A shea butter oil fermentation liquor, a preparation method and application thereof

Abstract

This invention belongs to the field of cosmetic raw material technology, and particularly relates to a shea butter fermentation broth, its preparation method, and its application. This invention employs a specific ratio of *Lactobacillus plantarum*, *Lactobacillus fermentum*, and *Lactobacillus gasseri* to construct a composite fermentation system, combined with acid-resistant *Aspergillus niger* lipase, to process shea butter through a one-step fermentation process. Utilizing the synergistic effect of the three strains and the synergistic effect of the enzyme and strains, not only is efficient fermentation achieved, significantly increasing the content of active ingredients such as polysaccharides, amino acids, and peptides in the fermentation broth, but the process is also simple, stable, and avoids the risk of contamination by other microorganisms. The fermentation broth obtained by this process enhances the original moisturizing and soothing effects of shea butter, effectively improving its oily feel and poor absorption, and further endowing it with new functions of repairing the skin barrier and balancing the skin microecology, greatly enhancing the application value of shea butter and its fermentation broth.

Description

Technical Field

[0001] This invention belongs to the field of cosmetic raw material technology, and particularly relates to a shea butter fermentation liquid, its preparation method and application. Background Technology

[0002] With the rapid development of biotechnology, the cosmetics industry has widely adopted microbial fermentation technology to modify plant oils. Microbially fermented plant oils not only improve their inherent problems such as heavy texture and poor permeability, but also produce a variety of beneficial components during fermentation, such as amino acids, polysaccharides, and other prebiotic metabolites. These active substances show high application potential in addressing various skin problems.

[0003] Shea butter, internationally known as "butyrospermum parkii" in cosmetics, is a high-quality natural plant oil rich in fatty acids, unsaponifiables, and vitamins. It is hailed as "soft gold for the skin" and has excellent moisturizing and soothing effects in cosmetics.

[0004] However, traditional shea butter suffers from high viscosity, greasiness, and poor skin penetration. To address these issues, numerous studies have employed microbial fermentation technology to improve it, aiming to alleviate these shortcomings and further enhance its active ingredient content and overall skincare efficacy, thereby broadening and enhancing the application value of shea butter. For example, patent CN118975953A discloses a method for fermenting shea butter with different melting points using *Candida beeica* or *Aphidida spp.*. While this technology significantly lowers the melting point of shea butter, it only analyzes the change in melting point before and after fermentation and does not verify any improvement in efficacy after fermentation. Patent CN112708652B proposes using *Saccharomyces cerevisiae* and *Lactobacillus pentosus* for mixed fermentation, generating beneficial components such as peptides and amino acids. However, the growth environment and fermentation process of yeast and lactobacillus are crucial factors. Significant differences in fermentation conditions make it difficult to achieve the ideal synergistic fermentation effect in practice. Patent CN117180143A adopts a "two-strain, two-stage" fermentation process, which ferments shea butter stepwise with Saccharomyces cerevisiae (or Candida albicans) and Candida spp. (or Candida spp.) and claims that its product has moisturizing and antioxidant properties. However, this process also incorporates camellia seed oil or sunflower seed oil, making it difficult to accurately assess the efficacy of shea butter after fermentation. Furthermore, the complex process also brings challenges to product cost and quality control.

[0005] Therefore, current shea butter fermentation technology still has significant limitations. Furthermore, existing research often uses yeasts (such as *Candida beemannii* and *Saccharomyces cerevisiae*) as fermentation strains. Although yeasts have a strong ability to produce lipases and can effectively break down oils, their fermentation process often involves the production of ethanol, resulting in the final product potentially containing trace amounts of alcohol, which is detrimental to the development of cosmetics claiming "alcohol-free." On the other hand, from a skin care perspective, lactobacilli are more advantageous in regulating the skin's microecology and enhancing barrier repair. Their metabolites, such as lactic acid and antimicrobial peptides, are also more compatible with the human skin's flora and pH environment. However, lactobacilli can only secrete trace amounts of low-activity endogenous lipases. If used alone to ferment shea butter, it is difficult to effectively hydrolyze large oil molecules, thus failing to significantly improve its sticky feel and absorption.

