JP2023072598A - Sake with high content isoamyl acetate - Google Patents

Abstract

To provide Sake which has a brilliant sake-like Ginjo flavor but is reduced in the solvent texture.SOLUTION: The invention provides Sake with an isoamyl acetate concentration of 18 mg/L or more, an E/A ratio of 5 or more, and an ethyl acetate concentration of less than 150 mg/L. The isoamyl acetate concentration can be 100 mg/L or less, and the E/A ratio can be 30 or less. The sake can be made as sake defined by the Japanese Liquor Tax Law.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to sake containing a high concentration of isoamyl acetate and a method for producing the same.

Sake contains many different aroma compounds, most of which are produced by yeast during fermentation. The confirmed aroma components are mainly alcohols, esters, organic acids, carbonyl compounds, amines and sulfur compounds.
Of these, there are only a few dozen components that can be detected independently in the amount contained in sake, that is, components whose concentration in sake divided by the discrimination threshold (order unit) is 1 or more. Most of the other ingredients are present alone in imperceptible amounts. Aroma components with an order unit of 1 or more are isoamyl acetate, isobutyl acetate, ethyl acetate, ethyl lactate, ethyl caproate, ethyl 4-hydroxybutyrate, ethyl caprylate, ethyl pelargonate, ethyl phenylacetate, phenethyl acetate, and capric acid. Esters such as ethyl and alcohols such as isoamyl alcohol, β-phenethyl alcohol, phenylethanol, and ethyl laurate (Non-Patent Document 1). These esters and alcohols have fruity or floral scents.

In particular, esters are important components that determine the quality of sake. Among them, isoamyl acetate has a gorgeous banana-like aroma and is one of the main components of the ginjo aroma of sake. In order to improve the isoamyl acetate content in sake, many studies have been made on brewing conditions, yeast strain breeding, and so on.
Increasing the isoamyl acetate content in sake usually also increases the isoamyl alcohol content. Isoamyl alcohol is a useful aroma component per se, but if its content is too high, it gives off a solvent odor. Concentration]×100, hereinafter referred to as E/A ratio) is known to produce sake with a better flavor (Patent Document 1). In Patent Document 1, a yeast strain capable of producing sake with a high isoamyl acetate content and a high E/A ratio is created by subjecting brewer's yeast to mutation treatment and selecting a hygromycin B-resistant strain from among the treated bacteria. I teach you what you can get.
In Patent Document 1, by using the yeast mutant strain selected as described above, the isoamyl acetate concentration is higher (20 .4-29.5 mg/L), a low isoamyl alcohol concentration (203-236 mg/L), and therefore a high E/A ratio (8.65-14.50) was obtained. there is

However, simply having a high concentration of isoamyl acetate and a low concentration of isoamyl alcohol does not sufficiently suppress the solvent sensation, and does not result in a sake with a gorgeous aroma typical of sake.

Japanese Patent Application Laid-Open No. 2007-89455

Chemistry and Biology, Vol. 29, No. 9, 1991, pp. 586-592

The main object of the present invention is to provide a refined sake having a gorgeous refined sake-like ginjo aroma and a suppressed solvent feeling.

In order to solve the above problems, the inventor of the present invention has made extensive research and obtained the following findings.
As the concentration of isoamyl acetate in sake increases, the concentration of ethyl acetate also tends to increase, giving the sake a stronger sense of solvent. Sake with an isoamyl acetate concentration of 18 mg/L or more and an E/A ratio of 5 or more has an ethyl acetate concentration of less than 150 mg/L, which suppresses the solvent sensation. Sake with a high isoamyl acetate concentration and a low ethyl acetate concentration has not been known in the past. Succeeded for the first time in producing refined sake by brewing.

