Whitening and freckle-removing composition containing composite plant extract and preparation method of whitening and freckle-removing composition

Abstract

The invention relates to a whitening and freckle-removing composition containing a composite plant extract and a preparation method of the whitening and freckle-removing composition, and belongs to the technical field of cosmetics. The composition disclosed by the invention is prepared from the following raw materials in parts by weight: 5 to 8 parts of pineapple leaf nano cellulose, 10 to 16 parts of modified starch, 10 to 15 parts of longan seed extract, 6 to 10 parts of mulberry bark extract, 5 to 8 parts of nicotinamide and 8 to 10 parts of hyaluronic acid. The pineapple leaf nanocellulose contains flavonoid and phenolic compounds with double-bond, conjugated double-bond and triple-bond structures, and modified starch is used as a filler to form a film on the surface of skin, so that an anti-ultraviolet protection wall is formed; the betaine-malate ionic liquid is added into the longan seeds, so that extraction of polyphenol in the longan seeds is improved, the longan seeds have acid-base buffering capacity, an auxiliary does not need to be added to adjust the pH value, the components of the prepared composition interact, and the whitening and freckle removing effects are achieved from multiple aspects of ultraviolet resistance, oxidation resistance, inflammation resistance and skin metabolism improvement.

Description

Technical Field

[0001] The invention belongs to the technical field of cosmetics and relates to a whitening and freckle-removing composition containing a composite plant extract and a preparation method thereof. Background Art

[0002] With the advancement of the times, people continue to conduct in-depth research in the field of skin care, especially the issue of whitening and freckle removal, which has always been a problem for everyone. The most direct cause of skin darkening and freckles is melanin deposition. The formation of melanin is mainly caused by ultraviolet radiation, skin inflammation, and slowed skin metabolism. UVA radiation (also known as melanin-effecting ultraviolet radiation) reaches the deeper layers of the epidermis and dermis, causing skin aging and the formation of freckles. Therefore, the existing technology uses plant extracts containing large amounts of flavonoids, polyphenols and other substances with antioxidant properties to block melanin formation and inhibit tyrosinase activity to reduce melanin formation.

[0003] Longan is a plant of the Sapindaceae family, mainly grown in tropical and subtropical regions. Studies have reported that longan tissue (core and shell) contains active substances such as polyphenols, flavonoids, and polysaccharides, which give longan tissue anti-aging, antioxidant, and anti-cancer physiological activities. Although longan core contains a large amount of active substances, it is not simple to improve the extraction effect of active substances. Chinese patent CN106728257A discloses a method for efficiently extracting longan core polyphenols. The invention uses ionizing radiation to treat the slurry with an organic acid solution to reduce its binding ability to polyphenols; a composite enzyme promoter is also added during the extraction process to break the chemical bonds that bind the polyphenols, thereby increasing the polyphenol yield. However, the use of ionizing radiation in the invention can cause chemical bond breakage and structural reorganization in the polyphenol molecules, thereby affecting its antioxidant, anti-inflammatory and other biological activities. In addition, the pH of the traditional organic acid slurry is difficult to control, and the addition of other auxiliary agents is required to adjust the pH value in the enzymatic hydrolysis step, thereby increasing the complexity of the experiment. Therefore, the present invention further optimizes the above existing technologies and prepares a composition containing composite plant extracts with excellent whitening and freckle removal effects. Summary of the Invention

[0004] The present invention relates to a whitening and freckle-removing composition containing a composite plant extract and a preparation method thereof, belonging to the technical field of cosmetics. The composition disclosed in the present invention comprises the following raw materials in parts by weight: 5-8 parts of pineapple leaf nanocellulose, 10-16 parts of modified starch, 10-15 parts of longan kernel extract, 6-10 parts of mulberry bark extract, 5-8 parts of niacinamide, and 8-10 parts of hyaluronic acid. Pineapple leaf nanocellulose contains flavonoids and phenolic compounds with double bonds, conjugated double bonds, and triple bonds. Modified starch is used as a filler to form a thin film on the skin surface, forming an anti-ultraviolet protective wall. The addition of betaine-malate ionic liquid to the longan kernel not only improves the extraction of longan kernel polyphenols, but also provides acid-base buffering capacity without the need to add auxiliary agents to adjust the pH. The components of the composition prepared by the present invention interact with each other to achieve whitening and freckle-removing effects from multiple angles, including anti-ultraviolet, anti-oxidation, anti-inflammatory, and improving skin metabolism.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] The invention discloses a whitening and freckle-removing composition containing a composite plant extract. The composition comprises the following raw materials in parts by weight: 5-8 parts of pineapple leaf nanocellulose, 10-16 parts of modified starch, 10-15 parts of longan kernel extract, 6-10 parts of mulberry bark extract, 5-8 parts of niacinamide, and 8-10 parts of hyaluronic acid.

