JP4496754B2 - Oil and fat purification method - Google Patents

Description

  The present invention relates to a method for purifying highly unsaturated oils and fats.

  The present invention relates to a method for purifying edible fats and oils. Specifically, a method for purifying oils and fats containing highly unsaturated fatty acids having 3 or more double bonds in fatty acid residues, such as α-linolenic acid, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid, and the like The present invention relates to edible fats and oils produced by a purification method.

  In recent years, studies on lipid nutrition have advanced, and intake of highly unsaturated fatty acids (highly unsaturated fatty acids) such as EPA and DHA is effective in preventing lifestyle-related diseases such as arteriosclerosis, myocardial infarction, stroke, and dementia. It is clear from numerous reports. While polyunsaturated fatty acids are necessary for health maintenance, they contain many double bonds, so they oxidize very quickly, and lipid peroxides are easily formed during storage (in contrast, in vivo, It is said that the presence of a large amount of highly unsaturated fatty acids increases the enzyme activity related to antioxidants).

  Lipid peroxide is a lipid having a hydroperoxy group (-OOH), and easily becomes a free radical of lipid by the action of heat, light, and transition metal, and the free radical forms a new radical with lipid peroxide. To do. In this way, lipid peroxide causes a radical chain reaction in an autocatalytic manner, and as a result, the lipid peroxide in fats and oils increases rapidly. The content of lipid peroxide is evaluated as the peroxide value (POV). Lipid peroxide free radicals, like active oxygen, have adverse effects on the body, such as gene damage and cell aging. Antioxidation by suppressing the generation of lipid peroxide is particularly effective for purified fish oil. This is an important issue in handling highly unsaturated fatty acid-containing fats and oils.

  As a method for preventing oxidation of edible fats and oils, blocking with oxygen and addition of an antioxidant such as tocopherol (vitamin E) are generally performed. In order to suppress the oxidation of refined fish oil, in addition to adding an antioxidant and sealing with an inert gas, refrigeration and freezing are performed, but this is only a delay in oxidation. If even a small amount of lipid peroxide remains in the fat and oil, it is difficult to prevent the autocatalytic radical chain reaction of the lipid peroxide, and the oxidation of the fat and oil proceeds gradually even in the absence of oxygen.

  Therefore, in order to improve the oxidation stability of highly unsaturated fatty acid-containing fats and oils such as fish oil, it is necessary to completely remove the lipid peroxide that triggers the radical chain reaction, that is, to make the POV of the refined fats and oils zero. It is most effective in prevention, and on that basis, it can be said that a method of suppressing oxidation such as an antioxidant is effective.

  Conventionally, it is known that lipid peroxide is reduced by activated clay in the decolorization process of fats and oils, and general animal and vegetable fats and oils that do not contain highly unsaturated fatty acids have a POV of 0.3 meq / kg or less by conventional purification methods. Can be reduced to the level of However, oils and fats containing highly unsaturated fatty acids such as fish oil are originally high in crude POV, and fish oil is generally squeezed from heat-pulverized fish, and there are proteins and heme compounds that cause odor and oxidation promotion. Many impurities are mixed, and it is difficult to sufficiently reduce POV and improve odor and flavor unless such impurities that adversely affect the quality of fats and oils are efficiently removed in the purification of fish oil.

  So far, edible fats and oils have been refined in the order of degumming, deoxidation, decolorization and deodorization regardless of fish oil, animal oil or vegetable oil. Degumming is a step of hydrating gums such as phospholipids dissolved in fats and oils by acid treatment such as phosphoric acid and removing the precipitated gums with a centrifuge. If a gummy substance exists in fats and oils, it will cause quality deterioration, such as coloring by heating. Deoxidation is a process in which free fatty acids contained in fats and oils are neutralized with an alkali such as caustic soda, and the resulting soap is removed by centrifugation or the like. Free fatty acids are produced by hydrolysis, which is the deterioration of fats and oils, and the remaining amount of free fatty acids is indicated as the acid value (AV). Decolorization is a process of adsorbing and removing pigment components and other trace components that have not been removed by degumming or deoxidation using activated clay. Deodorization is a process of distilling off volatile components that cause odor by heating oil and fat to 200 ° C. or higher under high vacuum and blowing water vapor. This process is also called steam distillation and is the final process of refining edible fats and oils. As described above, since fish oil originally has a large amount of lipid peroxide and impurities, it has been difficult to remove these components sufficiently by ordinary purification methods.

