JP2017148012A - Method for producing polyphenol-reduced beverage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a beverage having a reduced polyphenol content which is excellent in polyphenol removing efficiency and in which a handling of adsorbent material is facilitated.SOLUTION: According to the present invention, a method for producing a beverage having a reduced polyphenol content comprising contacting a polyphenol-containing beverage or the like with a polymer substrate obtained by graft polymerization of a polymerizable monomer comprising N-vinylalkylamide is provided. According to the present invention, a method for reducing polyphenol content in a polyphenol-containing beverage or the like comprising contacting the polyphenol-containing beverage or the like with the polymer substrate is also provided.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a beverage with reduced polyphenols. The invention also relates to a method for reducing the polyphenol content in a polyphenol-containing beverage.

  Polyphenols are attracting attention as functional food materials because they have various biological functions such as anti-oxidation, hormone-like effects, and interactions with proteins. On the other hand, polyphenols are also causative substances that cause problems related to beverage quality such as turbidity, precipitation, browning, and flavor stability in the field of beverage production. In particular, in a packaged beverage, it is required to produce a quality-stable product that does not cause turbidity or precipitation even after long-term storage.

  Polyphenols are known to interact with various substances and functional groups from their structures, and various techniques have been disclosed so far for methods for reducing and removing polyphenols using their properties. As a representative technique, a technique is known in which polyvinylpolypyrrolidone (PVPP) is added to a polyphenol-containing beverage, and polyphenol is reduced and removed by PVPP (see, for example, Patent Documents 1 and 2).

  However, PVPP is an insoluble powder, and it is not easy to handle because it is swellable. Also, in the polyphenol reduction / removal technology using PVPP, PVPP is added to a beverage containing polyphenol and fixed. It was necessary to remove the PVPP adsorbed with polyphenol from the beverage by contact with the mixture for a period of time. For this reason, in the method of reducing and removing polyphenols using PVPP, the manufacturing process is complicated, and the manufacturing efficiency is not necessarily good. In addition, the above method requires dedicated equipment such as a filtration device and a centrifuge for completely removing PVPP from the beverage, and further, PVPP is not an inexpensive adsorbent, which increases the cost. .

JP-A-62-61569 JP-A-8-28235

  An object of the present invention is to provide a method for producing a beverage with reduced polyphenol content, which is excellent in polyphenol removal efficiency and easy to handle an adsorbing material, and a method for reducing polyphenol content in a polyphenol-containing beverage. .

  The present inventors have now contacted a graft-polymerized nylon fiber body obtained by polymerizing various polymerizable monomers on a nylon base material by a radiation graft polymerization method and a green tea extract. -It has been found that a nylon fiber body obtained by graft polymerization of pyrrolidone has an excellent catechin removal effect and has a small fluctuation range of beverage pH after treatment. The present inventors have also confirmed that the polyphenol removal effect of the graft-polymerized nylon fiber body is exhibited in polyphenol-containing beverages other than green tea extract. The present invention is based on these findings.

According to the present invention, the following inventions are provided.
[1] A beverage having a reduced polyphenol content, comprising contacting a polyphenol-containing beverage or a raw material thereof with a polymer substrate obtained by graft polymerization of a polymerizable monomer containing N-vinylalkylamide. Production method.
[2] The production method according to the above [1], wherein the N-vinylalkylamide is N-vinyl-2-pyrrolidone.
[3] The production method according to the above [1] or [2], wherein the pH of the beverage after contacting with the polymer base material or the raw material thereof is within a range of ± 0.3 with respect to the pH before contact. .
[4] The production method according to any one of the above [1] to [3], wherein the polymer substrate is a polymer substrate subjected to a regeneration treatment.
[5] The regeneration treatment according to any one of [1] to [4], wherein the regeneration treatment is performed by bringing the polymer substrate adsorbed with polyphenol into contact with a neutral regeneration agent, an alkaline regeneration agent, or an acidic regeneration agent. Manufacturing method.
[6] A polyphenol-containing beverage is green tea, black tea, oolong tea, blended tea, brewed liquor, distilled liquor, vegetable beverage, fruit beverage, fruit / vegetable mixed juice, coffee beverage, cereal milk, vinegar beverage or non-alcoholic beer-taste beverage or The production method according to any one of [1] to [5], which is a combination of these.
[7] The production method according to any one of [1] to [6] above, which is a container-packed beverage.
[8] A polyphenol-containing beverage or a raw material thereof, wherein the polyphenol-containing beverage or the raw material thereof is brought into contact with a polymer base material obtained by graft polymerization of a polymerizable monomer containing N-vinylalkylamide. How to reduce the amount.

