Koji, method for production of koji, miso using koji and method for production of miso

Abstract

The present invention provides a koji characterized in that microfibers of Persicaria tinctoria are attached to the surface of a cereal employed as a starting material. The koji of the present invention is produced by a production method that includes: a step for immersing a cereal employed as a starting material in water; a step for heating the immersed cereal to obtain a heated cereal; a step for allowing the heated cereal to stand to cool; a step for pouring Aspergillus oryzae and a dry powder of Persicaria tinctoria onto the heated and cooled cereal followed by mixing to obtain a cereal mixture; and a step for maturing the cereal mixture under temperature control.

Description

Koji, method for producing koji, miso using koji, and method for producing miso

[0001] The present invention relates to koji used for producing fermented foods, miso using the koji, and methods for producing them.

[0002] Koji is made by cultivating microorganisms effective in food fermentation, such as koji mold, on grains such as rice, barley, and soybeans. In Japan, the action of various decomposing enzymes produced by koji mold has long been used to produce a variety of fermented foods, including sake, miso, vinegar, pickles, soy sauce, shochu, and awamori.

[0003] Koji is known to contain polyphenols, which have antioxidant properties. To increase the amount of polyphenols in koji, one could consider producing it in a different environment or using a different method than usual, or adding some other substance during koji production. However, because the growth of koji mold and the enzyme production by koji mold are important factors in producing koji, it is rare to produce it in an environment that is significantly different from usual, or to add some kind of additive.

[0004] If additives are added during koji production, they must naturally be safe and not have any adverse effects on the koji production process. Patent Document 1 describes a conventional technique for producing koji by adding "starch powder" to facilitate the growth of koji mold. Patent Document 2 describes a conventional technique for producing koji by adding "lactic acid fermentation liquid" to suppress the growth of miscellaneous bacteria. Both of the prior art techniques in Patent Documents 1 and 2 aim to efficiently grow koji mold, and given the nature of the added substances, it is easily assumed that they will not have any adverse effects on koji production. However, neither of the prior art techniques in Patent Documents 1 and 2 increases polyphenols. Within the scope of the inventor's investigation, no prior art techniques for increasing the polyphenols contained in koji using additives were found.

[0005] JP 2005-13205 A JP 2002-369678 A

[0006] The present invention has been made in light of the above-mentioned problems, and aims to provide koji with increased polyphenol content, a method for producing the koji, miso using the koji, and a method for producing the miso.

[0007] A first aspect of the present invention is a koji characterized in that fine fibers of Polygonum tularensis adhere to the surface of the grain used as the raw material.

[0008] A second aspect of the present invention is a method for producing koji, comprising the steps of (a) soaking the raw material derived grain in water, heating the soaked derived grain, (b) obtaining cooked grain, (c) allowing the cooked grain to cool, (d) sprinkling dried powders of koji mold and Polygonum polyglutamum onto the cooled cooked grain and mixing them to obtain mixed grain, and (e) adjusting the temperature of the mixed grain to mature it.

[0009] A third aspect of the present invention is a miso produced from koji in which fine fibers of Polygonum multiflorum adhere to the surface of the grain from which it is derived.

[0010] A fourth aspect of the present invention is a method for producing miso, comprising the steps of: (a) soaking soybeans in water; (b) steaming the soaked soybeans to obtain steamed beans; (c) crushing the steamed beans; (d) mixing the crushed steamed beans with koji and salt attached to the surface of grains derived from Polygonum polyglutamum fine fibers to obtain a mixture; and (e) fermenting the mixture.

[0011] According to the present invention, it is possible to provide koji with increased polyphenols, a method for producing the koji, fermented foods and beverages such as miso and amazake using the koji, and a method for producing these fermented foods and beverages.

[0012] 1 is a flowchart of a method for producing koji according to an embodiment of the present invention; 2 is a flowchart of a method for producing miso using koji according to an embodiment; 3 is a scanning electron microscope (SEM) photograph 1 of a cross section of koji according to an embodiment; and 4 is an SEM photograph 2 of a cross section of koji according to an embodiment.

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, it should be noted that the drawings are schematic and that the depictions of methods and the like may differ from the actual ones. Furthermore, even in the microscopic photographs used as drawings, some of the structures depicted are merely examples of embodiments of the present invention. Therefore, details of methods and the like according to embodiments of the present invention should be interpreted more broadly in light of the gist of the technical ideas that can be understood from the following description.

