Preparation method of ginseng polyphenol

Abstract

The invention is applicable to the technical field of natural product extraction, and provides a preparation method of ginseng polyphenol, which comprises the following steps: mixing a hydrogen acceptor and a hydrogen donor, stirring under a water bath condition until a uniform and stable liquid is formed, then adding water while the liquid is hot, and uniformly stirring to obtain a eutectic solvent as an extraction solvent; the preparation method comprises the following steps: uniformly mixing ginseng raw material powder and a deep-eutectic solvent, performing ultrasonic-assisted extraction, and centrifuging to take supernate, thereby obtaining a ginseng polyphenol extracting solution; according to the method, ginseng stems, leaves or flowers serve as raw materials, the eutectic solvent serves as the extraction solvent, the polyphenol compounds are extracted in an ultrasonic-assisted mode, under the optimized process condition, the total polyphenol yield can reach 19.55 + / -0.04 mg / g, the total flavone yield can reach 9.22 + / -0.15 mg / g, the preparation method is safe and environmentally friendly, the extraction yield is high, efficient extraction of ginseng polyphenol can be achieved, and the method is suitable for industrial production. The efficient utilization of ginseng stem, leaf and flower resources is promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of natural product extraction, and particularly relates to a preparation method of ginseng polyphenols. Background Art

[0002] Ginseng (Panax ginseng C.A.Mey.) is a perennial herb of the Araliaceae family and the genus Panax, including roots, stems, leaves, flowers, etc. The stems, leaves, flowers and other parts of the above-ground part of ginseng are rich in a variety of bioactive components, including ginsenosides, ginseng polyphenols, ginseng polysaccharides and other active components. These components are beneficial to human health and have antioxidant, anti-inflammatory and immune-enhancing effects. Polyphenolic compounds are a class of natural products widely present in plants, with antioxidant effects, capable of scavenging free radicals, slowing down cell aging, and preventing the occurrence of chronic diseases. Therefore, it is particularly important to adopt an efficient extraction method to obtain polyphenol components from ginseng. Traditional polyphenol extraction methods include the soaking method and the hot water extraction method, but not only the extraction efficiency is low, but there is also a risk of degrading heat-sensitive components. Therefore, how to improve the extraction yield of polyphenols has always been a difficult problem to be solved urgently.

[0003] Deep eutectic solvents are a kind of green solvents composed of a certain molar ratio of hydrogen acceptors and hydrogen donors, with low toxicity, easy degradation, high efficiency, environmental protection and excellent dissolution and extraction capabilities. Common hydrogen acceptors are choline chloride in quaternary ammonium salts, and hydrogen donors include amino acids, polyols, carboxylic acids, sugars, etc.; if ultrasonic-assisted extraction can be combined with deep eutectic solvents, using the ultrasonic effect to promote the penetration of the solvent and the diffusion of the solute to achieve an increase in the polyphenol yield and a shortening of the extraction time is a new attempt and has certain application prospects. Summary of the Invention

[0004] The purpose of the embodiments of the present invention is to provide a preparation method of ginseng polyphenols, aiming to solve the problems raised in the above background art.

[0005] The embodiments of the present invention are implemented as follows. A preparation method of ginseng polyphenols includes the following steps:

[0006] Preparation of deep eutectic solvent: Mix the hydrogen acceptor and the hydrogen donor, stir under water bath conditions until a homogeneous and stable liquid is formed, and then add water while it is hot, and stir evenly to obtain a deep eutectic solvent as the extraction solvent;

[0007] Extraction of ginseng polyphenols: Mix the ginseng raw material powder and the deep eutectic solvent evenly, adopt ultrasonic-assisted extraction, and then centrifuge to take the supernatant to obtain the ginseng polyphenol extract.

[0008] Preferably, in the step of preparing the deep eutectic solvent, the hydrogen acceptor is choline chloride, and the hydrogen donor is one of glucose, urea, glycerol, 1,2-propanediol, 1,3-butanediol and malic acid.

[0009] Preferably, the hydrogen donor is glycerol or urea.

