Preparation method of hemsleya amabilis polysaccharide

Abstract

The invention belongs to the technical field of natural plant extraction, and particularly discloses a preparation method of hemsleya amabilis polysaccharide. The preparation method comprises the following steps: (1) crushing medicinal materials; (2) performing ultrahigh-pressure crude extraction; (3) flash extraction; (4) concentrating; (5) drying; and (6) crushing. According to the method, the extraction rate of effective components of hemsleya amabilis polysaccharide is increased, the problems that heat-sensitive polysaccharide is damaged and the extraction rate is low due to a traditional water decoction method are solved, and the purposes of enhancing the curative effect and saving hemsleya amabilis medicinal resources are achieved.

Description

Technical Field

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

[0002] Hemsleya is the dried tuber of Hemsleya sphaerocarpa kuang et A.M.Lu of the Cucurbitaceae family. It is dug in late autumn when the leaves turn yellow, impurities are removed, sliced, and dried. It has the effects of clearing heat and detoxifying, dissipating swelling and nodules, and relieving pain. It is a medicine used by ethnic minorities in Guizhou and is officially recorded on page 327 of the "Quality Standards of Chinese Medicinal Materials and Ethnic Medicinal Materials in Guizhou" in 2003 edition. Modern research shows that hemsleya has activities such as anti-tumor and anti-HIV, and has extremely high medicinal value. Among them, polysaccharide is a main medicinal substance basis of hemsleya.

[0003] Currently, in the existing technology, the extraction of hemsleya polysaccharide mostly uses the water decoction method. Since there are many water-soluble components in hemsleya, the water decoction method has poor specificity. In order to increase the polysaccharide content in the extract, subsequent purification treatment is required, making the extraction process of hemsleya polysaccharide cumbersome and energy-consuming. In addition, the water decoction process requires heating, resulting in the destruction of thermosensitive polysaccharides and seriously reducing the therapeutic effect of hemsleya. Therefore, it is necessary to seek a simple, efficient and low-energy consumption preparation method of hemsleya polysaccharide. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of hemsleya polysaccharide, improve the extraction rate of the effective components of hemsleya polysaccharide, solve the problems of the destruction of thermosensitive polysaccharides and low extraction rate caused by the traditional water decoction method, and achieve the purpose of enhancing the curative effect and saving the medicinal resources of hemsleya.

[0005] In order to achieve the above object, the present invention is realized by the following technical solutions:

[0006] A preparation method of hemsleya polysaccharide, comprising the following steps:

[0007] Step 1, pulverize hemsleya into fine powder passing through 80 - 150 meshes;

[0008] Step 2, add 6 - 10 times the amount of water of the hemsleya fine powder, and extract for 8 - 12 min under a pressure of 300 - 400 MPa;

[0009] Step 3, continue to extract for 2 - 15 min under the conditions of an initial temperature of 30 - 45 °C and a voltage of 80 - 140 V, centrifuge and filter to obtain a filtrate;

[0010] Step 4, concentrate the filtrate into a thick paste under the conditions of a temperature of 50 - 60 °C and a pressure of - 0.04 to - 0.08 MPa;

[0011] Step 5: Dry the thick paste at a temperature of 50 - 60°C and a pressure of -0.04 to -0.08 MPa to obtain a dry paste;

[0012] Step 6: Crush the dry paste into fine powder in an environment with a relative humidity of 25% - 45% to obtain the product.

[0013] Preferably, Step 1 of the present invention is: Crush Hemsleya into fine powder passing through 100 - mesh sieve.

[0014] Preferably, Step 2 of the present invention is: Add water in an amount 6 - 8 times that of the Hemsleya fine powder, and extract at a pressure of 350 - 400 MPa for 10 - 12 minutes.

[0015] Preferably, Step 2 of the present invention is: Add water in an amount 6 times that of the Hemsleya fine powder, and extract at a pressure of 400 MPa for 12 minutes.

[0016] Preferably, Step 3 of the present invention is: Continue to extract for 5 - 15 minutes at an initial temperature of 35 - 45°C and a voltage of 100 - 140V, then centrifuge and filter to obtain a filtrate.

