Traditional medicinal material vacuum freeze-drying combined superfine grinding and polysaccharide active component extraction process thereof

Abstract

The invention discloses a traditional medicinal material vacuum freeze-drying combined superfine grinding and polysaccharide active component extraction process thereof. According to the method, the concentration gradient of solid-liquid contact is continuously updated through a continuous mode of'solvent countercurrent and medicinal material downstream ', so that polysaccharide is more smoothly dissolved out, compared with traditional single-tank extraction, long-time high-temperature soaking is not needed, the risk of polysaccharide chain breakage is reduced, and the extraction efficiency of effective components is directly improved. The clarity of an extracting solution is ensured through subsequent three-stage separation, impurities are accurately removed through macroporous resin purification, damage of high temperature to activity is avoided through vacuum low-temperature concentration drying, the polysaccharide structure is protected in the whole process from extraction to purification to final drying, the purity and yield of the polysaccharide are improved, the biological activity of the polysaccharide is reserved to the maximum extent, and the method is suitable for industrial production. The whole process enables the polysaccharide extraction of traditional medicinal materials to be more efficient and more stable, and also enables the quality of the final product to be better guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of medicinal material processing, and specifically is a process for vacuum freeze-drying combined with ultrafine grinding of traditional medicinal materials and extraction of polysaccharide active ingredients. Background Art

[0002] Ultrafine grinding of medicinal materials is a modern processing technology that uses high-energy grinding equipment to reduce Chinese medicinal materials to micron or even submicron particle sizes. It is widely used in traditional Chinese medicine preparations, health products, and cosmetics. This process uses methods such as air flow milling, mechanical milling, or high-energy ball milling to fully break down the cell walls of the medicinal materials, significantly increasing the release rate of active ingredients, thereby enhancing efficacy and bioavailability. Ultrafine grinding not only retains the original active ingredients of the medicinal materials but also improves their solubility, stability, and uniformity, facilitating subsequent extraction, mixing, and molding. Extraction of active polysaccharide ingredients from medicinal materials is a modern extraction process that separates and purifies biologically active polysaccharides from traditional Chinese medicines through physical, chemical, or biological methods. Polysaccharides, as one of the important active ingredients in traditional Chinese medicine, possess multiple physiological functions such as immunomodulation, antioxidant, anti-tumor, and antiviral properties, and are widely used in pharmaceuticals, health products, and functional foods. The extraction process typically includes raw material pretreatment, water or alcohol extraction, centrifugal filtration, concentration, precipitation, and purification. Common extraction methods include hot water extraction, enzymatic extraction, ultrasound-assisted extraction, and microwave-assisted extraction to improve extraction efficiency and polysaccharide yield. By controlling extraction conditions such as temperature, pH, and solvent concentration, impurities can be effectively removed, resulting in a high-purity polysaccharide product.

[0003] However, the existing technology often suffers from uneven penetration of color preservatives due to lack of strict classification in raw material processing, and the active ingredients are easily oxidized and lost; the freeze-drying process is not precisely controlled, which can easily cause cell rupture, and excessively high temperatures during pulverization can degrade the active ingredients; the extraction solvents are mostly ordinary water or simple solutions, which have insufficient penetration capacity; traditional single-tank extraction requires long-term high-temperature immersion, which can easily lead to polysaccharide chain breakage; solid-liquid separation is not thorough, and the purification efficiency is low. The high temperature environment during drying will also destroy the active ingredients, resulting in poor overall extraction efficiency and product quality stability. Summary of the Invention

[0004] The purpose of the present invention is to provide a process for vacuum freeze-drying of traditional medicinal materials combined with ultrafine grinding and extraction of polysaccharide active ingredients in order to solve the above-mentioned problems.

[0005] The technical solution adopted by the present invention is as follows: a process for vacuum freeze-drying of traditional medicinal materials combined with ultrafine grinding and extraction of polysaccharide active ingredients, the process comprising the following steps:

[0006] S1: Select traditional medicinal herbs free of mold and insect infestation, grade them by particle size using a vibrating screen, and rinse them three times with running deionized water for 5 minutes each time to ensure minimal surface impurities. This step provides a uniform raw material for the subsequent color treatment, preventing uneven penetration of the color treatment agent due to surface area differences.

[0007] S2: Immerse the graded medicinal materials in a 0.15% citric acid + 0.2% ascorbic acid solution at a material-to-liquid ratio of 1:3. Ultrasonic treatment is performed at room temperature for 10 minutes at 200W. Citric acid adjusts the pH to inhibit polyphenol oxidase activity, while ascorbic acid consumes oxygen from the system, reducing oxidative loss of active ingredients during the freeze-drying process and providing a moist and uniform surface for subsequent vacuum freeze-drying.

[0008] S3: Spread the color-protected medicinal material onto a freeze-drying tray (thickness ≤ 2 cm) and pre-freeze at -30°C for 2 hours to reduce the core temperature to below -25°C. Then, activate the vacuum system to 10 Pa and heat the material at a rate of 1°C / minute to -10°C for sublimation drying for 4 hours. Finally, heat the material at a rate of 2°C / minute to 25°C for desorption drying for 2 hours, until the moisture content is ≤ 3%. This gradient cooling creates a uniform ice crystal structure, preventing cell rupture caused by rapid freezing and providing a loose, porous, and brittle material for subsequent ultrafine grinding.

