Solanum nigrum fermentation method, fermentation product and application of fermentation product

Abstract

The invention belongs to the field of new materials for daily use chemicals, and discloses a method for fermenting solanum nigrum, which is characterized in that solanum nigrum roots are fermented by adopting one or more strains of lactic acid bacteria, bifidobacteria, bacillus, micrococcus, saccharomycetes and filamentous fungi to obtain a solanum nigrum fermentation product. The functions of wrinkle resistance, compactness and the like of the withanolaria nipponica fermentation product obtained by fermentation through the method are obviously better than those of unfermented withanolaria nipponica fermentation products and fermentation products taking withanolaria nipponica extracts as fermentation bases. Meanwhile, the invention also provides application of the fermentation product.

Description

Technical Field

[0001] This invention relates to the field of new materials for daily chemical products, specifically to a method for fermenting nightshade, the fermentation product, and its application. Background Technology

[0002] The following documents disclose technologies related to the fermentation of nightshade:

[0003] The patent application, with publication number ES2848828T3, is for the use of nightshade extract in the treatment of amyloid-related diseases.

[0004] The public notice number is US11129864B2, and the subject is a method for obtaining plant extracts and related compositions;

[0005] Of particular note is the patent application with publication number CN112075629A, which discloses a method for improving the antioxidant activity of Ashwagandha extract by probiotic fermentation. This method involves fermenting Ashwagandha extract with probiotics to enhance its antioxidant properties.

[0006] The above methods all use nightshade extract as the fermentation basis, but further research in this application found that it can be further improved in terms of specific cosmetic efficacy. Summary of the Invention

[0007] The purpose of this invention is to provide a method for fermenting eggplant, in which the fermented eggplant product obtained by this method has significantly better cosmetic effects such as firming and anti-wrinkle properties than unfermented products and fermented products based on eggplant extract.

[0008] In addition, the present invention also provides applications of the fermentation product.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a method for fermenting eggplant, which involves fermenting eggplant roots with one or more of the following microorganisms: lactic acid bacteria, bifidobacteria, Bacillus, micrococcus, yeast, and filamentous fungi, to obtain eggplant fermentation products.

[0010] In the above-mentioned method for fermenting nightshade, the lactic acid bacteria are one or more combinations of Lactobacillus plantarum, Lactobacillus sakei subsp., and Lactobacillus paracasei.

[0011] The Bifidobacterium is one or more of Bifidobacterium longum subsp. infantis, Bifidobacterium adolescentis, and Bifidobacterium longum.

[0012] The Bacillus species is Bacillus subtilis and / or Bacillus argentis;

[0013] The micrococcus is a strain of Micrococcus luteus and / or Micrococcus genus;

[0014] The yeast strain is *Saccharomyces cerevisiae* and / or *Saccharomyces triquetrum*.

[0015] The filamentous fungi are Aspergillus niger and / or Aspergillus oryzae.

[0016] In the above-mentioned method for fermenting eggplant, the fermentation temperature and oxygen content are set according to the fermentation requirements of the fermentation strain. The fermentation medium is a medium containing 1-20 wt% eggplant root powder. Preferably, the fermentation medium contains 5-15 wt% eggplant root powder. More preferably, the fermentation medium contains 7-13 wt% eggplant root powder.

[0017] In the above-mentioned method for fermenting nightshade, the culture medium contains only nightshade root powder and water, without the addition of carbon sources, nitrogen sources, or inorganic salts.

[0018] In the above-mentioned method for fermenting nightshade, the fermentation time is 10 to 48 hours, preferably 16 to 32 hours, and more preferably 20 to 28 hours.

[0019] In the above-mentioned method for fermenting nightshade, if the fermenting bacteria are Bifidobacterium, it is anaerobic fermentation; if the fermenting bacteria are Bacillus and / or Micrococcus, it is aerobic fermentation. Preferably, the aerobic fermentation is performed in a shaker; if the fermenting bacteria are lactic acid bacteria, yeast, or filamentous fungi, fermentation can be carried out in the air.

[0020] In the above-mentioned method for fermenting nightshade, the fermentation temperature is 28~40℃. Preferably, if the fermentation bacteria are lactic acid bacteria, bifidobacteria, or Bacillus, the fermentation temperature is 37±2℃, more preferably 37±1℃, and more preferably 37±0.5℃.

[0021] If the fermentation bacteria are micrococci, yeast, or filamentous fungi, the fermentation temperature is 30±2℃, preferably 30±1℃, and more preferably 30±0.5℃.

