TWI756464B - Method for producing decolorized green tea leaf extract - Google Patents

Abstract

The subject of the present invention is to propose: a tea extract and the use of the tea extract, such as a tea beverage; wherein, the tea extract is used when preparing near water and flavored water-like beverages , it is possible to impart the flavor derived from the tea leaves, especially the taste, to the beverage without coloring.

The solution is a method for producing a decolorized tea extract, which comprises the following steps (A) to (E).

The present invention discloses a method for manufacturing a decolorized tea extract comprising the following steps, and adding vitamin C to the tea extract as required and then adding water to manufacture a tea beverage, especially a method for manufacturing a container-packed tea beverage , and the aforementioned decolorized tea extract, and the aforementioned container-packed tea beverage.

(A) the step of mixing tea leaves and water; (B) the step of making the glycoside decomposing enzyme act after the step (A); (C) the step of separating the tea residue and the extract after the step (B), and obtaining the glycoside The step of enzyme-treated tea extract; (D) the step of heat-treating the glycoside enzyme-treated tea extract obtained in step (C); (E) from the step (D) obtained The step of removing insoluble components from the heated glycoside enzyme-treated tea extract and obtaining a decolorized tea extract.

Description

Method for producing decolorized green tea leaf extract

The present invention relates to a decolorized tea extract and a manufacturing method thereof. In more detail, it relates to a tea extract and a manufacturing method thereof; the tea extract has the good aroma, delicious taste and bitter taste of tea even though it is light in color, and the manufacturing method comprises tea leaves treated with glycoside decomposing enzymes. step.

In recent years, due to the diversification of consumers' preferences for packaged beverages in containers, many packaged beverages in which almost colorless and transparent beverages are filled in colorless and transparent containers have been seen in the market. Such beverages are also called near-water beverages, flavored waters, and the like, and colorless and transparent appearance is one of the important elements. Such almost colorless and transparent beverages have the flavor of citrus such as lemon, orange, and tangerine, the flavor of soft fruits such as grapes, apples, and peaches, and the flavor of fermented milk such as yogurt, but they have the flavor of tea. Flavored ones are less common.

Although the flavor of tea can be reproduced to a certain extent only with spices (blended spices or natural spices) that have the aroma of tea, in order to feel the real feeling of tea, by mixing water-soluble components from tea, it is changed. To be able to impart a better flavor.

On the other hand, the tea extract is usually colored, and if the tea extract is blended 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 in which metal ions are removed from the tea extract by treatment with a cation exchange resin, and then filtered with a microfiltration membrane to obtain a treatment solution (Patent Document 1) is known. There is a disadvantage that amino acids, which are delicious ingredients, are also removed by the cation exchange resin treatment.

As a decolorization method, the treatment by adsorption materials, such as activated carbon, is generally known, and various treatment techniques by adsorption agent treatment are also known in the case of tea. 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 there is no description about decolorization at all. In addition, Patent Document 3 discloses a method of contacting activated clay or acid clay with an aqueous solution containing caffeine such as tea extract, but the purpose of this method is also to remove caffeine, and there is no description about decolorization at all. In addition, Patent Document 4 or Patent Document 5 discloses a method of contacting a tea extract with polyvinylpolypyrrolidone, but the purpose is to remove catechins and tannins, and there is no description at all about decolorization.

As a method for producing a green tea extract that can be used in sports drinks and isotonic drinks, there is disclosed a method for dissolving the green tea extract in a mixed solution in which the weight ratio of ethanol and water is 91/9 to 97/3, A method for producing a decaffeinated green tea extract obtained by contacting it with activated carbon and acidic clay (Patent Document 6), but the main purpose is to remove caffeine. In Patent Document 6, it is considered to have the effect of not deteriorating the hue (paragraph [0009] etc.), but there is no specific description about the hue, and there is no description in the Examples.

On the other hand, the glycoside-degrading enzyme refers to an enzyme that hydrolyzes the bond (glycosidic bond) between the anormeric carbon of a glycoside and an aglycone moiety to generate a free aglycone. , as an application to teas, a method for producing a green tea beverage is known. In the method for producing a green tea beverage, prior to the heat sterilization treatment step of the green tea extract, a method for producing a green tea beverage by adding a glycoside decomposing enzyme is provided. Enzyme treatment step for converting glycosides into aroma component compounds (Patent Document 7); a method for producing a tea extract with enhanced aroma, characterized in that during and/or after treatment of tea leaves with tannase, A glycoside-degrading enzyme is allowed to act on tea leaves (Patent Document 8) and the like, but in any of them, there is only a description about the production of aroma. In addition, Citation 9 describes a production method in which, after concentrating an aqueous extract of tea such as oolong tea to Bx2 to 15°, a glycoside-decomposing enzyme acts on the concentrated solution, thereby producing high transparency and even long-term storage. Tea extract that does not produce sediment. However, there is no description at all about the color tone (color density, etc.).

[Prior Art Literature] [Patent Literature]

Patent Document 1: Japanese Patent Publication No. 11-504224

Patent Document 2: Japanese Patent Application Laid-Open No. 8-70772

Patent Document 3: Japanese Patent Application Laid-Open No. 6-142405

Patent Document 4: Japanese Patent No. 3315304

Patent Document 5: Japanese Patent Laid-Open No. 2003-204754

Patent Document 6: Japanese Patent No. 4181982

Patent Document 7: Japanese Patent Laid-Open No. 2004-147606

Patent Document 8: Japanese Patent Laid-Open No. 2006-75112

Patent Document 9: Japanese Patent No. 5818784

As mentioned above, in terms of methods for decolorizing tea extracts, there are mainly physical and chemical treatment methods, but sometimes there are disadvantages or drawbacks such as damage to the original flavor of tea leaves.

Therefore, the purpose of the present invention is to propose a green tea extract and a tea beverage using the green tea extract, especially a container-packed tea beverage; the green tea extract can be used to prepare beverages that are close to water and flavored water. Coloring imparts flavor, especially flavor, derived from tea leaves to the beverage.

It has been known for a long time that glycosides are converted into aroma component compounds by the action of glycoside-degrading enzymes on water extracts of tea leaves, but this time, surprisingly, it was found that in the presence of water, it is After the green tea leaves are treated with glycosidase under certain conditions, the obtained glycosidase-treated tea extract is subjected to heat treatment to form water-insoluble substances, and the water-insoluble substances can be removed. A clear and decolorized green tea extract is obtained that does not substantially impair the flavor derived from the tea leaves. Furthermore, it has also been found that the same extract can be obtained from a wide variety of tea leaves without being limited to green tea leaves by such a treatment.

Thus, according to the present invention, it is not limited, but the following are provided as inventions having main aspects or characteristics.

Aspect 1: A method for producing a decolorized tea extract, comprising the following steps (A) to (E): (A) a step of mixing tea leaves and water; (B) after step (A), making The step of acting on the mixture of (A) with glycosylase; (C) after step (B), the tea residue and the extract are separated, and the step of obtaining the tea extract treated with glycosidase; (D) the step of The step of heat-treating the glycosidase-treated tea extract obtained in step (C); (E) removing insolubility from the heated glycosidase-treated tea extract obtained in step (D) ingredients, and the steps to obtain a decolorized tea extract.

