JP6600227B2 - Method for producing fractionated fish oil - Google Patents

Description

  The present invention relates to a method for producing fractionated fish oil and a method for fractionating fish oil.

  Naturally produced fats and oils have a unique fatty acid composition, and the positions of binding of fatty acids to glycerin in triacylglycerol are determined by specific regularity. For example, it is known that ω3 polyunsaturated fatty acids that are abundant in fish oil are distributed in the second position of glycerol. In human breast milk, palmitic acid is mostly distributed at the 2nd position of glycerol, and unsaturated fatty acids and medium chain fatty acids are mainly distributed at the 1st and 3rd positions.

On the other hand, various so-called structured lipids in which a specific fatty acid is incorporated at a specific position of glycerin have been proposed for the purpose of nutritional improvement, physical property improvement, or substitution. For example, an oil having a large amount of n-3 long-chain polyunsaturated fatty acids at the 1-position and / or 3-position of the glyceride structure, and less than 40 mol% of the total amount of n-3 long-chain polyunsaturated fatty acids Is a fat or oil comprising triglyceride bonded to the 2nd position of glyceride (Patent Document 1), palmitic acid at the sn-2 position, oleic acid or docosahexaenoic acid at the sn-1,3 position (C22) : 6, DHA), breast milk substitute fat (Non-patent Document 1) and the like have been reported.
According to the above-mentioned patent documents and the like, ω3 polyunsaturated fatty acid is more advantageous for expression of physiological functions in the human body when the binding rate to the 1st and 3rd positions is higher than the 2nd position of triacylglycerol, Triacylglycerol having palmitic acid at position 2 is also useful as a human breast milk substitute fat.

JP-A-9-13075 Japanese Patent Laid-Open No. 2002-180083

J Am Oil Chem Soc, 2013, 90, p. 1311-1318 JAOCS, 1998, Vol. 75, No. 6, p. 733-736

However, in Patent Document 1 and Non-Patent Document 1, fats and oils are produced by converting the sn-1,3-position fatty acid to the target fatty acid by transesterification or acidolysis using a 1,3-position specific lipase. For this reason, the cost becomes high.
On the other hand, as disclosed in Patent Document 2 and Non-Patent Document 2, a method of separating fish oil and concentrating ω3 highly unsaturated fatty acid contained in fish oil is known. It is not intended to concentrate unsaturated fatty acids.
In view of such circumstances, the present invention provides a new method for producing triacylglycerol in which a large amount of ω3 highly unsaturated fatty acid having a large amount of palmitic acid bonded to the 2-position of glycerol and bonded to the 1- and 3-positions. It is something to be offered.

  The inventors of the present invention have intensively studied in view of the above problems, and are capable of fractionating high melting point glycerides by performing solvent fractionation in two stages under predetermined conditions, and are fats and oils that melt near human body temperature. Thus, it has been found that oils rich in triacylglycerol in which a large amount of palmitic acid is bonded to the 2-position of glycerol and many of the ω3 polyunsaturated fatty acids are bonded to the 1,3-positions can be recovered in a high yield.

That is, the present invention includes the following steps (1), (2) and (3):
(1) A step of dissolving fish oil in an organic solvent and then cooling it,
(2) The step of separating the solid part deposited in step (1) from the liquid part to obtain the liquid part,
(3) The step of obtaining the precipitated solid part after dissolving the liquid part obtained in step (2) in the organic solvent again and then cooling to a temperature lower than the cooling temperature in step (1).
The manufacturing method of the fractionated fish oil containing is provided.
The present invention also includes the following steps (1), (2) and (3):
(1) A step of dissolving fish oil in an organic solvent and then cooling it,
(2) The step of separating the solid part deposited in step (1) from the liquid part to obtain the liquid part,
(3) The step of separating the liquid part obtained by dissolving the liquid part obtained in the step (2) again in an organic solvent and then cooling to a temperature lower than the cooling temperature in the step (1),
And a method for fractionating fish oil.

  According to the present invention, a fractionated fish oil rich in triacylglycerol, in which a large amount of palmitic acid is bonded to the 2-position of glycerol and the ratio of ω3 polyunsaturated fatty acids bonded to the 1- and 3-positions, is easily obtained. Since this fractionated fish oil is similar to the triacylglycerol structure in human breast milk and melts near human body temperature, it is also useful as a human breast milk substitute fat.

In the method for producing fractionated fish oil according to the present invention, (1) a step of dissolving fish oil in an organic solvent and then cooling, and (2) separating the solid portion precipitated in step (1) from the liquid portion to obtain a liquid portion. A step of (3) dissolving the liquid part obtained in step (2) in an organic solvent again, and then cooling to a temperature lower than the cooling temperature in step (1) to obtain a precipitated solid part. Have.
In the method for fractionating fish oil of the present invention, (1) a step of dissolving fish oil in an organic solvent and then cooling, and (2) separating the solid portion deposited in step (1) from the liquid portion, And (3) the liquid part obtained in step (2) is dissolved again in an organic solvent, and then cooled to a temperature lower than the cooling temperature in step (1), and then the precipitated solid part and liquid part are Separating.
In this specification, “oil” and “oil / fat” are synonymous, and substances constituting the oil (oil / fat) include not only triacylglycerol but also monoacylglycerol and diacylglycerol. That is, in the present invention, the oil (oil / fat) contains at least one of monoacylglycerol, diacylglycerol, and triacylglycerol.