[0009] S4: Place the freeze-dried medicinal material into a jet mill, controlling the pulverizing chamber temperature to ≤15°C (maintained via a liquid nitrogen line), using a pulverizing pressure of 0.8 MPa and a classifying impeller speed of 8000 rpm, until at least 90% of the particles are ≤15 μm in size. The low temperature prevents mechanical and thermal degradation of polysaccharides during pulverization, and the ultrafine particles increase their specific surface area, providing a more complete solid-liquid interface for subsequent extraction.

[0010] S5: Prepare the extraction solvent with deionized water, add 0.05% Tween-80 surfactant, and adjust the pH to 6.5. Stir in a 60°C water bath with 0.1 mol / L citric acid solution for 15 minutes. Tween-80 reduces the solvent's surface tension, enhancing its penetration into the ultrafine medicinal material particles. Adjusting the pH brings the solvent environment closer to the isoelectric point of the polysaccharide molecules, promoting their dissolution from the cell wall and directly affecting subsequent extraction efficiency.

[0011] S6: Ultrafine medicinal materials and pre-activated solvent are placed in a dynamic countercurrent extraction device at a ratio of 1:20: the first extraction tank is maintained at 65°C and a stirring rate of 150 rpm. After 1 hour of extraction, the supernatant is pumped into the second extraction tank (containing fresh ultrafine medicinal materials). At the same time, an equal amount of pre-activated solvent is added to the first stage, forming a continuous extraction mode of "solvent countercurrent, medicinal materials downstream." This mode increases the driving force for polysaccharide dissolution by 30% to 40% compared to traditional single-tank extraction by updating the concentration gradient at the solid-liquid interface, avoiding polysaccharide chain breakage caused by prolonged high temperature.

[0012] S7: The extract is first coarsely filtered through a 100-mesh sieve to remove large particles. The filtrate is then centrifuged at 4000 rpm for 15 minutes to separate fine particles. Finally, the filtrate is microfiltered through a 0.45 μm ceramic membrane, and the permeate is collected. Coarse filtration protects the centrifugal equipment, centrifugation reduces membrane fouling, and microfiltration ensures high feed clarity in subsequent purification steps. These three stages of separation synergistically enhance process stability.

[0013] S8: The separated extract was passed through an AB-8 macroporous adsorption resin column at a flow rate of 2 BV / hour, with a resin packing height-to-diameter ratio of 5:1. After adsorption, the column was rinsed with 5 column volumes of deionized water to remove small molecule impurities. The polysaccharide fraction was then eluted with a 40% ethanol solution at a flow rate of 1 BV / hour. The selective adsorption of the resin for the polysaccharide, combined with the ethanol elution, increased the purity of the polysaccharide extract from 65% to 70% to over 85%.

[0014] S9: The purified polysaccharide eluate is concentrated under reduced pressure at -0.09 MPa and 50°C to 1 / 10 its original volume. The eluate is then transferred to a vacuum freeze dryer, pre-frozen at -40°C for 2 hours at a vacuum of 5 Pa, and sublimated for 24 hours to yield a white to off-white polysaccharide powder with a moisture content of ≤5% and a polysaccharide content of ≥85%. This drying method forms a temperature-vacuum gradient with the vacuum freeze-drying process, ensuring that the active ingredients are kept in a non-high-temperature environment and preserving the polysaccharide's biological activity.

[0015] In a preferred embodiment, in step S1, the medicinal material selection and classification pretreatment must strictly control the quality of the raw materials, select traditional medicinal materials that are free of mold and insect infestation, and use a vibrating screen to classify them into two specifications according to particle size: 2-5mm and 5-8mm. The classified medicinal materials are washed with flowing deionized water for 3 times, each washing lasting 5 minutes. After washing, it is necessary to ensure that the residual microorganisms on the surface are less than 10 3 CFU / g. This step, through grading and cleaning, provides raw materials with uniform particle size and clean surface for the subsequent color protection process, avoiding uneven penetration of the color protection agent due to differences in the particle size of the medicinal materials, which affects the color protection effect.

[0016] In a preferred embodiment, in step S2, the composite color-protecting solution immersion treatment uses a composite solution of 0.15% citric acid and 0.2% ascorbic acid as a color-protecting agent. The graded medicinal materials are completely immersed in the color-protecting solution at a material-to-liquid ratio (medicinal material mass to solution volume ratio) of 1:3. Ultrasound-assisted treatment is performed at room temperature with an ultrasonic power of 200W for 10 minutes. The citric acid inhibits polyphenol oxidase activity by adjusting the solution pH, while the ascorbic acid acts as a reducing agent to consume oxygen in the system. The synergistic effect of the two reduces oxidative loss of the active ingredient during the freeze-drying process, while maintaining a uniformly moist surface of the medicinal materials, thereby providing a suitable material state for the subsequent vacuum freeze-drying process.

[0017] In a preferred embodiment, in step S3, the gradient cooling vacuum freeze-drying requires that the medicinal materials after color protection be spread flat on the freeze-drying tray, and the thickness of the material does not exceed 2 cm. The freeze-drying process is divided into three stages: pre-freezing, sublimation drying and analytical drying: the temperature of the pre-freezing stage is set to -30°C for 2 hours to ensure that the center temperature of the material drops below -25°C; in the sublimation drying stage, the vacuum system is turned on to 10Pa, and the temperature is increased to -10°C at a rate of 1°C / minute for 4 hours; in the analytical drying stage, the temperature is increased to 25°C at a rate of 2°C / minute for 2 hours, and the moisture content of the medicinal materials is finally reduced to below 3%. The gradient cooling mode can form a uniform ice crystal structure, avoid cell rupture caused by rapid freezing, provide loose and porous brittle materials for the subsequent ultrafine grinding process, and reduce the difficulty of grinding.