[0017] Preferably, Step 3 of the present invention is: Continue to extract for 5 - 10 minutes at an initial temperature of 40 - 45°C and a voltage of 100 - 120V, then centrifuge and filter to obtain a filtrate.

[0018] Preferably, Step 3 of the present invention is: Continue to extract for 5 minutes at an initial temperature of 40°C and a voltage of 100V, then centrifuge and filter to obtain a filtrate.

[0019] Preferably, Step 4 of the present invention is: Concentrate the filtrate to a thick paste at a temperature of 50°C and a pressure of -0.08 MPa.

[0020] Preferably, Step 5 of the present invention is: Dry the thick paste at a temperature of 60°C and a pressure of -0.04 MPa to obtain a dry paste.

[0021] Preferably, Step 6 of the present invention is: Crush the dry paste into fine powder in an environment with a relative humidity of 35% to obtain the product.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. The extraction rate of hemsleya polysaccharide is high. Through experimental research and comparison, the present invention has compared various extraction methods such as traditional water decoction method, flash extraction method, fermentation method and enzymatic hydrolysis method. Among the five single extraction methods with the same comparison, the extraction rate of hemsleya polysaccharide by the ultra-high pressure extraction method (3.42 mg / ml) > fermentation method (2.16 mg / ml) > water decoction method (1.53 mg / ml) > enzymatic hydrolysis method (1.42 mg / ml) > flash extraction method (1.36 mg / ml). After adopting the "flash extraction assisted ultra-high pressure extraction method" of the present invention, the extraction rate of hemsleya polysaccharide is as high as 4.35 mg / ml.

[0024] 2. The content of the active ingredient hemsleya polysaccharide extracted is high. Through detection, for the hemsleya extract prepared by the present invention, the polysaccharide content is about 35%, and the existing extraction technologies have not reached this content level, maximizing the enrichment of the active ingredient content.

[0025] 3. The extraction time is short and the efficiency is high. Among the extraction methods with the same comparison, the "flash extraction assisted ultra-high pressure extraction method" not only has the highest extraction rate of hemsleya polysaccharide, but also has the shortest extraction time (20 minutes), which is a low-cost and high-efficiency extraction method. Specific implementation mode

[0026] Example 1 Preparation method of hemsleya polysaccharide

[0027] (1) Medicinal material pulverization

[0028] Pulverize hemsleya into fine powder passing through 100 meshes.

[0029] (2) Ultra-high pressure extraction

[0030] Add water 6 times the amount of hemsleya fine powder and extract at a pressure of 400 MPa for 12 minutes.

[0031] (3) Flash extraction

[0032] Under the conditions of an initial extraction temperature of 40 °C and an extraction voltage of 100 V, extract for 5 minutes, centrifuge and filter to obtain a filtrate.

[0033] (4) Concentration

[0034] Concentrate the filtrate to a thick paste at a temperature of 50 °C and a pressure of -0.08 MPa.

[0035] (5) Drying

[0036] Dry the thick paste at a temperature of 60 °C and a pressure of -0.04 MPa to obtain a dry paste.

[0037] (6) Pulverization

[0038] Pulverize the dry paste into fine powder at an environmental relative humidity of 35% to obtain the product.

[0039] Example 2 Preparation method of hemsleya polysaccharide

[0040] (1) Medicinal material pulverization

[0041] Pulverize hemsleya chinensis into fine powder passing through 100 meshes.

[0042] (2) Ultra-high pressure extraction

[0043] Add water 8 times the amount of hemsleya chinensis fine powder and extract for 10 minutes under a pressure of 350 MPa.

[0044] (3) Flash extraction

[0045] Under the conditions of an initial extraction temperature of 35°C and an extraction voltage of 100 V, extract for 5 minutes, centrifuge and filter to obtain a filtrate.

[0046] (4) Concentration

[0047] Concentrate the filtrate to a thick paste under the conditions of a temperature of 60°C and a pressure of -0.06 MPa.

[0048] (5) Drying

[0049] Dry the thick paste under the conditions of a temperature of 50°C and a pressure of -0.04 MPa to obtain a dry paste.

[0050] (6) Pulverization

[0051] Pulverize the dry paste into fine powder at an environmental relative humidity of 45% to obtain the product.