[0007] Furthermore, the preparation method of the longan seed extract comprises the following steps:

[0008] A1: Longan seeds were dried and crushed into powder, mixed with deionized water to prepare a slurry, and betaine-malate ionic liquid was added and heated to obtain a pretreated mixture;

[0009] A2: A complex enzyme is then added to the pretreated mixture. After enzymatic hydrolysis, solid-liquid separation is performed. Ethyl acetate is added to the liquid for extraction. The extract is adsorbed on a macroporous resin. The macroporous resin is then eluted with a solvent. The eluate is collected and concentrated under reduced pressure. The eluate is then dried in a vacuum drying oven into a powder, which is the longan seed extract.

[0010] Furthermore, in step A1, the water content and mesh size of the powder are 8-10% and 300-360 mesh, respectively; the mass ratio of the powder, deionized water, and betaine-malate ionic liquid is 2-5:10-12:10; the heating temperature and time are 50-60° C. and 2-3 hours, respectively; and the preparation method of the betaine-malate ionic liquid comprises: dissolving betaine in 75% ethanol at a mass ratio of 1:2; then adding sodium hydroxide at a molar ratio of 1:1 to betaine; heating at 50-60° C. for 2-3 hours to form a mixed solution; then adding malic acid at a volume ratio of 1:1-1.2 to the mixed solution; controlling the temperature at 60-90° C. for 2-3 hours; and finally removing the ethanol by rotary evaporation at a temperature of 78.5-80° C. to obtain the betaine-malate ionic liquid.

[0011] Furthermore, in step A2, the mass ratio of the pretreatment mixture to the complex enzyme is 100:0.2-0.5, wherein the complex enzyme is composed of cellulase and pectinase in a mass ratio of 1:1, and the enzymatic hydrolysis time and temperature are 12-18h and 40-45°C, respectively.

[0012] Furthermore, in step A2, the volume ratio of the liquid to ethyl acetate is 1:1-2, the volume ratio of the extract to the solvent is 3:1-2, wherein the solvent is anhydrous ethanol, the temperature and pressure of the reduced pressure concentration are 60-70°C and -0.1MPa, respectively, and the temperature of the vacuum drying is 80-90°C.

[0013] Furthermore, the preparation method of pineapple leaf nanocellulose comprises the following steps:

[0014] (1) Pineapple leaves are dried and ground into powder, added into an alkaline solution and heated, and then filtered to remove the liquid to obtain a pre-treated powder;

[0015] (2) adding ionic liquid to the pretreated powder, heating it, subjecting it to high-pressure shearing treatment, and passing it into a high-pressure homogenizer for high-pressure homogenization;

[0016] (3) Deionized water is then added and stirred, and after crystals are precipitated, centrifugation is performed, and the crystals are vacuum dried to a constant weight to obtain pineapple leaf nanocellulose.

[0017] Furthermore, in step (1), the water content and mesh size of the powder are 5-7% and 200-300 mesh respectively, the mass ratio of the powder to the alkaline solution is 2-3:20-25, wherein the alkaline solution refers to a sodium hydroxide solution with a mass fraction of 40-50%, and the heating temperature and time are 85-90° C. and 3-5 hours respectively.

[0018] Furthermore, in step (2), the mass ratio of the pretreated powder to the ionic liquid is 3-5:100, wherein the ionic liquid is 1-butyl-3-methylimidazolium chloride, the heating refers to heating to 80-90°C, the pressure and speed of the high-pressure shearing are 10-30MPa and 1400-1800rpm respectively, and the pressure and temperature of the high-pressure homogenization are 100MPa and 80-90°C respectively.

