A brewer's yeast fermentation product solution and its application in cosmetics

Abstract

This invention discloses a brewer's yeast fermentation product solution and its application in cosmetics. The brewer's yeast fermentation product solution is prepared using modern fermentation technology, employing soybean milk, buckwheat sprouts, rice bran, algae, etc., as a composite fermentation substrate. Utilizing the metabolic activity of ordinary yeast, combined with subsequent yeast autolysis / enzymatic hydrolysis, a brewer's yeast fermentation product solution rich in α-ketoglutarate, polysaccharides, oligosaccharides, free amino acids, polypeptides, and B vitamins is prepared. This brewer's yeast fermentation product solution possesses moisturizing, repairing, and anti-aging properties and can be applied to creams, lotions, and other cosmetics, thereby endowing these cosmetics with hydrating, moisturizing, sensitive skin repair, and anti-aging effects.

Description

Technical Field

[0001] This invention relates to the field of cosmetics, specifically to a brewer's yeast fermentation product solution and its application in cosmetics. Background Technology

[0002] With the rapid development of the cosmetics industry, consumer demand for skincare products has shifted from basic cleansing and moisturizing to natural, high-efficiency, and multifunctional products. The research and application of functional skincare ingredients have become a core direction for industry innovation. Yeast, as a single-celled eukaryotic organism, can synthesize various bioactive substances beneficial to the skin through its own metabolism, and it boasts advantages such as wide availability, high safety, and good biocompatibility. Yeast extract, extracted and purified from yeast cells through a specific process, retains its core active ingredients and can specifically improve various skin problems, meeting the skincare needs of modern consumers. It has become a "star ingredient" in the cosmetics field, widely used in various skincare products such as serums, creams, and masks, and its application value and market potential continue to stand out.

[0003] Yeast extract is rich in amino acids, peptides, and polysaccharides, making it a natural moisturizing factor. Among these, polysaccharides (such as beta-glucan and trehalose) have excellent hydrophilicity, capable of absorbing several times their own weight in water to form a breathable moisturizing film on the skin's surface, reducing moisture loss and deeply replenishing moisture to improve dryness and roughness. Amino acids, as important components of the stratum corneum, promote the synthesis and differentiation of keratinocytes, enhance the integrity of the stratum corneum, repair damaged skin barriers, and improve the skin's water-locking ability and resistance to external stimuli, making it especially suitable for sensitive and dry skin. Simultaneously, the peptides and nucleic acids in yeast extract promote the proliferation of skin fibroblasts, stimulate the synthesis of collagen and elastin fibers, increase skin elasticity, and reduce fine lines and wrinkles.

[0004] Specifically, the following technical challenges remain to be addressed in this field: First, the composition and efficacy of active ingredients in yeast fermentation products are highly dependent on the composition of the fermentation substrate. Most existing methods fail to adequately consider the interactions between different substrates, resulting in lower levels of certain key active ingredients (such as α-ketoglutarate, an important intermediate in the tricarboxylic acid cycle with potential regulatory effects on energy metabolism and collagen synthesis), thus limiting their full skincare efficacy. Second, in post-processing, simple mechanical crushing or a single autolysis process is insufficient to efficiently release and convert active substances (especially proteins and organic acids) within the yeast cells into forms more easily absorbed by the skin (such as free amino acids and small peptides). Optimizing the enzymatic hydrolysis process to achieve efficient lysis of yeast cells and targeted enrichment of target active ingredients is crucial for improving product efficacy. Third, existing technologies lack systematic research and verification of the synergistic effects between specific fermentation substrate combinations and specific enzymatic hydrolysis processes, making it difficult to prepare yeast fermentation products that simultaneously possess excellent moisturizing, repairing, and anti-aging effects.

[0005] Therefore, developing a brewer's yeast fermentation product solution that can efficiently enrich active ingredients such as α-ketoglutarate, polysaccharides, oligosaccharides, free amino acids, peptides and B vitamins, and has significant moisturizing, repairing and anti-aging effects, as well as providing its reliable preparation method and application in cosmetics, is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] The primary objective of this invention is to address the shortcomings of existing technologies by providing a brewing yeast fermentation product solution.

[0007] This invention uses soybean milk, buckwheat sprouts, rice bran, and algae as composite fermentation substrates. Utilizing the metabolic activity of yeast, combined with subsequent yeast autolysis / enzymatic hydrolysis processes, a brewer's yeast fermentation product solution rich in α-ketoglutarate, polysaccharides, oligosaccharides, free amino acids, polypeptides, and B vitamins is prepared. This brewer's yeast fermentation product solution possesses moisturizing, repairing, and anti-aging properties and can be used in cosmetics such as creams and lotions, thereby endowing these cosmetics with hydrating, moisturizing, sensitive skin repair, and anti-aging effects.

[0008] One of the technical solutions of the present invention is: a brewing yeast fermentation product solution, which is prepared by a method including the following steps: (1) inoculating brewing yeast in a culture medium containing soybean milk, buckwheat sprouts and rice bran to obtain fermentation liquid; (2) enzymatically hydrolyzing the fermentation liquid obtained in step (1), and then separating the solid and liquid phases to obtain the liquid phase.

[0009] The brewing yeast described in step (1) of this invention, scientifically named *Saccharomyces cerevisiae*, is one of the oldest and most thoroughly studied microorganisms domesticated and utilized by humans. Under microaerobic conditions and a suitable pH, the yeast of this invention utilizes substrate carbon and nitrogen sources for growth and metabolism, synthesizing α-ketoglutarate (as an intermediate metabolite) through the tricarboxylic acid cycle (TCA cycle), while simultaneously accumulating yeast cells. These cells are rich in high-quality protein, a complete amino acid profile, B vitamins, minerals such as selenium and zinc, and active ingredients such as glucan and mannan oligosaccharides. Suitable brewing yeast can be obtained from Angel Yeast Co., Ltd.'s Angel Brewing High-Activity Dry Yeast.

[0010] In some embodiments, the *Saccharomyces cerevisiae* is inoculated into the culture medium at a concentration of 1 × 10⁻⁶ after inoculation. 6 -1×10 7 At CFU / g, turn on the stirrer and stir for 10-20 minutes to ensure thorough mixing of the inoculum and substrate, avoiding localized excessively high or low inoculum concentrations. Then adjust the temperature to 28-30℃ and humidity to 60-70%, using an "intermittent aeration + intermittent stirring" mode. For the first 24 hours, stir once every 6 hours for 5-10 minutes each time, while simultaneously introducing sterile air; after 24 hours, stir once every 8 hours for 10-15 minutes each time. Fermentation cycle: 72-96 hours.