[0014] Furthermore, the embodiments of the present invention shown below are merely examples of products and methods for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention does not specify the raw materials, resulting products, methods, etc. to those described below. The technical idea of ​​the present invention is not limited to the contents described in the embodiments of the present invention, and various modifications can be made within the technical scope defined by the invention-specifying matters described in the claims.

[0015] The koji according to the embodiment of the present invention is koji to which Polygonum nigra fine fibers have been added during the production process, and the fine fibers adhere to the surface of the koji. The koji according to the embodiment of the present invention has increased polyphenol content compared to koji produced without the addition of Polygonum nigra fine powder. Preferably, the koji according to the embodiment of the present invention contains at least 1.2 times the polyphenol content of koji produced without the addition of Polygonum nigra fine powder.

[0016] Polygonum tinctoria (Persicaria tinctoria) refers to an annual plant of the Polygonaceae family, known primarily as a source of dyes. Polygonum tinctoria has long been known for its medicinal properties, including antipyretic, detoxifying, and anti-inflammatory properties, and has been used as a traditional Chinese medicine. Polygonum tinctoria contains various active ingredients, including tributanthrin, which has anticancer properties, and kaempferol, which exhibits antibacterial activity. Polygonum tinctoria is also useful as an edible plant, as tea is made from its leaves and stems. The finely powdered polygonum tinctoria added during the koji production process according to embodiments of the present invention is a dried powder of the leaves, stems, or both of the leaves and stems of the plant. The finely powdered polygonum tinctoria used in embodiments may also include parts of the plant other than the leaves and stems, such as the roots and seeds.

[0017] The grain from which koji according to the embodiment of the present invention is derived may be any grain, such as rice, barley, soybeans, or millet. The grain from which koji according to the embodiment is derived may also be a mixture of two or more grains, such as rice, barley, soybeans, or millet. As will be described later in the examples, in view of the amount of polyphenols contained in the koji and the characteristics of miso and amazake produced using the koji, rice or barley is preferred as the derived grain. In view of the characteristics of miso and amazake produced using the koji and the ease with which fine powder of Polygonum lucidum adheres to the surface, rice is particularly preferred. In this specification, "barley" includes wheat, barley, rye (Secale cereale), oat (Avena sativa), and Job's tears (Coix lacryma-jobi var. may-yuen). Typically, the wheat is wheat, barley, rye (Secale cereale) or oats (Avena sativa), with barley being particularly preferred.

[0018] As shown in FIG. 1 , koji according to an embodiment of the present invention is obtained by subjecting the raw material derived grain to step S101, a pretreatment step prior to steaming, to obtain pretreated grain. When the raw material derived grain is rice, in step S101 the rice is polished, washed, soaked in water, and then drained. The rice is preferably soaked in water for approximately 8 to 20 hours, depending on the water temperature, and preferably for approximately 1 to 2 hours to ensure sufficient drainage after soaking. When the derived grain is barley, in step S101 the barley is polished, washed, soaked in water, and then drained. The barley is preferably soaked in water for approximately 1 hour at a water temperature of 20°C. When the derived grain is soybean, in step S101 the rice is washed and soaked in water for approximately 24 hours.

[0019] In step S102 of Fig. 1, the pretreated grain is heated by a conventional method to perform a "steaming" or "stewing" process, thereby obtaining heated grain. Next, in step S103 of Fig. 1, the heated grain is allowed to cool. When the origin grain is rice or wheat, after the "steaming" process in step S102, the steamed grain is allowed to cool to a temperature of preferably about 30 to 40°C, more preferably about 30 to 35°C. When the origin grain is soybeans, the heating in step S102 is performed by "stewing," and in step S103, the temperature of the stewing soybeans is allowed to cool to a temperature of preferably about 30 to 50°C, more preferably about 30 to 40°C.