  ADVANTAGE OF THE INVENTION According to this invention, the drink by which the polyphenol content was reduced with the high polyphenol removal rate can be manufactured only by making a polyphenol containing drink or its raw material liquid contact the polymeric base material formed by graft polymerization. The polymer base material can be processed into various shapes such as a fiber shape, and can be easily produced with a reduced polyphenol content without any handling problems.

FIG. 1 is a graph showing the relationship between the graft polymer fiber addition rate (%) and the total catechin removal rate (%) when the green tea extract and the graft polymer fiber body are brought into contact with each other. FIG. 2 is a graph showing the relationship between the contact time (min) and the total catechin removal rate (%) when the green tea extract and the graft polymerized fiber body are brought into contact with each other. FIG. 3 is a diagram showing the relationship between the contact temperature (° C.) and the total catechin removal rate (%) when the green tea extract is brought into contact with the graft polymer fiber. FIG. 4 is a graph showing the relationship between the regeneration treatment condition and the adsorption regeneration rate (%) when the green tea extract and the graft polymerized fiber body are brought into contact with each other.

Detailed description of the invention

  The production method of the present invention can be used to reduce the content of polyphenol in a polyphenol-containing beverage. The beverage to be applied is not particularly limited as long as it is a beverage containing polyphenol.

  Here, “polyphenol” is a general term for compounds having a plurality of phenolic hydroxyl groups in the molecule. Polyphenols are roughly classified into monomeric polyphenols (eg, anthocyanins, isoflavones, catechins (eg, epigallocatechin, epicatechin gallate, epigallocatechin gallate, catechin, gallocatechin, catechin gallate, gallocatechin gallate), etc. Flavonoids, phenylpropanoids represented by caffeic acid, chlorogenic acid, sesamin, and the like, and polymer polyphenols obtained by polymerizing monomer polyphenols. The latter polymers include proanthocyanidins (especially And condensed tannins such as procyanidins obtained by polymerization of catechins) and hydrolyzable tannins such as gallotannins.

  Polyphenols are found in plant leaves, stems, fruits, peels, seeds, roots, etc., and polyphenol-containing beverages are typically tea leaves, malt, hops, grains, vegetables, fruits, coffee, cacao It is a drink manufactured using plant raw materials such as. Examples of the “polyphenol-containing beverage” in the present invention include tea beverages (for example, green tea, black tea, oolong tea, blended tea), brewed sake (for example, malt fermented beverages such as beer and happoshu, Japanese sake, wine and cider fruits, etc. Liquor such as liquor, plum wine), distilled liquor (eg whiskey, shochu, brandy), vegetable drink (eg tomato juice, carrot juice, tomato mix juice, carrot mix juice), fruit drink (eg apple juice, orange juice) , Fruit juice mixed drinks, fruit and vegetable mixed juices, coffee drinks, cereal milk (eg, soy milk, rice milk, coconut milk, almond milk), vinegar drinks (eg fruit vinegar drinks) and non-alcoholic beer-taste drinks. . In addition, the polyphenol-containing beverage provided in the present invention may be a combination of two or more of the above beverages, for example, a combination of a tea beverage such as lemon tea and a fruit beverage.

  The measurement of the polyphenol content in the polyphenol-containing beverage can be determined according to the nature of the beverage and the type of polyphenol contained in the beverage. For example, in the case of a tea beverage, the amount of tannin can be set as the polyphenol content, and the polyphenol content can be measured using the iron tartrate method, which is a standard for evaluating the polyphenol content of teas. For fermented malt beverages such as beer, the polyphenol content is determined according to the EBC method (EUROPEAN BREWERY CONVENTION. Analytica-EBC), and for beverages and wines such as wine and apple juice, according to the foreign thiocult method. Can be measured. Alternatively, each specific component may be measured using high performance liquid chromatography (HPLC) as described in the Examples below.