[0011] The culture medium described in this invention consists of soybean milk, buckwheat sprouts, and rice bran. Soybean milk provides abundant nitrogen sources (amino acids, proteins) and lipids, buckwheat sprouts provide rutin, quercetin, chlorogenic acid, quinic acid, and amino acid precursors, and rice bran provides biotin, phytic acid, and carbohydrates. The three components work synergistically to provide sufficient raw materials for yeast growth and α-ketoglutarate synthesis.

[0012] The culture medium described in this invention can also contain seaweed powder, which can be red algae, blue algae, or green algae. When the seaweed powder comes into contact with water, it forms a slightly colloidal gel structure, which can both lock in the moisture of the system (preventing drying in the later stages of fermentation) and form a "gel-fiber" composite framework with the coarse fiber of rice bran. This keeps the fermentation system loose, preventing substrate clumping and poor aeration, ensuring a microaerobic fermentation environment, reducing the metabolic diversion of yeast for anaerobic ethanol production, and allowing more carbon sources to flow to α-ketoglutarate synthesis.

[0013] In some embodiments, the pretreatment process of the soy milk is as follows: fresh soybeans are soaked at room temperature for 6-8 hours, peeled, and then 3 times the volume of deionized water is added. The soybeans are then ground into soy milk using a soy milk maker, refined by a colloid mill, filtered through a 100-mesh filter cloth to remove the soy residue, and the solid content is adjusted to 12-15% for later use.

[0014] In some embodiments, the pretreatment process for buckwheat sprouts is as follows: select fresh, rot-free, and pest-free buckwheat sprouts, rinse them three times with deionized water, drain the water, and grind them in a grinder to a particle size of 0.5-1mm for later use.

[0015] In some embodiments, the pretreatment process of the rice bran is as follows: take food-grade rice bran, remove impurities, put it into a pulverizer and pulverize it to 50-100 mesh, put it in an oven at 105℃ and dry it for 2 hours, and then cool it to room temperature for later use.

[0016] The present invention provides a preparation process for the culture medium: pretreated soybean milk, buckwheat sprout powder, and rice bran powder are placed in a sterile mixing tank, deionized water is added, and the mixture is stirred evenly. The water content of the system is adjusted to 60-70%, and the pH is adjusted to 5.0-5.5. The mixture is stirred for 10 minutes to ensure pH uniformity. The evenly mixed composite substrate is transferred to a sterile fermenter, the tank opening is sealed, and the tank is placed in a high-pressure steam sterilizer. The sterilization parameters are set as follows: 121℃, 0.1MPa, sterilization for 20 minutes, and then cooled to room temperature.

[0017] In some embodiments, the mass ratio of the soy milk, buckwheat sprout powder, and rice bran powder is 5-10:1-5:1-5.

[0018] The purpose of the enzymatic hydrolysis step described in step (2) of this invention is to decompose yeast cell protein into free amino acids (especially glutamic acid) through yeast autolysis and exogenous protease hydrolysis, and further convert glutamic acid into α-ketoglutarate, thereby significantly improving the α-ketoglutarate content and nutrient utilization rate in the product.

[0019] This application employs a combination enzyme of neutral protease and carboxypeptidase. The neutral protease is an endopeptidase that hydrolyzes yeast macromolecules into polypeptide fragments; the carboxypeptidase is an exopeptidase that gradually releases free amino acids from the C-terminus of the polypeptide. The combined use of these two enzymes achieves highly efficient synergy between endopeptidation and exopeptidation, significantly increasing the degree of protein hydrolysis and the content of free amino acids, and promoting the full release of intracellular active substances such as α-ketoglutarate.

[0020] In some embodiments, the enzymatic hydrolysis step includes the following process: adjusting the temperature to 50-55℃ and maintaining a constant temperature for yeast autolysis, with an autolysis time of 24-36 hours; during autolysis, stirring once every 6 hours for 5-10 minutes each time to promote yeast cell rupture and release intracellular substances. Then, the system temperature is lowered to 40-45℃, and the pH is adjusted to 5.5-6.0 (the optimal pH for enzymatic hydrolysis); a complex enzyme composed of neutral protease and carboxypeptidase in a mass ratio of 1:1 to 3:1 is added, with the amount of complex enzyme added being 0.3-0.5% of the total mass of the fermentation system, stirred evenly, and enzymatically hydrolyzed at a constant temperature of 45℃ for 6-12 hours; after enzymatic hydrolysis, the system temperature is raised to 90℃ and maintained for 15 minutes to terminate the enzymatic hydrolysis reaction (to avoid over-enzymatic hydrolysis leading to the destruction of nutrients). After the enzymatic hydrolysate is cooled to room temperature, it is placed in a centrifuge and centrifuged at 3000 r / min for 15 min to remove the precipitate (undigested substrate residue and yeast cell wall fragments); the supernatant is collected and filtered once with an 800-1000 mesh filter cloth to further remove fine impurities.

[0021] The second technical solution of the present invention is: the application of the above-mentioned brewer's yeast fermentation product solution in the preparation of cosmetics.

[0022] The brewing yeast fermentation product solution described in this invention has moisturizing, repairing, and anti-aging properties, and can be directly used as a raw material to prepare cosmetics.

[0023] The third technical solution of the present invention is: a cosmetic product comprising the above-mentioned brewer's yeast fermentation product solution.

[0024] In this invention, the cosmetic product can be any suitable product form, including, but not limited to, creams, lotions, serums, gels, toners, shampoos, shower gels, facial cleansers, and face masks.

[0025] In the cosmetic, the amount of the above-mentioned brewer's yeast fermentation product solution added is a conventional content in the art, preferably 0.1-99.9%, more preferably 1-10%, and the percentage is a mass percentage.

[0026] The beneficial effects of the technical solution provided in this invention are as follows: The brewing yeast fermentation product solution provided in this invention uses soybean milk, buckwheat sprouts, rice bran, algae, etc., as a complex fermentation substrate. Utilizing the metabolic activity of ordinary yeast, combined with subsequent yeast autolysis / enzymatic hydrolysis processes, a brewing yeast fermentation product solution rich in α-ketoglutarate, polysaccharides, oligosaccharides, free amino acids, polypeptides, and B vitamins is prepared. Experiments have confirmed that the brewing yeast fermentation product solution can be used as an active ingredient in cosmetics, providing excellent skincare effects such as hydration, moisturizing, sensitive skin repair, and anti-aging. Attached Figure Description

[0027] Figure 1 The content of α-ketoglutarate in each test group of Experiment 1; Figure 2 Photos of some volunteers from Experiment 4 showing effective wrinkle improvement; Figure 3 Photos of some volunteers from Experiment 4 showing improvement in the red zone. Detailed Implementation

[0028] The embodiments described in this specification are for illustrative purposes only and do not limit the scope of protection of this invention. The scope of protection of this invention is defined only by the claims, and any omissions, substitutions, or modifications made based on the embodiments disclosed in this invention will fall within the scope of protection of this invention.

