A method for extracting total polyphenolic active substances from Gastrodia elata in food and cosmetics

Abstract

This invention belongs to the field of natural product extraction technology, specifically relating to a method for extracting total polyphenolic active substances from Gastrodia elata in food and cosmetics. The method uses a eutectic solvent as the extraction solvent, combined with ultrasonic extraction. The hydrogen bond acceptors of the eutectic solvent include polyethylene glycol-200, polyethylene glycol-400, and Tween 80, while the hydrogen bond donors include ethylene glycol, 1,2-propanediol, glucose, glycerol, and xylitol. This invention, using a eutectic solvent combined with ultrasonic extraction, achieves high extraction efficiency of total polyphenolic substances from Gastrodia elata, reaching a maximum of 33.2 mg / g. The extraction method of this invention is simple, has a short extraction time, and is practical, showing great development potential in the fields of medicine, food, and cosmetics.

Description

Technical Field

[0001] This invention belongs to the field of natural product extraction technology, specifically relating to a method for extracting total polyphenolic active substances from Gastrodia elata in food and cosmetics. Background Technology

[0002] Gastrodia elata (Gastrodia elata) is a perennial herb belonging to the genus Gastrodia in the Orchidaceae family. It was first recorded in the *Shennong Bencao Jing* (Shennong's Classic of Materia Medica) in 2000. Over the past few decades, Gastrodia elata, as a medicinal and edible herb, has attracted widespread attention due to its potential health and economic value. Studies have shown that Gastrodia elata possesses sedative-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 of Gastrodia elata. They contain multiple hydroxyl structures, which can scavenge excess free radicals, defend against free radical damage, resist disease, and delay aging. In addition, these components also have various bioactive functions such as antidepressant, immunomodulatory, and neuroprotective activities. These excellent properties of Gastrodia elata polyphenols make them suitable for various fields. For example, in the pharmaceutical field, gastrodin has been used clinically to treat neurodegenerative diseases such as epilepsy, migraines, and convulsions; in the cosmetics field, polyphenols can be used as UV enhancers and whitening agents. In addition, it plays an important role in food processing as an antioxidant, preservative, and colorant. Although phenolic substances possess various biological activities, the current extraction efficiency of phenolic substances from natural products is low and cannot meet production needs. Therefore, there is an urgent need to explore a highly efficient method for extracting polyphenols.

[0003] However, the extraction of total polyphenols currently mainly employs organic solvent extraction. Traditional organic solvents such as methanol, ethanol, ethyl acetate, acetone, and chloroform are widely used for extracting bioactive components from plant materials. Generally speaking, solvent extraction methods have limitations such as cumbersome procedures, long extraction times, high production costs, low safety margins, and unsuitability for large-scale applications. Most traditional organic solvents have high volatility and toxicity, poor biodegradability, and cause serious environmental pollution.

[0004] Eutectic solvents (DES) are a new type of solvent similar to ionic liquids, possessing excellent physicochemical properties, including high biocompatibility, versatility, strong solubility, and designability. DES are mixtures formed by hydrogen bond acceptors (HBA) and hydrogen bond donors (HBD) in a certain proportion through hydrogen bond interactions, and their melting points are typically lower than those of their constituent components. Currently, there are no methods for extracting active ingredients from Gastrodia elata using eutectic solvents. Summary of the Invention

[0005] The purpose of this invention is to provide a method and application for extracting total polyphenols from Gastrodia elata using a eutectic solvent combined with ultrasound-assisted extraction technology. This invention uses a eutectic solvent as the extraction solvent for Gastrodia elata and combines it with ultrasound-assisted extraction technology, effectively combining the advantages of ultrasound extraction and DESs as solvent extraction processes. This method achieves high extraction efficiency of total polyphenols from Gastrodia elata and has broad application prospects in the pharmaceutical industry for extracting effective bioactive components. The raw materials involved in this method are widely available and inexpensive. The synthesized eutectic solvent has advantages such as high extraction efficiency, non-toxicity, and environmental friendliness.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This invention provides a method for extracting total polyphenolic active substances from Gastrodia elata in food and cosmetics using a eutectic solvent. The method uses a eutectic solvent as the extraction solvent, combined with ultrasonic extraction. The hydrogen bond acceptors of the eutectic solvent include polyethylene glycol-200 (PEG200), polyethylene glycol-400 (PEG400), and Tween-80, while the hydrogen bond donors include ethylene glycol (EG), 1,2-propanediol, glucose (GLU), glycerol (Gly), and xylitol (Xyl). This invention uses a eutectic solvent for extraction, effectively solving the problem of high toxicity associated with traditional organic solvents.

