JP2002233396A - Method for producing sterol fatty acid ester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing sterol fatty acid esters, obtained from a deodorized scum oil by a synthesizing reaction using an enzyme in supercritical carbon dioxide, by which the sterol fatty acid esters having an excellent quality can be produced at a low cost. SOLUTION: This method for producing the sterol fatty acid esters comprises using as a raw material a deodorizing scum oil produced as a volatile component-containing distillation fraction in a deodorizing process as one of processes for purifying vegetable oils or fats, subjecting the deodorized scum oil to a sterol fatty acid ester-synthesizing reaction using an enzyme in supercritical carbon dioxide, and then selectively recovering the product from the reactor, thereby producing the sterol fatty acid esters having an excellent quality at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing sterol fatty acid esters of excellent quality from deodorized scum oil using a supercritical reactor.

[0002]

2. Description of the Related Art In the process of refining vegetable oils such as soybean oil and rapeseed oil, many sterols including β-sitosterol are obtained as a part of unsaponifiable substances. It is known to have a cholesterol lowering effect. Also, recently, it has been revealed that β-sitosterol, a saturated form of β-sitosterol, has a stronger plasma cholesterol lowering effect than β-sitosterol, and has been receiving more and more attention.

[0003] However, the above-mentioned free sterols and free stanols are insoluble in the micellar phase in the digestive tract, and thus cannot be said to be an appropriate intake form for obtaining their physiological effects. In contrast, ingestion as a sterol fatty acid ester has been proposed to improve fat solubility, and recently,
Attempts have also been made to add it to various foods such as margarine containing plant sterols as sterol fatty acid esters, and some of them are commercially available.

[0004] By the way, sterol fatty acid esters have heretofore been used as a cholesteric liquid crystal and a hydrophilic base material for pharmaceutical cosmetics. Therefore, a chemical synthesis method using an acid catalyst or a base catalyst has been used as a method for producing the same.

[0005] However, in chemical synthesis, generally, the reaction conditions are severe, so that there is a problem that the quality is liable to be deteriorated and that by-products are easily generated, and the purification process after the synthesis reaction is very complicated. In addition, there is a problem that, when used for foods or pharmaceuticals, by-products or reaction catalysts may be mixed.

[0006] To avoid this problem, utilization of enzymes such as cholesterol esterase and lipase has been studied.

[0007] Cholesterol esterase and lipase are both classified as one of the carboxylate hydrolases, and cholesterol esterase is defined as an enzyme that produces free sterol and free fatty acid from cholesterol fatty acid ester by a hydrolysis reaction. On the other hand, lipase (mainly triacylglycerol lipase) is defined as an enzyme that produces glycerol and free fatty acids from glycerol fatty acid esters by a hydrolysis reaction. However, there are many cases where cholesterol esterase activity and lipase activity are found in the same enzyme (D. Lombardo et al., Biochem. Bi.
ophys. Acta, 611, (1980), 147-), cholesterol esterase and lipase have also been shown to catalyze the degradation of triacylglycerols (WEM).
omsen et al., Biochem. Biophys. Acta, 486, (1977), 103.
-) At present, not a few cases are known in which cholesterol esterase or lipase cannot be clearly classified.

By the way, it is known that the above-mentioned enzyme usually catalyzes a hydrolysis reaction of a carboxylic acid ester while catalyzing an ester synthesis reaction.

Lawrence A. et al. Have shown that cholesterol oleate can be synthesized from free cholesterol and free oleic acid by a sterol ester hydrolase from dog pancreatic juice, known as cholesterol esterase (Biochem. Biophys. Acta,
231, (1971), 558-560). Similarly, D. Lombardo et al. Have shown that cholesterol esterase from human pancreatic juice catalyzes the synthesis of cholesterol fatty acid esters (Biochimie et al, 1980, 62, 427-432).
). On the other hand, Meisei et al. Have confirmed that lipase can synthesize cholesterol fatty acid esters (Japanese Patent Application No. 60-45128). As described above, it has been shown that it is possible to synthesize a cholesterol fatty acid ester using an enzyme with respect to the aforementioned chemical synthesis.

