Savoriness and / or saltiness enhancer, and food or beverage product containing same

Abstract

Problem: To provide a savoriness and / or saltiness enhancer capable of enhancing the savoriness and / or saltiness of a food or beverage product. Also to provide a food or beverage product such as a food product, a beverage, or a seasoning that contains said savoriness and / or saltiness enhancer and has enhanced savoriness and / or saltiness due to the savoriness-enhancing effect of the enhancer. Solution: The present invention obtains a savoriness and / or saltiness enhancer for food or beverage products that contains ergothioneine as an active ingredient, and a food or beverage product having enhanced savoriness and / or saltiness as a result of containing 0.005 wt% or more of ergothioneine relative to the amount of one savory component in the food or beverage product.

Description

Umami and / or salty taste enhancer and food and drink containing same

[0001] The present invention relates to an umami and / or saltiness enhancer that enhances the umami and / or saltiness of foods and beverages, and to foods and beverages such as foods, beverages, or seasonings that contain the umami and / or saltiness enhancer and have enhanced umami and / or saltiness.

[0002] In recent years, society as a whole has been calling for a reduction in salt (sodium chloride) intake to prevent diseases such as high blood pressure, kidney disease, and heart disease, and there is a trend toward low-salt foods and beverages in general. However, simply reducing the salt content of conventional products results in a dull, unpalatable taste, and the use of salt substitutes such as potassium chloride reduces the taste due to unpleasant bitterness and other unpleasant flavors. A known salt reduction method is to increase the umami flavor of soup stock and other foods to compensate for the reduction in saltiness and satisfy the taste, but this method is limited to foods and beverages for which umami is an important flavor, and in such cases, it is necessary to significantly increase the umami components.

[0003] Therefore, research and development is being conducted on salty taste enhancers that can enhance the salty taste of foods and beverages even when the amount of salt is reduced, and umami taste enhancers that can enhance the umami taste of foods and beverages even when the salt content is low. As such salty taste enhancers, Patent Document 1 describes a salty taste enhancer containing methional, 4-hydroxy-3(2H)-furanones, or 3-hydroxy-2(5H)-furanones as an active ingredient, and Patent Document 2 describes a salty taste enhancer containing niacin, salicin, or helicin, but many of these salty taste enhancers are chemically synthesized substances, and some of them have not been confirmed to be safe for use as foods.

[0004] As for umami enhancers, Patent Document 3 describes an umami enhancer containing N-(1-deoxy-D-fructos-1-yl)-pyroglutamic acid, N-(1-deoxy-D-fructos-1-yl)-valine, or N-(1-deoxy-D-fructos-1-yl)-methionine as an active ingredient, and Patent Document 4 describes an umami enhancer containing pyroglutamyl dipeptide as an active ingredient. The components that contribute to umami are mainly amino acids and nucleic acids, and it is known that some nucleic acids have an umami enhancing effect when combined with glutamic acid. Patent Document 5 describes a salty and / or umami enhancer containing trehalose as an active ingredient.

[0005] Low-salt soy sauce, an essential ingredient in Japanese cuisine, is no exception, and technological developments are underway to produce soy sauce with a good salty taste and flavor even when the salt content is low. For example, Patent Document 6 describes soy sauce in which the umami taste of glutamic acid is enhanced by the addition of methional, and Patent Document 7 reports soy sauce containing 0.5 to 5% (w / v) salt and 0.2 to 4% (w / v) ammonium ions and having a pH of 3.2 to 5.0, which is excellent in saltiness and soy sauce-like flavor. Furthermore, Patent Document 8 describes the use of a salty and / or umami enhancer containing trehalose as an active ingredient to enhance the salty and umami taste of sodium chloride, resulting in the production of foods and beverages with a rich and excellent flavor.

[0006] JP 2012-223147 A JP 2023-135861 A JP 2012-29615 A ​​JP 2012-29616 A JP 10-66540 A JP 2014-18146 A Japanese Patent No. 5812864 A JP 10-66540 A International Publication No. 2019 / 240243 International Publication No. 2023 / 234307

[0007] BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY (2019) Vol. 83, No. 1, p. 181-184

[0008] The problem to be solved by the present invention is to provide an umami and / or salty taste enhancer that can enhance the umami and / or salty taste of a food or drink, and also to provide a food or drink, such as a food, beverage, or seasoning, that contains the umami and / or salty taste enhancer and has an enhanced umami and / or salty taste due to the umami and / or salty taste enhancing effect of the umami and / or salty taste enhancer.

[0009] As a result of extensive research into substances capable of enhancing umami and / or saltiness, the present inventors discovered that ergothioneine, which can be produced only by certain microorganisms, such as fungi such as mushrooms, koji mold and the like, actinomycetes, and cyanobacteria, can enhance the umami and / or saltiness of foods and beverages containing umami and / or saltiness components, and thus completed the present invention.

[0010] The present invention relates to an umami and / or salty taste enhancer as set forth in [1] below, or a food or drink as set forth in [2] to [7] below. [1] An umami and / or salty taste enhancer containing ergothioneine as an active ingredient. [2] A food or drink with enhanced umami taste, in which the umami taste enhancer ergothioneine is contained in an amount of 0.005% by weight or more relative to the content of one umami component in the food or drink. [3] A food or drink with enhanced saltiness, in which the salty taste enhancer ergothioneine is contained in a food or drink containing salt at any of the following concentrations: (1) 0.5 ppm or more of ergothioneine in a food or drink with a salt content of 0.1% by weight or more and less than 5% by weight. (2) 0.1 ppm or more of ergothioneine in a food or drink with a salt content of 5% by weight or more. [4] The food or drink according to [2] or [3] above, wherein the food or drink with enhanced umami and / or saltiness is soy sauce, miso, fish sauce, mirin, bonito stock, soup stock, umami seasoning, fermented umami seasoning, ketchup, sauce, or mycoprotein. [5] The food or drink according to any of [2] to [4], which is produced using an ergothioneine-high producing koji mold strain. [6] A food or drink with enhanced umami and / or saltiness, containing 10 ppm or more of ergothioneine. [7] A food or beverage with enhanced umami and / or saltiness that is not a soy sauce for retort foods, a retort food containing soy sauce, or a food or beverage containing ergothioneine-producing fungal fermentation biomass or its supernatant colored with a dye, containing 10 ppm or more of ergothioneine.

[0011] The present invention also relates to the soy sauces described in [8] and [9] below, the foods and beverages described in

[10] and

[11] , the koji fermentation product with a high ergothioneine content described in

[12] , the method for enhancing umami and / or saltiness described in

[13] , or the use of ergothioneine described in

[14] . [8] Soy sauce or soy sauce-containing seasonings that are not soy sauce for retort foods, containing 10 ppm or more of ergothioneine. [9] The soy sauce described in [8] above, which is reduced-salt soy sauce.

[10] The food and beverage described in [5] above, which is rice koji that is an ergothioneine-rich koji fermentation product containing 0.3 g of ergothioneine or more per kg of dried koji fermentation product, obtained by culturing an ergothioneine-rich koji mold strain in a medium composed of raw materials with a protein content of 5 to less than 10%.

[11] The food or beverage described in [5] above is a mycoprotein or soy sauce koji, which is an ergothioneine-rich koji fermentation product containing 0.4 g ergothioneine or more per kg of dry koji fermentation product, obtained by culturing a high-ergothioneine-producing koji mold strain in a medium composed of raw materials with a protein content of 10% or more.

[12] An ergothioneine-rich koji fermentation product containing 50 to 50,000 ppm ergothioneine.

[13] A method for enhancing the umami and / or saltiness of a food or beverage by incorporating ergothioneine into the food or beverage.

[14] Use of ergothioneine to enhance the umami and / or saltiness of a food or beverage.

