Grape seed fermentation raw pulp skin care product and preparation method and application thereof

Abstract

The present application relates to a kind of grape seed fermentation raw pulp skin care product and its preparation method and application.The preparation method includes that grape seed powder is mixed with water after cellulase and pectinase enzymolysis, then access lactic acid bacteria fermentation;When the fermentation liquor reaches specific pH and free lactic acid content, first add alginic acid oligosaccharide and sodium phytate, stir then add gluconolactone and low-substitution hydroxypropyl cellulose, continue fermentation, sterilization and filtration, obtain grape seed fermentation raw pulp;Then the raw pulp is mixed with humectant, thickening agent, preservative aid and water, and skin care product is prepared.The present application is controlled by two-stage during fermentation ripening stage, so that oligomeric procyanidins, organic acid salt and ripening control component form relatively stable dispersion state, reduce the risk of fine sedimentation, kneading mud and uneven coating film rubbing when applying after hard water cleaning.

Description

Technical Field

[0001] This invention relates to the technical field of cosmetics, and in particular to a grape seed fermented pulp skincare product, its preparation method, and its application. Background Technology

[0002] Grape seeds contain proanthocyanidins, polyphenols, fatty acids, and trace minerals. As a plant-based cosmetic ingredient, they are widely used in antioxidant, moisturizing, soothing, and skincare products. With the application of fermentation technology in cosmetic ingredient processing, the use of microbial fermentation to improve the release of active substances in plant-based ingredients, reduce roughness, and enhance aqueous dispersibility is gaining increasing attention. After fermentation, grape seeds can form a fermented pulp or broth containing polyphenols, organic acids, and fermentation metabolites, which has been used in skincare products such as serums, face masks, and toners.

[0003] For example, existing technologies include grape seed fermented pulp cosmetics and their preparation methods. These involve mixing grape seed powder, water, and bacterial solution, followed by fermentation to obtain grape seed fermented pulp, which is then applied to cosmetics. Other existing technologies disclose probiotic grape seed masks and their preparation methods. This involves fermenting grape seeds with probiotics to obtain grape seed fermentation liquid, which is then mixed with moisturizers, thickeners, preservatives, and other skincare excipients to prepare a mask product. These technologies demonstrate that grape seed fermentation products already have a certain application basis as active ingredients in skincare products.

[0004] However, grape seed fermented pulp typically contains polyphenols, organic acid salts, and fermentation small molecule components. Its film-forming properties in actual use are affected not only by the formulation but also by residues left after skin cleansing. In hard water areas, a certain amount of calcium and magnesium ions and a small amount of cleanser residue may remain on the skin surface after cleansing. When grape seed fermented pulp skincare products are applied under such residual conditions, they are prone to localized fine deposits, pilling, or uneven film formation, thus affecting the skin feel and application uniformity.

[0005] Therefore, how to reduce the risk of fine deposits, pilling, and uneven coating of grape seed fermented pulp skincare products during application after cleansing with hard water has become a technical problem that needs to be solved for the further application of this type of skincare product. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned problems existing in the prior art and to provide a grape seed fermented pulp skin care product, its preparation method and application, so as to reduce the risk of fine deposits, pilling and uneven coating friction during the application of grape seed fermented pulp skin care product after hard water cleansing.

[0007] To achieve the above objectives, the first aspect of the present invention provides a method for preparing a grape seed fermented pulp skincare product, comprising the following steps: S1: Mix grape seed powder with deionized water at a mass ratio of 1:(10-14), adjust the pH to 5.0-5.3, add cellulase and pectinase, and enzymatically hydrolyze at 42-46℃ for 2-3 hours to obtain grape seed hydrolysate; S2: After inactivating the enzymes in the grape seed hydrolysate, cool it to 34-37°C, and then inoculate it with Lactobacillus plantarum fermentation broth to make the initial viable cell count of the fermentation system 1×10⁻⁶. 6 ~2×10 7 CFU / mL, fermented at 34–37°C to obtain fermentation broth; S3: When the pH of the fermentation broth is 4.30-4.65 and the free lactic acid content is 0.32%-0.52%, alginate oligosaccharide and sodium phytate are added to the fermentation broth. After stirring for 20-40 minutes, gluconolactone and low-substituted hydroxypropyl cellulose are added. Fermentation continues for 3-5 hours, followed by sterilization and filtration to obtain grape seed fermentation broth. S4: Mix the grape seed fermented pulp, moisturizer, thickener, preservative and deionized water to obtain the grape seed fermented pulp skin care product; The free lactic acid content is calculated based on the mass of the fermentation broth; the mass ratio of the alginate oligosaccharide to the sodium phytate is 1:(0.35-0.60); the mass ratio of the glucono-delta-lactone to the sodium phytate is 1:(0.25-0.70); the mass ratio of the low-substituted hydroxypropyl cellulose to the alginate oligosaccharide is 1:(0.40-1.20); and the oligomeric proanthocyanidins in the grape seed fermentation broth account for 42%-56% of the total proanthocyanidins by mass.

[0008] Through the above preparation process, grape seed powder is first enzymatically hydrolyzed under suitable acidity and temperature, which moderately opens the cell walls and pectin structure, making it easier for polyphenols in grape seeds to enter the aqueous phase system. Subsequently, during the fermentation process of *Lactobacillus plantarum*, the system gradually forms a fermentation environment containing oligomeric proanthocyanidins, lactic acid, organic acid salts, and fermentation small molecule components. Crucially, a two-stage post-ripening regulation is performed when the fermentation broth reaches a specific pH and free lactic acid content. This ensures that alginate oligosaccharides, sodium phytate, glucono-delta-lactone, and low-substituted hydroxypropyl cellulose do not simply remain as ordinary additives, but participate in the formation of dispersed structures within the existing weakly acidic and organic acid salt environment of the fermentation broth. Sodium phytate provides competitive complexation sites for calcium and magnesium ions, alginate oligosaccharides provide flexible hydrophilic segments, glucono-delta-lactone gradually forms mild gluconic acid-related components in the post-ripening environment, and low-substituted hydroxypropyl cellulose provides subtle spatial isolation within the system. When these components work together in a defined ratio, grape seed oligomeric proanthocyanidins are less likely to aggregate into coarse particles in the subsequent hard water cleansing residue environment. This helps reduce fine deposits, pilling, and uneven application during the skin-feeling process. This effect doesn't simply rely on increasing viscosity to mask skin-feel issues; rather, it involves forming a more stable and dispersed pulp state during the post-fermentation ripening stage. This makes skincare products easier and more evenly applied, and better preserves the user experience of the fermented grape seed pulp.

