JP2012135265A - Method for efficiently producing black-tea leaf - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing black tea leaves having satisfactory flavors such as obtained by an orthodox process without using a CTC process while reducing the time for a crumpling step.SOLUTION: The method for producing black tea leaves substantially without twisting in leaves includes: the crumpling step characterized by obtaining tea leaves in a state substantially without twisting from withered leaves by mechanical treatment such as shearing and friction; a fermentation step; and a drying step. Black tea leaves obtained by the method and a food or beverage using the black tea leaves are also provided.

Description

  The present invention relates to a method for producing a tea leaf that is substantially free from kinking of leaves, characterized in that a twisting process is performed using a mechanical treatment by shearing and friction.

Black tea is produced by methods that include wilting, twisting, fermentation and drying.
Tea production methods can be broadly divided into the traditional orthodox production method and the CTC production method using a specially designed machine for the twisting process. The difference between the two is mainly in the twisting process.

  The orthodox manufacturing method uses a “twisting machine”. A typical twisting machine has a disk with a diameter of about 2 meters (called a "grinding board") on a solid support base of a casting, and a cylinder with a diameter of 1.3 meters and a height of 2 meters with a slight space above it. (It is called a rod body). In this, put the wilted leaves after wilting and make a flat circular motion on the board. There are two types: a single action with a fixed board and a double action that simultaneously moves the board with a crank. Initially it was without a lid, but then changed to a system in which a motor was attached to the lid and pressure was applied from above. There are protrusions (called cones) and horned scratched frames (called hills) on the board, and there are trimmings and scraping holes at the end of the work so as not to spill outside. When weaning leaves are weighed and put into the rod body and started, the tea leaves tend to spontaneously harden and form dumplings. To make broken tea, press the lid, press and cut with hills and cones, and when the temperature rises, raise the lid and dissipate heat. It takes 40 to 60 minutes per time. In the next step, the mashing sieve is divided and the top of the sieve is subjected to a second twist. The sieving proceeds to the fermentation process (Non-patent Document 1).

  On the other hand, the CTC manufacturing method is a manufacturing method which has been rapidly spread and developed in recent years as compared to the orthodox manufacturing method. The CTC manufacturing method is an abbreviation for crushing (crushing), tearing (tearing), and curling (rounding into granules). This is a specially designed twisting machine devised by Mackercher and refers to the manufacturing method using this machine. A fine blade is cut on the surface of two stainless cylindrical cylinders (diameter 20 cm, length 60 cm, 90 cm, 120 cm). It has a structure in which the leaf that has been twisted once and twisted is bitten into the slight gap. By making the difference between the rotation speed of the two rollers between 700 and 70 rpm and passing through the slight gap, the tea leaves are crashed, tiered and curled, and finely repetitively operated by three CTC machines. It is crushed and rounded into particles (Non-Patent Document 1).

  Although not related to the production of black tea, there are a tea paste production method (Patent Document 1), tea powder production (Patent Document 2) and the like regarding tea processing techniques using an electric mill and crusher. However, all of them are processing methods for rough tea or tea making, and are not used in the manufacturing process of rough tea.

JP 2006-174711 A Japanese Patent Laid-Open No. 11-15164

Yukimasa Araki and Masao Matsuda, Dictionary of black tea, 2002, Shibata Shoten

  The twisting process in the orthodox manufacturing method does not perform crushing but adds a twisting operation with a leaf. In this production method, an excellent flavored black tea leaf is supposed to be obtained, and the processing time requires about 70 to 120 minutes regardless of the amount of tea leaf from the viewpoint of flavor.

  On the other hand, in the CTC manufacturing method, operations such as crushing (crushing), tearing (tearing), and curling (rounding into granules) are performed by a roller using a dedicated machine, and twisting is performed in a short time. Although this method is efficient, the degree of crushing of the obtained tea leaves is large, the quality of the tea extract obtained therefrom is not satisfactory, and the initial investment cost is high for Japanese tea producers, etc. This is difficult to introduce.

  The present invention has been made in view of the above circumstances, and aims to provide a method for producing a satisfactory flavored tea leaf that can be obtained by an orthodox manufacturing method without shortening the twisting time and using a CTC manufacturing method. .

