Method for producing solid tea leaf extract

Abstract

The main objective is to provide a manufacturing method for obtaining a tea leaf extract solid that not only retains a large amount of the various active ingredients naturally present in fresh tea leaves, but is also easy to handle. [Solution] As an example of the present invention, a method for producing a tea leaf extract solid can be given, characterized by including the steps described in (1) to (4) below. (1) A process to deactivate the oxidizing enzymes contained in tea leaves harvested from the tea plant. (2) The process of shredding the inactivated tea leaves, (3) A process of extracting tea leaf extract by squeezing the shredded tea leaves, (4) A process of filling a mold with tea leaf extract and vacuum freeze-drying it to form a three-dimensional solid object from the tea leaf extract.

Description

[Technical Field]

[0001] This invention belongs to the technical field related to processed tea products. In this technical field, this invention relates to a method for producing solid tea leaf extract. [Background technology]

[0002] Generally, green tea is made by first steaming the fresh tea leaves picked from the tea plant to inactivate the oxidizing enzymes contained in the leaves. Then, it undergoes a series of processes including rough rolling, kneading, intermediate rolling, fine rolling, and drying to produce crude tea. After the leaves and stems in the crude tea are separated, it is dried again, and finally, it is produced with a moisture content of 5% or less. Because this process from picking the fresh tea leaves to becoming a green tea product requires manpower and time, processed green tea tends to have high production costs. Furthermore, processed green tea undergoes heat treatment during the manufacturing process, resulting in the loss or denaturation of large amounts of beneficial components such as amino acids, catechins, vitamins, and caffeine that were originally present in the raw tea leaves.

[0003] To address the above problem, Patent Document 1 solves the issue by steaming raw tea leaves to inactivate oxidative enzymes, then cooling them, crushing the leaves, pressing the resulting juice, drying it, and pulverizing it, without going through the usual green tea manufacturing process. The resulting tea leaf extract powder can be dissolved in hot water and easily enjoyed as green tea. In addition, Patent Document 1 states that there is less loss or denaturation of active ingredients such as amino acids, catechins, vitamins, and caffeine contained in the raw tea leaves.

[0004] On the other hand, Patent Document 2 describes a method for producing a green tea extract by extracting soluble solids from green tea leaves with hot water, concentrating it, adding dextrin to make a green tea beverage, pouring it into a resin mold, and vacuum freeze-drying it to produce a cubic solidified green tea beverage. This solidified green tea beverage can be easily restored to a green tea beverage by mixing it with water or hot water, and in addition, its cubic solid form makes it suitable for carrying around. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 9-275903 [Patent Document 2] Japanese Patent Publication No. 2022-161383 [Overview of the project] [Problems that the invention aims to solve]

[0006] The method for producing tea leaf extract powder described in Patent Document 1 does not involve the usual green tea manufacturing process, thus saving labor and time, and consequently reducing manufacturing costs. In addition, it can minimize the loss and alteration of various active ingredients originally contained in fresh tea leaves. However, because it is a powder, it is inconvenient to handle and to regenerate into beverage tea. On the other hand, the solidified green tea beverage described in Patent Document 2 is suitable for portability, but because it uses green tea leaves as a raw material, as mentioned above, production costs tend to be high, and it is thought that a large amount of active ingredients originally contained in fresh tea leaves are lost or altered. The main objective of this invention is to provide a method for obtaining a solid tea leaf extract that not only retains a large amount of various active ingredients naturally present in fresh tea leaves, as described in Patent Document 1, but is also easy to handle. [Means for solving the problem]

[0007] As a result of diligent research, the inventors have discovered a method for producing a solid tea leaf extract that can solve the above problems, and have completed the present invention.

