JP2008253196A - Method for producing fatty acids - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for efficiently producing fatty acids, having slight color and proper appearance by which both of low-trans unsaturated fatty acids and low-saturated fatty acids are produced by hydrolyzing oils and fats and carrying out natural classification. <P>SOLUTION: The method for producing the fatty acids, by hydrolyzing the oils and fats and subjecting the product to the natural classification includes partially hydrolyzing the oils and fats by using an immobilized enzyme obtained by immobilizing the enzyme on a carrier, further, hydrolyzing the product by high-temperature and high-pressure hydrolysis, and subjecting the product to natural classification. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing fatty acids by natural separation of fats and oils after hydrolysis.

  Fatty acids are widely used as intermediate raw materials for foods such as monoglycerides and diglycerides, additives for various other industrial products, and intermediate raw materials. Such fatty acids are generally produced by hydrolyzing vegetable oils such as rapeseed oil and soybean oil and animal oils such as beef tallow by a high pressure method or an enzymatic decomposition method.

  However, the fatty acids produced by simply hydrolyzing animal and vegetable oils as described above are not necessarily suitable as industrial raw materials with the same fatty acid composition. That is, depending on the purpose of use, it is necessary to have a low trans unsaturated fatty acid, a desired hue, and a fatty acid composition.

  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.

  Further, in the high-temperature and high-pressure decomposition method, there is an induction period until decomposition starts at the beginning of the reaction, but in order to eliminate or shorten the induction time, first, glyceride is used with a 1,3-position 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).

  Furthermore, adjustment is required to obtain the desired fatty acid composition. Generally, solvent fractionation and wetting agent fractionation methods are used for the separation of fatty acids, but these methods have high separation efficiency (yield), but they require running costs such as capital investment and recovery of solvents and aqueous solutions. Has the problem of taking. On the other hand, the natural separation method (solvent-free method) without using a solvent is an inexpensive separation method, and an emulsifier such as polyglycerin fatty acid ester should be used for a decrease in filtration speed, which has been regarded as a problem. (Patent Document 4).

JP 2003-113395 A JP 2000-160188 A Japanese National Patent Publication No. 8-507917 JP-A-11-106782

  In recent years, the effects of edible oils on health have attracted attention worldwide, and trans-unsaturated fatty acids and saturated fatty acids increase LDL (bad) cholesterol levels and increase the risk of coronary heart disease. But it is scientifically supported. 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) is required to label the content of trans-unsaturated fatty acids in addition to conventional lipids, saturated fatty acids and cholesterol. 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. As described above, reduction of trans-unsaturated fatty acids and saturated fatty acids in edible oil is desired worldwide.

  Undeodorized 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. 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. Moreover, when the obtained fatty acids are fractionated naturally, saturated fatty acids are removed and the concentration of unsaturated fatty acids in the liquid part increases. However, in the case of hydrolysis only by the enzymatic decomposition method, fatty acids such as palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid having 18 or less carbon atoms are easily hydrolyzed, but arachidic acid and behen having 20 or more carbon atoms are easily hydrolyzed. Since long-chain fatty acids such as acids and lignoceric acid are hardly hydrolyzed and remain as glycerides, many glycerides containing arachidic acid, behenic acid, and lignoceric acid that are saturated fatty acids remain in the liquid portion even after natural fractionation. It has been found.

  On the other hand, the fatty acids obtained by hydrolysis only by the high-temperature and high-pressure decomposition method have a good appearance due to the decomposition of the coloring components, and are not as selective for fatty acids as the enzymatic decomposition method, and palmitic acid, stearic acid Since oleic acid, linoleic acid, linolenic acid, arachidic acid, behenic acid, lignoceric acid, etc. are hydrolyzed uniformly, arachidic acid, behenic acid, lignoceric acid in the liquid part is reduced by natural fractionation. . However, the content of trans-unsaturated fatty acids in the constituent fatty acids increases.

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 fatty acid 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 make fatty acids having a good appearance with a good hue by efficiently producing fatty acids having a low content of trans-unsaturated fatty acids and saturated fatty acids in the constituent fatty acids by hydrolysis of fats and oils. It is to provide a manufacturing method.

