Meat-like koji fungus body obtained by subjecting koji to solid culture with food ground product, and production method of the same

Abstract

To provide a method for producing a meat-like Koji fungus body from a solid culture product obtained by subjecting Koji to solid culture with a culture substrate containing a food ground product, and to provide a meat-like Koji fungus body composition containing a food ground product.SOLUTION: Gelatinized grains are acted with amylase to saccharify starch followed by subjecting to liquid-solid separation so as to be separated into grain saccharified liquid and a grain protein composition, and a Koji fungus is subjected to solid culture by using as a culture substrate of solid culture, a culture medium in which the grain protein composition is mixed with the food ground product, or a culture medium in which the food ground product is mixed with the grain saccharified liquid so as to adjust a moisture content. The solid culture product obtained by culturing the Koji fungus contains the food ground product and a Koji fungus body whose Koji fungus hyphae are elongated, and is used as a meat-like Koji fungus body composition.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a meat-like koji mycelium composition using koji mycelium as a food material and a method for producing the same.

Background Art

[0002] In recent years, from the viewpoints of the increasing health consciousness, the depletion and soaring prices of protein resources, and the sustainable development goal of reducing the environmental load caused by meat production, research and development of alternative protein materials have been promoted. As one of such alternative proteins, mycoprotein using filamentous fungi as a raw material is known. The inventors of the present invention reported a technique in which a solid culture of koji mold obtained by solid-culturing koji mold on steamed rice is mixed with water, and a meat-like koji mycelium composed of koji mycelium is separated and recovered from the remaining rice culture substrate to be used as a main raw material for alternative proteins (Patent Document 1). However, the process of washing and removing the remaining substrate from the solid culture is complicated, and there is a problem that the umami components flow out in this process.

[0003] It was considered that this problem could be solved by directly eating the koji mycelium solid culture without removing the culture substrate as a meat-like koji mycelium. However, in practice, it was technically difficult to obtain a solid culture that functions as a culture substrate and is edible. For example, Patent Document 2 describes that in the method for producing a general-purpose basic seasoning, koji is inoculated into a raw material containing both a protein raw material of soybeans or defatted soybeans in an amount of 70 to 90 parts by weight and a starch raw material of wheat flour ground product containing at least 90% by weight of a powder having a particle size of at most 18 mesh pass in an amount of 10 to 30 parts by weight at a ratio of both. When culturing koji mold with a raw material such as soybeans containing a large amount of protein, it is necessary to supply a sugar source such as a finely ground wheat product having a particle size that is an easily assimilable sugar source.

[0004] In addition, the technical development of koji powder production using food powder as a culture medium has been carried out conventionally. For example, a koji-making method for koji powder (Patent Document 3) has been reported in which 25 to 50% by mass of water is added to a powder of taro or grains, uniformly mixed by a mechanical mixer, the hydrated powder is gelatinized, and then koji spores are inoculated and cultured. However, when the amount of added water is large, the hydrated powder becomes sticky and forms a dumpling-like state, which hinders the growth of koji mold and good koji cannot be obtained. Therefore, when using powder as a culture medium, a measure to sufficiently supply oxygen to koji mold is necessary.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of the present invention is to produce meat-like koji mold cells from a solid culture obtained by solid-culturing koji using a culture medium containing a food pulverized product in order to produce meat-like koji mold cells containing a food pulverized product. Specifically, when using a food pulverized product as a culture medium, it is for solving the problems that when the particle size of the food pulverized product is small, koji cannot be cultured well, or when the amount of sugar source that can be assimilated by the food pulverized product is small, koji cannot be cultured well.

Means for Solving the Problems

[0007] In the solid culture of koji, it is important that the medium has a bulk density that allows easy oxygen supply and contains a sugar source that can be easily assimilated by the medium. As a result of intensive creative efforts, the inventor has found that by subjecting grains such as rice to gelatinization by steaming or the like, allowing amylase to act thereon to saccharify the starch, and then performing solid-liquid separation, the grains can be separated into a grain saccharified liquid and a grain protein composition. Since the obtained grain protein composition has voids where the traces of the starch in the liquefied and removed central part are porous and has a low bulk density and is suitable for koji culture that easily supplies oxygen, and at the same time, the obtained grain saccharified liquid is a saccharified liquid that is easily assimilated, the inventor has focused on the fact that it is suitable as a sugar source for culturing koji mold.