[0008] In the above technical solution, the 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, the preparation of the eutectic solvent further includes: mixing hydrogen bond acceptor and 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, the mass ratio of hydrogen bond donor to hydrogen bond acceptor in the eutectic solvent is 1:2-5:1; preferably 2:1.

[0011] In the above technical solution, the water content of the eutectic solvent is further defined as 0%-80%, preferably 20%-40%. The low water content alters the viscosity and flowability of the DESs, allowing the target component to leach well from the plant matrix. When the water content in the DESs is too high, it increases the polarity of the system, disrupts the hydrogen bonds between the DESs components, weakens the interaction between the DESs and polyphenols, and thus reduces the yield of the target component.

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

[0013] In the above technical solution, the ultrasonic extraction time is further specified as 25-75 min, and the extraction temperature as 30-80℃; preferably, the ultrasonic extraction time is 55-65 min, and the extraction temperature is 50℃. Longer ultrasonic treatment can completely rupture the cell walls, which is more conducive to the release of total polyphenols. However, as the extraction time continues to increase, the extraction rate decreases. This may be because, with the increase of ultrasonic time, the solubility of Gastrodia elata polyphenols in DES gradually becomes saturated, while the dissolution of other compounds increases. It may also be that excessively long extraction times cause polyphenol degradation reactions, thus failing to further improve the extraction efficiency of total polyphenols. Increasing the extraction temperature enhances the cavitation effect during UAE extraction, accelerates the movement of solvent molecules, and helps to destroy cell structures, thereby increasing the leaching of target compounds in the extraction solvent. It can also reduce the viscosity and surface tension of DES, which is more conducive to polyphenol extraction. However, polyphenols contain multiple phenolic hydroxyl groups and are chemically unstable at high temperatures. When the temperature exceeds 50℃, polyphenols are prone to decomposition.

[0014] In the above technical solution, further, after ultrasonic extraction, the supernatant obtained by centrifugation is the Gastrodia elata polyphenol extract.

[0015] In the above technical solution, the method further includes mixing Gastrodia elata with a eutectic solvent until uniform, extracting by ultrasonication, and centrifuging to obtain the supernatant to obtain Gastrodia elata polyphenol extract; the centrifugation speed is 10000-12000 r / min, and the centrifugation time is 5-10 min.

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

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

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

[0019] Further, in the above technical solution, the determination of the total polyphenol content in Gastrodia elata is carried out by the following steps: (1) Preparation of reference solution: Take an appropriate amount of gallic acid standard, accurately weigh it, place it in a 10 mL volumetric flask, add deionized water to prepare a solution containing about 1 mg per 1 mL; (2) Preparation of standard curve: Take an appropriate amount of gallic acid reference solution, add water to dilute stepwise to prepare reference solutions with concentrations of 100 μg / mL, 80 μg / mL, 60 μg / mL, 40 μg / mL, and 20 μg / mL. Then, take 6 test tubes, take 1.0 mL of the above solutions of different concentrations respectively, add 5 mL of deionized water to each, mix, add 0.5 mL of Folin-Ciocalteu reagent to each, mix thoroughly; let stand for 3 min, add 1.5 mL of 20% Na2CO3 solution, mix, and dilute to 10 mL with water. React the reaction solution at room temperature in the dark for 2 h. Measure the absorbance at 738 nm using ultraviolet-visible spectroscopy. A standard curve was constructed with gallic acid concentration on the x-axis and absorbance on the y-axis. The linear equation was y = 0.1063x + 0.0148, R0. 2 =0.9993; (3) Determination method: Accurately measure 1 mL of total polyphenol extract from Gastrodia elata, add 5 mL of deionized water and 0.5 mL of Folin-Ciocalteu reagent, and mix thoroughly. Let stand for 3 min, add 1.5 mL of 20% Na2CO3 solution, and make up to 10 mL. Keep the reaction solution at room temperature in the dark for 2 h. Measure the absorbance at 738 nm using ultraviolet-visible spectroscopy. Calculate the polyphenol concentration using the regression equation of the standard curve.

