A binary sugar crystal and its preparation method

Abstract

The present invention discloses a disaccharide crystallization and a preparation method thereof. The preparation method of the disaccharide crystallization comprises: filtering, microfiltrating and ultrafiltrating a disaccharide solution, and performing vacuum concentration to obtain a concentrated sugar solution; the disaccharide solution comprises a disaccharide raw material and water; mixing the concentrated sugar solution with ethanol, cooling, and adding a seed crystal and then keeping warm; the volume ratio of the ethanol to the concentrated sugar solution is (0.4-0.6):1; the seed crystal is a disaccharide crystal; cooling, and mixing with ethanol during the cooling process, and the volume ratio of the ethanol to the concentrated sugar solution is (0.4-0.6):1. The preparation method of the present invention improves the yield and purity of the disaccharide crystal, greatly shortens the crystallization time, and improves the production efficiency; the obtained disaccharide crystallization has the advantages of light color, high purity, few impurities and low bacterial endotoxin.

Description

Technical Field

[0001] The present invention relates to a disaccharide crystallization and a preparation method thereof. Background Art

[0002] A disaccharide (also known as a double sugar or biose) is formed by the condensation of two molecules of monosaccharides (a sugar formed when two monosaccharides are linked by a glycosidic bond), or is formed by the hydrolysis of a polysaccharide with the help of an enzyme. After 1 molecule of disaccharide is completely hydrolyzed, it is only hydrolyzed into 2 molecules of monosaccharides. Like monosaccharides, disaccharides are water-soluble sugars. Common disaccharides include sucrose, trehalose, lactose, and maltose. Its chemical composition has 12 carbon atoms, and its general formula is C 12 H 22 O 11 .

[0003] Naturally occurring free and functional disaccharides are represented by maltose, lactose, trehalose, and sucrose. These sugars are used as energy sources for various organisms or as important substances for the composition of organisms, and they play an important role in storage or transportation. There are many preparation methods for disaccharide crystallization in the prior art. However, in the existing processes, the production cycle of disaccharide crystallization is long, the yield is low, and the purity is not high.

[0004] Patent No. CN107447058 discloses a preparation method of crystalline maltose. In this method, the maltose content of the malt syrup used is not pointed out. The actual situation is that if the maltose content in the syrup is too low, it is easy to have a sticky sugar paste during the crystallization process and the phenomenon of inability to crystallize.

[0005] Patent No. CN110938715A discloses a maltose crystallization process. This process requires a vacuum condition and a slow cooling rate during the crystallization process. Its crystallization time is about 38 hours or more, and the production cycle is long, which is not suitable for industrial production. Summary of the Invention

[0006] In order to overcome the defects of long production cycle, low yield, low purity, etc. of disaccharide crystallization in the prior art, the present invention provides a disaccharide crystallization and a preparation method thereof. The preparation method improves the yield and purity of disaccharide crystals, greatly shortens the crystallization time, and improves the production efficiency; the obtained disaccharide crystallization has the advantages of light color, high purity, few impurities, and low bacterial endotoxin.

[0007] In order to achieve the above object, the present invention is realized by the following technical solutions:

[0008] The present invention provides a preparation method of disaccharide crystallization, which comprises the following steps:

[0009] S1. Filter, microfilter, and ultrafilter the disaccharide solution, and concentrate it under reduced pressure to obtain a concentrated sugar solution. Among them, the disaccharide solution includes a disaccharide raw material and water. The molecular cut-off of the ultrafiltration is 1000 KD to 10000 KD.

[0010] S2. Mix the concentrated sugar solution with ethanol, cool down, and keep warm after adding crystal seeds. The volume ratio of the ethanol to the concentrated sugar solution is (0.4 - 0.6):1. The crystal seeds are disaccharide crystals.

[0011] S3. Cool down, and mix with ethanol during the cooling process. The volume ratio of the ethanol to the concentrated sugar solution is (0.4 - 0.6):1.

