WO2023090387A1

WO2023090387A1 - Mushroom sheet and method for producing same

Info

Publication number: WO2023090387A1
Application number: PCT/JP2022/042671
Authority: WO
Inventors: 真樹三鴨; 直文寺田
Original assignee: 株式会社伯耆のきのこ; 地方独立行政法人鳥取県産業技術センター
Priority date: 2021-11-18
Filing date: 2022-11-17
Publication date: 2023-05-25
Also published as: JPWO2023090387A1; JP7456577B2

Abstract

In order to obtain swollen fruiting bodies in which mushroom fibers in a mushroom fruiting body are swollen, a method for producing a mushroom sheet includes an alkali treatment step for treating the fruiting bodies with a low-concentration alkaline aqueous solution having a pH of 12.2-13.6 inclusive at room temperature, a fiber extraction step for filtering the swollen fruiting bodies obtained through the alkali treatment step to thereby extract wet mushroom fibers, and a drying step in which the wet mushroom fibers extracted in the fiber extraction step are dried into sheet form.

Description

Mushroom sheet and its manufacturing method

The present invention relates to a mushroom sheet and its manufacturing method. The "mushroom sheet" in the present invention means a sheet-like body containing fibers derived from mushrooms, and is not used in the sense of limiting properties such as thickness, strength, and elasticity.

Various industries are actively adopting sustainable products and materials to achieve SDGs. One of them is fake leather, which is a material that resembles natural leather (genuine leather) without using animal skins, and includes synthetic leather and artificial leather.
Furthermore, in recent years, plant-derived fake leather has also attracted attention from the viewpoint of animal protection and environmental consideration. Fake leather is also called vegan leather.

Patent Document 1 below describes a step of aerated and liquid-cultivating filamentous fungi containing chitin and/or chitosan in their cell walls, and crushing and/or papermaking of the cultured filamentous fungi to produce a crushed fungus or A leather-like material is disclosed which is produced through a step of deacetylating a bacterial cell paper product and a step of plasticizing the treated product obtained in the step.

Japanese Patent Application Laid-Open No. 2021-52698

However, the above-mentioned leather-like material has a problem in terms of production efficiency because filamentous fungi need to be aerated and liquid cultured to produce it. For example, special culture equipment is required. In addition, it takes time and labor to collect a large amount of filamentous fungi as raw materials, and it seems unsuitable for mass production.

The present invention has been made in view of such circumstances, and provides a mushroom sheet that can be efficiently manufactured by a simpler method and a method for manufacturing the same.

One aspect of the present invention relates to a mushroom sheet containing mushroom fibers extracted from mushroom fruiting bodies.
Another aspect of the present invention relates to a method for producing the mushroom sheet. In this production method, in order to obtain a swollen fruiting body in which the spaces between the mushroom fibers in the fruiting body of the mushroom are swollen, the fruiting body is treated with a low-concentration alkaline aqueous solution having a pH of 12.2 or more and 13.6 or less at room temperature. a fiber extraction step of extracting wet mushroom fibers by filtering the swollen fruit bodies obtained in the alkali treatment step; and a drying step of drying the wet mushroom fibers extracted in the fiber extraction step into a sheet. ,including.

According to the present invention, it is possible to provide a mushroom sheet that can be efficiently manufactured by a simpler method and a manufacturing method thereof.

4 is a flow chart showing a method for manufacturing a mushroom sheet according to the first embodiment. It is a figure which shows the mushroom sheet in 1st embodiment. 4 is a flow chart showing a method for manufacturing a mushroom sheet according to the second embodiment. FIG. 10 shows micrographs of two kinds of mushroom sheets in Example 3. FIG. 10 is a graph showing infrared absorption spectra of mushroom sheets produced from maitake mushroom stems and shiitake mushroom stems in Example 4. FIG. 10 is a flow chart showing a method for manufacturing a mushroom sheet in Example 6. FIG. 6 is a graph showing the results of a tensile test of each sample of Examples 6-1, 7-1, 7-4 and 8, and a comparative example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments listed below are examples, and the present invention is not limited to the configurations of the following embodiments.

The mushroom sheet in this embodiment contains mushroom fibers extracted from mushroom fruiting bodies.
Here, "fruiting body of mushroom" means the part of the fruiting body when mushrooms are considered to be composed of the fruiting body that points to the cap, folds, and stalk, and the mycelium that exists in the soil and trees. The fruiting body itself is often called a "mushroom".
By the way, raw shiitake mushrooms and raw maitake mushrooms are harvested and then packed in a pack container or the like during the commercialization process, and the ends of the stalks and the like are cut off and discarded. The Standard Tables of Food Composition in Japan states that the rate of discarding raw shiitake mushrooms is 5% (only the base of the stem), and even raw shiitake mushrooms alone will result in a discard amount of several thousand tons.
Focusing on such a situation, the inventors of the present invention produced a mushroom sheet using mushroom fruiting bodies as a raw material, thereby making it possible to effectively utilize materials that were discarded during the commercialization process of edible mushrooms. I got a new idea.
The mushroom sheet according to the present embodiment has merits in terms of production efficiency and production equipment, even when compared with the conventional technology that requires aeration and liquid culture of filamentous fungi. However, the above idea does not limit the present invention. The raw material used for the mushroom sheet of the present invention is not limited to waste discarded in the process of commercialization of edible mushrooms, but broadly includes mushroom fruiting bodies.

[First embodiment]
FIG. 1 is a flow chart showing a method for manufacturing a mushroom sheet according to the first embodiment.
A method for manufacturing a mushroom sheet according to the first embodiment (hereinafter referred to as the first manufacturing method) will be described below with reference to FIG.
In the first manufacturing method, first, a mushroom fruiting body, which is a raw material for the mushroom sheet, is prepared (S10). This step (S10) can also be called a pre-process (preparatory step) for manufacturing the mushroom sheet.
The fruiting body to be prepared may be the cap or fold of the mushroom, or the stalk (including the end of the stalk).
Moreover, the mushroom species of the fruiting body to be prepared is not particularly limited. For example, fruiting bodies of edible mushrooms such as shiitake, maitake, mushrooms, wood ear mushrooms, shimeji mushrooms, king oyster mushrooms, enoki mushrooms, nameko mushrooms, and matsutake mushrooms are used. Moreover, fruiting bodies of multiple kinds of mushrooms may be prepared in a mixed state.

In addition, the fruiting body may be in a dry state, may be in a non-dried raw state, or may be in a wet state by being soaked in water.
Further, the fruiting body may be shredded. However, since the mushroom sheet in the present embodiment contains mushroom fibers, it is desired that the mushroom fibers are shredded to the extent that they are not too fine.

The prepared fruiting body may also be the end of the mushroom stalk that has been cut off in the edible mushroom product.
In this way, the ends of the stalks of mushrooms, which are usually cut and discarded in the process of harvesting and commercializing edible mushrooms, can be collected from mushroom producers, mushroom sellers, etc., and used as raw materials. The fruiting bodies of mushrooms can be efficiently collected, and this leads to effective utilization of resources. In addition, mushroom producers, mushroom sellers, and the like can reduce disposal work and reduce disposal costs.

In the first production method, subsequently, an alkali treatment step (S12), a fiber extraction step (S14), and a drying step (S16) are performed in order.
In the alkali treatment step (S12), the mushroom fruiting body is treated with a low-concentration alkaline aqueous solution at room temperature in order to obtain a swollen fruiting body in which the spaces between the mushroom fibers are swollen.
The term "swollen fruiting body" means a product obtained by swelling a fiber-adhesive component such as a polysaccharide component, a protein component, or a glycoprotein component present between mushroom fibers in the fruiting body of a mushroom, or at least the swollen fiber-adhesive component. It means the remaining one partly dissolved in the low-concentration alkaline aqueous solution. By swelling the fiber bonding component, it is possible to facilitate dissolving the alkali-soluble component and the water-soluble component in the low-concentration alkaline aqueous solution.
"Normal temperature" means a room temperature that is not specially controlled, for example, the temperature range specified as normal temperature by Japanese Industrial Standards (JIS Z 8703-1983) etc. 5 ° C. to 35 ° C. 18° C. or higher and 33° C. or lower is preferable.

Moreover, "treating with a low-concentration alkaline aqueous solution" means immersing the fruiting body in a low-concentration alkaline aqueous solution.
At this time, it is preferable to weakly stir the fruiting body while immersed in the low-concentration alkaline aqueous solution. Immediately after the fruiting body is placed in the low-concentration alkaline aqueous solution, the fruiting body floats, but by stirring the fruiting body, the low-concentration alkaline aqueous solution can be more easily permeated throughout the fruiting body.
The speed or strength of this stirring is desired to be such a speed or strength as not to damage the mushroom fibers.

