Grapefruit extract, preparation method and application thereof

Abstract

This invention discloses a grapefruit extract, its preparation method, and its application, belonging to the field of plant extraction technology. The grapefruit extract prepared by the method provided by this invention has excellent penetration-enhancing effects and can be applied to the preparation of cosmetics with penetration-enhancing effects. Furthermore, the preparation method provided by this invention is easy to operate, requires no complex or special equipment, and has a stable production process, which is beneficial for actual production. At the same time, no organic reagents are involved in the preparation process except for the ethanol solution, and the reagents used, such as the alcohol solution, can be recycled and reused, and the acid solution can also be discharged through acid-base neutralization. That is, the overall preparation method is environmentally friendly and green.

Description

Technical Field

[0001] This invention belongs to the field of plant extraction technology, and particularly relates to a grapefruit extract, its preparation method, and its application. Background Art

[0002] Grapefruit is a woody plant belonging to the genus Citrus in the family Rutaceae. Its branches have long thorns, and its leaves are ovate-oblong or elliptical. The calyx is hairless, and the petals are slightly smaller than those of the grapefruit flower. The fruit is spherical or oblate, with a thick, difficult-to-peel peel. It is orange-yellow or vermilion, with an uneven surface, and the flesh is sour, sometimes with a bitter taste. The fruiting season is from October to November. When grapefruits are hanging on the tree, they are very close together, usually growing in clusters. Because the fruit is small and looks like grapes hanging down, it is called grapefruit.

[0003] Grapefruit peel can be used to extract essential oils, pectin, naringin, and neohesperidin. Grapefruit peel essential oil is used as a flavoring and aroma enhancer in beverages, beer, and candy. Naringin, rutin, and other flavonoids have antioxidant activity, which can reduce blood viscosity and prevent cerebrovascular diseases. Grapefruit seeds also contain a significant amount of flavonoids; the flavonoid content in their glycerol extract is as high as 6700 mg / kg. Previous studies have shown that grapefruit peel contains grapefruit pectin, and pectin has a significant effect on lowering plasma total cholesterol and low-density lipoprotein. However, in actual production, a large amount of grapefruit leaves, peel (accounting for about 30% of the grapefruit's weight), and seeds are not fully utilized, resulting in serious resource waste and environmental pollution. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a grapefruit extract, its preparation method, and its application.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a method for preparing grapefruit extract, the method comprising the following steps:

[0006] (1) Grapefruit peel powder was mixed with the first alcohol solution and then heated and refluxed for extraction, followed by filtration to obtain the first filter residue and the first crude extract.

[0007] (2) After mixing the first filter residue from step (1) with the second alcohol solution, heat and reflux to extract, then filter to obtain the second crude extract;

[0008] (3) After mixing the first crude extract and the second crude extract, the system is adjusted to acidity. Then activated carbon is added for decolorization, followed by filtration. The filtrate is collected and concentrated to obtain a concentrated solution.

[0009] (4) After mixing the concentrate from step (3) with hot water, filter and wash to obtain the second filter residue;

[0010] (5) After mixing the second filter residue with the third alcohol solution, filter the mixture, collect the filtrate and add water to obtain a diluted solution;

[0011] (6) Let the diluted solution stand, filter it, collect the third filter residue and dry it to obtain grapefruit extract.

[0012] The method for preparing grapefruit extract provided by this invention first extracts the active ingredients into a crude extract by heating and reflux extraction. Then, by adjusting the crude extract to acidity, acid-insoluble components (such as hesperidin) are removed. Under acidic conditions, some flavonoids undergo acid hydrolysis, disrupting the conjugated system of some coloring substances, thus lightening the color of the crude extract. Further, activated carbon decolorization reduces the color of the extract. Since the decolorization process involves heating, a high temperature is provided, allowing some components to undergo further acid hydrolysis under acidic conditions. Next, after concentration, the extract is mixed with hot water, filtered, and washed to remove hot water-soluble components (such as naringin), further achieving purification and decolorization. Finally, by mixing with a tertiary alcohol solution, filtering, diluting with water, and allowing to stand, components soluble in both water and alcohol are removed. Finally, after drying, a grapefruit extract with enhanced penetration is obtained. The preparation method of grapefruit extract provided by this invention involves interconnected steps. Under the overall technical solution provided by this invention, the obtained grapefruit extract not only has high whiteness and good extraction rate, but also has a good permeation-promoting effect.

