JP2009060823A - Method for producing purified green tea extract - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a purified green tea extract, by which the purified green tea extract reduced in impurities such as caffeine, having a reduced bitter taste and an improved hue, and containing non-polymer catechin compounds in a high concentration can be produced, while reducing non-recyclable wastes such as activated carbon. <P>SOLUTION: This method for producing the purified green tea extract containing the non-polymer catechin compounds in a concentration of 25 to 90 mass% based on the solid contents of the green tea extract comprises making a synthetic adsorbent to adsorb a green tea extract, contacting the synthetic adsorbent with a basic aqueous solution to elute the non-polymer catechin compounds, adjusting the pH of the eluted solution to ≤7, adjusting the concentration of the non-polymer catechin compounds to 0.1 to 4.0 mass%, filtering the adjusted eluted solution with a fine pore diameter membrane, and then contacting the filtrate with activated carbon. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a purified green tea extract with improved hue.

  As a physiological effect of catechin, an α-amylase activity inhibitory action and the like have been reported (for example, see Patent Document 1). In order to express such a physiological effect, since it is necessary to ingest a large amount of catechin more simply, a method of blending catechin with a high concentration in a beverage has been desired.

  As one of the methods, a method of adding catechin to a beverage in a dissolved state using a tea extract such as a concentrate of green tea extract (Patent Document 2) is used. However, depending on the type of beverage for which catechin is to be blended at a high concentration by this method, for example, when catechin is added to black tea extract or carbonated beverage, the bitterness remaining from caffeine and green tea may be a beverage product. It has been found to greatly detract from value.

As a method for removing impurities such as caffeine from the green tea extract, an adsorption method (Patent Documents 2 to 4), an extraction method (Patent Documents 5 to 6), and the like are known.
In the above method, when increasing the content of non-polymer catechins in the green tea extract, it is necessary to use an organic solvent. However, when viewed industrially, there is a problem that the recovery rate is low. . Moreover, when using alkaline aqueous solution, when mix | blending with a drink, there existed a subject that the water-insoluble component derived from a tea leaf remained, and there was no effective means with respect to this.

As a method for improving the color tone of a green tea extract, an antibacterial deodorant (Patent Document 7) is known, which is obtained by allowing activated carbon to act on a tea extract in the presence of cyclodextrin and adsorbing and removing colored components on the activated carbon. However, its use in beverage catechin preparations has been difficult. Moreover, although the catechin preparation can be purified by the activated carbon treatment, the amount of activated carbon used is increased and the amount of waste activated carbon used is increased, resulting in the problem of reducing industrial waste.
JP-A-3-133828 JP-A-5-153910 JP-A-8-109178 JP 2002-335911 A JP-A-1-289447 JP 59-219384 A JP 2001-299887 A

It is an object of the present invention to provide a purified green tea extract containing a high concentration of non-polymer catechins in which impurities such as caffeine are removed, bitterness is suppressed, and hue is improved (absorption at 450 nm is reduced). It is to provide a manufacturing method.
The second purpose is to reduce the amount of activated carbon.

  As a result of examining the purification treatment of non-polymer catechins in the green tea extract, the present inventors passed the green tea extract through the synthetic adsorbent, once adsorbed to the synthetic adsorbent, and then adsorbed non-heavy After eluting the union catechins with a basic aqueous solution, the pH of the eluate was adjusted to 7 or less, and then the eluate whose non-polymer catechins concentration was adjusted to 0.1 to 4.0% by mass was obtained as a microporous membrane. It was found that a purified green tea extract having a high non-polymer catechins concentration and a reduced caffeine content and improved taste and hue can be obtained by contacting with activated carbon.

  That is, the present invention adsorbs the green tea extract to a synthetic adsorbent, contacts the synthetic adsorbent with a basic aqueous solution to elute non-polymer catechins, and then adjusts the pH of the eluate to 7 or less. Next, the eluate whose non-polymer catechin concentration is adjusted to 0.1 to 4.0% by mass is filtered through a microporous membrane, and then subjected to activated carbon treatment, so that the non-polymer relative to the solid content of the green tea extract is obtained. The present invention provides a method for producing a purified tea extract containing 25 to 90% by mass of catechins.

  According to the present invention, a purified green tea extract containing a high concentration of non-polymer catechins in which impurities such as caffeine are removed, bitterness is suppressed, and the hue is improved is advantageously obtained industrially. It is done. Further, the amount of activated carbon used in the post-treatment is small, which is particularly useful industrially.

  In the present invention, the non-polymer catechins include non-epi catechins such as catechin, gallocatechin, catechin gallate and gallocatechin gallate and epi-catechins such as epicatechin, epigallocatechin, epicatechin gallate and epigallocatechin gallate. It is a general term.

  In the present invention, the non-polymer catechin gallate body is a general term including catechin gallate, gallocatechin gallate, epicatechin gallate, epigallocatechin gallate and the like.

  Examples of the green tea extract used in the present invention include an extract obtained from green tea leaves. More specifically, the tea leaves used include tea leaves made from tea leaves obtained from the genus Camellia, for example, C. sinensis, C. assamica, and camellia seeds or hybrids thereof. The tea leaves produced include green teas such as sencha, bancha, gyokuro, tencha, and kettle roasted tea. Moreover, you may use the tea leaf which gave the carbon dioxide contact process of the supercritical state.

  Extraction from green tea leaves is performed by stirring extraction or the like using water or a water-soluble organic solvent or a mixture thereof as an extraction solvent. In the extraction, an organic acid salt such as sodium ascorbate or an organic acid may be added in advance to water or a water-soluble organic solvent or a mixture thereof. Moreover, you may use together the method of extracting in so-called non-oxidative atmosphere, ventilating inert gas, such as boiling deaeration and nitrogen gas, and removing dissolved oxygen. The extract thus obtained can be used in the present invention as it is, even if it is dried and concentrated. Examples of the green tea extract include liquid, slurry, semi-solid, and solid state.