Aspect 2: The method for producing a decolorized tea extract as described in Aspect 1, which is simultaneously with or before or after step (B) and before step (C), further comprising making tannase and/or fruit Steps in the action of glue enzymes.

Aspect 3: The method for producing a decolorized tea extract as described in Aspect 1 or 2, which further comprises causing a protease simultaneously with step (B) and/or after step (B) and before step (C) action steps.

Aspect 4: The method for producing a decolorized tea extract according to any one of Aspects 1 to 3, wherein the heat treatment conditions in step (D) are a temperature of 70 to 135° C. and a time of 2 seconds to 30 minutes. In the range.

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: The method for producing a decolorized tea extract as described in any one of Aspects 1 to 5, comprising performing steam distillation on the tea leaves before step (A) to obtain an aroma recovered product, and using the obtained A step of mixing the aroma recovered product into the clear liquid obtained in step (E).

Aspect 7: The method for producing a decolorized tea extract according to any one of Aspects 1 to 6, wherein the amount of the glycoside degrading enzyme used relative to the tea leaves is 1 U/g or more, and the temperature of the enzyme reaction is 30 In the range of ~70°C, and the reaction time is 30 minutes or more.

Aspect 8: A method for producing the decolorized tea extract described in Aspect 1, wherein the soluble solid content (refractive sugar content, temperature 20°C) of the tea extract is set to At 0.3, the absorbance at 430 nm is 0.5 or less and the absorbance at 680 nm is 0.15 or less.

Aspect 9: A method for producing a decolorized tea extract as described in Aspect 8, wherein when the soluble solid content (refractive sugar content, temperature 20°C) of the tea extract is set to 0.3, the 430 nm The absorbance was 0.1 or less and the absorbance at 680 nm was 0.05 or less.

Aspect 10: A green tea leaf extract, wherein 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 when further When the soluble solid content (refractive sugar content, temperature 20° C.) is set to 15, the catechin content is 1.0 mass % or more.

Aspect 11: A green tea leaf extract, wherein 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 when further When the soluble solid content (refractive sugar content, temperature 20° C.) is set to 15, the amino acid content is 1.0 mass % or more.

Aspect 12: A method for producing a low-tannin tea extract, comprising the following steps (A) to (F): (A) a step of mixing tea leaves and water; (B) after step (A), making The step of acting on the mixture of (A) with glycosylase; (C) after step (B), the tea residue and the extract are separated, and the step of obtaining the tea extract treated with glycosidase; (D) the step of The step of heat-treating the glycosidase-treated tea extract obtained in step (C); (E) removing insolubility from the heated glycosidase-treated tea extract obtained in step (D) (F) after step (E), the obtained decolorized tea extract is further contacted with PVPP (polyvinyl polypyrrolidone), and the removal of the contact The step of extracting the PVPP after.

Aspect 13: A method for producing a low-tannin tea extract as described in Aspect 12, wherein when the soluble solid content (refractive sugar content, temperature 20°C) of the tea extract is set to 0.3, the 430 nm When the absorbance is 0.05 or less and the absorbance at 680 nm is 0.05 or less, and the soluble solid content (refractive sugar content, temperature 20° C.) is further set to 15, the amino acid content is 1.0 mass % or more and tannin (Folin-Denis (Folin-Denis) is set to 15. - Dennis) method) is 1.0 mass % or less.

Aspect 14: A green tea leaf extract, wherein the absorbance at 430 nm is 0.05 or less and the absorbance at 680 nm is 0.05 or less, when the soluble solid content (refractive sugar content, temperature 20° C.) of the tea extract is 0.3, and further When soluble solid content (refractive sugar content, temperature 20 degreeC) is set to 15, amino acid content is 1.0 mass % or more, and tannin (Folin-Denis method) is 1.0 mass % or less.

Aspect 15: A method for producing a container-packed tea beverage, comprising the following steps: (G) adding water to the tea extract obtained by the method described in any one of Aspects 1 to 9, 12 and 13 to obtain a The step of adjusting the soluble solid content from tea to 0.005 to 0.3% (Bx, 20°C); (H) the step of adding vitamin C or its edible salt (sodium) to the tea beverage obtained in the step (G) .

Aspect 16: A container-packed tea beverage containing the green tea extracts according to Aspects 10, 11 and 14 in 0.005 to 0.3% (Bx, 20°C) mass % as a tea-derived soluble solid component, and further containing vitamin C or its edible salt (sodium).

Aspect 17: The container-packed tea beverage according to Aspect 16, which contains 0.002 to 0.3 mass % of vitamin C or an edible salt (sodium) thereof.

Aspect 18: The container-packed tea beverage according to Aspect 16 or 17, wherein when the soluble solid content (refractive sugar content, temperature 20°C) of the tea extract is 0.3, the absorbance at 430 nm is 0.015 or less and the absorbance at 680 nm is 0.05 or less.

According to the present invention, it is possible to provide a tea extract, a low-tannin tea extract, and a tea beverage using the green tea extract, especially a container-packed tea beverage; Compared with the decolorized tea extract by the method, the flavor of the tea, especially the taste, is maintained.

Fig. 1 shows a photograph showing the appearance of a solution obtained by diluting the green tea extract obtained in Example 1 to Bx0.3°. From the left are Comparative Product 1, Invention Product 4, Invention Product 5, Invention Product 6, and Invention Product 7.

FIG. 2 shows a photograph of the appearance of the liquid in the middle of the step in Example 2 after being left at 20° C. for one night. From left are (1), (2), (3), (4).

Fig. 3 is a photograph showing the appearance of a solution obtained by diluting the green tea extract obtained in Example 3 to Bx0.3°. The left is the comparative product 4, and the right is the inventive product 8.

FIG. 4 shows a photograph showing the appearance of the liquid in the middle of the preparation step of Comparative Product 5 in Example 4. FIG. From the left is the comparative product 4, after enzyme inactivation, after filtration, and after centrifugation.

Fig. 5 shows, from the left, photographs of the appearance of the centrifuged supernatant, the washing solution when the precipitate was washed with water, and the solution obtained by dissolving the precipitate in methanol in Example 5.

FIG. 6 is a photographic photograph of the precipitate using a digital microscope in Example 7. FIG.

7 is a graph showing the absorbance (OD430nm and OD680nm) of the tea extract when the activity of the glycoside-degrading enzyme with respect to tea leaves was varied in Example 8. FIG.

8 is a photograph showing the appearance of Bx0.3° dilutions of tea extract No. 1 to No. 6 when the activity of the glycoside-degrading enzyme with respect to tea leaves was varied in Example 8. FIG.

[Detailed description of the invention]

As far as the tea leaves that can be used as raw materials in the method of the present invention are concerned, it is the leaves of the tea tree (Camellia sinensis) which is widely planted in the world, and any one of them can be used according to the purpose of the present invention, preferably not fermented. Examples of the tea include steamed green teas such as sencha, roasted tea, gyokuro, crown tea, and tencha, and kettle-fried teas such as Ureshino tea, green willow tea, and various Chinese teas. Furthermore, it can also be applied to semi-fermented teas such as Baochong tea, Tieguanyin tea, and oolong tea, fermented teas such as black tea, and the like.