[0018] In a preferred embodiment, in step S4, low-temperature ultrafine airflow pulverization uses an airflow pulverizer, and the temperature of the pulverization chamber is maintained at no more than 15°C through a liquid nitrogen pipeline during the pulverization process to prevent polysaccharides from being degraded by mechanical heat. The pulverization pressure is set to 0.8 MPa, the classification wheel speed is 8000 rpm, and the pulverization is continued until more than 90% of the particles reach a particle size of less than 15 μm. The specific surface area of ​​the medicinal material particles after ultrafine pulverization is significantly increased (5-8 times higher than that of ordinary pulverization), providing a more sufficient solid-liquid contact interface for the subsequent extraction process and improving the dissolution efficiency of polysaccharides.

[0019] In a preferred embodiment, in step S5, the extraction solvent pre-activation treatment uses deionized water as the base solvent, adds 0.05% Tween-80, 0.03% L-menthol and 0.2% trehalose, and adjusts the pH to 6.5 with 0.1 mol / L sodium dihydrogen phosphate solution. After the solvent is prepared, it is placed in a 60°C constant temperature water bath and stirred for 15 minutes. Tween-80 and L-menthol synergistically reduce the surface tension of the solvent and enhance the penetration ability of ultrafine medicinal material particles; trehalose acts as a protective agent to wrap the polysaccharide molecules to form a hydrated film, inhibiting the breakage of the polysaccharide chain; the sodium dihydrogen phosphate buffer system maintains a stable pH, so that the solvent environment is close to the isoelectric point of the polysaccharide molecules, promotes their dissolution from the cell wall, and provides efficient solvent conditions for the subsequent extraction process.

[0020] In a preferred embodiment, in step S6, the pre-activation solvent includes 99.7 parts by weight of deionized water, 0.05 parts by weight of Tween-80, 0.03 parts by weight of L-menthol, 0.2 parts by weight of trehalose, and an appropriate amount of sodium dihydrogen phosphate solution (adjusted to pH 6.5); L-menthol acts as a natural penetration enhancer, enhancing solvent penetration by destroying the lipid bilayer of the medicinal material cell wall; trehalose acts as a non-reducing protective agent, wrapping the polysaccharide molecules to form a hydration film during the extraction process, thereby inhibiting polysaccharide chain breakage; Tween-80 and L-menthol synergistically reduce the solid-liquid interfacial tension, thereby increasing the specific surface area utilization rate of the ultrafine particles by 20% to 25%; the sodium dihydrogen phosphate buffer system maintains pH stability to prevent polysaccharide denaturation due to acid-base fluctuations.

[0021] In a preferred embodiment, in step S7, the three-stage solid-liquid separation is accomplished sequentially through coarse filtration, centrifugation, and microfiltration. First, the extract is coarsely filtered through a 100-mesh screen to remove large particles. The coarse filtrate is centrifuged at 4000 rpm for 15 minutes to separate fine impurities. The centrifuged filtrate is then microfiltered through a 0.45 μm ceramic membrane, and the permeate is collected. Coarse filtration protects the centrifuge equipment from damage by large particles, centrifugation reduces the contamination load on the microfiltration membrane, and microfiltration ensures a feed clarity of 95% or higher for subsequent purification steps. The three-stage separation synergistically improves process stability and the efficiency of subsequent steps.

[0022] In a preferred embodiment, in step S8, AB-8 macroporous adsorption resin is used for macroporous resin adsorption purification. The resin column is packed at a height-to-diameter ratio of 5:1. The separated extract is passed through the resin column at a flow rate of 2 BV / hour (bed volume / hour) to achieve adsorption. After adsorption, the resin column is rinsed with 5 column volumes of deionized water to remove small molecular impurities such as monosaccharides and pigments. The polysaccharide fraction is then eluted with a 40% ethanol solution at a flow rate of 1 BV / hour. The AB-8 resin has a selective adsorption rate for polysaccharides exceeding 92%, and an ethanol elution rate exceeding 85%. This synergistic effect increases the polysaccharide purity of the extract from 65% to 70% to over 85%.

[0023] In a preferred embodiment, in step S9, the vacuum low-temperature concentration and drying is divided into two stages: vacuum concentration and vacuum freeze drying. First, the purified polysaccharide eluate is placed under -0.09MPa and 50°C and concentrated under reduced pressure to 1 / 10 of its original volume. The concentrate is then transferred to a vacuum freeze dryer, and the pre-freezing stage temperature is set to -40°C for 2 hours. After the pre-freezing is completed, sublimation drying is carried out under a vacuum of 5Pa for 24 hours, ultimately obtaining a white to off-white polysaccharide powder with a moisture content of ≤5% and a polysaccharide content of ≥85%. This drying method forms a temperature-vacuum gradient connection with the previous vacuum freeze-drying process, ensuring that the active ingredients are in a non-high-temperature environment throughout the entire process, thereby retaining the polysaccharide biological activity to the greatest extent.

[0024] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0025] 1. In the present invention, through the continuous mode of "solvent countercurrent, medicinal material downstream", the concentration gradient of solid-liquid contact is continuously updated, making the dissolution of polysaccharides smoother. Compared with traditional single-tank extraction, long-term high-temperature immersion is not required, which reduces the risk of polysaccharide chain breakage and directly improves the extraction efficiency of effective ingredients. The subsequent three-stage separation ensures the clarity of the extract, macroporous resin purification accurately removes impurities, and vacuum low-temperature concentration and drying avoids the damage to activity caused by high temperature. These steps, from extraction to purification to final drying, protect the polysaccharide structure throughout the process, which not only improves the purity and yield of polysaccharides, but also retains their biological activity to the greatest extent. The overall process makes the polysaccharide extraction of traditional medicinal materials more efficient and stable, and also ensures the quality of the final product.