[0009] Preferably, in S1, the grape seed powder has a particle size of 100-140 mesh, and the grape seed powder is dried with hot air at 45-55°C to a moisture content of no more than 8% before being mixed with deionized water.

[0010] This particle size range is beneficial for increasing the contact area between grape seed powder and water and enzyme preparations, making the enzymatic hydrolysis process more uniform, while avoiding excessively fine powder that would lead to excessively high initial viscosity of the system and increased filtration burden. Pre-controlling the moisture content of grape seed powder at a low level can reduce inconsistencies in the starting point of enzymatic hydrolysis caused by moisture fluctuations during raw material storage and feeding, making the subsequent pH decrease and polyphenol release processes of the fermentation broth easier to control.

[0011] Preferably, in S1, the amount of cellulase added is 0.20% to 0.45% of the mass of the grape seed powder, and the amount of pectinase added is 0.10% to 0.30% of the mass of the grape seed powder.

[0012] At the aforementioned dosages, cellulase and pectinase can moderately decompose the cell wall structure and pectin in grape seed powder, resulting in a more complete release of polyphenols and providing a more stable substrate environment for subsequent lactic acid bacteria fermentation. Controlling the enzymatic hydrolysis intensity within a mild range reduces the increase in turbidity and the concentrated release of astringent components caused by excessive hydrolysis, ensuring that the grape seed hydrolysate maintains both a high degree of active substance release and system cleanliness when entering the fermentation stage.

[0013] Preferably, in S2, the *Lactobacillus plantarum* fermentation broth is prepared by culturing *Lactobacillus plantarum* in MRS liquid medium until the viable count reaches 1 × 10⁻⁶. 8 ~5×10 9 The concentration of CFU / mL was obtained.

[0014] Controlling the viable cell count of *Lactobacillus plantarum* fermentation broth within this range ensures a more stable fermentation start-up after inoculation with grape seed hydrolysate, preventing excessively slow acidification or excessively high cell load during the initial fermentation stage. A stable fermentation start-up process facilitates the formation of a continuous and controllable lactic acid production curve, enabling better repeatability of subsequent two-stage after-ripening regulation at specific pH and free lactic acid levels.

[0015] Preferably, in S3, the number average molecular weight of the alginate oligosaccharide is 800-2500 Da, and the hydroxypropoxy content of the low-substituted hydroxypropyl cellulose is 5%-16%.

[0016] When alginate oligosaccharides are within the aforementioned number-average molecular weight range, their water solubility and flexible segment characteristics are well-suited for dispersion and association in fermentation broth, making them less likely to form a noticeably thick film. When the hydroxypropoxy content of low-substituted hydroxypropyl cellulose is controlled within the aforementioned range, it can form moderate swelling and steric support in the aqueous phase, resulting in a finer and more dispersed distribution of polyphenolic components, phytate complexation sites, and gluconic acid-related components, making it less likely for them to aggregate into large localized deposits.

[0017] Preferably, in S3, based on the mass of the fermentation broth, the amount of alginate oligosaccharide added is 0.06% to 0.22%, the amount of sodium phytate added is 0.025% to 0.11%, the amount of gluconolactone added is 0.010% to 0.077%, and the amount of low-substituted hydroxypropyl cellulose added is 0.024% to 0.264%.

[0018] The above-mentioned addition amounts ensure that the four post-ripening control components are maintained in a low-addition, finely controlled state in the fermentation broth. Alginic oligosaccharides provide a dispersion basis, sodium phytate provides a competitive complexation basis for calcium and magnesium ions, gluconolactone provides a milder subsequent acidification and weak complexation environment, and low-substituted hydroxypropyl cellulose provides spatial isolation and a smooth coating film. Maintaining the dosage of each component within a narrow range reduces stickiness, astringency, or localized aggregation caused by excessive amounts of a single component, thus balancing the stability of application under hard water residue conditions with the everyday feel on the skin.

[0019] Preferably, in S3, after fermentation is completed, the product is sterilized at 75–85°C for 10–20 min and filtered through a 0.45–1.0 μm filter membrane.

[0020] These sterilization conditions terminate the fermentation process, fixing the dispersed state formed during the post-ripening stage and reducing the risk of further pH decline due to continued microbial metabolism. Subsequent filtration using the aforementioned membrane removes large, poorly dispersed particles, resulting in a more stable appearance and coating fineness of the grape seed fermentation pulp. This also helps reduce the risk of sedimentation or visible particles appearing after skincare product preparation.

[0021] Preferably, in step S4, the grape seed fermented pulp skincare product comprises the following components by weight: 25-40 parts of grape seed fermentation pulp; 2-5 parts glycerin; 3 to 7 parts of 1,3-propanediol; Betaine 0.8–2.0 parts; Panthenol 0.3–1.0 parts; Hydroxyethyl cellulose 0.08–0.18 parts; Capryloyl hydroxamic acid 0.03–0.10 parts; Ethylhexylglycerin 0.07–0.25 parts; Add deionized water to bring the total to 100 parts.

[0022] This formulation uses fermented grape seed pulp as the main functional phase, combined with glycerin, 1,3-propanediol, and betaine to form a gentle moisturizing base. Panthenol improves the smoothness after application, hydroxyethyl cellulose regulates the rheological state of the system, and capryloyl hydroxamic acid and ethylhexylglycerin provide a base of preservatives. This formulation does not mask pilling issues with high levels of colloidal or heavy-film oil phases, but rather allows the inherent dispersion and stability of the fermented pulp to be maintained in the final product. This results in skincare products that offer both hydration and spreadability with low friction fluctuations during application.

[0023] The second aspect of this invention provides a grape seed fermented pulp skincare product, prepared by the method described above; the grape seed fermented pulp skincare product, in the artificial hard water residue test, has a 600nm transmittance retention rate of not less than 82%, a pilling amount of not more than 1.8mg / 100cm², and a standard deviation of the coating friction coefficient of not more than 0.026; the artificial hard water residue test is performed by pretreating the test substrate with artificial hard water with a hardness of 300-500mg / L (calculated as calcium carbonate).

