Method for enhancing bacteriostatic activity of beer-like beverage

Abstract

The present invention addresses the problem of providing a method for enhancing the bacteriostatic activity of a beer-like beverage without the need to lower the pH value of the beverage and without the need to maintain the amount of hop to be used for the beverage or the alcohol concentration in the beverage at high levels. The solution for the problem is a method for enhancing the bacteriostatic activity of a beer-like beverage, the method including adjusting the carbon dioxide gas pressure at 20°C to 0.23 MPa or more.

Description

Methods for enhancing the bacteriostasis of beer-like beverages

[0001] The present invention relates to a method for enhancing the bacteriostasis of a beer-like beverage, and more particularly to a method for enhancing the bacteriostasis of a low-alcohol beer-like beverage.

[0002] Beer has a distinctive bitterness and aroma. Beer is a beverage made from malt, hops, and water, fermented with yeast. Beer-like beverages are beverages designed to have a taste and aroma similar to that of beer. Specific examples of beer-like beverages include beer, happoshu (low-malt beer), miscellaneous alcoholic beverages, liqueurs, spirits, and low-alcohol beverages, all of which have a flavor reminiscent of beer.

[0003] Low-alcohol beer-like beverages have attracted attention because they are less likely to cause intoxication and have less impact on health. Such low-alcohol beer-like beverages generally have an alcohol concentration of about 4% v / v or less.

[0004] Patent Document 1 describes the relationship between alcohol concentration and carbon dioxide pressure for sufficiently sterilizing bottled carbonated alcoholic beverages by heating at low temperature for a short time. Examples of beverages to be sterilized include bottled carbonated alcoholic beverages containing lemon, grapefruit, or other fruit pulp or juice. Specific examples of sterilization conditions include a sterilization temperature of less than 65°C, a sterilization time of 10 to 20 minutes, an alcohol concentration of 5% by volume or more, and a gas pressure of 2.3 gas volumes or more.

[0005] In the sterilization method of Patent Document 1, the microorganisms for which the sterilization effect has been confirmed are limited to yeast. Furthermore, the carbon dioxide pressure of 2.3 gas volumes corresponds to 0.17 MPa at 20°C.

[0006] JP 2014-93945 A

[0007] From the viewpoint of preventing spoilage, beer-like beverages must have sufficient bacteriostatic properties to be distributed on the market. The antibacterial effect of hops is ineffective against some bacterial species, and is insufficient when the amount of hops used in the beer-like beverage is small. Furthermore, the antibacterial effect of alcohol is insufficient when the alcohol concentration of the beer-like beverage is low. The bacteriostatic properties of beer-like beverages can be enhanced by adding a pH adjuster such as an acid. However, beer-like beverages with a sufficiently lowered pH have a strong sour taste, a poor balance between sourness and sweetness, and are less palatable.

[0008] The present invention aims to solve the above-mentioned problems, and has as its object to provide a method for enhancing the bacteriostatic activity of beer-like beverages without the need to lower the pH or maintain a high amount of hops or alcohol concentration. In this specification, bacteriostatic activity refers to the ability to inhibit the growth of microorganisms.

[0009] The present invention provides the following aspects: [1] A method for enhancing the bacteriostasis of a beer-like beverage, which comprises adjusting the carbon dioxide pressure at 20°C to 0.23 MPa or more.

[0010] [2] The method for enhancing the bacteriostasis of a beer-like beverage according to Aspect 1, wherein the microorganisms to be bacteriostasized are bacteria capable of growing in the beer-like beverage.

[0011] [3] The method for enhancing the bacteriostasis of a beer-like beverage according to Aspect 2, wherein the bacteria include lactic acid bacteria or obligate anaerobes.

[0012] [4] The method for enhancing the bacteriostasis of a beer-like beverage according to Aspect 3, wherein the lactic acid bacteria include bacteria of the genus Levilactobacillus and bacteria of the genus Furfurilactobacillus, and the obligate anaerobic bacteria include bacteria of the genus Pectinatus and bacteria of the genus Megasphaera.