[0029] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0030] Example 1 A brewer's yeast fermentation product solution is prepared by the following steps: S1. Pretreatment of buckwheat sprouts: Select fresh buckwheat sprouts that are free from rot and pests, rinse them three times with deionized water, drain the water, and grind them into particles with a particle size of 0.5mm in a grinder for later use. Rice bran pretreatment: Take food-grade rice bran, remove impurities, grind it to 100 mesh in a grinder, dry it in a 105℃ oven for 2 hours, and cool it to room temperature for later use. Soy milk pretreatment: Soak fresh soybeans at room temperature for 6 hours, remove the skins, add 3 times the volume of deionized water, grind into soy milk using a soy milk maker, then refine through a colloid mill, filter with a 100-mesh filter cloth to remove soy pulp, adjust the solid content to 15%, and set aside. Mixing of composite substrates: Add pretreated soy milk, buckwheat sprout powder, and rice bran powder to a sterile mixing tank in a mass ratio of 5:5:1, add deionized water, stir evenly, adjust the water content of the system to 70%, adjust the pH to 5.0, stir for 15 minutes, and ensure pH uniformity. Substrate sterilization: Transfer the well-mixed composite substrate into a sterile fermenter, seal the tank opening, place it in a high-pressure steam sterilizer, set the sterilization parameters: 121℃, 0.1MPa, sterilize for 20 minutes, and cool to room temperature; S2. Inoculation: Inoculate the activated brewer's yeast seed culture into the cooled composite substrate. The inoculum concentration after inoculation is 1×10⁻⁶. 6 CFU / g; turn on the stirrer and stir for 20 minutes to ensure that the inoculum and substrate are fully mixed and avoid local inoculum concentrations that are too high or too low; Constant temperature fermentation: Adjust the temperature to 30℃ and humidity to 60%; adopt the "intermittent aeration + intermittent stirring" mode, stir once every 6 hours for 10 minutes each time in the first 24 hours, and introduce sterile air at the same time; after 24 hours, stir once every 8 hours for 10 minutes each time, fermentation cycle: 96 hours.

[0031] S3. Post-treatment: Adjust the temperature to 50℃ and maintain a constant temperature for yeast autolysis over 36 hours. During autolysis, stir for 5 minutes every 6 hours to promote yeast cell rupture and release intracellular substances. Then, lower the system temperature to 45℃ and adjust the pH to 5.5. Add a complex enzyme consisting of neutral protease and carboxypeptidase in a 3:1 mass ratio, at 0.3% of the total fermentation system mass. Stir well and maintain a constant temperature of 45℃ for 12 hours. After enzymatic hydrolysis, raise the system temperature to 90℃ and maintain a constant temperature for 15 minutes to terminate the enzymatic hydrolysis reaction. After cooling the hydrolysate to room temperature, centrifuge at 3000 rpm for 15 minutes to remove the precipitate. Collect the supernatant and filter it once through an 800-mesh filter cloth to obtain the brewer's yeast fermentation product solution.

[0032] Example 2 A brewer's yeast fermentation product solution is prepared by the following steps: S1. Buckwheat sprout pretreatment: Select fresh, rot-free, and pest-free buckwheat sprouts, rinse them 3 times with deionized water, drain the water, and grind them into 1mm particle size in a grinder for later use. Rice bran pretreatment: Take food-grade rice bran, remove impurities, grind it to 50 mesh in a grinder, dry it in a 105℃ oven for 2 hours, and cool it to room temperature for later use. Soybean milk pretreatment: Soak fresh soybeans at room temperature for 8 hours, remove the skins, add 3 times the volume of deionized water, grind into soy milk using a soy milk maker, then refine through a colloid mill, filter with a 100-mesh filter cloth to remove soy pulp, adjust the solid content to 12%, and set aside. Mixing of composite substrates: Add pretreated soy milk, buckwheat sprout powder, and rice bran powder to a sterile mixing tank in a mass ratio of 10:1:5, add deionized water, stir evenly, adjust the water content of the system to 60%, adjust the pH to 5.5, stir for 10 minutes, and ensure pH uniformity. Substrate sterilization: Transfer the well-mixed composite substrate into a sterile fermenter, seal the tank opening, place it in a high-pressure steam sterilizer, set the sterilization parameters: 121℃, 0.1MPa, sterilize for 20 minutes, and cool to room temperature; S2. Inoculation: Inoculate the activated brewer's yeast seed culture into the cooled composite substrate. The inoculum concentration after inoculation is 1×10⁻⁶. 7 CFU / g; turn on the stirrer and stir for 10 minutes to ensure that the inoculum and substrate are fully mixed and to avoid local inoculum concentrations that are too high or too low. Constant temperature fermentation: Adjust the temperature to 28℃ and humidity to 70%; adopt the "intermittent aeration + intermittent stirring" mode, stir once every 6 hours for 5 minutes in the first 24 hours, and introduce sterile air at the same time; after 24 hours, stir once every 8 hours for 15 minutes. Fermentation cycle: 72 hours.

[0033] S3. Post-treatment: Adjust the temperature to 55℃ and maintain a constant temperature for yeast autolysis over 24 hours. During autolysis, stir for 10 minutes every 6 hours to promote yeast cell rupture and release intracellular substances. Then, lower the system temperature to 40℃ and adjust the pH to 6.0. Add a complex enzyme consisting of neutral protease and carboxypeptidase in a 1:1 mass ratio, at a concentration of 0.5% of the total fermentation system mass. Stir well and maintain a constant temperature of 45℃ for 6 hours. After enzymatic hydrolysis, raise the system temperature to 90℃ and maintain this temperature for 15 minutes to terminate the reaction. After cooling the hydrolysate to room temperature, centrifuge at 3000 rpm for 15 minutes to remove the precipitate. Collect the supernatant and filter it once through a 1000-mesh filter cloth to obtain the brewer's yeast fermentation product solution.

