Pleurotus citrinopileatus extract

Abstract

To provide technology of Pleurotus citrinopileatus extract with less foreign taste and nasty smell.SOLUTION: Pleurotus citrinopileatus extract contains ergothioneine and amino-acid. Concentration of ergothioneine is 40 mg / g or more and 200 mg / g or less. When the total sum of contents of valine, histidine, glutamic acid, asparagine acid, arginine, alanine, lysine, threonine, glycine, serine, cystine, leucine, proline, phenylalanine, isoleucine, tyrosine, tryptophan, and methionine is set to be the total amount of amino acid, the content of ergothioneine relative to the total amount of amino acid is 0.12 or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a Pleurotus cornucopiae extract. [Background technology]

[0002] Recent research has identified a transporter, Carnitine / organic cation transporter 1 (OCTN1), that selectively uptakes ergothioneine, and it has been found that ergothioneine is localized in mammalian organs such as the liver and small intestine, as well as in the brain, which is part of the nervous system (see Non-Patent Document 1). Ergothioneine, which is actively taken up in this way, is thought to be closely involved in biological functions, and active research is being conducted on it. For example, Non-Patent Document 2 reports its effects on brain function. Furthermore, ergothioneine is expected to be effective on the skin due to its antioxidant properties, and ergothioneine is attracting attention for its use in the fields of food and cosmetics.

[0003] Ergothioneine is thought to play an important role in biological functions, but since it is not biosynthesized in mammals, it must be ingested from an external source. However, ergothioneine is generally expensive and rare, making it difficult to ingest.

[0004] Foods containing relatively high amounts of ergothioneine include mushrooms and fermented foods using koji mold. It has been proposed to produce ergothioneine using mushrooms as a raw material. For example, Patent Document 1 describes that ergothioneine can be produced from Armillaria glabra (Armillaria genus), Shimeji mushroom (Hypsifera genus), Coprinus comatus (Coprinus genus), Flammulina velutipes (Flamingula velutipes), Pleurotus oyster mushroom (Pleurotus eryngii), and Pleurotus umbellata (Pleurotus oyster) (Pleurotus oyster) (Pleurotus eryngii). Ergothioneine obtained from mushrooms can also be purified and used by the method described in Patent Document 2, for example. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-223051 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-126863 [Non-patent literature]

[0006] [Non-Patent Document 1] Pharmaceutical Research.2010;27:832-840 [Non-patent document 2] Pharmacology and Therapeutics Volume 48, Issue 4, 685-697(2020) Summary of the Invention [Problem to be solved by the invention]

[0007] Conventionally, mushroom extracts containing ergothioneine have had the problem of exhibiting an unpleasant taste and odor. The present invention has been made in consideration of the above-mentioned problems, and aims to provide a Pleurotus cornucopiae extract that has little unpleasant taste or odor. [Means for solving the problem]

[0008] One embodiment of the present invention is a Pleurotus cornucopiae extract containing ergothioneine and amino acids, wherein the ergothioneine concentration is 40 mg / g or more and 200 mg / g or less, and the ergothioneine content relative to the total amino acid content is 0.12 or more, where the sum of the contents of valine, histidine, glutamic acid, aspartic acid, arginine, alanine, lysine, threonine, glycine, serine, cystine, leucine, proline, phenylalanine, isoleucine, tyrosine, tryptophan, and methionine is taken as the total amino acid content. In the Pleurotus cornucopiae extract of the above embodiment, the content of the ergothioneine relative to the total content of histidine, cystine, and methionine may be 0.40 or more. The Pleurotus cornucopiae extract of the above embodiment may be obtained by extracting Pleurotus cornucopiae mycelia in the presence of water at 10 to 100° C. The Pleurotus cornucopiae mycelia may be a dried product. Another aspect of the present invention is a method for producing a Tamogitake extract, which comprises the steps of culturing Tamogitake in a liquid with stirring to obtain Tamogitake mycelium, recovering the Tamogitake mycelium, and adding the recovered Tamogitake mycelium to water at 10 to 100°C to obtain a Tamogitake extract. [Effects of the Invention]

[0009] According to the present invention, a technology is provided for a Pleurotus cornucopiae extract with little off-taste or off-odor. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Pleurotus ulmoides extract) The Pleurotus cornucopiae extract according to the embodiment contains ergothioneine and an amino acid.

[0011] In the Pleurotus cornucopiae extract of this embodiment, the concentration of ergothioneine is preferably 40 mg / g or more and 200 mg / g or less.

[0012] The amino acids contained in the maitake mushroom extract of this embodiment include valine, histidine, glutamic acid, aspartic acid, arginine, alanine, lysine, threonine, glycine, serine, cystine, leucine, proline, phenylalanine, isoleucine, tyrosine, tryptophan, and methionine. When the sum of the contents of valine, histidine, glutamic acid, aspartic acid, arginine, alanine, lysine, threonine, glycine, serine, cystine, leucine, proline, phenylalanine, isoleucine, tyrosine, tryptophan, and methionine is taken as the total amount of amino acids, it is preferable that the content of ergothioneine relative to the total amount of amino acids is 0.12 or more.