[0012] In step S1, the disaccharide raw material can be conventional in the art, preferably food-grade disaccharide powder or crystal. The disaccharide is preferably sucrose, trehalose, lactose, or maltose. The purity of the disaccharide raw material is preferably greater than 92%, and the purity of the disaccharide raw material refers to the mass percentage of the disaccharide in the disaccharide raw material. The water is preferably purified water.

[0013] In step S1, the mass percentage of the disaccharide in the disaccharide solution is preferably 30% - 50%, such as 40%.

[0014] In step S1, the disaccharide solution can be obtained by a conventional preparation method in the art, and the disaccharide raw material can be dissolved in water. The dissolution temperature of the disaccharide raw material is preferably 50 - 80°C, such as 60°C.

[0015] Among them, for the preparation of the disaccharide solution, after the dissolution, preferably, a decolorization treatment is further included.

[0016] Among them, the decolorization treatment can adopt a conventional decolorization method in the art, preferably using medicinal activated carbon powder for the decolorization treatment. The mass of the medicinal activated carbon powder is 0.05% - 1% of the mass of the disaccharide solution. The temperature of the decolorization treatment is preferably 65 - 70°C, such as 60°C. The time of the decolorization treatment is preferably 40 - 60 min, such as 30 min.

[0017] In step S1, the filtration refers to a filtration method with a filtration accuracy greater than 50 μm; the microfiltration refers to a filtration method with a filtration accuracy between 0.1 - 50 μm; the ultrafiltration refers to a filtration method with a filtration accuracy between 0.001 - 0.1 μm. Filtration and microfiltration can remove larger mechanical impurities.

[0018] In step S1, the ultrafiltration can be carried out using an ultrafiltration membrane; the molecular cut-off of the ultrafiltration is, more preferably 1000 KD to 5000 KD. The pressure at the inlet end of the ultrafiltration membrane is preferably 0.1 to 5 bar. The pressure at the reflux end of the ultrafiltration membrane is preferably 0.1 to 3 bar. The material of the ultrafiltration membrane can be conventional in the art, preferably modified polysulfone. The temperature of the ultrafiltration is preferably 20 to 35 °C.

[0019] In the present invention, the modified polysulfone is a blend of polysulfone, polymethyl methacrylate, and ABS; the ABS is a terpolymer of three monomers, acrylonitrile, butadiene, and styrene.

[0020] In step S1, the temperature of the vacuum concentration is preferably 65 to 70 °C.

[0021] In step S1, after the vacuum concentration, the mass percentage of the disaccharide in the concentrated sugar solution is preferably 65% to 80%, such as 70% and 75%.

[0022] In step S1, the temperature of the mixing is preferably maintained at 50 to 65 °C, such as 55 °C.

[0023] In step S2, the mixing method is preferably to add ethanol to the concentrated sugar solution; the addition rate of the ethanol is 80 to 180 mL / min.

[0024] In step S2, the volume ratio of the ethanol to the concentrated sugar solution is preferably 0.55:1, 0.50:1, or 0.45:1.

[0025] In step S2, the temperature of the mixing can be 65 to 70 °C.

[0026] In step S2, the cooling can be carried out by a conventional cooling method in the art, and the temperature can be reduced to 45 to 60 °C, such as 50 °C and 55 °C.

[0027] In step S2, the holding time is preferably 2 to 5 hours, such as 3 hours.

[0028] In step S2, the disaccharide crystal seeds can be conventional in the art, preferably food-grade disaccharide crystals or disaccharide crystals with a content of 92% to 100%.

[0029] In step S2, the mass ratio of the disaccharide crystal seeds to the disaccharide raw material is preferably 0.1% to 0.8%, such as 0.2%.

[0030] In step S3, the cooling can be carried out by a conventional cooling method in the art; the temperature can be reduced to 10 to 30 °C, such as 20 °C.

[0031] In step S3, the cooling rate is preferably 1 to 10 °C / h, for example, 5 °C / h.

