System for obtaining fructose feed liquid by separating, purifying and concentrating enzyme method and application of system

Abstract

The invention relates to a system for obtaining fructose feed liquid through a separation, purification and concentration enzyme method and application of the system. The system for obtaining the fructose feed liquid through the separation, purification and concentration enzyme method comprises an ultrafiltration membrane assembly, an electrodialyzer, a nanofiltration membrane assembly and a concentration membrane assembly which are sequentially connected. The system is based on a membrane technology, has the advantages of high degree of freedom of operation, small occupied space, simplicity and convenience in operation, no additional waste generation and the like, and can finally realize interception and recycling of zymoprotein in fructose feed liquid, removal of phosphate, chlorate and buffer salt and concentration of a fructose product so as to finally obtain a fructose solution product with relatively high purity and concentration. The system can be connected to a reaction device for preparing fructose through enzyme catalysis, and in-situ separation, purification and concentration of fructose feed liquid can be achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of fructose preparation technology, and relates to a system for obtaining fructose liquid by separation, purification, concentration and enzymatic method and its application, and specifically to a system for obtaining fructose liquid by separation, purification, concentration and enzymatic method using membrane technology and capable of realizing in-situ separation, purification and concentration and its application. Background Art

[0002] Fructose is a ketohexose. Compared with the traditional sweet condiment sucrose, fructose is 1.5-2 times sweeter and has lower calories. Fructose can avoid glucose metabolism and effectively prevent obesity, arteriosclerosis and other problems. Therefore, fructose has been widely used in the production of food, beverages, medicines and other commercial products since the 1980s.

[0003] The traditional fructose production method relies on the cultivation of crops. The fructose product is obtained by decomposing disaccharides or polysaccharides such as sucrose, starch, and inulin in the crops, and then further isomerizing and separating the decomposition products and crystallizing them.

[0004] With the development of synthetic biology, it is now expected that the biosynthesis of fructose can be achieved by enzymatic methods, thereby freeing fructose production from dependence on crop cultivation. Among them, the methanol enzymatic method synthesizes fructose using simple compounds such as methanol as substrates through multi-enzyme cascade catalysis. For example, CN113755543A discloses a method for biosynthesizing starch from simple compounds such as methanol, and D-fructose-6-phosphate is one of the intermediates in the synthesis route. Fructose can be obtained after removing the phosphate group.

[0005] The fructose liquid obtained by the enzymatic method is expected to contain a large amount of catalytic enzyme protein, as well as a large amount of product fructose, a large amount of byproduct phosphate, as well as buffer components and some other ions, such as chloride ions. The substrate will not exist in the fructose liquid because it is completely consumed. The accumulation of products and byproducts in the reaction system will inhibit the reaction rate of the multi-enzyme cascade catalytic reaction, so it is necessary to remove them in situ, and at the same time, the enzyme protein needs to be retained in the reaction system for continued catalysis. In order to obtain a higher purity fructose solution product, it is also necessary to remove and separate the buffer components and salt ions in the liquid, and then in order to increase the product concentration, the fructose solution needs to be concentrated.

[0006] Therefore, it is necessary to develop a method for in-situ separation, purification and concentration of enzymatic fructose liquid to obtain a fructose solution product with higher purity and concentration from the fructose liquid. This method will help realize the industrial application of in vitro multi-enzyme catalytic fructose synthesis. Summary of the invention

[0007] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a system for separating, purifying and concentrating fructose feed liquid obtained by enzymatic method and its application, specifically to provide a system for separating, purifying and concentrating fructose feed liquid obtained by enzymatic method using membrane technology and its application.

[0008] To achieve the purpose of this invention, the following technical solutions are adopted:

[0009] In the first aspect, the present invention provides a system for separating, purifying and concentrating fructose feed liquid obtained by enzymatic method, and the system for separating, purifying and concentrating fructose feed liquid obtained by enzymatic method includes an ultrafiltration membrane module, an electrodialyzer, a nanofiltration membrane module and a concentration membrane module connected in sequence.

