Method for semi-bionic extraction of antioxidant active product from roselle and application of antioxidant active product

Abstract

The invention discloses a semi-bionic method for extracting an antioxidant active product from roselle and application thereof, and the method comprises the following steps: mixing crushed roselle calyx powder with a lactic acid solution, carrying out ultrasonic extraction, and collecting a filtrate a and filter residues; mixing the filter residue with a urea solution, performing ultrasonic extraction, filtering, and collecting filtrate b; combining the filtrate a and the filtrate b, and performing low-temperature vacuum concentration to obtain a crude extract; the method comprises the following steps: soaking D101 resin in absolute ethyl alcohol to fully swell, packing by a wet method, and washing off ethyl alcohol in the resin by using deionized water; adding the crude extract, carrying out static adsorption, then respectively eluting with 2BV water, 30% ethanol, 70% ethanol and absolute ethanol, and collecting eluents to sequentially obtain a fraction I, a fraction II, a fraction III and a fraction IV; and concentrating the fraction II, and freeze-drying to obtain the antioxidant active product. The extract disclosed by the invention shows excellent antioxidant activity under optimal process conditions, and particularly, the DPPH free radical scavenging rate is remarkably improved.

Description

Technical Field

[0001] The invention belongs to the field of preparation of natural plant extracts, and specifically relates to a method for semi-bionic extraction of antioxidant active products in roselle and application thereof. Background Art

[0002] Roselle (Hibiscussabdariffa L.) is a common medicinal plant. Its calyx is rich in anthocyanins, polyphenols and other natural active substances, which have significant effects in lowering blood pressure, lowering blood lipids, anti-oxidation and inhibiting cardiovascular diseases.

[0003] However, traditional extraction methods often have problems such as low extraction efficiency and large loss of active ingredients, which limits their wide application in medicine and health foods. Therefore, it is particularly important to develop an efficient, environmentally friendly extraction process that can maximize the retention of active ingredients.

[0004] In recent years, ultrasound-assisted extraction technology has been widely used in natural product extraction due to its high efficiency, rapidity, and environmental protection. At the same time, the use of appropriate extraction aids can further improve the extraction efficiency and the solubility of the target components. Chinese herbal medicines often do not rely on a single substance in the treatment of diseases, but are the result of the combined action of multiple components.

[0005] Currently, there is no report on the extraction process that maximizes the retention of Roselle active ingredients. Summary of the invention

[0006] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0007] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0008] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for semi-bionic extraction of antioxidant active products from roselle.

[0009] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for semi-bionic extraction of antioxidant active products from roselle, comprising:

[0010] Mixing the crushed roselle calyx powder with the lactic acid solution for ultrasonic extraction, and collecting the filtrate a and the filter residue;

[0011] The filter residue is mixed with urea solution for ultrasonic extraction, and after filtering, the filtrate b is collected;

[0012] The filtrates a and b are combined, and concentrated under reduced pressure at low temperature to obtain a crude extract containing antioxidant active ingredients;

[0013] Soak D101 resin in anhydrous ethanol to make it fully swell, wet pack it into the column, and wash away the ethanol in the resin with deionized water;

[0014] Add the crude extract, allow to stand for adsorption, then elute with 2BV of water, 2BV of 30% ethanol, 2BV of 70% ethanol and 2BV of anhydrous ethanol, respectively, collect the eluates, and obtain fractions I, II, III and IV in sequence;

[0015] The fraction II is concentrated and freeze-dried to obtain the antioxidant activity product.

[0016] As a preferred embodiment of the method of the present invention, the mass concentration of the lactic acid solution is 30%.

[0017] As a preferred embodiment of the method of the present invention, the crushed Roselle calyx powder is mixed with lactic acid solution for ultrasonic extraction, wherein the ultrasonic temperature is 40° C. and the extraction time is 20 min.

[0018] As a preferred embodiment of the method of the present invention, the solid-liquid ratio of the crushed Roselle calyx powder to the lactic acid solution is 1:20 g / mL.

[0019] As a preferred embodiment of the method of the present invention, the mass concentration of the urea solution is 20%.

[0020] As a preferred embodiment of the method of the present invention, the filter residue is mixed with a urea solution and ultrasonically extracted, wherein the ultrasonic temperature is 60° C. and the extraction time is 50 min.

[0021] As a preferred embodiment of the method of the present invention, the solid-liquid ratio of the filter residue to the urea solution is 1:20 g / mL.

