JP6294676B2 - Method for producing tea extract - Google Patents

Description

  The present invention relates to a tea extract that imparts an excellent flavor to foods and beverages such as containerized tea beverages and a method for producing the same.

  Tea drinks, typified by green tea, provide moisture for daily life and are essential for the lives of Japanese people. In recent years, the antioxidant properties of tea have attracted attention, and as a non-calorie healthy drink, tea drinks have become representative of sugar-free drinks. More recently, various tea beverages have been put on the market due to diversification of palatability.

Tea beverages generally extract tea leaves with an aqueous solvent such as water to obtain a tea extract, and after adjusting the concentration by diluting this tea extract with water or the like to a concentration suitable for beverages, It is sold in sealed containers such as aluminum and iron cans, plastics such as polyethylene terephthalate (PET), and glass bottles.
However, tea extracts obtained by extraction with an aqueous solvent are often avoided by consumers because the bitter and astringent taste derived from caffeine and catechins contained in tea leaves remains strong. For this reason, various techniques have been proposed for the purpose of reducing the bitter and astringent taste of the tea extract.

  For example, by causing an enzyme aqueous solution prepared by dissolving tannase in water together with cell wall digestive enzymes to act on tea leaves, hydrolyze epicatechin gallate and epigallocatechin gallate having strong bitter taste among catechins, Mitigation method (Patent Document 1), and / or after extraction of tea using caffeine-containing teas such as green tea, black tea, oolong tea, mate tea, etc. after mixing or adding an appropriate amount of activated carbon to caffeine A method for obtaining a tea extract with reduced content (Patent Document 2), a green tea extract obtained from a raw material having a high gallate body rate is treated with a tannase by a conventional method, pH is adjusted, and a high concentration non-polymer A method for obtaining a green tea extract having excellent flavor and appearance even in a catechin-containing beverage (Patent Document 3), concentrating and extracting a tea extract from tea leaves, and a tea extract obtained by this concentrated extraction By treating with tannase or chlorogenic acid esterase, a method for producing a tea beverage with reduced astringency without impairing umami or richness (Patent Document 4), alkali-treated black tea extract or alkali-treated and neutralized By subjecting the obtained black tea extract to activated carbon treatment, an unpleasant astringency remaining in the mouth after ingestion and a sharp bitter taste are alleviated (Patent Document 5), an organic solvent aqueous solution of the green tea extract, Contacting 0.1 to 1 times mass of activated carbon with the catechins in the solid content of the extract for longer than the usual treatment time (12 hours to 5 days) causes deterioration of the green tea flavor. A method for producing a purified green tea extract with reduced flavonols in the green tea extract (Patent Document 6) has been proposed so far.

JP-A-5-308901 JP-A-8-70772 JP 2004-321105 A JP 2005-130809 A JP 2009-159833 A JP2012-55205A

However, the method of treating tea leaves with an enzyme such as tannase does not sufficiently reduce bitterness and astringent taste. However, if an adsorbent such as activated carbon is used, bitterness and taste can be reduced to some extent, but the rich flavor inherent in tea also decreases. .
Accordingly, an object of the present invention is to provide a method for producing a tea extract having a reduced bitter and astringent taste due to catechins and the like and having an excellent flavor.

  When the present inventors treated the extract obtained by extracting tea leaves with a tannase aqueous solution with activated carbon, the bitter and astringent taste was sufficiently reduced, but the flavor of tea was also reduced. Therefore, when coexisting activated carbon when extracting tea leaves with a tannase aqueous solution, it was surprisingly found that a decrease in flavor is suppressed, a bitter and astringent taste, and a tea-rich tea flavor is obtained. Was completed.

That is, the present invention
(1) A method for producing a tea extract, comprising subjecting tea leaves to extraction with an aqueous solution of an enzyme having tannin decomposing activity in the presence of an adsorbent,
(2) The production method according to (1), wherein the adsorbent is activated carbon or a synthetic adsorbent,
(3) The production method according to (1) or (2), wherein the enzyme having tannin degrading activity is tannase.
(4) The production method according to any one of (1) to (3), wherein the tea leaf is at least one tea leaf selected from unfermented tea, semi-fermented tea, and fermented tea,
(5) A tea extract produced by any one of the methods (1) to (4),
(6) A food or drink comprising the tea extract produced by the method according to any one of (1) to (4),
It is.