[0008] Then, by utilizing these grain protein compositions and grain saccharified liquids respectively, a food pulverized product having a relatively small particle size is mixed with the grain protein composition, the moisture content of this mixture is adjusted, and koji is solid-cultured as a culture medium, or a grain saccharified liquid is mixed with a food pulverized product having a relatively large particle size, the moisture content is adjusted, and koji is solid-cultured with the obtained culture medium. As a result, it has been found that the obtained solid cultures each have an appearance similar to ground meat and can be used as ground meat-like foods as they are, resulting in the completion of the present invention.

[0009] The present invention relates to a method for producing a ground meat-like koji mold cell composition as described in [1] to [5] below. [1] (1) A step of saccharifying the gelatinized starch in grains with amylase, and then performing solid-liquid separation of the grain saccharified liquid to obtain a grain protein composition; (2) A step of mixing a food pulverized product having a particle size of at most 18 mesh pass with the grain protein composition, adjusting the moisture content to 30 to 70% by weight, and preparing a solid culture medium containing the grain protein composition and the food pulverized product; and (3) A step of inoculating the solid medium with seed koji and producing koji, which is a method for producing a ground meat-like koji mold cell composition containing a solid culture containing koji mold hyphae extended in a mixed medium of a grain protein composition and a food pulverized product. [2] The production method according to [1] above, wherein the grain saccharified liquid separated in (1) is used for adjusting the moisture content in (2). [3] A step of saccharifying the α - starch in grains with amylase, followed by solid - liquid separation of the grain protein composition to obtain a grain saccharified liquid; (5) mixing the grain saccharified liquid with a food pulverized product having a particle size of at least 18 mesh on, adjusting the water content to 30 - 70% by weight to prepare a medium for solid culture containing the food pulverized product; and (6) inoculating the solid medium with koji mold and performing koji making, which is a method for producing a meat - like koji mold composition containing a solid culture containing koji mold mycelium with extended mycelium in a medium containing a food pulverized product. [4] The production method according to [3] above, wherein the grain protein composition separated in (4) is mixed with the food pulverized product in (5). [5] The production method according to [1] or [3] above, wherein the koji mold is a koji mold of the genus Aspergillus.

[0010] The present invention also relates to a meat - like koji mold composition in [6] below, or a food in [7]. [6] A meat - like koji mold composition containing a koji mold with extended mycelium in a food pulverized product, produced by the method according to any one of [1] to [4] above. [7] A food containing the meat - like koji mold composition according to [6] above. [Advantages of the Invention]

[0011] According to the present invention, a composition containing a meat - like koji mold for use in making the physical properties and texture similar to those of meat using a food pulverized product as a raw material can be mass - produced by a method that is not labor - intensive. Food pulverized products include, for example, rice bran, insects, sake lees, soybean processed products, algae, yeast, unused agricultural and fishery products, etc., which are not suitable for direct consumption and tend to be discarded as by - products. Therefore, it is possible to effectively utilize food pulverized products and increase their added value. Furthermore, since the flavors and textures of various food pulverized products are reflected in the flavor, etc. of the meat - like koji mold composition, the variety of the meat - like koji mold composition as a food increases, contributing to the development of foods that are more acceptable to consumers.

[0012] Generally, solid-cultured Aspergillus oryzae has high productivity and activity of enzymes such as amylase, peptidase, protease, and cellulase of Aspergillus oryzae. Therefore, the Aspergillus oryzae cells obtained from solid culture contain the autolysate of Aspergillus oryzae, enzymes, and enzyme degradation products, resulting in a meat-like Aspergillus oryzae cell body with good taste and a more heterogeneous feeling. The meat-like Aspergillus oryzae cell body composition of the present invention contains not only food pulverized matter but also a cereal protein composition and Aspergillus oryzae cell bodies with extended Aspergillus oryzae hyphae. Due to the enzymatic action of Aspergillus oryzae, the proteins of the substrate and Aspergillus oryzae itself are decomposed into amino acids, resulting in a meat-like Aspergillus oryzae cell body composition with a stronger umami taste and delicious ground meat-like taste. Using this, meat substitute foods and other foods with excellent taste and texture can be obtained.

Brief Description of the Drawings

[0013]

Figure 1

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Modes for Carrying Out the Invention

[0014] In the production of fermented foods such as miso, soy sauce, sake, shochu, and awamori, spores of Aspergillus oryzae, which is the seed koji, are sprayed onto a solid medium (solid substrate) such as steamed cereals and grains, and solid koji (solid culture) is produced by a solid culture method in which Aspergillus oryzae is grown on the surface. The present invention relates to a solid culture obtained by solid-culturing Aspergillus oryzae using food pulverized matter or a mixture of food pulverized matter and a cereal protein composition as a solid substrate, and to a meat-like Aspergillus oryzae cell body composition containing the food pulverized matter or the mixture of food pulverized matter and cereal protein composition as the substrate and Aspergillus oryzae cell bodies with extended Aspergillus oryzae hyphae, and a method for producing the same.

