Highly unsaturated fatty acid or highly unsaturated fatty acid ethyl ester and its production method, medicine, additive or food

Abstract

The present invention relates to highly unsaturated fatty acids or ethyl esters of highly unsaturated fatty acids and methods for producing the same, as well as medicines, additives or foods. The highly unsaturated fatty acids or ethyl esters of the present invention are produced using oils and fats containing highly unsaturated fatty acids as constituent fatty acids as raw material oils and have reduced content of environmental pollutants. Among the dioxins contained, the content of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans is less than 0.05 pg-TEQ / g, and the content of coplanar polychlorinated biphenyls is less than 0.03 pg-TEQ / g. In the method for producing highly unsaturated fatty acids or ethyl esters of highly unsaturated fatty acids, the content of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and coplanar polychlorinated biphenyls is reduced by the following steps: a) using thin film distillation to remove free fatty acids and environmental pollutants from the raw material oil containing highly unsaturated fatty acids as constituent fatty acids, b) hydrolyzing or ethyl esterifying the obtained oils and fats containing highly unsaturated fatty acids, and c) refining by distillation and column chromatography.

Description

[0001] This application is a divisional application of the Chinese patent application whose original application was filed on May 14, 2013, with application number 201380024834.X and invention name “Highly unsaturated fatty acids or highly unsaturated fatty acid ethyl esters with reduced environmental pollutants and their production method”. Technical Field

[0002] The present invention relates to a method for reducing environmental pollutants, especially dimethicone, contained in oils and fats when producing highly unsaturated fatty acids or highly unsaturated fatty acid ethyl esters using oils and fats containing highly unsaturated fatty acids as raw materials. The present invention further relates to foods, additives, supplements, pharmaceuticals, cosmetics and feeds using the fats and oils prepared by the method as raw materials. Background Art

[0003] Today, two Environmental pollutants such as chloramines are found almost everywhere on Earth. They are also known to affect the growth of fish that live in polluted waters. It is believed that trace amounts have no direct impact on health, but even so, it is expected that the amount of environmental pollutants contained in ingredients ingested by humans in the form of food and feed is small.

[0004] Marine oils such as fish oil contain highly unsaturated fatty acids such as EPA (eicosapentaenoic acid, C20: 5, n-3, all-cis-5,8,11,14,17-eicosapentaenoic acid) and DHA (docosahexaenoic acid, C22: 6, n-3, all-cis-4,7,10,13,16,19-docosahexaenoic acid). EPA and DHA are known to have various physiological functions and are used as components of medicines, health foods, foods, feeds, etc. In order to utilize EPA and / or DHA in marine oils, various refining processes are performed.

[0005] Non-patent document 1 describes the use of molecular distillation to remove the pesticide DDT and its metabolites from fish oil. Non-patent document 2 describes the use of vacuum stripping or thin film distillation to remove chlorinated hydrocarbons and free fatty acids from fats or oils. Non-patent document 3 describes the use of physical purification and molecular distillation to remove undesirable substances such as free fatty acids from oil compositions.

[0006] Patent document 1 and non-patent document 4 describe a method for reducing environmental pollutants in oils and fats, which includes the following processes: a process of adding a volatile working fluid to the mixture, and a process of transporting the volatile working fluid to which the mixture is added to at least one stripping treatment process.

[0007] Non-Patent Document 5 describes that when fish oil is deodorized at high temperature, highly unsaturated fatty acids are thermally decomposed.

[0008] Non-patent document 6 describes the removal of disulfide from fish oil by short-path distillation. English: Oxygen, free fatty acids, and cholesterol are the raw materials for making ethyl esters.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: Japanese Patent No. 3905538 (WO2004 / 007654)

[0012] Non-patent literature

[0013] Non-patent literature 1: K.Julshamn, L.Karlsen and ORBraekkan, Removal of DDT and its metabolites from fish oils by molecular distillation, Fiskeridirektoratetsskrifter; Serie teknologiske undersokelser, Vol.5No.15 (1973)

[0014] Non-patent document 2: Anthony P. Bimbo: Guidelines for characterization of food-grade fish oil. INFORM 9(5), 473-483 (1998)

[0015] Non-patent document 3: Jiri Cmolik, Jan Pokorny: Physical refining of edible oils, Eur. J. Lipid Sci. Technol. 102 (7), 472-486 (2000)

[0016] Non-patent document 4: Harald Breivik, Olav Thorstad: Removal of organic environmental pollutants from fish oil by short-path distillation, Lipid Technology, 17(3), 55-58 (2005)

[0017] Non-patent document 5: Veronique Fournier, et al.; Thermal degradation of long-chain polyunsaturated fatty acids during deodorization of fish oil., Eur.J.LipidSci.Technol., 108, 33-42 (2006)

[0018] Non-patent document 6: Oils and Fats, 62(11), 38-39, 2009 Summary of the invention

[0019] Problem that the invention aims to solve

[0020] The present invention aims to provide a method for reducing the environmental pollutants, especially diisocyanate, contained in fats and oils when producing ethyl esters from fats and oils containing highly unsaturated fatty acids as constituent fatty acids. Method for preparing brominated flame retardants and brominated flame retardants Ethyl esters with low content of anthracene and brominated flame retardants.

