JPS6272793A - Method for concentrating and separating eicosapentaenic acidfrom fish oil - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention provides eicosapentaenoic acid (E
The present invention relates to a method suitable for efficiently obtaining a high-4 degree product using the concentrated fraction 1 method of PA).

[Background of the invention]

Eicosapentaenoic acid (EPA), which is abundantly contained in fish oils such as sardine oil, has an effect such as preventing arteriosclerosis, and has recently been attracting attention as a material for health foods and medicines.

Fatty acids in fish oil exist in the form of triglycerides,
Depending on the structure and properties of the hydrocarbon group, it is roughly divided into the following three types.

+11 Saturated fatty acid triglycerides (those with a structure in which the hydrocarbon group has no double bonds) (2) Lowly unsaturated fatty acid triglycerides (those with a relatively small number of double bonds in the hydrocarbon group) (3) Highly unsaturated fatty acid triglycerides (Those with a relatively large number of double bonds in the hydrocarbon group) E
PA belongs to highly unsaturated fatty acids, and is a type of highly unsaturated fatty acids having a relatively large number of carbon atoms.

EPA currently uses (1) urea addition method, (2)
Vacuum distillation method and (3) chromatography method are employed.

In the urea addition method, alcohol and alkanoalkoxide are added to fatty acid triglyceride, and among the fatty acid esters obtained by transesterification of the fatty acid triglyceride, saturated fatty acid esters and low unsaturated fatty acid esters react with atoms to form crystals. In this method, a urea clathrate is produced in the body, which is separated by filtration and EPA is reduced. However, in this urea addition method, esters of highly unsaturated fatty acids other than EPA do not form urea clathrates and are not separated from EPA, so the EPA concentration in the product is only about 40% or less.

The vacuum distillation method is a method that takes advantage of the differences in boiling points of various fatty acids. However, in this method, since there are many fatty acids (including saturated fatty acids) that have almost the same boiling point as EPA in fish oil, the concentration of EPA obtained as a product is limited to about 40%. In addition, in the vacuum distillation method, fatty acid triglycerides undergo polymerization, isomerization, decomposition, etc. under normal pressure and at a temperature considerably lower than the boiling point, so it is necessary to distill under a high vacuum of about to-' to 10-' l Hg. be. Furthermore, it is necessary to provide several distillation columns for concentration and separation, which requires a large amount of steam, resulting in high utility costs.

Chromatography methods that utilize the difference in migration speed based on the adsorption properties and distribution coefficients of each fatty acid include thin layer chromatography, column chromatography,
There are gas chromatography methods, liquid chromatography methods, etc. In these methods, the concentration of the product EPA is as high as 70 to 90%, but the amount that can be separated in one operation is very small and is not currently used industrially.

As described above, the current EPA concentration and separation methods each have their drawbacks, and it is a major challenge to efficiently produce high-concentration EPA.

[Purpose of the invention]

An object of the present invention is to provide a method for efficiently concentrating and separating high-concentration EPA from fish oil, eliminating the drawbacks of the prior art described above.

[Summary of the invention]

The present invention involves the extraction of EPA-rich polyunsaturated fatty acids from highly unsaturated fatty acids obtained by separating saturated fatty acids and low-degree unsaturated fatty acids from fish oil by pretreatment using carbon dioxide in a supercritical state, and the subsequent extraction step. Adjust the temperature and pressure to predetermined values in the area, and extract EPA from EPA-rich polyunsaturated fatty acids.
This method selectively separates other components to produce high-concentration EPA. That is, the present invention adjusts the density of carbon dioxide in a supercritical state by adjusting the temperature and pressure in the extraction region, and extracts EP as an ester.
A and esters of highly unsaturated fatty acids other than EPA are extracted and separated using the difference in vapor pressure, that is, the difference in boiling point.

[Embodiments of the invention] Hereinafter, the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is an example of a flow for concentrating and separating EPA from fish oil.

Fish oil 1, which is a raw material, is supplied to an addition tank 5.

An alkali alkoxide 3 such as sodium ethoxide and a lower alcohol 4 such as ethanol are added to the addition tank 5. Fatty acid triglyceride, which is the main component of fish oil, is transesterified with lower alcohol using alkali alkoxide 3 as a catalyst and converted into fatty acid ester and glycerin.

