Rice koji cereal fermentation saccharified liquid and method for producing same

Abstract

Provided are: a fermented saccharified liquid of rice koji cereals containing beta-glucan derived from cereals; a food or beverage containing the fermented saccharified liquid of rice koji cereals; and a raw material for producing the food or beverage. The rice koji cereal fermentation saccharified liquid has the following characteristics: (a) the weight-average molecular weight of beta-glucan derived from cereal is 100,000-500,000, and the weight-average molecular weight of beta-glucan derived from cereal is 2,000-2,000,000; (b) the proportion of cereal-derived beta-glucan having a molecular weight of 10,000 or more and less than 800,000 in a total of 100 mass% of cereal-derived beta-glucan: 80 mass% or more; (c) the ratio of cereal-derived beta-glucan in 100% by mass of the solid content of the rice koji cereal fermentation saccharified liquid is 1-35% by mass; (d) iodine color development test: (-); and (e) a viscosity of 10 to 5000 mPa * s.

Description

Technical Field

[0001] The present invention relates to a koji cereal fermentation saccharified liquid containing cereal-derived β-glucan, a food or beverage containing the same, and a raw material for producing the food or beverage. The present invention also relates to a method for producing a koji cereal fermentation saccharified liquid containing cereal-derived β-glucan. Background Art

[0002] Cereals such as oats and barley are widely used as ingredients in cereal foods and other foods because they are rich in water-soluble dietary fiber. Most of the water-soluble dietary fiber contained in cereals is β-glucan. The β-glucan naturally contained in cereals (also referred to herein as "untreated β-glucan") is a linear high-molecular compound composed of glucose units polymerized by β-1,3 bonds and β-1,4 bonds. It has been reported that β-glucan has various physiological functions such as normalizing blood cholesterol levels, suppressing the rise in postprandial blood glucose levels, maintaining satiety, enhancing the proliferation of Bifidobacterium, and immunomodulatory effects. Due to these physiological functions, it has a positive health image, and therefore, in recent years, the demand for cereals as food ingredients has been expanding.

[0003] Generally, it is said that the molecular weight of oat β-glucan is 2,000,000 to 3,000,000, and the molecular weight of barley β-glucan is 50,000,000. Untreated β-glucan has a high molecular weight and is therefore highly viscous and poorly soluble in water.

[0004] One known method for suppressing such thickening problems is a method of crushing cereals, dissolving them in water or the like, and then subjecting them to enzymatic saccharification treatment with enzymes such as amylase and cellulase to obtain a liquid form. This method is used to produce oat milk because a natural sweetness is obtained during the saccharification treatment. However, since the enzymatic treatment completely decomposes β-glucan together with starch or since β-glucan is removed when removing insoluble components, a method of additionally adding a water-soluble dietary fiber with low viscosity and easy to handle such as inulin as needed to supplement the physiological effects is adopted.

[0005] Recently proposed methods include a method of producing a cereal saccharide using the function of β-glucan without completely decomposing β-glucan.

[0006] Specifically, Patent Document 1 discloses a method for preparing cereal saccharides. The method includes dispersing a cereal pulverized product containing β-glucan in water; performing a proteolytic reaction using a protease protein hydrolase with a β-glucanase activity of 0 to 10% before performing a liquefaction reaction and a saccharification reaction; decomposing starch by using a liquefying enzyme (α-amylase) with a β-glucanase activity of 0 to 10% and a saccharifying enzyme (β-amylase, glucoamylase) with a β-glucanase activity of 0 to 10%; and performing solid-liquid separation to remove insoluble portions, thereby preparing a cereal saccharide containing 1 to 15% by mass of β-glucan and showing a negative (-) iodine color test. In this method, it is crucial to perform the proteolytic reaction before the liquefying enzyme reaction. According to the disclosure, if these reactions are not carried out in this order, β-glucan will remain in the residue during solid-liquid separation, and the residue will be removed as an insoluble portion. Therefore, the resulting cereal saccharide will not have a sufficient β-glucan content.

[0007] Patent Document 2 discloses a method for preparing a plant-derived syrup containing β-glucan. The method includes filtering a cereal saccharide prepared by an enzyme treatment (proteolytic treatment, liquefying enzyme treatment, and saccharifying enzyme treatment) similar to the method disclosed in Patent Document 1 using diatomaceous earth or activated carbon, etc.; passing the liquid through a filter; and concentrating the liquid to a predetermined Brix value, thereby obtaining a plant-derived syrup containing β-glucan, in which a plant-derived β-glucan having a weight-average molecular weight of 2,500 to 40,000 is present in a proportion of 2 to 8% by mass of the total soluble solid content, the viscosity is 10,000 cP or less, and the Brix value is 30 to 80%.

[0008] In addition, Patent Document 3 states that a water-soluble β-glucan having a weight-average molecular weight of 5,000 to 100,000, which can be obtained by low-molecularizing β-glucan contained in seeds of gramineous plants such as barley and oats, has an immune-enhancing effect. The low-molecularization treatment is carried out by hydrolysis, for example, by pressurized heating in the presence of an acid or by using an enzyme such as β-glucanase.

[0009] As described above, conventionally, in the production of cereal saccharides containing β-glucan, methods such as hydrolysis by pressurized heating and hydrolysis using an enzyme have been proposed. However, these methods require precise control to obtain a predetermined amount of β-glucan low-molecularized to the desired degree without excessive decomposition of β-glucan.

[0010] Prior art documents

[0011] Patent documents

[0012] Patent Document 1: JP2009-050226A

[0013] Patent Document 2: JP2020-054399A

[0014] Patent Document 3: JP2001-323001A

[0015] Non-patent documents

[0016] Non-Patent Document 1: The retrogradation kinetics of starches of different botanical origin in the presence of glucose syrup. International Journal of Biological Macromolecules, Vol. 114, July 15, 2018, pp. 1288-1294 SUMMARY OF THE INVENTION

[0017] Problems to be solved by the invention

[0018] The present invention aims to provide a liquid koji-cereal fermentation saccharified product (koji-cereal fermentation saccharified liquid) containing low-molecular-weight β-glucan derived from cereals. The present invention also aims to provide a method for producing the same. The present invention also aims to provide a food or beverage containing the koji-cereal fermentation saccharified liquid or a processed product thereof, and a raw material for producing the food or beverage.

[0019] Solutions for solving the problems

[0020] As a result of in-depth research to obtain, by a simple method, a cereal-derived β-glucan-containing product that can be easily processed as a food or beverage or an ingredient thereof, the present inventors found that using a koji-fermented cereal crushed product allows a liquefaction reaction and a saccharification reaction to proceed while allowing low-molecular-weight β-glucan to be retained. As a result, the present inventors found that a saccharified liquid containing cereal-derived β-glucan can be obtained, which has an easily processable viscosity and good dispersion stability, and also has a high β-glucan content, and the β-glucan is low-molecular-weight to reach a desired weight-average molecular weight.