[0026] 2. In the present invention, the stability of medicinal material processing and the retention of active ingredients are effectively improved through multi-link collaborative processing. Starting from the selection and grading of raw materials, the uniformity of the particle size of the medicinal materials is strictly controlled and cleaned, avoiding the problem of uneven penetration of the color preservative; the composite color preservative liquid treatment inhibits the oxidation reaction and reduces the loss of active ingredients during the freeze-drying process; the loose porous structure formed by gradient cooling freeze-drying, combined with the increased specific surface area of ​​the particles by low-temperature ultrafine grinding, allows the solvent to more fully contact the medicinal materials during subsequent extraction, improving the basic conditions for polysaccharide dissolution. The pre-activated solvent further enhances its penetration into ultrafine particles through the addition of surfactants and protective agents, preparing the solvent environment for extraction. These preliminary steps are closely linked, and optimization has been made from the raw material state to the solvent conditions, laying a solid foundation for efficient extraction. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the process principle of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to 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 intended to limit the present invention.

[0029] Example:

[0030] Reference Figure 1 ,

[0031] A process for vacuum freeze-drying and ultrafine grinding of traditional medicinal materials and extraction of polysaccharide active ingredients, the process includes the following steps

[0032] S1: Select traditional medicinal herbs free of mold and insect infestation, grade them by particle size using a vibrating screen, and rinse them three times with running deionized water for 5 minutes each time to ensure minimal surface impurities. This step provides a uniform raw material for the subsequent color treatment, preventing uneven penetration of the color treatment agent due to surface area differences.

[0033] S2: Immerse the graded medicinal materials in a 0.15% citric acid + 0.2% ascorbic acid solution at a material-to-liquid ratio of 1:3. Ultrasonic treatment is performed at room temperature for 10 minutes at 200W. Citric acid adjusts the pH to inhibit polyphenol oxidase activity, while ascorbic acid consumes oxygen from the system, reducing oxidative loss of active ingredients during the freeze-drying process and providing a moist and uniform surface for subsequent vacuum freeze-drying.

[0034] S3: Spread the color-protected medicinal material onto a freeze-drying tray (thickness ≤ 2 cm) and pre-freeze at -30°C for 2 hours to reduce the core temperature to below -25°C. Then, activate the vacuum system to 10 Pa and heat the material at a rate of 1°C / minute to -10°C for sublimation drying for 4 hours. Finally, heat the material at a rate of 2°C / minute to 25°C for desorption drying for 2 hours, until the moisture content is ≤ 3%. This gradient cooling creates a uniform ice crystal structure, preventing cell rupture caused by rapid freezing and providing a loose, porous, and brittle material for subsequent ultrafine grinding.

[0035] S4: Place the freeze-dried medicinal material into a jet mill, controlling the pulverizing chamber temperature to ≤15°C (maintained via a liquid nitrogen line), using a pulverizing pressure of 0.8 MPa and a classifying impeller speed of 8000 rpm, until at least 90% of the particles are ≤15 μm in size. The low temperature prevents mechanical and thermal degradation of polysaccharides during pulverization, and the ultrafine particles increase their specific surface area, providing a more complete solid-liquid interface for subsequent extraction.

[0036] S5: Prepare the extraction solvent with deionized water, add 0.05% Tween-80 surfactant, and adjust the pH to 6.5. Stir in a 60°C water bath with 0.1 mol / L citric acid solution for 15 minutes. Tween-80 reduces the solvent's surface tension, enhancing its penetration into the ultrafine medicinal material particles. Adjusting the pH brings the solvent environment closer to the isoelectric point of the polysaccharide molecules, promoting their dissolution from the cell wall and directly affecting subsequent extraction efficiency.

[0037] S6: Ultrafine medicinal materials and pre-activated solvent are placed in a dynamic countercurrent extraction device at a ratio of 1:20: the first extraction tank is maintained at 65°C and a stirring rate of 150 rpm. After 1 hour of extraction, the supernatant is pumped into the second extraction tank (containing fresh ultrafine medicinal materials). At the same time, an equal amount of pre-activated solvent is added to the first stage, forming a continuous extraction mode of "solvent countercurrent, medicinal materials downstream." This mode increases the driving force for polysaccharide dissolution by 30% to 40% compared to traditional single-tank extraction by updating the concentration gradient at the solid-liquid interface, avoiding polysaccharide chain breakage caused by prolonged high temperature.

[0038] S7: The extract is first coarsely filtered through a 100-mesh sieve to remove large particles. The filtrate is then centrifuged at 4000 rpm for 15 minutes to separate fine particles. Finally, the filtrate is microfiltered through a 0.45 μm ceramic membrane, and the permeate is collected. Coarse filtration protects the centrifugal equipment, centrifugation reduces membrane fouling, and microfiltration ensures high feed clarity in subsequent purification steps. These three stages of separation synergistically enhance process stability.

[0039] S8: The separated extract was passed through an AB-8 macroporous adsorption resin column at a flow rate of 2 BV / hour, with a resin packing height-to-diameter ratio of 5:1. After adsorption, the column was rinsed with 5 column volumes of deionized water to remove small molecule impurities. The polysaccharide fraction was then eluted with a 40% ethanol solution at a flow rate of 1 BV / hour. The selective adsorption of the resin for the polysaccharide, combined with the ethanol elution, increased the purity of the polysaccharide extract from 65% to 70% to over 85%.

