An oat-derived amino acid surfactant complex and its application in the preparation of cosmetics

Abstract

The present invention relates to an amino acid surfactant complex derived from oats and its application in the preparation of cosmetics, belonging to the field of biotechnology. The surfactant contains glycerol, sodium lauroyl oat amino acid, and polyglyceryl-6 esters of Commiphora angolensis oil. When various components are used in combination, they have good acid and high-temperature resistance stability, good mildness, and good foaming stability. Sodium lauroyl oat amino acid is a product obtained by successively enzymolyzing raw oat kernel protein with trypsin and ficin, followed by lauroylation reaction and then neutralization reaction with sodium hydroxide. The combined use of trypsin and ficin for successive enzymolysis can obtain amino acid and small peptide products, which can improve the acid and high-temperature resistance stability, foaming stability of the surfactant, and have better mildness after preparing the surfactant with sodium lauroyl oat amino acid. The combined use of sodium lauroyl oat amino acid and polyglyceryl-6 esters of Commiphora angolensis oil can improve the foaming stability.

Description

Technical Field

[0001] The present invention belongs to the field of biotechnology, and particularly relates to an amino acid surfactant complex derived from oats and its application in the preparation of cosmetics. Background Art

[0002] In the field of cosmetics, surfactants play a crucial role. They are substances that can significantly change the properties of the two-phase interface, with unique chemical structures and properties, enabling the uniform mixing of originally immiscible substances. Natural surfactants, such as soapberry extract, etc., although having certain cleaning and emulsifying effects, have relatively limited performance. With the progress of the chemical industry, synthetic surfactants have gradually become the mainstream.

[0003] Synthetic surfactants have a wide range of uses in cosmetics. In cleaning products, such as facial cleansers, shampoos, and body washes, they can reduce the interfacial tension between dirt and the skin or hair, making the dirt easy to be rinsed off with water. In skin care products, they help the active ingredients to disperse and penetrate better, improving the efficacy of the products. In makeup products, synthetic surfactants contribute to the dispersion and stability of pigments, making the colors more uniform and long-lasting.

[0004] Currently, common cosmetic surfactants include sodium lauryl sulfate, quaternary ammonium salts, polysorbates, betaines, etc. Some surfactants have the risk of causing adverse reactions such as skin allergies, redness, and dryness, especially for people with sensitive skin. The biodegradability of some surfactants is poor, causing certain pressure on the environment. In addition, with the improvement of consumers' requirements for the quality of cosmetics, surfactants face higher challenges in terms of stability, mildness, functionality, etc.

[0005] Sodium lauroyl oat amino acid is a surfactant with excellent performance and has a wide range of applications in the fields of personal care, cosmetics, and cleaning products. Sodium lauroyl oat amino acid has the characteristics of mildness and low irritation, and is commonly used in personal cleaning products such as shampoos and body washes. It can effectively remove dirt and oil, while maintaining the moisture of the skin and hair, making the skin and hair remain soft and smooth after cleaning. In cosmetics, such as creams and lotions, sodium lauroyl oat amino acid can be used as an emulsifier to help other ingredients disperse evenly, improving the stability and use effect of the products. In addition, its mild characteristics also make it suitable for cosmetic formulations for sensitive skin. Used in facial cleansing products, hand sanitizers, etc., it can gently clean the dirt and pollutants on the skin surface without damaging the natural barrier of the skin.

[0006] However, there are currently many synthesis methods for sodium lauroyl oat amino acid. The stability of sodium lauroyl oat amino acid is relatively poor. In high-temperature, strong acid or strong alkali environments, its stability decreases, thereby reducing the quality and effectiveness of the product. In addition, the foam stability of sodium lauroyl oat amino acid still needs to be improved. Summary of the Invention

[0007] In view of the unsatisfactory stability, mildness, functionality, etc. of existing surfactants, there is still room for improvement. The present invention provides an amino acid surfactant complex based on oats and its application in the preparation of cosmetics. The surfactant contains glycerol, sodium lauroyl oat amino acid, and polyglyceryl-6 shea butterate. When used in combination, it has good acid and high-temperature resistance stability, good mildness, and good foaming stability. Among them, sodium lauroyl oat amino acid is obtained by successively enzymatically hydrolyzing raw oat kernel protein with trypsin and ficin to obtain substances below 3 kDa, then undergoing lauric acid acylation reaction, and then undergoing sodium hydroxide neutralization reaction. The amino acids and small peptide products obtained by the combined use of trypsin and ficin for successive enzymatic hydrolysis can improve the acid and high-temperature resistance stability and foaming stability of the surfactant after preparing the surfactant with sodium lauroyl oat amino acid, and the mildness is better. The combination of sodium lauroyl oat amino acid and polyglyceryl-6 shea butterate can improve the foaming stability and is more skin-friendly and comfortable. The specific technical solution is as follows:

[0008] An amino acid surfactant complex based on oats is made from the following raw materials in parts by mass: 1 part to 5 parts of glycerol, 0.1 part to 0.3 part of sodium lauroyl oat amino acid, 0.04 part to 0.1 part of polyglyceryl-6 shea butterate, and 15 parts to 20 parts of water; sodium lauroyl oat amino acid is obtained by successively enzymatically hydrolyzing raw oat kernel protein with trypsin and ficin to obtain substances below 3 kDa, then undergoing lauric acid acylation reaction, and then undergoing sodium hydroxide neutralization reaction.

