Gellan gum, preparation method thereof, composite gum and cosmetics

Abstract

The invention discloses gellan gum and a preparation method thereof, composite gum and cosmetics, and belongs to the field of cosmetics. The preparation method of the gellan gum comprises the following steps: inoculating a sphingomonas paucimobilis seed solution into a fermentation culture medium for aerobic fermentation; the fermentation culture medium comprises the following components in percentage by mass: 10%-60% of plant extraction residues, 0-5% of cane sugar, 0-1% of yeast extract powder, 0.05%-1% of monopotassium phosphate, 0.05%-1% of dipotassium phosphate, 0.05%-1% of magnesium sulfate, 0.05%-0.2% of monopotassium phosphate, 1%-5% of glucose and the balance of water; the water content of the plant extraction residues is 85%-95%, and the pH value of the culture medium is 6.5-7.5. The fermentation culture medium containing the plant extraction residues in the content range is used as a fermentation strategy to prepare the sphingomonas paucimobilis product gellan gum, so that the secretion of the gellan gum can be promoted, the flavone content of the gellan gum can be effectively increased, and the oxidation resistance of the gellan gum can be improved.

Description

Technical Field

[0001] The present application relates to the field of cosmetics, and in particular to gellan gum and a preparation method thereof, a composite gum and cosmetics. Background Art

[0002] Microbial gum is one of the important sources of gum substances. Microbial gum obtained by fermentation can be used in many aspects, such as cosmetic additives. As a new type of microbial gum, gellan gum combines thickening, suspension, emulsification and stabilization, and has extremely high commercial profits and market prospects.

[0003] However, the current production of gellan gum is low and its ingredients are single. Summary of the invention

[0004] The present application provides a gellan gum and a preparation method thereof, a composite gum and a cosmetic. The preparation method can alleviate the current problem of low gellan gum production and single ingredients.

[0005] The embodiment of the present application is implemented as follows:

[0006] In a first aspect, the present application provides a method for preparing gellan gum, which comprises:

[0007] The seed liquid of Sphingomonas paucimobilis is inoculated into a fermentation medium for aerobic fermentation;

[0008] Wherein, the fermentation medium comprises, by mass percentage: 10%-60% plant extract residue, 0-5% sucrose, 0-1% yeast extract powder, 0.05%-1% potassium dihydrogen phosphate, 0.05%-1% dipotassium hydrogen phosphate, 0.05%-1% magnesium sulfate, 0.05%-0.2% potassium dihydrogen phosphate, 1%-5% glucose, and the balance water;

[0009] The water content of the plant extract residue is 85%-95%, and the pH value of the fermentation medium is 6.5-7.5.

[0010] The preparation method of gellan gum provided in the present application uses a fermentation medium containing plant extract residues in the above-mentioned content range as a fermentation strategy to prepare gellan gum, a product of Sphingomonas paucimobilis. This method can promote the secretion of gellan gum, increase the yield of gellan gum, and effectively increase the flavonoid content of gellan gum. This method can not only enhance the antioxidant capacity of gellan gum, but also realize the green recovery of plant extract residues, reduce the cost of solid waste treatment, and has good environmental friendliness.

[0011] In some optional embodiments, the mass percentage of the plant extract residue in the fermentation medium is 40%-60%; and / or,

[0012] The mass percentage of sucrose in the fermentation medium is 3%-5%; and / or,

[0013] The mass percentage of yeast extract powder in the fermentation medium is 0.5%-1%.

[0014] In some optional embodiments, the plant extract residue includes at least one of finger orange extract residue, cocoa powder extract residue, and buddleja chinensis extract residue.

[0015] In some optional embodiments, the plant extract is finger orange extract.

[0016] In some optional embodiments, aerobic fermentation includes: fermentation at 25°C-32°C, 180r / min-250r / min for 48h-72h.

[0017] In some optional embodiments, the inoculation amount of the Sphingomonas paucimobilis seed solution in the fermentation medium is 7%-12% by volume.

[0018] In the second aspect, the present application provides a gellan gum, which is prepared using the preparation method provided in the first aspect of the present application.