[0008] Examples of the present invention include the following embodiments. [1] A method for producing a tea leaf extract solid, characterized by including the steps described in (1) to (4) below: (1) A process to deactivate the oxidizing enzymes contained in tea leaves harvested from the tea plant. (2) The process of shredding the inactivated tea leaves, (3) A process of extracting tea leaf extract by squeezing the shredded tea leaves, (4) A process of filling a mold with tea leaf extract and vacuum freeze-drying it to form a three-dimensional solid object from the tea leaf extract. [2] A method for producing a tea leaf extract solid according to [1] above, wherein both the shredding in step (2) and the juicing in step (3) are carried out at 30°C or below. [3] A method for producing a solid tea leaf extract according to [1] above, further comprising the step (3-1) of adding an additive to the tea leaf extract obtained in step (3) above to obtain a tea leaf extract containing the additive. [4] A method for producing a tea leaf extract solid according to [1] above, further comprising the step (3-2) of sterilizing the tea leaf extract obtained in step (3) at low temperature and high pressure. [5] A method for producing a tea leaf extract solid according to [1], further comprising the steps of freezing and storing the tea leaf extract (3-3), and then thawing it (3-4).

[0009] [6] A method for producing a solid tea leaf extract according to any one of the above [1] to [5], further comprising, as an extraction step, a step (3-5) of mixing the tea leaf extract obtained through at least step (3) with one or more tea leaf extracts obtained separately through at least step (3) to obtain a mixed tea leaf extract. [7] The method for producing a solid tea leaf extract according to [6] above, wherein the mixed tea leaf extract includes tea leaf extract that has been frozen and thawed in accordance with steps (3-3) and (3-4) above. [8] The method for producing a tea leaf extract solid according to [6] above, wherein the mixed tea leaf extract is a mixed tea leaf extract of tea leaf extract derived from first flush tea and tea leaf extract derived from first flush tea or tea leaf extract derived from second flush or later tea leaves obtained separately. [9] The method for producing a tea leaf extract solid according to [6] above, wherein the mixed tea leaf extract is a mixed tea leaf extract of tea leaf extract derived from first flush tea and tea leaf extract derived from second flush tea.

[10] The method for producing a tea leaf extract solid according to [3] above, wherein the additive is dextrin, inulin, or acacia.

Advantages of the Invention

[0010] According to the present invention, it is possible to produce a tea extract solid that retains many of the various active ingredients originally contained in fresh tea leaves and is easy to handle, etc.

Brief Description of the Drawings

[0011] [Figure 1] It is a flowchart showing one aspect of a method for producing a tea extract solid according to the present invention. [Figure 2] It is a flowchart showing another aspect of a method for producing a tea extract solid according to the present invention.

Modes for Carrying Out the Invention

[0012] Hereinafter, the present invention will be described in detail. A method for producing a tea extract solid according to the present invention (hereinafter referred to as "the production method of the present invention") is characterized by including the steps described in the following (1) to (4). (1) A step of inactivating the oxidase contained in the tea leaves picked from Castanopsis sclerophylla (inactivation step). (2) A step of finely cutting the inactivated tea leaves (finely cutting step). (3) A step of extracting a tea extract by squeezing the finely cut tea leaves (extraction step). (4) A step of filling the tea extract into a mold and forming the tea extract into a three-dimensional solid by vacuum freeze-drying (forming step).

[0013] 1 Tea leaves as raw materials The tea leaves used as raw material are not particularly restricted as long as they are derived from the species *Camellia sinensis* (L) O. Kuntze, scientific name: *Camellia sinensis*, an evergreen tree belonging to the genus *Camellia* in the family Theaceae. In other words, this species broadly includes subspecies such as the Chinese variety (*Camellia sinensis var. sinensis*), the Assam variety (*Camellia sinensis var. assamica*), the Chinese large-leaf variety (*Camellia sinensis f. macrophylla*), and their hybrids. There are no particular restrictions on the varieties used. Specifically, for example, Chinese varieties include Yabukita, Yamatomidori, Asatsuyu, Hatsumidori, as well as Hoshino Midori, Okuyutaka, Tsukasa Midori, Takanewase, Sato Wase, Okuhikari, Meiryoku, Fukumidori, Inaguchi, Terakawa Wase, Minekaori, Minamikaori, Shunmei, Saemidori, Chachukanbohon No. 1, Fushun, Minamisayaka, Sawamizuka, Benifuki, Hokumei, Mineyutaka, Matsuju, Marishi, and Mie Midori Moe 1. The following varieties can be listed: No. 2, Asanoka, Fujikaori, Yamano Ibuki, Tea Intermediate Mother Plant No. 2, Sagara Hikari, Sagara Midori, Koshun, Sagara Kaori, Sagara Wase, Sakimidori, Ryofu, Midori no Hoshi, Musashikaori, Ryokufu, Tea Intermediate Mother Plant No. 3, Narino, Okunoyama, Harumidori, Tsuyuhikari, Mieuejima, Sofu, Sai no Midori, Miyama Kaori, Harumoegi, Kiraka, Hoshun, Tenmei, Sayama Kaori, Sayama Midori, Okumidori, and Yamato Midori. You may use one or any two or more of these varieties.

