Manufacturing method of molded green tea beverage

Abstract

To provide a method of producing a molded green tea beverage that can easily prepare a green tea beverage having a green color and flavor similar to that of freshly brewed green tea even when a green tea infusion extracted from green tea is freeze-dried and molded without using any additives, and to provide a molded green tea beverage.SOLUTION: A method of producing a molded green tea beverage is characterized in that a mixture obtained by mixing green tea with water at 2 to 30°C is frozen at -30 to -10°C, and then thawed at 2 to 10°C to obtain a green tea infusion, which is then freeze-dried to produce a molded green tea beverage. A molded green tea beverage is a freeze-dried product for preparing a green tea beverage by mixing with water or hot water, and contains green tea ingredients and is additive-free without dextrin, sweeteners, and chemicals.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing a molded green tea beverage obtained by freeze-drying a green tea infusion, and to the molded green tea beverage. [Background technology]

[0002] Generally, green tea is drunk by steeping green tea leaves and stems in hot or cold water and removing solids, i.e. tea leaves, using a teapot or filter, but because it requires equipment such as a teapot and filters, and generates food waste, consumers are hesitant to make it, and demand is declining. For this reason, tea bags containing green tea leaves and stems were developed, but the tea bags after steeping must be disposed of as food waste.

[0003] On the other hand, matcha and powdered green tea can be drunk by simply pouring in hot water or water without using any utensils, and no waste is generated afterwards. However, matcha and powdered green tea, which have coarse particles, can leave an unpleasant foreign body sensation in the throat when mixed with hot water or water, and fine-grained matcha and powdered green tea do not mix with hot water or water and form lumps, so they must be mixed with a tea whisk. Furthermore, even if water is added to matcha or powdered green tea, it takes several hours for the tea to infuse sufficiently.

[0004] Therefore, instant green tea beverage powder is known as a green tea beverage that can be consumed quickly by pouring hot or cold water over it, but since the powder is prone to scattering and difficult to pour into a cup, there is a demand for a molded green tea beverage that is easier to handle. For example, Patent Document 1 proposes a freeze-dried green tea beverage solid (corresponding to a green tea beverage molded product), and Patent Document 2 proposes a system and method for preparing tablets of plant extracts including tea, which does not require the addition of chemical binders, chemicals, or sweeteners, and involves freeze-concentrating a tea infusion and then freeze-drying it. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2022-161383 A [Patent Document 2] Patent Publication No. 2021-69376 Summary of the Invention [Problem to be solved by the invention]

[0006] In the technology of Patent Document 1, a green tea beverage solid is proposed, but dextrin is added to improve moldability and to make it less hygroscopic. However, the addition of dextrin has the problem of changing the original flavor of green tea. In addition, in the technology of Patent Document 1, green tea is infused with hot water to produce a green tea infusion, but heating causes decomposition of chlorophyll, i.e., discoloration from green to yellow, and deterioration of flavor due to oxidation. Therefore, insoluble fine particles of tea raw materials are added to make the green color and flavor of freshly brewed green tea as close as possible. However, there is also the problem that the flavor from the insoluble fine particles of tea raw materials that were intentionally added is impaired due to the masking function of the added dextrin.

[0007] In addition, the technology of Patent Document 2 proposes tablet tea prepared without adding dextrin, etc., but when green tea is infused with hot water to produce a green tea infusion, the color and flavor change occurs, and the prepared tablet tea cannot reproduce the green color and flavor of freshly brewed green tea. In addition, the technology of Patent Document 2 also proposes producing a green tea infusion by infusing with water, but infusion with low-temperature water, although a large amount of amino acids such as theanine, which is a component of umami, is infused, the amount of catechins such as epigallocatechin gallate (EGCg), which is a component of astringency, is extremely small, and the balance between umami and astringency is not achieved, so the taste of freshly brewed green tea cannot be reproduced, and even if hot water is poured into the prepared tablet tea, both the green color and flavor are inferior to those of freshly brewed green tea, and it is not delicious to drink.

[0008] Thus, conventional green tea beverage molded products such as tablet tea and solidified green tea beverages produced by freeze-drying have not been able to provide green tea beverages that reproduce the green color and flavor of freshly brewed green tea.