Also, from the Yabukita species (Camellia sinensis var. sinenses cv. Yabukita), the tea tree can be of any variety, and the leaves are usually picked from the center of the bud to the four-leaf leaves that will be used as raw materials for green tea and the like. A heart with four leaves, and it can also be a leaf other than the more mature four leaves. The above-mentioned tea leaves or tea raw materials can be used as they are, but generally, those obtained by subjecting them to processes such as cutting, pulverizing, grinding, etc., which have been used in the manufacture of food products, are preferred.

Step (A) is to mix tea leaves with water. Generally speaking, soft water, ion-exchanged water, RO membrane-treated water, etc. can be conveniently used for water. The appropriate range of the ratio of tea leaves to water varies according to the drying state of the tea leaves. In terms of weight ratio, it is generally 1:5~50, preferably 1:8~20, and more preferably 1:10~15 . Mixing can be performed at room temperature, and considering the harvest time/maturity of the leaves to be used, etc., and further considering that it is preferable to sterilize before the enzymatic reaction, it can also be performed under heating conditions. The temperature at this time can be exemplified under conditions under which the purpose of sterilization is achieved and the thermal deterioration of the tea leaves is small. The mixing time is the time for the tea leaves to 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.

In addition, in the case of mixing under heating conditions with sterilization, after heat sterilization, the mixture of tea leaves and water is cooled to an appropriate temperature for the enzyme treatment.

The step (B) is to directly act on the mixture obtained in the step (A) by the glycosidase, and before this, an aqueous extract can be prepared from the mixture, or the glycosidase is not included in the tea. After preparing the enzyme-treated extract in the presence of various enzymes used in the extraction, the glycoside-degrading enzyme is allowed to act, or the glycoside-degrading enzyme is directly acted on the mixture at the same time or after that. Enzyme action other than glycosidase. The enzymes other than the glycoside-degrading enzymes are not limited, but include tannin-degrading enzymes tannase, protease, amylase, glucoamylase, pectinase, cellulase, hemicellulase, and the like. Among them, for the purpose of the present invention, that is, to obtain a transparent and decolorized tea extract that maintains the original flavor and taste of tea, suitable ones include tannase and pectinase. These enzymes can be used alone or in combination of two or more.

Glycolytic enzymes and other enzymes can be used without limitation as long as they follow the purpose of the present invention and are used in the technical field. Described below.

As for the glycoside degrading enzyme, it can be conveniently used: it can hydrolyze various glycosides that can exist in tea leaves, for example, glycosides composed of flavonols and glucose into free aglycones. Base and sugar enzymes. Such O-glycosides are abundant in the plant kingdom, and on the other hand, various enzymes that hydrolyze the O-glycosidic bonds exist in nature. Among these, without limitation, the following can be mentioned as those in accordance with the object of the present invention. For example, the production of β-glucose that belongs to the genus Aspergillus, Penicillum, Rhizopus, Pseudmonas, Pichia, etc. Bacteria containing β-glucosidase are subjected to solid or liquid culture using a solid nutrient medium or liquid nutrient medium such as wheat bran and rice bran according to a conventional method, and the obtained culture or its processed product is subjected to a conventional method. Refined and processed. Moreover, those obtained by refining treatment from plants such as vanilla beans and raw tea leaves can also be used, and almond-derived almond enzyme commercially available from Sigma-Aldrich Co., or an enzyme containing β-glucosidase can also be used. Enzyme preparations are isolated from cellulase A (Amano Enzyme), cellulase T (Amano Enzyme). As β-xylosidase (β-xylosidase), for example, β-xylosidase-producing bacteria belonging to the genus Penicillium, Kojimyces, Rhizopus, Mucor, etc. can be used, using wheat according to an ordinary method. Solid nutrient medium or liquid nutrient medium such as bran, rice bran and other solid nutrient medium or liquid nutrient medium, and the obtained culture or its processed product is purified according to the usual method, and it can also be obtained from Sigma-Aldrich Co. . Commercially available from Aspergillus niger or isolated from the enzyme preparation Sumizyme ACH (Shin Nippon Scientific Industries) containing β-xylosidase. β-primeverosidase (β-primeverosidase) includes, for example, β-primeverosidase-producing bacteria belonging to the genus Cellulomonas (Cellulomonas), the genus Penicillium, the genus Koji, etc., according to a conventional method. One obtained by performing solid or liquid culture in a solid medium or liquid medium such as wheat bran and rice bran, and purifying the obtained culture or its processed product according to an ordinary method, and plants made from raw tea leaves and the like may also be used. Isolated and refined. When used for the purpose of the present invention, the amount of these glycoside-decomposing enzymes used is generally based on the mass basis of the tea raw material, for example, based on the β-glucosidase activity using the p-NP glucose addition method. 1~100U/g, preferably 4~75U/g, more preferably 8~50U/g, further preferably 10~40U/g.

Tannase is an enzyme that hydrolyzes the depside carboxylic acid bond (depside bond) formed by gallic acid and hydroxyester in tannin, for example, epigallocatechin gallate. (epigallocatechin gallate) an enzyme that hydrolyzes epigallocatechin and gallic acid. Specific examples of the tannase usable in the present invention include those belonging to the genus Kojimyces, Penicillium, Rhizopus, Rhizomucor, Lactobacillus, and Staphylococcus. (Staphylococci), Streptococci (Streptococci), Lonepinella (Lonepinella) and other tannase-producing bacteria, according to the usual method using the culture medium of these filamentous fungus (filamentous fungus) usually available for solid state It is obtained by culturing or liquid culturing, and purifying the obtained culture or its processed product according to a conventional method. In addition, commercially available tannase, for example, tannase (500 U/g; manufactured by Kikkoman), tannase (5,000 U/g; manufactured by Kikkoman), tannase (500 U/g) can also be used ; Mitsubishi Chemical Foods Co., Ltd.), Sumizyme (registered trademark) TAN (Shin Nippon Chemical Industry Co., Ltd.) and the like. The amount of tannase used will vary due to the power value, etc., and the optimum range will vary, so it cannot be specified. Generally, based on the quality standard of tea raw materials, it can be in the range of 0.1~50U/g, preferably in the range of 0.5~20U/g .

