阅读说明：本技术 一种提取板栗壳中板栗壳棕色素的方法和在染发剂中的应用 (Method for extracting chestnut shell brown pigment from chestnut shells and application of chestnut shells brown pigment in hair dye ) 是由 李春美 朱婷 沈齐若男 于 2021-06-24 设计创作，主要内容包括：本发明提供了一种提取板栗壳中板栗壳棕色素的方法和在染发剂中的应用,该提取方法包括,将粉末状板栗壳加入到含有离子液体和断键剂的乙醇水溶液中,超声提取,离心分离后取上清液,即得板栗壳棕色素提取液。本发明所提供的提取方法采用素有绿色溶剂之称的离子液体与乙醇水溶液组成的混合溶剂代替传统提取剂,加入一定的断键剂,辅以超声技术,提取效率高且效果好,具有良好的实际应用价值；利用本发明所提供的方法提取的板栗壳棕色素制备得到的染发剂染发后,头发经反复水洗及紫外辐照后没有明显的褪色行为,头发表面毛鳞片较为平整,鲜有翘起现象,头发内部结构的破坏程度较小,较好的保持了头发的完整性。(The invention provides a method for extracting chestnut shell brown pigment from chestnut shells and application of the chestnut shell brown pigment in hair dye. The extraction method provided by the invention adopts the mixed solvent composed of the ionic liquid and the ethanol water solution which are called green solvents to replace the traditional extractant, adds a certain bond breaking agent and is assisted by the ultrasonic technology, has high extraction efficiency and good effect, and has good practical application value; after the hair dye prepared by the chestnut shell brown pigment extracted by the method is used for dyeing hair, the hair has no obvious fading behavior after repeated washing and ultraviolet irradiation, hair scales on the surface of the hair are relatively flat and have fresh tilting phenomenon, the damage degree of the internal structure of the hair is relatively small, and the integrity of the hair is well maintained.)

1. A method for extracting brown pigment from chestnut shells in chestnut shells is characterized in that,

the method comprises the following steps: adding powdered chestnut shells into an ethanol water solution containing ionic liquid and bond breaking agent, performing ultrasonic extraction, performing centrifugal separation, and taking supernatant to obtain chestnut shell brown pigment extracting solution.

2. A method for extracting chestnut shell brown pigment from chestnut shells as claimed in claim 1,

the bond breaking agent is sodium dodecyl sulfate and/or urea, preferably a mixture of the sodium dodecyl sulfate and the urea.

3. A method for extracting chestnut shell brown pigment from chestnut shells as claimed in claim 1,

the ionic liquid is one or more of [ Bmim ] OAc, [ Bmim ] Cl, [ Emim ] OAc, [ Emim ] Cl, [ Bmim ] BF4 and [ Hmim ] OAc, and is preferably [ Bmim ] OAc.

4. A method for extracting chestnut shell brown pigment according to any one of claims 1-3, characterized in that,

the volume fraction of ethanol in the ethanol water solution is 20-45%, and preferably 40%.

5. A method for extracting chestnut shell brown pigment from chestnut shells as claimed in claim 4,

the adding volume of the ionic liquid is 0.15-0.5 time of that of the ethanol water solution, and preferably 0.25-0.5 time;

and/or the concentration of the sodium dodecyl sulfate is 0.3-0.5 wt%, and the concentration of the urea is 2-3 wt%.

Preferably, the concentration of the sodium lauryl sulfate is 0.4 wt% and the concentration of the urea is 2.5 wt%.

6. A method for extracting chestnut shell brown pigment from chestnut shells according to claim 4 or 5,

the ratio of the added amount of the powdery chestnut shells to the added amount of the ethanol solution is controlled to be 1: 25-40.

7. A method for extracting chestnut shell brown pigment according to any one of claims 1 to 6, characterized in that,

the ultrasonic time of the ultrasonic extraction is 45-60min, preferably 50 min;

and/or the temperature of ultrasonic extraction is 75-90 ℃, preferably 80 ℃;

and/or the ultrasonic power of the ultrasonic extraction is 300-490W, preferably 350W.

