Tea beverage and method for manufacturing tea beverage

Abstract

To provide a tea beverage that is transparent even when a protein material is blended therein, and to provide a tea beverage which, even when the protein material is blended therein, offers a pleasant flavor without the inhibition of the natural flavor inherent to the tea beverage.SOLUTION: It was discovered that: a tea beverage that is transparent and offers a pleasant flavor can be obtained by using a plant-derived protein material where the protein content, the solution turbidity, and the molecular weight value are within specific ranges.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a tea beverage and a method for producing the tea beverage.

Background Art

[0002] Various beverages are commercially available in PET bottle containers and the like, and among them, tea beverages are often consumed. In recent years, there has been an increasing number of beverages containing protein, especially targeting people who exercise, as they can easily consume protein. In such a situation, there is also a need for tea beverages containing protein. As technologies for adding protein components to tea beverages, there are technologies for adding milk components to roasted tea beverages (Patent Document 1), technologies for producing matcha powder compositions containing proteins such as milk protein (Patent Document 2), and the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] When a protein material is added to a tea beverage, turbidity occurs, and there is a problem that a tea beverage with its original transparency cannot be produced. An object of the present invention is to provide a tea beverage with transparency even when a protein material is added. Further, an object of the present invention is to provide a tea beverage with a good flavor without inhibiting the original natural flavor of the tea beverage even when a protein material is added.

Means for Solving the Problems

[0005] As a result of diligent research to solve the above problems, the inventors of the present invention have found that by using a plant-derived protein material in which the protein content, solution turbidity, and molecular weight values ​​are within a specific range, a transparent tea beverage can be obtained, and furthermore, even when a protein material is added, the natural flavor derived from the tea leaves is not inhibited, resulting in a tea beverage with a good flavor, thus completing the present invention.

[0006] In other words, the present invention is (1) A tea beverage containing plant-based protein material that satisfies the following A to C, and whose turbidity is 1.0 or less when measured at OD610nm with a spectrophotometer. A: Protein content of 60% by weight or more on a solids basis. B: When a 5 wt% aqueous solution with pH 7.4 is measured with a spectrophotometer at OD 610 nm, the turbidity is 1.0 or less. C: In molecular weight distribution measurement by gel filtration, the weight-average molecular weight is 3kDa to 300kDa. (2) The plant protein material satisfies the following A to C, the tea beverage described in (1), A: Protein content of 70% by weight or more on a solids basis, B: When a 5 wt% aqueous solution with pH 7.4 is measured with a spectrophotometer at OD 610 nm, the turbidity is 1.0 or less. C: In molecular weight distribution measurement by gel filtration, the weight-average molecular weight is 3kDa to 300kDa. (3) The plant protein material satisfies the following A to C, the tea beverage described in (1), A: Protein content of 70% by weight or more on a solids basis, B: When a 5 wt% aqueous solution with pH 7.4 is measured with a spectrophotometer at OD 610 nm, the turbidity is 0.9 or less. C: In molecular weight distribution measurement by gel filtration, the weight-average molecular weight is 3kDa to 300kDa. (4) The tea beverage described in (1), wherein the protein content in the tea beverage is 0.05 to 5% by weight. (5) The tea beverage described in (2), wherein the protein content in the tea beverage is 0.05 to 5% by weight. (6) The tea beverage described in (3), wherein the protein content in the tea beverage is 0.05 to 5% by weight. (7) A method for producing a tea beverage, characterized by adding a plant protein material satisfying the following A to C to the tea beverage so that the protein content in the tea beverage is 0.05 to 5% by weight, wherein the turbidity measured at OD610nm with a spectrophotometer is 1.0 or less. A: Protein content of 60% by weight or more on a solids basis. B: When a 5 wt% aqueous solution with pH 7.4 is measured with a spectrophotometer at OD 610 nm, the turbidity is 1.0 or less. C: In molecular weight distribution measurement by gel filtration, the weight-average molecular weight is 3kDa to 300kDa. (8) A method for producing the tea beverage described in (7), wherein the plant protein material satisfies the following A to C. A: Protein content of 70% by weight or more on a solids basis, B: The turbidity of a 5 wt% aqueous solution with pH 7.4 measured at OD 610 nm using a spectrophotometer is 1.0 or less. C: In molecular weight distribution measurement by gel filtration, the weight-average molecular weight is 3kDa to 300kDa. (9) A method for producing the tea beverage described in (7), wherein the plant protein material satisfies the following A to C. A: Protein content of 70% by weight or more on a solids basis, B: When a 5 wt% aqueous solution with pH 7.4 is measured with a spectrophotometer at OD 610 nm, the turbidity is 0.9 or less. C: In molecular weight distribution measurement by gel filtration, the weight-average molecular weight is 3kDa to 300kDa. That is the case. [Effects of the Invention]