For the green tea extract used in the present invention, instead of using the extract extracted from the green tea leaves, the concentrate of the green tea extract may be dissolved in water or an organic solvent or diluted in water or an organic solvent, You may use together the extract from a green tea leaf, and the concentrate of a green tea extract.
Here, the concentrate of green tea extract is obtained by concentrating an extract extracted from green tea leaves with hot water or a water-soluble organic solvent. For example, JP-A-59-219384, JP-A-4- This refers to those prepared by the methods described in JP-A-20589, JP-A-5-260907, JP-A-5-306279, and the like. Specifically, commercially available crude catechin preparations such as “Polyphenone” manufactured by Tokyo Food Techno Co., “Theafuran” manufactured by ITO EN, “Sunphenon” manufactured by Taiyo Kagaku Co., Ltd. can be used as the solid green tea extract.

  Moreover, it is preferable that the green tea extract is hydrolyzed before being adsorbed to the synthetic adsorbent from the viewpoint of reducing the gallate content in non-polymer catechins and reducing bitterness. The concentration reduction of the non-polymer catechin gallate body in the non-polymer catechins by hydrolysis is preferably 5% by mass or more, more preferably 7% by mass or more, and particularly preferably 10% by mass or more from the viewpoint of improving taste. The hydrolysis method is carried out by treatment with enzymes, acid treatment, alkali treatment or the like. As the enzyme, an enzyme having tannase activity, a bacterial cell or a culture solution, hydrochloric acid, sulfuric acid, phosphoric acid as the acid, and caustic soda as the alkali are preferable. Among them, hydrolysis with enzymes is preferable from the viewpoint of reaction control. Here, having tannase activity means having activity of degrading tannin, and any enzyme, fungus body, or culture solution can be used as long as it has this activity.

Specifically, pectinase PL Amano (manufactured by Amano Enzyme), hemicellulase amano 90 (manufactured by Amano Enzyme), tannase KTFH (manufactured by Kikkoman), etc. can be used as commercially available enzymes having tannase activity. Of these, tannase is preferred. For example, tannase obtained by culturing tannase-producing bacteria belonging to the genus Aspergillus, Penicillium or Rhizopus. Of these, those derived from Aspergillus oryzae are preferred.
The microbial cell having tannase activity is a microbial cell capable of producing an enzyme having tannase activity, and examples thereof include koji molds. For example, Aspergillus genus, Penicillium genus and the like can be mentioned, among which Aspergillus oryzae is preferable.
The culture solution having tannase activity is a culture solution obtained by culturing a tannase-producing bacterium of the genus Aspergillus, Penicillium, or Rhizopus. Preferably, a culture solution obtained by culturing tannic acid as the sole carbon source can be mentioned, and it can be used regardless of whether it is a purified product or an unpurified product.
Hydrolysis is preferably completed in a short time as much as possible from the viewpoint of suppression of flavor deterioration and productivity, and it is preferable to use an enzyme or a culture solution.
The enzyme or culture solution having tannase activity used in the present invention preferably has an enzyme activity of 500 to 100,000 U / g, and is treated within a limited time industrially as 500 U / g or more. The enzyme reaction rate can be controlled to be 100,000 U / g or less. Here, 1 Unit represents the amount of enzyme that hydrolyzes 1 micromole of an ester bond contained in tannic acid in water at 30 ° C.

The concentration of non-polymer catechins when performing treatment with an enzyme having tannase activity and a culture solution is preferably 0.1 to 22% by mass, more preferably 0.1 to 15% by mass, and particularly preferably 0.5 to It is 10% by mass, particularly preferably 0.5 to 3% by mass. If it is 0.1% by mass or less, the amount of adsorption increases at the time of subsequent adsorption to the synthetic adsorbent, and if it is 22% by mass or less, the hydrolysis treatment is shortened, which is preferable in terms of productivity and the taste of the green tea extract.
In order to obtain a non-polymer catechin gallate ratio with improved taste, an enzyme or a culture solution is added to the non-polymer catechins in the green tea extract so as to be in the range of 0.01 to 10% by mass. Is preferred. In order to complete the hydrolysis treatment within 2 hours, which is an industrially optimal enzyme reaction time, including the enzyme deactivation step, the enzyme or culture solution concentration is 0.01 to 7% by mass, and further, It is preferable that it is 03-5 mass%.
An enzyme having a tannase activity with respect to non-polymer catechins in a green tea extract or a culture solution, preferably 1 to 300 Unit / g-non-polymer catechin, more preferably 3 to 200 Unit / g-non-polymer catechin, Especially preferably, it adds so that it may become 5-150Unit / g-non-polymer catechin.
The treatment temperature with the enzyme or the culture solution is preferably 0 to 70 ° C., more preferably 0 to 60 ° C., and particularly preferably 5 to 50 ° C. at which the optimum enzyme activity can be obtained.

  In order to terminate the hydrolysis reaction with the enzyme or the culture solution, it is necessary to deactivate the enzyme. Enzyme inactivation is achieved by heating. The enzyme deactivation temperature is preferably 70 to 100 ° C. If it is less than 70 ° C., it is difficult to deactivate the enzyme sufficiently in a short time, so that the hydrolysis reaction proceeds. The deactivation method of the enzyme reaction can be stopped by heating in a batch system or a continuous system such as a plate heat exchanger. In addition, after completion of inactivation of tannase, the tea extract can be clarified by an operation such as centrifugation.