[0019] The gellan gum provided in the present application not only has a high flavonoid content, but also has a strong antioxidant capacity by removing excess free radicals, while achieving the effects of antioxidant and thickening, and has excellent colloidal properties.

[0020] In a third aspect, the present application provides an example of a composite gum, which includes a first colloid and a second colloid, the first colloid is the gellan gum provided in the second aspect of the present application, and the second colloid includes at least one of xanthan gum, pectin, gelatin and carrageenan.

[0021] The composite adhesive provided by the present application is soft in texture and has both better density and better water retention through compounding and mixing of the first colloid and the second colloid.

[0022] In some optional embodiments, the mass ratio of the first colloid to the second colloid is 3:7-7:3; and / or,

[0023] The composite adhesive also contains salt for enhancing adhesive performance, and the salt is selected from soluble or slightly soluble alkali metal salts.

[0024] In a fourth aspect, the present application provides a cosmetic comprising at least one of the gellan gum provided in the second aspect of the present application and the composite gum provided in the third aspect of the present application. DETAILED DESCRIPTION

[0025] The embodiments of the present application will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0026] The following is a detailed description of the gellan gum and its preparation method, composite gum and cosmetics according to the embodiments of the present application:

[0027] The present application provides a method for preparing gellan gum, which comprises:

[0028] The seed liquid of Sphingomonas paucimobilis is inoculated into a fermentation medium for aerobic fermentation;

[0029] Wherein, the fermentation medium comprises, by mass percentage: 10%-60% plant extract residue, 0-5% sucrose, 0-1% yeast extract powder, 0.05%-1% potassium dihydrogen phosphate, 0.05%-1% dipotassium hydrogen phosphate, 0.05%-1% magnesium sulfate, 0.05%-0.2% potassium dihydrogen phosphate, 1%-5% glucose, and the balance water;

[0030] The water content of the plant extract residue is 85%-95%, and the pH value of the culture medium is 6.5-7.5.

[0031] Among them, the seed liquid of Sphingomonas paucimobilis refers to the result obtained by inoculating activated Sphingomonas paucimobilis into seed culture medium for cultivation. For example, Sphingomonas paucimobilis is transferred to TSA culture medium for activation, and cultured at 29-31°C until single colonies are obvious and round; then the single colonies are picked and transferred to liquid culture medium for expansion to obtain fermentation seed liquid. Among them, the above-mentioned expansion culture of Sphingomonas paucimobilis can be carried out by the common methods in the field, which will not be repeated here.

[0032] Plant extract residue refers to the residue remaining after the effective ingredients of the plant are extracted by chemical, physical and other methods (the residue contains sugar, flavonoids and other components). The inventors found that Sphingomonas paucimobilis can produce gellan gum using plant extract residue as raw material, and significantly increase the flavonoid content in gellan gum. Therefore, the present application adds plant extract residue to the fermentation medium and then inoculates Sphingomonas paucimobilis seed liquid into the fermentation medium. On the one hand, Sphingomonas paucimobilis uses plant extract residue as raw material for aerobic fermentation, which is beneficial to promote the secretion of gellan gum. On the other hand, it can not only effectively increase the flavonoid content of gellan gum and enhance its antioxidant capacity, but also help optimize the water retention and elasticity of gellan gum.

[0033] It is understandable that the plant extract residue can be the residue of a single plant or the mixed residue of different plants. Exemplarily, the plant extract residue includes but is not limited to at least one of finger orange extract residue, cocoa powder extract residue, buddleja extract residue, Centella asiatica extract residue, aloe extract residue, rose extract residue, etc.

[0034] In summary, in the technical solution provided by the present application, the fermentation medium containing the plant extract residue in the above-mentioned content range is used as the fermentation strategy to prepare the gellan gum produced by Sphingomonas paucimobilis, which can promote the secretion of gellan gum while effectively increasing the flavonoid content of gellan gum. It can not only enhance the antioxidant capacity of gellan gum, but also realize the green recycling of plant extract residue, reduce the cost of solid waste treatment, and has good environmental friendliness.

[0035] Exemplarily, the mass percentage of the plant extract residue in the fermentation medium is any value of 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60% or between any two values.

[0036] Exemplarily, the mass percentage of sucrose in the fermentation medium is any value of 0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0% or between any two values.