[0013] As a preferred embodiment of the preparation method of the present invention, at least one of the following (a)-(e) is used:

[0014] (a) The moisture content of the grapefruit peel powder is ≤10%, and the mesh size is 60-80 mesh;

[0015] (b) The first alcohol solution and the second alcohol solution are each independently selected from an aqueous ethanol solution with a mass concentration of 50-100%;

[0016] (c) The temperature for the heating and reflux extraction is 50-90℃, and the time is 1-3h;

[0017] (d) The mass ratio of the grapefruit peel powder to the first alcohol solution is 1:(5-30);

[0018] (e) The mass ratio of the grapefruit peel powder to the second alcohol solution is 1:(5-30).

[0019] Preferably, the grapefruit peel powder with a moisture content of ≤10% is obtained by drying the grapefruit peel at an environment of 50-80℃.

[0020] In a preferred embodiment of the preparation method of the present invention, the filtration in steps (1) and (2) is performed using a plate and frame filter press.

[0021] Preferably, the plate and frame filter has a mesh size of 500 mesh.

[0022] The inventors discovered that when the above-mentioned temperature and time for heating and reflux extraction, as well as the ratio of extractant to liquid and the initial raw materials are used, a product with a better yield can be obtained, and the product also has a better penetration-promoting effect.

[0023] In a preferred embodiment of the preparation method of the present invention, in step (3), the pH value of the system is adjusted to 1-5 when it is acidic.

[0024] The inventors discovered that by further selecting a pH value of 1-5, other components can be removed more effectively, resulting in a grapefruit extract with superior penetration-enhancing properties.

[0025] As a preferred embodiment of the preparation method of the present invention, in step (3), the amount of activated carbon added is 10-300% of the mass of grapefruit peel powder, the decolorization temperature is 40-80℃, and the time is 1-6h.

[0026] The addition of activated carbon enables adsorption and decolorization. The decolorization process is carried out at a temperature of 40-80℃, which provides a certain high-temperature environment to promote the further decomposition of temperature-unstable compounds. This not only improves the whiteness of the product but also enhances its penetration-promoting effect.

[0027] In a preferred embodiment of the preparation method of the present invention, in step (3), the concentration temperature is 30-60℃ and the pressure is ≥-0.1MPa; the mass percentage of alcohol in the concentrate is 0-30%.

[0028] In a preferred embodiment of the preparation method of the present invention, in step (3), the filtration is a plate and frame filtration with a mesh size of 500 mesh.

[0029] In a preferred embodiment of the preparation method described in this invention, the temperature of the hot water in step (4) is 60-90°C.

[0030] In a preferred embodiment of the preparation method of the present invention, in step (4), the volume ratio of the concentrate to hot water is 1:(4-6).

[0031] In a preferred embodiment of the preparation method of the present invention, in step (4), the endpoint of washing is that the water after washing is colorless as observed by the naked eye.

[0032] The inventors discovered that when hot water at 60-90°C is used to mix the concentrate with a specific volume ratio in step (4), and the washing after filtration is also done with hot water at this temperature range, hot water-insoluble substances can be further eliminated, the purity of the prepared extract can be further improved, and the effects of other impurities on the permeation-enhancing effect can be avoided.

[0033] In a preferred embodiment of the preparation method of the present invention, in step (5), the mass ratio of the second filter residue to the third alcohol solution is 1:(1-10), and the third alcohol solution is an aqueous ethanol solution with a mass concentration of 70-100%.

