JP6993418B2 - Decolorized tea extract and its manufacturing method - Google Patents

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, which is inherent in tea despite its light color, and a method for producing the same, which comprises a step of treating tea leaves with a glycoside-degrading enzyme.

In recent years, due to the diversification of consumer tastes for packaged beverages, many packaged beverages in which colorless and transparent containers are filled with almost colorless and transparent beverages are found in the market. Such beverages are also called near water or 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 lemon, orange and mandarin oranges, soft fruit flavors such as grapes, apples and peaches, and fermented milk flavors such as yogurt. Not many of them have the flavor of.

The flavor of tea can be reproduced to some extent only with the flavors that have the aroma of tea (mixed flavors or natural flavors), but in order to make the tea feel authentic, by blending water-soluble ingredients derived from tea. , It is possible to impart a more preferable flavor.

On the other hand, the tea extract is usually colored, and if the tea extract is mixed in an amount sufficient to impart flavor, the entire beverage will be colored 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 that amino acids, which are delicious components, are also removed by the cation exchange resin treatment.

As a decolorization method, treatment with an adsorbent such as activated carbon is generally known, and for tea, a treatment technique with various adsorbent treatments is also known. 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 the purpose is to remove caffeine, and decolorization is completely described. It has not been. Further, Patent Document 3 discloses a method of contacting an aqueous solution containing caffeine such as a tea extract with active 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 of contacting a tea extract with polyvinylpolypyrrolidone, but the purpose is to remove catechins or tannins, and decolorization is not described at all.

As a method for producing a green tea extract that can be used for sports beverages and isotonic beverages, the green tea extract is dissolved in a mixed solution having a weight ratio of ethanol and water of 91/9 to 97/3 and brought into contact with activated charcoal and acidic white clay. A method for producing the obtained low-caffeine green tea extract (Patent Document 6) is disclosed, but the main purpose is to remove caffeine. In Patent Document 6, it is also effective not to deteriorate the hue (paragraph [0009], etc.), but there is no description that can specifically specify the color tone, and there is no description in the examples.

On the other hand, glycoside-degrading enzyme means an enzyme that hydrolyzes the bond (glycoside bond) between the anomer carbon of the glycoside and the aglycon portion to produce free aglycon. In the method for producing a beverage, a method for producing a green tea beverage comprising an enzyme treatment step of changing 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 (the method for producing a beverage). Patent Document 7), a method for producing an aroma-enhanced tea extract, which comprises allowing a glycoside-degrading enzyme to act on tea leaves when and / or after treating the tea leaves with tanase (Patent Document 8). Is known, but all of them only describe the content related to the generation of aroma. Further, in Cited Document 9, after concentrating a water extract of tea such as oolong tea to Bx2 to 15 °, the concentrate is allowed to act on a glycosyllytic enzyme to have high transparency, and even if it is stored for a long period of time, it is liable. A method for producing a tea extract that does not generate oolong is described. However, the color tone (color depth, etc.) is not described at all.

Japanese Patent Publication No. 11-504224 Japanese Unexamined Patent Publication No. 8-70772 Japanese Unexamined Patent Publication No. 6-142405 Japanese Patent No. 3315304 Japanese Patent Application Laid-Open No. 2003-204754 Japanese Patent No. 4181982 Japanese Unexamined Patent Publication No. 2004-147606 Japanese Unexamined Patent Publication No. 2006-75112 Patent No. 5818784

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

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

It is already known that a sugar-degrading enzyme is allowed to act on a water extract of tea leaves to change the glycosyl component into an aroma component compound. After treatment with a glycosylation-degrading enzyme under certain conditions, the obtained glycosylation enzyme-treated tea extract is heat-treated to form a water-insoluble substance, and when the water-insoluble substance is removed, the 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. It was also found that, by such treatment, a similar extract can be obtained from a wide range of tea leaves, not limited to green tea leaves.

