JP4694939B2 - Method for producing fatty acids - Google Patents

Description

  The present invention relates to a method for producing fatty acids by hydrolyzing fats and oils.

  Fatty acids are produced by hydrolyzing fats and oils. As a method for hydrolyzing fats and oils, a high-temperature and high-pressure decomposition method (Patent Document 1) and an enzymatic decomposition method (Patent Document 2) are performed. The former is carried out under high temperature and high pressure conditions, and has the advantage of high productivity. However, if a raw material having a lot of unsaturated fatty acids is used, a large amount of trans unsaturated fatty acids may be produced depending on the conditions. On the other hand, the latter uses an enzyme such as lipase as a catalyst, and the reaction is carried out at a low temperature of 0 to 70 ° C., so that it does not produce a trans-unsaturated fatty acid, but is less productive than the high-temperature and high-pressure decomposition method.

  In the high-temperature and high-pressure decomposition method, there is an induction period until decomposition starts at the beginning of the reaction. In order to eliminate or shorten the induction time, glycerides are first used with a 1,3-specific lipase, There is also a technique in which a partially hydrolyzed glyceride is prepared by partial hydrolysis by an enzymatic decomposition method, and then a high temperature high pressure decomposition method is performed (Patent Document 3).

JP 2003-113395 A JP 2000-160188 A Japanese National Patent Publication No. 8-507917

  In recent years, the effects of edible oils on health have attracted attention worldwide, and trans-unsaturated fatty acids increase LDL (bad) cholesterol levels along with saturated fatty acids and cholesterol, increasing the risk of coronary heart disease It is scientifically supported that In the United States, approximately 13 million people suffer from coronary heart disease, and more than 500,000 die from coronary heart disease each year. Under these circumstances, in the United States, “Nutrition Facts” (nutritional labeling), in addition to the conventional lipid, saturated fatty acid and cholesterol labeling, will be required to label the content of trans-unsaturated fatty acids from January 1, 2006. It became. In Denmark, it is inevitable that the trans-unsaturated fatty acid concentration of edible oil will be 2.0% by mass or less from 2004, and that it will spread throughout the EU countries. Thus, reduction of the trans unsaturated fatty acid of edible oil is desired worldwide.

Unrefined raw material fat and oil that omits the deodorizing step has a trans-unsaturated fatty acid content in the constituent fatty acid of 1.5% by mass or less, and if this is hydrolyzed by an enzymatic decomposition method, the content of trans-unsaturated fatty acid is It will not rise. However, since the color derived from the raw material remains as it is, the appearance of the fatty acids obtained is poor. On the other hand, fatty acids obtained by hydrolysis only by the high-temperature and high-pressure decomposition method have a good appearance when the colored components are decomposed, but the content of trans-unsaturated fatty acids in the constituent fatty acids is high.
In addition, according to the method described in Patent Document 3, the reaction time of the high-temperature and high-pressure decomposition method can be shortened, and the fatty acids can be efficiently produced. It was found that fatty acids with low trans-unsaturated fat content can be produced, but fatty acids with good hue cannot always be produced when hydrolyzed by high-temperature and high-pressure decomposition method after partial hydrolysis by enzymatic decomposition method It has been found.
Accordingly, an object of the present invention is to produce fatty acids having a good appearance with reduced color, which can efficiently produce fatty acids having a low content of trans-unsaturated fatty acids in the constituent fatty acids by hydrolysis of fats and oils. It is to provide a method.

  Therefore, the present inventor conducted various studies on the combination of the enzymatic decomposition method and the high-temperature high-pressure decomposition method in the hydrolysis reaction of fats and oils. First, the fats and oils were obtained by enzymatic decomposition using an immobilized enzyme in which the enzyme was immobilized on a carrier. When fatty acids are partially hydrolyzed and then hydrolyzed by a high-temperature and high-pressure decomposition method, fatty acids having a low content of trans-unsaturated fatty acids in the constituent fatty acids can be efficiently produced and have good appearance. I found.

  That is, the present invention is a method for producing fatty acids by hydrolyzing fats and oils, wherein the fats and oils are partially hydrolyzed by an enzymatic decomposition method using an immobilized enzyme in which the enzyme is immobilized on a carrier. The present invention provides a method for producing fatty acids that are hydrolyzed by a high-temperature and high-pressure decomposition method.

