Composition containing bio-fermentation product for increasing stability of cosmetic and method of preparing the same

Abstract

The present application belongs to the technical field of fermentation engineering. More particularly, it relates to a new application of a fermentation product of a xyloacetobacterium. The present application provides a fermentation product of a xyloacetobacterium, wherein the xyloacetobacterium is inoculated into a fermentation medium added with soybean milk and a juice of Atriplex nummularia to culture for 48-72 hours, and the fermentation supernatant is collected to obtain the fermentation product. It is unexpectedly found that the product obtained by fermenting soybean milk and the juice of Atriplex nummularia with the xyloacetobacterium can obviously increase the stability of retinol and reduce the skin irritation caused by retinol.

Description

Technical Field

[0001] This invention belongs to the field of fermentation engineering technology. More specifically, it relates to new applications of fermenting soybean milk with Acetobacter xylinum and its fermentation products. Background Technology

[0002] Acetobacter xylinum is a microorganism with important applications in the food and chemical industries. Its cells are rod-shaped, generally 0.6–0.8 μm × 1.0–4.0 μm in size, arranged singly or in pairs, Gram-negative, non-spore-forming, and may or may not have flagella; they may be motile or non-motile. Acetobacter xylinum possesses a unique metabolic pathway, capable of utilizing various sugars and alcohols to metabolize them into a variety of metabolites. In particular, it can synthesize cellular cellulose from carbon sources such as glucose through a series of enzymatic reactions.

[0003] Numerous studies both domestically and internationally have confirmed the antioxidant function of soybeans. The tocopherols, vitamin C, isoflavones, and phenolic compounds contained in soybeans all possess antioxidant activity. (Yamasaki et al.) [1] Substances extracted from fermented soy milk were found to possess antioxidant activity, according to Geng et al. [2] By optimizing the fermentation conditions of the lactic acid bacteria combination, the free radical scavenging rate of fermented soy milk can reach 84.3%; Xu Yin et al. [3] In vitro experiments demonstrated that fermented soy milk had a higher DPPH scavenging rate and Fe content than before fermentation. 2+ The chelating capacity increased significantly, by 32.76% and 31.89%, respectively.

[0004] Those skilled in the art will know that fermenting soy milk with different strains of bacteria can yield products with different physiological activities, as demonstrated by Ruan Ziqi et al. [4] Fermentation with Bacillus natto and Lactobacillus casei can produce fermented soy milk containing both nattokinase and pyrroloquinoline quinone. The mycelium of Grifola frondosa has high medicinal value; fermented soy milk made from it shows a significant reduction in stachyose and raffinose content, and after fermentation, vitamin B1 and niacin levels increase from 3.27 mg / L and 3.84 mg / L, respectively. -1 Increased to 10.82 and 8.74 mg·L -1[5] Nagino et al. [6] Fermented soy milk made with Lactobacillus casei can also improve the bioavailability of isoflavones in women; Liu et al. [7] It was also found that fermented soy milk made from Lactobacillus plantarum has neuroprotective effects and can improve the learning and memory abilities of rats. Currently, there are no reports on fermenting soy milk using Acetobacter xylinum and exploring the efficacy and characteristics of its products.

[0005] [1]Yamasaki Y, Bakke M.Fermented soymilk extract and fermented hypocotyl extract:JP, 2013082603[P].2014-06-19.

[0006] [2] Geng YR, Li WJ, Wang J MR adical scavenging ability of soy milkfermented with compound lactic acid bacteria towards DPPH free radical[J]. Agricultural Science & Technology, 2015, 16(9):2036-2039.

[0007] [3] Xu Yin, Huang Yujun, Chen Xia, et al. Study on the in vitro and in vivo antioxidant effects of lactic acid bacteria fermented soybean milk [J]. China Dairy Industry, 2012, 40(8): 16-19.

[0008] [4] Ruan Ziqi, Xu Weiwei, Wu Yuan, et al. A method for preparing fermented soy milk rich in nattokinase and pyrroloquinoline quinone: China, 201410751782[P]2014-12-10.