[0013] It is also preferable that the ratio of the ergothioneine content to the total content of histidine, cystine, and methionine is 0.40 or more.

[0014] The Pleurotus cornucopiae extract of this embodiment may contain nicotinic acid as another component. The content of nicotinic acid relative to the total amount of amino acids is preferably 0.0030 to 0.0070. This has the effect of supporting the conversion of carbohydrates and lipids into energy.

[0015] The maitake mushroom extract of this embodiment can be provided as a dried product.

[0016] (Method for quantifying ergothioneine and nicotinic acid) Ten mg of Pleurotus cornucopiae extract was suspended in 1 ml of distilled water, centrifuged, and the supernatant was filtered through a 0.45 μm membrane filter. The resulting extract was analyzed by HPLC-UV. The HPLC conditions were: column: Inertsil® ODS 3V 5 μm 4.6 × 250 mm (GL Sciences), column temperature: 40°C, flow rate: 1.0 ml / min, mobile phase: 50 mM phosphate buffer solution (phosphate buffer pH 7.0 + 3% acetonitrile), and UV detector wavelength: 260 nm.

[0017] According to this embodiment, a Pleurotus cornucopiae extract having reduced off-taste and off-odor is provided. In particular, according to this embodiment, a Pleurotus cornucopiae extract having reduced off-taste and off-odor while containing ergothioneine at a high concentration is provided.

[0018] The Pleurotus cornucopiae extract of this embodiment is obtained by extracting Pleurotus cornucopiae mycelia with water at 10 to 100° C. (preferably 50 to 90° C.) A specific process for obtaining the Pleurotus cornucopiae extract will be described later.

[0019] (Method of manufacturing Tamogitake extract) The method for producing a maitake mushroom extract according to the embodiment comprises a step of culturing maitake mushroom in a liquid with aeration and agitation (shaking) to obtain maitake mushroom mycelium (mycelium preparation step), a step of recovering the maitake mushroom mycelium, and a step of adding the recovered maitake mushroom mycelium to water at 10 to 100°C to obtain a maitake mushroom extract (extraction step).

[0020] (Mycelium production process) Agitated liquid culture is preferred as a method for producing ergothioneine using Pleurotus cornucopiae mycelium. The carbon source of the medium used to culture Pleurotus cornucopiae strains may be any one of glucose, sucrose, maltose, fructose, mannose, trehalose, galactose, dextrin, starch, and cellulose, or a combination thereof. The nitrogen source of the medium used to culture Pleurotus cornucopiae strains may be any one of peptone, yeast extract, beef extract, soybean extract, oatmeal, coarse liquor, casamino acids, and various amino acids, or a combination thereof. In addition to the above nutrients, minerals and vitamins may also be added during culture. Culture conditions for Pleurotus cornucopiae strains include a temperature of 20 to 30°C, a rotation speed of 100 to 600 rpm during agitation, and a culture period of 1 to 4 weeks.

[0021] (Mycelium recovery process) The Pleurotus cornucopiae mycelium is separated from the culture solution by processes such as centrifugation, filtration, and filter filtration.

[0022] When the obtained Pleurotus cornucopiae mycelium is dried, it is dried, for example, by ventilation drying or freeze-drying until the moisture content is 10% or less.

[0023] (extraction process) Extraction can be performed using water, for example, at an extraction temperature of 10 to 100°C or 50 to 90°C for 1 to 5 hours. By setting the extraction temperature to 50 to 90°C, the growth of unwanted bacteria can be suppressed during the extraction process. Note that the extraction temperature is measured under normal pressure, and may exceed 100°C under pressure.

[0024] The extract can be concentrated and used as is. Alternatively, the concentrated extract can be purified by centrifugation, filter filtration, treatment with a filter aid such as activated carbon, gel filtration, adsorption chromatography, ion exchange chromatography, or the like. The extract and purified product can also be concentrated and dried for use as a dried product. In another embodiment, the extract can be concentrated and then freeze-dried until the water content is 10% or less, producing a powdered Pleurotus cornucopiae extract.

[0025] (Uses of Tamogitake Extract) The Pleurotus cornucopiae extract of this embodiment can be used as a food material or a cosmetic material. Ergothioneine can be extracted from the Pleurotus cornucopiae extract by any known method. For example, ergothioneine can be produced according to the method described in Patent Document 2.

[0026] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations can also be adopted. [Example]

[0027] EXAMPLES The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these.

