WO2020008990A1 - Fermented beer-like effervescent beverage, method for producing same, and method for reducing off-flavor of fermented beer-like effervescent beverage - Google Patents

Abstract

This method for reducing off-flavor of a fermented beer-like effervescent beverage is a method for reducing the content of off-flavor substances (excluding 3-methyl-2-butene-1-thiol) in the fermented beer-like effervescent beverage, by using one or more reduction-type iso-α-acids selected from the group consisting of rho iso-α-acids, tetrahydroiso-α-acids, and hexahydroiso-α-acids. In the fermented beer-like effervescent beverage, the content of one or more reduction-type iso-α-acids selected from the group consisting of rho iso-α-acids, tetrahydroiso-α-acids, and hexahydroiso-α-acids is 1 mg/L or more with respect to the total volume of the fermented beer-like effervescent beverage, and the content of 2-mercapto-3-methyl-1-butanol is 0.5 μg/L or less with respect to the total volume of the fermented beer-like effervescent beverage.

Description

Fermented beer-like sparkling beverage, method for producing the same, and method for reducing off-flavor of fermented beer-like sparkling beverage

The present invention relates to a method for reducing the generation of an onion-like odor, which is one type of off-flavor, in a fermented beer-like effervescent beverage, a method for producing a fermented beer-like effervescent beverage using the method, and a fermentation obtained by the method. It relates to a beer-like sparkling beverage.
Priority is claimed on Japanese Patent Application No. 2018-128369 filed on July 5, 2018, the content of which is incorporated herein by reference.

In fermented beer-like effervescent beverages such as beer and low-malt beer, off-flavors such as kogane odor, sunlight odor and onion-like odor may be observed. Control of these off-flavors is important. If the causative substances and their formation mechanism can be elucidated, it can be expected that off-flavors can be controlled efficiently. For example, it is known that the cause of onion-like odor in beer is 2-mercapto-3-methyl-1-butanol (2M3MB) (for example, non-mercapto-3-methyl-1-butanol, 2M3MB). Patent Document 1). The present inventors have purified a precursor of 2M3MB from hops and identified it as 2,3-epoxy-3-methyl-butanal (EMBal). . Also, it has been revealed that, during aeration of wort under high temperature conditions, the amount of EMBal in the wort increases with the oxidation of iso-α-acid, and that EMBal reacts with hydrogen sulfide during the formation of 2M3MB. (For example, see Patent Document 1). However, the conversion of EMBal to 2M3MB during fermentation is only about 10% of the expected maximum, and the behavior of the remaining EMBal has not yet been elucidated.

On the other hand, the reduced iso-α-acid obtained by hydrogenating (reducing) the iso-α-acid is less susceptible to decomposition by light, so that the fermented beer-like effervescent beverage filled in a transparent bottle can generate sunlight odor. Used to prevent. 3-Methyl-2-butene-1-thiol (MBT) generated by the photolysis of iso-α-acid is known as a causative substance of this sunlight odor. It is also known that the addition of the reduced iso-α-acid and the foamable protein improves the foam retention of the fermented malt beverage (for example, see Patent Document 2).

International Publication No. WO2018 / 008175 Japanese Patent Publication No. Hei 8-502641 Japanese Patent Publication No. 2004-500349

Olsen et al., Carlsberg Research Communication, 1988, vol.53, p.1-9. Iijima et al., Journal of Applied Microbiology, 2010, vol.109, p.1906-1913.

The present invention provides a method for reducing the generation of onion-like odor in a fermented beer-like effervescent beverage, a method for producing a fermented beer-like effervescent beverage using the method, and a fermented beer-like effervescent beverage obtained by the method. I do.

The present inventors have conducted intensive studies to achieve the above object, and as a result, in a fermented beer-like effervescent beverage containing iso-α acid, replacing some or all of the iso-α acid with reduced iso-α acid. Thus, the present inventors have found that the production of 2M3MB during fermentation is suppressed, and the content of 2M3MB in the manufactured fermented beer-like effervescent beverage can be reduced, thereby completing the present invention.