[0009] [5]Yang H, Zhang L, Xiao G, et al.Changes in some nutritional components of soymilk during fermentation by the culinary and dicinal mushroomGrifola frondosa[J].LWT-Food Science and Technology, 2015, 62(1): 468-473. Summary of the Invention

[0010] This invention relates to *Acetobacter xylinum*, products obtained from fermenting soy milk using *Acetobacter xylinum*, the properties of these products, and their applications. An unexpected discovery of this invention is that the product obtained from fermenting soy milk and Oceania quinoa juice using *Acetobacter xylinum* significantly increases the stability of retinol and reduces its skin irritation.

[0011] Specifically, the increase in retinol stability described herein includes increasing the stability of retinol or retinol-containing products, such as pharmaceuticals and cosmetics.

[0012] The above-mentioned objective of this invention is achieved through the following technical solution:

[0013] This invention provides a fermentation product of Acetobacter xylinum. The fermentation product is obtained by inoculating Acetobacter xylinum into a fermentation medium supplemented with soybean milk and culturing it for 48-72 hours, and collecting the fermentation supernatant.

[0014] In this article, the preferred fermentation time is 48 to 72 hours. Fermentation time is very important for obtaining fermentation products with ideal functional properties. Different fermentation times will cause many changes in the nutritional components of the fermentation products. For example, some components such as vitamins will accumulate, and some special metabolites may also be produced. These changes endow the products with different new properties.

[0015] In one embodiment of the present invention, the bioaccession number of the Acetobacter xylinum is ATCC 23769. Extensive screening and comparative experiments were conducted on the selection of strains, and the fermentation products produced after over-fermentation by lactic acid bacteria (Lactobacillus acidophilus) and yeast (Saccharomyces boulardii) showed no similar effects.

[0016] In one embodiment of the present invention, 3-10% by weight of Oceania quinoa juice was added to the fermentation medium. The addition of Oceania quinoa juice is essential to achieving the objectives of the present invention; the aforementioned statement that "this supernatant unexpectedly exhibited the effect of stabilizing retinol and reducing its skin irritation" is based on the addition of Oceania quinoa juice. This is because comparative experimental results showed that the fermentation supernatant obtained without the addition of Oceania quinoa juice exhibited the completely opposite effects.

[0017] In one embodiment of the present invention, the Oceania quinoa juice is obtained by juicing its stems and leaves. The juicing can be performed by any method of the prior art, such as pressing, grinding, enzymatic hydrolysis, ultrasonication, and microwave extraction. The present invention preferably uses the ultrasonic method, which specifically involves: selecting fresh Oceania quinoa, washing and crushing its stems and leaves, adding 3-6 times the volume of deionized water, and extracting under ultrasonic waves for 10-60 minutes at a frequency of 60-80 kHz, a power of 100-200 W, and a temperature controlled between 30-50°C; after ultrasonication, filtering and centrifuging the resulting mixture to obtain the Oceania quinoa juice.

[0018] In the preparation process of the above-mentioned Oceania quinoa juice, filtration is usually carried out by filter paper, filter screen or filtration equipment in order to remove solid residues and obtain juice.

[0019] In the preparation of the Oceania quinoa juice described above, centrifugation is used to remove any small particles or suspended matter remaining after filtration. Centrifugation allows solid impurities to settle to the bottom of the centrifuge tube, resulting in a clearer juice. The centrifugation speed can be 3000–10000 rpm, and the centrifugation time is 5–10 minutes.

[0020] In one embodiment of the present invention, the soy milk is obtained by grinding soybeans into a paste, followed by filtration, homogenization, and sterilization. In simple terms, this process includes the steps of washing, soaking, grinding, boiling, homogenizing, and sterilizing the soybeans.

[0021] Specifically, the detailed preparation steps are as follows: After cleaning and rinsing the soybeans to remove impurities, add deionized water at a material-to-liquid ratio of 1:3 to 10, soak in 0.1 to 0.5% NaHCO3 solution for 1 to 12 hours, add deionized water at a material-to-liquid ratio of 1:3 to 10, heat grind at 80 to 100°C for 10 to 30 minutes, pass through a 100-mesh sieve, homogenize at 10 to 30 MPa for 5 to 10 minutes, sterilize and cool to obtain soy milk.