[0034] In a preferred embodiment of the preparation method described in this invention, the mass percentage of ethanol in the diluent is 0-30%.

[0035] The inventors discovered that when the mass ratio of the selected second filter residue to the third alcohol solution is within 1:(1-10), the mass concentration of the third alcohol solution is 70-100%, and the mass percentage of ethanol in the diluent is 0-30%, it is possible to better remove components that are soluble in both water and alcohol, thereby improving the product's penetration-enhancing effect.

[0036] In a preferred embodiment of the preparation method of the present invention, the standing time in step (6) is 12-48h.

[0037] In a preferred embodiment of the preparation method of the present invention, in step (6), the drying temperature is 30-60℃, the drying time is 2-8h, and the drying pressure is ≥-0.1MPa.

[0038] In a second aspect, the present invention provides a grapefruit extract prepared using the preparation method of the present invention.

[0039] The grapefruit extract provided by this invention has high whiteness and good penetration-enhancing effect.

[0040] In a third aspect, the present invention provides the use of the grapefruit extract in the preparation of cosmetics with enhanced penetration effects.

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0042] The grapefruit extract prepared by the present invention has excellent penetration-enhancing effects and can be applied to the preparation of cosmetics with penetration-enhancing effects. Furthermore, the preparation method provided by the present invention is easy to operate, requires no complex or special equipment, and has a stable production process, which is beneficial to actual production. At the same time, no organic reagents are involved in the preparation process except for the ethanol solution, and the reagents used, such as the alcohol solution, can be recycled and reused, and the acid solution can also be discharged through acid-base neutralization. In other words, the overall preparation method is environmentally friendly and green. Attached Figure Description

[0043] Figure 1 The liquid chromatogram for exploring the osmotic enhancement effect of glycyrrhizin in the effect example;

[0044] Figure 2 The liquid chromatogram is shown for the penetration enhancement of the grapefruit extract prepared in Example 1 of the effect example.

[0045] Figure 3 The liquid chromatogram is shown for the penetration enhancement of the grapefruit extract prepared in Example 2 of the effect example.

[0046] Figure 4 The liquid chromatogram for the permeation-enhancing effect of the grapefruit extract prepared in Comparative Example 1 is shown in the example.

[0047] Figure 5 The liquid chromatogram for exploring the permeation enhancement of grapefruit extract prepared in Comparative Example 3 in the effect example;

[0048] Figure 6 The liquid chromatogram for exploring the permeation enhancement of grapefruit extract prepared in Comparative Example 4 in the effect example;

[0049] Figure 7 The liquid chromatogram is shown for the penetration enhancement of the grapefruit extract prepared in Comparative Example 5 in the effect example. Detailed Implementation

[0050] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0051] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in the field.

[0052] Example 1

[0053] This invention provides a grapefruit extract, the preparation method of which includes the following steps:

[0054] (1) Dry the grapefruit peel at 60°C until the moisture content is 8.6%, then crush and sieve to obtain 60-mesh grapefruit peel powder;

[0055] (2) Take 1 kg of grapefruit peel powder and mix it with 10 L of 80% ethanol aqueous solution. Heat and reflux at 70°C for 2 h. Then filter it with a 500 mesh plate and frame filter to obtain the first filter residue and the first crude extract.

[0056] (3) The first filter residue was mixed with 10L of ethanol aqueous solution with a mass concentration of 80%, and extracted by reflux at 70°C for 2h. Then, it was filtered by a 500-mesh plate and frame filter to obtain the second crude extract.

[0057] (4) After mixing the first crude extract and the second crude extract, the pH of the system was adjusted to 2 with 4% hydrochloric acid, and 1 kg of activated carbon was added. The mixture was decolorized at 70°C for 4 h, and then filtered with a 500 mesh plate and frame filter. The filtrate was collected and concentrated at 50°C and -0.1 MPa until the mass percentage of alcohol in the concentrate was 15%, thus obtaining the concentrate.