That is, the method for reducing the off-flavor of the fermented beer-like effervescent beverage, the method for producing the fermented beer-like effervescent beverage, and the fermented beer-like effervescent beverage according to the present invention include the following aspects (1) to (10). .
(1) A method for reducing the off-flavor of a fermented beer-like effervescent beverage, comprising reducing at least one type of reduced iso-α-acid selected from the group consisting of low iso-α-acid, tetrahydroiso-α-acid and hexahydroiso-α-acid. Method for reducing the off-flavor of a fermented beer-like effervescent beverage by reducing the content of an off-flavor substance of the above-mentioned fermented beer-like effervescent beverage except for 3-methyl-2-butene-1-thiol .
(2) The method for reducing the off-flavor of a fermentable beer-like sparkling beverage according to (1), wherein the off-flavor substance is 2-mercapto-3-methyl-1-butanol.
(3) reducing the content of 2-mercapto-3-methyl-1-butanol in the fermented beer-like effervescent beverage to 0.5 μg / L or less based on the total volume of the fermented beer-like effervescent beverage; 2. The method for reducing off-flavor of a fermented beer-like sparkling beverage according to 2).
(4) The method according to any one of (1) to (3), wherein the fermented beer-like effervescent beverage is substantially free of iso-α-acid.
(5) Any of (1) to (4), wherein the content of the reduced iso-α-acid in the fermented beer-like effervescent beverage is 1 mg / L or more based on the total volume of the fermented beer-like effervescent beverage. The method for reducing off-flavor of a fermented beer-like sparkling beverage according to any one of the first to third aspects.
(6) The method according to any one of (1) to (5), wherein the bitter taste of the fermented beer-like effervescent beverage is 5 BU or more.
(7) The method for reducing the off-flavor of a fermentable beer-like sparkling beverage according to any one of (1) to (6), wherein the reduced iso-α-acid is a tetrahydroiso-α-acid.
(8) An off-flavor substance of a fermentable beer-like effervescent beverage by using one or more reduced iso-α acids selected from the group consisting of low-iso-α-acid, tetrahydroiso-α-acid, and hexahydroiso-α-acid, A method for producing a fermentable beer-like effervescent beverage, wherein the content of the beverage is reduced except 3-methyl-2-butene-1-thiol.
(9) The content of at least one reduced iso-α-acid selected from the group consisting of low iso-α-acid, tetrahydroiso-α-acid and hexahydroiso-α-acid is 1 mg based on the total volume of the fermentable beer-like effervescent beverage. / L or more, and the content of 2-mercapto-3-methyl-1-butanol is 0.5 μg / L or less with respect to the total volume of the fermentable beer-like effervescent beverage, and is not more than 0.5 μg / L.
(10) The fermentable beer-like effervescent beverage according to (9), which substantially does not contain an iso-α-acid.

According to the method for reducing the off-flavor of the fermented beer-like effervescent beverage and the method for producing the fermented beer-like effervescent beverage of the above embodiment, a fermentable beer-like effervescent beverage with reduced generation of onion-like odor is obtained. According to the fermented beer-like effervescent beverage of the above embodiment, it is possible to provide a fermented beer-like effervescent beverage in which the generation of onion-like odor is reduced.

In the present invention and the present specification, "fermented beer-like effervescent beverage" is a beverage produced through a fermentation step, regardless of the use of alcohol content or malt, or equivalent to beer. A sparkling beverage having similar flavor, taste and texture, high thirst, and drinkability. That is, the fermented beer-like effervescent beverage may be an alcoholic beverage, or a so-called non-alcoholic beverage or a low alcoholic beverage having an alcohol content of less than 1% by volume. Further, the beverage may be a malt-based beverage, or may be a malt-free beverage. Specific examples of the fermented beer-like sparkling beverage include beer, malt sparkling using malt as a raw material, sparkling alcoholic beverage not using malt, low alcohol sparkling beverage, non-alcoholic beer, and the like. In addition, liqueurs obtained by mixing a beverage produced from malt through a fermentation step with an alcohol-containing distillate may be used. The alcohol-containing distillate is a solution containing an alcohol obtained by a distillation operation, and may be, for example, a raw material alcohol, such as spirits, whiskey, brandy, vodka, rum, tequila, gin, and shochu. Sake or the like can be used.

The method for reducing the off-flavor of the fermented beer-like sparkling beverage of the present embodiment (hereinafter, may be referred to as “the reduction method of the present embodiment”) includes low iso-α-acid, tetrahydroiso-α-acid, and hexahydroiso-α-acid. By using one or more reduced iso-α-acids selected from the group, the content of the off-flavor substance in the fermented beer-like effervescent beverage is reduced. The off-flavor substances to be reduced may be substances whose generation is suppressed in the presence of reduced iso-α, which is generated when iso-α-acid is used, but is generated when reduced iso-α-acid is used Substances that do not need to be used. Examples of such off-flavor substances include 3-methyl-2-butene-1-thiol (MBT) and 2-mercapto-3-methyl-1-butanol (2M3MB).
MBT is excluded as an off-flavor substance to be reduced in the reduction method of the present embodiment. Also, 2M3MB is particularly preferred.

# 2M3MB is a causative substance of the onion-like odor of fermented beer-like sparkling beverages such as beer, and the onion-like odor increases depending on the content of 2M3MB. 2,3-Epoxy-3-methylbutanal (EMBal), a precursor of 2M3MB, is mainly produced by aeration treatment before fermentation, and 2M3MB is mainly produced during fermentation. For this reason, by suppressing the amount of EMBal produced before fermentation, it is possible to produce a fermentable beer-like effervescent beverage having a low 2M3MB content and a suppressed onion-like odor.