8. Chestnut shell brown pigment extracted by the extraction method according to any one of claims 1 to 7.

9. Use of the extraction process according to any one of claims 1 to 7 or the chestnut shell brown pigment according to claim 8 in hair coloring agents.

10. Use according to claim 9,

the applications include reducing hair damage from hair dyeing, improving hair integrity, water wash stability and ultraviolet radiation stability after dyeing, and providing a repair effect to bleached hair.

Technical Field

The invention relates to the technical field of extraction of plant active ingredients, and particularly relates to a method for extracting chestnut shell brown pigment from chestnut shells and application of the chestnut shell brown pigment in hair dye.

Background

Chestnut is originated from China and belongs to the genus of chestnut of Fagaceae; the use of chestnut as a medicine is recorded in medical ancient books of all ages, and the part of the chestnut as the medicine comprises the root, bark, leaf, flower, epicarp, endocarp, involucre and the like of the chestnut.

The chestnut shell is the epicarp of chestnut, has sweet, astringent and mild properties, has the efficacy of lowering adverse qi and stopping bleeding, and is mainly used for treating regurgitation, epistaxis, hematochezia and other symptoms. The chestnut shell brown pigment is a natural pigment extracted from chestnut shells, has the characteristics of good water solubility, strong coloring power, good stability, strong antioxidation and bacteriostasis effects and the like, is one of rare natural pigments with stable properties in the world at present, and has high development value.

In the prior art, the extraction method of chestnut shell brown pigment in chestnut shell comprises the following steps: steam distillation, alkaline water or alkaline diluted alcohol extraction, solvent extraction, supercritical fluid extraction, microwave method, and the like, and there are many problems as follows: the crude extract has poor water solubility, and precipitates exist after the crude extract is dissolved; resin adsorption is adopted for purification and refining, the process is complex, and the cost is high; the extractant has high concentration of alkaline solution, relates to the problem of subsequent recovery, is easy to cause environmental pollution, has certain toxicity, and does not accord with the green chemical concept.

In conclusion, research and development of an efficient and environment-friendly method for extracting brown pigment from chestnut shells in the chestnut shells are key technical problems to be solved urgently in the field.

Disclosure of Invention

The invention aims to provide a method for extracting chestnut shell brown pigment from chestnut shells and application of the chestnut shell brown pigment in hair dye.

The invention adopts the following technical scheme:

a method for extracting chestnut shell brown pigment from chestnut shells comprises the following steps:

adding powdered chestnut shells into an ethanol water solution containing ionic liquid and bond breaking agent, performing ultrasonic extraction, performing centrifugal separation, and taking supernatant to obtain chestnut shell brown pigment extracting solution.

In the technical scheme, the bond breaking agent is sodium dodecyl sulfate and/or urea.

In a preferred embodiment of the invention, the bond breaking agent is a mixture of sodium lauryl sulfate and urea.

In the technical scheme, the ionic liquid is one or more of [ Bmim ] OAc, [ Bmim ] Cl, [ Emim ] OAc, [ Emim ] Cl, [ Bmim ] BF4 and [ Hmim ] OAc.

In a preferred embodiment of the invention, the ionic liquid is [ Bmim ] OAc.

Further, in the above technical solution, the volume fraction of ethanol in the ethanol aqueous solution is 20-45%.

In a preferred embodiment of the invention, the volume fraction of ethanol in the aqueous ethanol solution is 40%.

Still further, in the above technical solution, the volume of the added ionic liquid is 0.15-0.5 times of the ethanol aqueous solution.

In a preferred embodiment of the present invention, the ionic liquid is added in an amount of 0.25 to 0.5 times by volume to the aqueous ethanol solution.

Still further, in the above technical solution, the concentration of the sodium dodecyl sulfate is 0.3-0.5 wt%, and the concentration of the urea is 2-3 wt%.

In a preferred embodiment of the invention, the sodium lauryl sulfate concentration is 0.4 wt% and the urea concentration is 2.5 wt%.