[0006] To overcome the above problems, existing technologies typically employ a two-step process of "enzymatic hydrolysis followed by fermentation." For example, patent CN116509787B proposes a method for preparing a mixed fermented oil with whitening effects. This method involves first enzymatically hydrolyzing vegetable and synthetic oils with carboxylesterase or phosphatase, followed by inoculation with *Lactobacillus plantarum* for fermentation. While this method partially achieves lactobacillus fermentation, it still suffers from problems such as complex processes, time and energy consumption, susceptibility to contamination during intermediate transfers, and a lack of precise component analysis.

[0007] Therefore, it is necessary to develop a more efficient and valuable shea butter fermentation process, prioritizing the use of lactobacillus strains that are more compatible with skin health as the fermentation strain, and achieving efficient synergy between enzymatic hydrolysis and fermentation processes, so as to develop shea butter fermentation products that have a refreshing feel, high permeability, excellent microecological regulation function and multiple biological activities. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a shea butter fermentation liquid and its preparation method. The specific preparation process significantly increases the content of various active ingredients such as extracellular polysaccharides, amino acids and peptides in the final shea butter fermentation liquid, thereby greatly improving its comprehensive skin care efficacy.

[0009] To achieve the above objectives, the technical solution adopted by the present invention includes:

[0010] In a first aspect, the present invention provides a method for preparing shea butter fermentation broth, comprising the following steps:

[0011] S1. Mix shea butter with fermentation medium, emulsify, sterilize, and prepare shea butter fermentation medium;

[0012] S2. Inoculate the shea butter fermentation medium with lipase and compound lactobacillus seed liquid for fermentation;

[0013] S3. After fermentation, the product is sterilized and filtered to obtain the shea butter fermentation liquid.

[0014] The compound lactobacillus includes Lactobacillus plantarum, Lactobacillus fermentum, and Lactobacillus gasseri.

[0015] Preferably, the inoculation ratio of Lactobacillus plantarum, Lactobacillus fermentum and Lactobacillus gasseri is (1-3):(1-2):1.

[0016] The method described in this invention constructs a unique composite fermentation system by carefully selecting *Lactobacillus plantarum*, *Lactobacillus fermentum*, and *Lactobacillus gasseri*. These three strains form a highly efficient functional community during fermentation: *Lactobacillus plantarum*, as the basic strain, rapidly produces acid and decomposes macromolecular carbon and nitrogen sources, creating a stable acidic environment and physical matrix for the system; *Lactobacillus fermentum* efficiently produces extracellular polysaccharides and secretes antimicrobial peptides, precisely inhibiting contaminating bacteria and purifying the fermentation environment; and *Lactobacillus gasseri* excels at accumulating anti-inflammatory and soothing factors, thereby enhancing the repair efficacy of the final product.

[0017] The three components, combined in the specific proportions described in this invention, form a robust mutually beneficial symbiotic relationship through metabolic complementarity and environmental co-creation. They synergistically lower the environmental pH, efficiently utilize nutrients, and jointly enrich a variety of active metabolites, including polysaccharides, antimicrobial peptides, and organic acids. This overcomes the shortcomings of single or dual-strain fermentation systems, which often result in single metabolites and low fermentation efficiency, achieving a synergistic effect of "1+1+1>3".

[0018] In addition, the present invention adopts a "one-step enzyme-microbe synergistic" fermentation process, which optimizes the process design. This process is simple, stable, and easy to implement, while effectively reducing the risk of contamination by other microorganisms.

[0019] The fermentation modification of shea butter using the above process not only significantly improves its oily feel and enhances its permeability and absorption, but also solves the technical challenge of efficient fermentation of shea butter by lactobacillus. More importantly, the synergistic fermentation of three strains enables the efficient synthesis of various prebiotic metabolites, greatly enhancing the application value of shea butter and its fermentation broth.

