Oat amino acid surfactant and preparation method thereof

Abstract

The invention relates to the technical field of daily chemicals, and provides an oat amino acid surfactant and a preparation method thereof. The preparation method comprises the following steps: dissolving oat protein polypeptide in deionized water, heating to 50-70 DEG C, adjusting the pH value of a system to 4-10, adding proteolytic enzyme, stirring for 4-6 hours, maintaining the pH value of the system to 4-10, cooling to room temperature, and drying to obtain the oat oligopeptide. The preparation method comprises the following steps: dissolving a sodium hydroxide solution into deionized water, controlling the temperature to be 50-70 DEG C, adjusting the pH value of a system to be 11-12, dropwise adding fatty acyl chloride, keeping the pH value of the system to be 11-12, continuously keeping the pH value of the system to be 11-12 after dropwise adding, and reacting for 0.5-1.5 hours; performing curing; and cooling to 40-60 DEG C, decolorizing, and adjusting the pH value of the system to 6.5-7.5 to obtain the oat amino acid surfactant. The preparation method is simple in process, and the obtained oat amino acid surfactant is light in chromaticity and low in smell.

Description

Technical Field

[0001] This application relates to the field of daily chemical products technology, and in particular to an oat amino acid surfactant and its preparation method. Background Technology

[0002] As consumers increasingly demand safety and environmental friendliness in daily chemical products, mild and environmentally friendly surfactants are gaining popularity in the market. Compared to traditional sulfate surfactants, amino acid surfactants are milder, which is their biggest advantage, allowing them to successfully capture a certain share of the surfactant market.

[0003] Among numerous amino acid surfactants, oat amino acid surfactants have been extensively studied due to their natural origin and excellent surface activity. Currently, the preparation of oat amino acid surfactants mainly involves the amidation reaction of oat protein peptides obtained from the enzymatic hydrolysis of oat protein with fatty acyl chlorides. However, the enzymatic hydrolysis of oat protein into oat protein peptides is uncontrollable and difficult to selectively hydrolyze into single protein peptides, resulting in complex hydrolysis products. Therefore, certain free amino acids during hydrolysis can potentially lead to high color and strong odor in oat amino acid surfactants. Furthermore, the processes for producing oat amino acid surfactants with low color and low odor are complex, difficult to scale up for industrial production, and costly. Therefore, there is an urgent need to develop a simple and efficient method to solve the problems of high color and strong odor in oat amino acid surfactants. Summary of the Invention

[0004] The purpose of this application is to provide an oat amino acid surfactant and its preparation method, which reduces the color and odor of the oat amino acid surfactant. The preparation method is simple to operate, low in cost, and easy to industrialize. The specific technical solution is as follows:

[0005] The first aspect of this application provides a method for preparing an oat amino acid surfactant, comprising:

[0006] (1) Dissolve oat protein peptides in deionized water, stir and heat to 50℃~70℃, adjust the pH of the system to 4~10, add hydrolytic protease, stir continuously for 4h~6h, maintain the pH of the system at 4~10, cool to room temperature and dry to obtain oat oligopeptides; wherein, the hydrolytic protease is selected from trypsin or papain.

[0007] (2) Dissolve the oat oligopeptide in deionized water, control the temperature at 50℃~70℃, adjust the pH of the system to 11~12, add fatty acyl chloride dropwise, and keep the pH of the system at 11~12. After the dropwise addition is complete, continue to keep the pH of the system at 11~12 and react for 0.5h~1.5h.

[0008] (3) The temperature is controlled at 80℃~100℃ and the pH of the system is controlled at 10~11. The maturation is carried out under an inert atmosphere.

[0009] (4) Cool to 40℃~60℃, add oxidant for decolorization, and then adjust the pH of the system to 6.5~7.5 to obtain oat amino acid surfactant.

[0010] In one embodiment of this application, in step (1), the mass ratio of the hydrolytic protease to the oat protein polypeptide is 1:100 to 1:150.