Still further, in the above technical solution, the ratio of the added amount of the powdered chestnut shells and the ethanol solution is controlled to be 1: 25-40.

Still further, in the above technical solution, the ultrasound time of the ultrasound extraction is 45-60min, preferably 50 min.

Still further, in the above technical solution, the temperature of the ultrasonic extraction is 75-90 ℃, preferably 80 ℃.

Still further, in the above technical solution, the ultrasonic power of the ultrasonic extraction is 300-490W, preferably 350W.

The invention also provides the chestnut shell brown pigment extracted by the extraction method.

The invention also provides the extraction method or the application of the chestnut shell brown pigment in hair dye.

Specifically, the applications include reducing hair damage from hair coloring, improving hair integrity, water wash stability and ultraviolet radiation stability after coloring, and providing a repair effect to bleached hair.

Compared with the prior art, the invention has the beneficial effects that:

(1) the method for extracting the brown pigment of the chestnut shells in the chestnut shells adopts the mixed solvent consisting of the ionic liquid and the ethanol water solution which are called green solvents to replace the traditional extractant, adds a certain bond breaking agent and is assisted by the ultrasonic technology, has high extraction efficiency and good effect, can recycle the used ethanol solvent, has little influence on the environment in the extraction process, and has good practical application value;

(2) after the hair dye prepared by the chestnut shell brown pigment extracted by the method is used for dyeing hair, the hair has no obvious fading behavior after repeated washing and ultraviolet irradiation, hair scales on the surface of the hair are relatively flat and have fresh tilting phenomenon, the damage degree of the internal structure of the hair is relatively small, and the integrity of the hair is well maintained.

Drawings

FIG. 1 is a standard curve of total polyphenols in chestnut shell brown pigment plotted in the example of the present invention;

FIG. 2 shows the yields of SDS in different concentrations in example 1 according to the invention;

FIG. 3 shows the yields of urea at different concentrations in example 2 according to the present invention;

FIG. 4 shows the yields of different feed-to-liquid ratios in example 3 of the present invention;

FIG. 5 shows the yields of ionic liquids at different concentrations in example 4 according to the present invention;

FIG. 6 shows the yields of ionic liquids of different types in example 5;

FIG. 7 shows the yields at different sonication times in example 6 according to the present invention;

FIG. 8 shows the yields for different ethanol volume fractions in example 7 according to the present invention;

FIG. 9 shows the yields at different ultrasonic temperatures in example 8 of the present invention;

FIG. 10 shows the yields of the samples obtained in example 9 of the present invention at different ultrasonic powers;

FIG. 11 shows the yields under different process conditions in the examples of the present invention;

FIG. 12 is a graph showing the results of testing the lightness and tensile strength of hair dyed by different hair dyes in the example of the present invention;

FIG. 13 is an apparent morphology of bleached hair purchased in an example of the invention;

FIG. 14 is a drawing showing the appearance of hair dyed by natural chestnut shell brown pigment hair dye prepared from chestnut shell pigment extract according to the best process conditions in example 10;

FIG. 15 is an apparent shape of hair dyed by natural chestnut shell brown pigment hair dye prepared from chestnut shell pigment extract prepared by using a conventional organic solvent ethanol solution in the embodiment of the present invention;

FIG. 16 is the appearance of hair dyed by natural chestnut shell brown pigment hair dye prepared from chestnut shell pigment extract prepared by traditional NaOH solution in the embodiment of the present invention.

Detailed Description

The present invention is further described in detail below with reference to specific examples so that those skilled in the art can more clearly understand the present invention.

The following examples are given for the purpose of illustration only and are not intended to limit the scope of the invention.

All other embodiments obtained by a person skilled in the art based on the specific embodiments of the present invention without any inventive step are within the scope of the present invention.

In the examples of the present invention, unless otherwise specified, all technical means used are conventional means well known to those skilled in the art. In the examples of the present invention, the raw materials used were all commercially available products.