The fish oil to be used in the method of the present invention is a marine animal fat, and can be collected from raw materials such as herring, saury, mackerel, bonito, tuna, sardine, squid and cod liver.
The fish oil used in the method of the present invention may be so-called crude fish oil (crude oil) obtained by squeezing from a fish body or the like as a raw material, and 1 of the refining treatment performed on the crude fish oil. Or the fats and oils which performed the 2 or more process may be sufficient.
As a purification treatment performed on fats and oils, water is added to fats and oils, and in some cases, an acid is further added and mixed to remove gums such as phospholipids and proteins; Alkaline deoxidation treatment to remove free fatty acids; Water washing treatment that makes oil contact with water and oil-water separation; Decolorization treatment that removes colored components by bringing oil and fat into contact with an adsorbent such as activated clay or activated carbon . In addition, a distillation process that removes light by-products such as fatty acids and environmental pollutants by distilling fats and oils without using alkali, and a dewaxing process that separates solids from fats and oils at low temperatures. Etc.

The fish oil subjected to the method of the present invention contains triacylglycerol.
In the fish oil, the content of triacylglycerol is preferably 78% by mass or more, and from the viewpoint of suppressing deterioration of the fish oil, it is further 78 to 100% by mass, further 88 to 100% by mass, and further 90 to 99.5% by mass. %, More preferably 92 to 99% by mass.
The fish oil may contain diacylglycerol, and the content of diacylglycerol in the fish oil is preferably 0 to 19% by mass, more preferably 0 to 9% by mass, further 0.1 to 7% by mass, and further 0 It is preferable that it is 2-5 mass%.
The content of monoacylglycerol in fish oil is preferably 0 to 10% by mass, more preferably 0 to 5% by mass, and further preferably 0 to 3% by mass.

The content of the ω3 polyunsaturated fatty acid in the fatty acid constituting the fish oil to be subjected to the method of the present invention is 20% by mass or more, and further 25% by mass or more from the viewpoint that the effect of the present invention is effectively exhibited. Is preferred. As the ω3 highly unsaturated fatty acid, eicosapentaenoic acid (C20: 5, EPA) and docosahexaenoic acid (C22: 6, DHA) are preferable.
Further, the content of docosahexaenoic acid in the fatty acid constituting the fish oil is preferably 19% by mass or more, more preferably 22% by mass or more, and further preferably 25% by mass or more from the viewpoint that the effect of the present invention is effectively exhibited. .
Moreover, it is preferable that content of the palmitic acid in the fatty acid which comprises fish oil is 10 mass% or more from the same point, Furthermore, 13 mass% or more, Furthermore, it is 16 mass% or more.
In addition, the fatty acid amount in this specification is a free fatty acid equivalent amount.

  The remaining fatty acid constituting the fish oil is not particularly limited, and may be either a saturated fatty acid or an unsaturated fatty acid. The saturated fatty acid or unsaturated fatty acid preferably has 12 to 24, more preferably 14 to 24 carbon atoms.

[Step (1)]
In this step, fish oil is dissolved in an organic solvent and then cooled.
The organic solvent used in the present invention may be any solvent that can dissolve fish oil, and examples thereof include methanol, hexane, acetone, and methyl ethyl ketone. These may be used in combination. Of these, hexane and acetone are preferable and acetone is more preferable from the viewpoint of easily separating the precipitated high melting point component.
The amount of the organic solvent used is preferably 10 parts by mass or more, more preferably 30 to 1000 parts by mass, and further preferably 50 to 500 parts by mass with respect to 100 parts by mass of fish oil from the viewpoint of industrial productivity.

  The temperature at which the fish oil is dissolved in the organic solvent is preferably 20 ° C. or higher, more preferably 30 ° C. to 70 ° C., from the viewpoint of sufficiently dissolving the high melting point component to be precipitated later.

  The cooling temperature in the step (1) is a temperature at which the transparent oil phase starts to become cloudy, that is, a temperature at which a high melting point component in the fish oil crystallizes and precipitates, and a suitable range can be set depending on the type of the organic solvent and the like. Among them, the high melting point component precipitated as crystals can be easily separated, and the melting point of the second-stage fractionated solid part is set to 25 to 42 ° C. When acetone is used as a solvent, 15 ° C to 0 ° C is preferable. When hexane is used as a solvent, 5 ° C to -5 ° C is preferable.

  The cooling time is preferably 0.1 hours or more, more preferably 0.2 to 200 hours, and further preferably 0.5 to 100 hours from the viewpoint of sufficiently depositing crystals to be precipitated at the cooling temperature. In addition, the time here means the sum total of the time when fish oil exists in a cooling temperature range.

  The cooling rate up to the cooling temperature range of fish oil is preferably 10 ° C./h or less from the viewpoint of facilitating separation of the precipitated high melting point component and improving productivity, and from the viewpoint of industrial productivity, 0.1 C / h or more is preferable.

The cooling operation can be performed by jacket cooling, a heat exchanger, or the like.
The cooling operation may be performed under standing or under stirring. From the viewpoint of maintaining good dispersion of the precipitated crystals, it is preferably carried out under stirring. The degree of stirring varies depending on the apparatus, but it is preferable to select conditions that can suppress the crushing of the precipitated crystals.