[0014] Furthermore, tea leaves grown under cover for purposes such as gyokuro or tencha, or tea leaves grown outdoors for sencha, may also be used. Regarding the harvesting time, it is acceptable to use the first harvest of new shoots that grew in the year, i.e., first flush tea leaves, or tea leaves harvested later, i.e., second, third, or fourth flush tea leaves, but first flush tea leaves are preferred in terms of taste and nutritional value. These may be mixed before juicing (e.g., in a shredded state) or after juicing (e.g., in an extract state) to make a blended tea leaf or blended tea leaf extract, but if mixed, it is preferable to mix them in the state of tea leaf extract, as will be described later.

[0015] The timing of harvesting the raw tea leaves used as raw material varies depending on the region, variety, and climate, but it is generally fine to follow the usual schedule. Specifically, for example, the first flush of new tea is usually harvested in late April to early May, the second flush is usually harvested around June after the first flush, the third flush is usually harvested around July after the second flush, and the autumn / winter tea (fourth flush) is usually harvested around September to October after the third flush.

[0016] There are no particular restrictions on the method of harvesting tea leaves, and it can be done according to conventional methods, but examples include hand-picking, picking with scissors, and machine harvesting. In the case of machine harvesting, the machine may be portable, self-propelled, ride-on, or rail-type.

[0017] 2 process (1): Inactivation process The present invention includes a step of inactivating the oxidizing enzymes contained in the harvested tea leaves, that is, a steaming step.

[0018] Tea leaves picked from the tea plant begin to ferment immediately if left unattended, leading to a deterioration in quality. Therefore, to prevent quality deterioration and maintain freshness, it is preferable to blow humid air into the leaves using conventional methods before steaming to retain moisture and reduce respiration heat (air blowing process). After that, the picked tea leaves are placed in a steamer and heated (steamed) with high-temperature steam, for example, water vapor at about 80°C to 100°C, to deactivate the oxidizing enzymes contained in the tea leaves. The heating time or steaming time varies depending on the hardness of the tea leaves, but is usually within the range of 20 to 120 seconds, and preferably within the range of 30 to 90 seconds. Generally, the longer the heating time, the less astringency there is, but it can be adjusted as appropriate. There are no particular restrictions on the steamer, but for example, a rotating agitator type steamer can be used. Furthermore, the inactivation of oxidizing enzymes can also be achieved by blanching or immersion in hot water. For example, immersion in boiling water can be done by immersing the tea leaves in boiling water for 10 seconds to 5 minutes. However, steaming in a steamer is preferable to immersion in hot water in order to preserve the tea leaf components.

[0019] After the steaming process is complete, the tea leaves are usually cooled immediately, as leaving them at high temperatures will impair their color and flavor. This cooling can be done, for example, by blowing air onto the steamed tea leaves. Afterwards, hot air can be added to thoroughly dry the tea leaves. Furthermore, before proceeding to the next cutting process, a visual inspection is generally performed to remove any foreign objects.

[0020] 3. Process (2): Shredding process The present invention's manufacturing method includes a step of shredding inactivated tea leaves.

[0021] The oxidizing enzymes contained in the tea leaves are deactivated, and the cooled picked tea leaves are then shredded using a suitable shredder to allow for sufficient juice extraction in the next step. Such a shredder is not particularly limited as long as it is suitable for shredding tea leaves, but examples include a tea leaf shredder (cutter mixer) and a grinder (mill). The shredding can be done, for example, to a size within the range of 1 to 5 cm, preferably within the range of 1.5 to 3 cm.