However, all of the above examples show only the synthesis reaction of sterol fatty acid esters, and are not intended to produce sterol fatty acid esters as general food materials, health food materials or pharmaceutical materials. In other words, in the synthetic reaction conditions, and in the subsequent purification method, the quality in terms of sensory aspects such as purity, color, smell, taste, etc., which are important for use as general food materials, health food materials or pharmaceutical materials, and furthermore, safety Do not consider. For the sterols used as raw materials, it is assumed that the sterols are highly purified,
It is very difficult to obtain low-cost, high-quality products even if purification such as distillation and fractionation, which are usually carried out when using these, is also very difficult. If it is carried out, the product becomes more expensive because the raw material is expensive, and it is difficult to use the product produced by this method in foods and the like.

On the other hand, it is conceivable to use deodorized scum oil generated in the step of deodorizing vegetable oils and fats as an inexpensive raw material. This deodorized scum oil contains a high concentration of unsaponifiable substances such as sterols and fatty acids. However, on the other hand, this deodorized scum contains a large amount of pigment components and odor components in addition to the intended raw material components, and when used as a raw material for sterol fatty acid esters, distillation, separation, and column purification. , Etc., must be combined, which is very complicated.

[0012]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to produce sterol fatty acid esters of excellent quality at low cost from deodorized scum oil.

[0013]

SUMMARY OF THE INVENTION A feature of the present invention is to utilize a supercritical carbon dioxide method. Supercritical carbon dioxide is a carbon dioxide that has exceeded the critical temperature (31.7 ° C) and critical pressure (7.2MPa) and can dissolve fats and oils. It is applied to extraction of components and purification of fats and oils. Further, by changing the temperature and the pressure, the solubility of the substrate can be arbitrarily changed, so that it is possible to selectively take out only the target component. In addition, this supercritical carbon dioxide, in addition to its solubility in lipids, is harmless, has a very low effect on fatty acids with a high degree of unsaturation because it can be reacted under oxygen-free conditions, Since it can be easily removed, it is expected to be used as a medium for a reaction using lipase.

[0014] Therefore, using a deodorized scum oil as a raw material, a synthetic reaction of sterol fatty acid ester is performed by an enzyme in supercritical carbon dioxide to produce a sterol fatty acid ester of excellent quality.

That is, a deodorizing scum oil generated as a distillate containing volatile components in a deodorizing step which is one of the steps of refining vegetable oils and fats is used as a raw material, and a synthesis reaction of sterol fatty acid ester by an enzyme in supercritical carbon dioxide. Do
Further, the present invention is to produce an inexpensive sterol fatty acid ester of excellent quality by selectively recovering the product from the reaction tank.

Here, the invention of claim 1 according to the present invention relates to a method for producing a sterol fatty acid ester, wherein deodorized scum oil generated in a deodorizing step of vegetable oils and fats is used as a raw material, and deodorized scum oil and an enzyme are reacted. Charged into a tank, set to a desired temperature and pressure in supercritical carbon dioxide, perform a sterol fatty acid ester synthesis reaction, and then selectively supply sterols while supplying supercritical carbon dioxide into the reaction tank. The method is characterized in that fatty acid esters are recovered, and sterol fatty acid esters of excellent quality are recovered.

Further, the invention of claim 2 is characterized in that, in the invention of claim 1, cholesterol esterase or lipase is used as an enzyme when the sterol fatty acid ester synthesis reaction is carried out.

The invention of claim 3 is characterized in that, in the invention of claim 1, when the synthesis reaction of the sterol fatty acid ester is performed, the inside of the reaction tank is kept at 32 to 80 ° C. and 7.2 to 50 MPa.

The invention of claim 4 is the invention of claim 1, wherein the sterol fatty acid ester content in the sterol fatty acid ester obtained as a product is 98% by weight or more and the peroxide value is 2 or less; It is characterized by an acid value of 0.5 or less, a color of 3 or less (Gardner method), and almost tasteless and odorless.

Hereinafter, a method for producing a sterol fatty acid ester will be conceptually described with reference to FIG.

In the present invention, as the deodorized scum oil (step 100) used as a raw material, any deodorized scum oil derived from any vegetable oil can be used as long as it is generated in the step of deodorizing vegetable oils. Examples include soybean deodorized scum oil, rapeseed deodorized scum oil, palm deodorized scum oil, and other deodorized scum oils derived from sunflower oil, rice bran oil, corn oil, safflower oil, and the like.