[0020] In step S104 of Figure 1, the cooled grains are inoculated with koji mold (seed koji), and finely divided koji powder is added. The inoculation of koji mold is a process generally referred to as "seed cutting" or "seed attachment." The order of the inoculation of koji mold and the addition of the finely divided koji powder may be any. The finely divided koji powder may be added at any time while the cooled grains inoculated with koji mold are generating heat (cultivating), and does not have to be simultaneously with the inoculation of koji mold. Adding the finely divided koji powder simultaneously with the inoculation of koji mold is more preferable, as it makes it easier to control the temperature of the mixed grains and allows the temperature of the mixed grains to rise more quickly. Examples of koji mold include Aspergillus oryzae (known as yellow koji mold) and Aspergillus sojae (known as black koji mold), Aspergillus luchuensis (known as black koji mold), and Aspergillus luchuensis mut. kawachii (known as white koji mold). As described later in the examples, yellow koji mold is preferred due to the amount of polyphenols contained in the koji and the characteristics of miso and amazake produced using the koji. The amount of koji mold to be inoculated is arbitrary. Methods for stirring and mixing the cooled grain and koji mold include manual mixing, vibration mixing using a vibrator, and stirring and mixing using various stirring devices such as stirring blades. Mixing the cooled grain and koji mold is also commonly known as "floor kneading." When the finely powdered Polygonum polyglutamum is added simultaneously with the inoculation of koji mold, the same applies to the finely powdered Polygonum polyglutamum. For example, manual mixing, vibration mixing with a vibrator, or stirring and mixing with various stirring devices using a stirring blade or the like can be employed. The following describes the case where the finely powdered Polygonum polyglutamum is added simultaneously with the inoculation of koji mold, and mixed grains are obtained via step S104 in Figure 1. In this specification, "mixed grains" refers to grains that have been cooled and inoculated with at least koji mold, and then stirred and mixed, and does not necessarily need to contain the finely powdered Polygonum polyglutamum.

[0021] In step S105 of FIG. 1, the koji mold added to the mixed grain is cultured for two to three days, and step S106 of FIG. 1 is performed several times at appropriate times. Steps S104 to S106 of FIG. 1 are also known as "koji production." In the culture step S105 of FIG. 1, the mixed grain is prepared in an environment suitable for koji mold cultivation. For example, the mixed grain is rolled into small balls, wrapped in cloth, and kept warm in a fermenter. The koji temperature is maintained at 30 to 40 degrees Celsius by placing it in the fermenter. The mixed grain is periodically removed from the fermenter, and the rice is thoroughly mixed to uniformly maintain the temperature, humidity, and enzyme conditions, thereby creating a favorable environment. If the temperature is high, the product temperature (the temperature of the mixed grain) is lowered by stirring and blowing air. Any method can be used for the culture step S106 of FIG. 1, as long as it is possible to control the temperature of the mixed grain.

[0022] When the originating grain is rice and the koji mold is white koji mold or yellow koji mold, the temperature of the mixed rice in step S105 is maintained at 35-40°C, so the maintenance in step S106 is performed about five or six times during the two-day culture. When the originating grain is rice and the koji mold is black koji mold, the temperature is raised to about 40-45°C once, then lowered to about 30-35°C, and then maintained at 30-35°C, so the maintenance in step S106 is performed about seven or eight times during the two-day culture. When the originating grain is barley, the temperature of the mixed barley is maintained at about 30-32°C for the first day, and then maintained at about 35-40°C thereafter, so the maintenance in step S106 is performed several times during the two-day culture. When the originating grain is soybeans, the temperature of the mixed soybeans is maintained at 28-30°C. After the maintenance in step S106 in FIG. 1 is performed several times, koji according to the embodiment can be obtained. When the grain of origin is rice, rice koji is obtained, when the grain of origin is barley, barley koji is obtained, and when the grain of origin is soybean, soybean koji is obtained. The koji according to the embodiment may be obtained in the form of a solidified mass or in a state where the grains are separated one by one, but in either case, it has the properties of koji.

[0023] If the finely powdered Polygonum nigra is not added simultaneously with the inoculation of Aspergillus oryzae, it is added in the pre-treatment step S106 while the mixed grains are heating. The finely powdered Polygonum nigra may be added in any pre-treatment step, but is preferably added in the final pre-treatment step.

[0024] When the grain used as the raw material is rice, the koji according to the embodiment can be prepared by using about 0.5 to 1.0% by weight of koji mold and about 2.0 to 4.0% by weight of finely divided Polygonum tetani powder relative to the weight of the polished rice. More preferably, the koji according to the embodiment can be obtained by using about 0.6 to 0.8% by weight of koji mold and about 3.0 to 3.5% by weight of finely divided Polygonum tetani powder relative to the weight of the polished rice.

