A method for reducing the viscosity of carboxymethyl pachymaran solution

Abstract

The present invention discloses a method for regulating the viscosity of a carboxymethyl tuckahoe polysaccharide solution, which comprises preparing a carboxymethyl tuckahoe polysaccharide solution of a preset concentration; the preset concentration is within 50 mg / ml; high temperature treatment is used until the carboxymethyl tuckahoe polysaccharide solution becomes clear from turbidity, and cooled to room temperature; the viscosity of the carboxymethyl tuckahoe polysaccharide solution is reduced by more than 70%. The regulating method provided by the present invention can significantly reduce the viscosity of the CMP solution and cause little damage to the structure of the carboxymethyl tuckahoe polysaccharide, or even do not damage its structure, especially high temperature and high pressure homogenization combined treatment can make the CMP solution of high mass concentration flow from extremely viscous and have no obvious effect on its structure, which can significantly improve the solubility of CMP and is conducive to promotion and application.

Description

Technical Field

[0001] The invention belongs to the field of food processing, and more specifically, relates to a method for regulating the viscosity of a carboxymethyl pachymaran solution. Background Art

[0002] Poria polysaccharide (PCP) is the main component of Poria cocos, accounting for about 80% of its dry weight. It is mainly composed of linear β (1→3) -D-glucan, containing a small amount of β-(1-6) glycosidic bond side chains. Its conformation is generally a triple helix conformation and is insoluble in water. Since Poria polysaccharide is insoluble in water, its processing and utilization are greatly limited. In order to improve the processing and utilization rate of Poria polysaccharide, existing research mainly modifies Poria polysaccharide by introducing hydrophilic groups instead of hydroxyl groups in the sugar chain, such as sulfation, selenization and carboxymethylation, to improve its water solubility. Among them, it is more common to introduce carboxylmethyl groups on the sugar chain of Poria polysaccharide to prepare carboxymethyl Poria polysaccharide (CMP). Although the solubility of carboxymethyl Poria polysaccharide is significantly improved, its solubility performance is still very poor. Generally, the carboxymethyl Poria polysaccharide solution with a mass concentration of 3-4 mg / ml is viscous.

[0003] In recent years, CMP has been widely studied for its various biological activities, but its high molecular weight and high viscosity lead to poor processing performance, especially its high viscosity greatly limits its application in the food industry. Although studies have shown that the viscosity of astragalus polysaccharides can be reduced by physical means of γ-irradiation, the degree of reduction is limited. For example, after irradiation with a maximum irradiation dose of 150kGy, the viscosity of astragalus polysaccharides under steady-state conditions is reduced from 0.08Pa.s to about 0.035Pa.s, which is only a 56% reduction. At the same time, high-dose irradiation will also significantly degrade astragalus polysaccharides, destroy their polysaccharide structure, and even affect their biological activity. Therefore, studying a regulation method that has little effect on the structure of CMP and can significantly reduce its viscosity is conducive to promoting the research and application of CMP. Summary of the invention

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides a method for adjusting the viscosity of a carboxymethyl tuckahoe polysaccharide solution, the purpose of which is to find that high-temperature treatment can make a high-concentration carboxymethyl tuckahoe polysaccharide solution change from viscous to fluid, and the viscosity can be reduced by more than 70% and the effect on the structure of the carboxymethyl tuckahoe polysaccharide is small, especially by high-temperature treatment at 115-135°C and heat preservation for 10-30 minutes, the viscosity of the carboxymethyl tuckahoe polysaccharide solution can be reduced by 80%-90%, which is significantly better than the existing high-dose irradiation treatment polysaccharide solution. Thus, the technical problems of high viscosity and low utilization rate of the existing carboxymethyl tuckahoe polysaccharide solution are solved.

[0005] To achieve the above object, according to one aspect of the present invention, a method for reducing the viscosity of a carboxymethyl pachymaran solution is provided, which comprises the following steps:

[0006] Prepare a carboxymethyl pachymaran solution of a preset concentration; the preset concentration is within 50 mg / ml;

[0007] Treating with high temperature until the carboxymethyl pachymaran solution changes from turbid to clear, and cooling to room temperature;

[0008] The viscosity of the carboxymethyl pachymaran solution is reduced by more than 70%.

[0009] Preferably, in the method for reducing the viscosity of the carboxymethyl pachymaran solution, the high temperature treatment is performed at a temperature of 115 to 135° C. and a heat preservation time of 10 to 30 minutes.

