Beany odor reducing material

Abstract

To provide a novel beany odor reducing material capable of reducing an unpleasant odor characteristic of soybeans.SOLUTION: A beany odor reducing material comprising filamentous fungal bodies derived from a fungus, the material being capable of reducing beany odor, where the filamentous fungal bodies derived from the fungus are fungal bodies grown by liquid cultivation. The fungus is at least one strain selected from the genus Aspergillus.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a new bean odor-reducing material that reduces the unpleasant odor peculiar to soybeans, i.e., bean odor. [Background technology]

[0002] As the world's population grows, the balance between food supply and demand is collapsing, becoming a social issue. In particular, food production through livestock farming (animal protein) faces environmental issues due to the large amount of greenhouse gases produced by livestock, as well as production efficiency issues such as long rearing periods. This has led to a real-world issue of protein supply not keeping up, known as a "protein crisis." Therefore, the development of alternative proteins to livestock farming is progressing rapidly, with expectations for plant-based proteins rising. In particular, the number of processed foods using soy protein as meat substitutes is increasing year by year.

[0003] However, soy protein has an off-flavor (beany smell) characteristic of beans, which is composed of various aroma compounds derived from soybeans. The various aroma compounds derived from soybeans have been found to include the following: aliphatic carbonyl compounds such as acetaldehyde, acetone, and n-hexanal; aromatic carbonyl compounds such as benzaldehyde and protocatechualdehyde; volatile fatty acids such as acetic acid, propionic acid, n-valeric acid, isovaleric acid, n-caproic acid, isocaproic acid, n-caprylic acid, pelargonic acid, n-nonanoic acid, and capric acid; volatile amino acids such as ammonia, monomethylamine, dimethylamine, and piperidine; and volatile aliphatic alcohols such as methanol, ethanol, 2-pentanol, isopentanol, n-hexanol, and n-heptanol. Ketones found include 2-pentanone, 3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-octanone, 3-octanone, 2-nonanone, and 3-nonanone. Various methods have been proposed to mask and reduce these off-flavors.

[0004] For example, there are proposals for reducing odor by devising a manufacturing method for soy protein itself (Patent Document 1), for a protein odor inhibitor using one or a combination of two or more of various specific compounds (Patent Document 2), and for a method for masking protein odor using processed tomatoes (Patent Document 3).Furthermore, Patent Document 4, which relates to a bean odor-reducing material using an enzymatic hydrolyzate of pea protein, confirms the effect of reducing hexanal, one of the components that causes bean odor.

[0005] Proposals for flavor-improving effects derived from microorganisms include an off-flavor suppressant for foods containing an extract of a basidiomycete fungus of the genus Pleurotus (Patent Document 5), a method for suppressing bitterness in foods using an extract of Ganoderma lucidum mycelium (Patent Document 6), and a flavor-improving method using a liquid culture solution from which the mycelium has been removed from a liquid-cultured Aspergillus oryzae culture solution (Patent Document 7). All of these methods improve flavor using mycelium extracts or mycelium culture solutions, and the flavor-improving effect of the mycelium itself is not known.

[0006] Koji mold is an important microorganism that is essential for the production of fermented foods such as sake, shochu, awamori, miso, and soy sauce. Its main uses are to grow koji mold on grains such as rice, wheat, and soybeans in solid culture to produce fermented foods, and to use it as a useful enzyme-producing fungus in liquid culture. As mentioned above, koji mold has rarely been used as a cultured fungus itself until now.

[0007] However, recent examples of the use of koji fungus itself include a composition in which liquid-cultured koji fungus can be used as a meat substitute and a method for producing the same (Patent Document 8), and a method for producing meat-like koji fungus that includes a step of recovering koji fungus by adding water to a solid culture of koji fungus on grains (Patent Document 9). None of these documents mention or suggest the effect of koji fungus itself in reducing the unpleasant odors and off-flavors that are characteristic of foods. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] WO2002-028197 publication [Patent Document 2] WO2019 / 039490 publication [Patent Document 3] Japanese Patent Application Publication No. 2019-71851 [Patent Document 4] Japanese Patent Application Publication No. 2023-135067 [Patent Document 5] Patent No. 7168382 [Patent Document 6] Japanese Patent Application Publication No. 2023-148189 [Patent Document 7] Japanese Patent Application Publication No. 2023-173817 [Patent Document 8] Patent Publication No. 2021-23172 [Patent Document 9] Patent No. 7264556 Summary of the Invention [Problem to be solved by the invention]