  According to the present invention, it is possible to obtain a tea extract with little bitterness and astringency caused by catechins and the like, and rich in the original flavor of tea. Therefore, it is possible to widely apply to various foods and drinks as a new food material while the diversification of preferences in foods and drinks.

(1) Raw Tea Leaves Tea leaves, which are the raw material of the tea extract of the present invention, are prepared by subjecting tea (Camellia sinensis) buds, leaves, and stems to be used for beverages. Tea pretreatment methods include non-fermentation, semi-fermentation, and fermentation, and any treatment method may be used. Non-fermented tea is green tea (sencha, gyokuro, kabusecha, bancha, tamago green tea, matcha tea, hojicha, kettle roasted tea, tencha, etc.), semi-fermented tea is oolong tea, bald tea, etc., fermented tea is black tea, Pu-erh tea can be mentioned.
There are no restrictions on the type, grade, production area, and production method of tea leaves, and any tea leaves are possible. Alternatively, different types of tea leaves may be used alone or in combination of two or more.

(2) Enzyme In the present invention, an enzyme having an activity of hydrolyzing tannin can be used without particular limitation, but tannase (EC number 3.1.1.20) is preferably used. Tannase is an enzyme that selectively hydrolyzes the gallic acid ester bond of tannin and can be obtained from microorganisms belonging to the genus Aspergillus, Penicillium, and the like.
In the present invention, commercially available enzyme preparations may be used. Specifically, “Tannase” (manufactured by Mitsubishi Chemical Foods), “Sumiteam TAN” (manufactured by Shin Nippon Chemical Industry), “Tannase” (Kikkoman Biochemifa Co., Ltd.).
In addition, among the plant cell wall degrading enzymes (cellulase, hemicellulase, pectinase, etc.) and proteolytic enzymes (proteases, etc.), enzymes having tannase activity by contaminating enzymes can also be used.

(3) Adsorbent The adsorbent used in the present invention is activated carbon or a synthetic adsorbent, and any of them can be used without any particular limitation.
Activated carbon is obtained by carbonizing wood, charcoal, coconut shells, and coals as raw materials and activating with water vapor, etc., and is a porous carbonaceous material with a large specific surface area and adsorption capacity. There is a thing of the body. After sufficiently charcoalizing raw charcoal, palm, coal char, etc., it is activated and produced by high temperature treatment with steam or impregnation with an aqueous solution such as zinc chloride and high temperature firing.

Generally, the specific surface area 800~3000m ² / g, preferably from 1000 to 2000 ² / g, pore volume 0.2~2cm ³ / g, preferably from 1 to 2 cm ³ / g, pore size 1 to 5 nm, Preferably it is 2.5-4.5 nm. Furthermore, granular activated carbon having an average particle diameter of about 0.1 to 1.0 mm is preferable to powdered activated carbon from the viewpoint of separability after adsorption.
The composition of activated carbon is mainly composed of carbon, but also contains a small amount of hydrogen, oxygen, and inorganic components. The chemical structure is based on graphite, but it is amorphous and has functional groups such as hydroxyl and quinone groups on the surface. ing.
Examples of the activated carbon include “Kuraray Coal” (manufactured by Kuraray Chemical Co., Ltd.), “Shirakaba” (manufactured by Nippon Environ Chemicals Co., Ltd.), “Dazai” (manufactured by Phutamura Chemical Co., Ltd.), and the like.