[Step (2)]
This step is a step of separating the solid portion deposited in step (1) from the liquid portion to obtain the liquid portion.
Separation of the solid part from the liquid part can be performed, for example, by a method such as stationary separation, filtration, and centrifugation. Especially, filtration is preferable from the point of operativity.
The solid part separated from the liquid part is preferably washed with the organic solvent. The organic solvent used for washing is preferably 10% by mass or more, more preferably 20 to 200% by mass, and further preferably 30 to 100% by mass with respect to the deposited high melting point component.
The temperature at the time of solid-liquid separation and the temperature of the organic solvent used for washing are preferably the same as those at the time of cooling fish oil.

Examples of the high melting point component removed by fractionation as a solid part in the step (2) include triacylglycerol to which palmitic acid is bonded in an amount of 40% by mass or more, and further 44% by mass or more. The melting point of the high melting point component is preferably 40 ° C. or higher, more preferably 45 ° C. or higher.
The high melting point component varies depending on the concentration of the high melting point component contained in the fish oil, but is 0.2 to 6% by mass, further 0.4 to 4% by mass, and further 0.6 to 3% by mass with respect to the fish oil. Is preferable from the viewpoint of production efficiency.

[Step (3)]
In this step, the liquid part obtained in step (2) is dissolved again in an organic solvent, and then cooled to a temperature lower than the cooling temperature in step (1). Then, in the method for producing fractionated fish oil, the precipitated solid part is In the method for separating fish oil, the solid portion and the liquid portion that are precipitated are separated.
As described above, the organic solvent is preferably hexane or acetone, more preferably acetone.
The amount of the organic solvent used in the step (3) is preferably 10 parts by mass or more with respect to 100 parts by mass of the liquid part obtained in the step (2) from the viewpoint of industrial productivity, and further 30 to 1000 parts by mass, 50-500 mass parts is preferable.

  The temperature at which the liquid part is dissolved in the organic solvent is preferably 10 ° C. or higher, and more preferably 20 to 70 ° C. as described above.

The cooling temperature in the step (3) is lower than the cooling temperature in the step (1). By performing the second-stage fractionation at a temperature lower than that of the first-stage fractionation, there is an advantage that a fractionated fish oil in which desired amounts of palmitic acid, eicosapentaenoic acid and docosahexaenoic acid are bound as the second-stage fractionated solid part can be obtained. . The cooling temperature is a temperature that is 3 ° C. or more lower than the cooling temperature in the step (1) in that the precipitated high melting point component can be easily separated and the melting point of the second-stage fractionated solid part is 25 to 42 ° C. It is preferable that the temperature is lower by 5 ° C to 30 ° C, more preferably 7 ° C to 25 ° C.
The cooling temperature in the step (3) is within the temperature range of 0 ° C. to −15 ° C. when acetone is used as a solvent and −5 ° C. to −20 ° C. when hexane is used as a solvent. Is preferred.

  The cooling time is preferably 0.1 hours or more, more preferably 0.2 to 200 hours, and further preferably 0.5 to 100 hours from the viewpoint of sufficiently depositing crystals to be precipitated at the cooling temperature. In addition, time here means the sum total of the time when the liquid part obtained at the process (2) exists in the cooling temperature range.

  The cooling rate up to the cooling temperature range of the liquid part is preferably 10 ° C./h or less from the viewpoint of easy separation of the deposited high melting point component and from the viewpoint of productivity improvement, and from the viewpoint of industrial productivity, from the point of view of industrial productivity. 1 ° C./h or more is preferable.

The cooling operation can be performed by jacket cooling, a heat exchanger or the like as described above.
In addition, the cooling operation may be performed under standing or under stirring, but it is preferable to perform under cooling from the viewpoint of maintaining good dispersion of the precipitated crystals. The degree of stirring varies depending on the apparatus, but it is preferable to select conditions that can suppress the crushing of the precipitated crystals.

Solid-liquid separation can be performed by methods such as stationary separation, filtration, and centrifugation, for example. Among these, filtration is preferable from the viewpoint of operability and easy cleaning of the crystal part.
Moreover, it is preferable to wash | clean the depositing solid part with the organic solvent similarly to the above.
The temperature at the time of solid-liquid separation and the temperature of the organic solvent used for washing are preferably the same as the cooling temperature of the liquid part obtained in step (2).

Thus, fractionated fish oil is obtained as a solid part. The recovery rate (yield) of the liquid part obtained in the step (2) with respect to fish oil is preferably 0.2 to 6% by mass, more preferably 0.4 to 5% by mass, and further preferably 0.6 to 4% by mass.
On the other hand, the solid part separated by solid-liquid separation in the step (3) and the separated liquid part can be used as fish oil containing ω3 highly unsaturated fatty acid. Therefore, according to the method of the present invention, the ω3 polyunsaturated fatty acid contained in fish oil can be effectively used without loss.

  Further, the recovery rate (yield) of the fractionated fish oil to the fish oil used in the method of the present invention depends on the concentrations of palmitic acid, eicosapentaenoic acid and docosahexaenoic acid in the fish oil, but is 1 to 12% by mass, and further 2 to 9% by mass. %, More preferably 3 to 7% by mass.

The fractionated fish oil obtained by the production method of the present invention is rich in triacylglycerol in which a large amount of palmitic acid is bonded to the 2nd position of glycerol and the ratio of ω3 highly unsaturated fatty acids bonded to the 1st and 3rd positions is high.
In the total mass of fatty acids bonded to the 2-position of triacylglycerol, the content of palmitic acid is preferably 30% by mass or more, more preferably 40% by mass or more, and further preferably 45% by mass or more.
Also, the ratio of the ω3 highly unsaturated fatty acid bonded to the 1,3-position to the total mass of the ω3 highly unsaturated fatty acid (eicosapentaenoic acid + docosahexaenoic acid) bonded to the triacylglycerol (1,3-position EPA + DHA content) ) Is preferably 60% by mass or more, and more preferably 65 to 95% by mass.

