WO2019044474A1 - Decolored tea extract, and method for producing same - Google Patents

Abstract

[Problem] To provide: a tea extract which can impart a tea leaf-derived flavor, particularly a tea leaf-derived taste, to a beverage such as so-called "near water" and flavored water without coloring the beverage in the preparation of the beverage; and a use of the tea extract, such as a tea beverage. [Solution] Disclosed are: a method for producing a decolored tea extract, the method including steps (A) to (E) mentioned below; a method for producing a tea beverage, particularly a container-packed tea beverage, comprising hydrolyzing the tea extract optionally after adding vitamin C to the tea extract; the decolored tea extract; and the container-packed tea beverage: (A) a step of mixing tea leaves with water; (B) a step of allowing a glycoside-decomposing enzyme to act subsequent to step (A); (C) a step of separating a tea leaf residue from an extract to produce a glycoside enzyme-treated tea extract subsequent to step (B); (D) a step of heating the glycoside enzyme-treated tea extract obtained in step (C); and (E) a step of removing an insoluble component from a heated glycoside enzyme-treated tea extract obtained in step (D) to obtain a decolored tea extract.

Description

Decolorized tea extract and method for producing the same

The present invention relates to a bleached tea extract and a process for the preparation thereof. More specifically, the present invention relates to a tea extract having good aroma, umami and bitterness inherent to tea despite its light color, and a process for producing the same including a glycosidolytic enzyme treatment step of tea leaves.

In recent years, due to diversification of consumer preference for container-packed beverages, container-packed beverages in which a colorless and transparent container is filled with a substantially colorless and transparent beverage are often found in the market. Such beverages are also called near water, flavored water, etc., and the colorlessness of the appearance is one of the important factors. Examples of such almost colorless and transparent beverages are those having citrus flavors such as lemon, orange and orange, flavors of soft fruits such as grapes, apples and peaches, and fermented milk such as yoghurt. There are not many things that have a flavor of.

The flavor of tea can be reproduced to a certain extent only by the flavor having aroma of tea (compound flavor or natural flavor), but in order to give the true feeling of tea, it is possible to blend water-soluble ingredients derived from tea. It is possible to impart a more desirable flavor.

On the other hand, the tea extract is usually colored, and if it is attempted to mix the tea extract in an amount that imparts a flavor, the whole beverage will be colored light green to light brown.

As an invention for decoloring a tea extract, for example, a method is known in which a tea extract is subjected to cation exchange resin treatment to remove metal ions and then filtered through a microfiltration membrane to obtain a treated solution (Patent Document 1) However, there is a disadvantage that the amino acid which is a umami component is also removed by the cation exchange resin treatment.

Generally as a decoloring method, the process by adsorption materials, such as activated carbon, is known, and the processing technique by various adsorption agent processes is known also about tea. Patent Document 2 discloses a method for obtaining a tea extract by mixing or adding activated carbon during and / or after extraction of teas, but for the purpose of removing caffeine, decolorization is completely described. It has not been. Patent Document 3 discloses a method of bringing a caffeine-containing aqueous solution such as a tea extract into contact with activated white earth or acid white earth, but this method is also for the purpose of removing caffeine, and decoloration is completely described. It has not been. Moreover, although the method of making a tea extract liquid contact with polyvinylpolypyrrolidone is disclosed by patent document 4 or patent document 5, it is an objective in order to remove catechin or tannins, and it does not describe at all about decolorization.

As a process for producing green tea extract that can be used for sports drinks and isotonic drinks, the green tea extract is dissolved in a mixed solution of ethanol and water in a weight ratio of 91/9 to 97/3 and brought into contact with activated carbon and acid clay. Although the preparation method (patent document 6) of the obtained low caffeine green tea extract is disclosed, the main objective is removal of caffeine. In Patent Document 6, although it is considered that the hue is not deteriorated (eg, paragraph [0009]), a description that can be specifically identified regarding the color tone is not found, and is not described in the examples.

On the other hand, glucoside-degrading enzyme means an enzyme that hydrolyzes the bond (glycosidic bond) between the anomeric carbon of a glycoside and the aglycone part (glycosidic bond) to generate free aglycone. A method of producing a green tea beverage comprising an enzyme treatment step of converting a glycoside into an aroma component compound by adding a glycoside degrading enzyme prior to the heat sterilization treatment step of the green tea extract in the method of producing a beverage Patent Document 7), A method for producing a tea extract having enhanced aroma and the like, which comprises treating a tea leaf with tannase and / or after treating the tea leaf with a glycolytic enzyme (Patent Document 8), etc. Is known, but none of them describes only the content related to the odor generation. Further, in the cited reference 9, after concentrating a water extract of tea such as oolong tea to Bx 2 to 15 °, the concentrate is made to react with a glucoside degrading enzyme, so that the transparency is high, and it is possible to store for a long time. A method of producing a tea extract that does not occur is described. However, the color tone (such as the color depth) is not described at all.

Japanese Patent Publication No. 11-504224 JP-A-8-70772 JP-A-6-142405 Patent No. 3315304 JP 2003-204754 A Patent No. 4181982 JP 2004-147606 A JP, 2006-75112, A Patent No. 5818784

As described above, the method for decolorizing the tea leaf extract is mainly based on physicochemical treatment means, but it may have disadvantages or drawbacks such as the deterioration of the original flavor of tea leaves.

Therefore, an object of the present invention is to prepare a near water or flavored water-like beverage, a green tea extract capable of imparting a flavor derived from tea leaves, particularly taste, to the beverage without coloring, and It consists, for example, in presenting tea beverages, in particular container-packed tea beverages, using a green tea extract.

Although it is already known to cause glucoside-degrading enzymes to act on the water extract of tea leaves to convert glycosides into aroma component compounds, it is surprising that green tea leaves are now in the presence of water, After treating with glycoside degrading enzymes under certain conditions, the resulting glycoside enzyme-treated tea extract is heat treated to form a water-insoluble substance, and the water-insoluble substance is removed to give a flavor derived from tea leaves. It has been found that a clear and bleached green tea extract can be obtained without substantially damaging the In addition, it was also found that similar extracts were obtained from such a wide range of tea leaves not limited to green tea leaves by such treatment.