[0020] Preferably, the mass ratio of the lipase to shea butter is 1:(30-300).

[0021] Preferably, the lipase is an acid-resistant lipase derived from Aspergillus niger, which has high activity in the pH range of 2.0-7.0.

[0022] Preferably, the total bacterial concentration in the compound lactobacillus seed solution is 10. 8 -10 9CFU / mL; the volume ratio of the compound lactobacillus seed culture to the shea butter fermentation medium is 1:(10-50).

[0023] Preferably, the mass ratio of shea butter to fermentation medium is 1:(5-20).

[0024] Preferably, the melting point of the shea butter is 10-40°C.

[0025] Preferably, in step S2, the specific fermentation conditions are: fermentation at 30-40℃ and pH 2.0-7.0 for 48-72 hours.

[0026] Preferably, the fermentation medium comprises the following components in weight percentage: glucose 1.5-3.0%, yeast extract 0.2-0.4%, peptone 0.3-0.6%, KH2PO4 0.2-0.5%, (NH4)2SO4 0.15-0.3%, MgSO4·7H2O 0.03-0.06%, Tween-80 0.2-0.8%, and the balance being water.

[0027] Tween-80 can promote the growth and fermentation of lactobacillus and can also be used as an emulsifier for emulsifying shea butter and fermentation medium, which helps to form a uniform shea butter fermentation medium.

[0028] Preferably, in step S3, after sterilization, a preservative is added to the shea butter fermentation broth; the preservative includes at least one selected from p-hydroxyacetophenone, methylparaben, phenoxyethanol, pentylene glycol, hexanediol, octyl glycol, ethylhexylglycerin, and sodium benzoate. The preservative is used to prevent microbial contamination of the fermentation broth during storage, thereby improving its stability.

[0029] Secondly, the present invention provides a shea butter fermentation broth prepared by the preparation method described above.

[0030] The shea butter fermentation broth is rich in various skin-care active ingredients, including free fatty acids, monoglycerides, lactic acid, extracellular polysaccharides, amino acids, and peptides. Compared with single-strain fermentation, the fermentation broth obtained by the present invention through a specific preparation process significantly increases the content of various prebiotic metabolites such as lactic acid, extracellular polysaccharides, amino acids, and peptides.

[0031] Thirdly, the present invention provides the application of the aforementioned shea butter fermentation liquid in the preparation of cosmetics.

[0032] Preferably, the cosmetics include, but are not limited to, serums, creams, masks, and ointments or sticks. Cosmetics containing the fermented shea butter extract have multiple benefits, including moisturizing, soothing, repairing the skin barrier, and balancing the skin's microecology.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] (1) This invention provides a new method for preparing shea butter fermentation liquid. By using a unique composite fermentation system constructed by Lactobacillus plantarum, Lactobacillus fermentum and Lactobacillus gasseri in a specific ratio, the synergistic effect between the three strains is utilized to significantly increase the content of various active ingredients such as lactic acid, polysaccharides, amino acids and polypeptides in the final shea butter fermentation liquid.

[0035] (2) The present invention adopts a one-step fermentation process with acid-resistant Aspergillus niger lipase and compound lactobacillus to achieve efficient fermentation of shea butter. Compared with the existing two-step process of "enzymatic hydrolysis first and then fermentation", this method simplifies the process, reduces energy consumption and cost, and effectively reduces the risk of contamination by miscellaneous bacteria during fermentation.

[0036] (3) The fermented shea butter liquid prepared by the process described in this invention not only enhances the original moisturizing and soothing effects of shea butter, but also effectively improves its oily feel and poor penetration and absorption, and further endows it with new functions of repairing the skin barrier and balancing the skin microecology. Attached Figure Description

[0037] Figure 1 The image shows the appearance of the shea butter fermentation broth prepared by the method of Example 1 (at room temperature).