[0019] Furthermore, in step (3), the volume ratio of deionized water to ionic liquid is 4-5:1, the stirring time is 20-30 min, and the vacuum drying temperature is 0-10°C.

[0020] Furthermore, the preparation method of the whitening and freckle-removing composition containing the composite plant extract is to compound all the raw material components according to parts by weight.

[0021] Beneficial effects of the present invention:

[0022] 1. The pineapple leaf nanocellulose of the present invention and modified starch form a thin film on the skin surface, which can reflect a small portion of ultraviolet rays and protect the skin. At the same time, the pineapple leaf nanocellulose has flavonoids and phenolic compounds with double bonds, conjugated double bonds and triple bonds that can absorb ultraviolet rays, thus forming an anti-ultraviolet protective wall on the skin surface;

[0023] 2. By adding betaine-malate ionic liquid to longan kernel, the low surface tension of the ionic liquid makes it easier to penetrate into the cell, expand the pores of the cell wall, and promote the release of intracellular components. Malic acid combines with the hydroxyl groups in cellulose through hydrogen bonds and electrostatic interactions, weakening the hydrogen bond network between cellulose chains, causing it to swell or partially dissolve. At the same time, it has antioxidant properties. Betaine also has antioxidant effects, which can reduce the oxidative loss of polyphenols during the extraction process. In addition, malic acid is a dicarboxylic acid, and its acidic group will partially dissociate during the dissolution process, so that the solution automatically maintains a weak acidic environment (pH 3.5-5.0), neutralizing part of the H with the hydroxyl group (-OH) of the weakly alkaline betaine. + , forming a dynamic acid-base balance system to meet the acid-base environment of the next fermentation, breaking the tedious steps of directly adding organic acid and adjusting pH in traditional processes;

[0024] 3. The present invention forms an anti-ultraviolet film by using pineapple leaf nanocellulose and modified starch. At the same time, longan kernel extract, mulberry bark extract, niacinamide and hyaluronic acid directly interact with each other to achieve the whitening and freckle removal effects from multiple angles of anti-oxidation, anti-inflammation and improving skin metabolism. DETAILED DESCRIPTION

[0025] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.

[0026] The modified starch involved in the present invention was purchased from Dacheng Yibo Chemical Co., Ltd., model number yh0305; mulberry bark extract was purchased from Shanyang Lianfeng Biotechnology Co., Ltd.; hyaluronic acid was purchased from Hubei Haijia Biotechnology Co., Ltd., CAS number 9004-61-9; the macroporous resin was XAD-4 resin, with specific parameters of average pore size 0.35 μm, specific surface area 750 m 2 / g; malic acid is L-malic acid, purchased from Wuhan Kemik Biopharmaceutical Technology Co., Ltd., CAS No. 97-67-6; cellulase was purchased from Shandong Pingju Biotechnology Co., Ltd., CAS No. 9012-54-8; pectinase was purchased from Guangdong Mingtong Biotechnology Co., Ltd., CAS No. 9032-75-1; 1-butyl-3-methylimidazolium chloride was purchased from Wuhan Smack Biotechnology Co., Ltd.

[0027] Example 1

[0028] A whitening and freckle-removing composition containing a composite plant extract comprises the following raw materials in parts by weight: 5 parts of pineapple leaf nanocellulose, 10 parts of modified starch, 10 parts of longan kernel extract, 6 parts of mulberry bark extract, 5 parts of niacinamide, and 8 parts of hyaluronic acid.

[0029] The preparation method of the longan seed extract comprises the following steps:

[0030] A1: Longan seeds were dried and crushed into powder, mixed with deionized water to prepare a slurry, and betaine-malate ionic liquid was added and heated to obtain a pretreated mixture;

[0031] A2: A complex enzyme is then added to the pretreated mixture. After enzymatic hydrolysis, solid-liquid separation is performed. Ethyl acetate is added to the liquid for extraction. The extract is adsorbed on a macroporous resin. The macroporous resin is then eluted with a solvent. The eluate is collected and concentrated under reduced pressure. The eluate is then dried in a vacuum drying oven into a powder, which is the longan seed extract.