[0022] Shredding is preferably carried out at 30°C or below. Shredding at higher temperatures may cause loss or denaturation of tea leaf components. A more preferable temperature is, for example, 15°C or below. There are no particular restrictions on the lower temperature, but examples include 1°C or above, 5°C or above, and 15°C or above. Therefore, it is preferable to carry out the shredding at room temperature or ambient temperature as defined in the Japanese Pharmacopoeia.

[0023] After steps (1) and (2), the process can proceed to the next step, extraction step (3). However, if necessary, enzymes that break down cellulose or hemicellulose, which are the main components of plant cell walls (e.g., cellulase, hemicellulase, macerozyme), or pectinase, an enzyme that breaks down pectin contained in plant cell walls, can be added to the tea leaves before extraction to break down the cell walls before proceeding to extraction step (3). This allows for more efficient extraction of tea leaf extract and the production of a tea leaf extract solid richer in active ingredients. In this case, however, it is preferable to add the enzyme in the range of 0.0005 to 0.01 parts by mass per 1 part by mass of steamed tea leaves, and it is also preferable to leave the mixture in a pressing bag for 30 to 60 minutes with occasional stirring before pressing, adding additives as necessary, and drying.

[0024] 4 Process (3): Extraction process The present invention's manufacturing method includes an extraction step (basic extraction step) in which shredded tea leaves are squeezed to extract tea leaf extract. In addition to the basic extraction step, the extraction step may include one or more optional steps selected from the following steps (3-1) to (3-5).

[0025] The juicing can be carried out, for example, by pressing shredded tea leaves or shredded tea leaves to which plant cell wall-degrading enzymes have been added, using a suitable juicer, such as a screw-type juicer or a cold-press juicer. Juicing is preferably carried out at a relatively low temperature of 30°C or below, or 25°C or below, in order to prevent the decomposition of tea leaf components. Therefore, in the case of a machine that extracts juice while rotating, it is preferable to extract juice at a low rotation speed (approximately 30 to 90 revolutions per minute). Alternatively, this can be done by packing shredded tea leaves, or shredded tea leaves to which plant cell wall-degrading enzymes have been added, into a suitable pressing bag, applying appropriate pressure to the bag, and pressing.

[0026] The pressing pressure is not particularly limited, but for example, a range of 5 to 30 MPa is appropriate, preferably 10 to 25 MPa, and more preferably 15 to 20 MPa. From the viewpoint of obtaining a sufficient amount of tea leaf extract, it is preferable to avoid a pressure lower than 5 MPa.

[0027] If necessary, appropriate additives may be added in appropriate amounts to the tea leaf extract obtained in the basic extraction process for purposes such as improving the moldability of the final product, the tea leaf extract solid, improving its solubility (rapid dissolution) in water, or enhancing its flavor (step (3-1)). Examples of such additives include dextrin, inulin, acacia, highly branched cyclic dextrin, modified starch, hydroxypropyl starch, preservatives, disintegrants, solubilizers, antioxidants, sweeteners (e.g., sucrose, coconut sugar), colorants (e.g., gold powder), and flavorings (cherry blossom, yuzu, ginger).

[0028] The additive can be added after obtaining the tea leaf extract through this extraction process, but before filling the mold in the molding process described later. The amount of the additive varies depending on the type of additive, but a suitable amount is, for example, between 0.5% and 40% by mass of the tea leaf extract, preferably between 5% and 40% by mass, and more preferably between 15% and 35% by mass. If the additive is dextrin, a suitable dextrose equivalent (generally also called "DE value") is, for example, between 2 and 30, preferably between 6 and 21, and more preferably between 10 and 18. By adding dextrin with a high DE value, the solubility of the final tea leaf extract solid in water can be increased.

[0029] Furthermore, the tea leaf extract obtained in this extraction process can be concentrated or diluted with water as needed.