[0013] [5] The method for enhancing the bacteriostasis of a beer-like beverage according to Aspect 2, wherein the bacterium comprises at least one selected from the group consisting of Levilactobacillus brevis, Pectinatus haikarae, Furfurilactobacillus curtus, Pectinatus sottacetonis, Pectinatus cerevisiiphilus, Pectinatus frisingensis, Megasphaera sueciensis, Megasphaera paucivorans, and Megasphaera cerevisiae.

[0014] [6] The method for enhancing the bacteriostasis of a beer-like beverage according to any one of Aspects 1 to 5, wherein the carbon dioxide pressure at 20°C is 0.23 to 0.30 MPa, more preferably 0.23 to 0.27 MPa, and even more preferably 0.24 to 0.27 MPa.

[0015] [7] The method for enhancing the bacteriostasis of a beer-like beverage according to any one of Aspects 1 to 6, wherein the beer-like beverage has an alcohol concentration of 4 v / v% or less, preferably 1 to 4 v / v%, more preferably 2 to 4 v / v%, and even more preferably 3 to 4 v / v%.

[0016] [8] The method for enhancing the bacteriostasis of a beer-like beverage according to any one of Aspects 1 to 7, wherein the beer-like beverage has a pH of 4.1 to 5.0, preferably greater than 4.2 and not greater than 4.8, and more preferably 4.3 to 4.7.

[0017] [9] A method for producing a beer-like beverage, comprising: adjusting the carbon dioxide pressure at 20°C to 0.23 MPa or more, preferably 0.23 to 0.30 MPa, more preferably 0.23 to 0.27 MPa, and even more preferably 0.24 to 0.27 MPa; adjusting the pH to 4.1 to 5.0, preferably more than 4.2 but not more than 4.8, and even more preferably 4.3 to 4.7; and adjusting the alcohol concentration to 4 v / v% or less, preferably 1 to 4 v / v%, more preferably 2 to 4 v / v%, and even more preferably 3 to 4 v / v%.

[0018]

[10] A beer-like beverage having a carbon dioxide pressure at 20 ° C. of 0.23 MPa or more, preferably 0.23 to 0.30 MPa, more preferably 0.23 to 0.27 MPa, and even more preferably 0.24 to 0.27 MPa, a pH of 4.1 to 5.0, preferably more than 4.2 but not more than 4.8, and even more preferably 4.3 to 4.7, and an alcohol concentration of 4 v / v% or less, preferably 1 to 4 v / v%, more preferably 2 to 4 v / v%, and even more preferably 3 to 4 v / v%.

[0019]

[11] The beer-like beverage of Aspect 10, comprising a wort fermentation broth.

[12] The method for enhancing the bacteriostasis of a beer-like beverage of any one of Aspects 1 to 5, 7 and 8, the method for producing a beer-like beverage of Aspect 9, or the beer-like beverage of Aspect 10 or 11, wherein the carbon dioxide pressure at 20°C is 0.24 to 0.29 MPa, preferably 0.25 to 0.28 MPa, more preferably 0.26 to 0.27 MPa.

[13] The beer-like beverage of any one of Aspects 10 to 12, having an invertase activity of 50 U or more, preferably 100 to 1000 U, more preferably 300 to 700 U.

[0020] The present invention provides a method for enhancing the bacteriostasis of beer-like beverages without the need to lower the pH or maintain high hop loading or alcohol concentration.

[0021] In this specification, the term "process" does not only refer to an independent process, but also includes processes that cannot be clearly distinguished from other processes as long as the intended purpose of the process is achieved. Furthermore, when multiple substances corresponding to each component are present in the composition, the content of each component in the composition refers to the total amount of those multiple substances present in the composition, unless otherwise specified. Furthermore, the upper and lower limits of the numerical ranges in this specification can be arbitrarily selected and combined. Below, embodiments of the present invention are described in detail. However, the embodiments shown below are examples of beer-like beverages and methods for producing them to embody the technical concept of the present invention, and the present invention is not limited to the beer-like beverages and methods for producing them shown below.