[0012] The umami and / or salty taste enhancer of the present invention can bring out umami and / or salty taste by adding a very small amount of ergothioneine, thereby naturally enhancing umami and / or salty taste without impairing flavor. When the umami is enhanced by adding the enhancer to a food or beverage with umami, the saltiness can be felt more even if the salt content in the food or beverage is reduced. Therefore, by consuming a food or beverage such as a seasoning, food, or beverage to which the enhancer has been added, the taste is maintained and salt intake can be reduced without difficulty. Of course, the addition of a very small amount of ergothioneine to a food or beverage containing umami components such as monosodium L-glutamate, sodium inosinate, or sodium guanylate can enhance umami without the inclusion of salt.

[0013] Soy sauce containing extremely small amounts of ergothioneine has enhanced saltiness and umami, so that even if the salt content of soy sauce is reduced, the natural deliciousness of soy sauce is not impaired and the soy sauce is retained, making it particularly effective for reduced-salt soy sauce. Ergothioneine also enhances the sweetness of soy sauce. Soy sauce produced using a high-ergothioneine-producing koji mold strain not only has improved flavor, but also has the advantage of improved compressibility during the filtration process of soy sauce production, improving workability. Furthermore, koji mold fermentation products produced using high-ergothioneine-producing koji mold strains have a high ergothioneine content and can be used as foods, food ingredients, or food raw materials that can be eaten directly to provide sufficient ergothioneine intake. The high ergothioneine content results in more delicious foods with enhanced flavors such as umami, sweetness, and saltiness. Furthermore, the koji mold fermentation product of the present invention has a pleasant aroma because it has little of the odors characteristic of koji mold fermentation products, such as koji odor, bran odor, unrefined odor, and oxidized odor.

[0014] The present invention relates to an umami and / or salty taste enhancer for foods and beverages containing ergothioneine as an active ingredient, and to foods and beverages with enhanced umami and / or salty taste that contain the umami and / or salty taste enhancer ergothioneine. In the present invention, "%" means "% by weight" even if the unit is not specified, and 1 ppm is 0.0001% by weight.

[0015] Ergothioneine (hereinafter also referred to as "ERG") was discovered as a sulfur-containing amino acid isolated from the rye ergot fungus (Clavices purpurea), and its presence in the living bodies of plants and animals has been confirmed. However, plants and animals cannot synthesize ergothioneine, and ergothioneine in the living body is thought to be derived from ergothioneine synthesized by microorganisms such as basidiomycetes. It is contained in some edible mushrooms of basidiomycetes, such as oyster mushrooms, shiitake mushrooms, maitake mushrooms, and king oyster mushrooms, and is known to be particularly abundant in Pleurotus pilchardus. It is also known that Aspergillus oryzae produces ERG.

[0016] ERG is known to be biosynthesized from histidine in microorganisms, with the sulfur atom being supplied from cysteine. ERG has high antioxidant properties and has been reported to have elastase and tyrosinase inhibitory effects, attracting particular attention in the beauty and food industries for skin whitening and wrinkle prevention. It has also been found to be involved in the biological oxidation defense system, and attempts are being made to apply it in the medical field. ERG has high thermal and pH stability and can maintain its antioxidant activity even at high temperatures. It is therefore incorporated into foods for its physiological effects, and is also expected to be used in foods as an antioxidant.

[0017] Methods for producing ERG include extraction from basidiomycetes such as Pleurotus cornucopiae, chemical synthesis, and fermentation using microorganisms. Extraction from basidiomycetes such as Pleurotus cornucopiae requires time to obtain raw materials and is not suitable for mass production. Chemical synthesis is suitable for mass production, but requires the use of expensive synthetic reagents. Therefore, research is being conducted on fermentation production methods such as fermentation using bacteria or yeast that can assimilate C1 compounds, fermentation using microorganisms that overexpress ERG biosynthetic genes, and solid culture using koji mold that has been introduced with ERG biosynthetic genes and overexpresses ERG (Non-Patent Document 1).

[0018] The umami and / or salty taste enhancer of the present invention may be a commercially available chemically synthesized ERG, or an extract or purified product thereof from mushrooms containing ERG, an ERG-producing koji mold or a culture thereof, or sake lees produced using koji mold. Furthermore, for foods and beverages that use koji mold as a raw material, the amount of ERG in the foods and beverages can be increased by using koji mold that produces a high amount of ERG without adding ERG. Preferred mushrooms used for ERG extraction include Pleurotus cornucopiae var. citrinopileatus, Pleurotus ostreatus, Lentinula edodes, and Grifola frondosa, which belong to the Pleurotus genus of the Pleurotus family, due to their high ERG content. These mushrooms may be used alone or in combination.

[0019] Furthermore, any fungus belonging to the genus Aspergillus can be used as the koji mold that produces ERG. Examples include Aspergillus oryzae, Aspergillus sojae, Aspergillus niger, Aspergillus luchuensis, and Aspergillus tamarii. Examples of koji mold strains that can be used include strains available from depositories such as Aspergillus oryzae RIB326, strains contained in commercially available koji starters, and strains isolated from food and beverage production environments such as sake and soy sauce breweries.

[0020] In addition to the wild-type strains described above, mutant strains with high ERG production can be isolated and used as ERG-producing koji molds by common mutagenesis methods, such as ultraviolet (UV) or X-ray irradiation, which physically damage DNA and introduce mutations, or treatment with alkylating agents such as N-methyl-N'-nitro-N-nitrosoguanidine (NTG) or ethylmethanesulfonate (EMS), which chemically damage DNA and introduce mutations.

[0021] Furthermore, high-ERG-producing koji mold strains into which genes related to ERG biosynthesis have been introduced by genetic recombination can be used, including, but not limited to, koji mold mutants into which the egtA gene has been introduced (see Patent Document 9 and Non-Patent Document 1), and Aspergillus mutants into which the Aspergillus genus-specific AO090005000664 gene (encoded amino acid sequence: SEQ ID NO: 1) or its ortholog gene has been introduced, into which a specific gene mutation, such as a G428S mutation or a C459F mutation, or a deletion of 1 to 112 amino acids in the W404 to Q515 region, has been introduced, thereby increasing ERG expression (see Patent Document 10).

[0022] As used herein, a highly ERG-producing koji mold strain refers to one that produces 5 to 10 times or more, preferably 20 times or more, of ERG when cultured in liquid culture (Pafumin SM medium (a solution prepared by adding 5 to 10% Pafumin SM (Kikkoman Corporation) to water and suspending it) at 20 to 30°C for 3 to 14 days) compared to a non-mutated or non-transformed strain. Examples of such a strain include an Aspergillus sojae strain in which the above-mentioned egtA gene is forcibly expressed, or an Aspergillus oryzae mutant strain containing amino acid mutations or deletions in the W404 to Q515 regions of the above-mentioned mutant AO090005000664 gene and its orthologous gene. The AO090005000664 gene is a gene encoding the ERG of Aspergillus oryzae. The RIB40 strain was cloned and contains several conserved regions that are highly conserved with other species. A particularly conserved region is the region corresponding to amino acid positions 411 to 470 of SEQ ID NO: 1. Introducing a substitution mutation at positions 428 and / or 459 in this conserved region increases ERG expression in the mutant strain by 5-10 fold or more. Introducing a deletion mutation in which 1 to 112 amino acids are deleted from the region corresponding to positions 404 to 515 also increases ERG expression by 5-10 fold or more.

[0023] Furthermore, when foods and beverages are made using koji-fermented products as raw materials, such as soy sauce, sake, amazake, mirin, miso, etc., the ERG content in the foods and beverages can be increased by making koji using a high ERG-producing koji mold strain, even without adding ERG during production. In particular, when a high ERG-producing koji mold strain is used to produce fermented foods, fermented beverages, and fermented seasonings, effects other than the enhancement of umami and / or saltiness are exhibited compared to when ERG is added.

