Production method for transesterified oil / fat

Abstract

Provided is a method for producing a transesterified oil / fat having a high diacylglycerol purity while suppressing the formation of byproducts by carrying out a low-temperature glycerolysis reaction.　Specifically provided is a production method for a transesterified oil / fat, said method including a step in which an oil / fat and glycerin are reacted in the presence of a calcium-based catalyst at a reaction temperature of 90-165°C, wherein the calcium-based catalyst is added after the temperature of the oil / fat and the glycerin has been raised to 90°C or higher.

Description

Method for producing interesterified oils and fats

[0001] The present invention relates to a method for producing interesterified fats and oils rich in diacylglycerol.

[0002] Diacylglycerol is used in various industrial fields, such as food and cosmetics. Diacylglycerol is generally produced by an esterification reaction between glycerin and a fatty acid, or a glycerolysis reaction between glycerin and a fat or oil. These production methods are broadly classified into chemical methods using chemical catalysts such as hydroxides or alkoxides of alkali metals or alkaline earth metals, and enzymatic methods using enzymes such as lipase (see, for example, Patent Documents 1 and 2). In the glycerolysis method using a chemical catalyst, a chemical catalyst is added to the fat or oil and glycerin, and then the mixture is heated to a reaction temperature to produce diacylglycerol.

[0003] The glycerolysis method can produce diacylglycerol with fewer steps than the esterification method. However, in the glycerolysis method, the ratio of glycerin to fats and oils in the reaction raw material must be increased to increase the purity of diacylglycerol, which results in the production of a large amount of monoacylglycerol in the reaction oil, increasing the purification load. On the other hand, if the ratio of glycerin to fats and oils in the reaction raw material is reduced, there is a problem that the yield of diacylglycerol is low. Furthermore, the glycerolysis method has a high reaction temperature, which makes it easy for unsaturated fatty acids to be converted to trans acids, resulting in the production of large amounts of trans acids, and this is particularly noticeable in polyunsaturated fatty acids with a large number of unsaturated bonds.

[0004] (Patent Document 1) JP-A-2005-504862 (Patent Document 2) JP-A-2004-222595

[0005] The present invention provides a method for producing interesterified fats and oils, which includes a step of reacting fats and oils with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 90°C or higher and 165°C or lower, in which the calcium-based catalyst is added after the fats and oils and glycerin are heated to 90°C or higher. Detailed Description of the Invention

[0006] It has been found that when the glycerolysis reaction is carried out at high temperatures, a large amount of by-products other than trans acids are also produced. Therefore, a treatment at a lower temperature is desirable. Therefore, the present invention provides a method for producing interesterified oils and fats with high diacylglycerol purity in a high yield while suppressing the production of by-products by carrying out the glycerolysis reaction at a low temperature.

[0007] The present inventors have found that if fats and oils and glycerin are brought into contact with a calcium-based catalyst and reacted after they have reached a predetermined temperature, the reaction proceeds at a low temperature while suppressing the production of by-products, and transesterified fats and oils with high diacylglycerol purity can be obtained in good yield.

[0008] According to the present invention, interesterified oils and fats having high diacylglycerol purity can be obtained in high yield by a glycerolysis reaction at low temperatures. Furthermore, according to the present invention, the production of by-products can be suppressed.

[0009] In the present invention, "transesterified fats and oils" refers to fats and oils obtained by reacting raw fats and oils with glycerin, then removing the catalyst by neutralization, filtration, etc., and removing unreacted phase-separated glycerin, and "reacted oil" refers to fats and oils obtained by reacting raw fats and oils with glycerin, but before removing the catalyst and unreacted phase-separated glycerin. Furthermore, in the present invention, the "reacting step" refers to the step after the reaction temperature is reached, and does not include the step of raising the temperature to the reaction temperature.

[0010] The method for producing interesterified fats and oils of the present invention includes a step of reacting fats and oils with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 90°C or higher and 165°C or lower, and the calcium-based catalyst is added after the fats and oils and glycerin are heated to 90°C or higher. In this production method, the fats and oils and glycerin may be premixed as reaction raw materials and heated to 90°C or higher, or the fats and oils and glycerin as reaction raw materials may be heated separately to 90°C or higher and then mixed. However, from the viewpoint of ease of production, it is preferable to heat the reaction raw material obtained by mixing the fats and oils and glycerin to 90°C or higher. In this specification, "fat" and "oil" are synonymous. Furthermore, substances constituting fats and oils (oils) include not only triacylglycerols but also monoacylglycerols and diacylglycerols. In other words, fats and oils (oils) contain one or more of monoacylglycerols, diacylglycerols, and triacylglycerols.