[0011] In one embodiment of this application, step (1) further includes activated carbon adsorption. Step (1) is as follows: oat protein peptides are dissolved in deionized water, stirred and heated to 50°C~70°C, the pH of the system is adjusted to 4~10, hydrolytic protease is added, stirring is continued for 4h~6h, and the pH of the system is maintained at 4~10. After cooling to room temperature, activated carbon is added, stirred, filtered, and dried to obtain oat oligopeptides.

[0012] In one embodiment of this application, in step (1), the mass ratio of the activated carbon to the oat protein polypeptide is 1:20 to 1:25.

[0013] In one embodiment of this application, in step (2), the fatty acyl chloride is selected from at least one of octanoyl chloride, decanoyl chloride, lauroyl chloride and palmitoyl chloride.

[0014] In one embodiment of this application, in step (2), the mass ratio of the oat oligopeptide to the fatty acyl chloride is 43:18 to 43:35.

[0015] In one embodiment of this application, in step (3), the ripening time is 2h to 4h.

[0016] In one embodiment of this application, in step (4), the oxidant is selected from at least one of hydrogen peroxide, peracetic acid, sodium hypochlorite, perchloric acid and sodium percarbonate.

[0017] In one embodiment of this application, in step (4), the oxidant is selected from hydrogen peroxide, and the concentration of the hydrogen peroxide is 0.5wt%~1wt%.

[0018] The second aspect of this application provides an oat amino acid surfactant prepared according to the preparation method described in the first aspect of this application.

[0019] The beneficial effects of this application are:

[0020] This application provides an oat amino acid surfactant and its preparation method. On one hand, by selecting a suitable hydrolytic protease to hydrolyze oat protein peptides, the hydrolysis products contain little or no free amino acids that cause the oat amino acid surfactant to have a strong odor and high color. This results in an oat amino acid surfactant with light color and low odor, and the production process does not generate significant waste. On the other hand, the preparation process of this application is carried out in the same reactor, eliminating the need for material transfer. The technical route is simple, the conditions are mild, and the equipment requirements are low, making it suitable for industrial production. In summary, the oat amino acid surfactant obtained by this application has light color, low odor, is mild and non-irritating, is biodegradable, and can be widely used in the personal care field.

[0021] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these accompanying drawings.

[0023] Figure 1 This is a flowchart illustrating the preparation process of the oat amino acid surfactant in Example 1 of this application. Detailed Implementation

[0024] The technical solutions of this application will be clearly and completely described below with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0025] This application provides a method for preparing an oat amino acid surfactant, comprising:

[0026] (1) Dissolve oat protein peptides in deionized water, stir and heat to 50℃~70℃, adjust the pH of the system to 4~10, add hydrolytic protease, stir continuously for 4h~6h, maintain the pH of the system at 4~10, cool to room temperature and dry to obtain oat oligopeptides; wherein, the hydrolytic protease is selected from trypsin or papain.

[0027] (2) Dissolve oat oligopeptides in deionized water, control the temperature at 50℃~70℃, adjust the pH of the system to 11~12, add fatty acyl chloride dropwise, and keep the pH of the system at 11~12. After the dropwise addition is complete, continue to keep the pH of the system at 11~12 and react for 0.5h~1.5h.

[0028] (3) The temperature is controlled at 80℃~100℃ and the pH of the system is controlled at 10~11. The maturation is carried out under an inert atmosphere.

[0029] (4) Cool to 40℃~60℃, add an oxidant for decolorization, and then adjust the pH of the system to 6.5~7.5 to obtain the oat amino acid surfactant. For example, add an oxidant for decolorization at a temperature of 40℃, 45℃, 50℃, 55℃, 60℃ or any two of these values, and then add an acid to adjust the pH of the system to 6.5, 7, 7.5 or any two of these values ​​to obtain the oat amino acid surfactant.