Thus, according to the present invention, the following is provided as an invention having, but not limited to, main aspects or features.
Aspect 1: A process for producing a decolorized tea extract comprising the following steps (A) to (E):
(A) A step of mixing tea leaves and water (B) A step of causing a mixture of (A) to have a glycosidolytic enzyme after step (A) (C) After step (B), tea leaf residue and an extract And separating the glycoside enzyme-treated tea extract (D) a step of heat-treating the glycoside enzyme-treated tea extract obtained in step (C),
(E) Step 2: Step of obtaining insoluble decolorized tea extract from the heated glycoside enzyme-treated tea extract obtained in step (D) to obtain a decolorized tea extract: simultaneously with or before or after step (B) The method for producing a decolorized tea extract according to aspect 1, further comprising the step of reacting tannase and / or pectinase before step (C).
Aspect 3: The decolorized tea according to aspect 1 or 2, further comprising the step of allowing a protease to act simultaneously with and / or after step (B) and before step (C). Method for producing an extract.
Embodiment 4: The method for producing a decolorized tea extract according to any one of Embodiments 1 to 3, wherein the heat treatment conditions in the step (D) are a temperature of 70 to 135 ° C. and a time of 2 seconds to 30 minutes. .
Aspect 5: A method for producing a decolorized tea extract according to any one of aspects 1 to 4, wherein the tea leaf is green tea.
Aspect 6: Before the step (A), steam-distilling the tea leaves to obtain an aroma-collected substance, and mixing the obtained aroma-collected substance into the clear liquid obtained in the step (E). The manufacturing method of the decolorized tea extract liquid in any one of-.
Mode 7: In any of the modes 1 to 6, wherein the amount of glycoside degrading enzyme used for tea leaves is 1 U / g or more, the temperature of the enzyme reaction is in the range of 30 to 70 ° C., and the reaction time is 30 minutes or more. The manufacturing method of the decolored tea extract as described.
Aspect 8: A method for producing a decolorized tea extract according to aspect 1, wherein the absorbance at 430 nm is 0.3 when the soluble solid content (refractive sugar content, temperature 20 ° C.) of the tea extract is 0.3. The method, wherein the absorbance is 5 or less and the absorbance at 680 nm is 0.15 or less.
Aspect 9: The method for producing a decolorized tea extract according to aspect 8, wherein the absorbance at 430 nm is 0.3 when the soluble solid content (refractive sugar content, temperature 20 ° C.) of the tea extract is 0.3. 1 or less and the absorbance at 680 nm is 0.05 or less.
Aspect 10: The absorbance at 430 nm is 0.15 or less and the absorbance at 680 nm is 0.05 or less, assuming that the soluble solid content (refractive sugar content, temperature 20 ° C.) of the tea extract is 0.3, and further the soluble solid content The green tea leaf extract which has a catechin content of 1.0% by mass or more when the (refractive index sugar content, temperature 20 ° C.) is 15.
Aspect 11: The absorbance at 430 nm is 0.5 or less and the absorbance at 680 nm is 0.15 or less, assuming that the soluble solid content (refractive sugar content, temperature 20 ° C.) of the tea extract is 0.3, and further the soluble solid content The green tea leaf extract which has an amino acid content of 1.0% by mass or more when the (refractive index sugar content, temperature 20 ° C.) is 15.
Aspect 12: A method for producing a low tannin tea extract, comprising the following steps (A) to (F):
(A) A step of mixing tea leaves and water (B) A step of causing a mixture of (A) to have a glycosidolytic enzyme after step (A) (C) After step (B), tea leaf residue and an extract And (G) separation of the glycoside enzyme-treated tea extract obtained in step (C) by heat treatment (E) step (D) obtained in step (D) Step of removing insoluble components from the heated glycoside enzyme-treated tea extract to obtain a decolorized tea extract (F) The decolorized tea extract obtained after the step (E) is further treated with PVPP (polyvinyl poly) Process for obtaining an extract from which PVPP has been removed by contacting with pyrrolidone) Step aspect 13: The method for producing a low tannin tea extract according to aspect 12, which is a soluble solid content of tea extract (refractory sugar content, temperature Whether the absorbance at 430 nm is 0.05 or less when 0.3 at 20 ° C) The absorbance at 680 nm is 0.05 or less, and the amino acid content is 1.0% by mass or more and the tannin (Folin-Denis method) is 1. when the soluble solid content (refractive sugar content, temperature 20 ° C.) is 15. The method which is 0 mass% or less.
Aspect 14: The absorbance at 430 nm is 0.05 or less and the absorbance at 680 nm is 0.05 or less when the soluble solid content (refractive sugar content, temperature 20 ° C.) of the tea extract is 0.3, and the soluble solid content is further A green tea leaf extract solution having an amino acid content of 1.0% by mass or more and a tannin (Folin-Denis method) of 1.0% by mass or less when the (refractive sugar content, temperature 20 ° C.) is 15.
Aspect 15: (G) a tea extract obtained by the method according to any one of aspects 1 to 9, 12 and 13, wherein the soluble solids derived from tea is 0.005 to 0.3% (Bx, Adjusting to 20 ° C.),
(H) The manufacturing method of the container-packed tea beverage including the process of adding vitamin C or its edible salt (sodium) to the tea beverage obtained at the process (G).
Aspect 16: The green tea extract according to aspects 10, 11 and 14 comprises 0.005% to 0.3% (Bx, 20 ° C.)% by mass as a soluble solid content derived from tea, and further vitamin C or the edible thereof Container-packed tea beverage containing salt (sodium).
Aspect 17: The container-packed tea beverage according to aspect 16, which comprises 0.002 to 0.3% by mass of vitamin C or an edible salt thereof (sodium).
Aspect 18: In aspect 16 or 17 in which the absorbance at 430 nm is 0.015 or less and the absorbance at 680 nm is 0.05 or less when the soluble solid content (refractive sugar content, temperature 20 ° C.) of the tea extract is 0.3. Container-packed tea beverage described.

According to the present invention, compared to the tea extract which has been decolorized by the conventionally used physical and chemical method, the tea extract having the flavor of the tea, in particular, the taste, and further the low tannin tea extract For example, tea beverages, particularly container-packed tea beverages, can be provided using the green tea extract.

The photograph which showed the external appearance of the liquid which diluted the green tea extract obtained in Example 1 to Bx0.3 degree is shown. From the left, the comparative product 1, the invention product 4, the invention product 5, the invention product 6, and the invention product 7. In Example 2, the photograph of the external appearance after leaving the liquid in the middle of a process for one night at 20 degreeC is shown. From left to right are (1), (2), (3) and (4). The photograph of the external appearance of the liquid which diluted the green tea extract obtained in Example 3 to Bx0.3 degree is shown. The left is the comparative product 4 and the right is the product 8 of the present invention. The photograph which showed the external appearance of the liquid of the middle stage of the comparative product 5 preparation process in Example 4 is shown. Comparative product 4 from the left, after enzyme inactivation, after filtration and after centrifugation. In Example 5, the supernatant liquid of centrifugation from the left, the washing | cleaning liquid when the precipitate is washed with water, and the photograph of the external appearance of the liquid which melt | dissolved the precipitate in methanol are shown. FIG. 16 is a photograph taken with a digital microscope of the precipitate in Example 7. FIG. It is a graph of the light absorbency (OD430nm and OD680nm) of the tea extract when the activity of the glycoside degrading enzyme per tea leaf is changed in Example 8 In Example 8, tea extract No. 1 when changing the activity of the glucoside degrading enzyme per tea leaf was varied. 1 to No. It is the photograph which showed the external appearance of the Bx0.3 degree dilution liquid of 6.

Detailed Description of the Invention

Tea leaves which can be used as a raw material in the method of the present invention are tea leaves belonging to tea (Camellia sinensis) widely cultivated worldwide, and any tea leaves which are in line with the object of the present invention Although non-fermented tea is preferable, non-fermented tea is preferable, and for example, roasted tea such as Sencha, Maruji tea, Gyokuro, Kabute tea, steamed tea such as Tencha, Ureshino tea, Aoyagi tea, various Chinese teas and the like can be mentioned. In addition, it can be applied to semi-fermented teas such as Baked tea, iron kannon tea, oolong tea and the like, and fermented teas such as black tea and the like.

In addition, the tea may be of any variety, including the seed of camellia (Camellia sinensis var. Sinenses cv. Yabukita), and its leaves are usually from the center bud to the four leaves, which are raw materials for green tea etc. It may be a single-core quadruple-picked one containing leaves, or a leaf other than mature four-leaf. Although the above-mentioned tea leaves or tea raw materials can be used as they are, it is usually preferable to use those which have been subjected to treatments such as cutting, grinding and grinding using an apparatus used in food production and the like.

