JPH09233997A - Production of green tea by using high-humidity hot air - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide green tea which is sanitary and improves the elution property of components for drink, taste and flavor by applying thermal processing to raw tea leaves while respectively applying the high-humidity not air with prescribed humidity and temperature for prescribed time, and performing tea manufacture. SOLUTION: First of all, the raw tea leaves picked from a tea garden are washed while using a washer A, agricultural chemicals or the other dirt stuck on the raw tea leaves are removed, and thermal processing is performed to these tea leaves, for which moisture is stuck on their surfaces, by applying the high-humidity not air with 60-90% humidity and 250-390 deg.C provided by using a high-humidity hot air generator furnace 4 for several dozens of seconds. Next, tea manufacture is performed and green tea is provided. In this case, it is preferable to apply the thermal processing to the raw tea leaves, to crush them into paste or flake through crush rolls 5 more than two stages, to heat and dry them by applying the high-humidity hot air.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing green tea by heat-treating raw tea leaves picked from a tea field with hot air of high humidity at about 250 to 390 ° C.

[0002]

2. Description of the Related Art The production process of green tea consists of a rough tea process and a finishing process. Green tea is obtained by first contacting raw tea leaves picked in a tea garden with steam at 95 to 105 ° C. for several tens of seconds to steam. Stop fermentation, then coarsely knead, knead, medium knead this steamed tea leaf,
Processing such as fine rubbing, drying, etc. are each added for several tens of minutes to make rough tea,
Furthermore, it is manufactured by adding a fire, sieving, and other finishing treatments. This green tea has been the most commonly used in Japan in the past, and is commonly consumed daily. In particular, recently, this green tea has various medicinal ingredients in addition to vitamins such as tannin, caffeine, and vitamin C. Is recognized,
It is attracting attention not only as a favorite drink but also as a health drink, and is used as a part of food in powder form.

[0003]

Among the above-mentioned conventional green tea production processes, the first steaming heat treatment process is the most important process in the crude tea process, and the quality of the workability in this process is determined by the quality of the workability. It greatly affects the quality of green tea. However, in the conventional steam heat treatment method, as described above, low-temperature steam of 95 to 105 ° C is applied to the raw tea leaves, so that the steam that first comes into contact with the raw tea leaves is dewed and the surface of the raw tea leaves is covered with a thin film of water. And gradually heated by the contacting steam.
In addition, since the temperature of the steam is low, the water hardly evaporates, and the tea leaves are in a so-called “raw boiled” state. In addition, after the steaming heat treatment, rough rubbing treatment, kneading treatment, medium rubbing treatment, and fine rubbing treatment are added, so that at the stage of finishing the steaming heat treatment, the tea leaves are tough enough to perform the following treatments. Therefore, the steaming heat treatment time must be suppressed to about several tens of seconds. Therefore, the heating is insufficient for the tea leaves, and the green tea product has a problem that the umami and flavor are light and a blue smell remains. Conventionally, in order to eliminate such problems, it is necessary to add 110-130 to raw tea leaves.
A method of applying hot air of about ℃ was tried. However, according to this method, the water in the surface layer of the fresh tea leaves evaporates, the surface becomes a dead leaf state, and the inside is not heated and becomes a fresh leaf state. In the processing steps from the rough kneading step to the fine kneading step, which follow the steaming step, the steamed tea leaves are kneaded while being heated to gradually reduce the water content of the tea leaves.
This is twisted to give a rod-like finish. This processing method has a problem in that workability is poor because each process is a batch work and each process requires several tens of minutes. Moreover, in this work, in order to match the degree of decrease in the water content of the tea leaves in each process with the processing time, it is unavoidable to perform the processing at a relatively low temperature. For example, in the rough kneading step, since the treatment must be performed under the condition that the temperature of tea leaves is kept at about 35 to 40 ° C., there is a factor that it is not possible to obtain a green tea product having a strong umami and flavor.
The green tea product produced by this method is suitable for brewing using a teapot because it is stick-shaped, but it is difficult to fill it in a sachet, and the elution properties of drinking ingredients are low. There is a problem that it cannot be used as a bag. In the conventional green tea manufacturing method, dust, insect feces, pesticides and other contaminants attached to the tea leaves are processed as they are into the green tea product, which is a sanitary problem. Of course, conventionally, in the area where the volcanic ash adheres to the tea leaves being cultivated, a method of washing the plucked raw tea leaves and then subjecting them to steam heat treatment has been adopted. With this method, not only volcanic ash but also pesticides are removed, so there is no problem in hygiene,
On the other hand, it is almost impossible to completely remove water from the fresh tea leaves that have been washed, and the fresh tea leaves are steam-heat-treated in a wet state. Thus, the raw tea leaves become so-called "raw simmered", which causes the quality of the product green tea to deteriorate. The present invention provides a method of applying sufficient heat treatment to raw tea leaves, and further, to the tea leaves, a treatment comparable to conventional kneading treatment, middle kneading treatment, and fine kneading treatment is added, and at the same time, it is added into a paste or flakes. To provide a green tea that is hygienic, has a high elution of drinking ingredients, can be easily drunk without using a tea ware, and can be made edible. Is intended.