[0030] The tea leaf extract obtained above (including tea leaf extract with additives, concentrated or diluted tea leaf extract, etc.) can be used directly for the molding process in step (4), or the tea leaf extract can be sterilized. The sterilization method is not particularly limited as long as it can be used to sterilize the tea leaf extract; for example, high-pressure steam sterilization (autoclave) can be considered, but from the viewpoint of minimizing the loss or denaturation of active ingredients as much as possible, it is preferable to sterilize at low temperature and high pressure (step (3-2)). The sterilization temperature is preferably 30°C or lower, as in the case of shredding described above. From the viewpoint of preventing the loss or denaturation of tea leaf components, it is preferable to avoid temperatures higher than 30°C. A more preferable temperature is, for example, 28°C or lower. There is no particular limit to the lower temperature, but for example, it can be 1°C or higher, 5°C or higher, or 15°C or higher. Therefore, it is preferable to carry out the sterilization at room temperature or ambient temperature as defined in the Japanese Pharmacopoeia. Regarding the sterilization pressure, for example, a range of 50 MPa to 800 MPa is appropriate, a range of 100 MPa to 700 MPa is preferred, and a range of 300 MPa to 600 MPa is more preferred.

[0031] The combination of high-pressure sterilization and vacuum freeze-drying in the molding process described later can enhance food safety.

[0032] The tea leaf extract obtained above can be frozen and stored temporarily (step (3-3)). In this case, it is preferable to sterilize it using the low-temperature, high-pressure method described above before freezing. The freezing method is not particularly limited and can be carried out by conventional methods, but rapid freezing is preferred.

[0033] The frozen tea leaf extract is thawed to restore it to a liquid state before carrying out step (4) (steps (3-4)). There are no particular restrictions on the thawing method, and it can be carried out by any conventional method. Specifically, examples include natural thawing, refrigerator thawing, running water thawing, ice water thawing, microwave thawing, and microwave oven thawing. Of these, refrigerator thawing is preferred.

[0034] The tea leaf extract according to the present invention may be a mixed tea leaf extract of the tea leaf extract obtained through the steps described above and one or more tea leaf extracts obtained separately through the steps described above. Accordingly, the manufacturing method of the present invention may further include steps (3-5) for obtaining such a mixed tea leaf extract.

[0035] Preferably, the mixed tea leaf extract contains tea leaf extract that has been frozen and thawed according to steps (3-3) and (3-4). Examples of the mixed tea leaf extract include a mixed tea leaf extract of first flush tea leaves and a separately obtained mixed tea leaf extract of first flush tea leaves or a mixed tea leaf extract of second flush or later tea leaves. Among these, a mixed tea leaf extract of first flush tea leaf extract and second flush tea leaf extract, a mixed tea leaf extract of first flush tea leaf extract and third flush tea leaf extract, and a mixed tea leaf extract of first flush tea leaf extract, second flush tea leaf extract and third flush tea leaf extract are preferred. By using a mixed tea leaf extract, that is, by blending tea leaf extracts, productivity can be improved, as can the taste, flavor, and color, and the stability of the solid product. In addition, it is possible to adjust the moldability and water solubility (rapid solubility) of the final tea leaf extract solid product.

[0036] Furthermore, the process from picking the fresh tea leaves to freezing and storing them should preferably be carried out as quickly as possible to maintain the freshness of the picked leaves. Therefore, this series of processes (work) should be performed within a short distance from each other.

[0037] When mixing multiple tea leaf extracts obtained through different processes to create a mixed tea leaf extract, the mixing ratio of the two is arbitrary and not particularly restricted. However, in the case of a mixed tea leaf extract made from first flush tea leaves and tea leaf extract made from second flush or later tea leaves, it is preferable to use the first flush tea leaf extract as the base, as it has a better taste, flavor, color, and is rich in active ingredients. For example, it is preferable to use 50% or more by mass of first flush tea leaf extract and the remainder to be tea leaf extract made from second flush or later tea leaves. Specifically, the mixing ratio of first flush tea leaf extract to second flush or later tea leaf extract in a mixed tea leaf extract is appropriate in the range of 50-99% by mass:1-50% by mass, preferably in the range of 60-95% by mass:5-40% by mass, and more preferably in the range of 80-90% by mass:10-20% by mass. The same applies to the mixing ratio of first flush tea leaf extract to second flush tea leaf extract, or first flush tea leaf extract to third flush tea leaf extract.