[0038] Figure 2 The study examined the facial erythema of the subjects before and after using the serum from Example 1 for 4 weeks. Detailed Implementation

[0039] To better illustrate the objectives, technical solutions, and advantages of this invention, the invention will be further described below with reference to specific embodiments. Those skilled in the art should understand that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0040] Unless otherwise specified, all raw materials used in the following examples and comparative examples are commercially available general-purpose materials.

[0041] The shea butter used in the following examples and comparative examples was purchased from AAK Nordic Oils Group under the trade name LipexShea; the acid-resistant Aspergillus niger lipase was purchased from SIGMA under the trade code 62301.

[0042] The strains can be commercially purchased from common collection centers such as the China Industrial Microbial Culture Collection Center (CICC), for example, *Lactobacillus plantarum* CICC 20261, *Lactobacillus fermentum* CICC 21829, and *Lactobacillus gasseri* CICC 24878. However, the present invention is not limited thereto; any strain of the same species with the same or similar functions is applicable to the present invention and will not have a substantial impact on the technical effect of the present invention.

[0043] Example 1

[0044] This embodiment provides a method for preparing shea butter fermentation broth, including the following steps:

[0045] (1) Preparation of seed fermentation broth

[0046] The MRS solid and liquid media required for preparing seed fermentation broth are commonly used lactobacillus media.

[0047] The *Lactobacillus plantarum* strain preserved in glycerol tubes was inoculated onto MRS solid medium and incubated at 37°C for 24 hours for activation. Single colonies were then picked and inoculated into culture flasks containing MRS liquid medium and incubated at 37°C for another 24 hours. The colonies were then transferred at a 1:100 ratio to fresh MRS liquid medium and incubated under the same conditions for 24 hours. Finally, the bacterial concentration was adjusted to 10⁻⁶ with sterile water. 9 CFU / mL was used to prepare Lactobacillus plantarum seed culture for subsequent fermentation inoculation.

[0048] Following the same method described above, preparations were made with a concentration of 10... 9 CFU / mL Lactobacillus fermentation seed culture and Lactobacillus gasseri seed culture.

[0049] The above-mentioned Lactobacillus plantarum, Lactobacillus fermentum and Lactobacillus gasseri seed solutions were mixed in a volume ratio of 2:1:1 to prepare a compound Lactobacillus seed solution. Before mixing, the seed solutions of each strain must be shaken thoroughly.

[0050] (2) Preparation of fermentation medium for shea butter

[0051] Prepare the fermentation medium in the fermenter with the following composition per liter: 20g glucose, 2.5g yeast powder, 4g peptone, 3.5g KH2PO4, 1.5g (NH4)2SO4, 0.5g MgSO4·7H2O, and 7g Tween-80. Make up the volume to 1L with sterile deionized water. Preheat the medium to 40℃.

[0052] Shea butter, which has a melting point of 30°C, is also heated to 40°C to completely melt it, resulting in liquid shea butter.

[0053] Liquid shea butter and the above fermentation medium were added to the fermentation tank at a weight ratio of 1:10.

[0054] In the fermenter, the mixture is stirred for 10 minutes at 40°C and 600 rpm to fully emulsify the shea butter and the culture medium, thereby obtaining a homogeneous shea butter fermentation medium.

[0055] (3) Inoculation and fermentation

[0056] The shea butter fermentation medium prepared in step (2) was sterilized at 121°C for 30 minutes. After sterilization, it was stirred at 37°C and 600 rpm for 5 minutes to ensure uniform emulsification again. Then, sterile Aspergillus niger lipase and compound Lactobacillus seed liquid were simultaneously added. The weight ratio of Aspergillus niger lipase to shea butter was 1:50, and the volume ratio of compound Lactobacillus seed liquid to shea butter fermentation medium was 1:20.

[0057] The fermentation conditions were controlled at a temperature of 37℃, a stirring speed of 100 rpm, and a pH of 6.0, and fermented continuously for 48 hours to obtain the fermentation product.