These deodorized scum oils include free sterols, free fatty acids, triacylglycerol, diacylglycerol, monoacylglycerol, tocopherol, carotene, wax and the like. Of these, free sterols, including β-sitosterol, campesterol, brassicasterol, stigmasterol, cholesterol, etc. are included, while free fatty acids or triacylglycerol, diacylglycerol, monoacylglycerol are bound to monoacylglycerol. The fatty acids include linoleic acid, oleic acid, palmitic acid, stearic acid, α-linolenic acid, myristic acid and the like. When the deodorized scum oil as described above is used as a raw material, it can be used as it is, but since it often contains a pigment component and other solid substances, solid substances such as adsorbent treatment or filtration are used in advance. It is advisable to remove unnecessary components before use.

Further, as far as the cost permits, free sterols and fatty acids in the deodorized scum oil may be arbitrarily concentrated by distillation or fractionation in advance. What added sterol and free fatty acid may be used as a raw material.

However, an advantage of the present invention is that sterols and fatty acids serving as substrates for sterol fatty acid esters are already present in the deodorized scum oil as a raw material, and deodorized scum oil is used in a state where these are present. Thus, an inexpensive sterol fatty acid ester can be obtained.

Next, the supercritical apparatus used in the process of step 110 may be either a batch type or a continuous type. As a reaction tank, an extraction tank generally provided in a supercritical extraction apparatus can be used. Those with functions are desirable. Further, an apparatus in which a tower-type extraction tower is continuously connected to the reaction tank to further improve the product purification efficiency may be used. When using an extraction tower,
For example, a filler such as Raschig ring, Dickson, and Helipack is filled inside, and a temperature gradient is provided by gradually increasing the temperature from the lower part to the upper part, so that the rectification effect can be enhanced.

In the sterol fatty acid ester synthesis reaction using a supercritical apparatus (step 120), the cholesterol esterase or lipase used as a catalyst may be any of various microorganisms, animals and plants, and may be of microorganism origin. is, for example, Pseudomonas (Pseudomonas) genus Alcaligenes (Alcaligen
es ), Candida , Muco
r) genus, Rhizopus (Rhizopus) genus, Jiotorikamu (Geotr
cholesterol esterase or lipase derived from the genus icum ), and animal-derived cholesterol esterase or lipase derived from pig pancreas.

When the sterol fatty acid ester synthesis reaction is carried out under high temperature conditions, a heat-resistant enzyme may be used. Further, the enzyme may be purified, may be crudely purified, and when using an enzyme derived from a microorganism, the cells themselves may be used, or a culture solution may be used. . Further, the enzyme may be in free form,
Those immobilized by various carriers such as celite may be used. The enzyme can be reused as much as possible.

[0028] The amount of enzyme used is
The amount is preferably 50,000 units or less, more preferably 10,000 units or less (the amount of the enzyme that releases 1 micromol of fatty acid per minute from olive oil is defined as 1 unit). In order to obtain a cheaper product, it is desirable to reduce the amount of the enzyme used as much as possible.

In the present invention, the sterol fatty acid ester synthesis reaction proceeds regardless of the presence or absence of water. Usually, the temperature in the reaction tank is preferably from 32 to 80 ° C. Further, the pressure is preferably 7.2 to 50 MPa.

Product (product generated in step 140)
In this method, supercritical carbon dioxide is continuously passed through a reaction vessel, and only the generated sterol fatty acid ester can be taken out of the reaction system. Since the sterol fatty acid ester has a very low polarity, it has extremely high solubility in supercritical carbon dioxide as compared with other components in the deodorized scum oil, and can be taken out of the reaction system preferentially. The product taken out of the reaction system is immediately decompressed to remove carbon dioxide.

The sterol fatty acid ester (step 140) finally obtained according to the present invention comprises:
By the processing of step 130, the product is very pure, tasteless, odorless, and colorless and has excellent quality in terms of safety, and has appropriate quality as a general food, health food, or pharmaceutical material. This sterol fatty acid ester is expected to have a cholesterol lowering effect, and is expected to be used as a functional material in general foods such as margarine and dressings, as well as health foods, and in future pharmaceuticals.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments according to the present invention will be described below with reference to the drawings.

