TW201912036A - Decolored tea extract, and method for producing same - Google Patents

Abstract

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

Description

 Decolorized tea extract and preparation method thereof  

The present invention relates to a decolorized tea extract and a method of producing the same. More specifically, it relates to a tea extract and a method for producing the same; the tea extract has a good aroma, a taste, and a bitter taste of tea, although the color is light, and the method comprises the step of treating the tea with a glycoside degrading enzyme. step.

In recent years, due to the diversification of consumer preferences for container-packed beverages, many bottled beverages in which colorless and transparent containers are filled with almost colorless and transparent beverages can be seen in the market. Such beverages are also referred to as near-water beverages, flavored waters, etc., and the colorless and transparent feeling of appearance is one of the important elements. Such a beverage, which is almost colorless and transparent, has a flavor of citrus such as lemon, orange, orange, and has a flavor of soft fruits such as grapes, apples, peaches, and flavors of fermented milk such as sour buttermilk, but has a taste of tea. Flavorers are not common.

Only by using the aroma of tea (mixed spices or natural flavors), although the flavor of the tea can be reproduced to some extent, in order to feel the true feeling of the tea, by blending the water-soluble ingredients from the tea, it becomes To be able to give a better flavor.

On the other hand, the tea extract is usually colored, and if the tea extract is to be blended in an amount to impart a degree of flavor, the whole of the beverage is colored pale green to light brown.

As a method of decolorizing a tea extract, for example, a method in which a metal extract is removed by a cation exchange resin treatment and then filtered by a microfiltration membrane to obtain a treatment liquid is known (Patent Document 1). There is a disadvantage that the amino acid which is a delicious ingredient is also removed by the cation exchange resin treatment.

As the decolorization method, treatment with an adsorbent such as activated carbon is generally known, and various treatment techniques using an adsorbent treatment are also known for tea. Patent Document 2 discloses a method of obtaining a tea extract by mixing or adding activated carbon during tea extraction and/or after extraction, but the purpose is to remove caffeine, and there is no description about discoloration. Further, Patent Document 3 discloses a method of bringing a caffeine-containing aqueous solution such as a tea extract into contact with activated clay or acidic clay. However, the method is also intended to remove caffeine, and there is no description about discoloration. Further, Patent Document 4 or Patent Document 5 discloses a method of bringing a tea extract into contact with polyvinylpolypyrrolidone, but the purpose is to remove catechins or tannins, and there is no description about discoloration.

As a method for preparing a green tea extract which can be used for sports drinks and isotonic drinks, a mixed solution in which the green tea extract is dissolved in a weight ratio of ethanol to water of 91/9 to 97/3 is disclosed. A method for producing a low caffeine green tea extract obtained by a method of 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 that there is an effect of not deteriorating the hue (paragraph [0009], etc.), but the color tone is not specifically described, and there is no description in the examples.

On the other hand, the glycoside-degrading enzyme system means an enzyme which hydrolyzes the bond between the anormeric carbon and the aglycone moiety (glycosidic bond) to form a free aglycone. In the method for producing a green tea beverage, the method for producing a green tea beverage is characterized in that, prior to the heat sterilization treatment step of the green tea extract, the method further comprises adding a glycoside degrading enzyme. An enzyme treatment step of changing a glycoside to an aroma component compound (Patent Document 7); a method for preparing a tea extract having enhanced aroma, characterized in that, when the tea is treated with tannase and/or after the tea is treated, The glycoside-degrading enzyme acts on tea leaves (Patent Document 8) and the like, but any of them only describes the content of the aroma. Further, Citation 9 describes a production method in which a water extract of tea such as oolong tea is concentrated to Bx2 to 15°, and a glycoside degrading enzyme is allowed to act on the concentrate, thereby producing high transparency and long-term preservation. There is also no sediment tea extract. However, there is no description about the hue (concentration of color, etc.).

 [Previous Technical Literature]    [Patent Literature]  

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

Patent Document 2: Japanese Patent Publication No. 8-70772

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

Patent Document 4: Japanese Patent No. 3315304

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

Patent Document 6: Japanese Patent No. 4181982

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

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

Patent Document 9: Japanese Patent No. 5818784

As described above, the method of decolorizing the tea extract is mainly carried out by means of physicochemical treatment, but there are disadvantages or disadvantages that may impair the original flavor of the tea.

Accordingly, an object of the present invention is to provide a green tea extract, and a tea beverage, in particular a container-packed tea beverage, using the green tea extract; the green tea extract can be used in the preparation of a near-water and flavor-like beverage. The flavor, especially the taste, derived from the tea leaves is imparted to the beverage in a colored manner.

It has long been known that an aqueous extract that causes a glycoside degrading enzyme to act on tea leaves will change the glycoside into aroma component compound, but this time, surprisingly, it was found that if it is in the presence of water, it is certain After the green tea leaves are treated with the glycoside degrading enzyme under the conditions, the obtained tea extract obtained by the glycoside enzyme is heat-treated to form a water-insoluble substance, and the water-insoluble matter can be removed. A green tea extract which does not substantially impair the flavor, transparency and decolorization from the tea leaves is obtained. Further, it has been found that, by such treatment, it is not limited to green tea leaves, and the same extract can be obtained from a wide range of tea leaves.

Thus, the invention is not limited, but the following are provided as inventions having the main aspects or features.

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), a step of the saccharolytic enzyme acting on the mixture of (A); (C) after the step (B), separating the tea residue and the extract, and obtaining a glycoside-treated tea extract; (D) a step of heat-treating the glycoside-treated tea extract obtained in the step (C); (E) removing insolubleness from the heated glycoside-treated tea extract obtained in the step (D) Ingredients and a step of obtaining a decolorized tea extract.

Aspect 2: A method for producing a decolorized tea extract as described in Aspect 1, which comprises, simultaneously with or before or after Step (B) and before Step (C), further comprises a tannin enzyme and/or fruit The step of the action of the enzyme.

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

Aspect 4: The method for producing a decolorized tea extract according to any one of the aspects 1 to 3, wherein the heat treatment condition in the step (D) is 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 the aspects 1 to 4, wherein the tea leaves are green tea.

Aspect 6: The method for producing a decolorized tea extract according to any one of Aspects 1 to 5, which comprises subjecting the tea leaves to steam distillation and obtaining aroma recovery before the step (A), and obtaining the obtained The step of mixing the aroma recovery to the clear liquid obtained in the step (E).

