Purple monascus fermentation of high-fungus polysaccharide black fungus powder and preparation method and application thereof

Abstract

The present application belongs to the field of food processing, and particularly relates to a kind of high-fungal polysaccharide black fungus powder fermented by purple monascus and a preparation method and application thereof.The above-mentioned monascus strain is separated from the traditional red koji food on the market, and the monascus is subcultured, isolated and screened to obtain the present application.The present application uses the above-mentioned strain to ferment black fungus, and obtains black fungus powder with high polysaccharide content.Compared with the traditional broken wall method, the crude polysaccharide content is significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of food processing, specifically relating to a purple Monascus and its applications. Background Technology

[0002] Black fungus ( Auricularia auricularis As a traditional medicinal and edible fungus, black fungus is rich in polysaccharides, which possess various biological activities such as antioxidant, immune-enhancing, and lipid-lowering effects, making it highly valuable for development in the functional food and pharmaceutical fields. Currently, the main extraction methods for black fungus polysaccharides include hot water extraction, acid-base extraction, enzymatic-assisted extraction, and ultrasonic / microwave-assisted extraction. However, hot water extraction has low yield and is time-consuming; acid-base extraction easily damages the higher-order structure of polysaccharides, leading to reduced biological activity; while physical-assisted methods offer improved efficiency, they require high equipment investment, and the purity of the polysaccharides remains unsatisfactory.

[0003] In recent years, bio-fermentation has been considered a potential green and efficient extraction technology. Its principle involves utilizing extracellular enzymes such as cellulase, hemicellulase, and protease produced by microorganisms during metabolism to gently and specifically disrupt the dense cell wall structure and protein complexes of black fungus, thereby releasing intracellular polysaccharides. Despite its theoretical advantages, traditional fermentation processes and the microbial strains used still have the following significant drawbacks when practically applied to the extraction of black fungus polysaccharides: Long fermentation cycle and low production efficiency: Traditional natural fermentation or solid / liquid fermentation with specific strains usually takes anywhere from 72 hours to several days. The fruiting body of black fungus has a dense structure, and the enzyme production system of ordinary fermentation strains degrades its cell wall slowly, resulting in low polysaccharide dissolution efficiency, which makes it difficult to meet the time-sensitive requirements of industrial production.

[0004] Competition between carbon and nitrogen sources and consumption of polysaccharides: Traditional fermentation media usually require the addition of additional carbon sources (such as glucose and sucrose) and nitrogen sources to promote the growth of microorganisms. However, in the later stages of fermentation, when the nutrients in the medium are depleted, some fermentation microorganisms will "reabsorb" or metabolize the dissolved and released black fungus polysaccharides, using them as a carbon source for their own growth. This results in a decrease in the final polysaccharide yield instead of an increase, leading to a waste of raw materials.

[0005] Complex products and high post-processing costs: Traditional fermentation product systems are extremely complex. The fermentation process not only produces the target polysaccharide but also a large amount of mycelium, metabolic pigments, organic acids, and protein residues. This not only makes the fermentation broth too viscous and difficult to filter but also significantly increases the difficulty and cost of subsequent purification steps such as protein removal, decolorization, and alcohol precipitation. The extracted polysaccharides are dark in color and have low purity, directly impacting their commercial value.

[0006] Limited bacterial strain function and mismatched enzyme production profile: Current technologies are mostly limited to using single probiotics, such as lactic acid bacteria, yeast, or Bacillus subtilis. Although these strains are mature in the field of food fermentation, their enzyme production systems are mainly targeted at starch or pectin, lacking specialized enzyme systems (such as chitinase and β-glucanase) for efficiently degrading the chitin-glucan complex cell walls of black fungus. This mismatch between enzyme system and substrate results in limited cell wall disruption, making it difficult to achieve a breakthrough in polysaccharide extraction rate.

[0007] Fermentation conditions are strictly controlled, resulting in poor stability: Traditional lactic acid bacteria or mold fermentation is highly sensitive to pH, temperature, and dissolved oxygen. In environments with high crude fiber content in black fungus, the strains are prone to degeneration or metabolic imbalance, leading to significant fluctuations in polysaccharide yield between fermentation batches and poor process reproducibility, which severely restricts the large-scale application of this technology.

[0008] Potential safety risks and flavor degradation: Some traditional molds (such as certain Aspergillus species) pose a potential risk of toxin production when used in non-traditional fermentation substrates (black fungus), requiring rigorous toxicological evaluation. Furthermore, prolonged fermentation can cause the extract to develop a strong sour or musty odor, masking the natural quality of the black fungus polysaccharides and affecting the sensory evaluation of downstream functional foods.