[0010] Preferably, the method for reducing the viscosity of the carboxymethyl tuckahoe polysaccharide solution comprises the following steps: after high temperature treatment, the cooled carboxymethyl tuckahoe polysaccharide solution is subjected to high pressure homogenization combined treatment to improve fluidity;

[0011] The viscosity of the cooled carboxymethyl pachymaran solution is 0.01-0.15 Pa.s;

[0012] The high pressure homogenization has a homogenization pressure of 10 MPa to 40 MPa.

[0013] Preferably, the method for reducing the viscosity of the carboxymethyl tuckahoe polysaccharide solution is to firstly perform irradiation combined treatment when the viscosity of the carboxymethyl tuckahoe polysaccharide solution is above 0.15 Pa.s after high temperature treatment, and then perform high pressure homogenization combined treatment on the cooled carboxymethyl tuckahoe polysaccharide solution;

[0014] The irradiation has an irradiation dose of 5 to 30 kGy and an irradiation time of 1 to 12 hours.

[0015] Preferably, in the method for reducing the viscosity of the carboxymethyl pachymaran solution, the high temperature treatment is 121°C and the insulation time is 20 to 30 minutes; when the high-pressure homogenization adopts liquid pressurization, the homogenization pressure is 10 to 40 MPa, the liquid flow rate is 5 to 10 L / h, and the cycle is 2 to 6 times.

[0016] Preferably, in the method for reducing the viscosity of the carboxymethyl pachymaran solution, the high-pressure homogenization has a homogenization pressure of 30 to 40 MPa, a flow rate of 8 to 10 L / h, and is circulated 3 to 5 times.

[0017] Preferably, in the method for reducing the viscosity of the carboxymethyl tuckahoe polysaccharide solution, the viscosity of the carboxymethyl tuckahoe polysaccharide solution is 0.15-0.3 Pa.s after high temperature treatment; and the irradiation has an irradiation dose of 10-20 kGy and an irradiation time of 2-9 h.

[0018] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0019] The present invention provides a method for regulating the viscosity of a carboxymethyl tuckahoe polysaccharide solution. By treating the carboxymethyl tuckahoe polysaccharide solution with high temperature, the solution can be changed from viscous to fluid, the viscosity of the solution is reduced by more than 70% and the structure of the carboxymethyl tuckahoe polysaccharide is almost not damaged. After high temperature treatment, the viscosity of the carboxymethyl tuckahoe polysaccharide solution is significantly reduced, that is, the solubility of the carboxymethyl tuckahoe polysaccharide is significantly improved, which is beneficial to improving its utilization rate. The existing carboxymethyl tuckahoe polysaccharide solution with a concentration of 3 to 4 mg / ml is viscous, and the regulating method provided by the present invention can make the carboxymethyl tuckahoe polysaccharide solution with a concentration of 5 to 50 mg / ml be in a fluid solution state, which is beneficial to promoting the application of carboxymethyl tuckahoe polysaccharide.

[0020] According to a preferred embodiment, the present invention can adjust the solution of carboxymethyl pachymaran to a corresponding viscosity range according to the application requirements of the carboxymethyl pachymaran, cooperate with product development and well maintain the biological activity of the carboxymethyl pachymaran. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the result of measuring the viscosity of carboxymethyl tuckahoe polysaccharide solution after different high temperature treatments;

[0022] Figure 1 Middle curves 1-6 represent control group 1, control group 2, high temperature group 1, high temperature group 2, high temperature group 3, and high temperature group 4, respectively;

[0023] Figure 2 It is the result of measuring the viscosity of carboxymethyl tuckahoe polysaccharide solution after different high temperature-high pressure homogenization combined treatments;

[0024] Figure 2 Middle curves 1-4 represent the control group, high temperature-homogeneous group 1, high temperature-homogeneous group 2, and high temperature-homogeneous group 3, respectively;

[0025] Figure 3 It is the result of measuring the viscosity of carboxymethyl tuckahoe polysaccharide solution after different high temperature-irradiation-high pressure homogenization combined treatments;

[0026] Figure 3 Middle curves 1-4 represent the control group, high temperature-irradiation-homogenization group 1, high temperature-irradiation-homogenization group 2, and high temperature-irradiation-homogenization group 3, respectively;

[0027] Figure 4 It is the infrared spectra of carboxymethyl tuckahoe polysaccharide homogenized at high temperature and high pressure, irradiated and untreated;

[0028] Figure 4 Medium CMP is untreated carboxymethyl tuckahoe polysaccharide; HT-CMP is carboxymethyl tuckahoe polysaccharide after high temperature treatment; HP-CMP is carboxymethyl tuckahoe polysaccharide after high pressure homogenization treatment; GI-CMP is carboxymethyl tuckahoe polysaccharide after irradiation treatment;