[0024] "Enhanced umami and / or saltiness" means that the resulting umami and / or saltiness is perceived more strongly than in the absence of the umami and / or saltiness enhancer of the present invention. Specifically, this means that the addition of the umami and / or saltiness enhancer allows the same umami and / or saltiness to be perceived even when the umami and / or saltiness components are reduced by, for example, 1 to 50%. It also means that the addition of the umami and / or saltiness enhancer allows the same umami and / or saltiness to be perceived as when, for example, 1.1 to 2 times the amount of umami and / or saltiness components are contained. Alternatively, it means that when a small amount of umami components and / or saltiness is not perceived, the umami and / or saltiness can be perceived for the first time by adding the umami and / or saltiness enhancer.

[0025] The umami component in the present invention is monosodium L-glutamate, sodium inosinate, or sodium guanylate, and the content of one umami component in the present invention refers to the content of any one of these three umami components contained in a food or beverage. In a food or beverage containing an umami component, the umami of the food or beverage is enhanced by adding ergothioneine, an umami enhancer, in an amount of 0.005 wt. % or more relative to the content of the one umami component. Specifically, the umami is enhanced by adding 1 ppm or more of the umami component monosodium L-glutamate in a 2% solution, or 1 ppm or more in a 5% solution of sodium inosinate or sodium guanylate. In a food or beverage containing two or more umami components, it is sufficient to add 0.005 wt. % or more of ERG relative to the minimum content of the umami component.

[0026] Furthermore, the umami enhancer of the present invention exerts an umami enhancing effect in foods and beverages by being contained in general foods and beverages at 10 ppm or more, for example, 10 ppm or more, 15 ppm or more, 20 ppm or more, or 30 ppm or more, or 40 ppm or more, or 50 ppm or more. Since the umami enhancing effect does not increase even when a large amount of the umami enhancer of the present invention is contained, taking economical efficiency into consideration, ERG can be contained in foods and beverages at 0.15 wt% or less, for example, 0.12 or 0.09 wt% or less, 0.06 or 0.03 wt% or less. With respect to the umami component content of foods and beverages, ERG can be contained at 15 wt% or less, for example, 12 or 9 wt% or less, 6 or 3 wt% or less. The umami enhancer of the present invention exerts an umami enhancing effect in foods and beverages at all combinations of the lower and upper limits of the content of various umami components in foods and beverages.

[0027] The salty component in the present invention is sodium chloride (NaCl), and the salty taste enhancer of the present invention exerts a salty taste enhancing effect in foods and beverages by adding it to foods and beverages in a concentration of 1 ppm or more, for example, 1, 5, 10, 15, 20, or 30 ppm or more, or 40 ppm or 50 ppm or more, relative to the salt content of general foods and beverages. Specifically, in foods and beverages containing sodium chloride, the salty taste of the food and beverage is enhanced by adding the salty taste enhancer ergothioneine at a concentration of 0.5 ppm or more in foods and beverages with a salt content of 0.1 wt% or more but less than 5 wt%, or at a concentration of 0.1 ppm or more in foods and beverages with a salt content of 5 wt% or more. Furthermore, since the salty taste enhancing effect is not enhanced by adding a large amount of the salty taste enhancer of the present invention, in consideration of economic efficiency, ERG can be added to foods and beverages at a concentration of 0.15 wt% or less, for example, 0.12 wt% or less, 0.09 wt% or less, or 0.06 wt% or less. The salty taste enhancer of the present invention exerts the effect of enhancing the salty taste of foods and beverages at all combinations of the contents of these lower and upper limits for various salty components in foods and beverages.

[0028] The ERG concentration is measured by LCMS under the following conditions: (HPLC conditions) HPLC analysis is performed under the following conditions: Apparatus: HPLC Apparatus: HPLC: Nexera series set (Shimadzu Corporation) Column: COSMOSIL 2.5 HILIC column 3.0 x 150 2.5 μm 3.0 mm I.D. × 15.0 cm (manufactured by Nakarai) Flow rate: 0.5 mL / min Temperature: 40°C Mobile phase: A) 0.1% (v / v) formic acid aqueous solution, B) 0.1% (v / v) formic acid acetonitrile Isocratic: 0-10 min (B: 80%) Injection volume: 5 μL (Mass spectrometry) Apparatus: LCMS-2020 (manufactured by Shimadzu Corporation) (Mass spectrometry (LC-MS) analysis conditions) Ionization conditions: ESI+ MS conditions: SIM ERG: m / z 230.1 ([M+H] ＋ ) Holding time: about 5 minutes

[0029] The food and drink products of the present invention are foods, beverages, or seasonings. The food products can be any food, preferably foods containing umami components, and are not limited to these. Examples include retort pouch foods such as curry, stew, and meat sauce; processed vegetable products such as salads and pickles; seafood products such as salmon, tuna, sardines, shrimp, bonito, saury, squid, scallops, crab, and oysters; processed seafood and livestock foods such as kamaboko, hamburger steak, ham, and sausage; dairy products; cooked rice dishes such as rice balls, pilaf, fried rice, rice porridge, ochazuke (rice with green tea), oyakodon (chukadon), and katsudon (pork cutlet bowl); cooked foods such as spring rolls, shumai (steamed dumplings), gyoza (dumplings), curry, simmered dishes, and fried foods; mycoproteins; pet foods; and medical foods. Examples of mycoproteins include proteins derived from yeast, proteins derived from filamentous fungi, and proteins derived from fungi such as mushrooms.

[0030] Beverages are not limited, and examples include soft drinks, nutritional drinks, fruit drinks, lactic acid drinks, sports drinks, soups such as egg soup, seaweed soup, Chinese-style soup, consommé soup, and potage soup; clear soup, miso soup; alcoholic beverages such as beer, shochu, and cocktails; and quasi-drug nutritional drinks. These include not only liquids but also gels and semi-solids such as jelly drinks. Condiments are also not limited, and examples include soy sauce, reduced-salt soy sauce, mirin, miso, fish sauce, cooking sake, dashi (soup stock), bonito stock, and kelp stock, umami seasonings, fermented umami seasonings, sushi vinegar, dipping sauces, oyster sauce, and various other sauces, ketchup, dressing, mayonnaise, and the like.

[0031] Umami seasonings are chemical seasonings made by purifying compounds that have umami flavor, and specific examples include amino acid-based seasonings and nucleic acid-based seasonings. Examples of amino acid-based seasonings include glutamic acid and its salts (such as monosodium glutamate). Examples of nucleic acid-based seasonings include sodium inosinate and sodium guanylate. Fermented umami seasonings refer to enzyme hydrolysates of proteins such as wheat gluten and soybeans. Furthermore, when the umami enhancer of the present invention is added to a food or beverage in the process of producing the above-mentioned food or beverage, it may be added at any step, and the method of addition is not limited as long as the required amount is contained in the final food or beverage product.

[0032] Soy sauce is typically brewed soy sauce, which is produced by heat-treating plant-based ingredients such as soybeans and wheat, propagating koji mold on the ingredients, and then fermenting and maturing the ingredients in salt water. The salt concentration is generally 15 to 18% by weight. Other types of soy sauce include chemical soy sauce, which is made by decomposing plant-based ingredients with acid or enzymes, fish sauce, which is made by fermenting seafood, and meat sauce, which is made by fermenting livestock meat. However, the soy sauce of the present invention is preferably brewed soy sauce using koji mold. Brewed soy sauces vary in their production methods, such as the ratio of soybeans and wheat as raw materials, the method of raw material processing, and salt concentration, and examples include dark soy sauce, light soy sauce, tamari soy sauce, shiro soy sauce, and saishikomi soy sauce. Furthermore, there is reduced-salt soy sauce, which has nearly half the salt content of regular soy sauce, and the soy sauce of the present invention also includes reduced-salt soy sauce.