[0010] Preferably, the molar ratio of the hydrogen acceptor to the hydrogen donor is 1:1 - 4.

[0011] Preferably, in the step of extracting ginseng polyphenols, the ginseng raw material powder is one or more of ginseng stem powder, ginseng leaf powder, and ginseng flower powder, and the volume - mass ratio of the deep eutectic solvent to the ginseng raw material powder is 20 - 60 mL / g.

[0012] Preferably, the power of the ultrasonic - assisted extraction is 200 - 400 W, and the time is 8 - 16 min.

[0013] Preferably, the temperature of the ultrasonic - assisted extraction is 50 - 90 °C.

[0014] A preparation method of ginseng polyphenols provided by an embodiment of the present invention uses ginseng stems, leaves or flowers as raw materials, a deep eutectic solvent as an extraction solvent, and ultrasonic - assisted extraction of polyphenolic compounds. Under optimized process conditions, the total polyphenol yield can reach 19.55 ± 0.04 mg / g, and the total flavonoid yield can reach 9.22 ± 0.15 mg / g. This preparation method is safe, environmentally friendly, has a high extraction rate, can achieve the efficient extraction of ginseng polyphenols, and promotes the efficient utilization of ginseng stem, leaf, and flower resources. Description of the Drawings

[0015] Figure 1 It is a comparison of the data results of the extraction yields of ginseng polyphenols by different deep eutectic solvents provided by an embodiment of the present invention;

[0016] Figure 2 It is a comparison of the data results of the extraction yields of ginseng polyphenols at different extraction temperatures provided by an embodiment of the present invention;

[0017] Figure 3 It is a comparison of the data results of the extraction yields of ginseng polyphenols at different liquid - solid ratios provided by an embodiment of the present invention;

[0018] Figure 4 It is a comparison of the data results of the extraction yields of ginseng polyphenols at different ultrasonic powers provided by an embodiment of the present invention;

[0019] Figure 5 It is a comparison of the data results of the extraction yields of ginseng polyphenols at different ultrasonic times provided by an embodiment of the present invention. Detailed Embodiments

[0020] To make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0021] A preparation method of ginseng polyphenols comprises the following steps:

[0022] (1) Preparation of eutectic solvent:

[0023] Mix a hydrogen acceptor and a hydrogen donor in a certain molar ratio, stir in a water bath at 80 °C for 2 h until a homogeneous and stable liquid is formed; then, add 20% (g / g) of water while it is hot. Adding water can appropriately reduce the solvent viscosity, which is beneficial to extraction. After stirring evenly, the eutectic solvent is obtained as the extraction solvent; the molar ratio of the hydrogen acceptor to the hydrogen donor is selected from 1:1, 1:2, 1:4;

[0024] Among them, the hydrogen acceptor is choline chloride, and the hydrogen donors are glucose, urea, glycerol, 1,2-propanediol, 1,3-butanediol, and malic acid. The hydrogen acceptor and hydrogen donor preferably adopt choline chloride-glycerol system and choline chloride-urea system;

[0025] (2) Extraction of ginseng polyphenols:

[0026] Mix the ginseng stem, leaf or flower powder evenly with the eutectic solvent obtained in step (1), and adopt ultrasonic-assisted extraction. Under the conditions of set extraction temperature, liquid-solid ratio, ultrasonic power, and ultrasonic time, extract, and then centrifuge at 9000 r / min for 10 min to take the supernatant, and thus obtain an extract containing polyphenolic compounds;

[0027] Among them, the extraction temperature is 50-90 °C, preferably 73 °C, the volume-mass ratio (liquid-solid ratio) of the eutectic solvent to the ginseng raw material powder is 20-60 mg / L, preferably 31 mL / g, the ultrasonic power is 200-400 W, preferably 270 W, and the time is 8-16 min, preferably 14 min.

[0028] The specific implementation of the present invention will be described in detail below in conjunction with specific embodiments.

