Alkylresorcinol-containing liposoluble composition and method for producing the same

Abstract

To provide a method for producing an alkylresorcinol-containing liposoluble composition that comprises alkylresorcinol as a liposoluble constituent derived from bran of gramineous cereals, the concentration of alkylresorcinol being more than 5 mass%, and the composition having high purity; and to provide the alkylresorcinol-containing liposoluble composition.SOLUTION: This method comprises: adding and mixing n-hexane and an aqueous sodium chloride solution into a solution obtained by eluting liposoluble components from bran of gramineous cereals; separating by a liquid-liquid separation operation an n-hexane phase containing alkylresorcinol-containing liposoluble components; and volatilizing the n-hexane to obtain an alkylresorcinol-containing liposoluble composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an alkylresorcinol-containing fat-soluble composition and a method for producing the same. [Background technology]

[0002] In recent years, with the rise in health awareness, effective utilization of grains such as wheat and rye, which are rich in nutrients such as dietary fiber, vitamins, and minerals, has been investigated. Grains contain alkylresorcinols. Alkylresorcinols are compounds extracted or synthesized from the seed coats of grass grains and nuts, and are known to have anti-obesity, antioxidant, anti-immune, and other effects. Patent Document 1 describes that alkylresorcinols are localized in a region close to the aleurone layer of wheat husk.

[0003] Patent Document 2 describes the extraction of alkylresorcinols from wheat bran by shaking or stirring a mixture of wheat bran and raw oil and fat, followed by centrifugation to recover alkylresorcinols. However, the amount of alkylresorcinols extracted by this centrifugation method was small. Cited Document 3 describes the extraction of alkylresorcinols from barley or its fermentation products using a fat-soluble solvent. However, specific conditions for efficiently extracting alkylresorcinols have not been fully investigated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2021 / 065869 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-136909 [Patent Document 3] Japanese Patent Publication No. 2020-28227 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventionally, alkylresorcinols have been extracted from the bran of grass grains using an organic solvent, and the resulting extract is then evaporated to give an alkylresorcinol-containing composition. The alkylresorcinol concentration in the composition is 4 to 5% by mass, with the remainder consisting of impurities extracted from the bran.

[0006] In recent years, there has been a demand for a highly pure alkylresorcinol-containing fat-soluble composition that contains alkylresorcinol as a fat-soluble component derived from the bran of a grass family grain and has an alkylresorcinol concentration of more than 5% by mass, but such an alkylresorcinol-containing fat-soluble composition has not been provided.The problem that the present invention aims to solve is to provide a method for producing a highly pure alkylresorcinol-containing fat-soluble composition that contains alkylresorcinol as a fat-soluble component derived from the bran of a grass family grain and has an alkylresorcinol concentration of more than 5% by mass, and the fat-soluble composition. [Means for solving the problem]

[0007] The present inventors have conducted extensive research in light of the above-mentioned problems and have found that an alkylresorcinol-containing fat-soluble composition having a high purity of alkylresorcinol can be obtained by extracting alkylresorcinol from bran of a grass family grain using an ethanol-containing solvent, adding n-hexane and an aqueous sodium chloride solution to the extract, and then volatilizing the n-hexane from the extract.The present invention was completed based on these findings.

[0008] In addition, the acid value of the alkylresorcinol-containing fat-soluble composition is greatly affected by the acid value derived from the raw material bran, so depending on the storage condition of the raw material, the alkylresorcinol-containing fat-soluble composition may have a high acid value. Therefore, the present inventors have also found that an alkylresorcinol-containing fat-soluble composition having high alkylresorcinol purity and a low acid value can be obtained by adding an alkali to an extract obtained by extracting alkylresorcinol from the bran of a grass family grain using an ethanol-containing solvent, neutralizing the free fatty acids indicated by the acid value, and then volatilizing n-hexane from the extract obtained using n-hexane and an aqueous sodium chloride solution.

