JP7693302B2 - Beer-like fizzy drink - Google Patents

Description

The present invention relates to a beer-like sparkling beverage that does not use hops as an ingredient or uses a small amount of hops, thereby reducing bitterness, and a method for producing the same.

As consumer tastes become more diverse, a wide variety of beer-like sparkling beverages, such as beer and happoshu, are being sold on the market. For example, the characteristic bitterness and aroma of beer are mainly brought about by hops, but in recent years, beer-like sparkling beverages with reduced bitterness that do not use hops as an ingredient have also been developed.

Hops not only impart aroma and bitterness to beer-like sparkling beverages, but also have antibacterial properties that inhibit the growth of harmful bacteria in beer. In Japan in particular, due to the antibacterial properties of hops, thorough hygiene management, and advances in filtration technology, beer and beer-like sparkling beverages that are not heat-sterilized are widely available.

If hops are not used, their antibacterial effect cannot be utilized, and so heat sterilization (pasteurization) of beer-like sparkling beverages is necessary. However, heat sterilization can result in the generation of unpleasant odors (off-flavors). As a method for solving the problem of off-flavors caused by heat sterilization, for example, a method has been disclosed in which linalool, 2,5-dimethyl-4-hydroxy-3(2H)-furanone, or 2-acetylpyrazine is added to mask the off-flavors generated by the heating process (see Patent Document 1).

On the other hand, Patent Document 2 describes that the flavor can be improved by adding 2-(Methylthio)ethanol in combination with multiple other aroma components to a beer-flavored beverage that uses a small proportion of malt. Furthermore, Patent Document 3 discloses that the addition of γ-nonalactone to a so-called low-sugar beer-flavored beverage can impart a rich flavor and beer-like taste.

JP 2018-023295 A JP 2015-154738 A JP 2016-214262 A

Vesely et al., Journal of Agricultural and Food Chemistry, 2003, vol.51, p.6941-6944.

In beer-like sparkling beverages with less bitterness, the acidic odor caused by 2-methylthioethanol is more pronounced.

The present invention aims to provide a beer-like sparkling beverage that does not use hops as an ingredient or uses a reduced amount of hops, has a weak bitterness, and has a reduced acidic odor derived from 2-methylthioethanol, and a method for producing the same.

As a result of intensive research aimed at solving the above problems, the inventors discovered that the acidic odor caused by 2-methylthioethanol can be suppressed by adding a specific ratio of γ-nonalactone to the 2-methylthioethanol content in a beer-like sparkling beverage with a weak bitterness, and thus completed the present invention.

The beer-like sparkling beverage, the method for producing the beer-like sparkling beverage, and the method for reducing the acidic odor derived from 2-methylthioethanol in the beer-like sparkling beverage according to the present invention are as follows [1] to [13].
[1] [γ-nonalactone content (μg/L)]/[2-methylthioethanol content (μg/L)] is 0.65 or more;
The content of 2-methylthioethanol is 20 μg/L or more,
The content of γ-nonalactone is 150 μg/L or less,
A beer-like sparkling beverage having an international bitterness value of less than 5.
[2] The beer-like carbonated beverage according to [1], wherein the ratio of [γ-nonalactone content (μg/L)]/[2-methylthioethanol content (μg/L)] is 1.50 or less.
[3] The beer-like sparkling beverage according to [1] or [2] above, which does not use hops as a raw material.
[4] The beer-like carbonated beverage according to any one of [1] to [3] above, which does not contain a bittering agent.
[5] The beer-like sparkling beverage according to any one of [1] to [4] above, which contains a hop flavoring.
[6] The beer-like sparkling beverage according to any one of [1] to [5] above, which is a fermented beverage.
[7] A method for producing a beer-like sparkling beverage having a 2-methylthioethanol content of 20 μg/L or more and an international bitterness value of less than 5,
The method for producing a beer-like sparkling beverage comprises adjusting the content of γ-nonalactone and the content of 2-methylthioethanol so that the ratio [γ-nonalactone content (μg/L)]/[2-methylthioethanol content (μg/L)] is 0.65 or more and the content of γ-nonalactone is 150 μg/L or less .
[8] The method for producing a beer-like sparkling beverage according to [7] above, wherein one or more members selected from the group consisting of γ-nonalactone and 2-methylthioethanol are used as a raw material.
[9] The method for producing a beer-like sparkling beverage according to [7] or [8] above, which does not use hops as a raw material.
[10] The method for producing a beer-like sparkling beverage according to any one of [7] to [9] above, wherein the produced beer-like sparkling beverage is filled into a container and subjected to a heat sterilization treatment.
[11] A method for reducing an acidic odor derived from 2-methylthioethanol in a beer-like sparkling beverage having a 2-methylthioethanol content of 20 μg/L or more and an international bitterness value of less than 5, comprising:
The method includes adjusting the content of γ-nonalactone and the content of 2-methylthioethanol so that the ratio of [γ-nonalactone content (μg/L)]/[2-methylthioethanol content (μg/L)] is 0.65 or more and the content of γ-nonalactone is 150 μg/L or less .
[12] The method according to [11], wherein the beer-like carbonated beverage is produced without using hops as a raw material.
[13] The method according to [11] or [12], wherein the beer-like sparkling beverage is produced through a heat sterilization treatment.

