Method for processing edible mushroom
Irradiating mushrooms with UV light between 200 nm and 240 nm produces vitamin D while minimizing human exposure risks and taste degradation, enhancing mushroom quality.
Patent Information
- Application Number
- JP2024122526
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-07-29
- Publication Date
- 2026-02-10
AI Technical Summary
Ultraviolet light can have adverse effects on the human body depending on its wavelength, and existing methods for producing vitamin D in mushrooms using UV light may pose risks to humans in proximity.
Irradiate edible mushrooms with ultraviolet light having a peak wavelength between 200 nm and less than 240 nm, which is absorbed by the stratum corneum and does not penetrate further, minimizing impact on the human body while producing vitamin D.
This method allows for vitamin D production in mushrooms while significantly reducing the risk to humans nearby and suppressing taste deterioration, with controlled UV exposure during cultivation or after harvesting.
Smart Images
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Abstract
Description
[Technical Field]
[0001] The present invention relates to a method for processing edible mushrooms, and in particular to a method for processing edible mushrooms by irradiating them with ultraviolet light. [Background technology]
[0002] It has been known that vitamin D is produced in human skin when exposed to ultraviolet light. Specifically, vitamin D is produced in the skin when a vitamin D precursor (7-dehydrocholesterol) is exposed to ultraviolet light.
[0003] It is also known that vitamin D is produced in mushrooms when exposed to ultraviolet light (Non-Patent Document 1). The mechanism by which vitamin D is produced in mushrooms is said to be very similar to that in human skin. [Prior art documents] [Non-patent literature]
[0004] [Non-Patent Document 1] Kiribuchi et al., "Study on Vitamin D2 Content in Various Mushrooms by Ultraviolet Irradiation," Journal of the Japanese Society of Home Economics, 1990, Vol. 41, No. 5, pp. 401-406 Summary of the Invention [Problem to be solved by the invention]
[0005] However, ultraviolet light may have adverse effects on the human body depending on its wavelength.
[0006] In view of the above problems, the present invention aims to provide a method for processing edible mushrooms in which vitamin D is produced by irradiating edible mushrooms with ultraviolet light while minimizing the effects on the human body. [Means for solving the problem]
[0007] The method for processing edible mushrooms according to the present invention is characterized by including a step of irradiating edible mushrooms with ultraviolet light having a peak wavelength in the range of 200 nm or more and less than 240 nm.
[0008] Even if ultraviolet light with a peak wavelength in the range of 200 nm or more but less than 240 nm is irradiated onto human skin, it is absorbed by the stratum corneum and does not penetrate further inward (toward the basal layer). Because the keratinocytes contained in the stratum corneum are dead cells, there is almost no risk of DNA damage due to absorption by living cells in the spinous layer, granular layer, or dermis, as occurs with irradiation with ultraviolet light at a wavelength of 254 nm. Therefore, there is almost no impact on the human body. Therefore, according to the above method, it is possible to irradiate ultraviolet light onto edible mushrooms to produce vitamin D while minimizing the impact on the human body, even in an environment where humans are present nearby.
[0009] In addition, in the edible mushroom processing method according to the present invention, the step of irradiating with ultraviolet light may be carried out during cultivation of the edible mushrooms.
[0010] By irradiating edible mushrooms with ultraviolet rays during cultivation, it is possible to suppress deterioration in the taste of the edible mushrooms due to ultraviolet irradiation.
[0011] In addition, in the edible mushroom processing method according to the present invention, the step of irradiating with ultraviolet light may be carried out after harvesting the edible mushrooms.
[0012] By irradiating edible mushrooms with ultraviolet light after harvesting, vitamin D can be easily produced in the mushrooms.
[0013] In the method for processing edible mushrooms according to the present invention, the ultraviolet irradiation step is carried out at a rate of 162 mJ / cm 2 The method may be a step of irradiating the substrate with ultraviolet light so as to achieve the above exposure dose.
[0014] By irradiating with ultraviolet light so as to achieve the above exposure amount, it is possible to suppress deterioration in the taste of edible mushrooms due to ultraviolet light irradiation.