[0037] Illustratively, the mass percentage of yeast extract in the fermentation medium is any value of 0%, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, or between any two values.

[0038] Exemplarily, the mass percentage of potassium dihydrogen phosphate in the fermentation medium is any value of 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, or between any two values.

[0039] Exemplarily, the mass percentage of dipotassium hydrogen phosphate in the fermentation medium is any value of 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, or between any two values.

[0040] Exemplarily, the mass percentage of magnesium sulfate in the fermentation medium is any value of 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0% or between any two values.

[0041] Illustratively, the mass percentage of potassium dihydrogen phosphate in the fermentation medium is any value of 0.05%, 0.07%, 0.1%, 0.12%, 0.15%, 0.17%, 0.20%, or between any two values.

[0042] Exemplarily, the mass percentage of glucose in the fermentation medium is any value of 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0% or between any two values.

[0043] In some optional embodiments, the mass percentage of the plant extract residue in the fermentation medium is 40%-60%.

[0044] Controlling the mass percentage of the plant extract residue in the fermentation medium within the above range is beneficial to increasing the yield of gellan gum and the content of flavonoids in the gellan gum, and is beneficial to optimizing the water holding capacity and elasticity of the gellan gum.

[0045] Exemplarily, the mass percentage of the plant extract residue in the fermentation medium is any one of 40.0%, 41.0%, 42.5%, 45.0%, 47.5%, 50.0%, 52.5%, 55.0%, 57.5%, 60.0% or between any two values.

[0046] It should be noted that Sphingomonas paucimobilis can produce gellan gum using plant extract residues as raw materials alone, but in order to promote the production of gellan gum, sucrose can be added to the fermentation medium to further increase the yield.

[0047] In some optional embodiments, the mass percentage of sucrose in the fermentation medium is 3%-5%.

[0048] Controlling the mass percentage of sucrose in the culture medium within the above range and reasonably combining sucrose with plant extracts is not only beneficial to further increase the yield of gellan gum and increase the content of flavonoids in gellan gum, but also beneficial to optimize the water retention and elasticity of gellan gum.

[0049] Exemplarily, the mass percentage of sucrose in the fermentation medium is any value of 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, or between any two values.

[0050] In some optional embodiments, the mass percentage of yeast extract in the fermentation medium is 0.5%-1%.

[0051] Controlling the mass percentage of yeast extract powder in the culture medium within the above range is not only beneficial to further increase the yield of gellan gum and increase the content of flavonoids in gellan gum, but also beneficial to optimize the water holding capacity and elasticity of gellan gum.

[0052] Illustratively, the mass percentage of yeast extract powder in the fermentation medium is any value among 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, or between any two values.

[0053] In some optional embodiments, the plant extract residue includes at least one of finger orange extract residue, cocoa powder extract residue, and buddleja chinensis extract residue.

[0054] In some optional embodiments, the plant extract is finger orange extract.

[0055] Finger orange extract residue can effectively promote the production of gellan gum by Sphingomonas paucimobilis. At the same time, the generated gellan gum has a high content of flavonoids, which effectively improves the economic value of gellan gum.

[0056] In some optional embodiments, aerobic fermentation includes: fermentation at 25°C-32°C, 180r / min-250r / min for 48h-72h.

[0057] Illustratively, the temperature of the aerobic fermentation is any one of 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, or between any two values.

[0058] Exemplarily, the rotation speed of aerobic fermentation is any one of 180 r / min, 200 r / min, 230 r / min, 250 r / min or between any two values.

[0059] In some optional embodiments, the inoculation amount of the Sphingomonas paucimobilis seed solution in the fermentation medium is 7%-12% by volume.

[0060] Exemplarily, the inoculation amount of the Sphingomonas paucimobilis seed solution in the fermentation medium is any value of 7%, 8%, 9%, 10%, 11%, 12% or between any two values ​​by volume percentage.

[0061] It is understandable that the preparation method of gellan gum further comprises the steps of centrifuging the fermentation product after the aerobic fermentation is completed, removing the bacterial cells and collecting the supernatant for alcohol extraction and drying to obtain gellan gum.

[0062] The present application also provides a gellan gum, which is prepared by the preparation method provided in the present application.

