JPWO2019044474A1 - Decolorized tea extract and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a near-water or flavored water-like beverage, and a tea extract capable of imparting a flavor derived from tea leaves, particularly a taste, to the beverage without coloring, and use of the tea extract. , Submit tea drinks, for example. A method for producing a decolorized tea extract, comprising the following steps (A) to (E): (A) After the step (B) of mixing tea leaves and water, the step (A) of reacting a glycoside-degrading enzyme, the step (C) of the step (B) of separating tea leaves from the extract, Step (D) of obtaining a glycoside enzyme-treated tea extract, a step of heat-treating the glycoside enzyme-treated tea extract obtained in the step (C), and (E) a heated glycoside obtained in a step (D) A method for producing a decolorized tea extract, which comprises a step of removing insoluble components from an enzyme-treated tea extract to obtain a decolorized tea extract, and vitamin C was added to the tea extract if necessary. Disclosed is a method for producing a tea beverage after post-hydration, particularly a packaged tea beverage, and further, the decolorized tea extract and the packaged tea beverage.

Description

The present invention relates to a decolorized tea extract and a method for producing the same. More specifically, the present invention relates to a tea extract having a good aroma, umami and bitterness inherent to tea despite its light color, and a method for producing the same, which includes a step of treating a tea leaf with a glycoside degrading enzyme.

In recent years, due to the diversification of consumers' preference for packaged beverages, there are many marketed packaged beverages in which colorless and transparent containers are filled with almost colorless and transparent beverages. Such beverages are also called near water and flavored water, and the colorless and transparent appearance is one of the important factors. Some of these almost colorless and transparent beverages have citrus flavors such as lemons, oranges and tangerines, soft fruit flavors such as grapes, apples and peaches, and fermented milk flavors such as yogurt. There are not many things that have the flavor of.

The flavor of tea can be reproduced to some extent only with a flavor having a tea fragrance (prepared flavor or natural flavor), but in order to make tea feel like it is, by adding a water-soluble ingredient derived from tea. It becomes possible to impart a more preferable flavor.

On the other hand, the tea extract is usually colored, and if an attempt is made to add the tea extract in an amount such that flavor is imparted, the entire beverage will be colored in light green to light brown.

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

As a decolorizing method, generally, treatment with an adsorbent such as activated carbon is known, and tea is also known with various adsorbent treatment techniques. Patent Document 2 discloses a method for obtaining a tea extract by mixing or adding activated carbon during and/or after extraction of tea, but it is for the purpose of removing caffeine, and decolorization is completely described. It has not been. Further, Patent Document 3 discloses a method of bringing a caffeine-containing aqueous solution such as a tea extract solution into contact with activated clay or acid clay, but this method is also for the purpose of removing caffeine, and decolorization is completely described. It has not been. Further, Patent Document 4 or Patent Document 5 discloses a method in which a tea extract is brought into contact with polyvinylpolypyrrolidone, but the purpose is to remove catechins or tannins, and no decolorization is described at all.

As a method for producing a green tea extract that can be used for sports drinks and isotonic beverages, a method of dissolving a green tea extract in a mixed solution of ethanol and water in a weight ratio of 91/9 to 97/3 and contacting with activated carbon and acid clay is used. Although a method for producing the obtained low caffeine green tea extract (Patent Document 6) is disclosed, the main purpose is to remove caffeine. In Patent Document 6, the fact that the hue is not deteriorated (paragraph [0009] and the like) is also effective, but there is no description that can be specifically specified regarding the color tone, and there is no description in the examples.

On the other hand, a glycoside-degrading enzyme means an enzyme that hydrolyzes a bond (glycoside bond) between the anomeric carbon of a glycoside and an aglycone part to produce a free aglycone. In the method for producing a beverage, a method for 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 ( Patent Document 7), a method for producing an aroma-enhanced tea extract characterized by allowing a glycoside-degrading enzyme to act on tea leaves when and/or after treating the tea leaves with Tannase (Patent Document 8), etc. Are known, but all of them only describe the content related to aroma generation. Further, in Patent Document 9, after the aqueous extract of tea such as oolong tea is concentrated to Bx2 to 15°, and the glycoside-degrading enzyme is allowed to act on the concentrated liquid, the transparency is high, and the solution can be stored for a long time. A method for producing a tea extract that does not generate is described. However, the color tone (color depth, etc.) is not described at all.

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

As described above, as a method for decolorizing the tea leaf extract, there is a method mainly using a physicochemical treatment means, but there are cases where there are disadvantages or drawbacks such as impairing the original flavor of the tea leaf.

Therefore, an object of the present invention is to prepare a near water or flavored water-like beverage, a flavor derived from tea leaves without coloring, in particular, a green tea extract capable of imparting a taste to the beverage, and For example, it is to submit a tea beverage using the green tea extract, particularly a packaged tea beverage.

It is already known that a glycoside-degrading enzyme acts on an aqueous extract of tea leaves to change the glycoside into an aroma component compound, and this time, surprisingly, in the presence of water, After treatment with a glycoside-degrading enzyme under certain conditions, the resulting glycoside-enzyme-treated tea extract is heat-treated to form a water-insoluble substance, and when the water-insoluble substance is removed, a flavor derived from tea leaves is obtained. It was found that a transparent and decolorized green tea extract can be obtained without substantially impairing the above. In addition, it was also found that, by such a treatment, a similar extract can be obtained from a wide and constant range of tea leaves, not limited to green tea leaves.

