Method for producing ginger root extract

Abstract

To provide a method for producing a ginger root extract containing a high amount of fructosyl dipeptides while containing a reduced amount of 6-gingerol.　This method for producing a ginger root extract comprises the following steps (1) and (2): (1) a step for extracting ginger root in water or an aqueous solution of 30% (v / v) or less ethanol; and (2) a step for bringing activated carbon into contact with the extract obtained by the step (1) in an aqueous solution of 40-60% (v / v) alcohol.

Description

Manufacturing method of ginger extract

[0001] The present invention relates to a method for producing ginger extract.

[0002] Ginger is the rhizome of ginger (Zingiber officinale Roscoe) of the Zingiberaceae family, and is a herbal medicine that has long been used as an aromatic stomachic. Gingerols (6-gingerol, 8-gingerol, 10-gingerol, etc.) and shogaol are known as the main components of ginger, and ginger extracts are used in hair growth agents and other applications due to their effects of increasing blood flow.

[0003] However, since gingerols are highly irritating to the skin, ginger extracts that are substantially free of gingerols have been investigated, and a method for producing an aqueous ginger extract has been reported in which ginger is extracted with 20, 50, or 70% (v / v) aqueous alcohol, and then activated carbon is added to the extract to perform activated carbon treatment (Patent Document 1).

[0004] On the other hand, ginger contains fructosyl dipeptides such as Fru-Val-Tyr and Fru-Ile-Tyr, and it has been reported that these fructosyl dipeptides have the effect of preventing and improving wrinkles and inhibiting hair growth (Patent Document 2).

[0005] (Patent Document 1) JP 2003-48845 A (Patent Document 2) JP 2010-180240 A

[0006] The present invention relates to the following 1) and 2): 1) A method for producing a ginger extract, comprising the following steps (1) and (2): (1) extracting ginger with water or an aqueous ethanol solution of 30% (v / v) or less, and (2) contacting the extract obtained in step (1) with activated carbon in an aqueous alcohol solution of 40 to 60% (v / v). 2) A ginger extract containing 100 ppb or more of fructosyl dipeptide and less than 1 ppm of 6-gingerol.

[0007] 1 shows the results of component analysis of water or ethanol extract of ginger. 2 shows the results of component analysis of ginger extract. Detailed Description of the Invention

[0008] In Patent Document 2, fructosyl dipeptides are produced by separating and purifying a ginger extract by chromatography. However, this method requires complicated procedures, posing a problem in terms of industrial productivity. Furthermore, the method of Patent Document 1 can reduce the amount of gingerols, particularly 6-gingerol, which are pungent and stimulating components in ginger extract, but has the problem of low fructosyl dipeptide content. Therefore, the present invention provides a method for producing a ginger extract that is rich in fructosyl dipeptides while reducing 6-gingerol content.

[0009] The present inventors have conducted various studies on methods for extracting ginger and have found that a ginger extract containing a high amount of fructosyl dipeptides and a low amount of 6-gingerol can be obtained by extracting ginger with water or an aqueous ethanol solution of 30% (v / v) or less, and then contacting the extract with activated carbon in an aqueous alcohol solution of 40 to 60% (v / v).

[0010] According to the present invention, it is possible to produce a ginger extract that is rich in fructosyl dipeptides while reducing 6-gingerol. Therefore, the ginger extract of the present invention is expected to exhibit the beneficial physiological functions of fructosyl dipeptides.

[0011] The method for producing a ginger extract of the present invention comprises step (1) of extracting ginger with water or an aqueous ethanol solution of 30% (v / v) or less, and step (2) of contacting the extract obtained in step (1) with activated carbon in an aqueous alcohol solution of 40 to 60% (v / v). Steps (1) and (2) are described below.

[0012] [Step (1)] Step (1) is a step of extracting ginger with water or an aqueous ethanol solution of 30% (v / v) or less. In this specification, "ginger" refers to the rhizome of ginger, a member of the Zingiberaceae family, sometimes with the periderm removed. The ginger is preferably heated and dried, or may be processed by cutting, crushing, or the like. The extraction method is not particularly limited, and conventional means such as immersion, decoction, percolation, reflux extraction, ultrasonic extraction, microwave extraction, and stirring can be used.

[0013] The extraction solvent used is water or an aqueous solution of ethanol at 30% (v / v) or less. Examples of water include tap water, distilled water, ion-exchanged water, and purified water. In the present invention, "% (v / v)" refers to percent by volume at 25°C.

[0014] In the present invention, the extraction solvent is preferably an aqueous ethanol solution of more than 0% (v / v) and not more than 30% (v / v), more preferably an aqueous ethanol solution of 10% (v / v) or more and not more than 30% (v / v), from the viewpoints of preservation and increasing the concentration of fructosyl dipeptides and reducing gingerols in the extract.