[0022] <Method for Enhancing Bacteriostasis of Beer-like Beverages> The method for enhancing the bacteriostasis of beer-like beverages of the present invention comprises adjusting the carbon dioxide pressure of the beer-like beverage at 20°C to 0.23 MPa or more. This improves the resistance of the beer-like beverage to microorganisms, making it possible to impart bacteriostasis to products distributed on the market. Furthermore, it becomes possible to avoid heat treatment of the beer-like beverage, thereby suppressing the progression of deterioration. The carbon dioxide pressure is preferably 0.23 to 0.30 MPa, more preferably 0.23 to 0.27 MPa, and even more preferably 0.24 to 0.27 MPa. In one embodiment, the carbon dioxide pressure is 0.24 to 0.29 MPa, preferably 0.25 to 0.28 MPa, and more preferably 0.26 to 0.27 MPa. Here, the carbon dioxide pressure of the beer-like beverage is the carbon dioxide pressure of the manufactured product.

[0023] The carbon dioxide pressure of a beer-like beverage at 20°C can be measured and adjusted using methods commonly known to those skilled in the art.

[0024] <Microorganisms> The microorganisms that are bacteriostatically enhanced by the method of the present invention for enhancing the bacteriostasis of beer-like beverages are those that can grow in beer-like beverages. Even if they are microorganisms that can grow in beer-like beverages, microorganisms with relatively large diameters such as yeast are generally removed by filtration or other processes during the production process of beer-like beverages, and the above-mentioned method does not need to be effective against them.

[0025] Microorganisms that can be stablized by the bacteriostatic method of the present invention include bacteria. Specific examples of bacteria that can be stablized by the bacteriostatic method include lactic acid bacteria and obligate anaerobes. Some of these bacterial species are known to be able to grow in beer. They are also known to grow easily in low-alcohol beer. Examples of the lactic acid bacteria include bacteria of the genus Levilactobacillus and Furfurilactobacillus, and examples of the obligate anaerobes include bacteria of the genus Pectinatus and Megasphaera. Specifically, the following bacteria are considered to be stablized by the method of the present invention:

[0026]

[0027] <Beer-like beverages> Beer refers to a beverage obtained by fermenting malt, hops, and water using yeast as ingredients. A beer-like beverage is a beverage designed to have a taste and aroma similar to that of beer to the extent that it is reminiscent of beer. Specific examples of beer-like beverages include beer, happoshu (low-malt beer), miscellaneous alcoholic beverages, liqueurs, spirits, and low-alcohol beverages, all of which have a flavor reminiscent of beer. A beer-like beverage may be a beer-like alcoholic beverage or a beer-like non-alcoholic beverage.

[0028] One form of beer-like beverage is a low-alcohol beer-like beverage. A "low-alcohol beer-like beverage" refers to a beer-like beverage with a lower alcohol concentration than a regular beer-like beverage.

[0029] The low-alcohol beer-like beverage has an alcohol concentration of 4 v / v% or less, preferably 1 to 4 v / v%, more preferably 2 to 4 v / v%, and even more preferably 3 to 4 v / v%. The term "alcohol" refers to ethanol. In such cases, the bacteriostatic effect of the alcohol in the beer-like beverage becomes insufficient, thereby improving the utility of the method of the present invention.

[0030] The beer-like beverage may contain no hops or hop-derived components, or may contain only a small amount of hops. In such cases, the bacteriostatic effect of hops on the beer-like beverage becomes insufficient, thereby improving the utility of the method of the present invention. Specific examples of hop-derived components include iso-α acids.