[0033] The ERG of the present invention is added to soy sauce at 5 ppm or more, for example, 10 ppm, 15 ppm, 25 ppm, 30 ppm or more, or 35 ppm, 40 ppm, 45 ppm, 50 ppm or more, to enhance the salty and umami tastes of the soy sauce. Similarly, the addition of 5 ppm or more, for example, the above-mentioned concentrations, to reduced-salt soy sauce enhances the salty and umami tastes of the reduced-salt soy sauce. Furthermore, the addition of 5 ppm or more of ERG to soy sauce-containing seasonings enhances the salty and umami tastes of the soy sauce. Furthermore, since the addition of a large amount of ERG does not enhance the umami and salty taste enhancement effect of soy sauce, in consideration of economic efficiency, the ERG content in soy sauce can be 0.15 wt % or less, for example, 0.12 wt %, 0.09 wt %, or 0.06 wt % or less. The soy sauce of the present invention exhibits an umami and salty taste enhancing effect at all combinations of ERG contents between these lower and upper limits.

[0034] The ERG-rich koji mold fermentation product of the present invention is prepared by fermenting koji mold in either a conventional solid or liquid medium. Industrially used koji comes in two forms: solid koji, which is obtained by growing koji mold directly on soybeans, wheat, rice, etc., and liquid koji, which is obtained by growing koji mold in a liquid medium in which soybeans, wheat, rice, etc. are suspended. The koji mold fermentation product of the present invention includes solid koji and liquid koji. Fermentation conditions can be those conventionally used in the technical field.

[0035] Solid media used to produce solid koji include those composed of raw materials with a protein content of less than 5-10% (protein content according to the Food Nutritional Composition Table) and those composed of raw materials with a protein content of 10% or more (protein content according to the Food Nutritional Composition Table). Raw materials for such solid media include rice (6% protein), which is a raw material with a protein content of less than 5-10%, and raw materials with a protein content of 10% or more, such as beans, fish, meat, algae, and processed products thereof, which contain 20% or more protein. Examples of processed products containing 20% ​​or more protein include defatted soybeans, fish meal, meat meal, and spirulina powder. Solid media can be prepared by steaming or simmering the above-mentioned raw materials in boiling water, and optionally crushing them. Raw materials for liquid media used to produce liquid koji include wheat bran, rice, defatted soybeans, corn, soybean pulp, yeast extract, dextrin, etc.

[0036] After fermentation is complete, the ERG-rich koji mold fermentation product is recovered by solid-liquid separation of the liquid from the medium, concentrated using an ion exchange resin or the like depending on the application, and can be used as an ERG-containing food material as a raw material for other foods either directly or after drying, and seasoned as necessary. Furthermore, by using a specific solid or liquid medium as a material and adding seasoning as necessary, the ERG-rich koji mold fermentation product obtained can be used as a food material, such as a mycoprotein food, or as a rice koji or soy sauce koji. Thus, the ERG-rich koji mold fermentation product of the present invention can be used as an intermediate raw material for foods or foods made from koji mold fermentation products, such as fermented foods, fermented beverages, and fermented seasonings.

[0037] When an ERG-rich koji mold solid fermentation product is produced using the high ERG-producing koji mold strain of the present invention, it can contain, for example, 0.3 g or 0.4 g / kg or more of ERG per kg of koji mold solid fermentation product, preferably 0.5 g / kg or more, more preferably 0.6 g / kg or more, and even more preferably 0.8 g / kg or more of ERG. Rice koji obtained in a medium composed of rice, a raw material with a protein content of less than 5 to 10%, can produce an ERG-rich koji mold fermentation product containing 0.3 g or more of ERG per kg or more of dry koji mold fermentation product. Similarly, soy sauce koji obtained in a medium with a protein content of 25% from soybeans and wheat, and mycoprotein obtained in a medium composed of a raw material with a protein content of 10% or more, can produce an ERG-rich koji mold fermentation product containing 0.4 g or more of ERG per kg or more of dry koji mold fermentation product.

[0038] When an ERG-rich koji mold liquid fermentation product is produced using the high ERG-producing koji mold strain of the present invention, it is possible to produce an ERG-rich koji mold liquid fermentation product containing 50 to 50,000 ppm of ERG, for example, 50 ppm or more, 100, 300, 500, or 1,000 ppm or more of ERG, and 5%, 4, 3, 2, or 1% or less of ERG.

[0039] The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto. In the examples, "%" simply means "% by weight." For the sensory evaluation, samples at room temperature were used.

[0040] [Test 1: Umami Enhancement Effect of Monosodium Glutamate Solution by ERG] 0.2% NaCl was mixed with purified water. Monosodium L-glutamate (hereinafter also referred to as "MSG") was added to prepare six MSG samples with concentrations of 0%, 0.75%, 1%, 1.25%, 1.5%, and 1.75%. A seventh sample was prepared by adding purified ergothioneine (purity ≥99.5%, Tetrahedron) to 1% MSG to a final concentration of 60 ppm. 0.2% NaCl was added for sensory evaluation because MSG alone would dull the flavor. Umami was evaluated by a panel of five trained umami-sensitive subjects. A five-person panel of experts was asked to select the sample with the same umami taste as the seventh sample, a 1% MSG solution containing 60 ppm ERG, from among the first six MSG samples (the concentrations of which were not disclosed to the panelists). After tasting each sample, participants thoroughly rinsed their mouths with room-temperature water before tasting the next sample. In the sensory evaluation, four of the five panelists rated the seventh sample as being equivalent to the 1.25% MSG solution, and one panelist rated it as being equivalent to the 1.5% MSG solution. Consequently, all five panelists concluded that the addition of 60 ppm ERG enhanced the umami taste.

[0041] [Test 2: Amount of ERG Added to Enhance the Umami Taste of MSG] (1) In the Case of 2% MSG Sample (0.2% NaCl Added) As in Test 1, a 2% MSG sample was prepared by mixing 0.2% NaCl in pure water, and ergothioneine was added to the sample to final concentrations of 0.5 ppm, 1 ppm, 3 ppm, 5 ppm, 10 ppm, and 20 ppm to prepare samples (ERG0 to 20 in Table 1 below, and hereinafter, "ERGX" refers to a sample with X ppm of ERG added).

[0042]

[0043] A four-person expert panel conducted a sensory evaluation of umami taste for 2% MSG samples containing various concentrations of ERG (concentrations not disclosed to the panel) using a 2% MSG sample without added ergothioneine as a control. After tasting each sample, participants thoroughly rinsed their mouths with room-temperature water before tasting the next sample. The expert panel was presented with pairs of 2% MSG samples containing the control and 2% MSG samples containing various concentrations of ergothioneine, and the panel conducted a two-point discrimination test to determine which of the presented pairs they perceived as more umami. The results are shown in Table 2.

[0044] <Evaluation method for two-point discrimination test> Evaluation results of the umami taste of the test product compared to the control ◯: The umami taste is enhanced compared to the control. ◇: The umami taste is the same as the control. The evaluation method for the two-point discrimination test and the display of the evaluation results are the same for other tests.

[0045] All panelists rated the 2% MSG sample containing 1 ppm or more of ERG as having an enhanced umami flavor, which is equivalent to adding 0.005% or more by weight of ERG to the MSG content, which is an umami component.

[0046] (2) 1% MSG Sample (0.2% NaCl Added) A 1% MSG sample (purified water mixed with 0.2% NaCl) was prepared by adding ergothioneine to final concentrations of 15 ppm, 20 ppm, 40 ppm, 60 ppm, 80 ppm, 100 ppm, 400 ppm, and 900 ppm (ERG 15-900). The 1% MSG samples with ERG added at each concentration were subjected to a drinking test by the same four expert panelists as in Test 2, and the umami taste was evaluated. The four expert panelists were presented with pairs of 1% MSG samples with ERG added at successively different concentrations (e.g., ERG 20 ppm and 40 ppm), and the panelists performed a two-point discrimination test to determine which of the presented pairs they perceived as more umami-tasting. The results are shown in Table 3.