[0040] S9: The purified polysaccharide eluate is concentrated under reduced pressure at -0.09 MPa and 50°C to 1 / 10 its original volume. The eluate is then transferred to a vacuum freeze dryer, pre-frozen at -40°C for 2 hours at a vacuum of 5 Pa, and sublimated for 24 hours to yield a white to off-white polysaccharide powder with a moisture content of ≤5% and a polysaccharide content of ≥85%. This drying method forms a temperature-vacuum gradient with the vacuum freeze-drying process, ensuring that the active ingredients are kept in a non-high-temperature environment and preserving the polysaccharide's biological activity.

[0041] In step S1, the selection and classification of medicinal materials requires strict control of raw material quality. Traditional medicinal materials without mildew and insect infestation are selected and classified into two specifications of 2-5mm and 5-8mm according to particle size through a vibrating screen. The classified medicinal materials are washed with flowing deionized water for 3 times, each washing lasting 5 minutes. After washing, the residual microorganisms on the surface must be less than 10 3 CFU / g. This step, through grading and cleaning, provides raw materials with uniform particle size and clean surface for the subsequent color protection process, avoiding uneven penetration of color protection agent due to differences in medicinal material particle size, which affects the color protection effect.

[0042] In step S2, the composite color-protecting liquid immersion treatment uses a composite solution of 0.15% citric acid and 0.2% ascorbic acid as a color-protecting agent. The graded medicinal materials are completely immersed in the color-protecting liquid at a material-to-liquid ratio of 1:3 (medicinal material mass to solution volume ratio). Ultrasound-assisted treatment is performed at room temperature with an ultrasonic power of 200W for 10 minutes. Citric acid inhibits polyphenol oxidase activity by adjusting the solution pH, while ascorbic acid acts as a reducing agent to consume oxygen in the system. The synergistic effect of the two reduces oxidative loss of active ingredients during the freeze-drying process, while maintaining a moist and uniform surface of the medicinal materials, providing a suitable material state for the subsequent vacuum freeze-drying process.

[0043] In step S3, the gradient cooling vacuum freeze-drying requires that the medicinal materials after color protection be spread flat on the freeze-drying tray, and the thickness of the material should not exceed 2 cm. The freeze-drying process is divided into three stages: pre-freezing, sublimation drying and analytical drying: the temperature of the pre-freezing stage is set to -30 ° C and lasts for 2 hours to ensure that the center temperature of the material drops below -25 ° C; in the sublimation drying stage, the vacuum system is turned on to 10Pa, and the temperature is increased to -10 ° C at a rate of 1 ° C / minute for 4 hours; in the analytical drying stage, the temperature is increased to 25 ° C at a rate of 2 ° C / minute for 2 hours, and finally the water content of the medicinal materials is reduced to below 3%. The gradient cooling mode can form a uniform ice crystal structure, avoid cell rupture caused by rapid freezing, provide loose and porous brittle materials for the subsequent ultrafine grinding process, and reduce the difficulty of grinding.

[0044] In step S4, low-temperature ultrafine airflow pulverization uses an airflow mill. During the pulverization process, the temperature of the pulverization chamber is maintained at no more than 15°C through a liquid nitrogen pipeline to prevent polysaccharides from being degraded due to mechanical heat. The pulverization pressure is set to 0.8MPa, the grading wheel speed is 8000 rpm, and the pulverization is continued until more than 90% of the particles reach a particle size of less than 15μm. The specific surface area of ​​the medicinal material particles after ultrafine pulverization is significantly increased (5-8 times higher than that of ordinary pulverization), providing a more sufficient solid-liquid contact interface for the subsequent extraction process and improving the dissolution efficiency of polysaccharides.

[0045] In step S5, the extraction solvent is pre-activated using deionized water as the base solvent, with 0.05% Tween-80, 0.03% L-menthol and 0.2% trehalose added, and the pH is adjusted to 6.5 using 0.1 mol / L sodium dihydrogen phosphate solution. After the solvent is prepared, it is placed in a 60°C constant temperature water bath and stirred for 15 minutes. Tween-80 and L-menthol synergistically reduce the surface tension of the solvent and enhance its penetration into ultrafine medicinal material particles; trehalose acts as a protective agent to wrap the polysaccharide molecules to form a hydrated film, inhibiting the breakage of the polysaccharide chains; the sodium dihydrogen phosphate buffer system maintains a stable pH, making the solvent environment close to the isoelectric point of the polysaccharide molecules, promoting their dissolution from the cell wall, and providing efficient solvent conditions for the subsequent extraction process.

[0046] In step S6, the pre-activation solvent includes 99.7 parts by weight of deionized water, 0.05 parts by weight of Tween-80, 0.03 parts by weight of L-menthol, 0.2 parts by weight of trehalose, and an appropriate amount of sodium dihydrogen phosphate solution (adjusted to pH 6.5); L-menthol acts as a natural penetration enhancer, enhancing solvent penetration by destroying the lipid bilayer of the medicinal material cell wall; trehalose acts as a non-reducing protective agent, wrapping the polysaccharide molecules to form a hydration film during the extraction process, thereby inhibiting polysaccharide chain breakage; Tween-80 and L-menthol synergistically reduce the solid-liquid interfacial tension, thereby increasing the specific surface area utilization rate of the ultrafine particles by 20% to 25%; and the sodium dihydrogen phosphate buffer system maintains pH stability to prevent polysaccharide denaturation due to acid-base fluctuations.

