Preparation method and application of white tea fermentation liquor with effects of controlling oil and removing acne

Abstract

The invention discloses a preparation method and application of white tea fermentation liquor with oil control and acne removal effects, lactobacillus plantarum and lactobacillus gasseri are adopted to ferment white tea, other organic reagents do not need to be added, conditions are mild in the fermentation process, the structure of active ingredients of the white tea is not damaged, and the natural activity of the white tea is kept. The production cost is saved, the stability of the product quality is fully guaranteed, chemical components such as essence are not added into the fermentation primary pulp, and the safety to a human body is improved; the white tea can be directly used as a skin care product, and the white tea fermentation liquor is rich in polyphenols, amino acids and the like, and has a synergistic effect with some fermentation product probiotics in the fermentation liquor, so that a stronger effect is shown.

Description

Technical Field

[0001] This invention belongs to the field of bio-fermentation technology, specifically relating to a method for preparing and applying white tea fermentation liquid with oil-controlling and acne-removing effects. Background Technology

[0002] Polyphenols in tea are the most important health-promoting components, possessing various physiological activities such as anti-oxidation, anti-aging, anti-cancer, anti-radiation, lowering blood lipids, lowering blood pressure, and lowering blood sugar. White tea, a traditional Chinese lightly fermented tea, retains abundant polyphenols, amino acids, and other active ingredients due to its unique withering and drying processes. Traditionally, white tea is known for its health benefits, described as "poor in the first year, medicinal in the third, and precious in the seventh," primarily attributed to natural active substances such as catechins (especially EGCG), theanine, and flavonoids. Among these, tea polyphenols account for 16.23%–25.95% of the dry weight of white tea, averaging 21.54%. Catechins, as the main components of tea polyphenols, account for 7.79%–16.56% of the total amount in white tea, averaging 13.22%, with EGCG, ECG, EGC, EC, and C being the main components. However, polyphenols are known for their high instability. They are easily degraded by environmental factors (such as light, heat, oxygen, pH (especially when they are close to neutral or alkaline)) and their own chemical properties. This instability has become a key technical bottleneck restricting their market application and industrial production.

[0003] In recent years, "white tea fermentation liquid," obtained through deep fermentation of white tea extract using bio-fermentation technology, has become a new hot topic in the research and development of health products and cosmetics. Controlled fermentation of white tea extract using modern bio-fermentation techniques (such as yeast, lactic acid bacteria, acetic acid bacteria, or specific enzyme preparations) can effectively transform these substances, generating smaller molecules with higher bioactivity or new functions (such as gallic acid and specific secondary metabolites), thereby significantly enhancing its efficacy and application value. However, the inherent biological activity of microorganisms also determines the unavoidable instability of microbial fermentation technology. Controlling the stability of the strains and the extracted components during microbial fermentation remains difficult with current technology.

[0004] Existing microbial fermentation technologies still suffer from problems such as low content of effective components, insignificant effects, insufficient efficacy, and difficulty in mass production. Therefore, the development of a stable white tea fermentation liquid is urgently needed. Summary of the Invention

[0005] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments.

[0006] As one aspect of the present invention, the present invention provides a method for preparing white tea fermentation liquid with oil-controlling and acne-reducing effects, which includes the following steps:

[0007] S1. Raw material pretreatment: Take Bingdao white tea leaves, crush them, and sieve them to obtain white tea powder;

[0008] S2. Preparation of white tea extract: Mix the white tea powder obtained in step S1 with water, heat to extract, centrifuge, filter, and take the filtrate to obtain white tea extract;

[0009] S3. Preparation of white tea fermentation culture medium: Add glucose and rice flour to the white tea extract, adjust the pH to 4-7, and obtain white tea fermentation culture medium;

[0010] S4. Inoculation and fermentation of compound microorganisms: Activated Lactobacillus gasseri and Lactobacillus plantarum are combined to form a compound microorganism, which is inoculated into the white tea fermentation medium for fermentation.

[0011] S4. After the fermentation is terminated, the fermentation liquid is separated into solid and liquid components, and the filtrate is collected to obtain the white tea fermentation liquid.

[0012] As a preferred embodiment of the preparation method of the white tea fermentation liquid with oil-controlling and acne-removing effects described in this invention, the white tea includes Icelandic white tea.

[0013] As a preferred embodiment of the preparation method of the white tea fermentation liquid with oil-controlling and acne-removing effects described in this invention: the Lactobacillus gasseri has the accession number CCTCC NO:M 20252844 and is deposited at the China Center for Type Culture Collection on December 10, 2025.

