JP4630295B2 - Production method of tea extract - Google Patents

Description

  The present invention relates to an efficient method for producing a tea extraction processed product with reduced bitter astringency and astringent taste peculiar to catechins.

Tea has long been popular as a favorite beverage, but recently, canned beverages filled in cans or plastic bottles, etc., that can be easily consumed have been provided for more than a decade ago, and consumers can become sweet. As a result, the production volume has been increasing steadily. On the other hand, tea has recently attracted attention in terms of its functionality and has been actively studied, and physiological effects such as suppression of human body fat accumulation by catechins (Non-patent Document 1) have been reported. However, when a large amount of catechins were added as a container-packed beverage, the bitter astringency and astringent taste became strong, and the disadvantage of being very difficult to take in flavor was observed.
The main components of non-polymer catechins in tea are free catechin (epicatechin, epigallocatechin, catechin, gallocatechin) and ester catechin (epicatechin gallate, epigallocatechin gallate, catechin gallate, gallocatechin gallate) Among them, it is reported that free catechins have high astringency and astringency taste thresholds, and ester catechins have low astringency and astringency taste thresholds (Patent Document 1).

  On the other hand, it is known that tannase can be used for clarifying tea beverages, but it is an enzyme that acts on an ester bond between catechin and gallic acid to hydrolyze it into catechin and gallic acid. Cream-down (precipitation) in tea beverages is known to occur when gallate-type catechin (synonymous with ester-type catechin) and caffeine form a complex. A method has been reported in which gallate-type catechins are decomposed into non-gallate-type catechins (synonymous with free-type catechins) to make complex formation with caffeine difficult (Non-patent Document 2).

  In addition, by applying the tannase treatment to the tea-making process of green tea and treating epicatechin gallate and epigallocatechin gallate with strong bitter taste contained in tea leaves with tannase, epicatechin having refreshing bitterness with gallic acid And a method for decomposing it into epigallocatechin is disclosed (Patent Document 2).

  On the other hand, as described above, attention is paid to the functionality of catechins in container-packed beverages, and it is required to add a large amount of catechins. However, a tea beverage containing a high concentration of catechins should be treated with tannase. Discloses a method for reducing the bitter and astringent taste of catechins (Patent Document 3).

JP-A-6-343389 JP-A-5-308901 JP 2005-130809 A Journal of Oleo Science Vol. 50 (2001), no. 9 p717-728 "Food and Development" 32 (12), 1997, p14-16

However, when the conventional tea extract is extracted with water or tannase after water extraction, catechins in tea leaves are not sufficiently extracted and remain in the tea leaves, so an efficient extraction method is required. It was.
Therefore, an object of the present invention is to provide an efficient method for producing a tea extract having a high content of catechins and a low bitterness.

  The inventors of the present invention diligently studied to improve the flavor of the green tea extract. The tannase treatment was carried out in a water suspension state containing tea leaves to decompose the gallate-type catechin ester having a strong bitter taste. By reducing the taste and then performing extraction by adding ethanol to the system after the reaction, it was found that catechins migrate efficiently in the extract without remaining catechins in the tea leaf residue. Completed.

Thus, when extracting the tea raw material, the present invention performs the enzyme reaction by adding water and tannase to the tea leaves as the first step, and then obtains the tea step as the second step. A method for producing a tea extract comprising adding a 95% ethanol aqueous solution of 0.2 to 3 times the amount of water used in the first step to the treated product to obtain an extract Is to provide.

Further, the present invention is the use of water in the first stage of the process is characterized in that 5 to 30 times the tea leaves by weight, provides a method of manufacturing the tea extract.

  Furthermore, in the present invention, the reaction temperature of the tannase treatment in the first step is 30 to 50 ° C., and the extraction temperature in the second tea extraction product is 30 to 90 ° C. A method for producing the tea extract is provided.

The present invention also provides a tea extract concentrate obtained by concentrating a tea extract obtained by any one of the methods described above.
The present invention also includes foods and drinks containing the tea extract concentrate.

  According to the present invention, the tea leaves themselves are treated with tannase to reduce the content of gallate-type catechins in the catechin, thereby reducing bitterness and astringency, and further adding ethanol to the system after the reaction to extract bitterness. Since catechins with reduced taste can be extracted efficiently, it is advantageous from the viewpoint of production efficiency and manufacturing cost as compared with conventional water extraction methods.