[0021] Methods for solving problems

[0022] The present invention is accomplished by discovering that, in the purification of oils and fats containing highly unsaturated fatty acids that are easily modified by oxidation, isomerization, etc., as constituent fatty acids, molecular distillation or short-path distillation can be performed under certain conditions to suppress the modification of highly unsaturated fatty acids while reducing environmental pollutants to very low concentrations. By this method, the mass of environmental pollutants in oils and fats can be reduced to two The total content of oxalic acid in ethyl esters is less than 0.2 pg-TEQ / g in terms of toxic equivalent. Ethyl ester is further obtained by using it as a raw material. The diisocyanate in ethyl ester can be further reduced by distilling and column chromatography. English category.

[0023] The gist of the present invention lies in the following highly unsaturated fatty acids or highly unsaturated fatty acid ethyl esters and methods for producing the same, as well as feeds, foods, pharmaceuticals, etc. containing the same.

[0024] (1) A highly unsaturated fatty acid or an ethyl ester of a highly unsaturated fatty acid, wherein the highly unsaturated fatty acid or the ethyl ester of a highly unsaturated fatty acid is produced using a fat containing a highly unsaturated fatty acid as a constituent fatty acid as a raw material oil and wherein the content of environmental pollutants is reduced; Among the chlorinated dibenzo-p-dioxin, The content of polychlorinated dibenzofuran (PCDD) and polychlorinated dibenzofuran (PCDF) is less than 0.05pg-TEQ / g, and the content of coplanar polychlorinated biphenyl (Co-PCB) is less than 0.03pg-TEQ / g.

[0025] (2) The highly unsaturated fatty acid or ethyl ester of highly unsaturated fatty acid of (1), further comprising a brominated flame retardant content reduced to: less than 0.18 ng / g of BDE-47, less than 0.03 ng / g of BDE-100, less than 0.05 ng / g of BDE-49, or less than 0.05 ng / g of BDE-99.

[0026] (3) Ethyl ester of the highly unsaturated fatty acid of (1) or (2), wherein the concentration of the highly unsaturated fatty acid in the fatty acids is 80 area % or more, 85 area % or more, 90 area % or more, 95 area % or more, or 96 area % or more.

[0027] (4) The highly unsaturated fatty acid or the ethyl ester of highly unsaturated fatty acid according to any one of (1) to (3), wherein the oil or fat containing highly unsaturated fatty acids as constituent fatty acids is fish oil, krill oil, marine mammal oil or microbial oil.

[0028] (5) The highly unsaturated fatty acid or the ethyl ester of a highly unsaturated fatty acid according to any one of (1) to (4), wherein the highly unsaturated fatty acid is any one of eicosapentaenoic acid, docosahexaenoic acid, docosapentaenoic acid, dihomo-γ-linolenic acid, and arachidonic acid, or a combination thereof.

[0029] (6) A medicine, additive or food comprising the highly unsaturated fatty acid or ethyl ester of a highly unsaturated fatty acid according to any one of (1) to (5) as an active ingredient.

[0030] (7) A method for producing highly unsaturated fatty acids or ethyl esters of highly unsaturated fatty acids, which reduces the amount of polychlorinated dibenzo-p-dibenzoylmethane by the following steps: Content of polychlorinated dibenzofurans (PCDD), polychlorinated dibenzofurans (PCDF) and coplanar polychlorinated biphenyls (Co-PCB):

[0031] a) removing free fatty acids and environmental pollutants from a raw oil containing highly unsaturated fatty acids as constituent fatty acids by thin film distillation,

[0032] b) hydrolyzing or ethyl esterifying the obtained oil containing highly unsaturated fatty acids,

[0033] c) Purification by distillation and column chromatography.

[0034] (8) The method of (7) further reduces the content of brominated flame retardants.

