WO2013035832A1 - Method for producing green and dried eucommia leaf product - Google Patents

Abstract

The purpose of the present invention is to provide a processing method, whereby a green tea micropowder having a pure green color and high sweetness and containing a large amount of useful components can be produced while shortening the production time by 1/4 (compared with a conventional method requiring 120 minutes) and minimizing the heating of leaves in drying and milling, and a green micropowder produced by the processing method. A method for heating and drying fresh eucommia leaves by far infrared ray irradiation, said method comprising: irradiating fresh eucommia leaves with far infrared ray under blowing an air stream at 0-60^oC thereto from start to finish of the heating and drying treatment; and thus conducting the heating and drying treatment in such a manner that the moisture content of the leaves is reduced to 3% or less, relative to the moisture content thereof prior to drying, within 30 minutes after starting the heating, thereby giving a green and dried eucommia leaf product.

Description

Manufacturing method of green dried products

The present invention relates to a method for producing a green dried product of Tochu Naka, and more particularly to a method for drying Tochu Leaf while exhibiting a bright green color and without decomposing high-functional components contained in Tochu Tea.

Tochu's bark has long been prized as one of the five major Chinese herbal medicines, but in recent years, the high functionality and usefulness of components such as iridoids and polyphenols contained in Tochu's leaves have attracted attention. In particular, iridoids have been shown to be useful for blood pressure lowering action, analgesic action, and improvement of lipid metabolism (see Non-Patent Document 1 and Non-Patent Document 2), and are currently drunk mainly as tea.
The iridoids are known as compounds having 1-isopropyl-2,3-dimethylcyclopentane in the structure. The iridoids contained in the dried green product of Tonaka green obtained by the present invention are geniposide acid and asperoside.
The polyphenol compound is known as a compound having a plurality of phenolic hydroxyl groups in its structure. The polyphenol compound contained in the dried green rice leaf product obtained by the present invention is chlorogenic acid or flavonoids such as rutin, quercetin, nicotiflorin and kaempferol.

However, high functional components such as iridoids contained in Tochu leaves start to decrease due to self-digestion from the stage of harvesting the leaves. In addition, most of the products currently marketed as Tochu tea are brown fermented tea leaves, and during the fermentation process, the content of high-functional components of iridoids is greatly reduced, and bitterness is also increased. become. For this reason, in the dry tea leaves for beverages that are generally widely distributed, the content of iridoids is less than 1% of the total tea leaves.

Then, the manufacturing method of the Tochu dry tea leaf which contains these high functional ingredients abundantly is examined. In recent years, it has been found that green Tochu dry tea leaves produced in the same manner as Japanese tea contain more useful components such as iridoids and polyphenols than brown fermented tea.
For example, Patent Document 1 discloses a method for producing green potato Nakaba containing about 3.2% of geniposide acid. In this method, after roughly cutting the bamboo leaf to a width of about 2 cm, a step of steaming the tea leaf in the same manner as Japanese tea, a step of cooling the steamed bamboo leaf, and a step of roughly drying the cooled bamboo leaf Thereafter, the step of chopping the cocoon leaf to a width of about 5 mm or less, the step of scouring and scouring the chopped bamboo leaf, and then drying and scouring the far infrared rays as a heat source It has a process of roasting. Here, in the case of Tochu, it is considered that by suppressing the progress of fermentation by inactivating the enzyme by steaming heating, it is possible to maintain the green color and suppress the self-digestion action to prevent deterioration over time. However, high-performance components such as geniposide acid, iridoids, and polyphenols decrease due to thermal degradation and elution / dissipation due to steam, so the conventional steaming heating causes a decrease in these high-performance components. It is considered a thing.

The present inventor has made various studies so far in order to solve such problems.
As one of them, in Patent Document 2, green leaves containing geniposidic acid at a high concentration are obtained through a process including drying after a roasting process in which fresh leaves of Tochu are used as a raw material and fumigated at 300 to 350 ° C. A method for producing Tochu tea leaves is proposed.
Further, in Patent Document 3, an iridoid having a bright green color is obtained by intermittently applying microwave heating or high-frequency heating and performing a drying treatment under conditions where the leaf temperature is 50 to 100 ° C. It has been found that a dried green leafy green powder containing high-functional components such as sucrose and polyphenols at a high concentration can be obtained.