[0009] Therefore, the present invention aims to provide a method for producing a molded green tea beverage, which can easily prepare a green tea beverage close to the green color and flavor of freshly brewed green tea even if the green tea infusion extracted from green tea is freeze-dried and molded without using any additives, and a molded green tea beverage. [Means for solving the problem]

[0010] The inventors have conducted research to achieve the above-mentioned object, and have discovered that, not only by infusing green tea with water, but also by infusing green tea in water, freezing it, thawing it, and then freeze-drying the green tea infusion, it is possible to provide a molded green tea beverage that does not discolor the green color of the green tea even without additives, and that exudes a significantly greater amount of catechins, which are astringent components, than when infused with water, and that can be enjoyed immediately by pouring not only cold water but also hot water, and has thus completed the present invention.

[0011] According to the present invention, there are provided the following method for producing a molded green tea beverage and a molded green tea beverage produced by this method. 1. A method for producing a molded green tea beverage, comprising mixing green tea with water at 2 to 30°C, freezing the resulting mixture at -30 to -10°C, thawing it at 2 to 10°C to obtain a green tea infusion, and freeze-drying the green tea infusion. 2. A method for producing a molded green tea beverage as described in 1, characterized in that the green tea infusion is obtained by removing tea leaves after thawing. 3. The method for producing a molded green tea beverage according to 1, wherein the green tea infusion has a concentration of 9.0% by weight or more. 4. A method for producing a molded green tea beverage as described in 3, wherein the green tea infusion is obtained by thawing and then freeze-concentrating the infusion so that the concentration is 9.0% by weight or more. 5. The method for producing a molded green tea beverage described in 1, wherein the molded green tea beverage is additive-free and has a lightness (L*) of 40 to 60, a chroma (C*) of 30 to 40, and a hue angle (h*) of 95 to 110 according to the CIELCH color space. 6. A freeze-dried green tea beverage molded product for mixing with water or hot water to prepare a green tea beverage, which contains green tea ingredients and is additive-free with no added dextrin, sweeteners, or chemicals. Effect of the Invention

[0012] According to the present invention, a method for producing a molded green tea beverage and a molded green tea beverage can be provided that can easily prepare a green tea beverage close to the green color and flavor of freshly brewed green tea even when a green tea infusion obtained by infusing green tea is freeze-dried and molded without using any additives. [Brief description of the drawings]

[0013] [Figure 1] 1 is a flow chart illustrating a method for producing a molded green tea beverage according to an embodiment of the present invention. [Diagram 2] 1 is an electron microscope photograph showing the state of the stomata of tea leaves immersed in water. [Diagram 3] 1 is an electron microscope photograph showing the state of the stomata in tea leaves that have been immersed in water, frozen, and then thawed. [Figure 4] 1 is a photograph showing the appearance of a molded green tea beverage prepared in Example 1. [Diagram 5] FIG. 1 is a graph showing the scores for umami, astringency, and aroma when hot water is poured onto molded green tea beverages produced according to the present invention and molded green tea beverages produced by soaking in water, and the results are evaluated by tasting. [Figure 6] FIG. 1 is a diagram showing the preferences selected when a molded green tea beverage produced according to the present invention and a molded green tea beverage produced by soaking in water were subjected to a tasting evaluation in which cold or hot water was poured over them. [Figure 7] FIG. 1 is a graph showing the preferences selected when hot water was poured into a molded green tea beverage produced according to the present invention and a molded green tea beverage produced by adding dextrin and then the molded green tea beverage was subjected to a tasting evaluation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, specific embodiments of the method for producing a molded green tea beverage and the molded green tea beverage of the present invention will be described. The present invention is not limited to the contents described below, and various modifications are possible without departing from the spirit and scope of the present invention.

[0015] The method for producing a molded green tea beverage of the present invention will be described with reference to the flow chart in FIG.