[0035] (9) The method of (7) or (8), wherein the concentration of highly unsaturated fatty acids in the fatty acids of highly unsaturated fatty acids or in the fatty acids of ethyl esters of highly unsaturated fatty acids is 80 area % or more, 85 area % or more, 90 area % or more, 95 area % or more, or 96 area % or more.

[0036] (10) The method according to any one of (7) to (9), wherein the raw material oil containing highly unsaturated fatty acids as constituent fatty acids is fish oil, krill oil, marine mammal oil or microbial oil.

[0037] (11) Any one of the methods of (7) to (10), wherein the thin film distillation is carried out at a temperature of 200 to 270°C, 220 to 260°C, or 220 to 250°C.

[0038] (12) Any one of the methods of (7) to (11), wherein the thin film distillation is carried out at a pressure of 5 Pa or less, 2 Pa or less, or 1 Pa or less.

[0039] (13) Any one of (7) to (12), wherein the thin film distillation is carried out at a flow rate of 20 to 200 (kg / h) / m 2 Or 25~120(kg / h) / m 2 To implement.

[0040] (14) Any one of the methods of (7) to (13), wherein the thin film distillation is molecular distillation or short path distillation.

[0041] (15) Any one of the methods of (7) to (14), wherein the fractionation is performed using three or more distillation columns.

[0042] (16) Any one of (7) to (15), wherein the purification by column chromatography uses a reverse phase distribution column chromatography.

[0043] (17) A highly unsaturated fatty acid or an ethyl ester of a highly unsaturated fatty acid, produced by any one of the methods (7) to (16), wherein The content of anthracenes is less than 0.07 pg-TEQ / g, or less than 0.05 pg-TEQ / g.

[0044] (18) The highly unsaturated fatty acids or ethyl esters of highly unsaturated fatty acids of (17), further comprising a brominated flame retardant content reduced to: less than 0.18 ng / g of BDE-47, less than 0.03 ng / g of BDE-100, less than 0.05 ng / g of BDE-49, or less than 0.05 ng / g of BDE-99.

[0045] (19) The highly unsaturated fatty acid or ethyl ester of highly unsaturated fatty acid of (17) or (18), wherein the concentration of highly unsaturated fatty acid in the fatty acids is 80 area % or more, 85 area % or more, 90 area % or more, 95 area % or more, or 96 area % or more.

[0046] (20) A medicine, additive or food containing the highly unsaturated fatty acid or ethyl ester of a highly unsaturated fatty acid according to any one of (17) to (19).

[0047] Effects of the Invention

[0048] In the method of the present invention, by performing high temperature, high vacuum and short time distillation, the content rate of highly unsaturated fatty acids in fatty acids is not affected, and environmental pollutants, especially dimethicone, contained in fish oil and the like can be removed. The English class is reduced to a very low level, thus providing no need to worry about the Various products such as feed, food, additives, and medicines that use fish oil as raw materials and are contaminated by British oxalic acid. DETAILED DESCRIPTION

[0049] Hereinafter, the present invention will be described in detail.

[0050] In the present invention, highly unsaturated fatty acids refer to fatty acids having 18 or more carbon atoms and 3 or more double bonds, more preferably fatty acids having 20 or more carbon atoms and 3 or more double bonds, and particularly preferably fatty acids having 20 or more carbon atoms and 5 or more double bonds. Specific examples include: α-linolenic acid (18:3, n-3), γ-linolenic acid (18:3, n-6), dihomo-γ-linolenic acid (20:3, n-6), arachidonic acid (20:4, n-6), eicosapentaenoic acid (20:5, n-3), docosapentaenoic acid (22:5, n-6), docosahexaenoic acid (22:6, n-3), and the like.

[0051] They are known to be contained in large amounts in certain microbial oils, vegetable oils, marine oils, etc. Specific examples include: sardine oil, tuna oil, bonito oil, menhaden oil, cod liver oil, herring oil, capelin oil, salmon oil and other fish oils, krill and other crustacean marine oils, sesame, flax, soybean, rapeseed and other vegetable oils, and oils and fats produced by microorganisms belonging to the genera Mortierella, Penicillium, Aspergillus, Rhodotorula, and Fusarium.

[0052] The method of the present invention is particularly suitable for those who are concerned about the Oils and fats of marine origin that are contaminated by oxalic acid, for example, fish oil, krill oil, or marine mammal oil.

[0053] In the present specification, the fat or oil containing highly unsaturated fatty acids as constituent fatty acids refers to triglycerides or phospholipids.

[0054] When these oils and fats are used as the feedstock oil of the present invention, they may be pretreated before being sent to molecular distillation or short-path distillation. Examples of such pretreatment include a degumming step, a decolorization step using activated clay or activated carbon, and a water washing step.