[0031] Beer-like beverages may not contain iso-α acids, but preferably have an iso-α acid concentration of 5 BU or more, more preferably 10 BU or more, and even more preferably 15 BU or more in terms of bitterness value. If the bitterness value is less than 10 BU, the resistance of the beer-like beverage to microorganisms may be insufficient. The upper limit of the iso-α acid concentration may be 50 BU or less, preferably 40 BU or less, as in regular beer. However, if the iso-α acid concentration is reduced to, for example, 15 BU or less, typically 10 BU or less in terms of bitterness value, the bacteriostatic effect of the beer-like beverage is likely to be insufficient.

[0032] The bitterness value of a beer-like beverage refers to a value measured by the isooctane extraction-absorbance analysis method described in "8.15 Bitterness Value" of the Revised BCOJ Beer Analysis Method (published by the Brewery Society of Japan, a public interest incorporated foundation, edited by the International Technical Committee of the Brewers Association of Japan (Analysis Committee), revised and expanded in 2013).

[0033] The beer-like beverage has a pH of, for example, 3.8 to 4.8, preferably 4.1 to 5.0. If the pH of the beer-like beverage exceeds 5.0, its durability against microorganisms will be insufficient. On the other hand, if the pH is too low, the resulting beer-like beverage will have a strong sour taste, the balance between sourness and sweetness will be poor, and its palatability will be reduced. The pH of the beer-like beverage of the present invention is more preferably greater than 4.2 and not more than 4.8, and even more preferably 4.3 to 4.7. Here, the pH of the beer-like beverage is the pH of the final product.

[0034] The beer-like beverage preferably contains a wort fermentation liquid. By including the wort fermentation liquid in the beer-like beverage, the beer-like beverage is endowed with a complex taste, full body, and satisfying drinking sensation reminiscent of beer. The wort fermentation liquid refers to a liquid obtained by fermenting wort with brewer's yeast. The wort referred to in the present invention refers to the wort used in producing regular beer, and contains malt and, if necessary, hops. The beer-like beverage may consist of the wort fermentation liquid.

[0035] <Wort fermentation liquor> The wort fermentation liquor can be produced, for example, by the following method. First, crushed malt, auxiliary raw materials such as barley, and warm water are added to a mash tank and mixed to prepare a mash. The mash can be prepared by a conventional method, for example, by first holding the mixture at 35 to 60°C for 20 to 90 minutes to decompose proteins derived from the raw materials into amino acids, etc., and then proceeding to the saccharification process. During this process, enzymes such as transglucosidase, and flavor components such as spices and herbs are added as needed in addition to the main raw materials and auxiliary raw materials.

[0036] The mashed mash is then gradually heated and maintained at a predetermined temperature for a certain period of time, whereby the starch is saccharified using enzymes derived from malt or enzymes added to the mashed mash. The temperature and time during saccharification can be determined appropriately taking into consideration the type of enzyme used, the amount of mashed mash, the desired quality of the fermented wort, and other factors. For example, saccharification can be performed by maintaining the mashed mash at 60-72°C for 30-90 minutes. After saccharification, the mashed mash is maintained at 76-78°C for approximately 10 minutes, and then filtered in a wort filtration tank to obtain a clear sugar solution. Furthermore, an appropriate amount of enzymes may be added during saccharification, as needed.

[0037] The raw material to be subjected to saccharification, i.e., the starchy raw material, contains malt. The malt content in the raw material to be subjected to saccharification is 50% or more, preferably 67% or more, and more preferably 70% or more, from the viewpoint of not reducing the beer-like flavor. The raw material to be subjected to saccharification may have a 100% malt usage ratio. The malt usage ratio is the proportion (wt%) of malt relative to all raw materials excluding water and hops. The higher the malt usage ratio, the stronger the malt-derived umami and richness of the resulting beer-like beverage. Furthermore, the higher the malt usage ratio, the greater the content of nitrogen compounds in the resulting wort, which reduces the likelihood of fermentation irregularities when the wort is subjected to fermentation, and reduces the likelihood of unpleasant odors in the beer-like beverage.