[0029] Example 1. A high-efficiency preparation method of ginseng polyphenols comprises the following steps:

[0030] (1) Preparation of eutectic solvent:

[0031] Mix choline chloride and glycerol in a molar ratio of 1:2 and stir in a water bath at 80 °C for 2 h until a homogeneous and stable liquid is formed, and then add 20% (g / g) of water while it is hot;

[0032] (2) Extraction of ginseng polyphenols:

[0033] Mix the deep eutectic solvent and ginseng leaf powder, extract under the conditions of an extraction temperature of 70 °C, a liquid-solid ratio of 30 mL / g, an ultrasonic power of 250 W, and an ultrasonic time of 14 min. After centrifuging at 9000 r / min for 10 min, take the supernatant to obtain the ginseng polyphenol extract.

[0034] After testing, the total polyphenol yield obtained by extraction in this example is 16.13 ± 0.33 mg / g, and the total flavonoid yield is 7.59 ± 0.08 mg / g.

[0035] Example 2: A high-efficiency preparation method of ginseng polyphenols, comprising the following steps:

[0036] (1) Preparation of the deep eutectic solvent:

[0037] Mix choline chloride and glucose at a molar ratio of 1:1 and stir in a water bath at 80 °C for 2 h until a homogeneous and stable liquid is formed. Then, add 20% (g / g) water while it is still hot.

[0038] (2) Extraction of ginseng polyphenols:

[0039] Mix the deep eutectic solvent and ginseng leaf powder, extract under the conditions of an extraction temperature of 70 °C, a liquid-solid ratio of 30 mL / g, an ultrasonic power of 250 W, and an ultrasonic time of 14 min. After centrifuging at 9000 r / min for 10 min, take the supernatant to obtain the ginseng polyphenol extract.

[0040] After testing, the total polyphenol yield obtained by extraction in this example is 11.65 ± 0.20 mg / g, and the total flavonoid yield is 5.82 ± 0.17 mg / g.

[0041] Example 3: A high-efficiency preparation method of ginseng polyphenols, comprising the following steps:

[0042] (1) Preparation of the deep eutectic solvent:

[0043] Mix choline chloride and urea at a molar ratio of 1:2 and stir in a water bath at 80 °C for 2 h until a homogeneous and stable liquid is formed. Then, add 20% (g / g) water while it is still hot.

[0044] (2) Extraction of ginseng polyphenols:

[0045] Mix the deep eutectic solvent and ginseng leaf powder, extract under the conditions of an extraction temperature of 70 °C, a liquid-solid ratio of 30 mL / g, an ultrasonic power of 250 W, and an ultrasonic time of 14 min. After centrifuging at 9000 r / min for 10 min, take the supernatant to obtain the ginseng polyphenol extract.

[0046] After testing, the total polyphenol yield obtained in this example was 10.00 ± 0.44 mg / g, and the total flavonoid yield was 4.37 ± 0.07 mg / g.

[0047] Example 4: A method for efficiently preparing ginseng polyphenols, comprising the following steps:

[0048] (1) Preparation of deep eutectic solvent:

[0049] Mix choline chloride and 1,2-propanediol in a molar ratio of 1:4 and stir at 80 °C in a water bath for 2 h until a homogeneous and stable liquid is formed. Then, add 20% (g / g) water while it is still hot.

[0050] (2) Extraction of ginseng polyphenols:

[0051] Mix the deep eutectic solvent and ginseng leaf powder, and extract under the conditions of an extraction temperature of 70 °C, a liquid-solid ratio of 30 mg / mL, an ultrasonic power of 250 W, and an ultrasonic time of 14 min. After centrifugation at 9000 r / min for 10 min, take the supernatant to obtain the ginseng polyphenol extract.

[0052] After testing, the total polyphenol yield obtained in this example was 13.49 ± 0.37 mg / g, and the total flavonoid content yield was 6.23 ± 0.04 mg / g.