[0029] Figure 5 This is the one-dimensional NMR spectrum of carboxymethyl tuckahoe polysaccharide after high temperature treatment;

[0030] Figure 6 This is the one-dimensional NMR spectrum of carboxymethyl tuckahoe polysaccharide after high-pressure homogenization;

[0031] Figure 7 This is the one-dimensional NMR spectrum of carboxymethyl tuckahoe polysaccharide after irradiation;

[0032] Figure 8 It is the 2D NMR spectrum of carboxymethyl tuckahoe polysaccharide after high temperature treatment;

[0033] Fig. 9 It is the 2D NMR spectrum of carboxymethyl tuckahoe polysaccharide after high pressure homogenization;

[0034] Fig.10 This is the two-dimensional NMR spectrum of carboxymethyl tuckahoe polysaccharide after irradiation. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the 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. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] Existing studies have shown that the backbone of carboxymethyl pachymaran (CMP) is mainly connected by β-D-(1→3) glycosidic bonds, while the side chains are connected to the main chain by β-D-(1→6) glycosidic bonds, where the ratio of β-D-(1→3) glycosidic bonds to β-D-(1→6) glycosidic bonds is 3:1. It has a wide range of biological activities, but the dissolution rate of carboxymethyl pachymaran is slow and its solution viscosity is high. Although the viscosity of polysaccharide solutions can be reduced by irradiation treatment, the β-D-(1→6) glycosidic bonds in carboxymethyl pachymaran are easily damaged and degraded by high-dose irradiation, which may eventually destroy the structure of carboxymethyl pachymaran and affect its biological activity. It is difficult to control the biological activity by irradiation treatment, which will lead to significant differences in the biological activity of different batches of products.

[0037] The present invention finds that the viscosity of the carboxymethyl tuckahoe polysaccharide solution can be reduced to a certain extent by high-temperature, high-pressure homogenization or low-dose irradiation treatment. However, when only high-pressure homogenization is used, the concentration of the carboxymethyl tuckahoe polysaccharide solution cannot be too high, generally not exceeding 5 mg / ml (the viscosity of the CMP solution is about 0.15 Pa.s), mainly because the higher the concentration of the carboxymethyl tuckahoe polysaccharide solution, the greater its viscosity, and the carboxymethyl tuckahoe polysaccharide solution is too high in viscosity to be homogenized; and when only irradiation treatment is used, the irradiation dose required to reduce the viscosity of the polysaccharide solution by more than 50% is large (the irradiation dose is generally more than 100 kGy), which will significantly destroy the structure of the carboxymethyl tuckahoe polysaccharide. However, after high temperature treatment, the viscosity of carboxymethyl tuckahoe polysaccharide solution decreased significantly, which can be reduced by more than 70%, and there is no significant effect on the results of carboxymethyl tuckahoe polysaccharide; in addition, the high temperature treatment can generally be achieved by existing processing plants, such as using autoclaves, and high temperature treatment is also suitable for high viscosity carboxymethyl tuckahoe polysaccharide stock solution, which is conducive to improving the utilization rate of carboxymethyl tuckahoe polysaccharide. In particular, the high temperature treatment of 115-135℃ and heat preservation for 10-30min can reduce the viscosity of carboxymethyl tuckahoe polysaccharide solution by 80%-90%, which is significantly better than the existing high-dose irradiation treatment of polysaccharide solution.

[0038] Experiments show that the viscosity of a 50 mg / ml carboxymethyl pachymaran solution is reduced from 1.4 Pa.s to 0.2 Pa.s after being treated at 121°C for 20 minutes. The viscosity of the CMP solution can be reduced by 83%, and the solution becomes fluid from being very viscous without significant effect on the structure of the carboxymethyl pachymaran.

[0039] Furthermore, the viscosity of the carboxymethyl tuckahoe polysaccharide solution can be further reduced by using a high temperature-high pressure homogenization combined treatment, and compared with the high pressure homogenization treatment, the concentration of the carboxymethyl tuckahoe polysaccharide solution is increased from 5 mg / ml to 50 mg / ml, which can improve the utilization rate of the carboxymethyl tuckahoe polysaccharide. The viscosity of the carboxymethyl tuckahoe polysaccharide solution can be reduced by more than 99% by using a high temperature-irradiation combined treatment compared with high temperature treatment, which can significantly reduce the viscosity of the CMP solution, and compared with the high dose irradiation treatment, the required irradiation dose is low, generally not exceeding 40 kGy, and has little effect on the structure of the carboxymethyl tuckahoe polysaccharide.