[0032] In step S3, the volume ratio of the ethanol to the concentrated sugar solution is preferably 0.45:1, 0.55:1 or 0.50:1.

[0033] Both steps S2 and S3 can be carried out in a conventional container in the art, preferably a vacuum crystallizer.

[0034] Preferably, separation and drying may further be included after step S3.

[0035] Among them, the separation can adopt a conventional separation method in the art. Preferably, centrifugation or filtration can be used. The separation is preferably carried out at a temperature below 20 °C.

[0036] Among them, the drying can adopt a conventional drying method in the art, preferably drying in an oven. The drying temperature can be 80 °C.

[0037] The present invention provides a disaccharide crystal, which is prepared by the above-mentioned method for preparing a disaccharide crystal. Preferably, the bacterial endotoxin of the disaccharide crystal is less than 2 EU / g, for example, less than 0.52 EU / g.

[0038] The above preferred conditions can be combined arbitrarily to obtain various preferred examples of the present invention.

[0039] The reagents and raw materials used in the present invention are all commercially available.

[0040] The positive and progressive effects of the present invention are as follows:

[0041] 1. The present invention uses an ultrafiltration process to reduce the bacterial endotoxin and polysaccharide impurities in the disaccharide syrup. By combining the processes of cooling crystallization and antisolvent crystallization, and adding a poor solvent during the cooling crystallization process, the crystallization time of the disaccharide is shortened, and the saturation of the sugar solution tends to be stable.

[0042] 2. The disaccharide crystal obtained by the method of the present invention has the advantages of light color, high purity, few impurities and low bacterial endotoxin. Its product quality meets the standards of the Chinese Pharmacopoeia 2020 Edition, USP 43rd Edition, and JP 17th Edition. Specifically, the content of the prepared disaccharide product reaches more than 99%. The bacterial endotoxin of the obtained disaccharide product is less than 0.5 EU / g, which can meet the use requirements of high-risk (such as injection, biological products, etc.) pharmaceutical excipients.

[0043] 3. The method for preparing the disaccharide crystal of the present invention has a low reaction temperature, mild reaction conditions, a significantly shortened crystallization time, the crystallization process duration can be controlled within about 12 hours, shortening the production cycle, improving production efficiency; the yield can reach more than 80%; the equipment is simple and easy for industrialization and large-scale production. Brief Description of the Drawings

[0044] Figure 1 It is the HPLC chromatogram of Control 3 in Effect Example 3.

[0045] Figure 2 It is the HPLC chromatogram of Test Sample 3 in Effect Example 3. Detailed Description of the Invention

[0046] The present invention will be further described below by way of examples, but the present invention is not limited to the scope of the described examples. For the experimental methods without specific conditions noted in the following examples, they are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0047] Example 1

[0048] Step 1: Take 200 g of food-grade maltose crystals with a purity greater than 92%;

[0049] Step 2: Dissolve the maltose crystals in Step 1 in 200 g of purified water to obtain a maltose solution;

[0050] Step 3: Add 0.2 g of activated carbon powder, stir and heat to 60 °C, then continue stirring for 30 min for decolorization treatment;

[0051] Step 4: Filter, microfilter and ultrafilter, where the molecular cut-off flow rate of the ultrafiltration membrane is 1000 KD, the inlet pressure is 4.2 bar, and the reflux pressure is 2.5 bar; the ultrafiltration temperature is 20 °C;

[0052] Step 5: Concentrate the ultrafiltered maltose solution under reduced pressure at 65 °C to a mass fraction of 65% to obtain a concentrated sugar solution;

[0053] Step 6: Slowly add 45 g of ethanol to the concentrated sugar solution in Step 5 and cool to 50 °C. At this time, add 0.2 g of maltose crystals as seeds, and then keep warm for 2 hours; the addition rate of ethanol is 80 ml / min;

[0054] Step 7: Then slowly cool to 20 °C at a rate of 5 °C / h and dropwise add 55 g of ethanol during this process;

[0055] Step 8: Centrifuge the reaction solution in Step 7, place the obtained solid in an oven at 80 °C and dry for 4 h to obtain the final product maltose crystals, with a yield of 83.8%, a content of 99.9%, and an endotoxin limit of 0.5 EU.