  When, for example, gonococcus is used as the bacterial cell, the concentration of non-polymer catechins is preferably 0.1 to 22% by mass, more preferably 0.1 to 15% by mass, and particularly preferably 0.5 to 15% by mass. % Is added to the tea extract and hydrolyzed. Aspergillus oryzae has characteristics that vary greatly depending on its type, etc., but usually in the range of 0.5% by mass to 10% by mass, especially 1.0% by mass to 5% by mass with respect to the non-polymer catechins in the tea extract. % Is added. As temperature conditions, 45 to 70 degreeC, Furthermore, 50 to 60 degreeC is preferable. The fermentation time is usually 12 hours to 20 days, and preferably 1 day to 10 days. The inactivation of the enzyme activity of Aspergillus is the same as when the hydrolysis reaction with the enzyme or the culture solution is terminated.

In the present invention, first, a green tea extract is adsorbed on a synthetic adsorbent, and then a basic aqueous solution is contacted to elute non-polymer catechins. Caffeine and gallic acid can be reduced by the synthetic adsorbent treatment.
After adsorption, it is preferable to wash the synthetic adsorbent and remove gallic acid and impurities in the synthetic adsorbent before contacting the basic aqueous solution.
Synthetic adsorbents are generally insoluble three-dimensional crosslinked structure polymers that are substantially free of functional groups such as ion exchange groups. Preferably, those having an ion exchange group of less than 1 meq / g can be used. As the synthetic adsorbent used in the present invention, the matrix is styrene, such as Amberlite XAD4, XAD16HP, XAD1180, XAD2000 (Rohm & Haas, USA); Diaion HP20, HP21 (Mitsubishi Chemical); Sepabead SP850, SP825, SP700, SP70 (manufactured by Mitsubishi Chemical Corporation); VPOC1062 (manufactured by Bayer Corporation), modified styrene series in which the bromine atom is replaced with a nucleus to enhance the adsorptive power, such as Sepabeads SP205, SP206, SP207 (manufactured by Mitsubishi Chemical Corporation), methacrylic Systems such as Diaion HP1MG, HP2MG (Mitsubishi Chemical), phenols such as Amberlite XAD761 (Rohm and Haas), acrylics such as Amberlite XAD7HP (Rohm and Haas), polyvinyl, If example TOYOPEARL, HW-40C (manufactured by Tosoh Corporation), dextran-based, for example SEPHADEX, LH-20 (manufactured by Pharmacia), and the like can be used.
As the synthetic adsorbent, the matrix is preferably styrene, methacrylic, acrylic, or polyvinyl, and styrene is particularly preferable from the viewpoint of separability between catechin and caffeine.

As a means for adsorbing green tea extract to synthetic adsorbent, use a batch method in which synthetic adsorbent is added to green tea extract, stirred and adsorbed, and then recovered by filtration, or a column packed with synthetic adsorbent is used. A column method in which adsorption treatment is performed by continuous treatment is employed, but a continuous treatment method using a column is preferred from the viewpoint of productivity.
The column packed with the synthetic adsorbent is preliminarily SV (space velocity) = 0.5 to 10 [h ⁻¹ ], and 95 vol under a liquid passing condition of 2 to 10 [v / v] as the liquid passing ratio with respect to the synthetic adsorbent. It is preferable to remove the raw material monomer of the synthetic adsorbent, impurities in the raw material monomer, etc. by washing with a% ethanol aqueous solution. Then, SV = 0.5 to 10 [h ⁻¹ ], and a water passage condition of 1 to 60 [v / v] as a liquid passage ratio with respect to the synthetic adsorbent is performed to remove ethanol and remove the synthetic adsorbent. The ability to adsorb non-polymer catechins is improved by replacing the liquid-containing solution with an aqueous system.

As a means for adsorbing the green tea extract onto the synthetic adsorbent, it is preferable to pass the tea extract through a column packed with the synthetic adsorbent. The conditions for passing the green tea extract through the column filled with the synthetic adsorbent were SV (space velocity) = 0.5 to 10 [h ⁻¹ ], and 0 as the passage ratio for the synthetic adsorbent. It is preferable to pass through at 5 to 20 [v / v]. Adsorption of non-polymer catechins may be insufficient or unstable when the flow rate is 10 [h ^-1 ] or more and the flow rate is 20 [v / v] or more.

Furthermore, after adsorbing the green tea extract on the synthetic adsorbent, it is preferable to remove the gallic acid and impurities adhering to the synthetic adsorbent by washing with water or an organic solvent aqueous solution. The aqueous solution used for washing is preferably pH 7 or less from the viewpoint of catechin recovery, and a water-soluble organic solvent can be used as the organic solvent. Examples of the water-soluble organic solvent include acetone, methanol, ethanol and the like, and ethanol is preferable from the viewpoint of use in foods. The concentration of the organic solvent to be contained is preferably 0 to 20% by mass, preferably 0.1 to 10% by mass, and more preferably 1 to 5% by mass from the viewpoint of catechin recovery.
Gallic acid and impurities adhering to the synthetic adsorbent at a liquid passing speed of SV (space velocity) = 0.5 to 10 [h ⁻¹ ] and 1 to 10 [v / v] as the liquid passing ratio with respect to the synthetic adsorbent. Is preferably removed. Furthermore, it is possible to remove gallic acid and impurities and to recover non-polymer catechins by washing at a flow rate of SV = 0.5 to 5 [h ⁻¹ ] and a flow rate of 1 to 5 [v / v]. It is preferable in terms of rate.

  As the basic aqueous solution used for elution of non-polymer catechins, alkali metal salts, alkaline earth alkaline aqueous solutions, preferably sodium-based alkaline aqueous solutions such as sodium hydroxide aqueous solution and sodium carbonate aqueous solution are preferably used. Can do. The pH of the alkaline aqueous solution is preferably in the range of 7-14. From the point of non-polymer catechin recovery, 9 to 13.8, particularly 10 to 13.5 is preferable. Examples of the sodium-based aqueous solution having a pH of 7 to 14 include a 4% or less sodium hydroxide aqueous solution and a 4% or less sodium carbonate aqueous solution. The basic aqueous solution may contain a water-soluble organic solvent. As a density | concentration of an organic solvent, the range of 0-90 mass% is preferable from the point of the separability of caffeine and catechin, 0.1-50 mass% is more preferable, 1-20 mass% is still more preferable.