[0038] Furthermore, for example, regarding the blending ratio of a mixed tea leaf extract consisting of tea leaf extracts from the first flush, second flush, and third flush teas, in the proportion of tea leaf extracts derived from the second flush and later teas (50% by mass or less) as described above, the blending ratio of tea leaf extract derived from the second flush can be set to 50% by mass or more, preferably 70% by mass or more, and more preferably 90% by mass or more, with the remainder being tea leaf extract derived from the third flush.

[0039] Regarding the blending ratio of tea leaf extracts obtained through different processes, for example, those derived from first flush tea leaves, both can serve as a basis, but the proportion of each can be appropriately selected by considering factors such as taste, flavor, color, and quantity.

[0040] 5 Process (4): Molding process The present invention's manufacturing method includes a step of filling a mold with the tea leaf extract obtained in the extraction step described above, and then vacuum freeze-drying it to form the tea leaf extract into a three-dimensional solid.

[0041] The tea leaf extract used for the molding process (4) may be, for example, freshly extracted tea leaf extract from shredded tea leaves, tea leaf extract sterilized at low temperature and high pressure, tea leaf extract that has been frozen and stored according to steps (3-3) and (3-4) and then thawed, or the aforementioned mixed tea leaf extract.

[0042] Tea leaf extract or mixed tea leaf extract can be filled into a suitable container or mold and subjected to vacuum freeze-drying to form a solid, thereby obtaining the final product, tea leaf extract solid.

[0043] The material of the container or mold is not particularly limited as long as it does not hinder vacuum freeze-drying and the solid obtained by vacuum freeze-drying can be removed without sticking. Specifically, examples include glass, metal, and resin (e.g., plastic, polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP)). Among these, resin is preferred.

[0044] Here, the shape of the final product, the tea leaf extract solid, is not particularly limited as long as it is a three-dimensional shape, and examples include rectangular prisms, cubes, spheres, cylinders, cones, and polygonal prisms. Among these, rectangular prisms and cubes are preferred from the viewpoint of ease of processing. The volume is also not particularly limited and can be adjusted as appropriate according to the bottle capacity and the size (dimensions) of the opening, but for example, 0.5 to 15 cm. 3 (For a cube, a side length of 0.8cm to 2.5cm is appropriate, and 0.6 to 8cm) 3 A range of 0.8 to 4 cm is preferred. 3 A range within this range is more preferable. Therefore, the container or mold used for vacuum freeze-drying should be of a shape and volume appropriate to its nature. The density of the final product, the tea leaf extract solid, can also be adjusted as appropriate, but from the viewpoint of shape retention and moisture resistance, for example, 0.13 to 0.40 g / cm³ is preferable. 3 A range within that range is appropriate.

[0045] Vacuum freeze-drying can be performed, for example, by placing tea leaf extract, filled into a suitable container or mold, into a suitable vacuum freeze-dryer and leaving it undisturbed overnight at atmospheric pressure and -20 to -40°C. Then, to prevent the frozen liquid from thawing, the container or mold is left undisturbed overnight at a pressure of 130 Pa or less and a temperature of 30 to 70°C to dry.

[0046] 6. Obtained tea leaf extract solids The tea leaf extract solids obtained by vacuum freeze-drying can be packaged. Packaging is preferable from the viewpoint of preservation and transportation. The packaging material is not particularly limited, but moisture-resistant material is preferred. The packaging may be done by placing multiple tea leaf extract solids separately in a single package, or by packaging each tea leaf extract solid in an independent package. Alternatively, multiple tea leaf extract solids may be packaged individually in a single package, such as a PTP sheet.

[0047] The tea leaf extract solid obtained by the present invention is highly portable, and there is minimal loss or denaturation of various active ingredients (e.g., amino acids, catechins, caffeine, vitamins) originally contained in fresh tea leaves. Furthermore, since it does not go through the kneading process required in green tea production, costs can be reduced, making it economically advantageous.

[0048] The tea leaf extract solids obtained by the manufacturing method of the present invention can be easily consumed as tea by placing one or more of them in, for example, a teacup containing water or hot water, or a PET bottle containing 250 mL to 500 mL or 1 L of water or hot water, and shaking appropriately to dissolve or suspend them.