  In the production method of the present invention, a polymer substrate obtained by graft polymerization of a polymerizable monomer containing N-vinylalkylamide as a polyphenol adsorbing material (hereinafter sometimes referred to as “polymer substrate of the present invention”). It is characterized by using.

  In the present invention, the graft polymerization is preferably performed by a radiation graft polymerization method, that is, a method of irradiating a substrate with radiation and polymerizing a polymerizable monomer on the substrate using radicals generated on the substrate surface or inside the substrate. Can be implemented.

  Ionizing radiation can be used as the radiation to irradiate the polymer substrate. Examples include α rays, β rays, γ rays, electron beams, and neutron rays. Gamma rays and electron beams having the ability to do so are preferred. The irradiation condition of radiation is not particularly limited as long as an appropriate functional group density is achieved, but it can be 5 to 200 kGy, preferably 30 to 100 kGy in a deoxygenated state. A method for bringing the reaction system into a deoxygenated state is known to those skilled in the art. For example, a treatment such as bubbling an inert gas such as nitrogen into the reaction system can be performed.

  When ionizing radiation is irradiated to a polymer substrate, radicals are generated on the surface and inside of the polymer substrate, and when the irradiated substrate is brought into contact with a polymerizable monomer, the generated radical is used as a starting point for the irradiation. A monomer can be polymerized on the formed substrate. The radiation graft polymerization can be carried out, for example, by immersing the polymer substrate in a solution in which a polymerizable monomer is diluted.

  Here, the polymer substrate is not particularly limited as long as the graft polymerization reaction proceeds and the polymer substrate can be used for the polyphenol reduction treatment. For example, polyolefin resin (for example, polyethylene, polypropylene), polyamide-based polymer Resins (eg, nylon) and cellulose can be mentioned. In addition, the shape of the polymer base material can be made into a fiber shape, a hollow fiber shape, a nonwoven fabric shape, or a bead shape from the viewpoint of efficiently performing the polyphenol reduction treatment.

  Moreover, N-vinyl alkylamide is mentioned as a polymerizable monomer with which graft polymerization reaction with a polymer base material is carried out. N-vinylalkylamide can be represented by the following formula (I).

R ¹ —C (═O) —N (—R ² ) —CH═CH ₂ (I)
(In the above formula, R ¹ represents an alkyl group having 1 to 4 carbon atoms, R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, or R ¹ and R ² together represent the number of carbon atoms. Represents an alkylene group of 3 to 5.)

  The “C 1-4 alkyl group” may be linear, branched, cyclic, or a combination thereof, for example, methyl, ethyl, propyl, butyl, isopropyl, isobutyl, tert-butyl. , Cyclopropyl, cyclobutyl and the like, preferably a linear alkyl group having 1 to 3 carbon atoms, and more preferably methyl.

Preferred embodiments of the compound of formula (I) include the following.
A compound of formula (I) (N-vinylacetamide) wherein R ¹ represents a methyl group and R ² represents a hydrogen atom
The compound of formula (I) (N-vinyl-2-pyrrolidone) in which R ¹ and R ² together represent an alkylene group having 3 carbon atoms
A compound of formula (I) (N-vinylpiperidone) in which R ¹ and R ² together represent a C 4 alkylene group

  The ratio (functional group density) of the polymerizable monomer graft polymerized per unit mass of the polymer substrate can be arbitrarily set according to the polymerizable monomer and the graft polymerization conditions.

  The production method of the present invention includes a step of bringing a polyphenol-containing beverage or a raw material thereof into contact with the polymer substrate of the present invention. The contacting step can be performed by immersing the polymer substrate of the present invention in a polyphenol-containing beverage or its raw material, but the filter is filled with the polymer substrate of the present invention or the polymer substrate of the present invention. It can also be carried out by passing a polyphenol-containing beverage or its raw material through the column.