[0004]

[Means for Solving the Problems] The present invention is to treat raw tea leaves picked from a tea field with high humidity hot air having a humidity of 60 to 90% and a temperature of 250 to 390 ° C. for several tens of seconds to perform heat treatment instead of steam heat treatment. The above-mentioned object is achieved by adding. Raw tea leaves picked from the tea field are first washed to remove pesticides and other stains attached to the tea leaves, and then high humidity hot air is applied to the leaves to obtain almost the same heat treatment effect as above. Then, the heat-treated tea leaves are crushed with at least two or more crushing rolls to form a paste or flakes,
Then, the second object described above is achieved by a method in which this is dried by a hot-air dryer or a burner to a predetermined degree of dryness and heat-treated. In the above process, the paste-like or flake-like tea leaves are exposed to high-humidity hot air of about 250 to 390 ° C for a few dozen minutes to several tens of minutes and heat-treated to dry them to a predetermined dryness. Good quality green tea is obtained. The same applies when heat treatment is applied by a heat treatment apparatus of the same type as the heat treatment apparatus B shown in the embodiment. If there is a long interval between the heat treatment of fresh tea leaves and the crushing treatment with a crushing roll, and the temperature of the tea leaves has dropped to about room temperature, high-humidity hot air should be added before crushing the tea leaves. Can be applied and heated. The tea leaves that have been subjected to heat treatment can be made into rough tea by subjecting them to conventional tea making processes such as rough kneading, kneading, middle kneading, and fine kneading.
Depending on the degree of heat treatment, part or all of the rough kneading treatment, the kneading treatment, and the middle kneading treatment can be omitted. Further, it is also possible to adopt a method of applying high-humidity hot air to this rough tea and subjecting it to heat drying.

[0005]