[0015] The amount of solvent used for extraction can be selected appropriately depending on the extraction method, but from the viewpoint of fructosyl dipeptide yield and production efficiency, the amount is preferably 2 to 100 times, and more preferably 5 to 20 times, the mass of ginger (converted to dry mass). The extraction conditions are not particularly limited as long as they allow sufficient extraction. For example, the extraction time is preferably 0.5 hours to 10 days, and more preferably 1 to 7 days. The extraction temperature is preferably 5 to 60°C, and more preferably 5 to 30°C. Generally, extraction is performed for a long time at low temperatures and for a short time at high temperatures.

[0016] After the extraction step, the extract can be subjected to solid-liquid separation. Examples of solid-liquid separation include filter paper filtration, filter separation using a metal filter such as stainless steel, centrifugation, membrane treatment, etc., and these can be performed alone or in combination of two or more. The extract can also be concentrated. The concentration method is not particularly limited, and examples include atmospheric concentration, in which the solvent is evaporated at atmospheric pressure, reduced pressure concentration, in which the solvent is evaporated at reduced pressure, and membrane concentration, in which the solvent is removed by membrane separation. If necessary, the extract can be dried. Examples of drying methods include spray drying and freeze drying.

[0017] [Step (2)] This step involves contacting the extract obtained in step (1) with activated carbon in a 40 to 60% (v / v) aqueous alcohol solution. Examples of raw materials from which activated carbon can be derived include sawdust, coal, and coconut shells. Of these, coconut shell activated carbon derived from coconut shells is preferred from the viewpoint of reducing gingerols without reducing the concentration of fructosyl dipeptides. Activated carbon activated with a gas such as steam or a chemical is also preferred. The shape of the activated carbon is not particularly limited, and examples include powder, granules, and fibers. Commercially available activated carbons include Shirasagi P (Osaka Gas Chemicals Co., Ltd.) and Kuraray Coal GW (Kuraray Co., Ltd.). The amount of activated carbon used is preferably 0.1 to 100 times, more preferably 0.1 to 10 times, and even more preferably 1 to 5 times the mass of the solid content of the extract obtained in step (1), from the viewpoint of reducing the gingerols without reducing the concentration of fructosyl dipeptides. In this specification, the term "solid content" refers to the residue obtained by concentrating a sample under reduced pressure using a rotary evaporator, adding water, and freeze-drying the sample to remove volatile substances.

[0018] Examples of alcohols include monohydric, dihydric, and polyhydric alcohols. Examples of monohydric alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, and t-butanol. Examples of dihydric alcohols include alkylene glycols such as ethylene glycol, propylene glycol, 1,3-propanediol, and 1,3-butylene glycol. Examples of trihydric alcohols include glycerin. Alcohols can be used alone or in combination of two or more. From the viewpoint of reducing gingerols while leaving fructosyl dipeptides, monohydric and dihydric alcohols are preferred, with ethanol and 1,3-butylene glycol being more preferred, and ethanol being even more preferred. The alcohol concentration of the aqueous alcohol solution used in this step is 40 to 60% (v / v), from the viewpoint of reducing gingerols while leaving fructosyl dipeptides. Examples of methods for adjusting the concentration of the aqueous alcohol solution include a method in which alcohol and water are added to and mixed with the extract so that the alcohol concentration in the aqueous alcohol solution falls within the above range, and a method in which alcohol is added to and mixed with the extract, and then water is added to adjust the alcohol concentration to fall within the above range.

[0019] From the viewpoint of the yield of fructosyl dipeptide and production efficiency, the amount of the aqueous alcohol solution used is preferably 10 to 10,000 times by mass, and more preferably 100 to 1,000 times by mass, relative to the mass of the solid content of the extract obtained in step (1).

[0020] The method for contacting the extract obtained in step (1) with activated carbon can be, for example, a batch method or a continuous method. In the batch method, for example, activated carbon is added to an alcoholic aqueous solution containing the extract, stirred to allow adsorption, and then the activated carbon is recovered by filtration. The treatment atmosphere may be air or an inert gas (nitrogen gas, argon gas, helium gas, carbon dioxide). In the continuous method, for example, contact may be carried out by continuous treatment using a column packed with activated carbon. The liquid flow conditions can be set appropriately.

[0021] The temperature at which the extract obtained in step (1) is contacted with activated carbon is preferably 5°C to 35°C, more preferably 10°C to 30°C, from the viewpoints of gingerol removal efficiency, fructosyl dipeptide yield, and production efficiency.

[0022] The contact time between the extract obtained in step (1) and activated carbon can be appropriately selected depending on the contact means and scale. From the viewpoints of gingerol removal efficiency, fructosyl dipeptide yield, and production efficiency, the contact time is preferably 0.5 hours to 7 days, and more preferably 2 hours to 1 day.