Pectinase, also known as polygalacturonase, pectic enzyme, polymethylgalacturonase, pectin depolymerase, is a acid), pectin, pectic acid and other α-1,4 bonds to hydrolyze enzymes. Pectinases are known to be contained in bacteria, molds, yeasts, higher plants, snails, and the like, and pectinases collected from organisms typified by these can be widely used in the present invention. Moreover, a commercially available pectinase preparation can also be used. As commercially available pectinase preparations, for example, Sucrase (registered trademark) A, Sucrase (registered trademark) N, Sucrase (registered trademark) S (the above, manufactured by Mitsubishi Chemical Foods), and Pectinex Ultra (registered trademark) can be exemplified. SP-L (manufactured by Novo Nordisk A/S), Meicelase (registered trademark) (manufactured by Meiji Seika Co., Ltd.), Ultrazyme (registered trademark) (manufactured by Novo Nordisk A/S), NewlaseF (registered trademark) (Amano) Enzyme Co., Ltd.), Sumizyme (registered trademark) SPG (Shin Nippon Chemical Industry Co., Ltd.), and the like. Since pectinase preparations usually contain a variety of enzymes, the amount of pectinase used is not easy to express in activity units. Based on the mass basis of tea raw materials, it is generally 0.01% by mass to 5% by mass, preferably 0.1% by mass. within the range of 2% by mass.

Tea leaves contain about 25% by mass of protein (refer to the Japanese food ingredient table 5), and the effect of the subsequent heating reaction is particularly enhanced by protease treatment. However, since protein in tea leaves is bound to tannins, even if protease acts on tea leaves alone, amino acids are hardly produced. Therefore, by allowing 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. As the protease that can be used in the present invention, various commercially available proteases can be exemplified. The amount of protease used varies depending on the strength and the like, and cannot be generalized, but generally, based on the quality of the tea raw material, it is usually 0.01 to 100 U/g, preferably 1 to 80 U/g.

The tea processing step (especially including steps (A) and (B)) by the above-mentioned enzymes can be carried out according to a method known per se, for example, as described in the Patent Office Gazette of Known-Used Techniques (Perfume) Part II Methods of publications such as Food Flavor (issued on January 14, 2000) "2·1·7 Microorganism·Enzyme Flavor" (pp. 46-57).

In such a step, the so-called making the glycoside degrading enzyme act on the mixture of tea leaves and water, or the processed product thereof, means that the coloring causative substance can be removed, so that the subsequent step (D) The tea extract obtained by heat treatment and removal of insoluble components in step (E) will be substantially decolorized. Without being bound by theory, the so-called removal of coloring-causing substances in the glycosides of tea means: by the action of the enzyme, the original water-soluble form is converted into water-insoluble or Water insoluble. According to the present invention, it is to be understood as: in the suspension or sediment containing insoluble components removed by step (E), there is a substance that causes coloration, and the substance that causes coloration contains kanfei flavonoids, which are one of natural flavonols. Alcohol (kaempferol), quercetin (quercetin) and the like. This matter is not further bound by theory, but the aforementioned effect is understood as: among the glycosides that may exist in tea, at least all or most of the glycosides with flavonol and quercetin as aglycones will be used as aglycones. To be hydrolyzed, and generate water-insoluble free aglycone.

Therefore, step (B) is to carry out the enzymatic treatment under the conditions that the above-mentioned suspension or sediment is formed. Such conditions will vary depending on the strength of the enzyme used, and the optimum conditions will vary, but the temperature is generally 30 to 70°C, preferably 36 to 60°C, more preferably 40°C to 50°C, and further preferably 42°C ℃～48 ℃; The reaction time is theoretically more than 25 minutes, practically is 30 minutes～48 hours, preferably 1～36 hours, more preferably 1.5～24 hours, more preferably 2～16 hours; The optimum pH conditions vary depending on the source of the enzyme to be used, etc., but it is generally 4 to 6.

As described above, in the step (B), enzymes other than the glycoside-degrading enzyme can be simultaneously caused to act (in the step (B)), and the conditions for the enzymatic treatment can also be selected so as to allow the glycoside-degrading enzyme to act. of the above conditions.

In the step (C), as described above, in order to hydrolyze the aglycone moiety and the sugar moiety of the glycoside, the tea leaves are subjected to the action of the glycoside-decomposing enzyme for a sufficient period of time through the step (B), and the raw tea residues or other Insoluble solids are separated from other treatment liquids (also called extracts). Such separation is carried out by, for example, dewatering type centrifuges, filter presses, Nutsche filters coated with filter aids, etc., also simultaneously removing more solids if necessary.

Step (D) is to heat-treat the aforementioned enzyme-treated tea extract to denature proteins including the enzyme used in the aforementioned step. In addition, the interpretation of the technical scope of the present invention is not limited by theory, but it is considered that the enzyme not only loses activity due to denaturation by heat treatment, but also becomes insoluble due to the enzymatic treatment. The water component is in a state where it is easy to bond and aggregate with denatured proteins. The heat treatment conditions are generally in the range of temperature 70~135°C and time 2 seconds to 30 minutes, preferably in the range of temperature 75~121°C and time 10 seconds to 25 minutes, more preferably in the range of temperature 80°C It is in the range of ~100 degreeC and time of 30 seconds to 20 minutes, more preferably, it is in the range of temperature of 85 to 95 degreeC, and time of 20 seconds to 15 minutes.

Step (E) is to cool the above-mentioned heated treated product to below 45°C, preferably below 35°C, and to generate a suspension or precipitate containing insoluble components. Such an insoluble component itself, or a suspension or a sediment can be removed by, for example, a dehydration-type centrifugal separator, a sedimentation-type centrifugal separator, a filter press, a Nutsche filter coated with a filter aid, and the like, and usually , the use of sedimentation-type centrifugal separation will bring better results.

In this way, according to the present invention, it is generally possible to decolorize the coloring in the extract from the coloring matter or the enzyme extract of the tea leaves. On the other hand, it is possible to provide a tea extract in which the content of amino acids, caffeine, and catechins, which are known to contribute to the flavor of tea, in particular, are not substantially reduced. As such a tea extract, for example, when green tea leaves are used as a raw material, when the soluble solid content (refractive sugar content, temperature at 20°C) of the tea extract is 0.3, the absorbance at 430 nm is 0.5 or less, preferably 0.3 Below, it is more preferably 0.2 or less, 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 0.15 or less, preferably 0.10 or less, more preferably 0.08 or less, still more preferably It is 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 still more preferably about 4/5 or less of the absorbance at 430 nm of the tea extract without the equivalent enzyme treatment. 1/5 or less. Furthermore, it is possible to provide a green tea extract that has a catechin content of 1.0% by mass or more with respect to the total mass of the solid content when the soluble solid content (refractive sugar content, temperature 20° C.) is set to 15, Preferably it is 1.2 mass % or more, More preferably, it is 1.5 mass % or more. Furthermore, in the case of extracting tea leaves by acting on protease, it is possible to provide a green tea extract which, when the soluble solid content (refractive sugar content, temperature 20° C.) is set to 15, is relatively higher than the aforementioned solid content. The amino acid content of the total mass is 1.0 mass % 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 It is 1.5 mass % or more.

As mentioned above, the decolorized tea extract provided by the present invention with absorbance at 430nm and absorbance at OD680nm is diluted or added with water to make a tea beverage. At this time, relative to the total mass of the aforementioned tea beverage, if When the aforementioned solid content is adjusted to 0.005% by mass to 0.3% by mass, compared with the tea extract not treated by the method of the present invention, a tea beverage with a significantly reduced degree of coloration can be provided, and a substantially colorless and transparent tea can be provided drinks. The aforementioned water is not limited to so-called soft water or hard water as long as it is potable water. Such a tea beverage has an absorbance of 0.05 or less at 430 nm and an absorbance of 0.05 or less at 680 nm, while maintaining the flavor of tea is preferred. Therefore, in order to achieve the intended purpose of the present invention, for example, the amount of the glycosidase to act in the aforementioned step B can be controlled and prepared with reference to the data shown in FIG. 7 and the like described later, so that the tea is extracted When the soluble solid content of the liquid (refractive sugar content, temperature 20°C) is adjusted to 0.3, the two absorbances just described above are displayed.