[0058] (5) Dissolve the concentrate in pure water at 80°C. The mass ratio of the concentrate to the pure water is 1:5. Then filter it with a 500-mesh plate and frame filter press and wash it with pure water at 80°C until the water after washing is colorless. Collect the filter cake to obtain the second filter residue.

[0059] (6) Add the second filter residue to an ethanol aqueous solution with a mass concentration of 90% and the mass ratio of the second filter residue to the ethanol aqueous solution is 1:5. Then filter, take the filtrate, and add water to the filtrate to dilute it to a mass concentration of ethanol of 30% to obtain a diluted solution.

[0060] (7) The diluted solution was allowed to stand for 24 hours, then filtered under reduced pressure at -0.1 MPa, the filter cake was collected, and dried at 50°C and -0.1 MPa for 5 hours. Then it was pulverized and passed through an 80-mesh sieve, and the sieve residue was collected to obtain grapefruit extract.

[0061] Example 2

[0062] This invention provides a grapefruit extract, the preparation method of which includes the following steps:

[0063] (1) Dry the grapefruit peel at 60°C until the moisture content is 8.6%, then crush and sieve to obtain 60-mesh grapefruit peel powder;

[0064] (2) Take 1 kg of grapefruit peel powder and mix it with 10 L of 70% ethanol aqueous solution. Heat and reflux at 50°C for 3 h. Then filter it with a 500 mesh plate and frame filter to obtain the first filter residue and the first crude extract.

[0065] (3) The first filter residue was mixed with 10L of 70% ethanol aqueous solution and heated and refluxed at 50°C for 3h. Then it was filtered with a 500-mesh plate and frame filter to obtain the second crude extract.

[0066] (4) After mixing the first crude extract and the second crude extract, the pH of the system was adjusted to 5 with 4% hydrochloric acid solution, and 0.5 kg of activated carbon was added. The mixture was decolorized at 50°C for 6 h, and then filtered with a 500 mesh plate and frame filter. The filtrate was collected and concentrated at 50°C and -0.1 MPa until the mass percentage of alcohol in the concentrate was 30%, thus obtaining the concentrate.

[0067] (5) Dissolve the concentrate in pure water at 60°C. The mass ratio of the concentrate to the pure water is 1:5. Then filter it with a 500-mesh plate and frame filter press and wash it with pure water at 60°C until the water after washing is colorless. Collect the filter cake to obtain the second filter residue.

[0068] (6) Add the second filter residue to an ethanol aqueous solution with a mass concentration of 95% and the mass ratio of the second filter residue to the ethanol aqueous solution is 1:2. Then filter, take the filtrate, and add water to the filtrate to dilute it to a mass concentration of ethanol of 20% to obtain a diluted solution.

[0069] (7) The diluted solution was allowed to stand for 24 hours, then filtered under reduced pressure at -0.1 MPa, the filter cake was collected, and dried at 50°C and -0.1 MPa for 5 hours. Then it was pulverized and passed through an 80-mesh sieve, and the sieve residue was collected to obtain grapefruit extract.

[0070] Example 3

[0071] This invention provides a grapefruit extract, the preparation method of which includes the following steps:

[0072] (1) Dry the grapefruit peel at 60°C until the moisture content is 8.6%, then crush and sieve to obtain 60-mesh grapefruit peel powder;

[0073] (2) Take 1 kg of grapefruit peel powder and mix it with 10 L of 50% ethanol aqueous solution. Heat and reflux at 90°C for 1 h. Then filter it with a 500 mesh plate and frame filter to obtain the first filter residue and the first crude extract.

[0074] (3) The first filter residue was mixed with 10L of 50% ethanol aqueous solution and heated and refluxed at 90°C for 1h. Then it was filtered with a 500-mesh plate and frame filter to obtain the second crude extract.