[0011] In the present invention, the fats and oils to be reacted with glycerin are generally those mainly composed of triacylglycerol, and examples thereof include soybean oil, rapeseed oil, safflower oil, rice oil, corn oil, sunflower oil, cottonseed oil, olive oil, sesame oil, peanut oil, Job's tears oil, wheat germ oil, perilla oil, linseed oil, perilla oil, chia seed oil, sacha inchi oil, walnut oil, kiwi seed oil, salvia seed oil, grape seed oil, macadamia nut oil, and hazelnut oil. Examples of suitable oils include vegetable oils such as tallow oil, pumpkin seed oil, camellia oil, tea seed oil, borage oil, palm oil, palm olein, palm stearin, coconut oil, palm kernel oil, cocoa butter, monkey fat, shea butter, and algae oil; animal oils such as fish oil, seal oil, whale oil, lard, beef tallow, and butter fat; microbial oils such as oils derived from polyunsaturated fatty acid-producing microorganisms such as Zygomycetes; and interesterified oils, hydrogenated oils, and fractionated oils thereof. These oils and fats can be used alone or in combination of two or more. Among these, liquid oils and fats are preferred in terms of the emulsification properties and ease of handling of interesterified oils and fats. Liquid oils and fats refer to oils and fats that are liquid at 20°C when subjected to a cooling test according to Standard Fats, Oils, and Fat Analysis Test Method 2.3.8-27. Furthermore, in the present invention, unlike a typical glycerolysis reaction, the reaction is carried out at a low temperature, which suppresses the production of trans fatty acids. Therefore, it is preferable to use fatty acids with a carbon chain length of 18 or more and the number of double bonds of 3 or more, which are expected to have various physiological functions. In particular, it is preferable to use one or more oils and fats selected from oils and fats rich in ω3 unsaturated fatty acids, such as perilla oil, linseed oil, perilla oil, chia seed oil, sacha inchi oil, algae oil, fish oil, seal oil, whale oil, and oils and fats derived from microorganisms that produce polyunsaturated fatty acids.

[0012] Fish oil can be extracted from raw materials such as sardines, herring, saury, mackerel, bonito, tuna, squid, and cod liver. Algal oil can be extracted from algae belonging to the Chlorophyceae, Bacillariophyceae, etc. It is preferable to appropriately perform known separation and purification methods such as liquid-liquid separation, filtration, and centrifugation to remove impurities before the reaction. Alternatively, so-called concentrated oils can be used, which are obtained by selectively hydrolyzing fish oils or the like using lipase to increase the proportion of unsaturated fatty acids such as eicosapentaenoic acid (C20:5, EPA) and docosahexaenoic acid (C22:6, DHA) in the fatty acids that make up the oil.

[0013] The triacylglycerol content in the oil or fat may be 100% by mass, but in order to facilitate the concentration of highly unsaturated fatty acids, particularly eicosapentaenoic acid and docosahexaenoic acid, in the transesterified oil or fat, it is preferably 95% by mass or less, more preferably 92% by mass or less, and even more preferably 89% by mass or less. From the viewpoint of production efficiency, it is preferably 70% by mass or more, more preferably 75% by mass or more, and even more preferably 80% by mass or more. To reduce the triacylglycerol content in the oil or fat to be reacted with glycerin to less than 100% by mass, it is preferable to partially hydrolyze the oil or fat with lipase and then remove the resulting fatty acids by distillation. This operation allows selective removal of saturated fatty acids with 16 and 18 carbon atoms from the constituent fatty acids, thereby allowing the highly unsaturated fatty acids to be further concentrated in the oil or fat to be reacted with glycerin. Furthermore, the content of free fatty acids or salts thereof in the fats and oils is preferably 10% by mass or less, more preferably 7% by mass or less, even more preferably 4% by mass or less, and even more preferably 1% by mass or less, from the viewpoint of preventing catalyst deactivation, and is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and even more preferably 0.03% by mass or more, from the viewpoint of production efficiency.

[0014] The constituent fatty acids constituting the oils and fats are not particularly limited and may be either saturated or unsaturated fatty acids. From the viewpoint of handleability and industrial productivity of the oils and fats, the content of unsaturated fatty acids in the fatty acids constituting the oils and fats is preferably 60 to 100% by mass, more preferably 70 to 98% by mass, and even more preferably 80 to 96% by mass. From the viewpoint of physiological effects, the number of carbon atoms in the unsaturated fatty acids is preferably 14 to 24, more preferably 16 to 22, and even more preferably 18 to 22. The amount of fatty acid in this specification is the amount converted to free fatty acid.

[0015] In view of physiological activity, the fatty acids constituting the oils and fats preferably contain a large amount of fatty acids having a carbon chain length of 18 or more and three or more double bonds. Furthermore, according to the method of the present invention, it is possible to obtain an interesterified oil having a high proportion of fatty acids having a carbon chain length of 18 or more and three or more double bonds in the reacted oil, while preventing the proportion of such fatty acids in the reacted oil from becoming lower than the proportion of fatty acids having a carbon chain length of 18 or more and three or more double bonds in the reacted oil as the raw material. The total content of fatty acids having a carbon chain length of 18 or more and three or more double bonds in the fatty acids constituting the oils and fats is preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, and even more preferably 30% by mass or more, in view of physiological activity and ease of enjoying the effects of the present invention. Furthermore, in view of suppressing the by-production of trans fatty acids, it is preferably 99% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less. The total content of fatty acids having a carbon chain length of 18 or more and three or more double bonds in the fatty acids constituting the oil or fat is preferably 15 to 99% by mass, more preferably 20 to 90% by mass, even more preferably 25 to 80% by mass, and even more preferably 30 to 80% by mass. Examples of fatty acids having a carbon chain length of 18 or more and three or more double bonds in the fatty acids constituting the oil or fat include α-linolenic acid (C18:3), γ-linolenic acid (C18:3), arachidonic acid (C20:4), eicosapentaenoic acid (C20:5, EPA), docosapentaenoic acid (C22:5), and docosahexaenoic acid (C22:6, DHA). Among these, ω3 unsaturated fatty acids having a double bond at the third position from the methyl end of the carbon chain are preferred in terms of physiological activity and ease of enjoying the effects of the present invention.

[0016] The glycerin used in the present invention preferably has a purity of 95% by mass or more in order to improve reactivity.