The reaction in which EMBal is generated from iso-α acid and oxygen is a minor reaction with a yield of about 0.1% by mass, and a side chain bonded to 2-cyclopenten-1-one constituting iso-α acid. Among them, the reaction mechanism of which side chain is targeted to generate EMBal has not been elucidated so far. The present inventors have clarified for the first time that 2M3MB is produced by the following reaction mechanism.

Ｒ In the above reaction formula, R is an alkyl group having 2 to 5 carbon atoms. Specific examples of R include, for example, an ethyl group, an isopropyl group, an isobutyl group, a sec-butyl group and an isopentyl group. Examples of the isoα acid having R include isocohumulone, isohumulone, isoadhumulone, isoposthumulone, isoprehumulone, and the like. These iso-α-acids may be in cis form or trans form, or may be a mixture of these isomers.

(4) By the above reaction mechanism, the 4-methyl-3-pentenoyl group in the structure of the iso-α acid reacts with oxygen, whereby the iso-α acid is decomposed to generate EMBal. By using a reduced iso-α-acid in which a 4-methyl-3-pentenoyl group is reduced instead of the iso-α-acid as a bittering agent, generation of EMBal is suppressed.

Reduced iso-α-acid has bitterness like that of beer, like iso-α-acid. For this reason, a fermented beer-like effervescent beverage using a reduced iso-α-acid as a bittering agent has beer-like bitterness, does not produce 2M3MB, and has a reduced off-flavor. Further, by replacing part or all of the iso-α-acid as a bittering agent with reduced iso-α-acid, the content of 2M3MB of the fermented beer-like effervescent beverage is reduced. By reducing the content of the iso-α-acid, the production of EMBal is suppressed, and finally the content of 2M3MB of the fermentable beer-like effervescent beverage can be reduced. If the amount of the iso-α acid is too small, the beer-like bitterness becomes poor, but instead of iso-α-acid, EMBal is not generated, but by using a reduced iso-α-acid having beer-like bitterness, the beer-like bitterness is impaired. Without this, the content of 2M3MB can be reduced.

The reduced iso-α-acid in which EMBal is not generated includes low iso-α-acid (also referred to as dihydroiso-α-acid) (compound represented by the following general formula (I)) and tetrahydroiso-α-acid (represented by the following general formula (II)) Compound) and hexahydroiso-α-acid (a compound represented by the following general formula (III)). In each of the reduced iso-α-acids, the 4-methyl-3-pentenoyl group of the iso-α-acid is reduced, and the 1-hydroxy-4-methyl-3-pentenyl group and the 4-methyl-1 —Oxopentyl group and 4-methyl-1-hydroxypentyl group. These reduced iso-α-acids can be produced, for example, from the iso-α-acid using the method described in Patent Document 3. Specifically, for example, low acid α-acid can be produced by isomerizing and reducing α-acid under heating and in the presence of a strong alkali aqueous solution such as sodium borohydride. Further, for example, a tetrahydroiso-α-acid can be produced by bringing an iso-α-acid into contact with hydrogen gas in the presence of a noble metal catalyst such as palladium or platinum in the absence of a liquid organic solvent. Further, for example, hexahydroiso-α-acid can be produced by bringing low-iso-α-acid into contact with hydrogen gas in the presence of a noble metal catalyst such as palladium or platinum in the absence of a liquid organic solvent.

In the above general formulas (I), (II) and (III), R ¹¹ , R ²¹ and R ³¹ are the same as the above R.

In the reduction method of the present embodiment, only one type of reduced iso-α-acid may be used, or two or more types thereof may be used in combination.

テ ト ラ As the reduced iso-α-acid added to the fermentation raw material liquid or the like in the reduction method of the present embodiment, tetrahydroiso-α-acid is preferable because EMBal is less likely to be generated.

The fermented beer-like effervescent beverage obtained by the reduction method of the present embodiment may contain, as a bittering agent, iso-α-acid and reduced iso-α-acid, substantially does not contain iso-α-acid, and contains reduced iso-α-acid. May be included. Above all, it is preferable that substantially no iso-α-acid is contained and only reduced iso-α-acid is contained. Thereby, a fermentable beer-like effervescent beverage in which EMBal is less likely to be generated and the content of 2M3MB is further reduced is obtained. In addition, "substantially does not contain iso alpha acid" means that it does not contain iso alpha acid at all (iso alpha acid content is less than the detection limit value) or does not prevent the effect of the present embodiment, The amount of 2M3MB produced using iso-α-acid as a starting material is less than a threshold (preferably, 0.5 μg / L or less based on the total volume of the fermentable beer-like sparkling beverage); Means not included.