[0075] (4) After mixing the first crude extract and the second crude extract, the pH of the system was adjusted to 1 with 4% hydrochloric acid solution, and 2 kg of activated carbon was added. The mixture was decolorized at 80°C for 2 h, and then filtered with a 500-mesh plate and frame filter. The filtrate was collected and concentrated at 50°C and -0.1 MPa until the mass percentage of alcohol in the concentrate was 5%, thus obtaining the concentrate.

[0076] (5) Dissolve the concentrate in pure water at 90°C. The mass ratio of the concentrate to the pure water is 1:5. Then filter it with a 500-mesh plate and frame filter press and wash it with pure water at 90°C until the water after washing is colorless. Collect the filter cake to obtain the second filter residue.

[0077] (6) Add the second filter residue to an ethanol aqueous solution with a mass concentration of 70% and the mass ratio of the second filter residue to the ethanol aqueous solution is 1:10. Then filter, take the filtrate, and add water to the filtrate to dilute it to a mass concentration of ethanol of 10% to obtain a diluted solution.

[0078] (7) The diluted solution was allowed to stand for 24 hours, then filtered under reduced pressure at -0.1 MPa, the filter cake was collected, and dried at 50°C and -0.1 MPa for 5 hours. Then it was pulverized and passed through an 80-mesh sieve, and the sieve residue was collected to obtain grapefruit extract.

[0079] Example 4

[0080] This invention provides a grapefruit extract, the preparation method of which includes the following steps:

[0081] (1) Dry the grapefruit peel at 70°C until the moisture content is 6.7%, then crush and sieve to obtain 60-mesh grapefruit peel powder;

[0082] (2) Take 1 kg of grapefruit peel powder and mix it with 10 L of 80% ethanol aqueous solution. Heat and reflux at 70°C for 2 h. Then filter it with a 500 mesh plate and frame filter to obtain the first filter residue and the first crude extract.

[0083] (3) The first filter residue was mixed with 10L of ethanol aqueous solution with a mass concentration of 80%, and extracted by reflux at 70°C for 2h. Then, it was filtered by a 500-mesh plate and frame filter to obtain the second crude extract.

[0084] (4) After mixing the first crude extract and the second crude extract, the pH of the system was adjusted to 2 with 4% hydrochloric acid solution, and 1 kg of activated carbon was added. The mixture was decolorized at 80°C for 2 hours. Then, it was filtered with a 500-mesh plate and frame filter. The filtrate was collected and concentrated at 60°C and -0.1 MPa until the mass percentage of alcohol in the concentrate was 15%, thus obtaining the concentrate.

[0085] (5) Dissolve the concentrate in pure water at 90°C. The mass ratio of the concentrate to the pure water is 1:5. Then filter it with a 500-mesh plate and frame filter press and wash it with pure water at 90°C until the water after washing is colorless. Collect the filter cake to obtain the second filter residue.

[0086] (6) Add the second filter residue to an ethanol aqueous solution with a mass concentration of 90% and the mass ratio of the second filter residue to the ethanol aqueous solution is 1:5. Then filter, take the filtrate, and add water to the filtrate to dilute it to a mass concentration of ethanol of 30% to obtain a diluted solution.

[0087] (7) The diluted solution was allowed to stand for 24 hours, then filtered under reduced pressure at -0.1 MPa, the filter cake was collected, and dried at 60℃ and -0.1 MPa for 4 hours. Then it was pulverized and passed through an 80-mesh sieve, and the sieve residue was collected to obtain grapefruit extract.

[0088] Comparative Example 1

[0089] This invention provides a grapefruit extract in a comparative example, the preparation method of which includes the following steps:

[0090] (1) Dry the grapefruit peel at 60°C until the moisture content is 8.6%, then crush and sieve to obtain 60-mesh grapefruit peel powder;

[0091] (2) Take 1 kg of grapefruit peel powder and mix it with 10 L of 80% ethanol aqueous solution. Heat and reflux at 70°C for 2 h. Then filter it with a 500 mesh plate and frame filter to obtain the first filter residue and the first crude extract.