The present invention makes it possible to provide a beer-like sparkling beverage that does not use hops as an ingredient or uses only a small amount of hops, resulting in a weak bitterness, yet with a suppressed acidic odor derived from 2-methylthioethanol.

In the present invention and the present specification, "beer-like" means a taste that is reminiscent of beer in terms of aroma, regardless of the product name or labeling. In other words, a beer-like sparkling beverage (beer-like sparkling beverage) means a sparkling beverage that has a flavor, taste, and texture equivalent to or similar to that of beer, regardless of the alcohol content, the use of malt and hops, and the presence or absence of fermentation, and has high thirst quenching and drinkability (the ability to continue drinking multiple cups without getting bored). In other words, the beer-like sparkling beverage of the present invention may be an alcoholic beverage, or a so-called non-alcoholic beverage or low-alcohol beverage with an alcohol content of less than 1% by volume. It may also be a beverage made from malt, a beverage not made from malt, a fermented beverage produced through a fermentation process, or a non-fermented beverage produced without a fermentation process. Specific examples of beer-like sparkling beverages include beer, happoshu made from malt, sparkling alcoholic beverages not using malt, low-alcohol sparkling beverages, and non-alcoholic beer. In addition, liqueurs may be made by mixing a beverage made from malt through a fermentation process with an alcohol-containing distilled liquid.

The alcohol-containing distillate is a solution containing alcohol obtained by distillation, and can be anything generally classified as a distilled liquor. For example, it can be raw material alcohol, and can be distilled liquor such as spirits, whiskey, brandy, vodka, rum, tequila, gin, and shochu.

In the present invention and this specification, the term "International Bitterness Units (IBU)" refers to an index of bitterness based on the content of isohumulones. The international bitterness value of beverages, including beer-like sparkling beverages, can be measured, for example, by the EBC method (Beer Brewers Association: "Beer Analysis Methods" 8.15, 1990). Specifically, the IBU value is calculated by multiplying the absorbance at 275 nm of the isooctane layer obtained after adding an acid to a sample, extracting it with isooctane, and centrifuging it, using pure isooctane as a control, by a constant (50). The international bitterness value of beer-like sparkling beverages with a beer-like bitterness is generally 15 or more.

In the present invention and this specification, a "beer-like sparkling beverage having a bitterness intensity less than that of a 5 mg/L aqueous solution of iso-α-acids" corresponds to a beer-like sparkling beverage having an international bitterness value of less than 5. Hereinafter, a "beer-like sparkling beverage having a bitterness intensity less than that of a 5 mg/L aqueous solution of iso-α-acids" may be referred to as a "beer-like sparkling beverage having a weak bitterness (low-bitterness beer-like sparkling beverage)." In the case of a beer-like sparkling beverage that does not contain bitter components other than isohumulone, a low-bitterness beer-like sparkling beverage corresponds to a beer-like sparkling beverage having an international bitterness value of less than 5.

Beer-like sparkling beverages with an international bitterness value of less than 5 can be produced without using hops as a raw material or by sufficiently reducing the amount of hops used. In other words, low-bitterness beer-like sparkling beverages can be produced without using hops as a raw material or by keeping the amount of hops used low. Here, "hops" includes fresh hops, dried hops, hop pellets, and hop processed products. Examples of hop processed products include hop extracts in which bitter components are extracted from hops, iso-hop extracts, and hop processed products containing components obtained by iso-synthesizing bitter components in hops such as tetrahydroisohumulone and hexahydroisohumulone.

Even when beverages have the same aroma component composition, the perceived aroma and flavor often differ between beverages with a strong bitterness and beverages with a weak bitterness. This is presumably because in beverages with a strong bitterness, the bitterness masks the relatively weak aroma and flavor, but in beverages with a weak bitterness, this masking effect does not exist, making it easier to detect the distinctive aroma and flavor when drinking.

In beer-like sparkling beverages that contain hops and generally have a strong bitterness, increasing the content of 2-methylthioethanol tends to result in a vibrant, natural aroma and improved flavor. However, in low-bitterness beer-like sparkling beverages, the acidic odor derived from 2-methylthioethanol is noticeable. This acidic odor is undesirable for a beer-like sparkling beverage.