[0010] For the separation and purification of fructose feed liquid obtained by enzymatic method, the present invention designs a system composed of an ultrafiltration membrane module, an electrodialyzer, a nanofiltration membrane module and a concentration membrane module arranged in a certain order. Based on membrane technology, this system has the advantages of high operation freedom, small space occupation, simple operation, no additional waste generation, etc. It can finally realize the retention and recycling of enzyme proteins in fructose feed liquid, the removal of phosphates, chlorides and buffer salts, and the concentration of fructose products, and finally obtain a fructose solution product with high purity and concentration. This system can be connected to the reaction equipment for enzymatic preparation of fructose, that is, it can realize in-situ separation, purification and concentration of fructose feed liquid.

[0011] Preferably, the components of the fructose feed liquid obtained by enzymatic method include: enzyme protein, phosphate, chloride, fructose and optional non-phosphate buffer salts (such as 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid HEPES, etc.).

[0012] The fructose feed liquid obtained by enzymatic method is expected to contain a large amount of catalytic enzyme proteins, and also contains a large amount of product fructose, a large amount of by-product phosphates, as well as buffer components and some other ions, such as chloride ions, etc. The substrate will not exist in the fructose feed liquid because it has been completely consumed.

[0013] Preferably, the ultrafiltration membrane module is selected from plate-and-frame membrane modules, tubular membrane modules, spiral wound membrane modules or hollow fiber membrane modules.

[0014] Preferably, the operation mode of the ultrafiltration membrane module is selected from dead-end filtration or cross-flow filtration.

[0015] Preferably, the membrane material of the ultrafiltration membrane module includes any one or at least two combinations of polyethersulfone, polysulfone, polyacrylonitrile, regenerated cellulose or cellulose acetate; more preferably polyethersulfone and / or polysulfone.

[0016] Preferably, the molecular weight cut-off of the membrane of the ultrafiltration membrane module is 5,000-30,000 D, such as 5,000 D, 10,000 D, 12,000 D, 15,000 D, 18,000 D, 20,000 D, 22,000 D, 25,000 D, 28,000 D, 30,000 D, etc. Other specific point values within this numerical range can be selected and will not be elaborated one by one here.

[0017] Preferably, the operating pressure difference of the ultrafiltration membrane module is 0.1-1 MPa, such as 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, 1 MPa, etc. Other specific point values within this numerical range can be selected and will not be elaborated one by one here.

[0018] In the present invention, when the membrane material of the ultrafiltration membrane module is selected as polyethersulfone and / or polysulfone and the molecular weight cut-off of the membrane is selected as 5,000-30,000 D, the removal effects of non-target components such as membrane proteins, chlorides, phosphates, and buffer salts are more excellent.

[0019] Preferably, the electrodialyzer is selected from a pressure filter type electrodialyzer or a spiral wound electrodialyzer.

[0020] Preferably, the assembly form of the electrodialyzer includes parallel assembly of one-stage one-pass, parallel assembly of multi-stage one-pass, series assembly of one-stage multi-pass, and series assembly of multi-stage multi-pass.

[0021] Preferably, the electrode material of the electrodialyzer includes any one or a combination of at least two of stainless steel, graphite, ruthenium or its oxide, lead or its oxide, platinum or its oxide, titanium or its oxide, iridium or its oxide, tantalum or its oxide, tungsten or its oxide.

[0022] Preferably, the operating mode of the electrodialyzer includes constant current electrodialysis and / or constant voltage electrodialysis.

[0023] Preferably, the ion exchange membranes of the electrodialyzer are alternately arranged anion exchange membranes and cation exchange membranes.

[0024] Preferably, the active group of the cation exchange membrane includes any one of a sulfonic acid group, a phosphoric acid group, and a carboxylic acid group, and more preferably a sulfonic acid group.

[0025] Preferably, the active group of the anion exchange membrane includes any one of a quaternary amine group, a tertiary amine group, a secondary amine group, and a primary amine group, and more preferably a quaternary amine group.