  The contact time and contact temperature between the polyphenol-containing beverage or its raw material and the polymer substrate of the present invention can be appropriately determined according to the amount of polyphenol to be removed while referring to the examples described later. In addition, since the polyphenol removal ability of the polymer base material of the present invention does not decrease even when the liquid temperature is relatively high as shown in Examples below, for example, tea extract after hot water extraction Can be brought into contact with the polymer substrate of the present invention, and a tea beverage with a reduced polyphenol content can be produced efficiently.

  According to the production method of the present invention, a beverage having a reduced polyphenol content can be produced. Here, the “beverage with reduced polyphenol content” means a beverage with a reduced polyphenol content compared to a polyphenol-containing beverage produced without contact with the polymer substrate of the present invention, For example, a beverage having a polyphenol content of 90% or less (preferably 80% or less, more preferably 70% or less) of the polyphenol content of a beverage produced without being brought into contact with the polymer substrate of the present invention. .

  The production method of the present invention is characterized in that the fluctuation range of the pH of the beverage after being brought into contact with the polymer substrate of the present invention or its raw material can be suppressed to a small value. Specifically, the pH of the beverage or its raw material after contact with the polymer substrate of the present invention is within ± 0.3 (preferably within ± 0.2) relative to the pH before contact. Can be achieved. If there is a large variation in pH in the contact step, it is necessary to adjust the pH with a pH adjuster or the like in the subsequent step, and the flavor of the beverage may be affected by the pH adjuster or the like. Since the fluctuation range of the pH after contact with the polymer substrate of the invention is small, there is almost no need for pH adjustment with a pH adjuster, and a beverage with excellent flavor can be produced. Here, the fluctuation of the pH is within a range of ± 0.3, for example, when the pH of the beverage or its raw material before being brought into contact with the polymer base material of the present invention is 5.88. It means that later pH is 5.58-6.18.

  In the production method of the present invention, the polyphenol-containing beverage or its raw material is brought into contact with the polymer base material of the present invention, but whether to contact the polyphenol-containing beverage or its raw material depends on the polyphenol removal rate, production efficiency, It can be determined for each beverage in consideration of the influence on the flavor and the like. For example, when producing a tea beverage or a coffee beverage, the tea extract or the coffee extract can be brought into contact with the polymer substrate of the present invention. The tea extract used in the present invention is not only a tea extract extracted from tea leaves, but also commercially available products such as polyphenone (manufactured by Mitsui Norin Co., Ltd.), sunphenon (manufactured by Taiyo Kagaku Co., Ltd.), and theafuran (manufactured by ITO EN). Tea extracts and powders may be used, and those extracts and powders dissolved in water or hot water may be used. Furthermore, these concentrated tea extracts and purified tea extracts may be used alone, or may be used by mixing a plurality of types, or may be used by mixing with a tea extract.

  In the case of producing brewed liquor such as fermented malt beverage and fruit liquor, the fermentation solution before fermentation or after fermentation can be brought into contact with the polymer base material of the present invention. It is preferable to contact the liquid with the polymer substrate of the present invention. Moreover, when manufacturing a fruit drink and a vegetable drink, concentrated fruit juice and concentrated vegetable juice can be made to contact with the polymer base material of this invention.

  In the manufacturing method of this invention, it can implement according to the manufacturing procedure of a normal drink except making a polyphenol containing drink or its raw material and the polymer base material of this invention contact.

  For example, when producing a tea beverage or a coffee beverage, the tea extract or the coffee extract brought into contact with the polymer base material of the present invention is used for producing a normal tea beverage or a coffee beverage, if necessary. Tea drinks and coffee drinks can be produced by adding the blended ingredients. Examples of the above ingredients include sweeteners, acidulants, fragrances, pigments, bitterings, preservatives, antioxidants, thickening stabilizers, emulsifiers, dietary fibers, pH adjusters, enzymes, and reinforcing agents. Although an agent is mentioned, it is not limited to these.