  According to the present invention, fatty acids having a low content of trans-unsaturated fatty acids in constituent fatty acids can be efficiently produced by hydrolysis of fats and oils, and fatty acids having a good appearance can be produced.

  In the present invention, the “enzymatic degradation method” means that fatty acids and glycerin are added by reacting under low temperature conditions using an immobilized enzyme obtained by adding water to raw oil and fat and immobilizing an enzyme such as lipase on a carrier. The method of obtaining. Further, the “high temperature and high pressure decomposition method” in the present invention refers to a method of obtaining fatty acids and glycerin by adding water to raw material fats and reacting under conditions of high temperature and high pressure. Furthermore, “fatty acids” in the present invention include not only fatty acids but also those in which glycerin, monoacylglycerol, diacylglycerol, and triacylglycerol are present.

  In the present invention, the raw oil / fat to be hydrolyzed may be a vegetable oil / animal fat / oil. Specific examples of the raw material include rapeseed oil, sunflower oil, corn oil, soybean oil, linseed oil, rice oil, safflower oil, cottonseed oil, beef tallow, fish oil and the like. In addition, those obtained by separating and mixing these fats and oils, those obtained by adjusting the fatty acid composition by hydrogenation, transesterification, etc. can be used as raw materials. It is preferable from the viewpoint of reducing the content of trans-unsaturated fatty acid in the fatty acid.

  In the embodiment of the present invention, it is preferable to remove the solid content other than the oil by filtration, centrifugation, or the like after squeezing the raw material fat from the plant or animal as the respective raw material. Next, it is preferable to degum by separating the gum by centrifugation or the like after adding water and optionally further acid and mixing. Moreover, after adding and mixing an alkali, it is preferable to deoxidize raw material fats by washing with water and dehydrating. Furthermore, it is preferable to decolorize raw material fat by contacting the adsorbent such as activated clay and separating the adsorbent by filtration or the like. These processes are preferably performed in the above order, but the order may be changed. In addition to this, the raw oil and fat may be subjected to wintering for separating the solid content at a low temperature in order to remove the wax content. Furthermore, you may deodorize raw material fats and oils by making it contact with water vapor | steam under reduced pressure as needed. At this time, it is preferable to make the heat history as low as possible from the viewpoint of reducing the content of trans-unsaturated fatty acids in the fatty acids constituting the fats and oils. As for the conditions of the deodorizing step, the temperature is preferably controlled to 300 ° C. or less, particularly 270 ° C. or less, and the time is preferably 10 hours or less, particularly 5 hours or less.

  In the present invention, the raw fats and oils have a trans-unsaturated fatty acid content in the constituent fatty acids of 1.5% by mass or less, more preferably 1% by mass or less, particularly 0.5% by mass or less. It is preferable from the viewpoint of reducing the content of trans-unsaturated fatty acids in the constituent fatty acids of the fatty acids. For example, as raw material fats and oils, it is preferable to use undeodorized fats and oils for all or part of the raw materials because trans unsaturated fatty acids in fatty acids constituting fatty acids can be reduced. Here, the trans-unsaturated fatty acid content in the constituent fatty acid is the content in the total amount when two or more fats and oils are used.

  In the hydrolysis by the high-temperature and high-pressure decomposition method, the higher the degree of unsaturation of the constituent fatty acids of the raw material fats and oils, the easier it is to convert to heat. In particular, in the case of oleic acid having an unsaturation degree of 1, almost no trans-transformation occurs upon heating, and in the case of fatty acids having an unsaturation degree of 2 or more, such as linoleic acid or linolenic acid, trans-translation is remarkable. Become.

The raw fat and oil used in the production method of the present invention has a trans-unsaturated fatty acid content in the constituent fatty acid of 1.5% by mass or less, more preferably 0.01 to 1% by mass, and particularly 0.1 to 1% by mass. It is preferable from the viewpoint of physiological effects. The hue C is preferably 20 or more and more preferably 35 or more from the viewpoint that the effect of improving the appearance according to the present invention is remarkable.
The “content of trans-unsaturated fatty acid in the constituent fatty acid” and the “fatty acid composition” in the present invention are the “preparation method of fatty acid methyl ester” (2.4 1.2-1996) ”refers to a value obtained by preparing a fatty acid methyl ester according to American Oil Chemists. Society Official Method Ce 1f-96 (GLC method). The “hue C” of the raw oil or fatty acid is a value obtained by the following formula (1), measured by a 5.25 inch cell according to American Oil Chemists. Society Official Method Ca 13e-92 (Lovibond method). .
Hue C = 10R + Y (1)
(Where R = Red value, Y = Yellow value)