  In the elution step, two or more basic aqueous solutions having different pH values are used as the basic aqueous solution used for elution, and these basic aqueous solutions can be brought into contact with the synthetic adsorbent in order of decreasing pH. Different non-polymer catechins and other components can be desorbed in each pH category.

  The synthetic adsorbent used in the present invention can be reused after the practice of the present invention. Specifically, as the regeneration treatment, an insoluble component such as caffeine adsorbed on the synthetic adsorbent is passed through an organic solvent such as ethanol. Alternatively, a method of passing and washing an alkaline aqueous solution such as sodium hydroxide and desorbing all the water-soluble components remaining on the synthetic adsorbent can be used. Further, cleaning with water vapor may be combined.

  The eluate of non-polymer catechins is basic because it is eluted with a basic aqueous solution, and the pH of the eluate is adjusted to 7 or less from the viewpoint of the stability of the non-polymer catechins. Specifically, neutralization with an acid, removal of alkali metal ions by electrodialysis, or removal of alkali metal ions by a cation exchange resin can be used. As the ion exchange resin, it is particularly preferable to use an H-type cation exchange resin. From the simplicity of the process, pH adjustment with an ion exchange resin is preferred. Specifically, Amberlite 200CT, IR120B, IR124, IR118, Diaion SK1B, SK1BH, SK102, PK208, PK212, etc. can be used as the cation exchange resin.

The eluate whose pH is adjusted to 7 or less may be subjected to membrane filtration as it is, but after completion of pH adjustment of the eluate, it is concentrated, and then the supernatant obtained by separating and removing the precipitated suspension is diluted. Subsequent membrane filtration is preferred.
Here, the concentration is from 0.1 to 70% by mass, more preferably from 0.2 to 50% by mass, especially from 0.3 to 25% by mass, especially from the viewpoint of taste and separation of precipitates. Non-polymer catechins are preferably not precipitated under the conditions of 0.5 to 10% by mass, a pressure of 1.3 kPa to 20 kPa, and a temperature of 30 to 60 ° C. until impurities are precipitated. The concentration rate is preferably 2 to 500 times, more preferably 2 to 250 times, and particularly preferably 2 to 125 times from the viewpoint of taste and separability of precipitates. The resulting precipitate suspension is preferably subjected to solid-liquid separation by ordinary means. Here, examples of the solid-liquid separation means include filtration with a microfiltration membrane for the purpose of rough separation and / or centrifugation. The supernatant liquid after solid-liquid separation is diluted and then subjected to filtration of a microporous membrane. Here, the concentration of non-polymer catechins in the diluting solution is 0.1 to 4.0% by mass, more preferably 0.2 to 3.5% by mass, particularly 0.3 to 3.0% by mass, and particularly 0.5 It is preferable to set it to -2.0 mass% in terms of improving the film decolorization rate.

As the microporous membrane used for membrane filtration of the effluent after pH adjustment, a membrane having a fractional molecular weight of 100 to 500,000, more preferably 200 to 100,000, particularly 300 to 50,000, particularly 500 to 30,000 is preferable. It is preferable to use an outer filtration membrane or a reverse osmosis membrane.
As an ultrafiltration membrane to be used, SEP-3013, ACP-3013, AHP-3013, ACP-0013, SEP-0013 (manufactured by Asahi Kasei), FE10-FUS-5082 (manufactured by Daisen Membrane Systems), etc. A suitable membrane. Moreover, as a reverse osmosis membrane, common membranes, such as NTR-7410HG, NTR-7430HG, NTR-7450HG, are mentioned. The membrane used is preferably a continuous treatment type membrane such as a spiral or hollow fiber type. The membrane filtration improves the hue, and the purified green tea extract obtained is particularly preferable when used in beverages such as sports drinks and isotonic beverages.

  The purified green tea extract obtained by membrane filtration can also be used as it is for the production of beverages, but when brought into contact with activated carbon, effects of color tone improvement and flavor improvement can be obtained.

Examples of the raw material for the activated carbon include coconut shell, wood, and coal, with wood being preferred. Examples of the activated carbon activation method include a steam activation method, a gas activation method, and a chemical activation method, and the chemical activation method is preferable. For example, ZN-50, Y-10S, GS-1, GS-B (manufactured by Ajinomoto Fine Techno), Kuraray Coal GLC, Kuraray Coal PK-D, Kuraray Coal PW-D, Kuraray Coal GW, Kuraray Coal GA, Kuraray Coal GA-D, Kuraray Coal RP-15 (manufactured by Kuraray Chemical Co., Ltd.), white birch AW50, white birch A, white birch P, white birch KL, white birch M, white birch C, carborane, WH2C (manufactured by Nippon Envirochemicals), GM130A, CW130A, CW130AR , CW350AR, GL130A, SG, SGA, SGP (manufactured by Phutamura Chemical), coconut, MAS mark, plum bee mark, plum bee F mark (manufactured by Taihei Chemical Sangyo), CPG, CAL, S80A (manufactured by Mitsubishi Chemical Calgon), etc. Product can be used.
From the viewpoint of improving the color tone of the product, reducing the amount of activated carbon used, and improving the recovery rate, the following are preferable as the activated carbon. The average pore diameter is preferably 0.5 to 10 nm (nanometer), more preferably 1.0 to 9.0 nm, and particularly preferably 2.0 to 8.0 nm. The pore volume is preferably 0.01 to 2.5 mL / g, more preferably 0.1 to 2.0 mL / g, and particularly preferably 0.5 to 1.7 mL / g. The specific surface area is 800~2000m ² / g, further 900~1600m ² / g, particularly preferably in the range of 1000~1500m ² / g. These physical property values are values based on the nitrogen adsorption method.

