Sericin peptide having a moisturizing function, method for producing the same, and use thereof

Abstract

The present application provides a sericin peptide having moisturizing function, and a method for producing and using the same. The first aspect of the present application provides a sericin peptide having moisturizing function, the composition of the sericin peptide containing at least peptide fragments GGS, AS and GS, and based on the mass of the sericin peptide, the content of the peptide fragment GGS is 0.80% or more, the content of the peptide fragment AS is 0.20% or more, and the content of the peptide fragment GS is 0.50% or more. The sericin peptide provided by the present application contains three functional peptide fragments, GGS, AS and GS, and has a clear moisturizing effect.

Description

Technical Field

[0001] This application relates to sericin peptides having a moisturizing function, a method for producing the same, and uses thereof, and relates to the technical field of silk protein processing.

Background Art

[0002] Conventionally, silk has mainly been used as a spinning material, and the protein content of silk reaches 98% or more. Since the late 1970s, researchers have turned their attention to new uses of silk. So far, silk has been used to varying degrees in fields such as daily chemical products, pharmaceuticals and biological materials, and health functional foods. Therefore, the development of silk protein has become the focus of research in recent years.

[0003] Silk protein mainly contains silk fibroin and sericin. Among them, the mass of silk fibroin accounts for 70 - 80% of the total mass of silk protein. It is insoluble in water or ethanol and has a dense and orderly aggregated structure. Therefore, a highly polar solvent must be used to break the structure in order to dissolve it. The mass of sericin accounts for 20 - 30% of the total mass of silk protein. Sericin is a globular protein with a relative molecular weight of 14,000 - 314,000 and consists of 18 kinds of amino acids. Among them, the serine content is the highest at about 30%. It is not only easily soluble in water but also has good hygroscopicity. As the research on sericin deepens, it has been found that sericin has good cell affinity and biocompatibility, as well as functions such as tyrosinase inhibitory activity, anti-ultraviolet activity, moisturizing, beauty, and hair care.

[0004] Serine is a natural moisturizing factor in the human skin and has a good water molecule absorption function. Therefore, it is generally present as a basic moisturizer in cosmetics. Sericin or silk protein rich in serine has the structural advantage of natural moisturizing, as well as natural protein nutrition and skin care functional characteristics. Therefore, it holds potential in the development of raw materials for moisturizing functional cosmetics.

[0005] Currently, the methods for highly processing silk protein mainly focus on removing sericin at high temperature and high pressure, obtaining silk fibroin peptides by hydrolysis using acids or bases, or producing silk protein peptides by treating silk protein with acid / base composite enzyme hydrolysis. The content of free amino acids in the silk fibroin peptides or silk protein peptides obtained by such methods is high, reaching 13% or more. Also, in the process of treating with acid / base reagents, harmful substances may be generated or pollution may be caused.

Summary of the Invention

[0006] This application provides a sericin peptide with a moisturizing function. The sericin peptide, as a functional peptide fragment contained at a specific mass content, is Gly-Gly-Ser (GGS), Ala-Ser (AS), and Gly-Ser (GS), which show good effects regarding moisturization.

[0007] This application further provides a method for producing a sericin peptide with a moisturizing function. The sericin peptide produced by this production method, as a functional peptide fragment contained at a specific mass content, is Gly-Gly-Ser (GGS), Ala-Ser (AS), and Gly-Ser (GS), which show good effects regarding moisturization.

[0008] This application further provides the use of the sericin peptide in moisturizing products.

[0009] The first aspect of this application provides a sericin peptide with a moisturizing function. The composition of the sericin peptide contains at least GGS, AS, and GS as peptide fragments. Based on the mass of the sericin peptide, the content of the peptide fragment GGS is 0.80% or more, the content of the peptide fragment AS is 0.20% or more, and the content of the peptide fragment GS is 0.50% or more.