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

In the decolorized tea extract provided by the present invention, for example, it can be used as a raw material for beverages such as near water and flavored water, and can also be used as a raw material for a container-packed tea beverage.

Specifically, for the decolorized and optionally low-tanninized tea extract that can be obtained by the method described in any one of the above aspects 1 to 9 and 12 to 13, or described in the aspect 10 or 11 , add water and adjust the soluble solid content from tea to 0.005~0.3, or 0.01~0.3, or 0.05~0.3, or 0.1~0.3% (or °) according to the type of tea beverage to be provided, and adjust with the above Simultaneously or before and after the addition of vitamin C or its edible salt (sodium), a tea beverage and a container-packed tea beverage can be provided (refer to aspect 16 or 17). Where such a beverage is provided, in particular a tea beverage can be provided which, if obtained from the method of Aspect 12 or 13, or from a depigmented and low tannin tea extract according to Aspect 14, is stored or High storage stability. In the method of aspect 12, the use conditions of PVPP (polyvinyl polypyrrolidone) are not limited, and can be appropriately selected as long as the description of Patent Document 5 is taken as a reference and the object of the present invention can be achieved. In the present invention For example, with respect to the mass of the soluble solid content of the tea extract obtained in the aforementioned step (E), 1 mass % to 100 mass % of PVPP is used. The tea extract that can be obtained in this way is preferably obtained by adjusting the soluble solid content from tea as described above, and relative to the total mass of the adjusted tea beverage, vitamin C or its edible salt (sodium) can be added. 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 this treatment, after heat sterilization, the tea beverage will be stably maintained in the following conditions when the soluble solid content from tea is adjusted to 0.3% (Bx, 20°C) under the conditions normally filled in the container of the tea beverage. State: The absorbance at 430 nm is 0.015 or less, and the absorbance at 680 nm is 0.05 or less.

In addition, regarding transparency and colorless (coloring state) dimension, the following description can be referred.

(Transparent)

‧OD680nm 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 (substantially completely transparent)

(colorless)

‧Compared with pure water, ⊿E is 4.0 or less (slightly colored), preferably 3.0 or less (extremely slightly colored), more preferably 2.0 or less (almost colorless), and particularly preferably 1.4 when compared with pure water in Lab obtained from the light transmittance or less (substantially completely colorless), or OD430nm is 0.05 or less (slightly colored), preferably 0.038 or less (extremely slightly colored), more preferably 0.025 or less (almost colorless), particularly preferably 0.015 or less (substantially completely colorless) )

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

[Example] (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-produced second tea (Yuboku seed, steamed green method, cut into 5 mm) was put into this, heated while stirring, and heat-sterilized 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 performed at 45°C for 4 hours. After the tea residue and the extract were separated by a dehydration type centrifuge, the extract was heated at 95°C for 1 minute and cooled to 30°C. The extract was filtered with No. 2 filter paper (retained particle size 5 μm), cooled to 20° C., and centrifuged at 3000×g for 10 minutes to obtain a green tea extract. The obtained green tea extract was diluted to Bx0.3° (refractive sugar content, measured at 20°C), and the absorbance at 430 nm (indicator of coloration) and the absorbance at 680 nm (indicator of turbidity) were measured. The results are shown in Table 1. 1 shows photographs of the appearance of these Bx0.3° dilutions (from the left: Comparative Product 1, Invention Product 4, Invention Product 5, Invention Product 6, and Invention Product 7).

(Explanation of enzymes)

‧Glydolytic enzyme: commercially available β-glucosidase (1200U/g)

‧Tannase: Sumizyme (registered trademark) TAN (Tannase manufactured by Nippon Chemical Industry Co., Ltd.: 5000U/g)

‧Pectinase: Sumizyme (registered trademark) SPG (Pectinase manufactured by New Nippon Chemical Industry Co., Ltd.)

‧Invertase: Sumizyme (registered trademark) INV (Invertase manufactured by Nippon Chemical Industries, Ltd.)

‧Hemicellulase (β-mannanase): Sumizyme (registered trademark) ACH (hemicellulase manufactured by New Japan Chemical Industry Co., Ltd.)

As shown in Table 1, the comparative product 1 using tannase and pectinase in combination, the comparative product 2 using invertase, and the comparative product 3 using hemicellulase (mannase) were similar to these Compared with the products 1 to 7 of the present invention that have been subjected to the action of the glycoside degrading enzyme, the absorbance at 430 nm (an index of coloration) is lower in any one, and the absorbance at 680 nm (an index of turbidity) is almost the same or less. the following. Glycolytic enzymes are more decolorized than those using tannase alone (product 1 of the present invention) (product 2 of the present invention). 1/5) The result of decolorization (product 6 of the present invention). As a result of examining the addition amount of glycosidase in the case of using tannase and pectinase in combination, it was found that the color tone became lighter and the turbidity became clearer as the addition amount of the glycosidase increased. (Products 4 to 7 of the present invention).

(Example 2)

The liquid in the middle of the step was prepared under the same conditions as the aforementioned product 6 of the present invention. That is, the liquid (1) separated by the dehydration type centrifugal separator, the liquid (2) after heating the liquid at 95° C. for 1 minute, and then cooling the liquid and further filtering the No. 2 filter paper. Liquid (3), and then the liquid (4) was centrifuged at 3000×g for 10 minutes after cooling the liquid to 20° C. for 10 minutes. These were each left to stand overnight at 20°C.

As a result, the liquid of (1) was uniform as a whole, and had a thick and turbid yellow-green color, while the liquid of (2) produced a large amount of dark green precipitates, and the supernatant was pale and almost clear. In addition, the liquid of (3) was slightly precipitated, but the supernatant was pale and almost clear, and the liquid of (4) was pale and almost clear, and there was no precipitation at all. The photographs of these external appearances are shown in FIG. 2 . From left are (1), (2), (3), (4).

As a result of the above, it was found that a precipitate containing a coloring component was generated by heat treatment after the enzyme treatment, and decolorization was achieved by removing the precipitate. In addition, it was found that the present precipitate could not be completely removed by No. 2 filter paper (retained particle size: 5 μm), but could be efficiently removed by centrifugal precipitation treatment at a gravitational acceleration of 3000×g.