[0056] Example 2

[0057] Step 1: Take 200 g of food-grade trehalose crystals with a purity greater than 92%;

[0058] Step 2: Dissolve the trehalose crystals obtained in Step 1 in 200 g of purified water to obtain a trehalose solution;

[0059] Step 3: Add 0.4 g of activated carbon powder, stir and heat up to 60 °C, then continue stirring for 30 min for decolorization;

[0060] Step 4: Filter, perform microfiltration and ultrafiltration. The molecular cut-off of the ultrafiltration membrane is 5000 KD, the pressure at the inlet end is 1.2 bar, and the pressure at the reflux end is 0.5 bar; the ultrafiltration temperature is 25 °C;

[0061] Step 5: Concentrate the ultrafiltered trehalose solution under reduced pressure at 70 °C to a mass fraction of 70% to obtain a concentrated sugar solution;

[0062] Step 6: Slowly add 40 g of ethanol to the concentrated sugar solution obtained in Step 5 and cool down to 55 °C. At this time, add 0.4 g of trehalose crystals as crystal seeds, and then keep warm for 2 hours; the addition rate of ethanol is 120 ml / min;

[0063] Step 7: Then slowly cool down to 20 °C at a rate of 5 °C / h, and add 60 g of ethanol dropwise during this process;

[0064] Step 8: Centrifuge the reaction solution obtained in Step 7, place the obtained solid in an oven at 80 °C and dry for 4 h to obtain the final product, trehalose crystals, with a yield of 82.1%, a content of 99.9%, and an endotoxin limit of 1 EU.

[0065] Example 3

[0066] Step 1: Take 200 g of food-grade sucrose crystals with a purity greater than 92%;

[0067] Step 2: Dissolve the sucrose crystals obtained in Step 1 in 200 g of purified water to obtain a sucrose solution;

[0068] Step 3: Add 1 g of activated carbon powder, stir and heat up to 60 °C, then continue stirring for 30 min for decolorization treatment;

[0069] Step 4: Filter, perform microfiltration and ultrafiltration. The molecular cut-off of the ultrafiltration membrane is 10000 KD, the pressure at the inlet end is 3.2 bar, and the pressure at the reflux end is 2.0 bar; the ultrafiltration temperature is 35 °C;

[0070] Step 5: Concentrate the ultrafiltered sucrose solution under reduced pressure at 65 °C to a mass fraction of 75% to obtain a concentrated sugar solution;

[0071] Step 6: Slowly add 50 g of ethanol to the concentrated sugar solution obtained in Step 5 and cool down to 60 °C. At this time, add 0.2 g of sucrose crystals as crystal seeds, and then keep warm for 2 hours; the addition rate of ethanol is 180 mL / min;

[0072] Step 7: Then, slowly cool down to 20°C at a rate of 5°C / h, and add 50 g of ethanol during this process;

[0073] Step 8: Centrifuge the reaction solution from Step 7, and place the obtained solid in an oven at 80°C for drying for 4 h to obtain the final product sucrose crystals, with a yield of 81.3%, a content of 99.9%, and an endotoxin limit of 2 EU.

[0074] Comparative Example 1

[0075] Step 1: Take 200 g of food-grade maltose crystals with a purity greater than 92%;

[0076] Step 2: Dissolve the maltose crystals in Step 1 in 200 g of purified water to obtain a maltose solution;

[0077] Step 3: Add 0.2 g of activated carbon powder, stir and heat up to 60°C, then continue stirring for decolorization treatment for 30 min;

[0078] Step 4: Filter, perform microfiltration and ultrafiltration, where the molecular cut-off of the ultrafiltration membrane is 1000 KD, the inlet pressure is 4.2 bar, and the reflux pressure is 2.5 bar; the ultrafiltration temperature is 20°C;