[0023] After contact with activated carbon, the ginger extract of the present invention can be obtained by recovering the treated solution through solid-liquid separation procedures such as centrifugation and filtration. The form of the ginger extract of the present invention is not particularly limited, and may be solid, semi-solid, or liquid. The recovered treated solution can also be concentrated or dried. The concentration and drying methods are as described above.

[0024] The ginger extract of the present invention has a high content of fructosyl dipeptides and a low content of 6-gingerol. Herein, "fructosyl dipeptide" is a collective term for Fru-Val-Tyr, Fru-Ile-Tyr, Fru-Val-Phe, Fru-Ile-Val, and Fru-Val-Ile. Fru represents a fructosyl residue, Val represents a valine residue, Tyr represents a tyrosine residue, Ile represents an isoleucine residue, and Phe represents a phenylalanine residue. The fructosyl residue may be in either the D- or L-form, the α- or β-form, or the furanose or pyranose form. In solution, the α-, β-, furanose, and pyranose forms are interconverted to form a mixture of these. For example, in water, it becomes a mixture of β-pyranose type (67%), β-furanose type (12%), α-furanose type (15%), and α-pyranose type (6%). The configuration of each amino acid residue may be either D- or L-configuration, with the L-configuration being preferred. In the present invention, it is sufficient to contain at least one of the above five types of fructosyl dipeptides. The fructosyl dipeptide may be in the form of a salt or a hydrate. The salt is not particularly limited as long as it is physiologically acceptable, and examples thereof include alkali metal salts, alkaline earth metal salts, amine salts, amino acid salts, and acid addition salts.

[0025] The content of fructosyl dipeptides in the ginger extract of the present invention is preferably 100 ppb or more, more preferably 200 ppb or more. The content of fructosyl dipeptides can be measured by the method described in the Examples below, and the content of fructosyl dipeptides is defined based on the total amount of the above five types of fructosyl dipeptides.

[0026] The 6-gingerol content in the ginger extract of the present invention is preferably less than 1 ppm, more preferably less than 0.1 ppm, and even more preferably substantially free of 6-gingerol (e.g., below the detection limit of HPLC). The 6-gingerol content can be measured by the method described in the Examples below.

[0027] In addition, the mass ratio of the fructosyl dipeptide content to the 6-gingerol content in the ginger extract of the present invention is preferably 1 or more.

[0028] The ginger extract of the present invention can be used in various fields such as pharmaceuticals, quasi-drugs, cosmetics, and foods. It is particularly suitable for use in external skin preparations. The ginger extract of the present invention may be used alone or in combination with additives used in various formulations, such as oils, colorings, fragrances, preservatives, chelating agents, pigments, antioxidants, vitamins, minerals, sweeteners, seasonings, preservatives, binders, bulking agents, disintegrants, surfactants, lubricants, dispersants, buffers, coating agents, carriers, and diluents.

[0029] In relation to the above-described embodiment, the present invention further discloses the following aspects.

[0030] <1> A method for producing a ginger extract, comprising the following steps (1) and (2): (1) extracting ginger with water or an aqueous ethanol solution of 30% (v / v) or less; and (2) contacting the extract obtained in step (1) with activated carbon in an aqueous alcohol solution of 40 to 60% (v / v).

[0031] <2> The production method according to <1>, wherein the water or 30% (v / v) or less aqueous ethanol solution is preferably more than 0% (v / v) and 30% (v / v) or less aqueous ethanol solution, more preferably 10% (v / v) or more and 30% (v / v) or less aqueous ethanol solution. <3> The production method according to <1> or <2>, wherein the amount of activated carbon used is preferably 0.1 to 100 times by mass, more preferably 0.1 to 10 times by mass, and even more preferably 1 to 5 times by mass, relative to the mass of the solid content of the extract obtained in step (1). <4> The production method according to any of <1> to <3>, wherein the aqueous alcohol solution is preferably one or more selected from monohydric alcohols and dihydric alcohols, more preferably one or more selected from ethanol and 1,3-butylene glycol, and even more preferably ethanol.

[0032] <5> Ginger extract containing 100 ppb or more of fructosyl dipeptide and less than 1 ppm of 6-gingerol.

[0033] <6> The ginger extract according to <5>, wherein the content of fructosyl dipeptide is preferably 200 ppb or more and the content of 6-gingerol is preferably less than 0.1 ppm. <7> A ginger extract produced by the production method according to any one of <1> to <4>, or an external preparation for skin containing the ginger extract according to <5> or <6>.

[0034] In the following examples, "%" means "% (v / v)".