In the embodiment of the invention, the method for drawing the standard curve of the total polyphenol in the chestnut shell brown pigment is as follows:

precisely weighing 10.00mg of gallic acid standard substance in a 50ml volumetric flask, dissolving with water, fixing the volume to a certain scale, and shaking up to obtain gallic acid reference substance solution; accurately weighing 0, 1.00, 1.50, 2.00, 2.50, 3.00, 3.50, 4.50, 5.00, 7.00 and 8.00mL of gallic acid reference solution, diluting into stock solutions with different concentration gradients in a 10mL volumetric flask, respectively taking 0.2mL of the stock solutions, placing in a test tube, adding 0.50mL of Folin-Ciocalteu reagent, fully shaking, standing for 5min, adding 3.00mL of 7.5 wt% Na₂CO₃Shaking the solution evenly, and reacting for 60min at room temperature in the dark; taking the corresponding reagent as a blank, measuring the light absorption value at 760nm, drawing a standard curve by taking the light absorption as a vertical coordinate and the concentration as a horizontal coordinate, and obtaining the result shown in figure 1; the standard curve is that y is 4.3052x-0.0067, R²＝0.999。

Example 1

In this example, the effect of different Sodium Dodecyl Sulfate (SDS) concentrations on the extraction of chestnut shell brown pigment in chestnut shell was compared, and the specific process was as follows:

0.2g of chestnut shell powder is respectively taken, 0, 0.2, 0.4, 0.5, 0.6 and 0.8wt percent of SDS is added, and the other conditions are fixed: particle size of 60 meshes, 15 wt% of urea and V_[Bmim]OAc/V_{40% ethanol}Is 1:1, the ratio of material to liquid is 1:10g/ml, ultrasonic temperature 80 ℃, time 70min, power 350W, centrifuging and taking supernatant.

Determining the yield under different SDS concentrations; the results are shown in FIG. 2.

As can be seen from the analysis of FIG. 2, the yield increases with the increase of SDS concentration, and the yield is maximized when the SDS concentration is 0.4 wt%, and decreases after exceeding 0.4%; the reason why the addition of the SDS increases the yield is probably that the SDS has a special amphiphilic molecular structure, can obviously reduce the interfacial tension between the extraction solution and the cell membrane, is favorable for the extraction solution to enter the cell wall through capillary penetration, and dissolves more polyphenol substances.

Example 2

This example contrasts the influence of different urea concentrations to extracting chestnut shell brown pigment in the chestnut shell, and the concrete process is as follows:

respectively taking 0.2g of chestnut shell powder, adding 0, 2.5, 5, 10, 15 and 20 wt% of urea, and fixing other conditions: particle size 60 mesh, 0.4 wt% SDS, V_[Bmim]OAc/V_{40% ethanol}Is 1:1, the ratio of material to liquid is 1:10g/ml, ultrasonic temperature 80 ℃, time 70min, power 350W, centrifuging and taking supernatant.

Determining the yield under different urea concentrations; the results are shown in FIG. 3.

Analysis of FIG. 3 shows that the yield increases with increasing urea concentration, and is maximal at a urea concentration of 2.5 wt%, and decreases beyond 2.5%.

Example 3

In this embodiment, the influence of different feed liquid ratios on the extraction of brown pigment from chestnut shells in chestnut shells is compared, and the specific process is as follows:

respectively taking 0.2g of chestnut shell powder with the particle size of 60 meshes, the material-liquid ratio of 1:10, 1:20, 1:30, 1:40 and 1:50g/ml, and fixing the other conditions: 0.4 wt% SDS, 2.5 wt% urea, V_[Bmim]OAc/V_{40% ethanol}The ultrasonic temperature is 1:1, the ultrasonic temperature is 80 ℃, the time is 70min, the power is 350W, and supernatant is obtained after centrifugal separation.

Determining the yield under different feed-liquid ratios; the results are shown in FIG. 4.