[0034] Example 3 A brewer's yeast fermentation product solution is prepared by the following steps: S1. Pretreatment of buckwheat sprouts: Select fresh buckwheat sprouts that are free from rot and pests, rinse them three times with deionized water, drain the water, and grind them into particles with a particle size of 0.5mm in a grinder for later use. Rice bran pretreatment: Take food-grade rice bran, remove impurities, grind it to 80 mesh in a grinder, dry it in a 105℃ oven for 2 hours, and cool it to room temperature for later use. Soy milk pretreatment: Soak fresh soybeans at room temperature for 7 hours, remove the skins, add 3 times the volume of deionized water, grind into soy milk using a soy milk maker, then refine through a colloid mill, filter with a 100-mesh filter cloth to remove soy pulp, adjust the solid content to 14%, and set aside. Mixing of composite substrates: Pretreated soy milk, buckwheat sprout powder, and rice bran powder are placed in a sterile mixing tank in a mass ratio of 8:2:3. Deionized water is added, and the mixture is stirred evenly. The water content of the system is adjusted to 65%, and the pH is adjusted to 5.2. The mixture is stirred for 13 minutes to ensure that the pH is uniform. Substrate sterilization: Transfer the well-mixed composite substrate into a sterile fermenter, seal the tank opening, place it in a high-pressure steam sterilizer, set the sterilization parameters: 121℃, 0.1MPa, sterilize for 20 minutes, and cool to room temperature; S2. Inoculation: Inoculate the activated brewer's yeast seed culture into the cooled composite substrate. The inoculum concentration after inoculation is 5 × 10⁻⁶. 6 CFU / g; turn on the stirrer and stir for 15 minutes to ensure that the inoculum and substrate are fully mixed and to avoid local inoculum concentrations that are too high or too low. Constant temperature fermentation: Adjust the temperature to 29℃ and humidity to 65%; adopt the "intermittent aeration + intermittent stirring" mode, stir once every 6 hours for 8 minutes each time in the first 24 hours, and introduce sterile air at the same time; after 24 hours, stir once every 8 hours for 12 minutes each time, fermentation cycle: 80 hours.

[0035] S3. Post-treatment: Adjust the temperature to 53℃ and maintain a constant temperature for yeast autolysis for 30 hours. During autolysis, stir for 8 minutes every 6 hours to promote yeast cell rupture and release intracellular substances. Then, lower the system temperature to 42℃ and adjust the pH to 5.8. Add a complex enzyme consisting of neutral protease and carboxypeptidase in a 2:1 mass ratio, at a concentration of 0.4% of the total fermentation system mass. Stir well and maintain a constant temperature of 45℃ for 9 hours. After enzymatic hydrolysis, raise the system temperature to 90℃ and maintain a constant temperature for 15 minutes to terminate the enzymatic hydrolysis reaction. After cooling the hydrolysate to room temperature, centrifuge at 3000 rpm for 15 minutes to remove the precipitate. Collect the supernatant and filter it once through a 1000-mesh filter cloth to obtain the brewer's yeast fermentation product solution.

[0036] Comparative Example 1 A brewer's yeast fermentation product solution is prepared by the following steps: S1. Pretreatment of buckwheat sprouts: Select fresh buckwheat sprouts that are free from rot and pests, rinse them three times with deionized water, drain the water, and grind them into particles with a particle size of 0.5mm in a grinder for later use. Mixing of composite substrates: Place the pretreated buckwheat sprout powder into a sterile mixing tank, add deionized water, stir evenly, adjust the water content of the system to 65%, adjust the pH to 5.2, stir for 13 minutes, and ensure pH uniformity. Substrate sterilization: Transfer the well-mixed composite substrate into a sterile fermenter, seal the tank opening, place it in a high-pressure steam sterilizer, set the sterilization parameters: 121℃, 0.1MPa, sterilize for 20 minutes, and cool to room temperature; S2. Inoculation: Inoculate the activated brewer's yeast seed culture into the cooled composite substrate. The inoculum concentration after inoculation is 5 × 10⁻⁶. 6 CFU / g; turn on the stirrer and stir for 15 minutes to ensure that the inoculum and substrate are fully mixed and to avoid local inoculum concentrations that are too high or too low. Constant temperature fermentation: Adjust the temperature to 29℃ and humidity to 65%; adopt the "intermittent aeration + intermittent stirring" mode, stir once every 6 hours for 8 minutes each time in the first 24 hours, and introduce sterile air at the same time; after 24 hours, stir once every 8 hours for 12 minutes each time, fermentation cycle: 80 hours.

[0037] S3. Post-treatment: Adjust the temperature to 53℃ and maintain a constant temperature for yeast autolysis for 30 hours. During autolysis, stir for 8 minutes every 6 hours to promote yeast cell rupture and release intracellular substances. Then, lower the system temperature to 42℃ and adjust the pH to 5.8. Add a complex enzyme consisting of neutral protease and carboxypeptidase in a 2:1 mass ratio, at a concentration of 0.4% of the total fermentation system mass. Stir well and maintain a constant temperature of 45℃ for 9 hours. After enzymatic hydrolysis, raise the system temperature to 90℃ and maintain a constant temperature for 15 minutes to terminate the enzymatic hydrolysis reaction. After cooling the hydrolysate to room temperature, centrifuge at 3000 rpm for 15 minutes to remove the precipitate. Collect the supernatant and filter it once through a 1000-mesh filter cloth to obtain the brewer's yeast fermentation product solution.

[0038] Comparative Example 2 A brewer's yeast fermentation product solution is prepared by the following steps: S1. Rice bran pretreatment: Take food-grade rice bran, remove impurities, grind it into 80 mesh in a grinder, dry it in a 105℃ oven for 2 hours, and cool it to room temperature for later use. Composite substrate mixing: Place the pretreated rice bran powder into a sterile mixing tank, add deionized water, stir evenly, adjust the water content of the system to 65%, adjust the pH to 5.2, stir for 13 minutes, and ensure pH uniformity. Substrate sterilization: Transfer the well-mixed composite substrate into a sterile fermenter, seal the tank opening, place it in a high-pressure steam sterilizer, set the sterilization parameters: 121℃, 0.1MPa, sterilize for 20 minutes, and cool to room temperature; S2. Inoculation: Inoculate the activated brewer's yeast seed culture into the cooled composite substrate. The inoculum concentration after inoculation is 5 × 10⁻⁶. 6 CFU / g; turn on the stirrer and stir for 15 minutes to ensure that the inoculum and substrate are fully mixed and to avoid local inoculum concentrations that are too high or too low. Constant temperature fermentation: Adjust the temperature to 29℃ and humidity to 65%; adopt the "intermittent aeration + intermittent stirring" mode, stir once every 6 hours for 8 minutes each time in the first 24 hours, and introduce sterile air at the same time; after 24 hours, stir once every 8 hours for 12 minutes each time, fermentation cycle: 80 hours.

[0039] S3. Post-treatment: Adjust the temperature to 53℃ and maintain a constant temperature for yeast autolysis for 30 hours. During autolysis, stir for 8 minutes every 6 hours to promote yeast cell rupture and release intracellular substances. Then, lower the system temperature to 42℃ and adjust the pH to 5.8. Add a complex enzyme consisting of neutral protease and carboxypeptidase in a 2:1 mass ratio, at a concentration of 0.4% of the total fermentation system mass. Stir well and maintain a constant temperature of 45℃ for 9 hours. After enzymatic hydrolysis, raise the system temperature to 90℃ and maintain a constant temperature for 15 minutes to terminate the enzymatic hydrolysis reaction. After cooling the hydrolysate to room temperature, centrifuge at 3000 rpm for 15 minutes to remove the precipitate. Collect the supernatant and filter it once through a 1000-mesh filter cloth to obtain the brewer's yeast fermentation product solution.