Aspect 7: The method for producing a decolorized tea extract according to any one of the aspects 1 to 6, wherein the amount of the glycoside-degrading enzyme relative to the tea 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 a decolorized tea extract according to the 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 was 0.5 or less and the absorbance at 680 nm was 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 saccharide, temperature 20 ° C) of the tea extract is set to 0.3, 430 nm The absorbance is 0.1 or less and the absorbance at 680 nm is 0.05 or less.

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

Aspect 11: A green tea leaf extract, wherein when the soluble solid content (refractive saccharide, temperature: 20 ° C) of the tea extract is set to 0.3, the absorbance at 430 nm is 0.5 or less and the absorbance at 680 nm is 0.15 or less, and further When the soluble solid content (refractive saccharide, temperature: 20 ° C) is 15, the amino acid content is 1.0% by 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), a step of the saccharolytic enzyme acting on the mixture of (A); (C) after the step (B), separating the tea residue and the extract, and obtaining a glycoside-treated tea extract; (D) a step of heat-treating the glycoside-treated tea extract obtained in the step (C); (E) removing insolubleness from the heated glycoside-treated tea extract obtained in the step (D) a component, and a step of obtaining a decolorized tea extract; (F) after the step (E), the obtained decolorized tea extract is further contacted with PVPP (polyvinylpolypyrrolidone), and the contact is obtained. After the step of the PVPP extract.

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

Aspect 14: A green tea leaf extract, wherein when the soluble solid content (refractive saccharide, temperature 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, when further When the soluble solid content (refractive saccharide, temperature: 20 ° C) is 15, the amino acid content is 1.0% by mass or more and the tannin (Folin-Denis method) is 1.0% by mass or less.

Aspect 15: A method for producing a container-packed tea beverage, comprising the steps of: (G) adding water to a tea extract obtained by the method described in any one of the aspects 1 to 9, 12, and 13 a step of adjusting the soluble solid content of the 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 0.005 to 0.3% (Bx, 20 ° C) mass% of the green tea extracts as described in 10, 11 and 14 as a soluble solid component derived from tea, 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% by mass of vitamin C or an edible salt thereof (sodium).

Aspect 18: The container-packed tea beverage according to Aspect 16 or 17, wherein when the soluble solid content (refractive saccharide, 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 Less than 0.05.

According to the present invention, it is possible to provide a tea extract, a low tannin tea extract, and a tea beverage, in particular a containerized tea beverage, using the green tea extract; the tea extract and physical chemistry by the past The method maintains the flavor, especially the taste, of the tea compared to the decolorized tea extract.

Fig. 1 shows a photograph showing the appearance of a liquid obtained by diluting the green tea extract obtained in Example 1 to Bx0.3. From the left, it is a comparative product 1, the present invention 4, the present invention 5, the present invention 6, and the present invention 7.

Fig. 2 is a photograph showing the appearance of the liquid in the middle of the step in Example 2 after leaving it at 20 ° C for 1 night. From the left, they are (1), (2), (3), and (4).

Fig. 3 is a photograph showing the appearance of a liquid obtained by diluting the green tea extract obtained in Example 3 to Bx 0.3°. The left side is the comparative product 4, and the right is the invention product 8.

Fig. 4 shows a photograph showing the appearance of the liquid in the middle of the preparation step of the comparative product 5 in the fourth embodiment. From the left, it is the comparative product 4, after the enzyme is inactivated, after filtration, and after centrifugation.

Fig. 5 is a photograph showing the appearance of a liquid obtained by centrifuging the supernatant from the left, a washing liquid when the precipitate was washed with water, and a liquid obtained by dissolving the precipitate in methanol.

Fig. 6 is a photograph of a 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 relative to the tea leaves was changed in Example 8.

Fig. 8 is a photograph showing the appearance of a Bx 0.3° dilution of tea extract No. 1 to No. 6 when the activity of the glycoside-degrading enzyme with respect to tea leaves was changed in Example 8.

 [Detailed Description of the Invention]  

The tea leaves as the raw material can be used in the method of the present invention, and are the leaves of the tea tree of Camellia sinensis which is widely cultivated in the world, and may be any one, preferably not fermented, according to the purpose of the present invention. For example, tea, such as sencha, baked tea, jade, crown tea, and milled tea, steamed green tea, huwan tea, green tea, and various Chinese teas are also available. In addition, it can also be applied to semi-fermented tea such as tea, Tieguanyin tea, and oolong tea, and fermented tea such as black tea.

Also, it starts from the species of Yabulukita (Camellia sinensis var.sinenses cv. Yabukita), and the tea tree can be any variety. The leaves are usually picked from the bud heart to the leaves of the four leaves. One heart and four leaves, and also leaves other than the more mature four leaves. The tea or tea raw material may be used as it is, but it is usually used by a method which has been used for cutting, pulverization, grinding, etc., using a device used for food production or the like.

The step (A) is that tea leaves are mixed with water. Generally, water can be conveniently used as soft water, ion exchange water, RO membrane treatment water, and the like. The ratio of the use of tea and water depends on the dry state of the tea, and the suitable range may be 1.5 to 50, preferably 1:8 to 20, and more preferably 1:10 to 15 by weight. . The mixing can be carried out at room temperature, and considering the harvesting time/maturation of the leaves to be used, etc., it is preferable to carry out sterilization before the enzyme reaction, and it is also possible to carry out under heating conditions. The temperature at this time can be exemplified by the condition that the sterilization purpose is achieved and the thermal deterioration of the tea leaves is small, and for example, it can be carried out at 65 to 100 ° C, more preferably at 70 to 90 ° C. The mixing time is a time during which the tea leaves absorb water and becomes in an expanded state, and is not limited, but it is generally in the range of 1 minute to 60 minutes, preferably 5 minutes to 30 minutes.

Further, in the case where the mixture is sterilized and mixed under heating conditions, after the heat sterilization, the mixture of the tea leaves and water is cooled to a temperature suitable for the enzyme treatment.

Step (B) is a mixture capable of allowing the glycoside degrading enzyme to directly act on the step (A), or may be prepared from the mixture before the water extract or in addition to the glycoside degrading enzyme and in the tea After the enzyme-treated extract is prepared in the presence of various enzymes used for extraction, the glycoside degrading enzyme is allowed to act, or while the glycoside degrading enzyme is directly allowed to act on the aforementioned mixture, or after An enzyme other than a glycolytic enzyme. The enzyme other than the glycoside-degrading enzyme is not limited, and examples thereof include a tannin-decomposing enzyme tannin, a protease, an amylase, a glucoamylase, a pectinase, a cellulase, and a hemicellulase. Among these, for the purpose of the present invention, in order to obtain a tea extract which retains the original flavor and taste of the tea and which is transparent and decolored, as a suitable one, tannase or pectinase may be mentioned. These enzymes can be used alone or in combination of two or more.