The present invention has been completed based on the above findings, and provides the following [1] to [8].
[1] Sake having an isoamyl acetate concentration of 18 mg/L or more, an E/A ratio of 5 or more, and an ethyl acetate concentration of less than 150 mg/L.
[2] The sake according to [1], wherein the sake is defined by the Liquor Tax Law of Japan.
[3] The sake according to [1] or [2], which has an isoamyl acetate concentration of 100 mg/L or less.
[4] The sake according to any one of [1] to [3], which has an E/A ratio of 30 or less.
[5] The sake according to any one of [1] to [4], which has an isoamyl alcohol concentration of 280 to 450 mg/L.
[6] A method for producing sake, comprising a step of making the sake have an isoamyl acetate concentration of 20 mg/L or more, an E/A ratio of 5 or more, and an ethyl acetate concentration of less than 150 mg/L.
[7] The method for producing sake according to [6], wherein the sake is brewed to have an isoamyl acetate concentration of 20 mg/L or more, an E/A ratio of 5 or more, and an ethyl acetate concentration of less than 150 mg/L.
[8] The method for producing sake according to [6] or [7], wherein rice with a rice polishing ratio of 60% or more is used as the rice.

In general, when the isoamyl acetate concentration is increased, the ethyl acetate concentration is also increased. Whether or not the solvent odor of ethyl acetate is perceived depends on the composition of the other flavor components. If it is less than /L, the solvent odor of ethyl acetate is not felt, and a pleasant ginjo aroma is felt.
In the present invention, sake with an isoamyl acetate concentration of 20 mg/L or more, an E/A ratio of 5 or more, and an ethyl acetate concentration of less than 150 mg/L could be produced by brewing for the first time. Consumers do not like sake with added flavorings, so it is of great significance that we were able to adjust the composition of these ingredients through brewing to produce sake with a well-balanced ginjo aroma.
In addition, in the sake of the present invention, when the isoamyl alcohol concentration is 280 to 450 mg / L, the gorgeous aroma of isoamyl acetate can be felt firmly, and the ginjo aroma typical of sake with swelling, mellow or mild. will have

The present invention will be described in detail below. Unless otherwise specified, the names of various chemical substances, laws and regulations, measurement and analysis methods, display standards, and website URLs refer to those as of the day before the filing date of this application.
(1) Refined sake with high isoamyl acetate content
Sake
The sake of the present invention has an isoamyl acetate concentration of 18 mg/L or more, an E/A ratio of 5 or more, and an ethyl acetate concentration of less than 150 mg/L.

The sake of the present invention may be made by fermenting rice, rice malt, and water as main raw materials with yeast, but among them, it is preferable to be a sake defined by the Liquor Tax Law (especially, the Liquor Tax Law of Japan). . According to the Liquor Tax Law and various laws and regulations related to the Liquor Tax Law (for example, the Enforcement Order of the Liquor Tax Law) and notifications, the raw materials that can be used for sake are rice, rice koji, water, sake lees, brewed alcohol, specific organic acids, etc. However, the addition of flavorings, which are generally recognized as food additives, is not permitted. In addition, the usage amount and usage of the enzymatic agent are also limited.

In addition, the sake of the present invention may be ordinary sake, or the sake of alcoholic beverages stipulated by the "Standards for Quality Labeling of Sake Manufacturing Method"("Law Concerning Liquor Tax Preservation and Liquor Industry Associations, etc.") stipulated by the National Tax Agency. labeling standards), such as ginjo sake, daiginjo sake, junmai sake, junmai ginjo sake, junmai daiginjo sake, special junmai sake, honjozo sake, and special honjozo sake, etc. good too. Sake that does not meet these specific names is referred to as "futsushu" in this specification.
In addition, the sake of the present invention can be packed in a container, and the container is filled with words such as "refined sake" or "refined sake", which is a geographical indication (standard) for alcoholic beverages designated by the Commissioner of the National Tax Agency. It is preferable that the wording to do is displayed.

Isoamyl Acetate Concentration The isoamyl acetate concentration of the sake of the present invention is 18 mg/L or more, L or more. Within this range, sake with a strong banana-like aroma of isoamyl acetate can be obtained.
Also, the isoamyl acetate concentration can be 100 mg/L or less, 80 mg/L or less, 60 mg/L or less, 50 mg/L or less, 45 mg/L or less, or 40 mg/L or less. Within this range, the aroma of isoamyl acetate does not stand out too much, and sake having a mellow aroma more typical of sake can be obtained.