Thus, according to the present invention, the following are provided as inventions having, but not limited to, main aspects or features.
Aspect 1: A method for producing a decolorized tea extract, which comprises the following steps (A) to (E).
(A) A step of mixing tea leaves and water (B) A step of allowing a glycoside-degrading enzyme to act on the mixture of (A) after step (A) (C) After step (B), a tea leaf residue and an extract And a step of obtaining a glycoside enzyme-treated tea extract, (D) a step of heat-treating the glycoside enzyme-treated tea extract obtained in step (C),
(E) Step Aspect 2 in which insoluble components are removed from the heat-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, which further comprises a step of causing tannase and/or pectinase to act before the step (C).
Aspect 3: The decolorized tea according to Aspect 1 or 2, which comprises a step of allowing a protease to act at the same time as step (B) and/or after step (B) but before step (C). Method for producing extract.
Aspect 4: A method for producing a decolorized tea extract according to any one of Aspects 1 to 3, wherein the heat treatment conditions in the step (D) are within a range of a temperature of 70 to 135°C and a time of 2 seconds to 30 minutes. ..
Aspect 5: The method for producing a decolorized tea extract according to any one of Aspects 1 to 4, wherein the tea leaves are green tea.
Aspect 6: Aspects 1 to 5 including a step of steam-distilling tea leaves to obtain an aroma recovery product before the step (A), and mixing the obtained aroma recovery product with the clarified liquid obtained in the step (E) 5. The method for producing a decolorized tea extract according to any one of 1.
Aspect 7: In any one of Aspects 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. A method for producing the decolorized tea extract as described.
Aspect 8: The 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. A method wherein the absorbance at 5 or less and at 680 nm is 0.15 or less.
Aspect 9: The method for producing a decolorized tea extract described in 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. A method wherein the absorbance at 1 or less and 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 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 having a catechin content of 1.0 mass% or more when (refractive sugar content, temperature 20° C.) is 15.
Aspect 11: When the soluble solid content (refractive sugar content, temperature 20° C.) of the tea extract is 0.3, the absorbance at 430 nm is 0.5 or less and the absorbance at 680 nm is 0.15 or less, and further the soluble solid content is A green tea leaf extract having an amino acid content of 1.0% by mass or more when the (refractive sugar content, temperature 20° C.) is 15.
Aspect 12: A method for producing a low tannin tea extract, which comprises the following steps (A) to (F).
(A) A step of mixing tea leaves and water (B) A step of allowing a glycoside-degrading enzyme to act on the mixture of (A) after step (A) (C) After step (B), a tea leaf residue and an extract To obtain a glycoside enzyme-treated tea extract, (D) a step of heating the glycoside enzyme-treated tea extract obtained in the step (C), and a step (E) obtained in the step (D). Insoluble components are removed from the heat-treated glycoside enzyme-treated tea extract to obtain a decolorized tea extract (F) The decolorized tea extract obtained after the step (E) is further converted into PVPP (polyvinyl poly Pyrrolidone) to obtain an extract from which PVPP is removed after the contact Aspect 13: A method for producing a low tannin tea extract according to aspect 12, wherein the soluble solid content (refractive sugar content, temperature) of the tea extract is Amino acids when the absorbance at 430 nm is 0.05 or less and the absorbance at 680 nm is 0.05 or less when 20° C.) is 0.3, and when the soluble solid content (refractive sugar content, temperature 20° C.) is 15 A method in which the content is 1.0% by mass or more and the tannin (Folin-Denis method) is 1.0% by mass or less.
Aspect 14: The absorbance at 430 nm and the absorbance at 680 nm are 0.05 or less and 0.05 or less, respectively, when the soluble solid content (refractive sugar content, temperature 20° C.) of the tea extract is 0.3. A green tea leaf extract 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) The tea extract obtained by the method according to any one of Aspects 1 to 9, 12 and 13 is added with water to have a soluble solid content of 0.005 to 0.3% (Bx, 20° C.) adjusting step,
(H) A method for producing a packaged tea beverage, which comprises the step of adding vitamin C or an edible salt (sodium) thereof to the tea beverage obtained in step (G).
Aspect 16: The green tea extract according to Aspects 10, 11 and 14 is contained in an amount of 0.005 to 0.3% (Bx, 20° C.) mass% as a soluble solid content derived from tea, and further contains vitamin C or its edible A packaged tea beverage containing salt (sodium).
Aspect 17: The packaged tea beverage according to aspect 16, which contains 0.002 to 0.3% by mass of vitamin C or an edible salt thereof (sodium).
Aspect 18: Aspect 16 or 17, wherein the tea extract has a soluble solid content (refractive sugar content, temperature of 20° C.) of 0.3, the absorbance at 430 nm is 0.015 or less and the absorbance at 680 nm is 0.05 or less. The packaged tea beverage described.

According to the present invention, compared to the tea extract that has been decolorized by the conventional physical and chemical methods, the flavor of tea, in particular, the tea extract that retains the taste, and further the low tannin tea extract. , And, for example, using the green tea extract, it is possible to provide a tea beverage, particularly a packaged tea beverage.

2 is a photograph showing the appearance of a solution obtained by diluting the green tea extract solution obtained in Example 1 to Bx 0.3°. From the left, Comparative Product 1, Inventive Product 4, Inventive Product 5, Inventive Product 6, and Inventive Product 7. In Example 2, the photograph of the external appearance after leaving the liquid in the middle of the process at 20° C. overnight is shown. From left to right are (1), (2), (3), and (4). The photograph of the external appearance of the liquid obtained by diluting the green tea extract obtained in Example 3 to Bx0.3° is shown. Comparative product 4 is on the left, and product 8 of the present invention is on the right. In Example 4, the photograph which shows the external appearance of the liquid of the intermediate step of the comparative product 5 preparation process is shown. From left, Comparative product 4, after enzyme deactivation, filtration, and centrifugation. In Example 5, a photograph of the appearance of the supernatant liquid of centrifugation, the washing liquid when the precipitate was washed with water, and the liquid of the precipitate dissolved in methanol is shown from the left. 7 is a photograph of the precipitate taken in Example 7 with a digital microscope. 9 is a graph of the absorbance of the tea extract (OD430 nm and OD680 nm) when the activity of the glycoside degrading enzyme per tea leaf was changed in Example 8. In Example 8, the tea extract No. 1 when the activity of the glycoside degrading enzyme per tea leaf was changed. 1-No. 6 is a photograph showing the appearance of a Bx 0.3° diluted solution of No. 6;

Detailed description of the invention

The tea leaf that can be used as a raw material in the method of the present invention is a tea leaf that belongs to the widely-cultivated tea (Camellia sinensis), and is any one that meets the purpose of the present invention. However, unfermented tea is preferable, and examples thereof include steamed green tea such as sencha, roasted tea, gyokuro, kabusecha, and tencha, and roasted tea in kettles such as Ureshino tea, Aoyagi tea, and various Chinese teas. In addition, it is also applicable to semi-fermented tea such as baekse tea, iron kannon tea and oolong tea, fermented tea such as black tea and the like.

Further, the tea may be of any variety including Yabukita seeds (Camellia sinensis var. sinenses cv. Yabukita), and its leaves are usually the raw materials for green tea and the like, from core buds to four leaves. It may be one-core/four-leaf picked containing leaves, or may be a leaf other than the matured four-leaf. The above-mentioned tea leaves or tea raw materials can be used as they are, but it is generally preferable to use those that have been subjected to treatments such as cutting, crushing, and grinding using an apparatus used in food production and the like.

In the step (A), when tea leaves and water are mixed, generally, soft water, ion-exchanged water, RO membrane-treated water or the like can be conveniently used. The ratio of tea leaves to water used varies depending on the dry state of the tea leaves, but the weight ratio is generally 1:5 to 50, preferably 1:8 to 20, and more preferably 1:10 to 15. You can Mixing can be performed at room temperature, but in consideration of the harvest time and maturity of the leaves to be used, and also considering that it is preferable to sterilize before the enzyme reaction, it should be performed under warming conditions. Can also The temperature at that time can be exemplified under the condition that the purpose of sterilization is achieved and the heat deterioration of tea leaves is small. For example, the temperature can be 65 to 100°C, more preferably 70 to 90°C. The mixing time is a time for tea leaves to absorb water and become inflated, and is not limited, but it is generally 1 minute to 60 minutes, preferably 5 minutes to 30 minutes. it can.