The low-concentration alkaline aqueous solution preferably has a hydrogen ion index of pH 12.20 or more and pH 13.60 or less, more preferably pH 12.25 or more and pH 13.55 or less, and pH 12.30 or more and pH 13. More preferably, it has a hydrogen ion exponent of 0.50 or less. When a sodium hydroxide aqueous solution is used as the alkaline aqueous solution, the sodium hydroxide aqueous solution preferably has a concentration of 0.07% by weight or more and 8% by weight or less, and 0.08% by weight or more and 7% by weight or less. and more preferably 0.09% by weight or more and 6% by weight or less.
However, the alkaline aqueous solution is not limited to the sodium hydroxide aqueous solution, and other alkaline aqueous solutions such as a sodium bicarbonate aqueous solution and a potassium hydroxide aqueous solution may be used.
If an alkaline aqueous solution with a pH of less than 12.2 or a sodium hydroxide aqueous solution with a content of less than 0.07% by weight is used, the mushroom fibers may not be properly extracted (see Examples). The reason for this is considered to be that the fiber adhesive component present between mushroom fibers cannot be sufficiently dissolved due to the too low alkali concentration.
Also, when the hydrogen ion exponent of the alkaline aqueous solution is higher than pH 13.6, or when the concentration of the sodium hydroxide aqueous solution is higher than 8% by weight, the mushroom fibers may not be properly extracted (see Examples). This is probably because the alkali concentration is too high, and water permeation between the mushroom fibers is suppressed due to factors such as the osmotic pressure at room temperature, which makes it difficult for the mushroom fibers to swell.
Moreover, in the treatment using a high-concentration alkaline aqueous solution (30% sodium hydroxide aqueous solution) as described in Patent Document 1, the mushroom fibers are damaged due to molecular weight reduction or deacetylation.

Thus, in order to extract mushroom fibers from the fruiting body without damage through alkali treatment, the present inventors minimized damage such as demolecularization and deacetylation to the mushroom fibers themselves, The hydrogen ion exponent (pH 12.2 or more and 13.6 or less) of an alkaline aqueous solution was found that swells between fibers, promotes dissolution of the fiber adhesive component present between the mushroom fibers, and facilitates dissolution of the mushroom fibers in the fruiting body. be.
By treating the mushroom fruiting body with such a low-concentration alkaline aqueous solution, the fiber adhesion component present between the mushroom fibers is swollen and part or all of it is dissolved, thereby dissolving the mushroom fiber in the fruiting body. and succeeded in extracting mushroom fibers suitable for manufacturing mushroom sheets.

Here, the alkali treatment step (S12) may further include a step of immersing the fruiting body in a low-concentration alkaline aqueous solution and then filtering the alkali-treated liquid containing the swollen fruiting body to obtain the swollen fruiting body.
Therefore, in the alkali treatment step (S12), an alkali-treated liquid containing swollen fruit bodies may be obtained, or the swollen fruit bodies after the filtration step may be obtained.
The "alkaline-treated liquid containing swollen fruiting bodies" includes the swollen fruiting bodies after the fruiting bodies are immersed in a low-concentration alkaline aqueous solution in the alkali treatment step (S12) to turn the fruiting bodies into swollen fruiting bodies. means an aqueous alkaline solution.

In the next fiber extraction step (S14), wet mushroom fibers are extracted by filtering the swollen fruit bodies obtained in the alkali treatment step (S12).
When an alkali-treated liquid containing swollen fruit bodies is obtained in the alkali treatment step (S12), the alkali-treated liquid containing swollen fruit bodies is filtered, and when swollen fruit bodies are obtained in the alkali treatment step (S12), can filter the swollen fruiting bodies.
However, since the swollen fruiting body itself is in a state where the mushroom fibers are swollen and has high viscosity, it takes time to filter. In addition, from the viewpoint of safety, an additional operation is required to convert the wet mushroom fibers extracted in the fiber extraction step (S14) from alkaline to neutral.

Therefore, in the fiber extraction step (S14), it is more preferable to extract wet mushroom fibers by diluting and neutralizing the swollen fruit bodies obtained in the alkali treatment step (S12) before filtering. When an alkali-treated solution containing swollen fruit bodies is obtained in the alkali treatment step (S12), the alkali-treated solution containing swollen fruit bodies is diluted and neutralized, and the swollen fruit bodies are diluted in the alkali treatment step (S12). is obtained, dilution and neutralization may be performed by pouring some liquid (such as a diluent) onto the swollen fruiting body.
The dilution is preferably carried out with a diluent (such as water) in an amount sufficient to dissolve the water-soluble component in the swollen fruiting body. For example, at least three times as much water as the alkaline treatment liquid is used for dilution. The water-soluble component as used herein refers to a component that exists between mushroom fibers, is not dissolved in the alkali treatment step described above, and can be dissolved by a diluent such as water.
The neutralization is carried out by adding an acid such as hydrochloric acid until the liquid containing the swollen fruit body obtained in the process of dilution and neutralization reaches a neutral range (for example, pH 6.0 or more and pH 8.0 or less). The acid to be added is not limited as long as the liquid containing the swollen fruiting body can be made neutral.
In this way, the safety and efficiency of the manufacturing process involved in the extraction of wet mushroom fibers can be improved.

Filtration is a treatment for removing alkali-soluble components and water-soluble components contained in the swollen fruit bodies or the liquid containing the swollen fruit bodies using a net material. Therefore, the filtration in the fiber extraction step (S14) is intended to separate and extract the wet mushroom fibers by removing the alkali-soluble components and water-soluble components together with the water, so it can also be referred to as filtering. .
The mesh material used for filtration preferably has a mesh size of 30 or more and 150 or less and an opening of 0.1 mm or more and 0.5 mm or less. The mesh is the number of meshes (holes) present in a length of 1 inch (25.4 mm), and the mesh opening indicates the top-to-bottom width or left-right width of one mesh (hole).
If the individual meshes are too small, the size of the mushroom fibers will vary too much, which can lead to problems with the stability of the mushroom sheet. In addition, if the individual meshes are too large, short mushroom fibers cannot be collected, resulting in an excessive decrease in yield of mushroom fibers.
According to the first production method, it is possible to extract mushroom fibers having a relatively large width and length that can be papered using a mesh material with a relatively coarse mesh as described above, and thus, , a mushroom sheet with a certain degree of strength and stability can be obtained. Moreover, by using the mesh material as described above, the mushroom fibers in the fruiting body of the mushroom can be efficiently extracted without damage. It should be noted that fibers having a fiber length of 0.1 mm or less or a polymer solution cannot be made into paper using a netting material as in the present embodiment.

By using the wet mushroom fibers extracted by the net material as described above, the mushroom sheet in the present embodiment is mushroom fibers extracted from the fruiting body of the mushroom, and has an average fiber width of 50 μm or more and 500 μm or less. and mushroom fibers having an average fiber length of 0.5 mm or more and 5 mm or less.

The fiber extraction step (S14) may further include a step of weakly stirring the liquid containing the swollen fruiting body for a predetermined time in the process of dilution and neutralization. Also in this step, it is desired that the mushroom fibers contained in the swollen fruiting bodies be stirred at a slow speed (strength) so as not to be damaged.
In addition, in the fiber extraction step (S14), the step of dilution, neutralization and filtration may be performed multiple times. By doing so, alkali-soluble components and water-soluble components other than the mushroom fibers in the swollen fruiting body can be efficiently removed.

In the drying step (S16), the wet mushroom fibers extracted in the fiber extraction step (S14) are dried into a sheet. In other words, the drying step (S16) is a step of drying the wet mushroom fibers in an overlapping state to obtain a sheet-like body.
In the first production method, the wet mushroom fibers may be sheeted in the drying step (S16), or the sheeted wet mushroom fibers may be obtained in the fiber extraction step (S14). In the latter case, a mesh sheet (mesh sheet material) is used as a net material for filtration in the fiber extraction step (S14), and the swollen fruit bodies are uniformly dispersed on the surface of the mesh sheet for filtration and sheet formation. can be done.
Drying of the wet mushroom fibers may be performed at room temperature or in a drying room or the like, and the drying temperature is not particularly limited as long as the temperature does not degrade the mushroom fibers.

FIG. 2 is a diagram showing the mushroom sheet in the first embodiment.
According to the drying step (S16), a thin sheet-like body (mushroom sheet) formed by mutually overlapping mushroom fibers as shown in FIG. 2 is obtained. Although FIG. 2 is not colored due to limitations of patent drawings, light brown mushroom sheets are produced.