In the present invention, the 2-methylthioethanol content and the γ-nonalactone content in the low-bitterness beer-like sparkling beverage are adjusted so that the [γ-nonalactone content]/[2-methylthioethanol content] (mass ratio) (hereinafter sometimes referred to as the "N/M ratio") in the beverage is 0.65 or more. By adjusting the N/M ratio of the low-bitterness beer-like sparkling beverage to 0.65 or more, the acidic odor derived from 2-methylthioethanol is suppressed, and the beverage has a good, gorgeous aroma, as in the case of a beer-like sparkling beverage with a strong bitterness, and the flavor of the beverage is improved. The N/M ratio of the low-bitterness beer-like sparkling beverage is not particularly limited as long as it is 0.65 or more, but from the viewpoint of the quality of taste required for a beer-like sparkling beverage, the N/M ratio is preferably 0.65 or more and 1.50 or less, more preferably 0.65 or more and 1.35 or less, and even more preferably 0.70 or more and 1.30 or less.

The content of 2-methylthioethanol in the low-bitterness beer-like sparkling beverage of the present invention is not particularly limited as long as the N/M ratio is an amount that is 0.65 or more, but is preferably 20 μg/L or more, more preferably 30 μg/L or more, and even more preferably 40 μg/L or more. In addition, from the viewpoint of the quality of taste required for a beer-like sparkling beverage, the content of 2-methylthioethanol in the low-bitterness beer-like sparkling beverage is preferably 1000 μg/L or less, more preferably 200 μg/L or less, and even more preferably 100 μg/L or less.

The content of γ-nonalactone in the low-bitterness beer-like sparkling beverage of the present invention is not particularly limited as long as it is an amount that results in an N/M ratio of 0.65 or more, but is preferably 15 μg/L or more, more preferably 20 μg/L or more, and even more preferably 30 μg/L or more. In addition, from the standpoint of the quality of taste required of a beer-like sparkling beverage, the content of γ-nonalactone in the low-bitterness beer-like sparkling beverage is preferably 150 μg/L or less, more preferably 100 μg/L or less, and even more preferably 80 μg/L or less.

The N/M ratio of low-bitterness beer-like sparkling beverages can be adjusted by adding 2-methylthioethanol or γ-nonalactone itself as a raw material. The raw material used may be synthetic 2-methylthioethanol, 2-methylthioethanol extracted and refined from natural products, or a flavoring containing 2-methylthioethanol. Similarly, the raw material used may be synthetic γ-nonalactone, γ-nonalactone extracted and refined from natural products, or a flavoring containing γ-nonalactone.

The method for measuring the content of 2-methylthioethanol and γ-nonalactone in beer-like carbonated beverages is not particularly limited. 2-Methylthioethanol and γ-nonalactone can be quantitatively measured by derivatizing them, like other aldehydes and alcohols, and then analyzing them by gas chromatography-mass spectrometry (GC/MS), as in the method described in Non-Patent Document 1.

A low-bitterness beer-like sparkling beverage that improves the acidic odor by adjusting the N/M ratio may contain a bittering agent other than isohumulone, as long as the bitterness intensity is less than that of a 5 mg/L aqueous solution of iso-α-acids. It is preferable that the beverage does not contain a bittering agent, since the acidic odor improving effect is more fully exerted. Representative examples of the bittering agent include bitterness-imparting components such as magnesium salts, calcium salts, tributyl citrate, triethyl citrate, naringin, quasin, quinine, momordicine, quercitrin, theobromine, and caffeine, as well as bitterness-imparting materials such as bitter melon, Swertia japonica tea, Kuding tea, Artemisia absinthium extract, gentiana extract, and cinchona extract. Only one type of these bittering agents may be used, or two or more types may be used in combination.

As a low-bitterness beer-like sparkling beverage in which the N/M ratio is adjusted to improve the acidic odor, one that contains hop flavoring is preferable. In the case of a beer-like sparkling beverage that uses hops, off-flavors that arise due to the heating process or deterioration over time are masked by the aroma derived from the hops, and are therefore often not actually a problem. In the present invention, too, by containing a hop flavoring, off-flavors due to 2-methylthioethanol, γ-nonalactone, and the like can be reduced. As the hop flavoring, a flavoring derived from hops and containing as its main component an aroma component that is generally contained in beer can be used. In addition, various commercially available hop flavorings can also be used as appropriate.

The beer-like sparkling beverage of the present invention preferably has a color value of 4 to 12, more preferably 4 to 8, in EBC units in order to enhance the beer-like flavor and to evoke the refreshing taste of pilsner-type beer. The color value can be adjusted by appropriately adding coloring agents such as caramel color. The color value can be measured by the Analytica-EBC standard method of the EBC (European Brewery Convention) or a method equivalent thereto. EBC is a unit of color value in beer analysis, and is a numerical value that represents the shade of the color of beer (visually measured using a comparator with nine glass disks of EBC color value, or calculated based on the absorbance at a wavelength of 430 nm).

The beer-like sparkling beverage of the present invention can be produced in the same manner as general fermented beer-like sparkling beverages and non-fermented beer-like sparkling beverages, except that hops are not used as a raw material or the amount of hops used is sufficiently reduced, and the N/M ratio is adjusted. Here, the production methods for general fermented beer-like sparkling beverages and non-fermented beer-like sparkling beverages will be described.

Fermented beer-like sparkling beverages produced through a fermentation process can generally be produced through the following steps: preparation of fermented raw material liquid, fermentation, storage, and filtration.

