Production method of highly concentrated isomaltose koji fermented food

Abstract

To produce a highly concentrated isomaltose koji fermented food without adding an enzymatic agent.SOLUTION: A production method of a koji fermented food which is a production method of a highly concentrated isomaltose koji fermented food includes undergoing: a koji production step of producing a koji (A2 koji) having undergone koji discharge and a koji (A1 koji) obtained after a koji production time shorter than a time to the koji discharge; then, a primary saccharification step (saccharification step B1) of saccharifying the A1 koji, or the koji obtained after the shorter koji production time, to produce a primarily-saccharified product; and a secondary saccharification step (saccharification step B2) of adding the koji A2, or the koji having undergone the koji discharge, to the resultant and performing further saccharification.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing a koji-fermented food having a high concentration of isomaltose. [Background technology]

[0002] Koji amazake, a type of koji-fermented food, is made by adding an equal or double amount of water to rice koji and heating it at an appropriate temperature for a certain period of time. The isomaltose content of koji amazake made in this way is 1.73-3.01%, the isomaltooligosaccharide content is 1.86-4.37%, and the glucose concentration is 23.20-28.91% (Non-Patent Document 1).

[0003] In the production of koji amazake, the temperature at which rice koji is saccharified is 40°C, 50°C, 60°C or 70°C, and the sugar concentrations of samples sampled at each temperature after heating times of 0 hours, 2 hours, 4 hours, 6 hours and 8 hours were approximately 1.5% isomaltose, 1.7% isomaltooligosaccharide and 15% glucose (Non-Patent Document 2). Thus, by simply changing the saccharification conditions, the isomaltose concentration in koji amazake was not significantly different from that of koji amazake produced using the normal production process shown in Non-Patent Document 1, and was low.

[0004] Isomaltose is known to have health benefits, and taking 10 g of isomaltose per day is expected to improve bowel movements and intestinal flora (Non-Patent Document 3).

[0005] Currently, in order to obtain the health benefits of 10 g of isomaltose per day from koji amazake, one must consume a large amount or add isomaltose to it. The former raises concerns about excessive calorie intake from consuming a large amount of koji amazake, while the latter raises the issue of increased costs due to the addition of isomaltose.

[0006] An efficient method for producing isomaltose is to add an enzyme suitable for the purpose to starch or a starch hydrolysate and allow it to react (Patent Document 1).

[0007] If a method for producing koji-fermented foods with high concentrations of isomaltose could be developed without adding enzymes, by utilizing the enzymes produced by koji and the sugars that are the product of starch hydrolysis by koji, it would be possible to obtain the health benefits of isomaltose with a minimum number of calories consumed, and to offer it to the market at a low cost. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2022-24332 A [Non-patent literature]

[0009] [Non-Patent Document 1] The components contained in Koji Amazake Journal of the Brewing Society of Japan Vol. 112 No. 10 668-674 2017 [Non-Patent Document 2] Effect of temperature on saccharification and oligosaccharide production efficiency in koji amazake Journal of Bioscience and Bioengineering Vol.127 No. 5, 570-574, 2019 [Non-Patent Document 3] Effect of isomaltooligosaccharide intake on bowel movements and intestinal environment in healthy subjects Journal of the Japanese Society of Home Economics Vol.44 No.4 245-254,1993 Summary of the Invention [Problem to be solved by the invention]

[0010] To produce a koji-fermented food having a high concentration of isomaltose without adding an enzyme agent. [Means for solving the problem]

[0011] This is a method for producing a koji-fermented food with a high concentration of isomaltose, which is characterized by going through a koji-making process in which a koji that has been produced (A2 koji) and a koji that has been produced for a shorter time (A1 koji) are produced, followed by a primary saccharification process (saccharification process B1) in which the koji that has been produced for the shorter time, A1 koji, is saccharified to produce a primary saccharified product, and a secondary saccharification process (saccharification process B2) in which the koji that has been produced (A2 koji) is added to the primary saccharified product and further saccharified. Effect of the Invention