[0021] The present invention has been completed through further research based on the above findings and has the following embodiments.

[0022] In this document, unless otherwise specifically stated, the description of "〇 to △" (〇 and △ are arbitrary values) means "〇 or more and △ or less".

[0023] (I) Aspergillus oryzae cereal fermentation saccharified liquid containing β-glucan derived from cereals

[0024] (I-1) A koji-cereal fermentation saccharified liquid containing cereal-derived β-glucan, which has the following characteristics:

[0025] (a) The weight-average molecular weight of cereal-derived β-glucan: 100,000 to 500,000, preferably 250,000 to 500,000;

[0026] (b) The proportion of cereal-derived β-glucan with a molecular weight of more than 10,000 and less than 800,000 in the total 100% by mass of cereal-derived β-glucan: 80% by mass or more, preferably 80 to 98%;

[0027] (c) The proportion of cereal-derived β-glucan in the 100% by mass solid content of the koji-cereal fermentation saccharified liquid: 1 to 35% by mass, preferably 3 to 30%;

[0028] (d) Iodine color reaction test: (-); and

[0029] (e) Viscosity: 10 to 5000 mPa·s.

[0030] (I-2) The koji-cereal fermentation saccharified liquid according to (I-1), wherein the cereal-derived β-glucan further has the following characteristics:

[0031] (f) Molecular weight (mode value): 10,000 to 300,000, preferably 80,000 to 300,000.

[0032] (I-3) The koji-cereal fermentation saccharified liquid according to (I-1) or (I-2), which has the following characteristics:

[0033] (A) The precipitation amount per 100 mL volume is less than 10 mL; and

[0034] (B) The flow-down time of 100 g of the product is less than 60 seconds,

[0035] wherein the above (A) and (B) are measured by the methods and conditions described in test methods (6) and (7) in the examples.

[0036] (I-4) The koji-cereal fermentation saccharified liquid according to any one of (I-1) to (I-3), wherein the cereal is the seed of a Gramineae plant.

[0037] (I-5) The koji-cereal fermentation saccharified liquid according to (I-4), wherein the Gramineae plant is at least one selected from oats and barley.

[0038] (I-6) The koji-cereal fermentation saccharified liquid according to any one of (I-1) to (I-5), wherein the koji is Aspergillus oryzae.

[0039] (II) Method for producing Aspergillus oryzae cereal fermentation saccharified liquid containing β-glucan derived from cereals

[0040] (II-1) The method for producing a koji-cereal fermented saccharified liquid according to any one of (I-1) to (I-6), the method comprising: heating a pulverized cereal in the presence of water to completely or partially gelatinize starch; and fermenting the pulverized cereal using koji.

[0041] (II-2) The production method according to (II-1), wherein the mixing ratio of koji with respect to 1 part by mass of β-glucan (untreated β-glucan) in the pulverized cereal is 0.1 to 10 parts by mass, preferably 0.4 to 8.5 parts by mass.

[0042] (II-3) The production method according to (II-1) or (II-2), wherein the cereal is a seed of a Gramineae plant.

[0043] (II-4) The production method according to any one of (II-1) to (II-3), wherein the Gramineae plant is selected from at least one of oats and barley, preferably oats.

[0044] (II-5) The production method according to any one of (II-1) to (II-4), wherein the koji is Aspergillus oryzae.

[0045] (III) Food or beverage or raw material for producing food or beverage

[0046] (III-1) A food or beverage containing the koji-cereal fermented saccharified liquid according to any one of (I-1) to (I-6) or a processed product thereof, or a raw material for producing the food or beverage.

[0047] Effects of the invention

[0048] The present invention can provide a cereal fermented saccharified liquid having a low viscosity, being easy to handle, and having good dispersion stability. The cereal fermented saccharified liquid also has a desired high proportion of β-glucan that is low-molecularized to reach a desired weight-average molecular weight. The evaluation of the cereal fermented saccharified liquid of the present invention in an iodine color development test shows (-) and does not contain starch. Therefore, thickening due to heat treatment is suppressed. Therefore, it can be used as a food or beverage containing β-glucan derived from cereal or as a raw material for producing a food or beverage containing β-glucan derived from cereal. Detailed Embodiments

[0049] (I) Aspergillus oryzae cereal fermentation saccharified liquid containing β-glucan derived from cereals

[0050] The koji-cereal fermentation saccharified liquid contemplated by the present invention is a liquid saccharide, which can be obtained by heating cereals in the presence of water to completely or partially α -amylate starch and fermenting the crushed cereals with koji. The koji-cereal fermentation saccharified liquid contains β-glucan derived from cereals and has the characteristics described in the following (a) to (e).

[0051] (a) Weight-average molecular weight of β-glucan derived from cereals: 100,000 to 500,000;

[0052] (b) Proportion of β-glucan derived from cereals having a molecular weight of 10,000 or more and less than 800,000 in the total 100% by mass of β-glucan derived from cereals: 80% by mass or more;

[0053] (c) Proportion of β-glucan derived from cereals in the 100% by mass solid content of the koji-cereal fermentation saccharified liquid: 1 to 35% by mass;

[0054] (d) Iodine color development test: (-); and

[0055] (e) Viscosity: 10 to 5000 mPa·s.

[0056] Hereinafter, the koji-cereal fermentation saccharified liquid of the present invention will be described.

[0057] (Cereals)

[0058] Any cereal containing β-glucan can be used as a raw material for the koji-cereal fermentation saccharified liquid. However, seeds of Gramineae plants are preferred. Examples of seeds of Gramineae plants include seeds of rice, wheat, corn, sorghum, barnyard millet, foxtail millet, millet, barley, oat (wild oat (Avena fatua), oat (Avena sativa)), and rye. The strains and varieties of these seeds of Gramineae plants are not limited as long as they contain β-glucan. For example, rice has japonica and glutinous rice strains, and both can be used as long as β-glucan is present. Barley has varieties such as two-row barley, four-row barley, six-row barley, and naked barley, and all of them can be used as long as β-glucan is present. Cereals with a high β-glucan content are preferred, and examples of such cereals include barley and oat. Oat is more preferred because it allows the effects of the present invention to be more effectively achieved, that is, as described in the examples below, a koji-cereal fermentation saccharified liquid with good dispersion stability and operability and a high content of low-molecular-weight β-glucan can be obtained.

[0059] As raw materials, any of the above cereals can be used alone or two or more of them can be used in any combination.

[0060] The usable parts of the grains are any parts of each grain containing β-glucan, such as whole grains, milled wheat grains, and bran. In barley, since the endosperm has a high β-glucan content, it is preferable to use whole grains or milled wheat grains containing the endosperm. In the case of oats, since the bran has a high β-glucan content, it is preferable to use whole grains containing the bran and to use the bran itself. A more preferable ingredient is oat bran.