[0007] This invention makes it possible to produce a clear tea beverage containing protein. Furthermore, even when protein is added, the natural flavor derived from the tea leaves is not inhibited, making it possible to produce a tea beverage with a good flavor. [Modes for carrying out the invention]

[0008] (tea drink) The tea beverage of the present invention contains a plant-based protein material that satisfies the following A to C, and is characterized by having a turbidity of 1.0 or less when measured at OD610nm with a spectrophotometer. A: Protein content of 60% by weight or more on a solids basis. B: The turbidity of a 5 wt% aqueous solution with pH 7.4 measured at OD 610 nm using a spectrophotometer is 1.0 or less. C: In molecular weight distribution measurement by gel filtration, the weight-average molecular weight is 3kDa to 300kDa. By incorporating the above-mentioned specific plant-based protein material, it is possible to produce a tea beverage that is transparent and has a good flavor. In this invention, "transparent" means that the turbidity value of the tea beverage measured with a spectrophotometer at OD610nm is 1.0 or less. The protein content in the tea beverage is preferably 0.05 to 5% by weight, and more preferably 0.1 to 5% by weight. Even more preferably, 0.2 to 5% by weight, 0.5 to 5% by weight, 1 to 5% by weight, 0.1 to 4% by weight, 0.2 to 4% by weight, 0.5 to 4% by weight, 1 to 4% by weight, 0.2 to 3% by weight, 0.5 to 3% by weight, and 1 to 3% by weight can be selected. The plant protein material of the present invention should be incorporated into a tea beverage so that the protein content of the tea beverage falls within the above range.

[0009] The tea beverage of the present invention has low viscosity and a refreshing taste. Specifically, the viscosity of the tea beverage is preferably 10 mPa·s or less, more preferably 8 mPa·s or less, and even more preferably 6 mPa·s or less, or 5 mPa·s or less. The viscosity shall be measured using a B-type viscometer at room temperature of 20°C. The turbidity of the tea beverage of the present invention, when measured at OD610nm using a spectrophotometer, is preferably 0.9 or less, and more preferably 0.7 or less. The turbidity is measured using a Shimadzu UV-1800 model spectrophotometer with a quartz cell having a path length of 1 cm. In addition, the tea beverage of the present invention is also characterized by having less sediment when centrifuged, and in the present invention, it is calculated as the sedimentation rate. Specifically, 40 g of the tea beverage is placed in a centrifuge tube and centrifuged under the conditions of 3000×g for 5 minutes, and the ratio of the amount of sediment in the obtained wet state to the tea beverage is expressed as the sedimentation rate (weight %). The sedimentation rate is preferably 2% by weight or less, more preferably 1.5% by weight or less, and still more preferably 1% by weight or less.