(Example 3)

3.6 g of vitamin C was dissolved in 2600 g of pure water and heated to 75°C. 200 g of the first tea from Shizuoka (different tea leaves from Example 1: Yabukita seeds, steamed green method, cut into 5 mm) was put into it, heated while stirring, and heat-sterilized 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 stirred at 45°C for 4 hours. After the tea residue and the extract were separated by a dehydration type centrifuge, the extract was heated at 95°C for 1 minute, and then cooled to 30°C. Next, the extract was concentrated under reduced pressure to Bx17° by a rotary evaporator, cooled to 20°C, and centrifuged at 3000×g for 10 minutes to remove the precipitate, and then the supernatant was adjusted to Bx15°, After heating and sterilizing at 95° C. for 1 minute, it was cooled to 20° C. to obtain a green tea extract. The obtained green tea extract was measured for caffeine content (HPLC method), catechin content (HPLC method) and tannin content (Folin-denis method). Measured at °C), and measured the absorbance at 430 nm (indicator of coloration) and the absorbance at 680 nm (indicator of turbidity). The results are shown in Table 2. Moreover, the photograph of the external appearance of these Bx0.3 degree dilution liquids is shown in FIG. 3 (the left is the comparative product 4, and the right is the invention product 8).

Comparing the component values of Inventive Product 8 and Comparative Product 4, Inventive Product 8 has less caffeine, tannins, and catechins than Comparative Product 4, but only slightly.

<Sensory evaluation>

The Bx0.3° dilutions of Inventive Product 8 and Comparative Product 4 were evaluated by 5 professional panelists. In terms of the average evaluation results, compared with the comparative product 4, the present invention product 8 was slightly weaker in the taste portion, but the green tea flavor was clearly recognized. In addition, the mellow aroma of green tea can be felt in terms of aroma. The smell of potato characteristic of the enzyme-treated tea is masked.

(Example 4)

Further, a glycoside-degrading enzyme was allowed to act on the comparative product 4, and a confirmation experiment was carried out to confirm whether or not an extract similar to the product of the present invention could be obtained.

That is, a commercially available β-glucosidase (1200 U/g) (12 U per 1 g of tea leaves) was added to the comparative product 4, and the reaction was stirred at 45° C. for 4 hours, and then heated at 95° C. for 1 minute. Cool to 30°C. Then, it cooled to 20 degreeC, after filtering with No2. filter paper, centrifugation was performed for 10 minutes at 3000*g of gravity, 95 degreeC, 1 minute heat sterilization, and cooled to 20 degreeC, and obtained the green tea extract (comparative product 5). The obtained green tea extract was measured for caffeine content (HPLC method), catechin content (HPLC method) and tannin content (Folin-denis method). (measurement at °C), the absorbance at 430 nm (indicator of coloration) and the absorbance at 680 nm (indicator of turbidity) were measured. The results are combined with Comparative Product 4 and Inventive Product 8 and shown in Table 3.

When compared with the comparative product 4 (before the glycoside-degrading enzyme treatment), the comparative product 5 all decreased in caffeine, tannin, and catechins. On the other hand, the color tone (OD 430 nm) of the comparative product 5 was more visible than that of the invention product 8, but the color of the comparative product 4 tended to be lighter and the turbidity tended to decrease.

In addition, in the preparation step of Comparative Product 5, in the stage where the extract liquid subjected to the enzymatic reaction and heat treatment was left at 20° C. overnight, a green flocculent precipitate similar to (2) of Example 2 was produced . A photograph of the appearance of the liquid in the middle of the preparation step of Comparative Product 5 is shown in FIG. 4 (from the left, Comparative Product 4, after enzyme inactivation, after filtration, and after centrifugation).

(Example 5)

The precipitate produced in Example 4 was recovered, and the centrifugal precipitation treatment/washing was repeated 3 times, and a dark green precipitate was recovered.

The precipitate is insoluble in water, but dissolves clearly in methanol and has a dark green color. Although the detailed mechanism is unknown, it is presumed from this result that the water-soluble pigment component was precipitated as a water-insoluble precipitate due to the action of the glycoside-degrading enzyme on the green tea extract, which was separated and decolorized. .

Appearance photographs of the centrifuged supernatant, the washing solution when the precipitate was washed with water, and the solution obtained by dissolving the precipitate in methanol are shown in Fig. The washing liquid when the precipitate was washed with water, and the liquid obtained by dissolving the precipitate in methanol).

(Example 6)

The case where protease was used in combination was examined.

3.6 g of vitamin C was dissolved in 2600 g of pure water and heated to 75°C. 200 g of second tea from Shizuoka (the same tea leaves as in Example 1: Yabukita seeds, steamed green method, cut into 5 mm) was put into it, heated while stirring, and heat-sterilized at 95° C. for 15 minutes. After cooling to 45°C (pH at this point was 5.3), the enzymes shown in Table 4 were added, and a stirring reaction was performed at 45°C for 4 hours. After the tea residue and the extract were separated by a dehydration-type centrifuge, the extract was heated at 95°C for 1 minute, and then cooled to 30°C. Next, the extract was concentrated under reduced pressure to Bx17° using a rotary evaporator, cooled to 20°C, and centrifuged at 3000×g for 10 minutes to remove the precipitate, and then the supernatant was adjusted to Bx15°, and the temperature was adjusted to 95°C. , After heat sterilization for 1 minute, the green tea extract was obtained by cooling to 20°C. The obtained green tea extract was measured for caffeine (HPLC method), catechins (HPLC method), tannins (Folin-denis method) and amino acids (HPLC method), and was diluted to Bx0.3° (refractive index). Sugar content, measured at 20°C), absorbance at 430 nm (indicator of coloration) and absorbance at 680 nm (indicator of turbidity) were measured. The results are shown in Table 4.

(Explanation of enzymes)

‧Protease: Protease M "Amano" SD (Protease manufactured by Amano Enzyme Inc.)

As shown in Table 4, Inventive Product 9 has more amino acids than Comparative Product 6, and the contents of caffeine, tannin, and catechins are almost the same values. In addition, with regard to color tone, compared with the comparative product 6, it was confirmed that the product 9 of the present invention, which was subjected to the action of the glycoside-decomposing enzyme, was decolorized. In addition, when evaluating the fragrance (Bx0.03°) of ion-exchanged water with 0.2 mass % added, the present invention 9 has a slightly weaker mellow feeling than the comparative product 6. However, the flavor of green tea such as deliciousness and astringency can be fully felt, and it has a good green tea flavor.

(Example 7)

In Example 6, in the preparation step of product 9 of the present invention, the precipitate obtained by centrifugation at an acceleration of gravity of 3000×g for 10 minutes was recovered. dark green precipitate. The obtained precipitate was photographed with a digital microscope, and then subjected to fluorescence X-ray analysis and FT/IR analysis.

The sediment was separated into two layers by repeating the centrifugation/washing three times, and it was confirmed that the upper layer was a green and viscous object, and the lower layer was a pale green fine spherical object ( FIG. 6 ). From the fluorescence X-ray analysis, it was inferred that either the upper part or the lower part is the main component of organic matter, but from the FT/IR analysis, it is suggested that the upper part is mainly protein, and the lower part is one of natural flavonols , for example, the possibility of flavonols represented by the following chemical structure as the main body.