[0024] The skincare product prepared by the method described above maintains good dispersion and coating uniformity even under conditions of hard water residue. High 600nm transmittance retention indicates that calcium and magnesium ion-induced turbidity and coarse particle formation are suppressed; low pilling indicates that significant particle shedding is not easily formed during application and friction; and a low standard deviation of the coating friction coefficient indicates minimal variation in sliding resistance on the substrate surface, resulting in a more continuous coating. These characteristics collectively reflect that the polyphenols in the grape seed fermentation pulp maintain good dispersion and spreading even under conditions of hard water residue.

[0025] The third aspect of the present invention provides the application of the grape seed fermented pulp skin care product as described above in the preparation of skin care essence, skin care gel or mask liquid to be applied after hard water cleansing.

[0026] This application scenario matches the product's technical characteristics, making it particularly suitable for environments where calcium and magnesium ions remain on the skin's surface after cleansing. When the grape seed fermented pulp skincare product is formulated into a skincare essence, skincare gel, or mask, its low deposition, low pilling, and even coating characteristics can be utilized, resulting in more stable performance of grape seed fermented pulp products during daily application, layering of skincare products, and wet mask application.

[0027] The present invention, by adopting the above technical solution, has the following beneficial effects: The present invention has the following beneficial effects: 1. This invention utilizes continuous processing of grape seed powder through enzymatic hydrolysis and fermentation with Lactobacillus plantarum to allow polyphenols in the grape seed raw material to more fully enter the aqueous phase system. During the fermentation process, a grape seed fermentation paste containing oligomeric proanthocyanidins, lactic acid, organic acid salts, and fermentation small molecule components is formed, providing a foundation for the aqueous dispersibility, coating uniformity, and gentleness of subsequent skin care products.

[0028] 2. This invention performs two-stage post-ripening regulation when the fermentation broth reaches a specific pH and free lactic acid content, so that alginate oligosaccharides, sodium phytate, gluconolactone and low-substituted hydroxypropyl cellulose enter the fermentation system in an orderly manner and participate in the formation of the dispersion structure, so that the above components form a relatively stable weak association state with oligomeric proanthocyanidins and organic acid salts, rather than just playing the role of ordinary additives in the final preparation stage.

[0029] 3. This invention utilizes the calcium-magnesium competitive complexing effect of sodium phytate, the flexible hydrophilic dispersion effect of alginate oligosaccharides, the mild weak complexing effect of gluconolactone, and the spatial isolation effect of low-substituted hydroxypropyl cellulose to prevent local coarse particle aggregation in grape seed fermentation pulp under hard water residue conditions, thereby reducing the risk of fine deposition and mudding during the coating process.

[0030] 4. When the grape seed fermented pulp skin care product obtained by this invention is applied after cleaning with hard water, it can maintain good film continuity and spreading uniformity. This makes the product exhibit a high 600nm light transmittance retention rate, low pilling amount and low standard deviation of film friction coefficient in artificial hard water residue test, which is beneficial to improving the actual skin feel.

[0031] 5. The final product formulation of this invention uses grape seed fermentation pulp as the main functional phase, and forms a moisturizing system through glycerin, 1,3-propanediol, betaine, panthenol and a small amount of rheology adjustment components. It does not rely on high content of colloidal or heavy film-feeling oil phase to improve the application problem, thus it is beneficial to balance the stability of the formulation, the lightness of the spread and the comfort of daily skin care. Detailed Implementation

[0032] The specific embodiments of the present invention will be described in detail below. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0033] Unless otherwise defined, all scientific and technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art.

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0035] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0036] In the following examples and comparative examples, the grape seed powder was obtained by washing, drying at 45-55℃, pressing to remove oil, and pulverizing the grape seeds, a byproduct of Cabernet Sauvignon winemaking, with a residual oil content of 7.4%; the cellulase was acidic cellulase for food processing with an enzyme activity of 50,000 U / g and a suitable pH of 4.5-5.5; the pectinase was acidic pectinase for food processing with an enzyme activity of 30,000 U / g and a suitable pH of 4.0-5.5; and the Lactobacillus plantarum ATCC was used. 14917; Alginate oligosaccharide is a water-soluble oligosaccharide obtained by enzymatic hydrolysis of sodium alginate, containing both mannuronic acid and guluronic acid units, with a degree of polymerization of 4–15, and the number-average molecular weight determined by gel permeation chromatography; Low-substituted hydroxypropyl cellulose is a low-substituted cellulose derivative obtained by hydroxypropyl etherification of cellulose, which is in a swollen dispersion state in water, and the hydroxypropoxy content is determined according to the hydroxypropyl determination method in the Chinese Pharmacopoeia; Sodium phytate is sodium inositol hexaphosphate; Hydroxyethyl cellulose is cosmetic-grade hydroxyethyl cellulose with a viscosity of 300–1500 mPa·s in a 2% aqueous solution at 25℃; Gluconolactone, glycerol, 1,3-propanediol, betaine, panthenol, capryloyl hydroxyxamic acid, and ethylhexylglycerin are all cosmetic raw material grade.

[0037] Free lactic acid content was determined using a lactase assay kit, based on the mass of the fermentation broth. Oligomeric proanthocyanidins refer to proanthocyanidin components with a degree of polymerization of 2–5. The content of oligomeric proanthocyanidins and total proanthocyanidins was determined using high-performance liquid chromatography (HPLC), and the mass ratio of oligomeric proanthocyanidins to total proanthocyanidins was calculated. The mass ratio of low-substituted hydroxypropyl cellulose to alginate oligosaccharides was calculated with the mass of low-substituted hydroxypropyl cellulose being 1.

[0038] Example 1 This embodiment discloses a method for preparing a grape seed fermented pulp skin care product, including the following steps.