JP-A-10-150961 Japanese Patent No. 4340812 JP 2010-158230 A JP 2011-250725 A

However, in the method described in Patent Document 2 described above, the method in which the leaves are directly heat-treated using a kettle stirrer or the like to inactivate the enzyme causes the temperature of the leaves to become too high. Since the functional components are thermally decomposed, it is not always possible to say that these high-functional components are held in a sufficient content.
On the other hand, in order to avoid thermal degradation of these highly functional components or elution / dissipation due to vapor, it is possible to carry out heat treatment at a relatively low temperature. However, in this case, the enzyme is not sufficiently deactivated. Since it takes a very long time to dry tea leaves, there is a problem that an enzymatic reaction and an autodigestive action proceed during the treatment.
In particular, Tochu leaves have a strong vein covered with the fiber component Guttavelka, and therefore the drying time differs greatly between the leaf portion and the vein. Therefore, in the processing method of Patent Document 3 described above, it took 1 hour 30 minutes to 2 hours to dry the veins.
However, in particular, Guttavelca contains a large amount of geniposide acid, which is a unique component of Tochu, so drying of the veins is an important problem, and it is desirable to shorten the drying time.

The present invention has been made in view of the present situation, and the processing time, which conventionally took 120 minutes, is suppressed to a quarter or less, and the leaves are not subjected to as much temperature as possible during drying and pulverization. It is an object of the present invention to provide a processing method for producing fine powdered tea, having beautiful green and sweet ingredients with high numbers without wrinkles, and a green fine powder made from the processing method.

杜 Nakanaka leaves gradually purple when left after harvesting, and tends to be purple especially at high humidity, and especially the veins turn dark purple. Although the cause of this is not clear, for example, as seen in gardenia pigments, the production of natural pigments by iridoids can be considered. Recently, it has been reported that iridoid glycosides and glucosidase play an important role in protein denaturation due to insect damage in the mosquito family Ibota. Because of the tendency of discoloration from damaged or strained or stressed parts, the glucosidase, polyphenol oxidase and other enzymes contained in the organelles dissipate out of the endoplasmic reticulum for some reason. It is possible that the iridoid glycosides contained in the leaf act as a protein cross-linking agent and bind to the protein to produce a pigment.

Since these self-digestion effects are thought to occur under water-containing conditions, in order to prevent discoloration of 杜 nakasei leaves and reduction of iridoids, etc., it is necessary for enzyme reaction and self-digestion without stressing the leaves as much as possible. It is considered important to prevent the enzymatic reaction and autolysis from occurring by quickly removing moisture in the leaves.
From these results, the present inventor conducted an examination focusing on the rapid removal of water in the leaves necessary for the enzymatic reaction and autolysis action without stressing the leaves as much as possible. The leaves are arranged at almost equal intervals so that the leaves do not touch each other, and far-infrared rays are irradiated while maintaining the state of the arranged leaves, so that the moisture in the leaves is 30% or less of the moisture content before drying. It has been found that it is dried until it has become, and has already been proposed (Patent Document 4).

As a result of further investigations, the present inventor, in order to quickly absorb heat when performing drying until the moisture in the leaves becomes 3% or less of the moisture content before drying by irradiation with far-infrared rays of the green leaves The leaf surface temperature must be 60 ° C. or lower, preferably 50 ° C. or lower, and for that purpose, while blowing air at 0 to 60 ° C., preferably 0 to 40 ° C., more preferably 5 to 15 ° C. It has been found that by irradiating far infrared rays, the water content in the leaf can be reduced to 3% or less of the water content before drying within 30 minutes after the start of heating. And according to this method, as a result of being able to remove the moisture in the leaves necessary for the enzymatic reaction and the self-digesting action quickly and in a short time with almost no stress on the leaves, the vivid green color is maintained, and , Geniposide acid, iridoids, polyphenols, and other high-functional components can be kept from decreasing, and a dried green product of the company Nakaba can be obtained containing these high-functional components in high concentrations.