[0009] The present invention relates to a method for producing an alkylresorcinol-containing fat-soluble composition, which comprises a fat-soluble component extraction step of mixing an ethanol-containing solvent with bran from a grass grain to elute the fat-soluble components in the bran and recover a solution containing the fat-soluble components; an alkylresorcinol recovery step of mixing n-hexane and an aqueous sodium chloride solution with the solution obtained through the fat-soluble component extraction step to separate an ethanol-containing solvent phase from an n-hexane phase containing alkylresorcinol; and a concentration step of volatilizing n-hexane from the n-hexane phase obtained in the alkylresorcinol recovery step.

[0010] Preferably, in the concentration step, an alkylresorcinol-containing fat-soluble composition having an alkylresorcinol content of 5.5% by mass or more is obtained.

[0011] Preferably, the method further comprises a neutralization step of adding water and an alkali to the solution obtained in the fat-soluble component extraction step to neutralize the free fatty acids in the solution.

[0012] Preferably, the amount of alkali added in the neutralization step is in the range of 1.0 to 2.5 molar equivalents of the content of the free fatty acid.

[0013] The alkylresorcinol-containing fat-soluble composition obtained in the concentration step has an acid value of 4 or less.

[0014] The bran of the cereal of the Gramineae family includes at least one selected from the group consisting of rye bran and wheat bran.

[0015] The present invention further relates to an alkylresorcinol-containing fat-soluble composition containing alkylresorcinol as a fat-soluble component derived from the bran of a grass family grain and other fat-soluble components, wherein the alkylresorcinol-containing fat-soluble composition has an alkylresorcinol content of 5.5% by mass or more and an acid value of 4 or less. [Effects of the Invention]

[0016] The present invention provides a method for producing an alkylresorcinol-containing fat-soluble composition that contains alkylresorcinol as a fat-soluble component derived from the bran of a grass family grain, has an alkylresorcinol concentration of more than 5 mass%, is highly pure, and has an acid value of 4 or less, and also provides the fat-soluble composition. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will now be described in further detail. <Alkylresorcinol-containing fat-soluble composition> (Alkylresorcinol) The alkylresorcinol-containing fat-soluble composition of the present invention comprises an alkylresorcinol.

[0018] Alkylresorcinols are lipophilic substances having alkyl groups at the 2-, 4-, 5-, and / or 6-positions of the aromatic ring of resorcinol (1,3-dihydroxybenzene). They are commonly found in plants belonging to the Anacardiaceae, Ginkgoceae, Proteaceae, Ardisiaceae, Primulaceae, Myristicae, Iridaceae, Araceae, Fabaceae, and Poaceae families, as well as in plants such as Artemisia of the Asteraceae family. Among these plants, grasses such as wheat, rye, barley, oat, rice, millet, foxtail millet, barnyard millet, and corn contain relatively large amounts of alkylresorcinols in their edible parts (seeds), and therefore can be suitably used as raw materials for the alkylresorcinol-containing fat-soluble composition of the present invention. For example, the bran and whole grains of edible parts (seeds) of wheat, rye, etc. contain about 0.015 to 0.3 mass % of alkylresorcinols represented by the following formula (I). Fermented products such as miso paste made from wheat or rye are also suitable examples of suitable raw materials for the alkylresorcinol-containing fat-soluble composition of the present invention.

[0019] Examples of the alkylresorcinol include 4-butylresorcinol (rucinol), 4-hexylresorcinol, phenylethylresorcinol, and 1-(2,4-dihydroxyphenyl)-3-(2,4-dimethoxy-3-methylphenyl)-propane.

[0020] The alkylresorcinol of the present invention typically includes alkylresorcinol represented by the following formula (I):

[0021] [ka]

[0022] In formula (I), R1 represents a saturated or unsaturated, linear or branched alkyl group. The number of carbon atoms in the alkyl group represented by R1 is not limited, but is preferably 1 to 237, more preferably 3 to 27, and even more preferably 5 to 27.

[0023] In formula (I), R1 is preferably a saturated or unsaturated linear alkyl group, more preferably a saturated linear alkyl group. Examples of the saturated linear alkyl group represented by R1 include methyl, n-propyl, n-pentyl, n-heptyl, n-nonyl, n-undecyl, n-tridecyl, n-pentadecyl, n-heptadecyl, n-nonadecyl, n-henicosyl, and n-tricosyl.

