using lipase has recently become known.

(Protein Hybrid, edited by Yuji Inada, p. 97, A.
R, Macrae; J, ^, o, c, s, 60
．． 243A (1983)).

Unlike conventional acid and alkali catalysts, lipase has the characteristic of being able to react at normal pressure and room temperature, and takes advantage of the substrate and position specificity of lipase to bind the target fatty acid to a fixed position of the ester bond of triglyceride. can be done. These characteristics allow vegetable oils to be modified into fats and oils with specific properties, such as cocoa butter.

These transesterification reactions are possible even in water, but in order to increase the yield of the product, it is necessary to suppress the equilibrium reaction on the hydrolysis side, and it is better to use as little water as possible. In addition, since the water-insoluble substances called fats and oils are the target of the reaction,
The use of organic solvents such as hexane has also been attempted in these reactions.

(^, R, MacraeHJ, A', 0. C, 5
, 60, 243^ (1983)).

Transesterification using lipase can be said to be a selective and mild transesterification method, unlike the chemical random transesterification reaction described above. Therefore, for oils and fats containing advanced fatty acids that contain many double bonds, this method is considered to be superior to chemical methods because it has less influence on double bonds.

Recently, supercritical carbon dioxide gas (S, C) has been used instead of hexane.
, Cot) has been known for transesterification using lipase. (Nakamura et al., Japanese Society of Agricultural Chemistry, Abstracts of the 1985 Conference, p. 659 (1985)') Supercritical carbon dioxide gas has a critical temperature (31.1°C) and a critical pressure (75.
It is carbon dioxide gas in a state exceeding 2 kg/a, can dissolve fats and oils, and has the following characteristics.

(1) At the same pressure, lower temperatures dissolve fats and oils better.

(2) At the same temperature, higher pressure dissolves fats and oils better.

(3) By controlling temperature and pressure, various dissolving powers can be provided.

(4) It is harmless.

(5) Since the reaction can be performed in an oxygen-free state, there is little effect on the double bonds of fats and oils.

(6) It does not remain in the reaction product. That is, the transesterification reaction in supercritical carbon dioxide gas using lipase is considered to be an excellent technique for modifying fats and oils.

[Problem that the invention seeks to solve]

However, when producing fats and oils containing a large amount of a certain fatty acid or fats and oils containing a certain fatty acid in a specific position using lipase, transesterification in water, which is carried out on boat fishing, is of course, transesterification reaction in hexane, etc. However, even in supercritical carbon dioxide, there was a drawback that once the reaction reached equilibrium, the reaction did not proceed any further.

That is, there was a problem in that the following equilibrium reaction was established and it was difficult to proceed with the reaction any further.

(R+, Rz, R3, and R4 in the formula represent fatty chains).

In order to advance this reaction, it is necessary to increase the amount of fatty acids to be reacted or to remove by-product fatty acids from the reaction system.
Conventional transesterification reactions have had the problem that only the former method can be used.

Moreover, if the fatty acids are expensive, there is an economic disadvantage that many cannot be used.

This invention is aimed at solving the above-mentioned problems, and involves removing fatty acids or fatty acid lower alcohol esters produced as by-products when transesterifying transesterification in supercritical carbon dioxide using lipase as a catalyst. The purpose of this invention is to perform a transesterification reaction in high yield, and in particular to provide a method for producing glycerides rich in eicosapentaenoic acid, docosa, and hexaenoic acid.

[Means for solving problems]

This invention involves transesterifying glycerides and fatty acids or their lower alcohol esters in supercritical carbon dioxide using lipase, while removing by-product fatty acids or their lower alcohol esters using supercritical carbon dioxide. This is a method for producing fats and oils. In the present invention, preferred targets for production are glycerides containing a particularly large amount of eicosapentaenoic acid and docosahexaenoic acid among oils and fats; It is also possible to produce fats and oils having an oleic acid structure at the position.