[0015] Koji mold is a general term for filamentous fungi used to make koji. The koji mold used in the present invention is preferably the koji mold used in the production of the above-mentioned fermented foods, such as those belonging to the genus Aspergillus or Monascus, for example, Aspergillus oryzae, Aspergillus sojae, Aspergillus kawachii, Aspergillus luchuensis, Aspergillus awamori, Aspergillus niger, Aspergillus glaucus, Aspergillus tamari, Monascus pilosus, Monascus purpureus, Monascus anka, etc. are used. In addition, Rhizopus of Rhizopus used in the production of fermented foods made from filamentous fungi eaten in Southeast Asia, such as cake koji and tempeh, and Mucor of Mucor of mold are also used.

[0016] The grains used as raw materials for the solid medium in the present invention are seeds of Gramineae crops, for example, rice, wheat, corn, etc. These may be coarsely crushed, or may be those with rice bran such as brown rice and milled rice, or wheat bran and corn bran remaining. First, the grains are washed, immersed in water to absorb water, and then sufficiently steamed by a steaming machine, steam sterilizer, etc. to gelatinize the starch. For example, when using rice as the grain, usually steamed rice is obtained at a steaming temperature of 100 to 120 °C and a steaming time of 10 to 60 minutes, but it is not limited to this condition, and the steaming conditions are appropriately changed according to the type and shape of the grain.

[0017] Add a small amount of water to the cooked grains, let it cool, then add amylase and hydrolyze and liquefy the gelatinized starch in the grains at about 10 to 50 °C for several hours. The amount of water added is not particularly limited as long as it is suitable for hydrolyzing the starch in the grains by the enzyme. Amylase is a general term for enzymes that can hydrolyze starch. The amylase used in the present invention is mainly α-amylase, also known as liquefying enzyme, which cleaves the bonds between glucose in the gelatinized starch by hydrolysis to carry out liquefaction and saccharification.

[0018] In addition, when using a thermostable amylase with an optimum temperature of 70 °C or higher as amylase, gelatinization of the grains and liquefaction of the starch can be carried out simultaneously. When using a thermostable α-amylase with an optimum temperature of 70 °C or higher, preferably 80 °C or higher, the amylase treatment can be carried out at 70 °C to 100 °C, preferably 80 °C to 100 °C, so that the gelatinization and liquefaction of the starch can be carried out in the same step. As the thermostable α-amylase used in the present invention, known thermostable α-amylases can be used. For example, BIOTHERMOSIZE X-55D (Biogreen Enzyme Co., Ltd., Thailand) is stable at high temperatures and shows high enzyme activity, so it is preferable. The addition amount of the enzyme is preferably an amount such that the starch in the grains can be sufficiently hydrolyzed within 1 to 2 hours at a temperature of 80 to 100 °C.

[0019] After allowing amylase or thermostable amylase to act on the gelatinized grains for hydrolysis reaction, the starch in the grains is saccharified to form a highly viscous grain saccharification liquid. The grain saccharification liquid and the grain protein composition are separated by solid-liquid separation. Any known separation methods such as filtration, centrifugation, and pressing separation can be used for solid-liquid separation. For example, when using a filter press or a screw press, a grain protein composition with a moisture content of about 40 to 70% can be obtained. The moisture contained in the composition contains oligosaccharides, which can be directly used as nutrients for the solid medium of Aspergillus oryzae.

[0020] The obtained cereal protein composition has only the starch in the central part saccharified and removed by solid-liquid separation. Therefore, since it is hollow inside, porous, and has a low bulk density and is easy to supply oxygen, it becomes a substrate suitable for koji culture in terms of structure. Also, since about 75% by dry weight is protein and it also contains oligosaccharides, it becomes the main nutrient source for Aspergillus oryzae. On the other hand, since the obtained cereal saccharified liquid is an easily assimilable saccharified liquid, it is suitable as a sugar source for culturing Aspergillus oryzae.

[0021] The food pulverized product of the present invention is not particularly limited as long as the food is pulverized into a predetermined particle size range, but foods containing protein or starch that can be a culture medium for Aspergillus oryzae are preferred. Also, from the viewpoint of effective utilization of by-products, for example, rice bran, insects, sake lees, soy processed products, algae, yeast, unused agricultural and fishery products, etc., foods that are difficult to eat as they are are preferably used.