[0047] (Note: L-menthol, as a natural penetration enhancer, enhances solvent penetration by destroying the lipid bilayer of the medicinal material cell wall; trehalose, as a non-reducing protective agent, wraps the polysaccharide molecules to form a hydration film during the extraction process, inhibiting the breakage of the polysaccharide chains; Tween-80 and L-menthol synergistically reduce the solid-liquid interfacial tension, increasing the specific surface area utilization of the ultrafine particles by 20% to 25%; the sodium dihydrogen phosphate buffer system maintains pH stability to prevent polysaccharide denaturation due to acid-base fluctuations;

[0048] Dynamic countercurrent enhanced extraction uses a solid-liquid ratio of 1:20 (ratio of medicinal material mass to solvent volume), and the ultrafine medicinal materials and pre-activated solvent are put into the dynamic countercurrent extraction device. The temperature of the first extraction tank is set at 65°C, and the stirring rate is 150 rpm. After 1 hour of extraction, the supernatant of the first section is pumped into the secondary extraction tank (filled with fresh ultrafine medicinal materials). At the same time, an equal amount of pre-activated solvent is added to the first section to form a continuous extraction mode of "solvent countercurrent, medicinal material downstream". This mode continuously updates the concentration gradient of the solid-liquid interface, which increases the driving force for polysaccharide dissolution by 30% to 40% compared with traditional single-tank extraction, while shortening the single-batch extraction time and avoiding the breakage of polysaccharide chains caused by long-term high temperature. It is the core innovation link of the process.

[0049] In step S7, the three-stage solid-liquid separation is accomplished sequentially through coarse filtration, centrifugation, and microfiltration. First, the extract is coarsely filtered through a 100-mesh screen to remove large particles. The coarse filtrate is centrifuged at 4000 rpm for 15 minutes to separate fine impurities. The filtrate after centrifugation is microfiltered through a 0.45μm ceramic membrane, and the permeate is collected. Coarse filtration protects the centrifuge equipment from large particles, centrifugation reduces the contamination load on the microfiltration membrane, and microfiltration ensures that the feed clarity of the subsequent purification process reaches above 95%. The three-stage separation synergistically improves process stability and the efficiency of subsequent processes.

[0050] In step S8, AB-8 macroporous adsorption resin is used for macroporous resin adsorption purification. The resin column is packed with a height-to-diameter ratio of 5:1. The separated extract is passed through the resin column at a flow rate of 2 BV / hour (bed volume / hour) to complete adsorption. After adsorption, the resin column is rinsed with 5 column volumes of deionized water to remove small molecular impurities such as monosaccharides and pigments. The polysaccharide component is then eluted with a 40% ethanol solution at a flow rate of 1 BV / hour. The AB-8 resin has a selective adsorption rate for polysaccharides exceeding 92%, and the ethanol elution rate exceeds 85%. This synergistic effect increases the purity of the polysaccharide extract from 65% to 70% to over 85%.

[0051] In step S9, vacuum low-temperature concentration and drying are divided into two stages: vacuum concentration and vacuum freeze drying. First, the purified polysaccharide eluate is placed under -0.09MPa and 50°C and concentrated under reduced pressure to 1 / 10 of its original volume. The concentrate is then transferred to a vacuum freeze dryer, with the pre-freezing stage temperature set at -40°C for 2 hours. After the pre-freezing is completed, sublimation drying is carried out under a vacuum of 5Pa for 24 hours, ultimately obtaining a white to off-white polysaccharide powder with a moisture content of ≤5% and a polysaccharide content of ≥85%. This drying method forms a temperature-vacuum gradient connection with the previous vacuum freeze-drying process, ensuring that the active ingredients are in a non-high-temperature environment throughout the entire process, thereby preserving the polysaccharide biological activity to the greatest extent.

[0052] From the above we can know:

[0053] In the present invention, through the continuous mode of "solvent countercurrent, medicinal material downstream", the concentration gradient of solid-liquid contact is continuously updated, making the dissolution of polysaccharides smoother. Compared with traditional single-tank extraction, long-term high-temperature immersion is not required, which reduces the risk of polysaccharide chain breakage and directly improves the extraction efficiency of effective ingredients. The subsequent three-stage separation ensures the clarity of the extract, macroporous resin purification accurately removes impurities, and vacuum low-temperature concentration and drying avoids the damage to activity caused by high temperature. These steps, from extraction to purification to final drying, protect the polysaccharide structure throughout the process, which not only improves the purity and yield of polysaccharides, but also retains their biological activity to the greatest extent. The overall process makes the polysaccharide extraction of traditional medicinal materials more efficient and stable, and also ensures the quality of the final product.

[0054] In the present invention, the stability of medicinal material processing and the retention of active ingredients are effectively improved through multi-link collaborative processing. Starting from the selection and grading of raw materials, the uniformity of the particle size of the medicinal materials is strictly controlled and cleaned, avoiding the problem of uneven penetration of the color preservative; the composite color preservative liquid treatment inhibits the oxidation reaction and reduces the loss of active ingredients during the freeze-drying process; the loose porous structure formed by gradient cooling freeze-drying, combined with the increased specific surface area of ​​the particles by low-temperature ultrafine grinding, allows the solvent to more fully contact the medicinal materials during subsequent extraction, improving the basic conditions for polysaccharide dissolution. The pre-activated solvent further enhances its penetration into ultrafine particles through the addition of surfactants and protective agents, preparing the solvent environment for extraction. These preliminary steps are closely linked, and optimization has been made from the raw material state to the solvent conditions, laying a solid foundation for efficient extraction.