  In addition, when producing brewed liquor such as fermented malt beverage and fruit liquor, it is used for the production of ordinary brewed liquor, if necessary, in the fermented liquor after brewing brought into contact with the polymer base material of the present invention. The brewed liquor can be produced by adding the blended ingredients. Examples of the ingredients include sweeteners, acidulants, fragrances, pigments, foaming / foaming improvers, bitterings, preservatives, antioxidants, thickening stabilizers, emulsifiers, dietary fibers, pH adjusters, Although food additives, such as an enzyme and a fortifier, are mentioned, it is not limited to these.

  The beverage with reduced polyphenol content produced according to the present invention can be provided as a container-packed beverage through steps such as a filling step and a sterilizing step in addition to the blending step. For example, the blended liquid obtained in the blending step can be sterilized according to a conventional method and filled into a container. Sterilization may be before filling the container or after filling. The filling step and the sterilizing step are known in the art and can be appropriately determined according to the liquid type.

  The container used for the beverage produced according to the present invention may be any container that is usually used for filling beverages, and can be appropriately selected according to the liquid type. Examples of containers include metal cans, barrel containers, plastic bottles (for example, PET bottles, cups), paper containers, bottles, pouch containers, etc., preferably metal can / cask containers, plastic bottles ( For example, a PET bottle) and a bottle are mentioned. Although the container-packed beverage has a problem that turbidity, precipitation, etc. occur even after long-term storage, the production method of the present invention is suitable for the production of a container-packed beverage because polyphenol can be efficiently removed.

  In the production method of the present invention, a polymer substrate having a polyphenol adsorption function regenerated is prepared by subjecting the polymer substrate used for polyphenol adsorption to regeneration treatment, and the polymer group subjected to regeneration treatment is prepared. The material may again be used for polyphenol adsorption. That is, the production method of the present invention may include a step of bringing the polymer substrate after polyphenol adsorption into contact with a regenerant, and then obtaining a polymer substrate with regenerated polyphenol adsorption ability. Moreover, after making the polymer base material after polyphenol adsorption | suction contact with a regeneration agent, the process of collect | recovering the polyphenol eluted from the polymer base material may be further included. The regenerant that removes polyphenol from the used polymer base material may be any of a neutral regenerator, an alkaline regenerator, and an acidic regenerator as long as it is acceptable for food hygiene. Examples of the neutral regenerant include ion-exchanged water, and examples of the alkaline regenerator include one or more alkali components such as sodium hydroxide, sodium silicate, sodium bicarbonate, sodium carbonate, and the like. Examples of the acidic regenerant include aqueous solutions containing one or more acids such as phosphoric acid, hydrochloric acid, nitric acid, sulfuric acid, citric acid, and hypochlorous acid. Can be mentioned. Thus, since the polymer substrate used in the production method of the present invention can be recycled, it can be used repeatedly and does not require disposal, which is advantageous in that the production cost can be reduced.

  The polymer base material used in the production method of the present invention can also be processed into various shapes such as fibers, so that it is possible to easily produce a beverage with a reduced polyphenol content without any handling problems. it can. Moreover, since the maintenance process and the filtration process are unnecessary in the contact process with the polymer base material of the present invention, it is advantageous in that the process is simplified and the production efficiency is improved. Furthermore, since the polymer base material of the present invention is solid, it is advantageous in that there is no problem of swelling.

  According to another aspect of the present invention, a polyphenol-containing beverage or a raw material thereof, and a polymer substrate obtained by graft polymerization using N-vinylalkylamide as a monomer are brought into contact with each other. A method is provided for reducing the polyphenol content in the feedstock. The polyphenol content reduction method of the present invention can be carried out according to the description of the production method of the present invention.

Example 1: Addition rate and catechin removal characteristics in green tea (1) Preparation of green tea extract 400 g of hot water at 70 ° C. was added to 10 g of green tea leaves and extracted for 10 minutes. After extraction, a mesh having an opening of 100 μm was passed through and rapidly cooled to 20 ° C. on ice to obtain a green tea extract.

(2) Graft-polymerized fiber treatment to green tea extract A graft-polymerized nylon fiber (functional group density of about 4 mmol / g, obtained by polymerizing N-vinyl-2-pyrrolidone on a nylon base material by radiation graft polymerization. Was added to the green tea extract at different addition rates, and contacted with shaking at a predetermined temperature (20 ° C.) for 2 hours, and then the graft polymerized fiber was removed to obtain a green tea treatment liquid. .