[0010] In addition, the sericin peptide provided by the present application includes the above special peptide fragment, and the protein content of the sericin peptide is 85% or more, the free amino acid content is 5% or less, the acid-soluble protein content is 80% or more, and the content of components with a molecular weight of 1000 or less is 85% or more.

[0011] In one specific embodiment, the sericin peptide is obtained by using a non-pupated cocoon (a cocoon without a pupa, hereinafter referred to as a non-pupated cocoon) as a raw material, and passing through sericin elution, fermentation, enzymatic hydrolysis, adsorption decolorization, and drying treatment in this order. However, Torula yeast is used in the fermentation. The enzymatic hydrolysis includes performing enzymatic hydrolysis using alkaline protease and neutral protease.

[0012] The second aspect of the present application provides a method for producing the sericin peptide according to any one of the above, including the following steps. 1) Elute sericin from a non-pupated cocoon to obtain a sericin solution. 2) Ferment the sericin solution using Torula yeast, and after the fermentation is completed, obtain a sericin fermentation broth. 3) Add alkaline protease and neutral protease to the sericin fermentation broth to perform enzymatic hydrolysis, and after the enzymatic hydrolysis is completed, obtain a sericin enzymatic hydrolysis solution. 4) Add activated carbon to the sericin enzymatic hydrolysis solution to perform adsorption decolorization treatment, recover the filtrate after the treatment is completed, and dry the filtrate to obtain the sericin peptide.

[0013] In one specific embodiment, FIG. 1 is a flowchart of a method for producing a sericin peptide provided by an embodiment of the present application. As shown in FIG. 1, specifically, the method includes the following steps. Step 1) Elute sericin from non-pupated cocoons to obtain a sericin solution. Using commercially available non-pupated cocoons as raw materials, mix non-pupated cocoons and pure water at a mass ratio of 1:10 - 30, and treat at 110 - 125 °C for 10 - 90 minutes. During the treatment process, sericin is eluted from the cocoons into pure water to obtain a sericin solution.

[0014] Step 2) Ferment the sericin solution using Torula yeast. After fermentation, obtain a sericin fermentation broth. Sterilize the sericin solution obtained in Step 1). The sterilization may be carried out by ordinary technical means in the art. For example, sterilize at 115 - 121 °C for 15 - 30 minutes. Before sterilization, the sericin solution may be concentrated. Specifically, some moisture may be removed using a rotary evaporator.

[0015] After sterilization, add Torula yeast to the sericin solution and ferment. Since the process of growth and metabolism of Torula yeast can produce abundant short-chain peptides and enzymes, it helps to enrich the enzyme system in the subsequent enzymatic hydrolysis process, provides exogenous peptides that cannot be produced by the cocoons themselves, and Torula yeast does not produce ethanol under strict aerobic conditions, so it has good safety. Specifically, Torula utilis can be purchased from the China Center for Industrial Culture Collection (CICC), and the deposit number of the strain is CICC31170. The number of colonies of the Torula yeast per gram of the non-pupated cocoons is 10 5 ~10 7 colonies, limit the fermentation temperature to 28 - 32 °C, culture in a shaker, ferment for 36 - 72 hours. After fermentation, filter the cells and recover the fermentation broth to obtain a sericin fermentation broth.

[0016] Step 3) Add alkaline protease and neutral protease to the sericin fermentation broth for enzymatic hydrolysis. After enzymatic hydrolysis, obtain a sericin enzymatic hydrolysis solution. By adding alkaline protease and neutral protease to the sericin fermentation broth and performing enzymatic hydrolysis to cleave the peptide bonds in sericin, short-chain peptides are obtained. In the enzymatic hydrolysis process, per 1 gram of the non-pupated cocoon, the enzyme activity of the alkaline protease is 3000 - 6000 U, and the enzyme activity of the neutral protease is 500 - 1500 U. The temperature of enzymatic hydrolysis is limited to 45 - 55 °C, and the time is 4 - 6 hours. After the enzymatic hydrolysis is completed, a sericin enzymatic hydrolysis solution is obtained.