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have surprisingly found that in the twisting process, mechanical processing by shearing and friction, which has not been used for tea production so far, instead of a twisting machine, is performed. By using a pulverizing device, particularly a device that rotates one of the upper and lower grinders whose distance can be adjusted (for example, a stone mill, an electric mill), the twisting process time can be shortened. Moreover, from the black tea leaf manufactured using this twisting process, the flavorful black tea extract liquid which can feel the rich fragrance, reverberation, and thickness was able to be obtained. The flavor at this time was superior to the tea leaf extract obtained from the conventional production method using a twister. The present invention has been completed based on such findings.

That is, the present invention includes the following features.
(1) A leaf substantially comprising a twisting step and a fermentation step and a drying step characterized in that a tea leaf in a state substantially free of leaf kinking is obtained from a wilted tea leaf by mechanical treatment by shearing and friction A method for producing tea leaves without kinking.
(2) Using a device that rotates one of the two upper and lower grinders whose interval can be adjusted, the wilted tea leaves are introduced into the interval between the grinders, and substantially by compression, shearing and rolling friction by the grinder A method for producing a tea leaf that is substantially free of leaf kinking, comprising a twisting step, a fermentation step and a drying step, characterized in that the tea leaf is in a state free from kinking.
(3) The method according to (2) above, wherein the apparatus is a stone mill.
(4) The method according to (3) above, wherein the stone mill is an electric mill.
(5) Black tea leaf obtained by any one of the above methods (1) to (4) and substantially free from kinking of leaves.
(6) Black tea extraction comprising producing black tea leaves by any one of the above methods (1) to (4), and further producing a black tea extract with a rich aroma, reverberation and thickness from the black tea leaves Liquid manufacturing method.
(7) A black tea extract with a rich fragrance, reverberation and thickness obtained from the tea leaves of (5) above.
(8) Food / beverage products containing the tea leaf of said (5) or the black tea extract of said (7).
(9) A packed tea beverage containing the black tea extract of (7) above.

  In the method for producing black tea leaves of the present invention, the twisting step does not include an operation of twisting the leaves.

  According to the present invention, there is provided a method for producing a tea leaf having a twisting time shortened to 1/6 to 1/4 of that in the orthodox manufacturing method and having a flavor superior to that obtained by the orthodox manufacturing method.

  The mechanical treatment by shearing and friction, which is a feature of the present invention, in particular, the treatment by a device that rotates one of the upper and lower grinders, such as a stone mortar, is based on an orthodox production twister in that the leaves are not twisted. It differs from the processing and processing by the CTC manufacturing method.

  The present invention will be described in further detail.

<Manufacturing method of tea leaves>
The method for producing black tea leaves of the present invention can be performed according to the genus Camellia, such as C.I. sinensis, C.I. Fresh leaves obtained from assamica or hybrids thereof are wilted, subjected to a twisting process, and then subjected to a fermentation process and a drying process to give crude tea, and thereafter include a finishing process such as grading.

  The raw raw leaves may be either large leaf species or small leaf species, and the variety name, production area, etc. are not limited and any of them may be used.

  Below, a wilting process, a twisting process, a fermentation process, and a drying process are demonstrated.

  In the wilting process, the fresh leaves are wilted by removing about 50% of water over a long period of time (about 10 hours). In the present invention, wilting can be performed by any method.

  In the twisting process, pressure is applied to the wilted tea leaves using a twisting machine, and the tea leaves are thoroughly stirred. By doing so, the tissue and cells of the tea leaves are destroyed and the tea juice is squeezed out. The twisting process is performed by a general method such as a CTC manufacturing method or an orthodox manufacturing method.

  In the twisting process of the method for producing tea leaves of the present invention, a pulverizing apparatus capable of mechanical treatment by shearing and friction, which is not a conventional apparatus such as a CTC manufacturing method or an orthodox manufacturing method, is used. That is, it is characterized by using a device that rotates one of two upper and lower grinders whose interval can be adjusted or a device that rotates together with a hard ball.

Specifically, in the method according to the present invention, when a device for rotating one of the upper and lower two grinders is used, the wilted tea leaves are introduced into the gap between the grinders, and compression, shearing and rolling friction by the grinder are used. Including a twisting process characterized by obtaining a state in which the leaves are broken and the leaves are crushed but not substantially kinked, and a fermentation process and a drying process.