[0055] In the present invention, the environmental pollutants include: polychlorinated biphenyls (PCB), DDT, polychlorinated terphenyls (PCT), dibenzodiphenyl PCDD and PCDF, chlorophenol and hexachlorocyclohexane (HCH), toxaphene, oxime, brominated flame retardants, polyaromatic hydrocarbons (PAH), organic tin compounds (such as tributyltin, triphenyltin), organic mercury compounds (such as methyl mercury), etc. As a standard for the degree of removal of these substances, dibutyltin is used as a representative substance that is difficult to remove and exists everywhere. The total amount of toxicants is expressed in units of toxic equivalent (pg-TEQ / g).

[0056] In the present invention, Polychlorinated dibenzo-p-dibenzoylmethane is the The total of polychlorinated dibenzofurans (PCDD), polychlorinated dibenzofurans (PCDF) and coplanar polychlorinated biphenyls (Co-PCB) was measured, and the content of each component was multiplied by the toxicity equivalence factor and the total was calculated and expressed as toxicity equivalence (pg-TEQ / g).

[0057] In addition, brominated flame retardants were also measured. Brominated flame retardants are a general term for compounds such as those shown in Table 9. Pollution from oxalic acid has begun to decrease, but an increasing trend has been found for brominated flame retardants, which are substances that should be paid attention to. BDE-100, BDE-49, BDE-99, BDE-47, etc., which are relatively abundant in fish oil, can be used as indicators.

[0058] Table 1

[0059] Table-1 Items to be analyzed

[0060]

[0061] In the present invention, the two Removal of oxalic acid. Molecular distillation (Molecular Distillation) or short path distillation (SPD: Short Path Distillation) is also preferred in thin film distillation. In thin film distillation, there is a distillation in which a condenser is arranged within a distance short relative to the mean free path of vapor molecules evaporated from a heating surface under a certain pressure under high vacuum (<0.1Pa), and such distillation is called molecular distillation. The distillation developed to improve the distillation capacity of molecular distillation is short-path distillation. Regarding short-path distillation, it is carried out at a pressure in the medium vacuum region higher than 0.1Pa, and the condenser is also arranged before and after a distance equal to the mean free path of the evaporated molecules. Therefore, it is a practical method with significantly improved distillation capacity compared to molecular distillation.

[0062] Molecular distillation or short-path distillation is suitable for removing unnecessary components from triglycerides containing EPA, DHA, etc., which have poor heat resistance, because the distillate is exposed to high temperatures for a very short time.

[0063] The molecular distillation or short-path distillation of the present invention is carried out at a temperature of 200 to 270°C, preferably 220 to 260°C, and particularly preferably 220 to 250°C. In addition, it is carried out at a pressure of less than 5 Pa, preferably less than 2 Pa, and more preferably less than 1 Pa. In addition, the flow rate is 20 to 200 (kg / h) / m 2 , preferably 25 to 120 (kg / h) / m 2 If the flow rate is too small, the productivity will decrease, so it is preferred to confirm the removal of the second If distillation is performed under such conditions, although highly unsaturated fatty acids are poor in temperature resistance, there is basically no deterioration in quality.

[0064] By distilling under such conditions, the two PCDD and PCDF in the chlorinated biphenyls are controlled to be less than the detection limit, that is, substantially 0. Here, regarding 0, for example, when calculated based on the numerical value of the detection limit in Table 6, it can be set to less than 0.043pg-TEQ / g, that is, less than 0.05pg-TEQ / g. Coplanar polychlorinated biphenyls can also be reduced to less than 0.2pg-TEQ / g, further reduced to less than 0.1pg-TEQ / g, less than 0.05pg-TEQ / g, less than 0.02pg-TEQ / g, and less than 0.01pg-TEQ / g.

[0065] In addition, among brominated flame retardants, if BDE-100, BDE-49, BDE-99, BDE-47, etc. are used as indicators, they can be reduced to less than 0.05 μg / g, preferably less than 0.03 μg / g, and further less than 0.02 μg / g.

[0066] Embodiments of the method of the present invention are described below.

[0067] The raw material oil is preferably an oil obtained by degumming by water washing or the like. The washed raw material oil is directly sent to molecular distillation or short-path distillation under the above conditions, and cholesterol, free fatty acids, environmental pollutants, etc. are removed as fractions to obtain a residual fraction containing triglycerides. The residual fraction can also be used directly, or it can be further decolorized by activated carbon, activated clay, etc., or deodorized by steam distillation, etc. The refined oil produced in this way can be used as a component of feed, food, and additives.