  As a method for purifying fish oil, for example, a purification method using silica gel (Patent Document 1), a purification method using a polar porous resin (Patent Documents 2 and 3), a purification method using a superabsorbent resin (Patent Document 4), diatom A method using an adsorbent, such as a soil purification method (Patent Document 5), has been devised. However, any of the adsorbents effective for refining fish oil is an expensive material, and although it can be recycled, the production load is large and the production of the refined fish oil is a factor.

  In addition, antioxidants are effective for preventing the oxidation of oils after purification, and various antioxidants, deodorants, and masking agents have been devised (for example, Patent Document 6 and Patent Document 7). It has only a temporary effect on fish oil return odor and has no lasting power. As general antioxidants and deodorants, natural tocopherol, BHA (butylhydroxyanisole), BHT (butylhydroxytoluene), citric acid, ascorbic acid, ascorbic acid fatty acid ester, etc. are already used. It has little effect on the return odor of fish oil. In addition, commercially available preparations need to be added in the presence of an inert gas after deodorization, so workability is poor, and some preparations become cloudy when added to fats and oils, resulting in poor appearance and commercial value. Some of them can be lowered and cannot be used.

Patent Document 8 discloses a method of adding a tea extract, tocopherol, and ascorbic acid before deodorization. However, as in the present invention, decomposition of peroxide by phosphoric acid treatment after deoxidation or phosphoric acid treatment Since the iron content is not removed by subsequent activated carbon treatment, the types of tocopherols are limited, and ascorbic acid is used, so when emulsified products such as margarine are produced, they bind to iron in water and oxidize fats and oils. There is a possibility of promoting. There was also a problem of coloring due to the addition of tea extract.
Japanese Patent Laid-Open No. 62-181398 JP-A-5-331487 JP-A-8-302382 JP-A-8-311481 JP-A-9-137182 JP-A-2-55785 Japanese Patent Laid-Open No. 3-100093 JP-A-5-287294

  The object of the present invention is to contain edible fats and oils containing highly unsaturated fatty acids such as fish oil, without expensive adsorbents, having oxidative stability, no return odor and good flavor containing highly unsaturated fatty acids. It is to provide fats and oils at low cost. Furthermore, it is to suppress coloring when adding tea extract and deodorizing.

  As a result of intensive studies to solve the above problems, the present inventors have produced a colored component in the case of fish oil in the phosphoric acid treatment in the conventional degumming step, but the component is a component different from the gum quality Therefore, when the method of removing the component colored with phosphoric acid with the adsorbent (decolorization) was studied, the colored component could not be removed with activated clay, but the colored component was decolorized with activated carbon. It was found that can be removed by adsorption. In addition, POV immediately after removal of colored components is very close to zero, and by adding a specific amount of tea extract having a specific robibond color value during the deodorization process, highly unsaturated fatty acids such as fish oil It has been found that the return odor of fats and oils containing can be suppressed over a long period of time, and the present invention has been completed.

That is, the first of the present invention is the purification of edible fats and oils containing 10% by weight or more of highly unsaturated fatty acids, characterized in that the fats and oils are subjected to phosphoric acid treatment after deoxidation treatment, then activated carbon treatment and further deodorization treatment. A method for extracting tea with 100 parts by weight of fats and oils and 0.1 parts by weight of water and 100 parts by weight of water, with a Robibond color value of 2.5 or less yellow and 1.4 or less red things 0.005-0.5 parts by weight with the emulsifier, those dissolved in a solvent, after the activated carbon treatment, was added before deodorization treatment, 160 ° C. or higher, 10 wt, characterized in that the deodorization at 260 ° C. or less The present invention relates to a method for purifying edible fats and oils containing at least% highly unsaturated fatty acids . Preferably , the present invention relates to a method for purifying edible fats and oils containing 10% by weight or more of highly unsaturated fatty acid, wherein 0.01 to 1.0 part by weight of tocopherol is further added before deodorization.

  By the refining method of the present invention, it is possible to prevent oxidative degradation of fats and oils immediately after deodorization, and to prevent coloring of fats and oils due to addition of tea extract. By these methods, it is possible to obtain highly unsaturated fatty acid-containing fats and oils that are not colored and have a good flavor over a long period of time.