When iso-alpha acid and reduced iso-alpha acid are used together as a bittering agent, the ratio of the content (mass) of reduced iso-alpha acid to the total content (mass) of iso-alpha acid and reduced iso-alpha acid ( Hereinafter, the “reduced iso-α-acid ratio (%)” may be larger.) The 2M3MB content of the fermented beer-like sparkling beverage obtained after fermentation is further reduced. Even when the addition ratio of reduced iso-α-acid to iso-α-acid is small, a fermented beer-like effervescent beverage having a lower content of 2M3MB than in the case of using only iso-α-acid as a bittering agent can be obtained. The reduced iso-α-acid ratio of the fermented beer-like sparkling beverage finally obtained by using the reduction method of the present embodiment is preferably 30% by mass or more, more preferably 50% by mass or more, and preferably 70% by mass or more. It is still more preferably 80% by mass or more, further preferably 100% by mass.

The content of the reduced iso-α-acid in the fermented beer-like effervescent beverage finally obtained by using the reduction method of the present embodiment is within a range in which a moderate bitterness can be imparted to the fermented beer-like effervescent beverage. Well, it is not particularly limited. For example, the total content of the iso-α-acid and the reduced iso-α-acid of the fermented beer-like effervescent beverage produced by the reduction method of the present embodiment is such that the fermented beer-like effervescent beverage has a desired bitterness value. After being adjusted, the iso-α-acid content is further reduced to such an extent that the 2M3MB content can be reduced to about 0.5 μg / L or less based on the total volume of the fermented beer-like sparkling beverage. The content of the reduced iso-α-acid can be determined. Since the 2M3MB content can be sufficiently reduced while having a beer-like bitterness, the content of the reduced iso-α-acid in the fermented beer-like sparkling beverage finally obtained by using the reduction method of the present embodiment is as follows. For example, it can be 1 mg / L or more, and can be 1 mg / L or more and 100 mg / L or less, and can be 1 mg / L or more and 50 mg / L or less based on the total volume of the fermented beer-like sparkling beverage. And can be 30 mg / L or more and 50 mg / L or less.

As the content of the iso-α-acid in the fermented beer-like effervescent beverage finally obtained by using the reduction method of the present embodiment, the 2M3MB content of the finally obtained fermented beer-like effervescent beverage is defined as the fermented beer-like effervescent beverage. The amount is preferably reduced to about 0.5 μg / L or less based on the total volume of the sparkling beverage, more preferably to 0.4 μg / L or less, and more preferably 0.1 μg / L. More preferably, the amount can be reduced to about L or less, particularly preferably to about 0.02 μg / L or less, and more preferably to about 0 μg / L (less than the detection limit). Most preferably. The 2M3MB concentration of the fermented beer-like sparkling beverage can be measured according to the method of Iijima et al. (Non-Patent Document 2). Specifically, first, p-hydroxymercurybenzoic acid (p-HMB), tert-butyl-4-methoxyphenol (BHA) dissolved in a buffer, and 4-methoxy-2-methyl- A 2-mercapto-butane (4M2M2MB) solution (internal standard) is added, sealed, and vigorously stirred with a stirrer at room temperature to bind the sulfur-containing compound in the sample to p-HMB. After adsorbing the bound reactant to the strong anion exchange resin, the resin is washed with a buffer solution containing BHA (for example, pH of about 6 or more and about 7 or less). Next, the sulfur-containing compound is eluted from the resin with a buffer solution containing L-cysteine hydrochloride (for example, at a pH of about 6 to 7). The obtained eluate is subjected to solvent extraction several times using an organic solvent such as an ethyl acetate and dichloromethane solution. If necessary, the obtained organic solvent layer is dehydrated using a dehydrating agent such as anhydrous sodium sulfate. After concentrating the organic solvent layer after dehydration at room temperature under a nitrogen stream, the sulfur-containing compound contained in the organic solvent layer is measured by gas chromatography / mass spectrometry (GC / MS) to perform fermentation. The 2M3MB concentration of the beer-like sparkling beverage can be determined.

苦 The bitterness value of the fermented beer-like sparkling beverage finally obtained by using the reduction method of the present embodiment can be appropriately adjusted according to the type and taste quality of the fermented beer-like sparkling beverage. The bitterness is preferably 5 BU or more, more preferably 5 BU or more and 150 BU or less, still more preferably 5 BU or more and 100 BU or less, even more preferably 10 BU or more and 50 BU or less, and 12 BU or more and 30 BU or less. It is particularly preferred that there is.

