JPH0469980B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for producing kama-iri tea and an apparatus for producing kama-iri tea. [Conventional technology] The conventional method for producing kama-iricha is to put raw tea leaves into the rotary kettle of a direct-fired cylindrical leaf-shaking continuous leaf roasting machine consisting of a rotating cylindrical kettle and a fixed kettle. ~400
℃) to deactivate the oxidizing enzymes while making effective use of the moisture in the raw tea leaves, then transfer them to the fixed pot of the same machine, shake the leaves, and dry them to a certain condition. The tea leaves are rolled in a rolling machine, and then dried in a direct-fired continuous water dryer consisting of three rotary pots, which are sequentially moved through rotary pots with different pot temperatures and rotational speeds, while being heated and rotated. , further tighten to obtain rough tea. After drying and sorting, the product is obtained by putting it in a direct-fired rotary pot and heating and finishing it. (Refer to Chamber of Tea Industry, published July 1, 1981). The pot bodies of each machine used here are all made of iron materials such as steel plates. [Problem to be solved by the invention] The tea making machine used in the above-mentioned conventional method is an open fire type and heats it in an iron pot, so the tea leaves come into direct contact with the iron pot, resulting in burnt, uneven spots, etc. will occur. In addition, it had the disadvantage of exhibiting a strong bitter and astringent taste and lacking in the aromatic flavor characteristic of kamairicha. The present invention eliminates these drawbacks of conventional pot-irrigated tea, reduces the bitterness and astringency of tea, makes the tea clear and light blue,
The object of the present invention is to provide a method for producing kama-iri tea that enhances the aromatic taste peculiar to kama-iri tea. [Means for Solving the Problems] The method for producing kamairicha of the present invention uses a cylindrical direct-fired heating pot in which a ceramic material layer is provided on the inside of an iron pot and does not have a built-in heating element, or the pot itself is Raw tea leaves are placed in a cylindrical direct-fired heating pot made of ceramic material and without a built-in heating element, and the direct-fired heating pot is heated while rotating the direct-fired heating pot. Heat is applied to the ceramic material layer or the ceramic material of the direct-fired heating pot by heating with a heating device provided outside the pot, and the ceramic material layer or the ceramic material of the direct-fired heating pot is heated. The method is characterized in that the raw tea leaves are heated by radiation of far infrared rays from the tea leaves. In addition, water drying subsequent to the process of processing the leaves,
As the direct-fired heating pot used in each process of tightening and heating, it is desirable to use a pot made of iron with a ceramic material layer provided on the inside, or a pot made of a ceramic material. In addition, the kettle tea manufacturing apparatus of the present invention has a ceramic material layer provided inside the iron pot, or
A cylindrical direct-fired heating kettle for producing kettle-dried tea, the kettle itself being made of ceramic material and having no built-in heating element, and a heater provided outside the direct-fired heating kettle to heat the direct-fired heating kettle. The present invention is characterized by comprising a device and a drive mechanism that rotationally drives the direct-fired heating pot. [Function] In order to eliminate the defects caused by the conventional production of kama-iri tea mentioned above, the present inventors conducted repeated research on the production method, and found that during the production process of kama-iri tea, high temperature treatment, which most affects the quality, was found. It has been found that during the leaf process, the raw tea leaves that are introduced may stick to the walls of the pot or come in contact with the hot walls of the pot and burn. In addition, in the process that uses a heated iron kettle in the tea manufacturing process, that is, in the machines used for each process of roasting, water drying, tightening, and pasteurization, the action of iron ions is enhanced because the tea leaves come into contact with the heated iron kettle. It was found that the quality deteriorates if the product is exposed to strong exposure. Therefore, in the process of processing the tea leaves in the kettle over these open flames, a ceramic material layer is provided inside the iron material by means such as thermal spraying, or the kettle body itself is made of ceramics to form the kettle body. When kama-iricha was produced using these pot bodies, the tea leaves were not affected by iron ions at all, and the radiant heat from the far infrared rays from the ceramic material increased the thermal energy received by the treated leaves, increasing tea manufacturing efficiency. We found the following effects. That is, in the process of roasting leaves, the temperature at the bottom of the pot is
