A method for extracting flavonoids from roses

Abstract

The present invention provides a method for extracting flavonoids from rose flowers, belonging to the technical field of flavonoid extraction. The extraction method includes rose flower pretreatment, crude extraction, glycosylation, and hydrolysis. The hydrolysis method is to add crude flavonoid glycosides to a NaOH solution, stir until completely dissolved, then use an HCl solution to adjust the pH value to 3.8 - 4.5, hydrolyze at 55 - 65 °C for 5 - 7 h, then filter. After adjusting the pH value of the filtrate to neutral, evaporate and concentrate it to 8 - 12% of the original volume at 85 - 95 °C, add ethyl acetate for extraction, and add the extracted ethyl acetate to the ethyl acetate in step 3 for recycling. Wash the filter cake clean and dry it to a constant weight to obtain flavonoids. The flavonoid yield obtained by the present invention is 14.11% - 15.37%, and the purity is 94.94% - 95.83%.

Description

Technical Field

[0001] The present invention belongs to the technical field of flavonoid extraction, and particularly relates to a method for extracting flavonoids from roses. Background Art

[0002] Flavonoids are a class of natural polyphenolic compounds widely present in plants, with diverse biological activities and application values, such as anti-aging, improving blood circulation, anti-inflammatory, etc., and have broad application values in the fields of medicine, food, and health products.

[0003] The content of flavonoid compounds in roses is relatively high. The extraction methods of flavonoids from roses include water extraction method, organic solvent extraction method, CO 2 supercritical extraction method, ultrasonic-assisted extraction method, and microwave-assisted extraction method; the separation and purification methods of flavonoid compounds are commonly the following several kinds: column chromatography, thin-layer chromatography, macroporous resin adsorption method, aqueous two-phase extraction method, and capillary electrophoresis method.

[0004] At present, mainly the organic solvent extraction method is used in combination with the organic solvent extraction method to extract, separate, and purify flavonoids from roses. This method has high purity, low requirements for instruments and equipment, low energy consumption, and good stability. However, it requires multiple adsorptions and elutions, resulting in a large amount of organic solvent used, cumbersome operation, large loss of flavonoids, and low yield.

[0005] Patent CN106668234B discloses a process for extracting and purifying total flavonoids from roses. The steps of this scheme are as follows: taking dried rose medicinal materials, pulverizing them, adding ethanol for reflux extraction, filtering the extract, and subjecting the obtained extract to multiple cyclic adsorption and elution by AB-8 macroporous resin, polyamide column, column chromatography polyamide, and C18 column, and finally obtaining total flavonoids. Although the flavonoids obtained by this method have high purity, the amount of eluent used is large, the operation is cumbersome, and the elution rate cannot reach 100%, resulting in partial loss of flavonoids in each elution, and thus the low yield of the final product. Summary of the Invention

[0006] Aiming at the problems existing in the prior art, the present invention provides a method for extracting flavonoids from roses, achieving the following invention objectives: improving the purity and yield of flavonoids, and at the same time reducing the usage amount of organic solvents.

[0007] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0008] A method for extracting flavonoids from roses, comprising the following steps:

[0009] 1. Pretreatment of roses

[0010] Wash the rose flowers clean, then dry them at 35 - 45°C, grind them into a powder with a particle size of 0.18 - 0.28 mm to obtain rose flower powder, and store it for later use at 3 - 7°C.

[0011] 2. Coarse extraction

[0012] Add the rose flower powder to deionized water, extract it in a water bath at 60 - 75°C for 35 - 45 min, then filter. After evaporating and concentrating the filtrate to 15 - 25% of the original volume at 85 - 95°C, obtain the flavonoid glycoside concentrated solution for later use.

[0013] Add the filter cake to an ethanol solution, extract it in a water bath at 60 - 80°C for 100 - 130 min, then transfer it to a centrifuge and centrifuge at 4000 - 5000 r / min for 7 - 9 min. After centrifugation, extract the supernatant, concentrate and dry it at 55 - 65°C to obtain the crude flavonoids for later use.

[0014] The mass ratio of the rose flower powder to deionized water is 0.8 - 1.2∶45 - 55.

[0015] The mass ratio of the filter cake to the ethanol solution is 0.8 - 1.2∶17 - 23.

[0016] The mass fraction of the ethanol solution is 65 - 75%.