When mixing is performed under heating conditions for sterilization, the mixture of tea leaves and water is cooled to a temperature suitable for enzyme treatment after heat sterilization.

In the step (B), the glycoside-degrading enzyme can be directly acted on the mixture obtained in the step (A), but before that, a mixture other than a water extract or a glycoside-degrading enzyme from the mixture, After preparing an enzyme-treated extract in the presence of various enzymes used for the extraction of, the glycoside-degrading enzyme is allowed to act, or at the same time the glycoside-degrading enzyme is allowed to act directly on the mixture, or After that, an enzyme other than the glycoside-degrading enzyme can be allowed to act. Enzymes other than glycoside-degrading enzymes include, but are not limited to, tannin-degrading enzymes tannase, protease, amylase, glucoamylase, pectinase, cellulase, hemicellulase, and the like. Among these, tannase and pectinase can be mentioned as suitable for the purpose of the present invention, that is, for obtaining a transparent and decolorized tea extract which retains the original flavor or taste of tea. These enzymes can be used alone or in combination of two or more kinds.

Glycoside degrading enzyme and other enzymes can be used without limitation as long as they are used in the technical field according to the purpose of the present invention, glycoside degrading enzyme, tannase, Pectinase can be described in detail as follows.

As the glycoside degrading enzyme, among various glycosides that can be present in tea leaves, for example, an enzyme that can hydrolyze a glycoside composed of flavonols and glucose into a free aglycone part and a sugar part is conveniently used. can do. Since such O-glycoside glycosides are abundant in the plant kingdom, on the other hand, a wide variety of enzymes that hydrolyze the O-glycoside bond exist in nature. Among these, but not limited to, the following can be mentioned as ones meeting the object of the present invention. For example, β-glucosidase-producing bacteria belonging to Aspergillus genus, Penicillium genus, Rhizopus genus, Pseudomonas genus, Pichia genus, and the like are solid nutrients such as wheat bran and rice bran. Alternatively, it may be one obtained by performing solid culture or liquid culture in a liquid nutrient medium according to a conventional method, and purifying the obtained culture or a treated product thereof by a conventional method. In addition, vanilla beans, those obtained by purification treatment from plants such as green tea leaves can also be used, and further, almond-derived emulsin commercially available from Sigma-Aldrich, or enzyme preparation cellulase A (β-glucosidase) containing β-glucosidase. Enzymes, cellulase T (amanoenzyme) and the like separated from each other can also be used. Examples of β-xylosidase include, for example, penicillium, Aspergillus, Rhizopus, mucor, and the like, β-xylosidase-producing bacteria such as wheat bran, rice bran, or the like in solid nutrient medium or liquid nutrient medium in accordance with a conventional method. The resulting culture or a treated product thereof may be purified by a conventional method, and a commercially available product from Aspergillus niger or an enzyme containing β-xylosidase, which is commercially available from Sigma-Aldrich Co., Ltd. It is also possible to use those separated from the pharmaceutical preparation Sumiteam ACH (Shin Nippon Kagaku Kogyo) and the like. β-prime berosidase, for example, Cellulomonas, Penicillium, Aspergillus, etc. β-prime berosidase production strain wheat bran, solid culture or liquid culture of solid medium or liquid medium such as rice bran according to a conventional method, The obtained culture or a treated product thereof may be purified by a conventional method, and a product obtained by separating and purifying from a plant such as fresh tea leaf may also be used. When used for the purpose of the present invention, the amount of these glycoside-degrading enzymes used is generally based on the mass of the tea leaf material, for example, 1 to 100 U/g in β-glucosidase activity by the p-NP glucose addition method, It can be preferably in the range of 4 to 75 U/g, more preferably 8 to 50 U/g, and further preferably 10 to 40 U/g.

Tannase is an enzyme that hydrolyzes a depside bond in which gallic acid forms an ester bond with a hydroxyl group in tannin, for example, an enzyme that hydrolyzes epigallocatechin gallate into epigallocatechin and gallic acid. Specific examples of 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, and the like. Can be obtained by culturing solid culture or liquid culture in a medium usually used for culturing these filamentous fungi according to a conventional method, and purifying the obtained culture or a treated product thereof by a conventional method. Further, commercially available tannase, for example, tannase (500 U/g; Kikkoman Corp.), tannase (5,000 U/g; Kikkoman Corp.), tannase (500 U/g; Mitsubishi Kagaku Foods Corp.), Sumiteam (registered) Trademark) TAN (manufactured by Shin Nippon Chemical Industry Co., Ltd.) and the like can also be used. The amount of tannase used cannot be specified because the optimum range varies depending on the potency and the like, but it is generally within 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, which is also called polygalacturonase, pectic enzyme, polymethylgalacturonase, or pectin depolymerase, is an enzyme that hydrolyzes α-1,4 bonds such as pecrinic acid, pectin, and pectic acid. It is known that pectinase is 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. Moreover, a commercially available pectinase preparation can also be used. Examples of commercially available pectinase preparations include Sucrase (registered trademark) A, Sucrase (registered trademark) N, Sucrase (registered trademark) S (above, manufactured by Mitsubishi Kagaku Foods Co., Ltd.), Pectinex Ultra (registered trademark) SP-L ( Novo Nordix A/S), Meiserase (registered trademark) (Meiji Seika Co., Ltd.), Ultrazyme (registered trademark) (Novo Nordix A/S), Newase F (registered trademark) ( Amano Enzyme Co., Ltd. Sumiteam (registered trademark) SPG (manufactured by Shin Nippon Chemical Industry Co., Ltd.) and the like can be exemplified. The amount of pectinase to be used is difficult to be expressed in an activity unit because a pectinase preparation usually contains a plurality of types of enzymes, and is generally 0.01% by mass to 5% by mass, preferably 0.1% by mass of the tea leaf raw material. It can be in the range of 2% by weight to 2% by weight.

The tea leaves contain about 25% by mass of protein (refer to the 5th revised food composition table), and the effect of the subsequent heating reaction is particularly enhanced by the protease treatment. However, since the protein in tea leaves is bound to tannin, even if protease is allowed to act on tea leaves alone, almost no amino acids are produced. Then, by causing protease and tannase to act on the tea leaves, a part of the protein in the tea leaves is decomposed, and a tea extract liquid rich in amino acids can be obtained.