FIG. 2 is an overall configuration diagram showing a schematic configuration of an embodiment of the supercritical reactor used in the present embodiment.

In FIG. 2, the supercritical reactor 20 includes a carbon dioxide storage tank 1, a pressurizing apparatus 2, a heating apparatus 3, a reaction tank 4, a pressure reducing valve 5, a separation tank 6, a valve 7, a gas processing apparatus 8, and a pressure reducing valve 9. , A pressure reducing valve 10.

Here, the carbon dioxide storage tank 1 is a gas cylinder in which carbon dioxide to be supercritical carbon dioxide is stored.

The pressurizing device 2 is connected to the carbon dioxide storage tank 1.
Pressure is controlled so that the carbon dioxide delivered from the superconductor becomes supercritical carbon dioxide.

The heating device 3 controls the heating of the reaction tank 4 so that the carbon dioxide sent from the pressure device 2 into the reaction tank 4 becomes supercritical carbon dioxide.

Further, the reaction tank 4 is supplied with deodorized scum oil and enzyme as raw materials from a raw material oil / fat supply port and an enzyme supply port (not shown) and adjusted to a desired temperature and pressure to bring the inside of the reaction tank into a supercritical state. Is what you do. In the case where a stirring function is provided, stirring is arbitrarily performed.

The pressure reducing valve 5 decompresses supercritical carbon dioxide containing sterol fatty acid ester separated and extracted as a fraction from the upper part of the reaction tank 4 to vaporize carbon dioxide.

The supercritical carbon dioxide in the fluid state in the reaction tank 4 is in a state in which the solubility of the sterol fatty acid ester is increased by controlling the pressure. Therefore, only the fraction containing supercritical carbon dioxide is guided from above the reaction tank 4 to the pressure reducing valve 5.

The separation tank 6 separates the carbon dioxide and the sterol fatty acid ester separated by the pressure reducing valve 5. The separated carbon dioxide is further guided to the valve 7 and reduced in pressure, and the sterol fatty acid ester as a product (FIG. The first step 140) is led to the pressure reducing valve 9.

The carbon dioxide guided to the valve 7 is regenerated by the gas treatment device 8 and can be reused.

Further, the sterols and fatty acids in the raw material in the reaction tank 4 are consumed as much as possible as a substrate of the sterol fatty acid ester, and other remaining pigment components and odor components (step 130 in FIG. 1) are finally removed. It is led to the pressure reducing valve 10 and discarded.

The above is the configuration of the embodiment of the present invention.
Next, the operation will be described.

First, the carbon dioxide in the carbon dioxide storage tank 1 is supplied to the pressurizing device 2, pressurized by the pressurizing device 2,
Supplied to Since the heating device 3 is provided around the reaction tank 4, the inside of the reaction tank 4 can be set to a desired supercritical state by controlling the pressure of the pressurizing device 2 and the heating of the heating device 3.

Therefore, first, the deodorized scum oil and the enzyme, which are the raw materials, are charged into the reaction tank 4 and set to the desired temperature and pressure. Thereafter, the reaction is carried out for an arbitrary time, and subsequently, supercritical carbon dioxide is continuously supplied into the reaction tank 4 for a certain time. Thereby, the sterol fatty acid ester is extracted from the upper part of the reaction tank 4, guided to the pressure reducing valve 5, and further guided to the separation tank 6. On the other hand, in the reaction tank 4, since the products are continuously removed, the reaction equilibrium is inclined toward the synthesis reaction side, and the sterol contained in the raw deodorized scum oil is almost completely consumed.

Here, the supercritical carbon dioxide in the fraction is decompressed and separated by the pressure reducing valve 5, but is further guided to the valve 7 and to the gas treatment device 8. The sterols and fatty acids in the raw materials are consumed as much as possible as a substrate of the sterol fatty acid ester, and other remaining color components and odor components are further reduced in pressure by the pressure reducing valve 10.

