Extraction method of gastrodia elata total polyphenol active substances in food and cosmetics

Abstract

The invention belongs to the technical field of natural product extraction, and particularly relates to a method for extracting gastrodia elata total polyphenol active substances in food and cosmetics. According to the method, a eutectic solvent is used as an extraction solvent, and ultrasonic extraction is combined; a hydrogen bond acceptor of the eutectic solvent comprises polyethylene glycol-200, polyethylene glycol-400 and Tween 80, and a hydrogen bond donor comprises ethylene glycol, 1, 2-propylene glycol, glucose, glycerol and xylitol. According to the method, the eutectic solvent is used as an extraction solvent, and ultrasonic extraction is combined, so that the extraction efficiency of the total polyphenol substances of the gastrodia elata is high and can reach 33.2 mg / g at most; the extraction method disclosed by the invention is simple, short in extraction time and practical, and has a very good development prospect in the fields of medicines, foods, cosmetics and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of natural product extraction, and in particular relates to a method for extracting active substances of total polyphenols of gastrodia elata in food and cosmetics. Background Art

[0002] Gastrodia elata (G.elata) is a perennial herb of the genus Gastrodia in the orchid family. It was first recorded in the Shennong's Herbal Classic in 2000. In the past few decades, G.elata has attracted widespread attention as a Chinese medicinal material with both medicinal and edible properties due to its potential health and economic value. Studies have shown that G.elata has sedative and hypnotic, anticonvulsant, anti-Alzheimer's disease and anti-aging effects, as well as positive effects on the immune and cardiovascular systems. Gastrodin and gastrodin aglycone (p-hydroxybenzyl alcohol) are the main polyphenolic bioactive components in Gastrodia elata. They have multiple hydroxyl structures that can scavenge excessive free radicals, defend against free radical damage, resist diseases, and delay aging. In addition, these components also have multiple bioactive functions such as antidepressant, immunomodulatory and neuroprotective activity. These excellent properties of Gastrodia elata polyphenols make them suitable for various fields. For example, in the field of medicine, gastrodin has been used clinically to treat neurodegenerative diseases such as epilepsy, migraine and convulsions; in the field of cosmetics, polyphenols can be used as UV enhancers and whitening agents. In addition, it also plays an important role in the field of food processing as an antioxidant, preservative and colorant. Although phenolic substances have a variety of biological activities, the extraction efficiency of phenolic substances in natural products is currently low and cannot meet production needs. Therefore, it is urgent to explore an efficient method for extracting polyphenols.

[0003] However, the extraction of total polyphenols is currently mainly carried out by organic solvent extraction. Traditional organic solvents such as methanol, ethanol, ethyl acetate, acetone, chloroform, etc. are widely used in the extraction of bioactive components from plant materials. Generally speaking, the solvent extraction method has the limitations of cumbersome steps, long extraction time, high production cost, low safety factor, and unsuitability for large-scale application. Most traditional organic solvents have high volatility and toxicity, poor biodegradability, and serious environmental pollution.

[0004] Deep eutectic solvents (DES) are a new type of solvent similar to ionic liquids, with excellent physical and chemical properties, high biocompatibility, diversity, strong solubility, designability, etc. DES is a mixture formed by a certain proportion of hydrogen bond acceptors (HBA) and hydrogen bond donors (HBD) through hydrogen bond interactions, and its melting point is usually lower than its components. At present, there is no method to extract active ingredients from Gastrodia elata using deep eutectic solvents. Summary of the invention

[0005] The purpose of the present invention is to provide a method and application of extracting total polyphenols from Gastrodia elata based on a low eutectic solvent combined with ultrasound-assisted extraction. The present invention uses a low eutectic solvent as a solvent for extracting Gastrodia elata, combined with ultrasound-assisted extraction technology, effectively combining the advantages of ultrasonic extraction and DESs as a solvent extraction process, and has high extraction efficiency for total polyphenols from Gastrodia elata, and has a wide range of application prospects for extracting effective bioactive ingredients in the pharmaceutical industry. The raw materials involved in the method are widely available and inexpensive. The synthesized low eutectic solvent has the advantages of high extraction efficiency, non-toxicity, and green environmental protection.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] The present invention provides a method for extracting active substances of total polyphenolic substances of Gastrodia elata used in food and cosmetics by using a low eutectic solvent. The method uses a low eutectic solvent as an extraction solvent and combines ultrasonic extraction; the hydrogen bond acceptors of the low eutectic solvent include polyethylene glycol-200 (PEG200), polyethylene glycol-400 (PEG400), Tween 80 (Tween-80), and the hydrogen bond donors include ethylene glycol (EG), 1,2-propylene glycol, glucose (GLU), glycerol (Gly) and xylitol (Xyl). The present invention uses a low eutectic solvent for extraction, which effectively solves the problem of high toxicity of traditional organic solvents.