[Modification of First Embodiment]
The first manufacturing method described above can be modified as appropriate.
For example, a plasticizing step may be further performed before the drying step (S16). In this plasticizing step, a plasticizer such as glycerin is added to the wet mushroom fibers. The plasticizer utilized is not limited.
In this case, after the drying step (S16), a washing step of washing away the plasticizer from the obtained sheet-like body may be further performed.

In addition, a tanning process may be further performed before or after the drying process (S16). The tanning agent used in the tanning process is chrome tanning, tannin tanning, etc., and is not particularly limited. By adding this tanning process, the durability of the mushroom sheet can be improved.

[Second embodiment]
In the first embodiment, an example of a mushroom sheet containing mushroom fibers extracted from the fruiting body of a mushroom is shown, and the mushroom sheet contains a plasticizer or a tanning agent in addition to the mushroom fibers as the main raw material. exemplified that it can be added.
In the second embodiment, a mushroom sheet further containing non-mushroom-derived fibers in addition to mushroom fibers extracted from mushroom fruiting bodies is exemplified.
This "non-mushroom-derived fiber" may be one type of fiber not derived from mushrooms, or may be two or more types of fibers, and preferably has a higher strength than the mushroom fiber.
As described above, the mushroom sheet according to the second embodiment further contains non-mushroom-derived fibers, and therefore has a higher strength compared to a case where the sheet is formed only from mushroom fibers extracted from mushroom fruiting bodies. .

Moreover, the "non-mushroom-derived fibers" contained in the mushroom sheet according to the second embodiment are preferably non-mushroom-derived cellulose fibers. Non-mushroom-derived cellulose fibers are fibers mainly composed of non-mushroom-derived cellulose, and can also be referred to as non-mushroom-derived cellulose fibers. Non-mushroom-derived cellulose fibers include non-mushroom-derived plant fibers (kozo fiber, hemp fiber, softwood fiber, hardwood fiber, linter fiber, bagasse fiber, mitsumata fiber, gampi fiber, etc.), regenerated fibers (rayon, cupra , lyocell, etc.), semi-synthetic fibers (acetate, viscose rayon, cupra, etc.), cellulose nanofibers, chitin nanofibers, and the like.
According to this, since cellulose is a natural material like the mushroom fiber described above, an environmentally friendly mushroom sheet can be obtained.
Non-mushroom-derived cellulose fibers are preferably stronger than mushroom fibers extracted from mushroom fruiting bodies. For example, kozo/hemp fibers are preferred over cellulose fibers because they have higher strength than hardwood fibers, straw fibers, bagasse fibers, and the like.
On the other hand, from the viewpoint of easy procurement of materials and easy adjustment of strength, the non-mushroom-derived fibers are not cellulose fibers but synthetic fibers such as polyester, nylon, acrylic, and polyurethane. good too.

Thus, when the mushroom sheet according to the second embodiment contains mushroom fibers extracted from mushroom fruiting bodies and non-mushroom-derived cellulose fibers as main components, the weight ratio of the mushroom fibers to the non-mushroom-derived cellulose fibers is It is preferably in the range of 99:1 to 50:50, more preferably in the range of 90:10 to 60:40, even more preferably in the range of 80:20 to 65:35. In addition, the said weight ratio is a solid content weight ratio of mushroom fiber and non-mushroom-derived cellulose fiber.
In the weight ratio of mushroom fibers to non-mushroom-derived cellulose fibers, if the ratio of non-mushroom-derived cellulose fibers is high, the texture of the mushroom sheet is deteriorated. The strength of the mushroom sheet tends to decrease.
The mushroom sheet according to the second embodiment contains mushroom fibers and non-mushroom-derived cellulose fibers in the weight ratio as described above, thereby increasing the strength and realizing a soft and smooth feel like leather. .
In this specification, the strength of the mushroom sheet indicates the difficulty of breaking, and one measure of the quality of the texture of the mushroom sheet is indicated by leather-like flexibility or smooth touch.

FIG. 3 is a flow chart showing the mushroom sheet manufacturing method according to the second embodiment.
A method for manufacturing a mushroom sheet according to the second embodiment (hereinafter referred to as a second manufacturing method) will be described below with reference to FIG.
The second production method includes a step of preparing a mushroom fruiting body (S30), an alkali treatment step (S32), a fiber extraction step (S34), a mixing step (S36) and a drying step (S38).
Since the steps (S30) and (S32) may be the same as the steps (S10) and (S12) in the first manufacturing method, descriptions thereof are omitted here.

The fiber extraction step (S34) in the second production method may be the same as the step (S14) in the first production method, but the swollen fruiting body obtained in the alkali treatment step (S32) is diluted, neutralized, filtered and moistened. Extraction of mushroom fibers is preferred. The methods of dilution, neutralization and filtration here are as described in the first embodiment.
By doing so, impurities such as alkali-soluble components and water-soluble components contained in the swollen fruiting body or the liquid containing the swollen fruiting body and unnecessary water can be removed appropriately, so that a strange color and smell can be removed. A mushroom sheet that does not remain and is resistant to corrosion can be produced, and the quality of the finally produced mushroom sheet can be improved.
However, the dilution and neutralization may be performed in the later-described mixing step (S36) or after that step (S36). In this case, the impurities are more likely to remain than in the above method, and the final quality of the mushroom sheet may be slightly reduced.

In the second manufacturing method, the mixing step (S36) and the drying step (S8) are performed after the fiber extraction step (S34).
In the mixing step (S36), the non-mushroom-derived fibers, the wet mushroom fibers extracted in the fiber extraction step (S34), and the liquid dispersion medium are stirred and mixed, thereby dispersing and mixing the non-mushroom-derived fibers and the mushroom fibers. This is a step of obtaining a mixed liquid.
Liquid dispersion medium here means a liquid medium for dispersing non-mushroom-derived fibers and mushroom fibers. As the liquid dispersion medium, water may be used, an organic solvent other than water that is compatible with water may be used, or a plurality of such solvents may be mixed and used. Examples of organic solvents compatible with water include acetone and ethanol.

More specifically, in the mixing step (S36), a dispersion liquid in which non-mushroom-derived fibers are dispersed in a liquid dispersion medium and the wet mushroom fibers extracted in the fiber extraction step (S34) may be stirred and mixed. Then, the dispersion in which the non-mushroom-derived fibers are dispersed in the liquid dispersion medium and the dispersion in which the wet mushroom fibers are dispersed in the liquid dispersion medium may be stirred and mixed, or the wet mushroom fibers may be mixed in the liquid dispersion medium. Non-mushroom-derived fibers may be added to the dispersion dispersed in the liquid dispersion and stirred and mixed, or a liquid dispersion may be added to the non-mushroom-derived fibers or the dispersion containing the same and the wet mushroom fiber or the dispersion containing the same. A medium may be further added and stirred and mixed.
The stirring here is at a strength or speed that does not damage the mushroom fibers and non-mushroom-derived fibers as much as possible, and the non-mushroom-derived fibers and mushroom fibers are appropriately dispersed and mixed in the liquid. The stirring time required for

When non-mushroom-derived cellulose fibers are used as non-mushroom-derived fibers, in the mixing step (S36), a dispersion in which non-mushroom-derived cellulose fibers are dispersed in a liquid dispersion medium is prepared, and the dispersion and the fibers are It is preferable to stir and mix the wet mushroom fibers extracted in the extraction step (S34). For example, a dispersion in which the non-mushroom-derived cellulose fibers are dispersed in a liquid dispersion medium and the moist mushroom fibers are placed in a container having a predetermined capacity and mixed (for example, by a mixer) for a predetermined period of time.
The solid content concentration of the non-mushroom-derived cellulose fibers in the dispersion is not particularly limited as long as the non-mushroom-derived cellulose fibers are contained in a dispersed state. However, in order to properly mix the non-mushroom-derived fibers and the mushroom fibers, it is desirable that the dispersion has high fluidity. For example, the solid content concentration of non-mushroom-derived cellulose fibers in the dispersion is set to 5% by weight or less. On the other hand, when the solid content concentration of non-mushroom-derived cellulose fibers in the dispersion is high and the fluidity of the dispersion is low, a liquid dispersion medium may be additionally added during stirring.
By doing so, the non-mushroom-derived cellulose fibers are unraveled and dispersed in the dispersion, and the mushroom fibers are also in a state of being unraveled to some extent as wet mushroom fibers. can be mixed.