[0058] (4) Post-treatment of fermentation broth

[0059] The fermentation product obtained in step (3) was heated to 80°C in a fermenter and kept at that temperature for 30 minutes to inactivate lactic acid bacteria. Then, 0.8 wt% hexanediol and 0.8 wt% phenoxyethanol were added as a composite preservative and stirred thoroughly to mix evenly. Finally, the mixture was filtered through an 800-mesh stainless steel filter for primary filtration and a 1 μm diatomaceous earth filter for secondary filtration to obtain the shea butter fermentation broth.

[0060] Example 2

[0061] This embodiment provides a method for preparing shea butter fermentation liquid, which differs from Example 1 only in that the volume ratio of Lactobacillus plantarum, Lactobacillus fermentum and Lactobacillus gasseri seed liquid in the compound lactobacillus seed liquid in step (1) is 3:1:1.

[0062] Example 3

[0063] This embodiment provides a method for preparing shea butter fermentation liquid, which differs from Example 1 only in that the volume ratio of Lactobacillus plantarum, Lactobacillus fermentum and Lactobacillus gasseri seed liquid in the compound lactobacillus seed liquid in step (1) is 3:2:1.

[0064] Example 4

[0065] This embodiment provides a method for preparing shea butter fermentation liquid, which differs from Example 1 only in that the volume ratio of Lactobacillus plantarum, Lactobacillus fermentum and Lactobacillus gasseri seed liquid in the compound lactobacillus seed liquid in step (1) is 1:1:1.

[0066] Example 5

[0067] This embodiment provides a method for preparing shea butter fermentation broth, which differs from Example 1 only in that the weight ratio of liquid shea butter to fermentation medium in step (2) is 1:5;

[0068] In step (3), the weight ratio of Aspergillus niger lipase to shea butter is 1:30, and the volume ratio of compound lactobacillus seed liquid to shea butter fermentation medium is 1:50.

[0069] Example 6

[0070] This embodiment provides a method for preparing shea butter fermentation broth, which differs from Example 1 only in that the weight ratio of liquid shea butter to fermentation medium in step (2) is 1:20.

[0071] In step (3), the weight ratio of Aspergillus niger lipase to shea butter is 1:300, and the volume ratio of compound lactobacillus seed liquid to shea butter fermentation medium is 1:10.

[0072] Application Examples 1-6

[0073] Application Examples 1-6 provide a skin care essence, wherein the active ingredients in the skin care essence correspond to the shea butter fermentation liquid prepared in Examples 1-6 respectively.

[0074] The skincare essence comprises the following components in weight percentages: 3% shea butter ferment broth, 0.05% EDTA-2Na, 0.2% carbomer 981, 0.6% polyglycerol-10 oleate, and the balance being water. The skincare essence is obtained by homogenizing and mixing the above ingredients.

[0075] Comparative Example 1

[0076] This comparative example provides a method for preparing shea butter fermentation broth, which differs from Example 1 only in that it uses only Lactobacillus plantarum for fermentation.

[0077] Comparative Example 2

[0078] This comparative example provides a method for preparing shea butter fermentation broth, which differs from Example 1 only in that it uses only Lactobacillus fermentation for fermentation.

[0079] Comparative Example 3

[0080] This comparative example provides a method for preparing shea butter fermentation broth, which differs from Example 1 only in that it uses only Lactobacillus gasseri for fermentation.

[0081] Comparative Example 4

[0082] This comparative example provides a method for preparing shea butter fermentation broth, which differs from Example 1 only in that: two strains, Lactobacillus plantarum and Lactobacillus fermentum, are used for compound fermentation, and the volume ratio of Lactobacillus plantarum and Lactobacillus fermentum seed liquid is 1:1.

[0083] Comparative Example 5

[0084] This comparative example provides a method for preparing shea butter fermentation broth, which differs from Example 1 only in that: two strains, Lactobacillus plantarum and Lactobacillus gasseri, are used for compound fermentation, and the volume ratio of Lactobacillus plantarum and Lactobacillus gasseri seed liquid is 1:1.