[0053] Example 5: A method for efficiently preparing ginseng polyphenols, comprising the following steps:

[0054] (1) Preparation of deep eutectic solvent:

[0055] Mix choline chloride and 1,3-butanediol in a molar ratio of 1:4 and stir at 80 °C in a water bath for 2 h until a homogeneous and stable liquid is formed. Then, add 20% (g / g) water while it is still hot.

[0056] (2) Extraction of ginseng polyphenols:

[0057] Mix the deep eutectic solvent and ginseng leaf powder, and extract under the conditions of an extraction temperature of 70 °C, a liquid-solid ratio of 30 mL / g, an ultrasonic power of 250 W, and an ultrasonic time of 14 min. After centrifugation at 9000 r / min for 10 min, take the supernatant to obtain the ginseng polyphenol extract.

[0058] After testing, the total polyphenol yield obtained in this example was 14.56 ± 0.25 mg / g, and the total flavonoid yield was 6.90 ± 0.09 mg / g.

[0059] Example 6: A method for efficiently preparing ginseng polyphenols, comprising the following steps:

[0060] (1) Preparation of deep eutectic solvent:

[0061] Choline chloride and malic acid were stirred at a molar ratio of 1:1 in a water bath at 80 °C for 2 h until a homogeneous and stable liquid was formed, and then 20% (g / g) water was added while it was still hot.

[0062] (2) Extraction of ginseng polyphenols:

[0063] The eutectic solvent and ginseng leaf powder were mixed and extracted under the conditions of an extraction temperature of 70 °C, a liquid-solid ratio of 30 mL / g, an ultrasonic power of 250 W, and an ultrasonic time of 14 min. After centrifugation at 9000 r / min for 10 min, the supernatant was taken to obtain the ginseng polyphenol extract.

[0064] After testing, the total polyphenol yield obtained in this example was 9.97 ± 0.37 mg / g, and the total flavonoid yield was 4.56 ± 0.04 mg / g.

[0065] Example 7. A high-efficiency preparation method of ginseng polyphenols, comprising the following steps:

[0066] (1) Preparation of the eutectic solvent:

[0067] Choline chloride and glycerol were stirred at a molar ratio of 1:2 in a water bath at 80 °C for 2 h until a homogeneous and stable liquid was formed, and then 20% (g / g) water was added while it was still hot.

[0068] (2) Extraction of ginseng polyphenols:

[0069] The eutectic solvent and ginseng leaf powder were mixed and extracted under the conditions of an extraction temperature of 50 °C, a liquid-solid ratio of 30 mL / g, an ultrasonic power of 250 W, and an ultrasonic time of 14 min. After centrifugation at 9000 r / min for 10 min, the supernatant was taken to obtain the ginseng polyphenol extract.

[0070] After testing, the total polyphenol yield obtained in this example was 10.00 ± 0.44 mg / g, and the total flavonoid yield was 4.46 ± 0.08 mg / g.

[0071] Example 8. A high-efficiency preparation method of ginseng polyphenols, comprising the following steps:

[0072] (1) Preparation of the eutectic solvent:

[0073] Choline chloride and glycerol were stirred at a molar ratio of 1:2 in a water bath at 80 °C for 2 h until a homogeneous and stable liquid was formed, and then 20% (g / g) water was added while it was still hot.

[0074] (2) Extraction of ginseng polyphenols:

[0075] Mix the deep eutectic solvent and ginseng leaf powder, extract under the conditions of an extraction temperature of 70 °C, a liquid-solid ratio of 30 mL / g, an ultrasonic power of 250 W, and an ultrasonic time of 14 min. After centrifuging at 9000 r / min for 10 min, take the supernatant to obtain the ginseng polyphenol extract.

[0076] After testing, the total polyphenol yield obtained by extraction in this example is 17.18 ± 0.46 mg / g, and the total flavonoid yield is 8.11 ± 0.03 mg / g.