[0016] [Types of green tea] The green tea used as the raw material for producing the molded green tea beverage of the present invention is not particularly limited, and is generally commercially available green tea (for example, sencha, deep steamed tea, gyokuro, steamed gyokuryokucha, kamaicha, bancha, and tencha). The green tea may contain only tea leaves, or may contain tea leaves and their stems, or may contain tea leaves, their stems, and other parts. However, ground materials such as green tea powder and matcha are not preferred because the aroma is dispersed during grinding. According to the present invention, molded beverages can also be produced using tea leaves other than green tea as the raw material, such as roasted tea, oolong tea, black tea, and post-fermented tea.

[0017] [Green tea soaking process] A mixed liquid is prepared by mixing green tea with water at 2 to 30° C., preferably 10 to 20° C. The weight ratio of green tea to water is 1 part green tea to 5.5 to 12.5 parts water, preferably 1 part green tea to 6 to 8 parts water.

[0018] [Freezing / thawing process] The mixture is then frozen at -30°C to -10°C for at least an hour, and completely thawed at 2°C to 10°C. By freezing and thawing in this way, the state of the tea leaves before freezing and thawing shown in Figure 2 changes to the state of the tea leaves after freezing and thawing shown in Figure 3. As shown in the figure, after freezing and thawing, the cells of the tea leaves, especially the stomata, are damaged, so that the green tea components can be extracted at a low temperature, and the green tea components can be enriched, for example, to about twice as much as when not frozen. The thawing time is arbitrary, but since the product temperature of the green tea mixture may deteriorate if stored overnight at 18°C ​​to 20°C, it is not preferable for the product temperature to be higher than 10°C.

[0019] [Solid-liquid separation process] A first green tea infusion (hereinafter, the green tea infusion is simply referred to as infusion) is obtained from the thawed mixed liquid. The first infusion may be obtained by removing tea leaves from the thawed mixed liquid, or by extracting the supernatant of the thawed mixed liquid. When removing the tea leaves, the thawed green tea mixed liquid may be filtered through a sieve or filter to remove the tea leaves, or the thawed green tea mixed liquid may be subjected to solid-liquid separation by centrifugation and then filtered through a sieve or filter to remove the tea leaves. The sieve is preferably 30 mesh (opening 500-600 μm) to 100 mesh (opening 130-150 μm). If it is coarser than this, a foreign body sensation is felt in the throat when the product dissolved in hot water or water is drunk, and if it is finer, the product yield is poor and the workability is also deteriorated.

[0020] [Freeze concentration process] The obtained first infusion liquid is filled into a container or a mold, and frozen by leaving it to stand at atmospheric pressure at -50 to -30°C for 3 hours or more. Thereafter, the temperature is raised stepwise to 40 to 70°C, for example by +10°C per hour, under a pressure of 10 to 80 Pa so that the frozen first infusion liquid does not melt, to obtain a concentrated green tea liquid having a concentration of 9.0% by weight or more, preferably 13 to 16% by weight. However, if the concentration of the obtained first infusion liquid is 9.0% by weight or more, this freeze concentration step may be omitted.

[0021] Here, the concentration refers to the weight of the solidified residue after drying the first infusion or green tea concentrate, divided by the weight of the first infusion or green tea concentrate before drying, multiplied by 100. If the concentration is less than 9.0% by weight, the final product will have poor moldability and will be brittle. Hereinafter, the first infusion and green tea concentrate with a concentration of 9.0% by weight or more will be collectively referred to as the second infusion.

[0022] [Filling (molding) process, freeze-drying process] The obtained second infusion liquid is filled into a mold and frozen by leaving it to stand at atmospheric pressure at -50 to -30°C for 3 hours or more. Thereafter, the temperature is gradually raised to 60 to 70°C under a pressure of 10 to 80 Pa so that the frozen second infusion liquid does not melt, and it is freeze-dried by leaving it to stand for 6 hours or more to reduce the moisture content to 3% by weight or less, thereby obtaining a molded green tea beverage product as shown in the external photograph of Figure 4. However, the shape of the mold is not limited, and it is possible to process it into a rectangular parallelepiped, cube, sphere, cylinder, or any other shape. The size of the mold is 1 to 3 cm. 3 The thickness is preferably 0.5 to 1.5 cm. In the method for producing a molded green tea beverage of the present invention, only the first and / or second infusion liquid obtained by infusing green tea with water is used throughout the entire production method, and nothing is added.