[0012] The present invention provides a koji-fermented food containing a high concentration of isomaltose without adding enzymes. Because of the high concentration of isomaltose, a smaller amount than conventional products can improve bowel movements and intestinal environment, resulting in reduced calorie content and making it possible to produce a health-conscious koji-fermented food. Products with high isomaltose concentrations can be produced at low cost and made available on the market. [Brief description of the drawings]

[0013] [Figure 1] Flow diagram of the manufacturing method for making the two types of koji required for this invention separately from the beginning [Diagram 2] The flow diagram of the manufacturing method for the two types of koji required for this invention, in which the required amount of koji is taken in a short period of time during the process. [Diagram 3] Flow diagram of the normal production process of Amazake [Figure 4] Flow diagram of the production process for secondary saccharification of Shio-Koji [Diagram 5] Flow diagram of the secondary saccharified sweet miso manufacturing process DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, the embodiment of the present invention will be described in more detail with reference to Figures 1 to 5. In the explanatory diagrams, the koji-making process is represented by A (or A1 and A2), and the saccharification process is represented by B (or B1 and B2). Also, the "secondary saccharification product" in the process diagram is the "koji-fermented food with high concentration of isomaltose."

[0015] The koji-fermented foods that can be produced according to the present invention include sweet sake, rice saccharification products, syrups, and other saccharification products that are consumed as is. By adding auxiliary materials, it is also possible to produce fermented foods using koji with high isomaltose concentrations, such as shio koji, soy sauce koji, amami miso, mirin, and sake.

[0016] The raw material for koji can be either non-glutinous or glutinous rice, regardless of the degree of polishing. Also, as long as it is possible to make koji, wheat, millet, barley, and other grains, potatoes, or a mixture of two or more types can be used.

[0017] The species of the seed koji is not limited to Aspergillus oryzae, and other filamentous fungi may be used as long as they have amylase activity and maltose transferase activity.

[0018] The form of the seed koji is not limited to powder, granules, etc., and may be for amazake, sake, miso, or soy sauce. When making two types of koji, the seed koji used may be separate or a mixture of the two may be used.

[0019] According to the present invention, a koji-fermented food (secondary saccharification product) with high isomaltose concentration can be produced simply by making koji and saccharifying it as shown in FIGS. 1 and 2.

[0020] The purpose of the koji-making process is to produce two types of koji: koji that has been produced from the starting koji (A2 koji) and koji that has been produced in a shorter time than the starting koji (A1 koji).

[0021] A1 koji obtained by short-time koji making is intended to obtain a large amount of maltose, the substrate during saccharification, and is obtained by adjusting the temperature and time so as not to decompose the starch derived from the raw material into the monosaccharide glucose. The temperature and time vary depending on the type or strain of seed koji used, and are not limited thereto, but the koji making time is preferably within the range of 6 to 30 hours at a koji making temperature of 28 to 38°C, and more preferably 14 to 22 hours.

[0022] The other type, A2 koji, is used to utilize the transfer activity of α-glucosidase in the koji, and is preferably left for 38 to 52 hours, which is the usual time for koji to be left for fermentation, and more preferably for 38 to 48 hours after appropriate care.

[0023] The koji-making process of the present invention can be of two types, as shown in Figures 1 and 2. Figure 1 shows a method for making two types of koji separately from the beginning, while Figure 2 shows a method for taking the amount of koji needed for a short period of time midway through. Either method can be used.

[0024] As shown in Figures 1 and 2, the saccharification process involves first saccharification of A1 koji (saccharification process B1), followed by addition and mixing of A2 koji, followed by secondary saccharification (saccharification process B2). In the first saccharification step (saccharification step B1), 50 to 100% of the water of the koji A1 koji that has been produced in a short time is added, mixed, and saccharified. If the ultimate goal is to increase the isomaltose concentration, the amount of water to be added is not limited because it is considered desirable to minimize the amount.