The glycoside-degrading enzyme and each of the enzymes other than the same may be used without limitation as long as it is a user of the present invention and is useful for the glycoside-degrading enzyme, tannase, and pectinase. As described below.

In the case of a glycoside-degrading enzyme, it can be conveniently used: it can hydrolyze a glycoside which can be present in tea leaves, for example, a glycoside composed of a flavonol and a glucose to a free aglycone. Enzymes at the base and sugar. Such O-glycoside glycosides are abundant in the plant kingdom, and on the other hand, various enzymes which hydrolyze the O-glycosidic bond are also present in nature. The above is not limited, and the following may be mentioned as the object of the present invention. For example, it may be a production of β-glucose belonging to the genus Aspergillus, Penicillium, Rhizopus, Pseudmonas, Pichia, and the like. The bacterium of β-glucosidase is subjected to solid culture or liquid culture using a solid nutrient medium such as wheat bran or rice bran or a liquid nutrient medium according to a usual method, and the obtained culture or its treatment is carried out according to a usual method. Refining treatment. Further, those obtained by purifying plants such as vanilla beans and raw tea leaves may be used, and a bitter almond enzyme derived from almonds commercially available from Sigma-Aldrich Co. or from β-glucosidase may be further used. Enzyme preparations Cellulase A (Amano Enzyme), Cellulase T (Amano Enzyme) and the like are isolated. Examples of the β-xylosidase include β-xylosidase producing bacteria belonging to the genus Penicillium, Fusarium, Rhizopus, and Mucor, and the use of wheat according to the conventional method. A solid nutrient medium or a liquid nutrient medium such as bran or rice bran is subjected to solid culture or liquid culture, and the obtained culture or the treatment thereof is purified by a usual method, and may also be used from Sigma-Aldrich Co. Commercially available from Aspergillus niger or isolated from Sumizyme ACH (Nippon Science Industries), an enzyme preparation containing β-xylosidase. Β-primeverosidase, for example, a bacterium belonging to the genus Cellulomonas, Penicillium, Fusarium, etc., which produces β-primulinase, according to the usual method The solid culture medium or the liquid culture medium such as wheat bran or rice bran is used for solid culture or liquid culture, and the obtained culture or the treated product thereof is purified by a usual method, and plants such as raw tea leaves can also be used. The separation is refined. When used for the purpose of the present invention, the amount of the glycoside-degrading enzyme used is generally based on the mass of the tea raw material, for example, the β-glucosidase activity using the p-NP glucose addition method. 1 to 100 U/g, preferably 4 to 75 U/g, more preferably 8 to 50 U/g, still more preferably 10 to 40 U/g.

A tannase is an enzyme that hydrolyzes a depside bond formed by binding a gallic acid to a hydroxy ester of tannin, such as epigallocatechin gallate. (epigallocatechin gallate) is an enzyme that hydrolyzes to epigallocatechin and gallic acid. As the tannase which can be used in the present invention, specifically, for example, it belongs to the genus Trichophyton, Penicillium, Rhizopus, Rhizomucor, Lactobacillus, Staphylococcus a bacterium belonging to the genus (Staphylococci), the genus Streptococci, the genus Lonepinella, etc., which produces a tannin enzyme, and is solidified according to a usual method using a medium which is generally available for the cultivation of the filamentous fungus (filamentous fungus). The culture or the liquid culture is carried out, and the obtained culture or the processed material thereof is subjected to a purification treatment according to a usual method. Further, commercially available tannase may be used, for example, tannase (500 U/g; manufactured by Kikkoman Co., Ltd.), tannase (5,000 U/g; manufactured by Kikkoman Co., Ltd.), and tannase (500 U/g). (Mitsubishi Chemical Food Co., Ltd.), Sumizyme (registered trademark) TAN (manufactured by Shin-Nippon Chemical Industry Co., Ltd.), etc. The amount of tannase used may vary depending on the strength of the product, and thus the optimum range may not be specified. Generally, it may be in the range of 0.1 to 50 U/g, preferably 0.5 to 20 U/g, based on the mass of the tea raw material. .

Pectinase is also known as polygalacturonase, pectic enzyme, polymethylgalacturonase, and pectin depolymerase, which is a pectinic acid (pectinic). An enzyme in which the α-1,4 bond of pectin or pectic acid is hydrolyzed. It is known that pectinase is contained in bacteria, molds, yeasts, higher plants, snails, and the like, and pectinase taken from organisms represented by these are widely used in the present invention. Further, a commercially available pectinase preparation can also be used. As a commercially available pectinase preparation, for example, Sucrase (registered trademark) A, Sucrase (registered trademark) N, Sucrase (registered trademark) S (above, Mitsubishi Chemical Food Co., Ltd.), and Pectinex Ultra (registered trademark) can be exemplified. SP-L (made by Novo Nordisk A/S), Meicelase (registered trademark) (made by Meiji Seika Co., Ltd.), Ultrazyme (registered trademark) (Novo Nordisk A/S company), NewlaseF (registered trademark) (Tianno) Sumizyme (registered trademark) SPG (manufactured by Shin-Nippon Chemical Industry Co., Ltd.), etc., manufactured by Enzyme Co., Ltd. Since the pectinase preparation usually contains a plurality of enzymes, the amount of the pectinase used is not easily expressed in terms of the active unit, and is generally 0.01% by mass to 5% by mass, preferably 0.1% by mass, based on the mass of the tea raw material. Within 2% by mass.

The tea contains about 25% by mass of protein (see Table 5 for the Japanese food ingredient list), and the protease reaction is followed by a particularly high heating effect. However, since the protein in the tea leaves is bonded to the tannin, even if the protease is applied to the tea leaves alone, the amino acid is hardly formed. Thus, by allowing the protease and the tannin to act on the tea leaves, a part of the protein in the tea leaves is decomposed, and an amino acid-rich tea extract can be obtained.

A protease is an enzyme that hydrolyzes a peptide bond of a protein or a peptide. As the protease which can be used in the present invention, various commercially available proteases can be mentioned. The amount of the protease to be used varies depending on the strength and the like, and cannot be generalized. However, in general, the mass of the tea raw material is usually in the range of 0.01 to 100 U/g, preferably 1 to 80 U/g.

The tea treatment step (especially the steps (A) and (B)) carried out by the enzyme described above can be carried out according to a method known per se, for example, as described in the Patent Office Bulletin ‧ Conventional Technology Set (Spices) Part II Food Spices (released in 2001.14) "Methods for publications such as "2‧1‧ Microorganisms ‧ Enzyme Flavors" (46~57 pages).