[0017] In the present invention, the ratio of the number of moles of fatty acid groups to the number of moles of glycerin groups [FA / GLY] during the reaction of fats and oils with glycerin is preferably 0.60 or more, more preferably 0.65 or more, and even more preferably 0.70 or more, from the viewpoint of reducing the amount of glycerin that does not dissolve in the oil phase, and is preferably 2.0 or less, more preferably 1.7 or less, and even more preferably 1.4 or less, from the viewpoint of producing diacylglycerol. The ratio of the number of moles of fatty acid groups to the number of moles of glycerin groups [FA / GLY] during the reaction of fats and oils with glycerin is preferably 0.60 to 2.0, more preferably 0.65 to 1.7, and even more preferably 0.70 to 1.4. The ratio of the number of moles of fatty acid groups to the number of moles of glycerin groups [FA / GLY] is expressed by the following formula (1): FA / GLY=(moles of fatty acid+moles of monoacylglycerol+moles of diacylglycerol×2+moles of triacylglycerol×3) / (moles of glycerin+moles of monoacylglycerol+moles of diacylglycerol+moles of triacylglycerol) (1)

[0018] The reaction between fats and oils and glycerin is carried out in the presence of a calcium-based catalyst. The calcium-based catalyst used in the present invention is not particularly limited as long as it catalyzes the glycerolysis reaction, and examples thereof include calcium hydroxide, calcium carbonate, calcium oxide, calcium silicate, calcium alkoxides such as calcium methoxide, and the like. These catalysts can be used alone or in combination of two or more. Among these, calcium hydroxide, calcium oxide, and calcium silicate are preferred, and calcium hydroxide is more preferred, from the viewpoints of significantly suppressing the production of glycidol fatty acid esters as by-products and improving the diacylglycerol purity of the reaction oil.

[0019] In the present invention, the addition of the calcium-based catalyst to the fats and oils and glycerin is carried out at 90°C or higher when the temperature is raised to the reaction temperature. Here, "carrying out the addition at 90°C or higher" does not mean that no calcium-based catalyst is added to the reaction raw materials at temperatures below 90°C, but rather means that the amount required to catalyze the reaction is added at 90°C or higher. The temperature of the fats and oils and glycerin when adding the calcium-based catalyst is preferably 95°C or higher, more preferably 100°C or higher, and even more preferably 110°C or higher, from the viewpoints of suppressing catalyst deactivation and improving the diacylglycerol purity of the reaction oil. Furthermore, from the viewpoints of suppressing the generation of by-products and improving quality, the temperature is preferably 165°C or lower, more preferably 160°C or lower, even more preferably 155°C or lower, and even more preferably 150°C or lower. The temperature of the fats and oils and glycerin when adding the calcium-based catalyst is 90°C or higher, preferably 95 to 165°C, more preferably 100 to 155°C, and even more preferably 110 to 150°C. From the same viewpoint, the temperature of the fat or oil and glycerin when the calcium-based catalyst is added is preferably in the range of reaction temperature −15° C. to the reaction temperature, more preferably in the range of reaction temperature −10° C. to the reaction temperature, even more preferably in the range of reaction temperature −5° C. to the reaction temperature, and even more preferably at the reaction temperature. After adding the calcium-based catalyst to the reaction raw materials, the temperature is raised to the reaction temperature as necessary, and the glycerolysis reaction with the fat or oil and glycerin is carried out.

[0020] In the present invention, examples of the pattern of "adding a calcium-based catalyst after heating the fats and oils and glycerin to 90°C or higher" include a pattern in which a premixed reaction raw material of fats and oils and glycerin is added after heating to 90°C or higher; a pattern in which the reaction raw materials of fats and oils and glycerin are added separately after heating to 90°C or higher; a pattern in which the fats and oils are heated to 90°C or higher and then glycerin and the calcium-based catalyst are added separately, or glycerin and the calcium-based catalyst are mixed and then added. Note that when the fats and oils are heated to 90°C or higher and then glycerin is added, it is not necessary to raise the temperature of glycerin to 90°C or higher, as long as the fats and oils and glycerin are heated to 90°C or higher when the glycerin and calcium-based catalyst are added. When the fats and oils are heated to 90°C or higher and then glycerin and the calcium-based catalyst are added separately, it is preferable to dehydrate the glycerin and the calcium-based catalyst in advance, as this can prevent catalyst deactivation and improve the diacylglycerol purity of the reaction oil. Similarly, it is also preferable to dehydrate the oils and fats in advance.

[0021] In the present invention, the amount of calcium-based catalyst added to the reaction raw material at a temperature of 90°C or higher is such that the ratio of the molar amount of calcium-based catalyst to the molar amount of glycerin [mmol-calcium-based catalyst / mol-glycerin] is preferably 0.5 or more, more preferably 1.0 or more, even more preferably 2.0 or more, still more preferably 3.0 or more, still more preferably 4.0 or more, still more preferably 5.0 or more, and still more preferably 8.0 or more, from the viewpoint of improving reactivity, and is preferably 490 or less, more preferably 300 or less, still more preferably 150 or less, and still more preferably 100 or less, from the viewpoint of being able to reduce the amount of neutralizing agent. The amount of calcium-based catalyst added to the reaction raw material at a temperature of 90°C or higher is such that the ratio of the molar amount of calcium-based catalyst to the molar amount of glycerin [mmol-calcium-based catalyst / mol-glycerin] is preferably 0.5 to 490, more preferably 1.0 to 300, even more preferably 2.0 to 150, still more preferably 3.0 to 100, still more preferably 4.0 to 100, still more preferably 5.0 to 100, and still more preferably 8.0 to 100.