In the present invention, partial hydrolysis by the enzymatic degradation method of fats and oils requires the use of an immobilized enzyme in which the enzyme is immobilized on a carrier. By using the immobilized enzyme, coloring at the time of hydrolysis by a high-temperature and high-pressure decomposition method can be suppressed. In the embodiment of the present invention, lipase is preferable as the fat and oil-decomposing enzyme used in the enzymatic decomposition method. As the lipase, not only animal-derived and plant-derived lipases but also commercially available lipases derived from microorganisms, and also immobilized enzymes on which lipases are immobilized can be used. For example, the enzymes for decomposing fats are Rizopus genus, Aspergillus genus, Chromobacterium genus, Mucor genus, Pseudomonas genus, Geotrichum genus, Penicillium (Penicillium) Examples include lipases originating from microorganisms such as the genus and Candida, and animal lipases such as pancreatic lipase. In order to obtain a high decomposition rate, a lipase having no position specificity (random type) is good, and the genus Pseudomonas, Candida and the like are good. Immobilization carriers include celite, diatomaceous earth, kaolinite, silica gel, molecular sieves, porous glass, activated carbon, calcium carbonate, ceramics and other inorganic carriers, ceramic powder, polyvinyl alcohol, polypropylene, chitosan, ion exchange resin, hydrophobic adsorption Examples include organic polymers such as resins, chelate resins, and synthetic adsorption resins, and ion exchange resins are preferred from the viewpoint of water retention. Of the ion exchange resins, a porous surface is preferable from the viewpoint that a large amount of lipase can be adsorbed by having a large surface area.

  The particle diameter of the resin used as the immobilization carrier is preferably 100 to 1000 μm, particularly preferably 250 to 750 μm. The pore diameter is preferably 10 to 150 nm. Examples of the material include phenol formaldehyde, polystyrene, acrylamide, divinylbenzene, and the like, and phenol formaldehyde resin (for example, Duolite A-568 manufactured by Rohm and Hass) is particularly preferable.

  When immobilizing an enzyme, the enzyme may be directly adsorbed on a carrier. However, in order to achieve an adsorption state that expresses high activity, the carrier is treated with a fat-soluble fatty acid or its derivative before the enzyme adsorption. May be. Examples of the fat-soluble fatty acid to be used include saturated or unsaturated, linear or branched fatty acids having 8 to 18 carbon atoms, which may be substituted with a hydroxyl group. Specific examples include capric acid, lauric acid, myristylic acid, oleic acid, linoleic acid, α-linolenic acid, ricinoleic acid, isostearic acid and the like. Examples of the derivatives include esters of these fatty acids with mono- or polyhydric alcohols, phospholipids, and derivatives obtained by adding ethylene oxide to these esters. Specific examples include methyl esters, ethyl esters, monoglycerides, diglycerides, ethylene oxide adducts thereof, polyglycerin esters, sorbitan esters, and sucrose esters of the above fatty acids. Two or more of these fat-soluble fatty acids or derivatives thereof may be used in combination.

  As a method for contacting these fat-soluble fatty acids or derivatives thereof with a carrier, these may be added directly to a carrier in water or an organic solvent, but in order to improve dispersibility, a fat-soluble fatty acid or derivative thereof is added to an organic solvent. Once dispersed and dissolved, it may be added to a carrier dispersed in water. Examples of the organic solvent include chloroform, hexane, ethanol, and the like. The amount of the fat-soluble fatty acid or derivative thereof used is preferably 1 to 500 parts by mass, more preferably 10 to 200 parts by mass with respect to 100 parts by mass of the carrier. The contact temperature is preferably 0 to 100 ° C., more preferably 20 to 60 ° C., and the contact time is preferably about 5 minutes to 5 hours. The carrier after this treatment is collected by filtration, but may be dried. The drying temperature is preferably room temperature to 100 ° C., and drying under reduced pressure may be performed.