[0085] Comparative Example 6

[0086] This comparative example provides a method for preparing shea butter fermentation broth, which differs from Example 1 only in that: two strains, Lactobacillus fermentum and Lactobacillus gasseri, are used for compound fermentation, and the volume ratio of Lactobacillus fermentum and Lactobacillus gasseri seed liquid is 1:1.

[0087] Comparative Example 7

[0088] This comparative example provides a method for preparing shea butter fermentation liquid, which differs from Example 1 only in that the volume ratio of Lactobacillus plantarum, Lactobacillus fermentum and Lactobacillus gasseri seed liquid in the compound Lactobacillus seed liquid in step (1) is 5:1:1.

[0089] Comparative Example 8

[0090] This comparative example provides a method for preparing shea butter fermentation broth, which differs from Example 1 only in that: three types of lactobacilli, namely Lactobacillus plantarum, Lactobacillus paracasei, and Lactobacillus gasseri, are used for compound fermentation, and the volume ratio of Lactobacillus plantarum, Lactobacillus paracasei, and Lactobacillus gasseri seed liquid in the compound lactobacilli seed liquid is 2:1:1.

[0091] Comparative Example 9

[0092] This comparative example provides a method for preparing shea butter fermentation broth, which differs from Example 1 only in that lipase is not added during the fermentation process.

[0093] Application Comparative Examples 1-9

[0094] Comparative Examples 1-9 provide a skincare essence in which the active ingredients are respectively paired with the shea butter fermentation liquid prepared in Comparative Examples 1-9.

[0095] The skincare essence comprises the following components in weight percentages: 3% shea butter ferment broth, 0.05% EDTA-2Na, 0.2% carbomer 981, 0.6% polyglycerol-10 oleate, and the balance being water. The skincare essence is obtained by homogenizing and mixing the above ingredients.

[0096] Example 1

[0097] This study used the shea butter fermentation broth prepared in Examples 1-6 and Comparative Examples 1-9 as test samples to detect the contents of free fatty acids, lactic acid, extracellular polysaccharides, amino acids and peptides. The specific test results are shown in Table 1.

[0098] Table 1. Results of component content tests in the shea butter fermentation broth obtained from the comparative studies.

[0099]

[0100] The results indicate that, firstly, the free fatty acid content of the shea butter fermentation broth obtained through synergistic fermentation of enzymes and bacteria was significantly higher than that of the fermentation group without added lipase (Comparative Example 9). This is mainly attributed to the hydrolytic effect of lipase on shea butter, which directly promotes the generation of free fatty acids. The lower free fatty acid content in the three-strain composite fermentation group compared to other fermentation groups is because the lactobacillus utilized the enzymatic hydrolysis products such as free fatty acids as a carbon source during fermentation, resulting in a relatively lower content.

[0101] Secondly, experimental data show that the strain combination and ratio range specified in this invention are key to achieving synergistic effects. Fermentation under the conditions specified in this invention yields fermentation products with significantly higher levels of active ingredients such as amino acids, extracellular polysaccharides, and polypeptides compared to single strains, pairs of combined strains, and comparative examples using strains or ratios not specified in this invention. Simultaneously, the lactic acid production capacity of this system remains excellent. In contrast, comparative example 9, which did not add lipase, lacked the nutrient substrates for enzymatic hydrolysis of shea butter, resulting in generally lower levels of various active ingredients in its fermentation products.

[0102] This demonstrates that the strain complex and "enzyme-bacteria synergy" process specified in this invention can achieve synergistic effects, significantly increasing the yield of active ingredients, thereby enhancing the bioactivity of shea butter and giving it higher skincare application value.

[0103] Example 2

[0104] (1) Evaluation of moisturizing effect:

[0105] The moisturizing properties of skincare essence samples prepared using Examples 1, 5-6 and Comparative Examples 1, 4, 7-9 were evaluated according to the methods provided in "QB / T4256-2011 Guidelines for Evaluation of Moisturizing Efficacy of Cosmetics".