[0092] (3) The first filter residue was mixed with 10L of ethanol aqueous solution with a mass concentration of 80%, and extracted by reflux at 70°C for 2h. Then, it was filtered by a 500-mesh plate and frame filter to obtain the second crude extract.

[0093] (4) The first crude extract and the second crude extract are mixed and concentrated at 50°C and -0.1MPa until the mass percentage of alcohol in the concentrate is 15% to obtain the concentrate.

[0094] (5) The concentrate was dried at 50°C and -0.1MPa for 5 hours, then pulverized and passed through an 80-mesh sieve. The sieve residue was collected to obtain grapefruit extract.

[0095] Comparative Example 2

[0096] The present invention provides a grapefruit extract in a comparative example. The only difference between the preparation method of the grapefruit extract and that of Example 1 is that in step (4), the first crude extract and the second crude extract are mixed and 1 kg of activated carbon is added. The mixture is decolorized at 70°C for 4 h, and then filtered using a 500-mesh plate and frame filter. The filtrate is collected and concentrated at 50°C and -0.1 MPa until the mass percentage of alcohol in the concentrate is 15%, thus obtaining the concentrate.

[0097] Comparative Example 3

[0098] The present invention provides a grapefruit extract in a comparative example. The only difference between the preparation method of the grapefruit extract and that of Example 1 is that in steps (2) and (3), water is used instead of an 80% ethanol aqueous solution.

[0099] Comparative Example 4

[0100] The present invention provides a grapefruit extract in a comparative example. The only difference between the preparation method of the grapefruit extract and that of Example 1 is that in step (4), the pH value of the system is adjusted to 8.

[0101] Comparative Example 5

[0102] The present invention provides a grapefruit extract in a comparative example. The only difference between the preparation method of the grapefruit extract and that of Example 1 is that in step (5), the concentrate is dissolved in pure water at 50°C and washed with pure water at 50°C until the water after washing is colorless as observed by the naked eye.

[0103] Comparative Example 6

[0104] The present invention provides a grapefruit extract in a comparative example. The only difference between the preparation method of the grapefruit extract and that of Example 1 is that in step (6), the second filter residue is added to an ethanol aqueous solution with a mass concentration of 50%.

[0105] Comparative Example 7

[0106] The present invention provides a grapefruit extract in a comparative example. The only difference between the preparation method of the grapefruit extract and that of Example 1 is that in step (6), water is added to the filtrate to dilute it to a mass concentration of ethanol of 50%.

[0107] Example of effect

[0108] The present invention provides an example of testing the color, whiteness value, and amount of grapefruit extract obtained in Examples 1-4 and Comparative Examples 1-7, and also tests the corresponding penetration-enhancing ability. The whiteness is obtained by using a WSB series whiteness meter to measure the radiance energy value reflected from the sample surface through signal amplification, A / D conversion, and data processing, based on the photoelectric conversion principle and an analog-to-digital conversion circuit.

[0109] The penetration enhancement ability was tested by using 90% glycyrrhizin as the active ingredient. Grapefruit extracts prepared in Examples 1-4 and Comparative Examples 1-7 and azone, a commonly used penetration enhancer, were mixed with glycyrrhizin, and then transdermal experiments were conducted using the Franz diffusion method. The principle of this experiment is as follows: a complete pigskin is fixed between the supply pool and the diffusion pool, with the stratum corneum of the skin facing upwards. The sample containing the test substance is placed on the surface of the stratum corneum, while the bottom surface of the skin is in contact with the liquid in the diffusion pool. The sample is in contact with the stratum corneum of the skin for a certain period of time, and the receiving liquid is collected at different time points. The changes in the glycyrrhizin content in the receiving liquid collected at different time points are detected by high performance liquid chromatography, thereby reflecting the transdermal absorption status of glycyrrhizin and the penetration enhancement ability of grapefruit extracts and azone obtained in Examples 1-4 and Comparative Examples 1-7.