The present invention is applied to fresh tea leaves picked from a tea plantation at 250 to 39%.
Immediately heated by applying hot air with high humidity of about 0 ° C. Moreover, since this high-humidity hot air has a humidity of about 60 to 90%, evaporation of water from the surface layer of the tea leaves is suppressed, and the tea leaves are heated to the inside almost uniformly and sufficiently. It becomes the same as the one that has been treated like a roasted tea. When fresh tea leaves are first washed, rinsing water adheres to the surface of the fresh tea leaves to make them wet, but by applying high-humidity hot air to the wet tea leaves, the water content is rapidly heated and evaporates. , Tea leaves are heated almost as if they were not washed. By crushing the heat-treated tea leaves with a crushing roll, the mesophyll and stem of the tea leaves are crushed. Particularly, since the tea leaves are heat-treated, they become viscous when crushed. Therefore, by treating this tea leaf with two or more stages of crushing rolls, the kneading action is added to the crushing action of the tea leaves to form a paste or flakes. A treatment effect comparable to that of the treatment and the refining treatment can be obtained. Then, by applying high-humidity hot air to this, heat treatment is carried out in the usual manner to obtain a green tea product of the same quality as or better than the finish tea that has been fired.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention will be specifically described below with reference to the illustrated embodiments. In this embodiment, the green tea manufacturing apparatus is
It is composed of a fresh tea leaf cleaning device A, a heat treatment device B, a crushing roll device C, and a hot air drying device D. Further, although not shown, a tea leaf transfer / feed conveyor is provided between the respective processing devices. However, the tea leaves processed in the previous step are sent to the next step. Next to the hot air dryer D, there are a crusher, an electrostatic sorter, a burner,
A finishing machine such as a filling machine is provided so that product green tea for tea bags, drinks, and leaf teas can be obtained. Fresh tea leaf cleaning device A includes a cleaning machine 1 and a dehydrator 2.
The washing machine 1 is provided with a fixed amount feeding device (not shown), and fresh raw tea leaves T picked from the tea garden are quantitatively put into the washing device and washed with water to remove stains attached to the raw tea leaves. Is removed and transferred to the dehydrator 2, and the excess water is removed and sent to the heat treatment apparatus B. The washing machine 1 and the dehydrator 2 are the same as those conventionally used for washing fresh tea leaves. As an example, the dehydrator 2 includes a machine frame 21, a dehydration drum 22, and a drive motor 23. The dehydration drum 22 is a horizontal rotary drum whose body surface 24 is formed by using a perforated plate,
An input port 25 for raw tea leaves is formed on the front surface so that the raw tea leaves are input from here, and a rear face is opened to serve as an outlet port for dehydrated raw tea leaves. A partition plate 26 is spirally attached to the inner surface of the partition plate. Further, a rotating shaft 29 is attached to the center of the rear surface of the dewatering drum 22, which is connected to the drive motor 23 so as to rotate at a predetermined speed. In this centrifugal dehydrator, the front part and the rear part of the dewatering drum 22 are supported by the machine frame 21 by springs 27, so that the dewatering drum 22 can be moved in the front-rear direction and the up-down direction. By the way,
In this embodiment, the dewatering drum 22 is attached to the cover 28, and the cover 28 is supported by the machine frame 21 by the spring 27 and indirectly supported by the machine frame 21. That is, a support rail is formed on the front surface of the dewatering drum 22 at the inlet 25, and a support wheel is attached to the front of the cover 28 so that the support rail is supported by this support wheel. Makes the front part of the dehydration drum 22 cover the body.
Supported by 28. The rotary shaft 29 is pivotally supported on the rear portion of the cover drum 28, and thereby the rear portion of the dehydration drum 22 is supported by the cover drum 28 via the rotary shaft 29. The drive motor 23 transmits a rotational force to the dewatering drum 22 via a rotation shaft 29 to rotate the dewatering drum 22, and a mechanism (not shown) for switching the rotational speed is provided to rotate the dewatering drum 22 at regular intervals. It is possible to automatically switch between the speed for transferring the raw tea leaves into and out (transfer speed) and the speed for applying a predetermined centrifugal force to the raw tea leaves (dewatering speed). . In the dehydrator 2 configured in this way, when the dehydration drum 22 is rotated at the transfer speed, the raw tea leaves that have already been dehydrated inside the drum rise along the body surface and eventually reach an appropriate height. By the way, it falls. Then, the fresh tea leaves repeatedly rise and fall into an apparent fluid state, gradually move to the discharge port side, and are discharged from here. Further, at this time, when the raw tea leaves are fed from the feeding port 21, the raw tea leaves also gradually move toward the outlet side while repeating rising and falling like the previous one. Therefore, the rotation speed of the dewatering drum 22 is switched to the dewatering speed when the head of the raw tea leaves reaches a predetermined position. Then, the raw tea leaves are pressed against the body surface 24 by the action of centrifugal force,
Rotate with 24. At the same time, the water adhering to the raw tea leaves is also subjected to the action of centrifugal force, separated from the raw tea leaves, diffused through the body surface 24, and collected by the cover drum 28. In this dehydrator 2, it suffices that the water is removed to such an extent that the surface of the raw tea leaves is lightly wet, and the water is almost completely removed (for example, until it is in a semi-dried state). do not have to. The raw tea leaves dehydrated by the dehydrator 2 are then sent to the heat treatment apparatus B. In this embodiment, the heat treatment apparatus B uses the rotary drum type heater 3,
A high-humidity hot air generating furnace 4 is connected to this, and high-humidity hot air having a humidity of about 60 to 90% and a temperature of about 250 to 390 ° C. is sent to the horizontal rotary drum 31. Rotating drum type heater 3
The horizontal rotary drum 31 has a material tea leaf inlet 32 formed at one end thereof, and quantitatively introduces fresh green tea leaves from here, and an outlet 33 is formed at the other end thereof, which has a predetermined shape. The tea leaves that have undergone heat treatment are discharged from here. A guide ridge 34 is spirally attached to the inner wall surface of the horizontal rotary drum 31 from the inlet 32 to the outlet 33, whereby a spiral groove is formed on the inner wall surface of the horizontal rotary drum 31. Then, the raw tea leaves introduced into the horizontal rotary drum 31 are sequentially moved toward the outlet 33 through this groove. Further, the horizontal rotary cylinder 31 is formed by using a metal plate, and a heater 35 is provided under the horizontal rotary cylinder 31.
It is designed to be heated to about 290 ° C. Further, a jet nozzle 46 for high-humidity and high-heat air is arranged in the body so that the high-humidity and high-heat air sent from the high-humidity hot air generating furnace 4 is jetted toward the material tea leaves that move inside the body. It has become. The high-humidity hot air generating furnace 4 includes a steam generating tank 41 and a burner.
It consists of 42 and. The steam generation tank 41 is designed to store water at the bottom thereof, while the burner 42 is used for the water surface W of this water.
It is attached at an angle of 30 to 45 ° toward, and by blowing a flame onto the water surface W, the water in the vicinity is heated and evaporated. Steam generation tank 41
Has a delivery port 43 formed at an appropriate position, and is configured to deliver the high-humidity and high-heat air generated in the tank 41 from here, and an air supply port 44 is formed at the other end, From here, new air is supplied into the tank 41. In this embodiment, a blower 45 is connected to the delivery port 43 to suck high-humidity high-heat air from the steam generation tank 41 and send it to the tea steamer as high-humidity hot air. Further, a spray nozzle 47 is attached to a position where the flame ejected from the burner 42 of the steam generation tank 41 does not directly hit, and atomized water is ejected from here. This water mixes with the hot air in the tank 41, is vaporized, and is sent out as high-humidity high-heat air. In this case, since the steam generation tank 41 functions as a mixing tank of water sprayed from the spray nozzle 47 and hot air sprayed from the burner 42, water is accumulated at the bottom of the steam generation tank 41 or burner is used. It is not absolutely necessary to blow the flame of 42 onto the water surface W, but by doing so, it is possible to reliably control the temperature and the water content of the high temperature and high humidity air. The tea leaves that have been heat-treated by the rotary drum heater 3 are then sent to the crush roll device C. The crushing roll machine 5 of the crushing roll device C has several sets of crushing rolls 51a and 51b.
, 52a and 52b, and 53a and 53b, which are arranged one above the other, and which crush the material tea leaves to be fed by the constant quantity feeding conveyor by the crushing rolls 51a and 51b in the uppermost stage, and then in the lower stage in order. It is adapted to be dropped into a crushing roll and crushed repeatedly to make tea leaves into a paste or flakes. Each crush roll 51a and 51b, 52a
And 52b, and 53a and 53b, like ordinary rolls of this kind, when a certain amount of force is applied, the gap is widened, and there is a slight change in the amount of steamed tea leaves passing between both rolls. Even if there is a change, it absorbs the change and constantly crushes the steamed tea leaves with a constant crushing force, and at the same time, it forms pebbles mixed with the material tea leaves, the hard parts of the tea branches, or the lumps of the material tea leaves. When an object or the like enters between the rolls and a force of a certain level or more acts on the rolls, at least one of the rolls retracts to widen the gap between the rolls. The hot-air drying device D is composed of a tray conveyor type continuous heater 6 and a hot-air generating furnace 7. Particularly, in this embodiment, the hot air generating furnace 7 is a high humidity hot air generating furnace. A plurality of tray conveyors 62 are provided in the heating chamber 61 of the continuous heating device 6, and a raw material tea leaf input hopper 63 is formed on the upper surface of the heating chamber 61 and is fed from the crush roll device C. When the material tea leaves are put into the heating chamber 61 from here, the tea leaves are first loaded on the uppermost tray conveyor 62. Then, as the tray conveyor rotates, the tray conveyor is sequentially transferred to the lower tray conveyor while being heated by high-humidity hot air, and finally subjected to a predetermined heat treatment and taken out from the discharge port 64. The hot-air generating furnace 7 has the same structure as the high-humidity hot-air generating furnace 4 of the heat treatment apparatus B described above, and is composed of a steam generating tank 71 and a burner 72.
It is capable of generating high humidity hot air of about 390 ° C.