The ratio of docosahexaenoic acid bonded to the 1,3-position (content of 1,3-position DHA) to the total mass of docosahexaenoic acid bonded to triacylglycerol is 55% by mass or more, and further 60 to 95% by mass. It is preferable.
In addition, the ratio of the eicosapentaenoic acid bonded to the 1,3-position to the total mass of the eicosapentaenoic acid bonded to the triacylglycerol (1,3-position EPA content) is 65% by mass or more, and further 70 to 95% by mass. It is preferable that
The fatty acid composition at the 1st and 3rd positions of triacylglycerol can be determined by analyzing the composition of all fatty acids constituting the triacylglycerol and the composition of fatty acids bound to the 2nd position of triacylglycerol. . Details are described in Examples below.

  The content of docosahexaenoic acid in the fatty acid constituting the fractionated fish oil is preferably 5% by mass or more, further 7 to 17% by mass, and further 9 to 14% by mass from the point of melting point of the fractionated fish oil. Moreover, it is preferable that content of eicosapentaenoic acid in the fatty acid which comprises fractionated fish oil is 1 mass% or more, 1.5-5 mass%, and also 2-4 mass% from the same point.

  The content of triacylglycerol in the fractionated fish oil is preferably 90% by mass or more and more preferably 94% by mass or more from the viewpoint of industrial productivity of fats and oils and suppression of deterioration of fats and oils.

  The acid value (AV) of the fractionated fish oil is preferably 10 mgKOH / g or less, more preferably 5 mgKOH / g or less, from the viewpoint of suppressing the deterioration of fats and oils.

  The fractionated fish oil obtained by the production method of the present invention melts near the human body temperature. That is, the melting point of the fractionated fish oil is less than 42 ° C, preferably 25 to 41 ° C, more preferably 27 to 40 ° C.

  The fractionated fish oil obtained by the production method and the fractionation method of the present invention can be used in the same manner as general edible fats and oils, and can be widely applied to various foods and drinks using fats and oils. Among them, it is useful as a human breast milk substitute fat.

  Embodiments and preferred embodiments of the present invention will be exemplified below.

<1> Next steps (1), (2) and (3):
(1) A step of dissolving fish oil in an organic solvent and then cooling it,
(2) The step of separating the solid part deposited in step (1) from the liquid part to obtain the liquid part,
(3) The step of obtaining the precipitated solid part after dissolving the liquid part obtained in step (2) in the organic solvent again and then cooling to a temperature lower than the cooling temperature in step (1).
A method for producing fractionated fish oil, comprising:

<2> Next steps (1), (2) and (3):
(1) A step of dissolving fish oil in an organic solvent and then cooling it,
(2) The step of separating the solid part deposited in step (1) from the liquid part to obtain the liquid part,
(3) The step of separating the liquid part obtained by dissolving the liquid part obtained in the step (2) again in an organic solvent and then cooling to a temperature lower than the cooling temperature in the step (1),
A method for separating fish oil, including
<3> Fish oil preferably contains triacylglycerol in an amount of 78% by mass or more, more preferably 88% by mass or more, still more preferably 90% by mass or more, still more preferably 92% by mass or more, and preferably 100% by mass. Or less, more preferably 99.5% by mass or less, still more preferably 99% by mass or less, preferably 78 to 100% by mass, more preferably 88 to 100% by mass, still more preferably 90 to 99.5% by mass. %, More preferably 92 to 99% by mass, The method according to <1> or <2>.
<4> Fish oil preferably contains diacylglycerol in an amount of 0 to 19% by mass, more preferably 0 to 9% by mass, still more preferably 0.1 to 7% by mass, and still more preferably 0.2 to 5% by mass < The method according to any one of 1> to <3>.
<5> The fish oil preferably contains 0 to 10% by mass, more preferably 0 to 5% by mass, and further preferably 0 to 3% by mass of monoacylglycerol, according to any one of <1> to <4>. the method of.
<6> The fish oil according to any one of <1> to <5>, wherein the fatty acid constituting the fish oil preferably contains ω3 highly unsaturated fatty acid in an amount of 20% by mass or more, more preferably 25% by mass or more. Method.
<7> Any of <1> to <6>, wherein the fish oil contains docosahexaenoic acid in the fatty acid constituting the fish oil, preferably 19% by mass or more, more preferably 22% by mass or more, and even more preferably 25% by mass or more. The method according to 1.
<8> Any of <1> to <7>, wherein the fish oil contains palmitic acid in the fatty acid constituting the fish oil, preferably 10% by mass or more, more preferably 13% by mass or more, and still more preferably 16% by mass or more. The method according to 1.
<9> The organic solvent is preferably a solvent in which fish oil dissolves, more preferably one or more selected from methanol, hexane, acetone and methyl ethyl ketone, and even more preferably hexane, acetone or a combination thereof. The method according to any one of <1> to <8>, which is more preferably acetone.
<10> The amount of the organic solvent used in step (1) is preferably 10 parts by mass or more, more preferably 30 to 1000 parts by mass, and even more preferably 50 to 500 parts by mass with respect to 100 parts by mass of fish oil. The method according to any one of 1> to <9>.
<11> The method according to any one of <1> to <10>, wherein the temperature at which the fish oil is dissolved in the organic solvent is preferably 20 ° C. or higher, more preferably 30 ° C. to 70 ° C. .
<12> The cooling temperature in step (1) is preferably 15 ° C. to 0 ° C. when acetone is used as the solvent, and preferably 5 ° C. to −5 ° C. when hexane is used as the solvent. The method according to any one of> to <11>.
<13> Any of <1> to <12>, wherein the cooling time in step (1) is preferably 0.1 hour or more, more preferably 0.2 to 200 hours, and still more preferably 0.5 to 100 hours. The method according to claim 1.
<14> Any one of <1> to <13>, wherein the cooling rate until the fish oil reaches the cooling temperature range is preferably 10 ° C./h or less, and preferably 0.1 ° C./h or more. The method described in 1.
<15> In step (2), the high melting point component removed by fractionation as a solid part is preferably triacylglycerol to which palmitic acid is bonded in an amount of 40% by mass or more, more preferably 44% by mass or more. The method according to any one of <14>.
<16> The method according to <15>, wherein the melting point of the high melting point component is preferably 40 ° C. or higher, more preferably 45 ° C. or higher.
<17> In the step (2), the high melting point component removed by fractionation as a solid part is preferably 0.2 to 6% by mass, more preferably 0.4 to 4% by mass, and still more preferably based on fish oil. Is a method according to any one of <1> to <16>, wherein 0.6 to 3% by mass is removed.
<18> The cooling temperature in the step (3) is preferably a temperature 3 ° C. or more lower than the cooling temperature in the step (1), more preferably a temperature lower by 5 ° C. to 30 ° C., more preferably 7 ° C. to The method according to any one of <1> to <17>, which is a temperature lower by 25 ° C.
<19> The cooling temperature in step (3) is preferably 0 ° C. to −15 ° C. when acetone is used as the solvent, and preferably −5 ° C. to −20 ° C. when hexane is used as the solvent. The method according to any one of <1> to <18>.
<20> The amount of the organic solvent used in the step (3) is preferably 10 parts by mass or more, more preferably 30 to 1000 parts by mass, and still more preferably 50 with respect to 100 parts by mass of the liquid part obtained in the step (2). The method of any one of <1>-<19> which is -500 mass parts.
<21> The method according to any one of <1> to <20>, wherein the temperature at which the liquid part is dissolved in the organic solvent in the step (3) is preferably 10 ° C or higher, more preferably 20 to 70 ° C. . <22> Any of <1> to <21>, wherein the cooling time in step (3) is preferably 0.1 hour or more, more preferably 0.2 to 200 hours, and still more preferably 0.5 to 100 hours. The method according to claim 1.
<23> Any one of <1> to <22>, wherein the cooling rate until reaching the cooling temperature range of the liquid part is preferably 10 ° C./h or less, and preferably 0.1 ° C./h or more. The method according to 1.
The recovery rate (yield) of the liquid part obtained in <24> step (2) with respect to fish oil is preferably 0.2 to 6% by mass, more preferably 0.4 to 5% by mass, and still more preferably 0.6 to The method according to any one of <1> to <23>, which is 4% by mass.
The recovery rate (yield) of <25> fractionated fish oil to the fish oil used in step (1) is preferably 1 to 12% by mass, more preferably 2 to 9% by mass, and even more preferably 3 to 7% by mass < The method according to any one of 1> to <24>.
<26> The fractionated fish oil contains palmitic acid in the total mass of the fatty acid bonded to the 2-position of triacylglycerol, preferably 30% by mass or more, more preferably 40% by mass or more, and still more preferably 45% by mass or more, and The ratio of the ω3 highly unsaturated fatty acid bonded to the 1,3-position to the total mass of the ω3 highly unsaturated fatty acid bonded to triacylglycerol is preferably 60% by mass or more, more preferably 65 to 95% by mass The method according to any one of <1> to <25>.
<27> The proportion of docosahexaenoic acid bonded to the 1,3-position to the total mass of docosahexaenoic acid bonded to triacylglycerol in the fractionated fish oil (1,3-position DHA content) is preferably 55% by mass or more, more preferably <60> is a method according to any one of <1> to <26>, which is 60 to 95% by mass.
<28> The ratio of eicosapentaenoic acid bonded to the 1,3-position to the total mass of eicosapentaenoic acid bonded to triacylglycerol is preferably 65% by mass or more. The method according to any one of <1> to <27>, more preferably 70 to 95% by mass. <29> The fractionated fish oil contains docosahexaenoic acid in the fatty acid constituting the fractionated fish oil, preferably 5% by mass or more, more preferably 7 to 17% by mass, and even more preferably 9 to 14% by mass. <1> to <28 The method of any one of>.
<30> The fractionated fish oil contains eicosapentaenoic acid in the fatty acid constituting the fractionated fish oil, preferably 1% by mass or more, more preferably 1.5 to 5% by mass, and even more preferably 2 to 4% by mass <1>. ~ The method according to any one of <29>.
<31> The method according to any one of <1> to <30>, wherein the fractionated fish oil preferably contains 90% by mass or more, more preferably 94% by mass or more of triacylglycerol.
<32> The method according to any one of <1> to <31>, wherein the acid value (AV) of the fractionated fish oil is preferably 10 mgKOH / g or less, more preferably 5 mgKOH / g or less.
<33> The method according to any one of <1> to <32>, wherein the melting point of the fractionated fish oil is preferably less than 42 ° C, more preferably 25 to 41 ° C, and still more preferably 27 to 40 ° C.
<34> The method according to any one of <1> to <33>, wherein the liquid part separated from the solid part precipitated in the step (3) is used as a fish oil containing an ω3 highly unsaturated fatty acid.