Among such steps, the action of causing the glycoside-degrading enzyme to act on a mixture of tea leaves and water, or a treatment thereof, means that the coloring agent can be removed, so that the subsequent step (D) The heat treatment and the tea extract obtained by removing the insoluble components in the step (E) are substantially decolored. Without being bound by theory, the so-called coloring of the glycoside present in the tea leaves can be removed, which means that the original water-soluble form is converted to water-insoluble or by the action of the enzyme. Water is poorly soluble. According to the present invention, it is understood that: in the suspension or precipitate containing the insoluble component removed by the step (E), there is a substance causing coloration, and the coloring substance contains a non-flavonoid which is one of the natural flavonols. Alcohol (kaempferol), quercetin and the like. This matter is not further bound by theory, but the foregoing effect is understood to mean that at least all or most of the glycoside which may be aglycone, such as non-flavonol and flavonoids, may be present in the glycoside of the tea leaves. Hydrolysis is carried out to form a water-insoluble free aglycone.

Therefore, the step (B) is carried out under the conditions in which the above-mentioned suspension or precipitate is formed. Such conditions may vary depending on the strength of the enzyme used, and the optimum conditions may vary, but the temperature is generally 30 to 70 ° C, preferably 36 to 60 ° C, more preferably 40 to 50 ° C, and even more preferably 42 °C~48°C; the reaction time is theoretically 25 minutes or more, 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 conditions for the pH of the enzyme to be used, etc., vary, but are generally 4-6.

As described above, in the step (B), it is possible to simultaneously (in the step (B)) an enzyme other than the glycoside degrading enzyme, and the conditions of the enzymatic treatment can also be selected in accordance with the action of the glycoside degrading enzyme. The above conditions.

In the step (C), as described above, in order to hydrolyze the aglycone moiety of the glycoside and the sugar moiety, the glycoside degrading enzyme is allowed to act on the tea leaves for a sufficient period of time through the step (B), thereby causing the raw tea leaves residue or the like. The insoluble solids are separated from the other treatment liquids (also referred to as extracts). Such separation is carried out by, for example, a dewatering type centrifugal separator, a filter press, a Nutsche filter coated with a filter aid, or the like, and simultaneously removes more solid matter if necessary.

In the step (D), the enzyme-treated tea extract is subjected to heat treatment to denature the protein including the enzyme used in the above step. Further, the explanation of the technical scope of the present invention is not limited by the theory, but it is considered that the enzyme not only loses activity due to denaturation by heat treatment, but also is a coloring cause component and is insoluble due to enzymatic treatment. The composition of water is a state in which it is easily bonded and agglomerated with denatured proteins. The heat treatment condition is generally in the range of 70 to 135 ° C for a period of 2 seconds to 30 minutes, preferably at a temperature of 75 to 121 ° C, a time of 10 seconds to 25 minutes, and more preferably at a temperature of 80. In the range of ~100 ° C and time 30 seconds to 20 minutes, it is more preferably in the range of temperature 85 to 95 ° C and time 20 seconds to 15 minutes.

In the step (E), the heat-treated material is cooled to 45 ° C or lower, preferably to 35 ° C or lower, and a suspension or precipitate containing an insoluble component is produced. The insoluble component itself, or the suspension or the removal of the precipitate, can be carried out, for example, by a dewatering type centrifugal separator, a sedimentation type centrifugal separator, a filter press, a Nutsche filter coated with a filter aid, or the like, usually The use of sedimentation type centrifugation will bring better results.

As described above, according to the present invention, it is generally possible to decolorize the coloration of the extract or the enzyme extract from the coloring matter of the tea leaves. On the other hand, it is possible to provide a tea extract which is known to contribute to the flavor of the tea, and in particular to the content of the amino acid, caffeine and catechin which contribute to the taste. As such a tea extract, for example, when green tea leaves are used as a raw material, when the soluble solid content (refractive saccharide, temperature: 20 ° C) of the tea extract is 0.3, the absorbance at 430 nm is 0.5 or less, preferably 0.3. More preferably, it is 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, further Preferably, it is 0.05 or less, and 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, more preferably 1/3 or less, compared with the absorbance at 430 nm of the tea extract which is not subjected to the enzyme treatment. 1/5 or less. Furthermore, it is possible to provide a green tea extract having a catechin content of 1.0% by mass or more based on the total mass of the solid component when the soluble solid content (refractive saccharide, temperature: 20 ° C) is 15 It is preferably 1.2% by mass or more, and more preferably 1.5% by mass or more. Further, when the protease is applied to the tea leaves and extracted, it is possible to provide a green tea extract which is relative to the solid content when the soluble solid content (refractive saccharide, temperature 20 ° C) is 15 The content of the amino acid of the total mass is 1.0% by mass or more, preferably 1.5% by mass or more, more preferably 1.8% by mass or more, and the catechin content is 1.0% by mass or more, preferably 1.2% by mass or more, more preferably It is 1.5% by mass or more.

As described above, the decolorized tea extract provided by the present invention having an absorbance at 430 nm and an absorbance at OD 680 nm is diluted with water or added with water to produce a tea beverage, at which time, relative to the total mass of the tea beverage, When the content of the solid content is adjusted to 0.005 mass% to 0.3 mass%, it is possible to provide a tea beverage which significantly lowers the degree of coloration as compared with the tea extract which is not treated by the method of the present invention, and a substantially colorless and transparent tea. Drink. The water is not limited to so-called soft water or hard water as long as it is water 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 maintaining the flavor of the tea on the other hand. Therefore, in order to achieve the object of the present invention, for example, the data shown in Fig. 7 and the like can be referred to later, and the amount of the glycoside-degrading enzyme acting in the above step B can be controlled to prepare the tea extract. When the soluble solid content of the liquid (refractive saccharide, temperature 20 ° C) is adjusted to 0.3, the two absorbances just described above are displayed.

In the present specification, the soluble solid content (refractive saccharide, temperature 20 ° C) of the tea extract is referred to as 0.3% by mass or 0.3, which is used interchangeably. The same applies to the case where the soluble solid content (refractive saccharide, temperature: 20 ° C) or Bx (brix) (Brix) is 0.3°, and these are values obtained by measurement using a Brix meter.

In the decolorized tea extract provided by the present invention, for example, a raw material for a drink similar to water and flavor water can be used, and a raw material for a tea beverage as a container can be used.