[0023] [Product packaging process] The obtained molded green tea beverage is packaged for storage and transportation. The packaging material should be highly moisture-resistant and light-shielding, and it is preferable to enclose a desiccant. For example, a calcium oxide desiccant can be enclosed in an aluminum laminate bag.

[0024] [Green tea beverage molded product] The molded green tea beverage product of the present invention is characterized in that it is an additive-free molded green tea beverage product containing green tea components, which is freeze-dried for mixing with water or hot water to prepare a green tea beverage. Due to these characteristics, it is possible to provide a molded green tea beverage that can be easily prepared by mixing with water or hot water to produce a green tea beverage with a green color and excellent flavor close to the green color and flavor of green tea brewed by pouring water or hot water into green tea, particularly freshly brewed green tea.

[0025] Here, the terminology will be explained. The present invention defines freeze-thaw infusion as the process in which water at 0 to 30°C is added to green tea, frozen at -30 to -10°C, and thawed at 2 to 10°C to obtain a first or second green tea infusion in which green tea components have been infused.

[0026] The molded green tea beverage of the present invention can be produced by freeze-drying the first or second green tea infusion without adding any additives, i.e., without adding any sweetener or dextrin. Here, "dextrin" refers to a low molecular weight polysaccharide obtained by hydrolysis of starch.

[0027] Furthermore, the molded green tea beverage of the present invention has excellent moldability due to the freeze concentration process, and can be reliably molded without swelling or bursting due to freeze drying. Furthermore, since the molded green tea beverage of the present invention is composed only of the first or second infusion liquid obtained by infusing green tea, it has excellent instant solubility, and additive-free green tea beverages can be easily prepared by mixing with water or hot water and dispersing or dissolving it when necessary.

[0028] The molded beverage of the present invention does not contain dextrin and is produced by freeze-drying the first or second infusion liquid in which abundant green tea components are infused even at low temperatures. As a result, the original green color and flavor of green tea are not altered and sufficient green tea components are contained, resulting in a beverage with an excellent green color and flavor that is comparable to that of regular green tea brewed by pouring cold or hot water into it.

[0029] Next, the components and sensory evaluation of the molded green tea beverage of the present invention will be described.

[0030] The molded green tea beverage of the present invention has an increased soluble solid content, which increases its weight and makes it harder, and has excellent moldability, compared to a molded green tea beverage obtained by infusing the first infusion with water. In this case, infusion with water refers to adding water at 0 to 30°C to green tea to obtain a first infusion in which green tea components have been infused.

[0031] The shaped green tea beverage of the present invention has increased amounts of catechins and amino acids compared to the shaped green tea beverage obtained by infusing the first infusion solution with water.

[0032] When a green tea beverage prepared by pouring hot water over the green tea beverage molded product of the present invention is tasted, it has enhanced umami, astringency and aroma, making it possible to produce a taste that is more preferred by drinkers, compared to a green tea beverage molded product obtained by infusing the first infusion solution with water.

[0033] [Green tea drinks] The green tea beverage of the present invention is prepared by mixing the above-described molded green tea beverage of the present invention with water or hot water. The amount of water or hot water used when dissolving the molded green tea beverage to prepare a green tea beverage can be adjusted appropriately depending on the drinker's preferences. EXAMPLES

[0034] The present invention will be specifically described below based on examples, but the present invention is not limited to these examples in any way. <Example 1>

[0035] [Manufacturing method of molded green tea beverage] 1,000g of tap water was added to 81g of ordinary sencha produced in Minamikyushu City, and the tea leaves were squeezed on a metal sieve and used tea leaves were removed using a 30 mesh sieve to obtain a first infusion by three different infusion methods. One was a hot water infusion method, in which 90°C hot water was added, and after 5 minutes the used tea leaves were removed to obtain a first infusion (hot water). The second was a cold water infusion method, in which tap water was added, the mixture was left to stand overnight in a 5°C refrigerator, the used tea leaves were removed, and the first infusion (cold water) was obtained. The third was the freeze-thaw infusion method of the present invention, in which tap water was added, the mixture was frozen overnight in a freezer at -20°C, and then thawed at room temperature, the used tea leaves were removed, and the first infusion (the present invention) was obtained.