[0049] Tea leaf extract solids are 1 cm 3 For cube-shaped tablets, it is appropriate to dissolve or suspend one tablet in 100-150 mL of water or hot water and then drink it. When drinking from a 500 mL plastic bottle, about 4-5 tablets are appropriate. [Examples]

[0050] Examples are given below to explain the present invention, but the present invention is not limited to these examples at all.

[0051] [Example 1] 300 kg of fresh tea leaves (saemi midori, yabukita. The same applies hereinafter) harvested at the time of the first tea harvest were steamed with steam for 30 seconds (step (1)). After rapid cooling, the tea leaves were shredded with a shredding machine (step (2)), and then directly pressed using a pressing machine at a temperature of 28°C or lower and a pressure of 15 MPa to obtain a dark green and viscous pressed juice (tea leaf extract) (step (3)). The obtained tea leaf extract was subjected to low-temperature high-pressure sterilization treatment at a temperature of 15°C or lower and a pressure of 600 MPa (step (3-2)), and half of it was divided into small portions and stored frozen (step (3-3)). The remaining half was filled into a resin mold with a volume of 1 cm square per section, and by subjecting this to vacuum freeze-drying, a plurality of cubic tea leaf extract solids each with a size of 1 cm 3 were obtained (step (4)). 3

[0052] [Example 2] A plurality of cubic tea leaf extract solids each with a size of 1 cm 3 were obtained in the same manner as in Example 1, except that 10 parts by mass of dextrin was added to 100 parts by mass of the tea leaf extract obtained in Example 1. [Example 3] A plurality of cubic tea leaf extract solids each with a size of 1 cm 3 were obtained in the same manner as in Example 1, except that 8 parts by mass of inulin was used instead of dextrin. [Example 4] A plurality of cubic tea leaf extract solids each with a size of 1 cm 3 were obtained in the same manner as in Example 1, except that 5 parts by mass of inulin and 3 parts by mass of acacia were used instead of dextrin.

[0053] [Example 5] A plurality of cubic tea leaf extract solids each with a size of 1 cm 3 were obtained in the same manner as in Example 1, except that in addition to 10 parts by mass of dextrin, 5 parts by mass of inulin and 2 parts by mass of acacia were used. [Example 6] The tea leaf extract stored frozen in Example 1 was naturally thawed after one week, and the thawed tea leaf extract was prepared in the same manner as in Example 1, with a volume of 1 cm x 1 cm per section. 3 The material is filled into a resin mold and then vacuum freeze-dried, resulting in each piece being 1 cm in diameter. 3 Multiple cubic tea leaf extract solids were obtained.

[0054] [Example 7] Using fresh tea leaves picked during the second harvest season, steps (1), (2), (3), and (3-2) were carried out in the same manner as in Example 1 to obtain tea leaf extract derived from second-harvest tea leaves that had undergone low-temperature, high-pressure sterilization. Half of this was divided into smaller portions and frozen for storage (step (3-3)). The remaining half was mixed with the first-harvest tea leaf extract, which had been frozen and stored separately in Example 1 (step (3-4)), using a stirrer until uniform, to obtain a mixed tea leaf extract (first-harvest:second-harvest tea blending ratio = 70% by mass:30% by mass). Subsequently, in the same manner as in Example 1, each portion was divided into 1.5 cm square sections with a volume of approximately 3.4 cm³. 3 The material is filled into a resin mold and then vacuum freeze-dried, resulting in each piece being approximately 3.4 cm in diameter. 3 Multiple cubic tea leaf extract solids were obtained (step (4)).

[0055] Furthermore, the above mixed tea leaf extract is filled into a resin mold measuring 5cm (length) x 5cm (width) x 1cm (height), and this is vacuum freeze-dried, resulting in a 25cm 3 A plate-like solid of tea leaf extract was obtained. Furthermore, this was cut into 1 cm square pieces to obtain multiple cubic solids of tea leaf extract.

[0056] [Example 8] Following the same procedure as in Example 7, a mixed tea leaf extract with a first flush:second flush tea ratio of 80% by mass:20% by mass was obtained. Then, as in Example 1, a 1cm square volume of 1cm³ was obtained per section. 3 The material is filled into a resin mold and then vacuum freeze-dried, resulting in each piece being 1 cm in diameter. 3 Multiple cubic tea leaf extract solids were obtained.

