CN113197784A

CN113197784A - Preparation method and application of hair dyeing product containing melanin precursor prepared by biological fermentation

Info

Publication number: CN113197784A
Application number: CN202110395112.1A
Authority: CN
Inventors: 张然; 龚梦瑶; 薛俊
Original assignee: Beijing Yuantiancai Biotech Co ltd
Current assignee: Beijing Yuantiancai Biotech Co ltd
Priority date: 2021-04-13
Filing date: 2021-04-13
Publication date: 2021-08-03

Abstract

The invention relates to the technical field of sterilization of hair dyeing products prepared from melanin precursors, and particularly discloses a preparation method and application of a hair dyeing product containing the melanin precursors prepared by biological fermentation. The method specifically comprises the following steps: (1) extracting the edible fungus compound enzyme solution, fermenting, converting and concentrating to obtain a concentrated solution containing melanin precursor substances; (2) carrying out sectional high-temperature sterilization on the concentrated solution at the temperature of 90-95 ℃ for 30-40 minutes, standing for 14-16 hours after sterilization, and then carrying out sterilization at the same temperature and time as the first time; (3) the hair microorganism is detected completely and aseptically, and dyeing agent adjuvants are added to make into hair dyeing product. The invention can effectively kill product microorganisms and furthest retain melanin precursor substances and effective nutrient components, has simple and easy integral process, does not need special high-pressure and high-temperature equipment, and is beneficial to industrial popularization.

Description

Preparation method and application of hair dyeing product containing melanin precursor prepared by biological fermentation

Technical Field

The invention relates to the technical field of sterilization of hair dyeing products prepared from melanin precursors, in particular to a preparation method and application of a hair dyeing product containing the melanin precursors prepared by biological fermentation.

Background

The chemical hair dye contains aniline, hydroquinone and aminophenol substances and carcinogenic and sensitizing substances such as ammonia water and hydrogen peroxide, and has attracted great attention of consumers. Development work has been carried out for many years both at home and abroad in order to provide safe and harmless hair dyeing products for the public. Such as: extracting plant pigment hair blackening agent from plant (patent CN 101164528A); a method of oxidizing dopa and derivatives thereof by expressing catechol oxidase in filamentous fungi of the genus Mycoplasma by a microbial genetic engineering technique to convert dopa and derivatives thereof into a melanin precursor (patent CN 101914585B); biological melanin synthesis and combination products (patent CN 106854383A and CN 105267055A); extracting complex enzyme from Bacillus fermentation liquor for producing melanin to prepare melanin (patent CN 102586328A); natural melanin prepared from compound enzyme solution extracted from edible fungus Agaricus campestris, and its application method and multi-dosage form melanin precursor substance hair dye composition (patent CN 102586328A, CN106109258B and CN 106038411A).

In a melanin hair dye (Chinese patents CN103202795A, CN 101164528A, CN105411980A, CN106109258B and CN106038411A) prepared by a series of process flows by biologically fermenting complex enzyme extracted from organisms such as plants and the like, the complex enzyme liquid extracted from edible fungi described in patents CN 102586328A, CN106109258B and CN106038411A not only contains melanin substances capable of blackening hair, but also contains various nutrient components such as protein, amino acid, vitamin, sugar and the like, and the nutrient components have the function of nourishing hair and are nutrient substances bred by microorganisms. In the production process, the total number of bacteria is multiplied along with the concentration of effective components and nutrient components, and if no sterilization and preservation measures are taken, the bacteria-carrying products cannot become qualified commodities on the market. But because of 1. the property of raw materials: for example, plants, edible fungi, complex enzymes in the extracting solution and the like have biological properties, and the enzymes are easy to inactivate after high-temperature and high-pressure treatment; 2. the effective components of the product have the following effects: the complex enzyme is biologically fermented and converted into a melanin precursor which is easily aggregated into large melanin particles at high temperature and high pressure, namely the hair dyeing effect is lost. 3. The safety of the product is that the product is harmless to human bodies, and additives in a preparation formula need to meet the requirement of no harm to human bodies, so that the sterilization method with ultrahigh temperature and high pressure and the addition of chemical preservatives are not suitable for being adopted in the preparation of the product, and the safety quality of the product directly influences the marketing and the shelf storage period and the efficacy stability of the product. Therefore, the industrial production of biological melanin products is bound to face more unusual sterilization process problems. The safe products on the market are prepared by sterilizing when and in what way in the production of preparing the melanin hair-dyeing products by using complex enzymes extracted from organisms such as plants and the like through biological fermentation and conversion into melanin precursors, and no literature report exists so far.

