JP2538753B2 - How to extract fatty acids - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for extracting a fatty acid, and more particularly to a method for extracting a fatty acid capable of efficiently extracting a fatty acid from a natural lipid raw material such as animal and plant tissues.

[0002]

BACKGROUND OF THE INVENTION Fatty acids are obtained from a wide range of natural resources such as animals, plants, fish and microorganisms, and are used for food (edible oil, butter, etc.),
Used in various fields such as medical use (linseed oil, castor oil, ointment, adult disease preventives, etc.), cosmetics (soap, palm oil, etc.), chemical industry (candles, lubricants, paints, fuels, etc.) Has been done.

When separating fatty acids from natural raw materials such as animals and plants, first, the natural raw materials are crushed and then chloroform,
Lipids are separated from the proteins and organic pigments in the raw material by a method such as stirring and squeezing in an extraction solvent such as diethyl ether. For example, Botryococcus braunii, known to produce hydrocarbons that can be converted to liquid fuels,
After crushing the cells, they are extracted with benzene as an extraction solvent and roughly separated as lipids containing hydrocarbons (FEINBERG DA:
Fuel Options from Microalgae with Representative
Chemical Compositions: USDOE Rep .: No. SERI-TR-23
1-2427, 30 (1984)).

The lipid roughly separated from the natural raw material is then hydrolyzed to be decomposed into fatty acid and glycerin, and the fatty acid in the hydrolyzed solution is extracted with an extraction solvent or has a relatively high specific gravity with glycerin having a large specific gravity. It is obtained by separating small fatty acids in two layers. As the hydrolysis method, (1) Twitchell method using alkylbenzene sulfonic acid as a decomposition reagent and decomposing in an atmospheric pressure release can, (2)
One of the oldest lipid decomposition methods that has been performed since the 1850's, medium pressure decomposition method that decomposes in batch with a catalyst such as zinc oxide, (3) high pressure that decomposes lipids without catalyst under high temperature and high pressure conditions Decomposition method (industrialally, water is continuously injected into a decomposition tank to decompose), (4) Lipids are hydrolyzed in a highly alkaline state, and fatty acids are once extracted as a sodium or potassium salt with a solvent and then with a strong acid. Known are saponification and decomposition methods for neutralizing fatty acids, and (5) enzymatic decomposition method for enzymatically decomposing lipids with lipase extracted from animal internal organs or plant seeds.

However, in the above-mentioned conventional method of obtaining fatty acids from the hydrolyzed liquid after hydrolyzing lipids,
There are problems that it takes a long time to hydrolyze and that the degree of purification of the product and the efficiency of separating fatty acid and glycerin are poor. In particular
The method (1) is easy to operate and inexpensive in equipment cost.
The decomposition time is as long as 18 to 24 hours, and fatty acids are easily subjected to aerial oxidation, resulting in a high degree of product coloring. In the method (3), since the fatty acid and glycerin are separated by utilizing the difference in specific gravity of taking out the fatty acid from the bottom of the decomposition tower, it is difficult to completely separate the fatty acid and glycerin. The method (4) is a method that can easily obtain a small amount of fatty acid and is used as a cosmetic raw material for the production of soap as an emulsifier.However, since the fatty acid and glycerin are separated by solvent extraction, a large-scale method is used. Industrialization is difficult and its applications are limited. Furthermore, the method (5) is also a method that has been put into practical use at present, but there are problems in reaction time, decomposition rate, enzyme production cost, and the like.

[0006]

The object of the present invention is to obtain a crude lipid obtained by crushing, squeezing, solvent extraction or the like from a natural lipid raw material in a simple process without denaturation by air oxidation,
An object of the present invention is to provide a method for extracting a fatty acid that can obtain a fatty acid with high efficiency.

[0007]

The inventions claimed in this application are as follows. (1) The lipid separated from the natural lipid raw material is hydrolyzed in a supercritical fluid under high temperature and high pressure conditions, and then
A method for extracting a fatty acid, which comprises extracting the fatty acid from the hydrolyzed liquid in the reaction vessel in which the solution is performed . (2) Lipid in carbon dioxide supercritical fluid at a temperature of 100 to 3
The method for extracting a fatty acid according to (1), which comprises hydrolyzing under conditions of 00 ° C. and a pressure of 75 to 300 kg / cm ² . (3) A fatty acid is extracted by injecting a carbon dioxide supercritical fluid into the hydrolyzate at a temperature of higher than 31 ° C and lower than 200 ° C and a pressure of 100 to 400 kg / cm ² (1). Method of extracting fatty acids from.

