A decolorization method and application of camellia seed extract aqueous solution

Abstract

The present invention discloses a decolorization method and application of an aqueous camellia seed extract solution. The aqueous camellia seed extract solution is prepared by a water extraction method, the pH value of the aqueous camellia seed extract solution is adjusted to 6-11, hydrogen peroxide is added, zinc oxide or zinc sulfate is added, and a decolorized aqueous camellia seed extract solution is obtained. The aqueous camellia seed extract can be directly decolorized and added to a subsequent cosmetic formula, and an aqueous camellia seed extract with a high decolorization rate is obtained. The solution has good stability and the pH value of the solution will not gradually increase during the standing process. At the same time, since the method of the present invention does not require the addition of flammable and explosive components such as ethanol, ordinary factories can complete the preparation and decolorization of the aqueous camellia seed extract. The aqueous camellia seed extract is directly used as a raw material for decolorization, and the decolorized aqueous extract is directly used as a raw material in cosmetics.

Description

Technical Field

[0001] The invention belongs to the technical field of decolorization of tea saponin water extract, and particularly relates to a decolorization method and application of a tea seed extract aqueous solution. Background Art

[0002] Camellia oleifera extract contains tea saponin, a functional active component. The camellia oleifera extract used in the prior art mainly adopts alcohol extraction, because the camellia oleifera extract obtained by alcohol extraction is lighter in color and easier to decolorize, such as extracting camellia oleifera with a certain concentration of ethanol. However, the water extract of camellia oleifera is very heavy in color, which greatly limits its application in daily chemical products. However, the alcohol extraction cost is high, and supporting anti-riot facilities, regular fire inspections, etc. are required to avoid the safety problems of extracting raw materials such as ethanol. It can only be extracted in specific factories, and ordinary factories are currently not allowed to extract camellia oleifera with alcohol extraction. Therefore, if a decolorization method of camellia oleifera water extract can be found, a tea saponin extract with good decolorization effect can be obtained, which is very beneficial for the application of camellia oleifera water extract.

[0003] Previous studies have used hydrogen peroxide alone as an oxidant to decolorize tea seed extracts, but the efficiency is low and a large amount of hydrogen peroxide must be consumed to meet the decolorization requirements. On a solid basis, 3-4 kg of 30% hydrogen peroxide is required to process 1 kg of crude tea saponin, which has a very high economic cost.

[0004] In addition, cosmetic raw materials need to be acidic because the pH value of human skin is acidic. At present, the pH value of daily chemical products is mostly around 5.5, generally not exceeding 6.0. Therefore, the prepared camellia oleifera water extract cannot be alkaline. A high pH value will make the daily chemical products lose their practical use value. The camellia oleifera water extract itself is highly acidic, with a pH value of about 3-5. When decolorizing, care should be taken not to use a large amount of alkaline substances. Since the camellia oleifera water extract contains a large amount of organic acid, a pH buffer system will be formed at pH 5-7, causing the overall formula to change in the direction of increasing pH with storage time, making it difficult to apply. The pH stability of the formula is of great significance for the thickening and conditioning of daily chemical products. Developing a decolorization accelerator that can work at a lower pH can not only improve the decolorization efficiency, but also avoid the introduction of a large amount of alkali, which is more practical. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] As one aspect of the present invention, the present invention provides a method for decolorizing an aqueous solution of a camellia seed extract, which comprises the following steps:

[0007] The camellia seed extract aqueous solution is prepared by a water extraction method, the pH value of the camellia seed extract aqueous solution is adjusted to 6-11, hydrogen peroxide and zinc oxide or zinc sulfate are added, and a decolorized camellia seed extract aqueous solution is obtained; wherein the amount of zinc oxide or zinc sulfate added is 0.5%-1.5% of the mass of the camellia seed extract aqueous solution.

[0008] As a preferred embodiment of the decolorization method of the camellia seed extract aqueous solution of the present invention: the addition of hydrogen peroxide, wherein the amount of hydrogen peroxide added is 1 to 5 wt% of the mass of the camellia seed extract aqueous solution

[0009] As a preferred embodiment of the decolorization method of the camellia seed extract aqueous solution of the present invention: the reaction is carried out at 60-90° C. for 20-180 min.