[0022] The amount of calcium-based catalyst added to the reaction raw materials at a temperature of 90°C or higher is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, even more preferably 0.03% by mass or more, still more preferably 0.04% by mass or more, still more preferably 0.06% by mass or more, still more preferably 0.1% by mass or more, and still more preferably 0.15% by mass or more, relative to the reaction raw materials, from the viewpoint of improving reactivity; and is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 3.0% by mass or less, still more preferably 2.0% by mass or less, and still more preferably 1.5% by mass or less, from the viewpoint of being able to reduce the amount of neutralizing agent. The amount of calcium-based catalyst added to the reaction raw materials at a temperature of 90°C or higher is preferably 0.01 to 10% by mass, more preferably 0.02 to 5% by mass, even more preferably 0.03 to 3.0% by mass, still more preferably 0.04 to 2.0% by mass, still more preferably 0.06 to 1.5% by mass, still more preferably 0.1 to 1.5% by mass, and still more preferably 0.15 to 1.5% by mass, relative to the reaction raw materials.

[0023] The amount of calcium-based catalyst added at temperatures below 90° C. varies depending on the type of catalyst, but is preferably as small as possible from the viewpoints of reducing the amount of neutralizing agent and facilitating the purification of the produced interesterified oil. Specifically, the amount of calcium-based catalyst added at temperatures below 90° C. is preferably 8% by mass or less, more preferably 4% by mass or less, even more preferably 1.2% by mass or less, and still more preferably 0% by mass, based on the reaction raw materials.

[0024] The reaction temperature is 90°C or higher and 165°C or lower, but from the viewpoint of improving the reaction rate, it is preferably 95°C or higher, more preferably 100°C or higher, and even more preferably 110°C or higher. Furthermore, from the viewpoint of reducing the content of by-products, it is preferably 160°C or lower, more preferably 155°C or lower, and even more preferably 150°C or lower. The reaction temperature is 90 to 165°C, preferably 95 to 160°C, more preferably 100 to 155°C, and even more preferably 110 to 150°C. Furthermore, in order to suppress the formation of by-products, the present invention preferably does not substantially include a step of reacting at above 165°C. "Substantially free" preferably means 10% or less of the time required for the reaction step, more preferably 5% or less, even more preferably 2.5% or less, and even more preferably 0%. Furthermore, "substantially free" specifically means 24 minutes or less, more preferably 12 minutes or less, even more preferably 6 minutes or less, and even more preferably 0 minutes.

[0025] When the temperature is raised to the reaction temperature as needed after adding a calcium-based catalyst, the rate of temperature rise of the reaction raw materials to the reaction temperature is preferably 0.1°C / min or more, more preferably 0.15°C / min or more, and even more preferably 0.2°C / min or more, from the viewpoints of preventing catalyst deactivation and industrial productivity, and is preferably 20°C / min or less, more preferably 10°C / min or less, and even more preferably 3°C / min or less, from the viewpoint of increasing the heating load on the equipment. The rate of temperature rise of the reaction raw materials to the reaction temperature is preferably 0.1 to 20°C / min, more preferably 0.15 to 10°C / min, and even more preferably 0.2 to 3°C / min.

[0026] The reaction time is preferably 0.1 hours or more, more preferably 0.25 hours or more, and even more preferably 0.5 hours or more from the viewpoint of diacylglycerol production, and is preferably 15 hours or less, more preferably 12 hours or less, and even more preferably 9 hours or less from the viewpoint of industrial productivity. The reaction time is preferably 0.1 hours or more and 15 hours or less, more preferably 0.25 hours or more and 12 hours or less, and even more preferably 0.5 hours or more and 9 hours or less.

[0027] In order to improve reactivity and prevent a decrease in catalytic performance, it is preferable to carry out the reaction between fats and oils and glycerin after removing water contained in the reaction raw materials by reducing pressure or bubbling with nitrogen. The reaction may usually be carried out under reduced pressure or atmospheric pressure. The pressure when carried out under reduced pressure is not particularly limited, but is preferably 13,000 Pa or less in order to reduce the water content in the reaction system. When carried out at atmospheric pressure, it is preferable to carry out the reaction under a nitrogen atmosphere with nitrogen circulating in order to prevent oxidation of the resulting transesterified fats and oils. After completion of the glycerolysis reaction, it is preferable to remove the calcium-based catalyst by neutralization, filtration, or the like.

[0028] After the glycerolysis reaction, a purification process that is normally performed on fats and oils may be carried out. Specific examples include distillation, acid treatment, washing with water, bleaching, deodorization, etc. In the present invention, after the glycerolysis reaction, an enzymatic esterification reaction may be further carried out. However, from the viewpoint of industrial productivity, it is preferable to carry out a distillation treatment without carrying out an esterification reaction.