[0022] In one embodiment of the present invention, the amount of soy milk added to the culture medium is 10-35%.

[0023] In one embodiment of the present invention, the culture medium is Hestrin-Schramm medium. Hereinafter, the Hestrin-Schramm (HS) medium contains 20 g / L glucose, 5 g / L peptone, 5 g / L yeast extract, 2.7 g / L potassium dihydrogen phosphate, and 0.2 g / L magnesium sulfate heptahydrate, with a pH of 5.5–6.0.

[0024] In one embodiment of the present invention, the fermentation parameters are as follows: the inoculum amount of Acetobacter xylinum is 3-10%; the fermentation temperature is 25-30℃; the fermentation pH is 5.0-6.0; the aeration rate is 0.5-1.5 vvm; the stirring speed is 100-300 r / min; and the tank pressure is 0.05-0.15 MPa.

[0025] The present invention also provides the use of the fermentation product of Acetobacter xylinum in improving the stability of retinol or its derivatives.

[0026] In this paper, stability refers to the stability of retinol in solutions with different pH values ​​and solutions containing metal ions. Experiments showed that retinol solutions exhibited poor stability at pH 2.0 and pH 10.0, with residual rates of approximately 58% and 35% after 5 days of incubation at 37°C, respectively. Retinol remained relatively stable at pH 6.0–8.0. However, after adding the *Acetobacter xylinum* fermentation product of this invention, the retinol solution remained relatively stable in both acidic and alkaline solutions (pH 2.0–10.0), with residual rates exceeding 85% after 5 days of incubation at 37°C. This indicates that the *Acetobacter xylinum* fermentation product can improve the stability of retinol in acidic and alkaline solutions, but the specific mechanism of action requires further investigation.

[0027] In addition, it has been proven that Fe 3+ The presence of Fe relatively affects the stability of retinol, and with the increase of Fe... 3+ The higher the concentration of Fe, the stronger its destructive effect on retinol. 3+ After incubation at 37°C for 5 days in a (10 mmol / L) solution, only about 50% of retinol remained. The retinol's color changed to brownish-yellow, likely due to oxidative degradation. However, after adding Acetobacter xylinum fermentation products, the retinol content increased significantly in the same Fe solution. 3+ After incubation at 37°C for 5 days in the solution, the remaining retinol content was 90%. This indicates that the fermentation product of *Acetobacter xylinum* can significantly increase the retinol content in Fe... 3+ The stability in solution was significantly different compared to that without the addition (P<0.01).

[0028] Unfortunately, the Acetobacter xylinum fermentation product obtained in this invention does not improve the photostability of retinol.

[0029] The present invention also provides the use of the Acetobacter xylinum fermentation product in reducing skin irritation caused by retinol or its derivatives.

[0030] The irritation test results showed that, in addition to the aforementioned functions, surprisingly, this mixture of Acetobacter xylinum fermentation products and retinol had a remarkably low level of irritation.

[0031] The realization of the above functions depends on the presence of Acetobacter xylinum fermentation products obtained by specific preparation methods. Attached Figure Description

[0032] Figure 1 Image of Acetobacter xylinum cells.

[0033] Figure 2 The changes in TEWL values ​​before and after the use of Acetobacter xylinum fermentation products / retinol emulsions in each group;

[0034] Compared with the control group, *P < 0.05 ** P < 0.01. Detailed Implementation

[0035] The present invention will be further illustrated below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.

[0036] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0037] The HS culture medium described in this article contains 20 g / L glucose, 5 g / L peptone, 5 g / L yeast extract, 2.7 g / L potassium dihydrogen phosphate, and 0.2 g / L magnesium sulfate heptahydrate, with a pH of 5.5–6.0.

[0038] Example 1: Preparation of fermentation products of Acetobacter xylinum

[0039] (1) Preparation of soy milk: After cleaning the soybeans, add deionized water at a ratio of 1:6, soak in 0.25% NaHCO3 solution for 3 hours, add deionized water at a ratio of 1:10, heat grind at 100℃ for 30 minutes, pass through a 100-mesh sieve, homogenize at 25MPa for 8 minutes, sterilize and cool to obtain soy milk.