Ethyl acetate concentration The ethyl acetate concentration of the sake of the present invention is less than 150 mg/L, and can be 130 mg/L or less, 110 mg/L or less, 100 mg/L or less, 90 mg/L or less, or 80 mg/L or less. can. Within this range, sake with a reduced sense of solvent can be obtained.
Also, the ethyl acetate concentration can be 10 mg/L or higher, 20 mg/L or higher, 30 mg/L or higher, 40 mg/L or higher, or 50 mg/L or higher. Ethyl acetate gives a good aroma when present in small amounts, so within this range, a ginjo aroma that is more like sake can be obtained.

E/A ratio In the sake of the present invention, the E/A ratio ([isoamyl acetate concentration/isoamyl alcohol concentration] × 100) is 5 or more, and 6 or more, 7 or more, 8 or more, 9 or more, or 10 It can be as above. Within this range, the sake of the present invention will be a sake that has a gorgeous and sake-like ginjo aroma while suppressing the solvent feeling.
Also, the E/A ratio can be 30 or less, 25 or less, 20 or less, 18 or less, 16 or less, 14 or less, 12 or less, or 10 or less. Within this range, the gorgeous aroma derived from isoamyl acetate can be suppressed from protruding, resulting in sake having a milder aroma that is more typical of sake.

Isoamyl alcohol concentration The isoamyl alcohol concentration of the sake of the present invention is 100 mg/L or more, 200 mg/L or more, 280 mg/L or more, 300 mg/L or more, 320 mg/L or more, 340 mg/L or more, or 360 mg/L or more. be able to. Isoamyl alcohol itself is a component with a good aroma, so when it is contained in this range, the aroma derived from isoamyl acetate does not stand out too much, resulting in sake with a milder aroma that is more typical of sake.
Also, the isoamyl alcohol concentration can be 450 mg/L or less, 440 mg/L or less, 430 mg/L or less, 420 mg/L or less, or 410 mg/L or less. Within this range, sake with a reduced sense of solvent can be obtained.

Ethyl Caproate Concentration Ethyl caproate, together with isoamyl acetate, is generally a major ginjo aroma component in sake, and gives sake an apple-like fruity aroma. The ethyl caproate concentration of the sake of the present invention is 10 mg/L or less, 5 mg/L or less, 3 mg/L or less, 2 mg/L or less, 1 mg/L or less, 0.5 mg/L or less, 0.3 mg/L or less, Or it can be 0.1 mg/L or less. Within this range, the sake will have a mellow aroma typical of sake without an overpowering fruity aroma. Also, the ethyl caproate concentration can be 0.01 mg/L or higher, 0.05 mg/L or higher, 0.1 mg/L or higher, or 0.5 mg/L or higher. Within this range, sake with a reduced sense of solvent can be obtained.

Alcohol content In the sake of the present invention, the alcohol content, that is, the alcohol content (v/v%) may be in the range of 1% or more and less than 22% as defined by the Liquor Tax Law, but is preferably 3v/v% or more, and 5v /v% or more is more preferable, and 7v/v% or more is even more preferable. Also, the alcohol content is preferably 20 v/v % or less, more preferably 18 v/v % or less, and even more preferably 16 v/v % or less. Within this range, the sake has a gorgeous and refined sake-like aroma, a suppressed solvent feeling, and a flavor that is preferred by consumers as a whole.
The alcohol content (alcohol content) is the percentage of the volume concentration of alcohol (ethanol) with respect to the total amount of the alcoholic beverage. The alcohol content is determined by the National Tax Agency's prescribed analysis method recognized by the Liquor Tax Act, or the "National Research Institute of Brewing Standard Analysis Method" established by the National Research Institute of Brewing (partially revised on April 6, 2017, https://www. .nrib.go.jp/bun/nribanalysis.html), but the alcohol content in the present invention is defined by the National Research Institute of Brewing, "3. It is a value analyzed based on the regulation (hereinafter referred to as "sake analysis method").

