Method for producing ginger extract

Abstract

To provide a method for producing a ginger extract containing a large amount of fructosyl dipeptides with a reduced amount of 6-gingerol.SOLUTION: This method for producing a ginger extract comprises the following steps (1) and (2): (1) a step for extracting ginger 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.SELECTED DRAWING: None

Description

[Technical Field]

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

[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 products 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 for 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). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-48845 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-180240 Summary of the Invention [Problem to be solved by the invention]

[0006] In Patent Document 2, fructosyl dipeptides are produced by separating and purifying ginger extract by chromatography. However, this method is cumbersome and has problems 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 producing only a small amount of fructosyl dipeptides. Therefore, the present invention provides a method for producing a ginger extract that is rich in fructosyl dipeptides while reducing 6-gingerol. [Means for solving the problem]

[0007] The inventors have conducted various studies on methods for extracting ginger and have found that 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), a ginger extract containing a high amount of fructosyl dipeptides and a low amount of 6-gingerol can be obtained.

[0008] That is, the present invention relates to the following 1) and 2). 1) The following steps (1) and (2): (1) Extracting ginger with water or an aqueous solution of ethanol at 30% (v / v) or less (2) contacting the extract obtained in step (1) with activated carbon in a 40 to 60% (v / v) aqueous alcohol solution; A method for producing a ginger extract, comprising: 2) Ginger extract containing 100 ppb or more of fructosyl dipeptide and less than 1 ppm of 6-gingerol. [Effects of the Invention]

[0009] According to the present invention, it is possible to produce a ginger extract that is rich in fructosyl dipeptides while reducing 6-gingerol, and therefore the ginger extract of the present invention is expected to exhibit the beneficial physiological functions of fructosyl dipeptides. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 shows the results of component analysis of water or ethanol extract of ginger. [Figure 2] 1 shows the results of component analysis of ginger extract. DETAILED DESCRIPTION OF THE INVENTION

[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 for example, conventional means such as immersion, decoction, percolation, reflux extraction, ultrasonic extraction, microwave extraction, stirring, etc. 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)" means 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 standpoint of fructosyl dipeptide yield and production efficiency, it is preferably 2 to 100 times by mass, and more preferably 5 to 20 times by mass, relative to the ginger (converted to dry mass). The extraction conditions are not particularly limited as long as they allow sufficient extraction, but for example, the extraction time is preferably 0.5 hours to 10 days, more preferably 1 to 7 days. The extraction temperature is preferably 5 to 60° C., 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 filtration with filter paper, 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 thereof include atmospheric concentration, in which the solvent is evaporated at atmospheric pressure, vacuum concentration, in which the solvent is evaporated at reduced pressure, and membrane concentration, in which the solvent is removed by membrane separation. The extract may also be dried, if necessary. Examples of drying methods include spray drying and freeze drying.

[0017] [Step (2)] This step is a step in which the extract obtained in step (1) is brought into contact 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. Among 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. As the activated carbon, for example, commercially available products such as Shirasagi P (Osaka Gas Chemicals Co., Ltd.) and Kuraray Coal GW (Kuraray Co., Ltd.) can be used. 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 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, the alcohol is preferably a monohydric alcohol or a dihydric alcohol, more preferably ethanol or 1,3-butylene glycol, and even more preferably ethanol. The alcohol concentration of the aqueous alcohol solution in this step is 40 to 60% (v / v) from the viewpoint of reducing gingerols while leaving fructosyl dipeptide. 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 fructosyl dipeptide yield and production efficiency, the amount of 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 solid content mass of the extract obtained in step (1).

[0020] The extract obtained in step (1) can be contacted with activated carbon by, for example, a batch method or a continuous method. In the case of a batch process, activated carbon is added to an alcoholic aqueous solution containing the extract, stirred to adsorb the extract, 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, or carbon dioxide). In the case of a continuous system, for example, contact may be carried out by continuous treatment using a column packed with activated carbon. The liquid passing 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 treated liquid is recovered by solid-liquid separation such as centrifugation or filtration, thereby obtaining the ginger extract of the present invention. The form of the ginger extract of the present invention is not particularly limited, and may be solid, semi-solid, or liquid. The recovered treatment liquid may also be concentrated or dried. The concentration and drying methods are as described above.