The fatty acids used as raw materials in the method of the present invention, such as eicosapentaenoic acid and docosahexaenoic acid, are highly unsaturated fatty acids that are abundantly contained in fish oil and are known to have the following physiological activities. Namely, these include the effect of inhibiting the formation of blood clots, the effect of lowering serum costerol, the effect of lowering serum neutral fat, the effect of suppressing cancer, and the suppressing effect of chronic diseases (such as asthma).

These can be obtained from fish oil through the following steps.

First, fish oil is subjected to alcoholysis to obtain a lower alcohol ester of fish oil, which is then subjected to a urea addition reaction to remove the saturated acid, and then eicosapentaenoic acid and docosahexaenoic acid are concentrated and purified using supercritical carbon dioxide gas. By this operation, each lower alcohol ester containing about 80% of eicosapentaenoic acid and docosahexaenoic acid can be obtained. Next, by concentrating and purifying this by molecular distillation, lower alcohol esters containing about 90% of eicosapentaenoic acid and docosahexaenoic acid can be obtained, and by hydrolyzing these, fatty acids can be obtained.

The other raw material, glyceride, may be any ordinary vegetable oil or animal oil, but in order to remove by-product fatty acids or their lower alcohol esters, it is preferable to use one with a small number of carbon atoms, especially one with 12 or less carbon atoms. is preferred. Furthermore, when fish oil is used as the glyceride, a modified fish oil containing -i high concentrations of eicosapentaenoic acid and docosahexaenoic acid can be obtained.

There are various types of lipases, including those of animal origin and microbial origin, but it is preferable to use one that can easily express its function on the target fatty acid or the position where these are bound by transesterification. Those of microbial origin are preferred. Examples include those from the genera Aspergillus, Penicillium, Rhizopus, Mucor, Candida, Geotrichum, Pseudomonas, Chromobacterium, and the like. The amount used is based on the fatty acid or its lower alcohol ester and glyceride.
It may be about 0.1 to 5%. In addition, the ratio of fatty acids or their lower alcohol esters and glycerides in the preparation is 3.
A ratio of ~9 moles to 1 mole is sufficient. In addition to these raw materials, glycerin or water can be used as an important enzyme activator during the reaction. The amount to be used is 1 to 20% based on the fatty acid or its lower alcohol ester and glyceride, and preferably 1 to 10% of glycerin is used.

The pressure-resistant reaction vessel used in this reaction may be a supercritical fluid device equipped with a stirrer, but preferably a device equipped with a precision device having a reflux section.

Specifically, the transesterification reaction in the present invention is carried out as follows. That is, a predetermined amount of fatty acids, typically eicosapentaenoic acid and docosahexaenoic acid, or their lower alcohol esters, glycerides, lipase, and glycerin or water obtained as described above were charged into a reactor equipped with a stirrer, and the temperature was adjusted to 30°C. Set the temperature to ~70℃, introduce supercritical carbon dioxide gas, and while stirring, 80~300kg/
Keep it on CD.

Next, supercritical carbon dioxide gas is caused to flow at a constant rate, and the transesterification reaction proceeds while removing fatty acids or lower alcohol esters thereof, which are extracted byproducts. The reaction progress is measured by collecting the extraction by-products, measuring the amount of Ii, and checking with gas chromatography or liquid chromatography. After the reaction is complete, set the appropriate pressure, temperature, and flow rate of supercritical carbon dioxide gas. death,
Flush out unreacted fatty acids or their lower alcohol esters. Then, the conditions are changed again to increase solubility and the reaction product, glyceride, is recovered. By performing the above steps, it is possible to produce glyceride having desired fatty acid species depending on the intended use.

〔Effect of the invention〕

According to the present invention, glyceride and fatty acid or its lower alcohol ester are transesterified using lipase in supercritical carbon dioxide gas while removing the by-product fatty acid or its lower alcohol ester, so that the transesterification reaction is sufficiently carried out. This makes it possible to produce the desired useful modified oils and fats in high yield and at low cost through a safe and fast process.