  The temperature at which the enzyme is immobilized can be determined depending on the characteristics of the enzyme, but is preferably a temperature at which the enzyme is not deactivated, that is, 0 to 60 ° C., more preferably 5 to 40 ° C. Moreover, the pH of the enzyme solution used at the time of immobilization may be in a range where no denaturation of the enzyme occurs, and can be determined by the characteristics of the enzyme as well as the temperature, but is preferably pH 3-9. In order to maintain this pH, a buffer solution is used. Examples of the buffer solution include an acetate buffer solution, a phosphate buffer solution, and a Tris-HCl buffer solution. The enzyme concentration in the enzyme solution is preferably not more than the saturation solubility of the enzyme and sufficient from the viewpoint of immobilization efficiency. Moreover, the enzyme solution can also use what was refine | purified by the supernatant obtained by removing the insoluble part by centrifugation, ultrafiltration, etc. as needed. Moreover, although the enzyme mass to be used varies depending on the enzyme activity, it is preferably 5 to 1000 parts by mass, more preferably 10 to 500 parts by mass with respect to 100 parts by mass of the carrier.

  Soybean oil that becomes a reaction substrate without drying after recovering the immobilized enzyme by removing it from the enzyme solution by filtration from the point of making it suitable for the hydrolysis reaction after immobilization of the enzyme It is preferable to contact the oil and fat. The water content in the immobilized enzyme after contact varies depending on the type of carrier used, but is 0.1 to 100 parts by weight, more preferably 1 to 50 parts by weight, particularly 5 to 50 parts by weight, based on 100 parts by weight of the immobilized carrier. Preferably there is. At this time, it may be sealed in a packed container such as a column and the oil and fat may be circulated by a pump or the like, or the immobilized enzyme may be dispersed in the oil and fat. The contact temperature is preferably 20 ° C. to 60 ° C., and can be selected according to the characteristics of the enzyme. Furthermore, the contact time may be about 1 to 48 hours, and it is preferable from the viewpoint of industrial productivity that the immobilized enzyme is recovered by filtration after the contact.

  The hydrolysis activity of the immobilized enzyme is preferably 20 U / g or more, more preferably 100 to 10,000 U / g, and particularly preferably 500 to 5000 U / g. Here, 1 U of the enzyme is an enzyme that produces 1 μmol of free fatty acid per minute when hydrolyzed for 30 minutes at 40 ° C. while stirring and mixing a mixture of oil: water = 100: 25 (mass ratio). Shows the resolution.

  In the present invention, the partial hydrolysis of fats and oils by the enzymatic decomposition method can be carried out batchwise, continuously or semi-continuously. The immobilized enzyme may be used in a state where it is packed in a packed column or in a stirring tank, but it is preferably used in a state where it is packed in a packed column from the viewpoint of suppressing crushing of the immobilized enzyme. The supply of partially hydrolyzed fatty acids and water into the apparatus may be either cocurrent or countercurrent. From the viewpoint of suppressing oxidation of fatty acids, it is preferable to degas or deoxygenate the raw oil and water supplied to the hydrolysis reaction apparatus in advance.

  The amount of the immobilized enzyme used for the reaction of the enzymatic decomposition method can be appropriately determined in consideration of the activity of the enzyme, but is 0.01 to 30 parts by mass, and further 0.1 -20 mass parts, and especially 1-10 mass parts are preferable. The amount of water is preferably 10 to 200 parts by mass, more preferably 20 to 100 parts by mass, and particularly preferably 30 to 80 parts by mass with respect to 100 parts by mass of fatty acids to be decomposed. The water may be any of distilled water, ion exchange water, deaerated water, tap water, well water and the like. Other water-soluble components such as glycerin may be mixed. If necessary, a buffer solution having a pH of 3 to 9 may be used so that the stability of the enzyme can be maintained.

  The reaction temperature is preferably 0 to 70 ° C., more preferably 20 to 50 ° C., which is a temperature at which the activity of the enzyme is more effectively extracted and free fatty acids generated by decomposition do not become crystals. The reaction is preferably carried out in the presence of an inert gas so that contact with air is avoided as much as possible.

The hydrolysis reaction of the enzymatic decomposition method of fats and oils is controlled by the fatty acid concentration, and may be terminated when a predetermined fatty acid concentration is reached. The “fatty acid concentration” in the present invention refers to a value obtained by the following formula (2) by measuring the acid value and fatty acid composition of fatty acids and according to the knowledge of fats and oil products (Shoshobo Co., Ltd.). The acid value is measured by American Oil Chemists. Society Official Method Ca 5a-40.
Fatty acid concentration (mass%) = xxy / 56.1 / 10 (2)
(X = acid value [mg KOH / g], y = average molecular weight determined from fatty acid composition)