[0026] In the present invention, when the active group of the cation exchange membrane of the electrodialyzer is selected as the sulfonic acid group and the active group of the anion exchange membrane is selected as the quaternary amine group, the removal effects of non-target components such as membrane proteins, chlorides, phosphates, and buffer salts are more excellent.

[0027] Preferably, the operating mode of the nanofiltration membrane module is crossflow filtration.

[0028] Preferably, the washing and filtering method of the nanofiltration membrane module includes continuous washing and filtering or discontinuous washing and filtering.

[0029] Preferably, the nanofiltration membrane module includes a plate-and-frame membrane module, a tubular membrane module, a spiral-wound membrane module, or a hollow fiber membrane module.

[0030] Preferably, the membrane material of the nanofiltration membrane module includes any one or a combination of at least two of polyethersulfone, polysulfone, cellulose acetate, polyamide, or polyvinyl alcohol; more preferably polyamide.

[0031] Preferably, the molecular weight cut-off of the membrane of the nanofiltration membrane module is 250-400 D, such as 250 D, 280 D, 300 D, 320 D, 350 D, 370 D, 400 D, etc. Other specific point values within this numerical range can be selected and will not be elaborated one by one here.

[0032] Preferably, the operating pressure difference of the nanofiltration membrane module is 0.6-4 MPa, such as 0.6 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa, etc. Other specific point values within this numerical range can be selected and will not be elaborated one by one here.

[0033] In the present invention, when the membrane material of the nanofiltration membrane module is selected as polyamide and the molecular weight cut-off of the membrane is 250-400 D, the removal effects of non-target components such as membrane proteins, chlorides, phosphates, and buffer salts are more excellent.

[0034] Preferably, the operating mode of the concentration membrane module is crossflow filtration or dead-end filtration.

[0035] Preferably, the concentration membrane module includes a plate-and-frame membrane module, a tubular membrane module, a spiral-wound membrane module, or a hollow fiber membrane module.

[0036] Preferably, the membrane material of the concentration membrane module includes any one or a combination of at least two of polyethersulfone, polysulfone, cellulose acetate, polyamide, or polyvinyl alcohol; more preferably polyamide.

[0037] Preferably, the molecular weight cut-off of the membrane of the concentration membrane module is less than 150 D, such as 140 D, 120 D, 100 D, 90 D, 80 D, 70 D, 60 D, 50 D, 30 D, etc. Other specific point values within this numerical range can be selected and will not be elaborated one by one here.

[0038] Preferably, the operating pressure difference of the concentration membrane module is 0.6 - 4 MPa, such as 0.6 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa, etc. Other specific point values within this numerical range can be selected and will not be elaborated one by one here.

[0039] In a second aspect, the present invention provides a method for separating, purifying and concentrating a fructose feed solution obtained by an enzymatic method. The method is carried out using the system for separating, purifying and concentrating a fructose feed solution obtained by an enzymatic method as described in the first aspect, and specifically includes the following steps:

[0040] (1) Subjecting the fructose feed solution obtained by an enzymatic method to ultrafiltration treatment through an ultrafiltration membrane module to obtain an ultrafiltration permeate;

[0041] (2) Using the ultrafiltration permeate as the dilute chamber liquid and subjecting it to electrodialysis treatment through an electrodialyzer to obtain the treated dilute chamber liquid;

[0042] (3) Adjusting the pH of the treated dilute chamber liquid, and then subjecting it to nanofiltration washing filtration treatment through a nanofiltration membrane module to obtain a washing filtration permeate;

[0043] (4) Concentrating the washing filtration permeate through a concentration membrane module to obtain a concentrate.

[0044] Preferably, the components of the fructose feed solution obtained by an enzymatic method include: enzyme protein, phosphate, chloride, fructose and optionally non-phosphate buffer salts.

[0045] Preferably, in step (3), the pH is adjusted to 8.0 - 9.0, such as pH = 8.0, pH = 8.2, pH = 8.4, pH = 8.5, pH = 8.6, pH = 8.7, pH = 8.8, pH = 9.0, etc. Other specific point values within this numerical range can be selected and will not be elaborated one by one here.