Japanese Sake Degree In the sake of the present invention, the Japanese sake degree is preferably -90 or more, more preferably -60 or more, and still more preferably -30 or more, although it is not limited thereto. In addition, the Japanese sake degree is preferably +30 or less, more preferably +20 or less, and even more preferably +10 or less. Within this range, the sake has a gorgeous and refined sake-like aroma, a suppressed solvent feeling, and a flavor that is preferred by consumers as a whole.
The sake content is a value measured by the sake analysis method described above.

Acidity In the sake of the present invention, the acidity is not limited thereto, but is preferably 0.1 or more, more preferably 0.2 or more, and still more preferably 0.4 or more. The acidity is preferably 10 or less, more preferably 6 or less, and even more preferably 3 or less. Within this range, the sake has a gorgeous and refined sake-like aroma, a suppressed solvent feeling, and a flavor that is preferred by consumers as a whole.
Acidity is a value that indicates the total amount of free acids (mainly lactic acid, malic acid, succinic acid, etc.) contained in sake. Specifically, acidity refers to mL of 0.1 N sodium hydroxide solution required to neutralize 10 mL of sake. The acidity is a value measured by the sake analysis method described above.

(2) Method for producing sake with a high isoamyl acetate content It is a process of separating the fraction and the sake lees and collecting the liquid fraction, and it is manufactured by the "straining" process referred to in the Liquor Tax Law). Furthermore, heat treatment, removal of debris, filtration, and the like may be performed. In addition to rice koji, rice (kakemai) and water, sake lees may be used as raw materials.

The sake of the present invention, which has an isoamyl acetate concentration of 18 mg/L or more, an E/A ratio of 5 or more, and an ethyl acetate concentration of less than 150 mg/L, is obtained by mutating a non-fatty acid-assimilating yeast as a yeast in the yeast starter. It can be produced by using the obtained specific mutant yeast strain. This yeast strain is obtained by mutagenizing the K901 strain yeast strain to obtain a mutant strain with high ethyl acetate production as an index, and then subjecting this mutant strain to EMS mutagenesis and selecting with trifluoroleucine (TFL) resistance as an index. It was obtained by Except for using this mutant yeast strain, the sake of the present invention can be produced in the same manner as a general sake production method.
Thus, the sake of the present invention can be produced without using genetically modified yeast strains. Foods manufactured using genetically modified materials are not favored by consumers in Japan and overseas due to the recent non-GMO trend, so the ability to manufacture using non-genetically modified yeast strains is a great advantage.

If this yeast strain is used, for example, highly polished rice such as daiginjo or ginjo rice polishing ratio (60% or less or 50% or less) stipulated in the “Refined sake manufacturing method quality labeling standard” may be used. is higher than this (low-polished rice). Among them, the rice used as a raw material preferably has a rice-polishing ratio of 50% or more (especially more than 50%), 60% or more (especially more than 60%), or 70% or more (more than 70%). Rice polishing may be performed only a little, and for example, it is preferable that the rice polishing ratio is 99.9% or less, 95% or less, 90% or less, 85% or less, or 80% or less. Even if these rices are used as raw material rice (including koji rice), especially as kaked rice, the present invention has an isoamyl acetate concentration of 18 mg/L or more, an E/A ratio of 5 or more, and an ethyl acetate concentration of less than 150 mg/L. of sake can be produced. Sake having these concentrations and an isoamyl alcohol concentration of 280 mg/L or more can also be produced.

In general, when raw rice with a low degree of polishing is used, the content of fatty acids in the mash increases, so the expression of the enzyme that produces isoamyl acetate from isoamyl alcohol and acetyl-CoA is suppressed, resulting in a low isoamyl acetate concentration. Moreover, even if the fatty acid content in the mash increases, the ethyl acetate concentration remains high and does not decrease. Therefore, if low-polished rice is used as the raw material, it is usually difficult to lower the isoamyl alcohol concentration and the ethyl acetate concentration, resulting in a sake with a stronger solvent flavor than the ginjo aroma.
In this respect, if the mutant yeast strain is used, it is possible to obtain sake having the component composition of the present invention even if low-polished rice is used. In this case, low-polished rice can be used for koji rice used for koji rice in addition to kakemai.