  The partial hydrolysis of fats and oils by the enzymatic decomposition method has a fatty acid concentration of 20 to 90% by mass, particularly 25 to 85% by mass, particularly from the viewpoint of suppressing industrial production, good appearance, and the production of trans-unsaturated fatty acids. It is preferable to carry out until it becomes 30-80 mass%. As a result of partial hydrolysis, the content of the trans-unsaturated fatty acid in the constituent fatty acid is preferably 0 to 1.5% by mass, more preferably 0 to 1% by mass, and particularly preferably 0 to 0.7% by mass. The partially hydrolyzed fatty acids used for hydrolysis by the high-temperature and high-pressure decomposition method preferably have a low total nitrogen content in the fatty acids from the viewpoint of improving the hue of the fatty acids hydrolyzed by the high-temperature and high-pressure decomposition method. It is preferably 2 ppm or less, more preferably 1.5 ppm or less, and particularly preferably 0.1 to 1.5 ppm. From the same point, the increase amount of the total nitrogen amount in the enzymatic decomposition oil relative to the total nitrogen amount in the enzymatic decomposition raw material is preferably 50% by mass or less, more preferably 20% by mass or less, especially 0 to 15% by mass. Is preferred.

  In the present invention, it is necessary to hydrolyze fats and oils by a high-temperature and high-pressure decomposition method after partial hydrolysis by an enzymatic decomposition method. In the present invention, the hydrolysis by the high-temperature and high-pressure decomposition method can be carried out batchwise, continuously or semi-continuously, and the partially hydrolyzed fatty acids and water are supplied into the apparatus in a cocurrent flow manner. Either of the countercurrent type and the following reaction conditions may be used. The partially hydrolyzed fatty acids and water supplied to the hydrolysis reaction apparatus are preferred from the viewpoint of suppressing oxidation of fatty acids obtained by using raw oil and water that have been degassed or deoxygenated in advance if necessary.

  In the hydrolysis by the high-temperature and high-pressure decomposition method, water is added so as to be 10 to 250 parts by mass with respect to 100 parts by mass of partially hydrolyzed fatty acids, and the temperature is 200 to 270 ° C. and the pressure is 2 to 8 MPa. It is preferable to hydrolyze for 0.1 to 6 hours. The temperature is preferably 210 to 265 ° C, and more preferably 215 to 260 ° C, from the viewpoint of suppressing industrial productivity of fatty acids, decolorization, and generation of trans-unsaturated fatty acids. From the same point, the amount of water relative to 100 parts by mass of partially hydrolyzed fatty acids is preferably 15 to 150 parts by mass, particularly 20 to 120 parts by mass. Further, from the same point, the pressure is preferably 2 to 7 MPa, particularly preferably 2.5 to 6 MPa. Further, from the same point, the reaction time is further preferably 0.2 to 5 hours, particularly 0.3 to 4 hours.

As a preferable reaction apparatus, a counter-current Colgate-Emery method oil decomposition tower (for example, IHI) equipped with a hydrolysis reaction tank having a capacity of 7 to 40 m ³ can be exemplified. For small-scale decomposition, a laboratory-scale commercially available autoclave apparatus (for example, Nitto High Pressure Co., Ltd.) may be used as the hydrolysis reaction tank.

  The partially hydrolyzed fatty acids used for the hydrolysis of fats and oils by the high-temperature and high-pressure decomposition method may be used as they are, but if necessary, the fatty acids and the aqueous phase may be separated by a method such as static separation or centrifugation. Good. Furthermore, if necessary, the glycerin distributed in the oil phase may be removed and purified by centrifugation, washing with water or the like.

  The hydrolysis reaction is controlled by the fatty acid concentration represented by the above formula (2), and may be terminated when a predetermined fatty acid concentration is reached. After completion of the hydrolysis reaction, the fatty acids and the aqueous phase are preferably separated by a method such as stationary separation or centrifugation. If necessary, the glycerin distributed in the oil phase may be removed and purified by centrifugation, washing with water or the like.

  In the present invention, as described above, in the hydrolysis reaction of fats and oils, 0.01 to 30 parts by weight of immobilized enzyme and 10 to 200 parts by weight of water are added to 100 parts by weight of raw oil and fat, respectively, and the temperature is set to 0 to 70. After partial hydrolysis by an enzymatic decomposition method at 100 ° C., 10 to 250 parts by mass of water is added to 100 parts by mass of partially hydrolyzed fatty acids, and the temperature is 200 to 270 ° C. By subjecting to hydrolysis under a pressure of 2 to 8 MPa for 0.1 to 6 hours, fatty acids with reduced industrial productivity, good appearance and trans-unsaturated fatty acid content can be obtained.