[0106] Thirty subjects aged 18 to 60 years were selected, and the tests were conducted according to the testing environment and procedures specified in QB / T 4256-2011. Nine 3cm × 3cm test areas were marked and numbered on the inner sides of both arms of each subject, and one area was randomly selected as a blank control (without any sample applied).

[0107] Before applying the sample, the initial skin moisture content of each area was measured using a Corneometer CM 825 skin moisture meter and recorded as the initial value; at the same time, the transepidermal water loss (TEWL) value of each area was measured using a Tewameter TM 300 transepidermal water loss meter and recorded as the initial TEWL value.

[0108] After completing the initial value measurement, apply 2 mg / cm² to each sample application area. 2 The appropriate amount of product was evenly applied to the corresponding sample, and the skin moisture content and TEWL value of each area were measured at 2 hours (2h) and 4 hours (4h) after application, and recorded as test values. The results were used to calculate the rate of change of skin moisture content and the rate of change of TWEL value according to the following formulas:

[0109]

[0110] The results are shown in Table 2. The final skin moisture content change rate and TWEL value change rate of each test group were the average values ​​of the data from 30 subjects.

[0111] Table 2 shows the rate of change in skin moisture content and TWEL value at 2 and 4 hours for each test group.

[0112]

[0113] Changes in skin hydration are a key indicator for evaluating the moisturizing effect of a product, while transepidermal water loss (TEWL) value is another important indicator for evaluating skin barrier function and the water retention capacity and integrity of the stratum corneum. A higher rate of change in skin hydration indicates a better moisturizing effect; a lower rate of change in TEWL value indicates a more significant improvement in the skin's water retention capacity and barrier function. As shown in Table 2, the serum prepared using the shea butter fermentation broth obtained in this invention (Application Examples 1, 5-6) is significantly superior in terms of moisturizing effect and skin water retention capacity to the serum prepared using the single-strain fermentation group (Application Comparative Example 1), the dual-strain complex fermentation group (Application Comparative Example 4), the strains or proportions not specified in this invention (Application Comparative Examples 7-8), and the group without added lipase during fermentation (Application Comparative Example 9).

[0114] The above results indicate that the various active ingredients produced by fermentation of shea butter, such as amino acids, extracellular polysaccharides, and polypeptides, have excellent moisturizing and skin-enhancing effects. Moreover, the shea butter fermentation liquid prepared by the compound fermentation of three strains in a specific ratio provided by this invention has the most significant effect.

[0115] (2) Evaluation of barrier repair effect and skin microbiome balancing effect

[0116] By quantitatively analyzing the facial erythema index (EI value) and the absolute contents of Propionibacterium acnes, Staphylococcus aureus, Malassezia and Staphylococcus epidermidis before and after subjects used essences containing different shea butter fermentation methods, the efficacy of the shea butter fermented essence prepared in this invention in soothing redness, inhibiting harmful bacteria and promoting beneficial bacteria was comprehensively evaluated, and its role in repairing the skin barrier and regulating the skin microecology was verified.

[0117] Subject selection: This study recruited 48 participants with moderately red, oily skin, aged 18 to 40 years. Inclusion criteria were: ① Oily skin as measured by a sebum analyzer (forehead sebum secretion rate ≥180 μg / cm²). 2 ); ② Based on visual assessment and skin colorimeter (Mexameter MX 18) testing, the baseline erythema index on the cheeks is greater than 280 AU. Exclusion criteria include: severe acne or other active facial skin diseases; recent use of acid-containing products or potent anti-inflammatory skin care products; pregnant and lactating women.

[0118] Experimental Methods: Forty-eight subjects were randomly divided into four groups of 12 each. Each group applied skincare essence samples prepared in Example 1 and Comparative Examples 1, 4, and 7, respectively. Before the experiment, a fixed measurement point was marked on one cheek of each subject (the location was photographed). The erythema index (EI) at this point was measured using a skin colorimeter and recorded as the initial EI value. A measurement point was marked at the same location on the other cheek. A 1.5cm × 1.5cm sterile tape (D-Squame standard tape) was applied to the marked area, ensuring full contact by pressing evenly with the fingers. After standing for 10 seconds, the tape was removed and immediately placed in a sterile centrifuge tube and stored at -80℃. The absolute concentrations (unit: copies / cm³) of Propionibacterium acnes, Staphylococcus aureus, Malassezia, and Staphylococcus epidermidis) in the samples were subsequently determined using qPCR absolute quantification. 2 This is recorded as the initial bacterial strain content.