For example, the temperature is said to be 300 to 400 degrees Celsius, but in the present invention, the inside of the pot is coated with ceramic material, so the tea leaves do not come into direct contact with the iron pot, so the tea leaves do not burn and are not affected by iron ions. do not have. Further, the ceramic material generates far infrared rays of, for example, 2.5 to 25 μm, which includes the infrared absorption spectrum of tea leaves of 6 to 10 μm, which increases heat absorption efficiency. The same applies to the pots of the subsequent water dryer, tightening machine, and pasteurization machine. [Example] Hereinafter, the features of the present invention will be specifically explained based on an example with reference to the drawings. As the leaf milling machine used in the present invention, basically, a commonly used continuous leaf milling machine for pot-roasted tea can be used. FIGS. 1a, b, c, and d are a front view, a left side view, a right side view, and a sectional view of a main part of a leaf machine used in the present invention. Above the burner 2 provided in the machine frame 1, a cylindrical first rotary hook body 3 tilted to the lower right is disposed, and above it is a second rotary rotary rotary hook body 3 tilted slightly to the lower left. A pot body 4 is provided. Furthermore, the second
On the side of the rotary hook body 4, there is a fixed hook body 5 which is open from the top.
is installed. The above-mentioned first and second rotary hook bodies 3 and 4 are driven from the shaft or the outer periphery by a well-known drive mechanism. Then, when raw tea leaves are introduced from the fresh leaf inlet 6, the raw tea leaves are carried in from one end side of the first rotary pot body 3 by the rotating spiral blades 7. The raw tea leaves in the first rotating cauldron body 3 are roasted in the cauldron body 3 by direct fire from the burner 2, and move to the right in the drawing due to their own weight, and the first rotation Pot body 3
is carried out from the other end. After being carried out, the tea leaves are put into a cyclone 9 provided at one end of the second rotary kettle body 4 via a blower pipe 8. The tea leaves after being introduced are carried in from one end side of the second rotary kettle body 4 by the rotary spiral blade 10. The tea leaves in the second rotary pot body 4 are heated by convection heat from the burner 2, move to the left in the drawing due to their own weight, and are carried out from the other end of the second rotary pot body 4. After being carried out, the tea leaves are conveyed in the direction of the fixed pot body 5 by the rotary paddle 11. Further, inside the fixed pot body 5, leaf wiping is performed by a leaf wiping hand 12 shown in FIG. 1d. Note that instead of the fixed hook 5, a third rotary hook body may be used. Here, in this embodiment, as the first and second rotary hook bodies 3, 4 and fixed hook body 5 of this leaf cutting machine, as shown in FIG. Ceramics material 22 on the inside of 0.05~1
mm, desirably sprayed to a thickness of about 0.1 to 1 mm,
A pot body in which a ceramic layer is formed on the inner surface of the pot bodies 3, 4, and 5 is used. This ceramic material 22
Gray alumina (Al ₂ O ₃ 97.5%,
TiO ₂ 2.5%), alumina titania (Al ₂ O ₃ 58.3%,
_TiO2 41.4%), magnesia silica (MgO39.4
%, SiO ₂ 59.1%), Zircon (ZrO ₂ 65.4%,
SiO ₂ 33.1%), mullite (Al ₂ O ₃ 76.6%, SiO ₂ 22.9
%), alumina chromia (Al ₂ O ₃ 50.0%,
Cr ₂ O ₃ 49.3%) etc. can be used. Further, it is also possible to use a pot body in which each pot body itself is made of a ceramic material. The ceramic material in this case is cordierite (Al ₂ O ₃ 30
%, SiO ₂ 50%, CaO・MgO 15%), Lisia (Al ₂ O ₃ 20.0%, SiO ₂ 70.0%, CaO・MgO 0.5%,
LiO3.0%), zircon (Al ₂ O ₃ 12.0%, SiO ₂ 50.0
%, CaO・MgO2.0%, ZrO ₂ 25.0%), etc. can be used. Note that a ceramic material 22 is placed inside the iron material 21.