  Activated carbon is 0.2 to 3.0 parts by weight, more preferably 0.3 to 2.5 parts by weight, especially 100 to 100 parts by weight of the eluate after filtration through a microporous membrane (non-polymer catechins 4% solution). It is preferable to add 0.5 to 2.0 parts by mass. If the amount of activated carbon added is too small, caffeine and hue improvement efficiency will deteriorate, and if it is too large, the cake resistance in the filtration step will be large and waste will increase, which is not preferable.

  The contact treatment between the filtrate and activated carbon may be performed by any method such as a batch method or a continuous treatment using a column. In general, powdered activated carbon etc. is added and stirred, and after selectively adsorbing impurities such as caffeine, a method of obtaining a filtrate from which impurities have been removed by filtration operation, or a column packed with granular activated carbon etc. is used. For example, a method of selectively adsorbing impurities by continuous treatment is employed. It is good to carry out by a method such as continuous treatment using an activated carbon column.

  The contact treatment between the filtrate and the activated carbon is preferably carried out at a temperature of 10 to 60 ° C. and further 20 to 40 ° C. in a series of purification operations.

  The purified green tea extract obtained by the present invention contains 25 to 90% by mass of non-polymer catechins in the solid content, but it is 40 to 95% by mass, more preferably 50 to 90% by mass, particularly 55 to 80% by mass. % Content is preferable.

  Moreover, the ratio in the total non-polymer catechins of the gallate body which consists of catechin gallate, epicatechin gallate, gallocatechin gallate, and epigallocatechin gallate in the refined green tea extract obtained by this invention is 0-60 mass%. Further, it is preferably 5 to 55% by mass from the viewpoint of reducing the bitterness of non-polymer catechins.

  The concentration of caffeine in the purified green tea extract obtained in the present invention is such that caffeine / non-polymer catechins (mass ratio) = 0 to 0.15, more preferably 0 to 0.1 relative to non-polymer catechins. In particular, 0 to 0.05, particularly 0 to 0.035 is preferable in terms of improving taste.

  The concentration of gallic acid in the purified green tea extract obtained in the present invention is gallic acid / non-polymer catechins (mass ratio) with respect to non-polymer catechins in terms of taste such as bitterness and sourness. = 0 to 0.1, more preferably 0 to 0.07, and particularly preferably 0 to 0.05.

  The purified green tea extract obtained by the present invention includes 25 to 90% by mass of non-polymer catechins in the solid content, 0 to 60% by mass of non-polymer catechin gallate body, gallic acid / non-polymer catechins ( A mass ratio of 0 to 0.1 and a caffeine / non-polymer catechin (mass ratio) of 0 to 0.15 are preferred in terms of taste improvement.

  The purified green tea extract obtained in the present invention can be used as it is. Further, the solvent may be removed by a method such as vacuum concentration or thin film concentration. When powder is desirable as the product form of the green tea extract, it can be pulverized by a method such as spray drying or freeze drying.

  The purified green tea extract obtained in the present invention can be blended into a container-packed beverage (green tea beverage, sports drink, isotonic beverage, etc.). Containers to be used are provided in ordinary forms such as molded containers (so-called PET bottles) mainly composed of polyethylene terephthalate, metal cans, paper containers combined with metal foil or plastic film, bottles, etc., as with general beverages. be able to. The term “packaged beverage” as used herein means a beverage that can be drunk without dilution.

  Moreover, said container-packed drink is manufactured on the sterilization conditions prescribed | regulated to the food hygiene law, for example, when it can heat-sterilize after filling a container like a metal can. For PET bottles and paper containers that cannot be sterilized by retort, sterilize under the same conditions as above, for example, after sterilizing at high temperature and short time with a plate heat exchanger, etc. The method is adopted. Moreover, you may mix | blend another component with the filled container under aseptic conditions.

(Measurement method of catechin, caffeine and gallic acid)
The sample solution was filtered with a filter (0.45 μm), and a high performance liquid chromatograph (model SCL-10AVP) manufactured by Shimadzu Corporation was used to pack an octadecyl group-introduced packed column L-column TM ODS (4.6 mmφ × 250 mm). : Chemical Substance Evaluation Research Organization) and a gradient method at a column temperature of 35 ° C. As a standard product of catechins, a product manufactured by Mitsui Norin was used and quantified by a calibration curve method. The mobile phase A solution was a distilled aqueous solution containing 0.1 mol / L of acetic acid, the B solution was an acetonitrile solution containing 0.1 mol / L of acetic acid, the sample injection amount was 20 μL, and the UV detector wavelength was 280 nm. .

(Measurement method of tannase activity)
Reagent A: pH 5.5 citrate buffer solution 50 mmol: 10.5 g of citric acid is dissolved in 800 mL of distilled water, adjusted to pH 5.5 with 1N NaOH solution, and diluted to 1000 mL.
Reagent B: 0.35 mass% substrate aqueous solution (tannic acid): 175 mg of tannic acid is dissolved in 50 mL of citrate buffer solution (reagent A).
Reagent C: 90 vol% ethanol solution.
Measuring method 1. Collect 1.0 mL of the substrate solution (reagent B) in a test tube and keep at 30 ° C. for 5 minutes.
2. Add 0.25 mL of sample solution and incubate at 30 ° C. for 15 minutes. In the blank solution, a citrate buffer solution (reagent A) is added instead of the sample solution.
3. Add 5.0 mL of ethanol solution (reagent C) to the sample solution and blank solution to stop the enzyme reaction.
4. Measure absorbance at 310 nm [sample: A _s , blank: A ₀ ].
The activity is calculated by the following formula.
Activity per volume (U / mL) = (A _s −A ₀ ) × 20.3 × 1.0 (mL) × 1.04 × df / (0.71 × 0.25 (mL) × 15 (min )) = ΔA × 7.93 × df
Activity per mass (U / g) = (U / mL) × 1 / C
20.3: μmol of tannic acid contained in 1.0 mL of the substrate solution (reagent B).
0.71: Change in absorbance after complete hydrolysis of 20.3 μmol of tannic acid under analytical conditions, 1.04: conversion factor, df: dilution factor, C: in sample (g / mL) Tannase concentration.