In the preparation process (fermentation raw material liquid preparation process), a fermentation raw material liquid is prepared from one or more selected from the group consisting of grain raw materials and carbohydrate raw materials. Specifically, a mixture containing the fermentation raw materials and raw material water is heated, and the starch is saccharified to prepare a sugar liquid. The resulting sugar liquid is then boiled, and at least a portion of the solid content is then removed to prepare the fermentation raw material liquid.

First, a mixture containing at least one of a grain raw material and a carbohydrate raw material and raw material water is prepared and heated, and the starch in the grain raw material is saccharified to prepare a sugar liquid. As the raw material for the sugar liquid, only the grain raw material may be used, only the carbohydrate raw material may be used, or a mixture of both may be used.

Examples of grain raw materials include barley, wheat, rye, oats, and malts thereof, as well as rice, corn, soybeans, and other beans and potatoes. The grain raw materials can be used as grain syrup, grain extract, and the like, but are preferably used as grain pulverized products obtained by pulverization. The pulverization of grains can be carried out by conventional methods. The grain pulverized products may be products that have been subjected to conventional processing before or after pulverization, such as malt pulverized products, corn starch, corn grits, and the like. In the present invention, the grain pulverized products used are preferably malt pulverized products. By using malt pulverized products, a fermented beer-like sparkling beverage with a more pronounced beer-like flavor can be produced. The malt pulverized products may be barley, for example two-rowed barley, germinated by conventional methods, dried, and then pulverized to a predetermined particle size.

The grain raw material used in the present invention may be one type of grain raw material or a mixture of multiple types of grain raw materials. For example, ground malt may be used as the main raw material, and ground rice or corn may be used as the secondary raw material. The malt usage ratio (the ratio (mass ratio) of the amount of malt used to the total amount of grain raw materials and carbohydrate raw materials) is preferably low to achieve a clean taste, and is preferably 50% or less, and more preferably 40% or less. Furthermore, it is preferably high to achieve a full-bodied taste, and is preferably 50% or more, and more preferably 60% or more.

The carbohydrate raw material is a sugar, that is, a carbohydrate that is relatively low molecular weight, soluble in water, and generally has a sweet taste. The carbohydrate raw material is preferably a sugar as defined in Article 3 of the Interpretation Notice of the Liquor Tax Law and Liquor Administration Laws and Regulations dated June 25, 1999, that is, "a carbohydrate of trisaccharides or less that is soluble in water and generally has a sweet taste, or a mixture of these." The sugar used as the carbohydrate raw material may be at least one type selected from the group consisting of monosaccharides, disaccharides, and trisaccharides, and may further contain sugars of tetrasaccharides or more. Examples of monosaccharides include glucose, fructose, galactose, xylose, arabinose, tagatose, etc. Examples of disaccharides include sucrose, lactose, maltose, isomaltose, trehalose, cellobiose, etc. Examples of trisaccharides include maltotriose, isomaltotriose, raffinose, etc. Examples of sugars with tetrasaccharides or more include stachyose and maltotetraose. The sugars may be in the form of, for example, powder, granules, paste, liquid, etc. Liquid sugars may be, for example, liquid sugars such as glucose-fructose liquid sugar, fructose-glucose liquid sugar, high fructose liquid sugar, and sugar-mixed isomerized liquid sugar. The sugars may be granulated sugar or white sugar.

To the mixture, auxiliary ingredients other than water and grain ingredients that are usually blended into beverages may be added, so long as the desired effect of the present invention is not inhibited. Examples of such auxiliary ingredients include hops, dietary fiber, oligosaccharides such as galactooligosaccharides, starch hydrolysates (obtained by hydrolyzing starch with acid or enzymes), yeast extract, fruit juice, bittering agents, coloring agents, herbs, flavorings, sweeteners, high-intensity sweeteners, antioxidants, acidulants, salts, etc. In addition, saccharifying enzymes such as α-amylase, glucoamylase, pullulanase, and enzymes such as protease can be added as necessary. Each of these ingredients can be generally commercially available.

Sweeteners that can be used include, for example, high fructose glucose liquid sugar, glucose, galactose, mannose, fructose, lactose, sucrose, maltose, glycogen, and starch. High-intensity sweeteners that can be used include, for example, neotame, acesulfame potassium, sucralose, saccharin, sodium saccharin, disodium glycyrrhizinate, cyclamate, dulcin, stevia, glycyrrhizin, thaumatin, monellin, aspartame, and alitame. Antioxidants that can be used include, for example, vitamin C, vitamin E, and polyphenols. Examples of sour agents that can be used include adipic acid, citric acid, trisodium citrate, glucono-delta-lactone, gluconic acid, potassium gluconate, sodium gluconate, succinic acid, monosodium succinate, disodium succinate, sodium acetate, DL-tartaric acid, L-tartaric acid, sodium DL-tartrate, L-sodium tartrate, carbon dioxide, lactic acid, sodium lactate, glacial acetic acid, fumaric acid, monosodium fumarate, DL-malic acid, sodium DL-malate, acetic acid, and phosphoric acid. Examples of salts that can be used include table salt, potassium acid phosphate, calcium acid phosphate, ammonium phosphate, magnesium sulfate, calcium sulfate, potassium metabisulfite, calcium chloride, magnesium chloride, potassium nitrate, and ammonium sulfate. Examples of dietary fiber that can be used include indigestible dextrin, pectin, polydextrose, and decomposed guar gum.