[0029] The interesterified oils and fats obtained by the method of the present invention contain, in addition to diacylglycerol, monoacylglycerol and triacylglycerol, and also contain dissolved unreacted glycerin, although in a smaller amount than these. On the other hand, the method of the present invention can suppress the production of 3-chloropropane-1,2-diol ester (3-MCPD-E), as well as the total amount of 3-chloropropane-1,2-diol (3-MCPD), 3-chloropropane-1,2-diol ester (3-MCPD-E), glycidol, and fatty acid esters of glycidol (MCPD-FS). MCPD-FS can be measured by the method described in the German Society for Lipid Science (hereinafter also referred to as "DGF") Standard Method C-III 18(09) (DGF Standard Methods 2009 (14. Supplement), C-III 18(09), "Ester-bound 3-chloropropane-1,2-diol (3-MCPD esters) and glycidol (glycidyl esters)"). In the present invention, glycidol esters are quantified using Option A of Standard Method 7.1 ("7.1 Option A: Determination of the sum of ester-bound 3-MCPD and glycidol"). 3-MCPD-E can be measured using the method described in German Society for Lipid Research Standard Method C-VI 18(10) (DGF Standard Methods 2010 (16. Supplement), C-VI 18(10), "Fatty-acid-bound 3-chloropropane-1,2-diol (3-MCPD) and 2,3-epoxi-propane-1-ol (glycidol)"). In the present invention, the content of 3-MCPD-E is determined by the value obtained by the standard assay B. Details are described in the Examples.

[0030] The content of MCPD-FS in the interesterified oil obtained by the method of the present invention is preferably 15 ppm or less, more preferably 10 ppm or less, and even more preferably 5 ppm or less from the viewpoint of improving quality. Also, the content of 3-MCPD-E in the interesterified oil is preferably 6 ppm or less, more preferably 4 ppm or less, and even more preferably 2 ppm or less from the same viewpoint.

[0031] In the present invention, when fats and oils containing a large amount of ω3 unsaturated fatty acids in the constituent fatty acids are used as the reaction raw material fats and oils, the amount of reduction in ω3 unsaturated fatty acids in the interesterified fats and oils obtained by the method of the present invention is preferably 2% by mass or less, and more preferably 1% by mass or less, relative to the ω3 unsaturated fatty acids in the fatty acids constituting the reaction raw material fats and oils, in order to suppress the production of trans fatty acids.

[0032] The transesterified oils and fats obtained by the method of the present invention are rich in diacylglycerol, and from the viewpoint of improving physiologically active functions, the diacylglycerol content is preferably 35 to 55% by mass, more preferably 40 to 53% by mass. From the same viewpoint, the monoacylglycerol content in the transesterified oils and fats is preferably 20 to 50% by mass, more preferably 25 to 45% by mass. The transesterified oils and fats obtained by the method of the present invention can be used in the same way as general edible oils and fats, by removing monoacylglycerol, if necessary, by distillation or the like.

[0033] The transesterified oil or fat obtained by the method of the present invention preferably has a free fatty acid content of 5% by mass or less, more preferably 4% by mass or less, even more preferably 3% by mass or less, and even more preferably 2% by mass or less, from the viewpoints of reducing the load on the refining process and industrial productivity. Furthermore, from the viewpoint of carrying out the reaction efficiently, the free fatty acid content is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more.

[0034] In the interesterified oils and fats, the total content of diacylglycerol and triacylglycerol is preferably 50 to 80% by mass, more preferably 55 to 75% by mass, from the viewpoints of physiological effects and industrial productivity.

[0035] Furthermore, in the interesterified oil or fat obtained by the method of the present invention, the purity of diacylglycerol is preferably 55% by mass or more, more preferably 60 to 90% by mass, even more preferably 65 to 90% by mass, and still more preferably 69 to 90% by mass, from the viewpoints of physiological effects and industrial productivity. Here, the diacylglycerol purity is [diacylglycerol / (diacylglycerol+triacylglycerol)×100].