[0032] The water content and mesh size of the powder in step A1 are 8% and 300 mesh, respectively; the mass ratio of the powder, deionized water, and betaine-malate ionic liquid is 2:10:10; the heating temperature and time are 50° C. and 2 hours, respectively; and the preparation method of the betaine-malate ionic liquid comprises: dissolving betaine in 75% ethanol at a mass ratio of 1:2; then adding sodium hydroxide at a molar ratio of 1:1 to betaine; heating at 50° C. for 2 hours to form a mixed solution; then adding malic acid at a volume ratio of 1:1 to the mixed solution; maintaining the temperature at 60° C. for 2 hours; and finally removing the ethanol by rotary evaporation at 78.5° C. to obtain the betaine-malate ionic liquid.

[0033] In step A2, the mass ratio of the pretreatment mixture to the complex enzyme is 100:0.2, wherein the complex enzyme is composed of cellulase and pectinase in a mass ratio of 1:1, and the enzymatic hydrolysis time and temperature are 12 h and 40° C., respectively.

[0034] In step A2, the volume ratio of the liquid to ethyl acetate is 1:1, the volume ratio of the extract to the solvent is 3:1, wherein the solvent is anhydrous ethanol, the temperature and pressure of the reduced pressure concentration are 60°C and -0.1 MPa, respectively, and the temperature of the vacuum drying is 80°C.

[0035] The preparation method of pineapple leaf nanocellulose comprises the following steps:

[0036] (1) Pineapple leaves are dried and ground into powder, added into an alkaline solution and heated, and then filtered to remove the liquid to obtain a pre-treated powder;

[0037] (2) adding ionic liquid to the pretreated powder, heating it, subjecting it to high-pressure shearing treatment, and passing it into a high-pressure homogenizer for high-pressure homogenization;

[0038] (3) Deionized water is then added and stirred, and after crystals are precipitated, centrifugation is performed, and the crystals are vacuum dried to a constant weight to obtain pineapple leaf nanocellulose.

[0039] In the step (1), the water content and mesh size of the powder are 5% and 200 mesh respectively, the mass ratio of the powder to the alkaline solution is 2:20, wherein the alkaline solution refers to a sodium hydroxide solution with a mass fraction of 40%, and the heating temperature and time are 85° C. and 3 hours respectively.

[0040] In the step (2), the mass ratio of the pretreated powder to the ionic liquid is 3:100, wherein the ionic liquid is 1-butyl-3-methylimidazolium chloride, the heating refers to heating to 80°C, the pressure and speed of the high-pressure shearing are 10 MPa and 1400 rpm respectively, and the pressure and temperature of the high-pressure homogenization are 100 MPa and 80°C respectively.

[0041] In the step (3), the volume ratio of deionized water to ionic liquid is 4:1, the stirring time is 20 min, and the vacuum drying temperature is 0°C.

[0042] The preparation method of the whitening and freckle-removing composition containing the composite plant extract comprises compounding all raw material components according to parts by weight.

[0043] Example 2

[0044] A whitening and freckle-removing composition containing a composite plant extract comprises the following raw materials in parts by weight: 6.5 parts of pineapple leaf nanocellulose, 13 parts of modified starch, 12 parts of longan kernel extract, 8 parts of mulberry bark extract, 6.5 parts of niacinamide, and 9 parts of hyaluronic acid.

[0045] The preparation method of the longan seed extract comprises the following steps:

[0046] A1: Longan seeds were dried and crushed into powder, mixed with deionized water to prepare a slurry, and betaine-malate ionic liquid was added and heated to obtain a pretreated mixture;

[0047] A2: A complex enzyme is then added to the pretreated mixture. After enzymatic hydrolysis, solid-liquid separation is performed. Ethyl acetate is added to the liquid for extraction. The extract is adsorbed on a macroporous resin. The macroporous resin is then eluted with a solvent. The eluate is collected and concentrated under reduced pressure. The eluate is then dried in a vacuum drying oven into a powder, which is the longan seed extract.

[0048] The water content and mesh size of the powder in step A1 are 9% and 330 mesh, respectively; the mass ratio of the powder, deionized water, and betaine-malate ionic liquid is 3.5:11:10; the heating temperature and time are 55° C. and 2.5 hours, respectively; and the preparation method of the betaine-malate ionic liquid comprises: dissolving betaine in 75% ethanol at a mass ratio of 1:2; then adding sodium hydroxide at a molar ratio of 1:1 to betaine; heating at 55° C. for 2.5 hours to form a mixed solution; then adding malic acid at a volume ratio of 1:1.1 to the mixed solution; maintaining the temperature at 75° C. for 2.5 hours; and finally removing ethanol and ether by rotary evaporation at 79° C. to obtain the betaine-malate ionic liquid.