The saccharification process is carried out using enzymes derived from the grain raw materials, etc., or enzymes added separately. The temperature and time during the saccharification process are appropriately adjusted taking into consideration the type of grain raw materials used, the proportion of the grain raw materials in the total fermentation raw materials, the type of enzymes added and the amount of the mixture, and the quality of the desired fermented beer-like sparkling beverage. For example, the saccharification process can be carried out by conventional methods, such as by holding a mixture containing the grain raw materials, etc., at 35 to 70°C for 20 to 90 minutes.

The sugar liquid obtained after saccharification can be boiled to prepare a broth (a boiled product of the sugar liquid). It is preferable to filter the sugar liquid before the boiling treatment, and to boil the filtrate obtained. Alternatively, instead of the filtrate of the sugar liquid, a mixture of malt extract and warm water may be used and boiled. The boiling method and conditions can be determined as appropriate.

By adding herbs and the like as appropriate before or during the boiling process, a fermented beer-like sparkling beverage with the desired flavor can be produced. For example, by adding hops before or during the boiling process and performing the boiling process in the presence of hops, the flavor and aroma components of the hops, particularly the bitter components, can be efficiently boiled out. The amount of hops to be added, the manner of addition (e.g., adding in several portions), and the boiling conditions can be appropriately determined so that the bitterness of the final beer-like sparkling beverage is less than that of a 5 mg/L aqueous solution of iso-α-acids.

The broth obtained after the boiling process contains residues such as proteins that have been produced by precipitation. Therefore, at least a portion of the solid content such as residues is removed from the broth. The residues can be removed by any solid-liquid separation process, but typically a tank called a whirlpool is used to remove the precipitate. The temperature of the broth at this time needs to be 15°C or higher, and is generally around 50 to 100°C. The broth (filtrate) after the residues have been removed is cooled to an appropriate fermentation temperature using a plate cooler or the like. This broth after the residues have been removed becomes the fermentation raw material liquid.

Next, in the fermentation process, yeast is inoculated into the cooled fermentation raw material liquid to carry out fermentation. The cooled fermentation raw material liquid may be subjected to the fermentation process as is, or may be subjected to the fermentation process after being adjusted to the desired extract concentration. There are no particular limitations on the yeast used for fermentation, and it can be appropriately selected from yeasts normally used in the production of alcoholic beverages. It may be either top-fermenting yeast or bottom-fermenting yeast, but bottom-fermenting yeast is preferred because it is easily applicable to large-scale brewing equipment.

In addition, in the storage process, the obtained fermented liquid is aged in a storage tank and stored under low-temperature conditions of about 0°C for stabilization. In the filtration process, the fermented liquid after aging is filtered to remove yeast and proteins that are insoluble in the temperature range, thereby obtaining the desired fermented beer-like sparkling beverage. The filtration process may be any method that can filter out yeast, and examples of such methods include diatomaceous earth filtration and filter filtration using a filter with an average pore size of about 0.4 to 1.0 μm.

The beer-like sparkling beverage according to the present invention is preferably an alcoholic beverage, but may also be a non-alcoholic beverage or a low-alcoholic beverage. In the fermentation process, the fermentation conditions can be appropriately adjusted so that the degree of fermentation is low, the alcohol content can be removed from the obtained fermentation liquid, or the obtained fermentation liquid can be diluted to obtain a non-alcoholic beverage or a low-alcoholic beverage.

When 2-methylthioethanol and γ-nonalactone are added as raw materials, it is preferable to add them after the boiling process to avoid losses during the boiling process, and it is even more preferable to add them to the fermentation liquid after the storage process.

The produced fermented beer-like sparkling beverage is filled into a container. There is no particular limitation on the container into which the beer-like sparkling beverage is filled. Specific examples include glass bottles, cans, and flexible containers. Flexible containers include containers made by molding flexible resins such as PE (polyethylene), PP (polypropylene), EVOH (ethylene-vinyl alcohol copolymer), and PET (polyethylene terephthalate). Flexible containers may be made of a single-layer resin or a multi-layer resin.

The beer-like sparkling beverage according to the present invention does not use hops as a raw material or uses a sufficiently reduced amount of hops, and therefore does not contain any antibacterial components derived from hops or contains only a very small amount of such components. For this reason, it is preferable that the packaged fermented beer-like sparkling beverage filled in a container is heat sterilized. The heat sterilization should have a sufficient sterilization strength to prevent microbial growth during storage, and is appropriately determined taking into consideration the alcohol concentration of the beer-like sparkling beverage, etc. For example, the heat sterilization can be performed at 60 to 85°C for about 0.5 to 60 minutes, preferably at 60 to 80°C for about 1 to 30 minutes, and more preferably at 60 to 70°C for about 5 to 15 minutes.