[0068] Furthermore, by using the above-mentioned residual fraction as a raw material, it is possible to produce Ethyl esters containing oxalic acid.

[0069] Ethanol and a catalyst or an enzyme are added to the residual fraction to cause a reaction to produce esters of fatty acids constituting triglycerides and ethanol. Any known method may be used for the ethyl esterification.

[0070] After ethyl esterification, it can be further refined as needed. In order to improve the purity of EPA ethyl ester and DHA ethyl ester, molecular distillation, rectification, column chromatography and other methods can be further used. Specifically, it can be refined by the methods described in Japanese Patent Laid-Open No. 5-222392 (patent of the same family EP0610506), Japanese Patent Laid-Open No. 4-41457 (patent of the same family EP0460917), Japanese Patent Laid-Open No. 6-33088, etc.

[0071] The distillation is carried out using three or more distillation towers under high vacuum, and can be obtained by separating EPA ethyl ester and / or DHA ethyl ester as the main fraction from the more volatile initial fraction and the less volatile residual fraction. As the conditions for the distillation, the temperature is 150 to 200°C, preferably 160 to 190°C, more preferably 170 to 190°C, and the pressure is 1 to 300 Pa, preferably 1 to 200 Pa, more preferably 1 to 133 Pa. Preferably, a main fraction of 160 to 190°C, preferably 170 to 190°C, is obtained under a vacuum degree of 1 to 133 Pa.

[0072] The method of performing column chromatography after distillation is particularly preferred. The inventors of the present application have found that when EPA and DHA are concentrated by distillation, the two The concentration of oxalic acid is relatively high, but it can be reduced relative to the level before distillation by performing column chromatography. Silica gel, ion exchange resin, activated clay, silver nitrate, etc. can be used in column chromatography, but column chromatography of reverse phase distribution system is particularly preferred. According to the method of forming the reverse phase distribution system, for example, alkyl bonded silica filler (ODS column, etc.) can be used. In addition, as a solvent system, water, alcohol, ketone can be used. Methanol is preferred. They can be used alone or in combination.

[0073] By combining the above-mentioned distillation and column chromatography, highly unsaturated fatty acids can be concentrated, and the concentration of environmental pollutants can be reduced. The concentration of highly unsaturated fatty acids, such as EPA ethyl ester and / or DHA ethyl ester, can be increased to a purity of 80 area % or more, 85 area % or more, 90 area % or more, 95 area % or more, and further 96 area % or more, and the distillation can be made PCDD and PCDF among the chlorinated compounds are below the detection limit, that is, substantially 0 (less than 0.043 pg-TEQ / g in the calculation based on the detection limit), and coplanar polychlorinated biphenyls can also be reduced to less than 0.1 pg-TEQ / g, further less than 0.03 pg-TEQ / g, and less than 0.01 pg-TEQ / g. Alternatively, for brominated flame retardants, the amount of BDE-47 can be reduced to less than 0.18 ng / g, the amount of BDE-100 can be reduced to less than 0.03 ng / g, the amount of BDE-49 can be reduced to less than 0.05 ng / g, or the amount of BDE-99 can be reduced to less than 0.05 ng / g. BDE-100, BDE-49, BDE-99, and BDE-47 can be reduced to less than 0.05 μg / g, preferably less than 0.03 μg / g, and further less than 0.02 μg / g. As a pharmaceutical product, the concentration of EPA ethyl ester and / or DHA ethyl ester is preferably a purity of 96 area % or more.

[0074] Such free fatty acids and fatty acid esters having a high concentration of highly unsaturated fatty acids and a low concentration of environmental pollutants are suitable for use as raw materials for medicines and additives containing highly unsaturated fatty acids as active ingredients.

[0075] When used in medicines and food additives, the content of EPA and / or DHA in the fatty acids needs to be concentrated according to the purpose. In this case, the highly unsaturated fatty acids in the glycerides can be concentrated by a method for selectively concentrating highly unsaturated fatty acids using a lipase reaction (WO2009 / 17102, etc.). For glycerides treated in this way, the concentration of highly unsaturated fatty acids can also be increased by using the method of the present invention, while reducing environmental pollutants.

[0076] The highly unsaturated fatty acid can be obtained by hydrolyzing the ester of the highly unsaturated fatty acid produced by the above method.

[0077] Examples of the present invention are described below, but the present invention is not limited to these examples.

[0078] two Determination of Brominated Flame Retardants

[0079] In the embodiment of the present invention, The determination of the two types of food was entrusted to the Japan Food Analysis Center. The method for measuring the content of edible oils shall be determined in accordance with the Provisional Guidelines for the Measurement of Ethylene (February 2009) (Health Food No. 138, Health Milk No. 200, 2009).