Proteases are enzymes that hydrolyze peptide bonds of proteins and peptides. Examples of the protease that can be used in the present invention include various commercially available proteases. The amount of protease used varies depending on the potency and cannot be generally stated, but is usually 0.01 to 100 U/g, preferably 1 to 80 U/g based on the mass of the tea raw material. can do.

The above-described enzyme treatment process of tea leaves (in particular, including the steps (A) and (B)) is a method known per se, for example, Patent Office Publication, Known and Conventional Techniques Collection (Flavor), Part II Food Flavors (2000 1.14 issued) It can be carried out according to the method described in publications such as "2.1.7 Microorganism/enzyme flavor" (pages 46 to 57).

In such a step, the action of a glycoside-degrading enzyme on the mixture of tea leaves and water, or the treated product thereof means that the heat treatment in the subsequent step (D) and the insoluble component in the step (E) It means that the causative agent for coloration can be removed so that the tea extract obtained by the removal is substantially decolorized. Without being bound by theory, it is meant that among the glycosides present in tea leaves, it is possible to remove the coloring-causing substance from the glycosides that were originally water-soluble due to the action of the enzyme. It means to be converted to poorly water-soluble. According to the present invention, it is understood that a color-causing substance including kaempferol, quercetin, etc., which are one of the natural flavonols, is present in the suspension or precipitate containing the insoluble component removed in step (E). Has been done. This is not further bound by theory, but the above-mentioned action hydrolyzes all or most of the glycosides having at least kaempferol, quercetin, etc. as an aglycone, among glycosides that may exist in tea leaves. It is understood that it produces a poorly water-soluble free aglycone.

Therefore, in the step (B), the enzyme treatment is carried out under the condition that the above-mentioned suspended matter or precipitate is formed. Optimum conditions of such conditions vary depending on the titer of the enzyme used, etc., but generally the temperature is 30 to 70° C., preferably 36 to 60° C., more preferably 40° C. to 50° C., further preferably 42° C. At -48°C, the reaction time is theoretically 25 minutes or more, practically 30 minutes to 48 hours, preferably 1-36 hours, more preferably 1.5-24 hours, further preferably 2-16 hours. The pH is generally 4 to 6, although the optimum conditions vary depending on the origin of the enzyme used and the like.

As described above, in step (B), an enzyme other than the glycoside-degrading enzyme can be simultaneously acted (in step (B)). The conditions can be selected according to the conditions.

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 time sufficient to hydrolyze the aglycone part and the sugar part of the glycoside, and then the raw material Tea leaf residue or other insoluble solid matter is separated from other processing liquids (also referred to as extracts). Such separation is performed by, for example, a dehydration type centrifuge, a filter press, a Nutsche filter coated with a filter aid, or the like, and further solid matter is simultaneously removed if necessary.

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

In the step (E), the heat-treated product is cooled to 45° C. or lower, preferably 35° C. or lower to produce a suspension or a precipitate containing an insoluble component. The insoluble component itself or the suspended matter or the precipitate can be removed by, for example, a dehydration type centrifuge, a sedimentation type centrifuge, a filter press, a Nutsche filter coated with a filter aid, or the like. However, sedimentation centrifugation usually gives the preferred results.

Thus, according to the present invention, the coloring in the extract or enzyme extract, which is usually derived from the coloring matter of tea leaves, can be decolorized. On the other hand, it is possible to provide a tea extract in which the contents of amino acids, caffeine, and catechins, which are known to contribute to the flavor of teas, in particular the taste, are not substantially reduced. 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, even more preferably 0.1 or less, even 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, even more preferably 0.05 or less, even 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, and even more preferably 1 as compared with the absorbance at 430 nm of the tea extract without the corresponding enzyme treatment. /5 or less. Further, when the soluble solid content (refractive sugar content, temperature 20° C.) is 15, the catechin content based on the total mass of the solid content is 1.0% by mass or more, preferably 1.2% by mass or more, more preferably It is possible to provide a green tea extract having a content of 1.5% by mass or more. Furthermore, when tea leaves are extracted with a protease, when the soluble solid content (refractive sugar content, temperature 20° C.) is 15, the amino acid content is 1.0 mass% based on the total mass of the solid content. Or more, preferably 1.5 mass% or more, more preferably 1.8 mass% or more, and the catechin content is 1.0 mass% or more, preferably 1.2 mass% or more, more preferably 1.5. It is possible to provide a green tea extract having a mass% or more.

As described above, the decolorized tea extract provided by the present invention having the absorbance at 430 nm and the absorbance at OD680 nm is diluted with water or water to produce a tea beverage, and the total mass of the tea beverage is When the solid content is adjusted to 0.005% by mass to 0.3% by mass, a tea beverage having a coloring degree significantly reduced as compared with the tea extract not treated by the method of the present invention, and further, substantially A colorless and transparent tea drink can be provided. The water is not limited to so-called soft water or hard water as long as it is water that can be used for drinking. It is preferable that such a tea beverage 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 tea. Therefore, in order to achieve the intended purpose of the present invention, for example, referring to the data shown in FIG. 7 described later, the dose of the glycoside-degrading enzyme to be acted in the above step B is controlled, The tea extract may be prepared so that the soluble solid content (refractive sugar content, temperature of 20° C.) of the tea extract is adjusted to 0.3 to exhibit both absorbances described immediately above.

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

The decolorized tea extract provided by the present invention can be used, for example, as a drink for near water or flavored water, or as a raw material for packaged tea drinks.

Specifically, the tea extract obtained by the method according to any one of the above aspects 1 to 9 and 12 to 13 or the bleached and optionally reduced tannin tea extract according to aspect 10 or 11 The soluble solid content derived from tea by addition of water is 0.005-0.3, or 0.01-0.3, or 0.05-0.3, or 0 depending on the type of tea beverage to be provided. It is possible to provide a tea beverage or a packaged tea beverage by adjusting the content of the extract to 0.1 to 0.3% (or °) and adding vitamin C or an edible salt thereof (sodium) at the same time or before or after the adjustment ( Aspect 16 or 17). When providing such a beverage, it has a high storage or storage stability, especially when obtained from the process of aspect 12 or 13 or according to aspect 14, starting from a decolorized and low tannin tea extract, Tea beverages can be provided. The use conditions of PVPP (polyvinylpolypyrrolidone) in the method of Aspect 12 are not limited, but 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, but in the present invention, 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 solids derived from tea as described above, and then adding the vitamin C or the edible salt (sodium) thereof to the total amount of the tea beverage after adjustment of 0. 002% by mass to 0.3% by mass, preferably 0.005% by mass to 0.1% by mass, more preferably 0.01% by mass to 0.03% by mass. By such a treatment, when the tea beverage is sterilized by heating, and the soluble solid content derived from tea is adjusted to 0.3% (Bx, 20° C.) under the condition in a container filled with an ordinary tea beverage. The state in which the absorbance at 430 nm is 0.015 or less and the absorbance at 680 nm is 0.05 or less is stably maintained.