[0024] In formula (I), the position and number of unsaturated bonds in the unsaturated linear alkyl group represented by R1 are not particularly limited. Examples of the unsaturated linear alkyl group include the above-mentioned saturated linear alkyl groups having an unsaturated bond at any position on the carbon chain. In formula (I), the position and number of branches of the saturated or unsaturated branched alkyl group represented by R1 and the position and number of unsaturated bonds are not particularly limited.

[0025] Preferred examples of the compound of the above formula (I) include the following. 5-Pentylresorcinol [olivetol, or 1,3-dihydroxy-5-n-pentylbenzene (C5:0)] 5-heptylresorcinol [or 1,3-dihydroxy-5-n-heptylbenzene (C7:0)] 5-Nonylresorcinol [or 1,3-dihydroxy-5-n-nonylbenzene (C9:0)] 5-Undecylresorcinol [or 1,3-dihydroxy-5-n-undecylbenzene (C11:0)] 5-Tridecylresorcinol [or 1,3-dihydroxy-5-n-tridecylbenzene (C13:0)] 5-pentadecylresorcinol [or 1,3-dihydroxy-5-n-pentadecylbenzene (C15:0)] 5-heptadecylresorcinol [or 1,3-dihydroxy-5-n-heptadecylbenzene (C17:0)] 5-Nonadecylresorcinol [or 1,3-dihydroxy-5-n-nonadecylbenzene (C19:0)] 5-heneicosylresorcinol [or 1,3-dihydroxy-5-n-heneicosylbenzene (C21:0)] 5-tricosylresorcinol [or 1,3-dihydroxy-5-n-tricosylbenzene (C23:0)] 5-Pentacosylresorcinol [or 1,3-dihydroxy-5-n-pentacosylbenzene (C25:0)] 5-heptacosylresorcinol [or 1,3-dihydroxy-5-n-heptacosylbenzene (C27:0)]

[0026] The alkylresorcinol-containing fat-soluble composition of the present invention also contains fat-soluble components other than alkylresorcinol contained in the bran of a grass family grain. The alkylresorcinol content in the alkylresorcinol-containing fat-soluble composition of the present invention is 5.5% by mass or more, preferably 6% by mass or more, and more preferably 7% by mass or more. There is no particular upper limit to the content, but in practice it is 20% by mass or less.

[0027] The alkylresorcinol-containing fat-soluble composition of the present invention may be in the form of a solid such as a powder, a gel, or a solution dissolved in a solvent, and is preferably in the form of a gel.

[0028] The solvent may be Hydrocarbons such as n-hexane, benzene, toluene, etc.; lower alcohols such as methanol, ethanol, n-propanol, isopropanol, and n-butanol; Polyhydric alcohols such as 1,3-butylene glycol, propylene glycol, and glycerin; ethers such as diethyl ether and propyl ether; esters such as butyl acetate and ethyl acetate; ketones such as acetone and methyl ethyl ketone; Examples of the solvent include oils and fats, and organic solvents such as hexane and chloroform. One or more of these solvents can be used.

[0029] Examples of the oils and fats include those commonly used in the food industry, such as medium-chain fatty acid (MCT) oil, salad oil, palm oil, palm olein, palm stearin, lard, beef tallow, milk fat, coconut oil, palm kernel oil, rapeseed oil, soybean oil, corn oil, rice bran oil, cottonseed oil, sunflower oil, sesame oil, olive oil, fractionated oils thereof, hydrogenated oils, and interesterified oils. These oils and fats may be used alone or in combination of two or more.

[0030] The solvent used in the present invention preferably contains at least one selected from the group consisting of fats and oils, ethanol, and n-hexane, more preferably at least one selected from the group consisting of ethanol and n-hexane, and even more preferably n-hexane. The proportion of the at least one selected from the group consisting of fats and oils, ethanol, and hexane in the total amount of the solvent used in the present invention is preferably 80% by mass or more, more preferably 90% by mass or more, and particularly preferably 100% by mass.