As a sterilization method for biological fermentation products commonly used in production, production enterprises can adopt different sterilization methods according to the characteristics of various products and the safety quality standards thereof. Such as pasteurization, ultrahigh temperature instantaneous sterilization, ultra-high pressure sterilization, radiation sterilization, and the like. Specifically, pasteurization can be carried out at 61.7 deg.C-62.8 deg.C for 30 min, or at 71.6 deg.C or slightly higher for 15 min. The method can effectively kill growth-type pathogenic bacteria, but cannot thoroughly kill bacillus. The final product needs to be refrigerated and stored, has short shelf life which is generally different from 2 days to 15 days, and is mainly used for the sterilization process of milk and wine. The treatment method of the ultra-high temperature instant killing method (135-150 ℃ and 3-4 seconds of time maintenance) can completely kill the growing microorganisms and spores, but needs corresponding high temperature, high pressure and rapid temperature reduction equipment. The intermittent steam sterilization method needs continuous repeating for more than 3 days, and has time-consuming operation and low work efficiency. Ultra-high pressure sterilization and radiation sterilization require treatment in specialized institutions with special ultra-high pressure and radiation sterilization equipment.

The above listed sterilization methods are not suitable for biological melanin products prepared by biological fermentation techniques. Or various fungi are propagated in a large quantity due to no sterilization measures of the final product, and effective nutrient components are consumed by microorganisms, so that the final product has no utilization value; or the enzyme is inactivated due to the biological property of the biological enzyme, high temperature or high pressure, and the fermentation reaction cannot be carried out; or the high-temperature resistant microorganisms, particularly bacillus, in the product can not be completely killed due to improper high-temperature treatment, so that the product is bacteria and cannot be stored for a long time; under the conditions of ultrahigh temperature and high pressure, the effective substance melanin precursor is easy to be converted and aggregated into melanin, and the efficacy of the product is lost. Therefore, such products cannot be marketed products at present, and therefore, there is a need to provide a new method for solving the problem of sterilization of products containing biological melanin precursors, which solves the drawbacks of the existing production techniques.

Disclosure of Invention

Aims to solve the problem of corrosion prevention and quality guarantee of natural biological pigment dyeing products on the market, protect effective components and nutritional components in the biological melanin dyeing products to the maximum extent and ensure the dyeing and maintenance effects of the products. The invention provides a high-temperature sterilization process used in the production process of a biological melanin precursor, and provides an essential new sterilization process for the field of industrial production of biological melanin products.

In order to achieve the purpose of the invention, the technical scheme of the invention is as follows:

a process for preparing the hair dye containing the melanin precursor prepared by biologic fermentation includes such steps as sterilizing the concentrated solution of melanin precursor at 90-95 deg.C for 30-40 min under ordinary pressure, sterilizing at 14-16 hr for 30-40 min under ordinary pressure, and mixing with auxiliary.

In the present invention, the preparation method of the melanin precursor prepared by biological fermentation is the same as the preparation method of the melanin precursor in chinese patent CN106109258B or CN 106038411B.

In the invention, the melanin precursor prepared by biological fermentation comprises one or more of dopachrome, 5, 6-dihydroxyindole and 5, 6-dihydroxyindole-2-carboxylic acid. Preferably, 5, 6-dihydroxyindole is included.

Since the melanin precursor solution of the present invention is prepared by using edible fungi through a biological fermentation method, those skilled in the art can understand that the solution also contains proteins, amino acid polysaccharides, lipids, and the like.

In the preparation of the hair dye product, the object of the sterilization treatment may be an intermediate product for production such as a fermentation broth, a concentrated solution, or a finished product. The invention finds that the concentrated solution can achieve the effect of complete sterilization compared with the final product, so the concentrated solution is selected by a sterilization object. The sterilization method of the invention not only ensures the biological activity of the biological compound enzyme, but also has the advantages of no loss of the function of fermentation and transformation, easy process, convenient sampling and detection and reduced pollution chance.

The two times of sterilization are carried out under normal pressure, thereby being beneficial to the safe operation in production, avoiding adding new high-pressure sterilization equipment and reducing the production cost. The concentrated solution can be sterilized in normal pressure heating equipment such as water bath, drying oven or fermentation tank, and the damage of high pressure and high temperature to effective components is reduced. The specific heating temperature and time are selected, so that melanin precursor substances and nutrient components can be kept to the maximum extent, the microorganisms can be completely killed, the product safety is improved, and the quality guarantee period is prolonged.

