A method for efficiently extracting burdock inulin using a binary mixed solvent

Abstract

The present invention discloses a method for efficiently extracting burdock inulin using a binary mixed solvent. The method adopts a hydrophilic ionic liquid solvent and a weakly alkaline aqueous solution of an inorganic salt to mix to form a mutually immiscible binary two-phase system, thereby realizing efficient, stable and reliable extraction and preparation of burdock inulin, and achieving a high level of extraction efficiency. First, fresh burdock root is mixed with water to prepare pulp at room temperature; then, the ionic liquid and the inorganic salt aqueous solution are mixed to form a mutually immiscible binary system; next, the burdock pulp is mixed with the binary mixed solvent and extracted; finally, the extracted extract is centrifuged, filtered and concentrated to obtain burdock inulin. The invention has outstanding advantages such as high extraction efficiency, simple process and convenient operation. Therefore, the method has broad application prospects and has important scientific significance and practical application value for the production and extraction process of burdock inulin.

Description

Technical Field

[0001] The invention belongs to the technical field, and particularly relates to a method for efficiently extracting burdock inulin with a binary mixed solvent. Background Art

[0002] Burdock inulin is a natural food ingredient and an important functional food ingredient. It is an oligosaccharide extracted from burdock root. Its chemical structure is similar to natural oligosaccharides found in the human body and has been widely used in the food and pharmaceutical industries. The development of burdock inulin dates back to the 1950s. Initially, it was used as a substitute for burdock root. However, as research into its physiological functions deepened, it was discovered to possess numerous health benefits in nutrition, medicine, and food science. Burdock inulin primarily works through the following mechanisms: first, by regulating intestinal flora and improving intestinal health; second, by enhancing immunity and preventing and treating diseases; third, by lowering blood sugar and lipids and preventing cardiovascular disease; and fourth, by preventing metabolic diseases such as obesity and diabetes. Therefore, burdock inulin is a highly promising natural food ingredient, and efficient extraction of burdock inulin holds broad promise for future applications in the pharmaceutical and food industries.

[0003] Burdock inulin is a major polysaccharide in burdock root. Its chemical structure is α-D-glucose-(1→6)-β-D-fructose, and it can be extracted through various methods, including water extraction and acid extraction. Water extraction is a simple and easy method, where burdock root can be directly soaked in water or heated to produce an aqueous extract of burdock inulin, but the extraction efficiency is relatively low. Acid extraction requires acidic conditions and can yield higher levels of burdock inulin, but careful control of acidity and extraction time are required to avoid compromising product purity and quality. In addition, there are other extraction technologies, such as microwave-assisted extraction and supercritical CO2 extraction. These methods can improve the extraction efficiency while reducing environmental pollution and the impact on product quality. Therefore, the extraction of burdock polysaccharide is of great significance for developing its application potential and value. The extraction technology of burdock inulin is also constantly developing and improving. The development of new high-efficiency, low-cost and high-purity burdock inulin extraction technology and the promotion of the diversified industrialization of burdock inulin have important economic, social and environmental value for promoting the development of biotechnology and green manufacturing. Summary of the Invention

[0004] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0005] As one aspect of the present invention, a method for efficiently extracting burdock inulin using a binary mixed solvent comprises:

[0006] The burdock root and water are mixed evenly and beaten to prepare a burdock pulp mixture;

[0007] Binary solvent forms two-phase extraction: add ionic liquid solvent and inorganic salt to the burdock pulp mixture, fully dissolve and let it stand for extraction. After separation, the upper and lower phases are collected, centrifuged, washed, repeatedly centrifuged and dried to obtain burdock inulin.

[0008] As a preferred embodiment of the method for efficiently extracting burdock inulin using a binary mixed solvent according to the present invention, the ionic liquid solvent is 1-butyl-3-methylimidazolium hexafluorophosphate.

[0009] As a preferred embodiment of the method for efficiently extracting burdock inulin using a binary mixed solvent according to the present invention, the inorganic salt is sodium carbonate.