[0009] In summary, current methods for extracting polysaccharides from black fungus using traditional fermentation techniques generally face multiple technical bottlenecks, including long extraction cycles, easy polysaccharide loss, high purification difficulty, poor strain specificity, and unstable metabolism. Therefore, developing a method for extracting black fungus polysaccharides that is both highly efficient in cell wall disruption and does not consume the target product, while also ensuring a pure fermentation system and simple post-processing, is a pressing technical problem that needs to be solved in this field. Summary of the Invention

[0010] To address the above problems, this invention provides a purple Monascus (… Purple monkfish Yang-Y3000, this strain was deposited at the Guangdong Provincial Microbial Culture Collection Center on January 2, 2024; accession number GDMCC No:64057.

[0011] The present invention also provides the application of the above-mentioned purple red Monascus in food processing.

[0012] This invention also provides a method for preparing a mixed fermentation powder of black fungus and rice, comprising the following steps: (1) Pour the dried black fungus and rice into a fermentation tank, wash them, add water, soak for 3-5 hours, drain, and sterilize under high pressure. (2) Inoculate the sterilized and cooled black fungus and rice with the strain; (3) Mix the inoculated black fungus and rice evenly and place them in a fermentation tank for solid-state fermentation; (4) The inoculated substrate is fermented in a solid state at 30-35°C; (5) The product after fermentation is dried, ultra-finely pulverized and packaged to obtain the black fungus and rice mixed fermentation powder.

[0013] Furthermore, the strain mentioned in step (2) is the purple red Monascus as described in claim 1.

[0014] Furthermore, the inoculation amount in step (2) is 8% to 20%.

[0015] The present invention has the following beneficial effects: The Monascus purpureus strain provided in this invention is a strain isolated from commercially available traditional Monascus purpureus foods, and obtained through subculture, isolation, and screening. This invention utilizes the above strain to ferment black fungus, obtaining black fungus powder with a high polysaccharide content. Compared to traditional cell wall breaking methods, the crude polysaccharide content is significantly increased. Detailed Implementation

[0016] Various exemplary embodiments of the present invention are now described in detail. Unless otherwise specified, the methods used in the embodiments are conventional methods, and the reagents used are commercially available reagents or reagents prepared using conventional methods. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and embodiments of the present invention.

[0017] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0018] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0019] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0020] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0021] I. The strain used (preserved on 2024-01-02): Purple red yeast rice Purple monkfish Yang-Y3000, with accession number GDMCC No: 64057; The purple red Monascus preservation unit is the Guangdong Provincial Institute of Microbiology (Guangdong Provincial Microbial Analysis and Testing Center) and the Guangdong Provincial Microbial Culture Collection Center.

[0022] II. Isolation and culture of Monascus purpureus: The aforementioned Monascus strain was isolated from traditional Monascus foods available on the market and obtained through subculture, isolation, and screening.

[0023] A. Red Monascus Synthetic Culture Medium: Mix 10-15% rice flour or soluble starch, 0.1-0.3% sodium nitrate, 0.1-0.3% magnesium sulfate, 0.1-0.3% yeast extract, and 2-3% agar with water.

[0024] B. Natural culture medium for Monascus purpureus: 8 Bx to 20 Bx of malt extract, 2 to 3% of agar, and water.

[0025] III. Fungal Culture Conditions: 1. Purple Monascus Purple monkfish Yang-Y3000, with accession number GDMCC No: 64057; A. Red Monascus strain shake flask test formulation: Rice flour 8-20%, sodium nitrate 0.1%-0.3%, yeast extract 0.1%-0.5%, corn steep liquor 0.2%-0.5%; adjust the pH of the fermentation broth to 3.0-5.0 with lactic acid or acetic acid, boil, then transfer to Erlenmeyer flasks for sterilization (temperature 121-125℃, pressure 0.1-0.2 MPa, time 30-40 min), cool, and inoculate.

[0026] B. Conditions for shake-flask fermentation of Monascus purpureus: Incubation temperature: 28–35℃; pH value: 3.0–5.5; rotation speed: 150–200 r / min; incubation time: 96–124 h; IV. Solid-state fermentation process for black fungus made with red yeast: 1. Pour a certain proportion of black fungus and rice into a fermentation tank, wash them, then add a certain amount of tap water adjusted to pH 3.0-5.0 with lactic acid, soak for 2-5 hours, drain, and then autoclave. 2. After sterilization and cooling, inoculate the black fungus and rice with the purple red yeast rice in different proportions. Purple monkfish Yang-Y3000, with accession number GDMCC No: 64057, was deposited at the Guangdong Provincial Center for Microbial Culture Collection on January 2, 2024.