Specifically, the tea extract obtained by the method described in any one of the above aspects 1 to 9 and 12 to 13, or the decolorized and optionally tanned tea extract described in the aspect 10 or 11 may be obtained. Adjusting the soluble solid content from the tea to 0.005 to 0.3, or 0.01 to 0.3, or 0.05 to 0.3, or 0.1 to 0.3% (or °) in addition to the type of tea beverage to be provided, and adjusting with the foregoing Simultaneously or after it, vitamin C or its edible salt (sodium) is added, whereby a tea beverage or a container-packed tea beverage can be provided (reference form 16 or 17). In the case of providing such a beverage, it is especially possible to provide a tea beverage which, if obtained from the method of Aspect 12 or 13, or which is decolored according to the decolorized and low tannin tea extract of the aspect 14, is stored or High storage stability. In the method of the aspect 12, the use condition of the PVPP (polyvinylpolypyrrolidone) is not limited, and may be appropriately selected as long as it is based on the description of Patent Document 5 and can achieve the object of 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 component of the tea extract obtained in the above step (E). The tea extract obtained in this manner is preferably adjusted after the soluble solid component derived from the tea is adjusted as described above, and the vitamin C or its edible salt (sodium) is added to the total mass of the adjusted tea beverage. 0.002% by mass to 0.3% by mass, preferably 0.005% by mass to 0.1% by mass, more preferably 0.01% by mass to 0.03% by mass. By such treatment, after the heat sterilization, the soluble solid content from the tea is adjusted to 0.3% (Bx, 20 ° C) under the conditions of the container normally filled with the tea beverage, the tea beverage is stably maintained as follows State: The absorbance at 430 nm is 0.015 or less, and the absorbance at 680 nm is 0.05 or less.

Furthermore, the following description can be made for the scale of transparency and colorlessness (coloring condition).

(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)

‧ When compared with pure water, the ⊿E is 4.0 or less (slightly colored), preferably 3.0 or less (very slightly colored), further preferably 2.0 or less (almost colorless), and particularly preferably 1.4. The following (substantially completely colorless), ‧ or OD430nm is 0.05 or less (slightly colored), preferably 0.038 or less (very slightly colored), more preferably 0.025 or less (almost colorless), particularly preferably 0.015 or less (substantially completely colorless) )

Hereinafter, the present invention will be specifically described by way of examples and comparative examples.

 [Examples]    (Example 1)  

1.8 g of vitamin C was dissolved in 1300 g of pure water and warmed to 75 °C. 100 g of Shizuoka's second tea (the glutinous rice seed, steamed green method, and cut into 5 mm) was put thereinto, heated while stirring, and heat-sterilized at 95 ° C for 15 minutes. The mixture was cooled to 45 ° C (pH at this time point was 5.3), and the enzyme shown in Table 1 was added, and the mixture was stirred at 45 ° C for 4 hours. After the tea residue and the extract were separated by a dehydration centrifugal separator, the extract was heated at 95 ° C for 1 minute and cooled to 30 ° C. The extract was filtered through No. 2 filter paper (retained particle diameter: 5 μm), cooled to 20 ° C, and centrifuged at 3000 × g for 10 minutes under gravity to obtain a green tea extract. The obtained green tea extract was diluted to Bx0.3° (refractive saccharide, measured at 20° C.), and absorbance at 430 nm (indicator of coloration) and absorbance at 680 nm (indicator of turbidity) were measured. The results are shown in Table 1. Further, Fig. 1 shows photographs of the appearance of these Bx0.3° dilutions (from the left, comparative product 1, inventive product 4, inventive product 5, inventive product 6, and inventive product 7).

 (Explanation of enzymes)  

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

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

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

‧Invertase: Sumizyme (registered trademark) INV (invertase manufactured by Shin-Nippon Chemical Industry Co., Ltd.)

‧ hemicellulase (β-mannanase): Sumizyme (registered trademark) ACH (hemicellulose enzyme manufactured by Nippon Chemical Industry Co., Ltd.)

As shown in Table 1, a comparison product of tannase and pectinase, a comparative product using invertase 2, and a comparative product 3 using hemicellulase (mannosylase) were used in combination with the phases. In contrast, the present inventions 1 to 7 in which the glycoside-degrading enzyme acts, either have a low absorbance at 430 nm (an indicator of coloration), and the absorbance at 680 nm (an indicator of turbidity) is almost the same or the following. The glycoside-degrading enzyme is more decolorized than the use of the tannin enzyme (the present invention 2), and can be obtained by further adding pectinase (about 1/4~). 1/5) The result of discoloration (product 6 of the present invention). The results of the addition of the glycoside-degrading enzyme in the case of using tannase and pectinase were investigated, and it was found that the color tone became lighter and the turbidity became clearer as the amount of the glycoside-degrading enzyme was increased. (Inventive products 4 to 7).

 (Example 2)  

The liquid in the middle of the step was prepared under the same conditions as in the above-described inventive product 6. That is, the liquid (1) separated by a dehydration centrifugal separator, the liquid (2) heated at 95 ° C for 1 minute, and then cooled, and further filtered by No. 2 filter paper. The liquid (3) was then cooled to 20 ° C, and the liquid (4) separated by centrifugation was carried out for 10 minutes at a gravity acceleration of 3000 × g. The cells were allowed to stand overnight at 20 ° C.

As a result, the liquid of (1) was uniform as a whole, and was thick and turbid yellow-green, and the liquid of (2) produced a large amount of dark green precipitate, and the supernatant was light in color and became an almost clear liquid. Further, the liquid of (3) slightly precipitated, but the supernatant liquid was light in color and became a nearly clear liquid, and the liquid of (4) was light in color and became an almost clear liquid, and there was no precipitation at all. A photograph of these appearances is shown in Fig. 2 . From the left, they are (1), (2), (3), and (4).

As a result of the above, it was found that a precipitate containing a coloring component was produced by heat treatment after the enzyme treatment, and the precipitate was removed by removing the precipitate. Further, it was found that the precipitate was not completely removed by using No. 2 filter paper (retained particle diameter: 5 μm), and it was efficiently removed by centrifugal sedimentation treatment using a gravity acceleration of 3000 × g.

 (Example 3)  

3.6 g of vitamin C was dissolved in 2600 g of pure water and heated to 75 °C. 200 g of the Shizuoka first tea (the tea which is different from the first embodiment: the glutinous rice seed, the steaming method, and the cut into 5 mm) was put thereinto, heated while stirring, and heat-sterilized at 95 ° C for 15 minutes. . The mixture was cooled to 45 ° C (pH at this time point was 5.3), and the enzyme shown in Table 2 was added, and the mixture was stirred at 45 ° C for 4 hours. After the tea residue and the extract were separated by a dehydration type centrifugal separator, 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 for 10 minutes at a gravity acceleration of 3000×g to remove the precipitate, and then the supernatant was adjusted to Bx15°. The mixture was heat-sterilized at 95 ° C for 1 minute, and then cooled to 20 ° C to obtain a green tea extract. The obtained green tea extract is determined by caffeine content (HPLC method), catechin content (HPLC method) and tannin content (Folin-denis method), and diluted to Bx0.3° (refractive saccharide, at 20 The measurement was carried out at ° 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 2. Further, a photograph of the appearance of the Bx 0.3° dilution is shown in Fig. 3 (left is comparative product 4, right is inventive product 8).