[0010] The tea beverage of the present invention is not particularly limited, but preferably oolong tea, roasted tea, black tea, rooibos tea, barley tea, green tea, brown rice tea, jasmine tea, pu-erh tea, guava tea, turmeric tea, herb tea, mate tea, white tea, tencha, adzuki bean tea, corn tea, soybean tea, black soybean tea, azuki tea, buckwheat tea, kelp tea, houttuynia tea, licorice tea, amacha tea, eucommia tea, various blended teas, fruit teas such as peach, apple, pineapple, pear, orange, grapefruit, lemon, etc. More preferably, oolong tea, roasted tea, black tea, rooibos tea, white tea, adzuki bean tea, buckwheat tea. Still more preferably, oolong tea, roasted tea, black tea, rooibos tea.

[0011] (Vegetable protein material) The vegetable protein material of the present invention satisfies the following requirements A to C. A: The protein content is 60% by weight or more in terms of solid content. B: The turbidity measured at OD610nm with an absorptiometer for a 5% by weight aqueous solution at pH 7.4 is 1.0 or less. C: In the measurement of the molecular weight distribution by gel filtration, the weight average molecular weight is 3 kDa to 300 kDa. The protein content of requirement A is preferably 70% by weight or more, more preferably 80% by weight or more, and still more preferably 85% by weight or more, 88% by weight or more, 90% by weight or more can be selected. The protein content is determined by the Kjeldahl method for the total nitrogen amount in the sample, multiplied by the coefficient 6.25, and measured as a percentage with respect to the sample and expressed in terms of solid content. The turbidity of requirement B is preferably 0.9 or less, more preferably 0.7 or less. Turbidity will be measured using a Shimadzu UV-1800 model. The weight-average molecular weight of requirement C has a lower limit that is preferably 5 kDa or more, more preferably 6 kDa or more, and even more preferably 7 kDa or more, 8 kDa or more, 9 kDa or more, 10 kDa or more, 30 kDa or more, 50 kDa or more, 80 kDa or more, and 100 kDa or more. The upper limit is preferably 250 kDa or less, more preferably 230 kDa or less, and even more preferably 210 kDa or less, 200 kDa or less, 180 kDa or less, and 160 kDa or less. Specific preferred embodiments include, for example, 5kDa~300kDa, 10kDa~300kDa, 50kDa~300kDa, 100kDa~300kDa, 3kDa~250kDa, 5kDa~250kDa, 10kDa~250kDa, 50kDa~250kDa, 100kDa~250kDa, 3kDa~200kDa, 5kDa~200kDa, and 10kDa~200kDa. a. You can select 50kDa~200kDa, 100kDa~200kDa, 3kDa~180kDa, 5kDa~180kDa, 10kDa~180kDa, 50kDa~180kDa, 100kDa~180kDa, 3kDa~160kDa, 5kDa~160kDa, 10kDa~160kDa, 50kDa~160kDa, 100kDa~160kDa, etc. The measurement conditions for the weight-average molecular weight are shown below.

[0012] Measurement conditions for weight-average molecular weight The protein material is adjusted to a concentration of 0.1% by weight using the eluent, and the sample solution is obtained by filtering it through a 0.2 μm filter. A gel filtration system is assembled by connecting two columns in series, and first, known proteins that serve as molecular weight markers (Table 1) are charged, and a calibration curve is determined based on the relationship between molecular weight and retention time. Next, the sample solution is charged, and the percentage content of each molecular weight fraction is determined by the ratio of the area of ​​a specific molecular weight range (time range) to the total absorbance chart area (1st column: "TSK gel G3000SWXL" (SIGMA-ALDRICH), 2nd column: "TSK gel G2000SWXL" (SIGMA-ALDRICH), eluent: 1% SDS + 1.17% NaCl + 50 mM phosphate buffer (pH 7.0), 23°C, flow rate: 0.4 ml / min, detection: UV 220 nm).