[0040] (2) Preparation of Oceania quinoa juice: Select fresh Oceania quinoa, take its stems and leaves, wash them, crush them, add 6 times the amount of deionized water, place it under ultrasound for 30 minutes, the ultrasound frequency is 60kHz, the ultrasound power is 150W, and the temperature is controlled at 45℃; after ultrasound, filter the resulting mixture, centrifuge at 3000 rpm for 5 minutes, take the supernatant, and obtain the Oceania quinoa juice.

[0041] (3) Activation of bacterial strain: In a clean bench, pick up a small amount of Acetobacter xylinum with an inoculation loop and inoculate it into the prepared solid slant medium (HS medium + 1.5% agar, pH 5.5-6.0) under aseptic conditions. Gently slide the medium on the slant to distribute the bacterial strain evenly. Place the inoculated medium in a constant temperature incubator and incubate at 28-30℃ for 24 hours until obvious colonies appear on the medium. Collect the bacterial cells.

[0042] (4) Fermentation: 25 wt% soybean milk and 8 wt% Oceania quinoa juice were added to the HS medium to obtain the fermentation medium. 5% Acetobacter xylophilus was inoculated into the fermentation medium and fermented for 48-72 h. The fermentation temperature was 28℃, the fermentation pH was 5.5-6.0, the aeration rate was 1.0 vvm, the stirring speed was 150 r / min, and the tank pressure was 0.1 MPa. The fermentation supernatant was collected, filtered through a 0.22 μm ultrafiltration membrane, and the filtrate was collected to obtain the Acetobacter xylophilus fermentation product.

[0043] Example 2: Preparation of fermentation products of Acetobacter xylinum

[0044] (1) Preparation of soy milk: After cleaning the soybeans, add deionized water at a ratio of 1:3 and soak them in 0.25% NaHCO3 solution for 2 hours. Add deionized water at a ratio of 1:10 and heat grind at 80℃ for 30 minutes. Pass through a 100-mesh sieve, homogenize at 20MPa for 10 minutes, sterilize and cool to obtain soy milk.

[0045] (2) Preparation of Oceania quinoa juice: Select fresh Oceania quinoa, take its stems and leaves, wash them, crush them, add 3 times the amount of deionized water, place it under ultrasound for 15 minutes, the ultrasound frequency is 860kHz, the ultrasound power is 200W, and the temperature is controlled at 50℃; after ultrasound, filter the resulting mixture, centrifuge at 3000 rpm for 10 minutes, take the supernatant, and obtain the Oceania quinoa juice.

[0046] (3) Activation of bacterial strain: In a clean bench, pick up a small amount of Acetobacter xylinum with an inoculation loop and inoculate it into the prepared solid slant medium (HS medium + 1.5% agar, pH 5.5-6.0) under aseptic conditions. Gently slide the medium on the slant to distribute the bacterial strain evenly. Place the inoculated medium in a constant temperature incubator and incubate at 28-30℃ for 24 hours until obvious colonies appear on the medium. Collect the bacterial cells.

[0047] (4) Fermentation: 10 wt% soybean milk and 10 wt% Oceania quinoa juice were added to the HS medium to obtain the fermentation medium. 3% Acetobacter xylophilus was inoculated into the fermentation medium and fermented for 48 h at a fermentation temperature of 28℃. The fermentation pH was 5.5-6.0, the aeration rate was 1.0 vvm, the stirring speed was 150 r / min, and the tank pressure was 0.1 MPa. The fermentation supernatant was collected, filtered through a 0.22 μm ultrafiltration membrane, and the filtrate was collected to obtain the Acetobacter xylophilus fermentation product.

[0048] Example 3: Preparation of fermentation products of Acetobacter xylinum

[0049] (1) Preparation of soy milk: After cleaning and rinsing soybeans, add deionized water at a ratio of 1:10 and soak in 0.25% NaHCO3 solution for 12 hours. Add deionized water at a ratio of 1:10 and heat grind at 100℃ for 30 minutes. Pass through a 100-mesh sieve, homogenize at 25MPa for 5 minutes, sterilize and cool to obtain soy milk.