[0022] The particle size of the pulverized product with a relatively small particle size obtained by pulverizing these foods is preferably 18 mesh pass (opening 1 mm or less) at the largest, and the particle size of the pulverized product with a relatively large particle size is preferably 3 mesh pass (opening 7 mm or less) at the largest and 18 mesh on (opening 1 mm or more) at the smallest. Also, originally granular foods are sorted through a sieve to those within these particle size ranges. Also, ordinary pulverizers can be used for pulverizing foods, and a roll mill, grinder, stone mortar, etc. are used, and sieving is performed thereafter as necessary.

[0023] The medium for solid culture of Aspergillus oryzae of the present invention includes four modes. The first and second are (1) A mixed medium in which a food pulverized product with a relatively small particle size is mixed with the cereal protein composition and the water content is adjusted to 30 to 70% by weight (2) A mixed medium in which the water content preparation in (1) above is performed with the cereal saccharified liquid In these cases, the preferred blending ratio (dry weight ratio) of the cereal protein composition and the food pulverized product is about 50 parts:50 parts to 99 parts:1 part. Depending on the type of the food pulverized product, when the food pulverized product exceeds an equal weight, voids cannot be secured, and Aspergillus may not be cultured well.

[0024] The third and the fourth are (3) A medium in which a cereal saccharified solution is mixed with a food pulverized product having a relatively large particle size and the water content is adjusted to 30 to 70% by weight (4) A mixed medium in which a cereal protein composition is further mixed with the food pulverized product of (3) and a cereal saccharified solution is mixed In these cases, the preferred blending ratio (dry weight ratio) of the cereal protein composition and the food pulverized product is 0 parts:100 parts to 99 parts:1 part, and the mixing ratio is arbitrary. These media are particularly effective in the case of a food pulverized product rich in protein such as whole soybeans or defatted soybeans and having few easily assimilable sugar sources. In any of the media of (1) to (4) above, by adjusting the water content to 30 to 70% by weight, the growth of Aspergillus becomes good.

[0025] The resulting solid medium can be inoculated with the seed koji as it is. The form of the seed koji in the present invention may be spores or hyphae, and the addition amount of the seed koji is 0.1 to 1.5% by weight of the solid content of the solid medium, and about 1% by weight is preferable. The culture temperature after inoculation is preferably 20 to 40°C, and the culture time is arbitrary, but it is about 1 to 10 days. In order for the growth state of Aspergillus to become dense, in the case of the rice protein composition, static culture at room temperature requires about 2, 3 to 5 days.

[0026] When Aspergillus grows on a solid medium, breakdowns occur around food pulverized materials and cereal protein compositions where the hyphae of Aspergillus penetrate into the substrate. The solid culture in a state where the breakdowns are dense looks like ground meat as it is. This solid culture contains a cereal protein composition and Aspergillus mycelium with extended Aspergillus hyphae. Due to the enzymatic action of Aspergillus, not only the Aspergillus itself but also the protein in the substrate is decomposed into amino acids, resulting in a stronger umami taste. The hyphae surround the cereal protein composition, giving it a ground meat-like taste and texture.

[0027] The meat-like Aspergillus mycelium composition of the present invention can be used as a meat substitute food as it is, and can also be used after drying. Further, one or more other meat substitute ingredients such as plant protein materials like soybeans and eggs can be mixed into the meat-like Aspergillus mycelium composition of the present invention, or it can be mixed with meat. In particular, there is no sense of incongruity when mixed with ground meat. For example, hamburgers, meatballs, gyoza, shumai, fillings for meat buns, and various processed meat products can be mentioned.

[0028] Also, similar to soy meat, by processing the meat-like Aspergillus mycelium composition with a twin-screw extruder or the like, a meat substitute food with organized protein and changed texture and shape can be obtained. Furthermore, foods containing the meat-like Aspergillus mycelium composition of the present invention include those with arbitrarily processed shapes and textures other than meat substitute foods. For example, it can be used as a tablet-shaped supplement or high-protein granola, or in a powdered form and kneaded into breads and noodles, or as a high-protein seasoning or functional food material.

[0029] Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited by these examples. In the examples, “%” means “% by weight”.