In the above case, the weight of the dispersion administered in the mixing step (S36) is such that the weight ratio (solid content weight ratio) of mushroom fibers and non-mushroom-derived cellulose fibers in the fiber mixture is 99: 1 to 50. : The concentration of non-mushroom-derived cellulose fibers in the dispersion (solid content concentration) and the concentration of mushroom fibers in the wet mushroom fibers (solid content concentration) and the concentration of wet mushroom fibers so that the predetermined value is within the range of 50 determined according to weight.
As described above, the weight ratio of mushroom fibers and non-mushroom-derived cellulose fibers in the fiber mixture is more preferably in the range of 90:10 to 60:40, more preferably in the range of 80:20 to 65:35. More preferably within.

The solid concentration of mushroom fibers in the wet mushroom fibers extracted in the fiber extraction step (S34) and the solid concentration of non-mushroom-derived cellulose fibers in the dispersion can be measured.
For example, by measuring the water content of the wet mushroom fiber and the dispersion with a moisture meter and subtracting the water weight from those weights, the solid content weight of the mushroom fiber and the non-mushroom-derived cellulose fiber can be calculated. Further, by sufficiently drying a predetermined weight of wet mushroom fiber and measuring the weight of the dried mushroom fiber obtained, the solid content concentration of mushroom fiber in the wet mushroom fiber can be calculated. In addition, since the weight of the non-mushroom-derived cellulose fibers in the dispersion can be known in the process of generating the dispersion, it is also possible to calculate the solid content concentration of the non-mushroom-derived cellulose fibers in the dispersion.
Thereby, the weight of the dispersion is determined such that the weight ratio of both fibers to the weight of the wet mushroom fiber to be mixed is a predetermined value within the range of 99:1 to 50:50. be able to.
As a result, by presuming the solid content concentration of the wet mushroom fiber extracted in the fiber extraction step (S34) and the solid content concentration of the dispersion liquid, every time the wet mushroom fiber is extracted in the fiber extraction step (S34) It is possible to obtain an appropriate amount of dispersion liquid input according to the weight of the wet mushroom fiber to be mixed without the need to calculate the solid content concentration of the wet mushroom fiber, thereby simplifying the manufacturing process. be able to.

By the way, the solid content concentration of mushroom fibers in the wet mushroom fibers extracted in the fiber extraction step (S34) may differ depending on the size, growth state, etc. of the mushroom fruiting body that is the raw material. In such a case, the state of the mushroom fruiting body prepared in the step (S30) is determined, and the solid content concentration of the wet mushroom fiber extracted in the fiber extraction step (S34) is switched according to this state. can be Then, the weight of the dispersion liquid to be administered may be switched with respect to the weight of the wet mushroom fiber to be mixed.

Moreover, the mixing step (S36) preferably includes a plasticizing step of adding a plasticizer so that the liquid dispersion medium, the non-mushroom-derived fibers, and the wet mushroom fibers are stirred and mixed together.
In this plasticization step, the plasticizer may be stirred and mixed with the wet mushroom fibers after being added to the dispersion liquid in which the non-mushroom-derived fibers are dispersed in the liquid dispersion medium, or may be added to the wet mushroom fibers. After that, it may be stirred and mixed with the dispersion liquid, or may be added to the liquid mixture of the non-mushroom-derived fibers, the moist mushroom fibers, and the liquid dispersion medium. Also, the plasticizer may be added in a state dissolved in water as an aqueous solution.

The type of plasticizer is not particularly limited as long as it can give flexibility to the mushroom sheet, such as glycerin, ethylene glycol and polyethylene glycol. However, naturally derived plasticizers such as natural glycerin are more preferred.
Moreover, the amount of the plasticizer to be added may be adjusted according to the thickness, strength, flexibility, texture, etc. of the finally produced mushroom sheet, and is not particularly limited.
By adding the plasticizer so that it is stirred and mixed together with the liquid dispersion medium, the non-mushroom-derived fiber, and the wet mushroom fiber, the plasticizer is easily dispersed and penetrated between the fibers, so that the entire mushroom sheet has a moderate flexibility. You can give it character.

In the drying step (S38), the wet mixed fibers separated by filtering the fiber mixture obtained in the mixing step (S36) are dried into a sheet.
That is, in the drying step (S38), first, the fiber mixed liquid obtained in the mixing step (S36) is filtered to remove the liquid, and the wet mixed fibers dispersed and mixed in the fiber mixed liquid are separated. Thus, the separated wet-blended fibers are wet-state fibers in which mushroom fibers and non-mushroom-derived fibers are blended. Filtration here can also be referred to as filtration because the purpose is to remove the liquid from the fiber mixture to separate the wet mixed fibers.
Also in the filtration in the drying step (S38), the same mesh material as that used in the filtration in the fiber extraction step (S34) is used. That is, a mesh material having a mesh size of 30 or more and 150 or less and an opening of 0.1 mm or more and 0.5 mm or less is used.

In the drying step (S38), the wet mixed fibers separated as described above are then dried into a sheet. That is, a sheet-like mushroom sheet is obtained by drying the mushroom fibers and the non-mushroom-derived fibers in a state in which they are dispersed and mixed and overlapped.
For example, in the drying step (S38), a mesh sheet (mesh sheet material) is used as a net material for filtration, and the fiber mixture obtained in the mixing step (S36) is uniformly dispersed on the mesh sheet surface. Filtration and sheeting can be performed. Then, the wet-mixed fibers remaining in the form of a sheet on the surface of the mesh sheet can be allowed to stand until the liquid disappears, and further dried as it is.
The drying here may be performed at room temperature or in a drying room or the like, and the drying temperature is not particularly limited as long as the temperature does not degrade the mushroom fibers and non-mushroom-derived fibers.

[Modification of Second Embodiment]
The second manufacturing method described above can be modified as appropriate.
For example, although not explicitly stated in the above-described second manufacturing method, a tanning process may be further performed after the drying process (S38).

In the tanning step, a tanning agent is added to the mushroom sheet obtained in the drying step (S38). Specifically, in the tanning step, the mushroom sheet obtained in the drying step (S38) is immersed in a tanning solution containing a tanning agent for a predetermined period of time, then taken out and dried, which is repeated once or more.
The tanning agent is not particularly limited as long as it can increase cross-linking between fibers, such as chrome tanning and tannin tanning.
When a tanning process is performed, a drying process may be further performed after the tanning process, in which the sheet is dried until the water content reaches a predetermined amount.
By adding such a tanning process, it is possible to improve the durability of the mushroom sheet that is finally produced, and also to obtain a leather-like texture such as flexibility.

Moreover, the mixing step (S36) may further include a step of adding a paper strength agent so as to be stirred and mixed together with the dispersion and the wet mushroom fibers.
The paper strength agent may be an agent that improves the adhesive strength between fibers, and general paper strength agents such as polyvinyl alcohol-based paper strength agents and polyacrylamide-based paper strength agents may be used. .
By further including this step, the strength of the mushroom sheet can be increased.

Additionally, a surface treatment step may be performed. In the surface treatment step, a surface treatment agent such as a water-repellent coating agent, a surface coating agent, or a leather paint is applied to the surface of the mushroom sheet obtained through the drying step (S38) or the subsequent tanning step. be.
By further including this step, the resistance to water wetting can be improved, and the strength of the mushroom sheet can be increased.

In addition, although different from the above-described embodiments, it is possible to produce a mushroom sheet containing resin such as natural resin or synthetic resin together with mushroom fibers extracted from mushroom fruiting bodies. In this case, the mushroom sheet may contain a resin instead of the non-mushroom-derived fibers or together with the non-mushroom-derived fibers.

Examples will be given below to describe the above embodiments in more detail. The contents of the above embodiments and modifications are not limited to the following contents.

[Example 1]
In Example 1, a specific example of the first manufacturing method described above will be described with reference to FIG.
First, a portion of the stalk of an undried shiitake mushroom (hereinafter referred to as shiitake stem) was prepared as a mushroom fruiting body (S10). The prepared shiitake mushroom stem weighed 53 g.
Subsequently, the shiitake mushroom stem was placed in a plastic container, to which 147 g of pure water and 100 g of an 8% by weight sodium hydroxide (NaOH) aqueous solution were added (S12).
Here, the weight ratio of the solid content of the prepared shiitake mushroom stem is 18.6%, and assuming that it is about 10 g (9.86 g), the total water content is about 290 g. is 2.76% by weight.
The shiitake mushroom stems were immersed in the NaOH aqueous solution having the concentration described above while gently stirring the inside of the container in such a state for 48 hours (S12). As a result, an alkali-treated liquid containing swollen fruiting bodies of shiitake mushrooms was obtained.

After that, the contents of the container are transferred to a large container with a total volume of 2 L, and 200 g of pure water is added for dilution. An aqueous solution was added to neutralize (S14). Finally about 400 ml of aqueous hydrochloric acid was added.
Subsequently, the aqueous solution containing the swollen fruit bodies of shiitake mushroom stems in the large container was filtered through a 40-mesh net (S14).
Then, the filtered material was returned to the large container, 1 liter (L) of pure water was added, the mixture was gently stirred for 10 minutes, and the washing process was performed three times (S14). .