[0030] In step (1), the heating temperature can be 50℃, 55℃, 60℃, 65℃, 70℃, or any two of these values; the system pH can be 4, 5, 6, 6.5, 7.5, 9, 10, or any two of these values; and the stirring time after adding the hydrolytic protease can be 4h, 4.5h, 5h, 5.5h, 6h, or any two of these values. In step (2), the controlled temperature can be 50℃, 55℃, 60℃, 65℃, 70℃, or any two of these values; the system pH can be 11, 11.5, 12, or any two of these values; and the reaction time can be 0.5h, 1h, 1.5h, or any two of these values. In step (3), the aging temperature can be 80℃, 85℃, 90℃, 95℃, 100℃ or any two of these values; the system pH can be 10, 10.5, 11 or any two of these values; and the inert atmosphere can be N2 atmosphere, Ar atmosphere, etc. In step (4), the temperature can be cooled to 40℃, 45℃, 50℃, 55℃, 60℃ or any two of these values; and the pH of the system can be adjusted by adding acid to 6.5, 7, 7.5 or any two of these values.

[0031] Because the enzymatic hydrolysis of oat protein peptides into oat oligopeptides is uncontrollable and difficult to selectively hydrolyze into single oligopeptides, the hydrolysis products are quite complex. Therefore, certain free amino acids during the hydrolysis process are very likely the cause of the high color and strong odor of the final product. By pre-screening different amino acids (such as glycine, alanine, leucine, arginine (Arg), glutamic acid, and lysine (Lys)) and reacting them with fatty acyl chlorides, the inventors discovered that the components causing the off-odor of oat amino acid surfactants are free arginine and lysine. When using the hydrolytic protease within the scope of this application to hydrolyze oat protein peptides, the hydrolytic protease mainly acts on the peptide bond at the carboxyl terminus of arginine or lysine. This suitable hydrolysis site ensures that after hydrolysis, arginine or lysine exists in the form of "-Arg" or "-Lys" at the carboxyl terminus of the hydrolyzed fragment, rather than in a free state. Therefore, by using the hydrolytic protease within the scope of this application for hydrolysis, oat oligopeptides containing little or no free arginine and lysine can be obtained. These oligopeptides are then acylated with fatty acyl chlorides, followed by ripening and oxidative decolorization to finally obtain a light-colored, low-odor oat amino acid surfactant. Moreover, this preparation method is simple to operate, has mild reaction conditions, low equipment requirements, and is suitable for industrial production.

[0032] In this application, the room temperature is 20℃~30℃. For example, the room temperature can be 20℃, 23℃, 25℃, 27℃, 30℃, or a range of any two of these values.

[0033] In step (1) of this application, the drying method is not particularly limited, as long as it can achieve the purpose of this application. For example, vacuum distillation can be used to remove deionized water to obtain dried oat oligopeptides.

[0034] In step (2) of this application, when dissolving oat oligopeptides in deionized water, a water bath can be used for heating and stirring to ensure complete dissolution of the oat oligopeptides. For example, the water bath heating temperature can be 60°C. This application does not impose any particular limitation on the time for adding fatty acyl chloride, as long as the purpose of this application can be achieved. For example, the time for adding fatty acyl chloride can be 2h~2.5h.

[0035] In step (4) of this application, when adding oxidant for decolorization, the reaction can be accelerated by stirring. This application does not make a special limitation on the stirring time when adding oxidant, as long as the purpose of this application can be achieved. For example, the stirring time when adding oxidant can be 0.5h~1h. When adjusting the pH of the system, deionized water can be added at the same time to adjust the solid content of the system to obtain oat amino acid surfactant that can be directly used in the next production step. For example, the solid content of oat amino acid surfactant can be adjusted to 29wt%~31wt%.

[0036] In this application, the stirring method is not particularly limited, as long as it can achieve the purpose of this application. For example, an IKA RW 20 digital stirrer with a stirring speed of 200 rpm to 300 rpm can be used.