[0022] The inoculation amount of the strain is 1~30wt%, preferably 5~20wt%, and more preferably 7~15wt%.

[0023] In this invention, the viable bacterial content of the strain is 10. 6 -10 8 cfu / ml.

[0024] In addition, the present invention also discloses the fermentation product of nightshade basil obtained by any of the methods described above.

[0025] In addition, a *Solanum nigrum* root extract is disclosed, which is obtained by polyol-mediated solubilization and targeted enrichment of *Solanum nigrum* lactones from the aforementioned *Solanum nigrum* fermentation products. The polyol is one or more combinations of propylene glycol, butylene glycol, pentanediol, and hexanediol; the polyol and *Solanum nigrum* fermentation products are mixed at a weight ratio of 1-50:50-99, and after thorough extraction, centrifugation and filtration are performed; the supernatant is the *Solanum nigrum* root extract.

[0026] In the above-mentioned use of the fermented product of nightshade to prepare cosmetics, the cosmetics are cosmetics with one or more functions such as firming and anti-wrinkle.

[0027] Finally, this invention discloses a cosmetic containing 0.05-50% of nightshade fermentation product.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] The fermented product of *Solanum nigrum* obtained by the method of the present invention has significantly better cosmetic effects such as firming and anti-wrinkle properties than unfermented products and fermented products based on *Solanum nigrum* extract. Attached Figure Description

[0030] Figure 1 Bar chart showing the content of nightshade lactones after fermentation by different strains;

[0031] Figure 2 Bar chart showing the DPPH free radical scavenging rate of different strains after fermentation;

[0032] Figure 3 Bar chart showing the hydroxyl radical scavenging rate of different strains after fermentation;

[0033] Figure 4 Bar chart showing the levels of lipofuscin in nematodes in BIF1 fermentation filtrate (fermentation filtrate of *Bifidobacterium longum* subsp. *infanthizobium* root powder) and CON filtrate (unfermented *Solanum nigrum* root powder).

[0034] Figure 5 A bar chart showing the changes in solubilol content of nightshade lactones mediated by different polyols after solubilization;

[0035] Figure 6 A bar chart showing the changes in solubilizing solanacolic lactone content mediated by different amounts of hexanediol.

[0036] Figure 7 A bar chart showing the changes in solanol lactone content in each fermentation group after hexanediol-mediated solubilization.

[0037] Figure 8 Liquid chromatography spectra of the standards solanacolin A and solanacolin A;

[0038] Figure 9The liquid chromatogram of BIF1 fermentation filtrate (fermentation filtrate of Bifidobacterium longum subsp. infantis root powder of Solanum nigrum);

[0039] Figure 10 The liquid chromatogram of BIF1' fermentation filtrate (fermentation filtrate of Bifidobacterium longum subsp. infantis root extract of Solanum nigrum);

[0040] Figure 11 Liquid chromatogram for enriching solanacrolides in hexanediol-mediated solubilization of BIF1 fermentation filtrate (fermentation filtrate of Bifidobacterium longum subsp. infantis root powder);

[0041] Figure 12 Liquid chromatogram of solanacrolol enriched in hexanediol-mediated solubilization of BIF1' fermentation filtrate (fermentation filtrate of Bifidobacterium longum subsp. infantis root extract of Solanacrolol). Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Experiment Overview

[0044] In the preliminary experiments of this invention, we used several strains and a blank control group; the inoculum amount for all of them was 10 wt%.

[0045] Meanwhile, we also verified the compound preparation at a compound inoculation rate of 20 wt%.

[0046] In comparison, the present invention also conducted comparative fermentation on the extract of *Solanum nigrum*.

[0047] In addition, we also mixed the eggplant fermentation product obtained from the above-mentioned strains with polyols for extraction to obtain an extract.

[0048] The specific experimental procedure is as follows:

[0049] Fermentation of Solanum nigrum root powder and Solanum nigrum extract

[0050] I. Experimental Methods

[0051] The strains involved in this invention and some fermentation parameters are shown in Table 1.

[0052] Table 1. Information on strains and fermentation conditions for the fermentation of eggplant root powder.