[0061] When used as a raw material for koji-grain fermentation saccharified liquid, in terms of the efficiency of saccharification, it is preferable to crush the grains (grain crushings). Generally, the degree of crushing is classified into coarse crushing (up to about 1 mm), medium crushing (about 1 mm to about several tens of μm), fine crushing (about several tens of μm to about 10 μm), and ultrafine crushing (about 10 μm or less) according to the particle size of the crushed grain powder (crushing particle size). In the present invention, although there is no limitation, the usable grain crushings are preferably grain crushings having a particle size of medium crushing or less, more preferably grain crushings having a medium crushing to fine crushing particle size (about 1 mm to about 10 μm), and particularly preferably grain crushings having a fine crushing particle size (about several tens of μm to about 10 μm). As used herein, the term "crushing particle size" refers to the median diameter.

[0062] (β-glucan derived from grains)

[0063] The β-glucan derived from grains contained in the koji-grain fermentation saccharified liquid of the present invention is a natural β-glucan (untreated β-glucan) naturally contained in grains, and is made to be low-molecular-weight by using koji fermentation. Among grains, it is said that the molecular weight of the untreated β-glucan contained in barley is 50000000, and it is said that the molecular weight of the untreated β-glucan contained in oats is 2000000 - 3000000.

[0064] The molecular weight distribution of the β-glucan derived from grains contained in the koji-grain fermentation saccharified liquid is about 1000 - 1600000, preferably about 1000 - 1200000, and the weight-average molecular weight is 100000 - 500000. The lower limit value of the weight-average molecular weight is 100000, preferably 150000, more preferably 200000, still more preferably 250000. The upper limit value of the weight-average molecular weight is 500000, preferably 450000, more preferably 400000. These lower limit values and upper limit values can be selected in any combination. Examples include the following ranges: 150000 - 500000, 200000 - 500000, 250000 - 500000, 150000 - 450000, 200000 - 450000, and 250000 - 450000.

[0065] The method for determining the weight-average molecular weight and the following molecular weight distribution of cereal-derived β-glucan contained in koji rice cereal fermentation saccharified liquid is described in detail in the examples.

[0066] In the molecular weight distribution of cereal-derived β-glucan, the proportion of cereal-derived β-glucan with a molecular weight in the range of more than 10,000 and less than 800,000 in the total 100% by mass of cereal-derived β-glucan in koji rice cereal fermentation saccharified liquid is 80% by mass or more, preferably 80-98% or 80-95% by mass, and more preferably 85-95% by mass.

[0067] Similarly, in the molecular weight distribution of cereal-derived β-glucan, the proportion of cereal-derived β-glucan in each molecular weight range is as follows:

[0068] More than 10,000 and less than 600,000: 65% by mass or more, 70% by mass or more, preferably 75-95% by mass, and more preferably 75-92% by mass;

[0069] More than 10,000 and less than 400,000: 60% by mass or more, 65% by mass or more, preferably 65-85% by mass, and more preferably 65-83% by mass;

[0070] More than 10,000 and less than 300,000: 45% by mass or more, 50% by mass or more, preferably 55-80% by mass, and more preferably 55-76% by mass; and

[0071] More than 10,000 and less than 200,000: 27% by mass or more, 35% by mass or more, preferably 35-70% by mass, and more preferably 38-67% by mass.

[0072] Although not limited, among all the molecular weights of cereal-derived β-glucan contained in koji rice cereal fermentation saccharified liquid, the most common molecular weight (mode) is 10,000-300,000. The lower limit value of the molecular weight (mode) is 10,000, preferably 20,000, more preferably 30,000, still more preferably 40,000, and particularly preferably 80,000. The upper limit value of the molecular weight (mode) is 300,000, preferably 200,000, and more preferably 150,000. These lower limit values and upper limit values can be selected in any combination. Examples include the following ranges: 10,000-300,000, 40,000-300,000, 80,000-300,000, and 10,000-100,000.

[0073] Based on the weight-average molecular weight, molecular weight distribution, and molecular weight (mode) of such cereal-derived β-glucan, it should be understood that the cereal-derived β-glucan contained in koji rice cereal fermentation saccharified liquid is a low-molecular-weight β-glucan generated by the decomposition of high-molecular-weight untreated β-glucan.

[0074] Based on 100% by mass of the solid components of the koji rice grain fermentation saccharified liquid, the content of β-glucan derived from grains is 1 to 35% by mass. The lower limit value of the content of β-glucan derived from grains is 1% by mass, preferably 2% by mass, more preferably 3% by mass, still more preferably 4% by mass. The upper limit value is 35% by mass, preferably 30% by mass, more preferably 29% by mass. These lower limit values and upper limit values can be selected in any combination. Examples include the following ranges: 1 to 30% by mass, 3 to 30% by mass, and 3 to 29% by mass. The preferred koji rice grain fermentation saccharified liquid is the one containing β-glucan derived from grains in the above numerical ranges, such as up to 20 to 30% by mass, particularly preferably 25 to 30% by mass as described in the following examples (Examples 4 to 7).

[0075] The method for quantifying β-glucan and the method for measuring the solid components of the koji rice grain fermentation saccharified liquid are described in detail in the examples.

[0076] (Koji rice grain fermentation saccharified liquid)

[0077] The koji rice grain fermentation saccharified liquid is a liquid saccharide obtained by subjecting grains (preferably crushed grains) to a heat treatment in the presence of water and then fermenting with koji.

[0078] Therefore, the saccharified liquid is characterized in that the starch naturally contained in the grains is decomposed to such an extent that the evaluation in the "iodine color development test" shows (-). The iodine color development test method and its evaluation criteria are described in detail in the examples.

[0079] The grains are heat-treated in the presence of water to gelatinize the starch contained in the grains. When the starch contained in the grains is partially (not completely) or completely gelatinized by this heat treatment in advance, in the subsequent fermentation treatment using koji, the action rate of enzymes such as α-amylase contained in the koji can be increased. The degree of gelatinization (gelatinization degree) of the starch caused by the heat treatment is not limited as long as the above object is not impaired. For example, it is in the range of 80 to 100%, preferably 90 to 100% (measurement method: glucoamylase method).

[0080] There are no restrictions on the heating method and heating conditions, as long as the starch contained in the cereal can be partially or completely α - gelatinized as described above. For example, in one method, the cereal pulverized product is heat - treated in the presence of water at a temperature range of 50 to 90°C for about 1 to 30 minutes. This heat - treatment can be carried out under normal pressure (atmospheric pressure: 0.1 MPa) conditions or under pressurized conditions. Preferably, the method is to heat - treat the cereal pulverized product in the presence of water, under normal pressure, at 60 to 85°C for 5 to 20 minutes. More preferably, the treatment temperature and time are 70 to 85°C and 10 to 20 minutes respectively. It is speculated that by carrying out the heat - treatment under the above - mentioned conditions, a large amount or most of the starch in the cereal will be α - gelatinized (see Non - Patent Document 1).

