JP7522551B2 - Beer-flavored beverages - Google Patents

Description

The present invention relates to a beer-flavored beverage.

As consumer tastes have become more diverse in recent years, there is a demand for the development of beer-flavored beverages with a variety of flavor and taste characteristics.

Beer-flavored beverages may contain sugars or amino acids to impart richness, etc. For example, Patent Document 1 discloses a non-fermented alcohol-flavored beverage that contains gamma-aminobutyric acid (GABA).

JP 2017-184697 A

However, because sugars and amino acids are highly reactive, adding them can sometimes cause changes in flavor during storage.

The present invention relates to providing a beer-flavored beverage that is satisfying to drink and has excellent flavor stability.

The present invention relates to a beer-flavored beverage in which the mass ratio of the content of proteins with a molecular weight of 35 to 50 kDa to the content of total proteins is 0.005 or more and 0.1 or less.

The present invention makes it possible to provide a beer-flavored beverage that is satisfying to drink and has excellent flavor stability.

The inventors have investigated the above problem and have surprisingly discovered that by setting the mass ratio of the protein content with a molecular weight of 35 to 50 kDa to the total protein content at a specific ratio, a beer-flavored beverage that is satisfying to drink and also has excellent flavor stability can be obtained. Although the mechanism behind this is unclear, it is presumed that this is because proteins with a molecular weight of 35 to 50 kDa contribute to the satisfying taste of a beer-flavored beverage and do not produce aroma components with a low threshold value when reacting with sugar, as do amino acids.

The beer-flavored beverage of the present invention contains a protein with a molecular weight of 35 to 50 kDa.

In the beer-taste beverage of the present invention, the mass ratio of the content of proteins with a molecular weight of 35 to 50 kDa to the content of total proteins (proteins with a molecular weight of 35 to 50 kDa/total proteins) is 0.005 or more, preferably 0.008 or more, more preferably 0.012 or more, and even more preferably 0.014 or more, from the viewpoint of providing a satisfying drink while also providing excellent flavor stability. The upper limit is not particularly limited, and can be, for example, 0.1 or less, 0.05 or less, 0.03 or less, or any combination of these ranges.

Methods for adjusting the mass ratio of proteins with a molecular weight of 35 to 50 kDa to fall within the above range include adding proteins with a molecular weight of 35 to 50 kDa, using raw materials with a high content of 35 to 50 kDa proteins, and controlling the content of 35 to 50 kDa proteins through fermentation conditions.

When a protein with a molecular weight of 35 to 50 kDa is added, it is preferable to add a protein derived from barley. Such barley includes barley, wheat, rye, oats, oats, and the like, with barley being preferred. In addition, either germinated or ungerminated barley may be used, with germinated barley malt being preferred. These may be contained alone or in combination of two or more types.

When controlling the content of 35-50 kDa proteins through fermentation conditions, it can also be controlled by controlling the fermentation temperature. For example, by setting the temperature lower, the loss of 35-50 kDa proteins due to foam separation during fermentation can be reduced, resulting in more 35-50 kDa proteins being contained in the beer.

In this specification, quantification of 35-50 kDa proteins is performed by the Lowry method. The specific measurement method is shown below.

1. Purification of 35-50 kDa proteins 1) Concentration of proteins with ammonium sulfate Add 3,900 g of ammonium sulfate (60% saturated ammonium sulfate) to 10 L of beer, stir with a stirrer for 3 hours, and then centrifuge (12,000 g, 4°C, 1 hour) to obtain a precipitate. The resulting precipitate is suspended in as little 20 mM phosphate buffer (pH 9.0) as possible, and 20 mM phosphate buffer (pH 9.0) is added until the turbidity is eliminated. Then, ultrafiltration is performed using an Amicon Ultra-15 (10 KDa cut off, Merck, UFC901024) (2,800 g, 4°C, centrifugation until the final volume is about 1 ml). Then, about 10 ml of 20 mM phosphate buffer (pH 9.0) is added, and centrifugation is performed again under the same conditions to remove unnecessary ammonium sulfate. The supernatant thus obtained is used as the beer protein concentrated fraction for the next operation.

