Methods for producing koji-based foods

Abstract

This invention provides a method for producing koji-based food products from solid components that were by-products of liquid seasonings. [Solution] A method for producing food products using koji, comprising the steps of: fermenting a mixture containing rice, koji mold, and water; separating the mixture into solid and liquid; and heating the solid obtained by separation at 80°C to 140°C for 30 minutes to 5 hours.

Description

Technical Field

[0001] The present invention relates to a method for producing koji-utilized foods.

Background Art

[0002] In Patent Document 1, while maintaining the function of salt koji, as a liquid seasoning with a good balance of umami, sweetness, and saltiness, a liquid seasoning obtained by fermenting and aging a preparation liquid mixed with rice koji, salt, and water at a low temperature and then performing solid-liquid separation is described.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The liquid seasoning described in Patent Document 1 obtains the liquid at the time of solid-liquid separation after fermenting and aging a preparation liquid mixed with rice koji, salt, and water, and uses it as a seasoning. The solid component at the time of the solid-liquid separation is discarded as a by-product, and effective utilization of resources has been demanded. An object of the present invention is to provide a method for producing koji-utilized foods and koji-utilized foods from solid components and the like that were by-products of the liquid seasoning.

Means for Solving the Problems

[0005] Thus, a first aspect of the present invention is a method for producing koji-utilized foods, including a step of fermenting a mixture containing rice, koji mold, and water, a step of separating the mixture into a solid and a liquid, and a step of heating the solid obtained by the separation at 80°C or higher and 140°C or lower for 30 minutes or longer and 5 hours or shorter. A second aspect is the method for producing koji-utilized foods according to the first aspect, in which the mixture is fermented at 4°C or higher and 40°C or lower. A third aspect is a method for producing a koji-based food according to the first or second aspect, wherein the mixture comprises rice koji, which is made by cultivating koji mold on steamed rice, and water. [Effects of the Invention]

[0006] According to a first aspect of the present invention, it is possible to provide food products such as seasonings that have excellent flavor, including richness, while maintaining the umami of koji, from the by-products of liquid salt koji. According to the second embodiment, the flavor, such as richness, of the food can be improved. According to the third embodiment, a food product having the umami flavor of rice koji can be provided. [Brief explanation of the drawing]

[0007] [Figure 1] This is a process diagram showing an example of the manufacturing process for liquid salt koji using conventional technology. [Figure 2] This is a process diagram showing an example of the manufacturing process for a koji-based food product according to the first embodiment. [Figure 3] This figure shows the absorption spectra of the food product of the present invention, and a sample of the food product before heating. [Figure 4] These are FT-IR spectral diagrams of the food product of the present invention (a) and a sample of the food product before the heat drying process (b). [Figure 5] This graph shows the change in taste intensity over time (a) and the spread of taste in the mouth (b) as part of a sensory evaluation when the food product of the present invention is used in butter cookies. [Figure 6] This is a process diagram showing an example of the manufacturing process for koji-based food products according to the second and third embodiments. [Figure 7] This graph shows the results of gas chromatography-mass spectrometry of koji-based food products and other products according to the present invention. [Figure 8] This figure shows the HPLC chromatogram of the koji-based food product of the present invention. [Figure 9] The figure shows the results of HPLC analysis; (a) is the analysis graph for koji-based food products, and (b) is the graph of the Maillard reaction product of cysteine ​​and glucose. [Figure 10]This figure shows the UV spectrum of the sample. [Figure 11] This figure shows a mass spectrometry graph obtained by the positive ion mode of ESI-MS, where (a) is the koji-based food product of the present invention, and (b) is the Maillard reaction product of cysteine ​​and glucose. [Figure 12] This figure shows a mass spectrometry graph obtained by positive ion mode ESI-MS for a koji-based food product according to the first embodiment. [Modes for carrying out the invention]

[0008] The embodiments of the present invention will be described below. These descriptions and examples are illustrative and do not limit the scope of the invention. In this disclosure, unless otherwise specified, the expressions "greater than or equal to XX and less than or equal to XX" or "XX to XX" refer to the numerical range including the stated upper and lower limits. The method for producing koji-based food according to the first embodiment is characterized by comprising the steps of fermenting a mixture containing rice, koji mold, and water, and heating the solid contained in the mixture.

[0009] First, we will describe the koji-based food product manufactured according to the first embodiment. The koji-based food produced by this embodiment can provide a deep, rich umami flavor to the food obtained using it. The following mechanism is presumed to be responsible for this. As will be described later, by adding koji to rice and allowing it to ferment, sugars and proteins in the rice are broken down by various digestive enzymes, producing reducing sugars, amino acids, peptides, etc. Conventionally, food obtained by fermentation has not been further heated, but in this embodiment, heating the solid containing these decomposition products, especially the solid after solid-liquid separation, causes the Maillard reaction to occur, generating melanoidins, which give the flavor richness and also provide flavor persistence. Furthermore, it is known that the fermentation of koji produces aromatic compounds such as amines and aldehydes, and these aromatic compounds give food a rich flavor. Furthermore, by using rice, rice-derived dietary fiber, sugars produced by the decomposition of rice, etc. impart richness to the texture. It is considered that the richness of each of these tastes, aromas, and textures exhibits different effects depending on the food ingredients used in combination, and as a result, presents richness, umami, etc.

[0010] Hereinafter, the method for producing a koji-utilizing food according to the first embodiment will be described in detail. First, a mixture containing rice, koji mold, and water is fermented. There is no limitation on the type of food that can be obtained as long as it is obtained by fermenting rice, koji mold, and water. In this embodiment, typically, salt is further added to produce salted koji, but alternatively, it is also possible to produce amazake without adding salt, produce sake by adding yeast, or produce mirin by adding alcohol.

[0011] Hereinafter, the case of producing salted koji will be described. Normally, koji mold is added to rice to obtain a state called rice koji. The rice koji used in this embodiment can be prepared according to the normal koji-making method for rice koji. Specifically, it is obtained by spraying koji mold (also called seed koji) on steamed rice obtained by steaming rice and propagating it under conditions optimal for koji mold. The propagation of koji mold may be carried out by culturing at 25 to 40°C for 2 to 4 days using an automatic fermenter (e.g., HK-60, manufactured by Yaegaki Food & System Co., Ltd.). Commercially available products may be used as the rice koji used in the present invention. For the rice, polished rice (white rice) is preferably used, such as japonica rice, indica rice, or glutinous rice. Either japonica rice or indica rice can be used as the polished rice. The rice can be washed as needed, immersed in water, and drained as needed before use.

[0012] The koji mold used is not particularly limited as long as it is a type of koji mold commonly used in koji production. Suitable examples include Aspergillus species such as Aspergillus oryzae and Aspergillus sojae. The koji mold may be a commercially available product sold as starter koji, or it may be cultured. The koji mold may be in granular or powder form. The koji mold used in this embodiment is preferably one with high saccharification and protease production capabilities, specifically, koji mold for miso, koji mold for rice koji, or koji mold for soy sauce, more preferably koji mold for rice koji or miso, and even more preferably koji mold for miso. These may be used individually or in combination of two or more types.