When the component values of the present invention 8 and the comparative product 4 were compared, the inventive product 8 was less than caffeine, tannin, and catechins, but to a lesser extent than the comparative product 4.

 <sensory evaluation>  

The Bx 0.3° dilution of each of the present invention 8 and the comparative product 4 was evaluated by five professional reviewers. As a result of the average evaluation, the product 8 of the present invention was slightly weaker than the comparative product 4 in the taste portion, but the flavor of green tea was clearly confirmed. Also, the aroma of green tea can be felt in terms of aroma. The smell of potato, which is characteristic of the enzyme-treated tea, is masked.

 (Example 4)  

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

That is, a commercially available β-glucosidase (1200 U/g) (12 U with respect to 1 g of tea leaves) was added to Comparative Product 4, and the mixture was stirred at 45 ° C for 4 hours, and then heated at 95 ° C for 1 minute. Cool to 30 °C. Then, the mixture was cooled to 20 ° C, filtered through a No. 2 filter paper, centrifuged at 3000 × g for 10 minutes at a gravity acceleration rate, and heat-sterilized 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 is determined by caffeine content (HPLC method), catechin content (HPLC method) and tannin content (Folin-denis method), and diluted to Bx0.3° (refractive saccharide, at 20 The absorbance at 430 nm (indicator of coloration) and the absorbance at 680 nm (indicator of turbidity) were measured at ° C. The result of combining the comparative product 4 and the present invention 8 is shown in Table 3.

When compared with the comparative product 4 (before the glycoside degrading enzyme treatment), the caffeine, tannin, and catechin of the comparative product 5 were all reduced. On the other hand, although the color tone (OD430nm) of the present invention 8 is more colored than the product 8 of the present invention, the color of the comparative product 4 tends to be lighter and the turbidity tends to decrease.

Further, in the preparation step of the comparative product 5, the extract liquid subjected to the enzymatic reaction and heat treatment was allowed to stand at 20 ° C overnight, and the same green flocculating precipitate as in the second embodiment (2) was produced. . The photograph of the appearance of the liquid in the middle of the preparation step of the comparative product 5 is shown in Fig. 4 (from the left, the comparison product 4, after the enzyme was deactivated, after filtration, after centrifugation).

 (Example 5)  

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

The precipitate is insoluble in water but dissolves clarified in methanol and appears dark green. Although the detailed mechanism is not clear, it is presumed that the glycoside-degrading enzyme acts on the green tea extract, and the water-soluble pigment component is precipitated in a water-insoluble precipitate, and is separated by this to be decolorized. .

A photograph of the appearance of the supernatant obtained by centrifuging the supernatant, the washing liquid when the precipitate was washed with water, and the liquid obtained by dissolving the precipitate in methanol are shown in Fig. 5 (the supernatant from the left is centrifuged, The washing liquid in which the precipitate was washed with water and the liquid obtained by dissolving the precipitate in methanol).

 (Example 6)  

The case of using protease together was discussed.

3.6 g of vitamin C was dissolved in 2600 g of pure water and heated to 75 °C. 200 g of Shizuoka's second tea (the same tea leaf as in Example 1 : 薮bei, steamed, and cut into 5 mm) was placed therein, and heated while stirring, and heat-sterilized at 95 ° C for 15 minutes. The mixture was cooled to 45 ° C (pH at this time point was 5.3), and the enzyme shown in Table 4 was added, and the mixture was stirred at 45 ° C for 4 hours. After the tea residue and the extract were separated by a dehydration type centrifugal separator, 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, and centrifuged for 10 minutes at a gravity acceleration of 3000 × g to remove the precipitate, and then the supernatant was adjusted to Bx 15 ° for 95 ° C. After heat sterilization for 1 minute, it was cooled to 20 ° C to obtain a green tea extract. The obtained green tea extract is determined by caffeine (HPLC method), catechins (HPLC method) tannin (Folin-denis method) and amino acid (HPLC method), and diluted to Bx0.3° (refraction) The sugar content (measured at 20 ° C) was measured for absorbance at 430 nm (indicator of coloration) and absorbance at 680 nm (indicator of turbidity). 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, the amino acid of the present invention 9 was more than the comparative product 6, and the contents of caffeine, tannin, and catechins were almost the same. Further, in the color tone of the present invention, the product 9 of the present invention which had been subjected to the action of the glycoside-degrading enzyme was confirmed to be decolored. In addition, when the fragrance was evaluated by adding 0.2% by mass of the flavoring product (Bx0.03°) to the ion-exchanged water, the product of the present invention 9 was slightly weaker than the comparative product 6. However, you can fully feel the flavor of green tea such as delicious and astringent, and have a good green tea flavor.

 (Example 7)  

In the preparation step of the present invention 9, in the preparation step of the present invention 9, the precipitate obtained by centrifuging the mixture at a gravity acceleration of 3000 × g for 10 minutes was repeatedly subjected to centrifugal sedimentation treatment/water washing three times in the same manner as in Example 5, and recovered. A dark green precipitate. The obtained precipitate was photographed using a digital microscope and subjected to fluorescence X-ray analysis and FT/IR analysis.

The precipitate was divided into two layers by repeating three times of centrifugation/water washing, and it was confirmed that the upper layer portion was green and viscous, and the lower layer portion was a pale green minute spherical object (Fig. 6). It is estimated by fluorescence X-ray analysis that any of the upper layer and the lower layer are organic components, and FT/IR analysis suggests that the upper layer is protein-based and the lower layer is one of natural flavonols. For example, it is possible to use a non-flavonol which is represented by the following chemical structural formula.

It is known that the non-flavonol itself is only slightly soluble in water, but exists as a glycoside in tea leaves, so that it is easily eluted even by water extraction. This time, it is assumed that the non-flavonol which is detected as a precipitate is dehydrated by the action of the glycoside degrading enzyme, and the aglycone-incorporated non-flavonol is produced by insolubilization. The crystals of non-flavonols are yellow. It is believed that the green color of green tea is yellowish-yellow yellow. The precipitate detected in this study is green. It is speculated that the non-flavonols are complex with protein and chlorophyll. The ground bond, which is insoluble and precipitated.