[0040] Comparative Example 3 A brewer's yeast fermentation product solution is prepared by the following steps: S1. Soy milk pretreatment: Soak fresh soybeans at room temperature for 7 hours, remove the skins, add 3 times the volume of deionized water, grind into soy milk using a soy milk maker, then refine through a colloid mill, filter with a 100-mesh filter cloth to remove soy pulp, adjust the solid content to 14%, and set aside. Mixing of composite substrates: Place the pretreated soy milk into a sterile mixing tank, add deionized water, stir evenly, adjust the water content of the system to 65%, adjust the pH to 5.2, stir for 13 minutes, and ensure that the pH is uniform. Substrate sterilization: Transfer the well-mixed composite substrate into a sterile fermenter, seal the tank opening, place it in a high-pressure steam sterilizer, set the sterilization parameters: 121℃, 0.1MPa, sterilize for 20 minutes, and cool to room temperature; S2. Inoculation: Inoculate the activated brewer's yeast seed culture into the cooled composite substrate. The inoculum concentration after inoculation is 5 × 10⁻⁶. 6 CFU / g; turn on the stirrer and stir for 15 minutes to ensure that the inoculum and substrate are fully mixed and to avoid local inoculum concentrations that are too high or too low. Constant temperature fermentation: Adjust the temperature to 29℃ and humidity to 65%; adopt the "intermittent aeration + intermittent stirring" mode, stir once every 6 hours for 8 minutes each time in the first 24 hours, and introduce sterile air at the same time; after 24 hours, stir once every 8 hours for 12 minutes each time, fermentation cycle: 80 hours.

[0041] S3. Post-treatment: Adjust the temperature to 53℃ and maintain a constant temperature for yeast autolysis for 30 hours. During autolysis, stir for 8 minutes every 6 hours to promote yeast cell rupture and release intracellular substances. Then, lower the system temperature to 42℃ and adjust the pH to 5.8. Add a complex enzyme consisting of neutral protease and carboxypeptidase in a 2:1 mass ratio, at a concentration of 0.4% of the total fermentation system mass. Stir well and maintain a constant temperature of 45℃ for 9 hours. After enzymatic hydrolysis, raise the system temperature to 90℃ and maintain a constant temperature for 15 minutes to terminate the enzymatic hydrolysis reaction. After cooling the hydrolysate to room temperature, centrifuge at 3000 rpm for 15 minutes to remove the precipitate. Collect the supernatant and filter it once through a 1000-mesh filter cloth to obtain the brewer's yeast fermentation product solution.

[0042] Experiment 1: Determination of α-ketoglutaric acid content The content of α-ketoglutarate in the Saccharomyces cerevisiae fermentation product solutions prepared in Examples 1-3 and Comparative Examples 1-3 was determined according to the method described in the literature "Li Wei, Yu Han. Determination of α-ketoglutarate content in ornithine-α-ketoglutarate mixture by HPLC [J]. Chinese Journal of Modern Applied Pharmacy, 2010, 27(S1):1212-1214."

[0043] Accurately weigh approximately 70 mg of α-ketoglutaric acid reference standard and place it in a 25 mL volumetric flask. Add mobile phase to dissolve and dilute to the mark to prepare a stock solution containing 2.8 mg per mL. Accurately pipette appropriate amounts of the stock solution and add mobile phase to prepare solutions containing 0.014, 0.070, 0.35, and 2.8 mg per mL, respectively. Inject 20, 60, and 100 µL into a high-performance liquid chromatograph (HPLC). Analyze the solution using 0.1 mol·L⁻¹. 1 (NH4)H2PO4 (pH 2.65) was used as the mobile phase, with a flow rate of 1.0 mL·min. 1 The detection wavelength was 215 nm. The chromatographic peak area was recorded, and a linear regression was performed with α-ketoglutarate concentration (C) as the x-axis and peak area (A) as the y-axis, yielding the regression equation: Y = 285.33X + 14.642, R0. 2 =0.993 (n=3).

[0044] Take 100 mg of the yeast fermentation product to be tested, place it in a 25 mL volumetric flask, add mobile phase to dissolve and dilute to the mark, shake well, and use as the test solution. Inject 20 µL into the high-performance liquid chromatograph, record the peak area, and calculate the content of α-ketoglutaric acid using the external standard method. The results are as follows: Figure 1 .

[0045] from Figure 1It can be seen that the content of α-ketoglutarate in the brewer's yeast fermentation product solution prepared in the embodiments of the present invention is 1.2-1.5 mg / mL.

[0046] Comparative Example 4 A brewer's yeast fermentation product solution is prepared by the following steps: S1. Pretreatment of buckwheat sprouts: Select fresh buckwheat sprouts that are free from rot and pests, rinse them three times with deionized water, drain the water, and grind them into particles with a particle size of 0.5mm in a grinder for later use. Rice bran pretreatment: Take food-grade rice bran, remove impurities, grind it to 80 mesh in a grinder, dry it in a 105℃ oven for 2 hours, and cool it to room temperature for later use. Soy milk pretreatment: Soak fresh soybeans at room temperature for 7 hours, remove the skins, add 3 times the volume of deionized water, grind into soy milk using a soy milk maker, then refine through a colloid mill, filter with a 100-mesh filter cloth to remove soy pulp, adjust the solid content to 14%, and set aside. Mixing of composite substrates: Pretreated soy milk, buckwheat sprout powder, and rice bran powder are placed in a sterile mixing tank in a mass ratio of 8:2:3. Deionized water is added, and the mixture is stirred evenly. The water content of the system is adjusted to 65%, and the pH is adjusted to 5.2. The mixture is stirred for 13 minutes to ensure that the pH is uniform. Substrate sterilization: Transfer the well-mixed composite substrate into a sterile fermenter, seal the tank opening, place it in a high-pressure steam sterilizer, set the sterilization parameters: 121℃, 0.1MPa, sterilize for 20 minutes, and cool to room temperature; S2. Inoculation: Inoculate the activated brewer's yeast seed culture into the cooled composite substrate. The inoculum concentration after inoculation is 5 × 10⁻⁶. 6 CFU / g; turn on the stirrer and stir for 15 minutes to ensure that the inoculum and substrate are fully mixed and to avoid local inoculum concentrations that are too high or too low. Constant temperature fermentation: Adjust the temperature to 29℃ and humidity to 65%; adopt the "intermittent aeration + intermittent stirring" mode, stir once every 6 hours for 8 minutes each time in the first 24 hours, and introduce sterile air at the same time; after 24 hours, stir once every 8 hours for 12 minutes each time, fermentation cycle: 80 hours.