[0031] <Method for producing alkylresorcinol-containing fat-soluble composition> The method for producing the alkylresorcinol-containing fat-soluble composition of the present invention (hereinafter sometimes referred to as the production method of the present invention) includes a fat-soluble component extraction step in which an ethanol-containing solvent is mixed with bran of a grass family grain to elute the fat-soluble components in the bran, and a solution containing the fat-soluble components is recovered.

[0032] The content of ethanol in the ethanol-containing solvent is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0033] The production method of the present invention preferably further includes a neutralization step of adding water and an alkali to the solution obtained in the fat-soluble component extraction step to neutralize the free fatty acids in the solution. The alkali is not limited to a specific alkali. Examples of the alkali include alkali metal hydroxides, alkaline earth metal hydroxides, and salts thereof. The water and alkali preferably include at least one selected from the group consisting of an aqueous sodium hydroxide solution, an aqueous sodium carbonate solution, and an aqueous sodium bicarbonate solution, and more preferably an aqueous sodium hydroxide solution.

[0034] The alkali metal of the alkali metal hydroxide preferably includes at least one selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, and francium, more preferably includes at least one selected from the group consisting of lithium, sodium, and potassium, even more preferably includes at least one selected from the group consisting of sodium and potassium, and particularly preferably includes sodium or potassium. The alkaline earth metal of the alkaline earth metal hydroxide preferably contains at least one selected from the group consisting of beryllium, magnesium, calcium, strontium, and barium, more preferably contains at least one selected from the group consisting of magnesium, calcium, and barium, even more preferably contains at least one selected from the group consisting of magnesium and calcium, and particularly preferably contains calcium.

[0035] In the neutralization step, the amount of alkali added is preferably in the range of 1.0 to 2.5 molar equivalents of the free fatty acid content, and more preferably in the range of 1.2 to 2.0 molar equivalents. Adding an alkali in this range has the following advantages: (1) the free fatty acids can be sufficiently neutralized, making it easier to adjust the acid value of the alkylresorcinol-containing fat-soluble composition to 4 or less; and (2) the amount of alkylresorcinol dissolved in the n-hexane phase in the alkylresorcinol recovery step described below can be increased without neutralizing the alkylresorcinol. Here, the acid value of the alkylresorcinol-containing fat-soluble composition is preferably 4 or less, and more preferably 2 or less.

[0036] The production method of the present invention includes an alkylresorcinol recovery step in which n-hexane and an aqueous sodium chloride solution are added to and mixed with the solution obtained in the alkali treatment step, and the solution is separated into an n-hexane phase containing alkylresorcinol-containing fat-soluble components and the ethanol-containing solvent phase by a liquid separation operation. The free fatty acids in the solution containing the fat-soluble components obtained in the fat-soluble component extraction step are transferred to the ethanol-containing solvent phase.

[0037] The present invention includes a concentration step of volatilizing n-hexane from the n-hexane phase obtained in the alkylresorcinol recovery step. The concentration step is carried out, for example, by suctioning the n-hexane phase under reduced pressure with or without heating. [Example]

[0038] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0039] In the examples and comparative examples, various physical properties were measured or calculated as follows.

[0040] <Acid value measurement> A predetermined amount of alkylresorcinol-containing fat-soluble composition was added to diethyl ether (containing an antioxidant) and the mixture was thoroughly shaken until the sample was completely dissolved. The supernatant after dissolution was concentrated under reduced pressure, weighed, and titrated with 0.1 mol / L potassium hydroxide-ethanol solution until a light red color persisted for 30 seconds. A blank test (a blank test without the alkylresorcinol-containing fat-soluble composition) was also conducted in the same manner, separate from the test solution. The acid value was calculated using the following formula (1), where A is the titer (mL) of the 0.1 mol / L potassium hydroxide-ethanol solution, B is the titer (mL) of the blank test, and F is the factor of the 0.1 mol / L potassium hydroxide-ethanol solution. Acid value (mg KOH / g oil) = 5.611 × (AB) × F / sample amount (1)

[0041] <Qualitative and quantitative analysis of alkylresorcinols> Qualitative and quantitative analysis of alkylresorcinols was performed by high-performance liquid chromatography using Olivetol (a C5 linear alkyl resorcinol, manufactured by Sigma-Aldrich) as the alkylresorcinol standard and an Inertsil ODS4 analytical column manufactured by GL Science. The elution positions of Olivetol and alkylresorcinols with different alkyl chain lengths were determined in advance, and the measured peak areas were converted by multiplying each peak by a coefficient obtained by dividing the molecular weight of each peak by the molecular weight of Olivetol.