[0009] In response to the recent increase in vegetarians and the growing demand for vegan foods, various plant-based meat alternatives (plant-based meats) are being developed. Among these, soybeans are a very high-protein plant and are used as an ingredient in plant-based meats by various food manufacturers. However, soybeans are known to have a distinctive unpleasant odor, and there is an urgent need to develop technology to reduce this odor.

[0010] The object of this invention is to propose a new bean odor reducing material that reduces the unpleasant odor peculiar to soybeans, i.e., bean odor. [Means for solving the problem]

[0011] As a result of extensive research to achieve the above object, the present inventors have discovered that cultured koji fungus has a significant effect of reducing the unpleasant odor of soybeans, and have thus completed the present invention.

[0012] Examples of the present invention that achieve the above object include the following. [1] A bean odor reducing material made from filamentous fungal bodies that reduces the bean odor.

[0013] [2] The bean odor reducing material according to [1], wherein the filamentous fungal cells of the fungus are grown in liquid culture.

[0014] [3] The bean odor reducing material according to [1] or [2], wherein the fungi are one or more strains selected from the genus Aspergillus.

[0015] [4] The bean odor reducing material according to [3], which is involved in the reduction of one or more of acetic acid, benzaldehyde, 2-heptanone, and isopentanol, which are components involved in the bean odor.

[0016] [5] The bean odor reducing material, wherein the fungus is Aspergillus oryzae [4]. [Effects of the Invention]

[0017] According to the present invention, a new bean odor-reducing material can be provided that reduces the unpleasant odor peculiar to soybeans, i.e., bean odor. [Brief explanation of the drawings]

[0018] [Figure 1] Recipes of foods (foods made primarily from soybeans) used in a sensory evaluation of the soybean flavor masking effect of the three types of koji fungus powders prepared in Example 1: Aspergillus oryzae, Aspergillus sojae, and Aspergillus luchuensis. [Figure 2]FIG. 1 shows a sensory evaluation of the soybean flavor masking effect of the Aspergillus oryzae koji mycelium powder prepared in Example 1. [Figure 3] FIG. 1 shows a sensory evaluation of the soybean flavor masking effect of the Aspergillus sojae koji mycelium powder prepared in Example 1. [Figure 4] FIG. 1 is a graph showing a sensory evaluation of the soybean flavor masking effect of the koji mycelium powder of Aspergillus luchuensis prepared in Example 1. [Figure 5] This figure shows the relative reduction (%) of four bean-flavored components that are reduced when Aspergillus oryzae koji powder prepared in Example 1 is added to shumai paste, after identifying them using gas chromatography-mass spectrometry (GC-MS). DETAILED DESCRIPTION OF THE INVENTION

[0019] A bean odor-reducing material according to one embodiment of the present invention comprises koji fungus bodies.

[0020] The koji mold used in the bean odor-reducing material comprising koji fungus bodies can be koji mold (genus Aspergillus) that has been used in the production of foods such as sake, shochu, awamori, miso, soy sauce, etc. Specifically, strains such as Aspergillus oryzae, Aspergillus sojae, Aspergillus luchuensis, Aspergillus kawachii, Aspergillus awamori, Aspergillus tamari, and Aspergillus niger, as well as their white mutants, can be used.

[0021] Koji mold is recognized as a safe microorganism, as it is classified as biosafety level 1 in the National Institute of Infectious Diseases' pathogen safety management regulations and has been certified as GRAS (Generally Recognized as Safe) by the U.S. Food and Drug Administration.