[0050] (2) Preparation of Oceania quinoa juice: Select fresh Oceania quinoa, take its stems and leaves, wash them, crush them, add 5 times the amount of deionized water, place it under ultrasound for 60 minutes, the ultrasound frequency is 60kHz, the ultrasound power is 100W, and the temperature is controlled at 35℃; after the ultrasound is completed, filter the resulting mixture, centrifuge at 3000 rpm for 5 minutes, take the supernatant, and obtain the Oceania quinoa juice.

[0051] (3) Activation of strain: In a clean bench, pick up a small amount of Acetobacter xylophilus with an inoculation loop and inoculate it into a prepared solid slant culture medium (HS medium + 1.5% agar, pH 5.5-6.0) under aseptic conditions. Gently slide it on the slant to distribute the strain evenly. Place the inoculated culture medium in a constant temperature incubator and incubate at 28-30℃ for 24h until obvious colonies appear on the culture medium. Collect the bacterial cells. (4) Fermentation: Add 35wt% soybean milk and 3wt% Oceania quinoa juice to the HS medium to obtain a fermentation culture medium. Inoculate 5% activated Acetobacter xylophilus into the fermentation culture medium and ferment for 72h at a fermentation temperature of 28℃, a fermentation pH of 5.5-6.0, an aeration rate of 1.0 vvm, a stirring speed of 150 r / min, and a tank pressure of 0.1 MPa. Collect the fermentation supernatant, filter it through a 0.221 μm ultrafiltration membrane, collect the filtrate, and obtain the Acetobacter xylophilus fermentation product.

[0052] Comparative Example 1 differs from Example 1 in that Oceania quinoa juice is not added during the fermentation process in step (4), while the other parameters are the same as in Example 1.

[0053] Comparative Example 2 differs from Example 1 in that black truffle extract (purchased from Shanghai Haotai Biotechnology Co., Ltd.) is added during the fermentation process in step (4), while the other parameters are the same as in Example 1.

[0054] Comparative Example 3 differs from Example 1 in that Lactobacillus acidophilus is used instead of Acetobacter xylinum. The fermentation parameters are as follows: MRS medium, fermentation at 37°C on a shaker, pH 5.5–6.5, shaker speed 150 r / min, aeration rate 1.0 vvm, and other parameters are the same as in Example 1.

[0055] Comparative Example 4 differs from Example 1 in that Saccharomyces boulardii is used instead of Acetobacter xylinum. The fermentation parameters are as follows: YPD medium, fermentation at 30°C on a shaker, pH 5.0–6.0, aeration rate of 1.0 vvm, and shaker speed of 1500 r / min. The remaining parameters are the same as those in Example 1.

[0056] pH stability test

[0057] Solutions with pH values ​​of 2, 4, 6, 8, and 10 were prepared using phosphate buffer solutions with different pH values ​​and 100% DMSO solution. Appropriate amounts of retinol were accurately weighed and dissolved in these solutions at different pH values ​​to prepare retinol solutions of the same concentration (1%), ensuring complete dissolution of the retinol. The *Acetobacter xylinum* fermentation products from Examples 1 and Comparative Examples 1-4 were added to the above retinol solutions, ensuring a weight ratio of *Acetobacter xylinum* fermentation products to retinol of 1:0.5. The mixture was thoroughly mixed, and the pH of each sample solution was calibrated (the addition of *Acetobacter xylinum* fermentation products caused a slight pH deviation). Each sample tube was incubated in a constant temperature incubator (37°C) for 5 days. The samples were then removed, and the retinol content in each sample tube was determined using high-performance liquid chromatography (HPLC). Six replicates were performed for each sample, with the retinol solution without *Acetobacter xylinum* fermentation products serving as the control group. The residual retinol rate at different pH values ​​was calculated, and the results are shown in Table 1 below.

[0058] Residual rate = (Retinol content after incubation - Retinol content before incubation) / Retinol content before incubation × 100%

[0059] Table 1

[0060]

[0061] Note: Compared with the control group, * P<0.05, ** P < 0.01.