[0022] As a preferred embodiment of the method of the present invention, the deionized water is used to wash away ethanol in the resin, wherein the deionized water dosage is 2 BV.

[0023] Another object of the present invention is to overcome the deficiencies in the prior art and provide a Roselle antioxidant activity product.

[0024] Another object of the present invention is to overcome the deficiencies in the prior art and provide a roselle antioxidant activity product for use in food, health products and cosmetics.

[0025] Beneficial effects of the present invention:

[0026] (1) Efficient extraction: The present invention significantly improves the extraction efficiency of the antioxidant active components of Roselle by optimizing the mass concentrations of lactic acid and urea, ultrasonic temperature and extraction time.

[0027] (2) High antioxidant activity: The extract showed excellent antioxidant activity under the optimal process conditions, especially in terms of DPPH free radical scavenging rate.

[0028] (3) Environmentally friendly: The extraction aids used in the present invention are naturally occurring organic acids and organic bases, which are environmentally friendly.

[0029] (4) Broad application prospects: The extract has strong antioxidant activity and can be widely used in food, health products, cosmetics and other fields, with high economic value and market potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0031] Figure 1 This is a graph showing the effect of different mass concentrations of lactic acid on the DPPH radical scavenging rate in the present invention.

[0032] Figure 2 This is a graph showing the effect of extraction time on DPPH radical scavenging rate during lactic acid extraction in the present invention.

[0033] Figure 3 This is a graph showing the effect of ultrasonic temperature on DPPH radical scavenging rate during the lactic acid extraction process of the present invention.

[0034] Figure 4 The figure is the effect of different mass concentrations of urea on the DPPH free radical scavenging rate in the present invention.

[0035] Figure 5 This is a graph showing the effect of extraction time on DPPH radical scavenging rate during urea extraction in the present invention.

[0036] Figure 6 This is a graph showing the effect of ultrasonic temperature on DPPH free radical scavenging rate during urea extraction in the present invention. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0038] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0039] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments. The raw materials in the present invention are all common commercially available products.

[0040] Example 1

[0041] Lactic acid is used as an extraction aid to extract antioxidant components from roselle:

[0042] (1) 15 g of dried roselle calyx was crushed and passed through a 40-mesh sieve. 300 mL of 30% lactic acid solution was added and mixed well.

[0043] (2) The mixture was placed in an ultrasonic-assisted extractor and subjected to ultrasonic extraction at 40°C for 20 min.

[0044] (3) After the extraction is completed, the extract is filtered to obtain a crude extract, which is then concentrated to a concentration of 0.1 g crude drug / mL.

[0045] (4) Soak the D101 resin in anhydrous ethanol for 12 h to allow it to fully swell;

[0046] Wet-pack the column, wash with ethanol until the effluent does not become white turbid after adding deionized water, then wash with two column volumes (2BV) of 5% HCl solution, deionized water, 2% NaOH solution, and then wash with deionized water until the effluent becomes neutral;

[0047] According to the ratio of crude drug amount to resin amount of 1:30, 20 mL of crude extract (0.1 g crude drug / mL) was added to the top of D101 macroporous resin (60 g) column. After static adsorption for 1.5 h, it was eluted with 2 BV of water, 2 BV of 30% (volume ratio) ethanol, 2 BV of 70% ethanol and 2 BV of anhydrous ethanol, and the eluates were collected to obtain fraction I, fraction II, fraction III and fraction IV, which were concentrated to a concentration of 0.1 g crude drug / mL respectively.

[0048] (5) Determination of DPPH radical scavenging rate of fraction II

[0049] Weigh 8.0±0.1mg DPPH solid, add anhydrous ethanol to a 250mL brown volumetric flask to make up to volume, and store at -4℃ away from light. Since the roselle extract is dark in color, it needs to be diluted 200 times with water before it can be used for antioxidant activity test. At this time, the extract drug concentration involved in the antioxidant activity test is 0.1mg / mL;

[0050] The Tris buffer and anhydrous ethanol were prepared in a volume ratio of 1:1, and the Tris buffer, anhydrous ethanol and DPPH solution were diluted in a volume ratio of 1:1:2, and the corresponding extraction solvent used for the roselle extract was diluted by a corresponding multiple.

[0051] The DPPH free radical scavenging experiment was carried out in a 96-well plate, and the samples loaded in the 96-well plate are shown in Table 1.