The present invention has been completed based on these findings, and provides the following inventions.
[1] In the method of heating and drying cocoon leaves by far-infrared irradiation, 30 minutes after the start of heating by irradiating far-infrared rays while blowing air at 0 to 60 ° C. from the start to the end of the heat drying treatment A method for producing a dried green leaf green product, characterized in that heat drying is performed until the water content in the leaf becomes 3% or less of the water content before drying.
[2] The method for producing a dried dried green product of [1], wherein liquid nitrogen is used for the blowing.
[3] The method for producing a green dried green product of [1] or [2], wherein the far infrared heating and drying apparatus is heated and dried at a set temperature of 200 to 600 ° C. from the start to the end of the heat treatment. .
[4] Any one of [1] to [3], wherein the leaf surface temperature measured with an infrared non-contact thermometer is 60 ° C. or less from the start to the end of the heat drying treatment. Method for producing dried green leaves.
[5] The method for producing a dried dried green product of [1] to [4], wherein the drying is performed in an atmosphere of 30% or less from the start to the end of the heat drying treatment.
[6] Any one of [1] to [5], wherein the leaves are arranged at substantially equal intervals so that the leaves do not contact each other and are heated and dried while maintaining the state of the arranged leaves A method for producing dried green leaves.
[7] The method for producing a green dried green product of any one of [1] to [6], wherein the green leaf is a straight green leaf that has been appropriately cut without being cut in advance.
[8] The method for producing a green dried green product of any one of [1] to [6], wherein the pruned leaves are cut into three pieces of a vein and portions on both sides thereof after plucking.
[9] A green product characterized in that it comprises a step of pulverizing the green dried green leaf product obtained by any one of the methods [1] to [8] to a powder at a temperature of 0 to 70 ° C. or lower. A method for producing Tochu's powdered beverage.
[10] The method for producing a green Bunchu powdered drink according to [9], wherein the air is blown at 0 to 70 ° C. in the pulverizing step.
[11] The method for producing a green Tochu powder drink according to [10], wherein liquid nitrogen is used for the blowing.

According to the production method of the present invention, it is possible to quickly remove the water in the leaf required for the enzymatic reaction and autolysis action in a short time, with almost no stress on the leaf, thus maintaining a bright green color, In addition, a decrease in high-functional components such as geniposide acid, iridoids, and polyphenols is suppressed to a low level, and a dried Nakanaka green product containing these high-functional components at a high concentration is obtained.

Schematic which shows typically an example of the apparatus used in implementing the method of this invention.

The method for producing a dried dried green leaf product according to the present invention is a method in which dried dried leaves are irradiated with far-infrared rays, and the dried dried leaves are heated to 0 to 60 ° C, preferably 0 to 40 ° C. More preferably, heating is performed by irradiating far infrared rays while blowing air at 5 to 15 ° C., and heating and drying until the moisture content in the leaf becomes 3% or less of the moisture content before drying within 30 minutes after the start of heating. It is a feature.

In the production method of the present invention, the bamboo leaves used as a raw material mean the company leaves before being subjected to heat drying treatment after harvesting, and even if they are produced by cultivation, It may be produced. For example, fresh leaves collected before the fall of the current year, in Kanagawa Prefecture, for example, fresh leaves collected from April to October, preferably from May to August, more preferably from July to August can be used.

Tochu Nakaba is easily self-destructing and deteriorates quickly. Further, the cut Nakaba leaves rapidly deteriorated simultaneously with the cutting. Therefore, it must be dried quickly to prevent fermentation. A far-infrared drying method is desirable as a method for rapid drying.
And in order to shorten the drying time in far-infrared heating, the difference between the far-infrared and the leaf surface temperature must be made as large as possible. However, if the leaves are frozen, when they are heated, they are deteriorated by stress and discolored to purple, so they cannot be frozen.
Therefore, in the present invention, the heat-drying treatment is started by irradiating far-infrared rays with the far-infrared rays while heating them at 0-60 ° C, preferably 0-40 ° C, more preferably 5-15 ° C. Until completion, the leaf surface temperature is kept at 60 ° C. or lower, preferably 50 ° C. or lower, more preferably 40 ° C. or lower, and heat is absorbed quickly.
In addition, the method for blowing air at the predetermined temperature is not particularly limited. For example, the outside air may be simply blown, or the air may be blown by using an electric device. Preferably, By using liquid nitrogen for air blowing, air blowing at 0 to 40 ° C., preferably 0 to 20 ° C., can be performed efficiently.