[0052] Preparation method of hemsleya chinensis polysaccharide in Example 3

[0053] (1) Medicinal material pulverization

[0054] Pulverize hemsleya chinensis into fine powder passing through 100 meshes.

[0055] (2) Ultra-high pressure extraction

[0056] Add water 6 times the amount of hemsleya chinensis fine powder and extract for 8 minutes under a pressure of 300 MPa.

[0057] (3) Flash extraction

[0058] Under the conditions of an initial extraction temperature of 30°C and an extraction voltage of 80 V, extract for 2 minutes, centrifuge and filter to obtain a filtrate.

[0059] (4) Concentration

[0060] Concentrate the filtrate to a thick paste under the conditions of a temperature of 50°C and a pressure of -0.04 MPa.

[0061] (5) Drying

[0062] Dry the thick paste under the conditions of a temperature of 50°C and a pressure of -0.06 MPa to obtain a dry paste.

[0063] (6) Pulverization

[0064] The dry extract is pulverized into fine powder at an environmental relative humidity of 25% to obtain the product.

[0065] Preparation method of hemsleya polysaccharide in Example 4

[0066] (1) Medicinal material pulverization

[0067] The hemsleya is pulverized into fine powder passing through 120 meshes.

[0068] (2) Ultra-high pressure extraction

[0069] Add water 6 times the amount of the hemsleya fine powder and extract for 12 minutes at a pressure of 400 MPa.

[0070] (3) Flash extraction

[0071] Under the conditions of an initial extraction temperature of 35°C and an extraction voltage of 120 V, extract for 10 minutes, centrifuge and filter to obtain the filtrate.

[0072] (4) Concentration

[0073] The filtrate is concentrated to a thick paste at a temperature of 60°C and a pressure of -0.06 MPa.

[0074] (5) Drying

[0075] The thick paste is dried to obtain the dry extract at a temperature of 50°C and a pressure of -0.04 MPa.

[0076] (6) Pulverization

[0077] The dry extract is pulverized into fine powder at an environmental relative humidity of 35% to obtain the product.

[0078] Preparation method of hemsleya polysaccharide in Example 5

[0079] (1) Medicinal material pulverization

[0080] The hemsleya is pulverized into fine powder passing through 150 meshes.

[0081] (2) Ultra-high pressure extraction

[0082] Add water 8 times the amount of the hemsleya fine powder and extract for 10 minutes at a pressure of 350 MPa, then filter.

[0083] (3) Flash extraction

[0084] Under the conditions of an initial extraction temperature of 45°C and an extraction voltage of 100 V, extract for 10 minutes, centrifuge and filter to obtain the filtrate.

[0085] (4) Concentration

[0086] The filtrate is concentrated to a thick paste at a temperature of 50°C and a pressure of -0.08 MPa.

[0087] (5) Drying

[0088] The thick paste is dried under the conditions of a temperature of 60°C and a pressure of -0.04 MPa to obtain a dry paste.

[0089] (6) Crushing

[0090] The dry paste is crushed into fine powder at an ambient relative humidity of 35% to obtain the product.

[0091] Preparation method of hemsleya polysaccharide in Example 6

[0092] (1) Medicinal material crushing

[0093] Hemsleya is crushed into fine powder passing through 100 meshes.

[0094] (2) Ultra-high pressure extraction

[0095] Add water 10 times the amount of the hemsleya fine powder, and extract for 12 minutes at a pressure of 400 MPa, then filter.

[0096] (3) Flash extraction

[0097] Under the conditions of an initial extraction temperature of 45°C and an extraction voltage of 140 V, extract for 15 minutes, then centrifuge and filter to obtain the filtrate.

[0098] (4) Concentration

[0099] The filtrate is concentrated to a thick paste under the conditions of a temperature of 50°C and a pressure of -0.08 MPa.

[0100] (5) Drying

[0101] The thick paste is dried under the conditions of a temperature of 60°C and a pressure of -0.08 MPa to obtain a dry paste.

[0102] (6) Crushing

[0103] The dry paste is crushed into fine powder at an ambient relative humidity of 25% to obtain the product.