[0013] (Table 1) Molecular weight markers TIFF0007845401000001.tif135163

[0014] In the present invention, examples of plant-based protein materials include proteins derived from legumes such as soybeans, peas, mung beans, chickpeas, and cowpeas, as well as proteins derived from canola seeds, wheat, rice, hemp, walnuts, etc., and their origin is not particularly limited as long as they satisfy the requirements necessary for the plant-based protein material of the present invention. In one embodiment, the type of plant-based protein can be selected from one or more types selected from soybeans, peas, and mung beans. In another embodiment, the type of plant-based protein can be selected from soybeans, which are readily available and easy to obtain as raw materials.

[0015] As a typical example, when the plant-based protein material is derived from soybeans, defatted soybean flakes are used as the soybean raw material. These flakes are dispersed in an appropriate amount of water and subjected to water extraction. The extracted soybean protein (defatted soy milk), obtained by removing the insoluble fraction mainly composed of fiber, is included in the soybean protein material. Furthermore, the extracted soybean protein is adjusted to a pH of around 4.5 with an acid such as hydrochloric acid, the protein is precipitated at the isoelectric point to remove the acid-soluble fraction (whey), the acid-insoluble fraction (curd) is dispersed again in an appropriate amount of water to obtain a curd slurry, and then neutralized with an alkali such as sodium hydroxide to obtain a neutralized slurry. The isolated soybean protein obtained from this neutralized slurry is also included in the soybean protein material. These extracted soy proteins and isolated soy proteins are heat-sterilized in solution using a high-temperature heat treatment device, spray-dried using a spray dryer or the like, and finally manufactured into a product as soy protein material. However, the manufacturing method is not limited to the above method; any method that increases the purity of soy protein from the soy raw material is acceptable. Concentrated soy protein obtained by removing whey from defatted soybeans with ethanol or acid is also included in the category of soy protein materials. Of these, isolated soy protein is more commonly used than extracted soy protein because its protein content is usually high, around 90% by weight of the solids.

[0016] In addition to the requirements A to C above, the plant protein material of the present invention may preferably have the property of having a pH of 7.0 to 7.8 for a 5% by weight aqueous solution as requirement D. The pH is more preferably 7.4 to 7.8.

[0017] The plant-based protein material that satisfies all of the above requirements A to C to be added to this tea beverage can be easily obtained by purchasing it from a plant-based protein material manufacturer, such as Fuji Oil Co., Ltd., or by commissioning a manufacturer to produce it. Incidentally, Fuji Oil Co., Ltd. has been able to test manufacture the "Prolina TX" (tentative name) series, a new plant-based protein material that possesses all of the above characteristics A to C. Therefore, those skilled in the art can easily obtain the product or test samples by specifying it. It should be noted that conventional commercially available soy protein materials such as "Fujipro E," "Fujipro CL," "Fujipro AL," "Prolina RD-1," "Prolina HD101R," and the soy peptide "HighNut" do not meet the criteria for plant-based protein materials that satisfy all of the above characteristics A to C. Therefore, it is not possible to manufacture this tea beverage using these materials. Adding substances with a molecular weight of less than 3 kDa, such as the soy peptide "HighNut," to a tea beverage impairs the original natural flavor of the tea beverage, resulting in a poor flavor. In addition, the turbidity of the tea beverage also increases.

