Green tea manufacturing methods

Abstract

This invention provides a novel method for producing withered green tea. [Solution] A method for producing green tea having a wilting aroma, comprising vibrating a wilting aroma by vibrating the surface on which a fresh leaf is placed while in contact with other fresh leaves.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing green tea, and particularly to a method for manufacturing green tea having a withering aroma.

Background Art

[0002] Unlike ordinary green tea, green tea having a withering aroma, also referred to as a floral aroma (flower fragrance), is known (hereinafter also referred to as withered green tea). Generally, green tea is manufactured by subjecting fresh leaves to steaming without fermentation, followed by leaf beating, further kneading, and then drying. On the other hand, it is known that the aroma is generated by the action of oxidase in the leaves when the fresh leaves are fermented. When completely fermented, it becomes black tea. After exposing the fresh leaves to sunlight for semi-fermentation and then frying and kneading, it becomes oolong tea. Thus, various scented and colored teas can be manufactured depending on the difference in the fermentation method.

[0003] Withered green tea is manufactured by lightly kneading fresh leaves before steaming and then leaving them in a well-ventilated place or the like to wither the leaves, thereby promoting the development of the withering aroma. This treatment gives rise to the name of the withering aroma, and the withering aroma is produced by allowing the fresh leaves to wither and the fermentation to proceed slightly (micro-fermentation). Also, a method described in Patent Document 1 has been proposed as a method for manufacturing withered green tea.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In this specification, "green tea having a specific aroma, such as wilting aroma," means green tea in which the specific aroma can be perceived when smelling the green tea.

[0008] The gist of this invention is as follows: [1] This includes vibrating the surface on which a fresh leaf is placed while in contact with other fresh leaves, thereby emitting a wilting fragrance. The change in acceleration in the Z-axis direction perpendicular to the XY plane, which is parallel to the aforementioned mounting surface, is 20 to 110 m / s². 2 , and the composite vector of acceleration in the X-axis direction, Y-axis direction, and Z-axis direction: 10~30 m / s² 2 A method for producing green tea having a wilted aroma, comprising vibrating the fresh leaves with RMS and applying the vibration for 10 hours or less. [2] The manufacturing method according to [1], wherein the vibration is applied to the fresh leaves for 4 hours or more and 10 hours or less. [3] A manufacturing method according to [1] or [2], which involves vibrating fresh leaves at 15-35°C. [4] The manufacturing method described in [1] or [2], wherein the fresh leaves are fresh leaves of the species Camellia sinensis. [5] A packaged beverage containing an extract of green tea obtained by the manufacturing method described in [1] or [2]. [Effects of the Invention]

[0009] According to the present invention, a novel method for producing withered green tea can be provided. [Brief explanation of the drawing]

[0010] [Figure 1] The diagrams show an overview of the tests in the examples, where (a) shows an overview of a container containing fresh tea leaves set on a testing machine (vibration testing machine or conveyor), and (b) shows an overview of a container with an acceleration sensor attached set on the aforementioned testing machine. [Modes for carrying out the invention]

[0011] One embodiment of the present invention will be described in detail below. This embodiment is a method for producing green tea having a wilted aroma, and includes vibrating a fresh leaf that has been placed in contact with other fresh leaves by vibrating the surface on which it is placed, thereby releasing the wilted aroma.

[0012] Fresh tea leaves refer to leaves harvested from Camellia species such as Camellia sinensis and Camellia assamica, which have not undergone steam treatment. The fresh leaves in this embodiment may be those harvested immediately after harvesting or those stored in a fresh leaf management machine after harvesting. The species and varieties from which the fresh leaves are derived are not particularly limited and can be appropriately determined by those skilled in the art. Examples of varieties include Yabukita, Yutakamidori, Okumidori, Saemidori, Sayamakaori, Kanayamidori, Asatsuyu, Okuhikari, Benifuki, Kogou, or mixed varieties thereof. The tea season is also not particularly limited and can include first flush, second flush, third flush, fourth flush, autumn / winter flush, etc. Furthermore, the fresh leaves may be of one type, or a combination of two or more types may be subjected to the vibration treatment. Among these, from the viewpoints that the fresh leaves are slender and firm and the activity of the contained oxidase is gentle and suitable for withering aroma formation, compared with Camellia assamica, the fresh leaves of Camellia sinensis are preferred.

[0013] In the present embodiment, as described above, vibration is applied to the fresh leaves of tea while they are in contact with other fresh leaves to bring out the withering aroma. By applying vibration to the fresh leaves, the fresh leaves in contact rub against each other, and the action of the enzyme is promoted due to the formation of minute scratches on the leaf surface, etc., and as a result, micro-fermentation proceeds. The magnitude of the vibration to be applied and the time for applying the vibration are not particularly limited as long as the withering aroma can be felt when smelling the obtained green tea aroma, and can be appropriately set by those skilled in the art. Even when the vibration to be applied is weak, it is possible to bring out the withering aroma by lengthening the vibration time. On the other hand, if the vibration is applied for a longer time than necessary, the withering aroma changes to a fermentation aroma, and the withering aroma felt when smelling the green tea aroma may become weak or may not be felt at all.