[0047]

[0048] Three panelists evaluated the MSG sample with 80 ppm ERG as having the same umami flavor as the one with 60 ppm ERG. Therefore, even with 80 ppm ERG, the degree of umami enhancement was evaluated to be the same as that of the sample with 60 ppm ERG. This confirmed that the umami enhancement effect becomes constant at 60 ppm ERG. From the above, it was evaluated that, in a 1% MSG solution, the umami flavor is enhanced as the amount of ERG added increases up to 60 ppm. Above 60 ppm, the umami enhancement effect was not different from that of the 60 ppm addition.

[0049] (3) 10% MSG Sample (No NaCl) A test similar to that in Test 2(1) was conducted on 10% MSG (no NaCl). Ergothioneine was added to the 10% MSG sample to final concentrations of 1 ppm, 3 ppm, 5 ppm, 10 ppm, and 20 ppm to prepare samples (ERG0-20 in Table 4 below). A panel of four experts was presented with pairs of a control 10% MSG sample and 10% MSG samples with various concentrations of ergothioneine added, and the panelists evaluated which of the presented pairs tasted more umami by a two-point discrimination test. The results are shown in Table 5.

[0050]

[0051]

[0052] Three panelists rated the 10% MSG sample, in which 1 ppm or more of ERG was added to 10% MSG (without NaCl), as having enhanced umami flavor, while all panelists rated the 10% MSG sample, in which 3 ppm or more of ERG was added, as having enhanced umami flavor.

[0053] [Test 3: Umami Taste Enhancement Effect of Inosinic Acid] (1) 5% Inosinic Acid Samples: A 5% inosinic acid sample was prepared by mixing 0.2% NaCl in pure water with ergothioneine to prepare samples (ERG 0.1-20) containing final concentrations of 0.1 ppm, 0.5 ppm, 1 ppm, 3 ppm, 5 ppm, and 20 ppm. A four-person panel of experts conducted a sensory evaluation of the umami taste of the 5% inosinic acid samples containing various concentrations of ERG (the concentrations were not disclosed to the panelists) compared with a 5% inosinic acid sample without ergothioneine. After tasting each sample, participants thoroughly rinsed their mouths with room-temperature water before tasting the next sample. A panel of experts was presented with pairs of a control 5% inosinic acid sample and ergothioneine-added 5% inosinic acid samples at various concentrations, and the panel evaluated which of the pairs tasted more umami by a two-point discrimination test. The results are shown in Table 6.

[0054] Three panelists evaluated the 5% inosinic acid sample with 0.5 ppm of ERG as having an enhanced umami flavor, while all panelists evaluated the 5% inosinic acid sample with 1 ppm or more of ERG as having an enhanced umami flavor.

[0055] [Test 4: Effect of ERG on Saltiness Enhancement of NaCl Solutions] Five NaCl samples (0.3%, 0.35%, 0.4%, 0.45%, and 0.5%) were prepared by adding NaCl to pure water. A sixth sample was prepared by adding purified ergothioneine (purity ≥99.5%, Tetrahedron) to 0.4% NaCl to a final concentration of 60 ppm. The saltiness was evaluated by a panel of five trained salt-taste-sensitive subjects. The five panelists were asked to select the NaCl sample (concentration not disclosed to the panel) that had the equivalent saltiness to the sixth sample (60 ppm ERG-added 0.4% NaCl solution). After tasting each sample, participants thoroughly rinsed their mouths with room-temperature water before tasting the next sample. As a result of the sensory evaluation, all five panelists rated the sixth sample, 0.4% NaCl with 60 ppm ERG, as having the same saltiness as a 0.45% NaCl solution. As a result, all five panelists rated the saltiness as being enhanced by the addition of 60 ppm ERG.

[0056] [Test 5: Amount of ERG Added to Enhance the Salty Taste of NaCl] (1) For 0.1 to 20% NaCl Samples Samples were prepared by adding ergothioneine to 0.1 to 20% NaCl samples to final concentrations of 0.05 ppm, 0.1 ppm, 0.25 ppm, and 0.5 ppm (ERG 0.05 to 0.5 in Table 7 below, and hereinafter, "ERGX" refers to a sample with X ppm of ERG added).

[0057]

[0058] A drinking test was conducted by a four-person expert panel using 0.1-20% NaCl samples (concentrations not disclosed to the panel) containing various concentrations of ERG, with a 0.1-20% NaCl sample without added ergothioneine as a control. The expert panel was presented with pairs of 0.1-20% NaCl control samples and 0.1-20% NaCl samples containing various concentrations of ergothioneine, and the panel conducted a two-point discrimination test to determine which of the pairs they perceived as salty. The results are shown in Table 8.

[0059] <Evaluation method for two-point discrimination test> Evaluation results of saltiness of test product compared to control ◯: Saltiness is enhanced compared to the control. ◇: Saltiness is the same as the control. The evaluation method for the two-point discrimination test and the display of the evaluation results are the same for other tests.

[0060]

[0061] The results of the sensory evaluation showed that for samples containing 0.1% to less than 0.5% NaCl, all subjects rated the saltiness as enhanced when ERG was added at 0.5 ppm or more, and for samples containing 0.5% or more NaCl, all subjects rated the saltiness as enhanced when ERG was added at 0.1 ppm or more.

[0062] (2) 3% NaCl Samples: Samples (ERG 0.5-100) were prepared by adding ergothioneine to 3% NaCl samples to final concentrations of 0.5 ppm, 12 ppm, 24 ppm, 60 ppm, 72 ppm, and 100 ppm. A drinking test was conducted by a four-person expert panel for the 3% NaCl samples with ERG added at each concentration, and the saltiness was evaluated. The four expert panel members were presented with pairs of 3% NaCl samples with ERG added at successively different concentrations (e.g., ERG 24 ppm and 60 ppm), and the panelists evaluated which of the presented pairs tasted saltier using a two-point discrimination test. The results are shown in Table 9.

[0063]

[0064] All panelists rated the 3% NaCl samples containing 0.5 ppm or more of ERG as having an enhanced salty taste. Furthermore, the 3% NaCl sample containing 72 ppm of ERG was evaluated by three panelists for saltiness, similar to that of the sample containing 60 ppm of ERG. The panelists rated the saltiness enhancement at 72 ppm as being no different from that of the sample containing 60 ppm of ERG, confirming that the saltiness enhancement effect was consistent at 60 ppm of ERG. From the above, it was determined that the saltiness of the 3% NaCl solution was enhanced with increasing amounts of ERG added from 0.5 ppm to 60 ppm. Above 60 ppm, the saltiness enhancement effect was no different from that of the sample containing 60 ppm of ERG.

[0065] [Test 6: Amount of ERG Added to Enhance the Umami Taste of Soy Sauce] (1) In the Case of Dark Soy Sauce: Ergothioneine was added to a dark soy sauce concentrate solution at concentrations of 5 ppm, 10 ppm, 50 ppm, 100 ppm, and 200 ppm to prepare samples (ERG 5-200). A five-person expert panel conducted a drinking test of the dark soy sauces containing ERG at various concentrations (the concentrations were not disclosed to the panelists) using soy sauce without ergothioneine as a control. The expert panelists were presented with pairs of the control soy sauce and soy sauces containing ergothioneine at various concentrations, and the panelists performed a two-point discrimination test to determine which of the presented pairs they perceived as more umami-tasting. The results are shown in Table 10.

[0066] Four panelists rated the soy sauce containing 5 ppm or more of ERG as having an enhanced umami flavor, and all panelists rated the soy sauce containing 10 ppm or more as having an enhanced umami flavor.