The following explanation can be referred to for the scales of transparency and colorlessness (colored state).
(Transparent)
-OD680nm is 0.15 or less (slightly opaque), preferably 0.10 or less (slightly opaque), more preferably 0.07 or less (almost transparent), further preferably 0.05 or less ( (Approximately completely transparent)
(colorless)
Δ(delta)E is 4.0 or less (slightly colored), preferably 3.0 or less (slightly colored), and more preferably 2.0 or less when Lab is compared with pure water. (Almost colorless), particularly preferably 1.4 or less (approximately completely colorless),
-Or OD430nm is 0.05 or less (slightly colored), preferably 0.038 or less (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 described more specifically with reference to Examples and Comparative Examples.

(Example 1)
Vitamin C (1.8 g) was dissolved in pure water (1300 g) and heated to 75°C. 100 g of No. 2 tea produced in Shizuoka (Yabukita seed, steaming method, cut into 5 mm) was added thereto, heated with stirring and sterilized by heating at 95° C. for 15 minutes. The mixture was cooled to 45° C. (pH at this point was 5.3), the enzymes shown in Table 1 were added, and the reaction was carried out at 45° C. for 4 hours with stirring. After separating the tea leaf residue and the extract with a dehydrating centrifuge, the extract was heated at 95°C for 1 minute and cooled to 30°C. The extract was After filtering with 2 filter papers (holding particle diameter 5 μm), the mixture was cooled to 20° C. and centrifuged at a gravity acceleration of 3000×g for 10 minutes to obtain a green tea extract. The obtained green tea extract was diluted to Bx 0.3° (refractive sugar content, measured at 20° C.), and the absorbance at 430 nm (coloring index) and the absorbance at 680 nm (turbidity index) were measured. The results are shown in Table 1. In addition, photographs of the appearance of these Bx 0.3° diluted solutions are shown in FIG. 1 (from left, comparative product 1, invention product 4, invention product 5, invention product 6, invention product 7).
(Explanation of enzyme)
Glycoside degrading enzyme: commercially available β-glucosidase (1200 U/g)
Tannase: Sumiteam (registered trademark) TAN (tannase manufactured by Shin Nippon Chemical Industry Co., Ltd.: 5000 U/g)
Pectinase: Sumizyme (registered trademark) SPG (pectinase manufactured by Shin Nippon Chemical Industry Co., Ltd.)-Invertase: Sumiteam (registered trademark) INV (invertase manufactured by Shin Nippon Chemical Co., Ltd.)
Hemicellulase (β-mannanase): Sumiteam (registered trademark) ACH (Hemicellulase manufactured by Shin Nippon Chemical Industry Co., Ltd.)

As shown in Table 1, in comparison with Comparative product 1 using tannase and pectinase in combination, Comparative product 2 using invertase, and Comparative product 3 using hemicellulase (mannanase), a glycoside-degrading enzyme was used. In each of the invention products 1 to 7, the absorbance at 430 nm (index of coloring) was low, and the absorbance at 680 nm (index of turbidity) was almost the same or less. The glycoside-degrading enzyme was more decolorized when used in combination with tannase (Invention product 2) than when used alone (Invention product 1), and significantly increased by adding pectinase (about 1/4 to 1/5). ) Was obtained (invention product 6). As a result of examining the amount of glycoside-degrading enzyme added when tannase and pectinase were used in combination, it was found that as the amount of glycoside-degrading enzyme added was increased, the color tone became lighter and turbidity became clearer (the present invention product). 4-7).

(Example 2)
A liquid in the middle of the process was prepared under the same conditions as the product 6 of the present invention. That is, the liquid (1) separated by the dehydration type centrifuge, the liquid (2) after heating the liquid at 95° C. for 1 minute, and then the liquid was cooled and further No. 2 Liquid filtered with filter paper (3), and then the liquid was cooled to 20° C. and centrifuged for 10 minutes at a gravity acceleration of 3000×g (4). Each of these was allowed to stand overnight at 20°C.

As a result, the liquid of (1) was uniformly uniform and had a thick and turbid yellow green color, but the liquid of (2) caused a large amount of dark green precipitate, and the supernatant was pale and almost clear. It was a liquid. In addition, although the liquid of (3) had a slight precipitate, the supernatant was a light and almost clear liquid, and the liquid of (4) was a light and almost clear liquid. , There was no precipitation. A photograph of these appearances is shown in FIG. From left to right are (1), (2), (3), and (4).

As a result, it was found that heat treatment after enzyme treatment produced a precipitate containing a coloring component, and removal of this precipitate resulted in decolorization. In addition, this precipitate is 2 It was found that the filter paper (holding particle diameter: 5 μm) could not be completely removed, but it could be efficiently removed by performing a centrifugal sedimentation treatment with a gravity acceleration of 3000×g.

(Example 3)
Vitamin C (3.6 g) was dissolved in pure water (2600 g) and heated to 75°C. 200 g of No. 1 tea produced in Shizuoka (tea leaf different from that of Example 1: Yabukita seed, steamed blue method, 5 mm cut product) was added thereto, heated with stirring and sterilized by heating at 95° C. for 15 minutes. The mixture was cooled to 45°C (pH at this point was 5.3), the enzymes shown in Table 2 were added, and the reaction was carried out at 45°C for 4 hours with stirring. After separating the tea leaf residue and the extract with a dehydrating centrifuge, the extract was heated at 95°C for 1 minute and cooled to 30°C. The extract was then concentrated under reduced pressure to Bx17° by a rotary evaporator, cooled to 20°C, centrifuged at gravity acceleration of 3000×g for 10 minutes to remove the precipitate, and the supernatant was adjusted to Bx15°. Then, the mixture was heated and sterilized at 95°C for 1 minute and then 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 sugar content, 20 The mixture was diluted to 430 nm (measured at °C), and the absorbance at 430 nm (coloring index) and the absorbance at 680 nm (turbidity index) were measured. The results are shown in Table 2. In addition, photographs of the appearance of these Bx 0.3° diluted solutions are shown in FIG. 3 (comparative product 4 on the left, product 8 of the present invention on the right).

Comparing the component values of the product 8 of the present invention and the product 4 of the comparison, the product 8 of the present invention contained less caffeine, tannins and catechins than the product 4 of the comparison, but the amounts were insignificant.