[0017] Step 4) Add activated carbon to the sericin enzymatic hydrolysis solution for adsorption and decolorization treatment. After the treatment is completed, collect the filtrate, and dry the filtrate to obtain the sericin peptide. After the enzymatic hydrolysis is completed, raise the temperature of the sericin enzymatic hydrolysis solution to 85 - 95 °C, and keep it warm for 15 - 25 minutes to inactivate the enzyme. After the enzyme inactivation is completed, filter to remove insoluble substances such as high-molecular proteins. Specifically, a ceramic membrane with a pore size of 10KD - 20KD may be used. Collect the supernatant, add activated carbon to the supernatant for adsorption and decolorization treatment to adsorb the pigments in the supernatant. After the adsorption treatment is completed, remove the activated carbon, collect the filtrate and dry it to obtain the sericin peptide. The drying may be carried out in a spray dryer, and the inlet air temperature is limited to 120 - 140 °C, and the outlet air temperature is limited to 80 - 100 °C.

[0018] The third aspect of the present application provides the use of the sericin peptide described in any of the above in a moisturizing product.

[0019] The sericin peptide provided by the present application clearly contains GGS, AS, and GS as functional peptide fragments, and the content of the peptide fragment GGS is 0.80% or more, the content of the peptide fragment AS is 0.20% or more, and the content of the peptide fragment GS is 0.50% or more. It has been proven by tests that it has an obvious moisturizing effect.

Advantages of the Invention

[0020] When the present application is implemented, at least the following advantages can be obtained. 1. The sericin peptide provided by this application clearly contains GGS, AS, and GS as functional peptide fragments. The content of the peptide fragment GGS is 0.80% or more, the content of the peptide fragment AS is 0.20% or more, and the content of the peptide fragment GS is 0.50% or more, and it has an obvious moisturizing effect.

[0021] 2. In the manufacturing process of the sericin peptide provided by this application, there is no need to use acids and bases for treatment, and it is characterized by being green and environmentally considerate.

Brief Description of the Drawings

[0022] To more clearly explain the technical solutions in the embodiments of this application or the prior art, the drawings to be used in the following description of the embodiments or the prior art will be briefly introduced below. The drawings described below are self-evidently some embodiments of this application, and those skilled in the art can also obtain other drawings from these drawings without creative work.

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Mode for Carrying Out the Invention

[0023] To make the objectives, technical solutions and advantages of the present application clearer, hereinafter, with reference to the examples of the present application, the technical solutions according to the examples of the present application will be clearly and completely described. It is self-evident that the described examples are only a part of the examples of the present application, not all of them. All other examples obtained by those skilled in the art without creative work based on the examples of the present application shall fall within the scope of the claims of the present application.

[0024] The non-pupated cocoons used in the following examples and comparative examples are purchased. Torula yeast (Candida utilis) is purchased from the China Center for Industrial Culture Collection (CICC), and the deposit number of the strain is CICC31170. Alkaline protease is purchased from sigma-Aldrich, neutral protease is purchased from Guangxi Nanning Bowen Biological Engineering Co., Ltd., activated carbon is purchased from Guangdong Huayi Activated Carbon Co., Ltd., and sodium hydroxide is purchased from Xilong Chemical Co., Ltd.

[0025] (Example) The method for producing sericin peptides provided by this example includes steps 1 to 4. In step 1, weigh 100 g of non-pupated cocoons, put them into a crusher to crush and wash with pure water to remove the dust and impurities on the surface. After removing the washing water, mix with pure water at a mass ratio of 1:20, perform a pressure-holding treatment at 121 °C for 30 minutes. After the treatment, remove the insoluble matter and recover the supernatant. Concentrate the supernatant using a rotary evaporator, limit the temperature to 80 °C and the vacuum degree to -0.1 MPa. After half of the water in the solution evaporates, take out the remaining solution and sterilize the remaining solution at 121 °C for 15 minutes to obtain a sericin solution.