杜 Nakasei leaves may be heat-dried after cutting until the moisture content in the leaves is 3% or less of the moisture content before drying. It may be cut after drying until the moisture content in the leaf is 3% or less of the moisture content before drying.
カ ッ ト When cutting Nakasei leaves, they must be cut sharply so as not to stress the leaves, and the veins should be cut into squares of 2 cm or less, 1 cm squares, or rectangular shapes of 2 cm or less and 1 cm or less in a direction perpendicular to the veins. I must.

The heat drying in the present invention is performed using a far infrared heater equipped with a blower and an air conditioner. In order to accelerate the drying, the set temperature is 200 to 600 ° C., preferably 0 to 500 ° C., more preferably. Is dried at 300-400 ° C.
In the present invention, the far-infrared heater may be a conveyor type or a multi-stage type, and the wavelength of the far infrared ray to be irradiated is, for example, in the range of 1 to 1000 μm, preferably 2.5 to 50 μm. Can be appropriately selected.

In addition, in the production method of the present invention, when performing the heat drying treatment with far infrared rays, the leaves are arranged substantially evenly so that the leaves are not in contact with each other, and the far infrared rays are maintained in a state where the arranged leaves are maintained. Irradiation is preferred. For example, if you put a cocoon leaf in a rotary drum of a rotary drying furnace and heat and dry it with the leaf rotated, distortion or pressure will occur due to contact between the nakanaka leaf and the drum or between the leaves. Discoloration of 杜 中葉 tends to occur. In addition, since the distance between the far-infrared irradiation part and the leaf is not constant, uneven heating may occur, or the moisture around the leaf may increase due to water vapor evaporated from the leaf, and elution of useful components due to the vapor may occur. . On the other hand, the leaves or the leaves and the device contact each other by irradiating far-infrared rays while maintaining the state of the arranged leaves in a substantially uniform manner so that the leaves do not touch each other. The water in the leaves can be quickly removed in a state where there is almost no stress due to the occurrence of stress due to, and a green dried green product that contains vivid green and contains useful components at a high concentration is obtained. It is done. Moreover, as long as the leaves are not in contact with each other, for example, far infrared rays may be irradiated in a state where the leaves are arranged on three upper and lower drying shelves.

In the production method of the present invention, the heat drying treatment with far-infrared rays is performed until at least the moisture content of the Tochu Naka leaf is 3% or less of the moisture content before drying. Here, the moisture content before drying means the moisture content contained in the Tochu-nakaba immediately before being subjected to the heat drying treatment by far infrared rays. That is, in the production method of the present invention, for example, when the amount of water contained in the bamboo leaf before being subjected to the heat-drying treatment is 100 g, the far-infrared rays until the amount of water remaining in the leaves becomes 3 g or less. The heat drying process by is performed.
In the production method of the present invention, the progress of the enzymatic reaction and the self-digestion action is significantly hindered by quickly reducing the water content in the leaves to 3% or less of the water content before drying.

In addition, in the heat drying treatment process, when the water removal rate in the leaves is slow, the self-digestion reaction gradually proceeds according to the time required for the water removal, leading to discoloration of chunaka leaves and reduction of iridoids. . For this reason, for example, if it takes more than 30 minutes to reduce the moisture content in the leaf to 3% or less of the moisture content before drying, the color of the Nakanaka leaf may change or the useful components may be significantly reduced. is there. Therefore, in order to stop the enzyme reaction and autolysis more reliably, it is desirable to remove the moisture in the leaf more quickly, preferably within 20 minutes, more preferably within 10 minutes. It is desirable to dry to 3% or less of the moisture content before drying.