[Immobilized enzyme production method]
50 g of Duolite A-568 (Rohm & Hass) was stirred in 500 mL of 0.1N aqueous sodium hydroxide for 1 hour. Then, it was washed with 500 mL of distilled water for 1 hour, and the pH was equilibrated with 500 mL of 500 mM phosphate buffer (pH 7) for 2 hours. Thereafter, the pH was equilibrated twice with 500 mL of 50 mM phosphate buffer (pH 7) for 2 hours each. Thereafter, filtration was performed to recover the carrier, followed by ethanol replacement with 250 mL of ethanol for 30 minutes. After filtration, 250 mL of ethanol containing 50 g of ricinoleic acid was added and ricinoleic acid was adsorbed on the carrier for 30 minutes. Thereafter, the carrier was recovered by filtration, and then washed four times with 250 mL of 50 mM phosphate buffer (pH 7), ethanol was removed, and the carrier was recovered by filtration. Thereafter, the mixture was brought into contact with 1000 mL of a 10% solution of a commercially available lipase (Lipase AY “Amano” 30G, Amano Enzyme) acting on fats and oils for immobilization. After filtration, the immobilized enzyme was recovered and washed with 250 mL of 50 mM acetate buffer (pH 7) to remove non-immobilized enzyme and protein. All the above operations were performed at 20 ° C. The immobilization rate was determined to be 95% from the residual activity of the enzyme solution after immobilization and the activity difference between the enzyme solution before immobilization. Thereafter, 200 g of deodorized soybean oil was added and stirred at 40 ° C. for 2 hours, followed by filtration and separation from the deodorized soybean oil to obtain an immobilized enzyme. The immobilized enzyme thus obtained was washed three times with undeodorized soybean oil, which is a substrate that actually performs the reaction, and filtered before use.

[Raw oil]
As raw material fats and oils, undeodorized soybean oil shown in Table 1 was used. The glyceride composition was measured by the following method.

[Method for measuring glyceride composition]
To a glass sample bottle, 10 mg of a sample and 0.5 mL of a trimethylsilylating agent (“silylating agent TH”, manufactured by Kanto Chemical Co., Inc.) were added, sealed, and then heated at 70 ° C. for 15 minutes. Distilled water (1.0 mL) and hexane (2.0 mL) were added thereto, and after mixing, the hexane layer was measured by gas chromatography (GLC).
Apparatus: Hewlett Packard 6890 type column; DB-1HT (manufactured by J & W Scientific) 7m
Column temperature; initial = 80 ° C., final = 340 ° C.
Temperature rising rate = 10 ° C./min, hold at 340 ° C. for 20 minutes Detector; FID, temperature = 350 ° C.
Injection part; split ratio = 50: 1, temperature = 320 ° C.
Sample injection volume: 1 μL
Carrier gas; helium, flow rate = 1.0 mL / min

[Measurement of total nitrogen content]
5 g of undeodorized soybean oil and partially hydrolyzed fatty acids were weighed in a 10 mL volumetric flask, and a sample made up with toluene was measured with a trace total nitrogen analyzer. The standard solution used was a pyridine / toluene solution having various concentrations.
Equipment: Micro Chemical Total Nitrogen Analyzer Model TN-05 Type Temperature: INLET 800 ° C / CATALYST 900 ° C
Gas and flow rate used: Oxygen 600mL / min
Helium / oxygen Sub 100/100 mL / min
Time; helium 30 seconds / oxygen 120 seconds Sample injection volume and rate; 50 μL 1.0 μL / second