[0010] As a preferred embodiment of the method for efficiently extracting burdock inulin using a binary mixed solvent according to the present invention, the mass ratio of the ionic liquid solvent to the inorganic salt is 10 to 20:1.

[0011] As a preferred embodiment of the method for efficiently extracting burdock inulin using a binary mixed solvent according to the present invention, the mass ratio of the burdock pulp mixture to the ionic liquid solvent is 2 to 4:1.

[0012] As a preferred embodiment of the method for efficiently extracting burdock inulin using a binary mixed solvent according to the present invention, the mass fraction of burdock root in the burdock pulp mixture is 5-10%.

[0013] As a preferred embodiment of the method for efficiently extracting burdock inulin using a binary mixed solvent according to the present invention, the centrifugation is performed at 2000-3000 r / min for 10 minutes.

[0014] As a preferred embodiment of the method for efficiently extracting burdock inulin using a binary mixed solvent according to the present invention, the washing step is to rinse the precipitate after centrifugation with deionized water.

[0015] As a preferred embodiment of the method for efficiently extracting burdock inulin using a binary mixed solvent according to the present invention, the drying step is drying at 40-50° C. for 2-3 hours.

[0016] Beneficial effects of the present invention: The present invention uses a binary mixed solvent to extract burdock inulin, which achieves a huge improvement in efficiency. The same amount of burdock pulp mixture is extracted through binary phase, which can not only achieve normal extraction in the bottom salt solution environment, but also dissolve in the top ionic liquid phase, promoting a significant improvement in the extraction efficiency of burdock inulin. Secondly, through the extraction of the binary system, the extraction rate of the burdock pulp mixture can be increased, the time required for extraction can be greatly shortened, the operating cost is reduced, and a solid foundation is laid for high yield. The present invention develops a new high-efficiency, low-cost binary mixed solvent-based burdock inulin extraction technology, promotes the diversified industrialization development of burdock inulin, and has important economic, social and environmental value for promoting the development of biotechnology and green manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort. Among them:

[0018] Figure 1 Schematic diagram of the efficient extraction of burdock inulin using a binary mixed solvent. (a) shows the extraction of burdock inulin using a saline solution phase, (b) shows the extraction of burdock inulin using an ionic liquid phase, and (c) shows the extraction of burdock inulin using a binary mixed phase separation technique. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with specific embodiments.

[0020] Example 1:

[0021] (1) Preparation of burdock pulp mixture: 100 g of fresh burdock root and 100 g of water were evenly blended to prepare a total of 200 g of burdock pulp, and then 2000 g of water was added and evenly mixed to form a burdock pulp mixture for use.

[0022] (2) Preparation of single solvent: 100 g of Na2CO3 solid powder was added to the above burdock pulp mixture, and the mixture was stirred thoroughly to extract inulin for 20 min to obtain a burdock inulin extract.

[0023] (3) The burdock inulin-containing liquid was collected, centrifuged (3000 r / min, 10 min), washed, and the centrifugation steps were repeated. Finally, the burdock inulin was dried (40°C, 2 h) to obtain the burdock inulin. The extraction efficiency was calculated to be 98.3±4.1 mg / g fresh burdock.

[0024] Example 2:

[0025] (1) Preparation of burdock pulp mixture: Purchase fresh burdock root (100 g) and mix it with water (100 g) uniformly to prepare a total of 200 g of burdock pulp, and then add 2000 g of water and mix uniformly to form a burdock pulp mixture for use.

[0026] (2) Binary solvent formation of two-phase extraction: 100g of the hydrophilic ionic liquid solvent BMIM:PF6 (1-butyl-3-methylimidazolium hexafluorophosphate) and 100g of inorganic salt solid powder (Na2CO3) are added to the above burdock slurry mixture. The ionic liquid and inorganic salt are rapidly dissolved by stirring or ultrasound, forming a two-phase system to extract inulin. After standing and separating, the upper layer is the ionic liquid phase containing burdock inulin, and the lower layer is the salt solution phase containing burdock inulin.