[0049] In step A2, the mass ratio of the pretreatment mixture to the complex enzyme is 100:0.3, wherein the complex enzyme is composed of cellulase and pectinase in a mass ratio of 1:1, and the enzymatic hydrolysis time and temperature are 15 h and 43° C., respectively.

[0050] In step A2, the volume ratio of the liquid to ethyl acetate is 1:1.5, the volume ratio of the extract to the solvent is 3:1.5, wherein the solvent is anhydrous ethanol, the temperature and pressure of the reduced pressure concentration are 65°C and -0.1 MPa, respectively, and the temperature of the vacuum drying is 85°C.

[0051] The preparation method of pineapple leaf nanocellulose comprises the following steps:

[0052] (1) Pineapple leaves are dried and ground into powder, added into an alkaline solution and heated, and then filtered to remove the liquid to obtain a pre-treated powder;

[0053] (2) adding ionic liquid to the pretreated powder, heating it, subjecting it to high-pressure shearing treatment, and passing it into a high-pressure homogenizer for high-pressure homogenization;

[0054] (3) Deionized water is then added and stirred, and after crystals are precipitated, centrifugation is performed, and the crystals are vacuum dried to a constant weight to obtain pineapple leaf nanocellulose.

[0055] The water content and mesh size of the powder in step (1) are 6% and 250 mesh respectively, the mass ratio of the powder to the alkaline solution is 2.5:22.5, wherein the alkaline solution refers to a sodium hydroxide solution with a mass fraction of 45%, and the heating temperature and time are 87° C. and 4 hours respectively.

[0056] In the step (2), the mass ratio of the pretreated powder to the ionic liquid is 4:100, wherein the ionic liquid is 1-butyl-3-methylimidazolium chloride, the heating refers to heating to 85°C, the pressure and speed of the high-pressure shearing are 20 MPa and 1600 rpm respectively, and the pressure and temperature of the high-pressure homogenization are 100 MPa and 85°C respectively.

[0057] In the step (3), the volume ratio of deionized water to ionic liquid is 4.5:1, the stirring time is 25 min, and the vacuum drying temperature is 5°C.

[0058] The preparation method of the whitening and freckle-removing composition containing the composite plant extract comprises compounding all raw material components according to parts by weight.

[0059] Example 3

[0060] A whitening and freckle-removing composition containing a composite plant extract comprises the following raw materials in parts by weight: 8 parts of pineapple leaf nanocellulose, 16 parts of modified starch, 15 parts of longan kernel extract, 10 parts of mulberry bark extract, 8 parts of niacinamide, and 10 parts of hyaluronic acid.

[0061] The preparation method of the longan seed extract comprises the following steps:

[0062] A1: Longan seeds were dried and crushed into powder, mixed with deionized water to prepare a slurry, and betaine-malate ionic liquid was added and heated to obtain a pretreated mixture;

[0063] A2: A complex enzyme is then added to the pretreated mixture. After enzymatic hydrolysis, solid-liquid separation is performed. Ethyl acetate is added to the liquid for extraction. The extract is adsorbed on a macroporous resin. The macroporous resin is then eluted with a solvent. The eluate is collected and concentrated under reduced pressure. The eluate is then dried in a vacuum drying oven into a powder, which is the longan seed extract.

[0064] The water content and mesh size of the powder in step A1 are 10% and 360 mesh, respectively; the mass ratio of the powder, deionized water, and betaine-malate ionic liquid is 5:12:10; the heating temperature and time are 60° C. and 3 hours, respectively; and the preparation method of the betaine-malate ionic liquid comprises: dissolving betaine in 75% ethanol at a mass ratio of 1:2; then adding sodium hydroxide at a molar ratio of 1:1 to betaine; heating at 60° C. for 3 hours to form a mixed solution; then adding malic acid at a volume ratio of 1:1.2 to the mixed solution; maintaining the temperature at 90° C. for 3 hours; and finally removing ethanol and ether by rotary evaporation at 80° C. to obtain the betaine-malate ionic liquid.