[0038] "Secondary ingredients" refers to ingredients other than malt and hops. Examples of such secondary ingredients include starchy ingredients such as barley, wheat, cornstarch, corn grits, rice, and koryan, as well as carbohydrate ingredients such as liquid sugar and sugar. Here, liquid sugar is produced by decomposing and saccharifying starch with acid or a saccharifying enzyme, and primarily contains glucose, maltose, maltotriose, and the like. Other secondary ingredients include spices, herbs, and fruits used to impart or improve flavor.

[0039] The term "saccharifying enzyme" refers to an enzyme that breaks down starch to produce sugar, and examples of such enzymes include α-amylase, glucoamylase, and pullulanase.

[0040] The wort boiling operation may be carried out according to the method and conditions normally used in beer production. For example, the pH-adjusted sugar solution is transferred to a boiling kettle and boiled. Hops are added from the start of boiling the sugar solution until the sugar solution is left to stand in the whirlpool. Hop extract or components extracted from hops may be used as the hops. The sugar solution is then transferred to a settling tank called a whirlpool, where hop dregs and coagulated proteins resulting from boiling are removed, and the sugar solution is then cooled to an appropriate temperature using a plate cooler.

[0041] By carrying out the above-described operations up to boiling the wort, wort is obtained. The obtained wort is fermented with yeast to obtain a fermented wort liquid. The fermentation of the wort may be carried out according to a conventional method. For example, the cooled wort may be inoculated with brewer's yeast and transferred to a fermentation tank for alcoholic fermentation.

[0042] The final apparent degree of fermentation of the fermented wort is adjusted to 90% or more, preferably 90 to 110%, and more preferably 100 to 110%, from the viewpoint of not reducing the beer-like flavor. On the other hand, if the final apparent degree of fermentation is too low, a gunpowder smell, a chemical smell, and a sticky feeling after drinking may occur due to a reduction in the alcohol concentration.

[0043] The degree of fermentation is an important indicator of how much fermentation has progressed in fermented beer and how the fermentation has progressed. Furthermore, the final degree of fermentation refers to the ratio of the extract that can be assimilated by brewer's yeast to the original wort extract. Here, the extract that can be assimilated by brewer's yeast is the original wort extract minus the extract contained in the finished beer (i.e., the extract that remains after all the extract that can be used by brewer's yeast has been fermented (referred to as the final extract)). The apparent final degree of fermentation refers to the final degree of fermentation calculated using the value of the final extract and the extract concentration (w / w%) determined from the specific gravity of the apparent extract, i.e., the beer still containing alcohol.

[0044] The term "extract" refers to the solid residue of wort after evaporation. Extract is primarily composed of sugars. The extract content can be adjusted by changing the amount of raw malt, various starches, and sugars added. The true extract concentration of beer-like beverages can be measured, for example, by the EBC method (BCOJ Beer Analysis Methods, 7.2 (2004), edited by the Brewers Association of Japan). Depending on the context, the term "extract" can refer to the non-volatile solids themselves, the amount of non-volatile solids, or the concentration of non-volatile solids (w / w%).

[0045] The final apparent degree of fermentation Vend of the fermented wort liquid can be calculated, for example, by the following formula (1).

[0046] Vend (%) = {(P - Eend) / P} × 100 (1) (where P is the original wort extract and Eend is the apparent final extract).

[0047] The original wort extract (P) is calculated theoretically from the wort extract value before alcoholic fermentation according to Balling's formula using the alcohol concentration and extract value of the finished beer. Specifically, it can be determined by the method shown in Analytica-EBC (9.4) (2007). The apparent final extract (Eend) can be determined by collecting beer in a flask, adding a large amount of fresh compressed yeast, and fermenting the beer with stirring at 25°C until the extract value no longer decreases (24 hours), and then measuring the apparent extract value of the remaining beer.