In the step (A), where tea leaf and water are mixed, generally, soft water, ion exchanged water, RO membrane treated water, etc. can be conveniently used as water. The use ratio of tea leaf to water is preferably 1: 5 to 50, preferably 1: 8 to 20, more preferably 1:10 to 15 in weight ratio although the suitable range varies depending on the dry state of the tea leaf. Can. The mixing can be carried out at room temperature, but should be carried out under heating conditions in consideration of the harvest time, maturity, etc. of the leaves used, and also considering that sterilization is preferably performed before the enzyme reaction. You can also. The temperature at that time may be, for example, 65 to 100 ° C., more preferably 70 to 90 ° C., for the purpose of achieving the sterilization purpose and reducing the thermal deterioration of the tea leaves. The mixing time is a time during which the tea leaves absorb water and expand, and is not limited, but generally it is in the range of 1 minute to 60 minutes, preferably 5 minutes to 30 minutes it can.

In addition, when mixing is also performed on heating conditions while serving as sterilization, after heat sterilization, the mixture of tea leaves and water is cooled to a temperature suitable for the enzyme treatment.

In the step (B), the mixture obtained in the step (A) can be allowed to act directly on the glycoside degrading enzyme, but before that, the mixture is other than the water extract or the glycoside degrading enzyme, and tea The enzyme-treated extract is prepared in the presence of various enzymes used for the extraction of glucosides, and then allowed to act on glucoside degrading enzymes, or simultaneously upon acting glucoside degrading enzymes directly on the mixture, or After that, enzymes other than glucoside degrading enzymes can also be allowed to act. Examples of enzymes other than glycoside degrading enzymes include, but are not limited to, tannin degrading enzyme tannase, protease, amylase, glucoamylase, pectinase, cellulase, hemicellulase and the like. Among them, tannase and pectinase can be mentioned as preferable ones for the purpose of the present invention, that is, to obtain the clear and decolorized tea extract while retaining the original flavor and taste of tea. These enzymes can be used alone or in combination of two or more.

Glycoside degrading enzymes and enzymes other than them can be used without limitation as long as they are used in the technical field in accordance with the object of the present invention, glycosidase, tannase, Pectinase can be detailed as follows.

Among various glycosides which may be present in tea leaves, for example, an enzyme capable of hydrolyzing a glycoside consisting of flavonols and glucose to a free aglycone part and a sugar part is advantageously used as a glycoside degrading enzyme. can do. Such O-glycoside glycosides are abundantly present in the plant world, and on the other hand, a large variety of enzymes that hydrolyze the O-glycosidic bond exist in nature. Among these, although not limited thereto, the following can be mentioned as those meeting the object of the present invention. For example, solid nutrient culture media such as wheat bran and rice bran containing β-glucosidase-producing bacteria belonging to the genus Aspergillus, Penicillium, Rhizopus, Pseudomonas, Pichia, etc. Alternatively, it can be a solid culture or liquid culture in a liquid nutrient medium according to a conventional method, and the obtained culture or a treated product thereof can be purified by a conventional method. In addition, those obtained by purification treatment from plants such as vanilla bean and fresh tea leaves can also be used, and further, an enzyme preparation cellulase A containing almond-derived emulsin or β-glucosidase commercially available from Sigma-Aldrich, Inc. (Amano Enzymes), cellulase T (Amano enzyme) and the like can also be used. As β-xylosidase, for example, β-xylosidase-producing bacteria belonging to Penicillium, Aspergillus, Rhizopus, Mucor and the like are subjected to solid culture or liquid culture according to a conventional method in solid nutrient media such as wheat bran or rice bran or liquid nutrient media And the culture obtained or the treated product thereof may be purified by a conventional method, and may also be commercially available from Sigma-Aldrich Co., which is derived from Aspergillus niger or an enzyme containing β-xylosidase It is also possible to use those separated from the preparation Sumi Team ACH (New Nippon Kagaku Kogyo) and the like. The β-primeverosidase is, for example, a solid culture or liquid culture of β-primeverosidase producing bacteria belonging to the genus Cerulomonas, Penicillium, Aspergillus, etc. in a solid medium or liquid medium such as wheat bran or rice bran according to a conventional method, The obtained culture or the treated product thereof may be purified by a conventional method, and those separated and purified from plants such as fresh tea leaves may also be used. When used for the purpose of the present invention, the amount of these glycoside degrading enzymes is generally 1 to 100 U / g in terms of β-glucosidase activity by p-NP glucose addition method, for example, based on the mass of tea leaf material. Preferably, it can be in the range of 4 to 75 U / g, more preferably 8 to 50 U / g, still more preferably 10 to 40 U / g.

Tannase is an enzyme that hydrolyzes a depside bond in which gallic acid is ester-linked to a hydroxyl group in tannin, for example, an enzyme that hydrolyzes epigallocatechin gallate into epigallocatechin and gallic acid. Specific examples of the tannase that can be used in the present invention include tannase-producing bacteria belonging to, for example, Aspergillus, Penicillium, Rhizopus, Rhizomucor, Lactobacillus, Staphylococcus, Streptococcus, Ronepinella, etc. And solid culture or liquid culture according to a conventional method in a medium usually used for culture of these filamentous fungi, and obtained products obtained by purifying the obtained culture or the treated product thereof by a conventional method. In addition, commercially available tannases, for example, tannase (500 U / g; made by Kikkoman Corporation), tannase (5,000 U / g; made by Kikkoman Corporation), tannase (500 U / g; made by Mitsubishi Chemical Foods Corporation), Sumi Team (registered) It is also possible to use a trademark TAN (manufactured by Shin Nippon Chemical Industry Co., Ltd.) or the like. The use amount of tannase can not be specified because the optimum range varies depending on the titer etc., but it is generally in the range of 0.1 to 50 U / g, preferably 0.5 to 20 U / g based on the mass of the tea leaf raw material be able to.

Pectinase is also called polygalacturonase, pectin enzyme, polymethyl galacturonase, pectin de polymerase, and is an enzyme that hydrolyzes an α-1,4 bond such as peclinic acid, pectin, pectic acid. Pectinase is known to be contained in bacteria, molds, yeasts, higher plants, snails and the like, and in the present invention, pectinases collected from organisms including these can be widely used. Alternatively, commercially available pectinase preparations can be used. Examples of commercially available pectinase preparations include, for example, Sucrase (registered trademark) A, Sucrase (registered trademark) N, Sucrase (registered trademark) S (above, manufactured by Mitsubishi Chemical Foods Corporation), Pectinex Ultra (registered trademark) SP-L ( Novo Nordics A / S, Meicerase (registered trademark) (Meiji Seika Co., Ltd.), Ultrazyme (registered trademark) (Novo Nordics A / S), Neulase F (registered trademark) Amano Enzyme Co., Ltd. product Sumi team (registered trademark) SPG (made by Shin Nippon Chemical Industry Co., Ltd.) etc. can be illustrated. The amount of pectinase to be used is generally difficult to represent in activity units since a plurality of enzymes are contained in the pectinase preparation, and generally 0.01% by mass to 5% by mass, preferably 0.1% by mass on the basis of tea leaf material It can be in the range of mass% to 2 mass%.

The tea leaves contain about 25% by mass of protein (see the 5th edition food composition table), and the protease treatment particularly enhances the effect of the later heating reaction. However, since proteins in tea leaves are bound to tannins, little action of protease on tea leaves produces almost no amino acid. Therefore, by causing protease and tannase to act on the tea leaf, a part of the protein in the tea leaf is decomposed and a tea extract rich in amino acids can be obtained.

Proteases are enzymes that hydrolyze peptide bonds of proteins and peptides. As the protease that can be used in the present invention, various commercially available proteases can be mentioned. The amount of protease used varies depending on the titer etc. and can not be generally determined, but it is usually exemplified within the range of usually 0.01 to 100 U / g, preferably 1 to 80 U / g, based on the mass of the tea material. can do.