[0081] The koji for fermentation after heat - treatment is prepared by attaching koji mold to the steamed rice and culturing it under the temperature and humidity conditions optimal for growth. The types of koji mold include Aspergillus flavus (Aspergillus oryzae, Aspergillus sojae), Aspergillus kawachii (white koji mold), Aspergillus iuchuensis (black koji mold), Monascus, and Aspergillus glaucus. Aspergillus oryzae and Aspergillus sojae are preferred, and Aspergillus oryzae is more preferred. These types of koji are available on the market as raw materials for manufacturing miso, soy sauce, sake, shochu, awamori, red wine, and dried bonito, etc., and are commercially available.

[0082] The koji is used in an amount in the range of 0.1 to 10 parts by mass relative to 100 parts by mass of β - glucan (untreated β - glucan) contained in the cereal pulverized product to be fermented. The lower limit value of the koji mixing amount is 0.1 part by mass, preferably 0.4 part by mass, and more preferably 1 part by mass. The upper limit value is 10 parts by mass, preferably 8.5 parts by mass, and more preferably 5 parts by mass. These lower limit and upper limit values can be selected in any combination. Examples include the following ranges: 0.4 to 10 parts by mass, 0.4 to 8.5 parts by mass, 0.4 to 5 parts by mass, 1 to 8.5 parts by mass, and 1 to 5 parts by mass. Preferably, the proportion of the koji for fermentation is adjusted as described above, whereby a koji - cereal fermentation saccharified liquid containing the desired low - molecular - weight β - glucan having a desired weight - average molecular weight and a desired molecular weight distribution can be obtained without excessive decomposition of the β - glucan contained in the cereal pulverized product.

[0083] The fermentation method using Aspergillus oryzae can be carried out as follows: Cool the heat-treated ground grains (hereinafter also referred to as "heat-treated ground grains") to 50 to 70°C in the presence of water, inoculate Aspergillus oryzae on the ground grains, and maintain it at a predetermined temperature for a predetermined time.

[0084] The proportion of the heat-treated ground grains in the mixture of water and the heat-treated ground grains to be fermented (total raw materials) is not limited, but is preferably 4 to 35% by mass, more preferably 4 to 30% by mass. As described above, the β-glucan content varies depending on the grain part used as the raw material. Therefore, the above proportion can be appropriately adjusted according to the grain part. For example, when a part having a high β-glucan content (e.g., barley endosperm and oat bran) is used as the raw material, although not limited thereto, preferably, the proportion is selected from the range of 4 to 20% by mass. More preferably, the proportion is selected from the range of 4 to 10% by mass. When the whole grains of barley or oats are used as the raw material, although not limited thereto, preferably, the proportion is selected from the range of 15 to 35% by mass. More preferably, the proportion is selected from the range of 15 to 30% by mass.

[0085] The fermentation conditions are not limited as long as the starch contained in the heat-treated ground grains is decomposed to such an extent that the evaluation of the "iodine color test" shows (-), and as long as the untreated β-glucan in the ground grains is decomposed to produce a liquid saccharified product containing the low-molecular-weight β-glucan having the above-mentioned predetermined proportion, weight-average molecular weight, and molecular weight distribution.

[0086] For example, the temperature conditions for fermentation are preferably 50 to 70°C, more preferably 55 to 65°C. The fermentation time needs to be appropriately adjusted according to the amount of the ground grains used as the raw material, but it is usually 1 hour or more, preferably 3 hours or more. The upper limit of the fermentation time is not limited, but is about 20 hours. Even when the fermentation time is slightly longer, using Aspergillus oryzae makes it possible to obtain a saccharified liquid containing low-molecular-weight β-glucan having a desired weight-average molecular weight and desired molecular weight distribution without excessive decomposition of the untreated β-glucan. In other words, preferably using Aspergillus oryzae in the above proportion eliminates the need for strict control of the fermentation time. Although not limited, the fermentation time can be in the range of, for example, 3 to 10 hours or 3 to 5 hours.

[0087] Although not limited, the pH conditions during fermentation are neutral, preferably 6.0 to 6.5. The fermentation can be carried out with stirring or in a static state. In terms of fermentation efficiency, fermentation with stirring is preferred. Preferably, the fermentation is carried out in the dark.

[0088] Koji can be used alone for fermentation. However, in addition to koji, glucoamylase can also be used, and such use is not excluded as long as the koji-cereal fermentation saccharified liquid envisioned by the present invention can be obtained. Examples of glucoamylase include β-amylase, pullulanase, isoamylase, and glucoamylase. Preferably, each of these glucoamylases has a low β-glucanase activity (0 to 10% or less). In other words, in the present invention, the β-glucanase activity of the mixture before fermentation treatment (the mixture containing the heat-treated cereal powder and koji) is preferably 0 to 10% or less.

[0089] The β-glucanase activity is the enzyme activity for cleaving the β-1,3 bond and β-1,4 bond in β-glucan.

[0090] The β-glucanase activity of the enzyme sample can be measured by the following method.

[0091] Dissolve a standard sample of untreated β-glucan in pure water to a concentration of 5 mg / mL to produce a β-glucan aqueous solution. Dilute the enzyme sample with pure water to 5 mg / mL. Mix the β-glucan aqueous solution and the diluted enzyme sample in a test tube. Incubate the mixture in a constant temperature bath at 50 °C for 14 hours, and then cool it on ice (the enzyme mixture solution). The β-glucan with a molecular weight of 10 5 or more in the enzyme mixture solution is measured by the Congo red method. Use the β-glucan aqueous solution mixed with pure water (blank solution) instead of the enzyme sample, and perform the same operations as above to obtain the blank.

[0092] The β-glucanase activity is calculated using the following formula.

[0093] β-glucanase activity (%) = (1 - B / B0) × 100

[0094] B = the β-glucan concentration in the enzyme mixture solution

[0095] B0 = the β-glucan concentration in the blank solution

[0096] Although not limited, the fermentation can be terminated, for example, by heating the obtained saccharified liquid at 95 °C for 10 minutes, whereby the koji-cereal fermentation saccharified liquid envisioned by the present invention can be obtained. As evidence of fermentation using koji, the obtained koji-cereal fermentation saccharified liquid contains Aspergillus oryzae (dead fungus), and its presence can be confirmed by genetic analysis or a general method for detecting Aspergillus, such as detecting N-acetylglucosamine as a cell wall component.

[0097] The viscosity of the saccharified liquid obtained from the fermentation of rice koji and grains is preferably 10 to 5000 mPa·s. The lower limit value of the viscosity is 10 mPa·s, preferably 20 mPa·s, more preferably 25 mPa·s. The upper limit value is 5000 mPa·s, preferably 4500 mPa·s, more preferably 2000 mPa·s, and even more preferably 1500 mPa·s. These lower limit values and upper limit values can be selected in any combination. Examples include the following ranges: 20 to 4500 mPa·s, 20 to 2000 mPa·s, and 25 to 1500 mPa·s.

[0098] Under the condition that the temperature (product temperature) is 10°C, using a rotary B-type viscometer (TVB10 viscometer: manufactured by Toki Sangyo Co., Ltd.) and a rotor suitable for the viscosity to be measured, the viscosity is measured at a rotational speed of 60 rpm and a rotational time of 30 seconds. Details are described in the examples.