Further, in the heat drying process using infrared rays, it is desirable to perform the drying process in an atmosphere with a humidity of 30% or less, more preferably 10% or less, from the start to the end of the heat treatment. In a normal case, in the heat drying process, moisture evaporates from the leaf surface, so that the atmospheric humidity increases with the progress of drying. However, if the atmospheric humidity exceeds 10% during the heat-drying process using far infrared rays, it is difficult to evaporate moisture from the leaf surface, and it becomes difficult to remove moisture in the leaf in a short time. For example, when a hermetic dryer is used, the atmospheric humidity significantly increases due to the evaporation of moisture in the leaves. Further, when the humidity is further increased and the water vapor is saturated, the heat of vaporization is not generated and the leaf temperature is unnecessarily increased, or the useful component may be lost to the steam. In addition, what is necessary is just to adjust suitably with a ventilation means, in order to maintain the humidity in a heat drying process process at 30% or less.

Further, in the heat drying treatment with far infrared rays, it is desirable to appropriately control the blowing means so that the maximum leaf temperature measured by the infrared non-contact thermometer is 60 ° C. or less, more preferably 50 or less.

Although one Example of the heat drying process process by the far infrared rays in the manufacturing method of this invention is shown in FIG. 1, this invention is not limited to this.
The conveyor-type far-infrared heating and drying apparatus 10 is provided with a far-infrared irradiation unit 14 and a blower 16 inside a drying chamber 12. Moreover, the conveyor 18 is provided so that it can move from the one side through the drying chamber 12 and continuously with the other side.

杜 Nakasei leaves 20 to be subjected to a heat drying process using far infrared rays are arranged on the conveyor 18 at substantially equal intervals so that the leaves do not contact each other. Then, the green leaves 20 arranged on the conveyor 18 are sent into the drying chamber 12 while maintaining the state of the arranged leaves. Inside the drying chamber 12, far-infrared rays are radiated from the up-and-down direction to the cocoon leaves 20 by the far-infrared ray irradiation unit 14. Then, the foliage leaves 20 irradiated with far-infrared rays have a leaf temperature that rises, moisture is vaporized, and the amount of moisture decreases. Here, the inside of the drying chamber 12 is blown by the blower 16 so that the atmospheric humidity and the atmospheric temperature in the room are kept almost constant. That is, in normal cases, the moisture in the leaves is vaporized by heating to become water vapor, so that the humidity and temperature in the drying chamber 12 are increased. However, the water is exhausted to the outside by being blown by the blower unit 16. The humidity and temperature in the drying chamber 12 are kept almost constant. The dried green leaves 20 dried in the drying chamber 12 are sent to the outside of the drying chamber 12 by the conveyor 18. In addition, in the manufacturing method of this invention, the water | moisture content of the foliage leaf 20 has decreased to 3% or less of the water content before drying within 30 minutes after the start of far-infrared irradiation.

Here, in the drying chamber 12, the far-infrared irradiation intensity by the far-infrared irradiation unit 14 so that the indoor atmospheric humidity, the atmospheric temperature, and the leaf surface temperature are within the preferable numerical ranges shown above, and It is desirable to adjust the blowing temperature and the blowing amount by the blowing unit 16. That is, using the far-infrared heating and drying apparatus 10 of FIG. 1, the operating conditions of the far-infrared irradiation unit 14 and the blower unit 16 are adjusted, and the atmospheric temperature, atmospheric humidity, leaf surface temperature, etc. in the drying chamber 12 are adjusted. By appropriate control, the leaves are dried until the moisture content of the leaves becomes 3% or less of the moisture content before drying within 30 minutes after the start of heating. Furthermore, when the leaves are arranged at substantially equal intervals so as not to contact each other, the leaves are heated uniformly and efficiently by irradiation with far infrared rays, and the leaves or leaves There is no distortion or pressure due to the contact of the apparatus, and the leaves are hardly stressed, so discoloration is unlikely to occur during the drying process. In order for the enzymatic reaction and self-digestion to proceed, it is considered that free water must be included as the moisture in the leaves, and until the moisture content in the leaves becomes 3% or less of the moisture content before drying. In dried Tochu leaves, almost all of the free water contained in the leaves has been removed, so there is almost no discoloration or decrease in useful components.