[0026] In step 2, the temperature of the sericin solution is limited to 28 - 32°C, and after activation, Torula yeast (10 8 corresponding to 10 6 / g of non-pupated cocoons) is added, and fermentation is continuously carried out at 200 rpm for 48 hours in a shaker to obtain a sericin fermentation broth after fermentation ends.

[0027] In step 3, the pH of the sericin fermentation broth is adjusted to 9.0 using an NaOH solution, and then alkaline protease and neutral protease are added. Moreover, per gram of non-pupated cocoons, the enzyme activity of the added alkaline protease is 5000 U, and the enzyme activity of the added neutral protease is 1000 U. Enzymatic hydrolysis is carried out at 50°C for 6 hours. After the enzymatic hydrolysis ends, a sericin enzymatic hydrolysis solution is obtained.

[0028] In step 4, the temperature of the sericin enzymatic hydrolysis solution is raised to 95°C, and the protease is inactivated by holding for 15 minutes. The sericin enzymatic hydrolysis solution is filtered using a ceramic membrane with a pore size of 10 KD, and the supernatant is recovered and concentrated. Specifically, a rotary evaporator may be used, the temperature is set to 80°C, the vacuum degree is set to -0.1 MPa, and 920 mL of water in the filtrate is evaporated by rotary evaporation.

[0029] The remaining raw material solution is taken out, heated to 70°C, 4 g of activated carbon is added, and stirred at 70°C for 1 hour for adsorption decolorization treatment. After the treatment ends, the activated carbon is removed, and the supernatant is recovered. The supernatant is sent to a spray dryer (BH-100 pressure spray dryer, Jiangsu Bohong) for spray drying, and the inlet air temperature is limited to 140°C and the outlet air temperature is limited to 90°C to obtain sericin peptides.

[0030] (Comparative Example 1) The method provided by this comparative example can refer to the examples. The difference is that in step 3, the time of enzymatic hydrolysis is 4 hours. Specifically, while adjusting the pH of the sericin fermentation broth to 9.0 using an NaOH solution, alkaline protease and neutral protease are added, and enzymatic hydrolysis is carried out at 50 °C for 4 hours. After the enzymatic hydrolysis is completed, a sericin enzymatic hydrolysis solution is obtained.

[0031] (Comparative Example 2) The method provided by this comparative example can refer to the examples. The difference is that in step 3, enzymatic hydrolysis is carried out using only alkaline protease. Specifically, the pH of the sericin fermentation broth is adjusted to 9.0 using an NaOH solution, alkaline protease is added, and enzymatic hydrolysis is carried out at 50 °C for 6 hours. After the enzymatic hydrolysis is completed, a sericin enzymatic hydrolysis solution is obtained.

[0032] (Comparative Example 3) The method provided by this comparative example can refer to the examples. The difference is that in step 3, enzymatic hydrolysis is carried out using only alkaline protease. Specifically, the pH of the sericin fermentation broth is adjusted to 9.0 using an NaOH solution, alkaline protease is added, and enzymatic hydrolysis is carried out at 50 °C for 4 hours. After the enzymatic hydrolysis is completed, a sericin enzymatic hydrolysis solution is obtained.

[0033] (Comparative Example 4) The method provided by this comparative example can refer to the examples. The difference is that in step 3, enzymatic hydrolysis is carried out using only neutral protease. Specifically, the pH of the sericin fermentation broth is adjusted to 9.0 using an NaOH solution, neutral protease is added, and enzymatic hydrolysis is carried out at 50 °C for 4 hours. After the enzymatic hydrolysis is completed, a sericin enzymatic hydrolysis solution is obtained.