 (Example 8) The effect of decolorization of tea extract on the change of the activity of glycoside degrading enzyme per unit mass of tea leaves was investigated.  

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

OD430nm represents an indicator of coloration, and OD680nm represents an indicator of turbidity. OD430nm is 0.05 or less, and it can be said that it is almost non-colored; below 0.3, it can be said that it is slightly colored; at 0.5 or less, it can be said that it is light coloring. Further, when the OD680nm is 0.1 or less, there is almost no turbidity (clarification), and about 0.15 is a slight degree of turbidity.

As shown in Table 5, it was found that the color of the obtained extract became shallow as the amount of the glycoside enzyme used relative to the tea was increased. Further, when 10 U (No. 3) or more was used for 1 g of tea leaves, the coloring and turbidity were extremely small.

 (Example 9)  

To investigate the reaction time of glycoside degrading enzyme on tea and the effect of decolorization on tea extract

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

As shown in Table 6, the extract of 10 U or 20 U glycoside degrading enzyme was used for 1 g of tea leaves, and it was confirmed that either of them was reacted for 1 hour, and the color and turbidity were all lowered. Table 5 suggests that the OD430nm of the tea extract which is not subjected to the enzyme reaction is 0.562, and the OD680nm is 0.146. From the viewpoint of the degree of decolorization and turbidity reduction for 1 hour, even if the enzyme reaction time is 30 minutes, effect.

In addition, the longer the enzyme reaction time is, the lower the value of color and turbidity is. In the case of coloring, the system using 10 U of glucoamylase in 1 g of tea is reacted for 4 hours, and 20 U is used. The system was a reaction of 2 hours, and the OD430nm became 0.3 or less. Further, in terms of turbidity, a system using 10 U was a reaction for 3 hours, and a system using 20 U was a reaction at 2 hours, and the OD 680 nm was 0.1 or less. For any system, the color (OD430nm) and turbidity (OD680nm) are further reduced with more reaction time extension.

 (Example 10) β-Glucosidase and PVPP treatment  

Vitamin C (0.9 g) was dissolved in 660 g of pure water and warmed to 75 °C. 50 g of Shizuoka's second tea (the glutinous rice seed, steamed green method, and cut into 5 mm) was placed therein, and the mixture was heated while stirring, and heat-sterilized at 95 ° C for 15 minutes. The mixture was cooled to 45 ° C (pH at this time point was 4.9), and the enzyme shown in Table 7 (inventive product 10) was added thereto, and the mixture was stirred at 45 ° C for 8 hours. The tea residue and the extract were separated by a dehydration centrifugal separator, and 100 g of soft water was further introduced into the centrifuge to extrude the extract adhered to the tea residue to obtain an extract, and the extract was subjected to 95 ° C for 30 seconds. The mixture was sterilized by heating and deactivated, and cooled to 30 °C. Then, the extract was centrifuged (1200 × g, 8 minutes) to remove the precipitate, and then the extract was added with a soluble solid component (calculated using Bx at 20 ° C) of 40% by mass of PVPP, and at 30 ° C. Stir for 1 hour. Subsequently, the No. 2 filter paper (retained particle size 5 μm) was filtered, cooled to 20 ° C, adjusted to Bx (20 ° C) 3.0 with soft water, and heat-sterilized at 95 ° C for 30 seconds, and cooled to 30 ° C to carry out 200 mesh. Saran was filled and filled into a PET bottle to obtain a green tea extract (Invention 10).

 (Example 11)  

In Example 10, the same operation as in Example 10 was carried out except that the amount of PVPP added was changed to 80% by mass of the soluble solid component (calculated using Bx at 20 ° C) to obtain a green tea extract. (Inventive product 11).

 (Example 12) β-glucosidase treatment  

In Example 10, the same operation as in Example 10 was carried out except that PVPP was not added, and a green tea extract (Invention 12) was obtained.

 (Comparative Example 7) No β-glucosidase, and PVPP treatment  

In the same manner as in Example 10 except that β-glucosidase was not used as the enzyme (the enzyme of the present invention 12 of Table 7 was used), green tea extract (Comparative Product 7) was obtained. .

 (Comparative Example 8) None of β-glucosidase treatment and PVPP treatment  

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

 (Example 13)  

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

 (Results, inspection)  

‧ By the treatment with β-glucosidase, the degree of coloration of the tea beverage is lowered (Comparative product 8 and inventive product 12, and Comparative product 7 with inventive product 10).

‧The degree of coloration of tea beverages is reduced by PVPP treatment, especially in the case of heat sterilization. Further, the bitterness and astringency were weakened by the PVPP treatment (Comparative product 8 and Comparative product 7, and the product of the present invention 12 and the present invention 10).

‧In the case of the β-glucosidase treatment, the inventive products 10 and 11 which were subjected to PVPP treatment (removal of tannin) were diluted to the same solid concentration (Bx0.3°), and it was confirmed that maintenance was possible. The flavor of the tea, while the lightest color, more decolorized extract.

‧ By PVPP treatment (removal of tannin) in addition to β-glucosidase treatment, when the soluble solid content (refractive saccharide, temperature 20 ° C) of the tea extract is set to 0.3, the absorbance at 430 nm is 0.05. In the following, the absorbance at 680 nm is 0.05 or less. Further, when the soluble solid content (refractive saccharide, temperature: 20 ° C) is 15 (5-fold concentration of the above-mentioned invention), the amino acid can be 1.0% by mass or more. Further, the catechins are less than 1.0% by mass of the green tea extract (inventive products 10 and 11).

 (Example 14) Toning of a container-packed beverage using the present invention and a comparative product  

Diluted separately so that the inventive products 10, 11, 12, the comparative product 7 and the comparative product 8 became Bx0.005° (the respective inventive products or comparative products were 0.167% in each water), and the sodium ascorbate was adjusted to be 0.03%. The unadded solution was subjected to UHT sterilization at 135 ° C for 30 seconds, cooled to 90 ° C, filled into a PET bottle, and cooled to 30 ° C or lower to prepare a green tea beverage in a container.

Table 8 shows the hue of each beverage (OD430nm, OD680nm, and ⊿E with pure water).

 (Results, inspection)  

‧ In the case where the extract is diluted to Bx0.005° and 0.03% of sodium ascorbate is added, any of the present inventions 10, 11, 12, the comparative product 7 and the comparative product 8 can be modulated to be colorless transparent or close to Colorless and transparent drink.