<Sensory evaluation>
The Bx 0.3° diluted products of the present invention product 8 and the comparative product 4 were evaluated by 5 panelists. As an average evaluation result, the product 8 of the present invention had a slightly weaker body feeling in the taste portion than the product 4 of the comparison, but the flavor of green tea was clearly confirmed. Also, in terms of scent, you can feel the gorgeous aroma of green tea. The potato odor peculiar to enzyme-treated tea was masked.

(Example 4)
A glycoside-degrading enzyme was further allowed to act on Comparative Product 4 to confirm whether or not an extract similar to the product of the present invention could be obtained.

That is, commercially available β-glucosidase (1200 U/g) (12 U per 1 g of tea leaf) was added to Comparative Product 4, and the mixture was stirred at 45° C. for 4 hours, heated at 95° C. for 1 minute, and then heated at 30° C. Cooled down. Then, it was cooled to 20° C., and No2. After filtration with filter paper, centrifugation was performed at a gravity acceleration of 3000×g for 10 minutes, heat sterilization at 95° C. for 1 minute, and cooling 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 sugar content, 20 The mixture was diluted to 430 nm (measured at °C), and the absorbance at 430 nm (coloring index) and the absorbance at 680 nm (turbidity index) were measured. The results are shown in Table 3 for the comparative product 4 and the invention product 8.

Compared to Comparative product 4 (before glycoside-degrading enzyme treatment), Comparative product 5 had a decrease in all of caffeine, tannin, and catechins. On the other hand, although the color tone (OD430 nm) of the product 8 of the present invention was more colored than that of the product 8 of the present invention, the color and the turbidity tended to be smaller than those of the comparative product 4.

Further, in the step of preparing Comparative Product 5, a green floc-like precipitate similar to that in (2) of Example 2 was produced at the stage where the extract solution subjected to the enzyme reaction and heat treatment was left overnight at 20°C. .. A photograph of the appearance of the liquid at the intermediate stage of the comparative product 5 preparation process is shown in FIG. 4 (from the left, comparative product 4, after enzyme deactivation, after filtration, and after centrifugation).

(Example 5)
The precipitate generated in Example 4 was collected, and centrifugation treatment/washing with water was repeated 3 times to collect a dark green precipitate.

Although this precipitate was insoluble in water, it was clarified in methanol and had a deep green color. From this result, although the detailed mechanism is unknown, the action of the glycoside-degrading enzyme on the green tea extract causes the water-soluble pigment component to precipitate as an insoluble precipitate in water. It was estimated to be decolorized.

A photograph of the appearance of the supernatant liquid of centrifugation, the washing liquid when the precipitate was washed with water, and the liquid of the precipitate dissolved in methanol is shown in Fig. 5 (from the supernatant liquid of the centrifugation, when the precipitate was washed with water. Of the washing solution and the solution obtained by dissolving the precipitate in methanol).

(Example 6)
A study was conducted on the case where a protease was used in combination.

Vitamin C (3.6 g) was dissolved in pure water (2600 g) and heated to 75°C. 200 g of No. 2 tea produced in Shizuoka (the same tea leaf as in Example 1: Yabukita seed, steamed blue method, 5 mm cut product) was added thereto, heated with stirring and sterilized by heating at 95° C. for 15 minutes. It cooled to 45 degreeC (pH at this time is 5.3), the enzyme shown in Table 4 was added, and stirring reaction was performed at 45 degreeC for 4 hours. After separating the tea leaf residue and the extract with a dehydrating centrifuge, the extract was heated at 95°C for 1 minute and cooled to 30°C. Then, the extract was concentrated under reduced pressure to 17° Bx using a rotary evaporator, cooled to 20° C., centrifuged at a gravity acceleration of 3000×g for 10 minutes to remove the precipitate, and the supernatant was B×15°. The mixture was heat-sterilized at 95°C for 1 minute and then cooled to 20°C to obtain a green tea extract. The obtained green tea extract was measured for caffeine (HPLC method), catechins (HPLC method) tannin (Folin-denis method) and amino acid (HPLC method), and Bx 0.3° (refractive sugar content, 20° C.). And the absorbance at 430 nm (index of coloring) and the absorbance at 680 nm (index of turbidity) were measured. The results are shown in Table 4.
(Explanation of enzyme)
Protease: Protease M "Amano" SD (Protease manufactured by Amano Enzyme Inc.)

As shown in Table 4, the product 9 of the present invention contained more amino acids than the comparative product 6, and the contents of caffeine, tannin and catechins were almost the same. Further, regarding the color tone, it was confirmed that the product 9 of the present invention, which had been acted on by the glycoside-degrading enzyme, was decolorized as compared with the comparative product 6. Regarding the flavor, when a perfumed product (Bx0.03°) in which 0.2% by mass was added to ion-exchanged water was evaluated, the product 9 of the present invention had a slightly weaker body feeling than the comparative product 6, but had a good taste. The taste of green tea, such as astringency and astringency, was fully felt, and it had a good green tea flavor.

(Example 7)
In Example 6, in the step of preparing the product 9 of the present invention, the precipitate obtained by centrifuging at a gravitational acceleration of 3000×g for 10 minutes was recovered, and the centrifugation treatment/washing with water was repeated 3 times as in Example 5. Repeatedly, a dark green precipitate was collected. The obtained precipitate was photographed with a digital microscope and then subjected to fluorescent X-ray analysis and FT/IR analysis.

The precipitate was separated into two layers by repeating centrifugation/washing with water three times, and it was confirmed that the upper layer portion was a green and viscous substance, and the lower layer portion was a pale green minute spherical substance (Fig. 6). .. Organic substances are presumed to be the main component in both the upper and lower layers from the fluorescent X-ray analysis, and the upper layer is mainly composed of protein from the FT/IR analysis, and the lower layer is one of the natural flavonols. It was suggested that the main component is kaempferol represented by the chemical structural formula.

Kaempferol itself is only slightly soluble in water, but it is known to exist as a glycoside in tea leaves, and therefore easily dissolves even when extracted with water. It is speculated that the kaempferol detected as a precipitate was caused by the elimination of sugar due to the action of a glycoside-degrading enzyme and insolubilization of aglyconized kaempferol. The crystals of kaempferol are yellow, and it is considered that they contribute to the greenish yellow to bright yellow of the light blue color of green tea, but the precipitates detected in this study are green, and kaempferol, protein, chlorophyll, etc. It is presumed that they were complexly bound, insoluble and precipitated.

Example 8 Examination of Effect on Decolorization of Tea Extract when Varying Activity of Glycoside Degrading Enzyme per Mass of Tea Leaf The amount of enzyme added was adjusted as shown in Table 5 below, and 45° C. A green tea extract was obtained according to the method described in Example 1 except that the stirring reaction was performed for 4 hours. The obtained green tea extract was diluted to Bx 0.3° (refractive sugar content, measured at 20° C.), and the absorbance at 430 nm (coloring index) and the absorbance at 680 nm (turbidity index) were measured. The results are shown in Table 5.