Also, in the production method of the present invention, it is desirable to keep the chunaka leaf under the condition of humidity of 50% or less, more preferably 30% or less, until the pickled chunaka leaf is made into a product. If Nakanakayo is placed under high humidity exceeding 50% humidity, it may cause a decrease in high-functional components such as iridoids and polyphenols. In addition, the leaves turn purple and green The product may not be obtained.

Moreover, in the said drying process, although it can accelerate | stimulate rapidly by using the pre-cut finely-leaved green leaves, a self-digestion action advances from a cutting location and the useful component of iridoids will decompose | disassemble. At the same time, a vivid green color may not be obtained due to discoloration. For this reason, in the production method of the present invention, it is desirable to dry the appropriately picked potato leaves in the shape as possible. On the other hand, when dried in the shape as it is without chopping finely, it takes a very long time to completely dry the veins with the conventional drying method. Even if it is the shape of this, the water | moisture content in a leaf vein can be removed rapidly.

In addition, the leaves of Tochu are grown to 30 cm or more, and the veins are 5 mm or more in thickness. In the case of such a large cocoon leaf, a difference in water evaporation occurs between the vein portion and the portion other than the leaf vein in the drying process, and the leaf vein becomes purple due to self-digestion. This is considered to be due to the structure being stressed around the veins and the cells of the veins being destroyed in a state sufficiently containing water. As a result, useful components such as iridoids are decomposed to reduce the content, and in addition, the green color is lost due to discoloration. In particular, since the veins contain a lot of highly functional components, the drying of the veins is extremely important. However, with the conventional drying method, it is very difficult to quickly dry a vein portion having a thickness of 5 mm or more. For this reason, in the production method of the present invention, it is desirable to cut the bamboo leaf into three pieces of the vein and the portions on both sides thereof, and dry each piece. In other words, it is divided into the leaf vein part and other parts of Tochu Naka leaf, changing the heating temperature and treatment time, etc., and performing the drying treatment according to each, discoloration due to self-digestion action, thermal decomposition caused by excessive heating, etc. The loss of high-functional components can be kept low. In addition, the types and amounts of components contained in the vein portion and other portions are different. For example, the vein portion contains a large amount of geniposide acid and the other portions contain a large amount of chlorogenic acid. Therefore, it is possible to separate a product derived from the vein portion and a product derived from another portion according to the desired type of active ingredient.

For this reason, in the production method of the present invention, for example, the freshly-cured Toka Nakasei leaves, which have been appropriately collected without cutting in advance, are heat-dried with far-infrared rays until the water content of the leaves becomes 3% or less of the water content before drying. Or, after the pruned leaves of the shrunken leaves are cut into two pieces, the vein and the parts on both sides of the leaves, they can be heated and dried with far infrared rays until the moisture content is 3% or less of the moisture content before drying. Is possible.

In the dried green rice leaf product obtained as described above, since the reduction of highly functional components such as geniposide acid, iridoids, polyphenols during the drying process is suppressed to a low level, these geniposide acids, iridoids, and The content of polyphenols has been dramatically improved.

The content of iridoids and polyphenols contained in the Tochu Naka leaf varies depending on individual differences in Tochu Nakamoto, harvest time, etc., but in the dried green product of Tochu Naka leaf obtained by the present invention, the content of the iridoids, It is considered that about 70% by mass or more of the content (in terms of dry mass) of iridoids contained in the company Nakasei leaves immediately after harvest used as a raw material is maintained.

Moreover, since the dried green leaves of the Nakanaka leaf obtained by the production method of the present invention contain high concentrations of iridoids and polyphenol compounds, these highly functional components are extracted after being once treated as a dried Nakanaka leaf product. It is also useful as an extraction method.

