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CN-121991527-A - Method for extracting melanin from lentinus edodes and product

CN121991527ACN 121991527 ACN121991527 ACN 121991527ACN-121991527-A

Abstract

The invention discloses a method for extracting melanin from mushrooms and a product thereof, wherein the method comprises the following steps of (1) preparing a sample, namely taking mushroom cap epidermis tissues, drying and crushing to obtain mushroom powder, (2) carrying out alkaline extraction, namely mixing the mushroom powder with alkaline solution, carrying out ultrasonic auxiliary extraction, and then carrying out solid-liquid separation to obtain supernatant containing pigment, (3) carrying out acid precipitation, namely regulating the pH value of the supernatant to be acidic, carrying out pigment precipitation, collecting precipitates and washing, and (4) purifying, namely carrying out acid hydrolysis treatment on the precipitates obtained in the step (3), washing with an organic solvent, carrying out acid precipitation again after at least one time of redissolving in the alkaline solution, and finally drying to obtain purified mushroom melanin. The lentinus edodes melanin prepared by the invention has unique physicochemical properties and structural characteristics, and provides a material basis and a theoretical basis for subsequent development and application.

Inventors

  • LI NANYI
  • ZHU YITING
  • TAO MENGJIAO
  • ZHANG XIN

Assignees

  • 浙江农林大学

Dates

Publication Date
20260508
Application Date
20260122

Claims (10)

  1. 1. A method for extracting melanin from lentinus edodes, comprising the following steps: (1) Sample preparation, namely taking mushroom cap epidermis tissues, drying and crushing to obtain mushroom powder; (2) Alkali extraction, namely mixing the lentinus edodes powder with an alkaline solution, performing ultrasonic auxiliary extraction, and then performing solid-liquid separation to obtain a supernatant containing pigment; (3) Acid precipitation, namely regulating the pH value of the supernatant to be acidic, precipitating pigments, collecting precipitate and washing; (4) And (3) purifying, namely performing acid hydrolysis treatment on the precipitate obtained in the step (3), washing with an organic solvent, re-performing acid precipitation after at least one time of re-dissolving in an alkaline solution, and finally drying to obtain the purified lentinus edodes melanin.
  2. 2. The method according to claim 1, wherein in the step (2), the alkaline solution is a NaOH solution having a concentration of 0.5-2.5 mol-L -1 .
  3. 3. The method according to claim 1, wherein in step (2), the ratio of the material to liquid of the lentinula edodes powder to the alkaline solution is 1:20 to 1:50 g/mL.
  4. 4. The method of claim 1, wherein in step (2), the power of the ultrasound-assisted extraction is 200-300W for 60-240 minutes.
  5. 5. The method according to claim 1, wherein in step (3), the pH is adjusted to 1.0 to 3.0 using a hydrochloric acid solution.
  6. 6. The method according to claim 1, wherein in the step (4), the acid hydrolysis treatment is performed at 80 to 100 ℃ for 1 to 6 hours using a hydrochloric acid solution having a concentration of 5 to 8 mol ·l -1 .
  7. 7. The method according to claim 1, wherein in step (4), the organic solvent washing comprises washing with chloroform, ethyl acetate and ethanol in this order.
  8. 8. Lentinula edodes melanin, characterized in that it is prepared by the method according to any one of claims 1-7.
  9. 9. The lentinula edodes melanin according to claim 8, wherein the element composition comprises, by mass, 54.0-55.5% of C, 4.8-5.3% of H, 3.4-3.8% of N, 1.8-2.0% of S and 30.8-31.8% of O.
  10. 10. Lentinula edodes melanin according to claim 8, which is in an amorphous particulate aggregation state under a scanning electron microscope, the particle size being 1.0-2.0 μm.