The temperature and pressure in the reaction tank 4 when performing the sterol fatty acid ester synthesis reaction in the supercritical reactor 20 are 31.3 ° C., which is the critical point of carbon dioxide, and 7.
Although it is necessary to be 2 MPa or more, in the present invention, the temperature is 32 to
The temperature is preferably 80 ° C. and the pressure is 7.2 to 50 MPa. The supercritical fluid used in the present embodiment is carbon dioxide, separation after purification,
It is desirable to use it alone from the viewpoint of handleability, harmlessness and cost. Further, an entrainer such as water and ethanol may be mixed and used.

In the above embodiment, when the deodorized scum oil and the enzyme, which are the raw materials, are introduced into the reaction tank 4, the temperature and pressure in the reaction tank 4 are adjusted to desired values, and the synthesis of the sterol fatty acid ester is performed for an arbitrary time. After the reaction, supercritical carbon dioxide is supplied, and sterol fatty acid ester is extracted as a distillate from the upper part of the reaction tank 4 and led to the pressure reducing valve 5, and the sterol fatty acid ester separated by the pressure reducing valve 5 is separated in the separation tank 6. The sterol and the fatty acid in the deodorized scum oil were consumed as much as possible as a substrate of the sterol fatty acid ester in the reaction tank 4 so that other remaining coloring components and odor components were finally left.

Next, the present invention will be described with reference to more specific examples, but the present invention is not limited to these examples.

[0051]

Example 1 Soybean deodorized scum oil (sterol content 12.3)
%), 1.0 g of lipase powder (360,000 units / g) derived from the genus Candida and 1.0 ml of water are charged into the reaction tank 4, and the temperature in the reaction tank 4 is set to 40 ° C. and the extraction pressure is set to 10 MPa. The reaction was carried out for 12 hours. Subsequently, supercritical carbon dioxide is continuously ventilated into the reaction tank for 12 hours, and supercritical carbon dioxide containing sterol fatty acid ester is recovered, and the pressure is reduced by a pressure reducing valve.
The pressure was reduced to 2.9 MPa, and the sterol fatty acid ester as a product was separated in the separation layer 6. Thereafter, the sterols and fatty acids in the raw material deodorized scum oil were consumed from the reaction tank 4 and other remaining color components and odor components were collected. The recovered amount of the product was 19.2 g, and the purity of the sterol fatty acid ester was 99.5%, which was almost tasteless, odorless and colorless. The analysis results are shown in Table 1.

[0052]

Example 2 Soybean deodorized scum oil (sterol content 12.3)
%) 100 g of cholesterol esterase powder derived from Pseudomonas (50,000 units / g) 2.
0 and 1.0 ml of water are charged into the reaction vessel 4 and the temperature in the
C. and extraction pressure were set to 10 MPa, and the reaction was carried out for 12 hours. Subsequently, supercritical carbon dioxide is continuously passed through the reaction tank for 12 hours to recover supercritical carbon dioxide containing sterol fatty acid ester, and the pressure is reduced to 2.9 MPa by a pressure reducing valve. The fatty acid ester was separated. Thereafter, the sterols and fatty acids in the raw material deodorized scum oil were consumed from the reaction tank 4 and other remaining color components and odor components were collected. The recovered amount of the product is 18.9 g, the purity of the sterol fatty acid ester is 99.1%, almost tasteless,
It was odorless and colorless. The analysis results are shown in Table 1.

[0053]

Example 3 After completion of the reaction in Example 1, the sterols and fatty acids in the raw deodorized scum oil were consumed from the reaction tank 4 and the remaining dye components and odor components were recovered, and the reaction tank in which the lipase remained. Then, 100 g of soybean deodorized scum oil (sterol content: 12.3%) and water (1.0 ml) were again charged therein, the temperature in the reaction tank 4 was set to 40 ° C., and the extraction pressure was set to 10 MPa, and the reaction was carried out for 18 hours. Subsequently, supercritical carbon dioxide is continuously passed through the reactor for 12 hours to recover supercritical carbon dioxide containing sterol fatty acid ester, and the pressure is reduced to 2.9 MPa with a pressure reducing valve. The fatty acid ester was separated. Thereafter, sterols and fatty acids in the raw material deodorized scum oil were consumed from the reaction tank 4 and other remaining color components and odor components were collected. 18.2 g of product collected
The purity of the sterol fatty acid ester is 99.7%
It was almost tasteless, odorless and colorless. This indicates that the enzyme used for the sterol fatty acid ester synthesis reaction can be used repeatedly. The analysis results are shown in Table 1.