[0013] The mixture for fermentation, which contains rice, koji mold, and water, is usually in the form of rice and other ingredients in water. When producing salt koji by fermentation, salt and water are mixed with the rice koji obtained as described above. These can be added and mixed at the same time, or added and mixed sequentially. It is desirable to mix the rice koji into the mixture in an amount of 30% to 70% by mass, preferably 35% to 60% by mass, more preferably 40% to 55% by mass, and even more preferably 45% to 50% by mass. The salt should preferably be mixed in an amount of 2% to 20% by mass relative to the mixture, more preferably 3% to 18% by mass, more preferably 4% to 16% by mass, and even more preferably 5% to 15% by mass. This salt can suppress the growth of microorganisms in the mixture. If there is too little salt, microorganisms tend to proliferate.

[0014] A mixture containing rice, koji mold, and water is fermented. It is preferable to ferment and mature the mixture at a temperature that does not inactivate the enzymes derived from koji mold contained in the mixture. Here, enzymes derived from koji mold refer to enzymes produced by koji mold, and include, for example, amylase, protease, lipase, and cellulase. These enzymes are sensitive to heat, and protease in particular is inactivated when fermented at temperatures above 60°C. In the preferred configuration, the fermentation temperature is preferably 4-40°C, more preferably 20-38°C, more preferably 25-35°C, and even more preferably 28-32°C. At these temperatures, enzymes derived from Aspergillus oryzae are not inactivated. During fermentation, not only does the koji mold ferment, but enzymes derived from the koji mold typically break down starch, protein, and lipids contained in the rice. This breakdown is sometimes referred to as saccharification. The fermented mixture (fermented and aged product) is generally called "shio koji" (salted koji) and is sometimes sold commercially in this state.

[0015] In the preferred form, fermentation is preferably carried out until the Brix of the fermented mixture (fermented and aged product) increases by 4% or more, preferably by 6% or more, and more preferably by 9% or more, based on the Brix value on the first day of fermentation. Here, Brix refers to the value measured using a refractometer, and this value changes with increases or decreases in sucrose, salt, various amino acids, glucose, maltose, and other components. Therefore, the Brix value changes depending on the composition of the raw materials of the brewing liquid. For example, in the case of a brewing liquid mixed with 50% by mass of rice koji, 13% by mass of salt, and 37% by mass of water, fermentation is preferably carried out until the Brix of the fermented mixture reaches 37% or more, preferably by 39% or more, and more preferably by 41% or more. Brix can be measured using methods known to those skilled in the art, for example, using a commercially available handheld refractometer or a digital refractometer. Generally, measuring Brix is ​​simpler than measuring the sugar concentration.

[0016] In a preferred embodiment, fermentation is preferably carried out until the direct sugar concentration of the fermented mixture increases by 8% or more, preferably by 12% or more, and more preferably by 18% or more, based on the direct sugar concentration value on the first day of fermentation. Here, direct sugar refers to direct reducing sugar, and the direct sugar concentration varies depending on the composition of the raw materials of the brewing liquid. For example, in the case of a mixture consisting of 50% by mass of rice koji, 13% by mass of salt, and 37% by mass of water, fermentation is preferably carried out until the direct sugar concentration of the fermented brewing liquid reaches 16% or more, preferably by 20% or more, and more preferably by 26% or more. The direct sugar concentration can be measured using methods known to those skilled in the art, for example, by the Somogyi modification (Journal of the Japan Society for Bioscience, Biotechnology, and Agrochemistry 28(3)171-174(1954)) or by the method shown in the Japanese Agricultural Standards for Soy Sauce.

[0017] In a more preferred embodiment, fermentation is preferably carried out until the Brix of the fermented mixture (fermented and aged product) increases by 4% or more and the saturates increase by 8% or more, based on the value on the first day of fermentation; preferably, until the Brix increases by 6% or more and the saturates increase by 12% or more; and more preferably, until the Brix increases by 9% or more and the saturates increase by 18% or more. When the Brix of the fermented mixture (fermented and aged product) increases by 4% or more and the saturates increase by 8% or more, based on the value on the first day of fermentation, the balance of umami, sweetness, and saltiness becomes superior. According to one aspect of the present invention, for example, in the case of a brewing liquid blended to consist of 50% by weight of rice koji, 13% by weight of salt, and 37% by weight of water, fermentation is preferably carried out until the fermented mixture liquid (fermented and aged product) has a Brix of 37% or more and a saturates concentration of 16% or more, more preferably until the Brix is ​​39% or more and the saturates concentration is 20% or more, and even more preferably until the Brix is ​​41% or more and the saturates concentration is 26% or more.

[0018] In a preferred embodiment, fermentation is preferably carried out at a low temperature for 1 to 60 days, more preferably 2 to 30 days, more preferably 3 to 21 days, even more preferably 4 to 14 days, even more preferably 6 to 13 days, particularly preferably 8 to 12 days, and most preferably 10 days. Here, the fermentation period becomes longer as the temperature decreases because the enzyme activity derived from Aspergillus oryzae decreases. Therefore, in a more preferred embodiment, fermentation is preferably carried out at 20 to 38°C for 3 to 21 days, even more preferably 4 to 14 days, even more preferably 6 to 13 days, particularly preferably 8 to 12 days, and most preferably 10 days. According to a more preferred embodiment of the present invention, fermentation is carried out at 20-38°C for 3-21 days until the Brix of the fermented mixture (fermented and aged product) increases by 4% or more and the sucrose concentration increases by 8% or more, based on the value on the first day of fermentation.

[0019] In the post-fermentation process, the solids in the mixture are heated. In a preferred embodiment, the solid and liquid components are separated by a solid-liquid separation method, and the obtained solid component is heated. The solid-liquid separation method is not particularly limited and may be a method commonly used for mirin or soy sauce. Examples include press filtration using a press filter, pressing using a filter cloth, and solid-liquid separation using a centrifuge, with press filtration being preferred. The filtrate obtained by solid-liquid separation can be used directly as a liquid seasoning (liquid salt koji) using conventional technology.