[0048] The apparent final extract (Eend) may be a negative value because it is calculated from the specific gravity of the final extract including alcohol. As a result, the apparent final fermentation degree may exceed 100%.

[0049] The apparent final degree of attenuation of the wort fermentation liquid can be controlled, for example, by adjusting the saccharification conditions, such as whether or not an enzyme is used when saccharifying the raw materials, and the types and amounts of raw materials used. For example, extending the saccharification time of the raw materials can increase the sugar concentration available to yeast, thereby increasing the apparent final degree of attenuation of the wort fermentation liquid.

[0050] The wort fermentation liquid may be a top-fermented wort liquid or a bottom-fermented wort liquid, but is preferably a bottom-fermented wort liquid from the viewpoint of achieving a clean aftertaste. The top-fermented wort liquid refers to a wort fermentation liquid obtained by inoculating wort with a top-fermenting yeast and fermenting it under normal fermentation conditions, for example, at 15 to 25°C for several days. The bottom-fermented wort liquid refers to a wort fermentation liquid obtained by inoculating wort with a bottom-fermenting yeast and fermenting it under normal fermentation conditions, for example, at around 10°C for approximately one week.

[0051] The amount and concentration of the fermented wort liquid contained in the beer-like beverage can be adjusted as appropriate so as to provide a desired alcohol concentration or beer-like flavor.

[0052] <Original Wort Extract Concentration> The beer-like beverage preferably has an original wort extract concentration of less than 12.2% by mass. This has the advantage of allowing the alcohol content to be reduced and providing a light taste. The original wort extract concentration of the beer-like beverage of the present invention is more preferably 5.0 to 10.0% by mass, and even more preferably 6.0 to 8.0% by mass.

[0053] The original wort extract concentration of a beer-like beverage can be calculated, for example, by measuring ethanol using Section 8.3.6. Alcolyzer Method and true extract using Section 8.4.3. Alcolyzer Method in the Revised BCOJ Beer Analysis Methods (published by the Brewing Society of Japan, edited by the International Technical Committee of the Brewers Association of Japan (Analysis Committee), revised and expanded in 2013), and then calculating the original wort extract concentration using Section 8.5. Extract-related Calculation Method.

[0054] <Method for producing beer-like beverage> The method for producing a beer-like beverage of the present invention comprises adjusting the carbon dioxide pressure of the beer-like beverage at 20° C. to 0.23 MPa or more. The carbon dioxide pressure of the beer-like beverage at 20° C. can be adjusted using methods commonly known to those skilled in the art.

[0055] The method for producing a beer-like beverage of the present invention comprises adjusting the pH of the beer-like beverage to 4.1 to 5.0.

[0056] The pH of the beer-like beverage can be adjusted by adding a pH adjuster at any point during the production process. The pH adjuster may be, for example, at least one selected from the group consisting of phosphoric acid, citric acid, malic acid, succinic acid, lactic acid, and acetic acid. Among these, phosphoric acid or lactic acid is preferred.

[0057] The method for producing a beer-like beverage of the present invention includes adjusting the alcohol concentration of the beer-like beverage to 4 v / v % or less. The alcohol concentration of the beer-like beverage can be adjusted, for example, by diluting the liquid to be treated, such as wort. Dilution can be performed, for example, by adding water to the liquid to be treated.

[0058] In the method for producing a beer-like beverage, the liquid to be treated can be diluted in any step, such as the cooling step after boiling the wort, the fermentation step, the maturation step, or the filtration step.

[0059] Furthermore, by increasing the proportion of non-fermentable carbohydrates in the wort before the fermentation step, it is possible to suppress alcoholic fermentation during the fermentation step, thereby reducing the amount of alcohol produced by fermentation and thereby reducing the alcohol concentration of the beer-like beverage.

[0060] The method for producing a beer-like beverage of the present invention preferably includes incorporating a fermented wort liquid into a beer-like beverage. In this case, the fermented wort liquid may be used as a base liquid for the beer-like beverage.