[0015] In the method for processing edible mushrooms according to the present invention, the ultraviolet irradiation step is carried out at a rate of 10 μW / cm 2 The method may also include a step of irradiating the ultraviolet light at an illuminance of:
[0016] By irradiating with ultraviolet light at the above illuminance, it is possible to suppress deterioration in the taste of edible mushrooms due to irradiation with ultraviolet light.
[0017] In addition, in the method for processing edible mushrooms according to the present invention, the step of irradiating with ultraviolet light may be repeated multiple times, with the non-irradiation time between each step being less than 2 hours.
[0018] According to this method, the growth of edible mushrooms is not inhibited by ultraviolet irradiation. [Brief explanation of the drawings]
[0019] [Figure 1] 1 is a diagram showing a schematic diagram of an embodiment of the edible mushroom processing method of the present invention. [Figure 2] Graph showing the relationship between protein extinction coefficient and wavelength [Figure 3A] Taste sensor test results for enoki mushrooms irradiated with ultraviolet light after harvest [Figure 3B] Test results using a taste sensor on Bunashimeji mushrooms irradiated with ultraviolet light after harvest [Figure 4] A graph showing the change in free amino acid content in Enoki mushrooms relative to the amount of UV exposure. [Figure 5] A graph showing the change in free amino acid content in Bunashimeji mushrooms relative to the amount of UV exposure. [Figure 6] Graph showing the change in total amino acid content of Enokitake mushrooms and Bunashimeji mushrooms with respect to the amount of UV exposure DETAILED DESCRIPTION OF THE INVENTION
[0020] An embodiment of the edible mushroom processing method according to the present invention will be described below.
[0021] Figure 1 is a diagram showing an example of a scene in which an edible mushroom processing method is carried out. Edible mushrooms 20 being cultivated on a cultivation shelf 30 are irradiated with ultraviolet light L1 from a light source 1. The light source 1 is built into a light source device 10.
[0022] The edible mushroom 20 is not particularly limited, but examples thereof include mushrooms of the family Amphicaceae, to which Flammulina velutipes belongs, and mushrooms of the family Amphicaceae, to which Bunashimeji mushroom belongs. Fig. 1 shows a Flammulina velutipes as the edible mushroom 20.
[0023] The ultraviolet light L1 emitted from the light source 1 has a peak wavelength in the range of 200 nm or more and less than 240 nm. Even if ultraviolet light L1 with a wavelength of 200 nm or more and less than 240 nm is irradiated onto human skin, it is absorbed by the stratum corneum of the skin and does not travel further inside (towards the basal layer), so there is very little risk of damage to human DNA.
[0024] Furthermore, ultraviolet light L1 with a wavelength of 200 nm or more but less than 240 nm can sterilize or inhibit the growth (bacteriostasis) of unnecessary bacteria other than the edible mushrooms 20. Here, the term "bacteria" encompasses bacteria and mold (fungi). Although edible mushrooms 20 are a type of fungus, irradiating the edible mushrooms 20 with ultraviolet light L1 does not sterilize the interior of the edible mushrooms 20 because they have large fruiting bodies. However, mold (e.g., Aspergillus, Cladosporium, Penicillium) and other microorganisms attached to the surface of the edible mushrooms 20 or present in the air are sterilized. Thus, irradiating the edible mushrooms 20 with ultraviolet light L1 can sterilize or bacteriostasis unnecessary bacteria while producing vitamin D.
[0025] Furthermore, after extensive research, the inventors discovered that irradiating edible mushrooms 20 with ultraviolet light L1 increases the amount of specific amino acids. Generally, similar to the effect of sun-drying, irradiation with ultraviolet light in wavelengths such as UV-B degrades proteins through the action of proteases, resulting in an increase in amino acids. On the other hand, ultraviolet light L1 with a wavelength of 200 nm or more but less than 240 nm is thought to inactivate proteases and inhibit the increase in amino acids. However, the inventors speculate that ultraviolet light L1 with a wavelength of 200 nm or more but less than 240 nm directly degrades proteins and increases amino acids (see the relationship between the extinction coefficient of proteins and wavelength, described below). Furthermore, ultraviolet light with a wavelength of 240 nm or more has low absorption by proteins and therefore is almost unable to directly degrade proteins. However, irradiation with ultraviolet light with a wavelength of 240 nm or more does not inactivate proteases, resulting in the decomposition of proteins through the action of proteases and the increase in amino acids.