[0052] The sample group was added with 40 μL of sample solution diluted 200 times and 160 μL of DPPH diluent; the blank group was added with 40 μL of diluted extract solution and 160 μL of Tris diluent; the control group was added with 40 μL of corresponding extraction solvent diluted 100 times and 160 μL of DPPH diluent; each group was required to be done in triplicate.

[0053] After adding the sample using a pipette, the reaction needs to be allowed to proceed for 30 minutes at room temperature and away from light. After the reaction is complete, place the 96-well plate in an ELISA reader at a wavelength of 517 nm to detect the absorbance.

[0054] Table 196 well plate sample volume

[0055]

[0056]

[0057] The calculation formula of DPPH free radical scavenging rate is as follows:

[0058] DPPH free radical scavenging rate = (1-(A S -A B ) / A C )*100;

[0059] Among them, A S - absorbance after the sample solution reacts with the DPPH dilution solution; A B - Absorbance after the sample solution reacts with Tris diluent; A C -The absorbance of the sample after the extraction solvent reacts with the DPPH diluent.

[0060] It was determined that when the crude drug concentration was 0.1 mg / mL, the scavenging rate of fraction II on DPPH free radicals was 40.2%.

[0061] Take 10 mL of the concentrated fraction II solution (0.1 g crude drug / mL) and concentrate it to a small volume. After drying, weigh it. The yield of fraction II is 40.7%.

[0062] Example 2

[0063] Urea is used as an extraction aid to extract antioxidant components from roselle:

[0064] (1) 15 g of dried roselle calyx was crushed and passed through a 40-mesh sieve. 300 mL of 20% urea solution was added and mixed well.

[0065] (2) The mixture was placed in an ultrasonic-assisted extractor and subjected to ultrasonic extraction at 60°C for 50 min.

[0066] (3) After the extraction is completed, the extract is filtered to obtain a crude extract, which is then concentrated to a concentration of 0.1 g crude drug / mL.

[0067] (4) The crude extract was passed through a D101 macroporous resin column, eluted with 30% ethanol, and fraction II was collected. The specific process was the same as in Example 1.

[0068] (5) The DPPH free radical scavenging rate of fraction II was determined to be 33.9% and the yield was 45.5%. The testing method was the same as in Example 1.

[0069] Example 3: Single factor experimental method to optimize the extraction process

[0070] ①Effects of lactic acid and urea solution concentration on the antioxidant activity of roselle extract

[0071] Prepare 1%, 10%, 20%, 30% and 50% by mass lactic acid and urea aqueous solutions respectively;

[0072] Weigh 1±0.005 g of roselle powder (passed through a 40-mesh sieve) into a 50 mL centrifuge tube, add different concentrations of lactic acid and urea extraction solvents at a solid-liquid ratio of 1:20 g / mL, and perform ultrasonic extraction at 40°C for 40 min with an ultrasonic power of 100%.

[0073] After the extraction is completed, the system is cooled to room temperature, and the extract is obtained by vacuum filtration, and the extract is stored at room temperature away from light.

[0074] The extract was diluted with water to test its DPPH free radical scavenging rate. The crude drug concentration of the Roselle extract after dilution was 0.1 mg / mL, the same below.

[0075] ②Effect of extraction time on the antioxidant activity of roselle extract

[0076] Prepare the extraction solvent according to the optimal mass concentrations of lactic acid and urea in experiment ①.

[0077] Weigh 1±0.005g of roselle powder into a 50mL centrifuge tube, add extraction solvent at a solid-liquid ratio of 1:20g / mL, and perform ultrasonic extraction at 40°C for 20, 30, 40, 50, and 60min with an ultrasonic power of 100%;

[0078] After the extraction is completed, the system is cooled to room temperature, and the extract is obtained by vacuum filtration, and the extract is stored at room temperature away from light.

[0079] ③Effect of extraction temperature on the antioxidant activity of roselle extract

[0080] Prepare the extraction solvent according to the optimal mass concentration of lactic acid and urea in experiment ①;

[0081] Weigh 1±0.005g of roselle powder in a 50mL centrifuge tube, add the extraction solvent at a solid-liquid ratio of 1:20g / mL, and perform ultrasonic extraction at room temperature, 30, 40, 50, and 60°C according to the optimal extraction time of lactic acid and urea groups in experiment ②, with an ultrasonic power of 100%. After the extraction is completed, wait for the system to cool to room temperature, and vacuum filter to obtain the extract. The extract is stored at room temperature and protected from light.