[0110] The specific experimental steps for testing the penetration-enhancing ability are as follows:

[0111] 1) Sample preparation

[0112] The grapefruit extracts and azone obtained from Examples 1-4 and Comparative Examples 1-7 were mixed with glycyrrhizin at a ratio of 0.5:1 to obtain Samples 1-11 and the control sample;

[0113] 2) Skin tissue preparation

[0114] Take out the purchased and stored pigskins and cut them into appropriate sizes for later use;

[0115] 3) Experimental system

[0116] Experimental materials: pigskin used in the experiment;

[0117] Test reagents: ultrapure water, methanol, acetonitrile, butanediol, PBS, etc.

[0118] Experimental instruments: Franz diffusion apparatus, high performance liquid chromatograph;

[0119] 4) Transdermal skin tissue

[0120] After cleaning the prepared pig skin, fix it between the supply pool and the diffusion pool, and place the skin with the stratum corneum facing upwards. Place the sample on the surface of the stratum corneum, while the bottom of the skin is in contact with the liquid in the diffusion pool. Adjust the temperature and stirring speed of the water bath system, remove air bubbles, and set up a blank control group.

[0121] 5) High-performance liquid chromatography (HPLC) analysis

[0122] An appropriate amount of sample was placed on the skin surface. After transdermal absorption, the target analyte in the supply cell, diffusion cell and skin was collected and analyzed by HPLC. Three repeatable experiments were set up for each group. The permeability of glycyrrhizin was calculated (the total amount of glycyrrhizin in the diffusion cell and the total amount of glycyrrhizin in the skin divided by the amount of glycyrrhizin administered is the permeability of glycyrrhizin).

[0123] The results obtained from the effect examples are shown in Table 1; the liquid chromatograms of glycyrrhizin, Examples 1-2, Comparative Examples 1, 3-5, and the control sample are shown in Table 1. Figure 1-7 As shown; Figure 1-7 In the sample, peak a represents a 0.5% sample diluted 10 times; peak b represents a subcutaneous sample after 1 hour of transdermal treatment (no peak); peak c represents a subcutaneous sample after 2 hours of transdermal treatment (no peak); peak d represents a subcutaneous sample after 4 hours of transdermal treatment (no peak); peak e represents a subcutaneous sample after 8 hours of transdermal treatment (no peak); peak f represents a subcutaneous sample after 10 hours of transdermal treatment (no peak); peak h represents a subcutaneous sample after 24 hours of transdermal treatment (no peak); peak k represents an intradermal sample after 24 hours of transdermal treatment; and peak n represents an epidermal sample after 24 hours of transdermal treatment.

[0124] Table 1

[0125]

[0126]

[0127] As can be seen from Table 1, when the technical solution of the present invention is adopted, the grapefruit extract obtained is a white product with high whiteness, above 66.0, and the amount of product obtained is large, above 10.16g. In addition, the permeability of glycyrrhizin in the sample is high, above 1.47%, which is more than 77.11% higher than glycyrrhizin and more than 38.68% higher than the common penetration enhancer azone.

[0128] As can be seen from Example 1 and Comparative Example 1, when the steps of adjusting pH, decolorizing activated carbon, dissolving in hot water, and re-dissolving in ethanol are omitted in the preparation method, although the amount of product obtained is larger, the purity of the product is insufficient, which is reflected in the brown color, low whiteness, and a sharp decrease in permeability to only 0.92%, which is 37.41% lower than that of Example 1. As can be seen from Example 1 and Comparative Example 2, when the step of adjusting pH is omitted, the purity of the product obtained is not high, the color is light brown, the whiteness is not high, and the permeability of the product obtained also shows a significant downward trend compared to Example 1.