[0014] As a preferred embodiment of the preparation method of the white tea fermentation liquid with oil control and acne removal effects described in this invention, the ratio of Lactobacillus gasseri to Lactobacillus plantarum strains is (1:3)-(3:1).

[0015] As a preferred embodiment of the preparation method of the white tea fermentation liquid with oil-controlling and acne-removing effects described in this invention, the ratio of Lactobacillus gasseri to Lactobacillus plantarum strains is 2:1.

[0016] As a preferred embodiment of the preparation method of the white tea fermentation liquid with oil-controlling and acne-removing effects described in this invention: In step S3, before inoculation, the *Lactobacillus gasseri* and *Lactobacillus plantarum* are activated and cultured in MRS medium at 35-38℃ and 100-200 rpm for 18-24 hours, respectively, to achieve a bacterial concentration of 10. 6 -10 7 CFU / mL.

[0017] As a preferred embodiment of the preparation method of the white tea fermented liquid with oil-controlling and acne-removing effects described in this invention: in step S4, the fermentation time is 24-72 hours.

[0018] As a preferred embodiment of the preparation method of the white tea fermentation liquid with oil-controlling and acne-removing effects described in this invention: In step S5, the solid-liquid separation includes centrifugation and membrane filtration; the centrifugation conditions are: 4700-5200 r / min, centrifugation for 20-25 min; the membrane filtration uses a ceramic membrane with a pore size of 0.22 μm.

[0019] The present invention also provides the application of the white tea fermented liquid prepared by the method of preparing the white tea fermented liquid with oil control and acne removal effects in the preparation of cosmetics.

[0020] The white tea fermentation liquid is used in the preparation of cosmetics for controlling skin oil secretion, whitening and brightening the skin, moisturizing or improving acne.

[0021] The beneficial effects of this invention are as follows: This invention provides a method for preparing a white tea fermented liquid with oil-controlling and acne-reducing effects. It uses *Lactobacillus plantarum* and *Lactobacillus gasseri* to ferment white tea without adding other organic reagents. The fermentation process is mild, preserving the structure of the active ingredients in the white tea and maintaining its natural activity. This invention saves production costs, fully guarantees the stability of product quality, and does not add fragrances or other chemical components to the fermented liquid, improving its safety for human use. It can be used directly as a skincare product. Furthermore, the white tea fermented liquid is rich in polyphenols and amino acids, which have a synergistic effect with some probiotic fermentation products in the liquid, thus exhibiting a stronger efficacy. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below, wherein:

[0023] Figure 1 This is a comparison chart of the NO removal capacity of white tea fermentation liquid fermented with different strains in the embodiments of the present invention;

[0024] Figure 2 This is a comparison chart of the NO removal capacity of white tea fermentation liquid obtained by compound bacteria fermentation in the embodiments of the present invention;

[0025] Figure 3 This is a graph showing the IL-6 expression capacity of white tea fermentation liquid in an embodiment of the present invention;

[0026] Figure 4 This is a diagram illustrating the oil control capability of the white tea fermentation liquid in an embodiment of the present invention.

[0027] Figure 5 This is a diagram showing the skin stratum corneum moisture content of the white tea fermentation liquid in an embodiment of the present invention.

[0028] Figure 6 This is a graph showing the number of acne lesions in the white tea fermentation liquid in an embodiment of the present invention;

[0029] Figure 7 The appearance of the sample after stability testing in this embodiment of the invention. Detailed Implementation

[0030] To make the above-mentioned objectives, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to specific examples.

[0031] Example 1:

[0032] In this invention, Lactobacillus gasseri RTNL 225001, with accession number CCTCC NO:M 20252844, is deposited at the China Center for Type Culture Collection, Wuhan University, Wuhan, China, on December 10, 2025.

[0033] The remaining strains are all existing technology strains, and their specific accession numbers are as follows:

[0034] The brewing yeast (Sacharomyces cerevisiae) described in this invention has the accession number CICC32883.

[0035] The aforementioned Pichia kudriavzevii has the accession number CICC 33293;

[0036] The Rhodosporidium toruloides strain has the accession number CICC 32489.

[0037] The Lactobacillus plantarum mentioned has the accession number CCTCC NO:M20232390 and is deposited at the China Center for Type Culture Collection.

[0038] The Lactobacillus fermentum specimen has the accession number ATCC 9338.