[0036] Each first infusion was pre-frozen at -30°C using a vacuum freeze-drying device (ULVAC, DFR-5N-B), and freeze-dried for 4 hours with a controlled pressure of 70 Pa and a shelf temperature gradually raised from 0°C to 25°C, and concentrated to 1 / 6 the weight of each first infusion to obtain each second infusion. The concentrations of each second infusion at this time were 14.0% by weight for the second infusion (hot water), 7.6% by weight for the second infusion (cold water), and 11.9% by weight for the second infusion (present invention). Each second infusion was placed into a mold (shape: regular square pyramid (top side 1.55 cm, bottom side 0.95 cm, height 1.3 cm)) and pre-frozen at -40°C using a vacuum freeze-drying apparatus (same as above). The controlled pressure was 70 Pa and the shelf temperature was gradually raised from 0°C to 60°C, and finally the temperature was lowered to 40°C. The mixture was vacuum freeze-dried for 14 hours to produce a molded green tea beverage as shown in the external photograph in Figure 4.

[0037] <Characteristics of the molded product> Regarding the color tone of the molded green tea beverage products, a color difference meter (SD3000, manufactured by Nippon Denshoku Industries Co., Ltd.) was used to measure the lightness (L*), chroma (C*), and hue angle (h*) of the molded green tea beverage products using a reflectance measurement with a measuring diameter of 0.6 cm in diameter according to the CIELCH color space. Note that the higher the lightness value, the brighter the color, and the higher the chroma value, the more vivid the color. For the hue angle, 90 indicates yellow, 180 indicates green, and the higher the value between these, the greener the color. Regarding the hardness of the molded green tea beverage products, a rheometer (RE2-33005C, manufactured by Yamaden Co., Ltd.) was used to measure the hardness of the molded green tea beverage products using a load cell of 20 N (Newtons) and a wedge-shaped plunger (contact area 24 mm 2 The maximum load was measured at a measurement speed of 1 mm / sec. The characteristics and color of the molded green tea beverages obtained by each extraction method are shown in Table 1.

[0038] [Table 1]

[0039] In this example, the color of the green tea beverage molded product using the first infusion (hot water) (hereinafter referred to as hot water molded product) was yellow with a hue angle of 90.5, while the green tea beverage molded product using the first infusion (cold water) (hereinafter referred to as cold water molded product) had a hue angle of 94.6, and the green tea beverage molded product using the first infusion (the present invention) (hereinafter referred to as the molded product of the present invention) had a hue angle of 96.4, a yellow-green color. Furthermore, it was found that the molded product of the present invention was heavier, had a deeper green color, was harder, and had better moldability than the cold water molded product.

[0040] <Characteristics of beverages made by adding water to molded products> The evaluation of the beverage liquid obtained by adding hot water or water to the molded green tea beverage was carried out by pouring 30 g of 80°C or 28°C ion-exchanged water into one molded green tea beverage to dissolve the beverage liquid, and for comparison, 3 g of the same raw green tea was infused in 100 g of 80°C ion-exchanged water for 3 minutes or 28°C ion-exchanged water for 1 hour. The color tone was measured by measuring the lightness (L*), chroma (C*), and hue angle (h*) in the CIELCH color space using a color difference meter (SD3000, manufactured by Nippon Denshoku Industries Co., Ltd.). The lightness, chroma, and hue angle are as described above. The sensory evaluation and color tone of the beverage liquid obtained by pouring hot water or water into the molded green tea beverage using each infusion method are shown in Table 2.

[0041] [Table 2]

[0042] In this embodiment, the beverage liquid obtained by pouring water into the hot water molded product had a strong bitter and astringent taste and a deep yellow color with a brightness of 75.5, a saturation of 43.5, and a hue angle of 93.6, whereas the beverage liquid obtained by pouring cold water molded product had no bitter and astringent taste and a yellow-green color with a brightness of 85.7, a saturation of 31.3, and a hue angle of 100.2, whereas the beverage liquid obtained by pouring cold water molded product had no bitter and astringent taste and a deep yellow-green color with a brightness of 77.1, a saturation of 48.1, and a hue angle of 97.1, which was a yellow-green color similar to the color of the liquid obtained by brewing the raw green tea with hot water or cold water. Furthermore, it was found that the beverage liquid obtained by pouring water into the molded product of the present invention had a richer umami taste than the beverage obtained by pouring hot water into the cold water infusion product, while the beverage liquid obtained by pouring hot water into the molded product of the present invention had a more astringent taste and a better balance of umami and astringency, making it more delicious.