2) Fractionation of beer protein concentrate using cationic resin
An Econocolumn is packed with 100 ml of SP Sepharose Fast Flow (GE Healthcare Life Sciences), and 300 ml of water is poured through it, followed by 300 ml of 20 mM acetate buffer (pH 4.5) to equilibrate it.
Prepare a beaker, add 20mM acetate buffer (pH4.5) to the beer protein concentrated fraction obtained in 1) to make 400ml. Add 100ml of SP Sepharose equilibrated with acetate buffer (pH4.5) to the liquid, and perform batch adsorption for 3 hours while stirring with a spatula every 10 minutes. After that, pack the contents of the beaker into the column and collect the flow-through fraction (FT). Next, load 300ml of 20mM acetate buffer (pH4.5) (A). Load 300ml of 20mM acetate buffer (pH4.5) containing 0.1M NaCl (B), 300ml of 20mM acetate buffer (pH4.5) containing 0.2M NaCl (C), 300ml of 20mM acetate buffer (pH4.5) containing 0.3M NaCl (D), and 300ml of 20mM acetate buffer (pH4.5) containing 0.5M NaCl (E). The obtained fractions are analyzed by SDS-PAGE, and the fractions containing 35-50 kDa proteins are collected. These fractions containing 35-50 kDa proteins are used in the next step as the beer protein cation exchange resin binding fraction.

3) Concentration of beer protein cation exchange resin-bound fraction with ammonium sulfate Add 430 g of ammonium sulfate to 1 L of beer protein cation exchange resin-bound fraction in a beaker while stirring. After stirring for 3 hours, transfer the contents of the beaker to a centrifuge tube and centrifuge (12,000 g, 4°C, 3 hours) to obtain a precipitate.
The precipitate is suspended in as little 20 mM acetate buffer (pH 4.5) as possible, and 20 mM acetate buffer (pH 4.5) is added until the turbidity disappears. Then, ultrafiltration is performed using Amicon Ultra-15 (10 KDa cut off, Merck, UFC901024) (centrifugation at 2,800 g, 4°C, until the final volume is about 1 ml). Then, about 10 ml of 20 mM acetate buffer (pH 4.5) is added, and centrifugation is performed again under the same conditions to remove unnecessary ammonium sulfate. The supernatant thus obtained is used as the beer protein cation exchange resin binding fraction concentrate in the next operation.

4) Fractionation of beer protein cation exchange resin-bound fraction concentrate with anion resin
100 ml of Q Sepharose Fast Flow (GE Healthcare Life Sciences) is packed into an Econocolumn, and 300 ml of water is poured through it, followed by 300 ml of 20 mM phosphate buffer (pH 9.0) to equilibrate it.
Prepare a beaker and add 20 mM phosphate buffer (pH 9.0) to the beer protein cation exchange resin-bound fraction concentrate obtained in 3) to make the volume 400 ml. Add 100 ml of Q Sepharose equilibrated with 20 mM phosphate buffer (pH 9.0) to the liquid and perform batch adsorption for 3 hours while stirring with a spatula every 10 minutes. After that, pack the contents of the beaker into a column and collect the flow-through fraction (FT). Next, load 500 ml of 20 mM phosphate buffer (pH 9.0) (A). Load the following: 300 ml of 20 mM phosphate buffer (pH 9.0) containing 0.1 M NaCl (B), 300 ml of 20 mM phosphate buffer (pH 9.0) containing 0.2 M NaCl (C), 300 ml of 20 mM phosphate buffer (pH 9.0) containing 0.3 M NaCl (D), and 300 ml of 20 mM phosphate buffer (pH 9.0) containing 0.5 M NaCl (E). Analyze the resulting FT and fractions A to E by SDS-PAGE, and collect fractions containing 35-50 kDa proteins. These fractions containing 35-50 kDa proteins are used as 35-50 kDa protein ion exchange resin binding fractions in the next step.
For (A), (B), (C), (D), and (E), immediately after column elution, neutralize by adding 0.5 M disodium phosphate at a ratio of 15 ml per 500 ml of solution. Step 4) should be performed within one day to minimize changes in protein caused by alkali.