〔Example〕

□Hereinafter, the present invention will be explained in more detail with reference to Examples. Note that % in the text indicates weight %.

Example 1 3 kg of fish oil and 30 g of caustic soda were charged into a stirrer reactor equipped with a glass reflux device, and heated under reflux for 1.
The reaction was allowed to proceed for 5 hours. After the reaction is complete, 15% hydrochloric acid aqueous solution 80
Neutralize and wash with 0 g and warm water to obtain crude ethyl ester. Next, dissolve the crude ethyl ester in 201 hexane, add 11 ksr of urea and 0.5 i of methanol, and perform a urea addition reaction at room temperature for 2 hours. The saturated acid and monoene fatty acid moieties were separated and removed as crystals by filtration. The obtained concentrated ethyl ester of eicosapentaenoic acid and docosahexaenoic acid contains 41.8% eicosapentaenoic acid and 24.1% docosahexaenoic acid, and other components include palmitooleic acid, linoleic acid, octadecatetraenoic acid, and eicosapentaenoic acid. It contained tetraenoic acid, docosapene citric acid, etc. The amount recovered was 1.1 kg after dehexanization.

This ethyl ester was concentrated and purified using supercritical carbon dioxide gas in a supercritical fluid rectification tower having a reflux section. Conditions are bottom temperature 35℃, top temperature 50℃, pressure 120kg.
It was /-. The obtained ester contained 390 g of eicosapentaenoic acid 81.6%, docosahexaenoic acid 10.8%, and eicosapentaenoic acid 19.6%,
It was 100 g containing 70.4% docosahexaenoic acid. Each of these was subjected to molecular distillation at 3 x 10-3 mmHg to obtain 265 g of 90.9% eicosapentaenoic acid and 4.5% docosahexaenoic acid, and 265 g of 7.4% eicosapentaenoic acid and 90.2% docosahexaenoic acid. 110 g was obtained.

The eicosapentaenoic acid obtained by the above method is 90.9
% ester was hydrolyzed with caustic soda and converted back to fatty acid with hydrochloric acid to obtain 39 g of eicosapentaenoic acid. This eicosapentaenoic acid 39g and trilaurin 1
2g, and lipase originating from the genus Mucor (lipase No.
vo: manufactured by Novo) 1.5g and glycerin 2.5g
g was charged into a supercritical fluid precision model reactor equipped with a stirrer and a reflux section. Next, supercritical carbon dioxide gas is introduced,
The mixture was stirred for 30 minutes at a pressure of 150 kg/cJ and a temperature of 60°C. Thereafter, while flowing supercritical carbon dioxide gas, by-produced lauric acid was dissolved in carbon dioxide gas and removed from the system to allow the reaction to proceed. At that time, the temperature of the reflux section was maintained at 70°C. 1
After 5 hours of reaction, the temperature in the reactor was set at 40°C, the reflux section was set at 50°C, and the pressure was set at 180 kg/- to remove unreacted eicosapentaenoic acid from the system. Then increase the pressure to 200 kg
/cIa, the reflux section temperature was set at 40°C, and the transesterified glyceride was collected. The amount of glyceride recovered was 17 g, and its fatty acid composition was 71.4% eicosapentaenoic acid, 2.5% docosahexaenoic acid, and 22.8% lauric acid.

Example 2 Ethyl eicosapentaenoate obtained in Example 1 90.
50 g of 9% product, 15 g of tricaprin, 2 g of lipase originating from the genus Mucor (Lipase Novo, manufactured by Novo), and 3.5 g of glycerin were charged into a supercritical fluid rectification tower type reactor equipped with a stirrer and a reflux section. Next, supercritical carbon dioxide gas was introduced, and the mixture was stirred at a pressure of 100 kg/cJ and a temperature of 60° C. for 30 minutes. Thereafter, while flowing supercritical carbon dioxide gas, the by-produced ethyl caprate was dissolved in carbon dioxide gas and removed from the system to allow the reaction to proceed. At that time, the temperature of the reflux section was maintained at 70°C.