[0025] In the present invention, the saccharification process is characterized by having two stages, and consists of a secondary saccharification (saccharification process B2) in which the primary saccharification product obtained from the primary saccharification (saccharification process B1) in which A1 koji is saccharified is mixed with A2 koji and the like and saccharified. During this secondary saccharification, if necessary, in addition to the A1 koji and A2 koji, it is also possible to add auxiliary raw materials suitable for the purpose, such as fermentation microorganisms such as lactic acid bacteria or yeast, salt, grains, beans, and ethanol, to produce koji-fermented foods such as salt koji, sweet miso, or sake.

[0026] The temperature of the saccharification step may be within a range in which the enzyme reaction can be carried out in either the saccharification step B1 or the saccharification step B2, and is more preferably within a range of 50 to 60°C.

[0027] The time for the saccharification step, whether in saccharification step B1 or saccharification step B2, is preferably 6 to 24 hours in the case of saccharification step B1 and 20 to 72 hours in the case of saccharification step B2, within the above-mentioned range of 50 to 60°C.

[0028] Since the objectives of step B1 and step B2 are different, the temperature and time conditions may be different. If the objective is to increase the isomaltose concentration, the reaction time is not limited. However, other qualities must be considered.

[0029] The present invention will now be described in detail with reference to experiments.

[0030] <Experiment 1> The sugar concentration of the saccharified products of koji made for different koji-making times was analyzed by the following method. Two types each of a total of four types of seed koji for miso or seed koji for sake were each sown in an appropriate amount into 1 kg of separate steamed rice, and in the koji-making process with a starting temperature of 35°C, sampling was carried out at 18 hours (koji X, first turning), 25 hours (koji Y, second turning), and 42 hours (koji Z, koji removal) from the start of koji-making. Next, 100 ml of water was added to 50 g each of koji X, koji Y, and koji Z, and saccharification was carried out at 60°C for 6 hours. The sugar concentration of the saccharified solution of each koji was obtained by adding an equal amount of 50% ethanol, treating it with ultrasonic waves for 30 minutes, and extracting. The solution was centrifuged, and the supernatant was filtered to obtain a sample, which was analyzed using HPLC (high-performance liquid chromatography) under the following conditions. The sugar concentration of the saccharified products of each koji was as shown in Table 1.

[0031] <HPLC analysis conditions> Column Shodex Asahipak NH2P-50 4E Column temperature 35°C Eluent Acetonitrile:distilled water = 70:30 Flow rate 0.8 ml / min Detector Evaporative light scattering detector (ELSD)

[0032]

Table 1

[0033] <Experiment 2> Generally, isomaltose is produced by the transfer reaction of the enzyme glucosidase using maltose as a substrate. The enzymatic reaction by glucosidase produces glucose by hydrolysis at a low maltose concentration, but produces isomaltose by transfer at a high maltose concentration. In order to confirm this phenomenon in the saccharification process of koji, maltose was added during the saccharification of koji. From the koji made for different times in Experiment 1, 40g of each of the seed kojis, Koji X, Koji Y, and Koji Z, was added to 40ml of water, and then 10g of maltose was added and mixed. After heating at 50°C for 6 hours, the isomaltose concentration was analyzed. The isomaltose concentration was 0.4% for the saccharified solution of Koji X, 8.6% for the saccharified solution of Koji Y, and 10.6% for the saccharified solution of Koji Z. This confirmed that if a high concentration of maltose can be created during the koji saccharification process, it may be possible to increase the isomaltose concentration.

[0034] <Experiment 3> In the above experiment 1, it was found that the maltose concentration of the saccharified product of Koji X was high. Furthermore, in the above experiment 2, it was shown that if the maltose concentration of Koji Z is high during saccharification, the isomaltose concentration can be increased. Based on this, it was thought that a Koji saccharified product containing a high concentration of isomaltose could be obtained by adding Koji Z to the saccharified product of Koji X and further saccharifying it. 100g of Koji X was mixed with 100ml of water and heated at 50°C. Sampling was done 6 and 24 hours after the start of heating. The maltose concentration was 6.1% after 6 hours and 4.7% after 24 hours. 40g of Koji Z was added to 60g of the resulting saccharified products with different primary saccharification times and heated at 50°C. Sampling was done 6 and 24 hours after heating and the isomaltose concentration was analyzed (Table 2).