Steamed rice or liquefied melted rice may be used as kakemai for preparation. Preparation using fused rice is called liquefaction preparation. Melted rice is obtained by adding water and α-amylase, which is a thermostable enzyme, to rice or pulverized rice, and liquefying the mixture at 60-90°C. When not only liquefaction but also saccharification is performed, glucoamylase may be added and saccharification may be performed at about 50 to 55°C when cooling to about 60°C after completion of liquefaction.

There are no particular restrictions on the variety of rice, and it may be rice suitable for sake brewing (e.g., Yamada Nishiki, Gohyakumangoku, etc.), general food rice, non-glutinous rice, or glutinous rice, which is used for sake brewing. Any rice that can be used will do. In addition, although either domestic rice or foreign rice may be used, domestic rice is preferable in terms of geographical indications (standards).

Rice koji is produced by growing Aspergillus oryzae on steamed rice. The rice koji used in the production of sake was specified in the National Tax Agency Notification No. 8 on November 22, 1989, "Regarding the Standards for Labeling the Production Method and Quality of Sake" [1]. Sake with a specific name, the ratio of koji rice used (referring to the weight ratio of koji rice to the weight of white rice; the same shall apply hereinafter) is 15%. shall be limited to the above.”
The aspergillus oryzae to be used may be any as long as it can be used for the production of sake. For economic sake, good aroma, for liquefaction preparation, for Hikami Ginjo made by Higuchi Matsunosuke Shoten, High G, Diamond Mark, for base, for mash, for Hikami Moromi No. 20, for Hikami Moromi No. 30 No., Hikami Specialty Powdery A, Ace Higuchi, Higuchi powdery fungus, Shiramine, Kaori, strong saccharifying bacteria, and liquefaction preparation.

Preparation is carried out by putting the shubo, kakemai, rice koji and water prepared as described above into a fermentation tank. In the charging, all the ingredients may be added in one stage, or they may be added in multiple stages, or may be charged in four stages before the upper tank. A three-stage preparation is preferable so that the yeast concentration does not become diluted. Three-stage preparation is a method of adding rice koji and kakemai to shubo in three stages in moromi making, and it is a method that minimizes environmental changes to yeast and does not impair yeast activity. is.

Fermentation period of moromi may be 10 to 40 days, preferably 15 to 40 days, more preferably 20 to 30 days. In the case of three-stage charging, this period may be the period from distillation (after distillation) to the upper tank. Fermentation temperature of moromi may be 5 to 25°C, preferably 10 to 20°C.
After fermentation is completed, the sake lees are removed and the refined sake fraction (joso sake) is recovered. For example, the sake lees and the refined sake fraction may be separated by pressing, filtering, or the like. Joso-shu may be further subjected to filtration, removal of sediment, heat treatment, activated carbon treatment, etc., if necessary.

The refined sake of the present invention may be packed in a container. Container materials include glass, plastic, paper, pottery, wood, and combinations thereof. Types of containers include cups, paper packs, pouches, bottles, plastic tanks, and barrels.

The present invention provides a method for producing sake, comprising the steps of making the sake have an isoamyl acetate concentration of 18 mg/L or more, an E/A ratio of 5 or more, and an ethyl acetate concentration of less than 150 mg/L.
The produced refined sake has a gorgeous scent typical of refined sake, and has a reduced sense of solvent. This sake can be the sake specified by the Liquor Tax Law of Japan. That is, it can be produced by brewing without adding flavorings, adjusting the above composition so that it becomes "refined sake" as stipulated by the Liquor Tax Law of Japan. Others are as described for the sake of the present invention.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these.