The processing steps of tea leaves with enzymes described above (in particular, including the steps (A) and (B)) are methods known per se, such as the Patent Office Publications Well-known and Conventional Techniques Collection (Fragrance) Title II, Food flavors (2000) 1. 1.14) It can be carried out according to the method described in the publications such as “2.1 · 7 microorganism and enzyme flavor” (pages 46 to 57).

Among such processes, a mixture of tea leaves and water, or alternatively, allowing a treated product thereof to act as a glucoside degrading enzyme, refers to the heat treatment in the subsequent step (D) and the insoluble component in the step (E). It means that the tea extract liquid obtained by the removal can remove the color-causing substance so that it is substantially decolorized. Without being limited by theory, among the glycosides present in tea leaves, to make it possible to remove the color-causing substance, one that was originally in a water-soluble form or the like by the action of the enzyme is non-water-soluble or It means converting to poor water solubility. According to the present invention, it is understood that in the suspension or precipitate containing the insoluble component to be removed in the step (E), a coloring origin substance including kaempferol which is one of natural flavonols, quercetin and the like is present. It is done. Although this is not further limited by theory, the above-mentioned action hydrolyzes all or most of the glycosides having at least kaempferol or quercetin as aglycones among the glycosides which may be present in the tea leaf. It is understood to produce poorly water-soluble free aglycones.

Thus, in step (B), the enzyme treatment is carried out under conditions that form a float or precipitate as described above. Such conditions vary depending on the titer of the enzyme used, but generally the temperature is 30 to 70 ° C., preferably 36 to 60 ° C., more preferably 40 to 50 ° C., still more preferably 42 ° C. The reaction time is theoretically 25 minutes or more, practically 30 minutes to 48 hours, preferably 1 to 36 hours, more preferably 1 to 36 hours, more preferably 1.5 to 24 hours, further preferably 2 to 16 hours at -48 ° C. The pH is generally 4 to 6, although the optimum conditions vary depending on the source of the enzyme used and the like.

As described above, in the step (B), enzymes (other than the glucoside degrading enzymes) can be allowed to act simultaneously (in the step (B)), and these enzyme treatments also cause the glucoside degrading enzymes to act. The conditions according to the conditions can be selected.

In the step (C), as described above, in the step (B), the glycoside-degrading enzyme is allowed to act on the tea leaves for a sufficient time to hydrolyze the aglycone portion and the sugar portion of the glycoside Tea residue or other insoluble solids are separated from other processing solutions (also referred to as extracts). Such separation is carried out, for example, by a dewatering type centrifuge, a filter press, a filter filter coated Nutsche filter or the like, and simultaneously with the removal of further solids if necessary.

In step (D), the enzyme-treated tea extract is heat-treated to denature proteins including the enzyme used in the above step. Although the interpretation of the technical scope of the present invention is not restricted by theory, the modification by heat treatment not only causes the enzyme to lose its activity, but is also a causative component of coloring, and the enzyme treatment It is considered that the component which has become insoluble in water is bound to the denatured proteins to be in a state of being easily aggregated. The heat treatment conditions are generally a temperature of 70 to 135 ° C., a time of 2 seconds to 30 minutes, preferably 75 to 121 ° C., a time of 10 seconds to 25 minutes, more preferably 80 to 100 ° C. The time is in the range of 30 seconds to 20 minutes, more preferably in the range of 85 to 95 ° C., and the time range of 20 seconds to 15 minutes.

In the step (E), the heat-treated product is cooled to 45 ° C. or less, preferably 35 ° C. or less to form a float or precipitate containing an insoluble component. The removal of such insoluble components per se, or the suspension or precipitate can be carried out by, for example, a dewatering type centrifuge, a sedimentation type centrifuge, a filter press, a Nutsche filter coated with a filter aid, etc. However, it is usually preferred to obtain the results by sedimentation centrifugation.

Thus, according to the present invention, it is possible to decolorize the color in the extract or enzyme extract usually derived from the color of tea leaves. On the other hand, it is possible to provide a tea extract in which the contents of amino acids, caffeine and catechins are not substantially reduced, which are known to contribute to the flavor of teas, in particular, the taste. As such a tea extract, for example, when green tea leaves are used as a raw material, the absorbance at 430 nm is 0.5 or less when the soluble solid content (refractive sugar content, temperature 20 ° C.) of the tea extract is 0.3. , Preferably 0.3 or less, more preferably 0.2 or less, still more preferably 0.1 or less, still more preferably 0.05 or less, most preferably 0.015 or less, and the absorbance at 680 nm is 0. It is 15 or less, preferably 0.10 or less, more preferably 0.08 or less, still more preferably 0.05 or less, still more preferably 0.01 or less, and most preferably 0.005 or less. This is about 4/5 or less, preferably about 1/2 or less, more preferably 1/3 or less, still more preferably 1 or less, as compared to the absorbance at 430 nm of the tea extract when the corresponding enzyme treatment is not performed. / 5 or less. Further, when the soluble solid content (refractive sugar content, temperature 20 ° C.) is 15, the catechin content per total mass of the solid content is 1.0 mass% or more, preferably 1.2 mass% or more, more preferably The green tea extract which is 1.5 mass% or more can be provided. Furthermore, when a protease is made to act on tea leaf and it extracts, when the soluble solid content (refractive sugar content, temperature 20 degreeC) is set to 15, the amino acid content per total mass of said solid content is 1.0 mass% Or more, preferably 1.5% by mass or more, more preferably 1.8% by mass or more, and the catechin content is 1.0% by mass or more, preferably 1.2% by mass or more, more preferably 1.5 The green tea extract which is mass% or more can be provided.

As described above, the decolorized tea extract provided by the present invention having an absorbance at 430 nm and an absorbance at OD 680 nm is diluted or hydrolyzed with water to produce a tea beverage, based on the total mass of the tea beverage, When the solid content is adjusted to 0.005% by mass to 0.3% by mass, the tea beverage having a significantly reduced degree of color as compared to the tea extract not treated with the method of the present invention, further, the substance Provide a colorless and transparent tea beverage. The water is not limited to so-called soft water or hard water as long as the water can be provided for drinking. Such a tea beverage preferably has an absorbance at 430 nm of 0.05 or less and an absorbance at 680 nm of 0.05 or less, while retaining the flavor of the tea. Therefore, in order to achieve the intended purpose of the present invention, for example, with reference to the data shown in FIG. When the soluble solid content (refractive index sugar content, temperature 20 ° C.) of the tea extract is adjusted to 0.3, it may be prepared so as to show both the absorbances described immediately before.

In the present specification, 0.3 mass% or 0.3 is used interchangeably for soluble solids (refractory sugar content, temperature 20 ° C.) of tea extract. The same applies to soluble solids (refractory sugar content, temperature 20 ° C.) or Bx (bricks) 0.3 °, but these are values obtained by measurement with a Brix meter.

The decolorized tea extract provided by the present invention can be used, for example, as a near water or flavored water-like beverage, or as a raw material for container-packed tea beverages.