[0008]

As described above in detail, according to the present invention, since the high-humidity hot air of about 250 to 390 ° C. is applied to the raw tea leaves collected from the tea garden, the surface of the raw tea leaves is less likely to have water attached due to dew condensation. Raw tea leaves are immediately heated. Moreover, since this high-humidity hot air has a humidity of about 60 to 90%, evaporation of water from the surface layer of the tea leaves is suppressed, and the tea leaves are heated to the inside almost uniformly and sufficiently. The result is green tea, which is almost the same as the one that has been subjected to a treatment such as roasted green tea, and has no fishy odor and has a good taste and flavor. If fresh tea leaves are washed prior to heat treatment, the surface of the fresh tea leaves will be wet with rinsing water, but by applying high-humidity hot air to the wet tea leaves, the water content will be rapidly heated. Is evaporated, and the tea leaves are heated in much the same manner as those that are not washed to remove pesticides and other dirt adhering to raw tea leaves, and hygienic tea leaves are obtained. Further, by treating this tea leaf with a crushing roll device, the tea leaf is crushed by the crushing roll and at the same time is subjected to a kneading action to be in the form of paste or flakes, the cell membrane of the tea leaf is broken, and the umami component in the tea leaf is broken. As a result, the green tea having a strong umami and flavor and a high elution property can be obtained due to the fact that the flavor components are mixed with each other. In particular, when the tea leaves are subjected to high-humidity and high-temperature heat treatment before or after the crushing roll process, there is an advantage that the umami and flavor of the product crude tea become stronger.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an example of a rough tea manufacturing process apparatus used in the method of the present invention.

2 is a front view showing a main part of a dehydrator of a cleaning device A. FIG.

FIG. 3 is a vertical sectional side view of the same.

FIG. 4 is a vertical cross-sectional side view showing a main part of a rotary drum heater of a heat treatment apparatus B and a high humidity hot air generating furnace.

5 is a vertical cross-sectional side view showing a main part of the crush roll machine of the crush roll device C. FIG.

FIG. 6 is a vertical cross-sectional side view showing main parts of a continuous heater of a high-humidity hot-air drying device D and a high-humidity hot-air generating furnace.

[Explanation of symbols]

 A Cleaning device B Heat treatment device C Crushing roll device D Hot air drying device 1 Washing machine 2 Dewatering machine 3 Rotating drum type heating machine 4 High humidity hot air generating furnace 5 Crushing roll machine 6 Continuous heating machine 7 Hot air generating furnace 21 Machine frame 22 Dehydration drum 23 Drive motor 24 Body surface 25 Input port 26 Partition plate 27 Spring 28 Cover cylinder 29 Rotating shaft 31 Horizontal rotary cylinder 32 Input port 33 Outlet 34 Guide ridge 35 Heater 41 Steam generating tank 42 Burner 43 Outlet 44 Air supply port 45 Blower 46 Jet nozzle 47 Spray nozzle 51 Crush roll 52 Crush roll 53 Crush roll 61 Heating chamber 62 Tray conveyor 63 Input hopper 64 Discharge port 71 Steam generation tank 72 Burner

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[Procedure amendment]

[Submission date] November 8, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Detailed description of the invention

[Correction method] Change

[Correction contents]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing green tea by heat-treating raw tea leaves picked from a tea field with hot air of high humidity at about 250 to 390 ° C.