[0034] (1) Physical and chemical indicators of the sericin peptides provided by the examples and Comparative Examples 1 to 4 are detected, and the detection methods are as follows. Refer to Table 1 for the detection results. 1. Detection of moisture and ash: The national standard method GB5009.3 - 2010 is adopted to measure the moisture content, and the national standard method GB5009.4 - 2016 is adopted to measure the ash content.

[0035] 2. Detection of protein, peptide content, and free amino acids: The national standard method GB5009.5 - 2010 is adopted to measure the protein (dry basis) content, and with reference to the national standard method GB22729 - 2008, the acid-soluble protein content, free amino acid content, and peptide content are measured.

[0036] 3. Detection of the distribution of components with different molecular weights: Five kinds of peptide standard substances, namely glycine - glycine - glycine (molecular weight 189), glycine - glycine - tyrosine - arginine (molecular weight 451), subtilisin (molecular weight 1450), aprotinin (molecular weight 6500), and cytochrome C (molecular weight 12500), are each prepared as a 0.1% (m / v) solution, filtered through a polytetrafluoroethylene filter membrane with a pore size of 0.2 μm, and then injected into a high-performance liquid chromatograph (LC - 20AD type high-performance liquid chromatograph, Shimadzu Corporation, Japan) for analysis. The mobile phase is V(acetonitrile):V(water):V(trifluoroacetic acid)=45:55:0.1, the injection volume is 10 μL, the flow rate is 0.5 mL / min, the detection wavelength is 220 nm, the column temperature is 30 °C, detected using an ultraviolet detector, and the data is processed using GPC software. The chromatographic data of the sample is substituted into the calibration curve equation for calculation to obtain the peptide molecular weight and its distribution range of the sample. The relative percentage of components with different molecular weight ranges can be calculated using the peak area normalization method.

[0037]

Table 1

[0038] As can be seen from Table 1, the peptide content of the sericin peptide provided by the examples is high, the proportion of components with a relative molecular weight of 1000 or less is low, and the content of free amino acids is lower than that of existing silk fibroin peptide or silk protein peptide products, so it is easy to be absorbed by the human body.

[0039] (2) Detect the moisturizing properties of the sericin peptides provided by Examples and Comparative Examples 1 to 4, and the detection method is as follows. Dissolve ammonium sulfate (NH4)2SO4 (analytical grade, Shanghai Reagent Factory No. 1) in water to prepare a saturated ammonium sulfate (NH4)2SO4 aqueous solution, and place it in an empty desiccator to simulate an environment with a relative humidity (R.H.) of 81%. Prepare the test sample as an aqueous solution with a mass concentration of 2%, and use pure water, 2% serine, 2% glycerin, 5% glycerin, and 0.5% HA as the control group. Weigh each of them and record it as W0. Absorb 200 μL and add it to a watch glass with 3M tape attached. Weigh the mass after 4 hours and 8 hours respectively, and record it as W n and record it. The formula: Moisture retention rate (%) = (W n - W0) ÷ W0 × 100% is used to calculate the moisture retention rate. The test results are expressed as the mean value ± standard deviation. The Tukey's Method is adopted to analyze the data, and p < 0.05 indicates a significant difference. The alphabetical labeling method for multiple comparisons is adopted. Those with the same alphabetical label have no significant difference, and those with different alphabetical labels have a significant difference. Refer to Figure 2 for the test results.

[0040] As shown in Figure 2, in an environment with a relative humidity (R.H.) of 81%, when left standing for 4 hours and 8 hours with pure water as the negative control, the moisture retention rate of the sericin peptide provided by the examples is significantly different from that of pure water and Comparative Examples 1 to 4. Moreover, the moisture retention rate of the sericin peptide in the examples is higher than that of glycerin with the same concentration, but there is no significant difference from serine with the same concentration, 2% and 5% glycerin, and 0.5% HA. This indicates that the sericin peptide provided by the examples has a moisture retention effect equivalent to that of a 2% serine solution, 2% glycerin, 5% glycerin, and 0.5% HA.