As used herein, the term “bitterness” is an index of bitterness provided by a group of hop-derived substances containing isohumulone as a main component, and the bitterness of beverages such as beer-like effervescent beverages is determined, for example, by the EBC method ( Beer Brewing Association: "Beer Analysis Method", 8.15 (1990). Specifically, the acid was added to the sample, extracted with isooctane, and the absorbance at 275 nm of the isooctane layer obtained after centrifugation, which was measured using pure isooctane as a control, was multiplied by a constant (50) (BU). ).

行 う By performing the reduction method of the present embodiment in the process of manufacturing a fermented beer-like effervescent beverage, a fermented beer-like effervescent beverage having a low 2M3MB content and a suppressed onion-like odor can be manufactured. The method for producing a fermented beer-like sparkling beverage to which the reduction method of the present embodiment is applied is not particularly limited. Hereinafter, a method in which the reduction method of the present embodiment is applied to a general method for producing a fermented beer-like sparkling beverage will be described. A typical fermented beer-like effervescent beverage can be produced by the steps of preparation (preparation of fermentation raw material liquid), fermentation, storage, and filtration.

First, as a charging step (fermentation raw material liquid preparation step), a fermentation raw material liquid is prepared from at least one selected from the group consisting of cereal raw materials and saccharide raw materials. Specifically, first, a mixture containing at least one of the cereal raw material and the saccharide raw material and the raw water is prepared and heated to saccharify the starch such as the cereal raw material. As a raw material of the sugar liquid, only a cereal raw material may be used, only a saccharide raw material may be used, or both may be mixed and used.

Examples of the cereal raw material include barley and wheat, barley such as malt, rice, corn, beans such as soybean, potatoes, and the like. The cereal raw material can be used as a cereal syrup, a cereal extract, or the like, but is preferably used as a crushed cereal obtained by crushing.
The crushing of the cereals can be performed by a conventional method. The crushed cereal product may be one that has been subjected to a process usually performed before and after the crushing process, such as a crushed malt product, corn starch, and corn grits. In the present invention, the crushed grain used is preferably a crushed malt. By using the malt crushed product, it is possible to produce a fermentable beer-like effervescent beverage with more distinctive beer characteristics. The pulverized malt may be one obtained by germinating barley, for example, double-row barley by a conventional method, drying this, and then pulverizing the barley to a predetermined particle size.
In addition, the cereal raw material used in the present invention may be one kind of cereal raw material or a mixture of plural kinds of cereal raw materials. For example, crushed malt may be used as a main material, and crushed rice or corn may be used as a sub-material. Examples of the saccharide raw material include saccharides such as liquid sugar.

か か わ ら ず Regardless of the type and composition of the fermentation raw material, the 2M3MB content of the obtained fermented beer-like sparkling beverage can be reduced by reducing the content of the iso-α-acid in the fermentation raw material liquid. For this reason, the reduction method of this embodiment may be applied to a method for producing a fermentable beer-like sparkling beverage having a malt use ratio (ratio of malt used in the entire fermentation raw material) of 100% by mass. The ratio may be applied to a method for producing a fermented beer-like sparkling beverage having a ratio of more than 0% by mass and less than 100% by mass, or may be applied to a method for producing a fermented beer-like sparkling beverage that does not use malt as a fermentation raw material.

副 Other auxiliary raw materials may be added to the mixture containing the fermentation raw materials and the raw water. As the auxiliary material, for example, hops or processed hops (hereinafter sometimes collectively referred to as “hops and the like”), dietary fiber, yeast extract, fruit juice, bitter components other than hops, coloring agents, herbs and flavors And the like. If necessary, saccharifying enzymes such as α-amylase, glucoamylase and pullulanase, and enzyme agents such as proteases can be added.

The saccharification treatment is performed using enzymes derived from cereal raw materials or the like, or enzymes added separately. The temperature and time during the saccharification treatment depend on the type of the cereal raw material used, the ratio of the cereal raw material in the total fermentation raw material, the type of the added enzyme and the amount of the mixture, the quality of the intended fermented beer-like effervescent beverage, and the like. It is adjusted appropriately in consideration of the above. For example, the saccharification treatment can be carried out by a conventional method such as holding a mixture containing cereal raw materials and the like at 35 to 70 ° C for 20 to 90 minutes.

煮 By boiling the sugar solution obtained after the saccharification treatment, a broth (a boiled sugar solution) can be prepared. The sugar solution is preferably filtered before the boiling treatment, and the obtained filtrate is preferably subjected to the boiling treatment. Instead of the sugar solution filtrate, malt extract to which warm water is added may be used and boiled. The boiling method and its conditions can be determined appropriately.

前 A fermentable beer-like effervescent beverage having a desired flavor can be produced by appropriately adding a herb or the like before or during the boiling treatment. Particularly, hops and the like are preferably added before or during the boiling treatment. By performing boiling treatment in the presence of hops and the like, the flavor and flavor components of hops and the like can be efficiently boiled. The mode of addition of hops and the like (for example, addition in several portions) and boiling conditions can be determined as appropriate.