[0040] The present invention provides a method for reducing the viscosity of a carboxymethyl pachymaran solution, which comprises the following steps:

[0041] Prepare a carboxymethyl pachymaran solution of a preset concentration; the preset concentration is within 50 mg / ml;

[0042] Treating with high temperature until the carboxymethyl pachymaran solution changes from turbid to clear, and cooling to room temperature;

[0043] The viscosity of the carboxymethyl pachymaran solution is reduced by more than 70%.

[0044] The high temperature treatment is preferably performed at a temperature of 115-135° C. and a holding time of 10-30 min, so that the viscosity of the carboxymethyl pachymaran solution decreases by 80%-90%; more preferably, the temperature is 121° C. and the holding time is 20-30 min.

[0045] Furthermore, in some products that require a low viscosity of the carboxymethyl tuckahoe polysaccharide solution but a high content of carboxymethyl tuckahoe polysaccharide, such as carboxymethyl tuckahoe polysaccharide oral liquid, after high-temperature treatment, the viscosity of the CMP solution is made to be within the range that can be treated by high-pressure homogenization, and the cooled carboxymethyl tuckahoe polysaccharide solution is then treated with high-pressure homogenization to further reduce the solution viscosity and improve the utilization rate of CMP;

[0046] The viscosity of the cooled carboxymethyl pachymaran solution is 0.01-0.15 Pa.s; the high pressure homogenization has a homogenization pressure of 10MPa-40MPa.

[0047] In some embodiments, high-pressure homogenization uses liquid pressurization, and the homogenization pressure is 10-40 MPa, the liquid flow rate is 5-10 L / h, and it is circulated 2-6 times (one cycle is one cycle of liquid pressurization); preferably, the homogenization pressure is 30-40 MPa, the flow rate is 8-10 L / h, and it is circulated 3-5 times.

[0048] After high temperature treatment, if the viscosity of the carboxymethyl tuckahoe polysaccharide solution is above 0.15 Pa.s and it is difficult to directly homogenize under high pressure, irradiation treatment is first performed and then the cooled carboxymethyl tuckahoe polysaccharide solution is combined with high pressure homogenization treatment; the irradiation, the irradiation dose is 5 to 30 kGy, and the irradiation time is 1 to 12 hours;

[0049] In some embodiments, after high temperature treatment, the viscosity of the carboxymethyl pachymaran solution is 0.15Pa.s to 0.3Pa.s. After high temperature treatment, irradiation treatment is first used and then high-pressure homogenization is used. The irradiation dose is 10 to 20 kGy and the irradiation time is 2 to 9 hours.

[0050] The following are examples:

[0051] Example 1 High temperature treatment of carboxymethyl pachymaran

[0052] (1) Preparation of carboxymethyl tuckahoe polysaccharide: extracting polysaccharide from tuckahoe and performing carboxymethylation, as follows:

[0053] The dried powder of Poria cocos (10 g) was soaked in 85% ethanol (50 ml) at 50°C for 30 minutes for expansion, and then 3.4 g of NaOH was added to the reaction system for 1 hour of alkalization reaction. After that, 3.4 g of NaOH and 9.45 g of chloroacetic acid dissolved in a small amount of ethanol were added, and the etherification reaction was stirred at 60°C for 6 hours. Finally, the pH value of the solution was adjusted to 5-6 with glacial acetic acid. After the reaction was completed, the precipitate was dissolved in distilled water, then precipitated with 75% ethanol, and dried to obtain CMP.

[0054] (2) High temperature treatment of carboxymethyl pachymaran: Weigh the CMP obtained in (1), prepare different CMP solutions, and treat them under different high temperature conditions, as follows:

[0055] Control group 1: CMP concentration of 5 mg / ml, no treatment;

[0056] Control group 2: CMP concentration of 50 mg / ml, no treatment;

[0057] High temperature group 1: CMP concentration 5 mg / ml, 115°C, 20 min;

[0058] High temperature group 2: CMP concentration 5 mg / ml, 121°C, 20 min;

[0059] High temperature group 3: CMP concentration 5 mg / ml, 121°C, 30 min;

[0060] High temperature group 4: CMP concentration 50 mg / ml, 121°C, 20 min;

[0061] (3) Determination of viscosity of carboxymethyl tuckahoe polysaccharide solution: The viscosity of the CMP solution was measured using a rheometer (Ar2000ex, TA Instruments, USA). The steady-state viscosity of the sample (5 mg / ml) was measured. The diameter and gap of the plate were 40 mm and 0.5 mm, respectively. The sample solution to be tested was moved onto the sample plate of the rheometer, and the frequency scanning data acquisition mode was used to measure the viscosity change of the sample between the shear rate of 0 and 100 1 / s. The measurement results are shown in Figure 1 shown.