[0035] <Conditions for Fructosyl Dipeptide Analysis> A sample was diluted 10-fold with ultrapure water:methanol = 1:1, and the solution was filtered, followed by measurement by LC-MS / MS under the following conditions: [Measurement Conditions] Column: Inertsustain AQ-18 HP (3 mm x 250 mm, 3 μm) Column temperature: 40°C Mobile phase: A; 0.1% formic acid / H ２ OB;CH ３ CN

[0036]

[0037] Flow rate: 0.4mL / min Injection volume: 3μL Ionization: ESI (+) MS / MS: 443.2 / 359.4Da (Fru-Val-Tyr) 457.3 / 373.1Da (Fru-Ile-Tyr) 393.1 / 309.1Da (Fru-Ile-Val) 393.2 / 309.3 (Fru-Val-Ile) 427.2 / 343.2 (Fru-Val-Phe)

[0038] <Analysis conditions for 6-gingerol> A sample was diluted 100 times with ultrapure water:methanol = 1:1, and the solution was filtered and then measured by HPLC under the following conditions. [Measurement conditions] Column: Inertil ODS3 (3 mm x 150 mm, 5 μm) Column temperature: 40°C Mobile phase: A; 0.1% formic acid / H ２ OB;CH ３ CN

[0039]

[0040] Flow rate: 0.4 mL / min Injection volume: 5 μL Detection: UV 280 nm

[0041] Reference Example 1 50 mg of ginger (manufactured by Tochimoto Tenkaido Co., Ltd.) was extracted with ion-exchanged water and 1 mL of 10 to 100% aqueous ethanol solution at 25°C for 1 day, and then filtered to obtain an extract. The analytical results of the extract are shown in Figure 1.

[0042] As shown in Figure 1, it was confirmed that more fructosyl dipeptides were extracted from ginger extracts prepared with water or 30% or less aqueous ethanol than from extracts prepared with 40% or more aqueous ethanol.

[0043] Examples 1 to 6: 10 g of ginger (manufactured by Tochimoto Tenkaido Co., Ltd.) was extracted with 200 mL of 10% aqueous ethanol at 25°C for 3 days, followed by filtration to obtain an extract. 4 mL of each of the obtained extracts was concentrated and redissolved in 4 mL of each solvent. 500 μL of each of these redissolved solutions was taken, and 10 mg of activated carbon (Shirasagi P, Osaka Gas Chemicals Co., Ltd.) was added to each solution. After 1 hour, the solution was filtered to obtain a ginger extract (Table 3). The analytical results of the ginger extract are shown in Figure 2.

[0044] Comparative Example 1 10 g of ginger (manufactured by Tochimoto Tenkaido Co., Ltd.) was extracted with 200 mL of 20% aqueous ethanol solution at 25°C for 3 days, and then filtered to obtain an extract. 10 mg of activated carbon (Shirasagi P) was added to 500 μL of this extract, and the mixture was filtered after 1 hour to obtain a ginger extract (Table 3). The analytical results of the ginger extract are shown in Figure 2.

[0045] Comparative Example 2 A ginger extract was obtained in the same manner as in Comparative Example 1, except that a 50% aqueous solution of 1,3-butylene glycol was used as the extraction solvent (Table 3). The analytical results of the ginger extract are shown in FIG.

[0046] Comparative Example 3 A ginger extract was obtained in the same manner as in Comparative Example 1, except that a 70% aqueous solution of 1,3-butylene glycol was used as the extraction solvent (Table 3). The analytical results of the ginger extract are shown in FIG.

[0047]

[0048] As shown in Figure 2, it was confirmed that a ginger extract containing a large amount of fructosyl dipeptide but substantially no 6-gingerol can be obtained by extracting ginger with a low-concentration aqueous ethanol solution and then contacting the extract with activated carbon in a 40% to 60% aqueous alcohol solution. In contrast, the ginger extracts of Comparative Examples 1 to 3, which were treated with activated carbon in a 20% ethanol extract or a 50% or 70% 1,3-butylene glycol extract, contained substantially no 6-gingerol or only a small amount of 6-gingerol, but also contained a small amount of fructosyl dipeptide.

Claims

1. A method for producing a ginger extract, comprising the following steps (1) and (2): (1) extracting ginger with water or an aqueous ethanol solution of 30% (v / v) or less; and (2) contacting the extract obtained in step (1) with activated carbon in an aqueous alcohol solution of 40 to 60% (v / v).

2. A method for producing ginger extract according to claim 1, wherein the aqueous alcohol solution is an aqueous ethanol solution or an aqueous 1,3-butylene glycol solution.

3. A method for producing a ginger extract according to claim 1 or 2, wherein the amount of activated carbon used is 0.1 to 100 times the mass of the solid content of the extract obtained in step (1).

4. Ginger extract containing 100 ppb or more of fructosyl dipeptide and less than 1 ppm of 6-gingerol.

5. A skin external preparation containing ginger extract produced by the production method described in any one of claims 1 to 3, or the ginger extract described in claim 4.

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