‧ In the case where the extract was diluted to Bx0.005° and no sodium ascorbate was added, either of them was turbid and almost transparent, and 10 and 11 were substantially completely colorless, and coloring was observed.

 (Example 15) The correlation between the added concentration of the extract and the hue  

The product 10 of the present invention was diluted to the concentration shown in Table 9 (sodium ascorbate was not added), and after UHT sterilization was performed at 135 ° C for 30 seconds, it was cooled to 90 ° C and filled in a PET bottle, and then cooled to 30 ° C or lower. A green tea drink was prepared in a container.

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

 (Results, inspection)  

In the case of a container-packed beverage prepared by the addition of sodium ascorbate, the concentration of the present invention 10 is substantially completely colorless when the concentration is Bx0.005°, and the degree of Bx0.015 is slightly colored, and Bx0.025 is Coloring.

However, in order to fully ensure the flavor of green tea, it is considered to be around 0.025.

When the beverage was prepared in the container from the above-mentioned Example 13, since the addition of sodium ascorbate was confirmed to have an effect of preventing coloration, the following experiment was conducted.

 (Example 16) The concentration of sodium ascorbate, the relationship between storage conditions and hue  

Dilution was carried out so that the product 10 of the present invention became Bx0.025°. At this time, sodium ascorbate of the concentration of Table 10 was added, and UHT sterilization was performed at 135 ° C for 30 seconds, then cooled to 90 ° C and filled into a PET bottle, and then cooled to 30 ° C. In the following, a green tea beverage in a container was prepared.

Each containered beverage was stored at 10 ° C and 50 ° C for 10 days.

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

 (Results, inspection)  

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

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

‧ From the OD430nm and ⊿E stored immediately after sterilization and at 10 ° C for 10 days, the sodium ascorbate is substantially completely colorless and transparent as long as it is 0.01% or more.

‧ When the container is filled at 50 ° C for 10 days (abuse condition), the concentration of sodium ascorbate added is 0.03%, which is "almost colored", and 0.01% is "very slightly colored".

‧ In view of the above, the concentration of sodium ascorbate added is preferably 0.01% or more.

Claims (18)

 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), a glycoside degrading enzyme a step of acting on the mixture of (A); (C) after step (B), separating the tea residue and the extract, and obtaining a glycoside-treated tea extract; (D) will be in step (C) a step of heat treatment of the obtained glycoside-treated tea extract; (E) removing insoluble components from the heated glycoside-treated tea extract obtained in the step (D), and obtaining The step of decolorizing the tea extract.    The method for producing a decolorized tea extract according to claim 1, further comprising the step of allowing tanninase and/or pectinase to act simultaneously with or before or after step (B) and before step (C) .    A method for producing a decolorized tea extract according to claim 1 or 2, which further comprises the step of causing a protease to act simultaneously with step (B) and/or after step (B) and before step (C).    The method for producing a decolorized tea extract according to any one of claims 1 to 3, wherein the heat treatment conditions in the step (D) are in the range of 70 to 135 ° C for a period of 2 to 30 minutes.    The method for producing a decolorized tea extract according to any one of claims 1 to 4, wherein the tea leaves are green tea.    The method for producing a decolorized tea extract according to any one of claims 1 to 5, which comprises subjecting the tea leaves to steam distillation and obtaining aroma recovery before the step (A), and mixing the obtained aroma recovery products. The step of the clear liquid obtained in the step (E).    The method for producing a decolorized tea extract according to any one of claims 1 to 6, wherein the glycoside degrading enzyme is used in an amount of 1 U/g or more with respect to tea leaves, and the temperature of the enzyme reaction is in the range of 30 to 70 °C. Inside, and the reaction time is 30 minutes or more.    A method for producing a decolorized tea extract according to claim 1, wherein when the soluble solid content (refractive saccharide, temperature: 20 ° C) of the tea extract is set to 0.3, the absorbance at 430 nm is 0.5 or less. The absorbance at 680 nm is 0.15 or less.    A method for producing a decolorized tea extract according to claim 8, wherein when the soluble solid content (refractive saccharide, temperature: 20 ° C) of the tea extract is set to 0.3, the absorbance at 430 nm is 0.15 or less. The absorbance at 680 nm is 0.05 or less.    A green tea leaf extract, wherein when the soluble solid content (refractive saccharide, 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 the soluble solid component is further When the refractive index (temperature of 20 ° C) was 15, the content of catechin was 1.0% by mass or more.    A green tea leaf extract, wherein when the soluble solid content (refractive saccharide, 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 the soluble solid component is further When the refractive index (temperature of 20 ° C) is 15, the amino acid content is 1.0% by mass or more.    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), a glycoside degrading enzyme a step of acting on the mixture of (A); (C) after step (B), separating the tea residue and the extract, and obtaining a glycoside-treated tea extract; (D) will be in step (C) a step of heat treatment of the obtained glycoside-treated tea extract; (E) removing insoluble components from the heated glycoside-treated tea extract obtained in the step (D), and obtaining The step of decolorizing the tea extract; (F) after the step (E), the obtained decolorized tea extract is further contacted with PVPP (polyvinylpolypyrrolidone), and the PVPP after contact removal is obtained. The step of the extract.    A method for producing a low tannin tea extract according to claim 12, wherein when the soluble solid content (refractive saccharide, temperature: 20 ° C) of the tea extract is set to 0.3, the absorbance at 430 nm is 0.05 or less. The absorbance at 680 nm is 0.05 or less, and when the soluble solid content (refractive saccharide, temperature 20 ° C) is further set to 15, the amino acid content is 1.0% by mass or more and tannin (Folin-Denis method). It is 1.0% by mass or less.    A green tea leaf extract, wherein when the soluble solid content (refractive saccharide, 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, when the soluble solid component is further added ( When the refractive sugar content and the temperature (20 ° C) were 15 , the amino acid content was 1.0% by mass or more and the tannin (Folin-Denis method) was 1.0% by mass or less.    A method for producing a container-packed tea beverage, comprising the steps of: (G) adding water to a tea extract obtained by the method according to any one of claims 1 to 9, 12 and 13 The step of adjusting the soluble solid content 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).    A container-packed tea beverage containing 0.005 to 0.3% (Bx, 20 ° C) by mass of the green tea extracts of claims 10, 11 and 14 as a soluble solid component derived from tea, and further containing vitamin C or its edible properties Salt (sodium).    The container-packed tea beverage according to claim 16, which contains 0.002 to 0.3% by mass of vitamin C or an edible salt thereof (sodium).    The container-packed tea beverage according to claim 16 or 17, wherein when the soluble solid content (refractive saccharide, 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.