Preferably, the invention can adopt a water bath heating mode for sterilization, so as to be beneficial to the concentrated solution to obtain continuous and stable temperature, and can also utilize the concentrated solution to be matched with a concentration tank for sterilization with different yields, and a set of steam heating and pressurizing equipment is not required to be additionally arranged, thereby saving energy, saving time and being convenient for safe operation.

Preferably, the temperature for both sterilizations is 95 ℃.

Preferably, the time for both sterilizations is 30 minutes.

Preferably, the time between two sterilizations is 14 hours.

Preferably, the temperature of both sterilizations is 95 ℃, the sterilization time is 30 minutes, and the time between the two sterilizations is 14 hours.

The combined mode is adopted for sterilization, which is beneficial to effectively killing growth pathogenic bacteria and bacillus in the concentrated solution, the sterilization rate of the product reaches 100 percent through microbial detection after the product is stored for 90 days at normal temperature, and compared with a product treated at a non-high temperature, the melanin precursor substance is only reduced by 0.003 percent, thereby achieving the effects of effectively killing the product microorganisms and maximally retaining the melanin precursor substance and effective nutrient components.

In the invention, the auxiliary materials are common auxiliary agents for hair dyes and water.

In the invention, the composition of the common hair dye auxiliary agent and the using amount of the common hair dye auxiliary agent and water in the hair dye are the same as those of Chinese patent CN106109258B or CN 106038411B.

The invention also provides a hair dye prepared by the preparation method.

The hair dye can also comprise a compound preservative.

Preferably, the compound preservative is compatible with phenoxyethanol, benzoic acid or potassium sorbate.

Preferably, the ratio of the potassium sorbate to the benzoic acid in the paste is 0.3 percent and 0.25 percent by mass.

Preferably, the ratio of the potassium sorbate to the phenoxyethanol in the paste is 0.3 percent and 0.5 percent by mass.

Preferably, the ratio of the benzoic acid to the phenoxyethanol in the paste is 0.25 percent and 0.5 percent by mass.

Preferably, the hair dye is paste, and has high adhesion and stable dyeing effect.

Preferably, the common auxiliary agents for the hair dye are a wetting penetrating agent, a thickening agent, a surfactant, a humectant and a pH value regulator. The specific combination and content of the hair dye can be found in the formulas of Chinese patent CN106109258 and CN 106038411B.

The hair dye is sterile, has no irritation or sensitization to skin, has high safety, and can maintain natural black hair dyeing effect.

The invention also provides a melanin precursor sterilizing solution, which is prepared by the method for preparing the sterilized melanin precursor solution in the preparation method.

Compared with the melanin precursor solution prepared in a biological fermentation mode in the prior art, the melanin precursor sterilizing solution has the characteristics of completely not containing microorganisms and well retaining functional components and nutrient substances.

The preparation method specifically comprises the following steps:

(1) extracting the edible fungus compound enzyme liquid;

(2) fermenting and converting to obtain a solution containing melanin precursor substances;

(3) concentrating the solution obtained in the step (2), and adjusting the components (mainly converting the dopachrome into one or more of 5, 6-dihydroxyindole, 5, 6-dihydroxyindole-2-carboxylic acid) to obtain a concentrated melanin precursor solution;

(4) performing sectional high-temperature sterilization on the concentrated melanin precursor solution obtained in the step (3); a sterilization step:

(a) putting the concentrated melanin precursor solution into a heatable closed container, and putting into a sterilization device;

(b) starting a temperature switch of the sterilization equipment, and setting the temperature to be 90-95 ℃. When the temperature of the solution in the container rises to the set temperature, maintaining the temperature, sterilizing for 30-40 minutes, and naturally cooling after sterilizing;

(c) after being placed for 14 to 16 hours, the mixture is sterilized at the high temperature of 90 to 95 ℃ for 30 to 40 minutes for the second time;

(5) after sterilization, sampling, detecting microorganisms, and adding auxiliary materials of coloring agents to prepare the ointment.

The heatable closed container can be a high-temperature-resistant glass bottle or a fermentation tank.

The sterilization equipment can be one of a water bath, a drying oven and a fermentation tank.