[0017] 3. Glycosylation

[0018] Add the crude flavonoids to the ethyl acetate mixture, mix evenly, then add tetrabutylammonium bromide and bromoacetylglucose, and react at a stirring rate of 80 - 100 r / min for 14 - 16 h. After the reaction, rotary evaporate to remove ethyl acetate at 75 - 85°C, then mix evenly with the flavonoid glycoside concentrated solution obtained in step 2, and rotary evaporate to dryness at 50 - 70°C to obtain the crude flavonoid glycosides.

[0019] The mass ratio of the crude flavonoids, ethyl acetate mixture, tetrabutylammonium bromide, bromoacetylglucose, and flavonoid glycoside concentrated solution is 0.31 - 0.37∶15 - 17∶0.008 - 0.012∶0.5 - 0.9∶29 - 33.

[0020] The ethyl acetate mixture contains ethyl acetate and the ethyl acetate after extraction in step 4, and the mass ratio is 4.7 - 5.3∶0.8 - 1.2.

[0021] 4. Hydrolysis

[0022] Add the crude flavonoid glycoside to deionized water, stir for 25 - 35 min, filter out the insoluble impurities, adjust the pH value to 3.8 - 4.5 with HCl solution, hydrolyze at 55 - 65 °C for 5 - 7 h, then filter. After adjusting the pH value of the filtrate to neutral, evaporate and concentrate at 85 - 95 °C to 8 - 12% of the original volume, add ethyl acetate for extraction, add the extracted ethyl acetate to the ethyl acetate mixture in step 3 for recycling, wash the filter cake with deionized water until clean, and dry at 35 - 45 °C to constant weight to obtain flavonoids;

[0023] The mass ratio of the crude flavonoid glycoside, deionized water, and ethyl acetate is 0.8 - 1.2∶37 - 44∶8 - 10;

[0024] The mass fraction of the HCl solution is 6 - 13%.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] By utilizing the different solubilities of flavonoids and flavonoid glycosides in different solvents and through the mutual conversion between flavonoids and flavonoid glycosides, the yield of the finally obtained flavonoids is 14.11% - 15.37%, and the purity is 94.94% - 95.83%;

[0027] In the process of extracting flavonoids by using the method of the present invention, by utilizing the property that flavonoid glycosides are easily soluble in water and flavonoids are easily soluble in organic solvents, deionized water and ethanol are respectively used to extract flavonoid glycosides and flavonoids, obtaining a flavonoid glycoside concentrate and crude flavonoids. Compared with the conventional direct extraction using ethanol, this method improves the utilization rate of flavonoid glycosides and thus increases the yield of flavonoids;

[0028] Utilizing the principle of flavonoid glycosylation and the property that flavonoids are easily soluble in organic solvents, dissolve the crude flavonoids in ethyl acetate, then react with bromoacetyl glucose to generate flavonoid glycosides, then mix with the flavonoid glycoside concentrate, concentrate and dry to obtain crude flavonoid glycosides. After dissolving the crude flavonoid glycosides in deionized water, filter out the insoluble impurities, adjust the pH value to acidic with HCl solution. In an acidic environment, flavonoid glycosides are hydrolyzed to form flavonoids. Since flavonoids have low solubility in water, they crystallize out and are filtered to obtain flavonoids. Compared with macroporous resin separation and purification, the flavonoids obtained by crystallization purification have higher purity and less consumption of organic solvents;

[0029] When flavonoid glycosides are hydrolyzed to form flavonoids and filtered, there will still be a small amount of un-precipitated flavonoids in the filtrate. After extraction, the obtained extract can be added to the ethyl acetate mixture in step 3 for recycling, increasing the yield of flavonoids. Detailed implementation method

[0030] Example 1

[0031] 1. Pretreatment of rose flowers

[0032] Wash the rose flowers clean, then dry them at 40 °C, grind them into a powder with a particle size of 0.21 - 0.25 mm to obtain rose flower powder, and store it for later use at 5 °C.