[0104] Preparation method of hemsleya polysaccharide in Example 7

[0105] (1) Medicinal material crushing

[0106] Hemsleya is crushed into fine powder passing through 100 meshes.

[0107] (2) Ultra-high pressure extraction

[0108] Add water 6 times the amount of the hemsleya fine powder, and extract for 8 minutes at a pressure of 300 MPa.

[0109] (3) Flash extraction

[0110] Under the conditions of an initial extraction temperature of 35°C and an extraction voltage of 100 V, extract for 5 minutes, then centrifuge and filter to obtain the filtrate.

[0111] (4) Concentration

[0112] The filtrate is concentrated to a thick paste at a temperature of 60°C and a pressure of -0.06 MPa.

[0113] (5) Drying

[0114] The thick paste is dried at a temperature of 50°C and a pressure of -0.04 MPa to obtain a dry paste.

[0115] (6) Pulverization

[0116] The dry paste is pulverized into fine powder at an ambient relative humidity of 30% to obtain the product.

[0117] Example 8 Preparation method of hemsleya polysaccharide

[0118] (1) Medicinal material pulverization

[0119] Hemsleya is pulverized into fine powder passing through 100 meshes.

[0120] (2) Ultra-high pressure extraction

[0121] Add water 8 times the amount of hemsleya fine powder, extract for 10 minutes under a pressure of 350 MPa, and filter.

[0122] (3) Flash extraction

[0123] Under the conditions of an initial extraction temperature of 40°C and an extraction voltage of 120 V, extract for 10 minutes, centrifuge and filter to obtain the filtrate.

[0124] (4) Concentration

[0125] The filtrate is concentrated to a thick paste at a temperature of 50°C and a pressure of -0.06 MPa.

[0126] (5) Drying

[0127] The thick paste is dried at a temperature of 60°C and a pressure of -0.04 MPa to obtain a dry paste.

[0128] (6) Pulverization

[0129] The dry paste is pulverized into fine powder at an ambient relative humidity of 40% to obtain the product.

[0130] In order to further verify the feasibility and effectiveness of the present invention and screen out the best scheme, a series of tests were carried out for the present invention, and some test excerpts are as follows:

[0131] I. Extraction process research

[0132] 1. Comparison of hemsleya polysaccharide extraction methods

[0133] 1.1 Single extraction method

[0134] (1) Decoction method

[0135] Take 100 g of Hemsleya chinensis, pulverize it into fine powder of 100 mesh, add 8 times the amount of water, decoct for 30 minutes, filter, concentrate the filtrate and make up the volume to 500 ml, and determine the polysaccharide content. The results are shown in Table 1.

[0136] (2) Flash extraction method

[0137] Take 100 g of Hemsleya chinensis, pulverize it into fine powder of 100 mesh, add 8 times the amount of water, under the conditions of an initial extraction temperature of 40 °C and an extraction voltage of 120 V, extract for 10 minutes, centrifuge and filter, concentrate the filtrate and make up the volume to 500 mL, and determine the polysaccharide content. The results are shown in Table 1.

[0138] (3) Enzymatic hydrolysis method

[0139] Take 100 g of Hemsleya chinensis, pulverize it into fine powder of 100 mesh, add 8 times the amount of water and 2% cellulase, enzymatically hydrolyze at 50 °C and a pH value of 5.0 for 24 hours, filter, concentrate the filtrate and make up the volume to 500 mL, and determine the polysaccharide content. The results are shown in Table 1.

[0140] (4) Ultra-high pressure method

[0141] Take 100 g of Hemsleya chinensis, pulverize it into fine powder of 100 mesh, add 8 times the amount of water, extract at a pressure of 300 MPa for 10 minutes, filter, concentrate the filtrate and make up the volume to 500 mL, and determine the polysaccharide content. The results are shown in Table 1.

[0142] (5) Fermentation method

[0143] Take 100 g of Hemsleya chinensis, pulverize it into fine powder of 100 mesh, add 8 times the amount of water, add 10% starch, stir well, inoculate Lactobacillus acidophilus, the inoculum amount is 3×10 6 CFU / mL, ferment at 40 °C for 2 days, filter, concentrate the filtrate and make up the volume to 500 mL, and determine the polysaccharide content. The results are shown in Table 1.