[0008] In the above technical solution, further, the low eutectic solvent uses polyethylene glycol-200 as a hydrogen bond acceptor and ethylene glycol as a hydrogen bond donor.

[0009] In the above technical solution, further, the preparation of the low eutectic solvent includes: mixing the hydrogen bond acceptor and the hydrogen bond donor, heating and stirring at 55-65° C. until a clear, transparent and uniform liquid is formed.

[0010] In the above technical solution, further, the mass ratio of the hydrogen bond donor to the hydrogen bond acceptor in the low eutectic solvent is 1:2-5:1; preferably 2:1.

[0011] In the above technical solution, further, the water content of the low eutectic solvent is 0%-80%; preferably 20%-40%. Since the low water content changes the viscosity and fluidity of DESs, the target component can be well leached from the plant matrix. When the water content in DESs is too high, the polarity of the system will increase, the hydrogen bonds between the DESs components will be destroyed, and the interaction between DESs and polyphenols will be weakened, thereby reducing the yield of the target component.

[0012] In the above technical solution, further, the liquid-solid ratio of the low eutectic solvent to Gastrodia elata is 5:1-30:1, preferably 5:1-10:1. A larger amount of solvent can increase the contact area between the solvent and the solute, which is beneficial for the diffusion of the solute into the solvent, thereby promoting the increase of the extraction efficiency. As the amount of solvent continues to increase, the extraction efficiency no longer changes significantly.

[0013] In the above technical solution, further, the ultrasonic extraction time is 25-75min, and the extraction temperature is 30-80℃; preferably, the ultrasonic extraction time is 55-65min, and the extraction temperature is 50℃. Longer ultrasonic treatment can completely rupture the cell wall of the cell, which is more conducive to the release of total polyphenols. However, as the extraction time continues to increase, the extraction rate will decrease. This may be due to the fact that as the ultrasonic time increases, the dissolution rate of Gastrodia elata polyphenols in DES gradually becomes saturated, while the dissolution of other compounds increases, or it may be that the long extraction time causes the polyphenols to undergo degradation reactions, thereby failing to further improve the extraction efficiency of total polyphenols. The increase in extraction temperature enhances the cavitation effect during the UAE extraction process, accelerates the movement of solvent molecules, and contributes to the destruction of cell structure, thereby increasing the leaching of target compounds in the extraction solvent, and can also reduce the viscosity and surface tension of DES, which is more conducive to the extraction of polyphenols. However, polyphenols contain multiple phenolic hydroxyl groups, and their chemical properties are unstable at high temperatures. When the temperature is higher than 50℃, polyphenols are prone to decomposition.

[0014] In the above technical solution, further, after the ultrasonic extraction, the supernatant is centrifuged to obtain the Gastrodia elata polyphenol extract.

[0015] In the above technical scheme, further, the method includes uniformly mixing Gastrodia elata and a low eutectic solvent, and after ultrasonic extraction, centrifuging and taking the supernatant to obtain the Gastrodia elata polyphenol extract; the centrifugal speed is 10000-12000r / min, and the centrifugal time is 5-10min.

[0016] In the above technical solution, further, the uniform mixing is vortex mixing for 10s-50s.

[0017] In the above technical solution, further, before mixing the Gastrodia elata with the low eutectic solvent, the Gastrodia elata is first crushed and sieved to obtain Gastrodia elata powder; the sieving is a 30-60 mesh sieve.

[0018] In the above technical scheme, further, when the mass ratio of ethylene glycol and polyethylene glycol-200 in the low eutectic solvent is 2:1, the liquid-solid weight volume ratio (mL / g) is 5:1-10:1; the ultrasonic extraction time is 55-65min; the water added to the low eutectic solvent during extraction accounts for 20%-40% by mass; the ultrasonic extraction temperature is 50°C, and the centrifugation is 12000rpm for 5min. The content of total polyphenols in the extracted Gastrodia elata is above 33.2mg / g.