[0054]

Comparative Example 200 g of soybean deodorized scum oil (sterol content: 12.3%) used in Example 1 and 50 g of water were added to a lipase powder derived from Candida spp.
60,000 units / g) Add 1.0g suspension and add at 40 ℃
A sterol fatty acid ester synthesis reaction was carried out with stirring for 24 hours. After washing with hot water, a dehydration treatment was carried out at 80 ° C., followed by filtration to remove enzyme proteins.

Subsequently, a molecular distillation treatment was performed using a centrifugal molecular distillation apparatus at a degree of vacuum of 1.5 Pa and an evaporating surface temperature of 230 ° C.
Unreacted free fatty acids and sterols are removed as a distillate fraction. Then, activated clay is added to the remaining fraction at 10%, and the mixture is stirred under reduced pressure at 80 ° C for 30 minutes. The adsorbed activated clay was removed. Finally, using a batch-type steam distillation apparatus, vacuum degree 500 Pa, distillation temperature 1
Steam distillation treatment was performed at 50 ° C. for 1 hour to obtain 16.5 g of sterol fatty acid ester. The obtained sterol fatty acid ester was almost tasteless, odorless, and pale yellow, but its purity was 93.7%, which was lower than that obtained in the above Examples. The analysis results are shown in Table 1.

[0056]

[Table 1]

[0057]

As described above, in the present invention, the deodorizing scum oil generated as a distillate containing volatile components in the deodorizing step which is one of the refining steps of vegetable oils and fats is used as a raw material for supercritical carbon dioxide. An effect of synthesizing a sterol fatty acid ester by an enzyme in the reactor and selectively recovering the product from the reaction tank can produce an inexpensive sterol fatty acid ester of excellent quality.

[Brief description of the drawings]

FIG. 1 is a diagram conceptually showing a method for producing a sterol fatty acid ester to which the present invention is applied.

FIG. 2 is an overall configuration diagram showing a schematic configuration of a supercritical extraction apparatus used in one embodiment of the present invention shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Carbon dioxide storage tank 2 Pressurizing device 3 Heating device 4 Reaction tank 5 Pressure reducing valve 6 Separation tank 7 Valve 8 Gas treatment device 9 Pressure reducing valve 10 Pressure reducing valve 20 Supercritical reactor

Continuing from the front page (72) Inventor Shoji Kaneko 95-7 Minoki-cho, Fukuyama-shi, Hiroshima Ikeda Food Research Institute Co., Ltd. (72) Inventor Mitsumasa Mankura 95-7 Minoki-cho, Fukuyama-shi, Hiroshima F-term in Ikeda Shokuken Co., Ltd. 4B064 AH07 CA21 CB24 CD24 DA01 DA10

Claims (4)

[Claims] 1. A method for producing a sterol fatty acid ester, comprising: using a deodorized scum oil generated in a deodorizing step of a vegetable oil and fat as a raw material, charging the deodorized scum oil and an enzyme into a reaction tank, A sterol fatty acid ester is synthesized at a desired temperature and pressure, and then the sterol fatty acid ester is selectively recovered while supplying supercritical carbon dioxide into the reaction vessel. A method for producing a sterol fatty acid ester, comprising recovering the ester. 2. The method for producing a sterol fatty acid ester according to claim 1, wherein cholesterol esterase or lipase is used as an enzyme when performing a sterol fatty acid ester synthesis reaction. 3. The method for producing a sterol fatty acid ester according to claim 1, wherein the inside of the reaction tank is kept at 32 to 80 ° C. and 7.2 to 50 MPa when performing a synthesis reaction of the sterol fatty acid ester. 4. A sterol fatty acid ester obtained as a product has a sterol fatty acid ester content of 98% by weight or more, a peroxide value of 2 or less, and an acid value of 2 or less.
2. The method for producing a sterol fatty acid ester according to claim 1, wherein the sterol fatty acid ester is 0.5 or less, has a color of 3 or less (Gardner method), and is almost tasteless and odorless.