[0010] As a preferred embodiment of the decolorization method of the camellia seed extract aqueous solution of the present invention: the reaction is carried out at 70-80° C. for 20-60 minutes.

[0011] As a preferred solution of the decolorization method of the camellia seed extract aqueous solution of the present invention: the pH value of the camellia seed extract aqueous solution is adjusted to 6-11, and the pH value is adjusted to 8 with sodium hydroxide.

[0012] As a preferred solution of the decolorization method of the camellia seed extract aqueous solution of the present invention: the amount of zinc oxide or zinc sulfate added is 0.8% to 1% of the mass of the camellia seed extract aqueous solution.

[0013] As a preferred embodiment of the decolorization method of the camellia seed extract aqueous solution of the present invention: the camellia seed extract aqueous solution is prepared by water extraction, which comprises adding camellia seeds into water, heating, filtering and drying to obtain the camellia seed extract.

[0014] The present invention also provides the use of the product obtained by the decolorization method of the camellia seed extract aqueous solution in cosmetics. The cosmetics include shampoo and hair care products.

[0015] Beneficial effects of the present invention: The present invention has found that zinc oxide itself can be directly used as a decolorization promoter for hydrogen peroxide, and zinc sulfate can be used as a decolorization promoter for hydrogen peroxide at a relatively low pH. The decolorization method of the aqueous solution of the oil-tea camellia seed extract of the present invention directly uses the oil-tea camellia seed water extract as a raw material for decolorization, and does not require operations such as alcohol extraction, so that the oil-tea camellia seed water extract can be directly decolorized and added to subsequent cosmetic formulas, and an oil-tea camellia seed water extract with a high decolorization rate is obtained. The solution has good stability and will not gradually increase the solution pH during the standing process. At the same time, since the method of the present invention does not require the addition of flammable and explosive components such as ethanol, ordinary factories can complete the preparation and decolorization of the oil-tea camellia seed water extract. The oil-tea camellia seed water extract is directly used as a raw material for decolorization, and the decolorized water extract is directly used as a raw material in cosmetics. At the same time, the decolorization method of the aqueous solution of the oil-tea camellia seed extract of the present invention can complete decolorization at a relatively low pH value without the need to add a large amount of alkaline components. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0017] Figure 1 The decolorization effect comparison of each experimental group in Example 1 is shown in FIG.

[0018] Figure 2 The following is a comparison of the decolorization effects of the experimental groups in Example 2.

[0019] Figure 3 The pH stability test results of Example 1 are shown in FIG.

[0020] Figure 4 The pH stability test results of Example 2 are shown in FIG.

[0021] Figure 5 The experimental results of control example 1 are shown in FIG. DETAILED DESCRIPTION

[0022] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with specific embodiments.

[0023] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0024] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0025] Embodiment 1:

[0026] The preparation method of the camellia seed water extract (also known as the camellia seed extract aqueous solution) is as follows: the camellia seed cake is mixed with water in a ratio of 1:5, the mixture is heated to 80 degrees, stirred at a speed of 20 rpm, and soaked for 3 hours. The obtained camellia seed cake water extract is subjected to cross-flow filtration using a ceramic membrane device with a pore size of 450 nanometers to obtain a clear liquid, which is the aqueous solution of the camellia seed extract.

[0027] The subsequent examples all adopt this camellia seed water extract to study the decolorization method.

[0028] The decolorization was carried out using the extracted camellia seed water extract with 10wt% solid content and 6wt% tea saponin content as the raw material. 25ml of the extract was taken for decolorization test, the pH of the solution was adjusted to 11 with sodium hydroxide, 2.5mL of 30wt% hydrogen peroxide was added (i.e. 30% hydrogen peroxide accounts for 10wt% of the total solution), and then 0.2g of magnesium chloride hexahydrate or 0.2g of zinc oxide was added as a decolorization auxiliary agent, respectively, and the reaction was carried out at 80℃ for 120min. After the decolorization was completed, the decolorization efficiency was quantified by calculating the absorbance at 460nm. The experimental results are shown in the figure. Figure 1 and Table 1. Figure 1 In the middle, the left picture is a control group (stock solution group) without adding a decolorizing auxiliary agent and only using hydrogen peroxide for decolorization, the middle picture is a group adding zinc oxide as a decolorizing auxiliary agent, and the right picture is a group adding magnesium chloride as a decolorizing auxiliary agent. It can be seen from the figure that at pH 11, zinc oxide as a decolorizing auxiliary agent for hydrogen peroxide is significantly better than magnesium chloride. The decolorization rate calculated by absorbance at 460nm is shown in Table 1.