[0144] 1.2 Method for determining polysaccharide content

[0145] Accurately weigh 0.10 g of anhydrous glucose reference substance dried to constant weight, make it into a reference substance solution of 0.20 mg / mL with distilled water. Absorb the reference substance solution and dilute it to solutions of 0.05, 0.10, 0.15, and 0.20 mg / mL respectively. Absorb 1 mL of the above solutions, add 4 mL of 5% phenol solution, then add 5 mL of concentrated sulfuric acid, shake well, keep it in a water bath at 40 °C for 30 min, cool to room temperature, use the blank solution added with distilled water as a control, and measure the absorbance at a wavelength of 490 nm. Taking the glucose concentration as the abscissa and the absorbance as the ordinate, the regression equation is Y = 8.142X + 0.0113 (R 2 = 0.9998), and the linear relationship is good.

[0146] Absorb 0.5 mL of the extracts obtained by different extraction methods, dilute them to 10 mL with distilled water, then take 1 mL and perform the operation from "add 4 mL of 5% phenol solution" according to the above method to determine the polysaccharide content in the extracts of different extraction methods. The results are shown in Table 1.

[0147] Table 1 Polysaccharide content in the extracts of different extraction methods

[0148]

[0149] The test results show that among the five extraction methods with the same comparison, the polysaccharide extraction rate of the ultra-high pressure extraction method > fermentation method > water decoction method > enzymatic hydrolysis method > flash extraction method.

[0150] 1.3 Flash extraction-assisted ultra-high pressure combined extraction method

[0151] From the test results of the single extraction method in Table 1, it can be seen that the ultra-high pressure extraction method has the highest extraction rate of hemsleya polysaccharide and should be preferred as the best extraction method. Although the flash extraction method has the lowest extraction efficiency, its extraction time is short and the operation is simple. It is a very economical and practical extraction method and can be considered as an auxiliary extraction method for ultra-high pressure extraction, that is, first extract hemsleya by ultra-high pressure and then further perform flash extraction to further improve the extraction rate of hemsleya polysaccharide. To verify the above idea, the following tests were carried out in this study:

[0152] Take 100 g of hemsleya, crush it into fine powder of 100 meshes, add 8 times the amount of water, extract at a pressure of 300 MPa for 10 minutes, and then under the conditions of an initial extraction temperature of 40 °C and an extraction voltage of 120 V, extract for 10 minutes, centrifuge and filter, concentrate the filtrate and make the volume constant to 500 mL, and determine the polysaccharide content. The detection result shows that the polysaccharide content in the extract is 4.35 mg / mL. Compared with the single ultra-high pressure extraction method, the polysaccharide content in the extract has increased significantly, indicating that the flash extraction-assisted ultra-high pressure combined extraction method is reasonable and feasible.

[0153] 2. Optimization of the best process parameters of the ultra-high pressure extraction method for hemsleya polysaccharide

[0154] The main factors affecting the ultra-high pressure extraction effect are the amount of water added, extraction pressure and extraction time. To determine the best process parameters of each factor for the extraction of hemsleya polysaccharide, single factor and orthogonal tests were carried out in this study.

[0155] 2.1 Single factor investigation

[0156] (1) Amount of water added

[0157] Take 10 g of hemsleya powder passing through 100 meshes, divide it into 5 portions, add 4 times, 8 times, 12 times, 16 times and 20 times the amount of water respectively, extract at a pressure of 300 MPa for 10 min, filter, concentrate (or dilute) the filtrate and make the volume constant to 50 mL, and determine the polysaccharide content in the extract. The results are shown in Table 2.

[0158] Table 2 Influence of Different Water Addition Amounts on the Content of Hemsleya polysaccharide Extracted by Ultra-high Pressure

[0159]

[0160] The test results show that when the water addition amount is more than 8 times, the increase of Hemsleya polysaccharide in the extract is slow, and the water addition amount of 8 times can be selected to carry out the orthogonal test.