After 15 hours of reaction, the temperature was changed to 40°C in the reactor, 50°C in the reflux section,
The pressure was set at 130 kg/cd, and unreacted ethyl eicosapentaenoate was removed from the system. Next, the pressure was set to 2001 g/c+J, the reflux section temperature was set to 40°C, and the transesterified glyceride was recovered. The amount of recovered glycerin was 19 g, and its fatty acid composition was 70.1% eicosapentaenoic acid, 2.5% docosahexaenoic acid,
Capric acid was 24.2%.

Example 3 Bonito oil (Fatty acid composition Nidocosahexaenoic acid 25.7%
: eicosapentaenoic acid 7.8%) 15g, docosahexaenoic acid ethyl ester obtained in Example 1 90.2%
35g of product, lipase originating from the genus Candida (Lipase O
F, manufactured by Toyo Jozo Co., Ltd.) and 5 g of glycerin were charged into a supercritical fluid rectification tower type reactor equipped with a stirrer and a reflux section. Next, supercritical carbon dioxide gas is introduced and the pressure is increased to 110
kg/col and stirred for 30 minutes at a temperature of 40°C. After that, while circulating supercritical carbon dioxide gas, carbon number 2 was generated as a by-product.
0 or less fatty acid ethyl ester was dissolved in carbon dioxide gas and removed from the system to allow the reaction to proceed. The temperature of the reflux section at that time was maintained at 50°C. After 24 hours of reaction, the pressure was 140 kg/
cffl to remove unreacted docosahexaenoic acid ethyl ester from the system.Then, the pressure was increased to 200 k.
g/cti, the reflux section temperature was set at 40°C, and the transesterified glyceride was recovered. The amount of recovered glyceride was 15.5 g, and its fatty acid composition was 63.3% docosahexaenoic acid, 6.5% eicosapentaenoic acid, and other components such as valmitic acid and oleic acid.

Comparative Example Similar to Example 1, the transesterification reaction was carried out without removing the by-product lauric acid from the system. That is, 1139 g of eicosapentaene, 12 g of l-lilaurin, 1.5 g of lipase (Lipase Novo: manufactured by Novo), and 2 g of glycerin.
．． 5 g was charged into a supercritical fluid rectification tower type reactor equipped with a stirrer and a reflux section. Next, supercritical carbon dioxide gas was introduced, and the temperature was 15.
The reaction was carried out while stirring for 5 hours without flowing supercritical carbon dioxide gas. Next, the pressure reducing valve was gradually opened to lower the pressure and return it to normal pressure. The glyceride portion was separated by preparative TLC using a solvent with a ratio of chloroform to acetone of 96 to 4,
When the fatty acid composition was analyzed, it was found to be 26.3% eicosapentaenoic acid, 0.7% docosahexaenoic acid, and 69.1% lauric acid, and the exchange rate was lower than in Example 1.

Claims (5)

[Claims] (1) When transesterifying glyceride and fatty acids or their lower alcohol esters in supercritical carbon dioxide gas using lipase, transesterification is performed while removing by-product fatty acids or their lower alcohol esters using supercritical carbon dioxide gas. Characteristic method for producing fats and oils. (2) Claim 1 in which the fatty acid or its lower alcohol ester is eicosapentaenoic acid or docosahexaenoic acid or their lower alcohol ester.
Manufacturing method described in section. (3) The method according to claim 1 or 2, wherein the glyceride is an ester of a fatty acid having 12 or less carbon atoms and glycerin. (4) The method according to claim 1 or 2, wherein the glyceride is fish oil. (5) The method according to any one of claims 1 to 4, in which glycerin is used as a lipase activator.