[Hydrolysis by enzyme digestion using immobilized enzyme]
Undeodorized soybean oil shown in Table 1 was hydrolyzed by an enzymatic decomposition method using an immobilized enzyme. The hydrolysis reaction was performed by circulating the reaction solution between an enzyme tower using an immobilized enzyme and a substrate circulation tank.
Immobilized enzyme washed with undeodorized soybean oil (hydrolysis activity 2960 U / g) was packed in a jacketed stainless steel enzyme column column (inner diameter 22 mm, height 145 mm) on a dry basis with 20.0 g. The dry standard weight of the immobilized enzyme is the same batch of immobilized enzyme packed in the jacketed stainless steel enzyme column, using acetone and hexane, and removing the oil adhering to the immobilized enzyme, Further, dehydration was performed under reduced pressure to determine the weight of the original immobilized enzyme.
900 g of non-deodorized soybean oil and 540 g of distilled water were introduced into a jacketed substrate circulation tank having an inner diameter of 150 mm and a capacity of 3 L, and then mixed and heated to 40 ° C. with stirring (half moon blade φ90 mm × H25 mm: 600 r / min) did. During this period, the gas phase portion in the jacketed substrate circulation tank was replaced with nitrogen to be in a nitrogen atmosphere.
After the substrate was heated to 40 ° C., the substrate in the jacketed substrate circulation tank was supplied from the top to the jacketed stainless steel enzyme column using a liquid feed pump at a flow rate of 55 mL / min. The reaction solution obtained from the lower part of the jacketed stainless steel enzyme column was returned to the jacketed substrate circulation tank to start the batch circulation reaction. One hour after the start of the reaction, the entire amount of the reaction solution was extracted from the jacketed substrate circulation tank into a 3 L beaker, and left and separated at 40 ° C. for 120 minutes in a nitrogen atmosphere to remove the aqueous layer and obtain sample A. Sample A was partially sampled, centrifuged (5,000 × g, 10 minutes), the aqueous layer was removed, and the partially decomposed fatty acids were completely decompressed at a temperature of 70 ° C. and a vacuum of 400 Pa for 10 minutes. Analysis was performed after dehydration.
Furthermore, the immobilized enzyme-enclosed stainless steel enzyme tower column used for the preparation of Sample A was washed with undeodorized soybean oil. Thereafter, a batch circulation reaction was started under the same conditions as in Sample A. Three hours after the start of the reaction, the entire amount of the reaction solution was taken out from the jacketed substrate circulation tank into a 3 L beaker, and left and separated in a nitrogen atmosphere at 40 ° C. for 120 minutes to remove the aqueous layer, thereby obtaining Sample B. Sample B was analyzed after the same treatment as Sample A. As a result of analysis of partially hydrolyzed fatty acids, the total nitrogen amount was equivalent to that of undeodorized soybean oil, and there was no detachment of the enzyme from the immobilized enzyme.

[Hydrolysis by Enzymatic Decomposition Using Powdered Lipase]
Undeodorized soybean oil shown in Table 1 was hydrolyzed by an enzymatic decomposition method using powder lipase (Lipase AY “Amano” 30G, Amano Enzyme). After putting 1300 g of non-deodorized soybean oil and 750 g of distilled water into a four-necked flask with a capacity of 3000 mL, the mixture was mixed with stirring (half moon blade φ90 mm × H25 mm: 300 r / min) and heated to 40 ° C. During this period, the gas phase part of the 3000 mL capacity four-necked flask was replaced with nitrogen to create a nitrogen atmosphere. While stirring in a sealed atmosphere at 40 ° C. in a nitrogen atmosphere (half moon blade φ90 mm × H25 mm: 300 r / min), 3.9 g of powder lipase (lipase AY “Amano” 30G, Amano Enzyme) was added to 30 g of distilled water. After dissolution, the entire amount was charged and batch stirring reaction was started. 0.6 hours after the start of the reaction, the entire amount of the reaction solution was extracted from a 3000 mL four-necked flask into a 3 L beaker, and left to stand at 40 ° C. for 120 minutes in a nitrogen atmosphere to remove the aqueous layer and remove sample C. Obtained. Sample C was analyzed after the same treatment as Sample A.

[Hydrolysis by enzymatic decomposition using granule lipase]
The undeodorized soybean oil shown in Table 1 was hydrolyzed by an enzymatic decomposition method using granular lipase (Lipolase 100T, Novozyme). After putting 1300 g of non-deodorized soybean oil and 750 g of distilled water into a four-necked flask with a capacity of 3000 mL, the mixture was mixed and heated to 45 ° C. with stirring (half moon blade φ90 mm × H25 mm: 300 r / min). During this period, the gas phase part of the 3000 mL capacity four-necked flask was replaced with nitrogen to create a nitrogen atmosphere. While stirring in a sealed atmosphere in a nitrogen atmosphere at 45 ° C. (half moon blade φ90 mm × H25 mm: 300 r / min), 2.0 g of granule lipase (Lipolase 100T, Novozyme) was dissolved in 30 g of distilled water, and the whole amount was added. The batch stirring reaction was started. 43 hours after the start of the reaction, the entire amount of the reaction solution was drawn out from a 3000 mL four-necked flask into a 3 L beaker, and left and separated at 40 ° C. for 120 minutes in a nitrogen atmosphere to remove the aqueous layer and obtain sample D. . Sample D was analyzed after the same treatment as Sample A.