5) Concentration of 35-50 kDa protein ion exchange resin binding fraction with ammonium sulfate Add 430 g of ammonium sulfate to 1 L of 35-50 kDa protein ion exchange resin binding fraction in a beaker while stirring. After stirring for 3 hours, transfer the contents of the beaker to a centrifuge tube and centrifuge (12,000 g, 4°C, 3 hours) to obtain a precipitate.
The precipitate is suspended in as little 20 mM acetate buffer (pH 4.5) as possible, and 20 mM acetate buffer (pH 4.5) is added until the turbidity disappears. Then, ultrafiltration is performed using an Amicon Ultra-15 (10 KDa cut off, Merck, UFC901024) (centrifugation at 2,800 g, 4°C, until the final volume is about 1 ml). Then, about 10 ml of 20 mM acetate buffer (pH 4.5) is added, and centrifugation is performed again under the same conditions to remove unnecessary ammonium sulfate. The supernatant thus obtained is used for analysis as the 35-50 kDa protein purification product.

2. Protein quantification by the Lowry method Concentration occurs when preparing a 35-50 kDa protein purified product. In other words, the volume of a 35-50 kDa protein purified product obtained from a beer-taste beverage is smaller than the volume of the beer-taste beverage. For this reason, the protein content of a 35-50 kDa protein purified product of a beer-taste beverage of the present invention is calculated by dividing the protein content measured using a 35-50 kDa protein purified product prepared from a beer-taste beverage by the concentration ratio when the 35-50 kDa protein purified product is prepared from the beer-taste beverage (i.e., the ratio obtained by dividing the volume of the beer-taste beverage used in the preparation by the volume of the 35-50 kDa protein purified product obtained in the preparation). The protein quantification was performed by the Lowry method using a commercially available kit (DC Protein Assay, Bio-Rad). First, the concentration of the fraction was adjusted to be within an appropriate range. To 5 μL of the concentration-adjusted sample, 50 μL of solution A was added and stirred, and then 400 μL of solution B was added and stirred. After a color reaction was carried out at room temperature for 15 minutes, 350 μL was transferred to a 96-well plate and the absorbance at 750 nm was measured. The peptide concentration (mg/mL) was calculated based on the obtained absorbance and a calibration curve prepared in advance. The calibration curve was prepared using BSA (bovine serum albumin). The content of 35-50 kDa protein in the 35-50 kDa protein purified product was calculated based on the calibration curve.

In this specification, the total protein content is calculated by multiplying the total nitrogen amount by the protein conversion factor of 6.25. Here, the total nitrogen amount is measured by the Kjeldahl method. The nitrogen compounds in a beer-taste beverage are not necessarily only proteins, but may also be amino acids, amides, purine bases, creatines, etc., but the total nitrogen is calculated assuming that it is derived from protein.

The manufacturing method of the beer-taste beverage of the present invention is not particularly limited, but an example is a manufacturing method that includes a step of adding a 35-50 kDa protein. More specifically, an embodiment in which a barley-derived protein with a molecular weight of 35-50 kDa is added is exemplified below, and an example of a manufacturing method in this embodiment is given below. In another embodiment, the amount of 35-50 kDa protein may be increased by changing the conditions of the manufacturing process to produce more barley-derived protein with a molecular weight of 35-50 kDa than conventional conditions, such as using a high-nitrogen malt raw material from North America that has a high content of 35-50 kDa protein, or increasing the amount of 35-50 kDa protein through fermentation conditions.

The manufacturing method of the embodiment in which a barley-derived protein with a molecular weight of 35 to 50 kDa is added (the manufacturing method of this embodiment) is the same as the manufacturing method of a general beer-taste beverage, except that it includes a step of adding a 35 to 50 kDa protein. Examples of manufacturing modes of beer-taste beverages are given below. Beer-taste beverages can be manufactured in a variety of ways, including those that use malt as a raw material and those that do not, and can be manufactured as follows.

To produce an alcohol-containing beer-flavored beverage using malt as a raw material, first, enzymes such as amylase are added as necessary to a mixture containing malt and other wheat, as well as other grains, starch, sugars, bittering agents, or coloring agents, and water as necessary, to cause gelatinization and saccharification, and then the mixture is filtered to produce a saccharified liquid. Hops and bittering agents are added as necessary to the saccharified liquid, which is then boiled and solids such as coagulated proteins are removed in a clarifying tank. As an alternative to this saccharified liquid, hops may be added to malt extract and warm water, and then boiled. Hops may be mixed at any stage from the start of boiling to the end of boiling. Known conditions may be used for the saccharification process, boiling process, solids removal process, and the like. Known conditions may be used for the fermentation and storage processes. The resulting fermented liquid is filtered, and carbon dioxide gas is added to the resulting filtrate. The liquid is then filled into a container and sterilized to obtain the desired beer-flavored beverage. Grain-derived spirits may also be added as an alcohol component. Spirits refers to alcoholic beverages obtained by fermenting grains such as wheat, rice, buckwheat, and corn using yeast and then distilling them. Wheat is the preferred grain for the raw material of spirits. In each of the above steps, the step of adding the 35-50 kDa protein may be carried out at any step up to the filling step.