[0002]

2. Description of the Related Art The production process of green tea consists of a rough tea process and a finishing process. Green tea is obtained by first contacting raw tea leaves picked in a tea garden with steam at 95 to 105 ° C. for several tens of seconds to steam. Stop fermentation, then coarsely knead, knead, medium knead this steamed tea leaf,
Processing such as fine rubbing, drying, etc. are each added for several tens of minutes to make rough tea,
Furthermore, it is manufactured by adding a fire, sieving, and other finishing treatments. This green tea has been the most commonly used in Japan in the past, and is commonly consumed daily. In particular, recently, this green tea has various medicinal ingredients in addition to vitamins such as tannin, caffeine, and vitamin C. Is recognized,
It is attracting attention not only as a favorite drink but also as a health drink, and is used as a part of food in powder form.

[0003]

Among the above-mentioned conventional green tea production processes, the first steaming heat treatment process is the most important process in the crude tea process, and the quality of the workability in this process is determined by the quality of the workability. It greatly affects the quality of green tea. However, in the conventional steam heat treatment method, as described above, low-temperature steam of 95 to 105 ° C is applied to the raw tea leaves, so that the steam that first comes into contact with the raw tea leaves is dewed and the surface of the raw tea leaves is covered with a thin film of water. And gradually heated by the contacting steam.
In addition, since the temperature of the steam is low, the water hardly evaporates, and the tea leaves are in a so-called “raw boiled” state. In addition, after the steaming heat treatment, rough rubbing treatment, kneading treatment, medium rubbing treatment, and fine rubbing treatment are added, so that at the stage of finishing the steaming heat treatment, the tea leaves are tough enough to perform the following treatments. Therefore, the steaming heat treatment time must be suppressed to about several tens of seconds. Therefore, the heating is insufficient for the tea leaves, and the green tea product has a problem that the umami and flavor are light and a blue smell remains. Conventionally, in order to eliminate such problems, it is necessary to add 110-130 to raw tea leaves.
A method of applying hot air of about ℃ was tried. However, according to this method, the water in the surface layer of the fresh tea leaves evaporates, the surface becomes a dead leaf state, and the inside is not heated and becomes a fresh leaf state. In the processing steps from the rough kneading step to the fine kneading step, which follow the steaming step, the steamed tea leaves are kneaded while being heated to gradually reduce the water content of the tea leaves.
This is twisted to give a rod-like finish. This processing method has a problem in that workability is poor because each process is a batch work and each process requires several tens of minutes. Moreover, in this work, in order to match the degree of decrease in the water content of the tea leaves in each process with the processing time, it is unavoidable to perform the processing at a relatively low temperature. For example, in the rough kneading step, since the treatment must be performed under the condition that the temperature of tea leaves is kept at about 35 to 40 ° C., there is a factor that it is not possible to obtain a green tea product having a strong umami and flavor.
The green tea product produced by this method is suitable for brewing using a teapot because it is stick-shaped, but it is difficult to fill it in a sachet, and the elution properties of drinking ingredients are low. There is a problem that it cannot be used as a bag. In the conventional green tea manufacturing method, dust, insect feces, pesticides and other contaminants attached to the tea leaves are processed as they are into the green tea product, which is a sanitary problem. Of course, conventionally, in the area where the volcanic ash adheres to the tea leaves being cultivated, a method of washing the plucked raw tea leaves and then subjecting them to steam heat treatment has been adopted. With this method, not only volcanic ash but also pesticides are removed, so there is no problem in hygiene,
On the other hand, it is almost impossible to completely remove water from the fresh tea leaves that have been washed, and the fresh tea leaves are steam-heat-treated in a wet state. Thus, the raw tea leaves become so-called "raw simmered", which causes the quality of the product green tea to deteriorate. The present invention provides a method of applying sufficient heat treatment to raw tea leaves, and further, to the tea leaves, a treatment comparable to conventional kneading treatment, middle kneading treatment, and fine kneading treatment is added, and at the same time, it is added into a paste or flakes. To provide a green tea that is hygienic, has a high elution of drinking ingredients, can be easily drunk without using a tea ware, and can be made edible. Is intended.