Specifically, it is possible to use a decolorized, optionally low tanned tea extract obtained by the method according to any one of the above aspects 1 to 9, 12 to 13 or described in aspect 10 or 11. Depending on the type of tea beverage to be added, the soluble solids derived from tea can be added to 0.005 to 0.3, or 0.01 to 0.3, or 0.05 to 0.3, or 0 A tea beverage or container-packed tea beverage can be provided by adjusting to 1 to 0.3% (or °) and adding vitamin C or its edible salt (sodium) simultaneously with or before or after the adjustment Aspect 16 or 17). When such a beverage is provided, it is obtained by the method of the embodiment 12 or 13, or decolorized according to the embodiment 14 and having high storage or storage stability, starting from a low tannin tea extract, Tea beverages can be provided. Although the use conditions of PVPP (polyvinylpolypyrrolidone) in the method of the embodiment 12 are not limited, they can be appropriately selected as long as the object of the present invention can be achieved with reference to the description of Patent Document 5; For example, 1% by mass to 100% by mass of PVPP is used with respect to the mass of the soluble solid content of the tea extract obtained in the step (E). The tea extract thus obtained is preferably prepared by adjusting the soluble solid content derived from tea as described above, and then the vitamin C or its edible salt (sodium) per total mass of the tea beverage after adjustment. From 002% by mass to 0.3% by mass, preferably from 0.005% by mass to 0.1% by mass, more preferably from 0.01% by mass to 0.03% by mass. When the tea beverage is adjusted to 0.3% (Bx, 20 ° C.) of soluble solids derived from tea under the conditions in a container filled with a normal tea beverage after heating and sterilizing by such treatment. The absorbance at 430 nm is 0.015 or less, and the absorbance at 680 nm is 0.05 or less.

The following description can be referred to for the scale of transparency and colorlessness (coloring condition).
(Transparent)
The OD 680 nm is 0.15 or less (slightly opaque), preferably 0.10 or less (very slightly opaque), more preferably 0.07 or less (almost transparent), still more preferably 0.05 or less (slightly opaque) Almost completely transparent)
(colorless)
· Δ (delta) E is 4.0 or less (slightly colored), preferably 3.0 or less (very slightly colored), more preferably 2.0 or less, in comparison with Lab according to permeability with pure water (Almost colorless), particularly preferably 1.4 or less (approximately completely colorless),
Or, the OD 430 nm is 0.05 or less (slightly colored), preferably 0.038 or less (very slightly colored), more preferably 0.025 or less (almost colorless), particularly preferably 0.015 or less (approximately completely) colorless)

Hereinafter, the present invention will be more specifically described by Examples and Comparative Examples.

Example 1
In 1300 g of pure water, 1.8 g of vitamin C was dissolved and heated to 75 ° C. Thereto, 100 g of Shizuoka second tea (Yabukita seed, steaming method, cut product of 5 mm) was added, heated with stirring, and heat-sterilized at 95 ° C. for 15 minutes. The mixture was cooled to 45 ° C. (the pH at this point is 5.3), the enzymes shown in Table 1 were added, and a reaction of stirring at 45 ° C. for 4 hours was performed. After the tea leaf residue and the extract were separated by a dewatering centrifuge, the extract was heated at 95 ° C. for 1 minute and cooled to 30 ° C. The extract was no. 2 Filter paper (held particle diameter 5 μm) After filtration, cooled to 20 ° C. and centrifuged at 3000 × g for 10 minutes to obtain a green tea extract. The obtained green tea extract was diluted to Bx 0.3 ° (refractive index, measured at 20 ° C.), and the absorbance at 430 nm (index of color) and the absorbance at 680 nm (index of turbidity) were measured. The results are shown in Table 1. Further, photographs of appearances of these Bx 0.3 ° diluted solutions are shown in FIG. 1 (from the left, Comparative Product 1, Present Product 4, Present Product 5, Present Product 6, and Present Product 7).
(Description of the enzyme)
-Glycoside degrading enzyme: commercially available β-glucosidase (1200 U / g)
-Tannase: Sumi Team (registered trademark) TAN (Shin Nippon Chemical Industry Co., Ltd. tannase: 5000 U / g)
Pectinase: Sumi Team (registered trademark) SPG (Pectinase manufactured by Shin Nippon Chemical Industries Co., Ltd.) Invertase: Sumi Team (registered trademark) INV (Invertase manufactured by Shin Nippon Chemical Industrial Co., Ltd.)
・ Hemicellulase (β-mannanase): Sumizyme (registered trademark) ACH (Hemicellulase manufactured by Shin Nippon Chemical Co., Ltd.)

As shown in Table 1, compared with Comparative Product 1 in which tannase and pectinase were used in combination, Comparative Product 2 in which invertase was used, and Comparative Product 3 in which hemicellulase (mannanase) was used, this glycolipid degrading enzyme was allowed to act In each of Inventions 1 to 7, the absorbance at 430 nm (index of coloration) was low, and the absorbance at 680 nm (index of turbidity) was almost the same or less. Glycoside degrading enzymes are more decolorized when used in combination with tannase than when used alone (Invention product 1) (Invention product 2), and addition of pectinase significantly (about 1/4 to 1/5) The result of being decolorized to (6) was obtained. As a result of examining the addition amount of the glucoside decomposing enzyme in the case of using tannase and pectinase in combination, it was found that the color tone becomes lighter and the turbidity becomes clearer as the addition amount of the glucoside decomposing enzyme increases (this invention product 4-7).

(Example 2)
The solution in the middle of the process was prepared under the same conditions as those of the product 6 of the present invention. That is, the liquid (1) separated by the dewatering type centrifuge, the liquid (2) after heating the liquid at 95 ° C. for 1 minute, and then the liquid was further cooled. 2 Filtered solution (3), and then the solution was cooled to 20 ° C. and centrifuged at 3000 × g for 10 minutes (4). Each of these was allowed to stand overnight at 20 ° C.

As a result, the liquid of (1) is uniform throughout and shows thick and cloudy yellow-green color, but the liquid of (2) produces a large amount of dark green precipitate, and the supernatant is pale and almost clear. Had become a liquid. In addition, the liquid of (3) was slightly precipitated, but the supernatant was light and almost clear, and the liquid of (4) was light and almost clear. There was no precipitation at all. Photographs of these appearances are shown in FIG. From left to right are (1), (2), (3) and (4).

As a result of the above, it was found that the heat treatment after the enzyme treatment resulted in the formation of a precipitate containing a coloring component, and the removal of the precipitate resulted in decolorization. Moreover, this deposit is No. 2 It was found that the filter paper (retained particle diameter 5 μm) could not be completely removed, but could be efficiently removed by centrifuging at a gravity acceleration of 3000 × g.

(Example 3)
3.6 g of vitamin C was dissolved in 2600 g of pure water and heated to 75 ° C. Thereto, 200 g of Shizuoka No. 1 tea (a tea leaf different from that of Example 1: Yabuki seed, steamed blue, 5 mm cut product) was added, heated with stirring and heat sterilized at 95 ° C. for 15 minutes. The mixture was cooled to 45 ° C. (the pH at this point is 5.3), the enzymes shown in Table 2 were added, and a stirring reaction was performed at 45 ° C. for 4 hours. After the tea leaf residue and the extract were separated by a dewatering centrifuge, the extract was heated at 95 ° C. for 1 minute and cooled to 30 ° C. Next, the extract was concentrated under reduced pressure to Bx17 ° using a rotary evaporator, cooled to 20 ° C, centrifuged at 3000 × g for 10 minutes to remove precipitates, and then the supernatant was adjusted to Bx15 °. The mixture was heated and sterilized at 95 ° C. for 1 minute and cooled to 20 ° C. to obtain a green tea extract. The obtained green tea extract was measured for caffeine content (HPLC method), catechins content (HPLC method) and tannin content (Folin-denis method), and Bx 0.3 ° (refractive index, 20) C.), and the absorbance at 430 nm (indicator of color) and the absorbance at 680 nm (indicator of turbidity) were measured. The results are shown in Table 2. Moreover, the photograph of the external appearance of these Bx0.3 degree dilution liquid is shown in FIG. 3 (the left is the comparative product 4 and the right is this invention product 8).