[0063] The gellan gum obtained based on the above preparation method not only has a high flavonoid content, but also has a strong antioxidant ability by removing excess free radicals, while achieving the antioxidant and thickening effects and having excellent colloidal properties.

[0064] The present application also provides a composite glue, which includes a first colloid and a second colloid, the first colloid is the gellan gum provided in the present application, and the second colloid includes at least one of xanthan gum, pectin, gelatin and carrageenan.

[0065] By compounding and blending the first colloid and the second colloid, the composite glue has a soft texture and has both better density and better water retention.

[0066] In some optional embodiments, the mass ratio of the first colloid to the second colloid is 3:7-7:3.

[0067] Within the above range, the composite adhesive has lower hardness, higher elasticity, higher cohesion and better water retention.

[0068] Exemplarily, the mass ratio of the first colloid to the second colloid is any value of 3:7, 4:6, 4:9, 1:1, 2:1, 7:3 or between any two values.

[0069] Optionally, the mass ratio of the first colloid to the second colloid is 3:7-4:6.

[0070] Within the above range, the density and soft texture of the composite adhesive can be significantly improved on the basis of reducing the usage of the second colloid, so that it has better performance.

[0071] In some optional embodiments, the composite adhesive further contains a salt for enhancing adhesive properties, and the salt is selected from soluble or slightly soluble alkali metal salts.

[0072] Alkali metal salts can accelerate coagulation, thereby helping to enhance the performance of the composite adhesive.

[0073] Optionally, the alkali metal salt includes a calcium salt. Exemplarily, the calcium salt includes but is not limited to at least one of calcium chloride, calcium lactate, and the like.

[0074] It should be noted that the amount of alkali metal salt added to the composite adhesive can refer to relevant technologies and is not limited here.

[0075] It should be noted that the preparation method of the composite colloid comprises: mixing the first colloid and the second colloid, adding water to dissolve them, and then adding an alkali metal salt to accelerate coagulation, thereby obtaining the composite colloid.

[0076] The present application also provides a cosmetic comprising at least one of the gellan gum and the composite gum provided in the present application.

[0077] By adding the gellan gum and / or the composite gum provided in the present application to cosmetics, not only can the cosmetics be thickened, but also based on the active ingredient flavonoids contained in the gellan gum and / or the composite gum, the flavonoids can remove excess free radicals, thereby making the cosmetics have a certain antioxidant capacity.

[0078] The gellan gum and its preparation method, composite gum and cosmetics of the present application are further described in detail below in conjunction with the embodiments.

[0079] In the following examples, finger orange extract residue was purchased from Best Pharmaceutical (Guangzhou) Co., Ltd., with a wet weight (water content of 80-93%) and a total sugar content of 2.5-8.0%.

[0080] The Buddleja buddleja extract residue was purchased from Best Pharmaceutical (Guangzhou) Co., Ltd., with a wet weight (water content of 83-91%) and a total sugar content of 0.5-1.8%.

[0081] Cocoa powder extract residue was purchased from Best Pharmaceutical (Guangzhou) Co., Ltd., with a wet weight (water content of 79-88%) and a total sugar content of 0.3-1.5%.

[0082] Example 1

[0083] (1) Activation of Sphingomonas paucimobilis strains: The Sphingomonas paucimobilis strains were transferred to TSA liquid culture medium for activation and cultured at 30° C. for 2 days until single colonies were obvious and round; then, single colonies were selected and transferred to liquid culture medium and cultured for 1 day to obtain fermentation seed liquid;

[0084] (2) preparing a fermentation medium: the fermentation medium comprises the following components, by mass percentage, 52.5% finger orange extract residue, 4.5% sucrose, 0.6% yeast extract powder, 0.1% potassium dihydrogen phosphate, 0.15% potassium dihydrogen phosphate, 0.06% magnesium sulfate, and the remainder is distilled water, pH 7.0;

[0085] (3) Fermentation of plant extract residue by Sphingomonas: Sphingomonas paucimobilis was inoculated into the above fermentation medium and fermented at 30°C and 200 r / min, wherein the inoculation amount of Sphingomonas paucimobilis seed solution in the fermentation medium was 10% by volume. After 60 hours of fermentation, the fermentation product was centrifuged to remove the bacterial cells and collect the supernatant to obtain a fermentation broth, and 2 times the volume of alcohol was added to the fermentation broth for alcohol precipitation, and stirred overnight, and centrifuged at 14000×g and 4°C for 20 minutes, and the precipitate was collected and dried at 60°C to constant weight to obtain gellan gum, which was weighed to obtain the mass of gellan gum.