[0047] S3. Post-treatment: Adjust the temperature to 53℃ and maintain a constant temperature for yeast autolysis over 30 hours. During autolysis, stir for 8 minutes every 6 hours to promote yeast cell rupture and release intracellular substances. Then, lower the system temperature to 42℃ and adjust the pH to 5.8. Add neutral protease at 0.4% of the total fermentation system mass, stir well, and maintain a constant temperature of 45℃ for 9 hours. After enzymatic hydrolysis, raise the system temperature to 90℃ and maintain a constant temperature for 15 minutes to terminate the enzymatic hydrolysis reaction. After cooling the hydrolysate to room temperature, centrifuge at 3000 rpm for 15 minutes to remove the precipitate. Collect the supernatant and filter it once through a 1000-mesh filter cloth to obtain the brewer's yeast fermentation product solution.

[0048] Comparative Example 5 A brewer's yeast fermentation product solution is prepared by the following steps: S1. Pretreatment of buckwheat sprouts: Select fresh buckwheat sprouts that are free from rot and pests, rinse them three times with deionized water, drain the water, and grind them into particles with a particle size of 0.5mm in a grinder for later use. Rice bran pretreatment: Take food-grade rice bran, remove impurities, grind it to 80 mesh in a grinder, dry it in a 105℃ oven for 2 hours, and cool it to room temperature for later use. Soy milk pretreatment: Soak fresh soybeans at room temperature for 7 hours, remove the skins, add 3 times the volume of deionized water, grind into soy milk using a soy milk maker, then refine through a colloid mill, filter with a 100-mesh filter cloth to remove soy pulp, adjust the solid content to 14%, and set aside. Mixing of composite substrates: Pretreated soy milk, buckwheat sprout powder, and rice bran powder are placed in a sterile mixing tank in a mass ratio of 8:2:3. Deionized water is added, and the mixture is stirred evenly. The water content of the system is adjusted to 65%, and the pH is adjusted to 5.2. The mixture is stirred for 13 minutes to ensure that the pH is uniform. Substrate sterilization: Transfer the well-mixed composite substrate into a sterile fermenter, seal the tank opening, place it in a high-pressure steam sterilizer, set the sterilization parameters: 121℃, 0.1MPa, sterilize for 20 minutes, and cool to room temperature; S2. Inoculation: Inoculate the activated brewer's yeast seed culture into the cooled composite substrate. The inoculum concentration after inoculation is 5 × 10⁻⁶. 6 CFU / g; turn on the stirrer and stir for 15 minutes to ensure that the inoculum and substrate are fully mixed and to avoid local inoculum concentrations that are too high or too low. Constant temperature fermentation: Adjust the temperature to 29℃ and humidity to 65%; adopt the "intermittent aeration + intermittent stirring" mode, stir once every 6 hours for 8 minutes each time in the first 24 hours, and introduce sterile air at the same time; after 24 hours, stir once every 8 hours for 12 minutes each time, fermentation cycle: 80 hours.

[0049] S3. Post-treatment: Adjust the temperature to 53℃ and maintain a constant temperature for yeast autolysis over 30 hours. During autolysis, stir for 8 minutes every 6 hours to promote yeast cell rupture and release intracellular substances. Then, lower the system temperature to 42℃ and adjust the pH to 5.8. Add carboxypeptidase at 0.4% of the total fermentation system mass, stir well, and maintain a constant temperature of 45℃ for 9 hours. After enzymatic hydrolysis, raise the system temperature to 90℃ and maintain a constant temperature for 15 minutes to terminate the enzymatic hydrolysis reaction. After cooling the hydrolysate to room temperature, centrifuge at 3000 rpm for 15 minutes to remove the precipitate. Collect the supernatant and filter it once through a 1000-mesh filter cloth to obtain the brewer's yeast fermentation product solution.

[0050] Comparative Example 6 A brewer's yeast fermentation product solution is prepared by the following steps: S1. Pretreatment of buckwheat sprouts: Select fresh buckwheat sprouts that are free from rot and pests, rinse them three times with deionized water, drain the water, and grind them into particles with a particle size of 0.5mm in a grinder for later use. Rice bran pretreatment: Take food-grade rice bran, remove impurities, grind it to 80 mesh in a grinder, dry it in a 105℃ oven for 2 hours, and cool it to room temperature for later use. Soy milk pretreatment: Soak fresh soybeans at room temperature for 7 hours, remove the skins, add 3 times the volume of deionized water, grind into soy milk using a soy milk maker, then refine through a colloid mill, filter with a 100-mesh filter cloth to remove soy pulp, adjust the solid content to 14%, and set aside. Mixing of composite substrates: Pretreated soy milk, buckwheat sprout powder, and rice bran powder are placed in a sterile mixing tank in a mass ratio of 8:2:3. Deionized water is added, and the mixture is stirred evenly. The water content of the system is adjusted to 65%, and the pH is adjusted to 5.2. The mixture is stirred for 13 minutes to ensure that the pH is uniform. Substrate sterilization: Transfer the well-mixed composite substrate into a sterile fermenter, seal the tank opening, place it in a high-pressure steam sterilizer, set the sterilization parameters: 121℃, 0.1MPa, sterilize for 20 minutes, and cool to room temperature; S2. Inoculation: Inoculate the activated brewer's yeast seed culture into the cooled composite substrate. The inoculum concentration after inoculation is 5 × 10⁻⁶. 6 CFU / g; turn on the stirrer and stir for 15 minutes to ensure that the inoculum and substrate are fully mixed and to avoid local inoculum concentrations that are too high or too low. Constant temperature fermentation: Adjust the temperature to 29℃ and humidity to 65%; adopt the "intermittent aeration + intermittent stirring" mode, stir once every 6 hours for 8 minutes each time in the first 24 hours, and introduce sterile air at the same time; after 24 hours, stir once every 8 hours for 12 minutes each time, fermentation cycle: 80 hours.

[0051] S3. Post-treatment: Adjust the temperature to 53℃ and maintain a constant temperature for yeast autolysis over 30 hours. During autolysis, stir for 8 minutes every 6 hours to promote yeast cell rupture and release intracellular substances. Then, cool the system to room temperature and centrifuge at 3000 rpm for 15 minutes to remove the precipitate. Collect the supernatant and filter it once through a 1000-mesh filter cloth to obtain the brewing yeast fermentation product solution.