[0099] As described above, in the saccharified liquid obtained from the fermentation of rice koji and grains of the present invention, the starch is decomposed to the extent that the evaluation of the "iodine color test" shows (-). Therefore, even under heating, the viscosity does not increase significantly. Therefore, the saccharified liquid obtained from the fermentation of rice koji and grains of the present invention is advantageously easy to handle as a food or beverage or as a raw material for manufacturing food or beverages.

[0100] The pH of the saccharified liquid obtained from the fermentation of rice koji and grains of the present invention is in the range of 5.5 to 7.5, preferably 6.0 to 6.5.

[0101] (II) Food or beverage or raw material for producing food or beverage

[0102] The above-mentioned saccharified liquid obtained from the fermentation of rice koji and grains of the present invention can be directly used or used in a processed state (processed product) as a food or beverage or as a raw material for manufacturing food or beverages.

[0103] Although not limited, the processing of the saccharified liquid obtained from the fermentation of rice koji and grains includes, for example, the following treatments: adding edible components and mixing them with the saccharified liquid obtained from the fermentation of rice koji and grains; diluting with water or other edible liquids; concentrating by evaporating water; removing insoluble substances by solid-liquid separation (e.g., centrifugation or filtration), drying (e.g., spray drying or freeze drying), pulverizing, and sizing. These treatments can be carried out independently, or two or more treatments can be carried out in any combination. The processed product of the saccharified liquid obtained from the fermentation of rice koji and grains of the present invention includes the product obtained by processing the saccharified liquid obtained from the fermentation of rice koji and grains of the present invention with the above-mentioned treatments.

[0104] Any edible component can be added to the koji rice grain fermentation saccharified liquid as long as it is an edible component, and it can be appropriately selected according to the purpose. Examples include saccharides such as glucose, fructose, sucrose, maltose, starch syrup, and lactose; sugar alcohols such as sorbitol, erythritol, maltitol, and xylitol; high-intensity sweeteners such as aspartame, stevioside, sucralose, and acesulfame potassium; organic acids such as citric acid, tartaric acid, malic acid, succinic acid, and lactic acid; vitamins such as L-ascorbic acid, dl-α-tocopherol, B vitamins, nicotinamide, and calcium pantothenate; surfactants such as glycerol fatty acid esters, polyglycerol fatty acid esters, sucrose fatty acid esters, sorbitan fatty acid esters, and propylene glycol fatty acid esters; thickeners such as gum arabic, carrageenan, pectin, and agar; stabilizers such as casein and gelatin; amino acids; minerals such as calcium salts; and other additives that can be added to foods and beverages such as sodium erythorbate, glycerol, propylene glycol, acidulants, pH regulators, pigments, flavors, and preservatives.

[0105] There is no limitation on "food or beverage" in the food or beverage or the raw material for manufacturing food or beverage. Examples include beverages such as soft drinks (e.g., fruit juice drinks, fruit drinks, carbonated drinks, vegetable drinks, coffee drinks, cocoa drinks, tea-based drinks, sports drinks, milk-based drinks, jelly drinks, zenzai drinks, shiruko drinks, milkshakes, drinkable soups, and soy milk drinks), alcoholic beverages, non-alcoholic beverages, and lactic acid bacteria drinks; foods such as fruit processed products (jams, marmalades, and syrups, etc.), grain processed products (bread and mochi, etc.), meat processed products (hams and sausages, etc.), dairy products (butter, cheese, and yogurt, etc.), confectioneries (chocolates, cookies, cakes, and jellies, etc.), and seasonings (soy sauce, sauce, and mirin, etc.); and supplements.

[0106] In addition to the koji rice grain fermentation saccharified liquid of the present invention, various components can be added to the above-mentioned food or beverage and the raw material for manufacturing food or beverage according to the type of food or beverage. Examples include those mentioned above, such as saccharides, sugar alcohols, high-intensity sweeteners, organic acids, vitamins, surfactants, thickeners, stabilizers, amino acids, minerals, acidulants, pH regulators, pigments, flavors, preservatives, and other food or beverage ingredients.

[0107] The proportion of the rice koji cereal fermentation saccharified liquid or its processed product to be added to food or beverage or raw materials for manufacturing food or beverage can be adjusted according to the type of food or beverage or raw materials for manufacturing food or beverage and their uses and purposes. This proportion can be selected from the range of 0.01 to 100% by mass. Although there is no limitation, in one embodiment, the rice koji cereal fermentation saccharified liquid or its processed product can be added in a proportion such that the viscosity of the food or beverage or raw materials for manufacturing food or beverage is 1000 mPa·s or less, preferably 20 to 200 mPa·s. The measurement conditions of the viscosity are as described above.

[0108] As used herein, the terms "comprising" and "containing" and their variants mean "including", "consisting of", and "consisting essentially of".

[0109] Examples

[0110] For the convenience of understanding the constitution and effects of the present invention, the present invention will be described below with reference to experimental examples. However, these experimental examples are not intended to limit the present invention. Unless otherwise specified, the following experiments are carried out at room temperature (25 ± 5 °C) under atmospheric pressure conditions. Hereinafter, unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass".

[0111] The materials and test methods used in the following examples and experimental examples are as follows.

[0112] Materials

[0113] Oat whole grain flour: Fine oat powder with the outer skin removed; powder particle size (median diameter): 27 μm; untreated β-glucan content: 4% by mass, manufactured by Naturex

[0114] Oat bran flour: Fine oat bran powder with the outer skin (bran) removed; powder particle size (median diameter): 76 μm; untreated β-glucan content: 27.5% by mass, manufactured by Naturex

[0115] Powdered koji 1: Aspergillus oryzae, manufactured by Marukome Co., Ltd.

[0116] Powdered koji 2: Aspergillus oryzae, manufactured by Tsurumiso Jyozou Co., Ltd.

[0117] Lichenase solution: Lichenase (specific endo-β-(1-3)(1-4)-D-glucan 4-glucanohydrolase) suspension (attachment of Megazyme's β-glucan assay kit (model: K-BGLU))

[0118] 0.1M Phosphate Buffer (pH: 6.5): A mixture of 0.2M Sodium Dihydrogen Phosphate Solution (27.6 g / L) and 0.2M Disodium Hydrogen Phosphate Solution (53.6 g / L) in any proportion, with the pH adjusted to 6.5

[0119] Sodium Phosphate Buffer (20 mM, pH 6.5): A solution of Sodium Dihydrogen Phosphate Dihydrate (NaH2PO4·2H2O) (3.12 g) in distilled water (900 mL), with the pH adjusted to 6.5 using 100 mM Sodium Hydroxide (4 g / L), and made up to 1 L.

[0120] 200 mM Acetate Buffer (pH 4.0): A mixture of glacial acetic acid (11.6 mL) and distilled water (900 mL), with the pH adjusted to 4.0 by adding 1M Sodium Hydroxide, and made up to 1 L.