[Hydrolysis of partially decomposed fatty acids and undeodorized soybean oil by high-temperature and high-pressure decomposition method]
Samples A to D, which are partially hydrolyzed fatty acids shown in Table 1, and undeodorized soybean oil as a raw material, a batch type autoclave apparatus (capacity 2.2 L, design pressure 10 MPa, design temperature 300, manufactured by Nitto Koatsu Co., Ltd.) The hydrolysis was carried out by a high-temperature high-pressure decomposition method at 0 ° C. and material TB480H). 700 g of each raw material and 350 g of distilled water were put into an autoclave and sealed. Next, an airtight test was performed using hydrogen at a pressure of 5.0 MPa, and after confirming that there was no leakage in the autoclave apparatus, the atmosphere was replaced with nitrogen. Then, it heated up to 240 degreeC which is reaction temperature, stirring at 600 r / min. The temperature raising time to 240 ° C. was 40 minutes, and the ultimate pressure was 3.2 MPa. After reaching 240 ° C., the reaction solution was appropriately collected from the sampling port, sealed with nitrogen, and rapidly cooled to 25 ° C. in a light-shielded state. Thereafter, the mixture was centrifuged (5,000 g, 5 minutes), the aqueous layer was removed, the fatty acid layer was dehydrated under reduced pressure for 5 minutes at a temperature of 70 ° C. and a vacuum degree of 400 Pa, and the acid value was measured to calculate the fatty acid concentration. When the fatty acid concentration reached 85% by mass, the hydrolysis was terminated and cooled to 50 ° C. The cooling time to 50 ° C. was 50 minutes. All the hydrolyzed fatty acids were extracted from the autoclave apparatus into a 2 L beaker, and left and separated at 40 ° C. for 120 minutes under a nitrogen atmosphere to remove the aqueous layer. Further, after centrifugation (5,000 × g, 30 minutes) and removing the aqueous layer, the mixture was put into a 2000 mL four-necked flask and stirred (half moon blade Φ90 mm × H25 mm: 300 r / min) while fatty acids Was completely dehydrated under reduced pressure at a temperature of 70 ° C. and a vacuum degree of 400 Pa for 30 minutes, and then analyzed to obtain fatty acid samples E to I shown in Table 2.

  As is clear from Table 2, the raw material fats and oils are partially hydrolyzed by an enzymatic decomposition method using an immobilized enzyme, the fatty acid concentration of the fatty acids is set to 20 to 90% by mass, and thereafter, under conditions of high temperature and high pressure It was found that the fatty acids (samples F and G) having a good appearance can be obtained by hydrolysis with a low fatty acid content in the constituent fatty acids. In contrast, fatty acids (samples H and I) obtained by partially hydrolyzing raw material fats and oils by enzymatic decomposition using powder lipase and granular lipase, and then hydrolyzing under high temperature and high pressure conditions It was found that the content of trans-unsaturated fatty acids in the constituent fatty acids is low, but the appearance is impaired. Moreover, although the fatty acid (sample E) which obtained raw material fats and oils only by the hydrolysis of the conditions of high temperature and a high pressure is a favorable external appearance, it turned out that the trans unsaturated fatty acid content in a constituent fatty acid is high. Further, as is clear from Tables 1 and 2, when the total nitrogen content of the fatty acids partially hydrolyzed by the enzymatic decomposition method is low, the hue C of the fatty acids hydrolyzed under high temperature and high pressure conditions is low. I understood that.

Claims (2)

A method for producing fatty acids by hydrolyzing fats and oils, wherein the fats and oils are hydrolyzed by an enzymatic decomposition method until the fatty acid concentration is 20 to 90% by mass using an immobilized enzyme in which the enzyme is immobilized on a carrier. After that, the manufacturing method of the fatty acids hydrolyzed by a high temperature / high pressure decomposition method. The method for producing fatty acids according to claim 1 , wherein the content of trans-unsaturated fatty acids in the constituent fatty acids of the fats and oils subjected to the hydrolysis reaction is 1.5% by mass or less.