As a result, wet mushroom fibers with a shiitake mushroom pattern were extracted (S14), and dried into a sheet at room temperature to obtain a mushroom sheet (S16).
As a result, 5.69 g of mushroom sheets were recovered from 9.86 g of the solid content of the shiitake stem, and the yield was 57.82%.
In Example 1, a sheet manufacturing method using a mesh sheet was adopted in (S14) and (S16). The method of making a sheet using a mesh sheet is a method of forming a sheet from fibers. Fibers (swollen fruit bodies) having a fiber length and fiber width greater than the opening of the mesh sheet are uniformly dispersed on the surface of the mesh sheet, formed into a sheet, and dried. It is a method to let This method is a method of sheeting pulp, which is a fiber extracted from plants in the paper industry, and is called papermaking when pulp is used as a raw material. In this case, instead of pulp, mushroom fibers are formed into a sheet on a mesh sheet, so the method is referred to as "mesh sheet production method."
If the fiber is 0.1 mm or less, or if it is a polymer solution or polymer emulsion (aqueous solution, organic solvent solution, W/O emulsion, etc.), it is not possible to form a sheet by this "method for producing a sheet using a mesh sheet."

[Example 2]
In Example 2, in addition to the manufacturing method of Example 1, a plasticizing step was further performed. Specifically, the same steps as in Example 1 were performed up to the fiber extraction step (S14), and the sheet-like wet mushroom fibers obtained in the fiber extraction step (S14) were subjected to the following plasticization. A conversion step was performed.
That is, about twice the amount of glycerin as the solid content (9.86 g) of the sheet-like wet mushroom fiber is added, then dried at room temperature, and the dried sheet-like mushroom fiber is washed with water to remove excess glycerin. was done.
Then, the sheet-like mushroom fibers from which the glycerin was removed were dried again (S16) to obtain a mushroom sheet.
According to Example 2, it was demonstrated that the flexibility of the mushroom sheet can be controlled. However, it has also been demonstrated that the manufacturing method of Example 1, which does not include the plasticizing step, can also manufacture a mushroom sheet having sufficient flexibility.

[Example 3]
Two types of mushroom sheets were produced in the same manner as in Example 1 except for the alkali treatment step (S12), and designated Examples 3-1 and 3-2, respectively. Examples 3-1 and 3-2 each have a hydrogen ion exponent in the range of pH 12.20 or more and pH 13.60 or less, and using a sodium hydroxide aqueous solution different from the hydrogen ion exponent of Example 1 Alkaline treatment was performed. At this time, the sodium hydroxide aqueous solutions used in Examples 3-1 and 3-2 were adjusted to have different hydrogen ion exponents.
4 is a diagram showing micrographs of two types of mushroom sheets in Example 3. FIG.
The mushroom sheets of Examples 3-1 and 3-2 obtained as described above were each observed with a stereoscopic microscope (magnification of 50 times), and the micrograph shown in FIG. 4 was taken. FIG. 4(1) shows a micrograph of Example 3-1, and FIG. 4(2) shows a micrograph of Example 3-2.
The fiber width and fiber length were actually measured for mushroom fibers randomly selected from the obtained micrographs.

The fiber length of the mushroom sheet of Example 3-1 measured as described above was in the range of 796 μm to 1380 μm, and the fiber width was in the range of 111 μm to 140 μm. The average fiber length obtained by arithmetically averaging these measured values was about 1150 μm, and the average fiber width was about 126 μm.
The fiber length of the mushroom sheet of Example 3-2 measured as described above was in the range of 1172 μm to 3408 μm, and the fiber width was in the range of 397 μm to 493 μm. The average fiber length obtained by arithmetically averaging these measured values was about 2167 μm, and the average fiber width was about 445 μm.
From the above results, it was confirmed that the mushroom sheet obtained by this production method can be composed of mushroom fibers having an average fiber width of 50 μm or more and 500 μm or less and an average fiber length of 0.5 mm or more and 5 mm or less. rice field. Furthermore, it can be said that the mushroom sheet obtained by this production method can be composed of mushroom fibers having an average fiber width of 100 μm or more and 500 μm or less and an average fiber length of 1 mm or more and 3 mm or less.

[Example 4]
In Example 4, a mushroom sheet was produced in the same manner as in Example 1 except that the ends of maitake mushroom stems (hereinafter referred to as maitake mushroom stems) were used instead of the shiitake mushroom stems.

For each of the mushroom sheet of Example 1 and the mushroom sheet of Example 4, an infrared absorption spectrum of the mushroom sheet was obtained using Fourier transform infrared spectroscopy (FTIR) analysis.
FIG. 5 is a graph showing infrared absorption spectra of mushroom sheets produced from maitake stems and shiitake stems. FIG. 5 (1) is a graph showing the infrared absorption spectrum of the mushroom sheet derived from the maitake mushroom stem of Example 4, and FIG. 5 (2) is the infrared absorption spectrum of the mushroom sheet derived from the shiitake mushroom stem of Example 1. is a graph showing
The spectrum shape surrounded by a dashed circle including around 1660 cm ⁻¹ and 1560 cm ⁻¹ is an acetamide group bound to the carbon at the second position derived from chitin, an amide bond derived from a protein amide bond (peptide bond), or a sugar. It can be seen that the spectrum shape is similar in both FIG. 5(1) and FIG. Moreover, there is a peak near 1360 cm ⁻¹ in both FIGS. 5(1) and 5(2).
From the above, it was demonstrated that the mushroom sheet derived from the mushroom fiber of the fruiting body of the mushroom can be similarly produced with both the maitake pattern and the shiitake pattern.

[Example 5]
In Example 5, the relationship between the alkali concentration of the alkaline aqueous solution used in the alkali treatment step (S12) and the extraction of mushroom fibers from shiitake stems as mushroom fruiting bodies was demonstrated.
Specifically, mushroom sheets were produced in the same manner as in Example 1, except that the alkali concentration and hydrogen ion exponent pH of the aqueous sodium hydroxide solution used in the alkali treatment step (S12) were changed to the values shown in Table 1. and Examples 5-1 to 5-4. In addition, as a comparative experiment, a mushroom sheet was prepared in the same manner as in Example 1, except that the alkali concentration and hydrogen ion exponent pH of the aqueous sodium hydroxide solution used in the alkali treatment step (S12) were changed to the values shown in Table 1. Comparative Examples 1 and 2 were produced.

Table 1 shows the alkali concentration and mushroom fiber of the alkali aqueous solution used in the alkali treatment step of Example 5-1, Example 5-2, Example 5-3, Example 5-4, Comparative Example 1 and Comparative Example 2. shows the relationship with the extraction result of
In Example 5-1, an alkali treatment step using a 3% by weight sodium hydroxide aqueous solution was performed at room temperature of 30.2 degrees.
In Example 5-2, an alkali treatment step was performed using a 5% by weight sodium hydroxide aqueous solution at room temperature of 31.1 degrees.
In Example 5-3, an alkali treatment step was performed using a 0.5% by weight sodium hydroxide aqueous solution at room temperature of 27.1 degrees.
In Example 5-4, an alkali treatment step was performed using a 0.1% by weight sodium hydroxide aqueous solution at room temperature of 27.0 degrees.
In Comparative Example 1, an alkali treatment step was performed using a 0.05% by weight sodium hydroxide aqueous solution at room temperature of 19.0° C. in the laboratory.
In Comparative Example 2, an alkali treatment step using a 30% by weight sodium hydroxide aqueous solution was performed at room temperature in the laboratory, although no measurement was performed.

When the hydrogen ion exponent of the sodium hydroxide aqueous solution used in the alkali treatment step of each example was measured by the pH measurement method of JIS Z8802, it was pH 13.31 in Example 5-1 and pH 13.31 in Example 5-2. 41, pH 12.89 in Example 5-3, pH 12.34 in Example 5-4, and pH 12.18 in Comparative Example 1. The hydrogen ion exponent of Comparative Example 2 could not be measured because the alkali concentration was in the concentration range that dissolved the pH glass electrode. A glass electrode is used for accurate pH measurement (pH measurement conforming to JIS Z8802), but it is known that the glass surface dissolves at an alkali concentration of 10% by weight or more.