Thus, according to the present invention, the following inventions are provided as inventions having, but not limited to, main aspects or features.
Aspect 1: A method for producing a bleached tea extract, which comprises the following steps (A) to (E).
(A) A step of mixing tea leaves and water (B) After the step (A), a step of allowing a glycoside-degrading enzyme to act on the mixture of (A) (C) After the step (B), the tea leaf residue and the extract. A step of heat-treating the glycosylation enzyme-treated tea extract obtained in step (D) step (C).
(E) Step 2: Obtaining a decolorized tea extract by removing insoluble components from the heated glycosylation enzyme-treated tea extract obtained in step (D): Simultaneously with, before or after step (B). The method for producing a bleached tea extract according to aspect 1, further comprising a step of allowing tannase and / or pectinase to act before the step (C).
Aspect 3: Decolorized tea according to aspect 1 or 2, comprising the step of allowing the protease to act simultaneously and / or after step (B) and before step (C). Extract manufacturing method.
Aspect 4: The method for producing a decolorized tea extract according to any one of Aspects 1 to 3, wherein the heat treatment condition in the step (D) is in the 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.
Aspects 6: Prior to the step (A), aspects 1 to 5 include a 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 the step (E). The method for producing a bleached tea extract according to any one of.
Aspect 7: Any one of Aspects 1 to 6 in which 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 method for producing a decolorized tea extract according to the above method.
Aspect 8: The method for producing a decolorized tea extract according to Aspect 1, wherein the absorbance at 430 nm is 0 when the soluble solid content (refractive sugar content, temperature 20 ° C.) of the tea extract is 0.3. A method in which the absorbance at 5 or less and 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 when the soluble solid content (refractive sugar content, temperature 20 ° C.) of the tea extract is 0.3. A method in which the absorbance at 1 or less and 680 nm is 0.05 or less.
Aspect 10: 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 further, the soluble solid content. A green tea leaf extract having a catechin content of 1.0% by mass or more when (refractive sugar content, temperature 20 ° C.) is 15.
Aspect 11: When the soluble solid content (reflux sugar content, temperature 20 ° C.) of the tea extract is 0.3, the absorbance at 430 nm is 0.5 or less, the absorbance at 680 nm is 0.15 or less, and the soluble solid content is further. A green tea leaf extract having an amino acid content of 1.0% by mass or more when (reflux 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) After the step (A), a step of allowing a glycoside-degrading enzyme to act on the mixture of (A) (C) After the step (B), the tea leaf residue and the extract. And are separated to obtain a glycosylation enzyme-treated tea extract. (D) A step of heat-treating the glycosylation enzyme-treated tea extract obtained in step (C). (E) Obtained in step (D). Steps to remove insoluble components from the heated glycosylation enzyme-treated tea extract to obtain a decolorized tea extract (F) The decolorized tea extract obtained after the step (E) is further added to PVPP (polyvinyl poly). Step 13: The method for producing a low tannin tea extract according to Aspect 12 to obtain an extract from which PVPP has been removed after contact with pyrrolidone), wherein the soluble solid content (refractive sugar content, temperature) of the tea extract is obtained. 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 the soluble solid content (reflux 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: 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 further, the soluble solid content. 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 (refractive sugar content, temperature 20 ° C.) is 15.
Aspect 15: (G) Add water to the tea extract obtained by the method according to any one of Aspects 1 to 9, 12 and 13 to add 0.005 to 0.3% (Bx,) a soluble solid content derived from tea. 20 ° C) adjustment process,
(H) A method for producing a packaged tea beverage, which comprises a step of adding vitamin C or an edible salt (sodium) thereof to the tea beverage obtained in the 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.) by mass as a soluble solid content derived from tea, and is further composed of 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 (sodium) thereof.
Aspect 18: Aspect 16 or 17, wherein the soluble solid content (refractive sugar content, temperature 20 ° C.) of the tea extract is 0.3 and the absorbance at 430 nm is 0.015 or less and the absorbance at 680 nm is 0.05 or less. The described containerized tea beverage.

According to the present invention, as compared with the tea extract that has been decolorized by a conventional physicochemical method, a tea extract that retains the flavor of tea, particularly a tea extract that retains the taste, and a low tannin tea extract. , And, for example, tea beverages using the green tea extract, especially tea beverages in containers, can be provided.

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

Detailed description of the invention

The tea leaves that can be used as a raw material in the method of the present invention are tea leaves belonging to tea (Camellia sinensis) widely cultivated in the world, and any tea leaves that meet the object of the present invention. Although unfermented tea is preferable, non-fermented tea is preferable, and examples thereof include steamed green tea such as roasted tea, roasted tea, tamaro, kabuse tea, and tencha, and pot-roasted tea such as Ureshino tea, Aoyagi tea, and various Chinese teas. It can also be applied to semi-fermented tea such as Baozhong tea, Tieguanyin tea, and oolong tea, and fermented tea such as black tea.

In addition, the tea may be of any variety, including Camellia sinensis var. Sinnesses cv. Yabukita, and its leaves are usually from core buds to four leaves, which are raw materials for green tea and the like. It may be a single-core four-leaf picked leaf containing leaves, or may be a leaf other than a more mature four-leaf. The above-mentioned tea leaves or tea raw materials can be used as they are, but it is usually preferable to use those that have been subjected to processing such as cutting, crushing, and grinding using an apparatus used in food production and the like.

In the step (A), where the tea leaves and water are mixed, generally soft water, ion-exchanged water, RO membrane-treated water or the like can be conveniently used as the water. The ratio of tea leaves to water used varies depending on the dry state of the tea leaves, but is generally 1: 5 to 50, preferably 1: 8 to 20, and more preferably 1:10 to 15 in terms of weight ratio. Can be done. Mixing can be carried out at room temperature, but it should be carried out under warming conditions in consideration of the harvest time, maturity, etc. of the leaves to be used, and also in consideration that it is preferable to carry out sterilization before the enzymatic reaction. You can also. As the temperature at that time, a condition in which the purpose of sterilization is achieved and the heat deterioration of the tea leaves is small can be exemplified, and the temperature can be, for example, 65 to 100 ° C., more preferably 70 to 90 ° C. The mixing time is the time during which the tea leaves absorb water and become swollen, and is not limited, but is generally in the range of 1 minute to 60 minutes, preferably 5 minutes to 30 minutes. 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 prior to that, the mixture is not a water extract or a glycoside-degrading enzyme, and tea is used. After preparing the enzyme-treated extract in the presence of various enzymes used for the extraction of, the glycoside-degrading enzyme is allowed to act, or the mixture is allowed to act directly on the glycoside-degrading enzyme, or at the same time. After that, an enzyme other than the glycoside-degrading enzyme can be allowed to act. Examples of enzymes other than glycosylation-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 the ones suitable for the purpose of the present invention, that is, for obtaining a transparent and decolorized tea extract while retaining the original flavor or taste of tea. These enzymes can be used alone or in combination of two or more.

Glycoside-degrading enzymes and other enzymes can be used without limitation as long as they are used in the art for the purposes of the present invention, such as glycoside-degrading enzymes, tannase, and the like. Pectinase can be described in detail as follows.