A beer-flavored beverage containing alcohol that is produced without using malt as a raw material is prepared by mixing liquid sugar containing a carbon source, a nitrogen source as an amino acid-containing material other than wheat or malt, hops, a coloring, and the like with warm water to form a liquid sugar solution. The liquid sugar solution is boiled. When hops are used as a raw material, hops may be mixed into the liquid sugar solution during boiling, not before the start of boiling. As an alternative to this saccharified liquid, hops may be added to an extract using a raw material other than malt and warm water, and then the mixture is boiled. Hops may be mixed at any stage from the start of boiling to the end of boiling. Known conditions may be used for the fermentation and storage process. The resulting fermented liquid is filtered, and carbon dioxide gas is added to the resulting filtrate. The resulting filtrate is then filled into a container and sterilized to obtain the desired beer-flavored beverage. Grain-derived spirits may also be added as an alcoholic component. Spirits refers to alcoholic beverages obtained by fermenting grains such as wheat, rice, buckwheat, and corn using yeast, and then distilling the fermented grains. The grain used as the raw material for spirits is preferably barley. In each of the above steps, the step of adding the 35-50 kDa protein may be carried out at any step up to the filling step.

Non-fermented, alcohol-containing beer-taste beverages may or may not use malt, and may be those in which the alcohol content of the final product is adjusted by adding raw material alcohol or the like. The raw material alcohol may be added at any step from the saccharification step to the filling step. Spirits derived from grains may also be added as an alcohol component. Spirits refers to alcoholic beverages obtained by fermenting grains such as wheat, rice, buckwheat, and corn using yeast, and then distilling them. Wheat is preferred as the grain used as the raw material for spirits. In each of the above steps, the step of adding the 35-50 kDa protein may be performed at any step up to filling.

A non-alcoholic beer-flavored beverage produced using malt as a raw material is first prepared by adding enzymes such as amylase as necessary to a mixture containing malt and other wheat, as well as other grains, starch, sugars, bittering agents, or coloring agents as necessary, and water, and then gelatinizing and saccharifying the mixture, filtering the mixture, and obtaining a saccharified liquid. Hops and bittering agents are added as necessary to the saccharified liquid, which is then boiled and solids such as coagulated proteins are removed in a clarifying tank. As an alternative to this saccharified liquid, hops may be added to malt extract and warm water, and then boiled. Hops may be mixed at any stage from the start of boiling to before the end of boiling. Known conditions may be used for the saccharification process, boiling process, solids removal process, and other processes. After boiling, the resulting wort is filtered, and carbon dioxide gas is added to the filtrate obtained. The mixture is then filled into containers and sterilized to obtain the desired non-alcoholic beer-flavored beverage. In each of the above processes, the process of adding the 35-50 kDa protein may be performed at any stage up to filling.

When producing a non-alcoholic beer-flavored beverage that does not use malt as a raw material, first, liquid sugar containing a carbon source, a nitrogen source as an amino acid-containing material other than barley or malt, hops, coloring, etc. are mixed with warm water to form a liquid sugar solution. The liquid sugar solution is boiled. When hops are used as a raw material, hops may be mixed into the liquid sugar solution during boiling rather than before the start of boiling. Carbon dioxide gas is added to the liquid sugar solution after boiling. The liquid sugar solution is then filled into containers and sterilized to obtain the desired non-alcoholic beer-flavored beverage. In each of the above steps, the step of adding the 35-50 kDa protein may be performed at any step up to filling.

In the manufacturing method of this embodiment, an aliphatic alcohol may be added from the viewpoint of imparting a feeling of alcohol. The aliphatic alcohol is not particularly limited as long as it is a known one, but an aliphatic alcohol having 4 to 5 carbon atoms is preferable. In the manufacturing method of this embodiment, preferred aliphatic alcohols include those having 4 carbon atoms such as 2-methyl-1-propanol and 1-butanol, and those having 5 carbon atoms such as 3-methyl-1-butanol, 1-pentanol, and 2-pentanol. These may be used alone or in combination of two or more kinds. The content of the aliphatic alcohol having 4 to 5 carbon atoms is preferably 0.0002 to 0.0007% by mass, more preferably 0.0003 to 0.0006% by mass. In this specification, the content of the aliphatic alcohol can be measured using a headspace gas chromatography method.