[0027] (3) The two phases containing burdock inulin are collected and filtered into two containers to obtain a single phase rich in burdock inulin. After shaking or stirring, the precipitate is separated by centrifugation (3000 r / min, 10 min), and the precipitate is washed with deionized water 2 to 3 times, and the centrifugation step is repeated. Finally, it is dried (40°C, 2 h).

[0028] Example 3:

[0029] (1) Preparation of burdock pulp mixture: Purchase fresh burdock root (100 g) and mix it with water (100 g) uniformly to prepare a total of 200 g of burdock pulp, and then add 2000 g of water and mix uniformly to form a burdock pulp mixture for use.

[0030] (2) Binary solvent biphasic extraction: 500 g of a hydrophilic ionic liquid solvent (BMIM:PF6) and 100 g of an inorganic salt solid powder (Na2CO3) were added to the burdock slurry mixture. The mixture was stirred thoroughly or ultrasonically assisted to rapidly dissolve the ionic liquid and inorganic salt, forming a biphasic system for extracting inulin. After standing and separating the layers, the upper layer was the ionic liquid phase containing burdock inulin, and the lower layer was the salt solution phase containing burdock inulin.

[0031] (3) The two phases containing burdock inulin were collected and filtered into two containers to obtain a single phase rich in burdock inulin. After shaking or stirring, the precipitate was separated by centrifugation (3000 rpm, 10 min). The precipitate was washed with deionized water 2-3 times, the centrifugation step was repeated, and finally dried (40°C, 2 h) to obtain pure burdock inulin. The extraction efficiency was calculated to be 146.1 ± 9.3 mg / g fresh burdock.

[0032] Example 4:

[0033] (1) Preparation of burdock pulp mixture: Purchase fresh burdock root (100 g) and mix it with water (100 g) uniformly to prepare a total of 200 g of burdock pulp, and then add 2000 g of water and mix uniformly to form a burdock pulp mixture for use.

[0034] (2) Binary solvent biphasic extraction: 1000 g of a hydrophilic ionic liquid solvent (BMIM:PF6) and 100 g of an inorganic salt solid powder (Na2CO3) were added to the burdock slurry mixture. The mixture was stirred thoroughly or ultrasonically assisted to rapidly dissolve the ionic liquid and inorganic salt, forming a biphasic system for extracting inulin. After standing and separating the layers, the upper layer was the ionic liquid phase containing burdock inulin, and the lower layer was the salt solution phase containing burdock inulin.

[0035] (3) The two phases containing burdock inulin were collected and filtered into two containers to obtain a single phase rich in burdock inulin. After shaking or stirring, the precipitate was separated by centrifugation (3000 rpm, 10 min). The precipitate was washed with deionized water 2-3 times, the centrifugation step was repeated, and finally dried (40°C, 2 h) to obtain pure burdock inulin. The extraction efficiency was calculated to be 175.2 ± 10.1 mg / g fresh burdock.

[0036] In the present invention, by introducing a binary mixed solvent system of a salt solution and an ionic liquid, a mutually immiscible binary two-phase system can be formed, wherein the bottom is a salt solution system for dissolving burdock polysaccharide, and the top is an ionic liquid system for dissolving burdock polysaccharide. Because burdock polysaccharide contains a large number of polar groups, it has a certain affinity for water molecules, but this affinity is limited by the molecular weight of the polysaccharide. Therefore, burdock polysaccharide molecules have a certain solubility in water, but there will still be many polysaccharide molecules that do not participate in the reaction. By introducing a binary ionic liquid solvent, the anions or cations in the ionic liquid can form hydrogen bonds with hydrogen or oxygen atoms of hydroxyl groups on the burdock polysaccharide molecules that are not completely bound, breaking the hydrogen bond network structure existing within and between the original burdock polysaccharide molecules, promoting further dissolution of the polysaccharide, and thus improving the extraction efficiency of burdock polysaccharide.