[0039] S1: Weigh 100.0g of grape seed powder, with a particle size of 120 mesh and a moisture content of 6.7%. Add the grape seed powder to 1200.0g of deionized water and stir at 300rpm for 15min to ensure uniform dispersion. Adjust the pH of the system to 5.2 using a 10% (w / w) citric acid aqueous solution and a 10% (w / w) sodium citrate aqueous solution. Then add 0.32g of cellulase and 0.20g of pectinase, and incubate at 44℃ for 2.5h for enzymatic hydrolysis, maintaining a stirring speed of 250rpm throughout the process. After enzymatic hydrolysis, heat the system to 90℃ and incubate for 10min to inactivate the enzymes, obtaining the grape seed enzymatic hydrolysate.

[0040] S2: Cool the grape seed enzymatic hydrolysate to 36℃. Inoculate *Lactobacillus plantarum* into MRS liquid medium and incubate at 36℃ for 18 hours, yielding a viable count of 2.1 × 10⁻⁶.9 CFU / mL of *Lactobacillus plantarum* fermentation broth. *Lactobacillus plantarum* fermentation broth was inoculated into grape seed enzymatic hydrolysate to achieve an initial viable cell count of 7.9 × 10⁻⁶. 6 CFU / mL. Subsequently, the mixture was allowed to ferment at 36°C. During fermentation, the pH and free lactic acid content were measured every 2 hours to obtain the fermentation broth.

[0041] S3: When the pH of the fermentation broth is 4.47 and the free lactic acid content is 0.43%, take 1300.0g of the fermentation broth. Mix 10.0g of the fermentation broth with 0.812g of alginate oligosaccharide and stir until uniformly dispersed to obtain an alginate oligosaccharide predispersant. Mix 10.0g of the fermentation broth with 0.390g of sodium phytate and stir until uniformly dissolved to obtain a sodium phytate predispersant. Add the alginate oligosaccharide predispersant and sodium phytate predispersant to the remaining fermentation broth. The number-average molecular weight of the alginate oligosaccharide is 1518 Da, and the mass ratio of alginate oligosaccharide to sodium phytate is 1:0.48. Stir at 36℃ and 250rpm for 30min. Subsequently, 0.867 g of glucono-delta-lactone and 1.015 g of low-substituted hydroxypropyl cellulose were dry-mixed and slowly added to the fermentation broth over 5 minutes while stirring. The hydroxypropoxy content of the low-substituted hydroxypropyl cellulose was 10.3%, the mass ratio of glucono-delta-lactone to sodium phytate was 1:0.45, and the mass ratio of low-substituted hydroxypropyl cellulose to alginate oligosaccharide was 1:0.80. Fermentation was continued at 36℃ for 4 hours, and the pH of the fermentation broth was 4.21 at the end of the fermentation. After the fermentation was completed, the mixture was sterilized at 80℃ for 15 minutes and filtered through a 0.80 μm filter membrane to obtain grape seed fermentation pulp. Analysis showed that oligomeric proanthocyanidins accounted for 49.3% of the total proanthocyanidins in the grape seed fermentation pulp.

[0042] S4: By weight, add 32.0 parts of grape seed fermented pulp, 3.5 parts of glycerin, 5.0 parts of 1,3-propanediol, 1.4 parts of betaine, 0.6 parts of panthenol, and 57.185 parts of deionized water to an emulsifying pot and stir at 25°C and 300 rpm for 20 min; then add 0.12 parts of hydroxyethyl cellulose, heat to 45°C and stir for 40 min to fully hydrate the hydroxyethyl cellulose; after cooling to 35°C, add 0.055 parts of capryloyl hydroxamic acid and 0.140 parts of ethylhexyl glycerin, and continue stirring for 20 min to obtain the grape seed fermented pulp skin care product.

[0043] Example 2 This embodiment discloses a method for preparing a grape seed fermented pulp skincare product. Except for the following differences, the other raw materials and steps are performed as in Example 1.

[0044] In S1, the amount of grape seed powder is 100.0g, the amount of deionized water is 1000.0g, and the mass ratio of grape seed powder to deionized water is 1:10; the moisture content of grape seed powder is 6.9%; the pH is adjusted to 5.0; the amount of cellulase added is 0.20g, the amount of pectinase added is 0.10g; the enzymatic hydrolysis temperature is 42℃, and the enzymatic hydrolysis time is 2.0h.

[0045] In S2, the grape seed hydrolysate was cooled to 34°C, the fermentation temperature was 34°C, and the viable count of *Lactobacillus plantarum* fermentation broth was 1.8 × 10⁻⁶. 9 CFU / mL, the initial viable cell count of the fermentation system was 1.1 × 10⁻⁶. 6 CFU / mL.

[0046] In S3, when the pH of the fermentation broth is 4.31 and the free lactic acid content is 0.33%, 1100.0 g of the fermentation broth is taken. 8.0 g of the fermentation broth is mixed with 0.660 g of alginate oligosaccharide and stirred until uniformly dispersed to obtain an alginate oligosaccharide predispersant. 8.0 g of the fermentation broth is mixed with 0.231 g of sodium phytate and stirred until uniformly dissolved to obtain a sodium phytate predispersant. The alginate oligosaccharide predispersant and sodium phytate predispersant are added to the remaining fermentation broth. The number-average molecular weight of the alginate oligosaccharide is 1486 Da, and the mass ratio of alginate oligosaccharide to sodium phytate is 1:0.35. The mixture is stirred at 34℃ and 250 rpm for 20 min. Subsequently, 0.924 g of glucono-delta-lactone and 1.650 g of low-substituted hydroxypropyl cellulose were dry-mixed evenly and slowly added to the fermentation broth over 5 minutes while stirring. The hydroxypropoxy content of the low-substituted hydroxypropyl cellulose was 10.1%, the mass ratio of glucono-delta-lactone to sodium phytate was 1:0.25, and the mass ratio of low-substituted hydroxypropyl cellulose to alginate oligosaccharide was 1:0.40. Fermentation was continued at 34℃ for 3 hours, and the pH of the fermentation broth was 4.11 at the end of fermentation. The mixture was then sterilized and filtered to obtain grape seed fermentation pulp. The oligomeric proanthocyanidins accounted for 42.8% of the total proanthocyanidins in the grape seed fermentation pulp.