When the component values of the inventive product 8 and the comparative product 4 are compared, the inventive product 8 is lower in caffeine, tannin and catechins as compared with the comparative product 4, but is at a slight level.

<Sensory evaluation>
The Bx 0.3 ° diluted products of the inventive product 8 and the comparative product 4 were evaluated by five panelists. As the average evaluation result, although the inventive product 8 felt a slighter body feeling in the taste portion than the comparative product 4, the green tea flavor was clearly confirmed. Also, in terms of aroma, you can feel the colorful aroma of green tea. The peculiar odor of enzyme-treated tea was masked.

(Example 4)
A glycoside degrading enzyme was further allowed to act on Comparative Product 4, and a confirmation experiment was conducted to see if an extract similar to that of the present invention could be obtained.

That is, after adding commercially available β-glucosidase (1200 U / g) (12 U to 1 g of tea leaves) to Comparative product 4 and performing stirring reaction at 45 ° C. for 4 hours, heat at 95 ° C. for 1 minute; It cooled down. Then, it was cooled to 20 ° C., No. 2 After filter paper filtration, it was centrifuged at a gravity acceleration of 3000 × g for 10 minutes, heat-sterilized at 95 ° C. for 1 minute, and cooled to 20 ° C. to obtain a green tea extract (comparative product 5). The obtained green tea extract was measured for caffeine content (HPLC method), catechins content (HPLC method) and tannin content (Folin-denis method), and Bx 0.3 ° (refractive index, 20) C.), and the absorbance at 430 nm (indicator of color) and the absorbance at 680 nm (indicator of turbidity) were measured. The results are shown in Table 3 in which the comparative product 4 and the inventive product 8 are combined.

As compared with Comparative Product 4 (before glycosidolytic enzyme treatment), Comparative Product 5 had decreased caffeine, tannin and catechins. On the other hand, although the color tone (OD 430 nm) of the product 8 of the present invention was observed to be more colored than the product 8 of the present invention, the color and the turbidity tended to be smaller than the comparative product 4 because the color was thin.

Further, in the preparation step of Comparative product 5, the green flock-like precipitate similar to (2) in Example 2 was produced at the stage of leaving the extract solution subjected to the enzyme reaction and heat treatment overnight at 20 ° C. . The photograph of the external appearance of the liquid in the middle of the preparation process of the comparative product 5 is shown in FIG. 4 (from the left, the comparative product 4, after enzyme inactivation, after filtration, after centrifugation).

(Example 5)
The precipitate formed in Example 4 was collected, and centrifugation / washing with water was repeated three times to collect a deep green precipitate.

The precipitate was insoluble in water, but was clearly dissolved in methanol and turned deep green. Although the detailed mechanism is unknown from this result, the pigment component that was water soluble by causing the green tea extract to react with the glucoside degrading enzyme precipitates as a water insoluble precipitate, and this is separated. It was estimated to be bleached.

Figure 5 shows the appearance of the supernatant of the centrifugation, the washing liquid when the precipitate is washed with water, and the solution of the precipitate in methanol (from above, when the supernatant of the centrifugation and the precipitate are washed with water) And the solution of the precipitate in methanol).

(Example 6)
The case where protease was used in combination was examined.

3.6 g of vitamin C was dissolved in 2600 g of pure water and heated to 75 ° C. Thereto, 200 g of a second tea from Shizuoka (tea leaves as in Example 1: Yabuki seed, steamed blue, 5 mm cut product) was added, heated with stirring and heat sterilized at 95 ° C. for 15 minutes. After cooling to 45 ° C. (pH at this point is 5.3), the enzymes shown in Table 4 were added, and a reaction of stirring at 45 ° C. for 4 hours was performed. After the tea leaf residue and the extract were separated by a dewatering centrifuge, the extract was heated at 95 ° C. for 1 minute and cooled to 30 ° C. Next, the extract is concentrated under reduced pressure to Bx 17 ° using a rotary evaporator, cooled to 20 ° C., centrifuged at 3000 × g for 10 minutes to remove precipitates, and then the supernatant liquid is Bx 15 ° After heat sterilization at 95 ° C. for 1 minute, the mixture was cooled to 20 ° C. to obtain a green tea extract. The obtained green tea extract measures caffeine (HPLC method), catechins (HPLC method) tannin (Folin-denis method) and amino acid (HPLC method), and Bx 0.3 ° (refractive index, 20 ° C.) And the absorbance at 430 nm (indicator of color) and the absorbance at 680 nm (indicator of turbidity) were measured. The results are shown in Table 4.
(Description of the enzyme)
-Protease: Protease M "Amano" SD (Protease manufactured by Amano Enzyme Inc.)

As shown in Table 4, the amino acid content of the product 9 of the present invention was larger than that of the comparative product 6, and the contents of caffeine, tannin and catechins were almost equivalent values. Further, with regard to color tone, it was confirmed that the product 9 of the present invention treated with a glycoside degrading enzyme was decolorized as compared with the comparative product 6. With regard to the flavor, when the scented product (Bx 0.03 °) added with 0.2% by mass to ion-exchanged water was evaluated, the inventive product 9 had a slightly weaker body feeling than the comparative product 6, but the umami The flavor of green tea such as astringency was sufficiently felt, and it had a good green tea flavor.

(Example 7)
In Example 6, the precipitate obtained by centrifuging at a gravity acceleration of 3000 × g for 10 minutes in the preparation step of the product of the present invention 9 is recovered, and the centrifugation / water washing is performed three times in the same manner as in Example 5. Repeatedly, a dark green precipitate was collected. The obtained precipitate was photographed with a digital microscope and subjected to fluorescent X-ray analysis and FT / IR analysis.

The precipitate was divided into two layers by repeating centrifugation / washing 3 times, and the upper part was a green, viscous object, and the lower part was a light green, minute spherical object (FIG. 6). . In the upper layer and lower layer from the fluorescent X-ray analysis, the organic substance is assumed to be the main component, in the upper layer is mainly composed of protein and from the FT / IR analysis, the lower layer is one of natural flavonols. It is suggested that it may be mainly composed of kaempferol represented by the chemical structural formula.

Although kaempferol itself is only sparingly soluble in water, it is known to exist as a glycoside in tea leaves, so it easily dissolves even if it is extracted with water. Here, it is presumed that kaempferol detected as a precipitate is generated by insolubilization of kaempferol which is aglycone-eliminated due to the elimination of sugar by the function of a glycosidic degradation enzyme. The crystals of kaempferol are considered to be yellowish and contribute to greenish green to bright yellow, which is the water color of green tea, but the precipitate detected in this study is greenish, and kaempferol, protein, chlorophyll, etc. It is inferred that they are complexly bound, insolubilized and precipitated.

(Example 8) Examination of influence on decolorization of tea extract when varying activity of glycoside degrading enzyme per mass of tea leaf The amount of enzyme added is adjusted as described in Table 5 below, 45 ° C. The green tea extract was obtained according to the method described in Example 1 except that the reaction was carried out for 4 hours. The obtained green tea extract was diluted to Bx 0.3 ° (refractive index, measured at 20 ° C.), and the absorbance at 430 nm (index of color) and the absorbance at 680 nm (index of turbidity) were measured. The results are shown in Table 5.