It is known that the flavonol itself is only slightly soluble in water, but it exists as a glycoside in tea leaves, so it is easily dissolved even if it is extracted with water. This time, it is assumed that the kanfei flavonol detected as a precipitate is produced by insolubilization of the aglycone-based kanfei flavonol by the action of the glycoside-decomposing enzyme to remove the sugar. The crystals of flavonols are yellow, and it is believed that they contribute to the green tea color from greenish yellow to bright yellow. The precipitates detected in this study are green, and it is speculated that flavonols are complexed with proteins and chlorophyll. The earth is bound, insoluble and precipitated.

(Example 8) Investigate the influence on the decolorization of the tea extract when the activity of the glycoside-degrading enzyme per unit mass of tea is changed

A green tea extract was obtained according to the method described in Example 1, except that the addition amount of the enzyme was adjusted as described in Table 5 below, and the stirring reaction was performed at 45°C for 4 hours. The obtained green tea extract was diluted to Bx0.3° (refractive sugar content, measured at 20°C), and the absorbance at 430 nm (indicator of coloration) and the absorbance at 680 nm (indicator of turbidity) were measured. The results are shown in Table 5.

OD430nm is an index of coloration, and OD680nm is an index of turbidity. When OD430nm is less than 0.05, it can be said that there is almost no coloring; when it is less than 0.3, it can be said that there is very little coloring; when it is less than 0.5, it can be said that it is light coloring. In addition, when OD680nm is 0.1 or less, there is almost no turbidity (clear), and about 0.15 is a level with a little turbidity.

As shown in Table 5, it was found out that the color of the obtained extract became lighter as the amount of the glycosidase to be used increased with respect to the tea leaves. Moreover, with respect to the case where 10 U (No. 3) or more was used for 1 g of tea leaves, it can be said that both the coloring and the turbidity are extremely small.

(Example 9)

Investigate the reaction time of glycosidase on tea and its effect on decolorization of tea extract

Except for changing the enzymatic reaction time, the present invention product 4 (10 U of glycoside-degrading enzyme added to 1 g of tea) and the present invention 6 (20 U of glycoside-degrading enzyme added to 1 g of tea) in Example 1 were described. method to obtain green tea extract. The obtained green tea extract was diluted to Bx0.3° (refractive sugar content, measured at 20°C), and the absorbance at 430 nm (indicator of coloration) and the absorbance at 680 nm (indicator of turbidity) were measured. The results are shown in Table 6.

As shown in Table 6, with respect to 1 g of tea leaves, it was confirmed that 10 U or 20 U of the extracts of the glycoside-decomposing enzymes were used, and the color and turbidity decreased in either reaction for 1 hour. As implied from Table 5, if the OD430nm of the tea extract without enzymatic reaction is 0.562 and OD680nm is 0.146, and the degree of decolorization and turbidity reduction in 1 hour is assumed, the enzyme reaction time is 30 minutes. Effect.

In addition, the longer the enzymatic reaction time is, the lower the color and turbidity values will progress. In terms of coloring, the system using 10 U of saccharolytic enzyme for 1 g of tea leaves was reacted for 4 hours, and 20 U was used. In the system of 2 hours, the OD430nm became 0.3 or less. In addition, regarding the turbidity, the system using 10 U was a reaction of 3 hours, and the system using 20 U was a reaction of 2 hours, and the OD680nm was 0.1 or less. For either system, the color (OD430nm) and turbidity (OD680nm) were further reduced with more reaction time prolongation.

(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-produced second tea (Yuboku seed, steamed green method, cut into 5 mm) was put into this, heated while stirring, and heat-sterilized at 95° C. for 15 minutes. After cooling 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 performed at 45°C for 8 hours. The tea residue and the extract were separated by a dehydration type centrifuge, and 100 g of soft water was further put into the centrifuge to extrude the extract adhering to the tea residue to obtain an extract, and the extract was heated at 95°C for 30 seconds. Sterilization and enzyme inactivation are performed by heating, and it is cooled to 30 degreeC. Next, the extract was centrifuged (1200×g, 8 minutes) to remove the precipitate, then 40% by mass of PVPP of soluble solid content (calculated using Bx at 20°C) was added to the extract, and the extract was heated at 30°C. under stirring for 1 hour. Next, after filtering with No. 2 filter paper (retained particle size of 5 μm), it was cooled to 20°C, adjusted to Bx (20°C) 3.0 with soft water, heated and sterilized at 95°C for 30 seconds, cooled to 30°C, and 200 mesh was performed The saran was filtered and filled into a bottle 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 to the extract was set to 80% by mass of the soluble solid content (calculated using Bx at 20°C) to obtain a green tea extract (Product 11 of the present invention).

(Example 12) β-glucosidase treatment

In Example 10, the same operation as in Example 10 was performed except that the PVPP addition was not performed, and a green tea extract (product 12 of the present invention) was obtained.

(Comparative Example 7) Without β-glucosidase, and treated with PVPP

In Example 10, the same operation as in Example 10 was performed except that β-glucosidase was not used as the enzyme (the enzyme of the present invention 12 in Table 7 was used) to obtain a green tea extract (comparative product 7) .

(Comparative Example 8) Neither β-glucosidase treatment nor PVPP treatment

In Comparative Example 7, the same operation as in Comparative Example 7 was performed except that PVPP was not added, and a green tea extract was obtained (Comparative Product 8).

(Example 13)

The Bx, pH, amino acid (mg%), tannin (mg%), caffeine (mg%) of the invention product 10, the invention product 11, the invention product 12, the comparative product 7 and the comparative product 8 were measured . Moreover, it diluted with pure water to Bx0.3°, and measured OD430nm, OD680nm, Lab, and ⊿E (comparison with pure water). Furthermore, the Bx0.3° diluted product was subjected to sensory evaluation of green tea-like properties by five fully trained professional panelists. These analytical values and the average results of the sensory evaluation are shown in Table 7.

(results, investigation)

. By β-glucosidase treatment, the degree of coloration of tea beverages was reduced (comparison of comparative product 8 and invention product 12, and comparison product 7 and invention product 10).

. By PVPP treatment, the degree of coloration of tea beverages will be reduced, especially after heat sterilization, the coloring tends to be small. Moreover, the bitterness and astringency became weaker by PVPP treatment (Comparison of the comparative product 8 and the comparative product 7, and the comparison of the invention product 12 and the invention product 10).

. In addition to the β-glucosidase treatment, the products 10 and 11 of the present invention, which were subjected to PVPP treatment (removal of tannin), were confirmed to obtain maintenance tea when diluted to the same solid content concentration (Bx0.3°). flavor, while the lightest, more decolorized extract.

. By performing PVPP treatment (removal of tannin) in addition to β-glucosidase treatment, when the soluble solid content (refractive sugar content, temperature at 20°C) of the tea extract is set to 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, when the soluble solid content (refractive sugar content, temperature 20°C) is set to 15 (50 times the concentration of the above-mentioned invention product), the amino acid can be obtained. 1.0 mass % or more and The green tea extract with less than 1.0 mass % of catechins (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

Diluted respectively so that the invention product 10, 11, 12, the comparative product 7 and the comparative product 8 become Bx0.005° (so that each of the invention product or the comparative product is 0.167% in each water), and adjust the sodium ascorbate to add 0.03% and The solution without addition was subjected to UHT sterilization at 135° C. for 30 seconds, cooled to 90° C., filled into a bottle, and then cooled to 30° C. or lower to prepare a container-packed green tea beverage.