The paste making equipment can adopt one of a stirrer, an emulsifying pot and a fermentation tank.

The specific reference to steps (1) - (3) and (5) can be found in chinese patents CN106109258 and CN 106038411.

The invention has the beneficial effects that:

the hair dyeing product prepared by biological fermentation and conversion is not only provided with effective components and rich nutrient components for blackening hair, but also carries a large amount of microorganisms (such as bacteria, mold and the like brought by mushroom sources) because the raw materials come from plants, edible fungi and the like, and the products cannot be sold on the market because the microorganisms are easy to remain and reproduce due to the lack of a sterilization link in the production process. The invention solves the sterilization problem of preparing the melanin precursor solution in a biological fermentation mode, and finally obtains a dyeing product with good safety and effectiveness. Meanwhile, the retention of functional components and nutrient substances is considered, and the technical effect which cannot be achieved by the conventional sterilization method is realized.

In particular, the conventional method of pasteurizing cannot achieve complete sterilization and long-term aseptic effect; the compound preservative is used alone and cannot play a due role; the active ingredients in the biological coloring agent are inactivated by using the ultra-high temperature, so that the original nutritive value is reduced or inactivated, and the coloring and maintaining effects are reduced or ineffective; the intermittent steam sterilization method needs special equipment, needs continuous repeated working procedures for more than 3 days, and has time-consuming operation and low work efficiency. Are not suitable for the industrial production of the specific objects to be sterilized of the present invention.

The invention solves the sterilization problem of biological melanin products by adding a sectional high-temperature sterilization process in the preparation process of the existing melanin precursor coloring agent, and the process is simple and easy to implement, utilizes the existing equipment conditions, does not need special high-pressure and ultra-high temperature equipment, thoroughly kills microorganisms (pathogens, spores and the like) in the melanin products under the normal pressure state below 100 ℃, detects the total number of microbial colonies to be zero after the products are stored for 90 days under the normal temperature state, has little loss of effective substances in the products, only reduces 0.003 percent compared with the products which are not processed at high temperature, and does not reduce the dyeing effect of the final products. The effects of melanin precursor substances and effective nutrient components are retained to the maximum extent, and the whole process is simple and easy to implement and is beneficial to industrial popularization.

Drawings

FIG. 1 shows the results of visual inspection of samples treated differently in Experimental example 2 of the present invention;

FIG. 2 shows the microscopic examination results of the samples treated differently in Experimental example 2;

FIG. 3 is a microscopic examination result of a sample stored for 90 days in Experimental example 2 of the present invention;

wherein, the background in fig. 2 and 3 is the color of the backing paper;

FIG. 4 is an absorption spectrum of an active ingredient of a control treatment in Experimental example 3 of the present invention measured using an ultraviolet spectrophotometer;

fig. 5 is an absorption spectrum of the active ingredient of the paste of example 3 measured by an ultraviolet spectrophotometer in experimental example 3 of the present invention.

Detailed Description

Preferred embodiments of the present invention will be described in detail with reference to the following examples. It is to be understood that the following examples are given for illustrative purposes only and are not intended to limit the scope of the present invention. Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the spirit and scope of this invention.

The experimental procedures used in the following examples are all conventional procedures unless otherwise specified. Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.

The melanin precursor solution prepared by biological fermentation described in the detailed description of the present invention was prepared by the method of example 3 of chinese patent CN 106038411.

Comparative example 1

The comparative example performs sterilization operation on the melanin precursor solution prepared in a biological fermentation mode, and comprises the following specific steps:

(1) putting a concentrated solution obtained by concentrating the melanin precursor solution obtained after fermentation by 8 times into a high-temperature-resistant glass bottle, sealing, placing the bottle into a water bath kettle, adding clear water into the water bath kettle until the height of the concentrated solution in the bottle is reached, setting the temperature of the water bath kettle to 85 ℃, keeping the temperature for 20 minutes when the water temperature reaches 85 ℃, taking out the sealed bottle from the water bath kettle after the completion, and placing at room temperature.

(2) After 14 hours, the mixture was again placed in a water bath and sterilized at high temperature for the second time in the same manner as in the above-mentioned step. After the preparation, the concentrated solution is poured out from a sterile operating platform, and after various auxiliary materials for detecting sterility are added to prepare the biological melanin-dyed paste (the manufacturing method of the paste is specifically referred to as example 4 of Chinese patent CN 106038411), filling.