[0004]

[Means for Solving the Problems] The present invention is to treat raw tea leaves picked from a tea field with high humidity hot air having a humidity of 60 to 90% and a temperature of 250 to 390 ° C. for several tens of seconds to perform heat treatment instead of steam heat treatment. The above-mentioned object is achieved by adding. When the fresh tea leaves collected from the tea garden are first washed to remove pesticides and other stains adhering to the tea leaves, and high humidity hot air is applied to the wet fresh tea leaves , a further heat treatment effect can be obtained.
In addition, spray fog, sprinkle water on this fresh tea leaf, or
Soak the leaves in water to make the surface moist.
Also, the same heat treatment effect can be obtained. Then, the heat-treated tea leaves are crushed with at least two or more crushing rolls or crushed between a pair of crushers to form a paste or flakes, which are then crushed. The second object described above is achieved by a method of drying with a hot air drier or a fire drier to a predetermined degree of dryness and heat treatment. In the above process, the paste-like or flake-like tea leaves are exposed to high-humidity hot air of about 250 to 390 ° C for a few dozen minutes to several tens of minutes and heat-treated to dry them to a predetermined dryness. Good quality green tea is obtained. The same applies when heat treatment is applied by a heat treatment apparatus of the same type as the heat treatment apparatus B shown in the embodiment. The interval between the heat treatment of fresh tea leaves and the crushing treatment with a crushing roll is long,
When the temperature of the tea leaves has dropped to about room temperature, high-humidity hot air can be applied and heated prior to adding the crushing treatment. The tea leaves that have been subjected to heat treatment can be made into rough tea by subjecting them to conventional tea making processes such as rough kneading, kneading, middle kneading, and fine kneading. Depending on the degree of heat treatment, a part of rough kneading treatment, kneading treatment, and middle kneading treatment,
Alternatively, all can be omitted. Further, it is also possible to adopt a method of applying high-humidity hot air to this rough tea and subjecting it to heat drying.

[0005]