Description

Method for extracting melanin from lentinus edodes and product Technical Field The invention relates to the technical field of natural product extraction and identification, in particular to a method for extracting melanin from lentinus edodes and a product. Background Lentinus edodes (Lentinus edodes) is an important edible fungus widely cultivated worldwide, and the color of the mushroom cap is one of key agronomic traits affecting commodity value and consumer selection. Generally, dark colored mushroom caps are associated with better maturity, stronger aroma, and thicker meat quality. Therefore, the analysis of the pigment components of the mushroom cap is of great significance for understanding the color forming mechanism, guiding variety breeding and improving quality. Melanin is a natural phenolic or indole polymer pigment widely existing in organisms, has various biological activities such as oxidation resistance, radiation resistance, metal ion chelation and the like, and has good application potential in the fields of foods, cosmetics and medicines. At present, certain researches on the extraction, properties and structures of melanin in edible fungi such as black fungus, oyster mushroom and the like are carried out, for example, an alkali-dissolution and acid-precipitation method, an ultrasonic or microwave-assisted method, an enzymolysis method and the like are adopted for extraction, and the structures are identified by utilizing the technologies such as spectrum, chromatography and mass spectrum. However, no systematic extraction and structural identification study has been made on the pigment components of the fruiting bodies of Lentinus edodes, particularly in the epidermis of the fruiting cover. When the existing edible fungus melanin extraction process is applied to mushrooms, the efficiency and the product purity are not clear, and the structure and the properties of melanin from different sources are different. Therefore, the development of the method special for efficiently extracting and purifying the melanin from the mushroom cap, and the analysis of the fine structure of the melanin from the specific source have urgent needs and important values for expanding a natural melanin resource library and excavating high added value ingredients of the mushrooms. Disclosure of Invention In view of the above, it is a primary object of the present invention to provide a method for extracting melanin from lentinus edodes, which is efficient and stable, and can obtain high-purity melanin products. The invention also aims to provide the lentinus edodes melanin prepared by the method, and the unique physicochemical properties and structural characteristics of the lentinus edodes melanin are clarified, so that a material basis and a theoretical basis are provided for subsequent development and application. The adopted technical scheme is as follows: In a first aspect, the present invention provides a method for extracting melanin from lentinus edodes, comprising the steps of: (1) Sample preparation, namely taking mushroom cap epidermis tissues, drying and crushing to obtain mushroom powder; (2) Alkali extraction, namely mixing the lentinus edodes powder with an alkaline solution, performing ultrasonic auxiliary extraction, and then performing solid-liquid separation to obtain a supernatant containing pigment; (3) Acid precipitation, namely regulating the pH value of the supernatant to be acidic, precipitating pigments, collecting precipitate and washing; (4) And (3) purifying, namely performing acid hydrolysis treatment on the precipitate obtained in the step (3), washing with an organic solvent, re-performing acid precipitation after at least one time of re-dissolving in an alkaline solution, and finally drying to obtain the purified lentinus edodes melanin. Preferably, in the step (2), the alkaline solution is a NaOH solution, and the concentration thereof is 0.5-2.5 mol ·l -1. Preferably, in the step (2), the feed liquid ratio of the lentinus edodes powder to the alkaline solution is 1:20 to 1:50 g/mL. Preferably, in the step (2), the power of the ultrasonic auxiliary extraction is 200-300W, and the time is 60-240 minutes. Preferably, in step (3), the pH is adjusted to 1.0-3.0 using a hydrochloric acid solution. Preferably, in the step (4), the acid hydrolysis treatment is performed at 80-100 ℃ for 1-6 hours using a hydrochloric acid solution having a concentration of 5-8 mol-L -1. Preferably, in step (4), the organic solvent washing includes washing with chloroform, ethyl acetate and ethanol in this order. In a second aspect, the invention provides lentinula edodes melanin, which is prepared by any of the methods described above. The lentinula edodes melanin has the following characteristics: The alloy is characterized by comprising, by mass, 54.0-55.5% of C, 4.8-5.3% of H, 3.4-3.8% of N, 1.8-2.0% of S and 30.8-31.8% of O. It is in amorphous granular aggregation state under a scanning electron mi