[0057] [Example 9] Following the same procedure as in Example 7, a mixed tea leaf extract with a first flush:second flush tea ratio of 90% by mass:10% by mass was obtained, and then, as in Example 1, a 1cm square section with a volume of 1cm³ was obtained per section. 3 The material is filled into a resin mold and then vacuum freeze-dried, resulting in each piece being 1 cm in diameter. 3 Multiple cubic tea leaf extract solids were obtained.

[0058] [Example 10] Using fresh tea leaves picked during the third harvest season, steps (1), (2), (3), and (3-2) were carried out in the same manner as in Example 1 to obtain tea leaf extract derived from third-harvest tea that had undergone low-temperature, high-pressure sterilization. The obtained third-harvest tea leaf extract, along with the first-harvest tea leaf extract stored frozen in Example 1 and the second-harvest tea leaf extract stored frozen in Example 2, were thawed and mixed in a stirrer until uniform to obtain a mixed tea leaf extract (first-harvest:second-harvest:third-harvest blending ratio = 80% by mass:15% by mass:5% by mass). Subsequently, in the same manner as in Example 1, a volume of 1 cm³ was obtained per 1 cm square section. 3 The material is filled into a resin mold and then vacuum freeze-dried, resulting in each piece being 1 cm in diameter. 3 Multiple cubic tea leaf extract solids were obtained. [Industrial applicability]

[0059] This invention is useful in industries related to tea processing because it allows for the production of a tea leaf extract solid that retains a large amount of the various active ingredients naturally present in fresh tea leaves and is easier to handle. [Explanation of Symbols]

[0060] 1 process(1) 2 steps(2) 3 steps(3) 31 Process (3-1) 32 processes (3-2) 33 Process (3-3) 34 Process (3-4) 35 Process (3-5) 4. Project (4)

Claims

1. A method for producing a tea leaf extract solid, characterized by including the steps described in (1) to (4) below: (1) A process to deactivate the oxidizing enzymes contained in tea leaves harvested from the tea plant. (2) The process of shredding the deactivated tea leaves, (3) A process of extracting tea leaf extract by pressing the shredded tea leaves, (4) A process of filling a mold with tea leaf extract and forming the tea leaf extract into a three-dimensional solid by vacuum freeze-drying.

2. A method for producing a tea leaf extract solid according to claim 1, wherein both the shredding in step (2) and the juicing in step (3) are performed at a temperature of 30°C or lower.

3. A method for producing a solid tea leaf extract according to claim 1, further comprising the step (3-1) of adding an additive to the tea leaf extract obtained in step (3) above to obtain a tea leaf extract containing the additive.

4. A method for producing a tea leaf extract solid according to claim 1, further comprising step (3-2) of sterilizing the tea leaf extract obtained in step (3) at low temperature and high pressure.

5. A method for producing a tea leaf extract solid according to claim 1, further comprising the steps of freezing and storing the tea leaf extract (3-3), and then thawing it (3-4).

6. A method for producing a solid tea leaf extract according to any one of claims 1 to 5, further comprising, as an extraction step, a step (3-5) of mixing the tea leaf extract obtained through at least step (3) with one or more tea leaf extracts obtained separately through at least step (3) to obtain a mixed tea leaf extract.

7. The method for producing a solid tea leaf extract according to claim 6, wherein the mixed tea leaf extract includes tea leaf extract that has been frozen and thawed based on steps (3-3) and (3-4).

8. The method for producing a tea leaf extract solid according to claim 6, wherein the mixed tea leaf extract is a mixed tea leaf extract of tea leaf extract derived from first flush tea and tea leaf extract derived from first flush tea or tea leaf extract derived from second flush or later tea leaves obtained separately.

9. The method for producing a tea leaf extract solid according to claim 6, wherein the mixed tea leaf extract is a mixed tea leaf extract of tea leaf extract derived from first flush tea and tea leaf extract derived from second flush tea.

10. The method for producing a tea leaf extract solid according to claim 3, wherein the additive is dextrin, inulin, or acacia.

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