  Hereinafter, the present invention will be described in detail. The type of fats and oils that can be used in the present invention is not particularly limited as long as they are edible, and examples thereof include all types of fats and oils such as fish oils, animal fats and oils, vegetable fats and oils, and at least one kind can be used. The saturated fatty acid content may be 10% by weight or more. In particular, the effects of the present invention are exhibited in the removal of lipid peroxides from oxidatively deteriorated fats and oils whose POV is 2.0 meq / kg or more. Among them, when the content of highly unsaturated fatty acids is 10% by weight or more in the total edible fats It is preferable because a great effect can be obtained, and is preferably 20% by weight or more, because a larger effect can be obtained. If the POV is less than 2.0 meq / kg, it is possible to reduce the POV immediately after production to a level of 0.3 meq / kg or less by removing lipid peroxide even by a conventional purification method.

  Further, in the purification of fats and oils containing highly unsaturated fatty acids (polyunsaturated fatty acids) such as α-linolenic acid, EPA, DHA and the like having three or more double bonds in the fatty acid residues of the fats and oils, The (oxidation resistance) effect and the effect of improving odor and flavor are particularly significant. Among them, it is most suitable for refining fish oil containing EPA and DHA which is easily oxidized and deteriorated. Examples of fish oil include fish-derived fats and oils such as sardine oil, tuna oil, saury oil, mackerel oil, horse mackerel oil, and pollock oil.

  The oil and fat purification flow of the present invention is desirably performed in the order of deoxidation, phosphoric acid treatment, activated carbon treatment (degumming, decolorization), addition of tocopherol and tea extract, and deodorization. Hereinafter, the purification flow including the reason will be described.

<Deoxidation>
Conventionally, first, phosphoric acid treatment is performed during the degumming process, the degumming process is performed to remove the precipitate formed by hydrating the gum, and then the deoxidizing process is performed. A degumming step with phosphoric acid is not performed, and first, a raw acid and fat before purification is subjected to a deoxidation step with an alkali such as caustic soda according to a conventional method to remove free fatty acids contained in the fat and oil.

<Phosphoric acid treatment>
By subjecting the raw oil and fat after the deoxidation step to a phosphoric acid treatment, if there is a gum in the fat, the gum is hydrated to form a precipitate. Further, it is presumed that lipid peroxide in the oil and fat is denatured into an oil-soluble substance that is easily adsorbed on activated carbon. As in the past, only by phosphoric acid treatment before degumming process, lipid peroxide in fats and oils is once modified into an oil-soluble substance that is easily adsorbed on activated carbon, but it is difficult to adsorb on activated carbon again in the next deoxidation process. It seems to be denatured into a substance. Therefore, unless the phosphoric acid treatment is always performed after deoxidation, the effect of the present invention is not remarkably exhibited. Moreover, when deacidification is performed after the activated fat is treated on the phosphatized fats and oils, the highly unsaturated fatty acid may be deteriorated again by heating in the deoxidation step.

  The alkali-deoxidized fat is preferably heated to 60 ° C. or higher and 100 ° C. or lower, more preferably 80 ° C. or higher and 100 ° C. or lower while stirring under vacuum. After reaching a predetermined temperature, a predetermined amount of phosphoric acid is added and stirred for 30 minutes. If the ultimate temperature is lower than 60 ° C, the reaction with phosphoric acid may not occur sufficiently, and there is no particular upper limit on the ultimate temperature, but if it is 100 ° C or less, it is advantageous in terms of cost. Furthermore, in the case of fats and oils containing 3 or more polyunsaturated fatty acids such as fish oil that has been alkali deoxidized, the oils are 60 ° C. or higher and 120 ° C. or lower, preferably 80 ° C. or higher while stirring under vacuum. Heat to 100 ° C. or lower. When the reached temperature is lower than 60 ° C., the reaction with phosphoric acid does not sufficiently occur.

  The addition of phosphoric acid is preferably 0.1 parts by weight or more and 3 parts by weight or less, more preferably 0.5 parts by weight or more and 3 parts by weight or less based on 100 parts by weight of the fat and oil. Alternatively, stirring is performed in the presence of an inert gas. If the amount of phosphoric acid added is less than 0.1 parts by weight, the component that should react with phosphoric acid is not sufficiently denatured, and as a result, lipid peroxide may not be completely removed. In addition, phosphoric acid may be added in an excess amount of more than 3 parts by weight, but it becomes an obstacle to the decoloring step by the next activated carbon treatment, and therefore it may be necessary to remove phosphoric acid, which also requires extra cost. .