[0020] The solid component obtained by solid-liquid separation is obtained as press cake, which, as mentioned above, was conventionally discarded as a by-product. In this embodiment, the press cake is crushed into a powder of about 5 mm using a mincer or the like, and then heated. In this heating process, the powder dries out, and in order to impart richness and umami to the resulting food product, the heating temperature is preferably between 80°C and 140°C, and more preferably between 100°C and 120°C. The heating time is preferably between 30 minutes and 5 hours, more preferably between 30 minutes and 3 hours, and more preferably 1 hour or more. In particular, temperatures around and below 80°C do not result in sufficient heating, while temperatures around and above 140°C tend to cause the powder to develop a state close to "burnt," which is undesirable for food production. As mentioned above, the koji mold dies during the fermentation process, and if ethanol (alcohol) is added as described later, it dies even more due to the addition of ethanol. Normally, it is completely killed during heating of the pressed lees and remains inactive after drying. When used in dishes that involve a pickling process, it is preferable that all koji mold is dead, as any surviving koji mold will break down ingredients such as meat and fish. However, if the dish is cooked immediately after addition, or if ingredients that are not broken down by enzymes are used, it is acceptable for some koji mold to survive. If it is necessary to confirm the inactivation of Aspergillus oryzae, this can be done, for example, by culturing on potato dextrose agar. Alternatively, by using multiple dyes in a fluorescent staining method, it is possible to obtain images stained with respiratory activity and images stained with all bacteria. By superimposing these two images of different colors, it is possible to confirm the presence and proportion of non-respiratory bacteria (dead bacteria). Furthermore, whether or not the bacteria appearing in the image are the target Aspergillus oryzae can be confirmed, for example, by examining the DNA sequence of the bacteria. After heating, it is preferable that the powder changes in color to a darker shade, such as light brown, compared to before drying. This is thought to be because, as mentioned above, sugars and proteins in the rice are broken down by various digestive enzymes during fermentation, resulting in the presence of reducing sugars, amino acids, peptides, etc., and these are then subjected to the Maillard reaction that occurs during heating, producing melanoidins as reaction products. Since melanoidins are not a single substance, it is difficult to determine their formation, but in addition to the change in color, the absorption spectrum of Example 3 (Figure 3A) shows that, similar to Reference Example C where lysine and galactose were mixed and heated, the absorption peak has a longer wavelength than before heating, with the absorption peak position at approximately 325 nm, and the fingerprint region (1500 cm⁻¹) of the FT-IR spectrum of Example 4 (Figure 4(a)) -1 From 650cm -1 The increase in the number of peaks in ) serves as evidence.

[0021] The obtained powder is usually classified using methods commonly used in the food industry, such as sieving, to obtain the koji-based food of this embodiment. The smaller the powder particles, the better the texture. As described, the food is in a dry state and contains fermentation decomposition products of rice koji mold, salt, and inactivated koji mold. Due to its composition, this food product can be eaten as is, but it is particularly preferable to use it as a seasoning for other dishes and confectionery. The dishes to which it can be added are not particularly limited, but the following are some examples. • Prepared foods: Hamburg steak, curry, cod roe, rolled omelet, cream stew, etc. Sauces and soups: Consommé soup, meat sauce, white sauce, cheese sauce, miso ramen soup, miso soup, anchovy sauce, etc. • Confectionery: Ice cream, cookies, milk chocolate, white chocolate, potato chips, scones, etc. The amount added to dishes, etc., depends on the dish, but preferably it is between 0.1% and 5% by mass. The type of flavor obtained will vary depending on the dish, the amount used, the environment in which it is used, etc., but may include milky, cheesy, broth-like, spicy, and sour flavors. In addition, it may have effects on the taste of dishes such as suppressing saltiness, masking meat odors, and prolonging the spiciness of chili peppers, etc.

[0022] The food of this embodiment may also be further enriched with ethanol (alcohol), which is preferable from the viewpoint of improving flavor and shelf life through sterilization. The addition can be done at any stage, such as during the rice fermentation process or the heating of the pressed lees, and in some cases, yeast can be added before fermentation to generate ethanol in the mixture. The amount of ethanol is preferably 0.5% to 10% by mass, more preferably 1% to 6% by mass, and even more preferably 2% to 5% by mass, relative to the koji-based food of this embodiment. If the concentration is too low, the effect of the addition tends not to be apparent, and if the concentration is too high, the alcohol odor and taste tend to be prominent, which is undesirable.

[0023] Next, the methods for producing koji-based food products according to the second and third embodiments will be explained with reference to Figure 6. The method for producing koji-based food according to the second embodiment is characterized by including a step of heating rice koji, which is made by cultivating koji mold on steamed rice. Furthermore, the method for producing koji-based food according to the third embodiment is characterized by preheating the rice koji to 50°C to 75°C before heating the rice koji, as described above in the method for producing koji-based food according to the second embodiment. In Figure 6, the "preheating" step shown in the figure is not performed in the second embodiment, while in the third embodiment, the "preheating" step is performed before the "heating and drying" step. The koji-based foods produced according to the second and third embodiments (hereinafter referred to as "koji-based food of the second embodiment" and "koji-based food of the third embodiment," respectively) differ in their manufacturing method from the koji-based food produced according to the first embodiment, and in particular, do not require a step of fermenting a mixture containing rice, koji mold, and water. However, the koji-based foods of the second and third embodiments, like the koji-based food of the first embodiment, can provide a deep, rich umami flavor to the food obtained using them. The following mechanism is presumed to be responsible for this. Rice contains sugars, proteins, and other compounds. When koji is produced by cultivating Aspergillus oryzae on steamed rice, and when the resulting koji is heated, these compounds are broken down by various enzymes, producing reducing sugars, amino acids, peptides, and other substances. As mentioned above, conventionally, foods obtained through fermentation were not further heated. However, in the second and third embodiments, the koji contains these decomposition products, and heating the koji triggers the Maillard reaction, generating melanoidins, which add richness to the flavor and also contribute to the flavor's longevity. Furthermore, in the third embodiment, preheating the rice koji before heating allows the rice koji to mature and activate the enzymes it contains, thereby enhancing the rich flavor of koji-based foods. Furthermore, in the second and third embodiments as well, the use of rice provides a rich texture through the incorporation of rice-derived dietary fiber and sugars produced by the decomposition of rice. It is believed that these different flavors and textures contribute to the richness of the food, and that the combined food ingredients produce different effects, resulting in a rich and savory taste.

[0024] Next, the method for producing food products using koji according to the second embodiment will be described in detail. Steamed rice is then heated to make rice koji, which is made by cultivating koji mold on steamed rice. Rice koji can be produced according to the usual rice koji production method. Specifically, it is obtained by steaming rice, sprinkling koji mold (also called seed koji) onto the steamed rice, and allowing it to grow under optimal conditions. The koji mold can also be grown using an automatic fermentation machine (e.g., HK-60, manufactured by Yaegaki Food & System Co., Ltd.) at 25-40°C for 2-4 days. Commercially available rice koji may be used. The rice, koji mold, and other ingredients used to make the rice koji can be the same as those described in the koji-using food product of the first embodiment.

[0025] Next, the rice koji is heated. During this heating, the entire rice koji is dried, and to impart richness, umami, and flavor to the resulting food, the heating temperature is preferably between 80°C and 140°C, and more preferably between 100°C and 120°C. The heating time is preferably between 30 minutes and 5 hours, more preferably between 30 minutes and 3 hours, and more preferably 1 hour or more. In particular, temperatures around and below 80°C tend to result in insufficient heating, while temperatures around and above 140°C tend to cause the rice koji to develop a state close to "burnt," which is undesirable for food. The koji mold begins to die during this heating process and is usually completely inactivated after drying. When used in dishes that involve a pickling process, it is preferable that all koji mold is dead, as any surviving koji mold will break down ingredients such as meat and fish. However, if the dish is cooked immediately after addition, or if ingredients that are not broken down by enzymes are used, it is acceptable for some koji mold to survive. Confirmation of inactivation of Aspergillus oryzae, confirmation of the presence and proportion of dead fungi, and confirmation of whether or not the fungi are Aspergillus oryzae can be confirmed using the same methods as in the first embodiment described above. After heating, similar to the powder in the first embodiment, it is preferable that the rice koji changes in color to a darker shade, such as light brown, compared to before drying. This is thought to be because, as mentioned above, sugars and proteins in rice are broken down by various enzymes when it becomes rice koji, producing reducing sugars, amino acids, peptides, etc. Further decomposition occurs during heating, and melanoidins, which are reaction products, are produced by the Maillard reaction that occurs during heating. Since melanoidins are not a single substance, it is difficult to grasp their production, but in addition to the change in color, the production of some Maillard reaction products, as shown in Example 13, can be seen as evidence.