[0053]

[0054] Table 2. Fermentation group of Solanum nigrum root extract

[0055]

[0056] Table 3. Fermentation group of Solanum nigrum root extract with additional carbon and nitrogen sources

[0057]

[0058] 1.1 Strain activation

[0059] Fourteen strains of bacteria, including lactic acid bacteria (Lactobacillus plantarum, Lactobacillus sakei subsp. sakei, and Lactobacillus paracasei), bifidobacteria (Bifidobacterium longum subsp. infanti, Bifidobacterium adolescentis, and Bifidobacterium longum), Bacillus (Bacillus subtilis and Bacillus argentis), micrococci (Micrococcus luteus and a strain of Micrococcus), yeasts (Saccharomyces cerevisiae and Saccharomyces triquetrum), and filamentous fungi (Aspergillus oryzae and Aspergillus niger), were activated separately on plates for 24 hours. After activation, they were inoculated into liquid culture medium and cultured for 24 hours to obtain fermentation seed liquid for later use.

[0060] 1.2 Preparation of Fermentation Substrate

[0061] Preparation of fermentation substrate for nightshade

[0062] Eggplant root powder fermentation medium: The medium contains 8% eggplant root powder, without the addition of carbon source, nitrogen source, or inorganic salts. Depending on the fermentation requirements of the fermentation strain, the medium is treated with nitrogen purging / non-nitrogen purging, followed by sterilization at 121℃ for 30 minutes. In other words, the eggplant root powder fermentation medium is an 8wt% aqueous solution of eggplant root powder.

[0063] The test results showed that the content of lycorine lactone in 8% lycorine extract was 19.97 wt%.

[0064] Preparation of fermentation substrate for Solanum nigrum root extract

[0065] Fermentation medium for Solanum nigrum root extract: Take an appropriate amount of Solanum nigrum root extract, without adding any carbon source, nitrogen source or inorganic salt, and control the content of Solanum nigrum lactone in the medium to be consistent with the content of Solanum nigrum lactone in the medium obtained in ①. Then, according to the fermentation requirements of the fermentation strain, the medium is treated with nitrogen gas or without nitrogen gas. Finally, it is sterilized at 121℃ for 30 minutes.

[0066] The extract of *Solanum nigrum* root was obtained from Shaanxi Hongda Botanical Chemical Co., Ltd., and the specification was 10% lactone. The lactone content of *Solanum nigrum* extract in the culture medium was found to be consistent with that of *Solanum nigrum* root powder.

[0067] Prepared by adding carbon and nitrogen source matrix to eggplant root extract

[0068] The preparation process is the same as that for the fermentation medium of Solanum nigrum root extract, except that 2% glucose + 2% peptone is added.

[0069] 1.3 Inoculation and Fermentation

[0070] One or more strains of bacteria selected from Lactobacillus, Bifidobacterium, Bacillus, Micrococcus, Yeast, and filamentous fungi were inoculated into Solanum nigrum root powder culture medium and Solanum nigrum root extract culture medium for fermentation, respectively. The inoculation amount was 10%, and the fermentation time was 24 hours. (Specific fermentation conditions are shown in Tables 1, 2, and 3.)

[0071] Control group: No strains were added, and the mixture was placed in a constant temperature incubator at 37°C for 24 hours.

[0072] 1.4 Polyol-mediated solubilization

[0073] After fermentation, the fermentation products (with residue) from the BIF1 experimental group were subjected to mediated solubilization with distilled water, propylene glycol, butylene glycol, pentanediol, and hexanediol, respectively, to directionally enrich solanacrolides. The ratio was 20% polyol and 80% fermentation products (including residue). After centrifugation and filtration, the supernatant was obtained, and the solanacrolide content was determined to screen out the optimal polyol. Subsequently, the optimal polyol was further screened for optimal concentration using the fermentation products (including residue) from the BIF1 experimental group. After screening, mediated solubilization experiments were conducted on the products (including residue) from all fermentation groups using the optimal polyol and its optimal concentration.

[0074] II. Experimental Results

[0075] 2.1 Viable bacteria count

[0076] The seed culture concentration of each strain was measured to be approximately 10 before inoculation. 6 ~10 7 CFU / mL, inoculum size 10wt%, initial viable count before final fermentation 10 5 -10 6 (Logarithmic value of 5-6), as shown in Table 4 below, after 24 hours of fermentation in the eggplant root powder medium, the logarithmic viable counts of each strain were between 6 and 8.5, indicating that the bacteria could reproduce in the eggplant root powder medium. Among them, the BIF1 group showed the strongest growth advantage, with a logarithmic viable count of 8.18 (1.5 × 10⁻⁶). 7 (CFU / mL). In contrast, in the same solanum lactone content medium, the growth of each strain of bacteria was relatively slow, and the viable count was significantly reduced. Simultaneously, the growth of different strains in solanum root extract medium supplemented with 2% glucose and 2% peptone was compared, and the viable count was detected to be 10. 5 -10 6Compared with the group containing only eggplant root extract without added carbon and nitrogen sources, the number of viable bacteria was significantly increased by CFU / mL (log value of 5-7), indicating that the culture medium for eggplant root extract without additional nutrients could not meet the growth requirements of the bacteria, and the bacteria could not grow and reproduce well.