[0077] Example 9. A high-efficiency preparation method of ginseng polyphenols, comprising the following steps:

[0078] (1) Preparation of the deep eutectic solvent:

[0079] Mix choline chloride and glycerol in a molar ratio of 1:2 and stir in a water bath at 80 °C for 2 h until a homogeneous and stable liquid is formed. Then, add 20% (g / g) water while it is still hot;

[0080] (2) Extraction of ginseng polyphenols:

[0081] Mix the deep eutectic solvent and ginseng leaf powder, extract under the conditions of an extraction temperature of 90 °C, a liquid-solid ratio of 30 mL / g, an ultrasonic power of 250 W, and an ultrasonic time of 14 min. After centrifuging at 9000 r / min for 10 min, take the supernatant to obtain the ginseng polyphenol extract.

[0082] After testing, the total polyphenol yield obtained by extraction in this example is 17.69 ± 0.11 mg / g, and the total flavonoid yield is 8.23 ± 0.08 mg / g.

[0083] Example 10. A high-efficiency preparation method of ginseng polyphenols, comprising the following steps:

[0084] (1) Preparation of the deep eutectic solvent:

[0085] Mix choline chloride and glycerol in a molar ratio of 1:2 and stir in a water bath at 80 °C for 2 h until a homogeneous and stable liquid is formed. Then, add 20% (g / g) water while it is still hot;

[0086] (2) Extraction of ginseng polyphenols:

[0087] Mix the deep eutectic solvent and ginseng stem, leaf, and flower powder, extract under the conditions of an extraction temperature of 70 °C, a liquid-solid ratio of 10 mL / g, an ultrasonic power of 250 W, and an ultrasonic time of 14 min. After centrifuging at 9000 r / min for 10 min, take the supernatant to obtain the ginseng stem, leaf, and flower polyphenol extract.

[0088] After testing, the total polyphenol yield obtained in this example was 9.74 ± 0.36 mg / g, and the total flavonoid yield was 4.25 ± 0.13 mg / g.

[0089] Example 11. A high-efficiency preparation method of ginseng polyphenols, comprising the following steps:

[0090] (1) Preparation of deep eutectic solvent:

[0091] Choline chloride and glycerol were stirred at a molar ratio of 1:2 in a water bath at 80 °C for 2 h until a homogeneous and stable liquid was formed, and then 20% (g / g) of water was added while it was still hot.

[0092] (2) Extraction of ginseng polyphenols:

[0093] The deep eutectic solvent was mixed with the powder of ginseng stems, leaves and flowers, and extracted under the conditions of an extraction temperature of 70 °C, a liquid-solid ratio of 30 mL / g, an ultrasonic power of 250 W, and an ultrasonic time of 14 min. After centrifugation at 9000 r / min for 10 min, the supernatant was taken to obtain the polyphenol extract of ginseng stems, leaves and flowers.

[0094] After testing, the total polyphenol yield obtained in this example was 16.85 ± 0.41 mg / g, and the total flavonoid yield was 7.55 ± 0.08 mg / g.

[0095] Example 12. A high-efficiency preparation method of ginseng polyphenols, comprising the following steps:

[0096] (1) Preparation of deep eutectic solvent:

[0097] Choline chloride and glycerol were stirred at a molar ratio of 1:2 in a water bath at 80 °C for 2 h until a homogeneous and stable liquid was formed, and then 20% (g / g) of water was added while it was still hot.

[0098] (2) Extraction of ginseng polyphenols:

[0099] The deep eutectic solvent was mixed with the powder of ginseng stems, leaves and flowers, and extracted under the conditions of an extraction temperature of 70 °C, a liquid-solid ratio of 50 mL / g, an ultrasonic power of 250 W, and an ultrasonic time of 14 min. After centrifugation at 9000 r / min for 10 min, the supernatant was taken to obtain the polyphenol extract of ginseng stems, leaves and flowers.

[0100] After testing, the total polyphenol yield obtained in this example was 15.97 ± 0.23 mg / g, and the total flavonoid yield was 7.23 ± 0.13 mg / g.