As the glycoside-degrading enzyme, among various glycosides that can exist in tea leaves, for example, an enzyme capable of hydrolyzing a glycoside composed of flavonols and glucose into a free aglycone moiety and a sugar moiety is conveniently used. can do. Since such O-glycosidic glycosides are abundant in the plant kingdom, on the other hand, a wide variety of enzymes that hydrolyze the O-glycosidic bond also exist in the natural world. Among these, the following can be mentioned as those which meet the object of the present invention without limitation. For example, β-glucosidase-producing bacteria belonging to the genus Aspergillus, the genus Penicillum, the genus Rhizopus, the genus Pseudomonas, the genus Pichia, etc. Alternatively, it can be solid-cultured or liquid-cultured in a liquid nutrient medium according to a conventional method, and the obtained culture or a processed product thereof can be purified by a conventional method. In addition, those obtained by purification treatment from plants such as vanilla beans and raw tea leaves can also be used, and further, almond-derived emulsin or β-glucosidase-containing enzyme preparation cellulase A (Amano) commercially available from Sigma-Aldrich can be used. Enzymes), cellulase T (Amanoenzyme) and the like can also be separated. As β-xylosidase, for example, β-xylosidase-producing bacteria belonging to the genus Penicillium, Aspergillus, Rizopus, Mucor, etc. are cultivated in a solid or liquid nutrient medium such as wheat bran or rice bran according to a conventional method. The obtained culture or a processed product thereof may be purified by a conventional method, and an enzyme derived from Aspergillus niger or an enzyme containing β-xylosidase commercially available from Sigma Aldrich Co., Ltd. can be mentioned. Formulations separated from Sumiteam ACH (Shin Nihon Kagaku Kogyo) and the like can also be used. For β-primeberosidase, for example, β-primeberosidase-producing bacteria belonging to the genus Cellulomonas, Penicillium, Aspergillus, etc. are solid-cultured or liquid-cultured in a solid or liquid medium such as wheat bran or rice bran according to a conventional method. Examples thereof include those obtained by purifying the obtained culture or a processed product thereof by a conventional method, and those separated and purified from a plant such as raw tea leaves can 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 raw 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 even more preferably 10 to 40 U / g.

Tannase is an enzyme that hydrolyzes a depside bond in which gallic acid is ester-bonded to a hydroxyl group in tannin, for example, an enzyme that hydrolyzes epigallocatengalate to epigallocatekin and gallic acid. Specific examples of the tannase that can be used in the present invention include tanase-producing bacteria belonging to the genus Aspergillus, Penicillium, Resopus, Rizomcor, Lactobacillus, Staphylococcus, Streptococcus, Ronepinera and the like. Can be mentioned as those obtained by solid-culturing or liquid-culturing in a medium usually used for culturing these filamentous fungi according to a conventional method, and purifying the obtained culture or a processed product thereof by a conventional method. Also, commercially available tannase, for example, tannase (500 U / g; manufactured by Kikkoman), tannase (5,000 U / g; manufactured by Kikkoman), tannase (500 U / g; manufactured by Mitsubishi Chemical Foods), Sumiteam (registered). Trademark) TAN (manufactured by Shin Nihon Kagaku Kogyo Co., Ltd.) can also be used. The amount of tannase used cannot be specified because the optimum range varies depending on the titer and the like, 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, also called polygalacturonase, pectic enzyme, polymethylgalacturonase, or pectin depolymerizer, is an enzyme that hydrolyzes α-1,4 bonds such as pectinic acid, pectin, and pectinic acid. Pectinase is known to be contained in bacteria, molds, yeasts, higher plants, snails and the like, and in the present invention, pectinase collected from organisms such as these can be widely used. It is also possible to use a commercially available pectinase preparation. Examples of commercially available pectinase preparations include Scrase (registered trademark) A, Scrase (registered trademark) N, Scrase (registered trademark) S (all manufactured by Mitsubishi Chemical Foods), and Pectinex Ultra (registered trademark) SP-L (registered trademark). Novonordix A / S), Meiserase (registered trademark) (Meiji Confectionery Co., Ltd.), Ultrazyme (registered trademark) (Novonordix A / S), Neurase F (registered trademark) ( Amano Enzyme Co., Ltd.) Sumiteam (registered trademark) SPG (manufactured by Shin Nihon Kagaku Kogyo Co., Ltd.) can be exemplified. Since the pectinase preparation usually contains a plurality of types of enzymes, the amount of pectinase used is difficult to express in terms of active unit, and is generally 0.01% by mass to 5% by mass, preferably 0.1 based on the mass of the tea leaf raw material. It can be in the range of% by mass to 2% by mass.

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

Proteases are enzymes that hydrolyze the 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 titer and the like and cannot be unconditionally stated, but it is usually in the range of 0.01 to 100 U / g, preferably 1 to 80 U / g based on the mass of the tea raw material. can do.

The process of treating tea leaves with the enzyme described above (particularly, including steps (A) and (B)) is a method known per se, for example, a well-known and commonly used technical collection (fragrance) of the Japan Patent Office, Part II, Food Perfume (2000). 1.14) It can be performed according to the method described in publications such as "2.1.7 Microbial / Enzyme Flavor" (pages 46-57).

In such a step, the action of the glycosyl-degrading enzyme on the mixture of tea leaves and water, or the processed product thereof, means that the heat treatment in the subsequent step (D) and the insoluble component in the step (E) are allowed to act. It means that the color-causing substance can be removed so that the tea extract obtained by the removal is substantially decolorized. Although not bound by theory, the fact that the glycosides present in tea leaves can remove coloring-causing substances means that those originally in the form of water-soluble or the like due to the action of the enzyme are water-insoluble or water-insoluble. It means converting to sparingly water-soluble. According to the present invention, it is understood that the color-causing substances including kaempferol and quercetin, which are one of the natural flavonols, are present in the suspended matter or precipitate containing the insoluble component removed in the step (E). Has been done. Although this is not further constrained by theory, the above action hydrolyzes at least all or most of the glycosides having kaempferol, quercetin, etc. as aglycones among the glycosides that may exist in tea leaves. It is understood that it produces a poorly water-soluble free aglycone.