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

[0021] This invention uses a eutectic solvent as the extraction solvent and combines it with ultrasonic extraction, achieving a high extraction efficiency of total polyphenols from Gastrodia elata, reaching up to 33.2 mg / g. The eutectic solvent of this invention has a wide range of raw materials, is low in cost, and is environmentally friendly and low in toxicity. Furthermore, the preparation process of the eutectic solvent is simple and easy to operate, and the product is not easily volatile and has good thermal stability, making it suitable for large-scale applications. The extraction method of this invention is simple, has a short extraction time, and is practical, showing great development potential in the fields of medicine, food, and cosmetics. Attached Figure Description

[0022] Figure 1 The figure shows the effect of different types of eutectic solvents on the extraction efficiency of total polyphenols.

[0023] Figure 2 The graph shows the effect of different mass ratios on the extraction efficiency of total polyphenols.

[0024] Figure 3 The effect of different ultrasound-assisted extraction times on the extraction rate of total polyphenols is shown in the figure.

[0025] Figure 4 The graph shows the effect of different liquid-to-solid mass-to-volume ratios on the extraction rate of total polyphenols.

[0026] Figure 5 The graph shows the effect of different ultrasonic temperatures on the extraction rate of total polyphenols.

[0027] Figure 6 The effect of different water contents on the extraction rate of total polyphenols is shown in the figure.

[0028] Figure 7 The graph shows the effect of different extraction solvents on the extraction rate of total polyphenols.

[0029] Figure 8 This is a standard curve graph. Detailed Implementation

[0030] The claims of the present invention will be further described in detail below with reference to specific embodiments, but this does not constitute any limitation on 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 eutectic solvent at a mass ratio of 20%, and the mixture was heated and magnetically stirred until a transparent and homogeneous liquid was formed, which is DES. This mixture was then sealed and stored. Gastrodia elata (the Gastrodia elata used in this experiment was purchased from Yunnan Runying Pharmaceutical Chain Co., Ltd., and the Gastrodia elata slices are its dried tubers) was dried, pulverized using a pulverizer, and sieved to obtain Gastrodia elata powder, which was then sealed and stored.

[0033] Accurately weigh 0.1g of Gastrodia elata powder and place it in a test tube. Add 1mL of eutectic solvent (liquid-solid ratio 10:1), vortex to mix, and extract ultrasonically for 55min at 250W and 50℃. After vortexing, centrifuge at 12000r / min for 5min and collect the supernatant, which is the extract of total polyphenols from Gastrodia elata.

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

[0035] The determination of total polyphenol content in Gastrodia elata is carried out by the following steps: (1) Preparation of reference solution: Take an appropriate amount of gallic acid standard, accurately weigh it, place it in a 10 mL volumetric flask, add deionized water to prepare a solution containing about 1 mg per 1 mL; (2) Preparation of standard curve: Take an appropriate amount of gallic acid reference solution, add water to dilute stepwise to prepare reference solutions with concentrations of 100 μg / mL, 80 μg / mL, 60 μg / mL, 40 μg / mL, and 20 μg / mL. Then, take 6 test tubes, take 1.0 mL of the above solutions of different concentrations, add 5 mL of deionized water to each, mix, add 0.5 mL of Folin-Ciocalteu reagent to each, mix thoroughly; let stand for 3 min, add 1.5 mL of 20% Na2CO3 solution, mix, and dilute to 10 mL with water. React the reaction solution at room temperature in the dark for 2 h. Measure the absorbance at 738 nm using ultraviolet-visible spectroscopy. A standard curve was constructed with gallic acid concentration on the x-axis and absorbance on the y-axis. The linear equation was y = 0.1063x + 0.0148, R0. 2 =0.9993; (see appendix) Figure 8 (3) Determination method: Accurately measure 1 mL of the total polyphenol extract from Gastrodia elata, add 5 mL of deionized water and 0.5 mL of Folin-Ciocalteu reagent, and mix thoroughly. Let stand for 3 min, add 1.5 mL of 20% Na₂CO₃ solution, and make up to 10 mL. Incubate the reaction solution at room temperature in the dark for 2 h. Measure the absorbance at 738 nm using UV-Vis spectroscopy. Calculate the polyphenol concentration using the regression equation of the standard curve.

[0036] Extraction efficiency calculation: The formula for calculating polyphenol content (YTPC) is as follows:

[0037]

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

[0039] Example 2

[0040] Unlike Example 1, the hydrogen bond acceptor of the eutectic solvent is polyethylene glycol-200, and the hydrogen bond donor is glycerol.

[0041] Example 3

[0042] Unlike Example 1, the hydrogen bond acceptor of the eutectic solvent is polyethylene glycol-200, and the hydrogen bond donor is 1,2-propanediol.