As a result, mushroom fibers were extracted through the alkali treatment steps of Examples 5-1, 5-2, 5-3 and 5-4, but Comparative Examples 1 and 2 In the case of , mushroom fibers were not properly extracted.
In addition, when the progress from the fruit body to the swollen fruit body in the alkali treatment steps of Examples 5-1, 5-2, 5-3 and 5-4 was visually observed, Example 5 -1 and Example 5-2 formed a swollen fruiting body in about 4 hours, whereas in Examples 5-3 and 5-4 it took a longer time to become a swollen fruiting body. . Specifically, it took about 18 hours in Example 5-3 and about 24 hours in Example 5-4.

The reason why mushroom fibers could be appropriately extracted in Examples 5-1, 5-2, 5-3 and 5-4 is considered as follows. When the hydrogen ion exponent is pH 12.20 or higher, the dissociation constant of the hydroxyl group of the polysaccharide contained between the mushroom fibers promotes ionization (OH ^- conversion) and causes swelling between the mushroom fibers. This is because, as a result, water-soluble substances (acidic polysaccharides) and low-concentration alkaline aqueous solution-soluble substances (proteins, polysaccharides, etc.) bonding between mushroom fibers are easily dissolved.
However, in the case of low-concentration alkaline aqueous solutions such as those of Examples 5-3 and 5-4, the degree of dissociation of OH ⁻ is low, so swelling takes time.

On the other hand, the reason why mushroom fibers were not properly extracted with the 0.05% by weight sodium hydroxide aqueous solution of Comparative Example 1 is considered as follows. It is presumed that the hydrogen ion index of the alkaline aqueous solution decreases due to the effect of dissolution of the acidic polysaccharides contained in the fruiting bodies of mushrooms. This is because the mushroom fiber cannot be extracted because it cannot be dissolved in
The reason why the mushroom fibers were not properly extracted with the 30% by weight sodium hydroxide aqueous solution of Comparative Example 2 is considered as follows. The viscosity of the sodium hydroxide aqueous solution increases, inhibiting the penetration of the aqueous solution between the mushroom fibers and the swelling between the mushroom fibers does not progress, or the aqueous solution around the mushroom fibers contains high concentrations of Na ⁺ and OH ^- . It is assumed that this is because the water molecules are prevented from penetrating between the mushroom fibers, and the swelling between the mushroom fibers does not proceed.
Therefore, according to this embodiment, in the alkali treatment step (S12), it is preferable that the low-concentration alkaline aqueous solution has an alkaline concentration of pH 12.2 or more and 13.6 or less, and when sodium hydroxide aqueous solution is used as the alkaline aqueous solution , it was demonstrated that the concentration of the aqueous sodium hydroxide solution is preferably 0.07% by weight or more and 8% by weight or less.

[Example 6]
Next, as a specific example of the above-described second manufacturing method, a method for manufacturing a mushroom sheet in Example 6 will be described with reference to FIG.
FIG. 6 is a flow chart showing a method for manufacturing a mushroom sheet in Example 6. FIG.
The method for producing a mushroom sheet in Example 6 is a specific example of the second production method described above, and in addition to the steps of the second production method described above, the tanning step (S61) and the surface treatment step (S63) are further included. include.
In Example 6, kozo/hemp fibers, which are a mixture of kozo fibers and hemp fibers, were used as the non-mushroom-derived fibers. Kozo and hemp fibers correspond to non-mushroom-derived cellulose fibers.

First, a portion of the stalk of an undried shiitake mushroom (hereinafter referred to as shiitake stem) was prepared as a mushroom fruiting body (S30).
Subsequently, the same alkali treatment step as in Example 5-1 was performed on the shiitake mushroom stem (S32). That is, an alkali treatment step using a 3% by weight aqueous sodium hydroxide solution was carried out at room temperature of 30.2° C. to obtain an alkali-treated solution containing swollen fruiting bodies of shiitake mushrooms.

In the fiber extraction step (S34), pure water is added to the alkali-treated liquid obtained in the step (S32) to dilute it, and an aqueous solution of hydrochloric acid (HCL) is added to neutralize it. The aqueous solution containing the stalk-swollen fruiting bodies was filtered. Then, a washing process was performed three times in which pure water was added to the filtered material, weakly stirred, and filtered through the net material.
As a result, 525 g of wet mushroom fibers with shiitake stems were extracted (S34). When the solid content concentration of the wet mushroom fiber extracted here was measured, it was 4.5%. This measurement was performed by measuring 20 g out of 525 g of wet mushroom fiber using a moisture meter (infrared moisture meter FD-610 manufactured by Ketsuto Kagaku Kenkyusho Co., Ltd.). This gives about 23.6 g of solids (mushroom fiber) in 525 g of wet mushroom fiber.

In the mixing step (S36), first, 500 g of a dispersion containing dispersed kozo/hemp fibers was prepared. Specifically, 500 g of a dispersion was obtained by adding a slurry of kozo/hemp fibers for adjusting Japanese paper having a solid content (kozo/hemp fibers) weight of 7.1 g to pure water and stirring. 500 g of this dispersion was then placed in a 2 liter (L) plastic container along with 525 g of wet mushroom fibers obtained in step (S34).
In Example 6, 100 ml of a 1% by weight PVA (polyvinyl alcohol) aqueous solution (Nippon Synthetic Chemical Industry Co., Ltd. (currently: Mitsubishi Chemical Corporation) Gosenol (registered trademark) N-300) and 1% by weight glycerin aqueous solution 100 ml was added and stirred for 30 seconds with a commercially available mixer to obtain 1125 g of fiber mixed liquid. The PVA aqueous solution is added as a paper strength agent, and the glycerin aqueous solution is added as a plasticizer.
This fiber mixture contains about 23.6 g of shiitake-patterned mushroom fiber and 7.1 g of kozo/hemp fiber, so the weight ratio of mushroom fiber to non-mushroom-derived fiber is approximately 77:23. ing.

In the drying step (S38), 1125 g of the fiber mixture liquid obtained in the step (S36) is evenly sprinkled on the surface of a 40-mesh mesh sheet and filtered, and the wet sheet-like liquid filtered on the surface of the mesh sheet is filtered. The mixed fibers were dried at ambient temperature.

In Example 6, a tanning step (S61) was further performed in which a tanning treatment was applied to the sheet-like dry mixed fibers obtained in the drying step (S38). In this tanning treatment, the dry blended fiber was immersed in 5 L of a 5% by weight vegetable tannin aqueous solution for 30 seconds, then allowed to stand on a polyethylene plate and dried at normal temperature for 30 minutes, which was repeated three times. Mimosa was used here as a vegetable tannin.
Then, drying at room temperature was performed until the final water content was about 5% by weight to 12% by weight.

In Example 6, a surface treatment step (S63) was further performed after the above-described tanning step (S61).
In the surface treatment step (S63), the surface of the mushroom sheet obtained in the tanning step (S61) was coated with a water-repellent coating agent (Asahiguard manufactured by Meisei Chemical Industry Co., Ltd.).
By applying this water-repellent coating agent, the strength of the mushroom sheet can be increased and the resistance to water wetting can be improved.

In Example 6, four samples were produced as the final mushroom sheet by changing only the drying time in the tanning step (S61).
Example 6-1 shows a mushroom sheet obtained with a drying time of 24 hours, Example 6-2 shows a mushroom sheet obtained with a drying time of 2 hours, and Example 6-3 shows a dried mushroom sheet. The mushroom sheets obtained with drying time of 4 hours are shown, and Example 6-4 shows the mushroom sheets obtained with drying time of 8 hours. The drying time in each example is the drying time in an environment of 80°C.
The results demonstrate that the drying time can vary the thickness and basis weight of the mushroom sheets in the final form. The strength of the mushroom sheets tended to increase with longer drying time.

[Example 7] [Example 8]
In Example 7, the weight of wet mushroom fiber and the weight of non-mushroom-derived fiber used in the mixing step (S36), the number of tanning treatments in the tanning step (S61), and the surface treatment in the surface treatment step (S63) 6 samples (Examples 7-1 to 7-6) were produced as the final mushroom sheet by carrying out the same manufacturing method as in Example 6 above except that the number of times was changed to that shown in Table 3. was done. In Examples 7-5 and 7-6, the tanning step (S61) and the surface treatment step (S63) were not performed.
Furthermore, as Example 8, a mushroom sheet containing no non-mushroom-derived fibers was also produced. The method for producing a mushroom sheet of Example 8 includes the step (S30), step (S32) and step (S34) of Example 6, and 350 g of wet mushroom fiber extracted in step (S34) (solid content (mushroom fiber ) about 15.8 g) was dried into a sheet at room temperature in the same manner as in the step (S16) of Example 1 to obtain a mushroom sheet containing no non-mushroom-derived fibers. In Example 8, the tanning step (S61) and the surface treatment step (S63) were not performed in the same manner as in Examples 7-5 and 7-6. The weight of wet mushroom fiber and the weight of non-mushroom-derived fiber are sometimes referred to as the weight of ingredients.