[0037] Example 5:

[0038] (1) Preparation of burdock pulp mixture: Purchase fresh burdock root (100 g) and mix it with water (100 g) uniformly to prepare a total of 200 g of burdock pulp, and then add 2000 g of water and mix uniformly to form a burdock pulp mixture for use.

[0039] (2) Extraction: 1000 g of a hydrophilic ionic liquid solvent (BMIM:PF6) was added to the burdock pulp mixture. The mixture was stirred thoroughly or ultrasonically to allow the ionic liquid to rapidly mix and extract the inulin. After standing, no stratification occurred.

[0040] (3) The burdock inulin-containing system was collected and filtered into a container to obtain a burdock inulin-rich solution. After shaking or stirring, the solution was centrifuged (3000 rpm, 10 min) to separate the precipitate. The precipitate was washed 2-3 times, the centrifugation step was repeated, and finally, the solution was dried (40°C, 2 h) to obtain pure burdock inulin. The extraction efficiency was calculated to be 100.2 ± 5.2 mg / g fresh burdock.

[0041] Example 6:

[0042] (1) Preparation of burdock pulp mixture: Purchase fresh burdock root (100 g) and mix it with water (100 g) uniformly to prepare a total of 200 g of burdock pulp, and then add 2000 g of water and mix uniformly to form a burdock pulp mixture for use.

[0043] (2) Binary solvent biphasic extraction: 1000 g of a hydrophilic ionic liquid solvent (BMIM:PF6) and 50 g of an inorganic salt solid powder (Na2CO3) were added to the burdock slurry mixture. The mixture was stirred thoroughly or ultrasonically assisted to rapidly dissolve the ionic liquid and inorganic salt, forming a biphasic system for extracting inulin. After standing and separating the layers, the upper layer was the ionic liquid phase containing burdock inulin, and the lower layer was the salt solution phase containing burdock inulin.

[0044] (3) The two phases containing burdock inulin were collected and filtered into two containers to obtain a single phase rich in burdock inulin. After shaking or stirring, the precipitate was separated by centrifugation (3000 rpm, 10 min). The precipitate was washed with water 2-3 times, the centrifugation step was repeated, and finally dried (40°C, 2 h) to obtain pure burdock inulin. The extraction efficiency was calculated to be 168.9 ± 10.0 mg / g fresh burdock.

[0045] Table 1: Effect of inorganic salt and ionic liquid content on extraction efficiency in the examples

[0046]

[0047] Comparative Example 1:

[0048] (1) Preparation of burdock pulp mixture: Purchase fresh burdock root (100 g) and water (100 g) and mix them evenly in a mass ratio of 1:1 to prepare a total of 200 g of burdock pulp, then add 2000 g of water and mix evenly to form a burdock pulp mixture for use.

[0049] (2) Binary solvent formation of two-phase extraction: 1000g of the hydrophilic ionic liquid solvent 1-octyl-3-methylimidazolium hexafluorophosphate (OMIM:PF6) and 100g of inorganic salt solid powder (Na2CO3) were added to the above burdock slurry mixture in a certain proportion. The ionic liquid and inorganic salt were stirred thoroughly or with the assistance of ultrasound to quickly dissolve and form a two-phase system for inulin extraction. However, after standing and separating, no obvious separation occurred, indicating that the ionic liquid used for the two-phase extraction has a certain selectivity, and the cations in the ionic liquid have a regulatory effect on the formation of the two-phase system.

[0050] (3) The two phases containing burdock inulin were collected and filtered into two containers to obtain a single phase rich in burdock inulin. After shaking or stirring, the precipitate was separated by centrifugation (3000 rpm, 10 min). The precipitate was washed with water 2-3 times, the centrifugation step was repeated, and finally dried (40°C, 2 h) to obtain pure burdock inulin. The extraction efficiency was calculated to be 106.4 ± 7.1 mg / g fresh burdock.