  The tea raw materials that can be used in the present invention are made from tea leaves obtained from tea (scientific name: Camellia sinensis (L) O. Kuntze), which is an evergreen tree of the camellia family, for example, sencha, bancha, hojicha, gyokuro, Steamed non-fermented tea such as kabuse tea and tempura tea; Ureshino tea, Aoyagi tea, Chinese green tea and other non-fermented tea made from kettle; Baked tea, Frozen oolong tea, Touhou beauties such as Taiwan oolong tea and iron kannon, Semi-fermented tea of Chinese oolong tea such as golden katsura, wushuiwa tea, suisuisen, color types; fermented tea such as darjeeling, uva, java tea, keimon tea; Tea can be mentioned.

  In the present invention, the tea material described above is first subjected to an enzymatic reaction by adding water and tannase as the first step.

  The amount of water used can be any amount as long as it is necessary to perform the tannase treatment of the tea material, but the amount of the tea material can be sufficiently contacted with water, It is preferable that it is the quantity which can be stirred. Specifically, although it depends on the cut size of the tea material, the amount is 5 to 30 times, preferably 5 to 20 times that of the tea material. When the amount of water is too small, the contact between the tea leaves and water is not sufficient, and tannase does not work sufficiently, which is not preferable. Moreover, when there is too much quantity of water, although stirring is easy and tannase acts easily, the quantity of ethanol used for the process of the 2nd step will increase. Furthermore, a large amount of water and ethanol must be concentrated and removed in the concentration, which is not preferable because thermal degradation of the product, an increase in manufacturing time, an increase in manufacturing energy, and the like occur.

  As the tannase used in the present invention, any tannase can be used as long as it has an activity of decomposing gallate ester bonds of ester-type catechins. Specifically, a tannase-producing bacterium belonging to the genus Aspergillus, Penicillium, Rhizopus, Mucor, etc., using a medium used for culturing these filamentous fungi, is subjected to solid culture or liquid culture according to a conventional method, and a culture obtained Or the thing which refined the processed material by the conventional method can be mentioned. Of these, those derived from Aspergillus oryzae are particularly preferred. Commercially available tannase such as tannase (manufactured by Kikkoman), tannase (manufactured by Sankyo Co., Ltd.), tannase (manufactured by Shin Nippon Chemical Co., Ltd.) and the like may be used.

  The amount of tannase used for tea leaves cannot be generally stated depending on the type of tea leaves, the content of catechins in tea leaves, the titer of tannase, etc., but the range of 0.1 to 50 U / g is exemplified based on the weight of tea ingredients can do. 1 Unit is defined as the amount of enzyme that hydrolyzes the ester bond contained in tannic acid 1 micromole per minute in water at 30 ° C. As tannase treatment conditions, the pH of the system is suitably 4.0 to 6.0, preferably 4.5 to 5.5 under stirring or standing conditions. Is suitably performed at 30 to 50 ° C, preferably 35 to 40 ° C. The reaction time of tannase can be selected from any time as long as it degrades the bitter taste by decomposing the ester of gallate catechin having a strong bitter taste, and is 30 minutes to 24 hours, preferably 1 hour to 16 hours can be illustrated.

  Further, in the tannase treatment, cell wall degrading enzymes such as pectinase, cellulase, protopectinase, hemicellulase, β-glucosidase, protease, etc. can be allowed to act simultaneously.

  Subsequently, as a second step, extraction is performed by adding an aqueous ethanol solution to the treated product obtained in the first step. In this step, the use of ethanol significantly improves the catechin yield from tea leaves as compared with the case of extraction with water alone.