[0019] In the above technical scheme, further, the content of total polyphenols in Gastrodia elata is determined, and the detection steps are as follows: (1) Preparation of reference solution: Take an appropriate amount of gallic acid standard, accurately weigh, place in a 10mL volumetric flask, add deionized water to make a solution containing about 1mg per 1ml, and obtain; (2) Preparation of standard curve: Take an appropriate amount of gallic acid reference solution, add water to dilute step by step to concentrations of 100μg / mL, 80μg / mL, 60μg / mL, 40μg / mL, and 20μg / mL of reference solution. Afterwards, take another 6 test tubes, draw 1.0mL of the above solutions of different concentrations respectively, add 5mL of deionized water to each, mix, add 0.5mL of forlin phenol reagent to each, and mix thoroughly; let stand for 3 minutes, add 20% Na 2 CO 3 1.5 mL of solution was mixed and then diluted to 10 mL with water. The reaction solution was reacted at room temperature in the dark for 2 h. The absorbance was measured by UV-visible spectroscopy at 738 nm. A standard curve was constructed with the concentration of gallic acid as the horizontal axis and the absorbance as the vertical axis. The linear equation was y = 0.1063x + 0.0148, R 2 =0.9993; (3) Determination method: Accurately measure 1 mL of Gastrodia elata total polyphenol extract, add 5 mL of deionized water and 0.5 mL of Folin phenol reagent, mix thoroughly. Let stand for 3 minutes, add 1.5 mL of 20% Na 2 CO 3 The solution was diluted to 10 mL. The reaction solution was kept in the dark at room temperature for 2 h. The absorbance was measured by UV-visible spectroscopy at a wavelength of 738 nm. The polyphenol concentration was calculated by the regression equation of the standard curve.

[0020] Compared with the prior art, the present invention has the following characteristics:

[0021] The invention uses a low eutectic solvent as an extraction solvent and combines it with ultrasonic extraction, so that the extraction efficiency of total polyphenols of Gastrodia elata is high and can reach 33.2 mg / g at the highest. The low eutectic solvent of the invention has a wide range of raw materials, low cost, is green and low toxic, and the preparation process of the low eutectic solvent is simple and easy to operate. The product is not easy to volatilize and has good thermal stability, and is suitable for large-scale application. The extraction method of the invention is simple, the extraction time is short, and it is practical, and it has good development prospects in the fields of medicine, food, cosmetics, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a graph showing the effect of different types of deep eutectic solvents on the extraction efficiency of total polyphenols;

[0023] Figure 2 This is a graph showing the effect of different mass ratios on the extraction efficiency of total polyphenols;

[0024] Figure 3 This is the effect of different ultrasonic-assisted extraction time on the extraction rate of total polyphenols;

[0025] Figure 4 This is the effect of different liquid-solid mass volume ratios on the extraction rate of total polyphenols;

[0026] Figure 5 This is the effect of different ultrasonic temperatures on the extraction rate of total polyphenols;

[0027] Figure 6 This is the effect of different water contents on the extraction rate of total polyphenols;

[0028] Figure 7 This is a graph showing the effect of different extraction solvents on the extraction rate of total polyphenols;

[0029] Figure 8 It is a standard curve graph. DETAILED DESCRIPTION

[0030] The following is a further detailed description of the claims of the present invention in conjunction with specific implementation methods, but does not constitute any limitation to the present invention. Any limited modifications made within the scope of protection of the claims of the present invention are still within the scope of protection of the claims of the present invention.

[0031] Example 1

[0032] Ethylene glycol and polyethylene glycol-200 were mixed at a mass ratio of 2:1, water was added to the low eutectic solvent to account for 20% by mass, and then heated and magnetically stirred until a transparent and uniform liquid was formed, namely DES, which was sealed and stored. Gastrodia elata (Gastrodia elata in this experiment was purchased from Yunnan Runying Pharmaceutical Chain Co., Ltd., and Gastrodia elata slices were its dried tubers) was dried and crushed with a pulverizer, sieved, and Gastrodia elata powder was obtained, which was sealed and stored.

[0033] Take 0.1g of Gastrodia elata powder, weigh it accurately, put it in a test tube, add 1mL of low eutectic solvent, that is, the liquid-solid ratio is 10:1, vortex mix, and ultrasonic extraction for 55min, where the ultrasonic power is 250W and the temperature is 50℃. After vortex mixing, centrifuge at 12000r / min for 5min, and take the supernatant, which is the total polyphenol extract of Gastrodia elata.