ホ ッ プ The hop added before or during the boiling treatment contains an α-acid which is a precursor of iso-α-acid. Hops used as a raw material may be raw hops, dry hops, or hop pellets. The processed hops used as raw materials include a hop extract obtained by extracting a bitter component from hops, and a hop processed product containing a component obtained by isolating a bitter component (eg, α-acid) in hops (eg, iso-α-acid). (Hereinafter sometimes referred to as “isolated hop extract”), processed hops containing a component obtained by reducing an isomerized bitter component (eg, reduced iso-α-acid, etc.) (hereinafter referred to as “reduced isomerized hop extract”). Hop extract "). In the reduction method of the present embodiment, a reduced isomerized hop extract is used.

The total content of the iso-α-acid and reduced iso-α-acid in the fermented raw material liquid after the boiling treatment is an amount such that the bitterness of the finally obtained fermented beer-like sparkling beverage is in a desired range (5 BU or more). Preferably, there is. The content of the iso-α-acid in the fermented raw material liquid after the boiling treatment is determined so that the 2M3MB content of the finally obtained fermented beer-like effervescent beverage is in a desired range (for example, based on the total volume of the fermented beer-like effervescent beverage). Is preferably about 0.5 μg / L or less). The deficiency of the bitter component due to the reduction of the iso-α-acid content is compensated for by adding the reduced iso-α-acid.

後 After the charging step and before the fermentation step, it is preferable to remove lees such as proteins generated by precipitation from the prepared broth. The removal of the debris may be performed by any solid-liquid separation treatment, but generally the precipitate is removed using a tank called a whirlpool. The temperature of the broth at this time may be 15 ° C. or more, and is generally at about 50 to 95 ° C. The boiled juice (filtrate) after removing the cake is cooled to an appropriate fermentation temperature by a plate cooler or the like. The boiled juice after removing the residue becomes a fermentation raw material liquid.

The fermentation raw material liquid may be subjected to an aeration treatment in order to supply oxygen to the yeast. The injection amount of the air can be appropriately determined so that the dissolved oxygen in the fermentation raw material liquid is an amount necessary for activating the yeast. In the reduction method of the present embodiment, since the content of iso-α-acid in the fermentation raw material liquid is reduced, EMBal, which is a precursor of 2M3MB, is less likely to be generated even if the dissolved oxygen in the fermentation raw material liquid is large.

還 元 Also, the reduced iso-α-acid can be added at any time up to the end of fermentation, that is, at any time from the start of charging to the end of fermentation. For example, it may be added together with the hops before or during the boiling treatment of the fermentation raw material liquid, may be added to the fermentation raw material liquid after the boiling treatment and before fermentation, or may be added immediately before the end of fermentation.

Next, as a fermentation step, yeast is inoculated into the cooled fermentation raw material liquid to perform fermentation. The cooled fermentation raw material liquid may be subjected to the fermentation step as it is, or may be supplied to the fermentation step after adjusting to a desired extract concentration. The yeast used for fermentation is not particularly limited, and can be appropriately selected from yeasts usually used for producing alcoholic beverages. The fermentation yeast may be a top fermentation yeast or a bottom fermentation yeast, but is preferably a bottom fermentation yeast because it is easily applied to a large-scale brewing facility. The fermentation temperature is not particularly limited. For example, the fermentation can be performed at 0 to 15 ° C, and preferably at 4 to 12 ° C.

後 After the fermentation step, as a liquor storage step, the fermented liquid obtained is aged in a liquor storage tank and stored and stabilized at a low temperature condition of about 0 ° C. Thereafter, as a filtration step, the fermented liquid after aging is filtered to remove yeasts, proteins insoluble in the temperature range, and the like, thereby obtaining the desired fermented beer-like effervescent beverage. The filtration treatment may be any method capable of removing yeast by filtration, and examples thereof include diatomaceous earth filtration and filter filtration with a filter having an average pore size of about 0.4 to 0.6 μm.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to the following examples.

<Measurement of 2M3MB concentration of fermented beer-like sparkling beverage>
In the following Examples and the like, the 2M3MB concentration of the fermented beer-like sparkling beverage was measured according to the method of Iijima et al. (Non-Patent Document 2).

Specifically, first, 25 mL of 2 mM @ p-hydroxymercurybenzoic acid (p-HMB) and 20 mM dissolved in 500 μL of Tris buffer (0.1 M @Tris) were added to a fermentation solution from which yeast was removed after 500 mL of fermentation. Tert-butyl-4-methoxyphenol (BHA) and 100 μL of a 500 mg / mL solution of 4-methoxy-2-methyl-2-mercapto-butane (4M2M2MB) were added, sealed, and stirred at room temperature. Vigorously to bind the sulfur-containing compound in the fermentation liquor to p-HMB. 4M2M2MB was added as an internal standard. After the bound reaction product was adsorbed on Dowex-1 (strong anion exchange resin), the resin was washed using 100 mL of 0.1 M acetate buffer (pH 6) containing 0.2 mM BHA.