(Acidulant)
As the acidulant used in the manufacturing method of this embodiment, it is preferable to use one or more acids selected from the group consisting of citric acid, lactic acid, phosphoric acid, and malic acid. In addition, in the manufacturing method of this embodiment, succinic acid, tartaric acid, fumaric acid, glacial acetic acid, etc. can also be used as acids other than the above acids. These can be used without restrictions as long as they are approved for addition to foods. In the manufacturing method of this embodiment, it is preferable to use a combination of lactic acid from the viewpoint of appropriately imparting a mellow sour taste and phosphoric acid from the viewpoint of appropriately imparting a slightly stimulating sour taste.

The content of the acidulant in the beer-taste beverage obtained by the manufacturing method of this embodiment, calculated as citric acid, is preferably 200 ppm or more, more preferably 550 ppm or more, and even more preferably 700 ppm or more, from the viewpoint of imparting a beer taste, and is preferably 15,000 ppm or less, more preferably 5,500 ppm or less, and even more preferably 2,000 ppm or less, from the viewpoint of sourness. Therefore, in this embodiment, the content of the acidulant, calculated as citric acid, is preferably in a range of 200 ppm to 15,000 ppm, preferably 550 ppm to 5,500 ppm, and more preferably 700 ppm to 1,500 ppm. In this specification, the citric acid equivalent amount refers to the amount calculated from the acidity of each acidulant based on the acidity of citric acid. For example, the citric acid equivalent amount equivalent to 100 ppm of lactic acid is 120 ppm, the citric acid equivalent amount equivalent to 100 ppm of phosphoric acid is 200 ppm, and the citric acid equivalent amount equivalent to 100 ppm of malic acid is 125 ppm.

The amount of acidulant contained in a beer-flavored beverage is calculated by analysis using high-performance liquid chromatography (HPLC) or other methods.

(hop)
In the manufacturing method of this embodiment, hops can be used as part of the raw materials. Hops are desirably used as part of the raw materials because the flavor tends to be similar to that of beer. When using hops, ordinary pelleted hops, powdered hops, and hop extracts used in the production of beer and the like can be appropriately selected and used according to the desired flavor. In addition, processed hop products such as isosiated hops and reduced hops may also be used. The hops used in the manufacturing method of this embodiment include these. In addition, the amount of hops added is not particularly limited, but is typically about 0.0001 to 1% by mass based on the total amount of the beverage.

(Other raw materials)
In the manufacturing method of this embodiment, other raw materials may be used as desired. For example, sweeteners (including high-intensity sweeteners), bittering agents, flavorings, yeast extracts, coloring agents such as caramel color, plant-extracted saponin substances such as soybean saponin and quillaja saponin, plant protein and peptide-containing substances such as corn and soybeans, animal proteins such as whey, seasonings such as dietary fiber and amino acids, and antioxidants such as ascorbic acid may be used as necessary within a range that does not impair the effects of this embodiment.

The pH of the beer-taste beverage obtained by this manufacturing method is preferably 3.0 to 5.0, more preferably 3.0 to 4.5, and even more preferably 3.0 to 4.0, from the viewpoint of improving the flavor of the beverage.

(Packaged beverages)
The beer-taste beverage obtained by the production method of this embodiment can be packaged in containers. There are no limitations on the type of container, and the beverage can be filled into a sealed container such as a bottle, can, barrel, or plastic bottle to produce a packaged beverage.

The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples.

Preparation Example 1: Preparation of 35-50 kDa protein A 35-50 kDa protein was prepared according to the description in the above section "Purification of 35-50 kDa protein".

Preparation Example 2: Preparation of amino acid mixture
Various amino acid reagents were mixed to prepare an amino acid mixture so as to have the same amino acid ratio as the amino acid sequence of Protein Z shown in Figure 4 in Eur Food Res Technol (2010) 230:665-673.