[0067] Samples (ERG 5-200) were prepared by adding ergothioneine to dark soy sauce at concentrations of 5 ppm, 10 ppm, 50 ppm, 100 ppm, and 200 ppm, and each was diluted 10-fold with pure water. The soy sauces with ERG added at each concentration were subjected to a drinking test by the same five-person expert panel, and their umami was evaluated. The five-person expert panel was presented with pairs of soy sauces with ERG added at successively different concentrations (e.g., ERG 10 ppm and 50 ppm), and the panelists evaluated which of the presented pairs tasted umami better using a two-point discrimination test. The results are shown in Table 11.

[0068] Four panelists evaluated soy sauce with 200 ppm ERG added as having the same umami level as soy sauce with 100 ppm ERG added, indicating that the level of umami enhancement with 200 ppm ERG was not different from that with 100 ppm added. Based on the above, it was determined that the umami enhancement effect of adding 5 ppm to 100 ppm ERG in dark soy sauce was gradually enhanced with increasing amounts. Above 100 ppm, the umami enhancement effect was not different from that of adding 100 ppm.

[0069] (2) Special Selection Whole Soybean Soy Sauce, Light Soy Sauce, or Reduced-Salt Soy Sauce: Commercially available Special Selection Whole Soybean Soy Sauce (Kikkoman Corporation) was spiked with ergothioneine at concentrations of 5 ppm, 10 ppm, 50 ppm, 100 ppm, and 200 ppm (ERG 5-200). Similar to (1), a five-person expert panel conducted a drinking test. The panel presented pairs of control soy sauce and soy sauces spiked with ergothioneine at various concentrations. The panelists evaluated which of the presented pairs tasted more umami by a two-point discrimination test. Similar two-point discrimination tests were also conducted on commercially available light soy sauce and reduced-salt soy sauce. The results showed that all panelists rated the soy sauce spiked with 5 ppm or more of ERG as having enhanced umami flavor.

[0070] [Test 7: Amount of ERG Added to Enhance the Salty Taste of Soy Sauce] (1) Special Select Whole Soybean Soy Sauce: Commercially available Special Select Whole Soybean Soy Sauce (Kikkoman Corporation) was supplemented with ergothioneine at concentrations of 5 ppm, 20 ppm, and 50 ppm to prepare samples (ERG 5-50). A four-person expert panel conducted a drinking test of the Special Select Whole Soybean Soy Sauces with ERG added at various concentrations (the concentrations were not disclosed to the panelists) against a control soy sauce without ergothioneine. The expert panelists were presented with pairs of the control soy sauce and soy sauces with ergothioneine added at various concentrations, and the panelists evaluated which of the presented pairs tasted saltier using a two-point discrimination test. The results are shown in Table 12.

[0071] All panelists rated the soy sauce containing 5 ppm or more of ERG as having an enhanced salty taste.

[0072] (2) Light soy sauce: A similar two-point discrimination test was also conducted on commercially available light soy sauce. The results are shown in Table 13. All panelists rated the soy sauce containing 5 ppm or more of ERG as having an enhanced salty taste.

[0073] (3) Reduced-salt soy sauce: A similar two-point discrimination test was also conducted on commercially available reduced-salt soy sauce. The results are shown in Table 14. All panelists rated the soy sauce containing 5 ppm or more of ERG as having an enhanced salty taste.

[0074] [Test 8: Amount of ERG Added to Enhance the Umami Taste of Seasonings] (1) Yeast Extract Samples (ERG 0.5-10) were prepared by adding ergothioneine to a 1% solution of yeast extract (Springer 0402 / 20-MG-L) at concentrations of 0.5 ppm, 1 ppm, 3 ppm, 5 ppm, and 10 ppm. The umami and saltiness of the test samples were compared with a control without ERG and evaluated by a two-point discrimination test conducted by a panel of three experts. The results of the sensory evaluation are shown in Tables 15 and 16 below.

[0075]

[0076] All panelists evaluated that the umami and salty taste of the yeast extract were both enhanced by adding 0.5 ppm or more of ERG.

[0077] [Test 9: Amount of ERG Added to Enhance the Salty Taste of Yeast Extract] Samples (ERG 0.5-10) were prepared by adding ergothioneine to a 1% solution of yeast extract (Springer 0402 / 20-MG-L) at concentrations of 0.5 ppm, 1 ppm, 3 ppm, 5 ppm, and 10 ppm. The saltiness and umami of the test samples were compared with a control without ERG and evaluated by a two-point discrimination test conducted by a panel of three experts. The results of the sensory evaluation are shown in Tables 17 and 18 below.

[0078]

[0079] All panelists evaluated that the salty and umami tastes of the yeast extract were both enhanced by adding 0.5 ppm or more of ERG.

[0080] [Test 10: Taste-enhancing effect of ERG on various foods and beverages (Part 1)] Test products in which ERG was added to foods and beverages, and control foods and beverages to which ERG was not added, were evaluated by a two-point discrimination test by a panel of experts to see how the taste (umami, sweetness, bitterness) of the test products compared with the control. The results of the sensory evaluation are shown in Tables 19 to 24 below. Note that the test product "ERGX" refers to a test product to which X ppm of ERG was added. Sensory evaluation ◯: The taste is enhanced compared to the control. ◇: The taste is the same as the control.

[0081] (1) Hontsuyu (Hontsuyu) 5 ppm of ERG was added to a stock solution of Hontsuyu (Kikkoman Corporation), and then the solution was diluted 4 times and subjected to a sensory test. The addition of 5 ppm of ERG enhanced the umami and sweetness of the soup.

[0082] (2) Zaru Soba Soup Sauce 5 ppm of ERG was added to Zaru Soba Soup Sauce (straight soup: Kikkoman Corporation), and then a sensory test was carried out. The addition of 5 ppm of ERG enhanced the umami and sweetness of the zaru soba soup.

[0083] (3) Miso: 18 g of miso (Plus Koji Non-Additive Koji Bijin, Marukome Co., Ltd.) in 200 ml of hot water was mixed with 0.5 ppm of ERG and then subjected to a sensory test. The addition of 0.5 ppm of ERG enhanced the umami and sweetness of miso.

[0084] (4) Sauce: ERG was added to a sauce (Delicious Sauce Tonkatsu, Kikkoman Corporation) at 5 ppm, and then a sensory test was carried out. The addition of 5 ppm of ERG enhanced the umami and sweetness of the sauce.

[0085] (5) Shio-koji (salted rice malt) 5 ppm of ERG was added to salted rice malt (Plus Koji Nama Shio-koji, Marukome Co., Ltd.), and then a sensory test was performed. The addition of 5 ppm of ERG enhanced the umami, saltiness, and sweetness of the shio koji.

[0086] (6) Tomato Ketchup ERG (5 ppm) was added to tomato ketchup (Del Monte), and then a sensory test was carried out. The addition of 5 ppm of ERG enhanced the umami and sweetness of the tomato ketchup.

[0087] [Test 11: Taste-enhancing effect of ERG on various foods and beverages (Part 2)] A sensory evaluation was conducted by a panel of experts on test foods and beverages in which ERG was added, and control foods and beverages in which ERG was not added, to see how the saltiness of the test foods and beverages compared to the control. The results of the sensory evaluation are shown in Tables 25 to 29 below. Note that "ERGX" in the test products refers to test products to which X ppm of ERG was added. Sensory evaluation ◯: The saltiness is enhanced compared to the control. ◇: The saltiness is the same as the control.

[0088] (1) Zaru Soba Soup Sauce 5 ppm of ERG was added to Zaru Soba Soup Sauce (straight soup: Kikkoman Corporation), and then a sensory test was carried out. The addition of 5 ppm of ERG enhanced the saltiness of the zaru soba soup.