[0009] In the above technical solution, the preparation method of the sodium lauroyl oat amino acid includes the following steps:

[0010] S1: Take raw oat kernels and crush them to obtain a powder. Add an aqueous sodium chloride solution with a mass 6 to 8 times that of the powder to the powder, soak it by ultrasonic wave, perform centrifugal separation, collect the supernatant, add an aqueous ammonium sulfate solution to the supernatant, and continuously stir until the protein is completely precipitated. Then perform centrifugal separation and collect the precipitate to obtain the protein;

[0011] S2: Suspend the protein in a phosphate buffer solution with a pH of 7.8 - 8.5 and a concentration of 40 mM, which is 6 - 8 times the mass of the protein. Add trypsin at 0.5% - 1% of the protein mass and enzymatically hydrolyze at 36°C - 40°C for 50 min - 70 min. Inactivate the enzyme at high temperature. After cooling to room temperature, adjust the pH to 6.8 - 7.2. Add ficin at 1% - 1.5% of the protein mass and enzymatically hydrolyze at 60°C - 70°C for 2 h - 3 h. Inactivate the enzyme at high temperature. After cooling to room temperature, filter using a 3 kDa ultrafiltration membrane to obtain a filtrate below 3 kDa, and then perform freeze-drying to obtain product A;

[0012] S3: By mass ratio, product A: lauric acid: dimethylformamide: purified water: 4-dimethylaminopyridine = 1: (1 - 1.5): (20 - 30): (30 - 40): (2 - 2.5). Compound product A, lauric acid, dimethylformamide, purified water, and 4-dimethylaminopyridine, and stir at 60°C - 75°C for an acylation reaction for 8 h - 12 h. Cool to 20°C - 40°C, gradually add an aqueous sodium hydroxide solution, stir for a neutralization reaction until the pH reaches 6 - 7, stop adding the aqueous sodium hydroxide solution to terminate the reaction, and obtain product B;

[0013] S4: Use the vacuum distillation method for product B to distill and separate to discard dimethylformamide and obtain product C;

[0014] S5: Extract product C with ethyl acetate to dissolve 4-dimethylaminopyridine in ethyl acetate, separate the extraction layer, and retain the aqueous phase to obtain product D; Add activated carbon to product D, adsorb to remove color, and then filter to remove the activated carbon to obtain purified product E;

[0015] S6: Concentrate purified product E to precipitate a solid, filter, and take the solid; Wash the solid 3 - 5 times with water, concentrate and precipitate, filter, and finally dry to obtain sodium lauroyl oat amino acid.

[0016] In S1 of the above technical preparation method, the ultrasonic frequency of the ultrasonic soaking is 20 kHz - 40 kHz; the time of the ultrasonic soaking is 1.5 h - 2 h;

[0017] In S1 of the above technical preparation method, the concentration of the sodium chloride aqueous solution is 0.13 mol / L - 0.15 mol / L, and the concentration of the ammonium sulfate aqueous solution is 3.0 mol / L - 4.0 mol / L.

[0018] In S2 of the above technical preparation method, the enzyme activity of trypsin is 100,000 U / g; the enzyme activity of ficin is 100,000 U / g; the temperature for inactivating the enzyme at high temperature is 90°C - 100°C, and the time for inactivating the enzyme at high temperature is 15 min - 20 min.

[0019] In step S3 of the above-mentioned technical preparation method, the concentration of the sodium hydroxide aqueous solution is 0.5 mol / L to 2 mol / L; the stirring speed is 300 r / min to 500 r / min.

[0020] In step S4 of the above-mentioned technical preparation method, the parameters of the vacuum distillation method are: distillation separation at a pressure of 10 mmHg to 20 mmHg and a temperature of 50°C to 70°C.

[0021] In step S5 of the above-mentioned technical preparation method, the dosage of ethyl acetate is 0.5 times to 0.8 times the volume of product C; the dosage of activated carbon is 0.1% to 3% of the mass of product D.

[0022] The preparation method of a kind of oat-derived amino acid surfactant complex provided by the present invention comprises the following steps:

[0023] According to parts by mass, water, glycerol, sodium lauroyl oat amino acid, and polyglyceryl-6 esters of Commiphora angolensis oil are formulated at 40°C to 50°C to obtain a complex.

[0024] The above-mentioned oat-derived amino acid surfactant complex is used as a surfactant for formulating cosmetics.

[0025] A kind of oat-derived amino acid surfactant complex provided by the present invention and its application in the preparation of cosmetics have the following beneficial effects compared with the prior art:

[0026] First, the surfactant of the present invention contains glycerol, sodium lauroyl oat amino acid, and polyglyceryl-6 esters of Commiphora angolensis oil. When used in combination, it has good acid and high-temperature resistance stability, good mildness, and good foam stability. Among them, sodium lauroyl oat amino acid has mild cleaning properties, less irritation to the skin, is suitable for sensitive skin, has good skin compatibility, helps to maintain the moisture of the skin, and helps to maintain the natural barrier of the skin. The sodium lauroyl oat amino acid prepared by the present invention is a relatively high-quality cosmetic raw material and can play an active role in both cleaning and skin care.