[0026] The obtained powder is classified using methods commonly used in the food industry, such as sieving, to obtain powders of a desirable size, thereby yielding the koji-based food product of the second embodiment. The smaller the powder particles, the better the texture. As described, this food product is in a dry state and contains fermentation decomposition products of rice koji mold and inactivated koji mold.

[0027] Next, we will describe a method for producing koji-based food according to a third embodiment. In the third embodiment, the "preheating" enclosed by the dotted line in Figure 6 is performed before "heating and drying". Specifically, before heating the rice koji, which is made by cultivating koji mold on steamed rice, the rice koji is preheated. The preheating temperature is preferably between 50°C and 75°C, and more preferably between 55°C and 70°C. The preheating time is preferably 3 hours or more, and more preferably 4 hours or more. There is no theoretical upper limit to the preheating time, but since no effect is observed even if it is carried out for a long time, it is practically preferable to do it for 1 day or less. By selecting these temperatures and times, the enzymes derived from koji mold in the rice koji can be matured and activated at a temperature that does not inactivate (deactivate) the enzymes. As a result of maturation and activation, the richness of the koji-based food can be enhanced compared to the case in which the rice koji is not preheated (koji-based food of the second embodiment). In the third embodiment, the rice koji used and the steps after preheating are the same as those for the method of producing koji-based food according to the second embodiment described above. After preheating the rice koji, the koji-based food of the third embodiment is obtained as a powder product through heating, drying, pulverization, and classification, similar to the second embodiment (see Figure 6). The koji-based food product obtained in the third embodiment is in a dry state and contains fermentation decomposition products by koji mold and inactivated koji mold, similar to the koji-based food product in the second embodiment.

[0028] Both the koji-based food products of the second and third embodiments can be eaten as is due to their composition, but it is particularly preferable to use them as seasonings for other dishes and confectionery. The dishes to which they are added are not particularly limited, but examples of foods similar to those described for the koji-based food product of the first embodiment can be given. The amount added to dishes, etc., depends on the dish, but preferably it is between 0.1% and 5% by mass. The type of flavor obtained will vary depending on the dish, the amount used, the environment in which it is used, etc., but may include milky, cheesy, broth-like, spicy, and sour flavors. In addition, it may have effects on the taste of dishes such as suppressing saltiness, masking meat odors, and prolonging the spiciness of chili peppers, etc. In the koji-based food products of the second and third embodiments, it is also preferable to further add ethanol (alcohol) from the viewpoint of improving flavor and preservation through sterilization. Salt can also be added. The amount of ethanol and salt, and their effects, are the same as in the koji-based food product of the first embodiment.

[0029] The koji-based foods of the first to third embodiments all contain fermentation decomposition products of rice koji mold and inactivated koji mold, and are dried foods. By containing Maillard reaction products, these can enhance the richness, umami, etc., of other foods. As an example, although not limited to this, each koji-based food product preferably contains 3-fluoraldehyde, one of the intermediate products of the Maillard reaction, as described in Example 12. From the viewpoint of enhancing the richness, umami, etc., of other foods, the content of 3-fluoraldehyde relative to the koji-based food product is preferably 7 ng / g or more, and particularly preferably 10 ng / g or more. Furthermore, although not limited to these examples, it is preferable that each koji-based food product detects peak A, corresponding to the Maillard reaction product of cysteine ​​and glucose, in HPLC and LC-MS analyses, as described in Example 13. The compound of peak A has an absorption maximum wavelength in the UV spectrum within the range of 297 nm ± 5 nm, particularly within the range of 297 ± 3 nm, and contains a peak in m / z between 125.9 and 127.9 in mass spectrometry using the positive ion mode of ESI-MS. Furthermore, while the types of koji-based foods are not limited to these, (1) In a chromatograph obtained using the HPLC analysis conditions described in Example 13, when the retention time of peak A is set to 1.0, peak B has a relative retention time of 1.1 or more and 1.6 or less. (2) The absorption maximum wavelength of peak B is between 279 nm and 289 nm. (3) In mass spectrometry of peak B by positive ion mode of ESI-MS, the peak has a m / z of 125.9 or more and 127.9 or less. It is preferable. [Examples]

[0030] The embodiments of the present invention will be described in detail below with reference to examples, but the embodiments of the invention are not limited to these examples. In the following description, unless otherwise specified, quantities such as "parts" and "%" are based on mass. [Example 1] Rice koji and liquid seasoning were prepared according to the process shown in Figure 1, and the koji-based food product of the first embodiment was prepared according to the process shown in Figure 2. (1) Preparation of rice koji Rice was soaked in 1.2 times its volume of water for 12 hours, drained for 2 hours, and then steamed for 45 minutes using a steamer (manufactured by Hanyuda Iron Works Co., Ltd.) to obtain steamed rice. The steamed rice was cooled to 30°C, and seed koji (seed koji for miso, obtained from Higuchi Matsunosuke Shoten Co., Ltd.) was sprinkled in several batches at a ratio of 0.3g per 1kg of steamed rice (steamed rice:seed koji = 1000:0.3) and mixed (seed infusion). The rice mixed with seed koji was cultured at 35°C for 42 hours in an automatic fermentation machine (HK-60, manufactured by Yaegaki Food & System Co., Ltd.) while being stirred occasionally to obtain rice koji. (2) Preparation of liquid seasonings 50 kg of the obtained rice koji, 13 kg of salt (regular salt), and 37 L of water were mixed to make the fermentation liquid. The fermentation liquid was fermented and aged at 30°C for 10 days to obtain the aged product. The obtained aged product was pressed and filtered using a press filter (equipment name: laboratory press filter, manufactured by NSK Engineering Co., Ltd.), and the filtrate was obtained as a liquid seasoning, while the press residue was obtained as a solid component. (3) Preparation of koji-based foods The obtained pressed lees were roughly crushed using a chopper (manufactured by Zenmigo Co., Ltd., model: 10B), and then dried by heating at 105°C for 2 hours using a three-stage band dryer. The obtained lees were pulverized using a hammer mill, and the powder that passed through a 40-mesh vibrating sieve (manufactured by Tokuju Kogyosho Co., Ltd., model: TMC-70-2S) was obtained as the koji-based food product for the intended purpose. 65 kg of the koji-based food product of the first embodiment was obtained from 100 kg of pressed lees. The koji-based food obtained in (3) was used in the following examples up to Example 8.