[0025] The obtained koji according to the embodiment can be stored for long periods of time in a refrigerator or freezer, whether in a block or loose state. The properties of the koji according to the embodiment remain unchanged whether it is in the form of freshly made raw koji or in the form of slightly dried dried koji. The koji according to the embodiment can be used as a raw material for producing various fermented foods and beverages, such as sake, awamori, shochu, amazake, mirin, miso, and soy sauce. For example, when shio koji is produced using a conventional method using the koji according to the embodiment, it has the effect of enhancing the umami flavor compared to regular shio koji. Furthermore, the fermented foods and beverages produced using the koji of the present invention have an increased number of lactic acid bacteria (see Example 5). Lactic acid bacteria are known to have various beneficial effects, such as intestinal regulation, cholesterol reduction, immune enhancement, and anti-aging, and a high number of lactic acid bacteria is preferable in foods and beverages.

[0026] Fermented foods and beverages can be obtained by fermenting a mixture of raw grains and koji. For example, amazake can be produced by mixing rice, koji, and water and fermenting the mixture at 50 to 55°C for 8 to 12 hours.

[0027] The present invention also provides koji water obtained by mixing the koji of the present invention with water. Koji water is easy to drink even for those who dislike fermented beverages such as amazake, and can also be used as a cosmetic. Koji water can be produced, for example, by mixing koji with water to a concentration of 0.02 to 2 g / mL and leaving the mixture to stand for 5 hours or more. Koji water can typically be produced by mixing koji with water to a concentration of 0.1 to 0.3 g / mL and leaving the mixture to stand for 8 hours or more.

[0028] In particular, while miso production using conventional methods typically takes approximately three months, the miso production method using koji according to the embodiment shown in Figure 2 can be completed in as little as two months using the same procedures as conventional miso. This has the advantage of producing miso in approximately two-thirds the time compared to conventional miso. The miso production method according to the embodiment shown in Figure 2 is essentially the same as the conventional miso production method except for the use of koji according to the embodiment, except for the processing time. The miso production method according to the embodiment shown in Figure 2 uses three basic ingredients: soybeans (whole soybeans), koji, and salt, just like conventional methods. The weight ratio of soybeans to koji is approximately 1:1 to 1:3, depending on the desired miso flavor. The amount of salt is preferably 10 to 20% of the combined weight of the soybeans and koji, depending on the desired miso flavor. In the pretreatment step S201, the soybeans are washed, soaked in water for approximately 12 to 18 hours, and then drained. In step S202, the pretreated soybeans are steamed for approximately 3 to 5 hours, or steamed under pressure for approximately 30 minutes to 1 hour. In step S203, the soybeans are thoroughly crushed until they lose their graininess and cooled to below 35°C. In step S204, the cooled soybeans are mixed with koji and salt, and if necessary, cooled soybean broth is added. The mixture is rolled into balls (miso balls) and packed into airtight containers. In step S205, the packed mixture is aged while monitoring the progress until it reaches the desired level of maturity. In hot seasons, it takes 2 to 3 months for the mixture to be ready for use as miso, and if further maturation is desired, it is aged for several months to a year. In cold seasons, it takes 3 to 6 months for the mixture to be ready for use as miso, and if further maturation is desired, it is aged for several months to a year. In this specification, the term "finished" miso refers to the state in which miso has been fermented to the point where it can be used as miso, and is determined primarily by tasting. When miso is produced using the koji according to the embodiment of the present invention and the flow of steps shown in Figure 2, it can be completed in as little as two months, rather than the usual three months. Furthermore, from the viewpoint of the antioxidant power of miso, miso produced using koji made from rice-derived ingredients, using yellow Aspergillus oryzae, and adding indigo is particularly preferred.

[0029] In the koji production method according to the embodiment, despite the use of fine powder of Polygonum nigricans, which has antibacterial properties, koji can be produced without any problems without adversely affecting the growth of koji mold or the enzyme production of koji mold. Since the koji according to the embodiment has a polyphenol content increased by 1.2 times or more, it is possible to produce koji-fermented foods and beverages with enhanced antioxidant activity.