[0082] In this example, when the solid-liquid ratio was 1:20 g / mL, the ultrasonic temperature was 40 °C, and the extraction time was 40 min, the effect of the concentration of the lactic acid extraction solvent on the antioxidant activity of the roselle extract was as follows: Figure 1 As shown in the figure, it shows a trend of first increasing and then decreasing. When the concentration is 20%, the DPPH free radical scavenging rate of roselle extract reaches its peak. The reason for this trend may be that as the lactic acid solution presents polarity, it helps the effective components in the roselle calyx to precipitate; but as the concentration increases, the acidity of the system increases, the effective components are inactivated, and the antioxidant activity is reduced.

[0083] When the concentration of lactic acid extraction solvent was 20%, the solid-liquid ratio was 1:20 g / mL, and the ultrasonic temperature was 40°C, the effect of lactic acid extraction time on the antioxidant activity of roselle extract was as follows: Figure 2 , showing a trend of first increasing and then decreasing. When the extraction time is 20 minutes, the DPPH radical scavenging rate of roselle extract reaches its peak. The reason for this trend may be that the appropriate extraction time can fully precipitate the effective ingredients in the roselle calyx; but as the extraction time continues to increase, due to the high content of organic acids in roselle, the acidity of the system continues to increase, which will cause the effective ingredients to lose their activity under strong acidic conditions, and the DPPH radical scavenging rate will decrease.

[0084] When the concentration of lactic acid extraction solvent was 20%, the solid-liquid ratio was 1:20 g / mL, and the extraction time was 20 min, the effect of ultrasonic temperature on the antioxidant activity of roselle extract in the lactic acid group was as follows: Figure 3, also presenting a trend of first increasing and then decreasing. When the ultrasonic temperature is 30°C, the DPPH free radical scavenging rate of roselle extract reaches its peak. The reason for this trend may be that the appropriate increase in ultrasonic temperature helps to accelerate the molecular movement rate, allowing the raw materials to fully contact with the extraction solvent and help the effective components to precipitate; but when the temperature exceeds a certain range, the excessively high temperature inactivates the heat-sensitive components in roselle and reduces the antioxidant activity.

[0085] In this example, when the solid-liquid ratio was 1:20 g / mL, the ultrasonic temperature was 40 °C, and the extraction time was 40 min, the effect of the concentration of the lactic acid extraction solvent on the antioxidant activity of the roselle extract was as follows: Figure 4 , showing a trend of first increasing and then decreasing. When the concentration is 10%, the DPPH free radical scavenging rate of roselle extract reaches its peak. The reason for this trend may be that the urea aqueous solution is alkaline, which can promote the precipitation of acidic substances in the roselle calyx when the concentration is low; but when the concentration of urea solution is too high, the acidic substances in the system may react with urea, reducing the actual concentration of the extraction solvent, thereby reducing the precipitation of effective components in roselle and reducing the antioxidant activity.

[0086] When the urea extraction solvent concentration was 10%, the solid-liquid ratio was 1:20 g / mL, and the ultrasonic temperature was 40°C, the effect of urea extraction time on the antioxidant activity of roselle extract was as follows: Figure 5 , showing a trend of first increasing and then decreasing. When the extraction time is 40min, the DPPH free radical scavenging rate of roselle extract reaches its peak. The reason for this trend may be that the appropriate extraction time can fully precipitate the effective ingredients in the roselle calyx; but as the extraction time continues to increase, due to the high content of organic acids in roselle, the acidity of the system continues to increase, and more acidic substances may react with urea, which not only reduces the urea content, but also consumes the acidic components in the system, reducing the total antioxidant activity.

[0087] When the urea extraction solvent concentration was 10%, the extraction time was 30 min, and the solid-liquid ratio was 1:20 g / mL, the effect of ultrasonic temperature in the urea group on the antioxidant activity of roselle extract was as follows: Figure 6 , also presenting a trend of first increasing and then decreasing. When the ultrasonic temperature is 50°C, the DPPH free radical scavenging rate of roselle extract reaches its peak. The reason for this trend may be that the appropriate increase in ultrasonic temperature helps to accelerate the molecular movement rate, allowing the raw materials to fully contact with the extraction solvent and help the effective components to precipitate; but when the temperature exceeds a certain range, the excessively high temperature inactivates the heat-sensitive components in roselle and reduces the antioxidant activity.