Comparative example 2

(1) putting a concentrated solution obtained by concentrating the melanin precursor solution obtained after fermentation by 8 times into a high-temperature-resistant glass bottle, sealing, placing the bottle into a water bath kettle, adding clear water into the water bath kettle until the height of the concentrated solution in the bottle is reached, setting the temperature of the water bath kettle to 85 ℃, keeping the temperature for 30 minutes when the water temperature reaches 85 ℃, taking out the sealed bottle from the water bath kettle after the completion, and placing at room temperature.

Example 1

In this embodiment, the melanin precursor solution prepared by biological fermentation is sterilized, and the specific steps are as follows:

(1) putting a concentrated solution obtained by concentrating the melanin precursor solution obtained after fermentation by 8 times into a high-temperature-resistant glass bottle, sealing, placing the bottle into a water bath kettle, adding clear water into the water bath kettle to the height of the concentrated solution in the bottle, setting the temperature of the water bath kettle to 90 ℃, keeping the temperature for 30 minutes when the water temperature reaches 90 ℃, taking out the sealed bottle from the water bath kettle after the temperature is up, and placing at room temperature.

Example 2

(1) putting a concentrated solution obtained by concentrating the melanin precursor solution obtained after fermentation by 8 times into a high-temperature-resistant glass bottle, sealing, placing the bottle into a water bath kettle, adding clear water into the water bath kettle to the height of the concentrated solution in the bottle, setting the temperature of the water bath kettle to 95 ℃, keeping the temperature for 30 minutes when the water temperature reaches 95 ℃, taking out the sealed bottle from the water bath kettle after completion, and placing at room temperature.

Example 3

(1) and (3) filling concentrated solution obtained by concentrating melanin precursor solution obtained after fermentation by 8 times into a fermentation tank, sealing, setting the temperature to 95 ℃, starting stirring, keeping the temperature for 30 minutes when the temperature in the tank reaches 95 ℃, closing a stirring switch after sterilization, and naturally cooling at room temperature.

(2) After an interval of 14 hours, a second high-temperature sterilization was performed in the same manner as in the above-described step. And (3) after the sterilization is finished, adding various auxiliary materials for detecting sterility into a 10 ten thousand grade cleanliness workshop to prepare the biological melanin-dyed paste (the manufacturing method of the paste is specifically shown in example 4 of Chinese patent CN 106038411), and filling.

Experimental example 1

In this example, the paste samples prepared in comparative examples 1 to 2 and examples 1 to 3 were sampled at random, and the total number of microbial colonies was measured, and a control treatment was performed, wherein the control treatment was a sample that was not subjected to a high-temperature treatment (a dye paste directly prepared from a concentrated solution that was not subjected to a high-temperature treatment).

The detection steps of the total number of the microbial colonies refer to the second edition of food microbiology experimental technology, and the specific steps are as follows:

1. preparing nutrient agar culture medium, and sterilizing at 121 deg.C for 20 min;

2. each paste sample was diluted 10-fold and 100-fold in a clean bench and inoculated in 1 ml aliquots in sterilized petri dishes, with 3 replicates per concentration sample. 20 ml of the sterilized medium cooled to about 45 ℃ is poured into a petri dish and shaken with the sample.

3. After 48 hours of incubation at 37 ℃ in an incubator, counts were taken and the data was the average number of colonies of 3 replicates.

The results are shown in Table 1.

TABLE 1 Total microbial colony count assay results in concentrates treated differently

As is clear from the data in Table 1, the concentrated solution showed no growth of microorganisms in the concentrated solution after sterilization at 85 ℃ for 20 minutes, a small amount of colonies (10CFU/ml) in the medium diluted 10 times with the concentrated solution sterilized 2 times, and no growth of colonies in the case of the microorganism after preparation of the paste, and no growth of colonies (20CFU/ml) in the medium diluted 10 times at 85 ℃ for 30 minutes. None of the control-treated colonies were counted. The invention has good sterilization effect.

In this example, the paste samples prepared in comparative example 2 and examples 1 to 3 and the control-treated samples were further placed at room temperature (23 ℃ to 27 ℃) and the tests were carried out after 30 days, 60 days and 90 days, and microbial colonies of each sample were detected and grown without colonies, while the total number of colonies of the control-treated samples was not counted. The specific test results are shown in Table 2.

TABLE 2 Total microbial colony count test results of paste samples treated differently during different storage periods

As can be seen from the data in Table 2, the sterilization process method of the invention has good antiseptic effect under the condition of no unsealing and can be stored at room temperature for up to 90 days.