Further, the dried dried green leaves of dried Nakanaka leaves are preferably made into a finely pulverized powder having an average diameter of 3 to 14 μm. The pulverization method is not particularly limited, and for example, a jet mill pulverizer, an airflow pulverizer, or the like can be used. In this case, the pulverization temperature is 0 to 70 ° C. or less, preferably 0 to It is preferable to grind at 40 ° C. or lower, more preferably 0 to 20 ° C. or lower. Furthermore, it is preferable to improve ventilation and prevent heat and humidity from being stored by blowing air at 0 to 70 ° C. during pulverization. In particular, by using liquid nitrogen for blowing, It is preferable to perform pulverization while blowing cold air of 40 ° C., preferably 0 to 20 ° C.
And the green powder of green liquor made in this way becomes a fine powder of 3-14μm, preferably 6μm on average, with a refreshing green and beautiful sweetness, which is not only suitable for drinking but also geniposide peculiar to liquor A health food containing a large amount of acid, chlorogenic sun, asperroside, folic acid, vitamin E, and vitamin A can be provided.

Hereinafter, the present invention will be described in more detail based on the description of Examples, but the present invention is not limited to these Examples.
Example 1
Uncut cocoon leaves were arranged evenly on a far-infrared conveyor dryer equipped with a blower so that the leaves would not touch each other, and dried for 12 minutes and 30 seconds at a set temperature of 350 ° C. while blowing air at 25 ° C.
The maximum temperature of the leaf surface during the drying treatment (measured with an infrared non-contact thermometer) was about 46.5 ° C., and the moisture content after drying was 3% of the moisture content before drying.
The obtained dried leaves were pulverized for 10 to 20 minutes using a cyclone mill to obtain a green dry fine powder having an average of 7 μm.

(Example 2)
It dried for 13 minutes and 30 seconds like Example 1 except having set it as 20 degreeC ventilation.
The maximum temperature of the leaf surface during the drying treatment was about 37.0 ° C., and the moisture content after drying was 3% of the moisture content before drying.
From the obtained dried leaves, a green dry fine powder having an average of 7 μm was obtained in the same manner as in Example 1.

(Example 3)
Drying was carried out for 10 minutes in the same manner as in Example 1 except that the set temperature was 400 ° C. and liquid nitrogen was used for blowing air and 5 ° C. cold air was used for blowing air.
The maximum temperature of the leaf surface during the drying treatment was about 15.0 ° C., and the moisture content after drying was 3% of the moisture content before drying.
The resulting dried leaves were pulverized using a cyclone mill while feeding cold air at 5 ° C. using liquid nitrogen to obtain a green dry fine powder having an average of 6 μm.

(Comparative Example 1)
Using the apparatus of Example 1, the set temperature was set to 170 ° C. and dried for 10 minutes without blowing.
The maximum temperature of the leaf surface during the drying treatment was about 70 ° C., and the moisture content after drying was 47.3% of the moisture content before drying. The shelf dryer was set to 60 ° C. and dried for 30 minutes.
From the obtained dried leaves, a green dry fine powder having an average of 7 μm was obtained in the same manner as in Example 1.

(Comparative Example 2)
Using the apparatus of Example 1, the set temperature was set to 230 ° C., and drying was performed for 15 minutes without blowing.
The maximum temperature of the leaf surface during the drying treatment was about 110 ° C., and the moisture content after drying was 3% of the moisture content before drying, but it was partially burnt. However, the stem could not be dried.
From the obtained dried leaves, a green dry fine powder having an average of 7 μm was obtained in the same manner as in Example 1.

(Comparative Example 3)
Drying was carried out for 20 minutes in the same manner as in Example 1 except that the set temperature was 140 ° C. and the ventilation was 120 ° C.
The maximum temperature of the leaf surface during the drying treatment was about 130 ° C., and the moisture content after drying was 3% of the moisture content before drying.
From the obtained dried leaves, a green dry fine powder having an average of 7 μm was obtained in the same manner as in Example 1.

Table 1 shows the results of color, taste, and component analysis of the dry powders obtained in Examples 1 to 3 and Comparative Examples 1 to 3. In addition, the component analysis was measured by HPLC (high performance liquid chromatography; methanol extraction). All units are μg / g (active ingredient amount / sample mass).