[0026] FIG. 2 is a graph showing the relationship between the extinction coefficient of proteins and wavelength. FIG. 2 also shows the relationship between the molar extinction coefficient of the amino acids (tryptophan, glycylglycine, cystine, and tyrosine) that make up proteins and wavelength. For example, tryptophan and tyrosine absorb ultraviolet light with a wavelength of around 222 nm at an order of magnitude higher than ultraviolet light with a wavelength of around 254 nm. Glycylglycine, on the other hand, absorbs almost no ultraviolet light with a wavelength of 254 nm. This indicates that ultraviolet light with a wavelength of around 222 nm is more likely to decompose proteins to produce amino acids than ultraviolet light with a wavelength of around 254 nm. Furthermore, ultraviolet light L1 within the range of 200 nm or more but less than 240 nm, like ultraviolet light with a wavelength of around 222 nm, has a high extinction coefficient for proteins, and is therefore presumed to be more likely to decompose proteins.
[0027] Any light source 1 can be used as long as it is capable of emitting light with a peak wavelength within the above range. As an example, the light source 1 is a KrCl excimer lamp, a KrBr excimer lamp, or an LED. When an excimer lamp is used as the light source 1, the structure of the excimer lamp is not important.
[0028] Light source 1 is 10 μW / cm for 20 edible mushrooms. 2 The output is adjusted so that ultraviolet light L1 is irradiated at the following illuminance: As an example, as shown in Fig. 1, light source device 10 includes a control unit 2 for controlling the light output of light source 1, and this control unit 2 may set the light output of light source 1 so that the illuminance range is met.
[0029] Here, the "illuminance" of the ultraviolet light L1 irradiated onto the edible mushrooms 20 may be considered to be the illuminance on the surface of the edible mushrooms 20. In other words, an illuminance meter is installed where the edible mushrooms 20 are placed, and the value detected when ultraviolet light L1 is irradiated from the light source 1 can be used as the "illuminance."
[0030] As described above, the method for processing edible mushrooms in this embodiment includes a step of irradiating edible mushrooms 20 with ultraviolet light L1 having a peak wavelength in the range of 200 nm or more and less than 240 nm. This method allows the edible mushrooms 20 to be irradiated with ultraviolet light L1, thereby producing vitamin D while minimizing the effects on the human body. Furthermore, in the case of edible mushrooms 20 currently being cultivated, vitamin D can be produced while sterilizing or stabilizing excess bacteria. Furthermore, this method can increase the amino acid content of the edible mushrooms 20.
[0031] [About Vitamin D Production] An experiment was conducted in which ultraviolet light L1 was irradiated onto the cultivated Enoki mushroom. The light source 1 for ultraviolet light L1 was a KrCl excimer lamp with a peak wavelength of 222 nm. The irradiance of ultraviolet light L1 was 10 μW / cm 2 The ultraviolet light L1 irradiation conditions were as follows: light source 1 was on for 2, 4.5, 7, and 13 hours a day, and off for the remaining hours (22, 19.5, 17, and 11 hours, respectively). Cultivation was carried out under these irradiation conditions for two weeks. The results are shown in Table 1.
[0032] [Table 1]
[0033] According to the above results, irradiating the enoki mushrooms with ultraviolet light L1 during cultivation produced more than two orders of magnitude more vitamin D than unirradiated ones. Taste evaluations were also conducted by seven evaluators, and many rated the ones irradiated with ultraviolet light L1 as more delicious than the unirradiated ones. In other words, irradiating the edible mushrooms 20 with ultraviolet light L1 during cultivation can suppress the deterioration of the taste of the edible mushrooms 20 due to ultraviolet light L1 irradiation, and may even improve the taste of some types of edible mushrooms 20.
[0034] As shown in this experiment, when irradiating edible mushrooms 20 with ultraviolet light L1 during cultivation, the process of irradiating ultraviolet light L1 is preferably repeated multiple times, with the non-irradiation time between each iteration being less than two hours. If the non-irradiation time is less than two hours, mold can be stabilised and the edible mushrooms 20 can be protected from mold. On the other hand, if the non-irradiation time is more than two hours, mold may grow and inhibit the growth of the edible mushrooms 20.