Therefore, in step (B), the enzyme treatment is performed under the conditions for forming a suspended matter or precipitate as described above. The optimum 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, still more preferably 42 ° C. At ~ 48 ° C., the reaction time is theoretically 25 minutes or longer, practically 30 minutes to 48 hours, preferably 1 to 36 hours, more preferably 1.5 to 24 hours, still more preferably 2 to 16 hours. The optimum pH of the pH varies depending on the origin of the enzyme used and the like, but is generally 4 to 6.

As described above, in step (B), enzymes other than glycoside-degrading enzyme can be allowed to act at the same time (in step (B)), and these enzyme treatments also cause the glycoside-degrading enzyme to act as described above. You can choose the conditions 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 sufficient time to hydrolyze the aglycone portion and the sugar portion of the glycoside, and then the raw material is used. The tea leaf residue or other insoluble solid matter is separated from other treatment solutions (also referred to as extracts). Such separation is performed, for example, by a dehydrating centrifuge, a filter press, a Nutche filter coated with a filtration aid, and if necessary, further solids are removed at the same time.

In the step (D), the enzyme-treated tea extract is heat-treated to denature proteins such as the enzyme used in the step. Although the interpretation of the technical scope of the present invention is not restricted by theory, the enzyme not only loses its activity due to the denaturation by this heat treatment, but also is a causative component of coloring and is treated with the enzyme. It is considered that the components insoluble in water are bound to the denatured proteins and easily aggregated. 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 in the range of 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 suspended substance or a precipitate containing an insoluble component. Removal of such insoluble components themselves, or suspended matter or precipitates, can be performed, for example, by a dehydrating centrifuge, a settling centrifuge, a filter press, a Nutche filter coated with a filtration aid, or the like. However, usually, settling-type centrifugation gives favorable results.

Thus, according to the present invention, the coloring in the extract or enzyme extract, which is usually derived from the coloring of tea leaves, can be decolorized. On the other hand, it is possible to provide a tea extract having a substantially reduced content of amino acids, caffeine and catechins, which is known to contribute to the flavor of tea, particularly 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. It is preferably 0.3 or less, more preferably 0.2 or less, still more preferably 0.1 or less, even more preferably 0.05 or less, most preferably 0.015 or less, and has an absorbance at 680 nm of 0. It is 15 or less, preferably 0.10 or less, more preferably 0.08 or less, still 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, still more preferably 1 than the absorbance of the tea extract at 430 nm without the corresponding enzyme treatment. It is less than / 5. 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% by mass or more, preferably 1.2% by mass or more, more preferably. It is possible to provide a green tea extract having an amount of 1.5% by mass or more. Further, when the tea leaves are extracted by the action of protease, the amino acid content per total mass of the solid content is 1.0% by mass when the soluble solid content (refractive sugar content, temperature 20 ° C.) is 15. The above is 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% by mass. 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, which has an absorbance at 430 nm and an absorbance at OD 680 nm, is used when diluted or hydrated 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 degree of coloring of the tea beverage is significantly reduced as compared with the tea extract not treated by the method of the present invention, and further, the substance is substantially reduced. It is possible to provide a colorless and transparent tea beverage. The water is not limited to the so-called soft water or hard water as long as it is water that can be used for drinking. Such a tea beverage preferably has an absorbance at 430 nm of 0.05 or less and an absorbance of 680 nm of 0.05 or less, while retaining the flavor of tea. Therefore, in order to achieve the intended object of the present invention, for example, by referring to the data shown in FIG. 7 described later, the dose of the glycoside-degrading enzyme acting in the above-mentioned step B is controlled. When the soluble solid content (refractive sugar content, temperature 20 ° C.) of the tea extract is adjusted to 0.3, it may be adjusted so as to show both absorbances described immediately before.

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

The decolorized tea extract provided in the present invention can be used, for example, as a raw material for near water, flavored water-like beverages, and packaged tea beverages.

Specifically, the tea extract obtained by the method according to any one of the above-mentioned aspects 1 to 9 and 12 to 13, or the decolorized and optionally low tanning tea extract according to the above-mentioned aspect 10 or 11. Soluble solids derived from tea by adding water are 0.005 to 0.3, or 0.01 to 0.3, or 0.05 to 0.3, or 0, depending on the type of tea beverage to be provided. . Tea beverages, packaged tea beverages can be provided by adjusting to 1-0.3% (or °) and adding Vitamin C or its edible salt (sodium) at the same time as or before or after the adjustment (so). Aspect 16 or 17). Such beverages are highly storage or storage stable, especially when obtained by the method of embodiment 12 or 13, or according to embodiment 14, decolorized and starting from a low tannin tea extract. Tea beverages can be provided. The conditions for using 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, 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). In the tea extract thus obtained, preferably, after adjusting the soluble solid content derived from tea as described above, vitamin C or an edible salt thereof (sodium) is added to 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 is added. By such a treatment, the tea beverage is sterilized by heating, and then the soluble solid content derived from tea is adjusted to 0.3% (Bx, 20 ° C.) under the conditions in a container filled with a normal 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 taken into consideration for the scales of transparency and colorlessness (coloring status).
(Transparent)
OD680 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). Approximately completely transparent)
(colorless)
-Δ (Delta) E when comparing Labs based on permeability with pure water is 4.0 or less (slightly colored), preferably 3.0 or less (very slightly colored), and more preferably 2.0 or less. (Almost colorless), especially preferably 1.4 or less (approximately completely colorless),
Alternatively, OD430 nm is 0.05 or less (slightly colored), preferably 0.038 or less (very slightly colored), more preferably 0.025 or less (nearly colorless), and particularly preferably 0.015 or less (approximately completely). colorless)