[0065] In step A2, the mass ratio of the pretreatment mixture to the complex enzyme is 100:0.5, wherein the complex enzyme is composed of cellulase and pectinase in a mass ratio of 1:1, and the enzymatic hydrolysis time and temperature are 18 h and 45° C., respectively.

[0066] In step A2, the volume ratio of the liquid to ethyl acetate is 1:2, the volume ratio of the extract to the solvent is 3:2, wherein the solvent is anhydrous ethanol, the temperature and pressure of the reduced pressure concentration are 70°C and -0.1 MPa, respectively, and the temperature of the vacuum drying is 90°C.

[0067] The preparation method of pineapple leaf nanocellulose comprises the following steps:

[0068] (1) Pineapple leaves are dried and ground into powder, added into an alkaline solution and heated, and then filtered to remove the liquid to obtain a pre-treated powder;

[0069] (2) adding ionic liquid to the pretreated powder, heating it, subjecting it to high-pressure shearing treatment, and passing it into a high-pressure homogenizer for high-pressure homogenization;

[0070] (3) Deionized water is then added and stirred, and after crystals are precipitated, centrifugation is performed, and the crystals are vacuum dried to a constant weight to obtain pineapple leaf nanocellulose.

[0071] In the step (1), the water content and mesh size of the powder are 7% and 300 mesh respectively, the mass ratio of the powder to the alkaline solution is 3:25, wherein the alkaline solution refers to a sodium hydroxide solution with a mass fraction of 50%, and the heating temperature and time are 90° C. and 5 hours respectively.

[0072] In the step (2), the mass ratio of the pretreated powder to the ionic liquid is 5:100, wherein the ionic liquid is 1-butyl-3-methylimidazolium chloride, the heating refers to heating to 90°C, the pressure and speed of the high-pressure shearing are 30 MPa and 1800 rpm respectively, and the pressure and temperature of the high-pressure homogenization are 100 MPa and 90°C respectively.

[0073] In the step (3), the volume ratio of deionized water to ionic liquid is 5:1, the stirring time is 30 minutes, and the vacuum drying temperature is 10°C.

[0074] The preparation method of the whitening and freckle-removing composition containing the composite plant extract comprises compounding all raw material components according to parts by weight.

[0075] Comparative Example 1

[0076] On the basis of Example 2, only the modified starch was removed from the raw materials, and other conditions were the same as those in Example 2.

[0077] Comparative Example 2

[0078] On the basis of Example 2, the betaine-malate ionic liquid in the preparation process of longan seed extract was replaced by an equal mass of citric acid liquid, wherein the mass fraction of the citric acid liquid was 50%, and other conditions were consistent with Example 2.

[0079] Comparative Example 3

[0080] On the basis of Example 2, the longan kernel extract was removed from the raw material and replaced with an equal weight portion of mulberry bark extract. Other conditions were the same as those in Example 2.

[0081] Comparative Example 4

[0082] On the basis of Example 2, the mulberry bark extract in the raw material was removed and replaced with an equal weight portion of longan kernel extract. Other conditions were the same as those in Example 2.

[0083] Comparative Example 5

[0084] On the basis of Example 2, nicotinamide was removed from the raw material and replaced with mulberry bark extract in equal parts by weight. Other conditions were the same as those in Example 2.

[0085] Comparative Example 6

[0086] On the basis of Example 2, the hyaluronic acid in the raw material was removed and replaced with niacinamide in equal parts by weight. Other conditions were the same as those in Example 2.

[0087] Performance Testing

[0088] The longan kernel extracts prepared in Examples 1-3 and Comparative Example 2 were taken as samples, and the total phenol content and total flavonoid content of the samples were tested using the Folin-Ciocalteu method and the aluminum nitrate-sodium nitrite colorimetric method. The mass of the sample was 5 g, and the standard curve regression equation was obtained by linear fitting to obtain the total phenol content and total flavonoid content. The test results are shown in Table 1.