  Therefore, the present inventor conducted various studies on the combination of the enzymatic decomposition method and the high-temperature high-pressure decomposition method and the natural fractionation method in the hydrolysis reaction of fats and oils. First, using an immobilized enzyme in which the enzyme was immobilized on a carrier. Fatty acids that have been partially hydrolyzed by enzymatic digestion and then hydrolyzed by high-temperature and high-pressure digestion are naturally separated, and both low trans-unsaturated fatty acids and low-saturated fatty acids are compatible, and hue is good The present inventors have found that fatty acids having a good appearance can be produced efficiently.

  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 which is hydrolyzed by a high-temperature high-pressure decomposition method and then naturally separated.

  According to the present invention, fatty acids having a good appearance can be efficiently produced by hydrolyzing fats and oils and further naturally separating to efficiently produce fatty acids compatible with low trans unsaturated fatty acids and low saturated fatty acids. Can be manufactured.

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

  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.

  In the present invention, in order to perform partial hydrolysis by the enzymatic decomposition method of fats and oils, an immobilized enzyme in which an enzyme is immobilized on a carrier is used. 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. As immobilization carriers, 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 recovered 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 enzyme characteristics 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 which removed the insoluble part by centrifugation as needed, or ultrafiltration. 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 to 100 parts by mass of the raw oil and fat to be decomposed. -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 equation (1) by measuring the acid value and fatty acid composition of fatty acids and according to the knowledge of fats and oils products (Yukishobo 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 (1)
(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, fats and oils are partially hydrolyzed by an enzymatic decomposition method, and then hydrolyzed by a high temperature and high pressure 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 preferable from the viewpoint of inhibiting oxidation of fatty acids that can be obtained by degassing or deoxygenating 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 190 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 195 to 265 ° C., more preferably 200 to 260 ° C., from the viewpoint of suppressing industrial productivity of fatty acids, decolorization, and production 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, there can be mentioned a counter-current Colgate-Emery method oil and fat decomposition tower (for example, IHI) equipped with a hydrolysis reaction tank having a capacity of 7 to 40 m ³ . 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 managed by the fatty acid concentration represented by the above formula (1), 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 performing partial hydrolysis by enzymatic decomposition under the condition of ° 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 190 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.

  In the present invention, the “natural fractionation method” means that the raw fatty acids to be treated do not contain the amount of water to be phase-separated and do not use a solvent, and are cooled with stirring as necessary, and precipitated solid components Is a method of performing solid-liquid separation by filtering, centrifuging, sedimentation separation or the like.

  In the present invention, the raw fatty acids to be subjected to the natural fractionation method include vegetable oils such as rapeseed oil and soybean oil, and animal oils such as beef tallow. The fatty acids are hydrolyzed and then hydrolyzed by a high-temperature and high-pressure decomposition method. The amount of fatty acid in the fatty acids is more effective when it is 80% by mass or more, particularly 85% by mass or more, and partial glycerides may be present. Moreover, as this raw material fatty acid, the ratio of saturated fatty acids (C12-C22), such as a palmitic acid and a stearic acid, in a fatty-acid composition is 8-70 mass%, Especially the thing of 10-55 mass% is preferable.

  The natural fractionation method in the present invention is preferably performed by adding a crystal modifier to the raw fatty acids before the precipitation of crystals. The crystal modifier is not particularly limited, but is preferably a polyhydric alcohol fatty acid ester, which is a food additive, sucrose fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, organic acid monoglyceride, glycerin fatty acid ester, polyglycerin fatty acid ester. Among them, polyglycerol fatty acid ester is preferable. When polyglycerin fatty acid ester is used as the crystal modifier, it is preferable that the transparent melting point is in the range represented by the following formula (2).

0.38x + 13 ≦ y ≦ 0.54x + 44 (2)
[X: weight% of the raw material fatty acids fatty saturated fatty acids in the composition (C ₁₂ ~C ₂₂₎
y: transparent melting point of polyglycerol fatty acid ester (° C.)]