In the following examples, “%” means “mass%”.
[Analysis method]
(I) Measurement of constituent fatty acid composition According to “Methyl esterification method (boron trifluoride methanol method) (2.4.1.2-1996)” in “Standard oil analysis method 2003 edition” edited by Japan Oil Chemists' Society Fatty acid methyl ester was prepared, and the obtained sample was subjected to gas chromatography (GLC) to analyze constituent fatty acids.

(Ii) Measurement of glyceride composition The “glyceride composition” is obtained by adding 10 mg of a sample and 0.5 mL of a trimethylsilylating agent (“silylating agent TH”, manufactured by Kanto Chemical) to a glass sample bottle and sealing it at 70 ° C. Heated for 15 minutes. Distilled water (1.0 mL) and hexane (2.0 mL) were added thereto, and after mixing, the hexane layer was subjected to gas chromatography (GLC) to analyze the glyceride composition.

(iii) Measurement of Acid Value (AV) The acid value (AV) was measured according to “Acid Value (2.3.1-1996)” in “Standard Oil Analysis Test Method 2003” edited by Japan Oil Chemists' Society.

(Iv) Measurement of melting point The melting point was measured using a high-sensitivity differential scanning calorimeter (DSC7020, manufactured by SII). The analysis conditions were that 5 mg of the sample was held at 70 ° C. for 5 minutes and dissolved, then cooled to −40 ° C. at a rate of 20 ° C./minute, held for 5 minutes and solidified. Thereafter, the temperature was raised to a temperature 30 ° C. lower than expected at the melting point at a rate of 20 ° C./min. Next, the temperature was raised at a rate of 0.5 ° C./min, and the melting end temperature was taken as the melting point.

(V) Measurement of fatty acid composition at the 2nd position and fatty acid composition at the 1st and 3rd positions Novozyme 435 (Novozyme) which shows high 1, (3) position selectivity in the presence of high concentration of ethanol and low fatty acid selectivity with existing lipase agents Zymes Japan) was used. The fatty acid composition of 2-monoglyceride was calculated | required by decomposing | disassembling the 1, 3-position coupling | bonding fatty acid of a glyceride, and the fatty acid composition of the 1, 3-position was computed.
150 mg of the sample and 1.5 g of ethanol were mixed, 66 mg of Novozyme 435 was added and reacted at 30 ° C. for 3 hours. Thereafter, the lipase was filtered off and ethanol was distilled off under reduced pressure to obtain a reaction solution.
Subsequently, 2-monoglyceride was fractionated using a solid phase column (Sep-Pak Silica WAT051900, manufactured by Nihon Waters). The solid phase column was conditioned with 10 mL of a mixed solvent of 80% hexane and 20% diethyl ether. 100 mg of the reaction solution was dissolved in 1 mL of a mixed solvent of 80% hexane and 20% diethyl ether, and passed through a solid phase column. Subsequently, 30 mL of a mixed solvent of 80% hexane and 20% diethyl ether was passed through to separate free fatty acids and diglycerides. Thereafter, 10 mL of methanol was passed. Methanol was distilled off under reduced pressure to recover a 2-monoglyceride fraction. Thereafter, using trihenicosanoin (manufactured by Wako Pure Chemical Industries, Ltd.) as an internal standard, the same operation as the measurement of the constituent fatty acid composition was performed to analyze the constituent fatty acids of the 2-monoglyceride fraction.
Using this result, the constituent fatty acid composition (%) at positions 1 and 3 and the content (%) at positions 1 and 3 were calculated from the following formulas (1) and (2).
1st and 3rd constituent fatty acid composition (%) = {constituent fatty acid composition of glyceride (%) × 3rd constituent fatty acid composition of monoglyceride (%)} / 2 (1)

1,3-position content rate (%) = {constituent fatty acid composition of the 1,3-position (%) × 2} / {constituent fatty acid composition of glyceride (%) × 3} × 100 (2)

[Raw oil]
Distilled bonito tuna oil and tuna crude oil shown in Table 1 were used as raw material fats and oils.
Fatty acid composition of raw oil and fat, content of palmitic acid in the total mass of fatty acid bonded to the 2-position (2-position palmitic acid), EPA, DHA 1- and 3-position content, acid value (AV), glyceride composition, and The melting points are shown in Table 1. The melting point of distilled skipjack tuna oil was unclear.

[Example 1]
Distilled bonito tuna oil shown in Table 1 was used as a raw oil and fat, and the first-stage acetone fractionation was performed at 5 ° C. Using the obtained liquid fraction, second-stage acetone fractionation was performed at -5 ° C.
In the first stage acetone fractionation, 200 g of distilled bonito tuna oil and 400 mL of acetone (special grade, manufactured by Wako Pure Chemical Industries, Ltd.) were added to a 2 L beaker and dissolved at 40 ° C. while mixing. Subsequently, it left still in a 5 degreeC thermostat. After 70 hours, using a Buchner funnel, qualitative filter paper NO. The solution was filtered under reduced pressure using 2 (manufactured by ADVANTEC). The solid part was filtered under reduced pressure again while washing with 200 mL of acetone cooled to 5 ° C. The washing filtrate was added to the previously separated liquid portion. The acetone solution containing the solid part and the liquid part was distilled off under reduced pressure, and the yields of the solid fraction and the liquid fraction were determined and analyzed.