The present invention is applied to fresh tea leaves picked from a tea plantation at 250 to 39%.
Immediately heated by applying hot air with high humidity of about 0 ° C. Moreover, since this high-humidity hot air has a humidity of about 60 to 90%, evaporation of water from the surface layer of the tea leaves is suppressed, and the tea leaves are heated to the inside almost uniformly and sufficiently. It becomes the same as the one that has been treated like a roasted tea. Soaking raw tea leaves in water or washing
By doing so , rinsing water adheres to the surface of the fresh tea leaves and becomes damp.
It will be in a broken state . By applying high-humidity hot air to the damp tea leaves, the evaporation of water from the surface layer of the tea leaves is surely suppressed.
The tea leaves are heated evenly and fully to the inside.
It will be done . By crushing the heat-treated tea leaves, the mesophyll and stem of the tea leaves are crushed. Particularly, since the tea leaves are heat-treated, they become viscous when crushed. Therefore, this tea leaf is crushed in two or more stages and crushed.
By processing with a board , the tea leaves are kneaded and kneaded into paste or flakes, which is comparable to conventional kneading, middle kneading, and refinement in the rough tea manufacturing process. A processing effect can be obtained. When high-humidity hot air is applied to this, it becomes a green tea product of the same quality as or higher than the finish tea that has been heat-treated and burned in the usual manner.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention will be specifically described below with reference to the illustrated embodiments. In this embodiment, the green tea manufacturing apparatus is
It is composed of a fresh tea leaf cleaning device A, a heat treatment device B, a crushing roll device C, and a hot air drying device D. Further, although not shown, a tea leaf transfer / feed conveyor is provided between the respective processing devices. However, the tea leaves processed in the previous step are sent to the next step. Next to the hot air dryer D, there are a crusher, an electrostatic sorter, a burner,
A finishing machine such as a filling machine is provided so that product green tea for tea bags, drinks, and leaf teas can be obtained. Fresh tea leaf cleaning device A includes a cleaning machine 1 and a dehydrator 2.
The washing machine 1 is provided with a fixed amount feeding device (not shown), and fresh raw tea leaves T picked from the tea garden are quantitatively put into the washing device and washed with water to remove stains attached to the raw tea leaves. Is removed and transferred to the dehydrator 2, and the excess water is removed and sent to the heat treatment apparatus B. The washing machine 1 and the dehydrator 2 are the same as those conventionally used for washing fresh tea leaves.
Like that, immersing raw tea leaves in water to rinse, and then
It scoops water from the water and drains it. As an example, the dehydrator 2 includes a machine frame 21, a dehydration drum 22, and a drive motor 23. The dewatering drum 22 is a horizontal rotary drum whose body surface 24 is formed by using a perforated plate.
No. 25 is formed and raw tea leaves are input from here, and the rear surface is open and serves as an outlet for dehydrated raw tea leaves. A partition plate 26 is spirally attached to the inner surface of the partition plate. Further, a rotating shaft 29 is attached to the center of the rear surface of the dewatering drum 22, which is connected to the drive motor 23 so as to rotate at a predetermined speed. In this centrifugal dehydrator, the front part and the rear part of the dehydration drum 22 are supported by the machine frame 21 by springs 27,
It is possible to change in the front-back direction and the up-down direction. By the way, in this embodiment, the dewatering drum 22 is attached to the cover 28, and the cover 28 is a spring.
It is supported by the machine casing 21 by 27 and indirectly supported by the machine casing 21. That is, a support rail is formed on the front surface of the dehydration drum 22 at the inlet 25,
A support wheel is attached to the front part of the cover 28, and the front part of the dehydration drum 22 is supported by the cover 28 by the support rails being supported by the support wheel. The rotary shaft 29 is pivotally supported on the rear portion of the cover drum 28, and thereby the rear portion of the dehydration drum 22 is supported by the cover drum 28 via the rotary shaft 29. The drive motor 23 transmits a rotational force to the dewatering drum 22 via a rotation shaft 29 to rotate the dewatering drum 22, and a mechanism (not shown) for switching the rotational speed is provided to rotate the dewatering drum 22 at regular intervals. It is possible to automatically switch between the speed for transferring the raw tea leaves into and out (transfer speed) and the speed for applying a predetermined centrifugal force to the raw tea leaves (dewatering speed). . In the dehydrator 2 configured in this way, when the dehydration drum 22 is rotated at the transfer speed, the raw tea leaves that have already been dehydrated inside the drum rise along the body surface and eventually reach an appropriate height. By the way, it falls. Then, the fresh tea leaves repeatedly rise and fall into an apparent fluid state, gradually move to the discharge port side, and are discharged from here. Further, at this time, when the raw tea leaves are fed from the feeding port 21, the raw tea leaves also gradually move toward the outlet side while repeating rising and falling like the previous one. Therefore, the rotation speed of the dewatering drum 22 is switched to the dewatering speed when the head of the raw tea leaves reaches a predetermined position. Then, the raw tea leaves are subjected to the action of centrifugal force on the body surface.
It presses against 24 and rotates with the body surface 24. At the same time, the water attached to the raw tea leaves is also subjected to the centrifugal force,
Material Separated from raw tea leaves and diffused through the body surface 24, covering the body 28
Will be collected by. In this dehydrator 2, the water is
It is sufficient to remove the material so that the surface of the raw tea leaves becomes lightly wet, and it is not necessary to remove the water almost completely (for example, until it becomes a semi-dry state). The raw tea leaves dehydrated by the dehydrator 2 are then sent to the heat treatment apparatus B.
In this embodiment, the heat treatment apparatus B uses a rotary drum heater 3, a high humidity hot air generator 4 is connected thereto, and a horizontal rotary drum 31 has a humidity of 60 to 90% and a temperature of 250. ~ 390
It is designed to send in hot air with high humidity of about ℃. The horizontal rotary drum 31 of the rotary drum heater 3 has a feed port 32 for the material tea leaves formed at one end, from which fresh green tea leaves are quantitatively fed, and an outlet port 33 is formed at the other end. The tea leaves which have been subjected to a predetermined heat treatment are discharged from here. An inlet 32 is provided on the inner wall surface of the horizontal rotary drum 31.
Guide ridges 34 are attached spirally from the horizontal direction to the take-out port 33, whereby a spiral groove is formed on the inner wall surface of the horizontal rotary cylinder 31 and the raw material fed into the horizontal rotary cylinder 31 is formed. The tea leaves are sequentially moved toward the outlet 33 through this groove. Further, the horizontal rotary drum 31 is formed by using a metal plate, and a heater 35 is provided under the horizontal rotary drum 31,
It is designed to be heated to 250 to 290 ℃.
Further, a jet nozzle 46 for high-humidity and high-heat air is arranged in the body so that the high-humidity and high-heat air sent from the high-humidity hot air generating furnace 4 is jetted toward the material tea leaves that move inside the body. It has become. The high humidity hot air generator 4 is a steam generation tank
It consists of 41 and burner 42. The steam generating tank 41 is designed to store water at the bottom thereof, while the burner 42 is attached at an angle of 30 to 45 ° toward the water surface W of this water, and by blowing a flame onto the water surface W, It heats nearby water and evaporates it. The steam generation tank 41 has a delivery port 43 formed at an appropriate position,
The high-humidity, high-heat air generated inside is sent out from here, and an air supply port 44 is formed at the other end so that new air can be supplied to the tank 41 from here. ing. In this embodiment, a blower 45 is connected to the delivery port 43 to suck high-humidity high-heat air from the steam generation tank 41 and send it to the tea steamer as high-humidity hot air. Further, a spray nozzle 47 is attached to a position where the flame ejected from the burner 42 of the steam generation tank 41 does not directly hit, and atomized water is ejected from here. This water mixes with the hot air in the tank 41, is vaporized, and is sent out as high-humidity high-heat air. In this case, since the steam generation tank 41 functions as a mixing tank of water sprayed from the spray nozzle 47 and hot air sprayed from the burner 42, water is accumulated at the bottom of the steam generation tank 41 or burner is used. It is not absolutely necessary to blow the flame of 42 onto the water surface W, but by doing so, it is possible to reliably control the temperature and the water content of the high temperature and high humidity air. The tea leaves that have been heat-treated by the rotary drum heater 3 are then sent to the crush roll device C. The crush roll machine 5 of the crush roll device C has several sets of crush rolls 51.
a and 51b, 52a and 52b, and 53a and 53b, which are arranged above and below each other, and the material tea leaves fed by the constant quantity feeding conveyor are crushed by the uppermost crushing roll 51a,
After being crushed by 51b, they are successively dropped on a crushing roll in the lower stage and repeatedly crushed to make tea leaves into paste or flakes. Each crush roll 51a and 51
b, 52a and 52b, and 53a and 53b, like ordinary rolls of this type, are designed so that when a certain amount of force is applied, the gap is widened, and the amount of steamed tea leaves passing between the rolls is increased. Even if there is some change, it absorbs the change and always crushes the steamed tea leaves with a constant crushing force, and at the same time, the pebbles mixed with the material tea leaves and the hard parts of the tea branches,
Alternatively, when a lump of material tea leaves or the like enters between the rolls and a force of a certain level or more acts on the rolls, at least one of the rolls retreats to widen the gap between the rolls. The hot-air drying device D is composed of a tray conveyor type continuous heater 6 and a hot-air generating furnace 7. Particularly, in this embodiment, the hot air generating furnace 7 is a high humidity hot air generating furnace. A plurality of tray conveyors 62 are provided in the heating chamber 61 of the continuous heating device 6, and a raw material tea leaf input hopper 63 is formed on the upper surface of the heating chamber 61 and is fed from the crush roll device C. When the material tea leaves are put into the heating chamber 61 from here, the tea leaves are first loaded on the uppermost tray conveyor 62. Then, as the tray conveyor rotates,
While being heated by high-humidity hot air, they are transferred to the tray conveyor in the lower stage one by one, and finally subjected to the prescribed heat treatment and the discharge port 64
It will be taken out more. The hot air generator 7
It has the same structure as the high-humidity hot air generating furnace 4 of the heat treatment apparatus B described above, and comprises a steam generating tank 71 and a burner 72.
It is capable of generating high humidity hot air of about 0 to 390 ° C.