[0034] The extraction efficiency (mg / g) of the Gastrodia elata total polyphenol extract of this example was investigated.

[0035] The content determination of total polyphenols in Gastrodia elata is as follows: (1) Preparation of reference solution: Take an appropriate amount of gallic acid standard, weigh accurately, place in a 10mL volumetric flask, add deionized water to make a solution containing about 1mg per 1ml; (2) Preparation of standard curve: Take an appropriate amount of gallic acid reference solution, add water to dilute it step by step to make reference solutions with concentrations of 100μg / mL, 80μg / mL, 60μg / mL, 40μg / mL, and 20μg / mL. Afterwards, take another 6 test tubes, draw 1.0mL of the above solutions of different concentrations respectively, add 5mL of deionized water to each, mix, add 0.5mL of forlin phenol reagent to each, mix thoroughly; let stand for 3 minutes, add 20% Na 2 CO 3 1.5 mL of solution was mixed and then diluted to 10 mL with water. The reaction solution was reacted at room temperature in the dark for 2 h. The absorbance was measured by UV-visible spectroscopy at 738 nm. A standard curve was constructed with the concentration of gallic acid as the horizontal axis and the absorbance as the vertical axis. The linear equation was y = 0.1063x + 0.0148, R 2 =0.9993; (see attached Figure 8 ) (3) Determination method: Accurately measure 1 mL of Gastrodia elata total polyphenol extract, add 5 mL of deionized water and 0.5 mL of Folin phenol reagent, and mix thoroughly. Let stand for 3 minutes, then add 1.5 mL of 20% Na 2 CO 3 The solution was diluted to 10 mL. The reaction solution was kept in the dark at room temperature for 2 h. The absorbance was measured by UV-visible spectroscopy at a wavelength of 738 nm. The polyphenol concentration was calculated by the regression equation of the standard curve.

[0036] Calculation of extraction efficiency: The polyphenol content (YTPC) is calculated as follows:

[0037]

[0038] Where: C is the polyphenol concentration in the test sample (mg / L; N is the dilution factor; V is the fixed volume (mL); m is the mass of Gastrodia elata (g).

[0039] Example 2

[0040] The difference from Example 1 is that the hydrogen bond acceptor of the low eutectic solvent is polyethylene glycol-200, and the hydrogen bond donor is glycerol.

[0041] Example 3

[0042] The difference from Example 1 is that the hydrogen bond acceptor of the low eutectic solvent is polyethylene glycol-200, and the hydrogen bond donor is 1,2-propylene glycol.

[0043] Example 4

[0044] The difference from Example 1 is that the hydrogen bond acceptor of the low eutectic solvent is polyethylene glycol-200, and the hydrogen bond donor is xylitol.

[0045] Example 5

[0046] The difference from Example 1 is that the hydrogen bond acceptor of the low eutectic solvent is polyethylene glycol-200, and the hydrogen bond donor is glucose.

[0047] Example 6

[0048] The difference from Example 1 is that the hydrogen bond acceptor of the low eutectic solvent is polyethylene glycol 400, and the hydrogen bond donor is glucose.

[0049] Example 7

[0050] The difference from Example 1 is that the hydrogen bond acceptor of the low eutectic solvent is polyethylene glycol 400, and the hydrogen bond donor is glycerol.

[0051] Example 8

[0052] The difference from Example 1 is that the hydrogen bond acceptor of the low eutectic solvent is polyethylene glycol-400, and the hydrogen bond donor is 1,2-propylene glycol.

[0053] Example 9

[0054] The difference from Example 1 is that the hydrogen bond acceptor of the low eutectic solvent is polyethylene glycol 400, and the hydrogen bond donor is xylitol.

[0055] Example 10

[0056] The difference from Example 1 is that the hydrogen bond acceptor of the low eutectic solvent is polyethylene glycol 400, and the hydrogen bond donor is ethylene glycol.

[0057] Embodiment 11

[0058] The difference from Example 1 is that the hydrogen bond acceptor of the low eutectic solvent is Tween-80, and the hydrogen bond donor is ethylene glycol.

[0059] Example 12

[0060] The difference from Example 1 is that the hydrogen bond acceptor of the low eutectic solvent is Tween-80, and the hydrogen bond donor is 1,2-propylene glycol.