Table 3 shows the manufacturing conditions for manufacturing six samples (Examples 7-1 to 7-6), the sample of Example 6-1, and the sample of Example 8, as well as measurement results and evaluation results. It is a table.
The strength shown in Table 3 was obtained by evaluating the tear resistance of the mushroom sheet when a force was applied to tear one edge of the mushroom sheet of about 5 cm x 5 cm in a direction intersecting the sheet surface. Specifically, the magnitude of tear resistance (tear resistance) was evaluated as S0<S1<S2<S3<S4 in relative order.
The tensile strength in Table 3 was measured based on JISP8113:2006 (ISO1924-2:1994). A material strength tester manufactured by Shimadzu Corporation (Autograph AG-1) was used as the tester, and obtained in Examples 6-1, 7-1, 7-4, and 8, respectively. A part of the mushroom sheet was cut and used as a test piece. The width of the test piece was 15±0.1 mm, the position of the gripper was adjusted so that the test length (average distance between grip lines) was 180±1 mm, and the tensile speed was 20±5 mm/min. .
The texture (tactile sensation) in Table 3 indicates the result of sensory evaluation of the tactile sensation of the mushroom sheet. Specifically, multiple testers confirmed the tactile sensation of each sample, and felt any of the following: "smooth and moist/smooth and dry/rough". A sensory evaluation was performed for each of the selected samples, and the feeling finally determined as a consensus of the testers is shown in Table 3 as the texture (feel). The "moist" notation in Table 3 indicates an evaluation of "moist and smooth", and the "light" notation indicates an evaluation of "light and smooth."

Each sample is compared below with reference to Table 3.
Regarding the weight ratio of mushroom fibers and non-mushroom-derived fibers (both fiber weight ratios), the three samples of Examples 7-1 to 7-3 and the sample of Example 6-1 were approximately 77:23. They are substantially the same, 67:33 in the sample of Example 7-4, 91:9 in the sample of Example 7-5, and 91:9 in the sample of Example 7-6. The ratio is 83:17, and the sample of Example 8 is 100:0.

<Comparison of tensile strength>
As described above, the tensile strength of each sample (mushroom sheet) of Examples 6-1, 7-1, 7-4 and 8 was measured according to JISP8113.
FIG. 7 is a graph showing the results of a tensile test of each sample of Examples 6-1, 7-1, 7-4 and 8, and Comparative Example. Common copy paper (plain paper) was used for the sample of the comparative example in FIG.
As a result, the maximum test force (N), stroke (mm) and tensile strength (kN/m) when each sample broke were as follows.
・Comparative example: maximum test force = 23.038 N, stroke = about 8 mm, tensile strength = 1.536 kN / m
・Example 6-1: Maximum test force = 21.019 N, stroke = about 31 mm, tensile strength = 1.401 kN / m
・Example 7-1: Maximum test force = 19.323 N, stroke = about 26 mm, tensile strength = 1.288 kN / m
・Example 7-4: Maximum test force = 57.284 N, stroke = about 11 mm, tensile strength = 3.819 kN / m
・Example 8: Maximum test force = 1.867 N, stroke = about 23 mm, tensile strength = 0.124 kN / m

In this way, it was demonstrated that the mushroom sheet in each example had a higher tensile strength with non-mushroom-derived fibers than without, and that the higher the weight ratio of non-mushroom-derived fibers, the higher the tensile strength. .
This result is the same for the strength (tear resistance) shown in Table 3. That is, the strength (S0) of the sample of Example 8, which does not contain non-mushroom-derived fibers, is the lowest, and the strength (S4) of the sample of Example 7-4, which has a large weight ratio of non-mushroom-derived fibers, is the highest. . Further, there is a tendency that the higher the weight ratio of non-mushroom-derived fibers, the higher the strength.

<Comparison between Example 7-1 and Example 7-2>
The sample of Example 7-1 and the sample of Example 7-2 differ in the number of tanning treatments.
The strength of each sample is stronger in Example 7-2 than in Example 7-1, and the texture of each sample is moist and smooth in Example 7-1, and Example 7-2 It has a smooth and silky feel to the touch.
Further, the thickness and basis weight of Example 7-1 are larger than those of Example 7-2.
From the above, when the number of tanning treatments is large, the strength increases, but the thickness and basis weight decrease, and the moist feeling can be reduced to control the smooth feel. It can be seen that the thickness and the basis weight increased while the moist feeling also increased.
This is achieved by increasing the strength of the tanning process by increasing the cross-linking points, increasing the strength by increasing the hydrogen bonding associated with controlling the elution of the plasticizer (glycerin) between the fibers into the water-soluble portion of the tanning agent, and moistening the texture ( It shows that it is possible to control the texture from moist to dry.

<Comparison between Example 7-2 and Example 6-1>
The sample of Example 7-2 and the sample of Example 6-1 differ in the amount of raw materials (wet mushroom fiber and non-mushroom derived fiber weight).
The strength of each sample is approximately the same between Example 6-1 and Example 7-2, and the texture of each sample is moist in Example 6-1 and moist in Example 7-2. It has a smooth feel.
Further, the thickness of Example 6-1 is larger than that of Example 7-2, and the basis weight of Example 7-2 is larger than that of Example 6-1.

<Comparison between Example 7-1 and Example 7-4>
The sample of Example 7-1 and the sample of Example 7-4 differed in the amounts of raw materials (wet mushroom fiber and non-mushroom derived fiber weight) and weight ratio of both fibers.
The strength and tensile strength of each sample are stronger in Example 7-4 than in Example 7-1, and the texture of each sample is moist and smooth in Example 7-1. 7-4 shows a light and smooth touch.
Further, the thickness of Example 7-4 is larger than that of Example 7-1, and the basis weight of Example 7-1 is larger than that of Example 7-4.

<Comparison between Example 7-1, Example 7-5, Example 7-6, and Example 8>
Each sample of Example 7-1, Example 7-5, Example 7-6, and Example 8 had the same weight of wet mushroom fiber, but different weight ratios of non-mushroom-derived fiber and mushroom fiber. there is
The intensity of each sample is stronger in Example 7-6 (S1) than in Examples 7-5 and 8 (S0), and in Example 7-1 (S2) than in Example 7-6 (S1). is stronger, and becomes stronger as the weight ratio of non-mushroom-derived fibers increases.
The texture of each sample indicates a moist and smooth feel.

Comparison results between Example 7-2 and Example 6-1, comparison results between Example 7-1 and Example 7-4, and Example 7-1, Example 7-5, and Example 7-6 According to the comparison results of Example 8, when the weight ratio of non-mushroom-derived fibers increases, the tensile strength and strength increase, but the moist feeling decreases, and when the weight ratio of non-mushroom-derived fibers decreases, the tensile strength and strength decrease. On the other hand, it can be seen that the moist feeling increases.
Moreover, when the weight ratio of non-mushroom-derived fibers is 9% or less, the difference in strength shown in Table 3 is not so large. It can be seen that when the weight ratio of the non-mushroom-derived fibers is about 23%, it has a moist and smooth feel.

Thus, according to Examples 7 and 8, the mushroom sheet contains the mushroom fiber extracted from the fruiting body of the mushroom, so that it has a leather-like soft and smooth texture and is suitable as a sheet. It has been demonstrated that it can have strength.
Furthermore, according to Examples 7 and 8, it was demonstrated that the mushroom sheet can improve the tensile strength and strength of the sheet by containing non-mushroom-derived fibers.
In addition, in order for the mushroom sheet to have a soft and smooth texture like leather while having appropriate tensile strength and strength, the weight ratio of mushroom fibers to non-mushroom-derived fibers should be 83:17 rather than 91:9. 77:23 was found to be more preferable than 83:17 or 67:33. That is, the weight ratio of mushroom fibers to non-mushroom-derived fibers is more preferably in the range of 90:10 to 60:40, and more preferably in the range of 80:20 to 65:35. Proven.
It was also demonstrated that the number of tanning treatments and the amount of raw material (wet mushroom fiber and non-mushroom derived fiber weight) can increase or decrease the thickness and basis weight to change the strength and texture.