The twisting process using a device that rotates with a hard ball is a state in which tea leaves that have been withered together with a hard ball are put into a cylindrical pot, and the leaf is destroyed and the leaf is crushed by shearing and rolling friction by the ball. It is characterized in that it is substantially free of kinks.
The tea leaves obtained by the above series of steps are substantially free from kinks.

  Here, “substantially no kinking of leaves” means that tea leaves that are kinked visually but slightly crushed may be included.

  In the twisting process, the tea leaves are broken by tearing, compression and rolling friction so that the tea leaves are torn apart, the pieces are crushed, and the tea juice is squeezed out.

  The apparatus used in the twisting process of the method for producing tea leaves according to the present invention is an apparatus that rotates one of the two upper and lower grinders whose distance can be adjusted. Preferably, the upper grinder is fixed and the lower grinder is fixed. The gap between the grinders is sized so that the leaves are not broken by the compression, shear and rolling friction by the grinder, and the leaves are broken into small pieces and crushed. .

The material of the grinder is arbitrary, for example, mineral, metal, earthenware, ceramics, etc. The surface of the grinder has fine irregularities like the surface of a file.
Such devices include, for example, a millstone, preferably an electric millstone.

  The type of millstone is arbitrary. Examples of the electric stone mill include, but are not limited to, a mass collider (trade name; manufactured by Masuko Sangyo). In the case of using a device such as a mascoloider, the size and capacity are not limited, and an appropriate one may be selected according to the amount of tea leaves to be processed.

  As processing conditions, the clearance which shows the gap | interval of a grinder (for example, stone mortar) has preferable 1-4 mm, More preferably, it is 1.5-3 mm. Moreover, as a rotational speed of a grinder (for example, stone mill), 1,000-5,000 rpm is preferable, More preferably, it is 1,500-3,000 rpm. Moreover, the frequency | count of the process of a leaf is preferable 1-5 times, More preferably, it is 2-3 times.

  When the fresh leaves are wilted, they may be put into the apparatus as they are, such as an electric stone mill, or may be put after being cut into an appropriate size using a fresh leaf cutter or the like. The size of the raw leaves after cutting is not limited and is arbitrary. The purpose of cutting is to reduce the volume of fresh leaves and make it easier to put in the inlet of a grinder (for example, a stone mill). Note that cutting with a fresh leaf cutter is sometimes used in green tea production, but is not used in black tea production using a twister because there is a concern about a decrease in the flavor of the obtained tea leaves. The processing conditions of an apparatus such as an electric stone mill are not affected by the presence or absence of a raw leaf cutter.

  In the fermentation process, for example, tea leaves are spread on a fermentation shelf in a fermentation room maintained at room temperature (about 25 to 30 ° C.) and humidity of about 80 to 90%, and oxidative fermentation is performed with an oxidase from the tea leaves. Oxidase is activated by contact with oxygen in the air, and components such as polyphenol compounds, pectin, and chlorophyll contained in tea juice are oxidatively fermented. In the orthodox manufacturing method with a long twisting time, oxidation fermentation proceeds and generates heat even during the twisting process, so that cooling is necessary, and 60 to 70% of the tea leaves are oxidized and fermented during repeated twisting and cooling. In the present invention, since the twisting time is as short as 1/6 to 1/4 as compared with the orthodox manufacturing method, such a problem does not occur. The fermentation method is not limited and any method can be used.

  In the drying step, for example, the tea leaf water is roughly dried to about 20% with hot air at a temperature of about 80 to 90 ° C., and further hot air dried at about 75 ° C. until the water content is about 4%. The drying method after fermentation is not limited and any method can be used.

<Tea leaves>
The present invention further provides a tea leaf obtained by the above method and substantially free of leaf kinks.

On the other hand, what is obtained by either the orthodox manufacturing method or the CTC manufacturing method is a tea leaf having a rounded leaf, so that the tea leaf of the present invention is morphologically different from that according to the conventional method.
Furthermore, the tea extract obtained by pouring hot water into the leaves using the tea leaves of the present invention, solid-liquid separation with a strainer, cooling, pH adjustment and sterilization has a tannin value according to the conventional orthodox manufacturing method. The flavor is superior to that of the conventional orthodox manufacturing method. This flavor makes the person who drinks it feel rich aroma, reverberation and thickness.