[0043] Next, the component analysis of the molded green tea beverage of the present invention will be described based on examples. [Analysis of catechins] 1 mL of 2% ascorbic acid solution and 9 mL of 50% acetonitrile solution were added to 0.02 g of finely ground green tea beverage molded product, and the mixture was ground with a homogenizer for 30 seconds. The extracted solution was centrifuged (10,000 rpm x 5 minutes), filtered with a filter (0.45 μm), and then subjected to HPLC analysis. The HPLC measurement conditions were as follows. Column: Cadenza CD-C18 (Imtakt, particle size 3 μm, length 150 × width 3 mm), column temperature 40 °C Detector: UV-1570 (JASCO), measurement wavelength 210 nm Mobile phase: 0.1% formic acid aqueous solution (liquid A), methanol:acetonitrile = 3:2 solution (liquid B), flow rate 0.4 mL / min Gradient conditions: 0 to 7 minutes is 85% solution A, and from 7 to 20 minutes, solution A is changed uniformly from 85% to 50%.

[0044] The catechin content of the green tea beverage molded products obtained by each infusion method is shown in Table 3. In the table, EGCg stands for epigallocatechin gallate, and total catechins stands for the sum of EGCg, gallocatechin, epigallocatechin, catechin, epicatechin, epicatechin gallate, and catechin gallate, as well as an index when the total value of the hot water molded products is taken as 100.

[0045] [Table 3]

[0046] In this example, it was found that the catechin content of the hot water molding was higher than that of the cold water molding and the molding of the present invention. The total catechin content of the cold water molding was only 37% of that of the hot water infusion, but it increased to 73% in the molding of the present invention.

[0047] [Analysis of amino acids] 10 mL of ultrapure water was added to 0.05 g of finely ground green tea beverage molded product, and the mixture was placed in an ultrasonic cleaner for 10 minutes, then centrifuged (10,000×g, 10 minutes). The supernatant was filtered through a 0.45 μm filter, diluted appropriately, and the internal standard glycylglycine was added before analysis by LCMS. The measurement conditions for LCMS were as follows: Column: Intrada Amino Acid (Imtakt, particle size 3 μm, length 75 × width 3 mm), column temperature 40 ° C. Detector: LCMS-2020 (Shimadzu Corporation) Mobile phase: acetonitrile:formic acid = 100:1 (liquid A), 100 mM ammonium formate aqueous solution (liquid B), flow rate 0.6 mL / min

[0048] The amino acid content of the produced molded green tea beverage is shown in Table 4. The total of major amino acids is the sum of theanine, glutamic acid, aspartic acid, glutamine, and arginine, and is an index when the total of the molded product is set at 100.

[0049] [Table 4]

[0050] In this example, it was found that the total amount of major amino acids in the hot water molded product was greater than that in the cold water molded product and the molded product of the present invention. In detail, the total amount of major amino acids in the cold water molded product was 69% of that in the hot water molded product, but it was 99% in the molded product of the present invention, which was only slightly different from that in the hot water molded product.

[0051] [Sensory evaluation] Each of the cold-water molded product and the molded product of the present invention was dissolved in 30 g of 70°C ion-exchanged water to prepare green tea beverages, and 18 people in their 20s to 50s were sampled to compare the umami, astringency, and aroma. The results are shown in Figure 5. The vertical axis in the figure shows the evaluation score of the molded product of the present invention based on the cold-water molded product, with +2 being "quite strong," +1 being "slightly strong," 0 being "no difference," -1 being "slightly weak," and -2 being "quite weak."

[0052] When hot water was poured into the molded product of the present invention, it was rated as having slightly stronger umami, astringency, and aroma than the cold water infusion.