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

(Example 1)
1.8 g of vitamin C was dissolved in 1300 g of pure water and heated to 75 ° C. 100 g of Shizuoka No. 2 tea (Yabukita seed, steamed blue method, cut into 5 mm) was added thereto, and the mixture was 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 a stirring reaction was carried out at 45 ° C. for 4 hours. After separating the tea leaf residue and the extract by a dehydration type centrifuge, the extract was heated at 95 ° C. for 1 minute and cooled to 30 ° C. The extract was No. After filtering 2 filter papers (reserved particle diameter 5 μm), the mixture was cooled to 20 ° C. and centrifuged at a gravitational 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 (index of coloring) and the absorbance at 680 nm (index of turbidity) were measured. The results are shown in Table 1. In addition, a photograph of the appearance of these Bx0.3 ° diluted solutions is shown in FIG. 1 (from the left, Comparative product 1, the present invention product 4, the present invention product 5, the present invention product 6, and the present 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 Nihon Kagaku Kogyo Co., Ltd .: 5000 U / g)
・ Pectinase: Sumiteam (registered trademark) SPG (Pectinase manufactured by Shin Nihon Kagaku Kogyo Co., Ltd.) ・ Invertase: Sumiteam (registered trademark) INV (Invertase manufactured by Shin Nihon Kagaku Kogyo Co., Ltd.)
-Hemicellulase (β-mannanase): Sumiteam (registered trademark) ACH (hemicellulase manufactured by Shin Nihon Kagaku Kogyo Co., Ltd.)

As shown in Table 1, compared with Comparative Product 1 using tannase and pectinase, Comparative Product 2 using Invertase, and Comparative Product 3 using hemicellulase (mannanase), a book in which a glycoside-degrading enzyme was allowed to act. In the inventions 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. Glycoside-degrading enzyme is more decolorized when used in combination with tannase than when used alone (product 1 of the present invention) (product 2 of the present invention), and is significantly (about 1/4 to 1/5) by adding pectinase. ) Was decolorized (Product 6 of the present invention). As a result of examining the amount of glycoside-degrading enzyme added when tannase and pectinase were used in combination, it was found that the color tone became lighter and the turbidity became clearer as the amount of glycoside-degrading enzyme added increased (the product of the present invention). 4-7).

(Example 2)
A liquid in the middle of the process was prepared under the same conditions as the above-mentioned 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 cooling the liquid and further No. 2 Filter paper filtered liquid (3), then the liquid was cooled to 20 ° C. and centrifuged at a gravitational acceleration of 3000 × g for 10 minutes (4). Each of these was allowed to stand at 20 ° C. overnight.

As a result, the liquid of (1) is uniform as a whole and exhibits a thick and turbid yellowish green color, but the liquid of (2) produces a large amount of dark green precipitate and the supernatant is light in color and almost clear. It was a liquid. In addition, the liquid of (3) had a slight precipitate, but the supernatant was a light-colored and almost clear liquid, and the liquid of (4) was a light-colored and almost clear liquid. , There was no precipitation. A photograph of these appearances is shown in FIG. From the left, (1), (2), (3), (4).

As a result, it was found that a precipitate containing a coloring component was formed by performing a heat treatment after the enzyme treatment, and the color was decolorized by removing this precipitate. In addition, this precipitate is No. It was found that 2 filter papers (reserved particle diameter 5 μm) could not be completely removed, and could be efficiently removed by centrifuge treatment at a gravitational acceleration of 3000 × g.

(Example 3)
Vitamin C 3.6 g was dissolved in 2600 g of pure water and heated to 75 ° C. 200 g of Shizuoka No. 1 tea (tea leaves different from Example 1: Yabukita seeds, steamed blue method, cut into 5 mm) was added, 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 a stirring reaction was carried out at 45 ° C. for 4 hours. After separating the tea leaf residue and the extract by a dehydration type 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 Bx17 ° by a rotary evaporator, cooled to 20 ° C, and centrifuged at a gravitational acceleration of 3000 × g for 10 minutes to remove the precipitate, and then the supernatant was adjusted to Bx15 °. Then, it was sterilized by heating 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 (Lilin-denis method), and Bx0.3 ° (refractive sugar content, 20). (Measured at ° 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 2. A photograph of the appearance of these Bx0.3 ° diluted solutions is shown in FIG. 3 (comparative product 4 on the left and product 8 on the right).

Comparing the component values of the product 8 of the present invention and the product 4 of the present invention, the product 8 of the present invention contained less caffeine, tannins and catechins than the product 4 of the present invention, but only to a small extent.

<Sensory evaluation>
The Bx0.3 ° diluted products of the product 8 of the present invention and the product 4 of the comparative product 4 were evaluated by 5 panelists. As an average evaluation result, although the product 8 of the present invention seemed to have a slightly weaker body feeling in the taste portion than the comparative product 4, the flavor of green tea was clearly confirmed. In terms of aroma, 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, and an experiment was conducted to confirm whether an extract similar to that of the product of the present invention could be obtained.