  As the synthetic adsorbent, the matrix is a styrene polymer such as “Amberlite (registered trademark) XAD-16” (manufactured by Organo Corporation), or a styrene-divinylbenzene polymer such as “Diaion (registered trademark) HP-20”. (Mitsubishi Chemical Corporation), acrylic polymers such as “Diaion (registered trademark) WK-10” (Mitsubishi Chemical Corporation), methacrylic polymers such as “Diaion (registered trademark) HP-2MG” ( Mitsubishi Chemical Co., Ltd.), acrylic ester polymers such as “Amberlite (registered trademark) XAD-7” (manufactured by Organo Corporation), amide polymers such as “Amberlite (registered trademark) XAD-11” (organo) Co., Ltd.), silicon dioxide type, such as “Silo Pute® 202” (manufactured by Fuji Silysia Chemical Ltd.), Adex (registered trademark) G-25 "(manufactured by Amersham Pharmacia Biotech), polyvinyl-based, for example," Diaion (registered trademark) FP-II "(manufactured by Mitsubishi Chemical Corporation), polyvinylamide-based polyvinyl polypyrrolidone (PVPP) Examples thereof include “Polyclar (registered trademark)” (manufactured by IPS Japan), “Daibagan (registered trademark)” (manufactured by BASF), and the like.

In the present invention, the use of activated carbon or polyvinylpolypyrrolidone is preferred, and the use of activated carbon is particularly preferred. Further, among the adsorbents made of polyvinyl polypyrrolidone, those having an average particle diameter of 10 to 60 μm, a specific surface area of 0.5 to 3.5 m ² / g, and a bulk density of 0.1 to 0.5 g / cm ³ are preferable.

(4) Extraction treatment In the present invention, the tea leaves as raw materials are extracted with an aqueous solution of an enzyme in the presence of an adsorbent, thereby obtaining a tea extract that has little bitter and astringent taste due to catechins and the like and is rich in the original flavor of tea. be able to. That is, the present invention is characterized in that the extraction operation is performed in a mode in which the adsorbent and the enzyme coexist.
The extraction method using an aqueous enzyme solution is not particularly limited. Usually, tea leaves and an adsorbent are put into an aqueous solution of an enzyme prepared in advance, and extraction is performed simultaneously with the enzyme treatment under a fixed time or stirring condition.
The amount of the enzyme used varies depending on the titer and the like, but is usually 0.0001 to 0.1 part by weight of enzyme and 5 to 100 parts by weight of water, preferably 0.0002 to 0.02 part of enzyme for 1 part by weight of dried tea leaves. It is a mass part and 10-50 mass parts of water.

Although the amount of adsorbent used varies depending on the type, as described later, the Brix ratio of the extract is preferably in the range of 60 to 90%. From this viewpoint, the amount of adsorbent used is usually adsorbed on 1 part by weight of tea leaves. The agent is 0.01 to 1 part by mass, preferably 0.05 to 0.2 part by mass, more preferably 0.05 to 0.15 part by mass, and still more preferably 0.07 to 0.15 part by mass.
The extraction is usually carried out in the temperature range of 30 to 55 ° C, preferably 35 to 50 ° C, and usually 10 minutes to 3 hours, preferably 30 minutes to 2 hours.
The pH at the time of extraction is not particularly limited, and can be appropriately adjusted to an appropriate pH according to the type of enzyme and adsorbent used.
In addition, cell wall degrading enzymes such as cellulase, hemicellulase and pectinase, and proteolytic enzymes such as protease may be added for the purpose of degrading the cell wall of tea leaves and facilitating the leaching of cell contents during extraction. Ascorbic acid or a salt thereof may be added as an antioxidant.

  After extraction, tea leaves, adsorbents and other insoluble matters are removed by solid-liquid separation to deactivate the enzyme. Inactivation of the enzyme is performed, for example, by heating the extract at 80 to 95 ° C. for 1 to 20 minutes. After deactivation of the enzyme, a clear tea extract is obtained by treatment such as centrifugation and filtration.

From the viewpoint of excellent flavor, the tea extract of the present invention has a ratio of Brix of the produced tea extract to Brix of the extract prepared without performing the adsorbent treatment (hereinafter referred to as “Brix ratio”). It is preferable to adjust the amount of the adsorbent used at the time of extraction so that it becomes 60 to 90%, and 70 to 90% is more preferable from the viewpoint of fragrance strength. When the Brix ratio exceeds 90%, the bitter and astringent taste is strong, and when the Brix ratio is 60% or less, the fragrance becomes weak.
Here, Brix means the weight (g) of soluble solids per 100 g of solution.