[0031] [Example 2] The free amino acid composition and sugar composition of the obtained koji-based food product were measured by the following method. • Amino acid analysis Approximately 1g or 2g of koji-based food was accurately weighed out and refluxed with 50mL of 75% ethanol at 80°C for 30 minutes. Impurities were removed by filtration, and the volume was reduced to 100mL. 4mL of this extract was taken out, concentrated to dryness using an evaporator (Tokyo Rikakikai Co., Ltd., Rotary Evaporator K-1000), completely dissolved in 8mL of citrate buffer (pH 2.2), and filtered through a 0.45μm membrane filter (Toyo Roshi Co., Ltd., product name "DISMIC 26CS045AN"). The filtrate was then analyzed for amino acids using high-performance liquid chromatography with OPA (o-phthalaldehyde) post-column derivatization and fluorescence detection using a Shimadzu LC-VP amino acid analysis system (Shimadzu Corporation). • Reducing sugar analysis 10 g of koji-based food was added to 490 mL of water and stirred. 5 mL of the mixed solution was placed in a beaker, 95 mL of water was added, and it was stirred again. The resulting solution was filtered through a 0.45 μm membrane filter (manufactured by Toyo Roshi Co., Ltd., product name "DISMIC 26CS045AN"), and the reducing sugars were analyzed using a Shimadzu High-Performance Liquid Chromatography Reducing Sugar Analysis System (manufactured by Shimadzu Corporation). The measurement results are listed in Tables 1 and 2, respectively, along with the results for the state before the heating and drying process described in (3) above, and for commercially available liquid salt koji. In addition, the nutritional information (theoretical values ​​per 100 g) of the obtained koji-based food is shown in Table 3.

[0032] [Table 1]

[0033] [Table 2]

[0034] [Table 3] In Table 1, "-" indicates levels below the detection limit. From Table 1, it can be seen that the amount of free amino acids decreases compared to before the drying process, but no significant specificity is observed for each amino acid. Table 2 shows that, except for fructose, the levels of these substances have decreased compared to before the drying process. Furthermore, from Tables 1 and 2, it can be inferred that heating causes amino acids and reducing sugars to react with the Maillard reaction to produce melanoidins.

[0035] [Example 3] The absorption spectra of the resulting koji-based food product and the sample before the heating and drying process were analyzed. Specifically, ten times the volume of distilled water was added to each sample, and it was pulverized and micronized using a homogenizer (US-150T, manufactured by Nippon Seiki Seisakusho Co., Ltd.). The resulting solution was centrifuged at 3000 rpm for 20 minutes using a centrifuge (H-30R, cooled / benchtop centrifuge, manufactured by Kokusan Co., Ltd.), and the supernatant was filtered through a 0.45 μm membrane filter (DISMIC 26CS045AN, manufactured by Toyo Roshi Co., Ltd.), and the absorbance at each wavelength was measured using a spectrophotometer (UV-1280 ultraviolet-visible spectrophotometer, manufactured by Shimadzu Corporation). The results are shown in the absorption spectrum diagram in Figure 3. In the figure, A is a sample of food using koji (example), and B is the sample before the heating and drying process. As a reference example, a sample prepared by heating an aqueous solution containing equal amounts of lysine and galactose at 105°C for 2 hours was similarly ground, micronized, centrifuged, and filtered before measurement. The results are shown in Figure 3 as Reference Example C. As shown in Figure 3, the absorption spectrum peak of B before heating was around 300 nm, but after heating, the peak of the koji-based food A in Example A shifted to a longer wavelength side, around 325 nm. Reference Example C, in which a mixture of lysine and galactose was heated, also showed a peak around 325 nm, similar to Example A. In C, melanoidins formed by the Maillard reaction of lysine and galactose were produced, and in Example A, as inferred from Tables 1 and 2, melanoidins were also produced by the Maillard reaction caused by sugars, amino acids, peptides, etc., present in the pressed lees.

[0036] [Example 4] The resulting koji-based food product and the sample before the heating and drying process were both placed directly on a sample stage, and their FT-IR spectra were analyzed (measurement instrument: IRAffinity-IS, manufactured by Shimadzu Corporation). The results are shown in Figures 4(a) and (b). Fingerprint regions (1500 cm²) tend to exhibit a spectrum specific to the material. -1 From 650cm -1 In the present invention, the koji-based food product shows an increased number of peaks. During the heating and drying process, sugars, amino acids, peptides, etc. present in the pressed lees undergo the Maillard reaction, producing numerous substances including melanoidins.

[0037] [Example 5] <Sensory evaluation> Sensory evaluations were conducted by trained professional panelists (hereinafter referred to as "panelists") for each of the following foods, comparing the food with koji-based food added (example) and the food with the same composition except for the addition of koji (control). (5-1) Butter Cookies Butter cookies (control) were prepared by baking the following ingredients at 170°C for 10 minutes, and butter cookies (example) were prepared in the same manner except that 37.5g of the koji-based food product of the present invention was added. Sensory evaluation was then conducted by 10 panelists. -Butter Cookie Ingredients- · Flour: 250g Unsalted butter: 100g Brown sugar: 100g • Whole egg: 1 The change in taste intensity was evaluated on a scale of strength (strongest: 1, weakest: 0) at 0, 5, 10, 15, and 20 seconds after the object was placed in the mouth. The average value among the 10 panelists for each time period was calculated, and the results are shown as a graph of the change over time in Figure 5(a). At all time points, the example shown as "1" in the graph was perceived as having a stronger taste than control 2. In addition, the absolute strength of the spread of taste in the mouth was evaluated on a scale of strength (strongest: 1.2, weakest: 0), and the average value among the panelists was calculated and shown in Figure 5(b). A spread of taste in the mouth was observed in the example.

[0038] (5-2) Potato Chips A seasoning (control) consisting of the following ingredients was prepared, and a seasoning (example) was prepared in the same manner except that 7.2 parts of dextrin and 45 parts of the koji-based food product of the present invention were used instead of 52.2 parts of dextrin. -Seasoning- Ingredients- Anhydrous crystalline glucose: 40 parts • Butter flavor: 1 piece • Soy sauce flavor: 1 portion • Roasted soy sauce flavor: 1 portion • Finely powdered silicon dioxide: 0.8 parts • Potato starch: 4 parts Dextrin: 52.2 parts Commercially available lightly salted potato chips were purchased, and as much of the salt and other seasoning powder from the surface as possible was removed with a brush. The potato chips and seasoning (example or control) were mixed in a ratio of 92 parts to 8 parts, and a sensory evaluation was conducted by 13 panelists. Sensory evaluation was conducted using a two-point discrimination method, where participants tasted the product and then swallowed it, selecting the sample with the strongest, most desirable flavor. The number of participants who made a selection is shown in Table 4.

[0039] (5-3) Salted cod roe Commercially available salted cod roe was purchased, the membrane was removed, and only the roe grains were used. An amount of the koji-based food of the present invention, comprising 0.5%, was added and mixed to the salted cod roe and compared with salted cod roe without the additive (control). The sensory evaluation was conducted using a two-point discrimination method by 13 panelists. They tasted the samples, swallowed them, and selected the samples with the strongest umami and richness. The number of selections is shown in Table 4.