[0086] (4) Preparation of composite glue: The gellan gum and xanthan gum of step (3) are prepared in a mass ratio of 6:4, distilled water is added to make a solution with a total mass fraction of 1%, after heating and dissolving, calcium chloride solution (final concentration of 5 mmol / L) is added to obtain a composite glue.

[0087] Example 2

[0088] The difference between it and Example 1 is only that:

[0089] (2) Preparation of fermentation medium: The fermentation medium includes the following components, by mass percentage, 25% finger orange extract residue, 4.5% sucrose, 0.6% yeast extract powder, 0.1% potassium dihydrogen phosphate, 0.15% potassium hydrogen phosphate, 0.06% magnesium sulfate, and the remainder is distilled water, pH 7.0.

[0090] Example 3

[0091] The difference between it and Example 1 is only that:

[0092] (2) Preparation of fermentation medium: The fermentation medium includes the following components, by mass percentage, 52.5% finger orange extract residue, 0% sucrose, 0.6% yeast extract powder, 0.1% potassium dihydrogen phosphate, 0.15% potassium hydrogen phosphate, 0.06% magnesium sulfate, and the remainder is distilled water, pH 7.0.

[0093] Example 4

[0094] The difference between it and Example 1 is only that:

[0095] (2) Preparation of fermentation medium: The fermentation medium includes the following components, by mass percentage, 52.5% finger orange extract residue, 4.5% sucrose, 0% yeast extract powder, 0.1% potassium dihydrogen phosphate, 0.15% potassium hydrogen phosphate, 0.06% magnesium sulfate, and the remainder is distilled water, pH 7.0.

[0096] Example 5

[0097] The difference between it and Example 1 is only that:

[0098] (2) Preparation of fermentation medium: The fermentation medium includes the following components, by mass percentage, 52.5% Buddleja buddleja extract residue, 4.5% sucrose, 0.6% yeast extract powder, 0.1% potassium dihydrogen phosphate, 0.15% potassium hydrogen phosphate, 0.06% magnesium sulfate, and the rest is distilled water, pH 7.0.

[0099] Example 6

[0100] The difference between it and Example 1 is only that:

[0101] (2) Preparation of fermentation medium: The fermentation medium includes the following components, by mass percentage, 52.5% cocoa powder extract, 4.5% sucrose, 0.6% yeast extract powder, 0.1% potassium dihydrogen phosphate, 0.15% dipotassium hydrogen phosphate, 0.06% magnesium sulfate, and the remainder is distilled water, pH 7.0.

[0102] Example 7

[0103] The difference between it and Example 1 is only that:

[0104] (4) Preparation of colloid: The gellan gum of step (3) is added to distilled water to obtain a solution with a total mass fraction of 1%, and after heating to dissolve, a calcium chloride solution (final concentration of 5 mmol / L) is added to obtain a colloid.

[0105] Example 8

[0106] The difference between it and Example 1 is only that:

[0107] (4) Preparation of composite glue: The gellan gum and xanthan gum of step (3) are prepared in a mass ratio of 7:3, distilled water is added to make a solution with a total mass fraction of 1%, after heating and dissolving, calcium chloride solution (final concentration of 5 mmol / L) is added to obtain a composite glue.

[0108] Example 9

[0109] The difference between it and Example 1 is only that:

[0110] (4) Preparation of composite glue: The gellan gum and xanthan gum of step (3) are prepared in a mass ratio of 3:7, distilled water is added to make a solution with a total mass fraction of 1%, after heating and dissolving, calcium chloride solution (final concentration of 5 mmol / L) is added to obtain a composite glue.