(5) Formulation of tea extract The tea extract of the present invention may be further concentrated to give a paste-like extract, or may be used as a powder after being subjected to treatment such as spray drying, freeze drying or heat drying. .
In general, various components (sugar, acidulant, antioxidant, fragrance, etc.) are combined and dissolved in water, alcohol, glycerin, propylene glycol, etc., or a mixed solvent thereof at a suitable concentration, To do. Specifically, a mixed solvent such as water / ethanol, water / ethanol / glycerin, water / glycerin and the like is preferable.
Moreover, it is also possible to add an excipient | filler (for example, dextrin etc.) to each solution, and it can also be made into a powder form by spray drying, and various dosage forms can be employ | adopted according to a use.

(6) Application of tea extract The obtained tea extract can be drunk as it is as a tea beverage. Or it can add and use for other food-drinks.
For example, when added to tea beverages such as green tea, oolong tea and black tea, the original flavor of tea can be imparted to the beverage without increasing the bitter taste. When added to tea beverages, an addition amount (as an extract) of generally 0.05 to 2% by mass, preferably 0.1 to 1% by mass with respect to the beverage is appropriate.

Furthermore, since the tea extract of the present invention has an excellent flavor with little bitterness and astringency, foods and drinks having a tea flavor other than tea beverages, for example, snacks imparted with a tea flavor, nutritional food, ice cream Add to frozen confectionery such as sherbet, buns, sheep kan, wairo, cookies, cakes, chocolate, chewing gum, jelly, pudding, mousse, confectionery bread, bread such as bread, ramune confectionery, tablets, tablet confectionery, etc. be able to.
Specific examples include candies with tea extract, matcha ice cream, matcha mousse, milk drinks with matcha, green tea jelly, matcha chocolate, and the like.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to description of an Example.

[Examples 1 to 6]
A predetermined amount of water and 0.02 parts by mass of tannase enzyme “Sumiteam TAN” (manufactured by Shin Nippon Chemical Industry Co., Ltd.) were charged into an extractor and dissolved, and then 100 parts by mass of tea leaves and a predetermined amount of adsorbent were added. Extract at 1.5 ° C. for 1.5 hours.
Thereafter, solid-liquid separation was performed, and the obtained extract was heated at 85 ° C. for 5 minutes to deactivate the enzyme and cooled to 10 ° C.
Centrifugation was performed at 10 ° C., and the supernatant was collected to obtain a tea extract. The Brix of the extract was measured with a digital refractometer “RX-7000α” manufactured by Atago Co., Ltd.
In the present examples and comparative examples, commercially available green tea, black tea or oolong tea was used as the tea leaves. Moreover, activated carbon or polyvinyl polypyrrolidone (PVPP) was used as the adsorbent.

[Comparative Examples 1, 3, 9]
A predetermined amount of water and 0.02 parts by weight of “Sumiteam TAN” (manufactured by Shin Nippon Chemical Industry Co., Ltd.) were charged into an extractor and dissolved, and then 100 parts by weight of tea leaves were added and extracted at 40 ° C. for 1.5 hours. .
Thereafter, solid-liquid separation was performed, and the obtained extract was heated at 85 ° C. for 5 minutes to deactivate the enzyme and cooled to 10 ° C.
Centrifugation was performed at 10 ° C., and the supernatant was recovered. The Brix of the extract was measured by the same method as in Examples 1-6.