[0101] Example 13. A high-efficiency preparation method of ginseng polyphenols, comprising the following steps:

[0102] (1) Preparation of deep eutectic solvent:

[0103] Mix choline chloride and glycerol in a molar ratio of 1:2 and stir for 2 h under a water bath condition of 80 °C until a homogeneous and stable liquid is formed, and then add 20% (g / g) of water while it is still hot;

[0104] (2) Extraction of ginseng polyphenols:

[0105] Mix the deep eutectic solvent with the powders of ginseng stems, leaves and flowers, and extract under the conditions of an extraction temperature of 70 °C, a liquid-solid ratio of 30 mL / g, an ultrasonic power of 200 W and an ultrasonic time of 14 min. After centrifuging at 9000 r / min for 10 min, take the supernatant to obtain the ginseng stem, leaf and flower polyphenol extract.

[0106] After testing, the total polyphenol yield obtained by extraction in this example is 13.68 ± 0.52 mg / g, and the total flavonoid yield is 5.78 ± 0.10 mg / g.

[0107] Example 14. A high-efficiency preparation method of ginseng polyphenols, comprising the following steps:

[0108] (1) Preparation of deep eutectic solvent:

[0109] Mix choline chloride and glycerol in a molar ratio of 1:2 and stir for 2 h under a water bath condition of 80 °C until a homogeneous and stable liquid is formed, and then add 20% (g / g) of water while it is still hot;

[0110] (2) Extraction of ginseng polyphenols:

[0111] Mix the deep eutectic solvent with the powders of ginseng stems, leaves and flowers, and extract under the conditions of an extraction temperature of 70 °C, a liquid-solid ratio of 30 mL / g, an ultrasonic power of 250 W and an ultrasonic time of 14 min. After centrifuging at 9000 r / min for 10 min, take the supernatant to obtain the ginseng stem, leaf and flower polyphenol extract.

[0112] After testing, the total polyphenol yield obtained by extraction in this example is 17.65 ± 0.20 mg / g, and the total flavonoid yield is 8.43 ± 0.08 mg / g.

[0113] Example 15. A high-efficiency preparation method of ginseng polyphenols, comprising the following steps:

[0114] (1) Preparation of deep eutectic solvent:

[0115] Mix choline chloride and glycerol in a molar ratio of 1:2 and stir for 2 h under a water bath condition of 80 °C until a homogeneous and stable liquid is formed, and then add 20% (g / g) of water while it is still hot;

[0116] (2) Extraction of ginseng polyphenols:

[0117] Mix the deep eutectic solvent with the powders of ginseng stems, leaves and flowers, and extract under the conditions of an extraction temperature of 70 °C, a liquid-solid ratio of 30 mL / g, an ultrasonic power of 400 W, and an ultrasonic time of 14 min. After centrifuging at 9000 r / min for 10 min, take the supernatant to obtain the polyphenol extract of ginseng stems, leaves and flowers.

[0118] After testing, the total polyphenol yield obtained by extraction in this example is 14.48 ± 0.20 mg / g, and the total flavonoid yield is 6.05 ± 0.08 mg / g.

[0119] Example 16. A high-efficiency preparation method of ginseng polyphenols, comprising the following steps:

[0120] (1) Preparation of the deep eutectic solvent:

[0121] Mix choline chloride and glycerol in a molar ratio of 1:2 and stir in a water bath at 80 °C for 2 h until a homogeneous and stable liquid is formed, and then add 20% (g / g) of water while it is still hot;

[0122] (2) Extraction of ginseng polyphenols:

[0123] Mix the deep eutectic solvent with the powders of ginseng stems, leaves and flowers, and extract under the conditions of an extraction temperature of 70 °C, a liquid-solid ratio of 30 mL / g, an ultrasonic power of 250 W, and an ultrasonic time of 8 min. After centrifuging at 9000 r / min for 10 min, take the supernatant to obtain the polyphenol extract of ginseng stems, leaves and flowers.

[0124] After testing, the total polyphenol yield obtained by extraction in this example is 10.45 ± 0.92 mg / g, and the total flavonoid yield is 4.45 ± 0.25 mg / g.