[0033] 2. Coarse extraction

[0034] Add the rose flower powder to deionized water, extract it in a water bath at 70 °C for 40 min, then filter. After evaporating and concentrating the filtrate to 20% of its original volume at 90 °C, obtain the flavonoid glycoside concentrate for later use;

[0035] Add the filter cake to an ethanol solution, extract it in a water bath at 70 °C for 120 min, then transfer it to a centrifuge and centrifuge at 4500 r / min for 8 min. After centrifugation, extract the supernatant, concentrate and dry it at 60 °C to obtain the crude flavonoids for later use;

[0036] The mass ratio of the rose flower powder to deionized water is 1:50;

[0037] The mass ratio of the filter cake to the ethanol solution is 1:20;

[0038] The mass fraction of the ethanol solution is 70%.

[0039] 3. Glycosylation

[0040] Add the crude flavonoids to the ethyl acetate mixture, mix evenly, then add tetrabutylammonium bromide and bromoacetylglucose, and react at a stirring rate of 90 r / min for 15 h. After the reaction, rotate and evaporate to remove ethyl acetate at 80 °C, then mix evenly with the flavonoid glycoside concentrate obtained in step 2, and rotate and evaporate to dryness at 60 °C to obtain the crude flavonoid glycoside;

[0041] The mass ratio of the crude flavonoids, ethyl acetate mixture, tetrabutylammonium bromide, bromoacetylglucose, and flavonoid glycoside concentrate is 0.34:16:0.01:0.7:31;

[0042] The ethyl acetate mixture contains ethyl acetate and the ethyl acetate after extraction in step 4, and the mass ratio is 5:1.

[0043] 4. Hydrolysis

[0044] Add the crude flavonoid glycoside to deionized water, stir for 30 min, then filter to remove insoluble impurities. Adjust the pH value to 4 with HCl solution, hydrolyze at 60 °C for 6 h, then filter. After adjusting the pH value of the filtrate to neutral, evaporate and concentrate it to 10% of its original volume at 90 °C, then add ethyl acetate for extraction. Add the extracted ethyl acetate to the ethyl acetate mixture in step 3 for recycling. Wash the filter cake clean with deionized water and dry it to constant weight at 40 °C to obtain flavonoids;

[0045] The mass ratio of the crude flavonoid glycoside, deionized water, and ethyl acetate is 1:40:9;

[0046] The mass fraction of the HCl solution is 9%.

[0047] Example 2

[0048] 1. Pretreatment of rose flowers

[0049] Wash the rose flowers clean, then dry them at 35°C and grind them into a powder with a particle size of 0.18 - 0.21 mm to obtain rose flower powder, and store it at 3°C for later use.

[0050] 2. Coarse extraction

[0051] Add the rose flower powder to deionized water, extract it in a water bath at 60°C for 35 minutes, then filter. After evaporating and concentrating the filtrate to 15% of the original volume at 85°C, obtain the flavonoid glycoside concentrate for later use;

[0052] Add the filter cake to an ethanol solution, extract it in a water bath at 60°C for 100 minutes, then transfer it to a centrifuge and centrifuge at 4000 r / min for 7 minutes. After centrifugation, extract the supernatant, concentrate and dry it at 55°C to obtain the crude flavonoid for later use;

[0053] The mass ratio of the rose flower powder to deionized water is 0.8:45;

[0054] The mass ratio of the filter cake to the ethanol solution is 0.8:17;

[0055] The mass fraction of the ethanol solution is 65.

[0056] 3. Glycosylation

[0057] Add the crude flavonoid to an ethyl acetate mixture, mix it evenly, then add tetrabutylammonium bromide and bromoacetylglucose, and react at a stirring rate of 80 r / min for 14 hours. After the reaction, rotary evaporate to remove ethyl acetate at 75°C, then mix it evenly with the flavonoid glycoside concentrate obtained in step 2, and rotary evaporate to dryness at 50°C to obtain the crude flavonoid glycoside;

[0058] The mass ratio of the crude flavonoid, ethyl acetate mixture, tetrabutylammonium bromide, bromoacetylglucose, and flavonoid glycoside concentrate is 0.31:15:0.008:0.5:29;

[0059] The ethyl acetate mixture contains ethyl acetate and the ethyl acetate after extraction in step 4, and the mass ratio is 4.7:0.8.