[0018] (Manufacturing of plant-based protein materials) The following is a reference embodiment for producing a plant-based protein material that satisfies all of requirements A to C of the present invention, using soybeans as an example. However, since the technical idea of ​​the present invention is essentially to apply a plant-based protein material that satisfies requirements A to C to tea beverages, it is natural that the method for producing the plant-based protein material is not limited to a specific type of plant or a specific manufacturing method. To produce soy protein material, the conventional process for producing isolated soy protein can be used as a basis, as described below. However, the method for concentrating the protein can be the general acid precipitation method, or other methods such as membrane filtration for concentration or water extraction from concentrated soy protein can also be employed. While defatted soybeans are commonly used as the raw material for protein extraction, whole-fat or partially defatted soybeans can also be used. When whole-fat or partially defatted soybeans are used, high-speed centrifugation is performed after the extraction process to remove the oil separated to the upper layer, resulting in a low-oil derivative. Next, the soybean raw material and water are mixed and dispersed into a slurry, and the protein is extracted while stirring as necessary. Next, insoluble dietary fiber (okara) is removed from the slurry by separation means such as a centrifuge or filtration to obtain extracted soy protein solution (soy milk). Next, acid-soluble fractions (whey), such as oligosaccharides and acid-soluble proteins, are removed from the extracted soy protein solution to obtain a concentrated soy protein solution. A typical method is the acid precipitation method, in which the pH of the extracted soy protein solution is adjusted to around the isoelectric point of 4-5 with an acid such as hydrochloric acid or citric acid to insolubilize the protein and cause it to precipitate. Next, the acid-soluble fraction is removed by separation means such as centrifugation or filtration, and the acid-insoluble fraction, called "curd," is recovered and dispersed again in an appropriate amount of water to obtain a curd slurry. Other methods for concentrating soy protein besides the acid precipitation method include ultrafiltration. The resulting curd slurry is then neutralized to a pH of approximately 7. Next, the neutralized slurry is reacted with a protein hydrolase such as protease, and enzymatic decomposition is carried out under reaction conditions (temperature, time) that result in the desired degree of hydrolysis. Subsequently, after heat sterilization by high-temperature heat treatment, it is dried with a spray dryer or the like to obtain soy protein material. The aqueous solution of this plant protein material has a pH of approximately 6.5 to 8.0. For drying with a spray dryer, either a disc-type atomizer system or spray drying with one-fluid or two-fluid nozzles can be used.

[0019] Here, in order to obtain a soy protein material that satisfies all of requirements A to C of the present invention, the following additional steps may be taken. Specifically, firstly, the product is subjected to at least one heat treatment, and finally, two or more heat treatments are performed. In both of these two or more heat treatments, direct steam blowing high-temperature instantaneous heat treatment is preferred. This heat treatment is a UHT sterilization method in which high-temperature, high-pressure steam is blown directly into the soy protein solution, heated and held, and then the pressure is rapidly released in a vacuum flash pan. The appropriate heat treatment conditions are in the range of 100 to 170°C, preferably 110 to 165°C, and the heating time is 0.5 seconds to 5 minutes, preferably 1 second to 60 seconds. At this time, the solution or slurry containing soy protein to be heat-treated is heat-treated in the range of 3 to 12 according to the pH adjusted at each stage of the manufacturing process, but commercially available heat sterilization equipment that employs this heat treatment method can be used, such as VTIS sterilization equipment (manufactured by Alfa Laval) or jet cooker equipment.

[0020] In any embodiment, other protein materials may be used in combination with the above-mentioned specific plant-based protein material in this beverage, as long as they do not depart from the technical spirit of the present invention. For example, various milk protein materials such as casein and concentrated milk protein (MPC), plant protein-derived peptides such as soy peptides, and collagen peptides may be added to this beverage along with the plant-based protein material. In this case, the mixing ratio of the plant-based protein material and the milk protein material is preferably 60:40 to 99:1 on a solid content basis, more preferably 70:30 to 99:1, even more preferably 80:20 to 99:1, and most preferably 90:10 to 99:1.