As can be seen from the analysis of FIG. 4, when the feed-to-liquid ratio is from 1:10 to 1:30, the yield is significantly increased, probably because the amount of the extracting solution is increased, so that the chestnut shell polyphenol is more easily extracted. But when the ratio of the material to the liquid is 1:40, the yield is not changed greatly, no obvious difference exists, and the trend is stable; and when the ratio of the material to the liquid is more than 1:40, the material to liquid also has a descending trend, so that the yield cannot be improved even if the dosage of the solvent is continuously increased, the solvent consumption is increased, the subsequent solvent recovery is not facilitated, and the economic and efficient requirements are not met, so that the optimal solid-liquid ratio is selected to be 1: 30.

Example 4

This example contrasts the influence of different ionic liquid concentrations to extracting chestnut shell brown pigment in the chestnut shell, and the concrete process is as follows:

respectively taking 0.2g of chestnut shell powder with particle size of 60 meshes and V_[Bmim]OAc/V_{40% ethanol}1:15, 1:9, 1:7, 1:4, 1:1 [ Bmim ]]Using OAc ionic liquid solution as an extractant, and fixing other conditions: 0.4 wt% SDS, 2.5 wt% urea, the feed liquid ratio is 1:10g/ml, the ultrasonic temperature is 80 ℃, the time is 70min, the power is 350W, and supernatant is obtained after centrifugal separation.

Determining the yield under different ionic liquid concentrations; the results are shown in FIG. 5.

Analyzing the results of FIG. 5, it can be seen that when V is_[Bmim]OAc/V_{40% ethanol}The yield is obviously increased when the ratio is gradually increased from 1:15 to 1:4, and when V is increased_[Bmim]OAc/V_{40% ethanol}Above 1:4, the yield decreases, indicating that even further increases in [ Bmim ]]The yield of OAc is not increased but decreased because when V is increased_[Bmim]OAc/V_{40% ethanol}Less than 1:4, [ Bmim ]]The concentration of OAc is too low, the intermolecular attraction is weak, the extraction of chestnut shell polyphenol is incomplete when V is_[Bmim]OAc/V_{40% ethanol}When the ratio is more than 1:4, the viscosity of the solvent is greatly increased, so that the chestnut shell powder is unevenly dispersed in the solvent, and the chestnut shell polyphenol cannot be fully extracted, so that V is extracted_[Bmim]OAc/V_{40% ethanol}The ratio was set to 1: 4.

Example 5

This example contrasts the influence of different kinds of ionic liquids on extracting chestnut shell brown pigment in chestnut shell, and the specific process is as follows:

respectively taking 0.2g of chestnut shell powder with particle size of 60 meshes to obtain [ Bmim ]]OAc、[Bmim]Cl、[Emim]OAc、[Emim]Cl、[Hmim]OAc、[Bmim]BF4 ionic liquid is used as an extracting agent, and other conditions are fixed: 0.4 wt% SDS, 2.5 wt% urea, feed liquid ratio 1:10g/ml, ionic liquid concentration V_{Ionic liquids}/V_{40% ethanol}The solution is 1:4, the ultrasonic temperature is 80 ℃, the extraction time is 70min, the power is 350W, and the supernatant is obtained after centrifugal separation.

Determining the yield of different types of ionic liquids; the results are shown in FIG. 6.

Analyzing the results of fig. 6, it can be seen that the yield is greater as the cationic alkyl chain is lengthened from 1-ethyl-3-methylimidazole to 1-butyl-3-methylimidazole, and the yield is decreased when the cationic alkyl chain is further increased from 1-butyl-3-methylimidazole to 1-hexyl-3-methylimidazole. The ionic liquid with the cation of 1-butyl-3-methylimidazole is suitable for extracting the chestnut shell pigment, the alkyl chain is too short, and after the ionic liquid and cell wall cellulose form a hydrogen bond, the gaps of a cellulose microfibril network structure are too small, so that the dissolution of active ingredients is not facilitated; the alkyl chain is too long, the outstanding steric effect weakens the dispersion force between imidazole and aromatic ring, secondly, the alkyl chain is lengthened, so that the viscosity of the ionic liquid is relatively increased, the intermolecular attraction is hindered, and the chestnut shell powder cannot be uniformly dispersed in the solvent, thus being not beneficial to the dissolution of active ingredients. When the cations are the same, acetate ions in the anions have better effect, and because the hydrogen bonds of the acetate ions are stronger in alkalinity, the hydrogen bond interaction in the polymer chain can be effectively weakened.