OD430nm is an index of coloring, and OD680nm is an index of turbidity. It can be said that when the OD430nm is 0.05 or less, almost no coloring occurs, when it is 0.3 or less, it is very slight coloring, and when it is 0.5 or less, it is light coloring. Further, when OD680nm is 0.1 or less, there is almost no turbidity (clarification), and when OD680nm is about 0.15, slight turbidity is present.

As shown in Table 5, it was found that the color of the obtained extract became lighter as the amount of the glycoside enzyme used for tea leaves increased. Moreover, when 10 U (No. 3) or more is used for 1 g of tea leaves, it can be said that coloring and turbidity are very slight.

Example 9 Examination of Effect of Reaction Time of Glycoside Degrading Enzyme on Tea Leaf on Decolorization of Tea Extract Except that the enzyme reaction time was changed, the present invention product 4 of Example 1 A green tea extract was obtained in accordance with the method described in 10 g of 1 g) and the product 6 of the present invention (adding 20 U of glycoside degrading enzyme to 1 g of tea leaf). The obtained green tea extract was diluted to Bx 0.3° (refractive sugar content, measured at 20° C.), and the absorbance at 430 nm (coloring index) and the absorbance at 680 nm (turbidity index) were measured. The results are shown in Table 6.

As shown in Table 6, it was confirmed that the extract using 10 U or 20 U of glycoside-degrading enzyme per 1 g of tea leaves had a decrease in both color and turbidity in the reaction for 1 hour. Based on the fact that the tea extract without enzyme reaction shown in Table 5 has an OD430nm of 0.562 and an OD680nm of 0.146, it takes 30 minutes for the decolorization and turbidity reduction in 1 hour. It is suggested that the enzymatic reaction time is also effective.

In addition, the longer the enzymatic reaction time, the more the color and turbidity values decrease, and regarding coloring, the reaction was 4 hours in a system using 10 U of glycolytic enzyme for 1 g of tea leaf, and 2 hours in a system using 20 U. The OD430nm was 0.3 or less in the reaction. Regarding the turbidity, the OD680 nm was 0.1 or less after 3 hours of reaction in the system using 10 U and 2 hours of reaction in the system using 20 U. In each system, the color (OD430 nm) and the turbidity (OD680 nm) were further reduced as the reaction time was further extended.

(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. 50 g of No. 2 tea produced in Shizuoka (Yabukita seed, steaming method, cut into 5 mm) was added thereto, heated while stirring, and sterilized by heating at 95°C for 15 minutes. The mixture was cooled to 45° C. (pH at this point was 4.9), the enzymes shown in Table 7 (Invention product 10) were added, and the reaction was carried out at 45° C. for 8 hours with stirring. The tea leaf residue and the extract are separated by a dehydration type centrifuge, 100 g of soft water is further charged into the centrifuge, and the extract adhering to the tea leaf residue is extruded to obtain the extract, which is 95°C for 30 seconds. It was heated to sterilize and deactivate the enzyme, and cooled to 30°C. Then, the extract was centrifuged (1200×g, 8 minutes) to remove the precipitate, and 40% by mass of PVPP of soluble solid content (calculated using Bx at 20° C.) was added to the extract. The mixture was stirred at 30°C for 1 hour. Then No. 2 Filter paper (holding particle diameter 5 μm), 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 It was filled in a PET bottle while being filtered to obtain a green tea extract (invention product 10).

(Example 11)
In Example 10, except that the amount of PVPP added was 80% by mass of the soluble solid content (calculated using Bx at 20° C.) with respect to the extract, the same operation as in Example 10 was performed to obtain a green tea extract. Obtained (invention product 11).

(Example 12) β-Glucosidase treatment In Example 10, the same operation as in Example 10 was carried out except that PVPP was not added to obtain a green tea extract (product 12 of the invention).
(Comparative Example 7) Without β-glucosidase and PVPP treatment In Example 10, exactly the same operation as in Example 10 except that β-glucosidase was not used as the enzyme (using the enzyme of the product 12 of the present invention in Table 7). Then, a green tea extract was obtained (Comparative Product 7).
(Comparative Example 8) Neither β-glucosidase treatment nor PVPP treatment was performed. In Comparative Example 7, the same operation as in Comparative Example 7 was performed except that PVPP was not added to obtain a green tea extract (Comparative Product 8).

(Example 13)
Bx, pH, amino acid (mg%), tannin (mg%) and caffeine (mg%) of the present invention product 10, the present invention product 11, the present invention product 12, the comparative product 7 and the comparative product 8 were measured. Further, it was diluted to Bx 0.3° with pure water, and OD430nm, OD680nm, Lab, and ΔE (comparison with pure water) were measured. Furthermore, the Bx 0.3° diluted product was subjected to sensory evaluation of green tea likeness by 5 well-trained panelists. Table 7 shows the average results of these analysis values and sensory evaluations.

(Result, consideration)
-The β-glucosidase treatment reduces the degree of coloring of the tea beverage (comparative product 8 and invention product 12, and comparative product 7 and invention product 10).
-The PVPP treatment reduces the degree of coloring of the tea beverage, and in particular, there is a tendency that the coloring after heat sterilization is small. In addition, the bitterness and astringency are weakened by the PVPP treatment (comparison between comparative product 8 and comparative product 7, and invention product 12 and invention product 10).
-In addition to the β-glucosidase treatment, the products 10 and 11 of the present invention that have been subjected to PVPP treatment (removal of tannin), when diluted to the same solid content concentration (Bx 0.3°), while maintaining the flavor of tea, It was observed that the lightest color and more decolorized extract was obtained.
-In addition to β-glucosidase treatment, PVPP treatment (tannin removal) is performed to obtain a soluble solid content (refractive sugar content, temperature 20°C) of the tea extract of 0.3, the absorbance at 430 nm is 0.05 or less, Moreover, the absorbance at 680 nm is 0.05 or less, and when the soluble solid content (refractive sugar content, temperature 20° C.) is 15 (5 times the concentration of the above-mentioned invention product), the amino acid content is 1.0% by mass or more. Moreover, a green tea extract having less than 1.0% by mass of catechin could be obtained (invention products 10 and 11).

(Example 14) Color tone of packaged beverage using invented product and comparative product Invented products 10, 11, 12 and comparative product 7 and comparative product 8 were diluted to Bx 0.005° (respectively). 0.167% of each of the present invention product and comparative product), 0.03% sodium ascorbate added and non-added solutions were prepared, sterilized by UHT at 135°C for 30 seconds, and then cooled to 90°C. After filling the bottle, it was cooled to 30° C. or lower to prepare a container-packaged green tea beverage.
Table 8 shows the color tone of each beverage (OD430 nm, OD680 nm and ΔE with pure water).