[0088] Example 4

[0089] Orthogonal experimental method to optimize the extraction process:

[0090] On the basis of single factor experiments, orthogonal experiments were carried out on the mass concentration of lactic acid and urea extraction aids, extraction time and ultrasonic temperature. Therefore, the orthogonal experiment examined the effects of ultrasonic temperature (A), extraction time (B) and mass concentration (C) on the scavenging rate of DPPH free radicals, and 3 levels were selected for each factor to conduct orthogonal experimental method investigation.

[0091] It can be seen from Table 2 that when lactic acid is used as the extraction agent, the order of influence of various factors on the DPPH radical scavenging rate of roselle extract is temperature>concentration>time, and when the lactic acid mass concentration is 30%, the extraction time is 20min, and the extraction temperature is 40℃, the extraction process is optimal, and the DPPH radical scavenging rate is 55.59%.

[0092] Table 2 Lactic acid orthogonal test results

[0093]

[0094] It can be seen from Table 3 that when urea is used as the extraction agent, the order of influence of various factors on the DPPH radical scavenging rate of roselle extract is temperature>concentration>time, and when the lactic acid mass concentration is 20%, the extraction time is 50min, and the extraction temperature is 60℃, the extraction process is optimal, and the DPPH radical scavenging rate is 50.84%.

[0095] Table 3 Urea orthogonal test results

[0096]

[0097] The orthogonal experiment showed that when lactic acid was used as the extractant, the order of influence of various factors on the scavenging rate of DPPH free radicals of roselle extract was temperature>concentration>time, and the extraction process was optimal when the lactic acid concentration was 30%, the extraction time was 20min, and the extraction temperature was 40℃.

[0098] When urea was used as the extraction agent, the order of influence of various factors on the DPPH radical scavenging rate of Roselle extract was temperature>concentration>time, and the extraction process was optimal when the urea mass concentration was 20%, the extraction time was 50min, and the extraction temperature was 60℃.

[0099] Example 5

[0100] Separation and purification of roselle semi-bionic extraction process extract:

[0101] (1) mixing roselle calyx powder with 30% lactic acid solution at a mass ratio of 1:20, placing in an ultrasonic assisted extractor, ultrasonically extracting at 40° C. for 20 min, and filtering to collect the filtrate (a) and the residue respectively;

[0102] (2) The above filter residue was mixed with 20% urea solution at a mass ratio of 1:20, placed in an ultrasonic assisted extractor, ultrasonically extracted at 60° C. for 50 min, filtered, and the filtrate (b) was collected.

[0103] (3) Filtrates a and b were combined and concentrated under reduced pressure at low temperature to a concentration of 0.1 g crude drug / mL to obtain a crude extract containing antioxidant active ingredients.

[0104] (4) Take 1 mL of the crude extract, dilute to 200 mL, and test its ability to scavenge DPPH free radicals.

[0105] (5) Soak D101 resin in anhydrous ethanol for 12 h to allow it to fully swell. Wet pack the column and wash away the ethanol in the resin with 2 BV of deionized water;

[0106] 10 mL of the crude extract of roselle after the optimized process was added, and the mixture was adsorbed statically for 1.5 h. Then, 2 BV of water, 2 BV of 30% (volume ratio) ethanol, 2 BV of 70% ethanol, and 2 BV of anhydrous ethanol were used for elution, and the eluate was collected and fixed to 250 mL to obtain fractions I, II, III, and IV in sequence.

[0107] In order to keep the crude drug concentration consistent with the experiment in Example 1, the four eluates after the fixed volume were diluted and used for the DPPH free radical antioxidant activity test;

[0108] Take another 100 mL of the 30% ethanol eluate (fraction II) and perform vacuum rotary evaporation at 50°C to obtain the separated solid and weigh it to calculate the extraction rate.

[0109] It can be clearly observed that fraction II obtained by elution with 30% ethanol is red, fraction III obtained by elution with 70% ethanol is lavender, and fraction I and fraction IV are colorless and transparent;

[0110] The antioxidant activities of fractions Ⅰ, Ⅱ, Ⅲ and Ⅳ were detected by DPPH free radical scavenging experiment, and the DPPH free radical scavenging rates were 14.50%, 44.20%, 19.52% and 2.50% respectively;

[0111] It can be seen that 30% ethanol can effectively separate the antioxidant active substances in roselle extract;

[0112] Fraction II was taken for rotary evaporation, and the yield was 50.6%.