[0024] The ginger extract of the present invention contains a high amount of fructosyl dipeptide and a low amount 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 either the D- or L-form, the α- or β-form, or either the furanose or pyranose form. In solution, the α-, β-, furanose, and pyranose forms interconvert to form a mixture. For example, in water, the mixture is a mixture of the β-pyranose form (67%), the β-furanose form (12%), the α-furanose form (15%), and the α-pyranose form (6%). The configuration of each amino acid residue may be either D- or L-configuration, with L-configuration being preferred. The present invention may contain at least one of the five fructosyl dipeptides listed above. The fructosyl dipeptide may be in the form of a salt or 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 fructosyl dipeptide content in the ginger extract of the present invention is preferably 100 ppb or more, more preferably 200 ppb or more. The fructosyl dipeptide content can be measured by the method described in the Examples below, and 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] Furthermore, 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> Next steps (1) and (2): (1) Extracting ginger with water or an aqueous solution of ethanol at 30% (v / v) or less (2) contacting the extract obtained in step (1) with activated carbon in a 40 to 60% (v / v) aqueous alcohol solution; A method for producing a ginger extract, comprising:

[0031] <2> 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. <1> The manufacturing method described in <3> 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). <1> or <2> The manufacturing method described in <4> 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. <1> ~ <3> 1. The manufacturing method according to any one of the preceding claims.

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

[0033] <6> The content of fructosyl dipeptide is preferably 200 ppb or more, and the content of 6-gingerol is preferably less than 0.1 ppm. <5> The ginger extract described in . [Example]

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

[0035] <Conditions for fructosyl dipeptide analysis> The sample was diluted 10 times with ultrapure water:methanol = 1:1, and the solution was filtered, after which it was measured by LC-MS / MS under the following conditions. [Measurement conditions] Column: Inertiatain AQ-18 HP (3 mm x 250 mm, 3 μm) Column temperature: 40℃ Mobile phase: A; 0.1% formic acid / H2O B;CH3CN

[0036] [Table 1]

[0037] Flow rate: 0.4mL / min Injection volume: 3μL Ionization: ESI(+) MS / MS:443.2 / 359.4Da(Fru-Val-Tyr) 457.3 / 373.1 Da (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> The sample was diluted 100 times with ultrapure water:methanol = 1:1, and the solution was filtered, after which it was measured by HPLC under the following conditions. [Measurement conditions] Column: Inertil ODS3 (3 mm x 150 mm, 5 μm) Column temperature: 40℃ Mobile phase: A; 0.1% formic acid / H2O B;CH3CN

[0039] [Table 2]

[0040] Flow rate: 0.4mL / min Injection volume: 5μL Detection: UV280nm

[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% ethanol aqueous 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 solution at 25°C for 3 days, and then filtered 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 this redissolved solution was taken, and 10 mg of activated carbon (Shirasagi P, Osaka Gas Chemicals Co., Ltd.) was added to each, and after 1 hour, the mixture was filtered to obtain 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% 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 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] [Table 3]

[0048] As shown in Figure 2, it was confirmed that ginger extracts containing a large amount of fructosyl dipeptides but substantially no 6-gingerol were 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 small amounts of fructosyl dipeptides.

Claims

1. The following steps (1) and (2): (1) A step of extracting ginger with water or an aqueous solution of ethanol with a concentration of 30% (v / v) or less. (2) A step of contacting activated carbon with the extract obtained in step (1) in a 40-60% (v / v) aqueous alcohol solution. A method for producing ginger extract, which includes: The aforementioned alcohol aqueous solution is an ethanol aqueous solution or a 1,3-butylene glycol aqueous solution. A method for producing the ginger extract, wherein the ginger extract contains 100 ppb or more of fructosyl dipeptide and has a 6-gingerol content of less than 1 ppm.

2. A method for producing ginger extract according to claim 1, 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).

3. A method for producing a topical skin preparation containing ginger extract produced by the manufacturing method described in Claim 1 or 2.

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