[0014] For example, the fresh leaves are placed on a placement surface constituted by the bottom surface of a container or the like in a state of being in contact with other fresh leaves, and the placement surface is parallel to the placement surface and perpendicular to the XY plane constituted by the X-axis and the Y-axis. The change amount of the acceleration in the Z-axis direction: 20 to 110 m / s 2 and the combined vector of the acceleration in the X-axis direction, the acceleration in the Y-axis direction, and the acceleration in the Z-axis direction: 10 to 30 m / s 2 are vibrated at RMS (hereinafter, this vibration condition is also referred to as vibration condition (A). Also, the change amount of the acceleration in the Z-axis direction is also referred to as parameter (1), and the combined vector of the acceleration in the X-axis direction, the acceleration in the Y-axis direction, and the acceleration in the Z-axis direction is also referred to as parameter (2).). When performing the process of applying vibration under vibration condition (A), it is preferable to apply vibration for 10 hours or less. By applying vibration for 10 hours or less under vibration condition (A), the withering aroma can be brought out more efficiently. Further, it is more preferable to apply vibration for 4 hours or more and 10 hours or less under vibration condition (A) because the promotion of the withering aroma can be further promoted. Since the present inventors found that the generation of withered fragrance was promoted by applying vibration using either a conveyor or a vibration testing machine, they considered that there was a possibility that withered fragrance could be generated at a common vibration intensity, and investigated the relationship with vibration parameters, which are intensity indicators of vibration. As a result, when two types of parameters, namely, the parameter (1) related to vertical vibration and the parameter (2) related to vibration intensity, were examined as parameters, it was surprisingly revealed that when vibration was applied at a certain intensity in a state where there was vibration in the Z-axis direction, the generation of withered fragrance was promoted. The vibration intensity can be measured, for example, using a known vibration intensity measuring instrument (for example, Logtta Accel 3.0 (manufactured by Yuuni Electronics Co., Ltd.)).

[0015] The environment in which the fresh leaves are placed when applying vibration to the fresh leaves is not particularly limited and can be appropriately set by those skilled in the art. The vibration can be applied, for example, indoors. When it is carried out indoors, it may be either in a sealed state or an unsealed state. Also, if necessary, vibration may be applied while performing ventilation, and it is not particularly limited. Also, the temperature when applying vibration is not particularly limited and can be appropriately set by those skilled in the art. However, since withered fragrance can be more stably exhibited, 15 to 35°C is preferable. This temperature may be room temperature or a temperature controlled by air conditioning equipment. The humidity when applying vibration is not particularly limited and can be appropriately set by those skilled in the art, and can be, for example, 50 to 60%.

[0016] In the present embodiment, after applying vibration to fresh leaves to exhibit withered fragrance as described above, green tea can be produced, for example, by performing a normal tea manufacturing process. In the tea manufacturing process, first, a steaming process using a steaming machine, a rough rolling process using a rough rolling machine, a rolling process using a rolling machine, a medium rolling process using a medium rolling machine, a fine rolling process using a fine rolling machine, and a drying process using a dryer are carried out to produce raw tea. Then, a finishing process including a firing process using a firing machine is performed to produce green tea (sencha).

[0017] The green tea of ​​this embodiment can be used, for example, in the production of a beverage containing a green tea extract. Furthermore, this beverage can be packaged, and therefore, one embodiment of the present invention is a packaged beverage containing a green tea extract obtained by the manufacturing method of this embodiment.

[0018] In manufacturing a beverage containing the green tea extract of this embodiment, the raw materials used for extraction may be only the green tea of ​​this embodiment, or they may be a mixture with other raw materials (such as regular green tea or grains), and are not particularly limited. Alternatively, each may be extracted separately and then the extracts may be mixed together. The method of extracting the raw materials is not particularly limited, and known methods such as kneader extraction, stirring extraction, drip extraction, and column extraction can be employed. Suitable extraction solvents include water, organic solvents such as ethanol, and mixed solutions of water and ethanol, but water is preferred. Furthermore, the extraction conditions are not particularly limited and can be appropriately selected by those skilled in the art depending on the extraction method.

[0019] An example of a processing flow for the beverage manufacturing method according to this embodiment will be explained using the case of a packaged beverage as an example. First, the raw materials containing withered green tea according to this embodiment are subjected to an extraction process, and then solid matter is removed by filtration or the like to obtain an extract. Next, the obtained extract is subjected to treatments such as dilution, pH adjustment, and heat sterilization as necessary, and then filled into containers to produce bottled beverages.

[0020] The method of sealing the contents into the container is not particularly limited and can be carried out according to conventional methods, for example. Any known container can be appropriately selected and used, and there are no particular limitations on the material or shape. Specific examples of containers include transparent or translucent plastic containers such as PET bottles, transparent or translucent glass bottles, metal cans such as steel or aluminum cans, and paper containers.