[0089] Table 1

[0090] Sample Total phenol content mg / g Total flavonoids content mg / g Example 1 16.435 42.351 Example 2 16.574 43.124 Example 3 16.385 42.571 Comparative Example 2 15.469 41.158

[0091] From the analysis of the results in Table 1, it can be seen that the total phenol content and total flavonoid content of Examples 1-3 are greater than those of Comparative Example 2. In Comparative Example 2, the betaine-malate ionic liquid in the preparation process of the longan core extract is replaced by an equal mass of citric acid liquid. Citric acid is more acidic than malic acid, and the pH range is 2-3. Citric acid also has a good degradation effect on cellulose. However, during the enzymatic hydrolysis process, the pH value is lower than the enzymatic hydrolysis environment of cellulase and pectinase, resulting in a poor enzymatic hydrolysis effect, resulting in the total phenol content and total flavonoid content being less than those of Examples 1-3. In addition, the dual antioxidant effect of betaine and malic acid in Examples 1-3 prevents the oxidation of phenolic substances and increases their content.

[0092] Allergy test: The compositions prepared in Examples 1-3 and Comparative Examples 1-6 were diluted with 50 times the mass of deionized water to form body fluids as samples. 90 volunteers were randomly divided into 9 groups of 10 participants. 0.5 mL of the sample was applied to the flexed forearm of the volunteers. Skin reactions were observed after 2 hours, and the reaction results were recorded according to the "Skin Adverse Reaction Grading Standard Table."

[0093] Whitening and freckle removal test: Mouse B16 melanoma cells were inoculated in RPMI-1640 culture medium containing 10% fetal bovine serum under sterile conditions and cultured in a 37°C, 5% CO2 incubator for standby use. Mouse B16 melanoma cells were digested with 0.25% trypsin and collected, and the cell concentration was adjusted to 5×10 4 / mL, 100 μL per well was inoculated in a 96-well plate, and after culturing in an incubator for 24 hours, the supernatant was discarded and the cells were divided into 9 groups and the sample was added to each group. The blank control group was only added with an equal volume of RPMI-1640 medium. Each group had 6 replicate wells and was cultured for 24 hours. 20 μL of phosphate buffer solution was added to each well. The cells were cultured at a constant temperature of 37°C, 5% CO2 in a cell culture incubator for 4 hours, and the supernatant was discarded. During the culture, 150 μL of dimethyl sulfoxide solution was added to each well under normal light. After shaking for 10 minutes, the absorbance was measured at 490 nm on a microplate reader to calculate the inhibition rate of melanin. The specific formula is: inhibition rate (%) = [1-(absorbance of sample / absorbance of blank control group)] × 100%. The test results are shown in Table 2.

[0094] Sample Whether the skin is abnormal Inhibition rate (%) Example 1 no 98.56 Example 2 no 98.73 Example 3 no 98.62 Comparative Example 1 no 86.96 Comparative Example 2 no 88.41 Comparative Example 3 no 82.14 Comparative Example 4 no 83.56 Comparative Example 5 no 83.75 Comparative Example 6 no 84.21

[0095] Analysis of Table 2 indicates that the Examples and Comparative Examples do not cause skin allergies, with Examples 1-3 exhibiting greater inhibition rates than Comparative Examples 1-6. Comparative Example 1, due to the lack of modified starch, cannot form a film, cannot reflect ultraviolet light, and cannot evenly disperse the pineapple leaf nanocellulose, leading to ultraviolet light stimulating the active sites of tyrosinase. Comparative Example 2, due to the reduction of phenolic and ketone substances, exhibits a reduced antioxidant effect and reduced inhibition of melanoma cells. Comparative Examples 3-6, lacking one of longan kernel extract, mulberry bark extract, niacinamide, and hyaluronic acid, exhibit reduced antioxidant, anti-inflammatory, or skin metabolism effects, leading to a corresponding reduction in melanoma cell inhibition.

[0096] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A whitening and freckle-removing composition containing a composite plant extract, characterized in that: The whitening and freckle-removing composition comprises the following raw materials in parts by weight: 5-8 parts of pineapple leaf nanocellulose, 10-16 parts of modified starch, 10-15 parts of longan kernel extract, 6-10 parts of mulberry bark extract, 5-8 parts of niacinamide, and 8-10 parts of hyaluronic acid.