[0022] The koji fungus that constitutes the bean odor reducing material of this embodiment may be produced using either liquid culture or solid culture. Solid culture refers to growing the fungus by attaching koji fungus conidia (spores) to grains such as rice, barley, or soybeans. Depending on the grain used, it is called "rice koji," "barley koji," "soybean koji," or the like. Generally, it is difficult to recover fungus from solid culture, the recovery rate is low, and it is also thought that removing impurities is difficult. Therefore, it is preferable to obtain koji fungus by liquid culture.

[0023] However, according to Patent Document 9, when water is added to a solid culture and the mixture is allowed to stand for one hour or more, the grain substrate is dissolved by the action of hydrolytic enzymes, and a suspension is obtained in which the koji mycelia are separated from the solid culture in the form of pellets or pulp. Methods have been proposed for recovering the koji mycelia from this suspension by known solid-liquid separation methods such as filtration, centrifugation, and squeezing, and it is also possible to use the koji mycelia recovered from the solid culture.

[0024] When solid culture is selected, the grain used in the solid medium is not particularly limited as long as it is a grain that can be used for koji production. For example, in this embodiment, grains that can be used for koji production include rice, wheat, soybeans, corn, and the like. Other examples include grain-derived germs such as wheat bran, cellulosic biomass, and starch cake. These grains may be crushed, defatted, or dried.

[0025] As an example of solid culture selected in this embodiment, grains are first washed and soaked in water to absorb water, and then thoroughly steamed using a steamer, steam sterilizer, or the like. For example, when rice is used as the grain, the moisture content of raw rice such as non-glutinous rice or glutinous rice is typically 13 to 17% by weight. To increase the moisture content to 35% by weight or higher, which is the moisture content of typical koji rice, the rice is soaked in water and then steamed. When steaming rice, steamed rice is typically obtained at a steaming temperature of 100 to 120°C for a steaming time of 10 to 60 minutes, but the steaming conditions are not limited to these and can be changed as appropriate depending on the type and shape of the grain.

[0026] The steamed grains are cooled to 45° C. or less and then inoculated with the bacteria. In this embodiment, the inoculation may be in any form, such as spores or mycelia.

[0027] The culture temperature after inoculation is preferably 20 to 40°C, and the culture time is optional but is usually about 1 to 10 days. In the case of rice, it takes about 2 to 3 days at room temperature for the koji mold in the solid koji to grow uniformly and become dense.

[0028] The step of recovering koji mold from the solid culture is not particularly limited, and known separation methods, such as the method described in Patent Document 9, can be used as appropriate.

[0029] On the other hand, when liquid culture is selected, which allows for easy recovery of koji fungal bodies after culture, any liquid medium may be used as long as it allows the koji fungus to grow. For example, liquid media containing nitrogen sources, carbon sources, inorganic salts, etc., which are commonly used in the culture of filamentous fungi may be used. Furthermore, both natural and synthetic liquid media may be used in this embodiment as long as they allow the koji fungus to grow.

[0030] Examples of the nitrogen source that can be used include inorganic salts such as ammonia, ammonium chloride, ammonium sulfate, ammonium acetate, and ammonium phosphate, and ammonium salts of organic acids, other nitrogen-containing compounds, as well as peptone, meat extract, yeast extract, corn steep liquor, casein hydrolysate, soybean meal and soybean meal hydrolysate, defatted soybeans, isolated soybean protein, gluten, gelatin, collagen, and casein.

[0031] The carbon source may be glucose, maltose, fructose, sucrose, lactose, starch, soluble starch, etc. Alternatively, mixed sugars such as blackstrap molasses, which is a by-product of sucrose production, may also be used, and there is no particular limitation.

[0032] Examples of inorganic salts that can be used include monopotassium phosphate, dipotassium phosphate, magnesium phosphate, magnesium sulfate, sodium chloride, ferrous sulfate, manganese sulfate, copper sulfate, and calcium carbonate.

[0033] As the natural medium, koji juice obtained by adding water to rice koji and heating it to saccharify it can be used. Furthermore, solids such as sake lees and shochu lees, which are brewing by-products in the production of sake and shochu, or fermentation residues from the production of brewed seasonings, may be added to the liquid medium.

[0034] The koji mold added to the medium may be in any form, including spores or mycelia.