[0161] (2) Extraction Pressure

[0162] Take 10 g of Hemsleya powder passing through 100 meshes, 5 portions. After adding 8 times of water, extract for 10 min under the conditions of pressures of 50 MPa, 150 MPa, 250 MPa, 350 MPa and 450 MPa respectively, filter, concentrate and make the volume constant to 50 mL for the filtrate, and determine the polysaccharide content in the extract. The results are shown in Table 3.

[0163] Table 3 Influence of Different Extraction Pressures on the Content of Hemsleya polysaccharide Extracted by Ultra-high Pressure

[0164]

[0165] The test results show that when the extraction pressure reaches above 350 MPa, the increase of Hemsleya polysaccharide in the extract is slow, and the pressure of 350 MPa can be selected to carry out the orthogonal test.

[0166] (3) Extraction Time

[0167] Take 10 g of Hemsleya powder passing through 100 meshes, 5 portions. After adding 8 times of water, extract for 2 min, 6 min, 10 min, 14 min and 18 min respectively under the condition of pressure of 350 MPa, filter, concentrate and make the volume constant to 50 mL for the filtrate, and determine the polysaccharide content in the extract. The results are shown in Table 4.

[0168] Table 4 Influence of Different Extraction Times on the Content of Hemsleya polysaccharide Extracted by Ultra-high Pressure

[0169]

[0170] The test results show that when the extraction time reaches above 10 min, the amplitude of Hemsleya polysaccharide in the extract is not large, and the extraction time of 10 min can be selected to carry out the orthogonal test.

[0171] 2.2 Orthogonal Test

[0172] (1) Factor-Level Table

[0173] On the basis of single-factor experiments, the orthogonal test is adopted to optimize the ultra-high pressure extraction process conditions of Hemsleya polysaccharide. The experimental factors and levels are shown in Table 5.

[0174] Table 5 Factor-Level Table of Orthogonal Test

[0175]

[0176] (2) Sample preparation

[0177] Take 10 g of Hemsleya powder passing through 100 meshes, conduct extraction experiments according to the corresponding parameters in the orthogonal experiment table (Table 6), filter, concentrate the filtrate and make up the volume to 50 mL, and determine the polysaccharide content in the extract.

[0178] (3) Test results

[0179] The results of the orthogonal experiment are shown in Table 6, and the variance analysis is shown in Table 7.

[0180] Table 6 Results of orthogonal experiment

[0181]

[0182]

[0183] Table 7 Variance analysis table

[0184]

[0185] Note: F0.05(2,2) = 19.00;

[0186] It can be seen from the test results in Table 6 and the variance analysis results in Table 7 that the primary and secondary effects of each factor are C > B > A; there are significant differences in factors B and C, and there is no significant difference in factor A. Among factor A, A3 > A2 > A1, among factor B, B3 > B2 > B1, and among factor C, C3 > C2 > C1. Therefore, the optimal process parameters obtained from the variance analysis are A3B3C3. Considering that there is no significant difference in factor A, from the perspective of saving production costs and reducing energy consumption, A1 is selected as the parameter. Therefore, the optimal process parameters are adjusted to A1B3C3, that is, adding 6 times the amount of water and extracting for 12 min under the condition of a pressure of 400 MPa.

[0187] (4) Orthogonal verification experiment

[0188] Take 10 g of Hemsleya powder passing through 100 meshes, 4 portions, conduct extraction verification experiments according to the parameters in Table 8, and the results are shown in Table 8.

[0189] Table 8 Results of orthogonal experiment verification

[0190]

[0191] The results of the verification experiment show that the extraction effects of A1B3C3 and A3B3C3 are equivalent, indicating that the process of A1B3C3 is reasonable and feasible.

[0192] 3. Optimization of the optimal process parameters for flash extraction assisted extraction

[0193] The factors affecting the flash extraction-assisted extraction effect mainly include extraction temperature, voltage, and extraction time. To determine the optimal process parameters for each factor, the following experiments were conducted separately in this study.

[0194] 3.1 Extraction temperature

[0195] Take 10 g of snowbell root powder passed through 100-mesh sieve, in 4 portions, add 6 times the amount of water, extract for 12 min under the condition of a pressure of 400 MPa, and then under the conditions of initial temperatures of 30 °C, 35 °C, 40 °C, and 45 °C respectively, extract for 10 minutes with a voltage of 120 V, centrifuge and filter, concentrate the filtrate and make up the volume to 500 mL, and determine the content of snowbell polysaccharide. The results are shown in Table 9.