OD 430 nm represents an index of coloration, and OD 680 nm represents an index of turbidity. It can be said that when the OD 430 nm is 0.05 or less, there is almost no coloring, and if it is 0.3 or less, the coloring is very slight, and if it is 0.5 or less, it is light coloring. In addition, when the OD 680 nm is 0.1 or less, there is almost no turbidity (clear), and a slight turbidity of around 0.15 is a certain degree.

As shown in Table 5, it was found that as the amount of glucoside enzyme used for tea leaves increases, the color of the obtained extract becomes lighter. Moreover, when using 10 U (No. 3) or more with respect to 1 g of tea leaves, it can be said that coloring and turbidity are also very few.

(Example 9) Examination of the influence on the decolorization of the tea extract of the reaction time of the reaction time of the glucoside decomposing enzyme with respect to tea leaves Except for changing the enzyme reaction time, the product 4 of the present invention 1 A green tea extract was obtained according to the method described in 10 U added per 1 g) and the product 6 of the present invention (20 U added with glycoside degrading enzyme per 1 g of tea leaves). The obtained green tea extract was diluted to Bx 0.3 ° (refractive index, measured at 20 ° C.), and the absorbance at 430 nm (index of color) and the absorbance at 680 nm (index of turbidity) were measured. The results are shown in Table 6.

As shown in Table 6, it was confirmed that the extracts using 10 U or 20 U of glycoside-degrading enzyme per 1 g of tea leaves were both reduced in color and turbidity in the reaction for 1 hour. Based on the fact that the tea extract not subjected to the enzyme reaction according to Table 5 has an OD 430 nm of 0.562 and an OD 680 nm of 0.146, it is estimated from the degree of decolorization in 1 hour and turbidity reduction, 30 minutes It is suggested that the enzyme reaction time is also effective.

In addition, the longer the enzyme reaction time, the lower the color and turbidity values, and for coloring, a system using 10 U of glycolytic enzyme for 1 g of tea leaves gives a reaction for 4 hours, and a system using 20 U for 2 hours The reaction resulted in an OD 430 nm of 0.3 or less. With regard to turbidity, in the system using 10 U, the reaction was 3 hours, and in the system using 20 U, the OD 680 nm became 0.1 or less in the reaction for 2 hours. The color (OD 430 nm) and the turbidity (OD 680 nm) both decreased with further extension of the reaction time for any of the systems.

Example 10 β-Glucosidase and PVPP Treatment Vitamin C (0.9 g) was dissolved in 660 g of pure water and heated to 75 ° C. Thereto, 50 g of Shizuoka second green tea (Yabukita seed, steamed blue, 5 mm cut product) was charged, heated with stirring, and heat sterilized at 95 ° C. for 15 minutes. After cooling to 45 ° C. (the pH at this point is 4.9), the enzymes shown in Table 7 (Inventive product 10) were added, and the reaction of stirring at 45 ° C. for 8 hours was performed. Separate the tea leaf residue and the extract with a dewatering type centrifuge, and further add 100 g of soft water into the centrifuge to extrude the extract adhering to the tea leaf residue to obtain an extract, the extract at 95 ° C for 30 seconds Heated to sterilization and enzyme inactivation and cooled to 30 ° C. The extract is then centrifuged (1200 × g, 8 minutes) to remove precipitates, and then 40% by weight of soluble solid content (calculated using Bx at 20 ° C.) of PVPP is added to the extract. The mixture was stirred at 30 ° C. for 1 hour. Next, No. 2 Filter paper (holding particle diameter 5 μm) After filtration, cool to 20 ° C, adjust to Bx (20 ° C) 3.0 with soft water, heat sterilize at 95 ° C for 30 seconds, cool to 30 ° C, 200 mesh saran The resultant was filled in a plastic bottle while being filtered to obtain a green tea extract (Inventive product 10).

(Example 11)
In Example 10, the procedure for Example 10 is repeated except that the amount of added PVPP is 80% by mass of the soluble solid (calculated using Bx at 20 ° C.) to the extract, and the green tea extract is Obtained (inventive product 11).

(Example 12) β-glucosidase treatment In the same manner as in Example 10 except that PVPP was not added in Example 10, a green tea extract was obtained (Inventive product 12).
Comparative Example 7 No β-Glucosidase and PVPP Treatment In Example 10, the procedure was completely the same as Example 10 except that β-glucosidase was not used as the enzyme (the enzyme of the product of the present invention 12 in Table 7 was used). To obtain a green tea extract (comparative product 7).
Comparative Example 8 Neither β-Glucosidase Treatment nor PVPP Treatment The procedure of Comparative Example 7 was performed in the same manner as in Comparative Example 7 except that PVPP was not added in Comparative Example 7 to obtain a green tea extract (comparative product 8).

(Example 13)
The Bx, pH, amino acid (mg%), tannin (mg%), and caffeine (mg%) of the inventive product 10, the inventive product 12, the inventive product 12, and the comparative product 8 were measured. Moreover, it diluted to Bx0.3 degree with the pure water, and measured OD430nm, OD680nm, Lab, (DELTA) E (comparison with a pure water). Furthermore, the Bx 0.3 ° diluted product was sensory-evaluated for green teaness by five well-trained panelists. The average results of these analytical values and sensory evaluations are shown in Table 7.

(Result, consideration)
The degree of coloration of the tea beverage is reduced by the β-glucosidase treatment (comparative product 8 and the inventive product 12 and comparison between the comparative product 7 and the inventive product 10).
The degree of coloration of tea beverages is reduced by the PVPP treatment, in particular, the coloration tends to be small after heat sterilization. In addition, the PVPP treatment weakens bitterness (Comparison 8 and Comparison 7 and Comparison between Invention 12 and Invention 10).
Inventive products 10 and 11 treated with PVPP (removed tannin) in addition to β-glucosidase treatment, when diluted to the same solid concentration (B × 0.3 °), while maintaining the flavor of tea, It was observed that the lightest, more bleached extract was obtained.
-The absorbance at 430 nm is 0.05 or less when the soluble solid content (refractive index sugar content, temperature 20 ° C) of the tea extract is 0.3 by performing PVPP treatment (tannin removal) in addition to β-glucosidase treatment, And, the absorbance at 680 nm is 0.05 or less, and the amino acid content is 1.0 mass% or more when the soluble solid content (refractive sugar content, temperature 20 ° C.) is 15 (five times the concentration of the above-mentioned invention product). And the green tea extract which is less than 1.0 mass% of catechin was able to be obtained (this invention products 10 and 11).

(Example 14) Color tone of container-packed beverage using the product of the present invention and the comparative product The present products 10, 11, 12 and the comparative product 7 and the comparative product 8 are each diluted to Bx 0.005 ° (each The product of the present invention or the comparative product is adjusted to 0.167% in each water, adjusted to 0.03% with and without sodium ascorbate, UHT sterilized at 135 ° C for 30 seconds, and cooled to 90 ° C. After filling the bottle, it was cooled to 30 ° C. or less to prepare a container-packed green tea beverage.
The color tone (OD 430 nm, OD 680 nm and ΔE with pure water) of each beverage is shown in Table 8.

(Result, consideration)
· When the extract is diluted to Bx 0.005 ° and 0.03% of sodium ascorbate is added, the present invention products 10, 11, 12 and comparative product 7 and comparative product 8 are all colorless clear or close to the beverage prepared it can.
The extract was diluted to Bx 0.005 °, and in the case of no sodium ascorbate addition, it was neither hazy nor nearly clear, and 10 and 11 were almost completely colorless but otherwise colored .