The concentration of the aqueous ethanol solution used can be exemplified by an ethanol aqueous solution of 50 wt% to 99.5 wt%, for example, 95 degrees (92 wt%) of fermented alcohol. The amount of the aqueous ethanol solution to be used can be 5 to 30 times, preferably 5 to 20 times the tea leaf weight. Moreover, it is set as the ethanol density | concentration with sufficient extraction efficiency of catechins by being 0.2-3 times amount with respect to the weight of the water used at the process of the 1st step, Preferably it is 0.3-2 times amount. be able to. The extraction temperature and time in the second step are not particularly limited, and examples include 30 to 90 ° C. and 30 minutes to 24 hours. After extraction, the extract is cooled to about 0 to 30 ° C. and subjected to solid-liquid separation using an appropriate separation means such as centrifugation, filter press, filter paper filtration or the like, whereby an extract can be obtained.
The tea extract of the present invention obtained by the above-described method can be used as it is in the form of an ethanol aqueous solution as it is. However, if desired, ethanol can be removed by adopting an appropriate concentration means to form a concentrate. it can. Further, if desired, the concentrate may be dried by using an appropriate drying means such as spray drying, vacuum drying, freeze drying, or the like without adding or adding excipients such as dextrin, modified starch, cyclodextrin, gum arabic and the like. It can also be made into a powder form.

Thus, according to the present invention, foods and drinks, cosmetics, health / hygiene / pharmaceuticals, etc. containing catechins with reduced bitterness and astringency can be provided. Examples of these include, for example, beverages such as tea beverages, sports beverages, carbonated beverages, fruit juice beverages, milk beverages, alcoholic beverages; frozen confections such as ice creams, sorbets, and ice candy; Japanese / Western confectionery, chewing gum Foods and beverages with various functionalities provided by blending catechins obtained by the production method of the present invention into various snacks, etc. can do.
Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples.

Reference Example 1 (Measurement of catechin content in tea leaves)
About 100 g of steamed green tea made in China is pulverized with a mixer, 1 g is collected, 100 g of 70% ethanol is added, extracted at 60 ° C. for 30 minutes, filtered through filter paper, and the residue is extracted twice in the same manner. The three filtrates were combined (considered that catechins were completely extracted by three extractions), concentrated under reduced pressure, and the whole was made up to 100 ml with ion-exchanged water. Analysis was performed to calculate the catechin content in tea leaves.
Catechin content in tea leaves: 12.5%
Method for measuring catechins:
The sample is diluted with distilled water, filtered through a filter (0.45 μm), and packed using a high-performance liquid chromatography (Waters 2695 separation module, Waters 2996 photodiode array module) manufactured by Waters. -Column TM ODS (4.6 mmφ x 250 mm: manufactured by Chemical Substances Evaluation and Research Institute) was mounted by a gradient method at a column temperature of 35 ° C, and the mobile phase A liquid contained acetic acid at 0.1 mol / liter. The aqueous solution and solution B were acetonitrile solutions containing acetic acid at 0.1 mol / liter, the sample injection volume was 10 μL, and the UV detection wavelength was 280 nm.

Example 1
Add 1300 g of 0.04% sodium ascorbate aqueous solution heated to 40 ° C. to 100 g of steamed green tea made in China, stir at 40 ° C. for 1 hour, and then tannase (Sumiteam TAN: 5000 unit (manufactured by Shin Nippon Chemical Co., Ltd.)) 1 g was added and dissolved, and the mixture was further stirred at 40 ° C. for 4 hours. Subsequently, 600 g of 95% ethanol was added, and extraction was further performed at 40 ° C. for 4 hours. After cooling to 20 ° C., solid-liquid separation was performed with a basket-type centrifuge, and further filtration with filter paper was performed to obtain 1598 g of a clear extract. The extract was concentrated under reduced pressure using a rotary evaporator and then dried under vacuum to obtain 29.5 g of tea extract powder (product of the present invention 1: catechin content: 30.5%).

Example 2
In Example 1, the same operation as in Example 1 was performed except that 1700 g of 95% ethanol was used instead of 600 g, and 27.8 g of tea extract powder (present product 2: catechin content 33.4). %).

Comparative Example 1
In Example 1, the same operation as in Example 1 was performed except that 600 g of soft water was used instead of 600 g of 95% ethanol, and 30.4 g of tea extract powder (Comparative product 1: catechin content 17.4%) Got.

Comparative Example 2
In Example 1, except that 1700 g of soft water was used instead of 600 g of 95% ethanol, exactly the same operation as in Example 1 was performed, and 44.8 g of tea extract powder (Comparative product 2: catechin content 17.4%) Got.