[0047] In S4, the grape seed fermented pulp skincare product comprises, by weight, 25.0 parts grape seed fermented pulp, 2.0 parts glycerin, 3.0 parts 1,3-propanediol, 0.8 parts betaine, 0.3 parts panthenol, 0.08 parts hydroxyethyl cellulose, 0.03 parts capryloyl hydroxamic acid, 0.07 parts ethylhexylglycerin, and 68.72 parts deionized water.

[0048] Example 3 This embodiment discloses a method for preparing a grape seed fermented pulp skincare product. Except for the following differences, the other raw materials and steps are performed as in Example 1.

[0049] In S1, the amount of grape seed powder is 100.0g, the amount of deionized water is 1400.0g, and the mass ratio of grape seed powder to deionized water is 1:14; the moisture content of grape seed powder is 6.6%; the pH is adjusted to 5.3; the amount of cellulase added is 0.45g, the amount of pectinase added is 0.30g; the enzymatic hydrolysis temperature is 46℃, and the enzymatic hydrolysis time is 3.0h.

[0050] In S2, the grape seed hydrolysate was cooled to 37°C, the fermentation temperature was 37°C, and the viable count of *Lactobacillus plantarum* fermentation broth was 2.3 × 10⁻⁶. 9 CFU / mL, the initial viable cell count of the fermentation system was 1.9 × 10⁻⁶. 7 CFU / mL.

[0051] In S3, when the pH of the fermentation broth is 4.64 and the free lactic acid content is 0.51%, 1500.0 g of the fermentation broth is taken. 15.0 g of the fermentation broth is mixed with 3.300 g of alginate oligosaccharide and stirred until uniformly dispersed to obtain an alginate oligosaccharide predispersant. 15.0 g of the fermentation broth is mixed with 1.980 g of sodium phytate and stirred until uniformly dissolved to obtain a sodium phytate predispersant. The alginate oligosaccharide predispersant and sodium phytate predispersant are added to the remaining fermentation broth. The number-average molecular weight of the alginate oligosaccharide is 1527 Da, and the mass ratio of alginate oligosaccharide to sodium phytate is 1:0.60. The mixture is stirred at 37℃ and 250 rpm for 40 min. Subsequently, 2.829 g of glucono-delta-lactone and 2.750 g of low-substituted hydroxypropyl cellulose were dry-mixed evenly and slowly added to the fermentation broth over 5 minutes while stirring. The hydroxypropoxy group content of the low-substituted hydroxypropyl cellulose was 10.4%, the mass ratio of glucono-delta-lactone to sodium phytate was 1:0.70, and the mass ratio of low-substituted hydroxypropyl cellulose to alginate oligosaccharide was 1:1.20. Fermentation was continued at 37°C for 5 hours, and the pH of the fermentation broth was 4.35 at the end of fermentation. The mixture was then sterilized and filtered to obtain grape seed fermentation pulp. The oligomeric proanthocyanidins accounted for 55.6% of the total proanthocyanidins in the grape seed fermentation pulp.

[0052] In S4, the grape seed fermented pulp skincare product comprises, by weight, 40.0 parts grape seed fermented pulp, 5.0 parts glycerin, 7.0 parts 1,3-propanediol, 2.0 parts betaine, 1.0 part panthenol, 0.18 parts hydroxyethyl cellulose, 0.10 parts capryloyl hydroxamic acid, 0.25 parts ethylhexylglycerin, and 44.47 parts deionized water.

[0053] Example 4 This embodiment discloses a method for preparing a grape seed fermented pulp skincare product. Except for the alginate oligosaccharide having a number-average molecular weight of 812 Da, the other raw materials and steps are performed according to Example 1, and the grape seed fermented pulp skincare product is obtained via step S4. The oligomeric proanthocyanidins in the grape seed fermented pulp account for 48.7% of the total proanthocyanidins by mass.

[0054] Example 5 This embodiment discloses a method for preparing a grape seed fermented pulp skincare product. Except for the alginate oligosaccharide having a number-average molecular weight of 2486 Da, the remaining raw materials and steps are performed according to Example 1, and the grape seed fermented pulp skincare product is obtained via step S4. The oligomeric proanthocyanidins in the grape seed fermented pulp account for 49.0% of the total proanthocyanidins by mass.

[0055] Example 6 This embodiment discloses a method for preparing a grape seed fermented pulp skincare product. Except for the low-substituted hydroxypropyl cellulose having a hydroxypropoxy group content of 5.2%, the remaining raw materials and steps are performed according to Example 1, and the grape seed fermented pulp skincare product is obtained via step S4. The oligomeric proanthocyanidins in the grape seed fermented pulp account for 49.5% of the total proanthocyanidins by mass.

[0056] Example 7 This embodiment discloses a method for preparing a grape seed fermented pulp skincare product. Except for the low-substituted hydroxypropyl cellulose having a hydroxypropoxy group content of 15.8%, the remaining raw materials and steps are performed according to Example 1, and the grape seed fermented pulp skincare product is obtained via step S4. The oligomeric proanthocyanidins in the grape seed fermented pulp account for 48.9% of the total proanthocyanidins by mass.

[0057] Comparative Example 1 This comparative example discloses a method for preparing a grape seed fermented pulp skincare product. Except for the absence of alginate oligosaccharides in step S3, the other raw materials and steps were performed as in Example 1. To maintain the total mass of the fermentation broth close to that of Example 1, the corresponding mass of alginate oligosaccharides in step S3 was replaced with 0.812 g of deionized water. The oligomeric proanthocyanidins in the grape seed fermented pulp accounted for 49.1% of the total proanthocyanidins by mass.

[0058] Comparative Example 2 This comparative example discloses a method for preparing a grape seed fermented pulp skincare product. Except for the absence of sodium phytate in step S3, the other raw materials and steps were performed according to Example 1. To maintain the total mass of the fermentation broth close to that of Example 1, the corresponding mass of sodium phytate in step S3 was replaced with 0.390 g of deionized water. The oligomeric proanthocyanidins in the grape seed fermented pulp accounted for 49.4% of the total proanthocyanidins by mass.

[0059] Comparative Example 3 This comparative example discloses a method for preparing a grape seed fermented pulp skincare product. Except for the absence of glucono-delta-lactone in step S3, the remaining raw materials and steps were performed according to Example 1. To maintain the total mass of the fermentation broth close to that of Example 1, the corresponding mass of glucono-delta-lactone in step S3 was replaced with 0.867 g of deionized water. The oligomeric proanthocyanidins in the grape seed fermented pulp accounted for 49.0% of the total proanthocyanidins by mass.