[0035] [Table 2] It was found that a saccharified product with a high isomaltose concentration can be produced by a step-wise saccharification method in which koji X is saccharified to obtain a saccharified product with a high maltose concentration (primary saccharification), and then koji Z is added and saccharified further (secondary saccharification).

[0036] <Test 4> The time conditions for the secondary saccharification process were confirmed. When 40g of Koji Z was added to 60g of the primary saccharification product from 6 hours of saccharification in Experiment 3 and heated to 50°C, a koji saccharification liquid containing 19.2% isomaltose was produced after 24 hours of heating, 26.9% after 48 hours, 33.3% after 72 hours, and 50.5% after 144 hours. The yellow color deepened over time.

[0037] <Test 5> To confirm the blend ratio for the secondary saccharification, in addition to the blend ratio in Experiment 4, the blend ratio of the primary saccharification product and Koji Z was changed and saccharification was carried out at 50°C for 24 hours. The isomaltose concentration was 7.2% when 40g of the primary saccharification product was added with 60g of Koji Z, and 10.8% when 80g of the primary saccharification product was added with 20g of Koji Z. During 24 hours of saccharification, the isomaltose concentration was highest when 40g of Koji Z was added to 60g of the primary saccharification product.

[0038] Experiment 1 revealed that the maltose concentration of the saccharified product of Koji X in the early stage of koji production was high. Experiment 2 revealed that if the maltose concentration was high during saccharification, the later the koji production, the higher the isomaltose concentration. Combining these two phenomena, experiment 3 confirmed whether a koji saccharified product with a high concentration of isomaltose could be obtained through two-stage saccharification. Experiments 4 and 5 confirmed the conditions for the secondary saccharification. EXAMPLES

[0039] Next, examples of the present invention will be described below, but they are not intended to limit the scope of the present invention.

[0040] Hereinafter, the examples will be explained using Figures 1 to 5. In the explanatory diagrams, the koji-making process is represented by A (or A1 and A2), and the saccharification process is represented by B (or B1 and B2). Also, the "secondary saccharification product" in the process diagram is the "koji-fermented food with high concentration of isomaltose."

[0041] <Example 1> Koji making process (A1 and A2 in Figure 1) 2 kg of rice steamed for koji was allowed to cool to 35°C and divided into 1 kg portions. The recommended amount of sake or miso koji starter was added to each steamed rice, and then placed in a thermostatic chamber at 35°C. After 18 hours, both koji were given a first trimming, and the koji seeded with miso koji was harvested as A1 koji. The koji seeded with sake koji starter was then kept at a temperature of 33°C, and a second trimming was performed 24 hours after it was placed in the thermostatic chamber. The temperature was then kept at 30°C, and 42 hours after it was placed in the thermostatic chamber, it was called dekoji and A2 koji was harvested.

[0042] Saccharification process (B1 and B2 in Figure 1) An equal amount of water was added to 100 g of A1 koji, and the mixture was left in a warm bath at 50°C for 6 hours to obtain a primary saccharification product with a maltose concentration of 6.3%. 40 g of the A2 koji prepared above and water were added to 60 g of this primary saccharification product so that the moisture content was 50%, and the mixture was further heated at 50°C for 24 hours to obtain a secondary saccharification product. The sugar concentration of the saccharification product was analyzed according to the analysis in Experiment 1 (Table 3).

[0043] [Table 3]

[0044] <Comparative Example 1> For comparison, to obtain amazake using the conventional method for producing a koji saccharification product (Figure 3), an equal amount of water was added to 100 g of the A2 koji from Example 1, and the mixture was left in a warm bath at 50°C for 6 hours to obtain a saccharification product. The sugar concentration of the saccharification product was analyzed according to the analysis in Experiment 1 (Table 3).