<Manufacture of tea extract>
The present invention further provides a method for producing a black tea extract comprising producing a black tea leaf by the above-described method and producing a black tea extract from the black tea leaf. This method is characterized by the use of tea leaves produced by incorporating a new twisting process in the production of black tea extract.
The extraction method may be a conventional method such as stirring extraction or any method developed in the future.

  Although the extraction solvent is water, an organic acid such as sodium ascorbate and / or an organic acid salt may be added to the water in advance during extraction. When the black tea extract is produced under normal extraction conditions using water, the temperature of water when extracting from black tea leaves is preferably 50 to 100 ° C, more preferably 70 to 100 ° C. The amount of water at the time of extraction from black tea leaves is preferably 5 to 60 times by weight, more preferably 5 to 40 times by weight with respect to black tea leaves. The extraction time is preferably 1 to 60 minutes, more preferably 1 to 40 minutes, and further preferably 1 to 30 minutes.

  After extraction, the extract is recovered using a solid-liquid separator such as filtration or centrifugation, and sterilized as necessary.

  Further, the black tea extract produced as described above may be concentrated to give a black tea concentrate or black tea extract, followed by drying to produce black tea powder.

  In this specification, unless otherwise specified, the “black tea extract” is a mixture of at least one or more of the above black tea extract, black tea concentrate (black tea extract), and black tea powder. Say.

  The black tea extract obtained as described above is also included in the scope of the present invention. As described above, the black tea extract of the present invention has a tannin value comparable to that of the conventional orthodox manufacturing method, and the flavor is superior to that of the conventional orthodox manufacturing method. Feel the thickness.

<Food &Drink>
The present invention further provides a food or drink containing the tea leaf or black tea extract produced by the above method.

  The foods and drinks are not limited to the following, but include, for example, confectionery such as chiffon cakes and cookies, cooked products such as tea pigs and jams, and breads.

  Alternatively, in addition to black tea comprising the black tea leaf of the present invention, black tea obtained by mixing the black tea leaf of the present invention with spices and food flavors (fruit flavor, leaf flavor, etc.), black tea different from the black tea leaf of the present invention Black tea blended with leaves and the like are also included in the food and drink of the present invention.

<Packed tea beverage>
The present invention further provides a containerized black tea beverage containing the black tea extract.
An arbitrary additive can be added to the black tea extract to form a container-packed beverage. Additives include, for example, milk, minerals, vitamins, sweeteners (sugars, sugar alcohols, artificial sweeteners, etc.), stabilizers, antioxidants, anti-fading agents, pH adjusters, flavors and the like. The type of additive may consist of one or more substances.

  The beverage obtained by blending is filled into a container such as a metal can, a PET bottle, or a paper container. The contents can be sterilized before or after filling, depending on the material of the container.

  When heat sterilization can be performed after filling as in a metal can, sterilization is performed under the sterilization conditions defined in the Food Sanitation Law. On the other hand, for beverages that cannot be retort sterilized, such as PET bottles and paper containers, the beverage is preliminarily sterilized at high temperature and short time (UHT sterilization) using the same sterilization conditions as described above, for example, a plate heat exchanger. A method of cooling to a certain temperature and filling a sterilized container is adopted.

<Evaluation of black tea leaf, black tea extract or containerized black tea beverage by tannin amount>
The amount of tannin is measured using the iron tartrate method (referred to by Toshiro Nakabayashi et al., “Chemistry and Functions of Green Tea, Black Tea, and Oolong Tea”, Kogaku Publishing, page 137), which is the standard for evaluating polyphenol content in tea be able to. That is, the absorbance (540 nm) of a purple component produced by reacting a polyphenol in the liquid with an iron tartrate reagent can be measured, and quantified using a calibration curve prepared using ethyl gallate as a standard substance. The final value obtained by multiplying the quantitative value by 1.5 is defined as “tannin amount”. Tannin exhibits bitterness or astringency, and is an important substance that determines its taste among the luxury products using tea leaves. Therefore, the amount of tannin (extraction efficiency) obtained when the ratio of tea leaves to the extraction solvent is constant is very important for taste design of black tea beverages.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the technical scope of the present invention is not limited by these examples.