(3) Measurement of total catechin concentration After the green tea liquid obtained in (2) above was filtered with a membrane filter (DISMIC hydrophilic PTFE, 0.45 μm, manufactured by Advantech), the HPLC analysis conditions shown in Table 1 were performed at high speed. The total catechin concentration was measured by liquid chromatography (HPLC).

  The total catechin here is a total of catechins which are one kind of polyphenols generally present in green tea, and epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECg), epigallocatechin. The total of 8 types of gallate (EGCg), catechin (C), gallocatechin (GC), catechin gallate (Cg), and gallocatechin gallate (GCg).

  From the total catechin concentration of the green tea extract before and after the graft polymerized fiber treatment, the total amount of catechin adsorbed on the graft polymerized fiber was calculated as the total catechin removal rate. The total catechin concentration in the green tea extract before the graft polymerization fiber treatment was 179.8 mg / 100 ml.

(4) Results Table 2 shows the addition rate of nylon fibers grafted with N-vinyl-2-pyrrolidone, the total catechin concentration after treatment, and the total catechin removal rate. Moreover, the relationship between the graft polymer fiber addition rate (%) and the total catechin removal rate (%) was as shown in FIG.

  It has been found that the removal rate of total catechins increases as the addition rate of the graft polymerized fiber increases.

Example 2: Contact time and catechin removal characteristics in green tea (1) Preparation of green tea extract A green tea extract was obtained in the same manner as in (1) of Example 1.

(2) Graft-polymerized fiber treatment to green tea extract Graft-polymerized nylon fiber obtained by polymerizing N-vinyl-2-pyrrolidone on a nylon base material by radiation graft polymerization as in Example 1 (2) The body is added so as to be 2% by mass with respect to the extract, and after making contact with the green tea extract at a predetermined temperature (20 ° C.) for various contact times, the graft polymerized fiber is removed. A green tea treatment solution was obtained.

(3) Measurement of total catechin concentration In the same manner as in (1) of Example 1, the total catechin concentration was measured, and the total catechin removal rate was calculated. The total catechin concentration of the green tea extract before the graft polymerization fiber treatment was 201.0 mg / 100 mL.

(4) Results The contact time and the total catechin removal rate of the nylon fiber graft-polymerized with N-vinyl-2-pyrrolidone were as shown in Table 3 and FIG.

  It was found that the longer the contact time of the graft polymerized fiber body, the higher the total catechin removal rate.

Example 3: Contact temperature and catechin removal characteristics in green tea (1) Preparation of green tea extract A green tea extract was obtained in the same manner as in (1) of Example 1.

(2) Graft-polymerized fiber treatment to green tea extract Graft-polymerized nylon fiber obtained by polymerizing N-vinyl-2-pyrrolidone on a nylon base material by radiation graft polymerization as in Example 1 (2) The body was added to 2% by mass with respect to the extract and brought into contact with shaking for 1 hour under various temperature conditions, and then the graft polymerized fiber was removed to obtain a green tea treatment solution.

(3) Measurement of total catechin concentration In the same manner as in (1) of Example 1, the total catechin concentration was measured, and the total catechin removal rate was calculated. The total catechin concentration of the green tea extract before the graft polymerization fiber treatment was 216.6 mg / 100 ml.

(4) Results The contact temperature and the total catechin removal rate of the nylon fiber graft-polymerized with N-vinyl-2-pyrrolidone were as shown in Table 4 and FIG.

  It was found that the higher the contact temperature of the graft polymerized fiber, the higher the removal rate of total catechins, and the removal rate of total catechins does not decrease even at 50 to 60 ° C., and the contact process can be carried out even at a relatively high temperature.

Example 4: Regeneration treatment conditions and polyphenol removal characteristics (1) Preparation of green tea extract A green tea extract was obtained in the same manner as (1) of Example 1.