[0111] Comparative Example 1

[0112] The difference between it and the embodiment is only that:

[0113] (2) Preparation of fermentation medium: The fermentation medium includes the following components, by mass percentage, 0% finger orange extract residue, 4.5% sucrose, 0.6% yeast extract powder, 0.1% potassium dihydrogen phosphate, 0.15% potassium dihydrogen phosphate, 0.06% magnesium sulfate, and the remainder is distilled water, pH 7.0.

[0114] Test Example 1

[0115] Table 1 shows the gellan gum content in the fermentation broth prepared in Examples 1-9 and Comparative Example 1, wherein the gellan gum content in the fermentation broth = (mass of gellan gum / fermentation broth).

[0116] The gellan gum contents prepared in Examples 1-9 and Comparative Example 1 are shown in Table 1.

[0117] Table 1 Gellan gum content

[0118]

[0119]

[0120] According to Table 1, Examples 1-9 can effectively promote Sphingomonas paucimobilis to produce gellan gum because the fermentation medium contains plant extract residues.

[0121] According to Examples 1, 2, 5, 6 and Comparative Example 1, it was found that the addition of finger orange extract residue can greatly promote the production of gellan gum by Sphingomonas paucimobilis, among which Example 1 has the best effect on the production of gellan gum by Sphingomonas paucimobilis, and the gellan gum content is significantly higher than that of Example 2, Example 3, Example 4, Example 5, Example 6 and Comparative Example 1, and is increased by 52.4%, 212.1%, 342.2%, 274.4%, 188.6% and 1066.5%, respectively.

[0122] Test Example 2

[0123] The composite glues in Examples 1-6, 8 and Comparative Example 1, and the colloid prepared in step (4) of Example 7 were used as samples to test the total flavonoid content in the samples.

[0124] Total flavonoid content: Under neutral or weak alkaline conditions and the presence of sodium nitrite, flavonoid compounds and aluminum salts form chelates, which turn red-orange after adding sodium hydroxide solution, and the solution has a maximum absorption at 510nm. Rutin is used as a reference substance and aluminum nitrate is used as a colorimetric developer for flavonoid colorimetric determination. The absorbance is linearly related to the concentration of rutin, and the total flavonoid content is determined by spectrophotometry.

[0125] The specific experimental steps are as follows:

[0126] The sample was dissolved in anhydrous ethanol to prepare a solution with a total mass fraction of 1% as the test solution.

[0127] Rutin was dissolved in anhydrous ethanol to prepare a solution with a total mass fraction of 1% as a standard stock solution.

[0128] Pipette 2.4 mL of standard stock solution, water (for blank control) and test solution into stoppered test tubes, add 0.4 mL of 5% sodium nitrite solution to each test tube, shake well, and react for 6 minutes. Add 0.4 mL of 10% aluminum nitrate solution, shake well, and react for 6 minutes. Add 1.0 mL of 4% sodium hydroxide solution and 0.7 mL of water, shake well, and react for 15 minutes. Use a 10 mm cuvette and a spectrophotometer to measure the absorbance at a wavelength of 510 nm.

[0129] The results are shown in Table 2.

[0130] Table 2 Flavonoid content test results

[0131] sample Flavonoid content (μg / mL) Example 1 369.0 Example 2 148.5 Example 3 306.4 Example 4 297.3 Example 5 239.7 Example 6 277.1 Example 7 615.0 Example 8 430.5 Example 9 184.2 Comparative Example 1 4.8

[0132] According to Table 2, it can be seen that after adding plant extract residues, since Sphingomonas paucimobilis will use the nutrients in the plant extract residues to grow and release the endogenous active ingredients of the plant extract residues, the flavonoid content of gellan gum can be greatly increased. Therefore, the flavonoid content in the composite colloid is mainly affected by the addition ratio of gellan gum.

[0133] According to Table 2, at the same addition ratio (mass ratio of gellan gum to xanthan gum is 6:4), the compound colloid of Example 1 is significantly higher than that of Example 2, Example 3, Example 4, Example 5, Example 6, and Comparative Example 1, and increases by 249.3%, 20.6%, 24.2%, 153.9%, 133.2% and 7687.5%, respectively. Since the addition ratio of gellan gum in the compound colloid of Example 1 is lower than that of Examples 7 and 8, the flavonoid content in the compound colloid of Example 1 is significantly lower than that of Examples 7 and 8.