[0036] In relation to the above-described embodiments, the present invention further discloses the following methods for producing interesterified oils and fats. <1> A method for producing interesterified oils and fats, comprising a step of reacting oils and fats with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 95°C or higher and 160°C or lower, wherein the calcium-based catalyst is added after the oils and fats and glycerin are heated to 95°C or higher. <2> A method for producing interesterified oils and fats, comprising a step of reacting oils and fats with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 100°C or higher and 155°C or lower, wherein the calcium-based catalyst is added after the oils and fats and glycerin are heated to 100°C or higher. <3> A method for producing interesterified oils and fats, comprising a step of reacting oils and fats with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 110°C or higher and 150°C or lower, wherein the calcium-based catalyst is added after the oils and fats and glycerin are heated to 110°C or higher. <4> A method for producing interesterified fats and oils, comprising a step of reacting fats and oils with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 95°C or higher and 160°C or lower, wherein the fats and oils and glycerin are heated to 90°C or higher, and then the calcium-based catalyst is added such that the ratio of the molar amount of the calcium-based catalyst to the molar amount of glycerin [mmol-calcium-based catalyst / mol-glycerin] is 1.0 to 300. <5> A method for producing interesterified fats and oils, comprising a step of reacting fats and oils with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 95°C or higher and 160°C or lower, wherein the ratio of the molar number of fatty acid groups to the molar number of glycerin groups [FA / GLY] is 0.65 or higher and 1.7 or lower, and the calcium-based catalyst is added after the fats and oils and glycerin are heated to 90°C or higher. <6> A method for producing interesterified fats and oils having a diacylglycerol purity of 60 to 90% by mass, comprising a step of reacting fats and oils with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 95°C or higher and 160°C or lower, wherein the calcium-based catalyst is added after the fats and oils and glycerin are heated to 90°C or higher.<7> A method for producing interesterified fats and oils, comprising a step of reacting fats and oils with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 95°C or higher and 160°C or lower, wherein the total content of fatty acids having a carbon chain length of 18 or higher and 3 or more double bonds among the fatty acids constituting the fat and oil is 15% by mass or higher, and the calcium-based catalyst is added after the fat and oil and glycerin are heated to 90°C or higher. <8> A method for producing interesterified fats and oils, comprising a step of reacting fats and oils with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 95°C or higher and 160°C or lower, wherein the ratio of the molar amount of calcium-based catalyst to the molar amount of glycerin [mmol-calcium-based catalyst / mol-glycerin] is 1.0 to 300 after the fat and oil and glycerin are heated to 95°C or higher. <9> A method for producing interesterified fats and oils, comprising a step of reacting fats and oils with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 95°C or higher and 160°C or lower, wherein the ratio of the number of moles of fatty acid groups to the number of moles of glycerin groups [FA / GLY] is 0.65 or higher and 1.7 or lower, and the calcium-based catalyst is added after the fats and oils and glycerin are heated to 95°C or higher. <10> A method for producing interesterified fats and oils, comprising a step of reacting fats and oils with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 95°C or higher and 160°C or lower, wherein the calcium-based catalyst is added after the fats and oils and glycerin are heated to 95°C or higher. <11> A method for producing interesterified fats and oils, comprising a step of reacting fats and oils with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 95°C or higher and 160°C or lower, wherein the total content of fatty acids having a carbon chain length of 18 or higher and three or more double bonds among the fatty acids constituting the fat and oil is 15% by mass or higher, and the calcium-based catalyst is added after the fat and oil and glycerin are heated to 95°C or higher.<12> A method for producing interesterified fats and oils, comprising a step of reacting fats and oils with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 90°C or higher and 165°C or lower, wherein the ratio of the number of moles of fatty acid groups to the number of moles of glycerin groups [FA / GLY] is set to 0.65 or higher and 1.7 or lower, and after the fats and oils and glycerin are heated to 90°C or higher, a calcium-based catalyst is added in a ratio of the molar amount of the calcium-based catalyst to the molar amount of glycerin [mmol-calcium-based catalyst / mol-glycerin] of 1.0 to 300. <13> A method for producing an interesterified oil or fat having a diacylglycerol purity of 60 to 90% by mass, comprising a step of reacting an oil or fat with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 90°C or higher and 165°C or lower, wherein the oil or fat and glycerin are heated to 90°C or higher, and then the calcium-based catalyst is added such that the ratio of the molar amount of the calcium-based catalyst to the molar amount of the glycerin [mmol-calcium-based catalyst / mol-glycerin] is 1.0 to 300. <14> A method for producing interesterified fats and oils, the method comprising the step of reacting fats and oils with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 90°C or higher and 165°C or lower, wherein the total content of fatty acids having a carbon chain length of 18 or higher and 3 or more double bonds among the fatty acids constituting the fat and oil is 15% by mass or higher, and after the fat and oil and glycerin are heated to 90°C or higher, the calcium-based catalyst is added such that the ratio of the molar amount of the calcium-based catalyst to the molar amount of glycerin [mmol-calcium-based catalyst / mol-glycerin] is 1.0 to 300. <15> A method for producing an interesterified oil or fat having a diacylglycerol purity of 60 to 90% by mass, comprising a step of reacting an oil or fat with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 90°C or higher and 165°C or lower, wherein the ratio of the number of moles of fatty acid groups to the number of moles of glycerin groups [FA / GLY] is set to 0.65 or higher and 1.7 or lower, and the oil or fat and glycerin are heated to 90°C or higher, and then the calcium-based catalyst is added.<16> A method for producing interesterified fats and oils, comprising a step of reacting fats and oils with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 90°C or higher and 165°C or lower, wherein the total content of fatty acids having a carbon chain length of 18 or higher and 3 or more double bonds in the fatty acids constituting the fat and oil is 15% by mass or higher, the ratio of the number of moles of fatty acid groups to the number of moles of glycerin groups [FA / GLY] is 0.65 or higher and 1.7 or lower, and the calcium-based catalyst is added after the fats and oils and glycerin are heated to 90°C or higher. <17> A method for producing interesterified fats and oils having a diacylglycerol purity of 60 to 90% by mass, comprising a step of reacting fats and oils with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 90°C or higher and 165°C or lower, wherein the fats and oils contain fatty acids with a carbon chain length of 18 or higher and 3 or more double bonds in total at 15% by mass or higher, and the fats and oils and glycerin are heated to 90°C or higher, and then the calcium-based catalyst is added.

[0037] In the following examples, "%" means "% by mass".

[0038] [Analysis Method] (i) Measurement of Fatty Acid Composition A sample was subjected to fatty acid methyl esterification in accordance with "Methyl Esterification Method (Boron Trifluoride Methanol Method) (2.4.1.2-1996)" in "Standard Methods for the Analysis of Fats, Oils and Related Materials, 2003 Edition" compiled by the Japan Oil Chemists' Society, and the obtained sample was subjected to gas chromatography (GC).

[0039] (ii) Measurement of glyceride composition (each composition of MAG, DAG, and TAG) in total glycerides of interesterified oil when using linseed oil Approximately 10 mg of interesterified oil and 0.5 mL of trimethylsilylating agent ("Silylation Agent TH", manufactured by Kanto Chemical) were added to a glass sample bottle, sealed, and heated at 70°C for 15 minutes. 1.5 mL of water and 1.5 mL of hexane were added to the bottle and shaken. After standing, the upper layer was subjected to gas chromatography (GC) to analyze the glyceride composition.

[0040] (iii) Measurement of the glyceride composition (each composition of MAG, DAG, and TAG) of the total glycerides of interesterified oils and fats using fish oil or algae oil. Since the detection sensitivity of gas chromatography (GC) decreases when EPA or DHA is included, analysis was performed using a thin-layer chromatography detector. After TLC development using a mixed solvent of 70 vol% hexane and 30 vol% ethyl acetate, analysis was performed using an Iatroscan (manufactured by LSI Medience).