[0029] The decolorization rate calculation formula is:

[0030]

[0031] Where A is the absorbance of the solution after decolorization, and A0 is the absorbance of the solution before decolorization.

[0032] Table 1

[0033]

[0034] As can be seen from Table 1, under the strong alkaline condition of pH=11, zinc oxide is significantly better than magnesium chloride as a decolorization auxiliary agent for hydrogen peroxide. The present invention first discovered that zinc oxide can be used as a decolorization auxiliary agent for hydrogen peroxide for the decolorization of camellia seed water extract, which can enable the camellia seed water extract to be directly used without alcohol extraction and the use of flammable and explosive solvents such as ethanol. Ordinary factories can also implement the operation and have realistic application prospects. At present, the decolorization principle of this reaction is not very clear. It is speculated that zinc oxide can be used as a hydrogen peroxide catalyst, which significantly improves the catalytic oxidation efficiency of hydrogen peroxide for camellia seed water extract.

[0035] pH stability test of decolorized camellia seed water extract:

[0036] The pH of the decolorized camellia seed water extract and the undecolorized camellia seed water extract stock solution were adjusted to 5.5 with citric acid, and placed at room temperature. The pH changes were monitored every day. The results were as follows: Figure 3 The results show that the pH stability of the decolorized liquid at pH 11 is poor, and the change range is more than 2.5 within 7 days. The reason is that a large amount of alkali is added in the process of adjusting the pH of the water extract to 11, which forms a pH buffer system with the organic acids such as fruit acid contained in the oil-tea camellia seed water extract, thereby causing the solution adjusted to weak acidity to turn alkaline.

[0037] Embodiment 2:

[0038] The 10wt% solid content and 6wt% tea saponin content of tea seed water extract was used as the raw material for decolorization. 25ml of the extract was taken for decolorization test, the pH of the solution was adjusted to 8 with sodium hydroxide, 2.5mL of 30wt% hydrogen peroxide was added (i.e. 30% hydrogen peroxide accounted for 10wt% of the total solution), and then 0.2g of magnesium chloride hexahydrate or 0.2g of zinc oxide was added as a decolorization auxiliary agent, and the reaction was carried out at 80℃ for 80min. After the decolorization was completed, the decolorization efficiency was quantified by calculating the absorbance at 460nm. The experimental results are shown in the figure. Figure 2 and Table 2. Figure 2 In the middle, the left picture is a control group (stock solution group) without adding a decolorizing auxiliary agent and only using hydrogen peroxide for decolorization, the middle picture is a group adding zinc oxide as a decolorizing auxiliary agent, and the right picture is a group adding magnesium chloride as a decolorizing auxiliary agent. It can be seen from the figure that at pH 8, zinc oxide as a decolorizing auxiliary agent for hydrogen peroxide is significantly better than magnesium chloride. The decolorization rate calculated by absorbance at 460nm is shown in Table 2.

[0039] Table 2

[0040]

[0041] from Figure 2As shown in Table 2, at pH = 8, magnesium chloride cannot be used as a decolorization promoter for hydrogen peroxide. This is mainly because magnesium chloride can only generate magnesium hydroxide under alkaline conditions of pH 10 or above, and magnesium chloride cannot be used as a decolorization promoter for hydrogen peroxide in a weakly alkaline environment and a neutral or acidic environment. The zinc oxide used in the present invention is itself a decolorization promoter for hydrogen peroxide, which does not need to function under alkaline conditions, and can function as a decolorization promoter for hydrogen peroxide under neutral and weakly acidic conditions.

[0042] pH stability test of the decolorized camellia seed water extract: The pH of the decolorized camellia seed water extract was adjusted to 5.5, placed at room temperature, and its pH change was monitored every day. The results are as follows: Figure 4 The results show that the pH stability of the liquid decolorized at pH 8 is good, and the change range is within 1.0 within 7 days. The pH stability of the zinc oxide solution is better than that of the magnesium chloride solution.