[0077] Therefore, it can be seen that under the same solanolactone content, the solanol root powder culture medium without additional carbon and nitrogen sources can meet the growth requirements of the bacteria, and each strain can reproduce well. However, the bacteria cannot grow and reproduce in the solanol root extract culture medium without additional nitrogen sources.

[0078] Table 4 Viable cell counts after fermentation of different strains

[0079] Fermentation bacteria Log CFU / mL CFU / mL Fermented seed liquid 5-6 <![CDATA[10 5 -10 6 ]]> LAB1 7.54 <![CDATA[3.5×10 6 ]]> LAB2 7.30 <![CDATA[2.0×10 6 ]]> LAB3 6.95 <![CDATA[0.9×10 6 ]]> BIF1 8.18 <![CDATA[1.5×10 7 ]]> BIF2 7.95 <![CDATA[9.0×10 6 ]]> BIF3 7.70 <![CDATA[5.0×10 6 ]]> BAC1 7.15 <![CDATA[1.4×10 6 ]]> BAC2 7.26 <![CDATA[1.8×10 6 ]]> MIC1 7.58 <![CDATA[3.8×10 6 ]]> MIC2 7.62 <![CDATA[4.2×10 6 ]]> YEA1 6.49 <![CDATA[3.1×10 5 ]]> YEA2 6.52 <![CDATA[3.3×10 5 ]]> ASP1 6.46 <![CDATA[2.9×10 5 ]]> ASP2 6.45 <![CDATA[2.8×10 5 ]]> LAB1' 3.30 <![CDATA[2.0×10 3 ]]> BIF1' 3.63 <![CDATA[4.3×10 3 ]]> BAC1' 2.92 <![CDATA[8.3×10 2 ]]> MIC1' 3.90 <![CDATA[7.9×10 3 ]]> YEA1' 3.08 <![CDATA[1.2×10 3 ]]> ASP1' 2.99 <![CDATA[9.8×10 2 ]]> LAB1'' 6.43 <![CDATA[2.7×10 6 ]]> BIF1'' 6.91 <![CDATA[8.2×10 6 ]]> BAC1'' 5.87 <![CDATA[7.5×10 5 ]]> MIC1'' 6.32 <![CDATA[2.1×10 6 ]]> YEA1'' 5.73 <![CDATA[5.4×10 5 ]]> ASP1'' 5.27 <![CDATA[1.9×10 5 ]]>

[0080] 2.2 Content of nightshade lactone

[0081] Refer to Table 5 and Figure 1 When using eggplant root powder as a culture medium for fermentation, the eggplant lactone content in the products obtained after fermentation by each strain was higher than that in the unfermented group (CON). Among them, the increase in eggplant lactone after fermentation by Bifidobacterium (BIF1, BIF2, and BIF3 groups) was the largest, approximately 25-40%. In addition, when using eggplant root extract as a culture medium for fermentation, the eggplant lactone content in the products obtained by all strains decreased, with the largest decrease being 25%.

[0082] Therefore, it can be concluded that under the same solanaceous lactone content, the solanaceous lactone content increases when solanaceous root powder is used as the culture medium for fermentation, and the increase in solanaceous lactone content is most significant after fermentation with Bifidobacterium; while the solanaceous lactone content decreases when using solanaceous root extract as the culture medium for fermentation. In addition, the solanaceous lactone content in the solanaceous root extract fermentation group with additional carbon and nitrogen sources did not show significant changes compared with the control group.

[0083] The relevant testing methods can be found below. Figure 8 Liquid chromatography spectra of the standards solanacolin A and solanacolin A; Figure 9 The liquid chromatogram of BIF1 fermentation filtrate (fermentation filtrate of Bifidobacterium longum subsp. infantis root powder of Solanum nigrum); Figure 10 The liquid chromatogram of BIF1' fermentation filtrate (fermentation filtrate of Bifidobacterium longum subsp. infantis root extract of Solanum nigrum).