Non-fermented beer-like sparkling beverages that are produced without going through a fermentation process can generally be produced by a method of mixing the various ingredients (mixing method). For example, specifically, they can be produced by a mixing process in which the various ingredients are mixed to prepare a mixed liquid, and a gas introduction process in which carbon dioxide gas is added to the resulting mixed liquid.

First, in the blending process, the raw materials are mixed to prepare a blended liquid. In the blending process, it is preferable to prepare a blended liquid in which all raw materials except carbon dioxide gas are mixed. The order in which the raw materials are mixed is not particularly limited. All raw materials may be added to the raw material water at the same time, or the raw materials may be added sequentially, such as by adding the raw materials remaining after dissolving the raw materials added earlier. In addition, for example, solid raw materials (e.g., powder or granular) and alcohol as needed may be mixed with the raw material water, or the solid raw materials may be prepared as aqueous solutions in advance, and raw material water and alcohol as needed may be mixed with these aqueous solutions.

The raw materials include one or more selected from the group consisting of 2-methylthioethanol and γ-nonalactone, bittering agents, acidulants, sweetening agents, coloring agents, flavoring agents, ethanol (raw alcohol), emulsifiers, polysaccharides, water-soluble dietary fiber, proteins or their decomposition products, etc.

As the acidulant, it is more preferable to use an organic acid rather than an inorganic acid in terms of safety and flavor. The organic acid is not particularly limited as long as it is one that is generally used in the production of food and beverages, and examples thereof include lactic acid, citric acid, gluconic acid, malic acid, tartaric acid, fumaric acid, succinic acid, adipic acid, fumaric acid, and salts thereof. These organic acids may be used alone or in combination of two or more kinds.

As the bittering agent, those listed above can be used. In addition, isohumulones such as hops, iso-α acids, tetraiso-α acids, and oxides of β acids can be used as bittering agents. In this case, the content is appropriately adjusted so that the bitterness of the final beer-like sparkling beverage is less than that of a 5 mg/L aqueous solution of iso-α acids. Only one type of bittering agent may be used, or two or more types may be used in combination.

Sweeteners include sucrose, glucose, fructose, isomerized liquid sugar, and high-intensity sweeteners. High-intensity sweeteners include aspartame, sucralose, acesulfame potassium, neotame, stevia, and enzyme-treated stevia. These sweeteners may be used alone or in combination of two or more.

The coloring agent may be a caramel color, etc. The coloring agent may be used alone or in combination of two or more kinds.
Flavoring agents (excluding 2-methylthioethanol and γ-nonalactone) include beer extracts, beer flavors, hop flavors, etc. These flavoring agents may be used alone or in combination of two or more.

Examples of emulsifiers include polyglycerin fatty acid esters, glycerin fatty acid esters, sucrose fatty acid esters, polypropylene glycol fatty acid esters, sorbitan fatty acid esters, polysorbates, etc.

Polysaccharides include starch, dextrin, etc. Dextrin is a carbohydrate obtained by hydrolyzing starch and is larger than oligosaccharides (carbohydrates formed by polymerizing about 3 to 10 monosaccharides). These polysaccharides may be used alone or in combination of two or more types.

Water-soluble dietary fiber means carbohydrates that dissolve in water and are not or are difficult to digest by human digestive enzymes. Examples of water-soluble dietary fiber include soybean dietary fiber (soluble soybean polysaccharides), polydextrose, resistant dextrin, galactomannan, inulin, guar gum hydrolyzate, pectin, gum arabic, etc. These water-soluble dietary fibers may be used alone or in combination of two or more types.

If insoluble matter is generated in the preparation liquid prepared in the preparation step, it is preferable to subject the preparation liquid to a process for removing the insoluble matter, such as filtration, before the gas introduction step. The insoluble matter removal process is not particularly limited, and can be performed by a method commonly used in the technical field, such as filtration or centrifugation. In the present invention, it is preferable to remove the insoluble matter by filtration, and more preferably by diatomaceous earth filtration.

Next, in the gas introduction step, carbon dioxide gas is added to the preparation obtained in the blending step. This results in a non-fermented beer-like sparkling beverage. The addition of carbon dioxide gives the beverage a refreshing feeling similar to that of beer. The addition of carbon dioxide gas can be carried out by a conventional method. For example, the preparation obtained in the blending step and carbonated water may be mixed, or carbon dioxide gas may be added directly to the preparation obtained in the blending step and dissolved therein.

After the carbon dioxide gas is added, the resulting non-fermented beer-like sparkling beverage may be further treated to remove insoluble matter, such as by filtration. The insoluble matter removal process is not particularly limited, and may be carried out by a method commonly used in the art.