[0041] (3) Identify the characteristic structures of the sericin peptides provided by Examples and Comparative Examples 1 to 4, and the identification method is as follows. Accurately weigh 20.0 mg of the powders of GGS, AS, and GS reference substances respectively (all purchased from Suzhou Qiangyao Biotechnology Co., Ltd., with a purity of over 98% for all), add water to dissolve, vortex and mix to make uniform, and make up the volume to 100 mL to obtain a standard stock solution of 200 μg / mL. Take out 500 μL of each of the above standard stock solutions and make up the volume to 10 mL to obtain a mixed standard intermediate working solution of 10 μg / mL. Dilute the mixed standard intermediate working solution step by step with pure water to obtain a series of standard working solutions of 1.95, 3.91, 7.81, 15.63, 31.25, 62.5, 125, 250, and 500 ng / mL.

[0042] Prepare the peptide sample at 20.0 mg / mL using pure water and dilute it 10 3 times with pure water to obtain the test substance.

[0043] Test using a system that combines an ultra-high-speed liquid chromatography Nexera X2 and a triple quadrupole mass spectrometer (Shimadzu, Japan). Specifically, the system includes an LC-30AD×2 infusion pump, a SIL-30AC autosampler, a CTO-20AC column thermostat, a CBM-20A system controller, an LCMS-8060 triple quadrupole mass spectrometer, and a LabSolutions Ver.5.91 chromatography workstation. XS205DU analytical balance (Mettler Toledo, USA), QL-901 vortex mixer (Qilinbeier Instrument Manufacturing Co., Ltd., China) further comprising .

[0044] Conditions for liquid chromatography: Chromatography column: Inertsil ODS-3 (5 μm, 2.1×250 mm), mobile phase: A 0.1% aqueous formic acid solution, B 0.1% formic acid acetonitrile solution, gradient elution program: 0 - 15 min B 0 - 50%, 15 - 20 min B 50 - 100%, 20 - 25 min B 100%, 25.1 - 35 min B 0%, flow rate: 0.2 mL / min, injection volume: 5 μL, column temperature: 40°C.

[0045] Conditions for mass spectrometry: Ionization mode: ESI, positive ion mode, ion spray voltage: +4.5 kV, nebulizing gas flow rate: nitrogen 3.0 L / min, heating gas flow rate: nitrogen 10 L / min, drying gas flow rate: nitrogen 10 L / min, DL temperature: 250°C, heating module temperature: 400°C, ion source temperature: 300°C, scan mode: multiple reaction monitoring (MRM), retention time: 100 milliseconds, delay time: 3 milliseconds. Refer to Table 2 for MRM parameters.

[0046]

Table 2

[0047] Figures 3a - 5b are the chromatographic detection results and standard curves of GGS, AS, and GS standards respectively. Figures 6a - 10c are the chromatographic detection results of each characteristic peptide fragment in the sericin peptides provided by the examples and Comparative Examples 1 - 4. As can be seen from Figures 3a - 10c, the examples and Comparative Examples 1 - 3 all contain three types of characteristic peptide fragments, while Comparative Example 4 contains only the minor characteristic peptide fragments GGS and GS. Calculate the content of the characteristic structures in the sericin peptides of each group from the standard curve, and refer to Table 3 for the calculation results.

[0048]

Table 3

[0049] As can be seen from Table 3, compared with Comparative Examples 1 to 4, the sericin peptide provided by the Examples simultaneously has three types of characteristic peptide fragments GGS, AS, and GS, and the content is clearly superior to that of Comparative Examples 1 to 4. Therefore, it is shown that the production method provided by the Examples can effectively enzymatically hydrolyze silk protein and effectively obtain three types of characteristic peptide fragments GGS, AS, and GS.