2. The whitening and freckle-removing composition containing a composite plant extract according to claim 1, characterized in that: The preparation method of the longan seed extract comprises the following steps: A1: Longan seeds were dried and crushed into powder, mixed with deionized water to prepare a slurry, and betaine-malate ionic liquid was added and heated to obtain a pretreated mixture; A2: A complex enzyme is then added to the pretreated mixture. After enzymatic hydrolysis, solid-liquid separation is performed. Ethyl acetate is added to the liquid for extraction. The extract is adsorbed on a macroporous resin. The macroporous resin is then eluted with a solvent. The eluate is collected and concentrated under reduced pressure. The eluate is then dried in a vacuum drying oven into a powder, which is the longan seed extract.

3. The whitening and freckle-removing composition containing a composite plant extract according to claim 2, characterized in that: The water content and mesh size of the powder in step A1 are 8-10% and 300-360 mesh, respectively; the mass ratio of the powder, deionized water, and betaine-malate ionic liquid is 2-5:10-12:10; the heating temperature and time are 50-60° C. and 2-3 hours, respectively. The betaine-malate ionic liquid is prepared by dissolving betaine in 75% ethanol at a mass ratio of 1:2; then adding sodium hydroxide at a molar ratio of 1:1 to betaine; heating at 50-60° C. for 2-3 hours to form a mixed solution; then adding malic acid at a volume ratio of 1:1-1.2 to the mixed solution; maintaining the temperature at 60-90° C. for 2-3 hours; and finally removing the ethanol by rotary evaporation at a temperature of 78.5-80° C. to obtain the betaine-malate ionic liquid.

4. The whitening and freckle-removing composition containing a composite plant extract according to claim 2, characterized in that: In step A2, the mass ratio of the pretreatment mixture to the complex enzyme is 100:0.2-0.5, wherein the complex enzyme is composed of cellulase and pectinase in a mass ratio of 1:1, and the enzymatic hydrolysis time and temperature are 12-18h and 40-45°C, respectively.

5. The whitening and freckle-removing composition containing a composite plant extract according to claim 2, characterized in that: In step A2, the volume ratio of the liquid to ethyl acetate is 1:1-2, the volume ratio of the extract to the solvent is 3:1-2, wherein the solvent is anhydrous ethanol, the temperature and pressure of the reduced pressure concentration are 60-70°C and -0.1MPa, respectively, and the temperature of the vacuum drying is 80-90°C.

6. The whitening and freckle-removing composition containing a composite plant extract according to claim 1, characterized in that: The preparation method of pineapple leaf nanocellulose comprises the following steps: (1) Pineapple leaves are dried and ground into powder, added into an alkaline solution and heated, and then filtered to remove the liquid to obtain a pre-treated powder; (2) adding ionic liquid to the pretreated powder, heating it, subjecting it to high-pressure shearing treatment, and passing it into a high-pressure homogenizer for high-pressure homogenization; (3) Deionized water is then added and stirred, and after crystals are precipitated, centrifugation is performed, and the crystals are vacuum dried to a constant weight to obtain pineapple leaf nanocellulose.

7. The whitening and freckle-removing composition containing a composite plant extract according to claim 6, characterized in that: In the step (1), the water content and mesh size of the powder are 5-7% and 200-300 mesh respectively, the mass ratio of the powder to the alkaline solution is 2-3:20-25, wherein the alkaline solution refers to a sodium hydroxide solution with a mass fraction of 40-50%, and the heating temperature and time are 85-90° C. and 3-5 hours respectively.

8. The whitening and freckle-removing composition containing a composite plant extract according to claim 6, characterized in that: In the step (2), the mass ratio of the pretreated powder to the ionic liquid is 3-5:100, wherein the ionic liquid is 1-butyl-3-methylimidazolium chloride, the heating refers to heating to 80-90°C, the pressure and speed of the high-pressure shearing are 10-30MPa and 1400-1800rpm respectively, and the pressure and temperature of the high-pressure homogenization are 100MPa and 80-90°C respectively.

9. The whitening and freckle-removing composition containing a composite plant extract according to claim 6, characterized in that: In the step (3), the volume ratio of deionized water to ionic liquid is 4-5:1, the stirring time is 20-30 minutes, and the vacuum drying temperature is 0-10°C.

10. The whitening and freckle-removing composition containing a composite plant extract according to claim 1, characterized in that: The preparation method of the whitening and freckle-removing composition containing the composite plant extract comprises compounding all raw material components according to parts by weight.