[0039] The Lactobacillus helveticus was purchased from the China Industrial Microbial Culture Collection Center, with accession number CICC 20997;

[0040] The *Limosilactobacillus reuteri* strain was purchased from the China Industrial Microbial Culture Collection Center, accession number CICC 6132.

[0041] The Lactobacillus acidophilus was purchased from the China Industrial Microbial Culture Collection Center, with accession number CICC 20710;

[0042] The Lactococcus garvieae strain was purchased from the China Industrial Microbial Culture Collection Center, with accession number CICC 24975.

[0043] The Lacticaseibacillus paracasei, with accession number CICC20252, is deposited at the China Industrial Microbial Culture Collection Center.

[0044] Example 1:

[0045] The production process of white tea extract: Take Bingdao white tea leaves (from Mengku Town, Shuangjiang County, Lincang, Yunnan), crush them, pass them through a 100-mesh sieve, weigh 50g, mix them with 1L of distilled water, stir evenly, and reflux extract at 100℃ for 2h; centrifuge at 4900r / min for 20min, centrifugation radius 9cm, filter through a 200nm pore size membrane, collect the filtrate, and obtain white tea extract.

[0046] Example 2:

[0047] White tea fermentation liquid prepared by fermenting white tea with brewer's yeast:

[0048] YPD medium: yeast extract 10.0 g / L, glucose 20.0 g / L, peptone 20.0 g / L, agar powder 20.0 g / L, pH 6.5~7.0.

[0049] Saccharomyces cerevisiae was inoculated into YPD medium and cultured at 37°C and 200 rpm for 18–24 h until the cell concentration reached 10⁻⁶. 6At CFU / mL, 10% of the white tea fermentation medium was inoculated into the white tea fermentation medium. The formula of the white tea fermentation medium was: 15 g / L of white tea extract obtained in Example 1, 10 g / L of glucose, and 5 g / L of rice flour, added to deionized water, and the pH of the system was adjusted to 5.0~6.0 to obtain the white tea fermentation medium. The medium was cultured at 30℃ and 200 rpm for 72 h. After fermentation, the fermentation liquid was first centrifuged to remove the bacteria. The centrifugation speed was 4700 r / min, the centrifugation time was 20 min, and the centrifugation radius was 9 cm. Then the filtrate was filtered through a 200 nm ceramic membrane at a filtration pressure of 0.18 MPa and a temperature of 30℃ to obtain the white tea fermentation liquid.

[0050] Example 3:

[0051] White tea fermentation liquid prepared by fermenting white tea with Lactobacillus plantarum:

[0052] MRS medium: Beef meal 10.0 g / L, yeast powder 5.0 g / L, diammonium hydrogen citrate 2.0 g / L, glucose 20.0 g / L, Tween 80 1.0 g / L, sodium acetate 5.0 g / L, dipotassium hydrogen phosphate 2.0 g / L, magnesium sulfate 0.58 g / L, manganese sulfate 0.25 g / L, pH 6.2;

[0053] Lactobacillus plantarum was inoculated into MRS medium and cultured at 37 °C and 200 rpm for 24 h until the bacterial concentration reached 10. 6 At a concentration of CFU / mL, 10% of the inoculum was added to the white tea fermentation medium and cultured at 37°C and 200 rpm for 36 h. After fermentation, the fermentation broth was centrifuged to remove the bacterial cells at a speed of 4700 r / min for 20 min and a centrifugation radius of 9 cm. The filtrate was then filtered through a 200 nm ceramic membrane at a pressure of 0.18 MPa and a temperature of 30°C to obtain the white tea fermentation broth.

[0054] Example 4:

[0055] The difference from Example 2 is that the fermentation strain used in Example 4 was selected from Kudriazvichi yeast.

[0056] Example 5:

[0057] The only difference from Example 2 is that the fermentation strain used in Example 5 is selected from Rhodotorula buergerianum.

[0058] Example 6:

[0059] The only difference from Example 3 is that the fermentation strain used in Example 6 is selected from Lactobacillus fermentum.

[0060] Example 7:

[0061] The difference from Example 3 is that the fermentation strain used in Example 7 was selected from Lactobacillus helveticus, and the cell concentration was increased to 10. 6 When the concentration of CFU / mL was 10%, it was inoculated into a fermentation medium containing white tea and fermented at 37°C.

[0062] Example 8:

[0063] The difference from Example 3 is that the fermentation strain used in Example 8 was selected from Lactobacillus reuteri.

[0064] Example 9:

[0065] The difference from Example 3 is that the fermentation strain used in Example 9 is selected from Lactobacillus acidophilus.