The lipids hydrolyzed in the present invention include
Natural lipid raw materials such as animals and plants, fish, microorganisms are crushed, squeezed,
A crude lipid obtained through a process such as solvent extraction is used.
The supercritical fluid used in the present invention does not need to remove the extraction solvent from the extracted fatty acid, and does not need to consider the toxicity of the solvent to the product, carbon dioxide (CO ₂ ).
Is preferably used. The supercritical fluid hydrolyzes lipids under high temperature and high pressure, and further dissolves fatty acids decomposed by adjusting the pressure and temperature of the supercritical fluid.

The extraction method of the present invention will be described below. First, a supercritical fluid, an oil / fat sample, and decomposed water are put into a supercritical fluid extraction container, and hydrolysis is performed by controlling the pressure and temperature in the extraction container. The amount of decomposition water added is 10
˜50% by weight is preferred, and especially 20-40% by weight is preferred. By increasing the pressure and temperature in the extraction container, the solubility of water in the lipid can be increased and efficient hydrolysis can be performed.

The pressure during hydrolysis is 75 to 300 kg / cm ²
Is preferred, and 75 to 200 kg / cm ² is particularly preferred. The temperature at the time of hydrolysis is the temperature at which the target fatty acid is not thermally changed in the absence of oxygen, specifically 10
A temperature of 0 to 300 ° C is preferable, and a temperature of 100 to 200 ° C is particularly preferable. The hydrolysis time is usually 1 to 30 hours, preferably 2 to 15 hours, more preferably 2 to 5 hours.

In the supercritical fluid extraction container, a system for injecting decomposed water into the extraction container, which has been heated to high temperature and high pressure (the inlet is usually installed at the upper part of the extraction container), and glycerin which is a by-product of hydrolysis are discharged. It is also possible to provide a system (a discharge port is usually installed at the bottom of the extraction container) for performing hydrolysis while injecting decomposition water and simply removing by-products. Thereby, the equilibrium of the hydrolysis reaction can be canceled and the decomposition can be promoted.

After the hydrolysis is completed, the hydrolysis reaction
While maintaining the pressure in the used extraction container at that pressure,
Alternatively, the temperature is further raised to add a supercritical fluid, and the fatty acid is dissolved and extracted. Pressure during extraction is 100-400kg /
cm ² is preferable, and 150 to 300 kg / cm ² is particularly preferable. The extraction temperature is a temperature at which the target fatty acid is not thermally changed in the absence of oxygen, specifically, 31 ° C.
Over 200 ℃ is preferable, over 31 ℃ 1
A temperature of 00 ° C. is particularly preferred. The extraction time is preferably 5 minutes to 4 hours, and particularly preferably 30 minutes to 3 hours. A solvent such as methanol, N-hexane, or acetonitrile can be mixed in the supercritical fluid as an entrainer for the purpose of selectively dissolving only the decomposed fatty acid.

[0013]

[Function] When a crude lipid obtained from a natural lipid raw material is hydrolyzed in a supercritical fluid under high temperature and high pressure, it is decomposed into a fatty acid and glycerin. Keep the reaction vessel at that pressure, or
The further in the high-pressure supercritical fluid other only fatty by flowing into the reaction vessel is dissolved in the supercritical fluid, is collected in the collection container side.

[0014]

【Example】

Example 1 400 mg of oleic acid and 500 mg of glycerin were put into a supercritical fluid extraction container, and CO ₂ supercritical fluid was flowed into the extraction container at a flow rate of 2 ml / min under the conditions of temperature 70 ° C. and pressure 200 kg / cm ² for 2 hours. Extraction was performed. 355 g of oleic acid was recovered in the recovery container, and 472 mg of glycerin remained in the extraction container.

Example 2 Spirulina sp. 1 g (dry weight) of algal cells were crushed into cells, and crude lipids were extracted with chloroform under a nitrogen atmosphere. About 200 mg and about 100 mg of the obtained lipid were placed in a supercritical fluid extraction container, and the inside of the container was filled with CO ₂ supercritical fluid, and the atmosphere temperature was 150 ° C. and the pressure was 100 kg / cm ² . After 4 hours, when a CO ₂ supercritical fluid whose pressure had been raised to 200 kg / cm ² was flown into the container at a flow rate of 2 ml / min, about 140 mg of fatty acid was recovered in the recovery container on the CO ₂ outlet side.