[0121] β-Glucosidase Solution: Accessories of Megazyme's β-Glucan Assay Kit (Model: K-BGLU)

[0122] α-Amylase: Product name "BAN 480L", manufactured by Novozymes

[0123] Glucoamylase: Product name "Amylase AG 300L", manufactured by Novozymes

[0124] [Test Method]

[0125] (1) Measurement of molecular weight distribution of β-glucan

[0126] Extract β-glucan from the target test sample. Perform gel filtration high performance liquid chromatography analysis on the extract to measure the molecular weight distribution of β-glucan in the test sample.

[0127] Specifically, mix the target test sample (1.5 g) with an aqueous solution containing 95% (v / v) ethanol (4 g), and centrifuge the mixture at a relative centrifugal force of 1800G. Suspend the precipitate obtained by centrifugation in an aqueous solution containing 50% (v / v) ethanol (4 g), and centrifuge the suspension again at a relative centrifugal force of 1800G. Dissolve the precipitate obtained by centrifugation in 0.1M Phosphate Buffer (pH: 6.5) (3 g), keep it at 50 °C for 5 minutes, and then centrifuge at a relative centrifugal force equivalent to 1000G to recover the supernatant. The supernatant contains β-glucan. Then, dilute the recovered supernatant 2.5 times in 0.1M Phosphate Buffer (pH: 6.5). Perform gel filtration high performance liquid chromatography analysis on the resulting product under the following conditions. Determine the β-glucan molecular weight distribution from the resulting chromatogram.

[0128] [HPLC Conditions]

[0129] HPLC system: Agilent Technologies 1200 series Column: TSKgel G3000PWXL

[0130] Column temperature: 35 °C

[0131] Solvent: 0.1 M phosphate buffer (pH: 6.5)

[0132] Flow rate: 0.8 mL / min

[0133] Detector: RI detector G1362A (Agilent Technologies)

[0134] Detection temperature: 40 °C

[0135] (2) Quantification of β-glucan

[0136] The β-glucan content of the test sample was measured using the McCleary method (enzymatic method) with "Megazyme's β-glucan assay kit (Model: K-BGLU)".

[0137] Specifically, the following method was used for measurement.

[0138] Weigh 3 mL of the test sample into a test tube, boil it in a water bath for 5 minutes, and cool it to room temperature. Add an aqueous solution (6 mL) containing 95% (v / v) ethanol and disperse it in the test sample, then centrifuge at a relative centrifugal force of 1800 G to obtain a precipitate. Suspend the recovered precipitate in an aqueous solution (8 mL) containing 50% (v / v) ethanol, then centrifuge at a relative centrifugal force of 1800 G to obtain the precipitate again. Suspend the recovered precipitate in sodium phosphate buffer (20 mM, pH 6.5) (4.0 mL) and heat it at 50 °C for 5 minutes.

[0139] Add the lichenase solution (0.2 mL) included in Megazyme's β-glucan assay kit to the test tube containing the sample thus prepared, and allow the mixture to react at 50 °C for 1 hour. Then, add 200 mM acetate buffer (pH 4.0) (5 mL) and mix well. Let the mixture stand at room temperature for 5 minutes and centrifuge at a relative centrifugal force of 1800 G. Recover the supernatant in three test tubes (0.1 mL in each test tube). Add 50 mM acetate buffer (pH 4.0) (0.1 mL) to one test tube (for blank), and add β-glucosidase solution (0.1 mL) to each of the other two test tubes (for samples, n = 2), then react at 50 °C for 10 minutes. Subsequently, add glucose oxidase / peroxidase solution (3 mL) (an accessory of Megazyme's β-glucan assay kit) to each test tube, and then react at 50 °C for 20 minutes. Then, measure the absorbance of the samples (blank or samples) in each test tube at 510 nm. Additionally, measure the absorbance (EA) of the glucose oxidase / peroxidase solution (3 mL) containing 100 μg glucose at 510 nm.

[0140] From these measurement results, use the following formula to determine the β-glucan content of the test sample.

[0141] β-glucan content (%, w / w) = ΔA × F × 0.00276

[0142] ΔA = (absorbance of the sample) - (absorbance of the blank)

[0143] F = (100) / (absorbance of 100 μg glucose: EA)

[0144] (3) Measurement of solid content of test sample (sand mixing method)

[0145] The following method is used for the measurement.

[0146] (i) Dry an aluminum weighing dish containing 15 - 20 g of silica sand and a small glass rod in a hot air circulation dryer set at 102 °C for 1 hour, and then let it cool in a desiccator for about 30 minutes.

[0147] (ii) Weigh the aluminum weighing dish (containing silica sand and a small glass rod) dried in the above manner using an analytical balance. Subsequently, place 1.5 - 2.0 g of the test sample in the dish, and accurately weigh the mass of the test sample (sample mass).

[0148] (iii) Heat the weighing dish containing the sample on a hot plate while gently stirring the contents of the weighing dish (test sample, silica sand, and small glass rod) with a glass rod.

[0149] (iv) Once the silica sand becomes dry and loose, place the weighing dish containing the test sample in a hot air circulation dryer set at 102 °C for 2 hours for drying, and then let it cool in a desiccator for about 30 minutes.

[0150] (v) Weigh the weighing dish containing the above-prepared test sample on an analytical balance, and from the mass of the test sample (mass after drying), calculate the solid component content (mass %) of the test sample using the following formula.

[0151] Solid component content [mass %] = 100 - {([Sample mass - Mass after drying] / Sample mass) × 100}

[0152] (4) Iodine color reaction test

[0153] The test was conducted based on the description in "Denpun Kagaku Jikkenho [Starch Science Experimental Method]" (edited by Shigeo Suzuki and Michinori Nakamura, Asakura-shoten, 1979).

[0154] Specifically, adjust the target test sample to a solid component content of 10%, then mix it with 0.01 M iodine solution and let it stand at room temperature. After 5 minutes, visually confirm the color development. Prepare the 0.01 M iodine solution by dissolving 12.7 g of iodine and 40 g of potassium iodide in 25 mL of pure water and further diluting the solution 5 times with pure water.

[0155] Evaluate the color development as follows: yellow is (-); blue is (+3); and according to the degree of blue, the range between "yellow" (-) and "blue" (+3) is (+1) or (+2).

[0156] (5) Measurement of viscosity

[0157] Measure the viscosity at a temperature of 10 °C using a rotary B-type viscometer (TVB10 type viscometer, manufactured by Toki Sangyo Co., Ltd.). Specifically, place 100 mL of the target test sample (sample temperature: 10 °C) in a predetermined measuring container (shape: tall beaker; size: 100 mL), and place a rotor selected from various types (No. 1: 10 - 100 mPa·s; No. 2: 100 - 500 mPa·s; No. 3: 500 - 2000 mPa·s; and No. 4: 2000 - 10000 mPa·s) according to the viscosity of the test sample into the container, and regard the measured value after rotation (60 rpm, 30 seconds) as the viscosity.