  A more preferable range of the transparent melting point (y) of the polyglycerol fatty acid ester is 0.38x + 19 ≦ y ≦ 0.54x + 40, and a particularly preferable range is 0.38x + 28 ≦ y ≦ 0.54x + 36. The transparent melting point (y) of the polyglycerol fatty acid ester is preferably higher than the transparent melting point of the raw fatty acids.

  In addition, the average degree of polymerization of glycerin in the polyglycerin fatty acid ester is preferably 5 or more, particularly preferably 8 to 30 from the viewpoint of obtaining a crystalline state that can be easily filtered. The fatty acid in the polyglycerol fatty acid ester is preferably composed of a saturated or unsaturated fatty acid having 10 to 22 carbon atoms, particularly 12 to 18 carbon atoms, from the viewpoint of adjusting the transparent melting point of the polyglycerol fatty acid ester. Although the said fatty acid may be comprised with a single fatty acid, what is comprised with the mixed fatty acid is preferable from the point of obtaining the crystalline state especially easy to filter. As the polyglycerol fatty acid ester, a commercially available product can be used, or it may be synthesized by an esterification reaction between polyglycerol and a fatty acid. In the esterification reaction of polyglycerin and fatty acid, an alkali catalyst such as sodium hydroxide is added to these mixtures, and esterification is performed directly at 200 to 260 ° C. under an inert gas stream such as nitrogen, and an enzyme is used. Any method such as a method may be used.

  Two or more types of crystal modifiers may be used in combination, and the amount added is preferably 0.001 to 5% by mass, particularly about 0.05 to 1% by mass, based on the starting fatty acids.

  When using a polyglycerol fatty acid ester as a crystal modifier, it is preferable to mix and dissolve at a temperature higher than the transparent melting point of the polyglycerol fatty acid ester so that it can be completely dissolved in the raw fatty acids. The cooling time, cooling temperature and holding time after this mixing and dissolution vary depending on the amount of raw material, cooling capacity, etc., and may be appropriately selected depending on the composition of the raw fatty acids. For example, in the case of soybean fatty acid, the cooling time to −3 ° C. is 1 to 30 hours, preferably about 3 to 20 hours, and the holding time is 0 to 24 hours, preferably about 1 to 10 hours. The cooling may be a batch process or a continuous process. The cooling operation is preferably performed under the condition that the average particle size of the precipitated crystals is 100 μm or more, particularly 150 μm or more.

  As a method for separating the produced crystal, a filtration method, a centrifugal separation method, a sedimentation separation method, or the like can be applied, and batch processing or continuous processing may be used.

[Immobilized enzyme production method]
With respect to Duolite A-568 (manufactured by Rohm & Hass), it was stirred for 1 hour with 10 times volume of 0.1N sodium hydroxide aqueous solution, and then filtered to recover the carrier. Then, it was washed with 10 times the volume of distilled water for 1 hour, and the pH was equilibrated with 10 times the volume of 500 mM phosphate buffer (pH 7) for 2 hours. Thereafter, the pH was equilibrated twice for 2 hours with 10 volumes of 50 mM phosphate buffer (pH 7). After these operations, the carrier was recovered by filtration. Then, ethanol substitution was performed for 30 minutes with 5 volumes of ethanol. After filtration, 5 volumes of ethanol containing 1 mass of ricinoleic acid was added and ricinoleic acid was adsorbed on the carrier for 30 minutes. After filtration, the carrier was recovered, and then washed 4 times with 5 volumes of 50 mM phosphate buffer (pH 7) to remove ethanol and filtered to recover the carrier. Thereafter, the mixture was brought into contact with a 20-fold volume 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 5 volumes of 50 mM acetate buffer (pH 7) to remove unimmobilized 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, 4 times mass of deodorized soybean oil was added and stirred at 40 ° C. for 2 hours, followed by filtration and separation from 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 reacts before use, and filtered.

[Raw oil]
As raw material fats and oils, undeodorized soybean oil shown in Table 1 was used. The fatty acid composition, glyceride composition, hue C, and trans-unsaturated fatty acid content were measured by the following methods.