Experimental example 2

In this example, the coloring ability of the cream samples prepared in examples 1 to 3 to white hair was measured, and a control treatment was performed, wherein the control treatment was a sample that was not subjected to a high temperature treatment.

The specific detection steps are as follows:

1. after a beam of white hair is washed by shampoo, uniformly coating a paste sample on the surface of the hair, and washing the hair by clear water after 40 minutes;

2. the dyeing assistant agent B (see example 4 of Chinese patent CN 106038411) is uniformly coated on the surface of hair, and after 15 minutes, the hair is washed by clean water.

3. And (3) visual detection: the result of the dyeing is photographed with a camera and the result is shown in fig. 1.

4. Microscopic detection: the results of the hair dyeing were photographed using a dermoscope and the results are shown in FIG. 2.

As can be seen from FIGS. 1-2, the dyeing effect of the product is not changed by the high temperature treatment.

This example further examined the control treatment after 90 days of storage at room temperature (25 c-30 c) and the ability of the cream sample of example 3 to color white hair microscopically, and the results are shown in fig. 3.

As can be seen from fig. 3, the paste after high temperature treatment did not lose activity after being left at room temperature for 90 days, and was still able to dye the hair black.

Experimental example 3

In this example, the content of the melanin precursor in the paste sample prepared in example 3 was measured, and a control treatment was performed, wherein the control treatment was a sample that was not subjected to a high-temperature treatment.

The detection method of the content of the biological melanin precursor substance comprises the following steps: the sample is diluted by 10 times, and the absorption spectrum of the effective component of the melanin is detected by an ultraviolet spectrophotometer. The maximum absorption peak of the melanin precursor substance solution is at 300 nm. The results are shown in FIGS. 4-5.

As can be seen from fig. 4, the content of the active ingredient (5, 6-dihydroxyindole) in the paste prepared without autoclaving in the control treatment was 0.412%. As can be seen from fig. 5, the content of the active ingredient (5, 6-dihydroxyindole) in the paste prepared in example 3 after the pasteurization was 0.409%, and the loss of the active ingredient was only 0.003% after the pasteurization, indicating that the sterilization method of the present invention has little effect on the content of the active ingredient in the melanin precursor prepared by the biofermentation method.

Experimental example 4

This experimental example was conducted to examine the growth of microorganisms stored in the paste sample prepared in example 3 at room temperature (23 ℃ C. -27 ℃ C.) for 90 days and for a prolonged period (half year, one year) (the same test method as in experimental example 1). The specific results are shown in Table 3.

TABLE 3

Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims

1. A method for preparing hair dyeing products containing melanin precursors prepared by biological fermentation is characterized in that concentrated solution of the melanin precursors prepared by biological fermentation is sterilized at 90-95 ℃ for 30-40 minutes under normal pressure at intervals of 14-16 hours, sterilized at 90-95 ℃ for 30-40 minutes under normal pressure to obtain sterilized melanin precursor solution, and then the sterilized melanin precursor solution is mixed with auxiliary materials to prepare the hair dyeing products.

2. The method according to claim 1, wherein the method for producing the melanin precursor by biological fermentation is the same as that of the melanin precursor of chinese patent CN106109258B or CN 106038411B.

3. The method according to claim 1 or 2, wherein the melanin precursor prepared by biofermentation comprises one or more of dopachrome, 5, 6-dihydroxyindole, and 5, 6-dihydroxyindole-2-carboxylic acid.

4. The method according to any one of claims 1 to 3, wherein the temperature for both sterilizations is 95 ℃.

5. The method according to any one of claims 1 to 4, wherein the time for both sterilizations is 30 minutes.

6. The method of any one of claims 1-5, wherein the time between two sterilizations is 14 hours.

7. The method according to any one of claims 1 to 6, wherein the auxiliary materials are an auxiliary agent commonly used for hair dyes and water.

8. The method for preparing a hair dye composition as claimed in claim 7, wherein the composition of said common hair dye auxiliary and the amount of said common hair dye auxiliary and water used in the hair dye are the same as those described in Chinese patent CN106109258B or CN 106038411B.

9. A hair dye, characterized by being produced by the production method according to any one of claims 1 to 8.

10. A melanin precursor-containing sterile solution produced by the method for producing a sterilized melanin precursor solution according to any one of claims 1 to 6.