[0060] 4. Hydrolysis

[0061] The crude flavonoid glycoside is added to deionized water. After stirring for 25 min, the insoluble impurities are filtered off. After adjusting the pH value to 3.8 with HCl solution, hydrolysis is carried out at 55 °C for 5 h. Then, filtration is performed. After adjusting the pH value of the filtrate to neutral, evaporation and concentration are carried out at 85 °C to 8% of the original volume. Then, ethyl acetate is added for extraction. The ethyl acetate after extraction is added to the ethyl acetate mixture in Step 3 for recycling. The filter cake is washed clean with deionized water and dried to constant weight at 35 °C to obtain flavonoids;

[0062] The mass ratio of the crude flavonoid glycoside, deionized water, and ethyl acetate is 0.8∶37∶8;

[0063] The mass fraction of the HCl solution is 6%.

[0064] Example 3

[0065] 1. Pretreatment of rose flowers

[0066] The rose flowers are washed clean, then dried at 45 °C, ground into a powder with a particle size of 0.25 - 0.28 mm to obtain rose flower powder, and stored for later use at 7 °C.

[0067] 2. Coarse extraction

[0068] The rose flower powder is added to deionized water and extracted in a water bath at 75 °C for 45 min. Then, filtration is carried out. After evaporation and concentration of the filtrate at 95 °C to 25% of the original volume, a flavonoid glycoside concentrate is obtained and stored for later use;

[0069] The filter cake is added to an ethanol solution and extracted in a water bath at 80 °C for 130 min. Then, it is transferred to a centrifuge and centrifuged at 5000 r / min for 9 min. After centrifugation, the supernatant is extracted, concentrated, and dried at 65 °C to obtain crude flavonoids and stored for later use;

[0070] The mass ratio of the rose flower powder to deionized water is 1.2∶55;

[0071] The mass ratio of the filter cake to the ethanol solution is 1.2∶23;

[0072] The mass fraction of the ethanol solution is 75%.

[0073] 3. Glycosylation

[0074] The crude flavonoids are added to the ethyl acetate mixture. After mixing evenly, tetrabutylammonium bromide and bromoacetylglucose are added, and the reaction is carried out at a stirring rate of 100 r / min for 16 h. After the reaction, ethyl acetate is removed by rotary evaporation at 85 °C, and then it is mixed evenly with the flavonoid glycoside concentrate obtained in Step 2 and rotary evaporated to dryness at 70 °C to obtain crude flavonoid glycoside;

[0075] The mass ratio of the crude flavonoid, ethyl acetate mixture, tetrabutylammonium bromide, bromoacetylglucose, and flavonoid glycoside concentrate is 0.37∶17∶0.012∶0.9∶33;

[0076] The ethyl acetate mixture contains ethyl acetate and the ethyl acetate after extraction in step 4, and the mass ratio is 5.3∶1.2.

[0077] 4. Hydrolysis

[0078] Add the crude flavonoid glycoside to deionized water, stir for 35 min, filter out the insoluble impurities, adjust the pH value to 4.5 with HCl solution, hydrolyze at 65 °C for 7 h, then filter, adjust the pH value of the filtrate to neutral, evaporate and concentrate to 12% of the original volume at 95 °C, add ethyl acetate for extraction, add the extracted ethyl acetate to the ethyl acetate mixture in step 3 for recycling, wash the filter cake with deionized water until clean, and dry to constant weight at 45 °C to obtain flavonoid;

[0079] The mass ratio of the crude flavonoid glycoside, deionized water, and ethyl acetate is 1.2∶44∶10;

[0080] The mass fraction of the HCl solution is 13%.

[0081] Example 4

[0082] 1. Pretreatment of rose flowers

[0083] Wash the rose flowers clean, then dry them at 40 °C, grind them into powder with a particle size of 0.21 - 0.25 mm to obtain rose flower powder, and store it at 5 °C for standby.

[0084] 2. Coarse extraction

[0085] Add the rose flower powder to deionized water, extract in a water bath at 70 °C for 40 min, then filter, evaporate and concentrate the filtrate to 20% of the original volume at 90 °C to obtain flavonoid glycoside concentrate for standby;

[0086] Add the filter cake to ethanol solution, extract in a water bath at 70 °C for 120 min, then transfer it to a centrifuge, centrifuge at 4500 r / min for 8 min, after centrifugation, extract the supernatant, concentrate and dry it at 60 °C to obtain crude flavonoid for standby;

[0087] The mass ratio of the rose flower powder to deionized water is 1∶50;

[0088] The mass ratio of the filter cake to ethanol solution is 1∶20;

[0089] The mass fraction of the ethanol solution is 70%.