{Then, the sulfur-containing compound was eluted from the resin with 100 mL of 0.1 M sodium acetate buffer (pH 6) containing 10 mg / mL L-cysteine hydrochloride. The obtained eluate was subjected to solvent extraction twice using 0.5 mL of ethyl acetate and 5 mL of a dichloromethane solution, and the obtained organic solvent layer was dehydrated with anhydrous sodium sulfate. After concentrating the organic solvent layer after dehydration to 100 μL at room temperature under a nitrogen stream, the sulfur-containing compound contained in the organic solvent layer was quantified by gas chromatography / mass spectrometry (GC / MS).

(GC / MS conditions)
Gas chromatograph: "Agilent 6890 gas chromatograph" (manufactured by Agilent Technologies)
Detector: "MSD5975" (manufactured by Agilent Technologies)
Column: “DB-WAX capillary column” (length: 60 m, inner diameter: 0.25 mm, film thickness: 0.25 μm, manufactured by Agilent Technologies)
Inlet temperature: 250 ° C
Injection mode: pulsed splitless injection mode
Injection volume: 1 μL
Carrier gas: Helium (1 mL / min)
Column temperature setting: 40 ° C (hold for 5 minutes)-(5 ° C / min)-160 ° C (5 minutes)
Ionization conditions: 70 eV
Measurement mode: single ion-monitoring (SIM) mode
Quantification: Performed by comparing the peak area of 2M3MB with the peak area of the internal standard.

<Method for measuring 2,3-epoxy-3-methylbutanal (EMBal) (2M3MB precursor) concentration in fermentation raw material liquid>
In the following examples, the concentration of 2,3-epoxy-3-methylbutanal (EMBal) in the fermentation raw material liquid was measured as follows.
First, 20 g of a fermentation raw material liquid before fermentation in which a stable isotope of EMBal (D6-2,3-epoxy-3-methylbutanal) was added as an internal standard substance so as to be 100 μg / L with respect to the total volume of the fermentation raw material liquid. Was loaded onto a solid phase extraction column (anion exchange column “InertSep MA-1” (manufactured by GL Sciences Inc.)) conditioned with methanol and water. The liquid passed through the solid phase extraction column was collected, extracted with 3 mL of dichloromethane, and the solvent layer was recovered. This solvent extraction operation was repeated three times, and 5 g of anhydrous sodium sulfate was added to a mixture of all the collected solvent layers, followed by dehydration for 30 minutes or more. Thereafter, the mixture was concentrated to about 500 μL with a nitrogen purge. Next, the quantification was performed by GC / MS under the same conditions as in the above 2M3MB except that the quantification was performed by comparing the peak area area of the EMBal with the peak area area of the internal standard product.

<Sensory evaluation of onion-like odor intensity>
In the following Examples and the like, the strength of the onion-like odor of the fermentable beer-like sparkling beverage was evaluated with a blind according to the evaluation criteria shown in Table 1. The sensory evaluation was performed for each sample at n = 3, and the average of the scores was defined as the onion-like odor intensity value of the sample.

[Example 1]
In the production of fermented beer-like sparkling beverages, 2M3MB precursor, EMBal, is produced from iso-alpha acids. Therefore, the concentration of EMBal in the fermentation raw material liquid before fermentation and the concentration of 2M3MB in the fermentation liquid after fermentation when the total amount of iso-α acid was replaced with various reduced iso-α acids were examined.

(4) The fermentation raw material liquid was produced as follows. First, 500 g of barley malt was ground and mixed with 2 L of hot water at 50 ° C. Next, the mixture was incubated at 50 ° C. for 30 minutes to decompose proteins, and then the obtained mash was incubated at 65 ° C. for 30 minutes to saccharify. After filtering the wort obtained by saccharification, the concentration of the filtered wort was adjusted to obtain wort (fermentation raw material liquid) having an extract concentration of 12%. Into this wort, isop hop extract or various reduced isop hop extracts (low hop extract (containing low isoalpha acid), tetrahop extract (containing tetrahydroisoalpha acid), or hexahop extract (containing hexahydroisoalpha acid) ) Was added to the wort in an amount of 30 mg / L with respect to the total volume of the wort as the iso-α-acid concentration of the wort, and the mixture was boiled to obtain a test fermentation raw material liquid. In addition, a part of each of the boiled worts was aerated (aeration treatment) at 1.5 L / min for 5 minutes to prepare an aeration-treated test fermentation raw material liquid. Before fermentation, the EMBal concentration in each test fermentation raw material liquid was measured. Table 2 shows the measurement results.