[0089] (2) Miso A sensory test was carried out after adding 5 ppm of ERG to miso (Plus Koji Non-Additive Koji Bijin, Marukome Co., Ltd.). The addition of 5 ppm of ERG enhanced the salty taste of miso.

[0090] (3) Sauce: ERG was added to a sauce (Delicious Sauce Tonkatsu, Kikkoman Corporation) at 5 ppm, and then a sensory test was carried out. The addition of 5 ppm of ERG enhanced the saltiness of the sauce.

[0091] (4) Shio-koji (salted rice malt) 5 ppm of ERG was added to salted rice malt (Plus Koji Nama Shio-koji, Marukome Co., Ltd.), and then a sensory test was performed. The addition of 5 ppm of ERG enhanced the salty taste of the shio koji.

[0092] (5) Tomato Ketchup ERG (5 ppm) was added to tomato ketchup (Del Monte), and then a sensory test was carried out. The addition of 5 ppm of ERG enhanced the salty taste of the tomato ketchup.

[0093] [Test 12: Sweetness Enhancement Effect of Soy Sauce] (1) Special Selection Whole Soybean Soy Sauce Soy sauce was prepared by adding ergothioneine to commercially available Special Selection Whole Soybean Soy Sauce (Kikkoman Corporation) at concentrations of 10 ppm, 20 ppm, and 50 ppm (EGR 10, 20, and 50). A drinking test was conducted by a three-person expert panel using soy sauce with ERG added at each concentration (concentrations not disclosed to the panel) as a control, with soy sauce without ergothioneine added (ERG 0). The sweetness was evaluated sensorily using a two-point discrimination test. The results are shown in Table 30.

[0094] <Evaluation method for two-point discrimination test> Evaluation results of the sweetness of the test product compared to the control ○: Sweetness is enhanced compared to the control. ◇: Sweetness is the same as the control. The evaluation method for the two-point discrimination test and the display of the evaluation results are the same for other tests.

[0095] All panelists rated the soy sauce containing 10 ppm or more of ERG as having an enhanced sweetness.

[0096] (2) Sweet soy sauce ERG was added to commercially available sweet soy sauce (Golden Purple, Fundokin Soy Sauce) and the same test as in (1) above was carried out. The results are shown in Table 31. All panelists rated the sweet soy sauce containing 10 ppm or more of ERG as having an enhanced sweetness.

[0097] [Test 13: Production of Soy Sauce] Equal amounts of steamed, denatured defatted soybeans and crushed roasted wheat were mixed, inoculated with koji starter, and koji was produced for 42 hours using conventional methods to obtain soy sauce koji. For the koji starter, an Aspergillus sojae mutant strain (Example 1) into which four copies of the egtA gene had been introduced and in which the inserted gene had been overexpressed, and an Aspergillus oryzae strain (Example 2) into which the G428S mutation had been introduced into the AO090005000664 gene, respectively, were used. 100 parts by mass of the resulting soy sauce koji were added to 130 parts by mass of salt solution (salt concentration 26% (w / v)), and the resulting mixture was fermented and aged at 25-30 °C for 150 days with appropriate stirring, following conventional moromi control. The resulting aged moromi was squeezed and filtered to obtain raw soy sauce. The resulting raw soy sauce was pasteurized at 80°C for 1 hour and then subjected to clarifying filtration to obtain soy sauce. The ERG concentrations in the soy sauces obtained by the clarifying filtration were 566 ppm for Example 1 and 250 ppm for Example 2. The soy sauces of the Examples had enhanced umami, saltiness, and sweetness compared to commercially available products. Furthermore, the soy sauce of Example 2 had improved compressibility and workability during the filtration process during its production.

[0098] [Test 14: Mirin Production] After polished rice was subjected to standard raw material processing, including washing, soaking, draining, steaming, and cooling, seed koji was inoculated and mixed at 0.1% of the rice weight, and koji production was controlled in a thermo-hygrostat at the optimum koji production temperature of 32-38°C to obtain koji. Aspergillus oryzae strains (Example) in which the G428S mutation had been introduced into the AO090005000664 ortholog gene and its wild-type strain (Comparative Example) were used as seed koji. Following standard mirin production methods, 48 ​​g of the rice koji described above (approximately 40 g of raw polished non-glutinous rice) was placed in a mashing vessel and mixed with 290 g of glutinous rice (kakemai) that had been washed, soaked, drained, steamed, and cooled using standard methods. Next, 155 ml of neutral alcohol (alcohol content 35% (v / v)) was saccharified at 30°C for one month to obtain matured mirin mash. The matured mirin mash was then pressed in the usual way to obtain a crude mirin filtrate. This was heat sterilized at a temperature of 90°C and then clarified and filtered to obtain mirin. The ERG concentration in the mirin obtained by the clarification filtration was 11 ppm for the Example and 2 ppm for the Comparative Example. The mirin of the Example had enhanced umami as well as sweetness compared to the mirin of the Comparative Example.

[0099] [Test 15: Mycoprotein Production] Fermentation was carried out in a 30 L jar (Marubishi Bioengine Co., Ltd.). Water was added to 1.5 kg of okara powder to bring the total volume to 15 L, and 2.25 g of Shin-Etsu Silicone (registered trademark) KM72F (Shin-Etsu Chemical Co., Ltd.), an antifoaming agent, was added and sterilized at 123°C for 60 minutes. The enzyme solution filtered through a 0.22 μm pore size filter was added to a final concentration of arabinase of 0.6 U / ml and a final concentration of cellulase of 0.1 U / ml, and the mixture was stirred and reacted at 60°C for 2 hours. After the reaction, the mixture was cooled to 30°C. Pre-culture was carried out as follows: 5 g of okara powder and 100 ml of water were added to one 500 ml baffled Erlenmeyer flask for each strain, and the mixture was autoclaved (121°C, 30 minutes). The seed koji used was an Aspergillus oryzae strain in which the G428S mutation was introduced into the AO090005000664 orthologous gene (Example 1), and an Aspergillus oryzae strain in which the AO090005000664 orthologous gene was wild-type (Comparative Example 1). 0.5-1 ml of glycerol stock of the seed was added, and the initial number of spores in the preculture solution was 5 × 10 ５ The preculture solution was inoculated to a concentration of 1 / ml. This preculture solution was cultured for 24 hours with shaking (30°C, 160 rpm). This preculture solution was then inoculated into a 30 L jar and cultured at 30°C for 3 days. The aeration rate and stirring rate were initially set at 0.5 vvm and 250 rpm, and increased to 1 vvm and 330 rpm after 18 hours. After culture, the fermented product was heat sterilized (80°C, 30 minutes).

[0100] The heat-sterilized fermented product was dried for 1 minute in a drum dryer (manufactured by Katsuragi Kogyo Co., Ltd., product name "Drum Dryer D-00") set at a gap of 0.3 mm and a surface temperature of 150°C. This is referred to as fermented soy pulp. The ergothioneine content was 1.70 g / kg dry koji mold fermented product (Example 1) and 0.1 g / kg dry koji mold fermented product (Comparative Example 1). Using 16.7 g of the fermented soy pulp obtained by the above procedure, the dried product was mixed with water in a ratio of 1:2 by weight. This mixture was then mixed with 3% soy sauce and 1% yeast extract, and kneaded for 10 seconds in a kneading machine (manufactured by Tiger Corporation, product name "Microcomputer Food Processor SKF-H101"). The kneaded sample was then formed into a dough with a thickness of 1.8 cm and an inner diameter of 7.5 cm. 5 ml of oil was added to a frying pan, and the formed samples were baked over low heat for 1 minute 20 seconds on each side, for a total of 2 minutes 40 seconds. The ergothioneine content was 1 g / kg for the dried koji mold fermentation product (Example 1) and 0.05 g / kg for the dried koji mold fermentation product (Comparative Example 1). A sensory evaluation of the taste of the mycoproteins of Comparative Example 1 and Example 1 was conducted by a five-person expert panel, and all panelists rated the mycoprotein of Example 1 as having a stronger umami flavor and tastier taste. Furthermore, Example 1 had a weaker odor than Comparative Example 1, making it more suitable for processing.