[0041] (iv) Measurement of MCPD-FS (based on the German Society for Lipid Research (DGF) standard method C-III 18(09) option A) Approximately 100 mg of interesterified oil sample was weighed into a lidded test tube, and 50 μL of the internal standard (3-MCPD-d5 / t-butyl methyl ether), 500 μL of a t-butyl methyl ether / ethyl acetate mixed solution (volume ratio 8:2), and 1 mL of 0.5 N sodium methoxide were added and stirred, followed by standing for 10 minutes. 3 mL of hexane and 3 mL of a 3.3% acetic acid / 20% sodium chloride aqueous solution were added and stirred, and the upper layer was removed. Another 3 mL of hexane was added and stirred, followed by removing the upper layer. 250 μL of a 1 g phenylboronic acid / 4 mL 95% acetone mixed solution was added and stirred, followed by sealing and heating at 80°C for 20 minutes. 3 mL of hexane was added to this and stirred, and the upper layer was subjected to gas chromatography-mass spectrometry (GC-MS) to quantify the glycidol fatty acid esters.

[0042] (v) Measurement of 3-MCPD-E (based on the German Society for Lipid Research (DGF) standard method C-VI 18(10) assay B) Approximately 100 mg of interesterified oil sample was weighed into a lidded test tube, and 100 μL of the internal standard (3-MCPD-d5-dipalmitate / t-butyl methyl ether), 100 μL of t-butyl methyl ether, and 200 μL of 0.5 N sodium methoxide were added and stirred, followed by standing for 5 minutes. 600 μL of isohexane and 600 μL of an 8.75% by mass sulfuric acid / 60% by mass sodium bromide aqueous solution were added and stirred, and the upper layer was removed. Another 600 μL of isohexane was added and stirred, followed by removing the upper layer. The lower layer was extracted three times with 600 μL of a diethyl ether / ethyl acetate mixed solution (volume ratio 3:2), to which 100 μL of a saturated phenylboronic acid / diethyl ether solution was added and stirred. The organic solvent was distilled off under a nitrogen stream, and then 500 μL of isooctane was added to the residue, followed by stirring and subjecting the mixture to gas chromatography-mass spectrometry (GC-MS) to quantify the amount of 3-MCPD-E.

[0043] The values ​​determined in the above (iv) and (v) were converted into the content of glycidol (G) by the following formula (2): G [mg as G / kg] = (MCPD-FS [mg / kg] - 3 - MCPD-E [mg / kg]) × 74 / 110 (2)

[0044] Example 1 300.0 g of fish oil (DD Oil Type 2, manufactured by Nippon Suisan Co., Ltd.) and 100.0 g of glycerin, the raw material oil for the glycerolysis reaction, were placed in a 1000 mL four-neck flask equipped with a stirring blade (75 mm x 20 mm). The ratio of the number of moles of fatty acid groups to the number of moles of glycerin groups [FA / GLY] was 0.70. While stirring at 400 r / min, the mixture was dehydrated under reduced pressure at 70 ° C and 400 Pa for 30 minutes. The pressure was then adjusted to 9300 Pa and heated to the reaction temperature of 110 ° C at a heating rate of 1 ° C / min. Next, the pressure was returned to normal while introducing nitrogen, and 4.0 g of calcium hydroxide was added as a catalyst. The glycerolysis reaction was carried out at a temperature of 110 ° C and a pressure of 9300 Pa. Five hours after the start of the reaction, the pressure was returned to normal while introducing nitrogen, and the reaction oil was sampled. The reaction oil was collected in a test tube capable of centrifugation and centrifuged at 3000 rpm for 10 minutes to remove the precipitated glycerin and catalyst, thereby obtaining an interesterified oil.

[0045] Example 2 300 g of fish oil (Omega Oil 1812TG Gold, manufactured by BASF) and 101.9 g of glycerin were charged. After the reaction temperature reached 125°C, 0.241 g of calcium hydroxide was added, and the reaction time was set to 7 hours. A glycerolysis reaction was carried out in the same manner as in Example 1 to obtain an interesterified oil.

[0046] Example 3 A glycerolysis reaction was carried out in the same manner as in Example 2, except that the reaction temperature was 150°C and the reaction time was 2 hours, to obtain an interesterified oil.

[0047] Example 4 A glycerolysis reaction was carried out in the same manner as in Example 3, except that the amount of calcium hydroxide added was changed to 0.402 g, to obtain an interesterified oil.

[0048] Example 5: 302.6 g of algae oil (manufactured by DSM) and 97.4 g of glycerin were charged. After the reaction temperature reached 150°C, 0.60 g of calcium hydroxide was added, and the reaction time was set to 4 hours. A glycerolysis reaction was carried out in the same manner as in Example 1 to obtain an interesterified oil.

[0049] Comparative Example 1 A glycerolysis reaction was carried out in the same manner as in Example 2, except that the temperature at which calcium hydroxide was added was 70° C., to obtain an interesterified oil.

[0050] Comparative Example 2 A glycerolysis reaction was carried out in the same manner as in Example 3, except that the temperature at which calcium hydroxide was added was 70° C., to obtain an interesterified oil.

[0051] Comparative Example 3 A glycerolysis reaction was carried out in the same manner as in Example 4, except that the temperature at which calcium hydroxide was added was 70° C., to obtain an interesterified oil.