(Result, consideration)
-When the extract is diluted to Bx 0.005° and sodium ascorbate 0.03% is added, all of the products 10, 11, 12 of the present invention, Comparative product 7 and Comparative product 8 are colorless and transparent or beverages close thereto are prepared. it can.
When the extract was diluted to Bx 0.005° and sodium ascorbate was not added, it was almost transparent without turbidity, and 10 and 11 were almost completely colorless, but other colors were observed. ..

Example 15 Relationship between Additive Concentration of Extract and Color Tone The product 10 of the present invention was diluted to have the concentration shown in Table 9 (sodium ascorbate was not added) and UHT sterilized at 135° C. for 30 seconds, then 90 After being cooled to 30°C and filled in a PET bottle, it was cooled to 30°C or lower to prepare a packaged green tea beverage.
Table 9 shows the color tone of each beverage (OD430 nm and ΔE with pure water).

(Result, consideration)
In the case of a packaged beverage prepared without addition of sodium ascorbate, when the concentration of the product 10 of the present invention is Bx 0.005°, it is almost completely colorless, and when Bx 0.015 is slightly colored, it is colored at Bx 0.025.
However, in order to sufficiently secure the flavor like green tea, it seems that about 0.025 is necessary.
Since the addition of sodium ascorbate was found to have the effect of preventing coloration when preparing a packaged beverage from Example 13, the following experiment was conducted.

(Example 16) Relationship between sodium ascorbate addition concentration, storage condition and color tone The product 10 of the present invention was diluted to have Bx0.025°, and at that time, sodium ascorbate having a concentration shown in Table 10 was added to the mixture to give 135 After UHT sterilization at 30° C. for 30 seconds, the mixture was cooled to 90° C., filled in a PET bottle, and then cooled to 30° C. or lower to prepare a packaged green tea beverage.
Each packaged beverage was stored at 10°C and 50°C for 10 days.
Table 10 shows the color tone (OD430 nm and ΔE with pure water) of each beverage after storage.

(Result, consideration)
-Addition of sodium ascorbate suppressed coloration after sterilization.
-In the range of addition concentration of sodium ascorbate of 0 to 0.03%, it was confirmed that the coloring after sterilization was suppressed as the addition amount increased.
From the OD430 nm and ΔE immediately after sterilization and after storage at 10° C. for 10 days, if sodium ascorbate was 0.01% or more, it was almost completely colorless and transparent.
・When the packaged beverage was stored at 50°C for 10 days (abuse condition), it was "almost colored" at a sodium ascorbate concentration of 0.03%, but was "slightly colored" at 0.01%. there were.
-According to the above, it can be said that the addition concentration of sodium ascorbate is preferably 0.01% or more.

Claims (18)

A method for producing a decolorized tea extract, which comprises the following steps (A) to (E).
(A) A step of mixing tea leaves and water (B) A step of allowing a glycoside-degrading enzyme to act on the mixture of (A) after step (A) (C) After step (B), a tea leaf residue and an extract And a step of obtaining a 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 heat-glycoside enzyme-treated tea extract obtained in step (D) to obtain a decolorized tea extract The method for producing a decolorized tea extract according to claim 1, further comprising the step of allowing tannase and/or pectinase to act at the same time as or before or after step (B) and before step (C). .. Decolorized tea extract according to claim 1 or 2, further comprising the step of allowing a protease to act at the same time as step (B) and/or after step (B) but before step (C). Manufacturing method. The method for producing a decolorized tea extract according to any one of claims 1 to 3, wherein the heat treatment conditions in the step (D) are at a temperature of 70 to 135°C and a time of 2 seconds to 30 minutes. The method for producing a decolorized tea extract according to claim 1, wherein the tea leaves are green tea. Any of claims 1 to 5, including a step of steam-distilling tea leaves to obtain an aroma collection product before the step (A), and mixing the obtained aroma collection product with the clarified liquid obtained in the step (E). A method for producing a decolorized tea extract described in (1). 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. A method for producing a decolorized tea extract. The method for producing a 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. 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 sugar content, temperature 20° C.) of the tea extract is 0.3. 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, the absorbance at 430 nm is 0.15 or less and the absorbance at 680 nm is 0.05 or less. , And a catechin content of 1.0 mass% or more when the temperature is 20° C.) is 15. When the soluble solid content (refractive sugar content, temperature 20° C.) of the tea extract is 0.3, the absorbance at 430 nm is 0.5 or less and the absorbance at 680 nm is 0.15 or less. And a temperature of 20° C.) of 15, the green tea leaf extract having an amino acid content of 1.0 mass% or more. A method for producing a low tannin tea extract, which comprises the following steps (A) to (F).
(A) A step of mixing tea leaves and water (B) A step of allowing a glycoside-degrading enzyme to act on the mixture of (A) after step (A) (C) After step (B), a tea leaf residue and an extract To obtain a glycoside enzyme-treated tea extract, (D) a step of heating the glycoside enzyme-treated tea extract obtained in the step (C), and a step (E) obtained in the step (D). Insoluble components are removed from the heat-treated glycoside enzyme-treated tea extract to obtain a decolorized tea extract (F) The decolorized tea extract obtained after the step (E) is further converted into PVPP (polyvinyl poly (Pyrrolidone) to obtain an extract liquid after removing PVPP after contact 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 when the soluble solid content (refractive sugar content, temperature 20° C.) is 15, the amino acid content is 1.0% by mass or more and the tannin (Folin-Denis method) is 1. The method is 0 mass% or less. When the soluble solid content (refractive sugar content, temperature 20° C.) of the tea extract is 0.3, the absorbance at 430 nm is 0.05 or less and the absorbance at 680 nm is 0.05 or less, and the soluble solid content (refractive sugar content) is 0.05 or less. , And the tannin (Folin-Denis method) is 1.0 mass% or less when the temperature is 20° C.) and the amino acid content is 1.0 mass% or more. (G) A soluble solid content derived from tea is 0.005-0.3% (Bx, 20° C.) by adding water to the tea extract obtained by the method according to any one of claims 1 to 9, 12 and 13. ) Adjusting step,
(H) A method for producing a packaged tea beverage, which comprises the step of adding vitamin C or an edible salt (sodium) thereof to the tea beverage obtained in step (G). The green tea extract according to claim 10, 11 and 14 is contained in an amount of 0.005 to 0.3% (Bx, 20°C) mass% as a soluble solid content derived from tea, and further vitamin C or an edible salt thereof ( A packaged tea beverage containing sodium). The packaged tea beverage according to claim 16, which contains 0.002 to 0.3% by mass of vitamin C or an edible salt thereof (sodium). 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. Bottled tea beverage.

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