  In the present invention, “content of trans-unsaturated fatty acid in constituent fatty acid” and “fatty acid composition” are “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).

In the present invention, “hue C” refers to a value determined by the following formula (3), measured by a 5.25 inch cell using American Oil Chemists. Society Official Method Ca 13e-92 (Lovibond method).
Hue C = 10R + Y (3)
(Where R = Red value, Y = Yellow value)

[Method for measuring glyceride composition]
In the present invention, the “glyceride composition” is obtained by adding 10 mg of a sample and 0.5 mL of a trimethylsilylating agent (“silylating agent TH”, manufactured by Kanto Chemical) to a glass sample bottle and sealing the bottle at 70 ° C. for 15 minutes. Heated. 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

[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 the enzyme tower using the immobilized enzyme and the raw material stirring tank.
An immobilized enzyme washed with undeodorized soybean oil (hydrolysis activity 3000 U / g) was packed into a jacketed enzyme tower column (enzyme packed thickness 150 mm). The jacket temperature of the enzyme tower was set to 40 ° C. The amount of the immobilized enzyme charged was 5 parts with respect to 100 parts by mass (hereinafter referred to as “parts”) of the raw oil and fat. 100 parts of non-deodorized soybean oil and 60 parts of ion-exchanged water are put into a jacketed raw material stirring tank, heated to 40 ° C. with stirring at 30 r / min, and then between the jacketed enzyme tower and the jacketed raw material stirring tank. The hydrolysis reaction was carried out while circulating the reaction solution. During this period, the gas phase portion in the jacketed raw material stirring vessel was replaced with nitrogen to be in a nitrogen atmosphere.
Three hours after the start of the reaction, the reaction solution was sampled from a jacketed raw material agitation tank into a 1 L beaker, and left and separated in a nitrogen atmosphere at 40 ° C. for 120 minutes to remove the aqueous layer. Furthermore, after centrifugation (5,000 × g, 10 minutes), removing the aqueous layer, the partially decomposed fatty acids are completely dehydrated under the conditions of a temperature of 110 ° C. and a vacuum of 8 kPa to obtain a sample A. It was. Table 1 shows the analysis values of Sample A.
Sample C was obtained by setting the reaction time only to 7 hours under the same hydrolysis reaction apparatus and conditions as when Sample A was obtained. Table 1 shows the analysis values of Sample C.

[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 time, 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 closed state 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 extracted from a 3000 mL four-necked flask into a beaker of the same volume, and left and separated in a nitrogen atmosphere at 40 ° C. for 120 minutes to remove the aqueous layer, followed by centrifugation. After separation (5,000 × g, 10 minutes) and removal of the aqueous layer, the partially decomposed fatty acids were completely dehydrated under reduced pressure at a temperature of 70 ° C. and a vacuum of 400 Pa for 10 minutes. Obtained. Table 1 shows the analysis values of Sample B.

[Hydrolysis of fatty acids partially decomposed by enzymatic decomposition using immobilized enzyme and undeodorized soybean oil by high-temperature high-pressure decomposition method]
Oil-water counter-current type high-pressure hydrothermal decomposition apparatus using, as a raw material, sample A which is a fatty acid partially hydrolyzed by an enzymatic decomposition method using an immobilized enzyme shown in Table 1 or undeodorized soybean oil shown in Table 1 Hydrolysis was carried out. Partially decomposed fatty acids or undeodorized soybean oil was continuously fed from the lower side of the apparatus and water was continuously fed from the upper side of the apparatus to an oil-water countercurrent type high-pressure hydrothermal decomposition apparatus. The liquid feeding amount was 50 parts by mass of water with respect to 100 parts by mass of the raw material fat. In the apparatus, the raw fat / oil was heated with high-pressure hot water to a pressure of 5.0 MPa, and the sample A was hydrolyzed at 220 ° C. and the undeodorized soybean oil was hydrolyzed at 240 ° C. At this time, the average residence time (hr) in the cracking tower (oil phase volume (m ³ ) / flow rate of raw material oil (m ³ / hr) in the cracking tower) was about ³ hr. The reaction oil drained from the upper part of the oil-water countercurrent type high-pressure hydrothermal cracker is completely dehydrated under the conditions of a temperature of 110 ° C. and a vacuum degree of 8 kPa, and then cooled to 25 ° C., respectively. And F (made from undeodorized soybean oil as a raw material). Table 1 shows the analysis values of Samples D and F.