  Subsequently, in the second-stage acetone fractionation, 99.5 g of the liquid part obtained above and 200 mL of acetone (special grade, manufactured by Wako Pure Chemical Industries, Ltd.) were added and dissolved at 40 ° C. while mixing. Subsequently, it put into the separable flask which made jacket temperature -5 degreeC. After standing for 4 hours, using a Buchner funnel, qualitative filter paper NO. The solution was filtered under reduced pressure using 2 (manufactured by ADVANTEC). The solid part was filtered again under reduced pressure while washing with 200 mL of acetone cooled to −5 ° C. The washing filtrate was added to the previously separated liquid portion. The solid part and liquid part acetone solutions were distilled off under reduced pressure, and the yields of the solid fraction and the liquid fraction were determined and analyzed.

[Example 2]
The tuna crude oil shown in Table 1 was used as a raw oil and fat, and the first stage acetone fractionation was performed at 5 ° C. Using the obtained liquid fraction, second-stage acetone fractionation was performed at -5 ° C.
In the first stage acetone fractionation, 300 g of tuna crude oil and 900 mL of acetone (special grade, manufactured by Wako Pure Chemical Industries) shown in Table 1 were added to a 2 L jacket cooled separable flask (inner diameter 130 mm) equipped with a stirring blade 100 × 100 mm. . It melt | dissolved at 40 degreeC, stirring at 50 r / min, and cooled to 30 degreeC. Subsequently, it cooled at the speed | rate of 0.5 degree-C / min, and cooled to 5 degreeC. After 2 hours, using a Buchner funnel, qualitative filter paper NO. The solution was filtered under reduced pressure using 2 (manufactured by ADVANTEC). The solid part was filtered again under reduced pressure while washing with 300 mL of acetone cooled to 5 ° C. The washing filtrate was added to the previously separated liquid portion. The acetone solution containing the solid part and the liquid part was distilled off under reduced pressure, and the yields of the solid fraction and the liquid fraction were determined and analyzed.

  Subsequently, in the second-stage acetone fractionation, 280 g of the liquid part obtained above and acetone (special grade, manufactured by Wako Pure Chemical Industries, Ltd.) were placed on a 2 L jacket cooled separable flask (inner diameter 130 mm) equipped with a stirring blade 100 × 100 mm. 840 mL was added. It melt | dissolved at 30 degreeC, stirring at 50 r / min, and cooled to 20 degreeC. Subsequently, it cooled at the speed | rate of 0.5 degree-C / min, and cooled to -5 degreeC. After 2 hours, using a Buchner funnel, qualitative filter paper NO. The solution was filtered under reduced pressure using 2 (manufactured by ADVANTEC). The solid part was filtered again under reduced pressure while washing with 280 mL of acetone cooled to −5 ° C. The washing filtrate was added to the previously separated liquid portion. The acetone solution containing the solid part and the liquid part was distilled off under reduced pressure, and the yields of the solid fraction and the liquid fraction were determined and analyzed.

Example 3
First-stage acetone fractionation was performed at 10 ° C., and second-stage acetone fractionation was performed at −10 ° C. using the obtained liquid fraction. Other conditions were the same as in Example 2, and the yields of the solid fraction and the liquid fraction were determined and analyzed.

Example 4
The solvent used for fractionation was hexane, the first-stage hexane fractionation was performed at 0 ° C., and the second-stage hexane fractionation was performed at −15 ° C. using the obtained liquid fraction. The other conditions were the same as in Example 2, and the yields of the solid fraction and the liquid fraction were determined and analyzed. The solid fraction of the first-stage hexane fraction has a high melting point of 51.5 ° C. and solidifies at 30 ° C. even in ethanol, so it is difficult to measure the 1,3-position fatty acid composition and the 2-position fatty acid composition. there were.

[Comparative Example 1]
Solvent-free fractionation was performed at 5 ° C. using the distilled bonito tuna oil shown in Table 1 as a raw material fat.
Solvent-free fractionation was performed by adding 500 g of distilled bonito tuna oil to a 910 mL wide-mouth bottle (manufactured by Hitachi Koki) for centrifugation and dissolving at 40 ° C. Subsequently, the sample was centrifuged with a centrifuge (CR22GIII; manufactured by Hitachi Koki Co., Ltd.) cooled to 20 ° C. at a rotation speed of 5000 r / min for 30 minutes, but no crystal precipitation was observed. Centrifugation was performed for 60 minutes at a rotational speed of 5000 r / min with a centrifuge cooled to 10 ° C. Subsequently, the sample was centrifuged for 60 minutes at a rotational speed of 5000 r / min with a centrifuge cooled to 5 ° C., and the yields of the obtained solid fraction and liquid fraction were determined and analyzed.

[Comparative Example 2]
The same procedure as in Comparative Example 1 was performed except that the solid-liquid separation was performed by centrifuging at 5000 rpm for 60 minutes with a centrifuge cooled to 10 ° C., and the yield of the solid fraction and the liquid fraction was increased. Analysis was performed.