[0158] (6) Precipitation amount (mL) per 100 mL of test sample

[0159] Separate 50 mL portions of the 100 mL target test sample into two 50 mL graduated centrifuge tubes, and centrifuge at a relative centrifugal force of 480 G at 25 °C for 10 minutes. Consider the total volume (mL) of the colored precipitate in the two centrifuge tubes as the precipitation amount (mL) per 100 mL of the test sample.

[0160] The precipitation of each test sample is evaluated according to the following criteria, and the results are used for the evaluation of the dispersion stability of the test sample.

[0161] A: Precipitation amount: less than 10 mL / 100 mL

[0162] B: Precipitation amount: 10 mL or more and less than 15 mL / 100 mL

[0163] C: Precipitation amount: 15 mL or more / 100 mL

[0164] (7) Fluidity of test sample (time [seconds] required for flowing down)

[0165] Place the test sample (100 g) with the product temperature adjusted to 25 °C on a plastic funnel, and measure the time required for the entire amount to flow out and regard it as the "flow-down time (seconds)".

[0166] Specifically, place 100 g of the test sample in the funnel with the front end of the tube part (foot part) of the funnel closed, and then open the front end with the front end vertically downward. Measure the time from the start of the outflow of the test sample to the end of the outflow.

[0167] The plastic funnel used has a conical part with a diameter of 8 cm, an angle of 60 degrees, an inner diameter of the tube part of 1 cm, and a tube length of 2 cm.

[0168] The fluidity of the test sample is evaluated according to the following criteria.

[0169] 〇: Flow-down time: less than 60 seconds

[0170] △: Flow-down time: 60 seconds or more and less than 300 seconds

[0171] ×: Flow-down time: 300 seconds or more

[0172] (8) Comprehensive evaluation of precipitation amount and fluidity of test sample

[0173] Based on the precipitation amount and fluidity of each test sample measured in (6) and (7) above, the dispersion stability and operability of each test sample are comprehensively evaluated according to the following criteria.

[0174] [Comprehensive evaluation of dispersion stability and operability]

[0175] ◎: Both the precipitation amount and the fluidity are rated as 〇.

[0176] 〇: One of the sediment amount and the fluidity is rated as 〇, and the other is rated as △.

[0177] △: Both the sediment amount and the fluidity are rated as △; or one of them is rated as × and the other is rated as 〇.

[0178] ×: Both the sediment amount and the fluidity are rated as ×; or one of them is rated as × and the other is rated as △.

[0179] Example 1

[0180] Mix whole oat flour (150 g) with water (800 g). While heating at 85 °C for 10 minutes with stirring, partially or completely gelatinize the starch contained in the whole oat flour. Subsequently, cool the resulting product, and when the temperature reaches 55 °C, add powdered koji 1 (50 g). Ferment the mixture (pH: approximately 6) under dark conditions at 55 °C with stirring for 3 hours. Then, heat the mixture at 95 °C for 10 minutes for sterilization, thereby obtaining koji-fermented saccharified liquid 1 derived from oats.

[0181] Example 2

[0182] Mix whole oat flour (150 g) with water (800 g). While heating at 85 °C for 10 minutes with stirring, partially or completely gelatinize the starch contained in the whole oat flour. Subsequently, cool the resulting product, and when the temperature reaches 55 °C, add powdered koji 2 (50 g). Ferment the mixture (pH: approximately 6) under dark conditions at 55 °C with stirring for 3 hours. Then, heat the mixture at 95 °C for 10 minutes for sterilization, thereby obtaining koji-fermented saccharified liquid 2 derived from oats.

[0183] Example 3

[0184] Mix whole oat flour (300 g) with water (600 g). While heating at 85 °C for 10 minutes with stirring, partially or completely gelatinize the starch contained in the whole oat flour. Subsequently, cool the resulting product, and when the temperature reaches 55 °C, add powdered koji 1 (100 g). Ferment the mixture (pH: approximately 6) under dark conditions at 55 °C with stirring for 3 hours. Then, heat the mixture at 95 °C for 10 minutes for sterilization, thereby obtaining koji-fermented saccharified liquid 3 derived from oats.

[0185] Example 4

[0186] Mix oat bran powder (40 g) with water (945 g). While heating at 85 °C for 10 minutes with stirring, partially or completely gelatinize the starch contained in the oat bran powder. Subsequently, cool the resulting product, and when the temperature reaches 55 °C, add koji powder 1 (15 g). Ferment the mixture (pH: approximately 6) at 55 °C in the dark with stirring for 3 hours. Then, heat the mixture at 95 °C for 10 minutes for sterilization, thereby obtaining koji-fermented saccharified liquid 4 derived from oats.

[0187] Example 5

[0188] Mix oat bran powder (40 g) with water (945 g). While heating at 85 °C for 10 minutes with stirring, partially or completely gelatinize the starch contained in the oat bran powder. Subsequently, cool the resulting product, and when the temperature reaches 55 °C, add koji powder 1 (15 g). Ferment the mixture (pH: approximately 6) at 55 °C in the dark with stirring for 5 hours. Then, heat the mixture at 95 °C for 10 minutes for sterilization, thereby obtaining koji-fermented saccharified liquid 5 derived from oats.

[0189] Example 6

[0190] Mix oat bran powder (40 g) with water (940 g). While heating at 85 °C for 10 minutes with stirring, partially or completely gelatinize the starch contained in the oat bran powder. Subsequently, cool the resulting product, and when the temperature reaches 55 °C, add koji powder 1 (20 g). Ferment the mixture (pH: approximately 6) at 55 °C in the dark with stirring for 5 hours. Then, heat the mixture at 95 °C for 10 minutes for sterilization, thereby obtaining koji-fermented saccharified liquid 6 derived from oats.

[0191] Example 7

[0192] Mix oat bran powder (40 g) with water (955 g). While heating at 85 °C for 10 minutes with stirring, partially or completely gelatinize the starch contained in the oat bran powder. Subsequently, cool the resulting product, and when the temperature reaches 55 °C, add koji powder 1 (5 g). Ferment the mixture (pH: approximately 6) at 55 °C in the dark with stirring for 2 hours. Then, heat the mixture at 95 °C for 10 minutes for sterilization, thereby obtaining koji-fermented saccharified liquid 7 derived from oats.

[0193] Comparative Example 1

[0194] Mix oat whole grain flour (150 g) with water (850 g). While stirring, heat at 85 °C for 10 minutes to partially or completely gelatinize the starch contained in the oat whole grain flour. Subsequently, cool the resulting product, and when the temperature reaches 55 °C, add α-amylase (manufactured by Novozymes) (0.2 g) and glucoamylase (manufactured by Novozymes) (0.2 g). Enzymatically treat the mixture (pH: approximately 6) under stirring in the dark at 55 °C for 3 hours. Then, heat the mixture at 95 °C for 10 minutes for sterilization, thereby obtaining enzyme-treated saccharified liquid A derived from oats.