When thermally spraying, if the spraying thickness is less than 0.05mm, the base surface is likely to be exposed and the effect of far infrared rays will be weakened. Furthermore, in the process of roasting leaves, in order to prevent the tea leaves from sticking to the wall surface, the inner surface of the pot body is coated with a certain level of roughness, for example, 30 to 50 μm (10
Point average roughness) is required, but if the thermal spraying thickness is thin, there is a disadvantage that the roughness of the thermal spray coating cannot be ensured. Moreover, if the thickness is more than 1 mm, separation may occur due to the difference in coefficient of thermal expansion between the iron material and the thermally sprayed coating, resulting in disadvantages such as a decrease in temperature of the thermally sprayed surface layer and an increase in manufacturing costs. The method of using this leaf machine is basically the same as that of a conventional leaf machine with an iron pot body, but the processing time is shortened as will be described later. In the leaf blower used in the method of the present invention, the main body or the inside of the heating pot is made of ceramics, so far infrared rays are radiated from the ceramics and the radiant temperature increases. As shown in Table 1, when this example is compared with the conventional heating pot made of iron, the difference between the contact temperature and the radiation temperature of the pot surface is significantly different. Note that the temperature is the bottom temperature of the pot.

[Table] In the table, "sprayed" indicates that ceramics are sprayed on the inside of the pot body, and "base material" indicates that the pot body itself is made of ceramics. In other words, in the case of iron material, when the contact temperature is 287℃ (after 10 minutes), the radiation temperature is 324℃, which is 37℃ higher.
When the contact temperature is 354℃ (after 15 minutes), the radiation temperature is 338℃, which is 16℃ lower. In contrast, in the case of ceramic spraying, the contact temperature is 250℃ (after 15 minutes).
The radiant temperature always remained high from the low temperature range of 334°C (after 40 minutes) to the high temperature range of 334°C (after 40 minutes). Similarly, in the case of ceramic substrates, the radiation temperature was maintained higher than the contact temperature. Therefore, when tea leaves are heated in an iron pot, the outer edges of the tea leaves feel too dry, and the tea leaves tend to dry out with little weight loss. On the other hand, in the case of a pot made of ceramics, the roasted tea leaves are more flexible and the weight loss is greater. The degree of weight loss in the low temperature range of 300 to 330°C was 47% for iron pots, while it was 50% for ceramic pots. And in the high temperature range of 400℃, the iron pot has 52%
In contrast, it is 64% for the ceramic pot, and the weight reduction of the leaves in the ceramic pot body of the method of the present invention proceeds smoothly. Therefore, the tea leaves become bright green. In addition, the nominal input capacity of a tea machine is usually 60 for iron pots.
%, a 75Kg type leaf blower produces 45Kg per hour.
However, since 70 to 75% of the amount can be charged in a ceramic pot, the amount of input is 52 to 56 kg, and it has a processing capacity of 115 to 124% of that of an iron pot. As this leaf machine, for example,
A roasting device having the configuration described in Publication No. 9049, a continuous roasting machine manufactured by Mori Tekko Co., Ltd. "200K type", "120K type",
The basic configuration is the ``75K type,'' which can be modified and used. Note that the leaf blower is not limited to this type, and if it is a direct fire type leaf blower, one that has a ceramic layer on the inside of the iron material by ceramic spraying or the like, or one that has a pot body made of ceramic material, can be used. For example, it can be used in the present invention. Next, the steps after the above-mentioned iris leaf treatment will be explained. After processing the leaves, as described below, they are dried using a water dryer, a tightening machine, and a finishing machine, respectively.