As shown in the above table, the surface temperature of the leaves is kept at 60 ° C. or lower by irradiating far-infrared leaves while blowing air at 0 to 60 ° C. from the start to the end of the heat drying treatment, and heating starts. The green dried products of Tonaka tea leaves of Examples 1 to 3 obtained by quickly drying and removing the moisture in the leaves until the moisture content in the leaves became 3% or less of the moisture content before drying within 30 minutes later were asperoside and geniposide It can be seen that they contain a large amount of iridoids such as acids. Moreover, high content is also obtained about chlorogenic acid which is a kind of polyphenol.
In particular, in order to lower the blast temperature, the green dried product of Example 3 green tea of Example 3 performed at 5 ° C. using liquid nitrogen in the cold air of 5 ° C. using liquid nitrogen and pulverizing after drying is more suitable. In addition to showing a fresh green color, the contents of chlorogenic acid, asperoside and geniposide acid were increased as compared with the green dried green tea leaves obtained in Examples 1 and 2.

On the other hand, the dried green tea leaves of comparative example 1 obtained by drying for the same time at a set temperature lower than those of Examples 1 to 3 without blowing air gave a taste free of wrinkles, but were dried. However, the color was purple and dark green, and the contents of chlorogenic acid, asperoside and geniposide acid were all low.
In addition, comparison was obtained by setting the temperature higher than that of Comparative Example 1 and drying and removing the moisture in the leaf until the drying time was 1.5 times and the moisture content in the leaf was 3% or less of the moisture content before drying. The dried green tea leaf green product of Example 2 had a savory taste and a green color, but the contents of asperoside and geniposide acid were both lower than those of Comparative Example 1.
Furthermore, by irradiating far-infrared leaves while blowing air at 120 ° C., the moisture in the leaves is removed by drying until the moisture content in the leaves becomes 3% or less of the moisture content before drying 20 minutes after the start of heating. The obtained green dried green tea leaves of Comparative Example 3 had a refreshing green color, but had a bitter taste and had very low contents of chlorogenic acid, asperloside, and geniposide acid.

10: Far-infrared heating and drying device 12: Drying room 14: Far-infrared irradiation unit 16: Blowing unit 18: Conveyor 20: Tokinakaseiyo

Claims (11)

1. In the method of heating and drying cocoon leaves by far-infrared irradiation, the leaves are irradiated within 30 minutes after the start of heating by irradiating far-infrared leaves while blowing air at 0 to 60 ° C. from the start to the end of the heat drying process. A method for producing a dried dried green leafy green product, characterized in that the medium moisture content is heated and dried until it reaches 3% or less of the moisture content before drying.
2. 2. The method for producing a green dried green leaf product according to claim 1, wherein liquid nitrogen is used for the blowing.
3. The method for producing a dried green product of Tonaka green according to claim 1 or 2, wherein the far-infrared heat drying apparatus is heated and dried at a set temperature of 200 to 600 ° C from the start to the end of the heat treatment.
4. 4. From the start to the end of the heat drying treatment, heat drying is performed in a range in which the leaf surface temperature measured by an infrared non-contact thermometer is 60 ° C. or less. A method for producing dried green leaves.
5. The method for producing a dried dried green leaf product according to any one of claims 1 to 4, wherein the drying is performed in an atmosphere having a humidity of 30% or less from the start to the end of the heat drying treatment.
6. 6. The rice cake according to any one of claims 1 to 5, wherein the leaves are arranged at substantially equal intervals so that the leaves do not contact each other and are dried by heating while maintaining the state of the arranged leaves. A method for producing a dry green leaf product.
7. The method for producing a dried green product of Tochu Nakaba according to any one of Claims 1 to 6, wherein said Tochu Nakaba is a company Nakasei leaf that has been appropriately shaped without being cut in advance.
8. The method for producing a green dried green leaf product according to any one of claims 1 to 6, wherein after the plucking, the green leaf is cut into three pieces of a vein and portions on both sides thereof.
9. 9. A green green liquor powder drink comprising a step of pulverizing the dried green liquor green product obtained by the method according to any one of claims 1 to 8 at a temperature of 70 or less. Manufacturing method.
10. 10. The method for producing a green Tochu powdered beverage according to claim 9, wherein air is blown at 0 to 70 ° C. in the crushing step.
11. 11. The method for producing a green Tochu powder drink according to claim 10, wherein liquid nitrogen is used for the blowing.

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