[0028] <Strain> The Tamogitake mushrooms (Pleurotus cornucopiae var. citrinopileatus) used in the test were as follows: Strain 1: An ergothioneine-producing strain obtained by crossbreeding a wild strain from northern Kanto with an existing strain in our possession using the well-known dual culture method. Strain 2: NBRC-distributed strain (NBRC30528) Strain 3: NBRC-distributed strain (NBRC9614) Strain 4: Wild strain from northern Kanto

[0029] <Jar fermenter culture (agitated liquid culture)> Five liters of medium containing 20 g / L soluble starch, 16 g / L powdered corn steep liquor, 4 g / L hypopolypeptone S, 0.05 g / L potassium dihydrogen phosphate, 0.05 g / L magnesium sulfate heptahydrate, 0.06 g / L histidine, 0.06 g / L methionine, and 0.09 g / L cystine, and 0.8 ml / L antifoaming agent were placed in a 10-L jar fermenter and sterilized at 121°C for 100 minutes. After returning to room temperature, 200 ml of liquid medium containing peptone, glucose, and yeast extract was inoculated with a seed culture cultured for one week. Culture was continued at 25°C, stirring at 200 rpm, and aeration at 2.0 L / min for the number of days shown in Table 1. Because ergothioneine is sensitive to alkaline conditions, mycelia were harvested before the culture medium became alkaline, filtered, and lyophilized. The ergothioneine content was shown in Table 1. The amount of ergothioneine contained in the cells per medium was defined as the amount of ergothioneine produced, and the amount of ergothioneine leaked into the medium was defined as the amount of leaked ergothioneine.

[0030] [Table 1]

[0031] From the results in Table 1, it was confirmed that the mycelia used in Examples 1 to 3, which were selected by flask agitation culture, were able to produce a high amount of ergothioneine even when cultured in agitation liquid culture.

[0032] <Pleurotus ulmoides extract> The freeze-dried mycelium obtained from jar fermenter culture was finely pulverized, and 30 g of the powder was mixed with 300 ml of distilled water and heated to 95°C for hot water extraction. After leaving to stand at room temperature, the mixture was centrifuged at 7,000 rpm for 20 minutes at 10°C, and the supernatant was filtered to separate the extract. This extract was concentrated and freeze-dried to a moisture content of 10% or less to obtain a Pleurotus cornucopiae extract. The amount of ergothioneine in this Pleurotus cornucopiae extract, as well as the amount of protein (the main component), the total amount of 18 amino acids, and the amount of nicotinic acid are shown in Table 2. The amino acid content of the ergothioneine precursor is also shown in Table 3.

[0033] [Table 2]

[0034] The results in Table 2 indicate that the Pleurotus cornucopiae extract is primarily composed of protein and contains a large amount of amino acids. It was also confirmed that the hot water extracts of Examples 1 to 3 contained ergothioneine in an amount of 40 mg / g or more per dry matter. In particular, Examples 1 to 3 contained more than twice the amount of nicotinic acid as the comparative example.

[0035] [Table 3]

[0036] The results in Table 3 reveal that the total contents of histidine, methionine, and cystine are lower than that of the Comparative Example in Examples 1 to 3. In particular, it was confirmed that the histidine content was lower in Examples 1 to 3 than that of the Comparative Example. Table 4 shows the ratio (proportion) of ergothioneine content to the total amount of amino acids, and the ratio (proportion) of ergothioneine content to the total amount of histidine, methionine, and cystine.

[0037] [Table 4]

[0038] <Sensory evaluation> The Pleurotus cornucopiae extracts of Examples 1 to 3 and Comparative Examples 1 to 3 were diluted with water to an ergothioneine content of 5 mg / 800 ml, and five panelists blindly drank 50 μl of each and evaluated "off-flavor / off-odor" and "palatability." Each evaluation item was evaluated on a five-point scale according to the following evaluation criteria, and the average was calculated. Since the Pleurotus cornucopiae extract is unsuitable for use in food compositions if it has an unpleasant taste, even if it has only a minimal off-flavor / off-odor, it is unsuitable for use in food compositions, so "palatability" was also included as an evaluation item. The results are shown in Table 5. (Evaluation criteria) No problems at all: 5 points There is a slight discomfort that is not noticeable: 4 points There is some discomfort: 3 points Feeling uneasy: 2 points There is a major problem: 1 point (judgement) A total of 4 points or more for the two evaluation items was considered a pass.

[0039] [Table 5] [Industrial Applicability]

[0040] The Pleurotus cornucopiae extract of the present invention has little off-flavor or odor and can therefore be used as a food ingredient or cosmetic ingredient.

Claims

1. Ergothioneine and Amino acids and A Tamogitake extract comprising: The concentration of the ergothioneine is 40 mg / g or more and 200 mg / g or less, A Pleurotus culinarius extract in which the content of ergothioneine relative to the total amount of amino acids is 0.12 or more when the sum of the contents of valine, histidine, glutamic acid, aspartic acid, arginine, alanine, lysine, threonine, glycine, serine, cystine, leucine, proline, phenylalanine, isoleucine, tyrosine, tryptophan and methionine is taken as the total amount of amino acids.

2. The maitake mushroom extract according to claim 1, wherein the content of ergothioneine relative to the total content of histidine, cystine and methionine is 0.40 or more.

3. The maitake mushroom extract according to claim 1, obtained by extracting maitake mushroom mycelium with water at 10 to 100°C.

4. A step of culturing Tamogitake mushrooms in a liquid with stirring to obtain Tamogitake mushroom mycelium; A step of recovering the Pleurotus cornucopiae mycelium; A step of adding the collected Pleurotus cornucopiae mycelium to water at 10 to 100°C to obtain a Pleurotus cornucopiae extract; A method for producing a Tamogitake extract comprising:

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