[0079] Step 5: Concentrate the ultrafiltered maltose solution under reduced pressure at 65°C to a mass fraction of 65%;

[0080] Step 6: Add 0.2 g of maltose crystals as seed crystals to the concentrated sugar solution in Step 5, and then keep it warm for 2 hours;

[0081] Step 7: Then, slowly cool down to 20°C at a rate of 5°C / h, and add 100 g of ethanol during this process; the addition rate of ethanol is 80 ml / min;

[0082] Step 8: Centrifuge the reaction solution from Step 7, and place the obtained solid in an oven at 80°C for drying for 4 h to obtain the final product maltose crystals, with a yield of 79.8%, a content of 97.3%, and an endotoxin limit of 0.5 EU.

[0083] Comparative Example 2

[0084] Step 1: Take 200 g of food-grade maltose crystals with a purity greater than 92%;

[0085] Step 2: Dissolve the maltose crystals in Step 1 in 200 g of purified water to obtain a maltose solution;

[0086] Step 3: Add 0.2 g of activated carbon powder, stir and heat up to 60°C, then continue stirring for decolorization treatment for 30 min;

[0087] Step 4: Filtration, microfiltration and ultrafiltration, where the molecular cut-off of the ultrafiltration membrane is 1000 KD, the inlet pressure is 4.2 bar, and the reflux pressure is 2.5 bar; the ultrafiltration temperature is 20 °C;

[0088] Step 5: Concentrate the ultrafiltered maltose solution under reduced pressure at 65 °C to a mass fraction of 65%;

[0089] Step 6: Slowly add 25 g of ethanol to the concentrated sugar solution in Step 5, and cool it to 50 °C. At this time, add 0.2 g of maltose crystals as seeds, and then keep it warm for 2 hours; the addition rate of ethanol is 80 ml / min;

[0090] Step 7: Then slowly cool it to 20 °C at a rate of 5 °C / h, and add 75 g of ethanol dropwise during this process;

[0091] Step 8: Centrifuge the reaction solution in Step 7, and dry the obtained solid in an oven at 80 °C for 4 h to obtain the final product, maltose crystals, with a yield of 79.5%, a content of 97.2%, and an endotoxin limit of 0.5 EU.

[0092] Comparative Example 3

[0093] Step 1: Take 200 g of food-grade maltose crystals with a purity greater than 92%;

[0094] Step 2: Dissolve the maltose crystals in Step 1 in 200 g of purified water to obtain a maltose solution;

[0095] Step 3: Add 0.2 g of activated carbon powder, stir and heat to 60 °C, and then continue to stir for 30 min for decolorization treatment;

[0096] Step 4: Filtration, microfiltration and ultrafiltration, where the molecular cut-off of the ultrafiltration membrane is 1000 KD, the inlet pressure is 4.2 bar, and the reflux pressure is 2.5 bar; the ultrafiltration temperature is 20 °C;

[0097] Step 5: Concentrate the ultrafiltered maltose solution under reduced pressure at 65 °C to a mass fraction of 65%;

[0098] Step 6: Slowly add 70 g of ethanol to the concentrated sugar solution in Step 5, and cool it to 50 °C. At this time, add 0.2 g of maltose crystals as seeds, and then keep it warm for 2 hours; the addition rate of ethanol is 80 ml / min;

[0099] Step 7: Then slowly cool it to 20 °C at a rate of 5 °C / h, and add 30 g of ethanol dropwise during this process;

[0100] Step 8: Centrifuge the reaction solution from Step 7, and place the obtained solid in an oven at 80 °C for drying for 4 h to obtain the final product, maltose crystals, with a yield of 80.4%, a content of 97.3%, and an endotoxin limit of 0.5 EU.

[0101] Comparative Example 4

[0102] Step 1: Take 200 g of food-grade maltose crystals with a purity greater than 92%.

[0103] Step 2: Dissolve the maltose crystals in Step 1 in 200 g of purified water to obtain a maltose solution.