[0042] Example 1 500 mL of an ethanol-based solvent (ethanol content 99.5% by mass) consisting of ethanol and water was added to 100 g of rye bran (4.8% fat by mass, acid value 22), and the mixture was stirred at 60°C for 1 hour. The mixture was then filtered, and solid-liquid separation was performed to obtain a filtrate. The filtration residue was recovered, and 500 mL of the ethanol-based solvent was added again, and the mixture was stirred at 60°C for 1 hour. The mixture was then filtered, and solid-liquid separation was performed to obtain a second filtrate. The first and second filtrates were combined, and 500 mL of water, 1500 mL of n-hexane, and 50 mL of 1 M aqueous sodium chloride solution were added to perform liquid separation. The mixture separated into two layers: an n-hexane phase and an ethanol phase (containing ethanol and water), and the n-hexane phase was collected and stored. 1500 mL of n-hexane was added again to the separated ethanol phase, and the mixture was again separated into two layers: an n-hexane phase and an ethanol phase (containing ethanol and water). The separated ethanol phase was removed, and the n-hexane phase was collected.

[0043] The recovered n-hexane phase was transferred to a recovery flask, and the pressure was reduced using an evaporator to volatilize the n-hexane, yielding a gel-like alkylresorcinol-containing composition. The alkylresorcinol content (mg / g) in the alkylresorcinol-containing composition was measured, and the total amount of alkylresorcinol (g) was calculated. The alkylresorcinol recovery rate (%) was calculated using the total amount of alkylresorcinol in Comparative Example 1 (described below) as the standard using the following formula (2). The acid value of the alkylresorcinol-containing composition was also measured. Recovery rate of alkylresorcinol (%)=Total amount of alkylresorcinol in Example 1 / Total amount of alkylresorcinol in Comparative Example 1×100 (2)

[0044] The weight (g) of the alkylresorcinol-containing composition of Example 1, the content (mg / g) of alkylresorcinol contained in the alkylresorcinol-containing composition, the total amount (g) of alkylresorcinol, the alkylresorcinol recovery rate (%), and the acid value of the alkylresorcinol-containing composition are shown in Table 1.

[0045] Comparative Example 1 An ethanol-based solvent was added to the rye bran, and the procedure was repeated in Example 1 until a second filtrate was obtained. The first and second filtrates were combined, transferred to a recovery flask, and reduced pressure using an evaporator to obtain an alkylresorcinol-containing composition. The weight (g) of the alkylresorcinol-containing composition, the content (mg / g) of alkylresorcinol contained in the alkylresorcinol-containing composition, and the total amount (g) of alkylresorcinol were determined in the same manner as in Example 1, and the results are shown in Table 1.

[0046] Examples 2 to 5 An ethanol-based solvent was added to the rye bran, and the procedure was repeated in Example 1 until a second filtrate was obtained. The first and second filtrates were combined, and 500 mL of water and 0.28 mL, 0.41 mL, 0.55 mL, and 0.69 mL of 24 wt% aqueous sodium hydroxide, corresponding to 1.0 molar equivalent, 1.5 molar equivalent, 2.0 molar equivalent, and 2.5 molar equivalent of the free fatty acids in the extracted lipids, were added, and the mixture was stirred at 50 ° C for 20 minutes. 1500 mL of n-hexane and 50 mL of 1 M aqueous sodium chloride solution were added to the cloudy filtrate, and the mixture was separated. The n-hexane phase and the ethanol phase (containing ethanol and water) were separated into two layers, and the n-hexane phase was collected and stored. 1500 mL of n-hexane was added again to the separated ethanol phase, and the mixture was separated again into two layers, the n-hexane phase and the ethanol phase (containing ethanol and water). The separated ethanol phase was removed, and the n-hexane phase was collected.