Example 6

In this embodiment, the influence of different ultrasonic time on the extraction of chestnut shell brown pigment in chestnut shell is compared, and the specific process is as follows:

respectively taking 0.2g of chestnut shell powder, wherein the particle size is 60 meshes, the ultrasonic time is 30 min, 40 min, 50min, 60min, 70min and 80min, and fixing other conditions: bond breaking agent: 0.4% SDS, 2.5% urea, V_[Bmim]OAc/V_{40% ethanol}The ratio of material to liquid is 1:4, the ultrasonic temperature is 80 ℃, the power is 350W, and supernatant is obtained after centrifugal separation.

Determining the yield under different ultrasonic times; the results are shown in FIG. 7.

Analysis of fig. 7 shows that the extraction time increases and the yield tends to increase and decrease. When the ultrasonic time is 50min, the yield is highest. When the ultrasonic time is less than 50min, the extraction of the chestnut shell polyphenol is incomplete, and when the ultrasonic time is more than 50min, the chestnut shell polyphenol can be damaged by the excessively strong cavitation, so that the yield is reduced, the economy and the efficiency are comprehensively considered, and the optimal ultrasonic time is set to be 50 min.

Example 7

In this example, the effect of different ethanol volume fractions on the extraction of chestnut shell brown pigment in chestnut shell is compared, and the specific process is as follows:

respectively collecting 0.2g chestnut shell powder with particle size of 60 mesh and ethanol volume fraction of 0, 25, 40, 50, 60, 75, 100% [ Bmim ]]Using OAc ionic liquid solution as an extractant, and fixing other conditions: bond breaking agent: 0.4 percent of SDS, 2.5 percent of urea, the feed-liquid ratio is 1:30g/ml, and the concentration of ionic liquid is V_[Bmim]OAc/V_{40% ethanol}The ultrasonic temperature is 80 ℃, the extraction time is 50min, the power is 350W, and supernatant is obtained after centrifugal separation.

Determining the yield under different ethanol volume fractions; the results are shown in FIG. 8.

As can be seen from analysis of fig. 8, the ethanol volume fraction increases, the yield shows a trend of increasing first and then decreasing, and at a volume fraction of 40%, the yield is the highest and is significantly different from other volume fractions, so the ethanol volume fraction is set to 40%.

Example 8

This example contrasts the influence of different ultrasonic temperatures to extracting chestnut shell brown pigment in chestnut shell, and the concrete process is as follows:

respectively taking 0.2g of chestnut shell powder, wherein the particle size is 60 meshes, the ultrasonic temperature is 40, 50, 60, 70 and 80 ℃, and the other conditions are fixed: 0.4 wt% SDS, 2.5 wt% urea, V_[Bmim]OAc/V_{40% ethanol}The ratio of material to liquid is 1:4, the ultrasonic time is 50min, the power is 350W, and supernatant is obtained after centrifugal separation.

Determining the yield under different ultrasonic temperatures; the results are shown in FIG. 9.

Analysis of fig. 9 shows that, when the temperature is increased from 40 ℃ to 80 ℃, the thermal motion in the solvent is more severe than that when the temperature is low when the temperature is high, so that the reaction is more severe, the cell wall rupture of the chestnut shells is accelerated, and the target product can be better extracted, namely the whole mass transfer process is accelerated; on the other hand, when the temperature exceeds 80 ℃, the high temperature causes destruction of brown pigment of the extracted chestnut shells, thereby causing a decrease in yield. Therefore, the temperature of 80 ℃ was selected as the optimum extraction temperature.