[0062] Figure 1 Middle curves 1-6 represent control group 1, control group 2, high temperature group 1, high temperature group 2, high temperature group 3 and high temperature group 4, respectively.

[0063] Depend on Figure 1It can be seen that the shear viscosity of the above-mentioned groups of sample solutions decreased significantly with the increase of shear rate, and then tended to be stable, showing the characteristics of non-Newtonian fluids. However, compared with the untreated carboxymethyl tuckahoe polysaccharide in the control group, after high temperature treatment, the apparent viscosity of the solution decreased significantly, and the fluidity was greatly improved. Among them, the viscosity of the untreated carboxymethyl tuckahoe polysaccharide solution in the control group 1 was 0.1329 Pa.s in the stable state, while the viscosity of the carboxymethyl tuckahoe polysaccharide of the same concentration was reduced to 0.0154 Pa.s, 0.0124 Pa.s and 0.0122 Pa.s in the stable state after different high temperature treatments, that is, the viscosity of the samples of high temperature groups 1-3 after high temperature treatment was 11.58%, 9.3% and 9.2% of the untreated samples, respectively, which was reduced by 88.42%, 90.7% and 90.8%, respectively. Moreover, the effect of temperature on viscosity was more obvious than time. With the increase of temperature, the viscosity of the CMP solution decreased significantly, and the viscosity decrease was more than 85%.

[0064] The viscosity of the untreated carboxymethyl tuckahoe polysaccharide in the control group 2 was 1.4090 Pa.s in a stable state, while the viscosity of the carboxymethyl tuckahoe polysaccharide of the same concentration was reduced to 0.2387 Pa.s after being treated at 121°C for 20 minutes, that is, the viscosity of the sample in the high temperature group 4 was reduced by 83%. It can be seen that high temperature treatment can significantly reduce the viscosity of the carboxymethyl tuckahoe polysaccharide solution.

[0065] Example 2 High temperature and high pressure homogenization combined treatment of carboxymethyl pachymaran solution

[0066] (1) Preparation of carboxymethyl pachymaran: Same as Example 1.

[0067] (2) High temperature treatment of carboxymethyl pachymaran solution: weigh the CMP obtained in (1) to prepare a 40 mg / ml CMP solution, heat at 121° C. for 20 min, and then cool and perform high pressure homogenization;

[0068] (3) High-pressure homogenization treatment of the cooled carboxymethyl pachymaran solution: A nano homogenizer was used for high-pressure homogenization (HP) treatment, and the treatment was performed as follows:

[0069] Control group: 121℃, keep warm for 20min;

[0070] High temperature-homogenization group 1: 121℃, keep warm for 20min, and then use high pressure homogenization after cooling. The high pressure homogenization condition is 15MPa and room temperature homogenization twice;

[0071] High temperature-homogenization group 2: 121℃, keep warm for 20min, and then use high pressure homogenization after cooling. The high pressure homogenization condition is 5 times of homogenization at room temperature under 15MPa;

[0072] High temperature-high temperature-homogenization group 3: 121℃, keep warm for 20min, and then use high pressure homogenization after cooling. The high pressure homogenization condition is 5 times of homogenization at room temperature under 30MPa;

[0073] According to the above four groups of treatment methods, the samples to be tested are obtained after respective treatments.

[0074] (3) Determination of viscosity of carboxymethyl pachymaran solution: Same as in Example 1, the results are as follows Figure 2 shown.

[0075] Figure 2 Middle curves 1-4 represent the control group, high temperature-homogeneous group 1, high temperature-homogeneous group 2, and high temperature-high temperature-homogeneous group 3, respectively.