(Evaluation of color tone)
Using a spectrophotometer of HITACHI (model U-2001 type), measurement was performed by diluting with ion-exchanged water so that the concentration of non-polymer catechins in the sample was 0.175% by mass in a glass cell. The measurement wavelength of the spectrophotometer at the time of analysis was set to 450 nm.

(Membrane decolorization rate)
The “color tone of the solution after membrane filtration” measured by the method based on the evaluation of the color tone is divided by the “color tone of the solution before membrane filtration (membrane untreated solution)”.

(Evaluation of purified product)
The purified tea extract obtained in each example was diluted with deionized water so that the non-polymer catechins content was 0.175% [w / v], and 40 mL thereof was put into a 50 mL pressure-resistant glass container. I put it in. Thereto was added 0.1% by mass of Na ascorbate, the pH was adjusted to 6.4 with a 5% aqueous sodium bicarbonate solution, nitrogen substitution was performed, and the mixture was sterilized by heating in an autoclave at 121 ° C. for 10 minutes. Then, the evaluation panelists evaluated the bitterness, sourness, and hue of the aftertaste. The bitterness was evaluated by the quinine sulfate method.

(Evaluation of bitterness by quinine sulfate method (equivalent concentration test method))
Quinine sulfate dihydrate was adjusted to a concentration corresponding to the bitterness intensity described in the table. After tasting the evaluation sample, it was determined which sample of the standard bitterness solution had the same bitterness intensity. The bitterness intensity was confirmed by five evaluation panelists. (Reference: New edition Sensory Test Handbook, Nikkatsu Rensen Sensory Test Committee p448-449, Perception & Psychophysics, 5, 1696, 347-351)

Example 1
316 g of tannase-treated green tea extract is dissolved in 4784 g of ion-exchanged water to obtain “adsorption raw material liquid 1”. “Adsorption raw material liquid 1” contained 1.87% by mass of non-polymer catechins, and the gallate content of the non-polymer catechins composition was 31.3% by mass. Moreover, 0.37 mass% of caffeine and gallic acid / non-polymer catechins (mass ratio) were 0.107. It was 30.2 mass% of non-polymer catechins in the solid content of the tea extract.
Next, 2039 mL of a synthetic adsorbent SP-70 (manufactured by Mitsubishi Chemical Corporation) was packed in a stainless steel column 1 (inner diameter 110 mm × height 230 mm, volume 2185 mL). A stainless steel column 2 (inner diameter 38 mm × height 770 mm, 278 volume mL) was charged with 814 mL of ion exchange resin SK1BH (manufactured by Mitsubishi Chemical Corporation). In both columns, SV = 5 (h ⁻¹ ) and 95% (v / v) ethanol through 4 times volume (vs. packed resin), and then 10 times volume (vs. filled resin) of water. Washed. Thereafter, 5098 g (2.5 times volume vs. synthetic adsorbent) of the obtained “adsorption raw material liquid 1” was passed through the column 1 at SV = 1 (h ⁻¹ ), and the permeate was discarded. Then, it was washed with 2039 mL (1 volume vs. synthetic adsorbent) of ion exchange water at SV = 1 (h ⁻¹ ). After washing with water, 15293 mL of 0.4 mass% aqueous sodium hydroxide solution (pH 11.6) was passed at SV = 3 (h ⁻¹ ) (7.5 times volume vs. synthetic adsorbent). The eluate was continuously passed through the column 2 and deionized to obtain “resin-treated product 1” of 14720 g (pH 3.8) of a non-polymer catechin composition. This extract contained 0.50% by mass of non-polymer catechins (turbidity of 18 NTU), and the gallate content of the non-polymer catechins composition was 39.2% by mass. Moreover, 0 mass% of caffeine, gallic acid / non-polymer catechins (mass ratio) were 0.008, and the color tone at 400 nm was 0.65. It was 66.1% by mass of non-polymer catechins in the solid content of the tea extract.
Next, “resin-treated product 1” was directly filtered through an ultrafiltration membrane (ACP-0013 molecular weight cut off 13000) to obtain “membrane-treated product 1”. The gallate content of the non-polymer catechin composition in this liquid was 38.4% by mass. Further, 0% by mass of caffeine, gallic acid / non-polymer catechins (mass ratio) were 0.008, and the color tone at 400 nm was 0.46.
Next, after adjusting the concentration and dilution of “membrane treated product 1” to 4.0% by weight of catechin and 20% of ethanol, the resulting solution was brought into contact with 0.50 g of activated carbon (SGP manufactured by Phthamura Chemical Co., Ltd.) Ethanol was distilled off by concentration under reduced pressure (2.6 kPa, 40 ° C.) to obtain “Purified Green Tea Extract 1”. The color tone (OD450nm 0.09) of the purified product was good, and there was little bitterness and sourness.