[0061] The effects of different types of deep eutectic solvents in Examples 1-12 on the extraction efficiency of total polyphenols in Gastrodia elata are shown in Table 1.

[0062] Table 1 Comparison of extraction results of different types of deep eutectic solvents

[0063]

[0064]

[0065] From the results in Table 1, it can be seen that the extraction efficiency is highest when the deep eutectic solvent is prepared with polyethylene glycol-200 as the hydrogen bond acceptor and ethylene glycol as the hydrogen bond donor. Each DES forms a clear and transparent solution.

[0066] Example 13

[0067] The difference from Example 1 is that the mass ratio of the hydrogen bond donor ethylene glycol and the hydrogen bond acceptor polyethylene glycol-200 in the low eutectic solvent is 1:2.

[0068] Embodiment 14

[0069] The difference from Example 1 is that the mass ratio of the hydrogen bond donor ethylene glycol and the hydrogen bond acceptor polyethylene glycol-200 in the low eutectic solvent is 1:1.

[0070] Embodiment 15

[0071] The difference from Example 1 is that the mass ratio of the hydrogen bond donor ethylene glycol and the hydrogen bond acceptor polyethylene glycol-200 in the low eutectic solvent is 3:1.

[0072] Example 16

[0073] The difference from Example 1 is that the mass ratio of the hydrogen bond donor ethylene glycol and the hydrogen bond acceptor polyethylene glycol-200 in the low eutectic solvent is 4:1.

[0074] Embodiment 17

[0075] The difference from Example 1 is that the mass ratio of the hydrogen bond donor ethylene glycol and the hydrogen bond acceptor polyethylene glycol-200 in the low eutectic solvent is 5:1.

[0076] The effects of different mass ratios on the extraction rate of total polyphenols in Examples 1 and 13-17 are shown in Table 2.

[0077] Table 2 Comparison of extraction results at different mass ratios

[0078]

[0079]

[0080] From the results in Table 2, it can be seen that the extraction rate is the highest when the mass ratio is 2: 1. As the proportion of hydrogen bond donors in DES increases, the extraction of total polyphenols first increases and then decreases, reaching the highest level when the mass ratio is 2: 1.

[0081] Embodiment 18

[0082] The same process as in Example 1 was used, but the reaction conditions were different, except that the ultrasonic extraction time was changed to 25 min.

[0083] Embodiment 19

[0084] The same process as in Example 1 was used, but the reaction conditions were different, except that the ultrasonic extraction time was changed to 35 min.

[0085] Embodiment 20

[0086] The same process as in Example 1 was used, but the reaction conditions were different, except that the ultrasonic extraction time was changed to 45 min.

[0087] Embodiment 21

[0088] The same process as in Example 1 was used, but the reaction conditions were different, except that the ultrasonic extraction time was changed to 65 min.

[0089] Embodiment 22

[0090] The same process as in Example 1 was used, but the reaction conditions were different, except that the ultrasonic extraction time was changed to 75 min.

[0091] The effects of different ultrasonic-assisted extraction times on the extraction rate of total polyphenols in Examples 1 and 18-22 are shown in Table 3.

[0092] Table 3 Comparison of extraction results at different ultrasonic times

[0093] Serial number Ultrasonic time (min) Extraction efficiency (mg / g) Example 1 55 33.2337 Embodiment 18 25 27.6292 Embodiment 19 35 31.0855 Embodiment 20 45 31.3205 Embodiment 21 65 31.8430 Embodiment 22 75 24.8026

[0094] From the results in Table 3, it can be seen that the extraction rate is the highest when the ultrasonic time is 55 min. The advantage of ultrasonic extraction is that its cavitation effect can form a large number of cavitation bubbles in the liquid, and a large amount of energy is generated in the collision and rupture of the cavitation bubbles, making the cell membrane and cell wall more easily destroyed, thereby releasing the target substance.

[0095] Embodiment 23

[0096] The same process as in Example 1 was used, but the reaction conditions were different, except that the liquid-to-solid weight-to-volume ratio of the deep eutectic solvent was changed to 5:1.

[0097] Embodiment 24

[0098] The same process as in Example 1 was used, but the reaction conditions were different, except that the liquid-to-solid weight-to-volume ratio of the deep eutectic solvent was changed to 15:1.