[0062] Analysis of Table 1 shows that retinol exhibits poor stability in solutions with pH 2.0, 4.0, and 10.0, with residual rates of approximately 58%, 62%, and 35%, respectively. However, the addition of the *Acetobacter xylinum* fermentation product from Example 1 significantly improves the stability of retinol in solutions at different pH levels. Particularly under acidic and alkaline conditions, the residual rate of retinol is above 85%, reaching a maximum of 96%. Analysis of other comparative examples reveals that the *Acetobacter xylinum* fermentation product prepared without the addition of *Acer buergerianum* juice and the *Acetobacter xylinum* fermentation product prepared using *Lactobacillus acidophilus* instead of *Acetobacter xylinum* showed the opposite effect to Example 1, with a significantly lower residual rate of retinol compared to the control group (P<0.05). The *Acetobacter xylinum* fermentation product prepared with the addition of black truffle extract had no significant effect on the stability of retinol, but also did not show the opposite effect. The *Acetobacter xylinum* fermentation product prepared using *Saccharomyces boulardii* instead of *Acetobacter xylinum* had a certain improving effect on the stability of retinol in acidic and alkaline solutions, but the effect was not as strong as that of Example 1.

[0063] Metal ion influence test

[0064] Solution preparation: Retinol was prepared into a 1% ethanol solution, divided into 18 equal portions, and then randomly divided into 3 groups of 6 portions each, corresponding to three concentrations of ferric chloride solution (0.1 mmol / L, 1 mmol / L, and 10 mmol / L). The fermentation products of *Acetobacter xylinum* from Example 1 and Comparative Examples 1–4 were added to each of the 6 portions in each group, with the remaining portion serving as a blank control. All samples were mixed thoroughly to obtain a mixed solution. Different concentrations of FeCl3 solution were added to the three mixed solutions to achieve final concentrations of 0.1 mmol / L, 1 mmol / L, and 10 mmol / L, respectively. After incubating each group of samples at 37°C for 5 days, the retinol content was detected by HPLC, and the remaining retinol rate was calculated. The results are shown in Table 2 below.

[0065] Table 2

[0066]

[0067]

[0068] Note: Compared with the control group, * P < 0.05 ** P < 0.01.

[0069] Analysis of Table 2 shows that retinol has poor stability in a 10.0 mmol / L iron ion solution. After incubation at 37°C for 5 days, only 50% of the retinol remained, indicating a damage rate of 50%. However, after adding the *Acetobacter xylinum* fermentation product from Example 1, the stability of retinol in iron ion solutions of different concentrations was significantly improved, with a loss rate of less than 10% in a 10.0 mmol / L iron ion solution. Analysis of other comparative examples shows that the *Acetobacter xylinum* fermentation product prepared with the addition of black truffle extract showed good stability in iron ion solutions at concentrations of 0.1 mmol / L and 1 mmol / L. The fermentation product of Acetobacter xylophilus has a certain stabilizing effect on retinol in the solution, but no similar effect was observed in the high concentration of iron ions. The fermentation product of Acetobacter xylophilus prepared without the addition of Oceania stellaria juice has no obvious effect on the stabilization of retinol in the low concentration of iron ions, but the opposite effect was observed in the high concentration of iron ions. The fermentation products of Acetobacter xylophilus prepared by replacing Acetobacter xylophilus with Lactobacillus acidophilus and the fermentation products of Acetobacter xylophilus prepared by replacing Acetobacter xylophilus with Saccharomyces boulardii were not observed to have similar enhancing or opposite effects in the iron ion solutions of different concentrations.

[0070] Stimulation test

[0071] Preparation of retinol emulsion: Weigh 0.35g of carbamoyl ether into a 200mL beaker, add 7.5g of glycerol, and then add 79.55g of deionized water. Heat to 75-80℃ and stir to obtain phase A. Weigh 0.5g of p-hydroxyacetophenone and 0.5g of 1,2-hexanediol into a small beaker and stir at 60-70℃ until completely dissolved to obtain phase B. Add retinol and the *Acetobacter xylinum* fermentation product from Example 1 (1% and 2% by weight, respectively), and stir at 75-80℃ until completely dissolved to obtain phase C. Add phase C to phase A at 75-80℃, disperse for 5-10 minutes, cool to 40℃, add phase B, and adjust the pH to approximately 6.0 to obtain the sample emulsion of Example 1. Comparative sample emulsions 1-4 were prepared according to the above method, and the retinol emulsion without *Acetobacter xylinum* fermentation product was used as a blank control group.