[0195] Comparative Example 2

[0196] Mix oat whole grain flour (300 g) with water (698 g). While stirring, heat at 85 °C for 10 minutes to partially or completely gelatinize the starch contained in the oat whole grain flour. Subsequently, cool the resulting product, and when the temperature reaches 55 °C, add α-amylase (manufactured by Novozymes) (1 g) and glucoamylase (manufactured by Novozymes) (1 g). Enzymatically treat the mixture (pH: approximately 6) under stirring in the dark at 55 °C for 3 hours. Then, heat the mixture at 95 °C for 10 minutes for sterilization, thereby obtaining enzyme-treated saccharified liquid B derived from oats.

[0197] Comparative Example 3

[0198] Mix oat bran flour (50 g) with water (950 g). While stirring, heat at 85 °C for 10 minutes to partially or completely gelatinize the starch contained in the oat bran flour. Subsequently, cool the resulting product, and when the temperature reaches 55 °C, add α-amylase (manufactured by Novozymes) (0.2 g) and glucoamylase (manufactured by Novozymes) (0.2 g). Enzymatically treat the mixture (pH: approximately 6) under stirring in the dark at 55 °C for 3 hours. Then, heat the mixture at 95 °C for 10 minutes for sterilization, thereby obtaining enzyme-treated saccharified liquid C derived from oats.

[0199] Comparative Example 4

[0200] Mix oat whole grain flour (150 g) with water (850 g), and heat the mixture at 95 °C for 10 minutes for sterilization, thereby obtaining oat lysate 1.

[0201] Comparative Example 5

[0202] Mix oat bran flour (50 g) with water (950 g), and heat the mixture at 95 °C for 10 minutes for sterilization, thereby obtaining oat lysate 2.

[0203] Experimental Example 1

[0204] For each of the koji fermentation saccharified liquids 1 to 7 (Examples 1 to 7) derived from oats, the enzyme fermentation saccharified liquids A to C (Comparative Examples 1 to 3) derived from oats, and the oat lysates 1 to 2 (Comparative Examples 4 and 5) prepared by the above method, the molecular weight distribution of β-glucan, the β-glucan content, the solid component content, iodine color development, viscosity, precipitation amount, and fluidity were measured to obtain each measured value.

[0205] Table 1 shows the molecular weight distribution, weight-average molecular weight, and molecular weight (mode value) of β-glucan in Examples 1 to 7 and Comparative Examples 1 to 5. Tables 2 and 3 summarize the measurement results of Examples 1 to 7 and Comparative Examples 1 to 5.

[0206] [Table 1]

[0207]

[0208] In the table, "-" means not detected (absent).

[0209] [Table 2]

[0210]

[0211] [Table 3]

[0212]

[0213] As shown in Tables 1 to 3, when a saccharified liquid is obtained by heating a crushed cereal in the presence of water to gelatinize a large amount or most of the starch and then fermenting with koji until the result of the "iodine color development test" shows (-), it is confirmed that the cereal-derived β-glucan content in each saccharified liquid falls within the following ranges:

[0214] (a) Weight-average molecular weight of cereal-derived β-glucan: 100,000 to 500,000;

[0215] (b) Proportion of cereal-derived β-glucan having a molecular weight of more than 10,000 and less than 800,000 in the total 100% by mass of cereal-derived β-glucan: 80% by mass or more, specifically, 80 to 98%; and

[0216] (c) Proportion of cereal-derived β-glucan in 100% by mass of the solid components of the koji cereal fermentation saccharified liquid: 1 to 35% by mass, specifically, 3 to 30% by mass.

[0217] The saccharified liquid (product temperature: 10°C) also has a relatively low viscosity, that is, 10 to 5000 mPa·s, specifically, 100 to 4500 mPa·s, and it is confirmed that the viscosity does not increase significantly even under heating.

[0218] In addition, each of these Aspergillus oryzae-fermented saccharified liquids 1 to 7 derived from oats has good handleability (low viscosity and good fluidity), and at the same time has good dispersion stability. In particular, in each of the Aspergillus oryzae-fermented saccharified liquids 4 to 7 derived from oats, the proportion of β-glucan derived from low-molecular-weight oats is as high as 25 to 30% by mass of the total solid content, while the viscosity is relatively low, the fluidity is good, and the dispersion stability is also good.

[0219] These results show that it is preferable to adjust the inoculation amount of Aspergillus oryzae relative to the heat-treated cereal pulverized product within the range of 0.4 to 8.5 parts by mass, preferably 0.45 to 8.3 parts by mass, per 1 part by mass of β-glucan (untreated β-glucan) contained in the cereal.

[0220] In contrast, when the cereal pulverized product heat-treated under the same conditions as above is treated with enzymes (α-amylase and glucoamylase) instead of Aspergillus oryzae, it is confirmed that the β-glucan contained in the cereal is completely decomposed and hardly exists in the resulting saccharified liquid.

Claims

1. A koji-cereal fermentation saccharified liquid containing cereal-derived β-glucan, which has the following characteristics: (a) The weight-average molecular weight of the cereal-derived β-glucan: 100,000 to 500,000; (b) The proportion of cereal-derived β-glucan with a molecular weight of more than 10,000 and less than 800,000 in the total 100% by mass of the cereal-derived β-glucan: 80% by mass or more; (c) The proportion of cereal-derived β-glucan in the 100% by mass solid component of the koji-cereal fermentation saccharified liquid: 1 to 35% by mass; (d) Iodine color reaction test: (-); and (e) Viscosity: 10 to 5000 mPa·s.

2. The koji-cereal fermentation saccharified liquid according to claim 1, wherein the cereal-derived β-glucan further has the following characteristics: (f) Molecular weight (mode value): 10,000 to 300,000.

3. The koji-cereal fermentation saccharified liquid according to claim 1 or 2, wherein the cereal is the seed of a gramineous plant.

4. The koji-cereal fermentation saccharified liquid according to claim 3, wherein the gramineous plant is at least one selected from oats and barley.

5. The koji-cereal fermentation saccharified liquid according to claim 1 or 2, wherein the koji is Aspergillus oryzae.

6. A method for producing the koji-cereal fermentation saccharified liquid according to any one of claims 1 to 5, the method comprising: heating the cereal pulverized product in the presence of water to completely or partially gelatinize the starch; and fermenting the cereal pulverized product using koji.

7. The production method according to claim 6, wherein the mixing ratio of the koji with respect to 1 part by mass of β-glucan in the cereal pulverized product is 0.1 to 10 parts by mass.

8. The production method according to claim 6, wherein the cereal is the seed of a gramineous plant.

9. The production method according to claim 8, wherein the gramineous plant is at least one selected from oats and barley.

10. The production method according to claim 6 or 7, wherein the koji is Aspergillus oryzae.

11. A food or beverage containing the koji-cereal fermentation saccharified liquid according to any one of claims 1 to 5 or a processed product thereof, or a raw material for producing the food or beverage.

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