[0027] Second, polyglyceryl-6 esters of Commiphora angolensis oil can improve the fineness, richness, and stability of the foam. Polyglyceryl-6 esters of Commiphora angolensis oil have good emulsifying effects. When paired with sodium lauroyl oat amino acid, they can more effectively emulsify the oil phase and water phase, improving the stability of the product. Polyglyceryl-6 esters of Commiphora angolensis oil can bring a more comfortable and smooth skin feel, enhancing the consumer's use experience. Polyglyceryl-6 esters of Commiphora angolensis oil may help to enhance the moisturizing performance of the formula. When combined with sodium lauroyl oat amino acid, the product can maintain the moisture of the skin while cleaning or caring.

[0028] III. The present invention provides a preparation method of sodium lauroyl oat amino acid. Sodium lauroyl oat amino acid is obtained by successively enzymatically hydrolyzing raw oat kernel protein with trypsin and ficin to obtain substances below 3 kDa, then through lauric acid acylation reaction, and then through sodium hydroxide neutralization reaction. The combined use of trypsin and ficin for successive enzymatic hydrolysis to obtain amino acid and small peptide products can improve the acid and high-temperature resistance stability, foaming stability of the surfactant, and has better mildness after formulating the surfactant with sodium lauroyl oat amino acid.

[0029] IV. In the lauric acid acylation reaction of the present invention, 4-dimethylaminopyridine catalyst is added, which can promote the complete reaction of components to a certain extent, affect the product components, and thus affect the characteristics of the surfactant, and can improve the acid and high-temperature resistance stability, foaming stability of the surfactant to a certain extent, and has better mildness. Specific Embodiments

[0030] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited to these embodiments.

[0031] Example 1

[0032] An amino acid surfactant complex based on oats is made from the following raw materials in parts by mass: 3 parts of glycerol, 0.2 part of sodium lauroyl oat amino acid, 0.07 part of polyglyceryl-6 arganate, and 16 parts of water; sodium lauroyl oat amino acid is obtained by successively enzymatically hydrolyzing raw oat kernel protein with trypsin and ficin to obtain substances below 3 kDa, then through lauric acid acylation reaction, and then through sodium hydroxide neutralization reaction.

[0033] In the above technical solution, the preparation method of sodium lauroyl oat amino acid includes the following steps:

[0034] S1: Take raw oat kernels and crush them to obtain a powder. Add an aqueous sodium chloride solution with a concentration of 0.14 mol / L and a mass 7 times that of the powder to the powder, soak it with ultrasonic waves at 30 kHz for 1.5 h, perform centrifugal separation, collect the supernatant, add an aqueous ammonium sulfate solution with a concentration of 3.5 mol / L to the supernatant, continuously stir until the protein is completely precipitated, perform centrifugal separation, and collect the precipitate to obtain the protein;

[0035] S2: Suspend the protein in a phosphate buffer solution with a pH of 8.2 and a concentration of 40 mM, which is 7 times the mass of the protein. Add trypsin with an enzyme activity of 100,000 U / g, accounting for 0.8% of the mass of the protein. Conduct enzymatic hydrolysis at 38 °C for 60 min, inactivate the enzyme at 95 °C for 15 min. After cooling to room temperature, adjust the pH to 7.0. Then add ficin with an enzyme activity of 100,000 U / g, accounting for 1.2% of the mass of the protein, and conduct enzymatic hydrolysis at 65 °C for 2.5 h. Inactivate the enzyme at 95 °C for 15 min. After cooling to room temperature, filter using a 3 kDa ultrafiltration membrane to obtain a filtrate with a molecular weight below 3 kDa, and then conduct freeze-drying to obtain product A;

[0036] S3: According to the mass ratio of product A: lauric acid: dimethylformamide: purified water: 4-dimethylaminopyridine = 1: 1.2: 25: 35: 2.2, compound product A, lauric acid, dimethylformamide, purified water and 4-dimethylaminopyridine, stir at 70 °C, and conduct an acylation reaction for 10 h. Cool down to 30 °C, gradually add a sodium hydroxide aqueous solution with a concentration of 1 mol / L, stir at 400 r / min for a neutralization reaction until the pH reaches 6.5, then stop adding the sodium hydroxide aqueous solution to terminate the reaction and obtain product B;

[0037] S4: Use the vacuum distillation method for product B. The parameters of the vacuum distillation method are: at a pressure of 15 mmHg and a temperature of 60 °C; distill and separate to discard dimethylformamide to obtain product C;

[0038] S5: Extract product C with ethyl acetate with a volume 0.6 times that of product C to dissolve 4-dimethylaminopyridine in ethyl acetate, separate the extraction layer, and retain the aqueous phase to obtain product D; add activated carbon accounting for 2% of the mass of product D to product D, adsorb and remove color, then filter to remove the activated carbon to obtain purified product E;

[0039] S6: Concentrate purified product E to precipitate solids, filter, and collect the solids; wash the solids with water 4 times, concentrate and precipitate, filter, and finally dry to obtain sodium lauroyl oat amino acid.

[0040] The above method for preparing an amino acid surfactant complex based on oats includes the following steps:

[0041] According to the mass fraction, compound water, glycerol, sodium lauroyl oat amino acid, and polyglyceryl-6 esters of Commiphora molmol in 45 °C to obtain the complex.

[0042] The above amino acid surfactant complex based on oats is used for preparing cosmetics.