[Comparative Example 3]
Using the tuna crude oil shown in Table 1 as a raw oil and fat, the first-stage solvent-free fractionation was performed at 5 ° C., and the obtained liquid fraction was used for the second-stage solvent-free fractionation at −5 ° C.
In the first-stage solvent-free fractionation, 1500 g of tuna crude oil shown in Table 1 was placed in a 2 L jacket cooled separable flask (inner diameter 130 mm) equipped with a stirring blade 100 × 100 mm. It melt | dissolved at 40 degreeC, stirring at 50 r / min, and cooled to 30 degreeC. Subsequently, it cooled at the speed | rate of 0.5 degree-C / min, and cooled to 5 degreeC. After 2 hours, using a Buchner funnel, qualitative filter paper NO. 2 (ADVANTEC) was subjected to vacuum filtration. The yield of the separated solid fraction and liquid fraction was determined and analyzed.

  Subsequently, in the second-stage solvent-free fractionation, 850 g of the liquid fraction obtained above was put into a 2 L jacket cooled separable flask (inner diameter 130 mm) equipped with a stirring blade 100 × 100 mm. It melt | dissolved at 30 degreeC, stirring at 50 r / min, and cooled to 20 degreeC. Subsequently, it cooled at the speed | rate of 0.5 degree-C / min, and cooled to -5 degreeC. After 2 hours, using a Buchner funnel, qualitative filter paper NO. The solution was filtered under reduced pressure using 2 (manufactured by ADVANTEC). The yield of the separated solid fraction and liquid fraction was determined and analyzed.

[Comparative Example 4]
Acetone fractionation was performed at -5 ° C using tuna crude oil shown in Table 1 as raw material fat.
For acetone fractionation, 300 g of tuna crude oil and 900 mL of acetone (special grade, manufactured by Wako Pure Chemical Industries) shown in Table 1 were added to a 2 L jacket-cooled separable flask (inner diameter 130 mm) equipped with a stirring blade 100 × 100 mm. It melt | dissolved at 40 degreeC, stirring at 50 r / min, and cooled to 30 degreeC. Subsequently, it cooled at the speed | rate of 0.5 degree-C / min, and cooled to -5 degreeC. After 2 hours, using a Buchner funnel, qualitative filter paper NO. The solution was filtered under reduced pressure using 2 (manufactured by ADVANTEC). The solid part was filtered again under reduced pressure while washing with 300 mL of acetone cooled to −5 ° C. The washing filtrate was added to the previously separated liquid portion. The acetone solution containing the solid part and the liquid part was distilled off under reduced pressure, and the yields of the solid fraction and the liquid fraction were determined and analyzed.

Table 2 shows analysis values and yields of the examples and comparative examples.

As is clear from Table 2, when the raw oil / fat is subjected to two-stage solvent fractionation, palmitic acid is bound to the 2nd position of the glyceride as high as 40% or more, and the 1,3-position DHA content is as high as 60% or more. An oil which is considered to be a triacylglycerol structure in human breast milk was obtained. Moreover, melting | fusing point of such fats and oils was 25-41 degreeC, and it was confirmed that it melt | dissolves near body temperature.
On the other hand, high melting point glycerides could not be separated by solvent-free fractionation and one-step solvent fractionation, and the desired fats and oils could not be obtained.

Claims (6)

Next steps (1), (2) and (3):
(1) A step of dissolving fish oil collected from bonito and / or tuna in an organic solvent and then cooling it,
(2) The step of separating the solid part deposited in step (1) from the liquid part to obtain the liquid part,
(3) The step of obtaining the precipitated solid part after dissolving the liquid part obtained in step (2) in the organic solvent again and then cooling to a temperature lower than the cooling temperature in step (1).
A fractionated fish oil comprising 30% by mass or more of palmitic acid in the total mass of fatty acid bound to the 2-position of triacylglycerol and bound to triacylglycerol. The manufacturing method whose ratio of the omega-3 type | system | group highly unsaturated fatty acid couple | bonded with the 1st, 3rd position with respect to the gross mass of an unsaturated fatty acid is 60 mass% or more, and melting | fusing point is 25-41 degreeC . The method for producing fractionated fish oil according to claim 1, wherein the fish oil contains 19 mass% or more of docosahexaenoic acid in a fatty acid constituting the fish oil.   The method for producing fractionated fish oil according to claim 1 or 2, wherein the cooling temperature in the step (3) is lower by 3 ° C or more than the cooling temperature in the step (1).   The method for producing fractionated fish oil according to any one of claims 1 to 3, wherein the organic solvent is acetone, hexane, or a combination thereof. The method for producing fractionated fish oil according to any one of claims 1 to 4, wherein the fish oil contains 78% by mass or more of triacylglycerol. Next steps (1), (2) and (3):
(1) A step of dissolving fish oil collected from bonito and / or tuna in an organic solvent and then cooling it,
(2) The step of separating the solid part deposited in step (1) from the liquid part to obtain the liquid part,
(3) The step of separating the liquid part obtained by dissolving the liquid part obtained in the step (2) again in an organic solvent and then cooling to a temperature lower than the cooling temperature in the step (1),
The oily fractionation method comprising: a ω3 in which the precipitated solid part contains 30% by mass or more of palmitic acid in the total mass of fatty acid bonded to the 2-position of triacylglycerol and bonded to triacylglycerol. A fractionation method in which the ratio of the ω3 highly unsaturated fatty acid bonded to the 1,3-position to the total mass of the highly unsaturated fatty acid is 60% by mass or more and the melting point is 25 to 41 ° C.