[0053] Each of the green tea beverages was prepared by dissolving one cold-water molded product and one molded product of the present invention in 30 g of ion-exchanged water at room temperature or 70°C. Sixteen people (room temperature) and 18 people (70°C) aged between 20 and 50 years old tasted each of the beverages and selected their preference. The results are shown in Figure 6.

[0054] The molded product of the present invention was found to be preferred by many drinkers when poured with hot water, although there was no difference in the number of drinkers who preferred it when poured with cold water, compared with the product molded with cold water. <Example 2>

[0055] [Manufacturing method of molded green tea beverage] 81 g of ordinary sencha tea produced in Minamikyushu was mixed with 1,000 g of tap water, frozen overnight in a freezer at -20°C, and then thawed at room temperature to obtain a frozen-thawed infusion. Each was then squeezed on a metal colander, and the used tea leaves were removed using a 30-mesh sieve to obtain the first infusion (the present invention).

[0056] The first leachate (present invention) was pre-frozen at -30°C using a vacuum freeze-drying device (ULVAC, DFR-5N-B), and the control pressure was 70 Pa and the shelf temperature was gradually raised from 0°C to 60°C, and finally lowered to 40°C, and freeze-concentrated for 4 hours to obtain an additive-free second leachate (present invention). The additive-free second leachate (present invention) was divided into two, and one of them was mixed with the additive-free second leachate (present invention) and dextrin (trade name: Sanas 2002) in a weight ratio of 100:7.8 to obtain a dextrin-containing second leachate (present invention). The concentration of each concentrated second leachate at this time was 14.6% by weight for the additive-free second leachate (present invention) and 20.4% by weight for the dextrin-containing second leachate (present invention). Each second infusion solution (invention) was used to produce a molded green tea beverage in the same manner as in Example 1. The proportion of dextrin in the molded green tea beverage containing dextrin produced from the second infusion solution (invention) containing dextrin was 33% by weight.

[0057] <Characteristics of the molded product and the beverage made by adding water to the molded product> The hardness of the molded green tea beverage products was measured using a rheometer (Yamaden, RE2-33005C) with a load cell of 20 N (Newtons), a wedge-shaped plunger (contact area 24 mm2), and a measurement speed of 1 mm / sec to determine the maximum load. In addition, a sensory evaluation of the liquid obtained by adding hot water or water to the molded green tea beverage products was performed by pouring 30 g of 70°C or 25°C ion-exchanged water per molded green tea beverage product to prepare a dissolved liquid. The characteristics of the molded green tea beverage products with and without dextrin, and the sensory evaluation of the liquid obtained by adding hot water or water, are shown in Table 5.

[0058] [Table 5]

[0059] It has been found that the additive-free molded green tea beverage of the present invention has a stronger flavor than one containing dextrin when poured with hot or cold water, that is, the original aroma and flavor of the raw materials can be strongly felt.

[0060] Nineteen people in their 20s to 50s tasted each of the green tea beverages prepared by dissolving one molded piece of the additive-free or dextrin-containing green tea beverage of the present invention in 30 g of ion-exchanged water at 70°C, and selected their preference. The results are shown in Figure 7.

[0061] It was found that the additive-free molded green tea beverage of the present invention was preferred by many drinkers when poured with hot water, as compared with the molded green tea beverage containing dextrin.

Claims

1. The mixture obtained by mixing green tea with water at 2 to 30°C is frozen at -30 to -10°C and then thawed at 2 to 10°C to obtain a green tea infusion. A method for producing a molded green tea beverage, comprising freeze-drying the green tea infusion.

2. 2. The method for producing a molded green tea beverage according to claim 1, wherein the green tea infusion is obtained by removing tea leaves after thawing.

3. 2. The method for producing a molded green tea beverage according to claim 1, wherein the green tea infusion has a concentration of 9.0% by weight or more.

4. 4. The method for producing a molded green tea beverage according to claim 3, wherein the green tea infusion is obtained by thawing and then freeze-concentrating the infusion so that the concentration is 9.0% by weight or more.

5. The method for producing a molded green tea beverage according to claim 1, characterized in that the molded green tea beverage is additive-free and has a lightness (L*) of 40 to 60, a chroma (C*) of 30 to 40, and a hue angle (h*) of 95 to 110 according to the CIELCH color space.

Images