[0113] Comparative Example 1

[0114] Ultrasonic assisted extraction of antioxidant components from roselle using water as solvent:

[0115] Crush the dried roselle calyx and pass through a 40-mesh sieve;

[0116] Weigh 2 g of powder, add 20 times the amount of deionized water, extract in an ultrasonic-assisted extractor at 60 °C for 50 min, cool to room temperature, and filter;

[0117] The filtrate was taken and fixed to a certain volume so that the mass concentration of the obtained extract was 0.5 mg crude drug / mL, and its scavenging ability for DPPH free radicals was detected.

[0118] Comparative Example 2

[0119] Extraction of antioxidant components from roselle using semi-bionic extraction method with traditional acid-base additives:

[0120] Mixing roselle calyx powder and 1% hydrochloric acid solution at a ratio of 1:20, placing in an ultrasonic assisted extractor, ultrasonically extracting at 40° C. for 20 min, and filtering to collect the filtrate (a) and the filter residue respectively;

[0121] The above filter residue was mixed with 1% NaOH solution at a ratio of 1:20, placed in an ultrasonic assisted extractor, ultrasonically extracted at 60° C. for 50 min, filtered, and the filtrate (b) was collected;

[0122] The filtrates a and b were combined and fixed to a certain volume so that the mass concentration of the obtained extract was 0.5 mg crude drug / mL, and a crude extract containing antioxidant active ingredients was obtained, and its ability to scavenge DPPH free radicals was tested.

[0123] Comparative Example 3

[0124] Extraction of antioxidant components from roselle using the "urea first, then lactic acid" extraction method:

[0125] Mixing roselle calyx powder with 30% lactic acid solution at a ratio of 1:20, placing in an ultrasonic assisted extractor, ultrasonically extracting at 40° C. for 20 min, and filtering to collect the filtrate (a) and the residue respectively;

[0126] The above filter residue was mixed with 20% urea solution at a ratio of 1:20, placed in an ultrasonic assisted extractor, ultrasonically extracted at 60° C. for 50 min, filtered, and the filtrate (b) was collected;

[0127] The filtrates a and b were combined and fixed to a certain volume to obtain a crude extract containing antioxidant active ingredients (mass concentration of 0.5 mg crude drug / mL), and its scavenging ability for DPPH free radicals was detected.

[0128] Table 4 Roselle extracts obtained by different extraction methods

[0129]

[0130]

[0131] From the results in Table 4, it can be seen that the extract obtained in Example 5 has the highest antioxidant activity.

[0132] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the present invention.

Claims

1. A method for semi-bionic extraction of antioxidant active products from roselle, characterized in that: include, Mixing the crushed roselle calyx powder with the lactic acid solution for ultrasonic extraction, and collecting the filtrate a and the filter residue; The filter residue is mixed with urea solution for ultrasonic extraction, and after filtering, the filtrate b is collected; The filtrates a and b are combined, and concentrated under reduced pressure at low temperature to obtain a crude extract containing antioxidant active ingredients; Soak D101 resin in anhydrous ethanol to make it fully swell, wet pack it into the column, and wash away the ethanol in the resin with deionized water; Add the crude extract, allow to adsorb statically, then elute with 2BV of water, 2BV of 30% ethanol, 2BV of 70% ethanol and 2BV of anhydrous ethanol, respectively, collect the eluates, and obtain fractions I, II, III and IV in sequence; The fraction II is concentrated and freeze-dried to obtain the antioxidant activity product.

2. The method according to claim 1, characterized in that: The mass concentration of the lactic acid solution is 30%.

3. The method according to claim 1 or 2, characterized in that: The crushed Roselle calyx powder is mixed with the lactic acid solution for ultrasonic extraction, wherein the ultrasonic temperature is 40° C. and the extraction time is 20 minutes.

4. The method according to claim 3, characterized in that: The solid-liquid ratio of the crushed roselle calyx powder to the lactic acid solution is 1:20 g / mL.

5. The method according to claim 1 or 2, characterized in that: The mass concentration of the urea solution is 20%.

6. The method according to claim 5, characterized in that: The filter residue is mixed with the urea solution and ultrasonically extracted, wherein the ultrasonic temperature is 60° C. and the extraction time is 50 minutes.

7. The method according to claim 6, characterized in that: The solid-liquid ratio of the filter residue to the urea solution is 1:20 g / mL.

8. The method according to claim 1, characterized in that: The deionized water is used to wash away ethanol in the resin, wherein the deionized water usage is 2 BV.

9. The roselle antioxidant activity product obtained by the method according to any one of claims 1 to 8.

10. Use of the roselle antioxidant activity product according to claim 9 in food, health products and cosmetics.

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