That is, commercially available β-glucosidase (1200 U / g) (12 U for 1 g of tea leaves) was added to Comparative Product 4, and the mixture was stirred at 45 ° C. for 4 hours, then heated at 95 ° C. for 1 minute, and then heated at 30 ° C. Cooled down to. Then, it was cooled to 20 ° C., and No2. After filtering through the filter paper, the mixture was centrifuged at a gravitational acceleration of 3000 × g for 10 minutes, sterilized by heating at 95 ° C. for 1 minute, and then 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 (Lilin-denis method), and Bx0.3 ° (refractive sugar content, 20). (Measured at ° 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 3 together with the comparative product 4 and the product 8 of the present invention.

Compared with Comparative Product 4 (before treatment with glycoside-degrading enzyme), Comparative Product 5 had a decrease in caffeine, tannins, 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, it tended to be lighter in color and less turbid than the comparative product 4.

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

(Example 5)
The precipitate produced in Example 4 was collected, and the centrifuge treatment / washing with water was repeated three times to collect the dark green precipitate.

This precipitate was insoluble in water, but dissolved in methanol in a clear and dark green color. From this result, the detailed mechanism is unknown, but by allowing glycoside-degrading enzyme to act on the green tea extract, the dye component that was water-soluble is precipitated as a water-insoluble precipitate, and this is separated. It was presumed to be bleached.

FIG. 5 shows a photograph of the appearance of the centrifugation supernatant, the washing solution when the precipitate was washed with water, and the solution in which the precipitate was dissolved in methanol (from the left, when the centrifugation supernatant and the precipitate were washed with water). Cleaning solution and solution in which the precipitate is dissolved in methanol).

(Example 6)
We investigated the case of using protease in combination.

Vitamin C 3.6 g was dissolved in 2600 g of pure water and heated to 75 ° C. 200 g of No. 2 tea from Shizuoka (the same tea leaves as in Example 1: Yabukita seeds, steamed blue method, cut into 5 mm) was added, 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 4 were added, and a stirring reaction was carried out at 45 ° C. for 4 hours. After separating the tea leaf residue and the extract by a dehydration type 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 Bx17 ° using a rotary evaporator, cooled to 20 ° C, centrifuged at a gravitational acceleration of 3000 × g for 10 minutes to remove the precipitate, and then the supernatant was Bx15 °. The temperature was adjusted to 95 ° C., heat sterilized for 1 minute, and then 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 acids (HPLC method), and Bx0.3 ° (refractive sugar content, 20 ° C.). 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 Co., Ltd.)

As shown in Table 4, the amino acids of the product 9 of the present invention were higher than those of the comparative product 6, and the contents of caffeine, tannin and catechins were almost the same values. Regarding the color tone, it was confirmed that the product 9 of the present invention on which the glycoside-degrading enzyme was allowed to act was decolorized as compared with the comparative product 6. Regarding the flavor, when the flavored 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 delicious taste. The flavor of green tea such as umami and astringency was fully felt, and it had a good green tea flavor.

(Example 7)
In Example 6, in the preparation step of the product 9 of the present invention, the precipitate obtained by centrifugation at a gravitational acceleration of 3000 × g for 10 minutes was collected, and the settling treatment / washing with water was performed three times in the same manner as in Example 5. Repeatedly, the 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 divided into two layers by repeating centrifugation / washing three times, and a green and viscous object was confirmed in the upper layer, and a light green minute spherical object was confirmed in the lower layer (Fig. 6). .. From the fluorescent X-ray analysis, it is estimated that the upper and lower layers are mainly composed of organic substances. From the FT / IR analysis, the upper layer is mainly composed of proteins, and the lower layer is one of the natural flavonols. It was suggested that it may be mainly composed of kaempferol represented by the chemical structural formula.

Kaempferol itself is only slightly soluble in water, but since it is known to exist as a glycoside in tea leaves, it easily dissolves even when extracted with water. It is presumed that the kaempferol detected as a precipitate this time was generated by the insolubilization of aglycone-ized kaempferol due to the desorption of sugar by the action of glycoside-degrading enzyme. The crystals of kaempferol are yellow and are considered to contribute to the light blue of green tea, greenish yellow to bright yellow, but the precipitate detected in this study is green and contains kaempferol, protein, chlorophyll, etc. It is presumed that they were combined in a complex manner, insolubilized and precipitated.

(Example 8) Examination of the effect of the activity of glycoside-degrading enzyme per mass of tea leaves on decolorization of tea extract The amount of enzyme added was adjusted as shown in Table 5 below, and the temperature was 45 ° C. A green tea extract was obtained according to the method described in Example 1 except that the stirring reaction was carried out 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 (index of coloring) and the absorbance at 680 nm (index of turbidity) were measured. The results are shown in Table 5.

OD430 nm represents an index of coloring, and OD680 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, when the OD is 0.3 or less, the coloring is very slight, and when the OD is 0.5 or less, the coloring is light. Further, when the OD 680 nm is 0.1 or less, there is almost no turbidity (clarification), and when the OD is about 0.15, there is a slight turbidity to some extent.

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

(Example 9) Examination of the effect of the reaction time of the glycosyl-degrading enzyme on tea leaves on the decolorization of the tea extract Except for changing the enzyme reaction time, the product 4 of the present invention 4 of Example 1 (tea leaves with glycosyl-degrading enzyme). A green tea extract was obtained according to the methods described in 1 g of tea leaves with 10 U added) and product 6 of the present invention (20 U of glycosyllytic enzyme was added to 1 g of tea leaves). The obtained green tea extract was diluted to Bx 0.3 ° (refractive sugar content, measured at 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 6.