[0084] Table 5. Content of Solanum lactone after fermentation by different strains

[0085] Fermentation bacteria Nightshade lactone content / ppm LAB1 24.16 LAB2 23.7 LAB3 22.74 BIF1 28.43 BIF2 25.64 BIF3 26.08 BAC1 23.14 BAC2 24.67 MIC1 23.61 MIC2 25.42 YEA1 22.92 YEA2 21.78 ASP1 22.14 ASP2 21.98 CON 20.36 LAB1' 17.14 BIF1' 16.95 BAC1' 17.72 MIC1' 20.12 YEA1' 18.37 ASP1' 15.76 CON' 20.58 LAB1'' 19.87 BIF1'' 20.09 BAC1'' 20.02 MIC1'' 19.82 YEA1'' 19.57 ASP1'' 20.05 CON'' 19.98

[0086] 2.3 Free radical scavenging rate

[0087] Free radicals are reactive oxygen molecules produced by metabolism or external stimuli such as ultraviolet rays and pollution. They attack skin cells, damage collagen and elastin fibers, leading to skin sagging and accelerated wrinkle formation, thus causing skin aging. Therefore, eliminating free radicals can slow down oxidative damage, improve skin firmness and radiance, and reduce fine lines, thereby achieving a firming and anti-wrinkle effect.

[0088] 2.3.1 DPPH free radical scavenging rate

[0089] The test method for DPPH free radical scavenging rate is as follows: see below;

[0090] The test method for hydroxyl radicals is as follows: see below;

[0091] Test results are shown in Table 6 and Figure 2 and Figure 3 When the sample concentration was 25%, the DPPH free radical scavenging rate was improved after fermentation of the eggplant root powder culture medium by various strains. Among them, Bifidobacterium (BIF1, BIF2 and BIF3 groups) had the highest free radical scavenging rate after fermentation, which was 18-27%.

[0092] In addition, the DPPH free radical scavenging rate of the Solanum nigrum root extract decreased after fermentation by various strains.

[0093] 2.3.2 Hydroxyl radical scavenging rate

[0094] When the sample test concentration was 5%, the scavenging rate of hydroxyl radicals was improved after fermentation of the eggplant root powder culture medium by various strains. Among them, Bifidobacterium (BIF1, BIF2 and BIF3 groups) had the highest free radical scavenging rate after fermentation among the six major strains, which was 26-31%.

[0095] In addition, the scavenging rate of hydroxyl radicals decreased after fermentation by various strains of *Solanum nigrum* root extract.

[0096] Therefore, it can be concluded that under the same content of solanacrolium, the free radical scavenging rate of solanac root powder is higher than that of solanac root extract. Furthermore, the free radical scavenging rate of solanac root powder increases after fermentation, while the free radical scavenging rate of solanac root extract decreases after fermentation.

[0097] Table 6. Free radical scavenging rates of different bacterial strains after fermentation

[0098] Fermentation bacteria DPPH free radicals hydroxyl radicals LAB1 60.50% 39.47% LAB2 63.45% 40.72% LAB3 60.14% 37.56% BIF1 69.91% 46.65% BIF2 68.17% 44.98% BIF3 65.42% 45.33% BAC1 61.87% 41.39% BAC2 56.39% 35.91% MIC1 58.98% 38.76% MIC2 60.42% 41.15% YEA1 62.87% 43.37% YEA2 60.08% 40.13% ASP1 58.72% 42.49% ASP2 59.07% 41.78% CON 55.00% 35.58% LAB1' 9.98% 1.08% BIF1' 11.27% 0.60% BAC1' 13.28% 1.32% MIC1' 8.69% 1.67% YEA1' 12.76% 1.32% ASP1' 7.93% 2.86% CON' 18.71% 3.43%

[0099] 2.4 Nematode Lipofuscin Experiment

[0100] Lipofuscin is a non-degradable pigment formed by the cross-linking of lipid peroxides and biological macromolecules triggered by oxidative stress. It is mainly deposited in senescent cells and increases with age, making it one of the important indicators of aging. The main manifestations of aging include loss of skin elasticity, wrinkles, dullness, and pigmentation. Therefore, by inhibiting the production of lipofuscin, pigmentation can be improved, thereby slowing down cell aging to a certain extent and achieving an anti-wrinkle effect.

[0101] The test method for nematode lipofuscin is as follows: see below;

[0102] Refer to Table 7 and Figure 4 After fermentation with BIF1, the fermentation filtrate of eggplant root powder showed a significant inhibitory effect on lipofuscin from nematodes at concentrations of 1% and 2%, with the best effect observed at 1% concentration. In contrast, the extract CON group of unfermented eggplant root powder showed no effect on lipofuscin from nematodes. This indicates that the fermented eggplant product significantly inhibits lipofuscin production better than the unfermented product.