[0030] In the koji production method according to the embodiment, the addition of finely divided Polygonum polyglutamum powder increases the temperature of the mixed grains more easily than usual, resulting in the desired temperature being reached more quickly. Especially during the cold winter months, if the temperature of the mixed grains drops below the desired range, problems with the quality of the koji can occur. Therefore, adding finely divided Polygonum polyglutamum powder to increase the temperature is advantageous for koji production. Furthermore, particularly when using black koji mold, the temperature of the mixed grains must be raised to approximately 40-45°C in one go, making the koji production method according to the embodiment, which allows for a rapid temperature increase, particularly suitable.

[0031] As can be seen from the SEM photograph of Figure 3, in the koji according to the embodiment, Polygonum polyglutamum fibers adhere to the surface tissue of rice. Figure 3 shows a cross-section of koji according to the embodiment, taken using a Hitachi High-Technologies Corporation SU6600 SEM under conditions of SE mode, voltage 5.0 kV, and 200x magnification. The SEM photograph of the band-shaped area corresponding to the arrow A shows mainly Polygonum polyglutamum fine powder, while the SEM photograph of the band-shaped area corresponding to the arrow B shows mainly rice, the raw material for koji. The boundary between the Polygonum polyglutamum fine powder and rice is unclear. Figure 3 shows that the long, slender fibers of Polygonum polyglutamum intertwine with each other and adhere intricately to the irregularities on the rice surface. This type of adhesion cannot be achieved by adding Polygonum polyglutamum fine powder after the koji is completed. Figure 4 shows a cross-section of koji according to the embodiment, taken using the same SEM as Figure 3, under conditions of SE mode, voltage 5.0 kV, and 1000x magnification, at a different location from Figure 3. The upper part of Figure 4 is mainly fine knotweed powder, and the part from the center to the bottom of Figure 4 is mainly rice. Figure 4 shows that the knotweed fibers are slightly flattened, with a width of about 40 to 50 μm and a thickness of about 10 μm.

[0032] The present invention will be specifically explained below by showing examples. However, these examples are merely for illustrative purposes, and the present invention is not limited to these examples, including the product names, production areas, purchasing sources, etc. shown in the following examples.

[0033] Example 1: 750 g of polished Koshihikari rice from Niigata was prepared as the source grain for Example 1. The rice was washed, soaked in water for 12 hours, and steamed for 60 minutes to obtain steamed rice. The resulting steamed rice was spread on a flat surface and cooled to approximately 30°C. Then, 4 g of yellow koji mold (Aspergillus oryzae, manufactured by Hishiroku Co., Ltd., Kyoto) was inoculated onto the spread steamed rice, and 20 g of dried koji powder (indigo powder, manufactured by Bon Arm Co., Ltd.) was sprinkled evenly over the steamed rice and mixed by hand to obtain mixed rice. The resulting mixed rice was rolled into a ball, wrapped in cloth, and kept warm in a fermenter to begin cultivation. Over a two-day period, the mixed rice was removed from the cloth, spread out, and exposed to air six times to maintain the internal temperature (product temperature) of the mixed rice at 35-40°C. Approximately 900 g of koji according to Example 1 was obtained two days after the start of cultivation. The same procedure was repeated to obtain approximately 900 g of the koji of Example 1.

[0034] The polyphenol content of the koji according to Example 1 was analyzed. Approximately 0.8 to 2 g of the koji according to Example 1 was collected, 50 ml of 50% ethanol was added, and the mixture was homogenized for 1 minute. A small amount of 50% ethanol was then added, and the mixture was subjected to ultrasonic irradiation for 30 minutes to extract the components. The resulting extract was adjusted to a constant volume of 250 ml, centrifuged, and filtered to obtain the test solution according to Example 1. Next, 0.5 ml of Folin-Ciocalteu reagent and 5 ml of 0.4 mol / l aqueous sodium carbonate solution were added to 1 ml of the test solution according to Example 1, and the mixture was allowed to stand at 30°C for 30 minutes. After centrifugation, the absorbance was measured using a UV-visible spectrophotometer (measurement wavelength 660 nm). It was found that the koji according to Example 1 contained 0.14 g / 100 g of polyphenols. The polyphenol content is expressed as a converted value of (+)-catechin.

[0035] Using the koji of Example 1, the miso of Example 1 was obtained in about two months according to the standard method of miso production shown in Figure 2. That is, 450 g of soybeans were soaked in water for 15 hours, drained, and steamed for 3.5 hours. The steamed soybeans were then mashed and cooled to 30°C or below, and 1350 g of the koji of Example 1, 300 g of salt, and 300 ml of soybean broth were added and mixed. The mixture was filled into an airtight container and fermented, yielding 3000 g of the miso of Example 1 in about two months.