Comparative Example 3
100 g of tea leaves identical to those used in Example 1 were charged into a column extractor, and 1300 g of a 0.04% aqueous sodium ascorbate solution heated to 95 ° C. was added and immersed for 30 minutes. 961 g was obtained. Subsequently, 600 g of water at 95 ° C. was further added to the tea leaves after extraction and immersed for 30 minutes, and then 585 g of the extract was extracted. The extracts were combined and cooled to 40 ° C., then 0.1 g of tannase (Sumiteam TAN: 5000 unit (manufactured by Shin Nippon Chemical Co., Ltd.)) was added, dissolved, stirred at 40 ° C. for 4 hours, and heated to 90 ° C. The enzyme was inactivated and cooled. The tannase treatment solution was concentrated under reduced pressure using a rotary evaporator and then vacuum dried to obtain 42.2 g of tea extract powder (Comparative product 3: catechin content: 15.7%).

  Table 1 shows the yield of the extract from 100 g of tea leaves, the catechin content in the extract, the yield of catechin from 100 g of tea leaves, and the extraction rate of catechin from tea leaves in Example 1 and Comparative Examples 1 to 3. Shown in

  As is apparent from Table 1, the product 1 of the present invention had a catechin content of about 1.75 to 1.95 times that of the comparative products 1 to 3, and a highly pure catechin was obtained as compared with the water extraction. In the product 2 of the present invention having a high ethanol concentration, the catechin content in the extract was further increased, and high purity catechin was obtained in a high yield. The product 1 of the present invention has a catechin extraction rate of about 1.7 times that of the comparative product 1 extracted by replacing the ethanol of the product 1 of the present invention with water, and is used for the extraction of the comparative product 1. The catechin yield was also high compared to Comparative Example 2 in which the amount of water was increased and Comparative Product 3 in which column extraction was performed.

Example 3 (sensory evaluation)
2 g of sodium L-ascorbate and 0.1 g of sodium bicarbonate were added to ion-exchanged water, and the total amount was adjusted to about 5 kg with ion-exchanged water. In addition, the green tea extract processed products of the present invention products 1 and 2 and comparative products 1 to 3 or polyphenone HG (manufactured by Tokyo Food Techno: catechin content 33.7% by weight, gallate body ratio 50%) as catechin concentrations, respectively. It mix | blended so that it might become 500 ppm, 138 degreeC and 30-second UHT sterilization were performed, it cooled to 88 degreeC, it filled with the PET bottle, and also water-cooled to 30 degreeC. Each plastic bottle drink was stored at room temperature for 2 weeks and then subjected to sensory evaluation by 20 well-trained panelists. The sensory evaluation results are bitter astringency / astringency taste, miscellaneous taste / clean feeling, and overall evaluation, with 20 points as perfect score, very preferable: 17-20 points, somewhat good: 14-17 points, normal: 11-14 Points, slightly inferior: 8 to 11 points, inferior: Scored on an evaluation standard of 8 points or less, and the average score of 20 panelists is shown in Table 2.

  As shown in Table 2, the green tea beverage to which the product of the present invention was added did not feel any unnatural tastes such as bitter and astringent taste, astringent taste and sour taste and gummy taste. On the other hand, the comparative products 1 to 3 did not feel bitter astringency and astringent taste, but were somewhat miscellaneous and difficult to drink. Polyphenone HG was a bitter astringent and astringent taste with tea catechins not subjected to tannase treatment.

Claims (5)

When extracting tea raw materials, as the first step, water and tannase are added to the tea leaves to carry out an enzyme reaction, and then as the second step, the processed product obtained in the first step is used. A method for producing a tea extract, characterized in that an extract is obtained by adding a 95% ethanol aqueous solution that is 0.2 to 3 times the amount of water used in the first step to obtain an extract. The method for producing a tea extract according to claim 1, wherein the amount of water used in the first step is 5 to 30 times the tea leaf weight.   The reaction temperature of the tannase treatment in the first step is 30 to 50 ° C, and the extraction temperature in the second tea extraction product is 30 to 90 ° C, or The manufacturing method of the tea extract of Claim 2.   The tea extract concentrate obtained by concentrating the tea extract obtained by the method in any one of Claims 1-3.   A food or drink containing the tea extract concentrate according to claim 4.