[0043] Example 2

[0044] An oat-derived amino acid surfactant complex, which is made from the following raw materials in parts by mass: 1 part of glycerol, 0.1 part of sodium lauroyl oat amino acid, 0.04 part of polyglyceryl-6 shea butterate, and 15 parts of water; Sodium lauroyl oat amino acid is obtained by successively enzymolyzing raw oat kernel protein with trypsin and ficin to obtain substances below 3 kDa, followed by lauric acid acylation reaction and then sodium hydroxide neutralization reaction.

[0045] In the above technical solution, the preparation method of the sodium lauroyl oat amino acid includes the following steps:

[0046] S1: Take raw oat kernels and crush them to obtain a powder. Add an aqueous sodium chloride solution with a concentration of 0.13 mol / L and a mass 6 times that of the powder to the powder, soak it with ultrasonic waves at 20 kHz for 1.5 h, perform centrifugal separation, collect the supernatant, add an aqueous ammonium sulfate solution with a concentration of 3.0 mol / L to the supernatant, continuously stir until the protein is completely precipitated, perform centrifugal separation, and collect the precipitate to obtain the protein.

[0047] S2: Suspend the protein in a phosphate buffer solution with a pH of 7.8 and a concentration of 40 mM and a mass 6 times that of the protein. Add trypsin with an enzyme activity of 100,000 U / g and a mass of 0.5% of the protein, enzymolyze at 36°C for 50 min, inactivate the enzyme at 90°C for 15 min, adjust the pH to 6.8 after cooling to room temperature, add ficin with an enzyme activity of 100,000 U / g and a mass of 1% of the protein, enzymolyze at 60°C for 2 h, inactivate the enzyme at 90°C for 15 min, and filter through a 3 kDa ultrafiltration membrane after cooling to room temperature to obtain a filtrate below 3 kDa, and freeze-dry to obtain product A.

[0048] S3: According to the mass ratio, product A: lauric acid: dimethylformamide: purified water: 4-dimethylaminopyridine = 1:1:20:30:2, compound product A, lauric acid, dimethylformamide, purified water, and 4-dimethylaminopyridine, stir at 60°C, and perform an acylation reaction for 8 h. Cool down to 20°C, gradually add an aqueous sodium hydroxide solution with a concentration of 0.5 mol / L, stir at 300 r / min for a neutralization reaction until the pH reaches 6, stop adding the aqueous sodium hydroxide solution, and terminate the reaction to obtain product B.

[0049] S4: Use the product B by the vacuum distillation method. The parameters of the vacuum distillation method are: at a pressure of 10 mmHg and a temperature of 50°C; distill and separate to discard dimethylformamide to obtain product C.

[0050] S5: Extract the product C with ethyl acetate at 0.5 times the volume of the product C, dissolve 4-dimethylaminopyridine in the ethyl acetate, separate the extraction layer, retain the aqueous phase, and obtain the product D; add activated carbon at 0.1% of the mass of the product D to the product D, adsorb and remove the color, filter to remove the activated carbon, and obtain the purified product E;

[0051] S6: Concentrate the purified product E, precipitate solids, filter, and take the solids; wash the solids with water 3 times, concentrate and precipitate, filter, and finally dry to obtain sodium lauroyl oat amino acid.

[0052] The above preparation method of an amino acid surfactant complex based on oats includes the following steps:

[0053] Prepare water, glycerol, sodium lauroyl oat amino acid, and polyglyceryl-6 argan oil esters at 40 °C by mass parts to obtain the complex.

[0054] The above amino acid surfactant complex based on oats is used to prepare cosmetics.

[0055] Example 3

[0056] An amino acid surfactant complex based on oats, the complex is made from the following raw materials by mass parts: 1 part of glycerol, 0.3 part of sodium lauroyl oat amino acid, 0.04 part of polyglyceryl-6 argan oil esters, 17 parts of water; sodium lauroyl oat amino acid is obtained by sequentially enzymatically hydrolyzing raw oat kernel protein with trypsin and ficin to obtain substances below 3 kDa, then through lauric acid acylation reaction, and then through sodium hydroxide neutralization reaction.

[0057] In the above technical solution, the preparation method of the sodium lauroyl oat amino acid includes the following steps:

[0058] S1: Take raw oat kernels and crush them to obtain a powder. Add an aqueous sodium chloride solution with a concentration of 0.15 mol / L at 6 times the mass of the powder to the powder, soak it in an ultrasonic bath at 20 kHz for 2 h, centrifuge and separate, collect the supernatant, add an aqueous ammonium sulfate solution with a concentration of 3.0 mol / L to the supernatant, continuously stir until the protein is completely precipitated, centrifuge and separate, and collect the precipitate to obtain the protein;

[0059] S2: Suspend the protein in a phosphate buffer solution with a pH of 7.8 and a concentration of 40 mM, which is 8 times the mass of the protein. Add trypsin with an enzyme activity of 100,000 U / g, accounting for 1% of the protein's mass, and enzymatically hydrolyze at 36°C for 70 min. Inactivate the enzyme at 90°C for 20 min. After cooling to room temperature, adjust the pH to 6.8. Add ficin with an enzyme activity of 100,000 U / g, accounting for 1.5% of the protein's mass, and enzymatically hydrolyze at 60°C for 3 h. Inactivate the enzyme at 90°C for 20 min. After cooling to room temperature, filter using a 3 kDa ultrafiltration membrane to obtain a filtrate with a molecular weight below 3 kDa, and then perform freeze-drying to obtain product A;