Water-drying, tightening, and finishing processes are performed. The water dryer used in the present invention is basically a commonly used continuous water dryer or batch type water dryer. Continuous water dryers have three rotating cylindrical iron pots arranged above the burner, and the temperature of each pot is raised from below using an open flame. This is a machine that performs drying at a predetermined internal temperature and rotation speed. In addition, in a batch type water dryer, a rotary cylinder made of a cylinder made of iron plate rotates above the burner, and a cover made of iron plate is provided on the outside of this rotary cylinder, and the rotary cylinder, that is, the pot body, is heated with an open flame from below. Drying is performed by raising the temperature and setting the pot body to a predetermined temperature and rotation speed. In the present invention, as the pot body of these water dryers, a pot body with a ceramic material layer formed on the inside of the iron material of the rotary cylindrical pot body as in the case of the above-mentioned leaf blower, or a pot body made essentially only of ceramic material. Use the pot body you made. Furthermore, the tightening machine used in the present invention is based on a commonly used batch tightening machine such as the "80K" tightening machine manufactured by Mori Tekkosho Co., Ltd.; A rotary cylinder made of a cylinder made of iron plate rotates above the burner, and a cover made of iron plate is provided on the outside of this rotary cylinder, and the temperature of the rotary cylinder, that is, the pot body is raised by direct fire from below, and the pot body is heated to a predetermined position. This is a machine that performs drying at a temperature and rotation speed of . Further, the finishing machine used in the present invention is of the same type as the above-mentioned tightening machine, but the usage conditions such as the temperature inside the pot and the number of revolutions are different. Note that the water dryer, tightening machine, and finishing machine are not limited to the above-mentioned types, and the present invention can be applied to any machine that uses a direct-fired pot. In the water-drying, tightening, and finishing processes mentioned above,
In this embodiment, the direct-fire heating pot is made of an iron pot coated with a ceramic layer or made of ceramic material itself. Therefore, the emissivity of far-infrared rays is higher than when processing with a conventional iron pot, and the processing time for each step is shortened, even though the temperature of the pot is almost the same. For example, in the water drying process, 5
~10 minutes, about 25 minutes for the tightening process, and about 15 minutes for the finishing process. Example 1 50 kg of raw tea leaves were stored in a furnace with a furnace at the bottom and two furnaces at the top.
Irrigation leaves using a heating pot with approximately 0.2 mm of gray alumina sprayed on the inside of each heating pot of a continuous type leaf machine (manufactured by Mori Tekko Co., Ltd., 75K type) that has two rotary pots and one fixed pot. The leaves were put into a machine and roasted for 13 minutes at a temperature of 326°C, yielding 24.15 kg of roasted leaves. Note that each of the following machines also uses a heating pot in which gray alumina is sprayed on the inside of the original heating pot in the same manner as described above. This is put into a kneading machine (manufactured by Kawasaki Kiko Co., Ltd., model 60) and kneaded for 20 minutes. 24.15Kg of the obtained tea leaves,
A continuous water dryer (Mori Type 200, manufactured by Mori Iron Works Co., Ltd.) has a furnace at the bottom and a three-stage rotary pot at the top.
Dry for about 20 minutes at a pot temperature of 70 to 150°C (exhaust temperature 35°C), and then dry using a tightening machine (Mori Iron Works Co., Ltd., Mori Type 80).
Depending on the type (type), the pot temperature is 100 to 200℃ (exhaust temperature 45℃)
Tighten for about 25 minutes. Finally, the heat was heated to 110 to 200°C using a direct fire type pasteurization machine (manufactured by Mori Tekko Co., Ltd., model 80).