[0119] After the measurement was completed, each group of subjects applied the corresponding serum sample to their entire face every morning and evening, using 0.8g (approximately one pump) each time, for 4 consecutive weeks. At the end of the 2nd and 4th weeks, the EI value and the absolute content of the above four bacterial groups in the same test area on the subjects' cheeks were measured again as test values.

[0120] Experimental Results: The changes in facial skin EI value and the content changes of four bacterial species were calculated using the following formulas:

[0121]

[0122] The results are shown in Table 3. The final change rate of facial skin EI value and the change rate of the content of four bacterial species in each test group are the average values ​​of the data of 12 subjects.

[0123] Table 3. Changes in bacterial content and erythema index of subjects after 2 and 4 weeks of serum use.

[0124]

[0125] Results after 2 and 4 weeks of trial use of the various serums showed that the subjects using the serum prepared from the fermented shea butter broth obtained in this invention (Application Example 1) had significantly higher rates of decrease in facial erythema index, decrease in harmful bacteria (Propionibacterium acnes, Staphylococcus aureus, and Malassezia) content, and increase in beneficial bacteria (Staphylococcus epidermidis) content than the single-strain fermentation group (Application Comparative Example 1), the dual-strain complex fermentation group (Application Comparative Example 4), and the group without the strain ratio specified in this invention (Application Comparative Example 7).

[0126] The results show that the shea butter fermented liquid essence prepared by the method provided by the present invention can effectively reduce skin erythema symptoms, achieve barrier repair, and regulate the skin microecology by significantly inhibiting harmful bacteria and promoting the growth of beneficial bacteria. Moreover, the overall effect is significantly better than that of products prepared by methods other than those of the present invention.

[0127] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of the present invention and not to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing shea butter fermentation broth, characterized in that, Includes the following steps: S1. Mix shea butter with fermentation medium, emulsify, sterilize, and prepare shea butter fermentation medium; S2. Inoculate the shea butter fermentation medium with lipase and compound lactobacillus seed liquid for fermentation; S3. After fermentation, the product is sterilized and filtered to obtain the shea butter fermentation liquid. The compound lactobacillus includes Lactobacillus plantarum, Lactobacillus fermentum, and Lactobacillus gasseri. The inoculation ratio of Lactobacillus plantarum, Lactobacillus fermentum and Lactobacillus gasseri is (1-3):(1-2):

1.

2. The preparation method according to claim 1, characterized in that, The mass ratio of the lipase to shea butter is 1:(30-300).

3. The preparation method according to claim 1, characterized in that, The total bacterial concentration in the compound lactobacillus seed solution is 10. 8 -10 9 CFU / mL; the volume ratio of the compound lactobacillus seed culture to the shea butter fermentation medium is 1:(10-50).

4. The preparation method according to claim 1, characterized in that, The mass ratio of shea butter to fermentation medium is 1:(5-20).

5. The preparation method according to claim 1, characterized in that, In step S2, the specific fermentation conditions are: fermentation at 30-40℃ and pH 2.0-7.0 for 48-72 hours.

6. The preparation method according to claim 1, characterized in that, In step S3, after sterilization, a preservative is added to the shea butter fermentation liquid.

7. The preparation method according to claim 6, characterized in that, The preservative includes at least one of p-hydroxyacetophenone, methylparaben, phenoxyethanol, pentylene glycol, hexanediol, octyl glycol, ethylhexylglycerin, and sodium benzoate.

8. A shea butter fermentation broth prepared by the method according to any one of claims 1-7.

9. The application of the shea butter fermentation liquid as described in claim 8 in the preparation of cosmetics.

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