(2) Graft-polymerized fiber treatment to green tea extract Graft-polymerized nylon fiber obtained by polymerizing N-vinyl-2-pyrrolidone on a nylon base material by radiation graft polymerization as in Example 1 (2) The body is added to 2% by mass with respect to the extract and brought into contact with the green tea extract at a predetermined temperature (20 ° C.) for 1 hour. It was.

(3) Regeneration treatment About the graft-polymerized fiber body brought into contact with the green tea extract in (2) above, the regeneration treatment was performed by washing for 5 minutes under various temperature conditions using various regeneration treatment solutions. The test section using sodium hydroxide (NaOH) or phosphoric acid as a regeneration treatment solution was further neutralized and washed with ion exchange water at 20 to 25 ° C. Each of the graft polymer fibers after the regeneration treatment was again brought into contact with the green tea extract before treatment under the same conditions as in (2) above to obtain a green tea treatment solution.

(4) Measurement of total catechin concentration The total catechin concentration was measured in the same manner as in (3) of Example 1, and the adsorption regeneration rate was calculated according to the following formula from the first total catechin removal rate and the total catechin removal rate after regeneration treatment. Calculated. The total catechin concentration of the green tea extract before the graft polymerization fiber treatment was 203.7 mg / 100 ml.

(5) Results Table 5 and FIG. 4 show the relationship between the regeneration treatment condition and the adsorption regeneration rate of the nylon fiber graft-polymerized with N-vinyl-2-pyrrolidone.

  It was found that the polyphenol removal ability was restored almost 100% by carrying out the regeneration treatment of the graft polymerized fiber using 2% NaOH. It has also been found that the ability to remove polyphenols is greatly restored even when relatively high-temperature ion-exchanged water or phosphoric acid is used.

Example 5: Polyphenol removal characteristics for various beverages (1) Preparation of test beverage (a) Preparation of black tea extract 400 g of hot water at 90 ° C. was added to 10 g of black tea leaf and extracted for 10 minutes. After extraction, a mesh with an opening of 100 μm was passed through and rapidly cooled to 20 ° C. on ice to obtain a black tea extract, which was used as a sample liquid for test (Sample 5-1).

(I) Preparation of beer Warm water was added to the malt pulverized product, hops were added to the wort obtained through the saccharification step and the filtration step, and the resulting wort was cooled and yeast was added. After alcohol fermentation, an aging period was set to obtain beer (malt use ratio: 100%), which was used as a sample liquid for test (sample 5-2).

(C) Preparation of wine and fruit juice Commercially available red wine and apple fruit juice (10 ° Brix) were used as test sample liquids (Sample 5-3 and Sample 5-4), respectively.

(2) Graft-polymerized fiber treatment of test sample Graft-polymerized nylon fiber obtained by polymerizing N-vinyl-2-pyrrolidone by a radiation graft polymerization method on a nylon substrate in the same manner as in Example 1 (2) The body was added so as to be 2% by mass with respect to the sample liquid, and brought into contact with the sample liquid at a predetermined temperature (20 ° C.) for 1 hour by shaking, and then the graft polymerized fiber body was removed to obtain a sample processing liquid. .

(3) Measurement of polyphenol concentration Polyphenol concentrations were measured using the iron tartrate method for black tea, the EBC method (EUROPEAN BREWERY CONVENTION. Analytica-EBC) for beer, and the foreign thiocult method for wine and apple juice. Specifically, the measurement was performed as follows.

  In the iron tartrate method, the absorbance at 540 nm is measured for a purple component produced by reacting a polyphenol in a liquid with an iron tartrate reagent. The same procedure is performed with a standard substance such as ethyl gallate, and the amount of polyphenol is quantified in terms of the compound.

  In the EBC method, the amount of polyphenol is quantified by utilizing the property of coloring by reacting a polyphenol in a liquid with an iron salt. The sample was treated with a carboxymethyl cellulose (CMC / EDTA) solution and an EDTA mixed solution, and after reacting trivalent iron ions and polyphenol in an alkaline solution to which concentrated ammonia solution was added, the sample solution was compared with the blank solution. The absorbance is measured at 600 nm for red.

  The foreign thiocult method is based on the reduction of polyphenols in an alkaline solution. The sample solution was stirred for about 2 hours after adding a phenol reagent to the sample and stirring, and then adding a sodium carbonate solution and stirring. Measure absorbance at 750 nm.