[0052] Comparative Example 4 A glycerolysis reaction was carried out in the same manner as in Example 4, except that the reaction temperature was 175° C., the calcium hydroxide addition temperature was 175° C., and the reaction time was 1.5 hours, to obtain an interesterified oil.

[0053] Comparative Example 5 A glycerolysis reaction was carried out in the same manner as in Comparative Example 4, except that the temperature at which calcium hydroxide was added was 70° C., to obtain an interesterified oil.

[0054] The reaction conditions, the reaction raw materials, and the analytical values ​​of the obtained interesterified oils and fats are shown in Table 1. Note that the values ​​of the above-mentioned (v) 3-MCPD-E were all zero, and therefore not shown in Table 1. Furthermore, the glyceride composition of the oils and fats subjected to the reaction with glycerin was 100% by mass of triacylglycerol in all cases.

[0055]

[0056] Example 6: 331.1 g of undeodorized linseed oil (manufactured by ADM) and 68.9 g of glycerin (manufactured by Kao) were placed in a 1000 mL four-neck flask equipped with a stirring blade (75 mm x 20 mm). The ratio of the number of moles of fatty acid groups to the number of moles of glycerin groups [FA / GLY] was 1.00. The mixture was dehydrated under reduced pressure at 70°C and 400 Pa for 30 minutes while stirring at 400 r / min. The mixture was then returned to normal pressure while introducing nitrogen, and heated to the reaction temperature of 150°C at a heating rate of 1°C / min while circulating nitrogen in the space within the flask. Next, 0.20 g of calcium hydroxide (manufactured by Kanto Chemical) was added as a catalyst, and the glycerolysis reaction was carried out at 150°C and normal pressure (nitrogen flow). The reaction oil was sampled 3 hours after the start of the reaction. The reaction oil was collected in a test tube capable of centrifugation and centrifuged at 3000 rpm for 10 minutes to remove the precipitated glycerin and catalyst, thereby obtaining an interesterified oil.

[0057] Example 7 A glycerolysis reaction was carried out in the same manner as in Example 6, except that the amount of catalyst added was changed to 0.60 g, to obtain an interesterified oil.

[0058] Example 8 A glycerolysis reaction was carried out in the same manner as in Example 6, except that the amount of catalyst added was changed to 0.994 g, to obtain an interesterified oil.

[0059] Comparative Example 6 A glycerolysis reaction was carried out in the same manner as in Example 7, except that the temperature at which calcium hydroxide was added was 70° C., to obtain an interesterified oil.

[0060] Comparative Example 7 A glycerolysis reaction was carried out in the same manner as in Example 6, except that sodium hydroxide was used as the catalyst and the amount of catalyst added was 0.536 g, to obtain an interesterified oil.

[0061] The reaction conditions, the reaction raw materials, and the analytical values ​​of the obtained interesterified oils and fats are shown in Table 2. Note that the values ​​of the above-mentioned (v) 3-MCPD-E were all zero, and therefore it is not shown in Table 2. The glyceride composition of the oil and fat subjected to the reaction with glycerin was 0.1% by mass of fatty acids, 1.0% by mass of MAG, 2.4% by mass of DAG, and 96.5% by mass of TAG.

[0062]

[0063] As is clear from Tables 1 and 2, it was confirmed that when a calcium-based catalyst was added to carry out the glycerolysis reaction after the reaction raw materials had reached 90°C or higher at a low reaction temperature, the diacylglycerol purity was higher than when the catalyst was added at 70°C. On the other hand, when a sodium-based catalyst was used, the by-production of 3-MCPD-E and MCPD-FS could not be suppressed even when the catalyst was added after the reaction raw materials had reached 90°C or higher at a low reaction temperature (comparison between Example 8 and Comparative Example 7). Note that when the reaction temperature was high, the diacylglycerol purity was higher, but the by-production of 3-MCPD-E and MCPD-FS could not be suppressed regardless of the catalyst addition temperature (comparison between Comparative Examples 4 and 5).

Claims

1. A method for producing transesterified fats and oils, comprising the step of reacting fats and oils with glycerin in the presence of a calcium-based catalyst at a reaction temperature of 90°C or higher and 165°C or lower, in which the calcium-based catalyst is added after the fats and oils and glycerin are heated to 90°C or higher.

2. A method for producing transesterified oils and fats according to claim 1, wherein the amount of calcium catalyst added is 0.5 to 490 in terms of the ratio of the molar amount of calcium catalyst to the molar amount of glycerin [mmol-calcium catalyst / mol-glycerin].

3. A method for producing interesterified oils and fats according to claim 1 or 2, wherein the calcium-based catalyst is one or more selected from the group consisting of calcium hydroxide, calcium oxide and calcium silicate.

4. A method for producing transesterified oils and fats according to any one of claims 1 to 3, wherein the ratio of the number of moles of fatty acid groups to the number of moles of glycerin groups in the reaction raw materials [FA / GLY] is 0.60 or more and 2.0 or less.

5. A method for producing transesterified oils and fats according to any one of claims 1 to 4, wherein the rate of temperature rise up to the reaction temperature of the reaction raw materials is 0.1°C / min or more and 20°C / min or less.

6. A method for producing an interesterified oil or fat according to any one of claims 1 to 5, wherein the diacylglycerol purity of the interesterified oil or fat is 55% by mass or more.

7. A method for producing an ester-exchanged oil or fat according to any one of claims 1 to 6, wherein the total content of fatty acids constituting the oil or fat, the fatty acids having a carbon chain length of 18 or more and the number of double bonds of 3 or more, is 15 mass% or more.

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