Example 9

In this embodiment, the influence of different ultrasonic powers on extracting chestnut shell brown pigment in chestnut shell is compared, and the specific process is as follows:

respectively taking 0.2g of chestnut shell powder, wherein the particle size is 60 meshes, the ultrasonic power is 70, 210, 350, 490 and 630W, and the other conditions are fixed: bond breaking agent: 0.4 wt% SDS, 2.5 wt% urea, V_[Bmim]OAc/V_{40% ethanol}The ratio of material to liquid is 1:4, the ultrasonic temperature is 80 ℃, the time is 50min, and supernatant is obtained after centrifugal separation.

Determining the yield under different ultrasonic powers; the results are shown in FIG. 10.

Analysis of fig. 10 shows that the yield is a slow trend with increasing ultrasonic power, because the cavitation effect of the ultrasonic wave increases the destructive effect on the chestnut shell cell walls with increasing power. But the difference of the yield in the whole power range is not obvious, so the ultrasonic power is set to be 350W by comprehensively considering the economy and the energy consumption.

Example 10

On the basis of the single-factor experiments of the embodiments 1 to 9, the factor experiments are designed for 12 times, the center combination experiments are repeated for 5 times, and the extraction process parameters of the chestnut shell brown pigment are optimized by using a response surface method.

Further, the data in Table 1 below were analyzed using Design-Ex-pert 8.0.6 software, using yield as an index.

The regression equation obtained by analysis is: y ═ 9.96+5.12A +1.77B +14.39C-1.45AB-0.38AC-0.32BC-10.62A²-4.19B²-11.39C²。

TABLE 1 design and results of response surface method experiments

Analysis of variance is shown in table 2 below.

TABLE 2 analysis of variance of regression models

As can be seen from Table 2, the model P is less than 0.0001, reaching a highly significant level; and the mismatching value (P-0.0735 > 0.05) was not significant; the CV of the model variation coefficient is 2.58%, the CV value is low, the confidence coefficient is high, and the model equation can better reflect the real experimental value; coefficient of correlation R²Determining the coefficient R0.9950² _adj0.9886, indicating that the model built fits well. The influence of all factors on the yield is as follows in sequence: the feed-liquid ratio is greater than the SDS concentration and greater than the urea concentration. A. C, A²、B²、C²The method achieves a very significant level (P is less than 0.01), B achieves a significant level, and the others are not significant, namely, the factors are not simple linear relations to the yield, but have certain interaction.

Further, response surface analysis shows that the optimal extraction process conditions of the Chinese chestnut shell pigment are as follows: the SDS concentration is 0.44 wt%, the urea concentration is 2.87 wt%, the liquid-material ratio is 36.26mL/g, and the yield can theoretically reach 75.1547 mg/g. The verification experiment is carried out under the process condition, the actually obtained yield is 71.5977mg/g, and the difference between the actually obtained yield and the theoretical value is within 5 percent; the extraction process parameters obtained by adopting the response surface method for optimization are reliable, and have certain practical value.

Comparative example 1

The comparative example provides a method for extracting brown pigment from chestnut shells, the specific process is similar to the best extraction process of example 10, and the difference is that no SDS is added, and the steps are as follows:

taking 0.2g of chestnut shell powder with the grain diameter of 60 meshes, adding 2.87 wt% of urea and V_[Bmim]OAc/V_{40% ethanol}Is 1:1, the ratio of material to liquid is 1: 36.26g/ml, ultrasonic temperature 80 ℃, time 50min, power 350W, centrifuging and taking supernatant.

Comparative example 2

The present comparative example provides a method for extracting chestnut shell brown pigment from chestnut shells, the specific process is similar to the best extraction process of example 10, except that no urea is added, the steps are as follows:

taking 0.2g chestnut shell powder with particle size of 60 mesh, adding 0.44 wt% SDS, V_[Bmim]OAc/V_{40% ethanol}Is 1:1, the ratio of material to liquid is 1: 36.26g/ml, ultrasonic temperature 80 ℃, time 50min, power 350W, centrifuging and taking supernatant.

The yields of the optimum process conditions of example 10, the process conditions of comparative example 1 (no addition of SDS), the process conditions of comparative example 2 (no addition of urea), the process conditions of conventional organic solvent ethanol solution extraction, and the process conditions of conventional NaOH solution extraction were measured, respectively, and the results are shown in FIG. 11.