CH20COR 1 (CzHs○Na) CHOCOR+CH2CHjOH CH20COR CH2OH CHOH+ 3 RCOOCz Hs-infused H2OH Further, urea 2 is added to the addition tank 5. Among the fatty acid esters produced by the above-described transesterification, saturated fatty acid esters and low unsaturated fatty acid esters react with urea 2 to become urea clathrate fatty acid esters 6. Since the urea clathrate fatty acid ester 6 has a high specific gravity, it precipitates at the bottom of the addition tank 5, and because it has a high melting point, it crystallizes at room temperature. A heating trace 22 is installed at the bottom of the addition tank 5, and the inside of the addition tank 5 is maintained at 40° C. or higher. For this reason, addition tank 5
The urea clathrate fatty acid ester 6 precipitated at the bottom of the tank has high fluidity and can be easily extracted from the addition tank 5.

Among the fatty acid esters produced by the transesterification, highly unsaturated fatty acid esters 8, glycerin, unreacted alcohols 4, etc. have lower specific gravity than the urea clathrate fatty acid esters 6, so they are taken out from the addition tank 5 and sent to the pump 7. is pressurized and supplied to the extractor 12. At the bottom of the extractor 12, carbon dioxide in a supercritical state (hereinafter referred to as 5C-Co2
) 21 is supplied.

As shown in Figure 2, carbon dioxide has a temperature of 31°C or higher,
A supercritical state occurs when the pressure cuff is 8atn+ or more. This supercritical carbon dioxide (SC-Cog) has a strong dissolving power, a fast mass transport rate, and a large diffusion coefficient, and is excellent as an extractant for rapid precision extraction due to its stability and safety. The solubility of highly unsaturated fatty acid ester 8, glycerin, alcohol 4, etc. in 5c-co increases in the order of the vapor pressure of each component, that is, in the order of alcohol 4, highly unsaturated fatty acid ester 8, glycerin, and 5c-co. It is proportional to the density of C02 (Figure 2 shows the density of 5C-CO2 depending on temperature and pressure).

Therefore, by maintaining appropriate temperature and pressure conditions in the extractor 12, selective extraction of substances can be performed.

That is, first, among the highly unsaturated fatty acid esters 8, E
An ester of PA, an unsaturated fatty acid ester having a higher vapor pressure than the ester of EPA (and therefore a lower boiling point than the ester of BPA), and an alcohol are extracted. Low glycerin and highly unsaturated fatty acid esters are separated as extraction residue 9. The E P A concentration in the extract here is approximately 4
It is 0%.

The extracted material containing the ester form of EPA is transferred to the first separator 13
is supplied to Among this extract, the substance with the highest boiling point and lowest vapor pressure is EPA ester 15, and pressure reducing valve 1
By operating 0A and heater 11A to slightly lower the density of 5C-Cot in the first separator 13, the ester form of EPA can no longer be dissolved in SCCOz and is taken out as a residual liquid in the first separator 13. .

In addition, in the operation of lowering the density of 5C-CO2, it is desirable to avoid changing only one of the conditions of pressure reduction or heating. This is because decomposition, polymerization, etc. of fatty acids are likely to occur due to temperature drop due to reduced pressure or heating. The ester form of EPA obtained from the first separator 13 has a purity of about 80
% or more.

Next, the SCCot from which the ester body 15 of EPA to be a product has been separated is operated to reduce the density by operating the pressure reducing valve 10B and the heater 11B, and then is sent to the second separator 14. In the second separator 14, a component with a higher boiling point than the alcohol 4,
That is, the EPA ester body 1, the unsaturated ester having a low boiling point, and a part of the odor components are separated here as liquid IM16.

By operating the alcohol pressure reducing valve 10C, the pressure is further reduced and the alcohol is returned to a gaseous state, after which it is introduced into the alcohol liquefier 17. In the alcohol liquefier 17, carbon dioxide is converted into carbon dioxide using a refrigerant.
The alcohol 4 is cooled to below the boiling point of the alcohol 4 in that pressure state and separated by condensation. The separated alcohol 4 is depressurized via the pressure reducing valve 10D and then recirculated as an additive in the addition tank 5. used.