[0037] In one embodiment of this application, in step (1), the mass ratio of hydrolytic protease to oat protein polypeptide is 1:100 to 1:150. For example, the mass ratio of hydrolytic protease to oat protein polypeptide can be 1:100, 1:110, 1:120, 1:130, 1:140, 1:150, or a range consisting of any two of these values. Limiting the mass ratio of hydrolytic protease to oat protein polypeptide within the above range is beneficial for the oat protein polypeptide to be fully hydrolyzed into oat oligopeptides and for reducing the generation of hydrolysis impurities, thereby facilitating the obtaining of oat amino acid surfactants with light color and low odor.

[0038] In one embodiment of this application, step (1) further includes activated carbon adsorption. Step (1) is as follows: oat protein peptides are dissolved in deionized water, stirred and heated to 50℃~70℃, the pH of the system is adjusted to 4~10, hydrolytic protease is added, and stirring is continued for 4h~6h while maintaining the pH of the system at 4~10. After cooling to room temperature, activated carbon is added, stirred, filtered, and dried to obtain oat oligopeptides. In step (1) of this application, the stirring time for adding activated carbon is not particularly limited, as long as the purpose of this application can be achieved. For example, the stirring time for adding activated carbon can be 1h~3h. Adding activated carbon and stirring can adsorb impurities in the system and decolorize it, which is beneficial to further reduce the color of the system and obtain oat amino acid surfactants with lighter color. The purpose of the above filtration is to remove activated carbon.

[0039] In one embodiment of this application, in step (1), the mass ratio of activated carbon to oat protein peptides is 1:20 to 1:25. For example, the mass ratio of activated carbon to oat protein peptides can be 1:20, 1:22, 1:25, or a range consisting of any two of these values. Controlling the mass ratio of activated carbon to oat protein peptides within the above range not only allows for sufficient adsorption and decolorization of impurities in the system but also helps reduce filtration time and improve production efficiency.

[0040] In one embodiment of this application, in step (2), the fatty acyl chloride is selected from at least one of octanoyl chloride, decanoyl chloride, lauroyl chloride, and palmitoyl chloride. In another embodiment of this application, in step (2), the mass ratio of oat oligopeptide to fatty acyl chloride is 43:18 to 43:35. For example, the mass ratio of oat oligopeptide to fatty acyl chloride can be 43:18, 43:20, 43:25, 43:30, 43:35, or a range consisting of any two of these values. Using the above-mentioned types of fatty acyl chloride and controlling the mass ratio of oat oligopeptide to fatty acyl chloride within the above-mentioned range is beneficial to the full reaction of oat oligopeptide and fatty acyl chloride, resulting in a light-colored, low-odor, and mild non-irritating oat amino acid surfactant.

[0041] In one embodiment of this application, the maturation time in step (3) is 2h to 4h. For example, the maturation time can be 2h, 2.5h, 3h, 3.5h, 4h, or a range of any two of these values. Controlling the maturation time within the above range is beneficial for promoting the complete acylation reaction between oat oligopeptides and fatty acyl chlorides, reducing reaction byproducts, and simplifying subsequent processing procedures.

[0042] In one embodiment of this application, in step (4), the oxidant is selected from at least one of hydrogen peroxide, peracetic acid, sodium hypochlorite, perchloric acid, and sodium percarbonate. The above-mentioned oxidants can decolorize the system, which is beneficial for obtaining a light-colored oat amino acid surfactant.

[0043] In one embodiment of this application, in step (4), the oxidant is selected from hydrogen peroxide, and the concentration of hydrogen peroxide is 0.5wt% to 1wt%. For example, the concentration of hydrogen peroxide can be 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, or a range consisting of any two of these values. Using the above-mentioned hydrogen peroxide can not only further decolorize the system, but also does not introduce other impurities, and the oxidation products are non-toxic and harmless.