[0051] Comparative Example 2:

[0052] (1) Preparation of burdock pulp mixture: Purchase fresh burdock root (100 g) and water (100 g) and mix them evenly in a mass ratio of 1:1 to prepare a total of 200 g of burdock pulp, then add 2000 g of water and mix evenly to form a burdock pulp mixture for use.

[0053] (2) Binary solvent formation of two-phase extraction: 1000g of the hydrophilic ionic liquid solvent 1-decyl-3-methylimidazolium hexafluorophosphate (Demim:PF6) and 100g of inorganic salt solid powder (Na2CO3) were added to the above burdock slurry mixture in a certain proportion. The ionic liquid and inorganic salt were stirred thoroughly or with the assistance of ultrasound to quickly dissolve and form a two-phase system to extract inulin. However, after standing and separating, no obvious separation occurred, indicating that the ionic liquid used for the two-phase extraction has a certain selectivity, and the cations in the ionic liquid have a regulatory effect on the formation of the two-phase system.

[0054] (3) The two phases containing burdock inulin were collected and filtered into two containers to obtain a single phase rich in burdock inulin. After shaking or stirring, the precipitate was separated by centrifugation (3000 rpm, 10 min). The precipitate was washed with water 2-3 times, the centrifugation step was repeated, and finally dried (40°C, 2 h) to obtain pure burdock inulin. The extraction efficiency was calculated to be 104.9 ± 6.8 mg / g fresh burdock.

[0055] Comparative Example 3:

[0056] (1) Preparation of burdock pulp mixture: Purchase fresh burdock root (100 g) and water (100 g) and mix them evenly in a mass ratio of 1:1 to prepare a total of 200 g of burdock pulp, then add 2000 g of water and mix evenly to form a burdock pulp mixture for use.

[0057] (2) Binary solvent formation of two-phase extraction: 1000g of hydrophilic ionic liquid solvent (BMIM:PF6) and 100g of inorganic salt solid powder (NaCl) were added to the above burdock pulp mixture in a certain proportion. The ionic liquid and inorganic salt were quickly dissolved by stirring or ultrasound. However, after standing, the mixed phase did not show any stratification phenomenon, indicating that the formation of two phases is also highly dependent on the choice of inorganic salt. The addition of salt solution is required to make the solution have a certain weak alkalinity or present an alkaline environment.

[0058] (3) The two phases containing burdock inulin were collected, centrifuged, filtered, dried, and other post-processing operations to obtain pure burdock inulin. The extraction efficiency was calculated to be 109.2±6.2 mg / g fresh burdock.

[0059] Table 2: Effect of inorganic salt and ionic liquid content on extraction efficiency in comparative examples

[0060]

[0061] Comparative Example 4:

[0062] (1) Preparation of burdock pulp mixture: Purchase fresh burdock root (100 g) and water (100 g) and mix them evenly in a mass ratio of 1:1 to prepare a total of 200 g of burdock pulp, then add 2000 g of water and mix evenly to form a burdock pulp mixture for use.

[0063] (2) Two-step extraction: First, 100 g of inorganic salt solid powder Na2CO3 was added to the burdock pulp mixture, stirred thoroughly to dissolve the inorganic salt rapidly, and then centrifuged, filtered, and dried to obtain burdock inulin and incompletely extracted burdock inulin residue. Then, in the second step, 42 g of the residue was uniformly mixed with water at a mass ratio of 1:1 to prepare 84 g of burdock residue slurry. 840 g of water was added to the slurry and mixed to form a burdock pulp mixture for later use. 420 g of BMIM:PF6 was then added to the burdock pulp mixture and stirred thoroughly to allow the ionic liquid to mix rapidly and extract the inulin. After standing for separation, no separation occurred.

[0064] (3) The extracts containing burdock inulin from both steps were centrifuged (3000 rpm, 10 min), washed, and centrifuged repeatedly. Finally, the extracts were dried (40°C, 2 h) to obtain pure burdock inulin. The extraction efficiency of the first step was calculated to be 97.5 ± 4.1, the extraction efficiency of the second step was 19.3 ± 5.7 mg / g, and the total extraction efficiency was 116.8 ± 9.8 mg / g fresh burdock.