(1) Quantification method
Isoamyl acetate, isoamyl alcohol, and ethyl acetate The concentrations of isoamyl acetate, isoamyl alcohol, and ethyl acetate in sake were measured by GC-MS.

General Analysis Method for Sake We analyzed the quality of each sake, which will be described later. Specifically, the alcohol content is "3-4 alcohol content A)-2 vibrating density meter method", the Japanese sake degree is "3-3 specific gravity (Japanese sake degree) B) vibrating density meter method", and the acidity is , "3-5 Total Acids".

(2) Sensory test of sake Standard products of isoamyl acetate, isoamyl alcohol, and ethyl acetate were added to sake to obtain the compositions shown in Tables 1 and 2, and an experienced expert panel conducted sensory evaluation of the aroma. Sake is commercially available sake A (geographically labeled sake, ordinary sake, alcohol content 14%, sake content 1.0, acidity 1.2) and commercially available sake B (geographically labeled sake, junmai sake) mixed with water. (alcohol content: 8.5 degrees, Japanese sake content: -3.6, acidity: 1.1).
Isoamyl acetate standard is (Nacalai Tesque, reagent special grade GR), isoamyl alcohol standard is (Nacalai Tesque, reagent special grade GR), and ethyl acetate standard is (Nacalai Tesque, reagent grade GR). Reagent special grade GR) was used.

The evaluation of fragrance was carried out simultaneously with respect to gorgeousness and solvent feeling (solvent feeling) according to the following criteria.
(glamour)
7 points: almost no gorgeousness 6 points: slightly gorgeousness 5 points: a little gorgeousness 4 points: gorgeousness 3 points: somewhat gorgeousness 2 points: strong gorgeousness 1 point: very gorgeousness feel strongly

(Solvent feeling)
7 points: Very strong sense of solvent 6 points: Strong sense of solvent 5 points: Slightly strong sense of solvent 4 points: Slightly sense of solvent 3 points: Slight sense of solvent 2 points: Slight sense of solvent One point: almost no solvent sensation

Tables 1 and 2 show the results.

Multiple test comparison was performed by Tukey-Kramer test about the result of the sensory evaluation test. Regarding commercially available sake A, there was no significant difference between A-1 and A-2, and between A-3 and A-4, in both 'brightness' and 'solvent feeling'. On the other hand, when A-1 or A-2 was compared with A-3 or A-4, there was a statistically significant difference at p<0.01 for both "glamour" and "solvability". That is, A-3 or A-4 is significantly superior to A-1 or A-2 in terms of "glamour", and A-3 or A-4 is superior in terms of "solvent feeling" to A-1 or A-2. was significantly lower.

In addition, commercial sake B had the same result as commercial sake A, although the quality of alcohol and the like was completely different from that of commercial sake A. That is, between B-1 and B-2, and between B-3 and B-4, there was no significant difference in both "brightness" and "solvent feeling". On the other hand, when B-1 or B-2 was compared with B-3 or B-4, there was a statistically significant difference at p<0.01 for both "brightness" and "solvability". “That is, B-3 and B-4 are significantly superior to B-1 or B-2 in terms of “glamour”, and B-3 and B-3 and B- 4 was significantly less.

From the above results, the isoamyl acetate concentration has a critical point of 15 to 20 mg/L, the E/A ratio has a critical point of 3 to 5, the isoamyl alcohol concentration has a critical point of 400 to 500 mg/L, and acetic acid It was found that the ethyl concentration has a critical point at 100-200 mg/L.

Since the above critical point does not depend on the difference in liquor quality, the same sensory test was conducted using the samples shown in Table 3 with A-3 as the reference. In addition, since solvent impression and gorgeousness showed almost the same tendency, we decided to compare gorgeousness. The evaluation criteria were the same as in the above sensory test, and the panel consisted of 10 people. Table 3 shows the results.