The produced non-fermented beer-like sparkling beverage is preferably filled into a container and then heat sterilized. The container in which the beverage is filled and the method of heat sterilization can be the same as for the fermented beer-like sparkling beverage.

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

<Measurement of aroma component concentration>
In the following examples, the concentrations of 2-methylthioethanol, γ-nonalactone, γ-decalactone, ethyl caproate, and ethyl caprylate in beer-like sparkling beverages were measured by GC/MS in the same manner as in the measurement method described in Non-Patent Document 1, in which aldehydes were simultaneously collected (concentrated) and derivatized in a solid-phase microextraction (SPME) fiber.

Specifically, 100 μL of a 6 g/L aqueous solution of O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine (PFBOA) (Tokyo Chemical Industry Co., Ltd.) as a derivatization reagent and 10 mL of hexane washing water were placed in a 20 mL glass vial and sealed with a crimp cap. Next, a SPME fiber (PDMS/DVB: 65 μm, 1 cm, 57327-U 24 gauge, SPELCO Corporation) was exposed to the headspace of the 20 mL glass vial containing the PFBOA solution at 50°C for 10 minutes.

10 mL of the beer-like carbonated beverage sample was placed in a 20 mL glass vial and sealed with a crimp cap. The SPME fiber that had captured the PFBOA was then exposed to the headspace of the 20 mL glass vial containing the sample at 50°C for 60 minutes.

Next, the aldehydes and other compounds in the collected and PFBOA-derivatized samples were analyzed by GC/MS under the following conditions.

(GC/MS conditions)
GC/MS device: HP6890/5973 (Agilent Technologies)
Capillary column: Agilent J&W DB-5 (30 m x 0.25 mm x 0.50 μm, manufactured by Agilent Technologies)
Carrier gas: Helium Flow rate: 1.1 mL/min Injection port temperature: 250° C.
Purge valve time: 30 seconds Injection mode: splitless mode Temperature program: hold at 40°C for 2 minutes → increase temperature to 140°C at 10°C/min → increase temperature to 250°C at 7°C/min → hold at 250°C for 3 minutes → increase temperature to 300°C at 12°C/min → hold at 300°C for 5 minutes

The PFBOA derivatives were identified by measuring mass spectra in scan mode using electron impact ionization. As a result, it was confirmed that the m/z values shown in Table 1 were the main fragment ions of each of the analyzed substances.

Each peak was measured in SIM mode, and the PFBOA derivative was quantified by the standard addition method. For compounds with geometric isomers, the total area of the peaks due to the geometric isomers was used as the peak of that compound. The internal standards used for the measurement of each compound are as shown in Table 1.

[Reference example 1]
The effect of 2-methylthioethanol on the aroma, especially the acidic odor, of a fermented beer-like sparkling beverage was investigated.

First, a mixture of 20 kg of malt, 10 kg of corn starch, and raw water was heated and saccharified in the usual manner, and then the enzymes were inactivated at 76°C to produce a saccharified liquid. The resulting saccharified liquid was filtered, and the filtrate was placed in a boiling kiln, water was added to make the volume 200L, and the mixture was boiled for 70 minutes to obtain wort (grain broth). When hops were used as the raw material, an appropriate amount was added to the filtrate before boiling. Hot water was then added to the wort to readjust the volume to 200L, and solid-liquid separation was performed in a whirlpool (swirl separation tank). After solid-liquid separation, the wort was cooled by a heat exchanger. Brewer's yeast was inoculated into the cooled wort and fermented. After fermentation, the fermented liquid was filtered and clarified, diluted 1.2 times, and then adjusted to a carbon dioxide pressure of 0.23 MPa (20°C) and filled into a container. The resulting bottled fermented beer-like sparkling beverage with an alcohol concentration of 5% by volume was heat sterilized at 65°C for 10 minutes as required.

When hops were not used as the raw material, hop flavouring was added.
When hop flavoring, gamma-nonalactone, or 2-methylthioethanol was added, it was added before filling the container.

A panel of six experts conducted a sensory evaluation of the aroma of the resulting bottled, fermented, beer-like sparkling beverage. For each characteristic, 1 was the weakest, and the stronger the characteristic, the higher the score.

Regarding acid odor, carbon dioxide gas was introduced into a mixture of raw alcohol and water to adjust the alcohol concentration to 5% by volume and the carbon dioxide pressure to 0.23 MPa (20°C). Iso-α-acids, 2-methylthioethanol, and γ-nonalactone were then added to the mixture to achieve concentrations approximately the same as those of a hop-containing fermented beer-like sparkling beverage (iso-α-acids concentration 19.5 IBU, 2-methylthioethanol concentration 20 μg/L, and γ-nonalactone concentration 10 μg/L). This was given an evaluation score of 1.