[0103] Table 7. Levels of nematode lipofuscin in BIF1 Nightshade Fermentation Filtrate

[0104] sample lipofuscin level Standard error Significance analysis Blank group 100.93 2.28 / 1%CON 99.54 2.18 / 2%CON 92.16 2.24 / 1% BIF1 79.46 2.00 * 2% BIF2 88.78 1.85 * Positive control (0.2 μM curcumin) 63.13 0.98 *

[0105] 2.5 Polyol-mediated solubilization

[0106] 2.5.1 Screening for Optimal Polyols

[0107] Refer to Tables 8 and 9 and Figure 5 After fermentation, propylene glycol, butanediol, pentanediol, and hexanediol were used to solubilize the fermented group BIF1 (containing residue) and the unfermented group CON (containing residue) of *Solanum nigrum* root powder in a medium ratio of 20% polyol + 80% fermentation product (containing residue). The results showed that after solubilization with polyols, the content of *Solanum nigrum* lactones in both the fermented group (BIF1) and the unfermented group (CON) increased, indicating that polyol-mediated solubilization can directionally enrich *Solanum nigrum* lactones. Hexanediol showed the best solubilization effect, increasing the content by 4.78 times in the fermented group, while only increasing it by 1.7 times in the unfermented group. This indicates that fermentation releases more *Solanum nigrum* lactones, and polyol-mediated solubilization further enriches them.

[0108] Table 8. Changes in the content of *Solanum nigrum* lactone in fermented *Solanum nigrum* root powder after different polyol blends (BIF1)

[0109] sample Nightshade lactone content / ppm Before solubilization 22.74 Propylene glycol 41.24 Butylene glycol 42.13 Pentylene glycol 106.41 Hexanediol 108.81

[0110] Table 9. Changes in the content of *Solanum nigrum* lactones in the unfermented group (CON) of *Solanum nigrum* root powder after different polyol blends.

[0111] sample Nightshade lactone content / ppm Before solubilization 16.46 Propylene glycol 17.05 Butylene glycol 20.47 Pentylene glycol 25.54 Hexanediol 28.15

[0112] Figure 11 Liquid chromatogram for enriching solanacrolides in hexanediol-mediated solubilization of BIF1 fermentation filtrate (fermentation filtrate of Bifidobacterium longum subsp. infantis root powder);

[0113] Figure 12 Liquid chromatogram of solanacrolol enriched in hexanediol-mediated solubilization of BIF1' fermentation filtrate (fermentation filtrate of Bifidobacterium longum subsp. infantis root extract of Solanacrolol).

[0114] 2.5.2 Optimal Concentration Screening

[0115] After screening hexanediol as the optimal polyol, the optimal concentration of hexanediol was further explored. Different amounts of hexanediol (5%, 10%, 20%, 40%, 60% and 80%) were used to mediate the solubilization of the eggplant root powder fermentation group BIF1 (including residue). The total amount of fermentation product (including residue) and hexanediol was controlled to be 100%. At the same time, the corresponding concentration of fermentation product was diluted with secondary pure water as a control group.

[0116] Refer to Table 10 and Figure 6 The results showed that the addition of hexanediol (5-80%) increased the content of solanaceous lactone in the samples. Specifically, when the addition of hexanediol was 20%, the solanaceous lactone content increased from the initial 22.74 ppm to 108.81 ppm, an increase of 4.78 times. Therefore, a hexanediol addition of 20% was ultimately chosen for the mediated solubilization experiments in each fermentation group.

[0117] Table 10. Variation of solanacolic lactone content after solubilization mediated by different hexanediol addition amounts.

[0118]

[0119] 2.5.3 Compound Experiment of Each Fermentation Group

[0120] Hexanediol was used to mediate the solubilization of the fermentation group of eggplant root powder (including residue) and the fermentation group of eggplant root extract (including residue), respectively, at a ratio of 20% hexanediol + 80% fermentation product (including residue).

[0121] Results are shown in Table 11 and Figure 7 The results showed that the content of solanol was increased after fermentation of both the solanol-mediated soluble samples of eggplant root powder and the samples of eggplant root extract. However, the content of solanol was increased more in the eggplant root powder group and the solanol was increased most in the Bifidobacterium group, which had the highest increase rate of 4.5-4.78 times.