[0036] Example 2: 650 g of polished Koshihikari rice from Niigata was prepared as the source grain for Example 2. The rice was washed, soaked in water for 12 hours, and steamed for 60 minutes to obtain steamed rice. The resulting steamed rice was spread on a flat surface and cooled to approximately 30°C. Then, 4 g of black koji mold (shochu black koji mold, Akita Konno Shoten Co., Ltd.) was inoculated onto the spread steamed rice, and 20 g of dried Polygonum sieboldii powder (indigo powder, Bon Arm Co., Ltd.) was sprinkled evenly over the steamed rice and mixed by hand to obtain mixed rice. The resulting mixed rice was rolled into a ball, wrapped in cloth, and incubated in a fermenter to begin cultivation. First, the temperature of the mixed rice was raised to approximately 43°C, and then the same treatment as in Example 1 was carried out to maintain the temperature at approximately 30°C. During the two-day cultivation period, the mixed rice was treated eight times in the same manner as in Example 1 to maintain the internal temperature of the mixed rice at 30-35°C. Two days after the start of cultivation, approximately 900 g of koji according to Example 2 was obtained.

[0037] The amount of polyphenols was measured in the same manner as in Example 1, and it was found that the koji of Example 2 contained 0.12 g / 100 g of polyphenols.

[0038] Comparative Example 1: 650 g of polished Koshihikari rice from Niigata was prepared as the source grain for Comparative Example 1. The rice was washed, soaked in water for 12 hours, and steamed for 60 minutes to obtain steamed rice. The resulting steamed rice was spread on a flat surface and cooled to approximately 30°C. Four grams of yellow koji mold (Aspergillus oryzae, Chohakukin, Hishiroku Co., Ltd., Kyoto) was then inoculated onto the spread steamed rice and mixed by hand to obtain mixed rice. The resulting mixed rice was rolled into a ball, wrapped in cloth, and kept warm in a fermenter to begin cultivation. The same treatment as in Example 1 was repeated four times over two days to maintain the internal temperature of the mixed rice at 35-40°C. Approximately 900 g of koji according to Comparative Example 1 was obtained two days after the start of cultivation. The same procedure was repeated to obtain another approximately 900 g of koji according to Comparative Example 1.

[0039] The polyphenol content of the koji according to Comparative Example 1 was analyzed in the same manner as in Example 1. It was found that the koji according to Comparative Example 1 contained 0.11 g / 100 g of polyphenols. The polyphenol content is expressed as a converted value of (+)-catechin.

[0040] Using the koji of Comparative Example 1, miso of Comparative Example 1 was obtained in approximately three months by the same standard miso production method as in Example 1, as shown in Figure 2, starting on the same day as Example 1. That is, 450 g of soybeans were soaked in water for 15 hours, drained, and steamed for 3.5 hours. The steamed soybeans were then mashed and cooled to 30°C or below, and 1350 g of koji of Comparative Example 1, 300 g of salt, and 300 ml of soybean broth were added and mixed. The mixture was filled into an airtight container and fermented, yielding 3000 g of miso of Comparative Example 1 in approximately three months.

[0041] (Example 3) In addition to those described in the examples, koji production was carried out using various types of raw materials and koji mold, with the addition of Polygonum polyglutamum, as in Example 1. First, 750 g of derived grain was prepared, washed, soaked in water for 12 hours, and steamed for 60 minutes to obtain steamed derived grain. The resulting grain was spread on a flat surface and cooled to approximately 30°C. Then, 4 g of koji mold was inoculated into the spread steamed grain, and 20 g of Polygonum polyglutamum fine powder was sprinkled evenly over the grain and mixed by hand to obtain mixed grain. The resulting mixed grain was rolled up, wrapped in cloth, and incubated in a fermenter. Over a two-day period, the mixed grain was removed from the cloth, spread out, and exposed to air six times to maintain the internal temperature (product temperature) of the mixed grain at 35-40°C. Approximately 900 g of koji was obtained two days after the start of cultivation. The polyphenol content of the resulting koji was determined using the Folin-Ciocalteu method.