  Fats and oils seem to be almost instantaneously modified by the addition of phosphoric acid after deoxidation. In particular, fish oil has a large amount of denatured material and is colored dark brown almost instantaneously. In the case of fats and oils containing a highly unsaturated fatty acid having 3 or more double bonds in the fatty acid residue, such as fish oil, phosphoric acid treatment is performed for 10 to 30 minutes until the progress of coloring is not observed. In the case of other fats and oils, the phosphoric acid treatment for 10 to 30 minutes is sufficient.

  If the stirring is stopped after completion of the reaction, phosphoric acid has a large specific gravity, so it is promptly separated into the lower layer. At this time, pressurizing with an inert gas and extracting phosphoric acid from the bottom of the apparatus is advantageous in terms of cost because the efficiency of the activated carbon treatment can be increased. The phosphoric acid used in the present invention is not particularly limited, but may be 75% phosphoric acid used for food additives.

<Activated carbon treatment (degumming, decolorization)>
After completion of the phosphoric acid treatment, a predetermined activated carbon is added and then stirred for 20 to 60 minutes under vacuum. Decolorization is complete when there is no bubbling from the liquid surface. Thereafter, the activated carbon is removed by filtration or pressing in the same manner as in the normal decolorization step. In the case of fats and oils containing a highly unsaturated fatty acid having 3 or more double bonds such as fish oil, it is desirable to filter after cooling to 60 ° C. or lower in order to prevent oxidation.

  The type of activated carbon used for the activated carbon treatment is not particularly limited, and the addition amount is 0.1% by weight or more and 5% by weight or less, preferably 0.5% by weight or more, based on 100% by weight of the fat before adding phosphoric acid, And 5% by weight or less. If the amount of activated carbon added is less than 0.1% by weight, removal of lipid peroxide, which is a coloring component, may be insufficient. This is because if the added amount of activated carbon exceeds 5% by weight, the yield of refined fats and oils decreases, and the volume of the activated carbon becomes very large, resulting in poor workability. Further, the activated carbon may be combined with an adsorbent such as activated clay, silica gel, or diatomaceous earth.

<Addition of tea extract and tocopherol>
Next, before subjecting fats and oils to deodorization, a tea extract is added. Preferably, in order to further improve the oxidative stability, tocopherol is further added. In the addition of tea extract or tocopherol, there is no particular limitation on the addition method such as the order of addition. The type of tea extract in the present invention is not particularly limited, but tea leaves such as green tea, oolong tea, and black tea, or extracts of processed products thereof are preferable, and those extracted with ethanol or water are preferably used. . In addition, since polyphenols may be colored by oxidation or polymerization during deodorization, among these tea extracts, the Robibond color value when 0.1 part by weight is dissolved with respect to 100 parts by weight of water is It is preferable to use a tea extract having a yellow color of 2.5 or less and a red color of 1.4 or less. Although it does not specifically limit, For example, Taiyo Kagaku Co., Ltd. sun phenon BG etc. are mentioned. If the Robibond color value is not within the above range, the edible fat after purification may be colored from the tea extract. The tea extract only needs to be in a state of being dispersed in oil when added, and is not particularly limited. For example, a tea extract which is added to a solvent together with an emulsifier and stirred and dissolved is preferably used. The amount of tea extract added is preferably 0.005 to 0.5 parts by weight per 100 parts by weight of edible fats and oils. If it is 0.005 parts by weight or less, the antioxidant effect and the return odor suppressing effect may not be obtained, and if it exceeds 0.5 parts by weight, turbidity due to the tea extraction part may occur.

  The solvent used in the present invention is for dissolving and dispersing the tea extract in oil, and is not particularly limited, and for example, ethanol, medium chain fatty acid ester and the like are used. The amount of these solvents used is preferably 10 to 100 parts by weight with respect to 100 parts by weight of the tea extract. If the amount is less than 10 parts by weight, the tea extract may not be sufficiently dispersed. If the amount exceeds 100 parts by weight, the volatile components may increase during deodorization and a sufficient deodorizing effect may not be obtained.

  The emulsifier used in the present invention is for dissolving and dispersing the tea extract in oil and is not particularly limited, and examples thereof include glycerin fatty acid ester, propylene glycol fatty acid ester, sucrose fatty acid ester, lecithin and the like. These emulsifiers are preferably used in an amount of 0.01 to 100 parts by weight with respect to 100 parts by weight of tea extract. If the amount is 0.01 parts by weight or less, the tea extract may be deposited without being diffused into the oil or fat, and if it exceeds 100 parts by weight, the flavor of the oil or fat may be deteriorated by the emulsifier.