[0099] Embodiment 25

[0100] The same process as in Example 1 was used, but the reaction conditions were different, except that the liquid-to-solid weight-to-volume ratio of the deep eutectic solvent was changed to 20:1.

[0101] Embodiment 26

[0102] The same process as in Example 1 was used, but the reaction conditions were different, except that the liquid-to-solid weight-to-volume ratio of the deep eutectic solvent was changed to 25:1.

[0103] Embodiment 27

[0104] The same process as in Example 1 was used, but the reaction conditions were different, except that the liquid-to-solid weight-to-volume ratio of the deep eutectic solvent was changed to 30:1.

[0105] The effects of different liquid-to-solid mass volume ratios on the extraction rate of total polyphenols in Examples 1 and 23-27 are shown in Table 4.

[0106] Table 4 Comparison of extraction results at different liquid-solid weight-to-volume ratios

[0107] Serial number Liquid-solid weight-volume ratio (mL / g) Extraction efficiency (mg / g) Example 1 10:1 33.2337 Embodiment 23 5:1 26.4304 Embodiment 24 15:1 22.7510 Embodiment 25 20:1 17.9900 Embodiment 26 25:1 14.1050 Embodiment 27 30:1 12.5723

[0108] It can be seen from Table 4 that within the liquid-solid weight-to-volume ratio range of 5:1-30:1, as the proportion of the extraction solvent increases, the extraction first increases and then decreases, and the extraction rate reaches the maximum when the liquid-solid weight-to-volume ratio is 10mL / g. This may be because the increase in solvent will allow the Gastrodia elata powder to be fully mixed with DES, thereby promoting the leaching of polyphenol components. However, too high a solvent dosage will cause it to absorb too much ultrasound, weakening the crushing and cavitation effect of ultrasonic microwaves on Gastrodia elata, thereby reducing the dissolution of Gastrodia elata polyphenols, and also causing unnecessary solvent waste. Therefore, a liquid-to-solid ratio of 10mL / g was selected as the optimal condition.

[0109] Embodiment 28

[0110] The same process as in Example 1 was used, but the reaction conditions were different. Only the temperature during ultrasonic extraction was changed to 30°C.

[0111] Embodiment 29

[0112] The same process as in Example 1 was used, but the reaction conditions were different, except that the temperature during ultrasonic extraction was changed to 40°C.

[0113] Embodiment 30

[0114] The same process as in Example 1 was used, but the reaction conditions were different, except that the temperature during ultrasonic extraction was changed to 60°C.

[0115] Embodiment 31

[0116] The same process as in Example 1 was used, but the reaction conditions were different. Only the temperature during ultrasonic extraction was changed to 70°C.

[0117] Embodiment 32

[0118] The same process as in Example 1 was used, but the reaction conditions were different, except that the temperature during ultrasonic extraction was changed to 80°C.

[0119] The effects of different ultrasonic temperatures on the extraction efficiency of total polyphenols in Examples 1 and 28-32 are shown in Table 5.

[0120] Table 5 Comparison of extraction results at different ultrasonic temperatures

[0121] Serial number Ultrasonic temperature (℃) Extraction efficiency (mg / g) Example 1 50 33.2337 Embodiment 28 30 15.9542 Embodiment 29 40 26.2159 Embodiment 30 60 28.8772 Embodiment 31 70 23.0415 Embodiment 32 80 16.0669

[0122] From the results in Table 5, it can be seen that when the ultrasonic temperature is 50°C, the extraction efficiency of Gastrodia elata polyphenols is the highest.

[0123] Embodiment 33

[0124] The same process as in Example 1 was used, but the reaction conditions were different, except that the amount of water added to the deep eutectic solvent was changed to 0% by weight.

[0125] Embodiment 34

[0126] The same process as in Example 1 was used, but the reaction conditions were different, except that the amount of water added to the deep eutectic solvent was changed to 40% by weight.

[0127] Embodiment 35

[0128] The same process as in Example 1 was used, but the reaction conditions were different, except that the water added to the deep eutectic solvent accounted for 60% by weight.

[0129] Embodiment 36

[0130] The same process as in Example 1 was used, but the reaction conditions were different, except that the water added to the deep eutectic solvent accounted for 80% by weight.

[0131] The effects of different water contents on the extraction efficiency of total polyphenols in Examples 1 and 33-36 are shown in Table 6.