[0060] Comparative Example 4 This comparative example discloses a method for preparing a grape seed fermented pulp skincare product. Except for the absence of low-substituted hydroxypropyl cellulose in step S3, the other raw materials and steps were performed as in Example 1. To maintain the total mass of the fermentation broth close to that of Example 1, the corresponding mass of low-substituted hydroxypropyl cellulose in step S3 was replaced with 1.015 g of deionized water. The oligomeric proanthocyanidins in the grape seed fermented pulp accounted for 49.2% of the total proanthocyanidins by mass.

[0061] Comparative Example 5 This comparative example discloses a method for preparing a grape seed fermented pulp skincare product. Except for the different order of addition of the four post-ripening regulating components in S3, the other raw materials and steps are performed according to Example 1.

[0062] In S3, when the pH of the fermentation broth is 4.47 and the free lactic acid content is 0.43%, 1300.0 g of the fermentation broth is taken. 10.0 g of the fermentation broth is mixed with 0.812 g of alginate oligosaccharide and stirred until uniformly dispersed to obtain an alginate oligosaccharide predispersant. 10.0 g of the fermentation broth is mixed with 0.390 g of sodium phytate and stirred until uniformly dissolved to obtain a sodium phytate predispersant. 0.867 g of glucono-delta-lactone and 1.015 g of low-substituted hydroxypropyl cellulose are dry-mixed to obtain a dry mixture. The alginate oligosaccharide predispersant, sodium phytate predispersant, and dry mixture are added to the remaining fermentation broth within 5 min under stirring. The mixture is stirred at 36℃ and 250 rpm for 30 min, then fermented at 36℃ for 4 h, sterilized at 80℃ for 15 min, and filtered through a 0.80 μm filter membrane to obtain grape seed fermentation pulp. Oligomeric proanthocyanidins accounted for 49.6% of the total proanthocyanidins in the grape seed fermentation pulp.

[0063] Comparative Example 6 This comparative example discloses a method for preparing a grape seed fermented pulp skincare product. Except for the different timing of the addition of the four post-ripening regulating components, the other raw materials and steps are performed according to Example 1.

[0064] In S3, when the pH of the fermentation broth is 4.47 and the free lactic acid content is 0.43%, no alginate oligosaccharides, sodium phytate, glucono-delta-lactone, or low-substituted hydroxypropyl cellulose are added. Fermentation continues at 36°C for 4 hours, followed by sterilization at 80°C for 15 minutes and filtration through a 0.80 μm filter membrane to obtain the basic grape seed fermentation broth. After the basic grape seed fermentation broth cools to 35°C, 10.0 g of the basic grape seed fermentation broth is mixed with 0.812 g of alginate oligosaccharides and stirred until uniformly dispersed to obtain an alginate oligosaccharide predispersant; 10.0 g of the basic grape seed fermentation broth is mixed with 0.390 g of sodium phytate and stirred until uniformly dissolved to obtain a sodium phytate predispersant. The alginate oligosaccharide predispersant and sodium phytate predispersant were added to the remaining basic grape seed fermentation pulp and stirred at 35°C and 250 rpm for 30 min. Then, 0.867 g of glucono-delta-lactone and 1.015 g of low-substituted hydroxypropyl cellulose were dry-mixed and slowly added over 5 min while stirring, continuing stirring for another 30 min to obtain the grape seed fermentation pulp. The oligomeric proanthocyanidins accounted for 49.7% of the total proanthocyanidins in the grape seed fermentation pulp.

[0065] Comparative Example 7 This comparative example discloses a method for preparing a grape seed fermented pulp skincare product. Except for the different addition windows of the four post-ripening regulating components in S3, the other raw materials and steps are performed according to Example 1.

[0066] In step S3, fermentation continued until the pH of the fermentation broth reached 4.06 and the free lactic acid content was 0.57%. 1300.0 g of the fermentation broth was then collected. 10.0 g of the fermentation broth was mixed with 0.812 g of alginate oligosaccharide and stirred until uniformly dispersed to obtain an alginate oligosaccharide pre-dispersion. Another 10.0 g of the fermentation broth was mixed with 0.390 g of sodium phytate and stirred until uniformly dissolved to obtain a sodium phytate pre-dispersion. The alginate oligosaccharide pre-dispersion and sodium phytate pre-dispersion were added to the remaining fermentation broth and stirred at 36°C and 250 rpm for 30 min. Subsequently, 0.867 g of glucono-delta-lactone and 1.015 g of low-substituted hydroxypropyl cellulose were dry-mixed and slowly added over 5 min while stirring. Fermentation continued at 36°C for 4 h. Subsequent sterilization, filtration, and step S4 were performed as in Example 1. The oligomeric proanthocyanidins accounted for 57.8% of the total proanthocyanidins in the grape seed fermentation pulp.

[0067] Comparative Example 8 This comparative example discloses a method for preparing a grape seed fermented pulp skincare product. Except for the different amount of sodium phytate added in S3, the other raw materials and steps are performed according to Example 1.

[0068] In step S3, when the pH of the fermentation broth was 4.47 and the free lactic acid content was 0.43%, 1300.0 g of the fermentation broth was taken. 10.0 g of the fermentation broth was mixed with 0.812 g of alginate oligosaccharide and stirred until uniformly dispersed to obtain an alginate oligosaccharide pre-dispersion. 10.0 g of the fermentation broth was mixed with 0.731 g of sodium phytate and stirred until uniformly dissolved to obtain a sodium phytate pre-dispersion. The alginate oligosaccharide pre-dispersion and sodium phytate pre-dispersion were added to the remaining fermentation broth, with a mass ratio of alginate oligosaccharide to sodium phytate of 1:0.90. The mixture was stirred at 36°C and 250 rpm for 30 min. Subsequently, 0.867 g of gluconolactone and 1.015 g of low-substituted hydroxypropyl cellulose were dry-mixed and slowly added over 5 min while stirring, with a mass ratio of low-substituted hydroxypropyl cellulose to alginate oligosaccharide of 1:0.80. Subsequent fermentation, sterilization, filtration, and step S4 were performed as in Example 1. Oligomeric proanthocyanidins accounted for 49.5% of the total proanthocyanidins in the grape seed fermentation pulp.