[0196] Table 9 Effects of different extraction temperatures on the content of snowbell polysaccharide

[0197]

[0198] The experimental results show that the extraction rate of snowbell polysaccharide increases with the increase of extraction temperature, but the extraction rate changes little after the temperature reaches 35 °C. According to the experimental data, 40 °C can be selected as the optimal process parameter.

[0199] 3.2 Extraction voltage

[0200] Take 10 g of snowbell root powder passed through 100-mesh sieve, in 4 portions, add 6 times the amount of water, extract for 12 min under the condition of a pressure of 400 MPa, and then under the condition of an initial temperature of 40 °C, extract for 10 minutes with voltages of 80 V, 100 V, 120 V, and 140 V respectively, centrifuge and filter, concentrate the filtrate and make up the volume to 500 mL, and determine the content of snowbell polysaccharide. The results are shown in Table 10.

[0201] Table 10 Effects of different extraction voltages on the content of snowbell polysaccharide

[0202]

[0203] The experimental results show that the extraction rate of snowbell polysaccharide is relatively high and stable at 100 V - 140 V. Therefore, 100 V can be selected as the optimal process parameter.

[0204] 3.3 Extraction time

[0205] Take 10 g of snowbell root powder passed through 100-mesh sieve, in 4 portions, add 6 times the amount of water, extract for 12 min under the condition of a pressure of 400 MPa, and then under the condition of an initial temperature of 40 °C, extract for 2 minutes, 5 minutes, 10 minutes, and 15 minutes respectively with a voltage of 120 V, centrifuge and filter, concentrate the filtrate and make up the volume to 500 mL, and determine the content of snowbell polysaccharide. The results are shown in Table 11.

[0206] Table 11 Effects of different extraction times on the content of snowbell polysaccharide

[0207]

[0208] The test results show that the content change range of hemsleyan polysaccharide in the extract is not significant after 5 minutes of extraction. Therefore, 5 min can be selected as the optimal process parameter.

[0209] 4. Optimization of concentration process

[0210] Vacuum concentration is the most commonly used way to concentrate the extract at present. The main factors affecting the concentration effect are the concentration temperature and the vacuum degree. In order to reduce the damage of high temperature to thermosensitive polysaccharide, in this study, two temperatures of 50 °C and 60 °C were selected, and the concentration was carried out under the conditions of -0.04 MPa, -0.06 MPa and -0.08 MPa respectively. The content of hemsleyan polysaccharide in the thick extract was used as the index to optimize the best concentration process parameters.

[0211] Weigh 1200 g of fine hemsleya powder passing through 100 meshes, add 6 times the amount of water, extract for 12 min under the condition of a pressure of 400 MPa, then extract ultrasonically for 10 minutes under the condition of an ultrasonic power of 250 W, filter, divide the filtrate into 6 equal parts on average, concentrate to a thick paste according to the parameters in Table 12, and determine the content of hemsleyan polysaccharide in the thick paste. The results are shown in Table 12.

[0212] Table 12 Results of optimization of concentration process

[0213]

[0214] The test results show that the content of hemsleyan polysaccharide in the extracts after concentration in each test is not much different, indicating that the temperatures and vacuum degrees selected in this study are reasonable and feasible.

[0215] 5. Optimization of drying process

[0216] Vacuum drying is the most commonly used way to dry polysaccharide at present. The main influencing factors are the temperature and the vacuum degree. In order to reduce the damage of high temperature to thermosensitive polysaccharide, in this study, two temperatures of 50 °C and 60 °C were selected, and the drying was carried out under the conditions of -0.04 MPa, -0.06 MPa and -0.08 MPa respectively. The content of hemsleyan polysaccharide in the dry extract, the drying time and the color of the extract were used as the indexes to optimize the best drying process parameters.

[0217] Mix the thick paste prepared by "optimization of concentration process", divide it into 6 equal parts on average, dry according to the parameters in Table 12, and determine the content of hemsleyan polysaccharide in the dry paste. The results are shown in Table 13.