[0021] The proportion of withered green tea according to this embodiment in the beverage ingredients is not particularly limited and can be appropriately set by those skilled in the art depending on the desired aroma and taste. The degree to which it is perceived depends on the blending ratio of withered green tea in the ingredients according to this embodiment, but the resulting beverage will also have a floral-like withered aroma when tasted.

[0022] As described above, this embodiment provides a novel method for producing withered green tea. Compared to conventional methods that involve a large proportion of manual labor, this method allows for more stable production of withered green tea. Therefore, it can be expected to contribute to the industrial production of withered green tea. [Examples]

[0023] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0024] [Method of applying vibration] The tea leaves used were Yabukita third flush tea, Yabukita autumn / winter bancha tea, and Meiryoku autumn / winter bancha tea. Each type of fresh leaf was placed in an open container with a mesh bottom (mesh opening 4.00-4.75 mm), and then set up on a conveyor test machine and a vibration test machine as shown in Figure 1(a) under the conditions in Table 2, and vibration tests were conducted while ensuring proper ventilation. The conveyor test used a driven roller conveyor with a roller pitch of 100, operated at a conveying speed of 50 m / min, and run for a maximum of 10 hours under the vibration parameter conditions shown in Table 2. The vibration test was conducted in accordance with JIS Z 0200 Packaging Goods - General Rules for Performance Test Methods (Random Z Method Vibration Test), and the equipment was operated for a maximum of 9 hours under the vibration parameter conditions shown in Table 1. All test machines were installed in a test room where the temperature and humidity were maintained at the values ​​shown in Table 2. The temperature and humidity inside the containers holding the fresh leaves were measured throughout the test, and the average values ​​are shown in Table 2.

[0025] [How to set vibration parameters] The vibration parameters that determine the operation of the conveyor and vibration testing machine were set by attaching a Logtta Accel 3.0 wireless triaxial accelerometer (manufactured by Uni Electronics Co., Ltd.) to the bottom surface of the container holding the fresh leaves, setting it up in each testing machine as shown in Figure 1(b), and measuring under the conditions of accelerometer measurement pitch: 400Hz, acceleration range: ±78.5m / s^2 (8G), and measurement time: 145sec. The vibration parameters were calculated using acceleration values ​​in the X, Y, and Z axes obtained from the acceleration sensor. The vibration parameter (1), Δ(mean value of a ± 3σ), was determined from the change in the mean value ± 3σ of the measured Z acceleration a obtained from vertical vibration (Z axis). The vibration parameter (2), A RMS, was calculated by converting the acceleration values ​​of the three-axis vibration (X, Y, Z axes) into vector magnitudes and then creating a composite vector Ai(√(xi 2 +yi 2 +Trade 2 The effective value (Root Mean Square: RMS) of the composite vector A was calculated by calculating ).

[0026] [Sensory evaluation] Fresh tea leaves (picked the day after harvesting) were placed in an open container and subjected to vibration using the method described above, with sensory evaluations conducted every hour. In this evaluation, as shown in Table 1 below, a 7-point scale from 1 to 7 was used, with a baseline score (4 points) indicating that trained panelists could immediately recognize the wilting aroma when smelling the green tea. A higher number above the baseline indicated a "stronger" perception of the aroma. Furthermore, if the evaluation score reached 4 within the test time, it was judged that there was a promoting effect on the development of the wilting aroma.

[0027] [Table 1]

[0028] In addition, as a control, samples that were left undisturbed during the evaluation period were also evaluated. The results of the sensory evaluation are shown in Table 2.

[0029] [Table 2]

[0030] As can be seen from Table 2, vibrating the surface on which the fresh leaves were placed while they were in contact with other fresh leaves promoted the development of wilting fragrance. On the other hand, no wilting fragrance was detected throughout the entire evaluation period when the control fresh leaves were left undisturbed.

Claims

1. This includes vibrating the surface on which a fresh leaf is placed while in contact with other fresh leaves, thereby emitting a wilting fragrance. The change in acceleration in the Z-axis direction perpendicular to the XY plane parallel to the aforementioned mounting surface is 20 to 110 m / s². ２ , and the composite vector of acceleration in the X-axis direction, Y-axis direction, and Z-axis direction: 10-30 m / s² ２ A method for producing green tea having a wilted aroma, comprising vibrating the fresh leaves with RMS and applying the vibration for 10 hours or less.

2. The manufacturing method according to claim 1, wherein the vibration is applied to the fresh leaves for 4 hours or more and 10 hours or less.

3. The manufacturing method according to claim 1 or 2, wherein vibration is applied to fresh leaves at 15 to 35°C.

4. The manufacturing method according to claim 1 or 2, wherein the fresh leaves are fresh leaves of the Camellia sinensis species.

5. A packaged beverage containing a green tea extract obtained by the manufacturing method described in claim 1 or 2.

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