[0122] Table 11 Changes in the content of nightshade lactone in each fermentation group after hexanediol-mediated solubilization

[0123] Fermentation bacteria Before solubilization After solubilization LAB1 19.33 73.06 LAB2 18.96 74.32 LAB3 18.19 73.13 BIF1 22.74 108.81 BIF2 20.51 98.05 BIF3 20.86 94.31 BAC1 18.51 40.54 BAC2 19.74 45.20 MIC1 18.89 45.71 MIC2 20.34 39.86 YEA1 18.34 73.89 YEA2 17.42 72.48 ASP1 17.71 73.33 ASP2 17.58 71.57 CON 16.29 56.68 LAB1' 13.71 22.08 BIF1' 13.56 22.92 BAC1' 14.18 20.98 MIC1' 16.10 23.18 YEA1' 14.70 23.07 ASP1' 12.61 18.91 CON' 16.46 28.15

[0124] 2.6 Product Application

[0125] The fermented product filtrate of *Bifidobacterium longum* obtained by this invention has cosmetic effects such as firming and anti-wrinkle properties, and can be used in related products. A formula for applying the fermented filtrate of *Bifidobacterium longum* subsp. *infanthizobium* root powder in face cream is provided as a reference.

[0126] Table 12 Face Cream Formula Table

[0127]

[0128] The following are the relevant testing methods.

[0129] 1. DPPH free radical scavenging rate

[0130] (1) Preparation of DPPH test solution: Prepare 50.0µg / mL DPPH solution with anhydrous ethanol, sonicate for 5 min and mix thoroughly.

[0131] (2) Preparation of test samples: Dilute all fermentation filtrates with secondary pure water to a concentration of 25%, and use secondary pure water as a blank control.

[0132] (3) Set up the DPPH reaction system as shown in Table 13.

[0133] Table 13 DPPH Reaction System

[0134] Solution name experimental group control group Blank group DPPH solution 3.0ml - 3.0ml Sample solution 1.0ml 1.0ml - Sample solvent - - 1.0ml Anhydrous ethanol - 3.0ml -

[0135] (4) Shake well and react at room temperature in the dark for 30 min.

[0136] (5) Transfer each reaction solution into a 96-well plate and measure the absorbance (OD) at 517 nm.

[0137] (6) Calculate the free radical scavenging rate according to the formula.

[0138]

[0139] Scavenging rate – DPPH free radical scavenging rate;

[0140] Experimental Group A – Absorbance of the mixture of the sample solution and DPPH solution;

[0141] A. Control group – Absorbance of the mixture of the test sample solution and anhydrous ethanol solution;

[0142] A. Blank group – Absorbance of the mixture of DPPH solution and sample solvent solution.

[0143] 2. Hydroxyl radical scavenging rate

[0144] (1) Preparation of experimental reagents

[0145] ①6mmol / L FeSO4: Weigh 1.668g of anhydrous FeSO4 and dilute to 1L of water;

[0146] ②6mmol / L H2O2: Dissolve 0.227g of H2O2 in 1L of water;

[0147] ③6mmol / L salicylic acid: Weigh 0.828g of salicylic acid and dilute to 1L of water;

[0148] Preparation of test samples: Dilute all fermentation filtrates to a concentration of 5% with distilled water, and use distilled water as a blank control.

[0149] (3) Experimental methods:

[0150] ①A1: In a test tube, add 2 ml of 6 mmol / L FeSO4, 2 ml of 6 mmol / L H2O2 (H2O2 is added last to initiate the reaction), and 2 ml of the diluted sample. Shake well and let stand at room temperature for 15 min. Then add 2 ml of 6 mmol / L salicylic acid, shake well, heat in a 37℃ water bath for 30 min, and measure the absorbance A1.

[0151] ②A2: Add 2 ml of 6 mmol / L FeSO4, 2 ml of 6 mmol / L H2O2, and 2 ml of diluted sample to a test tube in sequence, shake well, let stand at room temperature for 15 min, then add 2 ml of deionized water, shake well, heat in a 37℃ water bath for 30 min, and then measure its absorbance A2;

[0152] ③A3: Add 2 ml of 6 mmol / L FeSO4, 2 ml of deionized water, and 2 ml of 6 mmol / L H2O2 to a test tube in sequence, shake well, let stand at room temperature for 15 min, then add 2 ml of 6 mmol / L salicylic acid, shake well, heat in a 37℃ water bath for 30 min, and then take it out and measure its absorbance A3.