[0008]

As described above in detail, according to the present invention, since the high-humidity hot air of about 250 to 390 ° C. is applied to the raw tea leaves collected from the tea garden, the surface of the raw tea leaves is less likely to have water attached due to dew condensation. Raw tea leaves are immediately heated. Moreover, since this high-humidity hot air has a humidity of about 60 to 90%, evaporation of water from the surface layer of the tea leaves is suppressed, and the tea leaves are heated to the inside almost uniformly and sufficiently. The result is green tea, which is almost the same as the one that has been subjected to a treatment such as roasted green tea, and has no fishy odor and has a good taste and flavor. If the fresh tea leaves are washed prior to heat treatment, they become wet due to the rinsing water adhering to the surface, but by applying high-humidity hot air to the wet tea leaves, the water content from the surface layer of the tea leaves is increased. The evaporation of
The tea leaves are heated evenly and sufficiently to the inside.
In addition, the pesticide and other stains attached to raw tea leaves are removed, and hygienic tea leaves are obtained.
When it is not necessary to wash the fresh tea leaves, spray a fog on it.
Baking, sprinkling water, or soaking raw tea leaves in water
Then, attach water to the surface and moisten the raw tea leaves appropriately.
When heat treatment is performed in a stale state, the tea leaves
The evaporation of water from the surface layer is reliably suppressed, and the tea leaves are
There is an effect that the part is heated uniformly and sufficiently. or,
By treating this tea leaf with a crushing roll device or a crushing machine , the tea leaf is crushed and at the same time is subjected to a kneading action into a paste or flakes, and the cell membrane of the tea leaf is broken and the umami component and flavor in the tea leaf are broken. Because the ingredients mix,
It is possible to obtain green tea having a strong umami and flavor and a high elution property. In particular, when the tea leaves are subjected to high-humidity and high-temperature heat treatment before or after the crushing step, there is an advantage that the umami and flavor of the rough tea product are further enhanced.

Claims (4)

[Claims] 1. Humidity: 60-for fresh tea leaves plucked from a tea garden
A method for producing green tea using high-humidity hot air, which comprises applying high-humidity hot air at a temperature of about 250 to 390 ° C for 90% to heat treatment for a few tens of seconds, and then subjecting this to tea-making treatment. 2. Raw tea leaves picked from a tea field are first washed to remove pesticides and other dirt adhering to the raw tea leaves, and then the humidity is 60 to 90%, and the temperature is 250 to 390 ° C. The method for producing green tea using high-humidity hot air according to claim 1, characterized in that hot air with humidity is applied for several tens of seconds for heat treatment. 3. Heat-treated fresh tea leaves are crushed with at least two or more crushing rolls to form a paste or flakes, and heated with high-humidity hot air to heat the leaves.
The method for producing green tea using high-humidity hot air according to claim 1 or 2, characterized by drying. 4. Heat-treated green tea leaves are then subjected to rough kneading treatment, kneading treatment, middle kneading treatment, and fine kneading treatment, and then dried, or after being subjected to middle kneading treatment and fine kneading treatment, dried. The method for producing green tea using the high-humidity hot air according to claim 1 or 2.