[0060] S3: According to the mass ratio of product A: lauric acid: dimethylformamide: purified water: 4-dimethylaminopyridine = 1:1:30:30:2.5, compound product A, lauric acid, dimethylformamide, purified water, and 4-dimethylaminopyridine. Stir at 60°C for an acylation reaction for 12 h. Cool to 20°C and gradually add a sodium hydroxide aqueous solution with a concentration of 2 mol / L, and stir at 300 r / min for a neutralization reaction until the pH reaches 7. Stop adding the sodium hydroxide aqueous solution to terminate the reaction and obtain product B;

[0061] S4: Use the vacuum distillation method for product B. The parameters of the vacuum distillation method are: at a pressure of 10 mmHg and a temperature of 70°C; distill and separate to discard dimethylformamide to obtain product C;

[0062] S5: Extract product C with ethyl acetate, which is 0.5 times the volume of product C, to dissolve 4-dimethylaminopyridine in ethyl acetate. Separate the extraction layer and retain the aqueous phase to obtain product D; Add activated carbon, accounting for 3% of the mass of product D, to product D for decolorization by adsorption, and then filter to remove the activated carbon to obtain purified product E;

[0063] S6: Concentrate purified product E to precipitate a solid, filter, and collect the solid; Wash the solid 3 times with water, concentrate and precipitate, filter, and finally dry to obtain sodium lauroyl oat amino acid.

[0064] The above method for preparing an amino acid surfactant complex based on oats includes the following steps:

[0065] According to the mass parts, compound water, glycerol, sodium lauroyl oat amino acid, and polyglyceryl-6 esters of Commiphora africana at 50°C to obtain the complex.

[0066] The above amino acid surfactant complex based on oats is used for preparing cosmetics.

[0067] Example 4

[0068] An oat-derived amino acid surfactant complex, which is made from the following raw materials in parts by mass: 5 parts of glycerol, 0.3 part of sodium lauroyl oat amino acid, 0.1 part of shea butter polyglyceryl-6 esters, and 20 parts of water; sodium lauroyl oat amino acid is obtained by successively enzymolyzing raw oat kernel protein with trypsin and ficin to obtain substances with a molecular weight below 3 kDa, then undergoing lauric acid acylation reaction, and then undergoing sodium hydroxide neutralization reaction to obtain the product.

[0069] In the above technical solution, the preparation method of the sodium lauroyl oat amino acid includes the following steps:

[0070] S1: Take raw oat kernels and crush them to obtain a powder. Add an aqueous sodium chloride solution with a concentration of 0.15 mol / L and a mass 8 times that of the powder to the powder, soak it with ultrasonic waves at 40 kHz for 2 h, perform centrifugal separation, collect the supernatant, add an aqueous ammonium sulfate solution with a concentration of 4.0 mol / L to the supernatant, continuously stir until the protein is completely precipitated, perform centrifugal separation, and collect the precipitate to obtain the protein.

[0071] S2: Suspend the protein in a phosphate buffer solution with a pH of 8.5 and a concentration of 40 mM and a mass 8 times that of the protein. Add trypsin with an enzyme activity of 100,000 U / g and a mass of 1% of the protein, enzymolyze at 40 °C for 70 min, inactivate the enzyme at 100 °C for 20 min. After cooling to room temperature, adjust the pH to 7.2, add ficin with an enzyme activity of 100,000 U / g and a mass of 1.5% of the protein, enzymolyze at 70 °C for 3 h, inactivate the enzyme at 100 °C for 20 min. After cooling to room temperature, filter with a 3 kDa ultrafiltration membrane to obtain a filtrate with a molecular weight below 3 kDa, and perform freeze-drying to obtain product A.

[0072] S3: According to the mass ratio, product A: lauric acid: dimethylformamide: purified water: 4-dimethylaminopyridine = 1:1.5:30:40:2.5, compound product A, lauric acid, dimethylformamide, purified water, and 4-dimethylaminopyridine, stir at 75 °C, perform acylation reaction for 12 h, cool to 40 °C, gradually add an aqueous sodium hydroxide solution with a concentration of 2 mol / L, stir at 500 r / min for neutralization reaction until the pH reaches 7, stop adding the aqueous sodium hydroxide solution, and terminate the reaction to obtain product B.

[0073] S4: Use the product B by vacuum distillation method. The parameters of the vacuum distillation method are: at a pressure of 20 mmHg and a temperature of 70 °C; distill and separate to discard dimethylformamide to obtain product C.

[0074] S5: Extract the product C with ethyl acetate at 0.8 times the volume of the product C, dissolve 4-dimethylaminopyridine in the ethyl acetate, separate the extraction layer, and retain the aqueous phase to obtain the product D; add activated carbon at 3% of the mass of the product D to the product D, adsorb and remove the color, and then filter to remove the activated carbon to obtain the purified product E;

[0075] S6: Concentrate the purified product E, precipitate solids, filter, and take the solids; wash the solids with water 5 times, concentrate and precipitate, filter, and finally dry to obtain sodium lauroyl oat amino acid.