Example 3 760 mg of triolein was placed in a supercritical fluid extraction container, and a CO ₂ supercritical fluid was circulated under the conditions of a temperature of 250 ° C. and a pressure of 80 kg / cm ² . At the same time, water at 0.5 ml / min for 1 min,
Then, 0.01 ml / min was added and hydrolysis was carried out for 3 hours. Next, the temperature inside the container is lowered to 70 ° C and the pressure is 200 kg.
/ Cm ² and CO ₂ supercritical fluid was passed at 2 ml / min for 2 hours. About 700 mg of oleic acid was recovered in the recovery container at the CO ₂ outlet, and glycerin water remained in the extraction container.

Example 4 650 mg of triolein was placed in a supercritical fluid extraction vessel, and a CO ₂ supercritical fluid was circulated under the conditions of a temperature of 200 ° C. and a pressure of 80 kg / cm ² . At the same time, water at 0.5 ml / min for 1 min,
Then, 0.01 ml / min was added and hydrolysis was carried out for 3 hours. Next, the temperature inside the container is lowered to 70 ° C and the pressure is 200 kg.
/ Cm ² and CO ₂ supercritical fluid was passed at 2 ml / min for 2 hours. About 230 mg of oleic acid was recovered in the recovery container at the CO ₂ outlet, and glycerin water remained in the extraction container.

Example 5 760 mg of triolein was placed in a supercritical fluid extraction vessel, and a CO ₂ supercritical fluid was circulated under the conditions of a temperature of 250 ° C. and a pressure of 80 kg / cm ² . At the same time, water at 0.5 ml / min for 1 min,
Then, 0.01 ml / min was added and hydrolysis was carried out for 5 hours. Next, the temperature inside the container is lowered to 70 ° C and the pressure is 250 kg.
/ Cm ² and CO ₂ supercritical fluid was passed at 2 ml / min for 2 hours. About 700 mg of oleic acid was recovered in the recovery container at the CO ₂ outlet, and glycerin water remained in the extraction container.

Example 6 760 mg of triolein was placed in a supercritical fluid extraction vessel, and a CO ₂ supercritical fluid was circulated under the conditions of a temperature of 250 ° C. and a pressure of 200 kg / cm ² . Simultaneously with water at 0.5 ml / min for 1 min
Then, 0.01 ml / min was added and hydrolysis was carried out for 3 hours. Next, the temperature inside the container is lowered to 70 ° C. and the pressure is set to 20.
Maintaining 0 kg / cm ² , a CO ₂ supercritical fluid was passed at 2 ml / min for 2 hours. About 700 mg of oleic acid was recovered in the recovery container at the CO ₂ outlet, and glycerin water remained in the extraction container.

Comparative Example 1 760 mg of triolein was placed in a supercritical fluid extraction vessel, and a CO ₂ supercritical fluid was circulated under the conditions of a temperature of 250 ° C. and a pressure of 80 kg / cm ² . At the same time, water at 0.5 ml / min for 1 min,
Then, 0.01 ml / min was added and hydrolysis was carried out for 3 hours. Next, the temperature inside the container was lowered to 70 ° C and the pressure was 80 kg /
The supercritical fluid of CO ₂ was flowed at 2 ml / min for 2 hours while being maintained at cm ² . There was almost no collected material in the collection container at the CO ₂ outlet, and oleic acid and glycerin water remained in the extraction container.

[0021]

EFFECTS OF THE INVENTION According to the method for extracting fatty acids of the present invention, the hydrolysis of lipids and the separation of the obtained fatty acids can be carried out in one step in a supercritical fluid in the same container.
In particular, unsaturated fatty acids having high added value can be obtained with high efficiency without being modified by air oxidation.

Claims (3)

(57) [Claims] 1. A lipid separated from a natural lipid raw material is hydrolyzed in a supercritical fluid under conditions of high temperature and high pressure, and then
A method for extracting a fatty acid, which comprises extracting a fatty acid from the hydrolyzed liquid in a reaction vessel in which the above-mentioned hydrolysis is performed . 2. A lipid at a temperature of 1 in a carbon dioxide supercritical fluid.
The method for extracting a fatty acid according to claim 1, wherein the hydrolysis is performed under the conditions of 00 to 300 ° C. and a pressure of 75 to 300 kg / cm ² . 3. A fatty acid is extracted by allowing a carbon dioxide supercritical fluid to flow into the hydrolyzate at a temperature of higher than 31 ° C. and lower than 200 ° C. and a pressure of 100 to 400 kg / cm ^2. Item 1. A method for extracting a fatty acid according to item 1.