[0047] The recovered n-hexane phase was transferred to a recovery flask, and the pressure was reduced using an evaporator to volatilize the n-hexane, yielding a gel-like alkylresorcinol-containing composition. The weight (g) of the alkylresorcinol-containing composition, the alkylresorcinol content (mg / g) in the alkylresorcinol-containing composition, the total amount (g) of alkylresorcinol, the alkylresorcinol recovery rate (%), and the acid value of the alkylresorcinol-containing composition were determined in the same manner as in Example 1, and the results are shown in Table 1.

[0048] [Table 1]

[0049] As shown in Table 1, in Examples 1 to 5, which involved a fat-soluble component extraction step in which an ethanol-containing solvent is mixed with rye bran to recover a solution containing fat-soluble components, an alkylresorcinol recovery step in which n-hexane and an aqueous sodium chloride solution are added and separated into layers, and a concentration step in which n-hexane is evaporated, the alkylresorcinol content in the extracted alkylresorcinol-containing composition was 55 mg / g (5.5 mass%) or more in all cases, and an alkylresorcinol-containing composition with a higher alkylresorcinol concentration was obtained than in Comparative Example 1, which did not involve the alkylresorcinol recovery step in which n-hexane and an aqueous sodium chloride solution are added and separated into layers.

[0050] Furthermore, in Examples 2 to 5, in which a neutralization step was carried out by adding an alkali to neutralize the free fatty acids, the acid value of the alkylresorcinol-containing fat-soluble composition was 4 or less, and an alkylresorcinol-containing fat-soluble composition with a lower acid value was obtained than in Example 1, in which no neutralization step was carried out.

Claims

1. A fat-soluble component extraction step of mixing the bran of a grass family grain with an ethanol-containing solvent to elute fat-soluble components in the bran and recovering a solution containing the fat-soluble components; an alkylresorcinol recovery step of mixing n-hexane and an aqueous sodium chloride solution with the solution obtained through the fat-soluble component extraction step, and separating an ethanol-containing solvent phase from an n-hexane phase containing alkylresorcinol; A method for producing an alkylresorcinol-containing fat-soluble composition, comprising a concentration step of volatilizing n-hexane from the n-hexane phase obtained in the alkylresorcinol recovery step.

2. 2. The method for producing an alkylresorcinol-containing fat-soluble composition according to claim 1, wherein the concentration step produces an alkylresorcinol-containing fat-soluble composition having an alkylresorcinol content of 5.5% by mass or more.

3. 2. The method for producing the alkylresorcinol-containing fat-soluble composition according to claim 1, further comprising a neutralization step of adding water and an alkali to the solution obtained in the fat-soluble component extraction step to neutralize the free fatty acids in the solution.

4. 4. The method for producing an alkylresorcinol-containing fat-soluble composition according to claim 3, wherein the amount of alkali added in the neutralization step is in the range of 1.0 to 2.5 molar equivalents of the content of the free fatty acid.

5. 4. The method for producing an alkylresorcinol-containing fat-soluble composition according to claim 3, wherein the alkylresorcinol-containing fat-soluble composition obtained in the concentrating step has an acid value of 4 or less.

6. 6. The method for producing an alkylresorcinol-containing fat-soluble composition according to claim 1, wherein the bran of a cereal of the Gramineae family comprises at least one selected from the group consisting of rye bran and wheat bran.

7. An alkylresorcinol-containing fat-soluble composition containing alkylresorcinol as a fat-soluble component derived from the bran of a cereal grain of the family Gramineae, and other fat-soluble components, the alkylresorcinol content in the alkylresorcinol-containing fat-soluble composition is 5.5% by mass or more; The alkylresorcinol-containing fat-soluble composition is characterized in that the alkylresorcinol-containing fat-soluble composition has an acid value of 4 or less.

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