[0061] The method for producing a beer-like beverage of the present invention preferably includes adjusting the amount of hops or hop-derived components used so as to have a specific range of iso-α acid concentration. The iso-α acid concentration of the beer-like beverage can be adjusted by adjusting the amount and timing of hop addition to the wort during the wort preparation process.

[0062] The method for producing a beer-like beverage of the present invention preferably includes adjusting the original wort extract concentration of the beer-like beverage within a specific range. The adjustment of the original wort extract concentration can be achieved, for example, by changing the ratio of raw material malt and brewing water (brewing composition) in the pre-fermentation step, by evaporating water by boiling to concentrate the brewing mixture, by changing the amount of warm water added to prepare the extract after boiling, or by using liquid sugar or malt extract.

[0063] The method for producing a beer-like beverage may further include a step of adding caramel coloring or the like, a boiling step, a pH adjustment step, a filtration step, a flavor adjustment step, a step of dissolving carbon dioxide gas, etc., using known equipment or the like.

[0064] The method for producing a beer-like beverage may further include a step of adding dietary fiber, soy peptides, carbon dioxide, extracts, flavorings, acidulants, sweeteners, bittering agents, coloring agents, antioxidants, pH adjusters, various nutritional components, etc., as necessary.

[0065] The beer-like beverage of the present invention is preferably a beverage produced without undergoing a heat treatment after the fermentation step (an unheated fermented beverage), which prevents the volatilization and thermal degradation of highly hydrophobic aroma components and enhances the function of suppressing oxidized odor and stale taste.

[0066] When heat treatment is not performed after the fermentation step, even if the yeast is removed by solid-liquid separation, some of the various yeast-derived enzymes remain active. Therefore, invertase activity and protease activity are detected in unheated fermented beverages. In other words, beer-like beverages according to the present invention are preferably those having invertase activity and protease activity.

[0067] In one embodiment, the beer-like beverage of the present invention has an invertase activity of 50 U or more, preferably 100 to 1000 U, and more preferably 300 to 700 U. The invertase activity and protease activity can be measured by a conventional method.

[0068] The present invention will be explained in more detail with reference to the following examples, but the present invention is not limited to these examples.

[0069] Example 1 30 kg of malt and 13 kg of corn starch as an auxiliary material were saccharified, followed by enzyme inactivation at 76°C. The resulting liquid (wort) was filtered and then placed in a boiling kettle. Water was added to make the total volume 230 L, and an appropriate amount of hops was then added. The wort after the addition of hops was boiled for 80 minutes, and then hot water was added to readjust the liquid volume to 230 L. An appropriate amount of hops was then added in a whirlpool (swirl separation tank), followed by solid-liquid separation. After solid-liquid separation, the wort was cooled using a heat exchanger to obtain a wort containing 13.0% by mass of raw wort extract.

[0070] Yeast was added to the cooled wort and fermented. The fermented liquid was clarified by filtration, and water was added to make the original wort extract 11.3% by mass. The liquid was then filled into a container to obtain beer with an alcohol concentration of 5.0 v / v%. Carbon dioxide was then added appropriately using a gasifier to obtain beer with different gas pressures. The pH was adjusted to 4.6 by adding NaOH solution.

[0071] Next, 1 to 3 x 10 test bacteria shown in Table 2 were added to each beer. ３ The cells were inoculated at a concentration of 1000 cells / mL and stored in a dark place at 25°C. The samples were visually inspected at regular intervals every day to determine the number of days until turbidity was observed. The results are shown in Table 2.

[0072]

[0073] For the test bacteria, Levilactobacillus brevis and Pectinatus frisingensis, the number of days until cloudiness was observed increased in proportion to the gas pressure of the beer, and increasing the gas pressure improved the bacteriostasis of the beer. Furthermore, Furfurilactobacillus curtus did not become cloudy when the gas pressure was increased. Therefore, it can be said that the bacteriostasis of Furfurilactobacillus curtus also improved.