[0066] Example 10:

[0067] The difference from Example 3 is that the fermentation strain used in Example 10 was selected from Lactobacillus gasseri.

[0068] Example 11:

[0069] The difference from Example 3 is that the fermentation strain used in Example 11 was selected from Lactococcus gasseri.

[0070] Example 12:

[0071] The difference from Example 3 is that the fermentation strain used in Example 12 was selected from Lactobacillus casei.

[0072] Example 13:

[0073] The selection process for white tea co-fermented with Lactobacillus gasseri and Lactobacillus plantarum:

[0074] Using *Lactobacillus gasseri* and *Lactobacillus plantarum* from Examples 10 and 3 respectively, *Lactobacillus gasseri* and *Lactobacillus plantarum* were inoculated into MRS medium and cultured at 37 °C and 200 rpm for 24 h until the bacterial concentration reached 102. 6 The total inoculation ratio was 10% of the fermentation system, with the inoculation volume ratio of *Lactobacillus plantarum* to *Lactobacillus gasseri* being 3:1, 2:1, 1:1, 1:2, and 1:3, respectively. The culture was carried out at 37℃ and 200 rpm for 36 h. After fermentation, the fermentation broth was centrifuged to remove the bacterial cells at 4700 r / min for 20 min with a centrifugation radius of 9 cm. The filtrate was then filtered through a 200 nm ceramic membrane at a filtration pressure of 0.18 MPa and a temperature of 30℃.

[0075] Example 14:

[0076] The NO scavenging ability of the white tea extracts or white tea fermentation liquids prepared in Examples 1-12 was compared:

[0077] The experimental steps are shown in Table 1:

[0078] Table 1

[0079]

[0080] Right now:

[0081] a) 50 μL of 0.5 mmol SNP solution + 50 μL of sample, irradiated under UVB in a UV crosslinker for 60 min.

[0082] b) First add Griess reagent A, then measure the absorbance at 550 nm using a microplate reader. (blank)

[0083] c) Add Griess' reagent B and react in the dark for 10 minutes.

[0084] d) Detection of absorbance at 550 nm using an ELISA reader

[0085] Calculation formula:

[0086] NO inhibition rate (%) = [1 - (A)] s - A b ) / (A c -A cb ) ] × 100

[0087] In the formula:

[0088] A s A represents the absorbance of the experimental group. c The absorbance value is for the control group; A b A represents the absorbance of the experimental blank group. cb The absorbance value is for the control group.

[0089] Experimental results are as follows Figure 1 As shown, the NO removal capacity of white tea fermented with lactic acid bacteria is better than that of white tea fermented with yeast; while the NO removal capacity of white tea fermented with Lactobacillus gasseri is the best among lactic acid bacteria, followed by white tea fermented with Lactobacillus plantarum. Lactobacillus plantarum and Lactobacillus gasseri were selected for fermentation of white tea.

[0090] Example 15:

[0091] The NO removal capacity of the white tea fermentation liquid prepared in Example 13 was compared using the same method as in Example 14.

[0092] Experimental results are as follows Figure 2As shown, when the inoculation ratio of Lactobacillus gasseri to Lactobacillus plantarum is 2:1, the NO removal capacity of the fermentation broth is optimal, and it is superior to that of white tea / Lactobacillus gasseri fermentation broth or white tea / Lactobacillus plantarum fermentation broth. Therefore, a ratio of Lactobacillus gasseri to Lactobacillus plantarum of 2:1 was selected for subsequent white tea fermentation.

[0093] The synergistic effect of the samples was calculated using the Bliss model:

[0094] Bliss co-value:

[0095] △E=E AB -(E A +E B -E A ·E B )

[0096] Where E AB NO inhibition rate of white tea / Lactobacillus gasseri / Lactobacillus plantarum fermentation broth at different concentrations and ratios;

[0097] E A The NO inhibition rate of white tea / Lactobacillus gasseri fermentation broth at different concentrations;

[0098] E B The NO inhibition rate of white tea / Lactobacillus plantarum fermentation broth at different concentrations;

[0099] Calculations showed that at different concentrations of each white tea / Lactobacillus gasseri / Lactobacillus plantarum fermentation broth, ΔE > 0, indicating a synergistic effect.