[0080] The measurement of brominated flame retardants was outsourced to Eurofins, an analysis company for food, etc. The measurement method was based on high-resolution mass spectrometry (HRGC / HRMS).

[0081] Determination of acid value (AV)

[0082] In the examples of the present invention, the acid value (AV) was measured in accordance with Standard Test Methods for Analysis of Oils and Fats (2003 edition) (edited by the Japan Oil Chemicals Society).

[0083] Determination of fatty acid composition

[0084] The fatty acid composition of the fish oil used as the raw material and the oil after the short-path distillation treatment was determined by ethyl esterification of the fish oil and gas chromatography. That is, 1 mL of 1N sodium ethoxide / ethanol solution was added to 40 μL of the fish oil and stirred for about 30 seconds. Then, 1 mL of 1N hydrochloric acid was added for neutralization, 2 mL of hexane and 3 mL of saturated ammonium sulfate aqueous solution were added, stirred, and allowed to stand, and then the upper layer was determined by gas chromatography.

[0085] Gas chromatography analysis conditions

[0086] Machine type: Agilent 6850 GC system (Agilent)

[0087] Column: DB-WAX J&W 123-7032E

[0088] Column temperature: 200°C

[0089] Injection temperature: 300℃

[0090] Injection method: split flow

[0091] Split ratio: 100:1

[0092] Detector temperature: 300°C

[0093] Detector: FID

[0094] Carrier gas: Helium

[0095] Example 1

[0096] Use acid value, Two kinds of sardine crude oil with different contents of oxadiazole were distilled under various distillation conditions and the removal of oxadiazole was carried out. The distillation apparatus used was a short path distillation apparatus (SPD) KD 10 (manufactured by UIC GmbH, with a distillation surface area of ​​0.1 m 2 The distillation conditions (temperature, pressure, flow rate) are shown in Table 2. The distillation temperature was fixed at 250°C, the pressure was varied in the range of 0.4 to 3.0 Pa, and the flow rate was varied in the range of 25 to 121 (kg / hr) / m 2 changes within the range of.

[0097] The crude oil and the distilled The concentration of oxalic acid and acid value are shown in Table 2.

[0098] Regardless of the acidity of the crude oil, The amount of oxalic acid can be adjusted under any conditions. The content of anthracenes was reduced to below 0.1 pg-TEQ / g.

[0099] Table 2

[0100]

[0101] Example 2

[0102] Using the same apparatus as in Example 1, tuna oil (refined oil subjected to degumming and deoxygenation treatment) was subjected to distillation under the conditions of Table 3. As shown in Table 3, even tuna oil can be removed by the method of the present invention (distillation temperature 250°C, pressure 0.1 Pa, flow rate 48 (kg / hr) / m 2 ), thus converting the two The content of anthracenes was reduced to below 0.1 pg-TEQ / .

[0103] In addition, another short path distillation apparatus (SPD) KD 6 (manufactured by UIC GmbH, with a distillation surface area of ​​0.06 m 2 ) and remove the two As shown in Table 3, the method of the present invention can also be used in this device (distillation temperature 270°C, pressure 0.6Pa, flow rate 20 (kg / hr) / m 2 ) The content of anthracenes was reduced to below 0.1 pg-TEQ / .

[0104] Table 3

[0105]

[0106] Example 3

[0107] A centrifugal molecular distillation apparatus MS380 (manufactured by Nippon Shakuba Corporation, with a distillation surface area of ​​0.11 m 2 ), the sardine crude oil was subjected to two distillation conditions as shown in Table 4. As shown in Table 4, even with the use of a molecular distillation apparatus, the dioxin can be removed in the same manner as in Examples 1 and 2. The content of anthracenes was reduced to below 0.2 pg-TEQ / .

[0108] Table 4

[0109]

[0110] Example 4

[0111] Sardine crude oil (acid value 6, EPA 19%, DHA 8%) was washed with 85°C warm water (5% relative to the crude oil) and then distilled using a short path distillation apparatus (SPD) KD1800 (manufactured by UIC GmbH, distillation area 18m 2 ) and short-path distillation was performed. The conditions were vacuum degree 0.7-1 Pa, body temperature 250°C, supply volume about 2000 kg / H (flow rate 110 (kg / h) / m 2 ).

[0112] The distilled oil (SPD oil) The results of the determination of the two types of oxaline are shown in Tables 5 and 6. The total amount of oxalic acid was reduced from 3.0 pg-TEQ / g to 0.014 pg-TEQ / g in terms of toxicity equivalent. In addition, the acid value of the oil after distillation was less than 0.2, and there was no change in the fatty acid composition.