[0035] Next, we conducted an experiment in which we irradiated harvested Enoki mushrooms with ultraviolet light L1. The light source 1 for ultraviolet light L1 was a KrCl excimer lamp with a peak wavelength of 222 nm. The irradiance of ultraviolet light L1 was 1000 μW / cm 2 The enoki mushrooms purchased from the supermarket were loosened and irradiated with UV light L1 on one side, then turned over and irradiated with UV light L1 on the other side. The UV light L1 irradiation conditions were such that the total exposure to the enoki mushrooms was 144 mJ / cm2. 2 , 324 mJ / cm 2 , 504 mJ / cm 2 , 936 mJ / cm 2 The results are shown in Table 2.
[0036] [Table 2]
[0037] According to the above results, irradiating harvested enoki mushrooms with UV-L1 light produced more than two orders of magnitude more vitamin D than unirradiated ones. Seven evaluators also evaluated the taste of the mushrooms irradiated with UV-L1 light, and many of them felt that the flavor was worse than that of unirradiated ones. This indicates that excessively high light intensity can lead to a deterioration in taste.
[0038] Next, we conducted an experiment in which we irradiated harvested Bunashimeji mushrooms with ultraviolet light L1. The light source 1 for ultraviolet light L1 was a KrCl excimer lamp with a peak wavelength of 222 nm. The irradiance of ultraviolet light L1 was 1000 μW / cm 2 Bunashimeji mushrooms purchased from a supermarket were loosened and irradiated with ultraviolet light L1 on one side, then turned over and irradiated with ultraviolet light L1 on the other side. The irradiation conditions for ultraviolet light L1 were such that the total exposure to the Bunashimeji mushrooms was 144 mJ / cm2. 2 , 324 mJ / cm 2 , 504 mJ / cm 2 , 936 mJ / cm 2 The results are shown in Table 3.
[0039] [Table 3]
[0040] According to the above results, irradiating harvested Bunashimeji with UV-L1 light produced more than double the amount of vitamin D compared to unirradiated mushrooms. Five panelists also evaluated the taste, and many of the judges said that the ones irradiated with UV-L1 had a better aroma than the unirradiated ones, and that the longer the irradiation time, the better the aroma became. Bunashimeji's results differed from those of enokitake mushrooms.
[0041] [Changes in taste] Next, the harvested enokitake mushrooms and bunashimeji mushrooms were irradiated with ultraviolet light L1, and their taste was examined using a taste sensor. The taste sensor used was the TS-5000Z manufactured by Intelligent Sensor Technology Co., Ltd. The light source 1 for ultraviolet light L1 was a KrCl excimer lamp with a peak wavelength of 222 nm. The illuminance of ultraviolet light L1 was 1000 μW / cm 2 The irradiation conditions for ultraviolet L1 were as follows: the total exposure dose for Enokitake and Bunashimeji was 72 mJ / cm 2 , 162 mJ / cm 2 , 252 mJ / cm 2 , 468mJ / cm 2 The light source 1 was turned on so that the light intensity was 1. The results are shown in Figures 3A and 3B.
[0042] As shown in Figures 3A and 3B, irradiation with ultraviolet light L1 increased bitterness and unpleasant flavors depending on the exposure dose. In particular, for Enoki mushrooms, at 72 mJ / cm 2 The bitterness and unpleasant taste of the fruit irradiated with ultraviolet light L1 increased significantly. However, as the exposure increased, the bitterness and unpleasant taste were gradually removed, and there was no difference between the fruit and the unirradiated fruit. Therefore, from the viewpoint of preventing the deterioration of taste, it is recommended to use 162 mJ / cm 2 It is preferable to irradiate ultraviolet light L1 so as to achieve the above exposure amount.
[0043] [About amino acid content] After harvesting, the free amino acids of the enokitake mushrooms and bunashimeji mushrooms were irradiated with ultraviolet light L1 under the above conditions and measured. The free amino acid content was measured by high-performance liquid chromatography (HPLC). The results are shown in Tables 4 and 5.