[0043] In addition, the decolorization reaction time also affects the decolorization efficiency. It is of great practical significance to achieve higher decolorization efficiency with shorter decolorization time, less amount of hydrogen peroxide, and less amount of alkali.

[0044] Embodiment 3:

[0045] Study the effect of zinc oxide addition on decolorization rate: Take the extracted camellia seed water extract with 10wt% solid content and 6wt% tea saponin content as raw material for decolorization. Take 25ml of extract for decolorization test, adjust the solution pH to 8 with sodium hydroxide, add 2.5mL of 30wt% hydrogen peroxide (i.e. 30% hydrogen peroxide accounts for 10wt% of the total solution), then add 0.10g, 0.15g, 0.20g, 0.25g, 0.30g of zinc oxide as each experimental group, react at 80℃ for 75min, and quantify the decolorization efficiency by calculating the absorbance at 460nm after decolorization. The experimental results are shown in Table 3.

[0046] Table 3

[0047] Sample name Decolorization rate (%) Decolorization time (min) Amount of hydrogen peroxide (mL) 0.10g group 57.93 75 3 0.15g group 73.79 75 3 0.20g group 83.11 75 3 0.25g group 76.22 75 3 0.30g group 74.82 75 3

[0048] As can be seen from Table 3, the higher the amount of zinc oxide added, the better the decolorization effect. When the amount of zinc oxide added is 0.2g, the best decolorization effect is achieved. It is speculated that this may be due to the fact that excessive zinc oxide causes the rapid decomposition of hydrogen peroxide, and the highly active oxidation intermediates stay in the system for too short a time and have no time to react with the pigment. In the presence of 0.2g of zinc oxide, the concentration of highly active oxidation intermediates released by the decomposition of hydrogen peroxide is more suitable, which can achieve a slow-release effect and thus have a better decolorization efficiency.

[0049] Embodiment 4:

[0050] Study the effect of solution pH on decolorization rate: Take the extracted camellia seed water extract with 10wt% solid content and 6wt% tea saponin content as raw material for decolorization. Take 25ml of extract for decolorization test, adjust the solution pH to 6, 7, 8, 9, 10 with sodium hydroxide as each experimental group, add 2.5mL of 30wt% hydrogen peroxide (i.e. 30% hydrogen peroxide accounts for 10wt% of the total solution), then add 0.2g zinc oxide as decolorization auxiliary agent, react at 80℃ for 120min, and quantify the decolorization efficiency by calculating the absorbance at 460nm after decolorization. The experimental results are shown in Table 4.

[0051] Table 4

[0052] Sample name Decolorization rate (%) Decolorization time (min) Amount of hydrogen peroxide (mL) pH-6 Group 78.25±1.22 120 2.5 pH-7 Group 83.50±1.25 120 2.5 pH-8 Group 85.72±1.15 120 2.5 pH-9 Group 87.06±2.13 120 2.5 pH-10 Group 88.27±1.62 120 2.5

[0053] As shown in Table 4, the pH value affects the decolorization efficiency. The higher the pH, the better the decolorization effect. However, a high pH will cause the solution to form a pH buffer system, which will cause problems with the stability of the formula. The present invention can obtain a good decolorization rate at pH=6 or above, and realizes the decolorization of the camellia seed water extract at a relatively low pH.

[0054] Embodiment 5:

[0055] The effect of zinc sulfate as a decolorization auxiliary agent was studied: the water extract of tea seed with 10wt% solid content and 6wt% tea saponin content was used as raw material for decolorization. 25ml of the extract was taken for decolorization test, and the pH of the solution was adjusted to 6, 7, 8, 9, and 10 with sodium hydroxide as each experimental group, 2.5mL of 30wt% hydrogen peroxide was added (i.e., 30% hydrogen peroxide accounted for 10wt% of the total solution), and then 0.2g of zinc sulfate heptahydrate was added as a decolorization auxiliary agent, and the reaction was carried out at 80℃ for 120min. After the decolorization was completed, the decolorization efficiency was quantified by calculating the absorbance at 460nm. The experimental results are shown in Table 5.