Preparation of beer-taste beverages Reference Example 1, Examples 1 to 5
30 kg of malt was crushed to an appropriate particle size and placed in a mash tank, after which 120 L of warm water was added to produce a mash at about 50°C. A portion of the mash was heated to 100°C and boiled, and the remainder was saccharified. The mash after saccharification was heated to 78°C, transferred to a wort filtration tank, and filtered to obtain a filtrate. Hops were added to the filtrate, and the filtrate was boiled for 80 minutes to obtain a conditioned wort. Hops were added even after the start of boiling as necessary. Brewer's yeast was added to the conditioned wort, and fermented at about 15°C for about 15 days to obtain a stored beer. The stored beer was then filtered to remove the yeast without being heat-treated, to produce the beer-taste beverage of Reference Example 1. When the beer-taste beverage of Reference Example 1 was analyzed according to the above-mentioned measurement method, the content of 35-50 kDa protein was 12 ppm, and the content of total protein was 3000 ppm. The 35-50 kDa protein obtained in Preparation Example 1 was added to this beer-taste beverage to give the concentrations shown in Table 1, thereby obtaining the beer-taste beverages of Examples 1-5.

Comparative Examples 1 to 3
Beer-taste beverages were obtained in the same manner as in Examples 1 to 5, except that the amino acid mixture obtained in Preparation Example 2 was added in place of the 35-50 kDa protein in Preparation Example 1 to give the concentrations shown in Table 2.

Flavor Evaluation The flavors of Examples 1 to 5 and Comparative Examples 1 to 3 were evaluated by a sensory test. Five well-trained sensory evaluators evaluated the flavors of "richness" and "freshness" on a 5-point scale. The richness evaluation was performed using samples stored at 4°C for 3 weeks after production. The freshness evaluation was performed using samples stored at 28°C for 3 weeks after production.

For richness, "very strong" was given 5 points, "strong" was given 4 points, "slightly strong" was given 3 points, "slightly strong" was given 2 points, and "not strong" was given 1 point. The average score was calculated and rated according to the following criteria according to the average score. For freshness (i.e., flavor stability), "very good" was given 5 points, "good" was given 4 points, "slightly good" was given 3 points, "slightly bad" was given 2 points, and "bad" was given 1 point. The average score was calculated and rated according to the following criteria according to the average score. The results are shown in Tables 1 and 2. For richness, Reference Example 1 was given 1 point, and for freshness, Reference Example 1 was given 5 points.

<Evaluation criteria>
×: average value 1.0 or more and less than 2.0 △: average value 2.0 or more and less than 3.0 ○: average value 3.0 or more and less than 4.0 ◎: average value 4.0 or more and less than 5.0

As can be seen from Table 1, the beer-taste beverages of Examples 1 to 5, in which the mass ratio of the protein content with a molecular weight of 35 to 50 kDa to the total protein content was 0.005 or more and 0.1 or less, were excellent in richness and flavor stability. On the other hand, as can be seen from Table 2, the beer-taste beverages of Comparative Examples 1 to 3, in which an amino acid mixture was added, were able to impart richness but had problems with flavor stability.

The present invention makes it possible to provide a beer-flavored beverage that is rich in flavor while also having excellent flavor stability.

Claims (2)

A beer-flavored beverage, in which the mass ratio of the content of a protein having a molecular weight of 35 to 50 kDa to the content of total protein is 0.014 or more and 0.03 or less, and the protein having a molecular weight of 35 to 50 kDa is a protein derived from a beer-flavored beverage produced using barley (provided that the beer has a haze protein content of 7.14 mg/100 mL having a molecular weight of about 40,000 and an isoelectric point of 4.0 to 5.0 as measured by the ELISA method, and a nitrogen content of 79.8 mg/100 mL as measured by the T-N method;
The beer has a molecular weight of about 40,000 and an isoelectric point of 4.0 to 5.0, a haze protein content of 8.62 mg/100 mL as measured by the ELISA method, a nitrogen content of 80.9 mg/100 mL as measured by the TN method, and a linalool content of 1 ppb and a 40 kDa protein content of 64 mg/L, except for the beer. A method for stabilizing the flavor of a beer-taste beverage, comprising the step of adjusting the mass ratio of the content of a protein having a molecular weight of 35 to 50 kDa to the content of all proteins in the beer-taste beverage to 0.005 or more and 0.1 or less, wherein the protein having a molecular weight of 35 to 50 kDa is a protein derived from a beer-taste beverage produced using barley .