  The type of tocopherol in the present invention is not particularly limited, and specific examples include E oil 400 and E oil 600 manufactured by Riken Vitamin Co., Ltd. As for the addition amount of tocopherol, 0.01-1.0 weight part is preferable with respect to 100 weight part of edible fats and oils. If it is 0.01 parts by weight or less, the antioxidant effect may not be obtained, and if it exceeds 1.0 parts by weight, tocopherol may become an initiator and conversely promote the oxidation of fats and oils. Further, the tea extract and tocopherol are more effective when used in combination than when used alone.

<Deodorization>
Thereafter, the operation is preferably performed at a deodorization temperature of 160 ° C. or more and 260 ° C. or less while blowing water vapor under a reduced pressure of 10 ⁻³ MPa or less according to a known method. If the temperature exceeds 260 ° C., the oil and fat may be decomposed, which is disadvantageous in terms of cost. Moreover, in the case of fats and oils containing highly unsaturated fatty acids having 3 or more double bonds in fatty acid residues, such as fish oil, it is preferable to operate at a deodorizing temperature of 180 ° C. or higher and 240 ° C. or lower. When the temperature is lower than 180 ° C., the removal of odor components and free fatty acids may be insufficient, and when the temperature exceeds 240 ° C., polymerization of highly unsaturated fatty acids may occur easily. Other deodorizing conditions are not particularly limited. The refined oil thus obtained has a POV immediately after production of 0 to 0.2 meq / kg.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In the examples, “parts” and “%” are based on weight.

<Lobibond color measurement method>
A sample was placed up to 12.9 cm in a glass cell having an outer diameter of 2.1 cm, an inner diameter of 1.7 cm, and a height of 17.1 cm, and was measured by visual comparison with a standard color. In the case of measuring fats and oils, the sample was used as it was, and when water was measured, a sample in which 0.1% by weight of tea extract was dissolved in distilled water was used.

<POV measurement method for fats and oils immediately after deodorization>
Within 10 minutes after the completion of the deodorization step, 10 g of a fat sample is precisely weighed into a 200 ml stoppered flask, dissolved by adding 50 ml of an acidic solvent in which isooctane and acetic acid are mixed at 2: 3 (v / v), and then saturated iodinated. Add 0.1 ml of potassium solution and stir for 1 minute under a nitrogen seal. After 5 minutes, 30 ml of water was added and stirred vigorously, followed by titration with 0.01N sodium thiosulfate solution using the starch solution as an indicator.

<POV measurement method for fats and oils after standing at 30 ° C. for 7 days>
As an oil and fat sample, 50 g of oil and fat within 10 minutes after the completion of the deodorization step is precisely weighed in a 100 ml stoppered stoppered flask and left to stand for 7 days in a thermostatic chamber set at 30 ° C. after being covered with the stopper. The POV was measured by the same method as the above “Method for measuring the POV of fats and oils immediately after deodorization”.

Example 1
According to Table 1, 100 parts by weight of highly unsaturated fatty acid-containing fat (tuna oil, POV≈8.3) containing 21.0% by weight of docosahexaenoic acid and 6.5% by weight of eicosapentaenoic acid at 90 ° C. under vacuum. 1 part by weight of phosphoric acid (Wako Pure Chemical Industries, Ltd., 75% for food addition) was added and stirred for 30 minutes. Stirring was performed at about 260 rpm. After stirring, 2 parts by weight of activated carbon (Dazai activated carbon S) and 2 parts by weight of white clay (Galeon Earth manufactured by Mizusawa Chemical Co., Ltd.) were added and stirred for 30 minutes, followed by filtration to remove the activated carbon and white clay. Tocopherol (RIKEN E Oil 400, tocopherol content 39% by weight) and tea extract (Sankator made by Taiyo Chemical, tea extract content 10% by weight, containing emulsifier and solvent) 0.2 parts by weight Was added for deodorization (210 ° C., 1 hour). Immediately after deodorization and after standing at 30 ° C. for 7 days, the POV and lobibond color of the refined fats and oils were evaluated, and the results are summarized in Table 2.