(Production of black tea leaf according to the present invention; method)
Introduced 5.5 to 7.5 kg of wilted domestic tea leaves into a mascolloider (made by Masuko Sangyo Co., Ltd., MKZA12-20J, grinder is equipped with MKB-C 24 #), and the leaves were destroyed and the leaves were crushed Although it was, it was crushed to a state where the leaves were not kinked. The treatment conditions were clearance; 2.0 mm, rotation speed: 1,650 rpm, number of treatments: 1 to 2 times, and the total treatment time was 8 to 15 minutes. Then, it was fermented at room temperature for 2 to 4 hours and dried with hot air to obtain tea leaves (Examples 1 to 3).

(Manufacture of tea leaves by conventional orthodox manufacturing method; method)
59 kg of domestic tea leaves that were withered were put into a twisting machine (manufactured by Terada Seisakusho, J-120 type), then twisted for 90 minutes, and fermented at room temperature for 2 hours. Then, it dried with hot air and was set as the tea leaf (Comparative Example 1).

Table 1 shows the production conditions of the tea leaves.

  600 g of 85 ° C. hot water was added to 20 g of each tea leaf shown in Table 1, and extracted for 5 minutes with occasional stirring. After the tea leaves are solid-liquid separated with a strainer, the solution is cooled to a temperature of 10 ° C., then centrifuged at 3000 rpm for 10 minutes, passed through a strainer again, and water is added to obtain 600 g of a clear extract. Obtained. To 300 g of this extract, the pH was adjusted to about 6.2 using ascorbic acid and sodium bicarbonate, and the volume was increased to 1000 g with water to obtain a preparation. After heating up this preparation liquid to 90 degreeC, it filled the metal can 190g at a time, and tightened the can lid, blowing nitrogen. This was subjected to a retort sterilization treatment at 121 ° C. for 5 minutes to prepare a packed tea beverage. After leaving at room temperature for 1 week, sensory evaluation was performed.

(result)
The tea leaves produced using a mascolloider in the twisting process were smaller in size than those produced by the orthodox method and were not kinked.

Table 2 shows the amount of tannin of the sample for sensory evaluation.

  As shown in Table 2, Examples 1 to 3 had no significant difference in the amount of tannin compared to Comparative Example 1, and the appearance (light blue, etc.) was also equivalent. In addition, as a result of sensory evaluation by a skilled panelist, Examples 1 to 3 were found to have a rich aroma, reverberation, thickness and the like that of tea as compared to Comparative Example 1, and were excellent in flavor.

  The present invention provides a black tea leaf having a flavor superior to that of a black tea leaf obtained by the orthodox manufacturing method, in which the twisting time is shortened to 1/6 to 1/4 compared with the conventional orthodox manufacturing method in the production of black tea leaf. Providing a production method makes it possible to produce high-quality tea leaves in a shorter time than the orthodox production method, which is useful in the food industry.

Claims (9)

  The process of twisting, characterized by obtaining tea leaves that are substantially free of leaf kinking from wilted tea leaves by mechanical treatment by shearing and friction, and substantially including leaf kinking, including a fermentation process and a drying process. No tea leaf manufacturing method.   Using a device that rotates one of the two upper and lower grinders whose distance can be adjusted, the wilted tea leaves are introduced into the gap between the grinders, and the leaves are substantially kinked by compression, shearing and rolling friction by the grinder. A method for producing a tea leaf that is substantially free from kinking, comprising a twisting step, a fermentation step and a drying step, characterized in that the tea leaf is free of tea leaves.   The method of claim 2, wherein the device is a stone mill.   The method according to claim 3, wherein the millstone is an electric millstone.   A black tea leaf obtained by the method according to any one of claims 1 to 4 and substantially free of kinks.   A black tea excellent in flavor with a rich fragrance, reverberation and thickness, comprising producing black tea leaves by the method according to any one of claims 1 to 4 and further producing a black tea extract from the black tea leaves. A method for producing an extract.   A rich tea fragrance, a lingering finish, and a flavorful tea extract obtained from the black tea leaf according to claim 5.   A food or drink comprising the black tea leaf according to claim 5 or the black tea extract according to claim 7.   A packaged black tea beverage comprising the black tea extract according to claim 7.