(4) Results Table 6 shows the polyphenol concentration before treatment and the polyphenol removal rate when nylon fibers graft-polymerized with N-vinyl-2-pyrrolidone were brought into contact with various beverages.

Example 6: Types of polymerizable monomers and catechin removal characteristics in green tea (1) Preparation of green tea extract A green tea extract was obtained in the same manner as in (1) of Example 1.

(2) Graft polymerization fiber treatment to green tea extract Obtained by polymerizing various polymerizable monomers (see Table 7) on a nylon base material by radiation graft polymerization to the green tea extract obtained in (1) above. The obtained graft-polymerized nylon fiber body was added so that it might become 1 mass% with respect to the extract, and it was made to contact by shaking at predetermined temperature (20 degreeC) for 3 hours. The functional group densities of the fibers obtained by graft polymerization of N-vinyl-2-pyrrolidone, glycidyl methacrylate, triethylenediamine, sodium iminodiacetate, and dimethylaminoethyl methacrylate were 3.9 mmol / g, 4.0 mmol / g, 2 It was 0.0 mmol / g, 1.9 mmol / g, 2.5 mmol / g. Thereafter, the graft-polymerized nylon fiber body was removed to obtain a green tea treatment liquid.

(3) Measurement of total catechin concentration In the same manner as in (1) of Example 1, the total catechin concentration was measured, and the total catechin removal rate was calculated. The total catechin concentration of the green tea extract before the graft polymerization fiber treatment was 188.0 mg / 100 mL.

(4) pH measurement About the green tea liquid obtained by said (2), it measured using the pH meter (made by Kubota), respectively. The pH of the green tea extract before the graft polymerization fiber treatment was 5.88.

(5) Results Table 7 shows the catechin removal rate, pH, and overall evaluation by various graft polymer fibers.

  Among various polymerizable monomers, it was found that a nylon fiber polymerized with N-vinyl-2-pyrrolidone has a high catechin adsorption ability and a small pH fluctuation after contact, and good results can be obtained. When the green tea extract is produced as a container-packed beverage, the additive for adjusting the pH affects the flavor. Therefore, in order to produce a beverage with a good flavor, adsorption with small fluctuations in the pH of the treatment liquid is performed. It is desirable to select an agent, but since a nylon fiber polymerized with N-vinyl-2-pyrrolidone has a small pH fluctuation and a high catechin removal rate, it is very much in comparison with other polymerized fiber bodies. It turns out to be advantageous.

Claims (8)

  A method for producing a beverage with reduced polyphenol content, comprising bringing a polyphenol-containing beverage or a raw material thereof into contact with a polymer base material obtained by graft polymerization of a polymerizable monomer containing N-vinylalkylamide.   The production method according to claim 1, wherein the N-vinylalkylamide is N-vinyl-2-pyrrolidone.   The production method according to claim 1 or 2, wherein the pH of the beverage or its raw material after being brought into contact with the polymer substrate is within a range of ± 0.3 with respect to the pH before the contact.   The manufacturing method according to any one of claims 1 to 3, wherein the polymer substrate is a polymer substrate subjected to a regeneration treatment.   The production method according to any one of claims 1 to 4, wherein the regeneration treatment is performed by bringing the polymer substrate adsorbed with polyphenol into contact with a neutral regeneration agent, an alkaline regeneration agent, or an acidic regeneration agent.   The polyphenol-containing beverage is green tea, black tea, oolong tea, blended tea, brewed liquor, distilled liquor, vegetable beverage, fruit beverage, fruit / vegetable mixed juice, coffee beverage, cereal milk, vinegar beverage or non-alcoholic beer-taste beverage or a combination thereof The production method according to any one of claims 1 to 5, wherein   The manufacturing method as described in any one of Claims 1-6 which is a container stuffing drink. Reduced polyphenol content in a polyphenol-containing beverage or its raw material, characterized by contacting the polyphenol-containing beverage or its raw material with a polymer base material obtained by graft polymerization of a polymerizable monomer containing N-vinylalkylamide how to.

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