[0104] Step 3: Add 0.2 g of activated carbon powder, stir and heat up to 60 °C, then continue stirring for 30 min for decolorization treatment.

[0105] Step 4: Filter, perform microfiltration and ultrafiltration, where the molecular cut-off flow rate of the ultrafiltration membrane is 20000 KD, the inlet pressure is 4.2 bar, and the reflux pressure is 2.5 bar; the ultrafiltration temperature is 20 °C.

[0106] Step 5: Concentrate the ultrafiltered maltose solution under reduced pressure at 65 °C to a mass fraction of 65% to obtain a concentrated sugar solution.

[0107] Step 6: Slowly add 45 g of ethanol to the concentrated sugar solution in Step 5, and cool down to 50 °C. At this time, add 0.2 g of maltose crystals as seeds, and then keep warm for 2 hours; the addition rate of ethanol is 80 ml / min.

[0108] Step 7: Then slowly cool down to 20 °C at a rate of 5 °C / h, and add 55 g of ethanol dropwise during this process.

[0109] Step 8: Centrifuge the reaction solution from Step 7, and place the obtained solid in an oven at 80 °C for drying for 4 h to obtain the final product, maltose crystals, with a yield of 84.1%, a content of 98.3%, and an endotoxin limit of 5 EU.

[0110] Perform content detection on the disaccharide crystals prepared in Examples 1-3 and Comparative Examples 1-4 using an HPLC high-performance liquid chromatograph. The calculation formula for the content detected by HPLC is:

[0111] Content = (rU / rS) × (CS / CU) × (C1 / C2) × 100%

[0112] In the formula: rU: peak area of the test sample;

[0113] rS: peak area of the reference substance;

[0114] CU: concentration of the test sample (mg / mL);

[0115] CS: Concentration of reference substance (mg / mL);

[0116] C1: Purity of reference substance;

[0117] C2: Purity of test sample.

[0118] Test samples 1, 2, 3, 4, 5, 6 and 7 were prepared by using the disaccharide crystals prepared in Examples 1 - 3 and Comparative Examples 1 - 4, and the concentrations of Test samples 1 - 7 were all about 5.02%.

[0119] Effect Example 1

[0120] The content of Test sample 1 of Example 1 and Test samples 4 - 7 of Comparative Examples 1 - 4 were detected respectively, and the reference substance used was Reference substance 1.

[0121] Reference substance 1: Maltose crystal with a purity of 94.4% (National Institutes for Food and Drug Control), and the concentration of the reference substance was 5.07 mg / mL

[0122] The chromatographic conditions were as follows:

[0123] Mobile phase: Acetonitrile - water, and the volume percentage of acetonitrile in the mobile phase was 70%

[0124] Detection time: 30 min

[0125] Chromatographic column: Amino - bonded silica gel as the filler

[0126] Column temperature: 35 °C

[0127] Flow rate: 0.8 ml / min

[0128] Detector: Evaporative light - scattering detector

[0129] Drift - tube temperature: 80 °C

[0130] Carrier gas flow rate: 1.5 L / min

[0131] The peak area and retention time of Reference substance 1 are shown in Table 1 below.

[0132] Table 1. Peak area and retention time data of Reference substance 1

[0133]

[0134] The peak area and retention time of Test sample 1 (Example 1) are shown in Table 2 below.

[0135] Table 2. Peak area and retention time data of Test sample 1

[0136]

[0137] Water content of Test sample 1: 5.5%

[0138] The content of maltose crystals in Test Sample 1 (i.e., Example 1) is calculated as follows:

[0139]

[0140] Water content of Test Samples 4 - 7: 5.5%

[0141] The peak areas and retention times of Test Sample 4 (Comparative Example 1) are shown in Table 3 below.

[0142] Table 3. Peak area and retention time data of Test Sample 4

[0143]

[0144] The peak areas and retention times of Test Sample 5 (Comparative Example 2) are shown in Table 4 below.