[Comparative Examples 2, 5-8, 10]
A predetermined amount of water and 0.02 parts by weight of “Sumiteam TAN” (manufactured by Shin Nippon Chemical Industry Co., Ltd.) were charged into an extractor and dissolved, and then 100 parts by weight of tea leaves were added and extracted at 40 ° C. for 1.5 hours. .
Thereafter, solid-liquid separation was performed, and the obtained extract was heated at 85 ° C. for 5 minutes to deactivate the enzyme and cooled to 40 ° C. A predetermined amount of adsorbent was added thereto, and adsorbent treatment was performed at 40 ° C. for 1.5 hours.
Thereafter, the mixture was cooled to 10 ° C. and centrifuged, and the supernatant was collected to obtain an extract. The Brix of the extract was measured by the same method as in Examples 1-6.

[Comparative Example 4]
After adding a predetermined amount of water and a predetermined amount of adsorbent to the extractor, 100 parts by mass of tea leaves were added and extracted at 40 ° C. for 1.5 hours.
Thereafter, solid-liquid separation was performed, and the obtained extract was cooled to 10 ° C.
Centrifugation was performed at 10 ° C., and the supernatant was recovered. The Brix of the extract was measured by the same method as in Examples 1-6.

[Test example]
The strength of the aroma and bitterness of the tea extracts obtained in Examples 1 to 6 and Comparative Examples 1 to 10 were evaluated by three specialist panels.
The standard of evaluation was as follows: Comparative Examples 1 and 3 without adsorbent were 4 points (strong), and 4 levels were 3 points (slightly strong), 2 points (slightly weak), and 1 point (weak). Table 1 shows the average evaluation score of each panel. In addition, the amount of adsorbent was displayed by the mass part of the adsorbent used with respect to 100 mass parts of tea leaves.

  Compared to Comparative Examples 1, 3, and 9 in which only the enzyme was used and no adsorbent was used, in Comparative Examples 2, 5 to 8, and 10 in which the adsorbent was used after the enzyme treatment, the bitter and astringent taste was reduced but the aroma was also present. Diminished. The same result was obtained in Comparative Example 4 in which only the adsorbent was used without using the enzyme. On the other hand, in Examples 1 to 6 in which the enzyme reaction was performed in the presence of the adsorbent, a decrease in fragrance was suppressed, and a tea extract with little bitter and astringent taste and rich flavor was obtained. Moreover, in Examples 1-6, when activated carbon was used as an adsorbent, the effect was high, and when the Brix ratio was 70-90%, a strong fragrant extract was obtained.

The effect of the present invention is that a tea extract with little bitter and astringent taste and rich flavor can be obtained.
That is, in Table 1, it is important that the average evaluation point of “scent intensity” is high and the average evaluation point of “bitter taste strength” is low.
For example, if Comparative Example 7 and Example 4 in which the intensity of bitterness and astringency is suppressed to 1.0 are compared, the fragrance intensity of Comparative Example 7 is 1.0, whereas Example 4 is 1.7. Even if the bitter and astringent taste is strongly suppressed, the effect is excellent in that the strength of the fragrance is maintained to a certain degree.

  According to the present invention, it is possible to obtain a tea extract rich in the original flavor of tea with less bitterness and astringency caused by caffeine, catechins and the like. The tea extract can be used in tea beverages as a material imparting tea flavor. Moreover, it can be used widely for food and drink other than tea drinks.

Claims (6)

A method for producing a tea extract, characterized in that tea leaves are extracted with an aqueous solution of an enzyme having tannin degrading activity in the presence of an adsorbent ,
Said manufacturing method whose adsorbent is activated carbon or polyvinyl polypyrrolidone, and the usage-amount of adsorbent is 0.05-0.15 mass part with respect to 1 mass part of tea leaves. The method according to claim 1 , wherein the enzyme having tannin degrading activity is tannase. The method according to claim 1 or 2 , wherein the tea leaf is at least one tea leaf selected from unfermented tea, semi-fermented tea, and fermented tea. The production method according to any one of claims 1 to 3, wherein the tea leaves are black tea. A tea extract produced by subjecting tea leaves to extraction with an aqueous solution of an enzyme having tannin decomposing activity in the presence of 0.05 to 0.15 parts by mass of activated carbon or polyvinylpolypyrrolidone with respect to 1 part by mass of tea leaves. A food or drink comprising the extract according to claim 5 .