[0069] In the above embodiments and comparative examples, the grape seed fermentation pulp skincare products obtained in S4 were all aqueous essence-type products. After preparation, each embodiment and comparative example was sealed and placed in an environment of 25°C for 24 hours for equilibration before subsequent performance testing.

[0070] Performance testing To verify the performance of the grape seed fermented pulp skincare products obtained in the above examples and comparative examples, the samples obtained in Examples 1-7 and Comparative Examples 1-8 were tested as follows.

[0071] 1. Test of transmittance retention rate induced by artificial hard water Artificial hard water was prepared, with a total calcium and magnesium ion hardness of 420 mg / L (calculated as calcium carbonate). Calcium chloride and magnesium sulfate were used as the sources of calcium and magnesium ions. 2.0 g of each sample was taken and added to 18.0 g of deionized water. After stirring thoroughly, a diluted solution was obtained. 10.0 mL of the diluted solution was taken and 10.0 mL of artificial hard water was added. The solution was gently shaken for 30 seconds and then allowed to stand at 25°C for 30 minutes. The system containing the same sample diluted solution and deionized water was used as the initial control. The transmittance at 600 nm was measured using a UV-Vis spectrophotometer. The transmittance retention rate was calculated as (transmittance after artificial hard water treatment / initial transmittance × 100%). Each sample was measured in triplicate, and the average value was taken.

[0072] 2. Desiccation of sludge production under hard water residue conditions Artificial leather was cut into 10cm × 10cm test pieces. The surface of each piece was wiped evenly with hard water (0.20 mL / piece). It was then wiped again with a 0.05% sodium dodecyl ether sulfate aqueous solution (0.10 mL / piece) to simulate trace detergent residue. After the test pieces were placed at 25℃ for 30 min, 0.20 g of sample was evenly applied to the surface and left for 5 min. A 500g weight wrapped in a lint-free cloth was used to rub the surface of the test pieces 30 times, with a rubbing distance of 8 cm. Particles detached from the test piece surface and particles adhering to the lint-free cloth were collected, dried at 45℃ for 30 min, and weighed, converted to mg / 100cm². Each sample was measured in triplicate, and the average value was taken.

[0073] 3. Standard deviation test of coating friction coefficient Artificial leather test pieces were pretreated with artificial hard water and sodium dodecyl ether sulfate residues as described above. 0.20 g of sample was coated onto the surface of a 10 cm × 10 cm test piece. After 5 minutes, a friction coefficient tester was used for testing. The test load was 200 g, the sliding speed was 100 mm / min, and the test stroke was 8 cm. Ten friction coefficient data points were recorded continuously for each sample, and the standard deviation of the friction coefficient was calculated. The lower the standard deviation of the friction coefficient, the smaller the fluctuation in the coating's sliding resistance and the more uniform the coating condition.

[0074] 4. Centrifugal stability test Take 10.0g of each sample and place it in a 15mL transparent centrifuge tube. Centrifuge at 3000rpm for 30min at 25℃. After centrifugation, first observe whether the sample in the centrifuge tube shows obvious stratification, flocculent matter, bottom sediment, or particles attached to the wall, and record the appearance. Then, take 1.0g of the supernatant from about 5mm below the liquid surface of the centrifuge tube, add 9.0g of deionized water to dilute, gently invert to mix, and let stand for 5min. Measure the transmittance at 600nm using a UV-Vis spectrophotometer. Measure each sample in triplicate and take the average value. The higher the transmittance of the supernatant at 600nm after centrifugation, the fewer fine suspended particles in the upper layer of the sample after centrifugation, and the better the dispersion stability.

[0075] 5. Detection of oligomeric proanthocyanidin retention rate Each sample was sealed and placed in a 40℃ incubator for 30 days. Samples were taken before and after the incubation period, and the content of oligomeric proanthocyanidins with a degree of polymerization of 2–5 was determined by high performance liquid chromatography (HPLC). The retention rate of oligomeric proanthocyanidins was calculated as "oligomeric proanthocyanidin content after 30 days at 40℃ / initial oligomeric proanthocyanidin content × 100%". Each sample was measured in triplicate, and the average value was taken.

[0076] The test results are shown in the table below.

[0077] Table 1 As shown in Table 1, Examples 1-7 all performed well in terms of artificial hard water-induced transmittance retention, sludge removal, and standard deviation of coating friction coefficient. Example 1, as a representative sample under median conditions, achieved an artificial hard water-induced transmittance retention of 89.4%, a sludge removal amount of 1.23 mg / 100 cm², and a standard deviation of coating friction coefficient of 0.018, indicating that this sample exhibits good dispersion stability and coating uniformity under residual hard water conditions. Examples 2 and 3 correspond to the lower and upper limits of the process conditions, respectively, and the relevant indicators still maintained good levels, indicating that the preparation method is feasible and stable within the specified range. After centrifugation, the transmittance of the supernatant diluted in Examples 1-7 remained between 87.5% and 91.2% at 600 nm, and no obvious stratification occurred, indicating that the samples maintained good dispersion even under strong external forces.

[0078] Comparative Examples 1-4, lacking alginate oligosaccharides, sodium phytate, glucono-delta-lactone, or low-substituted hydroxypropyl cellulose respectively, exhibited decreased transmittance retention rates induced by artificial hard water, increased sludge production, and higher standard deviations of the coating friction coefficient. They were also more prone to bottom deposition or flocculent deposition after centrifugation, indicating that all four post-ripening control components affect coating stability and system dispersion stability under hard water residual conditions. Specifically, Comparative Example 2, without sodium phytate, showed a significant decrease in transmittance retention, suggesting that insufficient calcium-magnesium competitive complexation sites make polyphenolic components in grape seed fermentation pulp more susceptible to coarse particle aggregation in hard water environments. Comparative Example 4, without low-substituted hydroxypropyl cellulose, showed a significant increase in the standard deviation of the friction coefficient, indicating that spatial isolation and fine dispersion support contribute to reducing coating friction fluctuations.