[0153] (4) Data processing

[0154] Hydroxyl radical scavenging rate (%) = [(A3 + A2) - A1] / A2 × 100%;

[0155] 3. Nematode lipofuscin test method

[0156] Caenorhabditis elegans, synchronized to stage L4, was transferred to an NGM culture plate containing the sample and 5-FU and cultured at 20°C for 5 days.

[0157] Five days later, the Caenorhabditis elegans filaments from the positive control plate, blank control plate, and sample plate were washed out and transferred to a 1% agarose plate, and the plate was anesthetized.

[0158] After the nematodes were anesthetized, the fluorescence intensity was observed and photographed under a fluorescence microscope at an excitation wavelength of 340-380 nm and an emission wavelength of 430 nm. The autofluorescence intensity of lipofuscin from *C. elegans* was analyzed and measured using ImageJ.

[0159] 4. Liquid chromatography detection methods

[0160] I. Chromatographic conditions

[0161] Mobile phase: Acetonitrile: 0.1% phosphoric acid aqueous solution = 75:25

[0162] Column: C18

[0163] Column temperature: 30℃

[0164] Flow rate: 1 mL / min

[0165] Detection wavelength: 215nm

[0166] Injection volume: 10 μL

[0167] Sample solvent: methanol.

[0168] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for fermenting nightshade, characterized in that, One or more strains of bacteria, including lactic acid bacteria, bifidobacteria, Bacillus, micrococcus, yeast, and filamentous fungi, are used to ferment the roots of *Solanum nigrum* to obtain fermentation products.

2. The method for fermenting nightshade according to claim 1, characterized in that, The lactic acid bacteria are one or more combinations of Lactobacillus plantarum, Lactobacillus sakei subsp. Lactobacillus paracasei. The Bifidobacterium is one or more of Bifidobacterium longum subsp. infantis, Bifidobacterium adolescentis, and Bifidobacterium longum. The Bacillus species is Bacillus subtilis and / or Bacillus argentis; The micrococcus is Micrococcus yunnanensis and a strain of Micrococcus genus; The yeast is Saccharomyces cerevisiae and / or Saccharomyces trigonella; The filamentous fungi are Aspergillus niger and / or Aspergillus oryzae.

3. The method for fermenting nightshade according to claim 1, characterized in that, The fermentation temperature and oxygen content are set according to the fermentation requirements of the fermentation strain. The fermentation medium is a medium containing 1-20 wt% eggplant root powder, preferably 5-15 wt% eggplant root powder, and more preferably 7-13 wt% eggplant root powder.

4. The method for fermenting nightshade according to claim 1, characterized in that, The culture medium contains only eggplant root powder and water, without any additional carbon source, nitrogen source, or inorganic salts.

5. The method for fermenting nightshade according to claim 1, characterized in that, The fermentation time is 10 to 48 hours, preferably 16 to 32 hours, and more preferably 20 to 28 hours.

6. The method for fermenting nightshade according to claim 1, characterized in that, If the fermenting bacteria are Bifidobacterium, then it is anaerobic fermentation; if the fermenting bacteria are Bacillus and / or Micrococcus, then it is aerobic fermentation. Preferably, the aerobic fermentation is performed in a shaker; if the fermenting bacteria are lactic acid bacteria, yeast, or filamentous fungi, then fermentation can be carried out in the air.

7. The method for fermenting nightshade according to claim 1, characterized in that, The fermentation temperature is 28~40℃. Preferably, if the fermentation bacteria are lactic acid bacteria, bifidobacteria, or Bacillus, the fermentation temperature is 37±2℃, more preferably 37±1℃, and more preferably 37±0.5℃. If the fermentation bacteria are micrococci, yeast, or filamentous fungi, the fermentation temperature is 30±2℃, preferably 30±1℃, and more preferably 30±0.5℃.

8. The method for fermenting nightshade according to claim 1, characterized in that, The inoculation amount of the strain is 1~30wt%, preferably 5~20wt%, and more preferably 7~15wt%.

9. The fermented product of *Solanum tuberosum* obtained by the method described in any one of claims 1 to 8.

10. A nightshade extract, characterized in that, The fermentation product of *Solanum tuberosum* as described in claim 9 was obtained by polyol-mediated solubilization and targeted enrichment of *Solanum tuberosum* lactone.

11. Use of the fermented product of *Solanum tuberosum* as described in claim 9 to prepare cosmetics; wherein the cosmetics are cosmetics with one or more functions including anti-wrinkle and firming.

12. A cosmetic product, characterized in that, It contains 0.05% to 50% of the fermentation products of nightshade.

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