The above content can also be specified as follows.
(Appendix 1)
A mushroom sheet containing mushroom fibers extracted from a mushroom fruiting body.
(Appendix 2)
The mushroom sheet according to Appendix 1, further containing non-mushroom-derived fibers.
(Appendix 3)
The non-mushroom-derived fibers are non-mushroom-derived cellulose fibers,
The weight ratio of the mushroom fiber to the non-mushroom-derived cellulose fiber is from 99:1 to 50:50.
The mushroom sheet according to appendix 2.
(Appendix 4)
A method for producing a mushroom sheet according to Appendix 1,
an alkali treatment step of treating the fruiting body with a low-concentration alkaline aqueous solution having a pH of 12.2 or more and pH 13.6 or less at room temperature in order to obtain a swollen fruiting body in which mushroom fibers in the fruiting body of the mushroom are swollen;
a fiber extraction step of extracting wet mushroom fibers by filtering the swollen fruit bodies obtained in the alkali treatment step;
a drying step of drying the wet mushroom fibers extracted in the fiber extraction step into a sheet;
A method for producing a mushroom sheet comprising:
(Appendix 5)
A method for producing a mushroom sheet according to Appendix 2 or 3,
an alkali treatment step of treating the fruiting body with a low-concentration alkaline aqueous solution having a pH of 12.2 or more and pH 13.6 or less at room temperature in order to obtain a swollen fruiting body in which mushroom fibers in the fruiting body of the mushroom are swollen;
a fiber extraction step of extracting wet mushroom fibers by filtering the swollen fruit bodies obtained in the alkali treatment step;
A mixing step of obtaining a fiber mixed liquid in which the non-mushroom-derived fibers and the mushroom fibers are dispersed and mixed by stirring and mixing the non-mushroom-derived fibers, the wet mushroom fibers extracted in the fiber extraction step, and a liquid dispersion medium;
a drying step of filtering the fiber mixture obtained in the mixing step and drying the separated wet mixed fibers into a sheet;
A method for producing a mushroom sheet comprising:
(Appendix 6)
In the fiber extraction step, the wet mushroom fiber is extracted by diluting, neutralizing, and filtering the swollen fruiting body,
In the mixing step, the wet mushroom fibers obtained by diluting, neutralizing, and filtering the swollen fruiting bodies in the fiber extraction step, the non-mushroom-derived fibers, and the liquid dispersion medium are stirred and mixed.
A method for producing a mushroom sheet according to appendix 5.
(Appendix 7)
The mixing step includes a plasticizing step of adding a plasticizer so that the liquid dispersion medium, the non-mushroom-derived fibers, and the wet mushroom fibers are stirred and mixed together.
A method for producing a mushroom sheet according to appendix 5 or 6.
(Appendix 8)
8. The method for producing a mushroom sheet according to any one of appendices 5 to 7, further comprising a tanning step of adding a tanning agent to the mushroom sheet obtained by the drying step.
(Appendix 9)
The non-mushroom-derived fibers are non-mushroom-derived cellulose fibers,
In the mixing step, the dispersion liquid in which the non-mushroom-derived cellulose fibers are dispersed in the liquid dispersion medium and the wet mushroom fibers are stirred and mixed,
The weight of the dispersion administered in the mixing step is such that the weight ratio of the mushroom fibers and the non-mushroom-derived cellulose fibers in the fiber mixture is a predetermined value within the range of 99:1 to 50:50. determined according to the concentration of the non-mushroom-derived cellulose fibers in the dispersion and the concentration of the mushroom fibers in the wet mushroom fibers and the weight of the wet mushroom fibers,
A method for producing a mushroom sheet according to any one of Appendices 5 to 8.
(Appendix 10)
The fruiting body is the end of the mushroom stalk that is excised in an edible mushroom product.
A method for producing a mushroom sheet according to any one of Appendices 4 to 9.
(Appendix 11)
The low-concentration alkaline aqueous solution used in the alkali treatment step is a sodium hydroxide aqueous solution of 0.07% by weight or more and 8% by weight or less.
A method for producing a mushroom sheet according to any one of Appendices 4 to 10.
(Appendix 12)
In the fiber extraction step, filtration is performed using a mesh material having a mesh size of 30 or more and 150 or less and an opening of 0.1 mm or more and 0.5 mm or less.
A method for producing a mushroom sheet according to any one of Appendices 4 to 11.
(Appendix 13)
The mushroom fibers have an average fiber width of 50 μm or more and 500 μm or less and an average fiber length of 0.5 mm or more and 5 mm or less.
4. The mushroom sheet according to any one of Appendices 1 to 3.
(Appendix 14)
The fruiting body is the end of the mushroom stalk that is excised in an edible mushroom product.
The mushroom sheet according to any one of appendices 1 to 3 or appendix 12.

This application claims priority based on the Japanese application (Japanese Patent Application No. 2021-188228) filed on November 18, 2021, and incorporates all of its disclosure herein.

Claims

A mushroom sheet containing mushroom fibers extracted from mushroom fruiting bodies.
The mushroom sheet according to claim 1, further containing non-mushroom-derived fibers.
The non-mushroom-derived fibers are non-mushroom-derived cellulose fibers,
The weight ratio of the mushroom fiber to the non-mushroom-derived cellulose fiber is from 99:1 to 50:50.
The mushroom sheet according to claim 2.
A method for producing a mushroom sheet according to claim 1,
an alkali treatment step of treating the fruiting body with a low-concentration alkaline aqueous solution having a pH of 12.2 or more and pH 13.6 or less at room temperature in order to obtain a swollen fruiting body in which mushroom fibers in the fruiting body of the mushroom are swollen;
a fiber extraction step of extracting wet mushroom fibers by filtering the swollen fruit bodies obtained in the alkali treatment step;
a drying step of drying the wet mushroom fibers extracted in the fiber extraction step into a sheet;
A method for producing a mushroom sheet comprising:
A method for producing a mushroom sheet according to claim 2 or 3,
an alkali treatment step of treating the fruiting body with a low-concentration alkaline aqueous solution having a pH of 12.2 or more and pH 13.6 or less at room temperature in order to obtain a swollen fruiting body in which mushroom fibers in the fruiting body of the mushroom are swollen;
a fiber extraction step of extracting wet mushroom fibers by filtering the swollen fruit bodies obtained in the alkali treatment step;
A mixing step of obtaining a fiber mixed liquid in which the non-mushroom-derived fibers and the mushroom fibers are dispersed and mixed by stirring and mixing the non-mushroom-derived fibers, the wet mushroom fibers extracted in the fiber extraction step, and a liquid dispersion medium;
a drying step of filtering the fiber mixture obtained in the mixing step and drying the separated wet mixed fibers into a sheet;
A method for producing a mushroom sheet comprising:
In the fiber extraction step, the wet mushroom fiber is extracted by diluting, neutralizing, and filtering the swollen fruiting body,
In the mixing step, the wet mushroom fibers obtained by diluting, neutralizing, and filtering the swollen fruiting bodies in the fiber extraction step, the non-mushroom-derived fibers, and the liquid dispersion medium are stirred and mixed.
The method for producing the mushroom sheet according to claim 5.
The mixing step includes a plasticizing step of adding a plasticizer so that the liquid dispersion medium, the non-mushroom-derived fibers, and the wet mushroom fibers are stirred and mixed together.
The method for producing the mushroom sheet according to claim 5 or 6.
The method for producing a mushroom sheet according to any one of claims 5 to 7, further comprising a tanning step of adding a tanning agent to the mushroom sheet obtained by the drying step.
The non-mushroom-derived fibers are non-mushroom-derived cellulose fibers,
In the mixing step, the dispersion liquid in which the non-mushroom-derived cellulose fibers are dispersed in the liquid dispersion medium and the wet mushroom fibers are stirred and mixed,
The weight of the dispersion administered in the mixing step is such that the weight ratio of the mushroom fibers and the non-mushroom-derived cellulose fibers in the fiber mixture is a predetermined value within the range of 99:1 to 50:50. determined according to the concentration of the non-mushroom-derived cellulose fibers in the dispersion and the concentration of the mushroom fibers in the wet mushroom fibers and the weight of the wet mushroom fibers,
A method for producing a mushroom sheet according to any one of claims 5 to 8.
The fruiting body is the end of the mushroom stalk that is excised in an edible mushroom product.
A method for producing the mushroom sheet according to any one of claims 4 to 9.
The low-concentration alkaline aqueous solution used in the alkali treatment step is a sodium hydroxide aqueous solution of 0.07% by weight or more and 8% by weight or less.
A method for producing a mushroom sheet according to any one of claims 4 to 10.
In the fiber extraction step, filtration is performed using a mesh material having a mesh size of 30 or more and 150 or less and an opening of 0.1 mm or more and 0.5 mm or less.
A method for producing a mushroom sheet according to any one of claims 4 to 11.
The mushroom fibers have an average fiber width of 50 μm or more and 500 μm or less and an average fiber length of 0.5 mm or more and 5 mm or less.
The mushroom sheet according to any one of claims 1 to 3.
The fruiting body is the end of the mushroom stalk that is excised in an edible mushroom product.
13. The mushroom sheet according to any one of claims 1 to 3 or claim 12.