[0076] The preparation method of the above-mentioned amino acid surfactant complex based on oats includes the following steps:

[0077] Prepare water, glycerol, sodium lauroyl oat amino acid, and polyglyceryl-6 esters of Commiphora africana oil in parts by mass at 50 °C to obtain the complex.

[0078] The above-mentioned amino acid surfactant complex based on oats is used for preparing cosmetics.

[0079] Example 5

[0080] An amino acid surfactant complex based on oats, the complex is made from the following raw materials in parts by mass: 5 parts of glycerol, 0.1 part of sodium lauroyl oat amino acid, 0.1 part of polyglyceryl-6 esters of Commiphora africana oil, 18 parts of water; sodium lauroyl oat amino acid is obtained by successively enzymatically hydrolyzing raw oat kernel protein with trypsin and ficin to obtain substances below 3 kDa, then through lauric acid acylation reaction, and then through sodium hydroxide neutralization reaction.

[0081] In the above technical solution, the preparation method of the sodium lauroyl oat amino acid includes the following steps:

[0082] S1: Take raw oat kernels and crush them to obtain a powder. Add an aqueous sodium chloride solution with a concentration of 0.13 mol / L at 8 times the mass of the powder to the powder, soak it in ultrasonic waves at 40 kHz for 1.5 h, centrifuge and separate, collect the supernatant, add an aqueous ammonium sulfate solution with a concentration of 4.0 mol / L to the supernatant, and continuously stir until the protein is completely precipitated, centrifuge and separate, and collect the precipitate to obtain the protein;

[0083] S2: Suspend the protein in a phosphate buffer solution with a pH of 8.5 and a concentration of 40 mM, which is 6 times the mass of the protein. Add trypsin with an enzyme activity of 100,000 U / g, accounting for 0.5% of the mass of the protein. Conduct enzymatic hydrolysis at 40 °C for 50 min, inactivate the enzyme at 100 °C for 15 min. After cooling to room temperature, adjust the pH to 7.2. Add ficin with an enzyme activity of 100,000 U / g, accounting for 1% of the mass of the protein. Conduct enzymatic hydrolysis at 70 °C for 2 h, inactivate the enzyme at 100 °C for 15 min. After cooling to room temperature, filter using a 3 kDa ultrafiltration membrane to obtain a filtrate with a molecular weight below 3 kDa. Freeze-dry to obtain product A;

[0084] S3: According to the mass ratio, product A: lauric acid: dimethylformamide: purified water: 4-dimethylaminopyridine = 1:1.5:20:40:2. Compound product A, lauric acid, dimethylformamide, purified water, and 4-dimethylaminopyridine. Stir at 75 °C for an acylation reaction for 8 h. Cool to 40 °C, gradually add an aqueous sodium hydroxide solution with a concentration of 0.5 mol / L, and stir at 500 r / min for a neutralization reaction until the pH reaches 6. Stop adding the aqueous sodium hydroxide solution to terminate the reaction and obtain product B;

[0085] S4: Subject product B to vacuum distillation. The parameters of the vacuum distillation method are: at a pressure of 12 mmHg and a temperature of 55 °C; distill and separate to discard dimethylformamide to obtain product C;

[0086] S5: Extract product C with ethyl acetate with a volume 0.6 times that of product C, so that 4-dimethylaminopyridine dissolves in ethyl acetate. Separate the extraction layer and retain the aqueous phase to obtain product D; Add activated carbon accounting for 1% of the mass of product D to product D, adsorb to remove color, and then filter to remove the activated carbon to obtain purified product E;

[0087] S6: Concentrate purified product E to precipitate solids, filter, and collect the solids; Wash the solids 4 times with water, concentrate and precipitate, filter, and finally dry to obtain sodium lauroyl oat amino acid.

[0088] The above method for preparing an amino acid surfactant complex based on oats includes the following steps:

[0089] According to the mass fraction, formulate water, glycerol, sodium lauroyl oat amino acid, and polyglyceryl-6 esters of Commiphora myrrha oil at 45 °C to obtain the complex.

[0090] The above amino acid surfactant complex based on oats is used for preparing cosmetics.

[0091] The polyglyceryl-6 esters of Commiphora myrrha oil used in the above examples are provided by Aoke New Materials Technology (Shanghai) Co., Ltd.

[0092] Comparative Example 1

[0093] In the complex, no argan oil polyglyceryl - 6 esters are added, and the argan oil polyglyceryl - 6 esters component is replaced with water; other parameters and methods are the same as in Example 1.

[0094] Comparative Example 2

[0095] In the preparation method S2 of sodium lauroyl oat amino acid, the protein is not enzymatically hydrolyzed with ficin; other parameters and methods are the same as in Example 1.

[0096] Comparative Example 3

[0097] In the preparation method S2 of sodium lauroyl oat amino acid, the protein is not enzymatically hydrolyzed with trypsin; other parameters and methods are the same as in Example 1.

[0098] Comparative Example 4

[0099] In the preparation method S2 of sodium lauroyl oat amino acid, the protein is suspended in a hydrochloric acid aqueous solution with a pH of 2 and 7 times the mass of the protein, 0.8% by mass of pepsin with an enzyme activity of 100,000 U / g is added, enzymatically hydrolyzed at 38°C for 60 min, inactivated at 95°C for 15 min, after cooling to room temperature, the pH is adjusted to 7.0, filtered through a 3 kDa ultrafiltration membrane, the filtrate below 3 kDa is obtained, and freeze - dried to obtain product A; other parameters and methods are the same as in Example 1.