[0052] Experiment 2 The effect of the Saccharomyces cerevisiae fermentation product solutions prepared in Examples 1-3 and Comparative Examples 4-6 on the expression of human type I collagen was determined according to the method described in the literature "Fan Xiangcui, Liu Renhao, Qin Yinyi, et al. Study on the effect of a quantumized banana fruit extract on human type I collagen [J]. Laboratory Detection, 2025, 3(18):158-161."

[0053] Human fibroblasts were distributed at 8 × 10⁸ cells per well. 4 Cells were seeded at a density of [insert density here] into 24-well plates and then incubated overnight at 37°C with 5% CO2. Three concentration gradients were set up for the sample groups in the experiment. When the cell deposition rate reached half, the sample groups were treated with a dose of 9 J / cm². 2 The control group received UVA irradiation, while the blank control group received 0 J / cm² irradiation under the same conditions. 2 The cells were irradiated with UVA. After irradiation, the drug was administered. 1 mL of cell culture medium was added to each well in the blank control group, and 1 mL of culture medium containing 1% v / v of the test substance was added to each well in the sample group. After 1 day of culture, the cell supernatant was collected into EP tubes and stored at -80°C. Subsequently, the Collagen I content was detected according to the ELISA kit instructions. The specific test results are shown in Table 1.

[0054] Table 1 Summary of Collagen I Results As can be seen from Table 1, the Saccharomyces cerevisiae fermentation product solutions prepared in Examples 1-3 of the present invention can significantly promote the expression of type I collagen in fibroblasts.

[0055] Experiment 3 Antioxidant Test The antioxidant properties of the brewer's yeast fermentation product solutions prepared in Examples 1-3 and Comparative Examples 4-6 were tested according to the method described in the literature "Fan Fan, Dong Xu, Li Yuanyuan, et al. Synergistic antioxidant effect of compound rosemary extract on plant moisturizing oil [J]. China Oils and Fats".

[0056] First, prepare a 0.12 mg / mL DPPH anhydrous ethanol solution. In a single well of a 96-well plate, mix 10 μL of the test sample (the above-prepared Saccharomyces cerevisiae fermentation product solution diluted 100 times with water) with 240 μL of DPPH anhydrous ethanol solution to form the sample group. Mix 10 μL of anhydrous ethanol with 240 μL of DPPH anhydrous ethanol solution to form the control group. Mix 10 μL of the test sample with 240 μL of anhydrous ethanol solution to form the blank group. Incubate the mixed samples at room temperature in the dark for 30 min. Then, measure the absorbance at 517 nm using a microplate reader. Each group is measured in triplicate. The DPPH clearance rate is calculated using the following formula: DPPH clearance rate % = [1 - (A sample - A blank) / A control] × 100%. Where A sample is the absorbance value of the sample group; A blank is the absorbance value of the blank group; and A control is the absorbance value of the control group. Specific test results are shown in Table 2.

[0057] Table 2 DPPH Free Radical Scavenging Rate Record Table

[0058] As can be seen from Table 2, the brewing yeast fermentation product solutions prepared in Examples 1-3 of the present invention have better free radical scavenging ability and better antioxidant capacity compared with those prepared in Comparative Examples 4-6.

[0059] Example 4 A multi-effect essence comprises the following components in weight percentages: 5% glycerin, 3% butylene glycol, 0.05% sodium hyaluronate, 0.1% sclerotium tumefaciens gum, 0.5% betaine, 0.5% p-hydroxyacetophenone, 0.5% 1,2-hexanediol, 0.05% disodium EDTA, 1% glyceryl polyether-26, 0.1% hydroxyphenylpropionamide benzoic acid, 5% of the brewer's yeast fermentation product solution prepared in Example 1, and the balance being water.

[0060] Example 5 A multi-effect face cream comprising the following components in weight percentages: PEG-100 stearate 0.25%, glyceryl stearate 0.25%, cetearyl alcohol 2%, polydimethylsiloxane 1%, C10-18 triglycerides 2.5%, tocopheryl acetate 0.5%, isononyl isononanoate 5%, cetyl alcohol 0.72%, glyceryl stearate 0.72%, PEG-75 stearate 0.3%, cetyl alcohol polyether-20 0.13%, stearyl alcohol polyether-20 0.13%, polydimethylsiloxane 0.6%, cyclic polydimethylsiloxane 0.3%, PEG-10 polydimethylsiloxane crosspolymer 0.1%, butanediol 5%, p-hydroxyacetophenone 0.5%, ammonium acryloyl dimethyl taurate / VP copolymer 0.4%, disodium EDTA 0.03%, polyacrylamide 0.08%, C13-14 Isoparaffins 0.04%, lauryl alcohol polyether-7 0.012%, 1,2-hexanediol 0.5%, betaine 1.5%, brewer's yeast fermentation product solution prepared in Example 3 5%, water balance.

[0061] Experiment 4: Volunteer Efficacy Test Thirty volunteers aged 35-55 were recruited to conduct volunteer trial tests on the multi-effect essence prepared in Example 4 and the multi-effect face cream prepared in Example 5 of this invention.

[0062] Volunteer selection criteria: No gender restrictions, but skin with wrinkles, dryness, tightness, aging issues, and sensitivity issues such as redness and stinging; no serious facial skin diseases (acne, eczema, dermatitis, etc.), no external injuries, and no history of hormone dependence; no use of potent skin care products containing hormones, retinoic acid, fruit acids, etc. within the past month, and no medical aesthetic procedures (photorejuvenation, mesotherapy, etc.). Able to strictly follow testing specifications, participate in testing on time, complete daily usage records, and have no frequent absences; Voluntarily sign the informed consent form, understand the testing process and precautions, and declare any known allergens or have no history of allergies in advance.

[0063] Subjects strictly followed the instructions to use the serum and face cream together, once in the morning and once in the evening, for one month. During this period, they avoided using other eye care products and cosmetics, and avoided behaviors that could affect their skin condition, such as staying up late and excessive eye strain.

[0064] At time points D0, D14, and D28, photos of volunteers' faces were taken using a VISIA 7 for archiving. On D28, volunteers completed a final questionnaire to comprehensively evaluate the improvement in skin problems. The results are summarized in Table 2.

[0065] A 1-5 point rating scale (1 point = no improvement / very poor, 5 points = significant improvement / excellent) was used. Participants completed the assessment through a questionnaire. The core indicators are as follows: I. Moisturizing Dimension 5 stars: Skin is moisturized and plump, without any tightness, and there is no dryness or peeling throughout the day; 4 points: Skin is relatively moisturized, with a slight tightness and no obvious dryness or peeling; 3 points: Skin is generally moisturized, occasionally feels tight, and has slight dryness in some areas; 2 points: Dry skin, noticeable tightness, with a small amount of dry peeling; 1 point: Severely dry skin, intense tightness, large areas of peeling and makeup caking.