[0050] (4) Evaluate the functions of the characteristic structures of the sericin peptides provided by the Examples and Comparative Examples 1 to 4, and the evaluation method is as follows. Prepare standard substances of three types of characteristic peptide fragments GGS, AS, and GS and the sericin peptide provided by the Examples as a 0.4% aqueous solution, and conduct a moisture retention rate test by the evaluation method of the moisture retention function provided in (2). The test results are as shown in Figure 11.

[0051] As shown in Figure 11, when pure water is used as the negative control, the sericin peptide provided by the Examples has a certain moisture retention function, and the change trends of the moisture retention rates of the sericin peptide and the peptide fragments GGS, AS, and GS after standing for 4 hours and 8 hours are the same. Therefore, it is shown that the production method provided by this Example can well retain the three types of peptide fragments GGS, AS, and GS in silk protein and thus has the corresponding moisture retention function.

[0052] It should be noted that each of the above Examples only explains the technical solution of the present application and does not limit it. Although the present application has been described in detail with reference to the above Examples, as is obvious to those skilled in the art, it is still possible to correct the technical solutions described in the above Examples, or perform equivalent substitutions on some or all of their technical features. Due to these corrections or substitutions, the gist of the targeted technical solution does not deviate from the scope of the technical solutions of the Examples of the present application.

[0053] This application claims the priority of a Chinese patent application with an application number of 202211022217.3 and an application title of "Sericin Peptide with Moisturizing Function, Its Manufacturing Method and Use", which was filed with the China National Intellectual Property Administration on August 25, 2022, and is hereby incorporated by reference in its entirety into this application.

Claims

1. A sericin peptide product having a moisturizing function, wherein the composition of the sericin peptide product contains at least peptide fragment GGS, peptide fragment AS, and peptide fragment GS, Based on the mass of the sericin peptide product, the content of the peptide fragment GGS is 0.80% or more, the content of the peptide fragment AS is 0.20% or more, and the content of the peptide fragment GS is 0.50% or more. Sericin peptide product.

2. The sericin peptide product according to claim 1, wherein the protein content of the sericin peptide product is 85% or more, the free amino acid content is 5% or less, the acid-soluble protein content is 80% or more, and the content of components with a relative molecular weight of 1000 or less is 85% or more.

3. 1) A step of eluting sericin from non-pupated cocoons to obtain a sericin solution, 2) Fermenting the sericin solution using Torula yeast, and after the fermentation is completed, obtaining a sericin fermentation broth, 3) Adding alkaline protease and neutral protease to the sericin fermentation broth for enzymatic hydrolysis, and after the enzymatic hydrolysis is completed, obtaining a sericin enzymatic hydrolysis solution, 4) Adding activated carbon to the sericin enzymatic hydrolysis solution for adsorption and decolorization treatment, recovering the filtrate after the treatment is completed, and drying the filtrate to obtain the sericin peptide product. The method for producing the sericin peptide product according to claim 1 or 2.

4. Step 1) specifically includes mixing non-pupated cocoons and pure water at a mass ratio of 1:10 to 30 and treating at 110 to 125 ° C for 10 to 90 minutes to elute sericin from the non-pupated cocoons and obtain the sericin solution. The production method according to claim 3.

5. The number of colonies of the Torula yeast per gram of the non-pupated cocoons is 10 ５ ~10 ７ pieces. The production method according to claim 3.

6. The temperature of the fermentation is 28 to 32 °C, and the time is 36 to 72 hours. The manufacturing method according to claim 3.

7. Per gram of the pupa-free cocoon, the enzyme activity of the alkaline protease is 3000 to 6000 U, and the enzyme activity of the neutral protease is 500 to 1500 U. The manufacturing method according to claim 3.

8. The temperature of the enzymatic hydrolysis is 45 to 55 °C, and the time of the enzymatic hydrolysis is 4 to 6 hours. The manufacturing method according to claim 3.

9. Use of the sericin peptide product according to claim 1 or 2 in a moisturizing product.

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