[0090] 3. Glycosylation

[0091] Add the crude flavonoids into ethyl acetate. After mixing evenly, add tetrabutylammonium bromide and bromoacetylglucose, and react at a stirring rate of 90 r / min for 15 h. After the reaction, rotary evaporate to remove ethyl acetate at 80 °C, then mix evenly with the flavonoid glycoside concentrate obtained in step 2, and rotary evaporate to dryness at 60 °C to obtain crude flavonoid glycosides;

[0092] The mass ratio of the crude flavonoids, ethyl acetate, tetrabutylammonium bromide, bromoacetylglucose, and flavonoid glycoside concentrate is 0.34∶16∶0.01∶0.7∶31.

[0093] 4. Hydrolysis

[0094] Add the crude flavonoid glycosides into deionized water. After stirring for 30 min, filter off the insoluble impurities. Adjust the pH value to 4 with HCl solution, then hydrolyze at 60 °C for 6 h, and then filter. Wash the filter cake with deionized water until clean, and dry to constant weight at 40 °C to obtain flavonoids;

[0095] The mass ratio of the crude flavonoid glycosides to deionized water is 1∶40;

[0096] The mass fraction of the HCl solution is 9%.

[0097] Example 5

[0098] 1. Pretreatment of rose flowers

[0099] Wash the rose flowers clean, then dry them at 40 °C, grind them into powder with a particle size of 0.21 - 0.25 mm to obtain rose flower powder, and store it at 5 °C for later use.

[0100] 2. Coarse extraction

[0101] Add the rose flower powder into deionized water, extract in a water bath at 70 °C for 40 min, then filter. Evaporate and concentrate the filtrate to 20% of the original volume at 90 °C to obtain a flavonoid glycoside concentrate for later use;

[0102] Add the filter cake into an ethanol solution, extract in a water bath at 70 °C for 120 min, then transfer it to a centrifuge and centrifuge at 4500 r / min for 8 min. After centrifugation, extract the supernatant, concentrate and dry it at 60 °C to obtain crude flavonoids for later use;

[0103] The mass ratio of the rose flower powder to deionized water is 1∶50;

[0104] The mass ratio of the filter cake to the ethanol solution is 1∶20;

[0105] The mass fraction of the ethanol solution is 70%.

[0106] 3. Separation and purification

[0107] Mix the crude flavonoids and the concentrated flavonoid glycoside solution, add them to a 30% wt ethanol solution, stir to dissolve, then adsorb through macroporous resin. Control the sample loading flow rate at 1.5 mL / min. After sample loading, let it stand for 30 min, then elute with a 70% wt ethanol solution at an elution flow rate of 30 mL / min. Collect the eluate, concentrate the eluate at 60 °C, and dry to obtain flavonoids.

[0108] The mass ratio of the crude flavonoids, the concentrated flavonoid glycoside solution, the 30% wt ethanol solution, and the 70% wt ethanol solution is 1∶10∶60∶240.

[0109] Example 6

[0110] Use the same extraction method as in Example 5 to obtain the eluate. The difference is that after mixing and diluting the obtained eluate with deionized water, perform secondary adsorption through macroporous resin. Control the sample loading flow rate at 1.5 mL / min. After sample loading, let it stand for 30 min, then elute with a 70% wt ethanol solution at an elution flow rate of 30 mL / min. Collect the secondary eluate, concentrate the secondary eluate at 60 °C, and dry to obtain flavonoids.

[0111] The mass ratio of the eluate, deionized water, and the 70% wt ethanol solution is 1∶3∶10.

[0112] Test Example

[0113] Test the flavonoids extracted in Examples 1 - 6. The test items include the flavonoid yield and the flavonoid purity.

[0114] The test method for the flavonoid yield is as follows:

[0115] Flavonoid yield = flavonoid mass / rose powder mass;

[0116] Using rutin reference substance as a control, adopt the NaNO 2 -Al(NO 3 ) 3 -NaOH colorimetric method to determine the flavonoid content, and then obtain the purity of the flavonoids.

[0117] The test results of the flavonoid yield and the flavonoid content are shown in Table 1.

[0118] Table 1.