[0074] Example 2 Two types of beer with different gas pressures, each with an alcohol concentration of 3% and a pH of 4.6, were prepared in the same manner as in Example 1, except that water was added to the original wort extract to a concentration of 7.5% by mass. Additionally, as a control sample, Beer 1 obtained in Example 1, with an alcohol concentration of 5% and a pH of 4.6, was prepared. The gas pressure of each beer was measured. Next, 1 to 3 x 10 test strains shown in Table 3 were added to each beer. ３ The cells were inoculated at a concentration of 1000 cells / mL and stored in a dark place at 25°C. The samples were visually inspected at regular intervals every day to determine the number of days until turbidity was observed. The results are shown in Table 3.

[0075]

[0076] For the test bacteria, the number of days until turbidity was observed increased in proportion to the gas pressure of the beer, and the bacteriostasis of beer with an alcohol concentration of 3% was able to be increased to the same level as beer with an alcohol concentration of 5%.

[0077] Example 3 Four types of beer with different gas pressures, an alcohol concentration of 3%, and a pH of 4.6 were prepared in the same manner as in Example 1, except that water was added to make the original wort extract 7.5% by mass. The gas pressure of each beer was measured. Next, 1 to 3 x 10 test strains shown in Table 4 were added to each beer. ３ The cells were inoculated at a concentration of 1000 cells / mL and stored in a dark place at 25°C. The samples were visually inspected at regular intervals every day to determine the number of days until turbidity was observed. The results are shown in Table 4.

[0078] For the test strains, the number of days until turbidity was observed increased in proportion to the gas pressure of the beer.

[0079]

Claims

1. A method for enhancing the bacteriostasis of a beer-like beverage, comprising adjusting the carbon dioxide pressure at 20°C to 0.23 MPa or more.

2. A method for enhancing the bacteriostasis of a beer-like beverage according to claim 1, wherein the microorganisms to be bacteriostatic are bacteria capable of growing in the beer-like beverage.

3. The method for enhancing the bacteriostasis of a beer-like beverage according to claim 2, wherein the bacteria comprises lactic acid bacteria or obligate anaerobes.

4. The method for enhancing the bacteriostasis of a beer-like beverage according to claim 3, wherein the lactic acid bacteria include bacteria of the genus Levilactobacillus and Furfurilactobacillus, and the obligate anaerobic bacteria include bacteria of the genus Pectinatus and Megasphaera.

5. The method for enhancing the bacteriostasis of a beer-like beverage according to claim 2, wherein the bacteria comprises at least one selected from the group consisting of Levilactobacillus brevis, Pectinatus haikarae, Furfurilactobacillus curtus, Pectinatus sottacetonis, Pectinatus cerevisiiphilus, Pectinatus frisingensis, Megasphaera sueciensis, Megasphaera paucivorans, and Megasphaera cerevisiae.

6. A method for enhancing the bacteriostasis of a beer-like beverage according to any one of claims 1 to 5, wherein the carbon dioxide pressure at 20°C is 0.23 to 0.27 MPa.

7. A method for enhancing the bacteriostatic activity of a beer-like beverage according to any one of claims 1 to 6, wherein the beer-like beverage has an alcohol concentration of 4 v / v % or less.

8. A method for enhancing the bacteriostasis of a beer-like beverage according to any one of claims 1 to 7, wherein the beer-like beverage has a pH of 4.1 to 5.

0.

9. A method for producing a beer-like beverage, comprising: adjusting the carbon dioxide pressure at 20°C to 0.23 MPa or more; adjusting the pH to 4.1 to 5.0; and adjusting the alcohol concentration to 4 v / v% or less.

10. A beer-like beverage having a carbon dioxide pressure at 20°C of 0.23 MPa or more, a pH of 4.1 to 5.0, and an alcohol concentration of 4 v / v% or less.

11. The beer-like beverage according to claim 10, comprising a fermented wort liquid.

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