[0045] <Example 2> The manufacturing process flow of the secondary saccharified Shio-koji is shown in Figure 4. The primary saccharified product was prepared in the same manner as in Example 1 up to the saccharification step B1. 40g of A2 koji, water to a moisture content of 56%, and salt to a moisture content of 13% were added to 60g of the primary saccharified product, and the mixture was heated at 50°C for 24 hours (saccharification step B2). The mixture was then further matured at 25°C for 14 days. The sugar concentration of the sample was analyzed according to the analysis in Experiment 1 (Table 3).

[0046] <Example 3> The manufacturing process flow of the second saccharified sweet miso is shown in Figure 5. The first saccharified product is prepared in the same manner as in Example 1 up to the saccharification step B1. After washing and rinsing the soybeans with water, they are soaked in water for 20 hours. The water is drained and the soybeans are soaked in water at 0.7 kg / cm in a steamer. 2 The mixture was steamed at 40°C for 35 minutes. It was then crushed using a miso chopper. 40g of A2 koji and the same amount of crushed soybeans, water to a moisture content of 48%, and salt to 6% were added to 60g of the primary saccharification product, and the mixture was heated at 50°C for 24 hours (saccharification step B2). It was then further matured at 35°C for 5 days. The sugar concentration of the sample was analyzed according to the analysis in Experiment 1 (Table 3).

[0047] As shown in Table 3, the koji amazake of Example 1 has a high isomaltose content of 19.2%, and 53 ml is needed to ingest 10 g of isomaltose, which is necessary to improve bowel movements and intestinal environment. In contrast, the saccharified product of A2 koji in Comparative Example 1, ordinary amazake, had a low isomaltose concentration of 1.5%. To obtain the above-mentioned health benefits, 667 ml is needed. When 10 g of isomaltose is ingested from the secondary saccharified product of Example 1, it can be ingested with 7.8% of the calorie value of the ordinary method of the Comparative Example.

[0048] The isomaltose concentration of Shio-koji made using the method of the present invention was 14.0%, which was 11.7 times higher than the concentration of Shio-koji made using the conventional method, which was 1.2%.

[0049] The isomaltose concentration of sweet miso produced by the method including the present invention was 10.1%, while the concentration of sweet miso produced by the conventional method was 1.7%, which was 5.9 times higher.

[0050] By applying the secondary saccharification method and combining the method of this invention with the production methods of salt koji and sweet miso, it became clear that fermented foods containing higher concentrations of isomaltose could be produced than with the conventional methods. In this way, it was thought that the application of this invention could be used in the production of other fermented foods that use koji, such as mirin and sake. [Industrial Applicability]

[0051] According to the present invention, it has become possible to produce a koji-fermented food product with a high concentration of isomaltose without adding enzymes. When ingesting an isomaltose concentration sufficient to improve bowel movements and intestinal environment, the calorie content can be reduced compared to conventional products, making it possible to produce and sell this health-conscious koji-fermented food product and provide it to the market at a low cost.

Claims

1. This method for producing a koji-fermented food with a high concentration of isomaltose is characterized by the steps of a koji-making process in which a koji that has been produced (A2 koji) and a koji that has been produced for a shorter time (A1 koji) are produced, a primary saccharification process (saccharification process B1) in which the koji that has been produced for the shorter time, A1 koji, is saccharified to produce a primary saccharified product, and a secondary saccharification process (saccharification process B2) in which the koji that has been produced (A2 koji) is added to the primary saccharified product and further saccharified.

2. 2. The method for producing a high-concentration isomaltose koji fermented food according to claim 1, wherein in the step of preparing the discharged koji (A2 koji), a portion is taken before the discharged koji, and this portion is designated as A1 koji.

3. A method for producing a koji-fermented food with a high concentration of isomaltose according to any one of claims 1 to 3, characterized in that in the secondary saccharification step (saccharification step B1), auxiliary materials suitable for the desired fermented food are added, mixed, and subjected to secondary saccharification.

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