Similarly, the Tukey-Kramer test was used to compare the results of the sensory evaluation test. A-3-1, A-3-2 and A-3-3 groups and A-3, A-3-4, A-3-5, A-5 and A-6 groups was statistically significant at p<0.01.
A-3 and A-3-4 were significantly superior to A-3-1 and A-3-2 in terms of gorgeousness, so the ethyl acetate concentration reached a critical point of 100 mg/L to 150 mg/L. It turns out that there is
From the results in Tables 1 and 2, the more vivid the feeling, the less solvent sensation, and the significant difference between the groups was the same for the vividness and the solvent sensation. /L to 150 mg/L.
In addition, since A-3-5 is significantly more gorgeous than A-3-3, even when the isoamyl alcohol concentration is low, the isoamyl acetate concentration has a critical point of 15 mg/L to 20 mg/L. was suggested. It has been confirmed that commercially available alcoholic beverages A and B used have an ethyl caproate concentration of 1 mg/L or less.

(3) Acquisition of Mutant Yeast Strain Kyokai yeast (arginine-requiring strain of No. 901) was used as a parent strain, subjected to mutation treatment, and a mutant strain was obtained with high ethyl acetate production as an indicator. Mutation treatment was carried out by suspending the parent strain in potassium phosphate buffer containing 5% by weight of EMS, incubating at 30°C for 60 minutes while stirring, and applying it to YNB agar medium (0.67% Difco yeast nitrogen base, 2% glucose, 2% agar) to select strains with good growth. Among them, in a small preparation test using a rice-polishing rate of 70%, we happened to obtain several strains that had the same fermentation as the parent strain and had higher ethyl acetate productivity than the parent strain (Condition 1).
The group of mutant strains thus obtained was individually subjected to the method described in paragraph 0074 of JP-A-2018-186759 to obtain mutant strains with increased production of isoamyl acetate. Specifically, the same EMS mutagenesis treatment as described above was performed, and strains with good growth were selected on a YNB agar medium containing 1 mmol/L 5',5',5'-trifluoroleucine. Mutant B (GL-96) was obtained, which produced an increased amount of isoamyl acetate, a lower amount of isoamyl alcohol, and a low ethyl acetate production (Condition 2) compared to the direct parent mutant strain.
In this way, by repeating the mutation treatment on the parent strain so as to satisfy the substantive conditions 1 and 2, it was possible to accidentally obtain a mutant strain having the desired properties.
The yeast strain of this mutant strain finally obtained is: 1) Receiving institution name: National Institute of Technology and Evaluation, Patent Microorganism Depositary Center, 2) Acceptance date November 11, 2021 (acceptance date November 2021 11th), 3) Accession number: NITE P-03554 (Accession number: NITE AP-03554), Identification mark: GL-96.

(4) Production of refined sake with high isoamyl acetate content Mutant strain B was used to prepare malted rice with a rice-polishing ratio of 72% (domestic), rice with a rice-polishing ratio of 78% (domestic), and 1000 g of total rice. It was topped on the 20th day. The temperature was controlled to be 10-14°C.
The resulting Joso sake (converted to alcohol content of 15.5 degrees) has an isoamyl acetate concentration of 29.0 mg/L, an isoamyl alcohol concentration of 349 mg/L, an E/A ratio of 8.3, an ethyl acetate concentration of 98.0 mg/L, The Japanese sake value was -14.7 and the acidity was 2.0.
When the temperature was controlled at a high temperature under the same conditions, the resulting Joso sake (converted to an alcohol content of 15.5 degrees) had an isoamyl acetate concentration of more than 34.0 mg/L, an E/A ratio of more than 12, and The ethyl acetate concentration can be lowered below 80 mg/L, indicating the possibility of increasing the E/A ratio and reducing ethyl acetate.
It was confirmed that the concentration of ethyl caproate in the obtained sake was 1 mg/L or less at both the temperature of 10 to 14° C. and the temperature higher than that.