(Example 2)
According to Table 1, 1 part by weight at 90 ° C. under vacuum with respect to highly unsaturated fatty acid-containing fat (tuna oil, POV≈8.3) containing 21.0% by weight of docosahexaenoic acid and 6.5% by weight of eicosapentaenoic acid Of phosphoric acid (Wako Pure Chemical Industries, Ltd., 75% for food addition) was added and stirred for 30 minutes. Stirring was performed at about 260 rpm. After stirring, 2 parts by weight of activated carbon (Dazai activated carbon S) and 2 parts by weight of white clay (Galeon Earth manufactured by Mizusawa Chemical Co., Ltd.) were added and stirred for 30 minutes, followed by filtration to remove the activated carbon and white clay. In this oil and fat, 0.02 parts by weight of tea extract (Sunphenon BG manufactured by Taiyo Kagaku) was dissolved in 0.1 parts by weight of ethanol and 0.1 part by weight of MCT, and 0.02 parts by weight of an emulsifier (Poem J-0381) was added. Further, 0.3 parts by weight of tocopherol (RIKEN E Oil 400, tocopherol content of about 39% by weight) was added and deodorized (210 ° C., 1 hour). Immediately after deodorization and after standing at 30 ° C. for 7 days, the POV and lobibond color of the refined fats and oils were evaluated, and the results are summarized in Table 1.

(Comparative Example 1)
According to Table 1, 1 part by weight at 90 ° C. under vacuum with respect to highly unsaturated fatty acid-containing fat (tuna oil, POV≈8.3) containing 21.0% by weight of docosahexaenoic acid and 6.5% by weight of eicosapentaenoic acid Of phosphoric acid (Wako Pure Chemical Industries, Ltd., 75% for food addition) was added and stirred for 30 minutes. Stirring was performed at about 260 rpm. After stirring, 2 parts by weight of activated carbon (Dazai activated carbon S) and 2 parts by weight of white clay (Galeon Earth manufactured by Mizusawa Chemical Co., Ltd.) were added and stirred for 30 minutes, followed by filtration to remove the activated carbon and white clay. This fat was deodorized at 210 ° C. for 1 hour. After deodorization, 0.3 part by weight of tocopherol (RIKEN E Oil 400, tocopherol content: about 39% by weight) and 0.2 part by weight of tea extract (Sankator made by Taiyo Kagaku, tea extract content: 10% by weight) were added. Immediately after deodorization and after standing at 30 ° C. for 7 days, the POV and lobibond color of the refined fats and oils were evaluated, and the results are summarized in Table 1.

(Comparative Example 2)
According to Table 1, a highly unsaturated fatty acid-containing fat / oil (tuna oil, POV≈8.3) containing 21.0% by weight of docosahexaenoic acid and 6.5% by weight of eicosapentaenoic acid was activated at 90 ° C. under vacuum (Taiko) 2 parts by weight of activated carbon S) and 2 parts by weight of white clay (Galeon Earth manufactured by Mizusawa Chemical Co., Ltd.) were added and stirred for 30 minutes (stirring was performed at about 260 rpm), followed by filtration to remove the activated carbon and white clay. This fat was deodorized at 210 ° C. for 1 hour. Within 10 minutes after deodorization, 0.3 parts by weight of tocopherol (RIKEN E Oil 400, tocopherol content: about 39% by weight) and 0.2 parts by weight of tea extract (Taiyo Chemical Sankator, tea extract content: 10% by weight) are added. did. Immediately after deodorization and after standing at 30 ° C. for 7 days, the POV and lobibond color of the refined fats and oils were evaluated, and the results are summarized in Table 1.

  As shown in Table 1, in Example 1, phosphoric acid treatment was performed after deoxidation, and by adding tea extract and tocopherol before deodorization, the degree of increase in POV was low and the return odor was small, so the flavor was also good. is there. Moreover, in Example 2, it is colored rather than Example 1 by using the tea extract whose Lobibond color value when dissolved 0.1% by weight in water is yellow 2.5 or less and red 1.4 or less. Is reduced, and since the return odor is small, the flavor is also good.

Claims (2)

A method for purifying edible fats and oils containing 10% by weight or more of highly unsaturated fatty acids, characterized in that the fats and oils are subjected to phosphoric acid treatment after deoxidation treatment, then activated carbon treatment , and further deodorization treatment, which comprises 100% by weight of fats and oils. Tea extract having a Robibond color value of 2.5 or less yellow and 1.4 or less red when dissolved by 0.1 part by weight with respect to 100 parts by weight of water the parts with the emulsifier, those dissolved in a solvent, after the activated carbon treatment, was added before deodorization treatment, 160 ° C. or higher, 10% or more by weight of polyunsaturated fatty acids, characterized in that the deodorization at 260 ° C. or less A method for refining edible fats and oils. The method for purifying edible fats and oils containing 10% by weight or more of highly unsaturated fatty acid according to claim 1 , wherein 0.01 to 1.0 part by weight of tocopherol is further added before deodorization.