[0044] [Table 4]
[0045] [Table 5]
[0046] Figure 4 shows a graph of the free amino acids whose concentrations changed significantly with increasing exposure dose from the results in Table 4. As shown in Figure 4, when enokitake mushrooms were irradiated with UV light L1, the levels of L-serine, L-alanine (responsible for umami and sweetness), L-methionine (responsible for bitterness), and γ-aminobutyric acid (GABA) increased with increasing exposure dose. In particular, γ-aminobutyric acid (GABA) ultimately increased by approximately 30 mg (approximately 35%) at 468 mJ compared to unirradiated mushrooms.
[0047] Furthermore, L-Ornithine did not continue to increase with the amount of exposure, but rather showed a sharp decrease at 72 mJ and then a steady increase, ultimately increasing by approximately 40 mg (approximately 35%) compared to unexposed samples. It is said that approximately 10 mg of L-Ornithine is contained in 35 clams, so approximately 40 mg is equivalent to the amount in approximately 140 clams.
[0048] Figure 5 shows a graph of the free amino acids whose concentrations changed significantly with increasing exposure dose from the results in Table 5. As shown in Figure 5, when Bunashimeji mushrooms were irradiated with UV L1, the concentration did not continue to increase with increasing exposure dose, but rather decreased at 72 mJ and 162 mJ, but then increased again. Ultimately, L-glutamic acid, L-glutamine, L-alanine (related to umami and sweetness), and L-ornithine increased compared to unirradiated mushrooms. In particular, L-ornithine increased by approximately 40 mg (approximately 35%), equivalent to the amount of approximately 140 clams.
[0049] Figure 6 shows the change in the total free amino acid content of enokitake and bunashimeji mushrooms relative to the amount of UV light exposure. As the amount of exposure increased, the total free amino acid content increased for both enokitake and bunashimeji mushrooms. Ultimately, the total free amino acid content of both enokitake and bunashimeji mushrooms increased by approximately 1.3 times compared to unirradiated mushrooms.
[0050] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configurations should not be considered to be limited to these embodiments. The scope of the present invention is defined not only by the description of the above embodiments but also by the claims, and further includes all modifications within the meaning and scope of the claims.
[0051] The structures employed in the above-described embodiments can be employed in any other embodiment. The specific configurations of the components are not limited to the above-described embodiments, and various modifications are possible within the scope of the present invention.
[0052] [Other embodiments] In the edible mushroom processing method according to the above embodiment, the step of irradiating with ultraviolet light L1 is carried out during the cultivation of the edible mushrooms 20. However, the edible mushroom processing method is not limited to this method. For example, the step of irradiating with ultraviolet light L1 may be carried out after the edible mushrooms 20 are harvested. According to this method, irradiating the harvested edible mushrooms 20 with ultraviolet light L1 produces vitamin D and increases amino acids. [Explanation of symbols]
[0053] 1:Light source 2: Control section 10:Light source device 20: Edible mushrooms 30:Cultivation shelf L1: Ultraviolet light
Claims
1. A method for processing edible mushrooms, comprising the step of irradiating edible mushrooms with ultraviolet light having a peak wavelength in the range of 200 nm or more and less than 240 nm.
2. The method for processing edible mushrooms according to claim 1, wherein the step of irradiating with ultraviolet light is carried out during cultivation of the edible mushrooms.
3. The method for processing edible mushrooms according to claim 1, wherein the step of irradiating with ultraviolet light is carried out after the edible mushrooms are harvested.
4. The step of irradiating ultraviolet light is 162 mJ / cm ２ The method for processing edible mushrooms according to claim 1 or 3, characterized in that the ultraviolet light is irradiated so as to achieve an exposure amount of at least 1000 nm.
5. The step of irradiating ultraviolet light is performed at a concentration of 10 μW / cm ２ The method for processing edible mushrooms according to claim 1 or 2, characterized in that the ultraviolet light is irradiated at an illuminance of 1000 nm or less.
6. The method for processing edible mushrooms according to claim 2, characterized in that the ultraviolet irradiation step is repeated multiple times, and the non-irradiation time between each step is less than 2 hours.