[0076] Depend on Figure 2 It can be seen that the shear viscosity of the above-mentioned groups of sample solutions decreased significantly with the increase of shear rate, and then tended to be stable, showing the characteristics of non-Newtonian fluids. However, compared with the carboxymethyl tuckahoe polysaccharide solution in the control group treated with high temperature only, the apparent viscosity of the solution decreased significantly after combined high-pressure homogenization treatment, and the fluidity was greatly improved. The viscosity of the carboxymethyl tuckahoe polysaccharide solution in the control group was 0.1429 Pa.s in a stable state, while the viscosity of the solution in the high-temperature-high-pressure homogenization group after combined treatment in a stable state was reduced to 0.0263 Pa.s, 0.0198 Pa.s and 0.0058 Pa.s, respectively, that is, the viscosity of the samples of the high-temperature-homogenization groups 1-3 after combined treatment with high-pressure homogenization was 18.5%, 13.9% and 4.1% of the samples of the high-temperature control group, respectively, which was reduced by 81.5%, 86.1% and 95.9%, respectively. Although high-pressure homogenization can also reduce the viscosity of the carboxymethyl tuckahoe polysaccharide solution, the concentration of the carboxymethyl tuckahoe polysaccharide solution that can be treated is limited, and the concentration of the CMP solution is generally not higher than 5 mg / ml. It can be seen that the high temperature-high pressure homogenization combined treatment can not only further reduce the viscosity of the carboxymethyl tuckahoe polysaccharide solution, but also increase the concentration of carboxymethyl tuckahoe polysaccharide in the solution during high pressure homogenization treatment.

[0077] Example 3 High temperature-irradiation-high pressure homogenization combined treatment of carboxymethyl tuckahoe polysaccharide solution

[0078] (1) Preparation of carboxymethyl pachymaran: As in Example 1, weigh the CMP obtained in (1) and prepare a 50 mg / ml CMP solution.

[0079] (2) High temperature treatment of carboxymethyl pachymaran solution: 121°C, keep warm for 20 min; the viscosity of the CMP solution after high temperature treatment is 0.2387 Pa.s;

[0080] (3) Irradiation treatment of carboxymethyl pachymaran solution: The CMP solution after high temperature treatment in (2) was added to a HEPE bottle and irradiated with a cobalt 60 source irradiator at room temperature at a dose rate of 3.6 kGy / h. The treatments were performed as follows:

[0081] Control group: 50 mg / ml CMP solution, 121°C, kept warm for 20 min;

[0082] High temperature-irradiation-homogenization group 1: irradiation dose was controlled at 10 kGy, and irradiation time was 2.7 h;

[0083] High temperature-irradiation-homogenization group 2: irradiation dose was controlled at 20 kGy, and irradiation time was 5.5 h;

[0084] High temperature-irradiation-homogenization group 3: irradiation dose was controlled at 30 kGy, and irradiation time was 8.3 h;

[0085] (4) High-pressure homogenization: After irradiation, the groups in (3) were subjected to high-pressure homogenization. The high-pressure homogenization conditions were 30 MPa, a flow rate of 8 L / h, and homogenization at room temperature for 3 times to obtain the samples to be tested.

[0086] (5) Determination of viscosity of carboxymethyl pachymaran solution: Same as in Example 1, the results are as follows Figure 3 shown.

[0087] Figure 3 Middle curves 1-4 represent the control group, high temperature-irradiation-homogenization group 1, high temperature-irradiation-homogenization group 2 and high temperature-irradiation-homogenization group 3, respectively.

[0088] Depend on Figure 3 It can be seen that the shear viscosity of the above-mentioned groups of sample solutions decreased significantly with the increase of shear rate, and then tended to be stable, showing the characteristics of non-Newtonian fluids. However, compared with the carboxymethyl tuckahoe polysaccharide solution in the control group, the solution was first irradiated and then combined with high-pressure homogenization after high-temperature treatment, and the apparent viscosity of the solution decreased significantly, and the fluidity was greatly improved. The viscosity of the carboxymethyl tuckahoe polysaccharide solution in the control group was 0.2387 Pa.s in a stable state. After combined γ-ray irradiation and high-pressure homogenization, the viscosity of the three groups of solutions treated with high-pressure-irradiation-high-pressure homogenization in a stable state was reduced to 0.00054 Pa.s, 0.00035 Pa.s and 0.00030 Pa.s, respectively, that is, the viscosity of the high-temperature-irradiation-homogenization groups 1-3 samples after the combined treatment was 0.23%, 0.15% and 0.13% of the control group samples, respectively, which were reduced by more than 99%. It can be seen that the combined treatment of high temperature-irradiation-homogenization can significantly reduce the viscosity of the carboxymethyl tuckahoe polysaccharide solution.