[0040] (5-4) Miso Ramen Soup A miso ramen soup (control) and a miso ramen soup containing 0.25% of the koji-based food product of the present invention (example) were compared. The sensory evaluation was conducted using a two-point discrimination method by 13 panelists. They tasted the samples, swallowed them, and selected the samples with the strongest umami and richness. The number of selections is shown in Table 4.

[0041] (5-5) Chocolate 150 parts of chocolate (dark chocolate or white chocolate) were melted in a double boiler, and 100 parts of feuilletine chocolate and 1.5 parts of the koji-based food product of the present invention were mixed together. The mixture was then chilled in a refrigerator to create round feuilletine chocolates. Meanwhile, a control portion of feuilletine chocolate was prepared in the same manner except that the koji-based food product of the present invention was not mixed in, and a sensory evaluation was performed. The sensory evaluation was conducted using a two-point discrimination method by 13 panelists. They tasted the chocolate, swallowed it, and selected the sample with the strongest umami and richness. Table 4 shows the number of people who selected each sample for dark chocolate and white chocolate.

[0042] (5-6) Dashi-maki Tamago (Japanese rolled omelet) The following ingredients were mixed together to form an egg mixture which was then poured into a mold and baked in a steam convection oven at 160°C for 30 minutes to obtain a dashi-rolled omelet (control). -Ingredients for rolled omelet- • Eggs: 10 • Bonito broth: 150mL • Mirin: 27mL • Japanese sake: 40mL White dashi: 27mL Furthermore, a rolled omelet (example) was prepared in the same manner except that 7.5g of the koji-based food product of the present invention was added. Sensory evaluation was conducted on the example and control samples of dashi-rolled omelet. The sensory evaluation was performed using a two-point discrimination method by eight panelists. They tasted the omelet, swallowed it, and selected the sample with the strongest umami and richness. The number of people who made selections is shown in Table 4.

[0043] (5-7) White sauce A white sauce (control) was prepared by simmering the following ingredients. A white sauce (example) was prepared in the same manner, except that 9 parts of the koji-based food product of the present invention were added to the following ingredients. -White Sauce Ingredients- • Chicken breast: 300 units • Liquid salt koji (manufactured by Hanamaruki Co., Ltd.): 15 units White sauce: 300 copies • Milk: 150 copies Salt: 2.4 parts • Onions: 200 copies • Buna Shimeji mushrooms: 100 copies • Unsalted butter: 15 portions Sensory evaluation was conducted on the white sauces of the examples and the control. The sensory evaluation was performed using a two-point discrimination method by eight panelists. They tasted the sauce, swallowed it, and selected the sample with the strongest umami and richness. The number of people who made selections is shown in Table 4.

[0044] (5-8) Scones A control scone was prepared using the following ingredients. An example scone was prepared in the same manner, except that 12g of the koji-based food product of the present invention was added to the following ingredients. The scones were made by mixing cake flour, baking powder, sugar, and salt, along with koji-based food products if used, then adding butter and kneading until it resembled ground meat. Meanwhile, beaten eggs were mixed with milk, and this was lightly mixed into the previously prepared flour mixture. The mixture was then shaped and baked in an oven at 180°C for 15 minutes to make the scones. -Scone ingredients- • Cake flour: 200g • Baking powder: 8g Sugar: 30g Butter: 70g • Egg: 1 • Milk: 50g • Salt: 1g Sensory evaluation was conducted on the example and control scones. The sensory evaluation was performed using a two-point discrimination method by eight panelists. They tasted the scones, then swallowed them, and selected the samples with the strongest umami and richness. The number of selections made by each panelist is shown in Table 4.

[0045] [Table 4] In all of the food products, the results showed a significant difference in flavor and other characteristics when using the koji-based food product of the present invention.

[0046] <Sensory evaluation> The descriptive responses for the sensory evaluation of each food product, specifically for the examples and controls of the present invention, are described below in comparison. (5-2) Potato Chips Examples • The initial taste (saltiness) is mild. • The buttery (milky) flavor has been enhanced. The umami flavor lingers afterwards. control The salty flavor is the first thing you notice. I didn't really taste much of the buttery (milky) flavor. (5-3) Salted cod roe Examples • The taste is strongly felt from the beginning to the aftertaste. The saltiness is perceived as mild. control The saltiness was quite strong. (5-4) Miso Ramen Soup Examples • The initial taste (saltiness) is mild. The aftertaste intensifies from the initial flavor, leaving a lingering umami taste. control The saltiness was the first thing I tasted, and the subsequent flavors quickly disappeared. (5-5) Chocolate White chocolate Examples • The milky sensation is enhanced. • The contents are enhanced. control • A milky sensation is felt first, then quickly disappears. Dark chocolate Examples The bitterness is masked. • The richness of the fats and oils is enhanced. • The aftertaste is enhanced from the inside out. control The bitterness comes first. • The richness of the flavor is not very noticeable. (5-6) Dashi-maki Tamago (Japanese rolled omelet) Examples • It has a lingering aftertaste. • I can really taste the dashi (broth). control • You can taste both the egg and the broth, but it quickly disappears. (5-7) White sauce Examples • I now feel a stronger sensation of milkiness. The buttery flavor is now much more pronounced. control The salty taste is the first thing you notice. • The flavor isn't very strong either. (5-8) Scones Examples • The buttery flavor has increased. It has a crispy texture. control The flavor wasn't very strong. The texture was dry and crumbly.

[0047] [Example 6] The koji-based food products obtained in Example 1 exhibited a lighter brown to yellowish-brown color than the pressed lees upon heating, and, as shown in Example 5, imparted richness, umami, and other flavors to each food product. Instead of heating at 105°C for 2 hours as in Example 1, the following temperatures and times were used for heating, and the resulting powders were evaluated based on their color tones. • 70°C, 1 hour: There was almost no change in color between before and after heating. • 80°C for 30 minutes: The color change was slightly less than in Example 1. • 100℃, 1 hour: A color change similar to that in Example 1 was observed. • 120℃, 1 hour: The color became slightly redder than in Example 1. • 140℃, 30 minutes: The color was more reddish than in Example 1, and a faint burnt smell was present.