[0035] The pH and temperature during cultivation are not particularly limited and may be those generally used for mycelia such as koji. The pH of the medium is adjusted to, for example, about 3 to 8, and the cultivation is carried out under aerobic conditions at a temperature of about 20 to 40°C, preferably about 25 to 35°C, for a cultivation period of 1 to 10 days, preferably about 2 to 5 days.

[0036] In this embodiment, under the above-described culture conditions, a culture method generally used in liquid culture can be employed. For example, shaking culture, aeration and agitation culture using a jar fermenter, or bubble column culture can be used. Generally, shaking culture with aeration and agitation culture is employed, and the higher the dissolved oxygen concentration, the better, preferably 1 ppm or higher.

[0037] When koji mold is cultured in liquid, the koji mycelium aggregates and may take the form of pellets (marimo-like), which are spherical with a diameter of about 1 to 10 mm, or may take the form of linear or fibrous pulp (fiber-like).

[0038] In this embodiment, the hyphal form after culture is not particularly limited, and may be in the form of pellets, pulp, or a mixture of pellets and pulp, as described above. Those skilled in the art can appropriately adjust the hyphal form by adjusting the culture conditions.

[0039] The above-mentioned pulp-like form refers to the mycelium dehydrated with a Nutsche or the like and completely becoming a sheet, whereas the above-mentioned pellet-like form refers to a form in which the mycelium mass is partially or completely retained even after dehydration with a Nutsche or the like.

[0040] The step of recovering koji mold from the culture liquid is not particularly limited, and known separation methods such as centrifugation, filtration separation, compression separation, slide culture separation, etc. can be used as appropriate.

[0041] As described above, koji mold cells recovered from a liquid culture or solid culture can be used as wet cells in the bean odor reducing material of this embodiment. The recovered wet koji mold cells can also be dried to form dried flakes, which can then be used as the bean odor reducing material of this embodiment. Furthermore, they can be crushed and sieved to form a uniform powder, which can then be used as the bean odor reducing material of this embodiment. Known methods can be used for drying and drying / powdering, and there are no particular limitations. For example, a vacuum belt dryer, a drum dryer, a vacuum drum dryer, etc. can be used.

[0042] The powdering can be carried out with or without an excipient depending on the suitability of various drying equipment.

[0043] The excipients are not particularly limited as long as they are edible, and examples thereof include salt (special grade salt, common salt, regular salt, white salt, etc.), starch (e.g., corn starch, potato starch, tapioca starch, waxy corn starch, wheat starch, rice starch, sago starch, sweet potato starch, etc.), modified starch (pregelatinized starch, partially pregelatinized starch, acid-treated starch, oxidized starch, oxygen-treated starch, starch acetate, starch phosphate, starch succinate, starch octenylsuccinate, hydroxypropyl starch, etc.), starch hydrolysates (dextrin, maltodextrin, powdered sugar, etc.), sugars (monosaccharides (glucose, fructose, etc.), disaccharides (e.g., sucrose, lactose, maltose, trehalose, etc.), oligosaccharides (cellooligosaccharides, maltooligosaccharides, fructooligosaccharides, etc.), sugar alcohols ( Examples of suitable sugars include sugars containing gluten, gluten-containing sugars (e.g., xylitol, sorbitol, lactitol, maltitol, etc.), reduced sugars, etc.), and dietary fiber (e.g., indigestible dextrin, polydextrose, enzymatically decomposed guar gum, etc.).

[0044] The bean odor reducing material comprising koji fungus bodies of this embodiment may be used alone or may be blended with other components, such as excipients, additives, and various food and beverage ingredients.

[0045] As the excipient to be blended, various excipients exemplified above as excipients to be added during powdering can be used.

[0046] The additives to be added are not particularly limited, but examples thereof include amino acids (e.g., glutamates such as sodium L-glutamate, glycine, DL-alanine, etc.), nucleic acids (e.g., disodium 5'-inosinate, disodium 5'-guanylate, etc.), organic acids or their salts (disodium succinate, succinic acid, trisodium citrate, potassium gluconate, calcium citrate, acetic acid, etc.), inorganic salts (potassium chloride, sodium phosphate, potassium phosphate, calcium chloride, magnesium sulfate, etc.), emulsifiers (e.g., sucrose fatty acid esters, glycerin fatty acid esters, lecithin, saponin, etc.), alcohols, thickeners, buffers, preservatives, antioxidants, colorants, fragrances, pH adjusters, etc.