[0043] Example 4

[0044] Unlike Example 1, the hydrogen bond acceptor of the eutectic solvent is polyethylene glycol-200, and the hydrogen bond donor is xylitol.

[0045] Example 5

[0046] Unlike Example 1, the hydrogen bond acceptor of the eutectic solvent is polyethylene glycol-200, and the hydrogen bond donor is glucose.

[0047] Example 6

[0048] Unlike Example 1, the hydrogen bond acceptor of the eutectic solvent is polyethylene glycol 400, and the hydrogen bond donor is glucose.

[0049] Example 7

[0050] Unlike Example 1, the hydrogen bond acceptor of the eutectic solvent is polyethylene glycol 400, and the hydrogen bond donor is glycerol.

[0051] Example 8

[0052] Unlike Example 1, the hydrogen bond acceptor of the eutectic solvent is polyethylene glycol-400, and the hydrogen bond donor is 1,2-propanediol.

[0053] Example 9

[0054] Unlike Example 1, the hydrogen bond acceptor of the eutectic solvent is polyethylene glycol 400, and the hydrogen bond donor is xylitol.

[0055] Example 10

[0056] Unlike Example 1, the hydrogen bond acceptor of the eutectic solvent is polyethylene glycol 400, and the hydrogen bond donor is ethylene glycol.

[0057] Example 11

[0058] Unlike Example 1, the hydrogen bond acceptor of the eutectic solvent is Tween-80, and the hydrogen bond donor is ethylene glycol.

[0059] Example 12

[0060] Unlike Example 1, the hydrogen bond acceptor of the eutectic solvent is Tween-80, and the hydrogen bond donor is 1,2-propanediol.

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

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

[0063]

[0064]

[0065] As shown in Table 1, the extraction efficiency was highest when polyethylene glycol-200 was used as the hydrogen bond acceptor and ethylene glycol as the hydrogen bond donor in the eutectic solvent. Each DES formed a clear and transparent solution.

[0066] Example 13

[0067] Unlike Example 1, the mass ratio of the hydrogen bond donor ethylene glycol and the hydrogen bond acceptor polyethylene glycol-200 in the eutectic solvent is 1:2.

[0068] Example 14

[0069] Unlike Example 1, the mass ratio of the hydrogen bond donor ethylene glycol and the hydrogen bond acceptor polyethylene glycol-200 in the eutectic solvent is 1:1.

[0070] Example 15

[0071] Unlike Example 1, the mass ratio of the hydrogen bond donor ethylene glycol and the hydrogen bond acceptor polyethylene glycol-200 in the eutectic solvent is 3:1.

[0072] Example 16

[0073] Unlike Example 1, the mass ratio of the hydrogen bond donor ethylene glycol and the hydrogen bond acceptor polyethylene glycol-200 in the eutectic solvent is 4:1.

[0074] Example 17

[0075] Unlike Example 1, the mass ratio of the hydrogen bond donor ethylene glycol and the hydrogen bond acceptor polyethylene glycol-200 in the eutectic solvent is 5:1.

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

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

[0078]

[0079]

[0080] As shown in Table 2, the extraction rate was highest when the mass ratio was 2:1. With the increase in the proportion of hydrogen bond donors in DES, the extraction rate of total polyphenols first increased and then decreased, reaching its highest point at a mass ratio of 2:1.

[0081] Example 18

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

[0083] Example 19

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

[0085] Example 20

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

[0087] Example 21

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

[0089] Example 22

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

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

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

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

[0094] As shown in Table 3, the extraction rate was highest when the ultrasonic time was 55 min. The advantage of ultrasonic extraction lies in its cavitation effect, which can form a large number of cavitation bubbles in the liquid. The collision and rupture of these cavitation bubbles generate a large amount of energy, making it easier to break down cell membranes and cell walls, thereby releasing the target substance.

[0095] Example 23

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

[0097] Example 24

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

[0099] Example 25

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

[0101] Example 26

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

[0103] Example 27

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

[0105] The effect of different liquid-to-solid mass-to-volume ratios on the total polyphenol extraction rate in Examples 1, 23-27 is shown in Table 4.