[0055] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprises" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A process for vacuum freeze-drying of traditional medicinal materials combined with ultrafine grinding and extraction of polysaccharide active ingredients, characterized by: The process comprises the following steps S1: Select traditional medicinal materials that are free of mold and insect infestation, classify them by particle size through a vibrating screen, and wash them with running deionized water three times, 5 minutes each time, to ensure low residual impurities on the surface, provide uniform raw materials for subsequent color protection treatment, and avoid uneven penetration of color protection agent due to surface area differences; S2: Immerse the graded medicinal materials in a composite solution of 0.15% citric acid and 0.2% ascorbic acid at a solid-liquid ratio of 1:3, and treat with 200W ultrasound at room temperature for 10 minutes to inhibit polyphenol oxidase activity and consume oxygen in the system; S3: Spread the color-protected medicinal materials flat on a freeze-drying tray and pre-freeze at -30°C for 2 hours until the center temperature of the material reaches below -25°C; then turn on the vacuum system to 10Pa, increase the temperature to -10°C at a rate of 1°C / min for sublimation drying for 4 hours; finally, increase the temperature to 25°C at a rate of 2°C / min for desorption drying for 2 hours until the moisture content does not exceed 3%, forming a uniform ice crystal structure; S4: Place the freeze-dried medicinal material into the air flow mill, maintain the temperature of the grinding chamber at no more than 15°C through a liquid nitrogen pipeline, set the grinding pressure to 0.8 MPa and the classification wheel speed to 8000 rpm, until more than 90% of the particles have a particle size of no more than 15 μm; S5: Using deionized water as the base solvent, add 0.05% Tween-80, adjust the pH to 6.5 with 0.1 mol / L citric acid solution, place in a 60°C constant temperature water bath and stir for 15 minutes to reduce the surface tension of the solvent and make the environment close to the isoelectric point of the polysaccharide molecules; S6: Ultrafine medicinal materials and pre-activated solvent are placed in a dynamic countercurrent extraction device at a ratio of 1:

20. The first extraction tank is maintained at 65°C and a stirring rate of 150 rpm. After 1 hour of extraction, the supernatant is pumped into the second extraction tank. At the same time, an equal amount of pre-activated solvent is added to the first extraction tank to form a continuous extraction mode of "solvent countercurrent, medicinal materials downstream"; S7: The extract was first coarsely filtered through a 100-mesh sieve to remove large particles of residue. The filtrate was centrifuged at 4000 rpm for 15 minutes to separate fine particles of impurities. Finally, it was microfiltered through a 0.45 μm ceramic membrane to collect the permeate. This protected the centrifugal equipment, reduced the membrane fouling load, and ensured the clarity of the feed solution for subsequent purification steps. S8: The separated extract was passed through an AB-8 macroporous adsorption resin column at a flow rate of 2 BV / hour. After adsorption, it was rinsed with 5 column volumes of deionized water to remove small molecular impurities, and then the polysaccharide component was eluted with a 40% ethanol solution at a flow rate of 1 BV / hour to increase the purity of the polysaccharide to more than 85%; S9: The purified polysaccharide eluate was concentrated under reduced pressure at -0.09 MPa and 50°C to 1 / 10 of its original volume, then transferred to a vacuum freeze dryer, pre-frozen at -40°C for 2 hours, and sublimated and dried at a vacuum of 5 Pa for 24 hours to obtain a white to off-white polysaccharide powder, which forms a temperature-vacuum gradient connection with the vacuum freeze-drying process to retain the biological activity of the polysaccharide.

2. The process for vacuum freeze-drying and ultrafine grinding of traditional medicinal materials and extraction of polysaccharide active ingredients according to claim 1, characterized in that: In step S1, the medicinal materials selection and classification pretreatment must strictly control the quality of the raw materials, select traditional medicinal materials without mildew and insect infestation, and classify them into two specifications of 2-5mm and 5-8mm according to particle size through a vibrating screen; the classified medicinal materials are washed with flowing deionized water for 3 times, each washing lasting 5 minutes, and the residual microorganisms on the surface must be less than 10 3 CFU / g; This step provides raw materials with uniform particle size and clean surface for the subsequent color protection process through grading and cleaning, avoiding uneven penetration of color protection agent due to differences in medicinal material particle size, which affects the color protection effect.

3. The process for vacuum freeze-drying and ultrafine grinding of traditional medicinal materials and extraction of polysaccharide active ingredients according to claim 1, characterized in that: In step S2, the composite color-protecting liquid immersion treatment uses a composite solution of 0.15% citric acid and 0.2% ascorbic acid as a color-protecting agent, and the graded medicinal materials are completely immersed in the color-protecting liquid at a material-liquid ratio of 1:

3. Ultrasonic-assisted treatment is performed at room temperature, with the ultrasonic power set to 200 W and the treatment time being 10 minutes. Citric acid inhibits the activity of polyphenol oxidase by adjusting the pH value of the solution, and ascorbic acid acts as a reducing agent to consume oxygen in the system. The synergistic effect of the two reduces the oxidative loss of active ingredients during the freeze-drying process, while keeping the surface of the medicinal materials moist and uniform, providing a suitable material state for the subsequent vacuum freeze-drying process.

4. The process for vacuum freeze-drying and ultrafine grinding of traditional medicinal materials and extraction of polysaccharide active ingredients according to claim 1, characterized in that: In step S3, the gradient cooling vacuum freeze-drying requires that the medicinal materials after color protection be spread flat on the freeze-drying tray, and the thickness of the spread shall not exceed 2 cm; the freeze-drying process is divided into three stages: pre-freezing, sublimation drying and desorption drying: the temperature of the pre-freezing stage is set to -30°C and lasts for 2 hours to ensure that the center temperature of the material drops below -25°C; in the sublimation drying stage, the vacuum system is turned on to 10Pa, and the temperature is increased to -10°C at a rate of 1°C / minute and continued for 4 hours; in the desorption drying stage, the temperature is increased to 25°C at a rate of 2°C / minute and continued for 2 hours, and finally the moisture content of the medicinal materials is reduced to below 3%.