[0021] (Tea beverage manufacturing) The tea beverage of the present invention can be manufactured by known methods. For example, a tea beverage can be made by adding water to a tea extract obtained by extracting from raw materials such as tea leaves, grains, legumes, cereals, herbs, and fruits using water, warm water, or hot water, and then blending it with the plant protein material of the present invention. The tea beverage can be filled into containers as needed. During extraction, stirring may be performed as needed. After extraction, the tea extract can be obtained by solid-liquid separation using filtration with a cartridge filter, filter paper, filter press, membrane filtration, centrifugation, or decantation. Plant protein material may be added at the same time as the tea extract, or the plant protein material may be added to the water first and then the tea extract may be added. In addition, antioxidants such as ascorbic acid, pH adjusters, sweeteners, and colorants may be used as raw materials as needed. When using tea extract, the concentration of the tea extract in the tea beverage is not particularly limited, but is generally 0.05 to 3% by weight, preferably 0.05 to 2% by weight, and more preferably 0.1 to 2% by weight. Alternatively, the plant protein material of the present invention can be incorporated into any step of the process for manufacturing a tea beverage from tea leaves to produce the tea beverage. In this case, it is sufficient to produce a tea beverage with a concentration equivalent to that of the tea extract in the tea beverage. Furthermore, if necessary, heat sterilization may be performed, and commonly used heat sterilization equipment includes retort sterilizers, plate sterilizers, and tube sterilizers. [Examples]

[0022] The present invention will be explained below by describing examples. In the examples, parts and percentages refer to weight unless otherwise specified.

[0023] (Test material) As a plant-based protein material, we conducted tests using soy protein material. We prepared commercially available product A (Prolina RD-1) as an existing soy protein material. We also prepared newly manufactured prototypes B and C ("Prolina TX" (provisional name)) as soy protein materials. Furthermore, we prepared commercially available product D, which is a soy peptide called HighNut AM. All of these can be obtained by contacting Fuji Oil Co., Ltd. For these soy protein materials, we analyzed the protein content in the solids, the turbidity of the 5% solution, and the weight-average molecular weight. The results are shown in Table 2.

[0024] (Table 2) TIFF0007845401000002.tif59155

[0025] As shown in Table 2, prototypes B and C, which are plant-based protein materials of the present invention, have a protein content of 60% or more, a turbidity of 1.0 or less, and a weight-average molecular weight in the range of 3 kDa to 300 kDa. On the other hand, commercially available product A has a turbidity value greater than 1.0, and commercially available product D has a weight-average molecular weight of less than 3 kDa. The pH of the 5% by weight aqueous solutions was 7.2 for commercial product A, 7.6 for prototype B, 7.6 for prototype C, and 6.2 for commercial product D.

[0026] (Examples 1-2, Comparative Examples 1-2) Investigation of Oolong Tea Beverages Based on Table 3, each plant-based protein material and oolong tea extract (oolong tea extract, manufactured by Sato Foods Co., Ltd.) were mixed and dissolved in water. After adjusting the pH of the solution to 7.4 with baking soda, the solution was sterilized using UHT at 140°C for 30 seconds, filled into containers, and cooled to obtain a tea beverage. The obtained tea beverages were evaluated for turbidity, viscosity, sedimentation rate, and flavor, and the results are shown in Table 3. Note that, since the instrument's detection limit for turbidity is 4.0, values ​​above 4.0 are indicated as "4.0 or higher".

[0027] (Table 3) TIFF0007845401000003.tif88149

[0028] The oolong tea beverages in Examples 1 and 2 had a turbidity of 1.0 or less and had good flavor. On the other hand, the oolong tea beverage in Comparative Example 1 had a turbidity of 4.0 or more, was cloudy, and the original natural flavor of the tea beverage was suppressed, resulting in a poor quality product. Similarly, the oolong tea beverage in Comparative Example 2 also had a suppressed original natural flavor, was poor quality, and also had high turbidity.

[0029] (Examples 3-8) Examination of various tea beverages A tea beverage was prepared in the same manner as in Example 1, except that the tea extracts used were rooibos tea extract (Rooibos Tea Extract T-75, manufactured by Sato Foods Industry Co., Ltd.), roasted green tea extract (Rooibos Tea Extract H0102, manufactured by Sato Foods Industry Co., Ltd.), and black tea extract (Black Tea Extract B0101, manufactured by Sato Foods Industry Co., Ltd.), as listed in Table 4. The obtained tea beverage was evaluated in the same manner as in Example 1. The formulation and evaluation results are shown in Table 4.