Next, yeast was added to each test fermentation raw material liquid at a concentration of 20 × 10 ⁶ cells / mL and fermented at 15 ° C. for 7 days. The fermented liquid after the fermentation was centrifuged (7000 rpm x 15 minutes) to remove yeast (fermented beer-like effervescent beverage) was measured for 2M3MB concentration. Further, the strength of the onion odor of the obtained fermented beer-like sparkling beverage was sensory evaluated. Table 2 shows the results.

From Table 2, compared with the test conditions using the isomerized hop extract, under the test conditions using the low hop extract, the tetrahop extract and the hexahop extract, both the EMBal concentration before the fermentation and the 2M3MB concentration after the fermentation were obtained. Had been reduced. This is because the reduced iso-α-acid is hardly oxidized due to its structure, and the generation of EMBal in the fermentation raw material liquid before fermentation was suppressed.
In addition, even when the aeration treatment was performed, under the test conditions using the low hop extract and the hexahop extract, the EMBal concentration before the fermentation increased respectively compared to the case without the aeration, but the 2M3MB concentration after the fermentation was increased. It is 0.02 μg / L or less based on the total volume of the fermented beer-like effervescent beverage, and is subjected to an aeration-untreated test condition using an isomerized hop extract (0.24 μg based on the total volume of the fermented beer-like effervescent beverage). / L). Further, under the test conditions using the tetrahop extract, the EMBal concentration before fermentation was slightly reduced as compared with the case without aeration treatment, and the 2M3MB concentration after fermentation was 0.1% with respect to the total volume of the fermented beer-like effervescent beverage. 01 μg / L, which was sufficiently reduced.

According to the method for reducing the off-flavor of the fermented beer-like effervescent beverage and the method for producing the fermented beer-like effervescent beverage of the present embodiment, the fermented beer-like effervescent having reduced onion-like odor, which is a kind of off-flavor, A beverage is obtained. According to the fermented beer-like effervescent beverage of the present embodiment, it is possible to provide a fermented beer-like effervescent beverage in which generation of an onion-like odor, which is a kind of off-flavor, is reduced.

Claims (10)

A method for reducing the off-flavor of a fermented beer-like sparkling beverage,
By using one or more reduced iso-α acids selected from the group consisting of low iso-α-acid, tetrahydroiso-α-acid and hexahydroiso-α-acid, the off-flavor substance of the fermented beer-like effervescent beverage, A method for reducing the off-flavor of a fermented beer-like sparkling beverage, wherein the content of the beverage is reduced except for methyl-2-butene-1-thiol. 方法 The method for reducing the off-flavor of a fermented beer-like sparkling beverage according to claim 1, wherein the off-flavor substance is 2-mercapto-3-methyl-1-butanol. The method according to claim 2, wherein the content of 2-mercapto-3-methyl-1-butanol in the fermented beer-like sparkling beverage is reduced to 0.5 μg / L or less based on the total volume of the fermented beer-like sparkling beverage. The method for reducing off-flavor of a fermented beer-like sparkling beverage according to the above. The method for reducing the off-flavor of a fermented beer-like effervescent beverage according to any one of claims 1 to 3, wherein the fermented beer-like effervescent beverage does not substantially contain an iso-α-acid. 5. The fermented beer-like sparkling beverage according to claim 1, wherein the content of the reduced iso-α-acid in the fermented beer-like sparkling beverage is 1 mg / L or more based on the total volume of the fermented beer-like sparkling beverage. A method for reducing off-flavor of fermented beer-like sparkling beverages. The method for reducing the off-flavor of a fermented beer-like effervescent beverage according to any one of claims 1 to 5, wherein the fermented beer-like effervescent beverage has a bitterness of 5 BU or more. The method for reducing the off-flavor of a fermentable beer-like sparkling beverage according to any one of claims 1 to 6, wherein the reduced iso-α-acid is tetrahydroiso-α-acid. By using one or more reduced iso-α-acids selected from the group consisting of low-iso-α-acid, tetrahydroiso-α-acid and hexahydroiso-α-acid, an off-flavor substance of a fermentable beer-like sparkling beverage, provided that 3-methyl A method for producing a fermentable beer-like effervescent beverage in which the content of 2-butene-1-thiol is reduced. The content of one or more reduced iso-α-acids selected from the group consisting of low iso-α-acid, tetrahydroiso-α-acid and hexahydroiso-α-acid is 1 mg / L or more based on the total volume of the fermented beer-like effervescent beverage. Wherein the content of 2-mercapto-3-methyl-1-butanol is 0.5 μg / L or less based on the total volume of the fermentable beer-like effervescent beverage. The fermented beer-like effervescent beverage according to claim 9, which does not substantially contain α-α-acid.