For liveliness, carbon dioxide gas was introduced into a mixture of raw alcohol and water to adjust the alcohol concentration to 5% by volume and the carbon dioxide pressure to 0.23 MPa (20°C). Iso-α-acid, 2-methylthioethanol and gamma-nonalactone were then added to the mixture to achieve concentrations approximately the same as those of a non-hop-containing fermented beer-like sparkling beverage (iso-α-acid concentration 2.9 IBU, 2-methylthioethanol concentration 20 μg/L, gamma-nonalactone concentration 10 μg/L).

The evaluation results are shown in Tables 2 and 3. In the tables, samples with "None" in the "Hops" column were produced without using hops as a raw material, but with the addition of hop flavoring. The values in the aroma component column indicate the amount contained in the beverage, with the number in parentheses "+X" meaning that X μg/L of a synthetic product was added separately.

In hop-containing beer-like sparkling beverages, as the content of 2-methylthioethanol increased, the acidic odor remained unchanged, but the aroma tended to become more lively. On the other hand, in hop-free beer-like sparkling beverages, as the content of 2-methylthioethanol increased, the acidic odor increased, and at the same time, the aroma also increased, although not as much as in hop-containing beer-like sparkling beverages.

[Example 1]
The hop-free beer-like sparkling beverage (2.9 IBU, containing hop flavoring) produced in Reference Example 1 was varied in content of 2-methylthioethanol and γ-nonalactone, and the effects on the acidic odor and rich aroma were examined in the same manner as in Reference Example 1. Additionally, the beer-likeness was also evaluated. The results are shown in Tables 4 to 8.

As shown in Tables 4 to 8, among samples with the same 2-methylthioethanol content, the higher the γ-nonalactone content, the more the acidic odor was suppressed and the more gorgeous the aroma tended to be. In particular, samples with a ratio of γ-nonalactone to 2-methylthioethanol content (N/M ratio) of 0.65 or more had sufficiently suppressed acidic odor and produced highly palatable beer-like sparkling beverages with a gorgeous aroma. However, when the γ-nonalactone content increased to an N/M ratio of more than 1.50, the sweet aroma of γ-nonalactone became more noticeable.

[Comparative Example 1]
γ-Decalactone, ethyl caproate, or ethyl caprylate was added instead of γ-nonalactone to the hop-free beer-like sparkling beverage (2.9 IBU, containing hop flavoring) produced in Reference Example 1, and the effects on the acidic odor and richness of the aroma were examined in the same manner as in Example 1. The results are shown in Table 9.

As a result, as shown in Table 9, when γ-decalactone, ethyl caproate, or ethyl caprylate was added, the sweet aroma became too prominent and the acidic odor could not be suppressed even if the amount of each was increased to a level that was unnatural for beer.

Claims (13)

[γ-nonalactone content (μg/L)]/[2-methylthioethanol content (μg/L)] is 0.65 or more,
The content of 2-methylthioethanol is 20 μg/L or more,
The content of γ-nonalactone is 150 μg/L or less,
A beer-like sparkling beverage having an international bitterness value of less than 5. The beer-like carbonated beverage according to claim 1, in which the ratio of [γ-nonalactone content (μg/L)]/[2-methylthioethanol content (μg/L)] is 1.50 or less. The beer-like sparkling beverage according to claim 1 or 2, which is not made from hops. The beer-like carbonated beverage according to any one of claims 1 to 3, which does not contain a bittering agent. The beer-like sparkling beverage according to any one of claims 1 to 4, which contains a hop flavoring. The beer-like sparkling beverage according to any one of claims 1 to 5, which is a fermented beverage. A method for producing a beer-like sparkling beverage having a 2-methylthioethanol content of 20 μg/L or more and an international bitterness value of less than 5, comprising:
The method for producing a beer-like sparkling beverage comprises adjusting the content of γ-nonalactone and the content of 2-methylthioethanol so that the ratio [γ-nonalactone content (μg/L)]/[2-methylthioethanol content (μg/L)] is 0.65 or more and the content of γ-nonalactone is 150 μg/L or less . The method for producing a beer-like sparkling beverage according to claim 7, wherein one or more ingredients selected from the group consisting of γ-nonalactone and 2-methylthioethanol are used as raw materials. The method for producing a beer-like sparkling beverage according to claim 7 or 8, which does not use hops as a raw material. The method for producing a beer-like sparkling beverage according to any one of claims 7 to 9, wherein the produced beer-like sparkling beverage is filled into a container and subjected to a heat sterilization treatment. A method for reducing an acidic odor derived from 2-methylthioethanol in a beer-like sparkling beverage having a 2-methylthioethanol content of 20 μg/L or more and an international bitterness value of less than 5, comprising:
The method includes adjusting the content of γ-nonalactone and the content of 2-methylthioethanol so that the ratio of [γ-nonalactone content (μg/L)]/[2-methylthioethanol content (μg/L)] is 0.65 or more and the content of γ-nonalactone is 150 μg/L or less . The method according to claim 11, wherein the beer-like carbonated beverage is produced without using hops as an ingredient. The method according to claim 11 or 12, wherein the beer-like sparkling beverage is produced through a heat sterilization process.