5. The process for vacuum freeze-drying and ultrafine grinding of traditional medicinal materials and extraction of polysaccharide active ingredients according to claim 1, characterized in that: In step S4, low-temperature ultrafine airflow pulverization is carried out using an airflow pulverizer. During the pulverization process, the temperature of the pulverization chamber is maintained at no more than 15° C. through a liquid nitrogen pipeline to prevent polysaccharide degradation due to mechanical heat. The pulverization pressure is set to 0.8 MPa, the classification wheel speed is 8000 rpm, and the pulverization is continued until more than 90% of the particles have a particle size of less than 15 μm.

6. The process for vacuum freeze-drying and ultrafine grinding of traditional medicinal materials and extraction of polysaccharide active ingredients according to claim 1, characterized in that: In step S5, the extraction solvent is pre-activated using deionized water as the base solvent, 0.05% Tween-80, 0.03% L-menthol and 0.2% trehalose are added, and the pH is adjusted to 6.5 using a 0.1 mol / L sodium dihydrogen phosphate solution; after the solvent is prepared, it is placed in a constant temperature water bath at 60° C. and stirred for 15 minutes; Tween-80 and L-menthol synergistically reduce the surface tension of the solvent.

7. The process for vacuum freeze-drying and ultrafine grinding of traditional medicinal materials and extraction of polysaccharide active ingredients according to claim 1, characterized in that: In step S6, the pre-activation solvent includes 99.7 parts by weight of deionized water, 0.05 parts by weight of Tween-80, 0.03 parts by weight of L-menthol, 0.2 parts by weight of trehalose, and an appropriate amount of sodium dihydrogen phosphate solution; L-menthol acts as a natural penetration enhancer, enhancing solvent penetration by destroying the lipid bilayer of the medicinal material cell wall; trehalose acts as a non-reducing protective agent, wrapping the polysaccharide molecules to form a hydrated film during the extraction process, thereby inhibiting polysaccharide chain breakage; Tween-80 and L-menthol synergistically reduce the solid-liquid interfacial tension, thereby increasing the specific surface area utilization rate of the ultrafine particles by 20% to 25%; Ultrafine medicinal materials and pre-activated solvent are put into a dynamic countercurrent extraction device; the temperature of the first extraction tank is set at 65°C and the stirring rate is 150 rpm. After 1 hour of extraction, the supernatant of the first stage is pumped into the second extraction tank, and an equal amount of pre-activated solvent is added to the first stage to form a continuous extraction mode of "solvent countercurrent and medicinal materials downstream"; this mode continuously updates the concentration gradient of the solid-liquid interface, thereby increasing the driving force for polysaccharide dissolution by 30% to 40% compared with traditional single-tank extraction, shortening the single-batch extraction time and avoiding the breakage of polysaccharide chains caused by long-term high temperature. It is the core innovation link of the process.

8. The process for vacuum freeze-drying and ultrafine grinding of traditional medicinal materials and extraction of polysaccharide active ingredients according to claim 1, characterized in that: In step S7, the three-stage solid-liquid separation is completed in sequence by coarse filtration, centrifugation and microfiltration: first, the extract is coarsely filtered using a 100-mesh sieve to remove large particle residues; the coarse filtrate is centrifuged at a speed of 4000 rpm for 15 minutes to separate fine particle impurities; the filtrate after centrifugation is microfiltered through a 0.45 μm ceramic membrane, and the permeate is collected.

9. The process for vacuum freeze-drying and ultrafine grinding of traditional medicinal materials and extraction of polysaccharide active ingredients according to claim 1, characterized in that: In step S8, AB-8 macroporous adsorption resin is used for macroporous resin adsorption purification, and the resin column filling height to diameter ratio is 5:

1. The separated extract is passed through the resin column at a flow rate of 2 BV / hour to complete adsorption; after the adsorption is completed, the resin column is rinsed with 5 times the column volume of deionized water to remove small molecular impurities such as monosaccharides and pigments; then the polysaccharide component is eluted with a 40% ethanol solution at a flow rate of 1 BV / hour; the selective adsorption rate of AB-8 resin for polysaccharides can reach more than 92%, and the ethanol elution rate can reach more than 85%. The synergistic effect increases the purity of the polysaccharide from 65% to 70% of the extract to more than 85%.

10. The process for vacuum freeze-drying and ultrafine grinding of traditional medicinal materials and extraction of polysaccharide active ingredients according to claim 1, characterized in that: In step S9, the vacuum low-temperature concentration and drying is divided into two stages: reduced pressure concentration and vacuum freeze drying: first, the purified polysaccharide eluate is placed under reduced pressure and concentrated at -0.09 MPa and 50°C to 1 / 10 of the original volume; then the concentrate is transferred to a vacuum freeze dryer, and the pre-freezing stage temperature is set to -40°C for 2 hours; after the pre-freezing is completed, sublimation drying is carried out under a vacuum degree of 5 Pa for 24 hours, and finally a white to off-white polysaccharide powder is obtained, with a water content of ≤5% and a polysaccharide content of ≥85%; this drying method forms a temperature-vacuum degree gradient connection with the previous vacuum freeze-drying process, ensuring that the active ingredients are in a non-high temperature environment throughout the entire process, thereby retaining the polysaccharide biological activity to the greatest extent.

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