As shown in Table 6, it was confirmed that the color and turbidity of the extracts using 10 U or 20 U of glycoside degrading enzyme per 1 g of tea leaves were all reduced by the reaction for 1 hour. Based on Table 5, the tea extract not subjected to the enzymatic reaction has an OD430 nm of 0.562 and an OD680 nm of 0.146, and it takes 30 minutes, assuming the degree of decolorization and reduction of turbidity in 1 hour. It is suggested that the enzyme reaction time is also effective.

In addition, the longer the enzyme reaction time, the more the color and turbidity values decreased, and for coloring, the reaction was 4 hours in the system using 10 U of sugar degrading enzyme per 1 g of tea leaves, and 2 hours in the system using 20 U. In the reaction, the OD 430 nm became 0.3 or less. Regarding turbidity, the OD 680 nm was 0.1 or less in the system using 10 U in the reaction for 3 hours and in the system using 20 U in the reaction for 2 hours. In each system, the color (OD430 nm) and turbidity (OD680 nm) further decreased with the further extension of the reaction time.

(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 Shizuoka No. 2 tea (Yabukita seed, steamed blue method, cut into 5 mm) was added thereto, and the mixture was 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 4.9), the enzyme shown in Table 7 (Product 10 of the present invention) was added, and a stirring reaction was carried out at 45 ° C. for 8 hours. The tea leaf residue and the extract are separated by a dehydration type centrifuge, and 100 g of soft water is further put into the centrifuge to extrude the extract adhering to the tea leaf residue to obtain an extract, and the extract is kept at 95 ° C. for 30 seconds. The mixture was heated to sterilize and inactivate the enzyme, and cooled to 30 ° C. The extract is then centrifuged (1200 xg, 8 minutes) to remove the precipitate, and then PVPP with a mass of 40% of soluble solids (calculated using Bx at 20 ° C.) is added to the extract. , Stirred at 30 ° C. for 1 hour. Next, No. 2 Filter paper (holding particle diameter 5 μm), cool to 20 ° C, adjust to Bx (20 ° C) 3.0 with soft water, sterilize by heating at 95 ° C for 30 seconds, cool to 30 ° C, 200 mesh Saran A PET bottle was filled with filtration to obtain a green tea extract (Product 10 of the present invention).

(Example 11)
In Example 10, the same operation as in Example 10 was carried out 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, and the green tea extract was obtained. Obtained (Product 11 of the present invention).

(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 present invention).
(Comparative Example 7) No β-glucosidase and PVPP treatment In Example 10, the operation is exactly the same as in Example 10 except that β-glucosidase is not used as an enzyme (the enzyme of the product 12 of the present invention in Table 7 is used). To obtain a green tea extract (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 product 10, the product 11, the product 12, the comparative product 7, and the comparative product 8 were measured. Further, it was diluted with pure water to Bx 0.3 °, and OD430 nm, OD680 nm, Lab, and ΔE (comparison with pure water) were measured. Furthermore, the Bx0.3 ° diluted product was sensory evaluated for its green tea-likeness by five well-trained panelists. Table 7 shows the average results of these analytical values and sensory evaluations.

(Results, consideration)
-The degree of coloring of the tea beverage is reduced by the β-glucosidase treatment (comparison between Comparative Product 8 and Product 12 of the present invention, and Comparative Product 7 and Product 10 of the present invention).
-The degree of coloring of tea beverages is reduced by the PVPP treatment, and there is a tendency that the coloring after heat sterilization is particularly small. Further, the PVPP treatment weakens the bitterness and astringency (comparison between the comparative product 8 and the comparative product 7, and the present invention product 12 and the present invention product 10).
-Products 10 and 11 of the present invention subjected to PVPP treatment (tannin removal) in addition to β-glucosidase treatment were diluted to the same solid content concentration (Bx0.3 °) while maintaining the tea flavor. It was found that the lightest color and more decolorized extract was obtained.
-By performing PVPP treatment (tannin removal) in addition to β-glucosidase treatment, 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. Moreover, the absorbance at 680 nm is 0.05 or less, and the amino acid content is 1.0% by 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). Moreover, it was possible to obtain a green tea extract having a catechin content of less than 1.0% by mass (products 10 and 11 of the present invention).

(Example 14) Color tone of the packaged beverage using the product of the present invention and the comparative product Dilute the products 10, 11, 12, the comparative product 7 and the comparative product 8 of the present invention to Bx0.005 °, respectively (each of them). The product of the present invention or the comparative product was added to each water at 0.167%), a solution containing 0.03% sodium ascorbate and no addition was prepared, and the solution was sterilized by UHT at 135 ° C. for 30 seconds and then cooled to 90 ° C. for PET. After filling the bottle, it was cooled to 30 ° C. or lower to prepare a packaged green tea beverage.
Table 8 shows the color tones (OD430 nm, OD680 nm and ΔE with pure water) of each beverage.

(Results, consideration)
-When the extract is diluted to Bx0.005 ° and 0.03% of sodium ascorbate is added, all of the products 10, 11, 12, the comparative product 7 and the comparative product 8 of the present invention are prepared as colorless and transparent beverages or close to them. can.
-When the extract was diluted to Bx0.005 ° and no sodium ascorbate was added, there was no turbidity and it was almost transparent, and 10 and 11 were almost completely colorless, but other than that, coloring was observed. ..

(Example 15) Relationship between the concentration of the extract added and the color tone The product 10 of the present invention was diluted to the concentration shown in Table 9 (sodium ascorbate was not added), sterilized by UHT at 135 ° C. for 30 seconds, and then 90. After cooling to ℃ and filling in a PET bottle, it was cooled to 30 ℃ or less to prepare a packaged green tea beverage.
The color tone of each beverage (ΔE with OD430 nm and pure water) is shown in Table 9.