[0030] (Table 4) TIFF0007845401000004.tif104166

[0031] The tea beverages in Examples 3-8 had a turbidity of 1.0 or less and also had good flavor.

[0032] From the above results, it was confirmed that by adding a plant-based protein material that satisfies the following requirements to a tea beverage—A: protein content of 60% by weight or more in terms of solid content, B: turbidity of 1.0 or less when a 5% by weight aqueous solution at pH 7.4 is measured with a spectrophotometer at OD 610 nm, and C: weight-average molecular weight of 3 kDa to 300 kDa as measured by gel filtration—it is possible to produce a tea beverage with low turbidity, transparency, and a good flavor that does not impair the original natural flavor of the tea beverage.

Claims

1. A tea beverage containing protein material derived from one or more species selected from soybeans, peas, and mung beans that satisfy all of the following conditions A to C, and whose turbidity is 1.0 or less when measured at OD610nm with a spectrophotometer. A: Protein content is 60% by weight or more on a solids basis. B: The turbidity of a 5% by weight aqueous solution with pH 7.4 measured at OD610nm using a spectrophotometer is 1.0 or less. C: In molecular weight distribution measurement by gel filtration, the weight-average molecular weight is 5 kDa to 300 kDa.

2. The tea beverage according to Claim 1, wherein the protein material derived from one or more selected from soybeans, peas, and mung beans satisfies all of the following A to C. A: Protein content is 70% by weight or more on a solids basis. B: The turbidity of a 5% by weight aqueous solution with pH 7.4 measured at OD610nm using a spectrophotometer is 1.0 or less. C: In molecular weight distribution measurement by gel filtration, the weight-average molecular weight is 5 kDa to 300 kDa.

3. The tea beverage according to Claim 1, wherein the protein material derived from one or more selected from soybeans, peas, and mung beans satisfies all of the following A to C. A: Protein content is 70% by weight or more on a solids basis. B: The turbidity of a 5 wt% aqueous solution with pH 7.4 measured at OD 610 nm using a spectrophotometer is 0.9 or less. C: In molecular weight distribution measurement by gel filtration, the weight-average molecular weight is 5 kDa to 300 kDa.

4. A tea beverage according to any one of claims 1 to 3, wherein the protein content in the tea beverage is 0.05 to 5% by weight.

5. A method for producing a tea beverage in which the turbidity measured at OD610nm with a spectrophotometer is 1.0 or less, characterized by adding a protein material derived from one or more selected from soybeans, peas, and mung beans that satisfy all of the following A to C to the tea beverage, such that the protein content of the tea beverage is 0.05 to 5% by weight. A: Protein content is 60% by weight or more on a solids basis. B: The turbidity of a 5% by weight aqueous solution with pH 7.4 measured at OD610nm using a spectrophotometer is 1.0 or less. C: In molecular weight distribution measurement by gel filtration, the weight-average molecular weight is 5 kDa to 300 kDa.

6. The method for producing a tea beverage according to claim 5, wherein the protein material derived from one or more selected from soybeans, peas, and mung beans satisfies all of the following A to C. A: Protein content is 70% by weight or more on a solids basis. B: The turbidity of a 5% by weight aqueous solution with pH 7.4 measured at OD610nm using a spectrophotometer is 1.0 or less. C: In molecular weight distribution measurement by gel filtration, the weight-average molecular weight is 5 kDa to 300 kDa.

7. The method for producing a tea beverage according to Claim 5, wherein the protein material derived from one or more selected from soybeans, peas, and mung beans satisfies all of the following A to C. A: Protein content is 70% by weight or more on a solids basis. B: The turbidity of a 5% by weight aqueous solution with pH 7.4 measured at OD610nm using a spectrophotometer is 0.9 or less. C: In molecular weight distribution measurement by gel filtration, the weight-average molecular weight is 5 kDa to 300 kDa.

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