[0100] Example 16:

[0101] IL-6 assay: RAW264.7 cells were grown in complete medium (high glucose DMEM medium containing 10% FBS and 1% penicillin antibiotics). Cells were digested with trypsin at a ratio of 2 × 10⁻⁶. 4 Two culture media were inoculated per well into 6-well plates, 2 mL per well, and incubated at 37°C with 5% CO2 for 18 h. The culture medium was aspirated and residual medium was washed away with PBS. 2 mL of DMEM was added to the blank group, 1 μg / mL of DMEM was added to the LPS group, and 1 μg / mL of DMEM-prepared LPS and a certain concentration of white tea / Lactobacillus plantarum fermentation broth were added to the experimental groups. All were co-cultured for 24 h. The supernatant was collected, centrifuged at 13000 rpm for 5 min, and the supernatant was collected. Following the manufacturer's instructions, the effect of the white tea / Lactobacillus plantarum fermentation broth on LPS-induced inflammatory cytokine levels was determined using an IL-6 assay kit.

[0102] The results are as follows Figure 3As shown in the figure above, the IL-6 content generated by white tea fermentation liquid with a content of 0.05%-0.5wt% under LPS induction was lower than that of the LPS group (control group), which effectively inhibited the IL-6 inflammatory factor induced by LPS, proving that white tea fermentation liquid has anti-inflammatory and soothing effects.

[0103] Example 17:

[0104] Sebum secretion:

[0105] SZ95 cells (human immortalized sebaceous gland cells) were grown in complete culture medium (high glucose DMEM medium containing 10% FBS and 1% penicillin-dextrose antibiotics). Cells were digested with trypsin for 3 min (depending on trypsin activity, digestion continued until visible cell detachment was observed), at a rate of 2 × 10⁻⁶. 5 Two cells were inoculated per well into a 6-well plate, 2 mL per well, and incubated at 37 °C in a 5% CO2 incubator for 18 h.

[0106] The model group was treated with 32 μM OL (oleic acid / linoleic acid) solution, the experimental group with a mixture of OL and white tea / Lactobacillus plantarum fermentation broth, and the blank group without OL and white tea / Lactobacillus plantarum fermentation broth. Each group was divided into three replicates and incubated for 48 h. The DMEM medium was discarded, and the cells were washed twice with PBS. 500 μL of 10 μg / mL Nile Red (stock solution prepared with acetone, working solution diluted with PBS) was added to each well, and the cells were incubated at 37 ℃ in the dark for 15 min. The fluorescence was detected using a multi-functional microplate reader with fluorescence function at an excitation wavelength of 485 nm and an absorption wavelength of 565 nm. The lipid synthesis of SZ95 cells was calculated using the following formula.

[0107] Lipid inhibition rate / % = (fluorescence value of blank group - fluorescence value of sample group) / fluorescence value of blank group × 100

[0108] The results are as follows Figure 4 As shown, compared with the negative control group, 0.025%-0.1% of white tea fermentation liquid could inhibit the oil produced by OL stimulation and effectively control the overexpression of SZ95 oil, proving that white tea fermentation liquid has oil control effect.

[0109] Example 18:

[0110] Skin stratum corneum moisture content detection: Essence products containing white tea fermentation liquid were prepared. The formula consisted of the following components: 2% white tea fermentation product, 0.05% EDTA-2Na, 3% glycerin, 4% 1,3-propanediol, 3% butylene glycol, 0.15% acrylate / C10-30 alkanol acrylate crosspolymer, 0.5% hydrogenated lecithin, 1% undecane, 1% squalane, 0.1% sodium hydroxide, 0.7% 1,2-hexanediol, 0.3% p-hydroxyacetophenone, and the remainder being water. All components were mixed and dissolved evenly at 75℃ to obtain the test essence. A blank control product containing the same formula but without white tea fermentation product was used as the white tea fermentation product.

[0111] The blank formula containing 2% white tea fermentation liquid was applied to different areas, and the skin moisture content of the applied areas was measured at 2h, 4h, and 8h.

[0112] The results are as follows Figure 5 As shown, after applying an essence containing 2% white tea fermentation liquid, the moisture content of the stratum corneum increased over time, proving its moisturizing effect.

[0113] Example 19

[0114] Acne detection:

[0115] The essence formula is the same as in Example 18.

[0116] Thirty subjects were selected. After cleansing their faces, they applied the serum twice daily for seven consecutive days, starting on day 0 (before use) and continuing until the end of the seven-day period. Before testing, subjects cleansed their faces, allowed them to air dry, and marked the measurement areas. Subjects sat quietly in a compliant room for at least 30 minutes before testing, refraining from drinking water and remaining relaxed. The Visia CR facial image analysis system was used to detect the number of acne follicles and the amount of porphyrins; lower values ​​indicated fewer acne follicles.