[0132] Table 6 Comparison of extraction results with different water contents

[0133] Serial number Water content (%) Extraction efficiency (mg / g) Example 1 20 33.2337 Embodiment 33 0 30.4915 Embodiment 34 40 30.6810 Embodiment 35 60 29.8595 Embodiment 36 80 28.8952

[0134] From the results in Table 6, it can be seen that as the water content increases from 0% to 20%, the polyphenol content gradually increases, and then the polyphenol content shows a downward trend. This may be because the low water content changes the viscosity and fluidity of DESs, allowing the target components to be well leached from the plant matrix. When the water content in DESs is too high, it will increase the polarity of the system, destroy the hydrogen bonds between DESs components, weaken the interaction between DESs and polyphenols, and thus reduce the yield of the target component. Therefore, the optimal water content of the low eutectic solvent is 20%.

[0135] Embodiment 37

[0136] The same process as in Example 1 was used, but the extraction solvent was different. Only the extraction solvent was changed to 80% methanol.

[0137] Embodiment 38

[0138] The same process as in Example 1 was used, but the extraction solvent was different. Only the extraction solvent was changed to 80% ethanol.

[0139] Embodiment 39

[0140] The same process as in Example 1 was used, but the extraction solvent was different. Only the extraction solvent was changed to methanol.

[0141] Embodiment 40

[0142] The same process as in Example 1 was used, but the extraction solvent was different. Only the extraction solvent was changed to water.

[0143] Table 7 Comparison of extraction results of different extraction solvents

[0144] Serial number Extraction solvent Extraction efficiency (mg / g) Example 1 DES 33.2337 Embodiment 37 80% Methanol 26.4377 Embodiment 38 80% ethanol 26.1917 Embodiment 39 Methanol 12.1028 Embodiment 40 water 15.9009

[0145] The above description of the embodiments is only used to illustrate the technical solution of the present invention, rather than to limit it; for ordinary technicians in this technical field, various improvements can still be made to the above embodiments, or some of the technical features can be replaced by equivalents. Therefore, improvements and equivalent replacements made without departing from the scope of the present invention do not depart from the spirit and scope of the technical solution claimed for protection by the present invention.

Claims

1. A method for extracting active substances of total polyphenols of Gastrodia elata using a deep eutectic solvent, characterized in that: The method uses a low eutectic solvent as an extraction solvent and combines ultrasonic extraction; The hydrogen bond acceptors of the low eutectic solvent include polyethylene glycol-200, polyethylene glycol-400 and Tween 80, and the hydrogen bond donors include ethylene glycol, 1,2-propylene glycol, glucose, glycerol and xylitol.

2. The method according to claim 1, characterized in that The low eutectic solvent uses polyethylene glycol-200 as a hydrogen bond acceptor and ethylene glycol as a hydrogen bond donor.

3. The method according to claim 1, characterized in that: The preparation of the low eutectic solvent comprises: mixing a hydrogen bond acceptor and a hydrogen bond donor, heating and stirring at 55-65° C. until a transparent and uniform liquid is formed.

4. The method according to claim 1, characterized in that: The mass ratio of the hydrogen bond donor to the hydrogen bond acceptor in the deep eutectic solvent is 1:2-5:1, preferably 2:

1.

5. The method according to claim 1, characterized in that The water content of the low eutectic solvent is 0%-80%, preferably 20%-40%.

6. The method according to claim 1, characterized in that The liquid-to-solid ratio of the low eutectic solvent to Gastrodia elata is 5:1-30:1, preferably 5:1-10:

1.

7. The method according to claim 1, characterized in that The ultrasonic extraction time is 25-75 minutes, and the extraction temperature is 30-80°C; preferably, the ultrasonic extraction time is 55-65 minutes, and the extraction temperature is 50°C.

8. The method according to claim 1, characterized in that After the ultrasonic extraction, the supernatant is centrifuged to obtain the Gastrodia elata polyphenol extract.

9. The method according to claim 1, characterized in that: The method comprises mixing gastrodia elata with a low eutectic solvent, performing ultrasonic extraction, and centrifuging to obtain a supernatant to obtain a gastrodia elata polyphenol extract; the centrifugal speed is 10000-12000 r / min, and the centrifugal time is 5-10 min.

10. The method according to claim 9, characterized in that Before the Gastrodia elata is mixed with the low eutectic solvent, it is first crushed and sieved to obtain Gastrodia elata powder; the sieving is a 30-60 mesh sieve.

Images