[0089] Example 4 Effects of high temperature, high pressure homogenization and irradiation on the structure of carboxymethyl tuckahoe polysaccharide

[0090] A carboxymethyl tuckahoe polysaccharide solution with a mass concentration of 5 mg / ml was prepared and treated with high temperature (HT), high pressure homogenization (HP) and irradiation (GI), wherein the high temperature condition was 121°C for 20 min; the high pressure homogenization condition was homogenization at room temperature for 5 times at 30 MPa; the irradiation condition was irradiation with a cobalt 60 source irradiator at room temperature, with a dose rate of 3.6 kGy / h, and the irradiation dose was controlled at 30 kGy. After high temperature, high pressure homogenization and irradiation treatment, the structure of carboxymethyl tuckahoe polysaccharide was determined, and the specific determination and results are shown below.

[0091] (1) Infrared spectroscopy: FT-IR spectra were measured by Nexus 470 FT-IR spectrometer (Thermo Nicolet, USA). The sample was mixed with dry potassium bromide (KBr) at a ratio of 1:100 and pressed into powder. The spectrum was measured at 4000 and 400 cm -1 Scanning between wave numbers, the infrared spectrum is as follows Figure 4 shown.

[0092] Figure 4 Medium CMP is untreated carboxymethyl tuckahoe polysaccharide; HT-CMP is carboxymethyl tuckahoe polysaccharide after high temperature treatment; HP-CMP is carboxymethyl tuckahoe polysaccharide after high pressure homogenization treatment; GI-CMP is carboxymethyl tuckahoe polysaccharide after irradiation treatment;

[0093] Depend on Figure 4 The results of infrared spectroscopy and nuclear magnetic resonance spectroscopy show that the base units and sugar rings of carboxymethyl tuckahoe polysaccharide have not changed after high temperature, high pressure homogenization and irradiation. In addition, the structures of all samples in the FT-IR spectrum are similar, indicating that high temperature, high pressure homogenization and irradiation have no obvious effect on the functional group state of carboxymethyl tuckahoe polysaccharide.

[0094] (2) One-dimensional and two-dimensional nuclear magnetic resonance: The nuclear magnetic resonance spectra were measured at 25°C using a Bruker AV-600 nuclear magnetic resonance spectrometer. 15 mg of HT-CMP, HP-CMP, and GI-CMP were dissolved in 0.55 ml of deuterium oxide (D2O, 99.9% D) and placed in a nuclear magnetic resonance tube for measurement. The nuclear magnetic resonance spectra were as follows: Figure 5-10 shown.

[0095] The structural characteristics of the polysaccharide are described by nuclear magnetic resonance spectroscopy. Since the solubility of the untreated carboxymethyl tuckahoe polysaccharide did not meet the requirements, the obtained nuclear magnetic resonance spectrum did not show effective signals. This example only analyzed the nuclear magnetic resonance of the samples after high temperature, high pressure homogenization and irradiation treatment, among which the one-dimensional nuclear magnetic spectrum was as follows Figure 5-7 As shown, the one-dimensional NMR spectrum shows that there is only one peak in the isomeric carbon region (95-110 ppm), which indicates that all samples are composed of only one monosaccharide.

[0096] Usually the signal of β-isomer proton is between 4.5-5ppm, while the signal of α-isomer proton is between 5-5.5ppm. According to the 2D NMR HSQC spectrum, e.g. Figure 8-10 As shown in the figure, the isomeric proton signals of carboxymethyl tuckahoe polysaccharide after high temperature, high pressure homogenization and irradiation treatment are at 4.75, 4.74 and 4.72 ppm, respectively, which indicates that the carboxymethyl tuckahoe polysaccharide after treatment is composed of β-configuration monosaccharides, while previous studies have shown that untreated CMP is composed of β-glucose, indicating that the composition of carboxymethyl tuckahoe polysaccharide is not changed after high temperature, high pressure homogenization and irradiation treatment.

[0097] It is known that the CMP skeleton is mainly connected by β-D-(1→3) glycosidic bonds, while the side chains are connected to the main chain by β-D-(1→6) glycosidic bonds. The ratio of β-D-(1→3) glycosidic bonds to β-D-(1→6) glycosidic bonds is 3:1. In the two-dimensional NMR HSQC spectrum, we integrated the cross peaks of 1H and 13C to determine the relative ratios between different connection modes. The results showed that the ratio of β-D-(1→3) glycosidic bonds to β-D-(1→6) glycosidic bonds of HT-CMP and HP-CMP was about 3:1, while that of GI-CMP was 5:1. The β-D-(1→6) glycosidic bonds were more easily destroyed during irradiation treatment, indicating that after irradiation treatment, the side chains were mainly partially degraded, resulting in a decrease in the molecular weight of the treated carboxymethyl pachymaran, but the monosaccharide composition did not change significantly compared with the untreated CMP.