(Example 15) Relationship between added concentration of extract and color tone The product 10 of the present invention is diluted to a concentration shown in Table 9 (without sodium ascorbate), and after UHT sterilization at 135 ° C. for 30 seconds, 90 After cooling to ° C. and filling in a plastic bottle, it was cooled to 30 ° C. or less to prepare a containerized green tea beverage.
The color tone (OD 430 nm and ΔE with pure water) of each beverage is shown in Table 9.

(Result, consideration)
In the case of a container-packed beverage prepared without the addition of sodium ascorbate, the concentration of the product 10 according to the present invention is almost completely colorless at Bx 0.005 °, slightly colored at Bx 0.015, and colored at Bx 0.025.
However, about 0.025 was considered to be necessary in order to secure sufficient green tea-like flavor.
The following experiment was carried out since the addition of sodium ascorbate has an effect of preventing coloration in preparation of the packaged beverage from Example 13 above.

(Example 16) Relationship between sodium ascorbate addition concentration, storage conditions, and color tone The product 10 of the present invention is diluted to Bx 0.025 °, and at this time, sodium ascorbate at the concentration in Table 10 is added, 135 After UHT sterilization at 30 ° C. for 30 seconds, it was cooled to 90 ° C., filled in a plastic bottle, and then cooled to 30 ° C. or less to prepare a containerized green tea beverage.
Each bottled beverage was stored at 10 ° C. and 50 ° C. for 10 days.
The color tone (OD 430 nm and ΔE with pure water) of each beverage after storage is shown in Table 10.

(Result, consideration)
-Coloration after sterilization was suppressed by the addition of sodium ascorbate.
It was found that the coloring after sterilization was suppressed as the addition amount increased in the range of 0 to 0.03% of the concentration of sodium ascorbate addition.
Immediately after sterilization and at OD 430 nm and ΔE stored at 10 ° C. for 10 days, sodium ascorbate was almost completely colorless and transparent when it was 0.01% or more.
-When the packaged beverage was stored at 50 ° C for 10 days (abuse condition), it was "almost colored" at a concentration of 0.03% with sodium ascorbate addition concentration, but at "nearly slightly colored" at 0.01%. there were.
-According to the above, it can be said that 0.01% or more of the addition density | concentration of sodium ascorbate is preferable.

Claims (18)

1. A process for producing a decolorized tea extract comprising the following steps (A) to (E):
   (A) A step of mixing tea leaves and water (B) A step of causing a mixture of (A) to have a glycosidolytic enzyme after step (A) (C) After step (B), tea leaf residue and an extract And separating the glycoside enzyme-treated tea extract (D) a step of heat-treating the glycoside enzyme-treated tea extract obtained in step (C),
   (E) A step of removing insoluble components from the heated glycoside enzyme-treated tea extract obtained in step (D) to obtain a decolorized tea extract
2. The method for producing a decolorized tea extract according to claim 1, further comprising the step of allowing tannase and / or pectinase to act simultaneously with or before or after step (B) and before step (C). .
3. The decolorized tea extract according to claim 1 or 2, further comprising the step of allowing a protease to act simultaneously with and / or after step (B) and before step (C). Manufacturing method.
4. The method for producing a decolorized tea extract liquid according to any one of claims 1 to 3, wherein the heat treatment conditions in the step (D) are within a temperature range of 70 to 135 ° C and a time of 2 seconds to 30 minutes.
5. The method for producing a decolorized tea extract according to any one of claims 1 to 4, wherein the tea leaf is green tea.
6. The method according to any one of claims 1 to 5, further comprising the step of steam-distilling the tea leaves to obtain an aroma recovery product, and mixing the obtained aroma recovery product with the clear liquid obtained in step (E) before the step (A). The manufacturing method of the decolorized tea extract as described in a crab.
7. 7. The method according to any one of claims 1 to 6, wherein the amount of the glycoside degrading enzyme used for tea leaves is 1 U / g or more, the temperature of the enzyme reaction is in the range of 30 to 70 ° C, and the reaction time is 30 minutes or more. Method for producing a decolorized tea extract.
8. It is a manufacturing method of the decolorized tea extract according to claim 1, wherein the absorbance at 430 nm is 0.5 or less when the soluble solid content (refractive sugar content, temperature 20 ° C) of the tea extract is 0.3. And the absorbance at 680 nm is 0.15 or less.
9. The method for producing a decolorized tea extract according to claim 8, wherein the absorbance at 430 nm is 0.15 or less when the soluble solid content (refractive index, temperature 20 ° C) of the tea extract is 0.3. And the absorbance at 680 nm is 0.05 or less.
10. The absorbance at 430 nm is 0.15 or less and the absorbance at 680 nm is 0.05 or less when the soluble solid content (refractive index, temperature 20 ° C.) of the tea extract is 0.3, and the soluble solid content (refractive index The green tea leaf extract which has a catechin content of 1.0% by mass or more when the temperature is set to 20 ° C.
11. The absorbance at 430 nm is 0.5 or less and the absorbance at 680 nm is 0.15 or less when the soluble solid content (refractive index, temperature 20 ° C.) of the tea extract is 0.3, and the soluble solid content (refractive index The green tea leaf extract which has an amino acid content of 1.0% by mass or more when the temperature is set to 20 ° C.
12. A method for producing a low tannin tea extract comprising the following steps (A) to (F):
    (A) A step of mixing tea leaves and water (B) A step of causing a mixture of (A) to have a glycosidolytic enzyme after step (A) (C) After step (B), tea leaf residue and an extract And (G) separation of the glycoside enzyme-treated tea extract obtained in step (C) by heat treatment (E) step (D) obtained in step (D) Step of removing insoluble components from the heated glycoside enzyme-treated tea extract to obtain a decolorized tea extract (F) The decolorized tea extract obtained after the step (E) is further treated with PVPP (polyvinyl poly) Contacting with pyrrolidone) to obtain an extract from which PVPP has been removed after contact
13. The method for producing a low tannin tea extract according to claim 12, wherein the absorbance at 430 nm is 0.05 or less when the soluble solid content (refractive sugar content, temperature 20 ° C) of the tea extract is 0.3. The absorbance at 680 nm is 0.05 or less, and the amino acid content is 1.0% by mass or more and the tannin (Folin-Denis method) is 1. when the soluble solid content (refractive sugar content, temperature 20 ° C.) is 15. The method which is 0 mass% or less.
14. The absorbance at 430 nm is 0.05 or less and the absorbance at 680 nm is 0.05 or less when the soluble solid content (refractive index, temperature 20 ° C.) of the tea extract is 0.3, and the soluble solid content (refractive index A green tea leaf extract solution having an amino acid content of 1.0% by mass or more and a tannin (Folin-Denis method) of 1.0% by mass or less when a temperature of 20 ° C. is 15.
15. (G) The tea extract obtained by the method according to any one of claims 1 to 9, 12 and 13, wherein the soluble solid content derived from tea is 0.005 to 0.3% (Bx, 20 ° C) Process to adjust to
    (H) The manufacturing method of the container-packed tea beverage including the process of adding vitamin C or its edible salt (sodium) to the tea beverage obtained at the process (G).
16. A green tea extract according to claim 10, containing 0.005% to 0.3% (Bx, 20 ° C.)% by mass as a soluble solid content derived from tea, further comprising vitamin C or an edible salt thereof ( Container-packed tea beverage containing sodium).
17. The container-packed tea beverage according to claim 16, which comprises 0.002 to 0.3% by mass of vitamin C or an edible salt thereof (sodium).
18. 18. The tea extract according to claim 16, wherein the absorbance at 430 nm is 0.015 or less and the absorbance at 680 nm is 0.05 or less when the soluble solid content (refractive sugar content, temperature 20 ° C.) of the tea extract is 0.3. Container packed tea beverage.

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