[0079] Comparative Example 5 added all four post-ripening control components at once, while Comparative Example 6 added them after sterilization and filtration. The results for both were weaker than in Example 1, indicating that the four components entering the system in stages during the post-ripening stage is more conducive to forming a stable dispersion. Comparative Example 7, corresponding to a post-ripening window deviating from the over-acidification state, showed a decrease in hard water-induced transmittance retention, mud-shedding amount, and standard deviation of the friction coefficient. This indicates that when the pH and free lactic acid content of the fermentation broth are within a suitable window, it is more conducive to forming a fermentation slurry state that combines weak complexation, hydrophilic dispersion, and spatial isolation. In Comparative Example 8, increasing the relative amount of sodium phytate increased both deposition and friction fluctuations, indicating that an excessively high proportion of sodium phytate can easily lead to increased local complexation strength, which is detrimental to coating uniformity.

[0080] Based on the above test results, it can be seen that the present invention, through enzymatic hydrolysis of grape seeds, fermentation with Lactobacillus plantarum, and two-stage regulation under a specific fermentation ripening window, enables the resulting grape seed fermented pulp skincare product to exhibit good anti-deposition, low pilling, and low friction fluctuation performance in the context of use after hard water cleaning. At the same time, it can still maintain good light transmittance and appearance stability of the supernatant after centrifugation, which can support the technical effects of the present invention on improving the coating state, dispersion stability, and skin feel under hard water residue conditions.

[0081] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a grape seed fermented pulp skincare product, characterized in that, Includes the following steps: S1: Mix grape seed powder with deionized water at a mass ratio of 1:(10-14), adjust the pH to 5.0-5.3, add cellulase and pectinase, and enzymatically hydrolyze at 42-46℃ for 2-3 hours to obtain grape seed hydrolysate; S2: After inactivating the enzymes in the grape seed hydrolysate, cool it to 34-37°C, and then inoculate it with Lactobacillus plantarum fermentation broth to make the initial viable cell count of the fermentation system 1×10⁻⁶. 6 ~2×10 7 CFU / mL, fermented at 34–37°C to obtain fermentation broth; S3: When the pH of the fermentation broth is 4.30-4.65 and the free lactic acid content is 0.32%-0.52%, alginate oligosaccharide and sodium phytate are added to the fermentation broth. After stirring for 20-40 minutes, gluconolactone and low-substituted hydroxypropyl cellulose are added. Fermentation continues for 3-5 hours, followed by sterilization and filtration to obtain grape seed fermentation broth. S4: Mix the grape seed fermented pulp, moisturizer, thickener, preservative and deionized water to obtain the grape seed fermented pulp skin care product; The free lactic acid content is calculated based on the mass of the fermentation broth; the mass ratio of the alginate oligosaccharide to the sodium phytate is 1:(0.35-0.6); the mass ratio of the glucono-delta-lactone to the sodium phytate is 1:(0.25-0.7); the mass ratio of the low-substituted hydroxypropyl cellulose to the alginate oligosaccharide is 1:(0.4-1.2); and the oligomeric proanthocyanidins in the grape seed fermentation broth account for 42%-56% of the total proanthocyanidins by mass.

2. The method for preparing the grape seed fermented pulp skincare product according to claim 1, characterized in that, In step S1, the grape seed powder has a particle size of 100-140 mesh, and the grape seed powder is dried with hot air at 45-55°C to a moisture content of no more than 8% before being mixed with deionized water.

3. The method for preparing the grape seed fermented pulp skincare product according to claim 1, characterized in that, In step S1, the amount of cellulase added is 0.20% to 0.45% of the mass of the grape seed powder, and the amount of pectinase added is 0.10% to 0.30% of the mass of the grape seed powder.

4. The method for preparing the grape seed fermented pulp skincare product according to claim 1, characterized in that, In step S2, the *Lactobacillus plantarum* fermentation broth is prepared by culturing *Lactobacillus plantarum* in MRS liquid medium until the viable count reaches 1 × 10⁻⁶. 8 ~5×10 9 The concentration of CFU / mL was obtained.

5. The method for preparing the grape seed fermented pulp skincare product according to claim 1, characterized in that, In step S3, the number average molecular weight of the alginate oligosaccharide is 800-2500 Da, and the hydroxypropoxy content of the low-substituted hydroxypropyl cellulose is 5%-16%.

6. The method for preparing the grape seed fermented pulp skincare product according to claim 1, characterized in that, In step S3, based on the mass of the fermentation broth, the amount of alginate oligosaccharide added is 0.06% to 0.22%, the amount of sodium phytate added is 0.025% to 0.11%, the amount of gluconolactone added is 0.010% to 0.077%, and the amount of low-substituted hydroxypropyl cellulose added is 0.024% to 0.264%.

7. The method for preparing the grape seed fermented pulp skincare product according to claim 1, characterized in that, In step S3, after fermentation is completed, the product is sterilized at 75–85°C for 10–20 minutes and then filtered through a 0.45–1.0 μm filter membrane.

8. The method for preparing the grape seed fermented pulp skincare product according to claim 1, characterized in that, In step S4, the grape seed fermented pulp skincare product comprises the following components by weight: 25-40 parts of grape seed fermentation pulp; 2-5 parts glycerin; 3 to 7 parts of 1,3-propanediol; Betaine 0.8–2.0 parts; Panthenol 0.3–1.0 parts; Hydroxyethyl cellulose 0.08–0.18 parts; Capryloyl hydroxamic acid 0.03–0.10 parts; Ethylhexylglycerin 0.07–0.25 parts; Add deionized water to bring the total to 100 parts.

9. A grape seed fermented pulp skincare product prepared by the preparation method according to any one of claims 1 to 8, characterized in that, In the artificial hard water residue test, the grape seed fermented pulp skin care product has a 600nm transmittance retention rate of not less than 82%, a pilling amount of not more than 1.8mg / 100cm², and a standard deviation of the coating friction coefficient of not more than 0.

026. The artificial hard water residue test is conducted by pretreating the test substrate with artificial hard water with a hardness of 300-500mg / L (calculated as calcium carbonate).

10. The application of the grape seed fermented pulp skincare product according to claim 9 in the preparation of skincare essence, skincare gel or mask liquid to be applied after hard water cleansing.

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