[0125] Example 17. A high-efficiency preparation method of ginseng polyphenols, comprising the following steps:

[0126] (1) Preparation of the deep eutectic solvent:

[0127] Mix choline chloride and glycerol in a molar ratio of 1:2 and stir in a water bath at 80 °C for 2 h until a homogeneous and stable liquid is formed, and then add 20% (g / g) of water while it is still hot;

[0128] (2) Extraction of ginseng polyphenols:

[0129] Mix the deep eutectic solvent with the powders of ginseng stems, leaves and flowers, and extract under the conditions of an extraction temperature of 70 °C, a liquid-solid ratio of 30 mL / g, an ultrasonic power of 250 W, and an ultrasonic time of 14 min. After centrifuging at 9000 r / min for 10 min, take the supernatant to obtain the polyphenol extract of ginseng stems, leaves and flowers.

[0130] After testing, the total polyphenol yield obtained by extraction in this example is 19.07 ± 0.33 mg / g, and the total flavonoid yield is 8.47 ± 0.07 mg / g.

[0131] Example 18. A high-efficiency preparation method of ginseng polyphenols, comprising the following steps:

[0132] (1) Preparation of deep eutectic solvent:

[0133] Mix choline chloride and glycerol in a molar ratio of 1:2, stir in a water bath at 80 °C for 2 h until a homogeneous and stable liquid is formed, and then add 20% (g / g) of water while it is still hot;

[0134] (2) Extraction of ginseng polyphenols:

[0135] Mix the deep eutectic solvent with the powder of ginseng stems, leaves and flowers, extract under the conditions of an extraction temperature of 70 °C, a liquid-solid ratio of 30 mL / g, an ultrasonic power of 250 W, and an ultrasonic time of 16 min, centrifuge at 9000 r / min for 10 min, and then take the supernatant to obtain the polyphenol extract of ginseng stems, leaves and flowers.

[0136] After testing, the total polyphenol yield obtained by extraction in this example is 16.67 ± 0.66 mg / g, and the total flavonoid yield is 6.00 ± 0.05 mg / g.

[0137] Graph the total polyphenol yield and total flavonoid yield data of Examples 1-19 according to the selection of hydrogen acceptor and hydrogen donor, extraction temperature, liquid-solid ratio, ultrasonic power, and ultrasonic time respectively, to obtain as Figures 1-5 shown, according to Figure 1 and Examples 1-6, it can be seen that the hydrogen acceptor and hydrogen donor are preferably the choline chloride-glycerol system, which can make the yields of total polyphenols and total flavonoids obtained by extraction higher; according to Figure 2 and Examples 1, 7-9, it can be seen that the optimal extraction temperature is 70 °C, and through response surface experiments, 73 °C is the best, which can make the yields of total polyphenols and total flavonoids obtained by extraction high; according to Figure 3 and Examples 1, 10-12, it can be seen that the mixing ratio of the deep eutectic solvent and the ginseng raw material powder of 30 mL / g is the best, and through response surface experiments, 31 mL / g is the best, so that the yields of total polyphenols and total flavonoids obtained by extraction are high; according to Figure 4 and Examples 13-15, it can be seen that the ultrasonic power is preferably 250 W, and through response surface experiments, 270 W is the best, so that the yields of total polyphenols and total flavonoids obtained by extraction are high; according to Figure 5As can be seen from Examples 16 - 18, the ultrasonic time is preferably 14 min. After further response surface experiments, it is found that 14 min is the best, so as to obtain a high yield of total polyphenols and total flavonoids during extraction.

[0138] Therefore, the optimal extraction process is as follows: the extraction temperature is 73 °C, the liquid - solid ratio is 31 mg / L, the ultrasonic power is 270 W, and the ultrasonic time is 14 min. Under these conditions, three verification experiments are carried out, and the yield of total polyphenols is 19.55 ± 0.04 mg / g, and the yield of total flavonoids is 9.22 ± 0.15 mg / g.