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

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

[0108] Table 4 shows that within the liquid-to-solid weight-volume ratio range of 5:1 to 30:1, the extraction rate initially increases and then decreases with increasing solvent ratio, reaching its maximum at a liquid-to-solid weight-volume ratio of 10 mL / g. This may be because increasing the solvent content allows for more thorough mixing of the Gastrodia elata powder with DES, thereby promoting the leaching of polyphenolic components. However, excessive solvent usage leads to the absorption of too much ultrasound, weakening the ultrasonic microwave's effect on the Gastrodia elata's fragmentation and cavitation, thus reducing the dissolution of Gastrodia elata polyphenols and causing unnecessary solvent waste. Therefore, a liquid-to-solid ratio of 10 mL / g was selected as the optimal condition.

[0109] Example 28

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

[0111] Example 29

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

[0113] Example 30

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

[0115] Example 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] Example 32

[0118] The same process as in Example 1 was used, but the reaction conditions were different. Only 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, 28-32 are shown in Table 5.

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

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

[0122] As shown in Table 5, the extraction efficiency of Gastrodia elata polyphenols is highest when the ultrasonic temperature is 50℃.

[0123] Example 33

[0124] The same process as in Example 1 was used, but the reaction conditions were different. The only change was that water was added to the eutectic solvent at a mass ratio of 0%.

[0125] Example 34

[0126] The same process as in Example 1 was used, but the reaction conditions were different. The only difference was that water was added to the eutectic solvent at a mass ratio of 40%.

[0127] Example 35

[0128] The same process as in Example 1 was used, but the reaction conditions were different. The only change was that water was added to the eutectic solvent at a mass ratio of 60%.

[0129] Example 36

[0130] The same process as in Example 1 was used, but the reaction conditions were different. The only difference was that water was added to the eutectic solvent at a mass ratio of 80%.

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

[0132] Table 6 Comparison of extraction results at different moisture contents

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

[0134] As shown in Table 6, the polyphenol content gradually increased from 0% to 20% water content, followed by a decreasing trend. This is likely because low water content alters the viscosity and flowability of DESs, allowing the target component to leach well from the plant matrix. Excessive water content in DESs increases the polarity of the system, disrupts hydrogen bonds between DES components, weakens the interaction between DESs and polyphenols, and thus reduces the yield of the target component. Therefore, the optimal water content for the eutectic solvent is 20%.

[0135] Example 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] Example 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] Example 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] Example 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 with different extraction solvents

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

[0145] The above description of the embodiments is only used to illustrate the technical solutions of the present invention, and is not intended to limit them; for those skilled in the art, various improvements can still be made to the above embodiments, or equivalent substitutions can be made to some of the technical features. Therefore, improvements and equivalent substitutions made without departing from the scope of the present invention do not depart from the spirit and scope of the technical solutions claimed by the present invention.

Claims

1. A method for extracting total polyphenolic active substances from Gastrodia elata using a eutectic solvent, characterized in that, The method uses a eutectic solvent as the extraction solvent, combined with ultrasonic extraction; Gastrodia elata powder is taken, added to the eutectic solvent, vortexed and mixed, and then extracted with ultrasound; the hydrogen bond acceptors of the eutectic solvent include: polyethylene glycol-200, polyethylene glycol-400, and Tween 80, and the hydrogen bond donors include: ethylene glycol, 1,2-propanediol, glucose, glycerol, and xylitol. The preparation of the eutectic solvent includes: mixing hydrogen bond acceptors and hydrogen bond donors, heating and stirring at 55-65°C until a transparent and homogeneous liquid is formed; The mass ratio of hydrogen bond donor to hydrogen bond acceptor in the eutectic solvent is 1:2-5:1; The water content of the eutectic solvent is 0%-80%; The liquid-to-solid ratio of the eutectic solvent to Gastrodia elata is 5:1-30:1; After ultrasonic extraction, the supernatant obtained by centrifugation is the Gastrodia elata polyphenol extract.

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

1.

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

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

1.

6. The method according to claim 1, characterized in that, The ultrasonic extraction time is 25-75 min, and the extraction temperature is 30-80℃.

7. The method according to claim 6, characterized in that, The preferred ultrasonic extraction time is 55-65 min, and the extraction temperature is 50℃.

8. The method according to claim 1, characterized in that, The method involves mixing Gastrodia elata with a eutectic solvent, extracting by ultrasound, and centrifuging to obtain the supernatant to obtain Gastrodia elata polyphenol extract; the centrifugation speed is 10000-12000 r / min, and the centrifugation time is 5-10 min.

9. The method according to claim 8, characterized in that, Before mixing the Gastrodia elata with the eutectic solvent, it is first crushed and sieved to obtain Gastrodia elata powder; the sieve is a 30-60 mesh sieve.

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