Cook for about 15 minutes at a pot temperature of (exhaust temperature 60℃). Example 2 Same as Example 1, but each heating pot itself was
Constructed from a ceramic base of 10 to 30 mm. In addition,
Cordierite was used as the ceramic base. The teas produced in Examples 1 and 2 as described above were bright green in color, the leached water was yellowish green, and the tea had a refreshing aroma and a good nutritious taste. The sensory evaluation and chemical analysis values of the tea leaves obtained in this example are shown. (1) Sensory evaluation 10 experienced sensory judges evaluated the tea obtained in Examples 1 and 2 above in five categories: shape, color, aroma, light color, and flavor, compared to kamairi tea produced using the conventional method. compared. The results are shown in Table 2.

[Table] (2) Chemical analysis values In addition, the amounts of amino acids and tannins were measured in the infusion solution obtained by infusing the tea obtained in this example and the pot-dried tea produced by the conventional method in hot water at 80° C. for 30 minutes. The results are shown in Table 3. Note that mg% represents the amount of the component contained in 100 g of dry matter in mg.

〔Effect of the invention〕

In the present invention, since the tea leaves are heated through the ceramic material, the tea leaves are not affected by iron ions from the iron pot. Therefore, it is possible to obtain tea with excellent nutritious taste without any inconveniences such as the light blue color of the tea becoming reddish or the tea becoming bitter. In addition, in the roasting process, the leaves are roasted in a state where the radiant temperature is always higher than the contact temperature, so it is possible to obtain supple leaves without drying out the top of the tea leaves or producing a burnt odor.
Excellent color and flavor. Furthermore, the radiant heat generated by the far infrared rays of the ceramics increases the thermal energy received by the treated leaves, which has the effect of increasing the efficiency of tea production.

[Brief explanation of the drawing]

Figures 1 a, b, c, and d are a schematic front view, left side view, right side view, and partial cross-sectional view of a leaf cutting machine used in carrying out the present invention, and Figure 2 is a cross-sectional view of the main part of the hook body. It is a diagram. 1: machine frame, 2: burner, 3: first rotary hook body,
4: second rotating pot body, 5: fixed pot body, 6: fresh leaf inlet, 7: rotating spiral blade, 8: blower pipe,
9: Cyclone, 10: Rotating spiral blade, 11:
Rotating paddle, 12: Leaf scraper, 21: Iron material, 2
2: Ceramics material.

Claims (1)

[Scope of Claims] 1. A cylindrical direct-fired heating pot in which a ceramic material layer is provided inside the iron pot and does not have a built-in heating element;
Alternatively, raw tea leaves are put into a cylindrical direct-fired heating pot whose pot itself is made of ceramic material and does not have a built-in heating element, and the direct-fired heating pot is heated while rotating the direct-fired heating pot. Heat is applied to the ceramic material layer of the direct-fired heating oven or the ceramic material of the direct-fired heating oven by heating with a heating device provided outside the direct-fired heating oven; , or a method for producing pot-dried tea, characterized in that the raw tea leaves are heated and roasted by far-infrared radiation from the ceramic material. 2. As a direct-fired heating pot used in the water-drying, tightening, and pasteurization steps that follow the above-mentioned process of processing leaves, a pot body with a ceramic material layer provided on the inside of an iron pot, or a pot itself made of ceramics is used. 2. The method for producing pot-irrigated tea according to claim 1, characterized in that a pot body made of a raw material is used. 3. A cylindrical direct-fired heating pot for producing kettle-irradiated tea, which has a ceramic material layer on the inside of an iron pot and does not have a built-in heating element, and a direct-fired heating pot that is provided outside of the direct-fired heating pot. 1. A kettle tea manufacturing apparatus comprising: a heating device that heats the tea; and a drive mechanism that rotationally drives the direct-fired heating pot. 4. A cylindrical direct-fired heating kettle for producing kettle-irradiated tea, the kettle itself being made of a ceramic material and having no built-in heating element, and a direct-fired heating kettle provided outside the direct-fired heating kettle to heat the direct-fired heating kettle. A kettle tea manufacturing apparatus, comprising: a heating device; and a drive mechanism that rotationally drives the direct-fired heating pot.