[0139] Among them, the calculation method of the total polyphenol yield is as follows: Place 1 mL of ginseng polyphenol extract in a brown test tube, add 5 mL of 10% Folin - Ciocalteu reagent, mix well, react for 5 min, add 4 mL of Na2CO3 solution (7.5%, g / mL), shake well, react in the dark for 1 h, and measure the absorbance at a wavelength of 765 nm.

[0140] Y1=(C1×V1×N1) / M1

[0141] In the formula: Y1 is the total polyphenol yield in the sample (mg / g); C1 is the total polyphenol concentration in the sample (mg / mL); V1 is the volume of the sample solution (mL); N1 is the dilution factor; M1 is the sample mass (g).

[0142] The calculation method of the total flavonoid yield is as follows: Mix 1 mL of ginseng polyphenol extract with 0.3 mL of NaNO2 (5%, g / mL) and react for 5 min, then add 0.3 mL of Al(NO3)3 (10%, g / mL) and react for 5 min. Then add 4 mL of NaOH (4%, g / mL) and 4.4 mL of water and mix well. After reacting for 15 min, measure the absorbance at a wavelength of 510 nm.

[0143] Y2=(C2×V2×N2) / M2

[0144] In the formula: Y2 is the total flavonoid yield in the sample (mg / g); C2 is the total flavonoid concentration in the sample (mg / mL); V2 is the volume of the sample solution (mL); N2 is the dilution factor; M2 is the sample mass (g).

[0145] In the prior art, cellulase and pectinase are used to extract ginseng leaf polyphenols. The addition amounts of cellulase and pectinase are 15 U / mL, the enzymatic hydrolysis pH is 5.0, the enzymatic hydrolysis temperature is 50 °C, and the enzymatic hydrolysis time is 90 min. The total polyphenol yield is (840.81 ± 5.45) mg / 100 g; the addition amounts of cellulase and pectinase are 25 U / mL, the enzymatic hydrolysis pH is 4.5, the enzymatic hydrolysis temperature is 50 °C, and the enzymatic hydrolysis time is 120 min. The total flavonoid yield is (348.56 + 2.10) mg / 100 g (Zhao Yujuan. Research on the Extraction and Application of Ginseng Leaf Polyphenols [D]. Jilin: Jilin University, 2020.). It can be seen that this is far lower than that of the examples of the present invention.

[0146] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A preparation method of ginseng polyphenols, characterized in that, It includes the following steps: Preparation of deep eutectic solvent: Mix a hydrogen acceptor and a hydrogen donor, stir under a water bath condition until a homogeneous and stable liquid is formed, then add water while it is still hot, and stir evenly to obtain a deep eutectic solvent as the extraction solvent; Extraction of ginseng polyphenols: Mix the ginseng raw material powder and the deep eutectic solvent evenly, perform ultrasonic-assisted extraction, and then centrifuge to take the supernatant to obtain a ginseng polyphenol extract.

2. The preparation method of ginseng polyphenols according to claim 1, wherein, In the step of preparing the deep eutectic solvent, the hydrogen acceptor is choline chloride, and the hydrogen donor is one of glucose, urea, glycerol, 1,2-propanediol, 1,3-butanediol, and malic acid.

3. The preparation method of ginseng polyphenol according to claim 2, characterized in that The hydrogen donor is glycerol or urea.

4. The preparation method of ginseng polyphenol according to claim 1, characterized in that, The molar ratio of the hydrogen acceptor to the hydrogen donor is 1:1 - 4.

5. The preparation method of ginseng polyphenols according to claim 1, wherein, In the step of extracting ginseng polyphenols, the ginseng raw material powder is one or more of ginseng stem powder, ginseng leaf powder, and ginseng flower powder, and the volume-mass ratio of the deep eutectic solvent to the ginseng raw material powder is 20 - 60 mL / g.

6. The preparation method of ginseng polyphenol according to claim 1, characterized in that, The power of the ultrasonic-assisted extraction is 200 - 400 W, and the time is 8 - 16 min.

7. The preparation method of ginseng polyphenol according to claim 1, characterized in that The temperature of the ultrasonic-assisted extraction is 50 - 90 °C.

Images