[0066] II. Sensitive Dimensions 5 points: No redness or stinging on the skin, all sensitivity symptoms are completely relieved, and the skin barrier is stable; 4 points: Slight redness of the skin, significant improvement in sensitivity symptoms, no stinging or itching; 3 points: Skin redness and sensitivity have improved to some extent, with occasional slight stinging. 2 points: Skin redness and sensitivity show no significant improvement, with frequent stinging and itching; 1 point: Skin redness and increased sensitivity, with obvious discomfort or allergic reactions.

[0067] III. Anti-aging Dimensions 5 points: Fine lines on the face are significantly reduced and become shallower, the skin is firm, elastic and radiant, and the contours are improved; 4 points: Fine lines on the face are somewhat reduced and become shallower, the skin elasticity and radiance are improved, and there is no obvious sagging. 3 points: No obvious change in facial fine lines, and basically no improvement in skin elasticity and radiance; 2 points: Fine lines on the face have deepened slightly, skin elasticity has decreased slightly, and skin tone is dull; 1 point: Facial fine lines are significantly deepened, skin laxity worsens, skin tone is dull, and anti-aging effect is poor.

[0068] Table 3. Results of the Volunteer Questionnaire Survey As shown in Table 3, after volunteers used the multi-effect essence prepared in Example 4 and the multi-effect face cream prepared in Example 5 of this invention together for one month, in terms of moisturizing, more than 95% of the volunteers gave a rating of 4 or higher; in terms of sensitivity, more than 90% of the volunteers gave a rating of 4 or higher; and in terms of anti-aging, more than 70% of the volunteers gave a rating of 4 or higher.

[0069] Typical cases Figure 2As shown, after 28 days of using the product, volunteers (numbers 3 and 23) showed a significant reduction and lightening of fine lines around their eyes compared to before use (D0). Figure 3 The study showed that two other volunteers (numbered 2 and 8) showed significant improvement in the area and color depth of the red zone on their faces after using the product for 28 days compared to before use (D0).

[0070] Overall, the multi-effect essence and multi-effect face cream containing the brewer's yeast fermentation product solution prepared according to the embodiments of the present invention achieve good skin care effects such as moisturizing, sensitive skin repair, and anti-aging.

[0071] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A brewer's yeast fermentation product solution, characterized in that, The preparation method includes the following steps: (1) inoculating brewer's yeast in a culture medium containing soybean milk, buckwheat sprouts and rice bran to obtain fermentation liquid; (2) enzymatically hydrolyzing the fermentation liquid obtained in step (1), then separating the solid and liquid phases and taking the liquid phase.

2. The brewing yeast fermentation product solution according to claim 1, characterized in that, In step (1), the yeast is inoculated into the culture medium at a concentration of 1 x 10 6 -1 x 10 7 CFU / g, the stirrer is turned on for 10-20 min to ensure that the yeast and the substrate are mixed well, avoiding local over-concentration or under-concentration of the yeast; then the temperature is adjusted to 28-30°C and the humidity to 60-70%, and the "intermittent aeration + intermittent stirring" mode is adopted, i.e. stirring once every 6 h for 5-10 min and simultaneously aeration with sterile air for the first 24 h; stirring once every 8 h for 10-15 min after 24 h, and the fermentation period being 72-96 h.

3. The brewing yeast fermentation product solution according to claim 1, characterized in that, In step (1), seaweed powder is also added to the culture medium, wherein the seaweed is one or more of red algae, blue algae and green algae.

4. The brewing yeast fermentation product solution according to claim 1, characterized in that, In step (1), the pretreatment process of the soy milk is as follows: fresh soybeans are soaked at room temperature for 6-8 hours, peeled, and then 3 times the volume of deionized water is added. The soybeans are then ground into soy milk using a soy milk maker, refined by a colloid mill, filtered with a 100-mesh filter cloth to remove the soybean residue, and the solid content is adjusted to 12-15% for later use.

5. The brewer's yeast fermentation product solution according to claim 1, characterized in that, In step (1), the pretreatment process of buckwheat sprouts is as follows: select fresh buckwheat sprouts that are free from rot and pests, rinse them three times with deionized water, drain the water, and grind them into a pulverizer to a particle size of 0.5-1mm for later use.

6. The brewing yeast fermentation product solution according to claim 1, characterized in that, In step (1), the pretreatment process of rice bran is as follows: take food-grade rice bran, remove impurities, put it into a pulverizer and pulverize it to 50-100 mesh, put it in a 105℃ oven to dry for 2 hours, and cool it to room temperature for later use.

7. The brewer's yeast fermentation product solution according to claim 1, characterized in that, In step (1), the preparation process of the culture medium is as follows: the pretreated soybean milk, buckwheat sprout powder and rice bran powder are put into a sterile mixing tank, deionized water is added, the mixture is stirred evenly, the water content of the system is adjusted to 60-70%, the pH is adjusted to 5.0-5.5, and the mixture is stirred for 10 minutes to ensure that the pH is uniform; the evenly mixed composite substrate is transferred into a sterile fermenter, the tank opening is sealed, and the mixture is placed in a high-pressure steam sterilizer. The sterilization parameters are set as follows: 121℃, 0.1MPa, sterilization for 20 minutes, and then cooled to room temperature.

8. The brewer's yeast fermentation product solution according to claim 1, characterized in that, In step (1), the mass ratio of the soy milk, buckwheat sprouts, and rice bran is 5-10:1-5:1-5.

9. The brewer's yeast fermentation product solution according to claim 1, characterized in that, In step (2), the enzymatic hydrolysis step includes the following process: adjusting the temperature to 50-55℃, maintaining a constant temperature, and performing yeast autolysis for 24-36 hours; during the autolysis process, stirring once every 6 hours for 5-10 minutes each time to promote yeast cell rupture and release intracellular substances; then lowering the system temperature to 40-45℃ and adjusting the pH to 5.5-6.0; adding a complex enzyme composed of neutral protease and carboxypeptidase in a mass ratio of 1:1 to 3:1, with the amount of complex enzyme added being 0.3-0.5% of the total mass of the fermentation system, stirring evenly, and hydrolyzing at a constant temperature of 45℃ for 6-12 hours; after the enzymatic hydrolysis is completed, raising the system temperature to 90℃ and maintaining the temperature for 15 minutes to terminate the enzymatic hydrolysis reaction; after the enzymatic hydrolysate is cooled to room temperature, it is placed in a centrifuge and centrifuged at 3000 r / min for 15 minutes to remove the precipitate; Collect the supernatant from centrifugation and filter it once with an 800-1000 mesh filter cloth to further remove fine impurities.

10. Use of the brewing yeast fermentation product solution according to any one of claims 1-9 in the preparation of cosmetics.

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