[0056] Table 5

[0057] Sample name Decolorization rate (%) Decolorization time (min) Amount of hydrogen peroxide (mL) pH-6 Group 75.30±1.33 120 2.5 pH-7 Group 77.69±2.10 120 2.5 pH-8 Group 82.33±1.26 120 2.5 pH-9 Group 85.31±2.18 120 2.5 pH-10 Group 86.22±1.37 120 2.5

[0058] As shown in Table 5, the decolorization efficiency of the camellia seed water extract is high when zinc sulfate is used as a decolorization auxiliary agent for hydrogen peroxide, and it is not limited by the pH value of the solution. It has a good decolorization efficiency above pH 6, which is conducive to adding the decolorized camellia seed water extract directly as a raw material to the cosmetic formula, so that the introduction of strong alkaline raw materials into the cosmetic formula will not affect the pH value of the cosmetic formula. And the decolorized camellia seed water extract as a raw material can adapt to the acidic environment.

[0059] Comparative Example 1:

[0060] The decolorization was carried out using the water extract of tea seeds with 10wt% solid content and 6wt% tea saponin content as the raw material. 25ml of the extract was taken for the decolorization test, and the pH of the solution was adjusted to 6, 8, and 11 as each experimental group. 0.2g of zinc oxide was added as a decolorizing agent and reacted at 80℃ for 75min. The experimental results show that adding zinc oxide alone as a decolorizing agent does not have a decolorizing effect. Under various pH conditions, there is no significant difference in the absorbance of the solution at 460nm before and after the reaction. Figure 5 .

[0061] This shows that although zinc oxide can be used as a decolorization auxiliary for hydrogen peroxide, zinc oxide itself has no decolorization effect on the aqueous extract of camellia seeds.

[0062] Comparative Example 2:

[0063] The decolorization was carried out using the water extract of tea seed with 10wt% solid content and 6wt% tea saponin content as raw material. 25ml of the extract was taken for decolorization test, and the solution pH was adjusted to 6, 8, and 11 as each experimental group. 0.2g of zinc sulfate heptahydrate was added as a decolorizer and reacted at 80℃ for 75min. The experimental results show that adding zinc sulfate alone as a decolorizer does not have a decolorization effect. Under various pH conditions, there is no significant difference in the absorbance of the solution at 460nm before and after the reaction.

[0064] This indicates that although zinc sulfate can be used as a decolorization auxiliary for hydrogen peroxide, zinc sulfate itself has no decolorization effect on the aqueous extract of camellia seeds.

[0065] Comparative Example 3:

[0066] The zinc oxide in Example 1 is replaced by zinc chloride, and the rest of the preparation method is the same as Example 1. The experiment found that zinc chloride is easily hydrolyzed to form a colloid after being dissolved in water, making the system turbid and unstable, and the colloid is difficult to separate, which is not good for the decolorized product and affects further use. Therefore, zinc chloride is not suitable for use as a decolorization auxiliary agent.

[0067] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for decolorizing an aqueous solution of camellia oleifera seed extract, characterized in that: It consists of the following steps: The camellia seed extract aqueous solution is prepared by a water extraction method, the pH value of the camellia seed extract aqueous solution is adjusted to 7-8 with sodium hydroxide, 1-5wt% of hydrogen peroxide by weight of the camellia seed extract aqueous solution is added, zinc oxide is added, and the reaction is carried out at 60-90°C for 20-180 min to obtain a decolorized camellia seed extract aqueous solution; wherein the amount of zinc oxide added is 0.8%-1% by weight of the camellia seed extract aqueous solution.

2. The method for decolorizing the aqueous solution of camellia oleifera seed extract according to claim 1, characterized in that: The reaction is carried out at 70-80°C for 20-60 min.

3. The method for decolorizing the aqueous solution of camellia seed extract according to claim 1 or 2, characterized in that: The aqueous camellia seed extract aqueous solution is prepared by the water extraction method, which comprises adding camellia seeds into water, heating, and filtering to obtain the camellia seed extract aqueous solution.

4. Use of the product obtained by the decolorization method of the camellia seed extract aqueous solution according to claim 1 in cosmetics.

5. The use according to claim 4, characterized in that: The cosmetics are shampoo and hair care products.

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