The carbon dioxide from which the alcohol 4 has been removed in this way and which also contains odor components is introduced into the odor component liquefier 18 . The carbon dioxide is cooled in the odor component liquefier 18, and the odor components 20 contained in this gas are condensed and removed. This operation can prevent odor components from accumulating in the carbon dioxide circulation system and ultimately increasing the amount of odor components in the product.

The carbon dioxide from which most impurities have been removed through the above steps is supplied to the CO□ liquefier 19, where it is cooled and liquefied, then pressurized by the pump 7, and then heated by the heater 11C to reach a supercritical state. This is used as an extractant for the extractor 12.

Since the CO and carbon dioxide supplied to the liquefier 19 have already been cooled to a low temperature range in the odor component liquefier 18, they can be easily liquefied with a small amount of cooling capacity.

In addition, the present invention can exhibit the same effect on concentration and separation of docosahexaenoic acid (DHA) from fish oil as well as EPA.

〔Effect of the invention〕

As described above, according to the present invention, EPA and highly unsaturated fatty acids other than EPA can be separated with high accuracy, and therefore EPA with a high concentration of about 80% or more can be extracted and separated in large quantities from fish oil. Because it is processed with CO□, which is free of CO□, safe products can be obtained.

[Brief explanation of drawings]

FIG. 1 is a flow sheet of an apparatus for implementing the method of concentrating and separating EPA from fish oil according to the present invention, and FIG. 2 is a graph showing the relationship between temperature, pressure, and density of carbon dioxide in a supercritical state. 1...Fish oil, 2...Urea, 3.
... Alkali alkoxide, 4 ... Alcohol, 5 ... Addition tank, 6 ... Urea clathrate fatty acid ester, 7 ...
・Pump, 8...Highly unsaturated fatty acid ester, 9...
・・Glycerin, 10A, IOB, IOC, IOD・・・・・・Reducing valve,
11A, IIB, IIC... Heater, 12...
...Extractor, 13...First separator, 14...Second separator, 15...Product EPA ester, 16...
...Low boiling point unsaturated fatty acid ester, 17...
・Alcohol liquefier, 18...Odor component liquefier, 19...CO□ liquefier, 20...Odor component, 21...COt, 22. ...Heating trace.

Claims (5)

[Claims] (1) After extracting polyunsaturated fatty acids rich in eicosapentaenoic acid from the polyunsaturated fatty acids obtained by separating saturated fatty acids and low-degree unsaturated fatty acids from fish oil by pretreatment with carbon dioxide in a supercritical state, the subsequent step The temperature and pressure are adjusted to predetermined values in the extraction region, and components other than eicosapentaenoic acid are selectively separated from the eicosapentaenoic acid-rich polyunsaturated fatty acids to purify high-concentration eicosapentaenoic acid. A method for concentrating and separating eicosapentaenoic acid from fish oil. (2) The fish oil according to claim 1, wherein the pretreatment is performed by adding alcohol, alkali alkoxide, and urea to the fish oil, and separating the saturated fatty acids and low-degree unsaturated fatty acids in the fish oil by precipitation as urea clathrates. Concentration and separation method of eicosapentaenoic acid from. (3) A patent claim for cooling carbon dioxide after separating fatty acids such as eicosapentaenoic acid, condensing and separating the alcohol accompanying the carbon dioxide, and then recycling this alcohol as an additive for pretreatment. A method for concentrating and separating eicosapentaenoic acid from fish oil according to item 2. (4) Further cooling the carbon dioxide from which the alcohol has been separated,
4. A method for concentrating and separating eicosapentaenoic acid from fish oil according to claim 3, wherein odor components accompanying carbon dioxide are condensed and separated. (5) The fish oil according to claim 4, wherein carbon dioxide in a low-temperature state from which odor components have been removed is further cooled and liquefied, and then brought to a supercritical state by pressurization and temperature elevation, and then recycled as an extractant. Method for concentrating and separating eicosapentaenoic acid from.