Example 2
32 kg of green tea extract is dissolved in 968 kg of tap water to obtain “adsorption raw material liquid 2”. “Adsorption raw material liquid 2” contained 0.99% by mass of non-polymer catechins, and the gallate content of the non-polymer catechins composition was 54.4% by mass. Moreover, they were 0.17 mass% of caffeine and 0.022 gallic acid / non-polymer catechins (mass ratio). It was 34.3 mass% of non-polymer catechins in the solid content of the tea extract.
Next, 250 L of a synthetic adsorbent SP-70 (manufactured by Mitsubishi Chemical Corporation) was packed in a stainless steel column 3 (inner diameter 700 mm × height 1358 mm, volume 524 L). A stainless steel column 4 (inner diameter 400 mm × height 1160 mm, volume 131 L) was charged with 75 L of ion exchange resin SK1BH (manufactured by Mitsubishi Chemical Corporation). In both columns, after SV = 1.5 (h ⁻¹ ), water was passed 5 times volume (vs. packed resin) and 95 (v / v) ethanol was passed 10 times volume (vs. filled resin). Then, water was washed by passing 10 times volume (vs. filled resin). Thereafter, 1000 kg (4.0 times volume vs. synthetic adsorbent) of the obtained “adsorption raw material liquid 2” was passed through the column 1 at SV = 1 (h ⁻¹ ), and the permeate was discarded. Then, it was washed with 250 L (1 volume vs. synthetic adsorbent) of tap water at SV = 1 (h ⁻¹ ). After rinsing with water, 2500 L of 0.1 mass% sodium hydroxide aqueous solution (pH 12.6) was passed at SV = 3 (h ⁻¹ ) (10 times volume vs. synthetic adsorbent). The eluate was continuously passed through the column 4 and deionized to obtain “resin-treated product 2” of 2500 kg (pH 1.2) of the non-polymer catechin composition. This extract contained 0.41% by mass of non-polymer catechins, and the gallate content of the non-polymer catechins composition was 52.7% by mass. The content of caffeine was 0% by mass, gallic acid / non-polymer catechins (mass ratio) were 0.004, and the non-polymer catechins in the solid content of the tea extract were 67.6% by mass.
Furthermore, “resin-treated product 2” was subjected to concentration treatment under reduced pressure (2.6 kPa, 40 ° C.) with a non-polymer catechin concentration of 6.71% by weight (turbidity 542 NTU), and then centrifuged (8000 rpm, 15 ° C.). 15 minutes), and the suspension is subjected to solid-liquid separation (turbidity 38 NTU / OD450 nm 0.20) to obtain “green tea extract clarified liquid 1”.
Next, the “green tea extract clarified liquid 1” was diluted with ion-exchanged water to a catechin concentration of 0.46% by weight and then filtered through an ultrafiltration membrane (ACP-0013 molecular weight cut off 13000). Product 2 "was obtained. The gallate content of the non-polymer catechin composition in this liquid was 50.5% by mass. Moreover, 0 mass% of caffeine, gallic acid / non-polymer catechins (mass ratio) were 0.004, and the color tone at 450 nm was 0.12.
Next, after “Membrane treated product 2” was concentrated and diluted to 4.0% by weight of catechin and 20% of ethanol, and adjusted to 30 g of ethanol, 0.42 g of activated carbon (SGP manufactured by Phthamura Chemical Co., Ltd.) was contacted The ethanol was distilled off by concentration under reduced pressure (2.6 kPa, 40 ° C.) to obtain “Purified Green Tea Extract 2”. The color tone (OD450nm 0.07) of the purified product was good and the acidity was low.

Example 3
The “green tea extract clarified liquid 1” obtained in Example 2 was diluted with ion-exchanged water to a catechin concentration of 1.86% by weight, and then filtered through an ultrafiltration membrane (ACP-0013 molecular weight cut off 13,000). To obtain “Membrane treated product 3”. The gallate content of the non-polymer catechin composition in this liquid was 50.9% by mass. Moreover, 0 mass% of caffeine, gallic acid / non-polymer catechins (mass ratio) were 0.003, and the color tone at 450 nm was 0.16.
Next, after concentrating and diluting “Membrane treated product 3” to 4.0% by weight of catechin and 20% ethanol as a solvent, 30 g of the adjustment liquid was brought into contact with 0.55 g of activated carbon (SGP manufactured by Phthamura Chemical). Then, ethanol was distilled off by concentration under reduced pressure (2.6 kPa, 40 ° C.) to obtain “Purified Green Tea Extract 3”. The color tone (OD450nm 0.07) of the purified product was good and the acidity was low.

Example 4
The “green tea extract clarified liquid 1” obtained in Example 2 was diluted with ion-exchanged water to a catechin concentration of 0.49% by weight, and then filtered through an ultrafiltration membrane (SEP-0013 molecular weight cut off 3000). To obtain “Film-treated product 4”. The gallate content of the non-polymer catechin composition in this liquid was 50.7% by mass. Moreover, 0 mass% of caffeine, gallic acid / non-polymer catechins (mass ratio) were 0.003, and the color tone at 450 nm was 0.14.
Next, after “Membrane treated product 4” was concentrated and diluted to 4.0% by weight of catechin and 20% of the solvent, ethanol was contacted with 0.44 g of activated carbon (SGP manufactured by Phthamura Chemical Co.) with respect to 30 g of the adjustment liquid. Then, ethanol was distilled off by concentration under reduced pressure (2.6 kPa, 40 ° C.) to obtain “Purified Green Tea Extract 4”. The color tone (OD450nm 0.07) of the purified product was good and the acidity was low.

Example 5
The “green tea extract clarified liquid 1” obtained in Example 2 was diluted with ion exchange water to a catechin concentration of 0.49% by weight, and then reverse osmosis membrane (NTR-7410HG-S2F molecular weight cut off 500). Filtration was performed to obtain “Membrane treated product 5”. The gallate content of the non-polymer catechin composition in this liquid was 46.7% by mass. Further, 0% by mass of caffeine, gallic acid / non-polymer catechins (mass ratio) were 0.005, and the color tone at 450 nm was 0.13.
Next, after “Membrane treated product 5” was concentrated and diluted to 4.0% by weight of catechin and 20% of ethanol, and adjusted to 30 g of ethanol, 0.45 g of activated carbon (SGP manufactured by Phthamura Chemical Co., Ltd.) was brought into contact with 30 g of the adjustment liquid. Then, ethanol was distilled off by concentration under reduced pressure (2.6 kPa, 40 ° C.) to obtain “Purified Green Tea Extract 5”. The color tone (OD450nm 0.07) of the purified product was good, the bitterness was slightly less, and the acidity was less.