[0134] Test Example 3

[0135] The composite glues in Examples 1-6, 8 and Comparative Example 1, and the colloid prepared in step (4) of Example 7 were used as samples to test the antioxidant capacity of the samples.

[0136] Antioxidant capacity 1:

[0137] DPPH, also known as 1,1-diphenyl-2-trinitrophenylhydrazine, is a very stable nitrogen-centered free radical. Its stability mainly comes from the spatial barrier of the three benzene rings due to the resonance stabilization, which prevents the unpaired electrons on the nitrogen atom in the middle from playing their due electron pairing role. Its anhydrous ethanol solution is purple, with maximum absorption at a wavelength of 517nm, and the absorbance is linearly related to the concentration. When a free radical scavenger is added to it, it can be combined with or replaced by DPPH to reduce the number of free radicals, reduce the absorbance, and lighten the color of the solution, thereby evaluating the ability to scavenge free radicals.

[0138] The specific experimental steps are as follows:

[0139] The sample was dissolved in anhydrous ethanol to prepare a solution with a total mass fraction of 1% as the sample solution.

[0140] Separately pipette 2.0 mL of sample solution (or anhydrous ethanol) and 2.0 mL of DPPH solution into stoppered test tubes and mix well; react in the dark for 30 minutes and measure the absorbance at a wavelength of 517 nm.

[0141] Wherein: A0: no sample added, DPPH added; A1: sample or anhydrous ethanol added, DPPH added; A2: sample or anhydrous ethanol added, no DPPH added.

[0142] Table 3 DPPH free radical scavenging rate of the composite colloids in different embodiments

[0143]

[0144]

[0145] As shown in Table 3, at the same addition ratio (the mass ratio of gellan gum to xanthan gum is 6:4), the DPPH free radical scavenging ability of the compound colloid of Example 1 is significantly higher than that of Example 2, Example 3, Example 4 and Comparative Example 1, which is consistent with the flavonoid content results in Table 2, indicating that the DPPH free radical scavenging ability of the compound colloid is derived from the flavonoid content of the plant extract residue. At the same time, since the flavonoid content of the compound colloid of Example 1 is significantly lower than that of Example 7 and Example 8 (the addition ratio of gellan gum is higher), the DPPH free radical scavenging ability of the compound colloid of Example 1 is lower than that of Example 7 and Example 8.

[0146] Antioxidant capacity 2:

[0147] The scavenging ability of the present invention on ABTS+· was examined. ABTS is oxidized into green ABTS+ under the action of appropriate oxidants. When antioxidants are added to the reaction, the generation of ABTS+· will be inhibited. The total antioxidant capacity of the sample can be determined and calculated by measuring the absorbance at 734nm.

[0148] The specific experimental steps are as follows:

[0149] (1) Take 7 mmol / L ABTS solution and dilute it 60 times with 10 mmol / L PBS (pH = 7.4) to obtain ABTS working solution;

[0150] (2) Pipette 190 μL ABTS working solution (or PBS), add 10 μL sample solution (or PBS), shake for 10 seconds, let stand at 30°C for 6 minutes, and measure the absorbance A at 734 nm.

[0151]

[0152] Wherein: A0: no sample added, ABTS added; A1: sample or PBS added, ABTS added; A2: sample or PBS added, no ABTS added.

[0153] Table 4 ABTS+·Free Radical Scavenging Rate of Compound Colloids in Different Examples

[0154]

[0155] As shown in Table 4, at the same addition ratio (the mass ratio of gellan gum to xanthan gum is 6:4), the ABTS+·free radical scavenging ability of the compound colloid of Example 1 is significantly higher than that of Example 2, Example 3, Example 4 and Comparative Example 1, which is consistent with the flavonoid content results in Table 2, indicating that the ABTS+·free radical scavenging ability of the compound colloid is derived from the flavonoid content of the plant extract residue. At the same time, since the flavonoid content of the compound colloid of Example 1 is significantly lower than that of Example 7 and Example 8 (the addition ratio of gellan gum is higher), the ABTS+·free radical scavenging ability of the compound colloid of Example 1 is lower than that of Example 7 and Example 8.