[0027] 3. Mix the inoculated black fungus and rice evenly, and place them in a fermentation tank for solid-state fermentation; As an improvement to the above scheme, the inoculum amount of the purple red Monascus is 8% to 20%; 4. The inoculated substrate is then subjected to solid-state fermentation at 30-35℃; 5. After fermentation, the product is dried, ultra-finely pulverized, and packaged to obtain the product.

[0028] V. Production process of black fungus by liquid fermentation with red yeast: Crush the black fungus, add rice flour and tap water in a certain proportion, mix well, adjust the pH to 3.0-5.0 with lactic acid, sterilize (temperature 121-125℃, pressure 0.1-0.2Mpa, time 30min), cool, inoculate, ferment, filter, concentrate, spray dry, break down the cell wall and pulverize, and package.

[0029] VI. Comparison of crude polysaccharide content results Modern fermentation can replace cell wall disruption extraction; the comparison of crude polysaccharide content is as follows: The above results were tested and verified by Huace Testing Company, and the report number is A2230566333101001C.

[0030] Example 1 Pour 95% dried black fungus and 5% rice into a solid-state fermentation tank, wash them, soak them in tap water with lactic acid to adjust the pH to 3.0-5.0 for 5 hours, drain the water, introduce steam to start heating (temperature 121-125℃, pressure 0.1-0.2Mpa, time 30min), cool, inoculate (inoculation amount 18%), ferment (temperature 30-33℃, pressure 0.03-0.05Mpa, time 140H), vacuum dry, break down the cell walls and pulverize, and package.

[0031] Example 2 Pour 85% dried black fungus and 15% rice into a solid-state fermentation tank, wash them, soak them in tap water with lactic acid to a pH of 3.0-5.0 for 5 hours, drain the water, introduce steam to start heating (temperature 121-125℃, pressure 0.1-0.2Mpa, time 30min), cool, inoculate (inoculation amount 12%), ferment (temperature 32-35℃, pressure 0.03-0.05Mpa, time 128H), vacuum dry, break down the cell walls and pulverize, and package.

[0032] Example 3 Pour 80% of dried black fungus and 20% of rice into a solid-state fermentation tank, wash them, soak them in tap water with lactic acid to adjust the pH to 3.0-5.0 for 5 hours, drain the water, introduce steam to start heating (temperature 121-125℃, pressure 0.1-0.2Mpa, time 30min), cool, inoculate (inoculation amount 8%), ferment (temperature 32-35℃, pressure 0.03-0.05Mpa, time 120H), vacuum dry, break down the cell walls and pulverize, and package.

[0033] Example 4 Mix the pulverized black fungus powder and rice flour in a 9:1 ratio, pour the mixture into a liquid fermentation tank, add 60-70% tap water, adjust the pH to 3.0-5.0 with lactic acid, and sterilize under high temperature and pressure for 30 minutes by introducing steam. Cool to 25-35℃, inoculate (12% inoculation amount), ferment (temperature 32-35℃, pressure 0.03-0.07Mpa, time 110H), filter, vacuum concentrate, spray dry, break down the cell walls and pulverize, and package.

[0034] Example 5 Mix the pulverized black fungus powder and rice flour in an 8:2 ratio, pour the mixture into a liquid fermentation tank, add 60-70% tap water, adjust the pH to 3.0-5.0 with lactic acid, and sterilize under high temperature and pressure for 40 minutes by introducing steam. Cool to 25-35℃, inoculate (20% inoculation amount), ferment (temperature 32-35℃, pressure 0.03-0.07Mpa, time 96H), filter, vacuum concentrate, spray dry, break down the cell walls and pulverize, and package.

[0035] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A purple red yeast rice ( Monascus purpureus Yang-Y3000, characterized in that, This strain was deposited at the Guangdong Provincial Center for Microbial Culture Collection on January 2, 2024, with accession number GDMCC No: 64057.

2. The application of Monascus purpureus as described in claim 1 in food processing.

3. A method for preparing a mixed fermentation powder of black fungus and rice, characterized in that, Includes the following steps: (1) Pour the dried black fungus and rice into a fermentation tank, wash them, add water, soak for 3-5 hours, drain, and sterilize under high pressure. (2) Inoculate the sterilized and cooled black fungus and rice with the strain; (3) Mix the inoculated black fungus and rice evenly and place them in a fermentation tank for solid-state fermentation; (4) The inoculated substrate is fermented in a solid state at 30-35°C; (5) The product after fermentation is dried, ultra-finely pulverized and packaged to obtain the black fungus and rice mixed fermentation powder.

4. The preparation method according to claim 3, characterized in that, The strain mentioned in step (2) is the purple red Monascus as described in claim 1.

5. The preparation method according to claim 3, characterized in that, The inoculation amount mentioned in step (2) is 8%~20%.

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