[0100] Comparative Example 5

[0101] In the preparation method S3 of sodium lauroyl oat amino acid, 4 - dimethylaminopyridine is not added; other parameters and methods are the same as in Example 1.

[0102] Detect the surfactants of the above - mentioned examples and comparative examples.

[0103] I. Stability test:

[0104] Take 500 mL of each surfactant complex sample, store it unsealed at a temperature of 60°C under a light environment, and observe the high - temperature deterioration situation; take 500 mL of each surfactant complex sample, adjust the pH to 4.5, store it at a temperature of 60°C under a light environment, and observe the acidic high - temperature deterioration situation; the results are shown in Table 1 below.

[0105] Table 1 Stability test results

[0106]

[0107] Deterioration phenomenon:

[0108] Odor change: Produce unpleasant odors, such as sour smell, putrid smell, etc.

[0109] Appearance change: The color becomes darker, turbid, or there are precipitates or layering

[0110] Rating criteria:

[0111] 0 - Not deteriorated: No property change;

[0112] 1 - Slightly deteriorated: Slight off - odor, slightly darker color, no turbidity, precipitation, or layering;

[0113] 2 - Moderately deteriorated: Obvious off - odor, significantly darker color, turbidity, no precipitation or layering;

[0114] 3 - Severely deteriorated: Severe off - odor, severely darker color, turbidity, precipitation, and layering.

[0115] From the above results, it can be seen that the surfactants in Examples 1 to 5 have good acid - and high - temperature - resistant storage stability. From the results of Comparative Examples 2 and 3, it can be known that the products obtained by omitting the enzymatic hydrolysis step affect the composition of the surfactant, and thus affect the storage stability. From the results of Comparative Example 4, it can be seen that the surfactant prepared from the product obtained by enzymatic hydrolysis with pepsin also has good storage stability. From the results of Comparative Example 5, it can be known that without adding 4 - dimethylaminopyridine catalyst, it affects the product composition, and thus affects the storage stability of the surfactant.

[0116] II. Mildness test:

[0117] The irritation of the surfactant was tested by the zein method. Zein is insoluble in water, but its water solubility increases after interacting with the surfactant; the greater the skin irritation degree of the surfactant, the greater the dissolution degree of zein.

[0118] Take 250 mL of the surfactant and dilute it to 4 times its volume, add saturated - solubility zein and stir for dissolution for 2 h, filter to remove the undissolved zein, take the filtrate to detect the nitrogen content (N g / L), and record the value as B; at the same time, take 500 mL of pure water, add 5 g of zein and stir for dissolution for 2 h, filter to remove the undissolved zein, take the filtrate to detect the nitrogen content (N g / L), and record the value as A; Zein value = A - B. The test results are shown in Table 2 below.

[0119] Table 2 Mildness test results

[0120] Specimen zein value Specimen zein value Example 1 0.055 Comparative Example 1 0.052 Example 2 0.050 Comparative Example 2 0.073 Example 3 0.052 Comparative Example 3 0.081 Example 4 0.058 Comparative Example 4 0.064 Example 5 0.052 Comparative Example 5 0.058

[0121] As can be seen from the above results, the surfactants of Comparative Examples 1 to 5 have good mildness and relatively low irritation. From the result of Comparative Example 1, the shea butter polyglyceryl-6 esters will increase a certain degree of irritation, but adding a small amount of shea butter polyglyceryl-6 esters will not have too much impact on irritation. From the results of Comparative Examples 2 and 3, the products obtained by omitting the enzymatic hydrolysis step affect the composition of the surfactant, thereby increasing the irritation. From the result of Comparative Example 4, using the product obtained by pepsin enzymatic hydrolysis to prepare the surfactant, the irritation increases. From the result of Comparative Example 5, not adding 4-dimethylaminopyridine catalyst affects the product composition and thus has a certain increase in the irritation of the surfactant.

[0122] III. Foaming stability test:

[0123] Dilute each surfactant to 2 times its volume to obtain a diluted solution; slowly pour the diluted solution along the inner wall of the Ross-Miles foam apparatus to the specified scale (50 ml), taking care to avoid generating bubbles. Plug the upper opening of the tube with a stopper, then move the tube body up and down uniformly (30 times per minute), with the moving distance being approximately half of the tube length, for a duration of 5 minutes. After stopping the movement, immediately record the volume of the generated foam (in ml) as the initial foam volume A. Wait for 5 minutes and then record the foam volume B again. The foam change rate = (A - B) / A%, and the smaller the foam change rate, the better the foaming stability. The test results are shown in Table 3 below.

[0124] Table 3 Test results of foaming stability

[0125] Specimen Foam change rate % Specimen Foam change rate % Example 1 16 Comparative Example 1 28 Example 2 20 Comparative Example 2 22 Example 3 17 Comparative Example 3 25 Example 4 12 Comparative Example 4 24 Example 5 18 Comparative Example 5 21

[0126] As can be seen from the above results, the surfactants of Comparative Examples 1 to 5 have relatively good foaming stability. From the result of Comparative Example 1, the combination of shea butter polyglyceryl-6 esters and sodium lauroyl oat amino acids has the effect of improving foaming stability. From the results of Comparative Examples 2 and 3, the products obtained by omitting the enzymatic hydrolysis step affect the composition of the surfactant and reduce the foaming stability. From the result of Comparative Example 4, using the product obtained by pepsin enzymatic hydrolysis to prepare the surfactant, the foaming stability is poor. From the result of Comparative Example 5, not adding 4-dimethylaminopyridine catalyst affects the product composition and thus reduces the foaming stability of the surfactant.