[0145] Table 4. Peak area and retention time data of Test Sample 5

[0146]

[0147] The peak areas and retention times of Test Sample 6 (Comparative Example 3) are shown in Table 5 below.

[0148] Table 5. Peak area and retention time data of Test Sample 6

[0149]

[0150] The peak areas and retention times of Test Sample 7 (Comparative Example 4) are shown in Table 6 below.

[0151] Table 6. Peak area and retention time data of Test Sample 7

[0152]

[0153] Effect Example 2

[0154] The content of Test Sample 2 in Example 2 was detected, and the reference substance used was Reference Substance 2.

[0155] Reference Substance 2: Trehalose crystals with a purity of 99.7% (National Institutes for Food and Drug Control), reference substance concentration: 5.06 g / mL

[0156] Chromatographic conditions:

[0157] Mobile phase: water

[0158] Detection time: 30 min

[0159] Chromatographic column: Sulfonated cross-linked styrene - divinylbenzene copolymer packing

[0160] Column temperature: 80 °C

[0161] Flow rate: 0.4 ml / min

[0162] Detector: Differential refractive index detector

[0163] Detector temperature: 40 °C

[0164] The peak area and retention time of Reference Substance 2 are shown in Table 7 below.

[0165] Table 7. Peak area and retention time data of Reference Substance 2

[0166]

[0167] Water content of Test Substance 2: 9.5%

[0168] The peak area and retention time of Test Substance 2 (Example 2) are shown in Table 8 below.

[0169] Table 8. Peak area and retention time data of Test Substance 2

[0170]

[0171] Effect Example 3

[0172] The content of Test Substance 3 in Example 3 was detected, and the reference substance used was Reference Substance 3.

[0173] Reference Substance 3: Sucrose crystal with a purity of 100% (National Institutes for Food and Drug Control), and the concentration of the reference substance is 5.02 mg / mL.

[0174] Chromatographic conditions:

[0175] Mobile phase: Water

[0176] Detection time: 30 min

[0177] Chromatographic column: Sugar analysis column

[0178] Column temperature: 60 °C

[0179] Flow rate: 0.5 ml / min

[0180] Detector: Differential refractive index detector

[0181] Detector temperature: 40 °C

[0182] Figure 1 This is the HPLC chromatogram of Reference Substance 3, and the peak area and retention time are shown in Table 9 below.

[0183] Table 9. Peak area and retention time data of Reference Substance 3

[0184]

[0185]

[0186] Water content of Test Sample 3: 0.3%

[0187] Figure 2 It is the HPLC chromatogram of Test Sample 3 (Example 3), and the peak areas and retention times are shown in Table 10 below.

[0188] Table 10. Peak area and retention time data of Test Sample 3

[0189]

Claims

1. A method for preparing a disaccharide crystal, characterized in that, It includes the following steps: S1. Filter, microfilter, and ultrafilter the disaccharide solution, and concentrate it under reduced pressure to obtain a concentrated sugar solution. Among them, the disaccharide solution includes a disaccharide raw material and water; the disaccharide raw material is a food-grade disaccharide powder or crystal; the disaccharide is sucrose, lactose, or maltose; the ultrafiltration is carried out using an ultrafiltration membrane; the molecular cut-off of the ultrafiltration is 1000KD - 5000KD; after the reduced-pressure concentration, the mass percentage of the disaccharide in the concentrated sugar solution is 65% - 80%; S2. Mix the concentrated sugar solution and ethanol, cool down, and keep warm after adding crystal seeds. The mixing method is to add ethanol to the concentrated sugar solution; the addition rate of the ethanol is 80 - 180 mL / min; the volume ratio of the ethanol to the concentrated sugar solution is (0.4 - 0.6):1; the crystal seeds are the disaccharide crystals; S3. Cool down, and the cooling rate is 1 - 10 °C / h. During the cooling process, mix with ethanol, and the volume ratio of the ethanol to the concentrated sugar solution is (0.4 - 0.6):

1.