[0113] Table 5

[0114]

[0115] Note 1: When the measured concentration is less than the detection limit, it is indicated by "ND"

[0116] 2. Toxicity equivalent (TEQ) is calculated by setting the measured concentration below the detection limit to "0"

[0117] 3. Toxicity equivalence factor (TEF) uses WHO (2006)

[0118] 4. 1,2,3,7,8-PeCDF and 1,2,3,4,7,8-HxCDF cannot be separated by SP-2331 column, so they are expressed as total values.

[0119] Table 6

[0120]

[0121] Note 1: When the measured concentration is less than the detection limit, it is indicated by "ND"

[0122] 2. Toxicity equivalent (TEQ) is calculated by setting the measured concentration below the detection limit to "0"

[0123] 3. Toxicity equivalence factor (TEF) uses WHO (2006)

[0124] 4. 1,2,3,7,8-PeCDF and 1,2,3,4,7,8-HxCDF cannot be separated by SP-2331 column, so they are expressed as total values.

[0125] Example 5

[0126] The crude sardine oil was short-path distilled under the same conditions as in Example 4, and the fatty acid composition before and after distillation was determined by the method described above. The results are shown in Table 7. The proportion of fatty acids with more than 18 carbon atoms and more than 3 double bonds, which are easily modified by oxidation, isomerization, etc. due to heating, in the total fatty acids of the raw oil and after distillation, and their increase and decrease are shown. The increase and decrease of any fatty acid is slight, and the change is not particularly large for fatty acids with a large number of double bonds. This result confirms that the method of the present invention is effective in removing diunsaturated fats without modifying highly unsaturated fats. In Table 7, ARA is arachidonic acid and DPA is docosapentaenoic acid.

[0127] Table 7

[0128]

[0129] Example 6

[0130] EPA ethyl ester was produced using the distilled oil produced in Example 4 as a raw material.

[0131] Regarding the production method, the oil distilled by SPD was subjected to an ethanol decomposition reaction with ethanol in the presence of an alkaline catalyst to produce ethyl ester. The oil was washed with warm water, then dehydrated, and the main fraction was obtained by rectification (vacuum degree 13 Pa, temperature of the main fraction about 176°C), and further HPLC treatment was performed using a reverse phase distribution system (ODS) column chromatography to distill off the solvent, thereby producing EPA ethyl ester with an EPA purity of 97%.

[0132] The diisocyanate of the ethyl ester was determined in the same manner as in Example 4. The results are shown in Table 8. The ethyl esterification and subsequent purification process are used to avoid diisocyanate. The oxalic acid is concentrated, and the treated raw material of Example 4 can be used to produce dioxin. The total amount of EPA ethyl esters was 0.07 pg-TEQ / g or less in terms of toxic equivalent. Table 8 shows the results of the experiments using three different batches of raw materials. It was confirmed that the method of the present invention can stably produce dioxin. The total amount of ethoxylates is 0.006 to 0.021 pg-TEQ / g of EPA ethyl ester in terms of toxic equivalent. ND below the detection limit means that even if the value of the detection limit is inserted for calculation, the value is only increased by 0.005, and 0.011 to 0.026 pg-TEQ / g of EPA ethyl ester can be produced.

[0133] Table 8

[0134]

[0135] Example 7

[0136] The distillation and column chromatography treatment in the purification process after ethyl esterification has an effect on the The influence of the concentration of dioxins was confirmed. As the feedstock oil, sardine crude oil was used which was only deoxidized and bleached but not subjected to film distillation. This is because the crude oil containing slightly more dioxins was used. When it comes to oils and fats of the English type, it is easy to observe the influence of the refining treatment.

[0137] The feedstock oil was ethyl esterified using a basic catalyst. The ethyl ester was first subjected to a distillation step to collect a fraction containing ethyl esters of fatty acids having 20 carbon atoms. Next, an eicosapentaenoic acid ethyl ester fraction was collected using ODS column chromatography.

[0138] At each stage, two English category.

[0139] Table 9 shows the four components with large changes (absolute amounts and toxic equivalents) and two Total of oxadiazoles (toxic equivalent). Compared with the esterification, the distillation process has greatly concentrated the components of #105 and #118. On the other hand, the concentration of #77 has been reduced. In terms of distillation, it is believed that ethyl eicosapentaenoate and diisocyanate have Ethyl esters showed similar behavior, with the concentration of ethyl ester and diethyl ester. The English class has been concentrated.