[0047] The various food and beverage ingredients to be blended are not particularly limited, but examples include protein hydrolysates, meat and seafood-derived ingredients (chicken extract, pork extract, beef extract, bonito extract, bonito powder, etc.), vegetable-derived ingredients (vegetable powder, vegetable extract, shiitake mushroom extract, etc.), fruit-derived ingredients (fruit juice, fruit juice powder, fruit pulp, fruit peel, fruit extract, etc.), seaweed-derived ingredients (kelp extract, kelp powder, etc.), oils and fats, spices, yeast extract, etc. These other ingredients may be used alone or in combination of two or more.

[0048] The bean odor reducing material made from koji fungus bodies of this embodiment can be used in foods that use soybeans as their main ingredient (i.e., foods in which soybeans or soybean products account for the largest proportion of the weight of each ingredient used, excluding water), to exert an effect of reducing the unpleasant odor of soybeans, i.e., bean odor.

[0049] In this case, it is desirable to add the bean odor reducing material consisting of koji fungus of this embodiment to foods whose main ingredient is soybeans in such a proportion that the solid content of the koji fungus constituting the bean odor reducing material is 0.1 mass % or more in order to exert the above-mentioned reduction effect.

[0050] By adding the bean odor reducing material consisting of koji fungus of this embodiment to the above-mentioned food products whose main ingredient is soybeans so that the solid content of the koji fungus constituting the bean odor reducing material is 0.1 mass % or more, the strength of the soy flavor when eaten can be reduced compared to foods whose main ingredient is soybeans and that do not contain the added material.

[0051] For example, if the solid content of the bean odor reducing material (the koji fungus cells of this embodiment described above) is 50% for 100g of the above-mentioned food made primarily from soybeans, it is preferable to add 0.2g or more (of which the solid content is 0.1g).Furthermore, if the solid content of the bean odor reducing material (the koji fungus cells of this embodiment described above) is 40% for 100g of the above-mentioned food made primarily from soybeans, it is preferable to add 0.25g or more (of which the solid content is 0.1g).

[0052] The effect of reducing the unpleasant soybean odor, i.e., the beany odor, exhibited by using the beany odor-reducing material made of koji fungus cells of this embodiment in the above-mentioned foods whose main ingredient is soybeans can be evaluated by a sensory test by panelists or by qualitative analysis of aroma components that cause off-flavors using a gas chromatograph-mass spectrometer (GC-MS) or the like. [Example]

[0053] The following describes in more detail the embodiments of the present invention, but the present invention is not limited to the above-described embodiments and the examples described below, and can be modified in various ways within the technical scope understood from the claims.

[0054] Example 1: Cultivation, harvesting, and preparation of dried powder of koji mold <Koji mold cultivation> Six pre-culture media were prepared by placing 150 ml of 3xDPY medium (6% dextrin, 3% hipolypepton, 3% yeast extract, 0.5% KH2PO4, 0.05% MgSO4 7H2O) in 500 ml Sakaguchi flasks. Two pre-culture media were inoculated with 1 ml of each spore suspension of Aspergillus oryzae, Aspergillus sojae, and Aspergillus luchuensis, followed by reciprocal osmotic culture at 30°C for 48 hours.

[0055] Next, three 10-L jar fermentors were filled with 6 L of 3xDPY medium (6% dextrin, 3% hipolypepton, 3% yeast extract, 0.5% KH2PO4, 0.05% MgSO4·7H2O, 0.025% Adekanol LG-109) to prepare the main culture medium. 300 ml (2 x 150 ml bottles) of each of the precultures of the three koji mold strains mentioned above was inoculated into each jar fermentor, and the medium was cultured at 30°C for 120 hours with aeration and agitation (300 rpm, 1 vvm, pH 5.0 with 5N H2SO4).