[Hydrolysis of fatty acids partially decomposed by enzymatic decomposition using granular lipase by high-temperature high-pressure decomposition method]
Sample B, which is a fatty acid partially hydrolyzed by an enzymatic decomposition method using granule lipase shown in Table 1, is used as a raw material, and a batch-type autoclave apparatus (capacity 2.2 L, design pressure 10 MPa, design temperature) 300 ° C., material TB480H) was subjected to hydrolysis by a high-temperature high-pressure decomposition method. 700 g of sample B 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. The reaction was performed for 1.0 hour, and when the fatty acid concentration reached 85% by mass, the hydrolysis was terminated and the mixture was 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 The sample was 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 a sample E. Table 1 shows the analysis value of Sample E.

[Natural separation]
Using samples C, D and F shown in Table 1 as raw materials, 0.2% by weight of the polyglycerol fatty acid ester shown in Table 2 was added to the raw material fatty acid, and dissolved uniformly at a temperature of 60 ° C. higher than the transparent melting point of the polyglycerol fatty acid ester. . Next, while stirring at a required power of stirring of 0.24 kW / m ³ , the mixture was cooled at a rate of 2 ° C./h, and kept at −3 ° C. for 2 hours. Next, 1 L of the slurry was sampled and subjected to pressure filtration at 0.03 MPa using a nylon filter cloth NY1260D (Nakao Filter Industry Co., Ltd.) (filtration area 39 cm ² ) to obtain a sample G of a liquid part (unsaturated fatty acid) ( Sample D was used as a raw material), H (sample C was used as a raw material), and I (sample F was used as a raw material). Table 1 shows the analytical values of samples G, H and I.

  As is clear from Table 1, when the non-deodorized fat and oil is partially decomposed using granular lipase and then decomposed at high temperature and high pressure (sample E), the trans unsaturated fatty acid is decreased, but the hue C is increased. When undeodorized fats and oils are naturally separated after high-temperature and high-pressure decomposition (sample I), hue C is low and saturated fatty acids having 20 or more carbon atoms are low, but trans-unsaturated fatty acids are high. In addition, when undeodorized fats and oils are naturally separated after partial decomposition using an immobilized enzyme (sample H), trans unsaturated fatty acids are low, but saturated fatty acids having 20 or more carbon atoms are high, and hue C is Get higher. In contrast, only when undeodorized soybean oil is partially decomposed using an immobilized enzyme and then naturally separated after high-temperature and high-pressure decomposition (sample G), saturated fatty acids having 20 or more carbon atoms are low and trans-unsaturated fatty acids. Was low and the hue C was found to be low.

Claims (4)

  A method for producing fatty acids by hydrolyzing fats and oils, using an immobilized enzyme in which an enzyme is immobilized on a carrier, partially hydrolyzing fats and oils by an enzymatic decomposition method, and then by a high-temperature and high-pressure decomposition method. A method for producing fatty acids which is hydrolyzed and then fractionated naturally.   The method for producing fatty acids according to claim 1, wherein hydrolysis by an enzymatic decomposition method is performed until the fatty acid concentration becomes 20 to 90% by mass.   The method for producing fatty acids according to claim 1 or 2, wherein the content of trans-unsaturated fatty acids in the constituent fatty acids of the fats and oils subjected to a hydrolysis reaction by an enzymatic decomposition method is 1.5% by mass or less.   4. The method according to claim 1, wherein the natural fractionation is a method in which a crystal modifier is added to and mixed with the fatty acids after hydrolysis, and the crystals are precipitated by cooling to separate the liquid part. Production method.