Comparative Example 1
After concentrating and diluting “green tea extract clarified liquid 1” obtained in Example 2 to 4.0% by weight of catechin and adjusting the solvent to 20% of ethanol, activated carbon (SGP manufactured by Phthamura Chemical Co., Ltd.) was added to 30 g of the adjusted liquid. After contacting with 0.71 g, ethanol was distilled off by concentration under reduced pressure (2.6 kPa, 40 ° C.) to obtain “purified green tea extract 6”. The color tone (OD450nm 0.07) of the purified product is good and the acidity is small, but the amount of activated carbon used is large and the amount of waste increases.

Comparative Example 2
“Resin-treated product 2” obtained in Example 2 was subjected to concentration treatment under reduced pressure (2.6 kPa, 40 ° C.) with a non-polymer catechin concentration of 5.41% by weight (turbidity 436 NTU), and then centrifuged. (8000 rpm, 15 ° C., 15 minutes), and the suspension is subjected to solid-liquid separation (turbidity 38 NTU / OD450 nm 0.19) to obtain “green tea extract clarified liquid 2”.
Next, “green tea extract clarified liquid 2” was filtered through an ultrafiltration membrane (ACP-0013 molecular weight cut off 13000) to obtain “membrane treated product 7”. The gallate content of the non-polymer catechin composition in this liquid was 51.0% by mass. Moreover, 0 mass% of caffeine, gallic acid / non-polymer catechins (mass ratio) were 0.003, and the color tone at 450 nm was 0.18.
Next, after “Membrane treated product 7” was concentrated and diluted to 4.0% by weight of catechin and 20% of ethanol, and adjusted to 30 g of ethanol, 0.67 g of activated carbon (SGP manufactured by Phthamura Chemical Co., Ltd.) was brought into contact with 30 g of the adjustment liquid. Then, ethanol was distilled off by concentration under reduced pressure (2.6 kPa, 40 ° C.) to obtain “Purified Green Tea Extract 7”. The color tone (OD450nm 0.07) of the purified product is good and the acidity is small, but the amount of activated carbon used is large and the amount of waste increases.

Comparative Example 3
The “resin-treated product 1” obtained in Example 1 was subjected to concentration treatment under reduced pressure (2.6 kPa, 40 ° C.) with a non-polymer catechin concentration of 6.56% by weight (turbidity: 325 NTU). A concentrate is obtained.
Next, the “green tea extract concentrate” was diluted with ion-exchanged water to a catechin concentration of 0.5% by weight and then filtered through a microfiltration membrane (microfiltration membrane, flat membrane pore size 0.2 μm). 8 ”was obtained.
The gallate content of the non-polymer catechin composition in this liquid was 39.0% by mass. Moreover, 0 mass% of caffeine, gallic acid / non-polymer catechins (mass ratio) were 0.006, and the color tone at 450 nm was 0.52.
Next, after concentrating and diluting the “clarified liquid 8” to 4.0% by weight of catechin and adjusting the solvent to 20% of ethanol, 30 g of the adjusted liquid was contacted with 0.60 g of activated carbon (SGP manufactured by Phthamura Chemical), Ethanol was distilled off by concentration under reduced pressure (2.6 kPa, 40 ° C.) to obtain “Purified Green Tea Extract 8”. The refined product has a good color tone (OD450nm 0.09) and has a low acidity, but the amount of activated carbon used is large and the amount of waste increases.

  The green tea extracts described in Examples 1 to 6 and Comparative Examples 1 to 3 were sterilized based on the Food Sanitation Law, and the flavor was evaluated. The results are also shown in Table 2.

  In Examples 1 to 5, a green tea extract having a high recovery rate of non-polymer catechins before and after the treatment, a reduced caffeine concentration, and an improved hue was obtained by using a small amount of activated carbon. Comparative Example 1 Then, the hue before activated carbon treatment is dark because no membrane filtration is performed, and in Comparative Example 2, the membrane decolorization rate is low from the point of performing filtration through a microporous membrane while maintaining a high concentration. Although the rate is low and decolorization with activated carbon is possible in Comparative Examples 1 to 3, a large amount of activated carbon is required and the amount of waste increases.

Claims (5)

  The green tea extract is adsorbed on a synthetic adsorbent, and a basic aqueous solution is contacted with the synthetic adsorbent to elute non-polymer catechins. Then, the pH of the eluate is adjusted to 7 or less, and then the non-polymer catechins are obtained. The eluate adjusted to a concentration of 0.1 to 4.0% by mass is filtered through a microporous membrane, and the filtrate is brought into contact with activated carbon. The manufacturing method of the refined tea extract which obtains the refined tea extract containing%.   The method according to claim 1, wherein after completion of the adsorption step, the synthetic adsorbent is washed with water or an organic solvent aqueous solution, and then the basic aqueous solution is contacted with the synthetic adsorbent.   The production method according to claim 1 or 2, wherein the microporous membrane is an ultrafiltration membrane or a reverse osmosis membrane.   The production method according to any one of claims 1 to 3, wherein after the pH adjustment of the eluate is completed, the supernatant liquid obtained by concentrating and then separating and removing the precipitate suspension is diluted and subjected to filtration of a microporous membrane.   The method according to any one of claims 1 to 4, wherein the green tea extract is obtained by hydrolysis treatment.