[0048] [Example 7] <Sensory evaluation: Suppression of saltiness> To investigate the effect of the koji-based food product of the present invention on suppressing saltiness (saltiness that directly stimulates the tongue), the following sensory evaluation was conducted by panelists. (7-1) Saltwater A 1.0% (w / v, mass-to-volume ratio) saline solution (control) and a saline solution with a koji-based food product obtained in Example 1 added to this saline solution to create a saline solution with a koji-based food product concentration of 0.2% (w / v) (Example; containing 2g of koji-based food product in 1L of saline solution), and sensory evaluation was performed. For the sensory evaluation, 11 panelists tasted and swallowed each of the control and example saline solutions, and evaluated the saltiness using the following 5-point rating system, and the average of the panelists' ratings was calculated. "Saltiness Rating" Weak 1 2 3 4 5 Strong The evaluation results are as follows: The koji-based food product of the present invention showed a statistically significant (p<0.01) effect in suppressing the saltiness. "Evaluation Results": Average evaluation of the 11 panelists • Control: 3.8 • Example: 2.6 (7-2) Anchovy Sauce A commercially available anchovy sauce (control) and an anchovy sauce (example) prepared by adding the koji-based food obtained in Example 1 to this anchovy sauce, resulting in a koji-based food concentration of 0.5% by mass, were prepared and sensory evaluation was conducted. In the sensory evaluation, 11 panelists tasted and swallowed each of the control and example anchovy sauces, and selected the one with the stronger saltiness using a two-point discrimination method. The evaluation results are as follows, and a statistically significant (p<0.05) salt-sharpening effect was observed in the koji-based food of the present invention. "Evaluation Results": Number of selections by panelists • Controls: 9 • Example: 2

[0049] [Example 8] <Sensory evaluation: Persistence effect of spiciness> To investigate the effect of sustained spiciness in the koji-based food product of the present invention, the following sensory evaluation was conducted by panelists. (8-1) Chili liquid A chili pepper extract solution containing 0.3% (w / v, mass-to-volume ratio) of chili pepper extract, obtained by extracting with water (control), and a chili pepper extract solution containing 0.3% (w / v) of the koji-based food obtained in Example 1, obtained by adding the koji-based food to this chili pepper extract solution (example), were prepared, and sensory evaluations were conducted. For the sensory evaluation, 11 panelists took each chili pepper extract solution (control and example) into their mouths and swallowed it, and evaluated the persistence of the spiciness using the following 5-point scoring method, and the average score of the panelists was calculated. "Spiciness duration" Short 1 2 3 4 5 Long The evaluation results are as follows: The koji-based food product of the present invention showed a statistically significant (p<0.01) effect in maintaining spiciness. "Evaluation Results": Average evaluation of the 11 panelists • Controls: 3.2 • Example: 4.3 (8-2) Curry A commercially available curry roux (control) and a curry roux (example) prepared by adding the koji-based food obtained in Example 1 to this curry roux, resulting in a concentration of 0.3% by mass of the koji-based food, were prepared and sensory evaluation was conducted. In the sensory evaluation, seven panelists tasted and swallowed each of the control and example curry roux, and selected the one with the longer-lasting spiciness using a two-point discrimination method. The evaluation results are as follows, and the koji-based food of the present invention showed a statistically significant effect (p<0.01) on the persistence of spiciness. "Evaluation Results": Number of selections by panelists Control: 0 • Example: 7

[0050] [Example 9] The koji-based food products of the second and third embodiments were prepared according to the process shown in Figure 6. However, the classification process was omitted. (1) Food product using koji according to the second embodiment The rice koji obtained in Example 1(1) was heated at 105°C for 2 hours using a steam convection oven (Rational, SelfCookingCenter XS) and dried. The heated rice koji was ground in a milling machine to obtain the desired koji-based food product in powder form. 0.78 kg of koji-based food product according to the second embodiment was obtained from 1.0 kg of rice koji. (2) Food product using koji according to the third embodiment The rice koji obtained in Example 1(1) was preheated at 60°C for 6 hours using a constant temperature oven (ESPEC SH-221), and then heated at 105°C for 2 hours using a steam convection oven (Rational SelfCookingCenter XS) to dry it. The heated rice koji was pulverized using a milling machine to obtain the desired koji-based food product in powder form. 0.85 kg of koji-based food according to the third embodiment was obtained from 1.0 kg of rice koji. Table 5 shows the nutritional information (theoretical values ​​per 100 g) of the koji-based food according to the second and third embodiments obtained.

[0051] [Table 5]

[0052] [Example 10] <Sensory evaluation: Umami flavor persistence> To investigate the effect of sustained umami flavor in koji-based foods of the second and third embodiments, panelists conducted sensory evaluations of the following consommé soups. A commercially available consommé soup (control) and a consommé soup prepared by adding a koji-based food product of the second or third embodiment to this soup, resulting in a concentration of 1.0% by mass of the koji-based food product (example), were prepared, and sensory evaluation was conducted. In the sensory evaluation, nine panelists tasted and swallowed each of the control and example consommé soups, and selected the one with the longer-lasting umami flavor using a two-point discrimination method. The evaluation results are as follows: The koji-based food product of the third embodiment showed a statistically significant difference (p<0.05) in umami persistence, while six panelists selected the koji-based food product of the second embodiment, which was more than the three who selected the control, but the difference was not statistically significant. "Evaluation Results": Number of selections by panelists Food product using koji in the second embodiment • Controls: 3 • Example: 6 Food product using koji in the third embodiment (p<0.05) • Control: 1 • Examples: 8

[0053] [Example 11] <Sensory evaluation: Persistence effect of spiciness> To investigate the effect of the koji-based food product of the third embodiment on the persistence of spiciness, the panelists conducted a sensory evaluation of the following chili pepper extracts. A chili pepper extract (control; concentration of chili pepper extract in water: 0.3% by mass) and a chili pepper extract (example) prepared by adding the koji-based food product of the third embodiment to this extract to a concentration of koji-based food product of 1.0% by mass were prepared, and a sensory evaluation was conducted. In the sensory evaluation, nine panelists took each chili pepper extract from the control and example into their mouths and swallowed them, and selected the one with the longer duration of spiciness using a two-point discrimination method. The evaluation results are as follows, and the effect of spiciness persistence was observed to be statistically significant (p<0.05). "Evaluation Results": Number of selections by panelists • Control: 1 • Examples: 8

[0054] [Example 12] We investigated the substances in the koji-based food product of this invention. First, the koji-based food product, the sample before the heating and drying process, and the rice koji were qualitatively analyzed using a gas chromatograph-mass spectrometer (Shimadzu Corporation, GCMS-QP2010 Ultra). The analysis conditions were as follows, and the resulting graphs are shown in Figure 7. In the figure, A is the sample of the koji-based food product of the first embodiment obtained in Example 1(3) (Example), B is the sample of the pressed lees (before heating and drying of the koji-based food product) obtained in Example 1(2) (Comparative Example), and D is the sample of the rice koji obtained in Example 1(1). <Analysis conditions> • Solid-phase microextraction (SPME) SPME fiber: 65μm Stable Flex PDMS / DVB (Supelco 57293-U, manufactured by Merck KGaA Life Sciences) Incubation time: 10 minutes Oven: 105℃ SPME adsorption time: 5 minutes Desorption time: 1 minute • Gas chromatograph Column oven: Maintain at 40°C for 5 minutes. Then, increase the temperature by 8°C per minute up to 220°C and maintain at 220°C for 5 minutes. Evaporation chamber temperature: 250℃ Column: ZB-WAX-PLUS (60m, 0.25mm ID, df=0.25m) Carrier gas: Helium Carrier gas control: Constant linear velocity, 31.2 cm / sec Injection mode: Split • Mass spectrum Interface: 230℃ Ion source: 220℃ Measurement mode: Scan Mass range: m / z 20~400 Event duration: 0.3 seconds The peak with a retention time of 18.8 minutes in graph A is absent in graphs B and D. This peak was identified as 3-fluoraldehyde by the search database: NIST 11 Mass Spectral Library.