[0098] (3) Chain conformation determination: The weight average molar mass (Mw), number average molar mass (Mn), peak molar mass (Mp), polydispersity index (Mw / Mn) and root mean square (RMS) radius of the samples were measured using a DAWN HELEOS-II laser photometer. The results are shown in Table 1.

[0099] Table 1 Chain conformation determination results

[0100] sample CMP HT-CMP HP-CMP GI-CMP <![CDATA[M w (kDa)]]> 787.9±31.5 429.8±12.89 569.5±5.69 6.0±0.72 <![CDATA[M n (kDa)]]> 316.9±16.5 242.8±12.6 353.8±8.3 4.8±0.29 <![CDATA[M p (kDa)]]> 334.6±8.7 228.7±4.9 312.0±1.9 5.0±0.5 <![CDATA[M w / M n ]]> 2.48±0.27 1.77±0.16 1.61±0.03 2.28±0.37 <![CDATA[R Z (nm)]]> 137.5±1.6 72.7±2.9 55.2±1.2 5.2±0.6 ν value 0.51 0.45 0.33 --

[0101] RMS radius in the table <s2>The relationship between z1 / 2(Rg) and Mw is expressed by the formula: (RMS) radius = kMwν. Generally speaking, the corresponding ν values ​​for rigid rods, flexible random coils, compact coil chain conformations, and spheres are 0.6-1.0, 0.5-0.6, 0.2-0.4, and 0.33, respectively.

[0102] According to the double logarithmic relationship in Table 1, the ν values ​​of CMP, HT-CMP and HP-CMP are 0.51, 0.45 and 0.33, respectively. The results show that CMP is a flexible random coil in solution and changes to a spherical conformation after HP treatment, while the conformation of carboxymethyl tuckahoe polysaccharide is between the flexible random coil and the compact coil chain conformation after HT treatment, indicating that the conformation of the carboxymethyl tuckahoe polysaccharide chain changes after high temperature and high pressure homogenization treatment, which may be related to the reduction of solution viscosity.

[0103] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for reducing the viscosity of a carboxymethyl pachymaran solution, characterized in that: The following steps are involved: Prepare a carboxymethyl pachymaran solution of a preset concentration; the preset concentration is within 50 mg / ml; Treating at 115-121°C until the carboxymethyl pachymaran solution changes from turbid to clear, and cooling to room temperature; The viscosity of the carboxymethyl pachymaran solution is reduced by more than 70%.

2. The method for reducing the viscosity of a carboxymethyl pachymaran solution according to claim 1, characterized in that: The high temperature treatment is performed at a temperature of 115° C. or 121° C. and the heat preservation time is 10 to 30 minutes.

3. The method for reducing the viscosity of a carboxymethyl pachymaran solution according to claim 1 or 2, characterized in that: After high temperature treatment, the cooled carboxymethyl tuckahoe polysaccharide solution is subjected to high pressure homogenization combined treatment to improve fluidity; The viscosity of the cooled carboxymethyl pachymaran solution is 0.01-0.15 Pa·s; The high pressure homogenization has a homogenization pressure of 10 MPa to 40 MPa.

4. The method for reducing the viscosity of a carboxymethyl pachymaran solution according to claim 1 or 2, characterized in that: After the high temperature treatment, the viscosity of the carboxymethyl tuckahoe polysaccharide solution is above 0.15 Pa·s, and the irradiation combined treatment is first performed, and then the cooled carboxymethyl tuckahoe polysaccharide solution is subjected to high pressure homogenization combined treatment; The irradiation has an irradiation dose of 5 to 30 kGy and an irradiation time of 1 to 12 hours.

5. The method for reducing the viscosity of carboxymethyl pachymaran solution according to claim 3, characterized in that: The high temperature treatment is 121° C., and the heat preservation time is 20 to 30 minutes. When the high pressure homogenization is carried out by liquid pressurization, the homogenization pressure is 10 to 40 MPa, the liquid flow rate is 5 to 10 L / h, and the cycle is 2 to 6 times.

6. The method for reducing the viscosity of a carboxymethyl pachymaran solution according to claim 5, characterized in that: The high-pressure homogenization has a homogenization pressure of 30-40 MPa, a flow rate of 8-10 L / h, and is circulated 3-5 times.

7. The method for reducing the viscosity of a carboxymethyl pachymaran solution according to claim 4, characterized in that: After high-temperature treatment, the viscosity of the carboxymethyl tuckahoe polysaccharide solution is 0.15-0.3 Pa·s; the irradiation has an irradiation dose of 10-20 kGy and an irradiation time of 2-9 hours.

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