The hue (OD430nm, OD680nm, and ⊿E with pure water) of each beverage is shown in Table 8.

(results, investigation)

‧When the extract was diluted to Bx0.005° and 0.03% sodium ascorbate was added, any of the products 10, 11, 12 of the present invention, the comparative product 7 and the comparative product 8 could be prepared as colorless, transparent or close to Colorless and transparent drink.

• In the case where the extract was diluted to Bx0.005° and sodium ascorbate was not added, neither was cloudy and was almost transparent, 10 and 11 were almost completely colorless, and other than that, coloring was seen.

(Example 15) Correlation between the concentration of the extract 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), UHT sterilized at 135°C for 30 seconds, cooled to 90°C, filled into a bottle, cooled to 30°C or less, and then cooled to 90°C. A container-packed green tea beverage was prepared.

The color tone (OD430nm and ⊿E with pure water) of each drink is shown in Table 9.

(results, investigation)

In the case of a container-packed beverage prepared with no sodium ascorbate added, the product 10 of the present invention is almost completely colorless when the concentration of the product 10 is Bx0.005°, slightly colored when Bx0.015, and slightly colored when Bx0.025. coloring.

However, it is considered that about 0.025 is required in order to sufficiently secure the green tea-like flavor.

When preparing a packaged beverage from the aforementioned Example 13, since it was confirmed that the addition of sodium ascorbate has an effect of preventing coloration, the following experiment was carried out.

(Example 16) Correlation between the concentration of sodium ascorbate added, storage conditions and color tone

Dilute the product 10 of the present invention so that Bx0.025°, at this time, add sodium ascorbate at the concentration of Table 10, perform UHT sterilization at 135° C. for 30 seconds, cool to 90° C., fill in a PET bottle, and cool to 30° C. Hereinafter, a container-packed green tea beverage was prepared.

The beverages in each container were stored at 10°C and 50°C for 10 days.

The color tone (OD430nm and ⊿E with pure water) of each drink after storage is shown in Table 10.

(results, investigation)

‧By adding sodium ascorbate, the coloring after sterilization is suppressed.

‧It was confirmed that the addition concentration of sodium ascorbate was in the range of 0 to 0.03%, and the coloring after sterilization was suppressed as the addition amount increased.

‧The OD430nm and ⊿E stored at 10℃ for 10 days immediately after sterilization are almost completely colorless and transparent as long as the sodium ascorbate is 0.01% or more.

‧When the containerized beverage is stored at 50°C for 10 days (abuse condition), sodium ascorbate concentration of 0.03% is "almost colored", and 0.01% is "extremely slightly colored".

‧On the basis of 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 decolorized green tea leaf extract, comprising the following steps (A) to (E) and (B'): (A) a step of mixing green tea leaves and water; (B) in step (A) Then, the step of making a glycosidase to act on the mixture of (A), wherein the amount of the glycosidase to be used relative to the green tea leaves is 10 to 100 U/g, and the temperature of the enzymatic reaction is in the range of 30 to 70° C. , and the reaction time is more than 30 minutes; (B') at the same time as step (B) or before or after and before the following step (C), the step of further making tannase and pectinase act; (C) After step (B'), the steps of separating the green tea leaves residue and the extract, and obtaining the green tea leaf extract treated with glycosidase; (D) treating the glycosidase obtained in step (C) The step of heat-treating the green tea leaf extract; (E) removing insoluble components from the heated glycosidase-treated green tea extract obtained in step (D), and obtaining a decolorized green tea extract step, wherein when the soluble solid content (refractive sugar content, temperature 20°C) of the green tea leaf extract is set to 0.3, the absorbance at 430 nm is 0.1 or less. The method for producing a decolorized green tea leaf extract according to claim 1, which further comprises a step of causing a protease to act simultaneously with the step (B') or after the step (B') and before the step (C). As claimed in claim 1 or 2, the method for producing a decolorized green tea leaf extract, wherein the heat treatment conditions in step (D) are in the range of a temperature of 70 to 135° C. and a time of 2 seconds to 30 minutes. The method for producing a decolorized green tea leaf extract according to claim 1 or 2, which comprises steam-distilling the green tea leaves before step (A) to obtain an aroma recovery product, and mixing the obtained aroma recovery product into the step (A) (E) Step of the obtained green tea leaf extract. The method for producing a decolorized green tea leaf extract according to claim 1 or 2, wherein when the soluble solid content (refractive sugar content, temperature at 20° C.) of the green tea leaf extract is set to 0.3, the absorbance at 680 nm is 0.15 or less. The method for producing a decolorized green tea leaf extract according to claim 5, wherein when the soluble solid content (refractive sugar content, temperature 20° C.) of the green tea leaf extract is set to 0.3, the absorbance at 430 nm is 0.05 or less and the absorbance at 680 nm is 0.05 or less. A method for producing a decolorized low-tannin green tea leaf extract, comprising the following steps (A) to (F) and (B'): (A) a step of mixing green tea leaves and water; (B) in the step After (A), the step of causing the glycosidase to act on the mixture of (A), wherein the amount of the glycosidase to be used relative to the green tea leaves is 10 to 100 U/g, and the temperature of the enzymatic reaction is 30 to 70° C. and the reaction time is more than 30 minutes; (B') at the same time as step (B) or before or after and before the following step (C), the step of further making tannase and pectinase act; (C) after step (B'), the step of separating green tea leaves residue and extract, and obtaining the green tea leaf extract treated with glycosidase enzyme; (D) using the glycoside obtained in step (C) The step of heat-treating the enzyme-treated green tea leaf extract; (E) a step of removing insoluble components from the heated glycosidase-treated green tea leaf extract obtained in step (D), and obtaining a decolorized green tea leaf extract, wherein the green tea leaf extract is When the soluble solid content (refractive sugar content, temperature 20° C.) is set to 0.3, the absorbance at 430 nm is below 0.1; (F) after step (E), the obtained decolorized green tea leaf extract is further mixed with PVPP (poly Vinyl polypyrrolidone) is contacted, and the step of obtaining an extract from which the contacted PVPP is removed. The method for producing a decolorized low-tannin green tea leaf extract according to claim 7, wherein when the soluble solid content (refractive sugar content, temperature 20°C) of the green tea leaf extract is set to 0.3, the absorbance at 680 nm is 0.05 or less, Further, when the soluble solid content (refractive sugar content, temperature 20° C.) is set to 15, the amino acid content is 1.0 mass % or more, and the tannin (Folin-Denis method) is 1.0 mass % or less. A method for producing a beverage containing near water or flavored water in a container, comprising the following steps: (G) to the green tea leaf extract obtained by the method according to any one of claims 1 to 6, 7 and 8 A step of adding water to adjust the soluble solid content from green tea leaves to 0.005-0.3% (Bx, 20°C); (H) adding vitamin C or its edible salt ( sodium) steps.

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