[0042] As a result, assuming the amount of polyphenols when rice was used as the source grain and Aspergillus oryzae was used as the koji mold to be 100%, the amount of polyphenols detected when rice was used as the source grain and Shiro Aspergillus oryzae was used as the koji mold was approximately 73%, when rice was used as the source grain and Monas oryzae was used as the koji mold was approximately 55%, and when wheat (barley) was used as the source grain and Aspergillus oryzae was used as the koji mold was approximately 132%. Furthermore, when soybeans were used as the source grain and Aspergillus oryzae was used as the koji mold, the koji obtained had a stickiness similar to natto, and koji could not be successfully obtained. The combinations of source grain and Aspergillus oryzae and the amount of polyphenols in the resulting koji are shown below.

[0043] These results demonstrate that, in order to successfully obtain koji with a high polyphenol content using Polygonum polyglutamic acid, the combination of rice as the grain of origin and Aspergillus oryzae as the koji mold, and the combination of barley as the grain of origin and Aspergillus oryzae as the koji mold, are preferable compared to the other combinations shown in Table 1.

[0044] (Example 4) The effect of different koji on miso was examined. Specifically, according to the standard miso production method shown in Figure 2, 450 g of soybeans were soaked in water for 15 hours, drained, and steamed for 3.5 hours. The steamed soybeans were then mashed and cooled to below 30°C, and 1,350 g of various koji, 300 g of salt, and 300 ml of soybean broth were added and mixed. The mixture was filled into a sealed container and fermented to obtain miso. Various koji were produced under different conditions, with or without the addition of grain origin, koji mold, and Japanese knotweed, and the antioxidant capacity of the miso was tested. The antioxidant capacity was measured by measuring the radical scavenging activity of DPPH (2,2-diphenyl-1-picrylhydrazyl). Specifically, 40 ml of 70% methanol solution was added to 5 g of each sample, and the mixture was subjected to shaking extraction at 200 rpm for 1 hour at room temperature. The mixture was then centrifuged at 8700 rpm for 15 minutes, and the supernatant was collected and filtered through a 0.45 μm filter to prepare the measurement sample solution. The measurement sample solution was subjected to antioxidant activity measurement using the DPPH radical scavenging activity measurement method. The results were expressed as DPPH radical scavenging activity values, calculated in terms of Trolox equivalents. The koji preparation method followed Example 1 for those with indigo added and Comparative Example 1 for those without indigo added, except for the type of grain and the type of koji mold used. *1 1050g of koji (without indigo) made from brown rice and yellow koji, and 300g of koji (without indigo) made from soybeans and soybean koji starter (Aspergillus sojae). *2 1050g of koji (with indigo) made from rice and yellow koji, and 300g of koji (without indigo) made from soybeans and soybean koji starter.

[0045] As can be seen from Table 1, miso made using koji made from rice-derived ingredients, using yellow Aspergillus oryzae and adding indigo had higher antioxidant power than miso made without it.

[0046] (Example 5) Amazake was produced using various koji and its properties were tested. 100g of each koji, 100g of cooked rice, and 250g of water were kept at 50-55°C for 8 hours to obtain amazake. The amazake was cooled, filled into a pouch, left at 20-25°C for 24 hours, and then frozen. The number of lactic acid bacteria was tested using BCP-added plate count agar medium. The results are shown below.

[0047] As can be seen from Table 2, the number of lactic acid bacteria in amazake increased when koji made with indigo was used. The increase was remarkable in amazake made with koji made from barley as the grain of origin, yellow Aspergillus oryzae as the koji mold, and indigo added, and the increase was especially remarkable in amazake made with koji made from rice as the grain of origin, yellow Aspergillus oryzae as the koji mold, and indigo added.

[0048] As described above, the present invention has been described by one embodiment and several examples, but the descriptions and drawings that form part of this disclosure should not be understood to limit the present invention. Various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure.

[0049] For example, koji according to the embodiment can be produced using Monascus purpureus, M. anka, M. pilosus, M. vitreus, M. rubber, etc., also known as red koji mold, in addition to yellow koji mold, black koji mold, and white koji mold. The koji according to the embodiment produced using red koji mold can be used in fermented foods such as red wine and tofu yo.

[0050] Although the above example shows the production of koji according to the embodiment by inoculating the koji mold as a seed, koji according to the embodiment can also be produced by using koji containing koji mold as a substitute for the koji mold. When mixing koji with heated grains, koji according to the embodiment can be produced by sprinkling dried powder of Polygonum nigra on top.