[0044] In this application, the acid used to adjust the pH of the system is selected from at least one of concentrated hydrochloric acid, sulfuric acid solution, and citric acid solution, wherein the concentration of concentrated hydrochloric acid is 33wt%~36wt%, the concentration of sulfuric acid solution is 45wt%~55wt%, and the concentration of citric acid solution is 95wt%~98wt%. The base is selected from sodium hydroxide solution and potassium hydroxide solution, wherein the concentration of sodium hydroxide solution is 30wt%~32wt%, and the concentration of potassium hydroxide solution is 30wt%~32wt%.

[0045] In this application, oat protein polypeptides, trypsin or papain, fatty acyl chloride, activated carbon and oxidant are all commercially available conventional substances. This application does not have any particular limitation on their source, as long as they can achieve the purpose of this application.

[0046] The second aspect of this application provides an oat amino acid surfactant prepared according to the preparation method described in the first aspect of this application. The oat amino acid surfactant of this application has light color, low odor, is mild and non-irritating, and is biodegradable.

[0047] Example:

[0048] The embodiments and comparative examples provided below illustrate the implementation of this application in more detail. Various tests and evaluations were conducted according to the methods described below. Furthermore, unless otherwise specified, "parts" and "%" are quality standards.

[0049] Test methods and equipment:

[0050] Oat amino acid surfactant color test:

[0051] Referring to GB / T 3143-1982, "Determination of Color of Liquid Chemical Products (Hazen Units - Platinum-Cobalt Color Number)," the platinum-cobalt color of oat amino acid surfactants was tested using a BYK LCM-IV liquid colorimeter. A lower platinum-cobalt color indicates a lighter color of the oat amino acids.

[0052] Oat amino acid surfactant odor test:

[0053] 150 ml of oat amino acid surfactant was placed into 200 ml glass bottles and placed in ovens at room temperature (25°C) and 80°C for 2 hours respectively. After removal, 10 people each smelled the oat amino acid surfactant, with a 10-minute interval between two smell tests. Odor ratings were given according to the standards in the table below, and the average of each person's rating was taken as the final result.

[0054] Example 1:

[0055] Figure 1 The preparation process of the oat amino acid surfactant in Example 1 of this application is shown in the following flowchart:

[0056] Weigh 70g of oat protein peptides (Benhe Bio, molecular weight approximately 500 Da) and dissolve them in 240ml of deionized water. Stir and heat to 60℃, adjust the pH to approximately 7, add 0.5g of papain, stir continuously for 5h, and maintain the pH of the system not higher than 7. After the reaction is complete, cool to room temperature, add 3g of activated carbon and stir for 2h, filter to remove the activated carbon, and use vacuum distillation to remove the deionized water to obtain dried oat oligopeptides.

[0057] Take 43g of the above-mentioned oat oligopeptides into a five-necked flask, add 125ml of deionized water, adjust the water bath temperature to 60℃, and stir for 15min until the oat oligopeptides are completely dissolved, obtaining a clear and transparent solution. Control the temperature at 60℃, add 32wt% sodium hydroxide aqueous solution to adjust the pH of the system to 11.5, and then simultaneously add 32wt% sodium hydroxide aqueous solution and 25g lauroyl chloride, maintaining the pH of the system at 11.5. Control the lauroyl chloride addition time to 2h, and after the addition is complete, maintain the above pH and continue the reaction for 1h; then control the system temperature at 90℃ and pH at 10.5, and age under N2 atmosphere for 3h; after aging, cool the system to 50℃, add 0.6wt% hydrogen peroxide, and stir for 1h. After decolorization, add concentrated hydrochloric acid and deionized water to adjust the pH of the system to approximately 7, and the solid content to 30wt%, to obtain the oat amino acid surfactant.

[0058] Example 2:

[0059] Except for replacing lauroyl chloride with a mixture of lauroyl chloride, decanoyl chloride and octanoyl chloride, and the mass ratio of lauroyl chloride, decanoyl chloride and octanoyl chloride being 8:1:1, everything else is the same as in Example 1.