(5) Acquisition of mutant yeast strains and production of sake with a high isoamyl acetate content Kyokai yeast No. 701 is used as the parent strain, and Kyokai yeast No. 901 strains described in the item "(3) Acquisition of mutant yeast strains" are obtained. I did breeding. Using the obtained mutant strains, rice with a rice-polishing rate of 70%, malted rice with a rice-polishing rate of 72%, and a constant temperature of 15° C. were placed on the 16th day. Ethyl acetate is 96.4 mg/L, isoamyl acetate is 34.7 mg/L, isoamyl alcohol is 422 mg/L, and the E/A ratio is 8.2 in terms of alcohol content of 15.5 degrees. It was shown that the composition of the aroma components of the present invention can be reproduced even with the yeast of

The sake of the present invention has a gorgeous sake-like ginjo aroma and a suppressed solvent feeling. It also has the advantages of being able to be produced using low-polished rice, being able to be produced without adding fragrance components, and being able to be produced without using genetically modified yeast strains. Therefore, the sake of the present invention has a very high commercial value.

The present invention has been completed based on the above findings, and provides the following [1] to [8].
[1] Sake having an isoamyl acetate concentration of 18 mg/L or more, an E/A ratio of 5 or more, and an ethyl acetate concentration of less than 150 mg/L.
[2] The sake according to [1], wherein the sake is defined by the Liquor Tax Law of Japan.
[3] The sake according to [1] or [2], which has an isoamyl acetate concentration of 100 mg/L or less.
[4] The sake according to any one of [1] to [3], which has an E/A ratio of 30 or less.
[5] The sake according to any one of [1] to [4], which has an isoamyl alcohol concentration of 280 to 450 mg/L.
[6] A method for producing sake, comprising a step of making the sake have an isoamyl acetate concentration of 18 mg/L or more, an E/A ratio of 5 or more, and an ethyl acetate concentration of less than 150 mg/L.
[7] The method for producing sake according to [6], wherein the sake is brewed to have an isoamyl acetate concentration of 18 mg/L or more, an E/A ratio of 5 or more, and an ethyl acetate concentration of less than 150 mg/L.
[8] The method for producing sake according to [6] or [7], wherein rice with a rice polishing ratio of 60% or more is used as the rice.

In general, when the isoamyl acetate concentration is increased, the ethyl acetate concentration is also increased. Whether or not the solvent odor of ethyl acetate is perceived depends on the composition of the other flavor components. If it is less than /L, the solvent odor of ethyl acetate is not felt, and a pleasant ginjo aroma is felt.
In the present invention, sake with an isoamyl acetate concentration of 18 mg/L or more, an E/A ratio of 5 or more, and an ethyl acetate concentration of less than 150 mg/L could be produced by brewing for the first time. Consumers do not like sake with added flavorings, so it is of great significance that we were able to adjust the composition of these ingredients through brewing to produce sake with a well-balanced ginjo aroma.
In addition, in the sake of the present invention, when the isoamyl alcohol concentration is 280 to 450 mg / L, the gorgeous aroma of isoamyl acetate can be felt firmly, and the ginjo aroma typical of sake with swelling, mellow or mild. will have

Claims (8)

Sake having an isoamyl acetate concentration of 18 mg/L or more, an E/A ratio of 5 or more, and an ethyl acetate concentration of less than 150 mg/L. 2. The sake according to claim 1, wherein the sake is defined by the Liquor Tax Law of Japan. 3. The sake according to claim 1, wherein the isoamyl acetate concentration is 100 mg/L or less. The sake according to any one of claims 1 to 3, which has an E/A ratio of 30 or less. The sake according to any one of claims 1 to 4, which has an isoamyl alcohol concentration of 280 to 450 mg/L. A method for producing sake, comprising a step of making the sake have an isoamyl acetate concentration of 20 mg/L or more, an E/A ratio of 5 or more, and an ethyl acetate concentration of less than 150 mg/L. 7. The method for producing sake according to claim 6, wherein the sake is brewed to have an isoamyl acetate concentration of 20 mg/L or more, an E/A ratio of 5 or more, and an ethyl acetate concentration of less than 150 mg/L. 8. The method for producing sake according to claim 6 or 7, wherein rice with a rice-polishing ratio of 60% or more is used as rice for brewing.