(Results, consideration)
In the case of a packaged beverage prepared without the addition of sodium ascorbate, the concentration of the product 10 of the present invention is approximately completely colorless at Bx0.005 °, slightly colored at Bx0.015, and slightly colored at Bx0.025.
However, it seems that about 0.025 is necessary to sufficiently secure the flavor like green tea.
In preparing the packaged beverage from Example 13, the addition of sodium ascorbate was found to have an effect of preventing coloration, and therefore the following experiment was conducted.

(Example 16) Relationship between the concentration of sodium ascorbate added, storage conditions and color tone The product 10 of the present invention was diluted to Bx 0.025 °, and at that time, the concentration of sodium ascorbate shown in Table 10 was added to 135. After UHT sterilization at ° 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.
The color tone (ΔE with OD430 nm and pure water) of each beverage after storage is shown in Table 10.

(Results, consideration)
-The addition of sodium ascorbate suppressed coloring after sterilization.
-It was found that the coloration after sterilization was suppressed as the amount of sodium ascorbate added was in the range of 0 to 0.03%.
-Immediately after sterilization and from OD 430 nm and ΔE stored at 10 ° C. for 10 days, sodium ascorbate was almost completely colorless and transparent if 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 sodium ascorbate added 0.03%, but it was "very 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 (9)

A method for producing a bleached green tea leaf extract, which comprises the following steps (A) to (E) and (B') .
(A) Step of mixing green tea leaves and water (B) After step (A), a step of allowing a glycoside-degrading enzyme to act on the mixture of (A), wherein the glycoside-degrading enzyme is used for green tea leaves. A step in which the amount is 10 to 100 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.
(B') A step of further acting tannase and pectinase at the same time as, before or after step (B) and before the next step (C).
(C) After the step ( B' ), the green tea leaf residue and the extract are separated to obtain a glycoside enzyme-treated green tea leaf extract. (D) The glycoside enzyme treatment obtained in the step (C). The process of heat-treating green tea leaf extract
(E) A step of removing insoluble components from the heated glycosyl enzyme-treated green tea leaf extract obtained in step (D) to obtain a decolorized green tea leaf extract, which is a soluble solid of the green tea leaf extract. A step in which the absorbance at 430 nm is 0.1 or less when the fraction (reflux sugar content, temperature 20 ° C.) is 0.3. The bleached green tea leaf according to claim 1 , further comprising a step of allowing a protease to act at the same time as the step ( B' ) or after the step ( B' ) and before the step (C). Extract manufacturing method. The method for producing a decolorized green tea leaf extract according to claim 1 or 2, wherein the heat treatment conditions in the step (D) are in the range of a temperature of 70 to 135 ° C. and a time of 2 seconds to 30 minutes. A1 to claim 1, comprising a step of steam-distilling green tea leaves to obtain an aroma recovery product and mixing the obtained aroma recovery product with the green tea leaf extract obtained in the step (E) before the step (A). 3. The method for producing a decolorized green tea leaf extract according to any one of 3. A method for producing a green tea leaf extract, wherein the absorbance at 680 nm is 0.15 or less when the soluble solid content (refractive sugar content, temperature 20 ° C.) of the green tea leaf extract is 0.3 . 4. The method for producing a decolorized green tea leaf extract according to any one of 4 . The method for producing a decolorized green tea leaf extract according to claim 5 , wherein the absorbance at 430 nm is 0 when the soluble solid content (refractive sugar content, temperature 20 ° C.) of the green tea leaf extract is 0.3. A method in which the absorbance at 05 or less and 680 nm is 0.05 or less. A method for producing a decolorized low tannin green tea leaf extract, which comprises the following steps (A) to (F) and (B') .
(A) Step of mixing green tea leaves and water (B) After step (A), a step of allowing a glycoside-degrading enzyme to act on the mixture of (A), wherein the glycoside-degrading enzyme is used for green tea leaves. A step in which the amount is 10 to 100 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.
(B') A step of further acting tannase and pectinase at the same time as, before or after step (B) and before the next step (C).
(C) After the step ( B' ), the green tea leaf residue and the extract are separated to obtain a glycoside enzyme-treated green tea leaf extract. (D) The glycoside enzyme treatment obtained in the step (C). The process of heat-treating green tea leaf extract
(E) A step of removing insoluble components from the heated glycosyrrolitic enzyme-treated green tea leaf extract obtained in step (D) to obtain a decolorized green tea leaf extract, which is a soluble solid of the green tea leaf extract. Step (F) The decolorized tea extract obtained after step (E), in which the absorbance at 430 nm is 0.1 or less when the fraction (reflux sugar content, temperature 20 ° C.) is 0.3, is further added to PVPP. Step of contacting with (polyvinylpolypyrrolidone) to obtain an extract from which PVPP has been removed after contact The method for producing a decolorized low tannin green tea leaf extract according to claim 7 , wherein the solubility at 680 nm is 680 nm when the soluble solid content (refractive sugar content, temperature 20 ° C.) of the green tea leaf extract is 0.3. It 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 (Green-Denis method) is 1.0% by mass or less. Is the way. (G) The soluble solid content derived from green tea leaves is 0.005 to 0.3% (Bx,) by adding water to the green tea leaf extract obtained by the method according to any one of claims 1 to 6 , 7 and 8 . 20 ° C) adjustment process,
(H) A method for producing a packaged near water or flavored water-like beverage, which comprises a step of adding vitamin C or an edible salt (sodium) thereof to the tea beverage obtained in step (G).

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