[0055] Next, the quantification of 3-fluoraldehyde contained in the koji-based food products of the first to third embodiments, the sample before the heating and drying process (pressed lees obtained in Example 1(2)), and the rice koji obtained in Example 1(1) was performed by headspace gas chromatography-mass spectrometry. 2 g of the sample was weighed into a 20 mL vial and measured under the following analytical conditions. <Analysis conditions> • Headspace Auto Injector: AOC-5000 Syringe Heater: MSH 02-00B Syringe size: 2.5 mL Injection volume: 1.0 mL Incubation time: 20 minutes Oven: 80℃ Syringe needle temperature: 80℃ • Gas chromatography and mass spectrometry The above-mentioned gas chromatograph mass spectrometer (manufactured by Shimadzu Corporation, GCMS-QP2010 Ultra) was used under the same conditions. The 3-furaldehyde content in each sample is shown in Table 6.

[0056]

Table 6

[0057] 〔Example 13〕 High-performance liquid chromatography (HPLC) analysis was performed on the koji-utilized food of the present application using Nexera (manufactured by Shimadzu Corporation) as the apparatus to attempt to identify the contained substances. <000054۲>HPLC analysis was performed on the koji-utilized food of the first embodiment obtained in Example 1(3) under the following conditions. <HPLC analysis conditions> Extract: Extract with water at a weight ratio of 4 times the weight of the analysis object. Mobile phase A: 0.1 mass% trifluoroacetic acid aqueous solution<00۰۰۵۴۶> Mobile phase B: Acetonitrile Isocratic condition: Mobile phase A 95%, mobile phase B 5%<۰۰۰۰۵۴۸> Flow rate: 0.6 mL / min Column: CAPCELL PAK C18 AQ (manufactured by Osaka Soda Co., Ltd., <4.6mm×100mm, 3μm>) Detection wavelength: 297 nm }The obtained chromatograph is shown in Figure 8. As shown in Figure 8, there are two characteristic peaks at retention times of 7.07 minutes (peak A) and 9.55 minutes (peak B). The koji-based food product of the second embodiment and the koji-based food product of the third embodiment also have two similar peaks, as shown below. <Peak position: Retention time> • Food product using koji in the second embodiment: 7.06 minutes, 9.56 minutes • Food product using koji in the third embodiment: 7.03 minutes, 9.50 minutes

[0058] (1) Peak A Peak A is the Maillard reaction product of cysteine ​​and glucose, as shown below. The control Maillard reaction product was obtained by heating 1 mole of cysteine, 2 moles of glucose, and 0.2 moles of sodium bicarbonate at 105°C for 2 hours. HPLC analysis, UV spectral comparison, and LC-MS analysis were performed on koji-based foods and the Maillard reaction product of cysteine ​​and glucose. For the HPLC analysis, the koji-based food product of the first embodiment was used as the koji-based food product. The koji-based food product was extracted with water, and the resulting liquid was adsorbed onto an ODS column (a reversed-phase chromatography column packed with a silica gel support and a packing material chemically bonded to octadecylsilyl groups). The sample was eluted with a 10% aqueous ethanol solution, and the Maillard reaction product of cysteine ​​and glucose was adsorbed onto an ODS column and eluted with a 10% aqueous ethanol solution. Both samples were then subjected to HPLC analysis under the same conditions. The HPLC analysis results are shown in Figure 9. Figure 9(a) is the HPLC analysis graph of the koji-based food product, and (b) is the graph of the Maillard reaction product of cysteine ​​and glucose. Both graphs show a peak with almost the same retention time of approximately 3.9 minutes (the peak enclosed by the dotted line). Furthermore, Figure 10 shows the superimposed UV spectral diagrams of the components corresponding to the peaks with a retention time of approximately 3.9 minutes in the two samples. A represents the spectrum of the peak contained in the koji-based food product, and C represents the Maillard reaction product of cysteine ​​and glucose. As is clear from Figure 10, the absorption maximum wavelength of the UV spectra of the components from both samples coincided at 297 nm. Furthermore, Fig. 11 shows a mass spectrometry graph in the positive ion mode of ESI-MS obtained by analyzing the components corresponding to the aforementioned peaks in the two samples by LC-MS method. Fig. 11(a) is a koji-utilizing food of the first embodiment, and (b) is a graph of the Maillard reaction product of cysteine and glucose. Both graphs have peaks around m / z 144.9. From the above, the first to third koji-utilizing foods contain the Maillard reaction product of cysteine and glucose. Note that Figs. 9 and 10 used Nexera (manufactured by Shimadzu Corporation) as the apparatus, and the HPLC analysis conditions in Fig. 9 are as follows. Fig. 11 is a graph obtained by performing mass spectrometry on the peaks corresponding to the peaks shown in Fig. 10 using Waters Alliance (manufactured by Waters Japan) connected with QDa as the detector, and the LC-MS analysis conditions are as follows. <HPLC analysis conditions> Mobile phase A: 0.1 mass% trifluoroacetic acid aqueous solution Mobile phase B: acetonitrile Isocratic condition: Mobile phase A 95%, Mobile phase B 5% Flow rate: 1.0 mL / min Column: CAPCELL PAK C18 MGII (manufactured by Osaka Soda Co., Ltd., 4.6 mm × 100 mm, 3 μm) Detection wavelength: 297 nm <LC-MS analysis conditions> Mobile phase A: 0.1% formic acid Mobile phase B: acetonitrile (containing 0.1% formic acid) Isocratic condition: Mobile phase A 95%, Mobile phase B 5% Flow rate: 1.0 mL / min Column: CORTECS C18 (manufactured by Waters Japan, 4.6 mm × 150 mm, 2.7 μm) Detector: QDa (scan range m / z 30 - 1250)

[0059] (2) Peak B Table 7 shows the retention time of peak B in HPLC analysis, the relative retention time ratio of peak B to peak A (peak B retention time / peak A retention time), and the absorption maximum wavelength of the UV spectrum for the koji-based food products of the first to third embodiments. From these results, it is considered that peak B is the same compound for all koji-based food products.

[0060] [Table 7]

[0061] Furthermore, Figure 12 shows the mass spectrometry graph obtained by LC-MS using the positive ion mode of ESI-MS. Each analysis for peak B was performed in the same manner as for peak A. [Explanation of symbols]

[0062] A: Example, B: Before heating, C: Reference example, 1: Example, 2: Control

Claims

1. The process includes the steps of fermenting a mixture containing rice, koji mold, and water, separating the mixture into solid and liquid, and heating the solid obtained by separation at a temperature of 80°C to 140°C for 30 minutes to 5 hours. Method for producing food products using koji.

2. A method for producing a koji-based food according to claim 1, comprising fermenting the mixture at a temperature of 4°C or higher and 40°C or lower.

3. The mixture is further fermented by adding ethanol. A method for producing a food product using koji according to claim 1 or 2.

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