[0056] During the cultivation, after 72 hours, a feed solution (500 ml of 40% Dextrin, 10% Hipolypepton+10% Yeast extract+0.15% Adekanol LG-109) was added to each jar fermenter.

[0057] <Recovery of koji fungus cells> The culture medium from each jar fermenter in which the three types of koji mold mentioned above were cultivated was collected and the fungal cells were collected by suction filtration. The collected fungal cells were washed once with approximately 5 L of distilled water and then collected again by suction filtration.

[0058] <Preparation of dried koji fungus> The three types of koji mycelia collected as described above (wet mycelia, approximately 13% solids) were dried and powdered using a vacuum drum dryer to obtain koji mycelia powder, which was used as the sample.

[0059] (Example 2) Test to reduce bean odor of koji fungus Using the koji mycelium powders from the three strains prepared by the method described above, a test was conducted to test each strain to reduce the beany odor of soy meat as follows. <How to prepare test samples> Foods containing soy as the main ingredient (i.e., foods in which soy or soy products account for the largest proportion by weight of each ingredient used, excluding water) were prepared by mixing ingredients according to the recipe in Figure 1.

[0060] The prepared food to which no koji fungus powder was added was designated the "non-added group."

[0061] The three types of koji mycelium powders from Example 1 were added to the prepared foods so that the amounts of the powders were 0.1%, 0.5%, 1.0%, and 2.0% by mass, respectively, and these were designated the "Koji mycelium-added group." The three types of koji mycelium powders from Example 1 were added so that the solid content was 0.1%, 0.5%, 1.0%, and 2.0% by mass, respectively, and these were designated the "Koji mycelium-added group."

[0062] The non-added group and the koji-added group were steamed for 10 minutes to create soy meat-based shumai paste. <Sensory evaluation> A sensory evaluation was conducted by 13 panelists (Aspergillus oryzae) or 14 panelists (Aspergillus sojae, Aspergillus luchuensis) to determine whether the shumai fillings in each group had a masking effect on the soybean flavor.

[0063] Compared to the non-added group, those who felt that the koji fungus comparison group had a soybean flavor masking effect were rated as ○, and those who did not were rated as ×. The results of the sensory evaluation by 13 or 14 panelists are shown in Figure 2 (Aspergillus oryzae), Figure 3 (Aspergillus sojae), and Figure 4 (Aspergillus luchuensis).

[0064] As shown in Figures 2, 3 and 4, compared to the non-added group, it can be confirmed that there is a masking effect on the unpleasant odor of soybeans when added at 0.1% or more, preferably 0.5% or more, and more preferably 1.0% or more.

[0065] That is, in the case of the shumai paste containing Aspergillus oryzae cells, the results of which are shown in Figure 2, when compared to the non-added group, the addition of 0.1% by mass was rated as having a soybean flavor-masking effect, and at the 0.5% by mass addition level, more than half of the panelists rated the addition of 0.1% by mass as having a soybean flavor-masking effect compared to the non-added group.

[0066] In the case of the shumai paste containing Aspergillus sojae cells, the results of which are shown in Figure 3, when compared to the non-added group, the addition of 0.1% by mass of cells was rated as having a soybean flavor-masking effect, and at the 0.5% by mass addition level, nearly half of the panelists rated the addition of 0.5% by mass as having a soybean flavor-masking effect compared to the non-added group, and at the 1.0% by mass addition level, most panelists rated the addition of 1.0% by mass as having a soybean flavor-masking effect compared to the non-added group.

[0067] In the case of the shumai paste containing Aspergillus luchuensis cells, the results of which are shown in Figure 4, when compared to the non-added group, it was rated as having a soybean flavor masking effect at the 0.1% by mass addition stage, and at the 0.5% by mass addition stage, half of the panelists rated as having a soybean flavor masking effect compared to the non-added group.

[0068] These results confirmed that all three types of koji fungus body powders prepared in Example 1 could be used as bean odor-reducing materials that reduce the unpleasant odor specific to soybeans, i.e., bean odor.