2. The method for preparing a disaccharide crystal according to claim 1, characterized in that, The purity of the disaccharide raw material is greater than 92%; and / or, the mass percentage of the disaccharide in the disaccharide solution is 30% - 50%.

3. The method for preparing a disaccharide crystal according to claim 2, characterized in that, The mass percentage of the disaccharide in the disaccharide solution is 40%.

4. The method for preparing a disaccharide crystal according to claim 1, characterized in that, The preparation of the disaccharide solution is to dissolve the disaccharide raw material in water; the dissolution temperature of the disaccharide raw material is 60 °C.

5. The method for preparing a disaccharide crystal according to claim 4, characterized in that, For the preparation of the disaccharide solution, after the dissolution, it further includes a decolorization treatment; The decolorization treatment is carried out using medicinal activated carbon powder; the mass of the medicinal activated carbon powder is 0.05% - 1% of the mass of the disaccharide solution; The temperature of the decolorization treatment is 65 - 70 °C; The time of the decolorization treatment is 40 - 60 min.

6. The method for preparing a disaccharide crystal according to claim 5, characterized in that, The temperature of the decolorization treatment is 60 °C; and / or, the time of the decolorization treatment is 30 min.

7. The method for preparing a disaccharide crystal according to claim 1, characterized in that, The pressure at the inlet end of the ultrafiltration membrane is 0.1 - 5 bar; and / or, the pressure at the reflux end of the ultrafiltration membrane is 0.1 - 3 bar; and / or, the material of the ultrafiltration membrane is modified polysulfone; and / or, the temperature of the ultrafiltration is 30 - 35 °C.

8. The method for preparing a disaccharide crystal according to claim 1, characterized in that, In step S1, the temperature of the reduced-pressure concentration is 65 - 70 °C.

9. The method for preparing a disaccharide crystal according to claim 1, characterized in that, The mass percentage of the disaccharide in the concentrated sugar solution is 70% or 75%.

10. The method for preparing a disaccharide crystal according to claim 1, characterized in that, In step S2, the volume ratio of the ethanol to the concentrated sugar solution is 0.55:1, 0.50:1, or 0.45:1; and / or, in step S2, the mixing temperature is 65 - 70 °C; and / or, in step S2, cool down to 45 - 60 °C; and / or, in step S2, the holding time is 2 - 5 hours.

11. The method for preparing a disaccharide crystal according to claim 10, characterized in that, In step S2, cool down to 50 °C or 55 °C; and / or, in step S2, the holding time is 3 hours.

12. The preparation method of the disaccharide crystal according to claim 1, characterized in that, The disaccharide crystal seeds are food-grade disaccharide crystals or disaccharide crystals with a content of 92% - 100%; and / or, the mass ratio of the disaccharide crystal seeds to the disaccharide raw material is 0.1% - 0.8%.

13. The preparation method of the disaccharide crystal according to claim 12, characterized in that, The disaccharide crystal seeds are maltose crystals with a purity of 94.4% or sucrose crystals with a purity of 100%; And / or, the mass ratio of the disaccharide seed crystal to the disaccharide raw material is 0.2%.

14. The preparation method of the disaccharide crystal according to claim 1, characterized in that, In step S3, the temperature is reduced to 10 - 30°C; And / or, in step S3, the rate of temperature reduction is 5°C / h; And / or, in step S3, the volume ratio of ethanol to the concentrated sugar solution is 0.45:1, 0.55:1 or 0.50:1; And / or, the equipment for step S2 or step S3 is a vacuum crystallizer.

15. The preparation method of the disaccharide crystal according to claim 1, characterized in that, In step S3, the temperature is reduced to 20°C.

16. The preparation method of the disaccharide crystal according to claim 1, characterized in that, After step S3, separation and drying are further included; wherein, the separation is by centrifugation or filtration.

17. The preparation method of the disaccharide crystal according to claim 16, characterized in that, The separation is carried out at a temperature below 20°C; And / or, the drying is in an oven; And / or, the drying temperature is 80°C.

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