[0101] [Test 16: Production of Shio Koji] Production of Rice Koji 1250 g of polished rice was soaked overnight, transferred to a colander, and drained for 2 hours. The rice was then wrapped in Tetoron® cloth (Toray Industries, Inc.) and steamed at 100°C for 40 minutes. The steamed rice was cooled to 45°C and inoculated with koji starter. An Aspergillus oryzae strain (Example 2) in which the G428S mutation was introduced into the AO090005000664 orthologous gene and an Aspergillus oryzae strain (Comparative Example 2) in which the AO090005000664 orthologous gene was wild-type were used as koji starters. The rice was wrapped in Pylen cloth and koji production was initiated at 35°C and 95% humidity. 19 hours after the start of koji production, the rice koji was loosened and again wrapped in Pylen cloth. When the product temperature reached 40°C, a Pylen cloth was spread to flatten the rice koji. After another 40 hours, the rice koji was thoroughly loosened and allowed to stand again. After 42 hours, the koji was dumped. The ergothioneine content was 0.35 g / kg of the dried koji mold fermentation product (Example 2) and 0.03 g / kg of the dried koji mold fermentation product (Comparative Example 2).

[0102] To 50 g of the obtained rice koji, 20 g of salt and 100 ml of hot water at 50°C were added, and the mixture was reacted at 50°C and 130 rpm for 14 hours. The ergothioneine content was 0.1 g / kg of the dried koji mold fermentation product (Example 2) and 0.01 g / kg of the dried koji mold fermentation product (Comparative Example 2). A sensory evaluation of the taste of the shio koji of Comparative Example 2 and Example 2 was conducted by a four-member expert panel, and all panelists rated the shio koji of Example 2 as having a stronger umami flavor and tastier taste.

[0103] [Test 17: Production of Amazake] Production of Amazake 800 g of rice koji obtained in Comparative Example 2 and Example 2 was added with 2.5 times the amount of hot water at 60°C, and a saccharification reaction was carried out at 55°C and 200 rpm. After 16 hours, the Brix was adjusted to 18%, transferred to a heat-resistant container, and sterilized at 85°C for 30 minutes. The ERG content of the resulting amazake was 115 ppm (Example 3) and 7 ppm (Comparative Example 3). Compared to Comparative Example 3, Example 3 had a stronger sweetness, a whiter color, a stronger chestnut aroma, and a better aroma due to less koji odor and bran odor. It also had fewer particles with large particle sizes, resulting in a smoother mouthfeel.

[0104] [Test 18: Production of soy sauce-soaked rice koji] Production of soy sauce-soaked rice koji 4 g of salt and 75 ml of soy sauce were added to 50 g of the rice koji obtained in Comparative Example 2 and Example 2, and the mixture was allowed to react for 14 hours at 50°C and 130 rpm. The ergothioneine content was 0.14 g / kg of the dried soy sauce-soaked rice koji (Example 4) and 0.01 g / kg of the dried soy sauce-soaked rice koji (Comparative Example 4). A sensory evaluation of the taste of the soy sauce-soaked rice koji of Comparative Example 4 and Example 4 was conducted by a four-member expert panel, and all panelists rated the soy sauce-soaked rice koji of Example 4 as having a stronger umami flavor and tastier.

[0105] [Test 19: Production of soy sauce (hishiho)] Production method of soy sauce Equal amounts of steamed and denatured defatted soybeans and crushed roasted wheat were mixed, inoculated with koji starter, and koji was produced for 42 hours by conventional methods to obtain soy sauce koji. For the koji starter, an Aspergillus oryzae strain (Example 5) in which the G428S mutation was introduced into the AO090005000664 orthologous gene and an Aspergillus oryzae strain (Comparative Example 5) in which the AO090005000664 orthologous gene was wild-type were used. 100 parts by mass of the resulting soy sauce koji were added to 130 parts by mass of salt water (salt concentration 26% (w / v)), and the mixture was fermented and aged at 25 to 30 ° C. for 150 days with appropriate stirring, following conventional moromi control. The ergothioneine content was 0.23 g / kg (Example 5) and 0.04 g / kg (Comparative Example 5). A sensory evaluation of the tastes of the soy sauces of Comparative Example 5 and Example 5 was conducted by a four-person expert panel, and all panelists evaluated that the soy sauce of Example 5 had a stronger umami flavor and was more delicious. Furthermore, Example 5 had reduced stale odor and oxidized odor compared to Comparative Example 5.

[0106] [Test 20: Production of Koji Mold-Fermented Seasoning Liquid] Production Method of Koji Mold-Fermented Seasoning Liquid: An Aspergillus oryzae strain with a G428S mutation introduced into the AO090005000664 orthologous gene was inoculated into a 2.15% dextrin, 4.5% yeast extract medium and cultured at 26°C for 7 days. The resulting culture was heated in a tank at 90°C for 30 minutes and then filtered. The ERG in the resulting filtrate was adsorbed onto ion exchange resin UBK08 (manufactured by Mitsubishi Chemical Corporation) and eluted with ammonia water to obtain a koji mold-fermented seasoning liquid. The ERG concentration of the resulting koji mold-fermented seasoning liquid was 30,000 ppm. The koji mold-fermented seasoning liquid was observed to have enhanced saltiness, sweetness, and umami.

Claims

1. An umami and / or salty taste enhancer containing ergothioneine as an active ingredient.

2. Food or beverage with enhanced umami, which contains ergothioneine, an umami enhancer, in an amount of 0.005% by weight or more of one umami component contained in the food or beverage.

3. Foods and beverages with an enhanced saltiness, in which ergothioneine, a saltiness enhancer, is contained in salt-containing foods and beverages at any of the following concentrations: (1) 0.5 ppm or more of ergothioneine in foods and beverages with a salt content of 0.1% by weight or more and less than 5% by weight; (2) 0.1 ppm or more of ergothioneine in foods and beverages with a salt content of 5% by weight or more.

4. The food or beverage according to claim 2 or 3, wherein the food or beverage with enhanced umami and / or saltiness is soy sauce, miso, fish sauce, mirin, bonito stock, soup stock, umami seasoning, fermented umami seasoning, ketchup, sauce, or mycoprotein.

5. The food or drink according to claim 2 or 3, which is produced using an ergothioneine-rich koji mold strain.

6. A food or beverage containing 10 ppm or more of ergothioneine and having enhanced umami and / or saltiness.

7. Soy sauce or soy sauce-containing seasonings that are not soy sauce for retort foods and contain 10 ppm or more of ergothioneine.

8. The soy sauce according to claim 7, which is a reduced-salt soy sauce.

9. The food or beverage according to claim 5 is a rice koji fermented product of koji mold with a high ergothioneine content of 0.3 g ergothioneine or more per kg of dried koji mold fermented product, the rice koji being obtained by culturing a koji mold strain that is highly ergothioneine-producing in a medium composed of raw materials with a protein content of 5 to less than 10%.

10. The food or beverage according to claim 5 is a mycoprotein or soy sauce koji, which is a high-ergothioneine koji fermentation product containing 0.4 g ergothioneine or more per kg of dried koji fermentation product, obtained by culturing a high ergothioneine-producing koji strain in a medium composed of raw materials with a protein content of 10% or more.

11. An ergothioneine-rich koji mold fermentation product containing 50 to 50,000 ppm of ergothioneine.

12. A method for enhancing the umami and / or saltiness of food or beverage by incorporating ergothioneine into the food or beverage.

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