[0065] Comparative Example 5:

[0066] (1) Preparation of burdock pulp mixture. Purchase fresh burdock root (100 g) and water (100 g) and mix them evenly in a mass ratio of 1:1 to prepare a total of 200 g of burdock pulp. Then add 2000 g of water and mix evenly to form a burdock pulp mixture for use.

[0067] (2) Two-step extraction: First, 1000 g of the ionic liquid solvent BMIM:PF6 is added to the above-mentioned burdock pulp mixture, and the mixture is stirred thoroughly to allow the ionic liquid to mix rapidly and extract the inulin. After standing, if no stratification occurs, centrifugation, filtration, drying and other process operations are performed to obtain burdock inulin containing ionic liquid and burdock inulin residue that has not been completely extracted. Then, in the second step, 35 g of the residue is uniformly mixed with water at a mass ratio of 1:1 to prepare a total of 70 g of burdock residue slurry, 700 g of water is added to the slurry and uniformly mixed to form a burdock pulp mixture for later use. 35 g of Na2CO3 is then added to the above-mentioned burdock pulp mixture, and the mixture is stirred thoroughly to allow the inorganic salt to mix rapidly and extract the inulin.

[0068] (3) The extracts containing burdock inulin from both steps were centrifuged (3000 rpm, 10 min), washed, and centrifuged repeatedly. Finally, the extracts were dried (40°C, 2 h) to obtain pure burdock inulin. The extraction efficiency of the first step was calculated to be 109.5 ± 6.7, the extraction efficiency of the second step was 15.9 ± 4.2 mg / g, and the total extraction efficiency was 125.4 ± 10.9 mg / g fresh burdock.

[0069] Table 3: Effect of the two-step solvent method on the extraction efficiency in the comparative example

[0070]

[0071] It can be seen that by introducing a binary mixed solvent, the extraction efficiency of burdock inulin can be significantly improved (nearly 1 times improvement) compared with a single solvent or a two-step solvent extraction method, and the problem of low extraction efficiency in a single aqueous solution is effectively solved. The results also show that the addition of inorganic salts in a weakly alkaline or alkaline salt solution environment is conducive to the formation of a binary phase system. The dominant factor is the content and selection of the top ionic liquid phase. The greater the addition amount, the higher the burdock inulin extraction rate. The new extraction technology of the present invention effectively improves the extraction efficiency of burdock inulin.

[0072] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for efficiently extracting burdock inulin using a binary mixed solvent, characterized in that: include, The burdock root and water are mixed evenly and beaten to prepare a burdock pulp mixture; Binary solvents form a two-phase extraction: add ionic liquid solvent and inorganic salt to the burdock pulp mixture, fully dissolve and then let it stand for extraction. After separation, the upper and lower phases are collected, centrifuged, washed, and repeatedly centrifuged before drying to obtain burdock inulin; The ionic liquid solvent is 1-butyl-3-methylimidazolium hexafluorophosphate; The inorganic salt is sodium carbonate; The mass ratio of the ionic liquid solvent to the inorganic salt is 10-20:1; The mass ratio of the burdock pulp mixture to the ionic liquid solvent is 2-4:

1.

2. The method for efficiently extracting burdock inulin using a binary mixed solvent according to claim 1, wherein: In the burdock pulp mixture, the mass fraction of burdock root is 5-10%.

3. The method for efficiently extracting burdock inulin using a binary mixed solvent according to claim 1 or 2, characterized in that: The centrifugation is performed at 2000-3000 r / min for 10-20 min.

4. The method for efficiently extracting burdock inulin using a binary mixed solvent according to claim 1 or 2, characterized in that: The washing is to rinse the precipitate after centrifugation with deionized water.

5. The method for efficiently extracting burdock inulin using a binary mixed solvent according to claim 1 or 2, characterized in that: The drying step is drying at 40-50° C. for 2-3 hours.

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