[0072] Screening of retinol-sensitive individuals: 1g of a retinol-containing lotion sample was applied to the inner forearm of the subjects, spreading it evenly in circular motions 20 times. This was done twice daily, morning and evening, for two consecutive days. Subjects who reported stinging, burning, or pain were selected. A total of 30 subjects meeting this criterion were selected for irritation testing.

[0073] Irritation test procedure: Thirty subjects were randomly divided into six groups of five. Before the experiment, the inner forearm of each subject was rinsed with water and dried. The subjects were then placed in a constant temperature and humidity environment (temperature 20–22℃, humidity 40%–60%) for 30 minutes. Six square areas (2×2cm) were marked on the inner forearm of each subject. The TEWL value of each area before sample application was measured using a Tewameter RTM Hex. Sample emulsion (1g) was applied to each of the six square areas, swirling 20 times for even distribution. This was done twice daily (morning and evening) for two consecutive days. The TEWL value was measured on the third day. The collected data were compiled and statistically analyzed. The results are shown in Table 3. Figure 2 As shown.

[0074] TEWL difference = TEWL value after use - TEWL value before use

[0075] Table 3

[0076] Group Change in average TOWL value before and after use Blank control group 1.35 Example 1 -0.44 Comparative Example 1 0.89 Comparative Example 2 -0.12 Comparative Example 3 1.67 Comparative Example 4 0.53

[0077] The results are shown in Table 3 and Figure 2 As shown, the subjects' TEWL increased after using a solution containing only retinol, indicating that the transepidermal water loss of the skin increased after using retinol and the skin barrier was significantly damaged; while the subjects' skin TEWL values ​​decreased after applying the emulsion samples containing the fermentation products of Acetobacter xylinum in Example 1 and Comparative Example 2, indicating that it had less skin irritation.

[0078] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A fermentation product of Acetobacter xylinum, characterized in that, Acetobacter xylophilus was inoculated into a fermentation medium supplemented with soybean milk and cultured for 48-72 hours. The fermentation supernatant was collected to obtain the fermentation product. The bioaccession number of the Acetobacter xylophilus was ATCC23767. The fermentation parameters were: Acetobacter xylophilus inoculum size 3-10%; fermentation temperature 25-30℃; fermentation pH 5.0-6.0; aeration rate 0.5-1.5 vvm; stirring speed 100-300 r / min; tank pressure 0.05-0.15 MPa. The culture medium also contains 3-10% by weight of Oceania quinoa juice; the Oceania quinoa juice is obtained by juicing its stems and leaves and then filtering it. The specific operation is as follows: select fresh Oceania quinoa, take its stems and leaves, wash them, crush them, add 3-6 times the amount of deionized water, and extract them under ultrasound for 10-60 minutes. The ultrasound frequency is 60-80kHz, the ultrasound power is 100-200W, and the temperature is controlled between 30-50℃. After ultrasound, filter the resulting mixture and centrifuge it to obtain the Oceania quinoa juice.

2. The fermentation product according to claim 1, characterized in that, The soy milk is obtained by grinding soybeans into a paste, then filtering, homogenizing, and sterilizing it.

3. The fermentation product according to claim 2, characterized in that, The amount of soy milk added to the culture medium is 10-35%.

4. The fermentation product according to claim 1, characterized in that, The culture medium is Hestrin-Schramm medium.

5. Use of the Acetobacter xylinum fermentation product according to any one of claims 1 to 4 in improving the stability of retinol.

6. Use of the Acetobacter xylinum fermentation product according to any one of claims 1 to 4 in reducing skin irritation caused by retinol, wherein the use is for non-diagnostic and non-therapeutic purposes.

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