[0140] Through column treatment, #77 remained unchanged or increased slightly, while other components decreased significantly. The English classes display different behaviors and are thus separable.

[0141] Therefore, by combining distillation with column treatment, it is possible to simultaneously concentrate the target ethyl ester and reduce the diethyl ester to its original state. The English category decreased.

[0142] Table 9

[0143]

[0144] Example 8

[0145] Using crude sardine oil as raw material, the same operation as in Example 4 was performed to obtain SPD oil distilled with SPD, and further ethyl esterification and refining were performed using the same method as in Example 6 to obtain EPA ethyl ester. The content of brominated flame retardants in them was determined. The determination was entrusted to eurofins as an analytical agency. The results are shown in Table 10. Any of the brominated flame retardants contained in the raw sardine oil was reduced to below the detection limit. It can be confirmed that any of BDE-100, BDE-49, BDE-99, BDE-47, BDE-28, BDE-66, and BDE-154 contained in the raw oil above the detection limit was reduced, especially BDE-100, BDE-49, BDE-99, and BDE-47 were clearly reduced.

[0146] Table 10

[0147]

[0148] Industrial Availability

[0149] According to the present invention, it is possible to provide an oil that can significantly reduce environmental pollutants, particularly dihydrogen phosphate, contained in oils and fats containing highly unsaturated fatty acids as constituent fatty acids, such as fish oil containing EPA and DHA. Brominated flame retardants. Can be used in feed, food, additives, medicines, etc.

Claims

1. A method for producing highly unsaturated fatty acids or ethyl esters of highly unsaturated fatty acids, which reduces the amount of polychlorinated dibenzo-p-dibenzoylmethane by the following steps: The content of PCDD, PCDF and Co-PCB as well as the content of brominated flame retardants: a) bleaching a raw material oil containing highly unsaturated fatty acids as constituent fatty acids, b) hydrolyzing or ethyl esterifying the obtained oil containing highly unsaturated fatty acids, c) purification by distillation and column chromatography, The method further comprises a step of removing free fatty acids and environmental pollutants by thin film distillation before step b.

2. A method for producing highly unsaturated fatty acids or ethyl esters of highly unsaturated fatty acids, which reduces the amount of polychlorinated dibenzo-p-dibenzoylmethane by the following steps: The content of PCDD, PCDF and Co-PCB as well as the content of brominated flame retardants: a) deodorizing a raw material oil containing highly unsaturated fatty acids as constituent fatty acids, b) hydrolyzing or ethyl esterifying the obtained oil containing highly unsaturated fatty acids, c) purification by distillation and column chromatography, The method further comprises a step of removing free fatty acids and environmental pollutants by thin film distillation before step b.

3. The method according to claim 1 or 2, wherein the concentration of the highly unsaturated fatty acids in the fatty acids of the highly unsaturated fatty acids or in the fatty acids of the ethyl esters of the highly unsaturated fatty acids is 80 area % or more.

4. The method according to claim 1 or 2, wherein the concentration of the highly unsaturated fatty acids in the fatty acids of the highly unsaturated fatty acids or in the fatty acids of the ethyl esters of the highly unsaturated fatty acids is 95% by area or more.

5. The method according to claim 1 or 2, wherein the raw material oil containing highly unsaturated fatty acids as constituent fatty acids is fish oil, krill oil, marine mammal oil or microbial oil.

6. The method according to claim 1 or 2, wherein the thin film distillation is carried out at a temperature of 200 to 270°C.

7. The method according to claim 1 or 2, wherein the thin film distillation is performed at a temperature of 220 to 250°C.

8. The method according to claim 1 or 2, wherein the thin film distillation is carried out at a pressure below 5 Pa.

9. The method according to claim 1 or 2, wherein the thin film distillation is carried out at a pressure below 2 Pa.

10. The method according to claim 1 or 2, wherein the thin film distillation is carried out at a pressure below 1 Pa.

11. The method according to claim 1 or 2, wherein the thin film distillation is carried out at a flow rate of 20 to 200 (kg / h) / m 2 To implement.

12. The method according to claim 1 or 2, wherein the thin film distillation is carried out at a flow rate of 25 to 120 (kg / h) / m 2 To implement.

13. The method according to claim 1 or 2, wherein the thin film distillation is molecular distillation or short path distillation.

14. The method according to claim 1 or 2, wherein the rectification is performed using three or more distillation columns.

15. The method according to claim 1 or 2, wherein in the purification by column chromatography, a reverse phase distribution column chromatography is used.

16. The method according to claim 1 or 2, wherein the raw material oil is sardine oil or tuna oil.

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