As can be seen from fig. 11, the yields of the optimum process conditions of example 10 are respectively increased by 42.24% and 38.70% compared to the conventional NaOH solution extraction and the conventional organic solvent ethanol solution extraction, and the yields of the optimum process conditions of example 10 are also significantly higher than those of comparative example 1 (no addition of SDS) and comparative example 2 (no addition of urea), which indicates that the yields are significantly increased after the addition of both urea and SDS.

Effect verification

1g of bleached hair was taken, and the optimal process conditions of example 10, the chestnut shell pigment extract solutions prepared in comparative examples 1-2, and the chestnut shell pigment extract solutions (same concentration) prepared by extracting traditional organic solvent ethanol solutions and NaOH solutions were used to prepare natural chestnut shell brown pigment hair dyes (same and known in composition, different only in pigment source), and the hair dyes were dyed in the optimal hair dyeing manner to compare the hair dyeing effects.

1. Influence on color and tensile strength of dyed hair

The hair dyeing effect of the hair dyed by the natural chestnut shell brown pigment hair dye prepared by adopting different types of chestnut shell pigment extracting solutions is respectively detected, and the results are shown in the following table 3.

TABLE 3 Effect on hair dyeing

The lightness and tensile strength of the hair dyed by the natural chestnut shell brown pigment hair dye prepared by adopting different types of chestnut shell pigment extracting solutions are respectively detected, and the result is shown in fig. 12.

As can be seen from Table 3 and FIG. 12, the chestnut shell pigment extract obtained under the optimum process conditions of example 10 produces natural chestnut shell brown pigment hair dye having relatively deeper hair depth and relatively stronger hair tensile strength.

2. Influence on the apparent morphology of dyed hair

The appearance forms of the hair dyed by the natural chestnut shell brown pigment hair dye prepared by adopting different types of chestnut shell pigment extracting solutions are respectively detected by adopting SEM, and the results are shown in figures 13-16.

As can be seen from the analysis of fig. 13 to 16, the damage of the bleached hair was severe, the hair scale on the surface of the hair was highly lifted, and the flaking phenomenon was observed after SEM magnification, and most of the external scales were removed during bleaching, which facilitated the diffusion of molecules into the hair; the hair dyed by the natural chestnut shell brown pigment hair dye prepared by adopting the optimal process conditions of the embodiment 10 and the chestnut shell pigment extracting solution prepared by extracting the traditional organic solvent ethanol solution is found under SEM, the warping degree of hair scales is obviously weakened, and the hair surface scales are flat and the surface state is better than that of the freshly bleached hair in an enlarged view of 2000 times; the phenomenon of partial hair scale stripping of hair after the natural chestnut shell brown pigment hair dye is prepared by the chestnut shell pigment extracting solution prepared by the traditional NaOH solution extraction is serious.

3. Effect on alpha-Keratin content of dyed Hair

Respectively detecting T of hair dyed by natural chestnut shell brown pigment hair dye prepared from different chestnut shell pigment extracting solutions_d、ΔH_dAnd RHC, results are shown in table 4 below.

TABLE 4 pairs of T_d、ΔH_dAnd the influence of RHC

The delta Hd of the hair sample dyed with the natural chestnut shell brown pigment hair dye prepared from the chestnut shell pigment extracting solution obtained under the optimal process conditions in example 10 is closer to that of the undyed sample, the RHC value of the hair sample is 98.35%, and the delta Hd of other hair samples is higher, which indicates that the damage degree of the internal structure of the hair dyed with the natural chestnut shell brown pigment hair dye prepared from the chestnut shell pigment extracting solution obtained under the optimal process conditions in example 10 is smaller, and the integrity of the hair is better maintained.

It should be noted that the above examples are only for further illustration and description of the technical solution of the present invention, and are not intended to further limit the technical solution of the present invention, and the method of the present invention is only a preferred embodiment, and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.