[0069] Furthermore, it was confirmed that adding each of the three types of koji fungus powder prepared in Example 1 so that the solid content of the koji fungus was 0.1% by mass produced an effect of reducing the unpleasant odor specific to soybeans, i.e., beany odor; preferably, adding it so that the solid content was 0.5% by mass produced a better effect, and adding it at 1.0% by mass or more produced an even better effect.

[0070] (Example 3) Evaluation by gas chromatograph-mass spectrometer (GC-MS) Two grams of the shumai paste from the Aspergillus oryzae cell-added group in Example 2 was weighed and placed in a 20 mL headspace vial. The gas chromatograph and mass spectrometer conditions were as follows: <Gas chromatograph analysis conditions> Measurement equipment: GCMS-QP2020 (Shimadzu Corporation) GC column: Rtx-5MS (Restek), length 30 m, inner diameter 0.25 mm, film thickness 0.25 μm Carrier: He gas, gas flow rate 1.78 mL / min Temperature conditions: 40°C for 1 minute, then increase to 280°C at 10°C / minute Headspace Conditions (trap mode) Number of extractions: 5 Standby: Transfer temperature 150℃, Sample line temperature: 150℃, Trap heating temperature: 250℃ Sample heating: 70℃ Vial retention time: 30 minutes Pressure: 40kPa, 0.5 minutes

[0071] <Mass spectrometry conditions> Measurement equipment: GCMS-QP2020 (Shimadzu Corporation) Ionization method: EI (ionization voltage 70 eV) Ion source temperature: 200℃ Scan mass: m / z = 35.0 to 500.0 Analysis of the aroma components of each sample revealed that the four beany-smelling components shown in Table 1 below (acetic acid, benzaldehyde, 2-heptanone, and isopentanol) that decreased depending on the amount of koji fungus powder added were identified based on their confirmatory ions, their peak areas were calculated, and the amount of each beany-smelling component contained in each sample was calculated taking into account the dilution rate with water. Figure 5 shows the relative component amounts, with the amount of beany-smelling components when no koji fungus was added being set at 100%.

[0072] [Table 1] Acetic acid, benzaldehyde, 2-heptanone, and isopentanol are all bean-smelling components that have been found to be derived from soybeans. Acetic acid has a pungent odor, benzaldehyde has an almond-like odor or bitter almond oil (a medicinal oil extracted from a type of almond), 2-heptanone has a blue cheese-like odor or a pungent almond odor, and isopentanol has an unpleasant, grassy odor.

[0073] As shown in Figure 5, it was confirmed that these four components tended to decrease depending on the amount of koji fungus powder added.

[0074] As a result, it was confirmed by GC-MS that Aspergillus oryzae, one of the three types of koji fungus powder that were confirmed in Example 2 to be a bean-odor reducing material that reduces the unpleasant odor specific to soybeans, i.e., bean odor, was involved in reducing the four components mentioned above that are related to bean odor.

[0075] The sensory evaluation in Example 2 confirmed that the effect of Aspergillus oryzae in reducing the unpleasant odor specific to soybeans, i.e., beany odor, depends on the amount of Aspergillus oryzae added. The GC-MS evaluation in Example 3 confirmed that the effect of reducing the soybean-derived aroma components acetic acid, benzaldehyde, 2-heptanone, and isopentanol also depends on the amount of Aspergillus oryzae added.

[0076] It is thought that a similar tendency may be observed for Aspergillus sojae and Aspergillus luchuensis, two of the three types of koji fungus powder that were confirmed in Example 2 to be bean-odor reducing materials that reduce the unpleasant odor specific to soybeans, i.e., the bean odor.

Claims

1. A bean odor reducing material made from filamentous fungal bodies that reduces the bean odor.

2. 2. The bean odor reducing material according to claim 1, wherein the filamentous fungal cells of the fungus are grown in liquid culture.

3. 3. The bean odor reducing material according to claim 1, wherein the fungi are one or more strains selected from the genus Aspergillus.

4. 4. The bean odor reducing material according to claim 3, which is involved in the reduction of one or more of acetic acid, benzaldehyde, 2-heptanone, and isopentanol, which are components that contribute to the bean odor.

5. 5. The bean odor reducing material according to claim 4, wherein the fungus is Aspergillus oryzae.

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