Claims

1. An amino acid surfactant complex based on oats, characterized in that: The compound is made of the following raw materials in parts by weight: 1 to 5 parts of glycerin, 0.1 to 0.3 parts of sodium lauroyl oat amino acid, 0.04 to 0.1 parts of argan oil polyglycerol-6 esters, and 15 to 20 parts of water; The preparation method of sodium lauroyl oat amino acids comprises the following steps: S1: grind raw oat kernels to obtain powder, add sodium chloride aqueous solution 6 to 8 times the mass of the powder to the powder, soak with ultrasound, centrifuge, collect the supernatant, add ammonium sulfate aqueous solution to the supernatant, continue stirring until the protein is completely precipitated, centrifuge, collect the precipitate, and obtain the protein; S2: The protein was suspended in a pH 7.8-8.5, 40 mM phosphate buffer solution which was 6 to 8 times the mass of the protein, and trypsin was added which was 0.5% to 1% of the mass of the protein, and the solution was enzymatically hydrolyzed at 36°C to 40°C for 50 min to 70 min, and the enzyme was inactivated at high temperature. After the solution was cooled to room temperature, the pH was adjusted to 6.8 to 7.2, and fig protease which was 1% to 1.5% of the mass of the protein was added, and the solution was enzymatically hydrolyzed at 60°C to 70°C for 2 h to 3 h, and the enzyme was inactivated at high temperature. After the solution was cooled to room temperature, the solution was filtered using a 3 kDa ultrafiltration membrane to obtain a filtrate below 3 kDa, and the filtrate was freeze-dried to obtain product A; S3: According to the mass ratio, product A: lauric acid: dimethylformamide: purified water: 4-dimethylaminopyridine = 1: (1-1.5): (20-30): (30-40): (2-2.5), product A, lauric acid, dimethylformamide, purified water and 4-dimethylaminopyridine are compounded, stirred at 60°C-75°C, acylation reaction for 8h-12h, cooled to 20°C-40°C, sodium hydroxide aqueous solution is gradually added, stirred, neutralized reaction, until pH reaches 6-7, stop adding sodium hydroxide aqueous solution, terminate the reaction, and obtain product B; S4: distill and separate the product B by vacuum distillation to remove dimethylformamide, thereby obtaining product C; S5: extracting the product C with ethyl acetate to dissolve 4-dimethylaminopyridine in ethyl acetate, separating the extraction layer, retaining the aqueous phase, and obtaining the product D; adding activated carbon to the product D to adsorb and remove color, filtering to remove the activated carbon, and obtaining a purified product E; S6: Concentrate the purified product E to precipitate a solid, filter, and take the solid; wash the solid with water 3 to 5 times, concentrate to precipitate, filter, and finally dry to obtain sodium lauroyl oat amino acid.

2. The oat-derived amino acid surfactant complex according to claim 1, characterized in that: In S1, the ultrasonic frequency of the ultrasonic immersion is 20kHz to 40kHz; and the time of the ultrasonic immersion is 1.5h to 2h.

3. The oat-derived amino acid surfactant complex according to claim 1, characterized in that: In S1, the concentration of the sodium chloride aqueous solution is 0.13 mol / L to 0.15 mol / L, and the concentration of the ammonium sulfate aqueous solution is 3.0 mol / L to 4.0 mol / L.

4. The oat-derived amino acid surfactant complex according to claim 1, characterized in that: In S2, the enzyme activity of the trypsin is 100,000 U / g; the enzyme activity of the ficin is 100,000 U / g; the temperature of the high-temperature enzyme inactivation is 90°C to 100°C, and the time of the high-temperature enzyme inactivation is 15min to 20min.

5. The oat-derived amino acid surfactant complex according to claim 1, characterized in that: In S3, the concentration of the sodium hydroxide aqueous solution is 0.5 mol / L to 2 mol / L; and the stirring speed is 300 r / min to 500 r / min.

6. The oat-derived amino acid surfactant complex according to claim 1, characterized in that: In S4, the parameters of the reduced pressure distillation method are: distillation separation at a pressure of 10 mmHg to 20 mmHg and a temperature of 50° C. to 70° C.

7. The oat-derived amino acid surfactant complex according to claim 1, characterized in that: In S5, the amount of ethyl acetate used is 0.5 to 0.8 times the volume of product C; the amount of activated carbon used is 0.1% to 3% of the mass of product D.

8. The oat-derived amino acid surfactant complex according to claim 1, characterized in that: The preparation method of the composite comprises the following steps: Water, glycerin, sodium lauroyl oat amino acids and argan oil polyglycerol-6 esters are prepared at 40° C. to 50° C. according to their mass proportions to obtain a complex.

9. The use of an amino acid surfactant complex based on oats as claimed in claim 1, characterized in that: The complex is used as a surfactant in the formulation of cosmetics.

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