Examples

[0030] [Example 1] [Production of rice protein composition and rice saccharified liquid] To 35 kg of washed rice in a heating container, water was added so that the total volume became 100 L. 2.5 mL of lactic acid was added and the pH was adjusted to about 5.0. The temperature increase was started, and at 70 °C before the gelatinization of starch began, 50 mL of heat-resistant amylase BIOTHERMOSIZE X-55D (Biogreen Enzyme (Thailand) Co., Ltd.) was added. After reaching the boiling point, it was held for 1 hour, and then the rice saccharification liquid was separated from the saccharification reaction product by a screw press to recover the rice protein composition. A photograph of the rice protein composition is shown in Figure 1.

[0031] [Example 2] [Koji Making with a Medium of Rice Protein Composition and Rice Bran] 1 kg of roasted rice bran with an 18-mesh pass was mixed with 3 kg of the rice protein composition obtained in Example 1 (water content 50%), inoculated with 1 wt% of rice koji with respect to the medium, and statically cultured at room temperature for 48 hours. Figure 2 shows a photograph of the meat-like koji mycelium obtained from the mixed medium of the rice protein composition and roasted rice bran.

[0032] [Example 3] [Koji Making with a Medium of Rice Protein Composition and Distillers' Grains] 1 kg of distillers' grains powder with an 18-mesh pass was mixed with 3 kg of the rice protein composition obtained in Example 1 (water content 50%), inoculated with 1 wt% of rice koji with respect to the medium, and statically cultured at room temperature for 48 hours. Figure 2 shows a photograph of the meat-like koji mycelium obtained from the mixed medium of the rice protein composition and distillers' grains powder.

[0033] [Example 4] [Koji Making with a Medium of Cricket Powder, Rice Protein Composition, and Rice Saccharification Liquid] 1 kg of distillers' grains powder with a 12-mesh pass was mixed with 3 kg of the rice protein composition obtained in Example 1, adjusted to a water content of 60% with the rice saccharification liquid obtained in Example 1, inoculated with 1 wt% of rice koji with respect to the medium, and statically cultured at room temperature for 48 hours. Figure 4 shows a photograph of the meat-like koji mycelium obtained from the mixed medium of cricket powder and rice protein composition.

[0034] [Example 5] [Production of koji using a medium of soybean processed crushed product and rice saccharified liquid] 1 kg of the soybean processed crushed product passing through a 3-mesh sieve was adjusted to a water content of 60% with the rice saccharified liquid obtained in Example 1, inoculated with 1% by weight of rice koji with respect to the medium, and statically cultured at room temperature for 48 hours. Fig. 5 shows a photograph of the meat-like koji mycelium obtained from the medium of the soybean processed crushed product. In the case of food crushed products with relatively large particle sizes, since the bulk density is small, a grain protein composition is not necessarily required, and if the water content is adjusted with a grain saccharified liquid as a sugar source, koji mold can be solid-cultured.

Claims

1. (1) A step of saccharifying the alpha - starch in grains with amylase, and then subjecting the grain saccharification liquid to solid - liquid separation to obtain a grain protein composition; (2) A step of mixing a food pulverized product having a particle size of at most 18 - mesh pass with the grain protein composition, adjusting the water content to 30 - 70% by weight, and preparing a medium for solid - culture containing the grain protein composition and the food pulverized product; and (3) A step of inoculating the solid medium with koji - starter and making koji, A method for producing a meat - like koji - mycelium composition containing a solid - culture product containing koji - mycelium with extended koji - mold hyphae in a mixed medium of a grain protein composition and a food pulverized product.

2. The production method according to Claim 1, wherein the separated grain saccharification liquid in (1) is used for adjusting the water content in (2).

3. (4) A step of saccharifying the alpha - starch in grains with amylase, and then subjecting the grain protein composition to solid - liquid separation to obtain a grain saccharification liquid; (5) A step of mixing the grain saccharification liquid with a food pulverized product having a particle size of at least 18 - mesh on, adjusting the water content to 30 - 70% by weight, and preparing a medium for solid - culture containing the food pulverized product; and (6) A step of inoculating the solid medium with koji - starter and making koji, A method for producing a meat - like koji - mycelium composition containing a solid - culture product containing koji - mycelium with extended koji - mold hyphae in a medium containing a food pulverized product.

4. The production method according to Claim 3, wherein the grain protein composition separated in (4) is mixed with the food pulverized product in (5).

5. The production method according to Claim 1 or 3, wherein the koji - mold is a koji - mold of the genus Aspergillus.

6. A meat - like koji - mycelium composition containing koji - mycelium with extended koji - mold hyphae in a food pulverized product, produced by the method according to any one of Claims 1 to 4.

7. A food containing the meat - like koji - mycelium composition according to Claim 6.

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