[0156] Test Example 4

[0157] Determination of gel texture and water holding capacity of compound colloids:

[0158] The composite adhesives in Examples 1-6, 8 and Comparative Example 1, and the colloid prepared in step (4) of Example 7 were used as samples.

[0159] Texture determination: Pour the sample into a 20×20mm plate and place it at room temperature for 24 hours before texture determination. Use a physical property tester to analyze the texture profile of the blended gel prepared under different conditions. Determination conditions: pre-test speed 2.0mm / s, test speed 1.0mm / s, post-test speed 1.0mm / s, trigger force 0.049N, compression degree 40%. Compare the hardness, elasticity and cohesion of the gel. Repeat the measurement 5 times and take the average value.

[0160] Test of water holding capacity: add 1 mL of sample into a 1.5 mL plastic centrifuge tube, wait for it to gel, centrifuge at 10000 r / min for 30 min, remove the upper layer of water, measure the mass difference, and calculate the water holding capacity. The water holding capacity calculation formula is as follows:

[0161]

[0162] Where: m0: mass of empty centrifuge tube, g; m1: mass of centrifuge tube filled with gel before centrifugation, g; m2: mass of centrifuge tube after water is removed, g.

[0163] Table 5 Gel texture and water holding capacity of composite colloids of different embodiments and comparative examples

[0164]

[0165]

[0166] It can be seen from Table 5 that at the same addition ratio (the mass ratio of gellan gum to xanthan gum is 6:4), the gel texture and water holding capacity of the compound colloid of Example 1 are significantly better than those of Example 2, Example 3, Example 4, and Example 5, which are specifically manifested in the lowest hardness, the highest elasticity, cohesion and water holding capacity, indicating that Example 1 forms a compound colloid with a softer texture, better stability, a tighter gel structure, and higher water holding capacity.

[0167] The above are only specific embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing gellan gum, characterized in that: include: The seed liquid of Sphingomonas paucimobilis is inoculated into a fermentation medium for aerobic fermentation; Wherein, the fermentation medium comprises, by mass percentage: 10%-60% plant extract residue, 0-5% sucrose, 0-1% yeast extract powder, 0.05%-1% potassium dihydrogen phosphate, 0.05%-1% dipotassium hydrogen phosphate, 0.05%-1% magnesium sulfate, 0.05%-0.2% potassium dihydrogen phosphate, 1%-5% glucose, and the balance water; The water content of the plant extract residue is 85%-95%, and the pH value of the fermentation medium is 6.5-7.

5.

2. The preparation method according to claim 1, characterized in that: The mass percentage of the plant extract residue in the fermentation medium is 40%-60%; and / or, The mass percentage of sucrose in the fermentation medium is 3%-5%; and / or, The mass percentage of the yeast extract powder in the fermentation medium is 0.5%-1%.

3. The preparation method according to claim 1, characterized in that: The plant extract residue comprises at least one of finger orange extract residue, cocoa powder extract residue and buddleja buddleja extract residue.

4. The preparation method according to claim 1, characterized in that: The plant extract residue is finger orange extract residue.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The aerobic fermentation includes: fermenting at 25°C-32°C and 180r / min-250r / min for 48h-72h.

6. The preparation method according to any one of claims 1 to 4, characterized in that: In terms of volume percentage, the inoculation amount of the Sphingomonas paucimobilis seed solution in the fermentation medium is 7%-12%.

7. A gellan gum, characterized in that: The method is prepared by the preparation method according to any one of claims 1 to 6.

8. A composite adhesive, characterized in that: The invention comprises a first colloid and a second colloid, wherein the first colloid is the gellan gum according to claim 7, and the second colloid comprises at least one of xanthan gum, pectin, gelatin and carrageenan.

9. The composite adhesive according to claim 8, characterized in that: The mass ratio of the first colloid to the second colloid is 3:7-7:3; and / or, The composite adhesive also contains salt for enhancing adhesive performance, and the salt is selected from soluble or slightly soluble alkali metal salts.

10. A cosmetic, characterized in that: It comprises at least one of the gellan gum according to claim 7 and the composite glue according to any one of claims 8 to 9.

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