[0117] The results are as follows Figure 6 As shown, after using a formula containing 2% white tea fermented liquid for 7 days, the number of acne follicles and the amount of porphyrins both decreased. Furthermore, as can be seen from the VISIA chart, skin brightness improved after 7 days of use. Therefore, white tea fermented liquid has the effects of oil control, acne removal, and brightening.

[0118] Example 20:

[0119] Stability testing:

[0120] The samples were dispensed into 50mL PE plastic bottles. After testing pH and conductivity, observing, and photographing the results on the first day, the samples were placed under the following conditions: -18℃, 4℃, room temperature in the dark, room temperature in the light, light exposure, 50℃, and cycling. The cycling conditions were 50℃ on the first day, room temperature on the second day, and -20℃ on the third day; this cycle was repeated twice a week. Data were recorded on days 7, 14, 21, and after one month. The results were then analyzed and discussed.

[0121] The results are as follows Figure 6 As shown, from left to right, the conditions are -18℃, 4℃, room temperature away from light, room temperature without light, light exposure, 50℃, and cyclic conditions. The color did not change significantly within one month. The results of pH, conductivity, and odor stability are shown in Table 2.

[0122] Table 2 Stability data of white tea fermentation liquid

[0123]

[0124] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. 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 spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing a white tea fermentation liquid with oil-controlling and acne-reducing effects, characterized in that: Includes the following steps, S1. Raw material pretreatment: Take Bingdao white tea leaves, crush them, and sieve them to obtain white tea powder; S2. Preparation of white tea extract: Mix the white tea powder obtained in step S1 with water, heat to extract, centrifuge, filter, and take the filtrate to obtain white tea extract; S3. Preparation of white tea fermentation culture medium: Add glucose and rice flour to the white tea extract, adjust the pH to 4-7, and obtain white tea fermentation culture medium; S4. Inoculation and fermentation of compound microorganisms: Activated Lactobacillus gasseri and Lactobacillus plantarum are combined to form a compound microorganism, which is inoculated into the white tea fermentation medium for fermentation. S4. After the fermentation is terminated, the fermentation liquid is separated into solid and liquid components, and the filtrate is collected to obtain the white tea fermentation liquid.

2. The method for preparing white tea fermented liquid with oil-controlling and acne-removing effects according to claim 1, characterized in that: The white tea mentioned includes Icelandic white tea.

3. The method for preparing white tea fermented liquid with oil-controlling and acne-removing effects according to claim 1 or 2, characterized in that: The Lactobacillus gasseri has the accession number CCTCC NO:M 20252844 and is deposited at the China Center for Type Culture Collection on December 10, 2025.

4. The method for preparing white tea fermented liquid with oil-controlling and acne-removing effects according to claim 1 or 2, characterized in that: The ratio of Lactobacillus gasseri to Lactobacillus plantarum strains was (1:3)-(3:1).

5. The method for preparing white tea fermented liquid with oil-controlling and acne-removing effects according to claim 1 or 2, characterized in that: The ratio of Lactobacillus gasseri to Lactobacillus plantarum strains was 2:

1.

6. The method for preparing white tea fermented liquid with oil-controlling and acne-removing effects according to claim 1 or 2, characterized in that: In step S3, before inoculation, *Lactobacillus gasseri* and *Lactobacillus plantarum* are activated and cultured in MRS medium at 35-38℃ and 100-200 rpm for 18-24 hours to achieve a bacterial concentration of 10. 6 -10 7 CFU / mL.

7. The method for preparing white tea fermented liquid with oil-controlling and acne-removing effects according to claim 1 or 2, characterized in that: In step S4, the fermentation time is 24-72 hours.

8. The method for preparing white tea fermentation liquid with oil-controlling and acne-removing effects according to claim 1 or 2, characterized in that: In step S5, the solid-liquid separation includes centrifugation and membrane filtration; the centrifugation conditions are: 4700-5200 r / min, centrifugation for 20-25 min; the membrane filtration uses a ceramic membrane with a pore size of 0.22 μm.

9. The application of the white tea fermented liquid prepared by the method for preparing white tea fermented liquid with oil-controlling and acne-removing effects according to claim 1 in the preparation of cosmetics.

10. The application according to claim 9, characterized in that: The white tea fermentation liquid is used in the preparation of cosmetics for controlling skin oil secretion, whitening and brightening the skin, moisturizing, or improving acne.

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