[0218] Table 13 Results of optimization of drying process

[0219]

[0220] The test results show that the selected temperature and vacuum degree in this study have little effect on the content of hemsleyan polysaccharide in the dry extract, and there is no obvious difference in the color of the dry extract. Only the higher the temperature and the greater the vacuum degree, the shorter the drying time. Generally speaking, it is reasonable and feasible to choose vacuum drying method to dry the thick extract of hemsleyan polysaccharide.

[0221] 6. Investigation on the pulverization process of dry extract

[0222] Due to the strong hygroscopicity of polysaccharide substances, the relative humidity of the environment should be strictly controlled during pulverization. In this study, the pulverization effects of hemsleya dry extract in environments with different relative humidities were compared, and the results are shown in Table 14.

[0223] Table 14 Results of the investigation on the pulverization process

[0224]

[0225]

[0226] The test results show that when the relative humidity of the environment reaches 55%, there is a phenomenon of moisture absorption and caking during sieving after the hemsleyan polysaccharide dry extract is pulverized. When the relative humidity of the environment reaches 65%, it is difficult to pulverize. According to the test results, the relative humidity of the pulverization environment should be controlled between 25% - 45%, and preferably 35%.

[0227] Although the present invention has been described in detail above with general descriptions, specific embodiments and tests, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A method for preparing snow dandelion polysaccharide, characterized in that: The following steps are involved: Step 1: crush the snow gall into 80-150 mesh fine powder; Step 2, adding 6 to 10 times the amount of water as the fine powder of snow gall, and extracting at a pressure of 300 to 400 MPa for 8 to 12 minutes; Step 3, continue extraction for 2-15 minutes at an initial temperature of 30-45°C and a voltage of 80-140V, and centrifuge to obtain a filtrate; Step 4, concentrating the filtrate to a thick paste at a temperature of 50-60°C and a pressure of -0.04 to -0.08 MPa; Step 5, drying the thick paste at a temperature of 50-60° C. and a pressure of -0.04 to -0.08 MPa to obtain a dry paste; Step six, crush the dry paste into fine powder under a relative humidity of 25%-45%.

2. The method for preparing the snow dandelion polysaccharide according to claim 1, characterized in that: The step 1 is: crushing the snow gall into fine powder with a mesh size of 100.

3. The method for preparing snow dandelion polysaccharide according to claim 1, characterized in that: The second step is: adding 6 to 8 times the amount of water as the snow bile fine powder, and extracting for 10 to 12 minutes at a pressure of 350 to 400 MPa.

4. The method for preparing snow bile polysaccharide according to claim 3, characterized in that: The second step is: adding 6 times the amount of water as the snow bile fine powder, and extracting for 12 minutes under a pressure of 400 MPa.

5. The method for preparing snow dandelion polysaccharide according to claim 1, characterized in that: The step three is: continue to extract for 5-15 minutes under the conditions of initial temperature of 35-45° C. and voltage of 100-140 V, and centrifuge and filter to obtain a filtrate.

6. The method for preparing snow dandelion polysaccharide according to claim 5, characterized in that: The step three is: continue to extract for 5-10 minutes under the conditions of an initial temperature of 40-45° C. and a voltage of 100-120 V, and centrifuge and filter to obtain a filtrate.

7. The method for preparing snow dandelion polysaccharide according to claim 6, characterized in that: The step three is: continue to extract for 5 minutes under the conditions of an initial temperature of 40° C. and a voltage of 100 V, and centrifuge and filter to obtain a filtrate.

8. The method for preparing snow dandelion polysaccharide according to claim 1, characterized in that: The step 4 is: concentrating the filtrate to a thick paste at a temperature of 50° C. and a pressure of -0.08 MPa.

9. The method for preparing snow dandelion polysaccharide according to claim 1, characterized in that: The step five is: drying the thick paste at a temperature of 60° C. and a pressure of -0.04 MPa to obtain a dry paste.

10. The method for preparing snow dandelion polysaccharide according to claim 1, characterized in that: The step six is: crushing the dry paste into fine powder under a relative humidity of 35%.

Images