[0119]

[0120] It can be seen from Examples 1 to 6 that in Example 4, the hydrolyzed filtrate was not recycled, resulting in a decrease in the yield of flavonoids; in Example 5, macroporous resin method was used to separate and purify the crude flavonoids. The yield of flavonoids was not much different from that of the example, but the purity was relatively low. Therefore, when using the macroporous resin method to separate and purify the crude flavonoids, it usually needs to be purified cyclically many times, but this will reduce the yield of flavonoids; in Example 6, the macroporous resin method was used to separate and purify the crude flavonoids cyclically twice. Compared with Example 5, the yield decreased and the purity increased.

Claims

1. A method for extracting flavonoids from rose, characterized in that: The method for extracting flavonoids comprises rose pretreatment, crude extraction, glycosylation, and hydrolysis; The glycosylation method comprises the following steps: adding the crude flavonoids obtained in the crude extraction step to an ethyl acetate mixture, mixing them evenly, adding tetrabutylammonium bromide and bromoacetyl glucose, stirring and reacting for 14 to 16 hours, and after the reaction is completed, removing the ethyl acetate by rotary evaporation at 75 to 85° C., and then mixing them evenly with the flavonoid glycoside concentrate obtained in the crude extraction step, and rotary evaporation and drying to obtain the crude flavonoid glycosides; The hydrolysis method comprises the following steps: adding crude flavonoid glycosides to deionized water, stirring for 25 to 35 minutes, filtering out insoluble impurities, adjusting the pH value to 3.8 to 4.5 using an HCl solution, hydrolyzing at 55 to 65° C. for 5 to 7 hours, filtering, adjusting the pH value of the filtrate to neutral, evaporating and concentrating the filtrate to 8 to 12% of the original volume at 85 to 95° C., adding ethyl acetate for extraction, adding the extracted ethyl acetate to the ethyl acetate mixed solution in the glycosidation step for recycling, cleaning the filter cake, and drying to constant weight to obtain flavonoids.

2. A method for extracting flavonoids from rose according to claim 1, characterized in that: In the glycosylation method, the mass ratio of crude flavonoids, ethyl acetate mixed solution, tetrabutylammonium bromide, bromoacetyl glucose, and flavonoid glycoside concentrate is 0.31-0.37:15-17:0.008-0.012:0.5-0.9:29-33, the ethyl acetate mixed solution comprises ethyl acetate and ethyl acetate extracted in the hydrolysis step, the mass ratio is 4.7-5.3:0.8-1.2, the stirring rate is 80-100 r / min, and the rotary evaporation drying temperature is 50-70°C.

3. A method for extracting flavonoids from rose according to claim 1, characterized in that: In the hydrolysis method, the mass ratio of crude flavonoid glycosides, deionized water and ethyl acetate is 0.8-1.2:37-44:8-10, and the mass fraction of the HCl solution is 6-13%.

4. A method for extracting flavonoids from rose according to claim 1, characterized in that: The rose pretreatment method comprises the following steps: cleaning the rose, drying the rose at 35-45°C, grinding the rose into 0.18-0.28 mm powder, obtaining rose powder, and storing the powder at 3-7°C for later use.

5. A method for extracting flavonoids from rose according to claim 1, characterized in that: The crude extraction method comprises the following steps: adding rose powder to deionized water, extracting in a water bath for 35 to 45 minutes, filtering, evaporating and concentrating the filtrate to 15 to 25% of the original volume at 85 to 95° C., obtaining a flavonoid glycoside concentrate for later use; adding the filter cake to an ethanol solution, extracting in a water bath for 100 to 130 minutes, transferring the filter cake to a centrifuge, centrifuging for 7 to 9 minutes, extracting the supernatant after the centrifugation, concentrating at 55 to 65° C., and drying the solution to obtain a crude flavonoid for later use.

6. A method for extracting flavonoids from rose according to claim 5, characterized in that: In the crude extraction method, the mass ratio of rose powder to deionized water is 0.8-1.2:45-55, the mass ratio of filter cake to ethanol solution is 0.8-1.2:17-23, and the mass fraction of ethanol solution is 65-75%.

7. A method for extracting flavonoids from rose according to claim 5, characterized in that: In the crude extraction method, the water bath extraction temperature of the rose powder is 60-75° C., the water bath extraction temperature of the filter cake is 60-80° C., and the centrifugal speed is 4000-5000 r / min.

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