[0060] Example 3:

[0061] Except for replacing papain with trypsin and adjusting the pH of the hydrolyzed oat protein peptides to approximately 8, the rest is the same as in Example 1.

[0062] Example 4:

[0063] Except for adjusting the amount of oat protein peptides to 50g, the rest is the same as in Example 1.

[0064] Example 5:

[0065] Except for adjusting the amount of oat protein peptides to 75g, the rest is the same as in Example 1.

[0066] Example 6:

[0067] Except for adjusting the amount of lauroyl chloride to 18g, the rest is the same as in Example 1.

[0068] Example 7:

[0069] Except for adjusting the amount of lauroyl chloride to 35g, the rest is the same as in Example 1.

[0070] Comparative Example 1:

[0071] Except for replacing papain with pepsin, the rest is the same as in Example 1.

[0072] Comparative Example 2:

[0073] Except for replacing papain with alkaline protease, the rest is the same as in Example 1.

[0074] The color and odor parameters of each embodiment and comparative example are shown in Table 1.

[0075] Table 1:

[0076] As can be seen from Examples 1 to 7 and Comparative Examples 1 and 2, using hydrolytic proteases within the scope of this application to hydrolyze oat protein polypeptides can yield oat amino acid surfactants with light color and low odor.

[0077] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for preparing an oat amino acid surfactant, comprising: (1) Dissolve oat protein peptides in deionized water, stir and heat to 50℃~70℃, adjust the pH of the system to 4~10, add hydrolytic protease, stir continuously for 4h~6h, maintain the pH of the system at 4~10, cool to room temperature and dry to obtain oat oligopeptides; wherein, the hydrolytic protease is selected from trypsin or papain. (2) Dissolve the oat oligopeptide in deionized water, control the temperature at 50℃~70℃, adjust the pH of the system to 11~12, add fatty acyl chloride dropwise, and keep the pH of the system at 11~12. After the dropwise addition is complete, continue to keep the pH of the system at 11~12 and react for 0.5h~1.5h. (3) The temperature is controlled at 80℃~100℃ and the pH of the system is controlled at 10~11. The maturation is carried out under an inert atmosphere. (4) Cool to 40℃~60℃, add oxidant for decolorization, and then adjust the pH of the system to 6.5~7.5 to obtain oat amino acid surfactant.

2. The preparation method according to claim 1, wherein, In step (1), the mass ratio of the hydrolytic protease to the oat protein polypeptide is 1:100 to 1:

150.

3. The preparation method according to claim 1, wherein, Step (1) further includes activated carbon adsorption. Step (1) is as follows: oat protein peptides are dissolved in deionized water, stirred and heated to 50℃~70℃, the pH of the system is adjusted to 4~10, hydrolytic protease is added, stirring is continued for 4h~6h, and the pH of the system is maintained at 4~10. After cooling to room temperature, activated carbon is added, stirred, filtered, and dried to obtain oat oligopeptides.

4. The preparation method according to claim 3, wherein, In step (1), the mass ratio of activated carbon to oat protein polypeptide is 1:20 to 1:

25.

5. The preparation method according to claim 1, wherein, In step (2), the fatty acyl chloride is selected from at least one of octanoyl chloride, decanoyl chloride, lauroyl chloride and palmitoyl chloride.

6. The preparation method according to claim 1, wherein, In step (2), the mass ratio of the oat oligopeptide to the fatty acyl chloride is 43:18 to 43:

35.

7. The preparation method according to claim 1, wherein, In step (3), the ripening time is 2h to 4h.

8. The preparation method according to claim 1, wherein, In step (4), the oxidant is selected from at least one of hydrogen peroxide, peracetic acid, sodium hypochlorite, perchloric acid and sodium percarbonate.

9. The preparation method according to claim 1, wherein, In step (4), the oxidant is selected from hydrogen peroxide, and the concentration of the hydrogen peroxide is 0.5wt%~1wt%.

10. An oat amino acid surfactant prepared by any one of claims 1 to 9.

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