[0051] It is also possible to combine parts of the technical ideas described in the embodiments of the present invention as appropriate. As such, the present invention naturally includes various embodiments not described here. Therefore, the technical scope of the present invention is defined only by the invention-specifying matters according to the claims, which can be interpreted appropriately from the above description.

[0052] The present invention provides, for example, the following items: (Item 1) Koji characterized in that fine fibers of Polygonum polyglutamum adhere to the surface of the derived grain used as a raw material. (Item 2) Koji according to Item 1 characterized in that the polyphenol content is increased by 1.2 times or more compared to when the fine fibers are not attached. (Item 3) Koji according to Item 1 or 2 characterized in that the derived grain is rice. (Item 4) Koji according to any one of Items 1 to 3 characterized in that it is produced using Aspergillus oryzae. (Item 5) Koji according to any one of Items 1 to 3 characterized in that it is produced using Aspergillus oryzae. (Item 6) A method for producing koji characterized by comprising the steps of soaking the derived grain used as a raw material in water, heating the soaked derived grain to obtain heated grain, allowing the heated grain to cool, sprinkling dried powders of Aspergillus oryzae and Polygonum polyglutamum onto and mixing the cooled heated grain to obtain mixed grain, and aging the mixed grain by adjusting the temperature. (Item 7) Miso characterized by being produced from koji in which fine Polygonum polyglutamum fibers adhere to the surface of the derived grain. (Item 8) A method for producing miso characterized by comprising the steps of soaking soybeans in water, steaming the soaked soybeans to obtain steamed beans, crushing the steamed beans, mixing the crushed steamed beans with koji and salt that have adhered to the surface of the derived grain from which Polygonum polyglutamum fibers are used as a raw material to obtain a mixture, and fermenting the mixture. (Item A1) A method for producing koji characterized by comprising the steps of mixing koji mold and Polygonum polyglutamum dried powder with heated grain to obtain mixed grain, and fermenting the mixed grain. (Item A2) The production method according to Item A1, wherein the derived grain is rice or wheat. (Item A3) The production method according to Item A1 or 2, wherein the koji mold is Aspergillus oryzae. (Item A4) Koji characterized by mixing Koji mold and Polygonum polyglutamum fine powder with heated derived grain and fermenting the mixture. (Item A5) The koji according to Item A4, wherein the grain of origin is rice or barley. (Item A6) The koji according to Item A4 or 5, wherein the koji mold is Aspergillus oryzae. (Item A7) Koji water obtained by mixing the koji according to any one of Items A4 to A6 with water.(Item A8) A method for producing a fermented food or drink, comprising the steps of mixing a raw material grain with the koji described in any one of Items A4 to A6 to obtain a mixture, and fermenting the mixture. (Item A9) The production method described in Item A8, wherein the raw material grain is soybeans and the fermented food or drink is miso. (Item A10) Miso produced by the production method described in Item A9. (Item A11) The production method described in Item A8, wherein the raw material grain is rice and the fermented food or drink is amazake. (Item A12) Amazake produced by the production method described in Item A8.

Claims

1. Mixing the heated grain with dried powder of koji mold and Polygonum gracilis to obtain mixed grain; fermenting the mixed grain; A method for producing koji, comprising:

2. The method according to claim 1 , wherein the grain of origin is rice or wheat.

3. The method according to claim 1 or 2, wherein the koji mold is yellow koji mold.

4. This koji is made by mixing heated grains with fine powder of koji mold and Polygonum gracilis and fermenting the mixture.

5. The koji according to claim 4, wherein the grain of origin is rice or barley.

6. The koji according to claim 4 or 5, wherein the koji mold is yellow koji mold.

7. 7. Koji water, obtained by mixing the koji according to any one of claims 4 to 6 with water.

8. A cosmetic comprising the koji described in any one of claims 4 to 6 or the koji water described in claim 7.

9. A step of mixing raw material grains with the koji according to any one of claims 4 to 6 to obtain a mixture; fermenting the mixture; A method for producing a fermented food or drink, comprising:

10. The method according to claim 9, wherein the raw grain is soybean, and the fermented food or drink is miso.

11. Miso produced by the method according to claim 10.

12. The method according to claim 9, wherein the raw grain is rice and the fermented food or drink is amazake.

13. Amazake produced by the production method according to claim 9.

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