[0129] As can be seen from Example 1 and Comparative Example 3, when the extraction solvent is changed to water, although the amount of sample obtained increases, the purity is low, the sample is brown, the whiteness is low, and the permeability is low, only 0.83%, which is 43.54% lower than that of Example 1.

[0130] As can be seen from Example 1 and Comparative Example 4, when the pH of the system is adjusted to be alkaline rather than acidic, the purity of the obtained product decreases significantly, and the permeability also shows a decreasing trend, decreasing by 11.56% compared to Example 1.

[0131] As can be seen from Example 1 and Comparative Example 5, when the concentrate is dissolved in hot water at a lower temperature in step (5), the permeability of the product will also be reduced to some extent.

[0132] As can be seen from Example 1 and Comparative Example 6, when the second filter residue is added to an ethanol aqueous solution with a low mass concentration, although the whiteness of the obtained product is high, the product yield decreases significantly and the permeability also decreases significantly. Compared with Example 1, the permeability decreases by 43.54%.

[0133] As can be seen from Example 1 and Comparative Example 7, when water is added to the filtrate in step (6) to dilute it to an excessively high concentration of ethanol, although the whiteness of the product is high, the yield of the product decreases significantly and the permeability also decreases significantly. Compared with Example 1, the permeability decreased by 43.54%.

[0134] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of the present invention and not to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing grapefruit extract, characterized in that, The preparation method includes the following steps: (1) Grapefruit peel powder was mixed with the first alcohol solution and then heated and refluxed for extraction, followed by filtration to obtain the first filter residue and the first crude extract. (2) After mixing the first filter residue from step (1) with the second alcohol solution, heat and reflux to extract, then filter to obtain the second crude extract; (3) After mixing the first crude extract and the second crude extract, the system is adjusted to acidity. Then activated carbon is added for decolorization, followed by filtration. The filtrate is collected and concentrated to obtain a concentrated solution. (4) After mixing the concentrate from step (3) with hot water, filter and wash to obtain the second filter residue; (5) After mixing the second filter residue with the third alcohol solution, filter the mixture, collect the filtrate and add water to obtain a diluted solution; (6) Allow the diluted solution to stand, filter, collect the third filter residue and dry it to obtain grapefruit extract. The first alcohol solution and the second alcohol solution are each independently selected from an aqueous ethanol solution with a mass concentration of 50-100%; In step (3), the pH value of the system is adjusted to 1-5 when it is acidic; In step (4), the temperature of the hot water is 60-90℃; In step (5), the mass ratio of the second filter residue to the third alcohol solution is 1:(1-10), and the third alcohol solution is an aqueous ethanol solution with a mass concentration of 70-100%. The mass percentage of ethanol in the diluent is 0-30%.

2. The preparation method according to claim 1, characterized in that, At least one of the following (a)-(d): (a) The moisture content of the grapefruit peel powder is ≤10%, and the mesh size is 60-80 mesh; (b) The temperature for the heating and reflux extraction is 50-90℃, and the time is 1-3h; (c) The mass ratio of the grapefruit peel powder to the first alcohol solution is 1:(5-30); (d) The mass ratio of the grapefruit peel powder to the second alcohol solution is 1:(5-30).

3. The preparation method according to claim 1, characterized in that, In step (3), the amount of activated carbon added is 10-300% of the mass of grapefruit peel powder, the decolorization temperature is 40-80℃, and the time is 1-6h.

4. The preparation method according to claim 1, characterized in that, In step (3), the concentration temperature is 30-60℃ and the pressure is ≥-0.1MPa; the mass percentage of alcohol in the concentrate is 0-30%.

5. A grapefruit extract, characterized in that, The grapefruit extract is prepared by the preparation method described in any one of claims 1-4.

6. The application of the grapefruit extract as described in claim 5 in the preparation of cosmetics with enhanced penetration.

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