[0046] When the pH of the treated dilute chamber liquid is adjusted to 8.0 - 9.0, the removal effects of non-target components such as membrane protein, chloride, phosphate and buffer salt are more excellent.

[0047] In a third aspect, the present invention provides the application of the system for separating, purifying and concentrating a fructose feed solution obtained by an enzymatic method as described in the first aspect and / or the method for separating, purifying and concentrating a fructose feed solution obtained by an enzymatic method as described in the second aspect in the preparation of fructose products.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] For the separation and purification of the fructose liquor obtained by the enzymatic method, the present invention designs a system composed of an ultrafiltration membrane module, an electrodialyzer, a nanofiltration membrane module and a concentration membrane module and arranged in a certain order. Based on the membrane technology, the system has the advantages of high operating freedom, small space occupation, simple operation, no additional waste generation, etc. It can finally realize the retention and recycling of enzyme proteins in the fructose liquor, the removal of phosphates, chlorides and buffer salts, and the concentration of fructose products, and finally obtain a fructose solution product with high purity and concentration. The system can be connected to the reaction equipment for preparing fructose by enzymatic catalysis, that is, in-situ separation, purification and concentration of the fructose liquor can be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 is a schematic diagram of the system for separating, purifying and concentrating the fructose liquor obtained by the enzymatic method involved in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0051] The technical solution of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0052] The feed liquor to be treated used in the following examples is a simulated system feed liquor with a composition similar to that of the methanol enzymatic fructose liquor. The composition of the simulated system feed liquor includes: bovine serum albumin (BSA) 10 g / L, HEPES 0.1 mol / L, NaCl 0.1 mol / L, MgCl2 0.02 mol / L, Na2HPO4 0.42 mol / L, NaH2PO4 0.08 mol / L, and fructose 20 g / L. The pH of the simulated system feed liquor is 7.5.

[0053] The analysis methods and minimum detection concentrations of the components in the simulated system feed liquor are shown in the following table:

[0054]

[0055] Example 1

[0056] This example provides a method for separating, purifying and concentrating the enzymatic fructose liquor, and uses the Figure 1 shown system for treatment, specifically as follows:

[0057] (1) The feed liquor to be treated is ultrafiltered through the ultrafiltration membrane module to obtain an ultrafiltration permeate; the operation mode adopted in this process is cross-flow filtration. The ultrafiltration membrane module is a plate-and-frame membrane module, and a polyethersulfone flat membrane with a molecular weight cut-off of 10,000 D is used in the module. The operating pressure difference of the cross-flow filtration system is 0.2 MPa.

[0058] (2) Use the ultrafiltration permeate as the dilute chamber liquid and perform electrodialysis treatment through an electrodialyzer to obtain the treated dilute chamber liquid; in this process, a pressure filtration type electrodialyzer is used, the assembly form is one-stage and one-pass, the number of membrane stacks in the electrodialyzer is 4 pairs, that is, the membrane stack consists of 4 concentrated chambers and 4 dilute chambers. Select a sulfonic acid type homogeneous cation exchange membrane and a quaternary amine type homogeneous anion exchange membrane, and the effective membrane area of a single ion exchange membrane is 88.32 cm 2 . This electrodialysis system adopts an operating mode combining constant current circulating electrodialysis and constant pressure circulating electrodialysis. When operating at a constant current, the current density is 39 mA / cm 2 , and when operating at a constant pressure, the voltage is 9 V. The electrodialysis electrode chamber liquid is selected as a Na2SO4 solution with a concentration of 0.3 mol / L, the electrodialysis concentrated chamber liquid is selected as a sodium phosphate buffer solution with a concentration of 0.05 mol / L (pH = 7.6), the volumes of the dilute chamber liquid, concentrated chamber liquid, and electrode chamber liquid are all 1 L, and the linear velocity of the dilute chamber liquid and concentrated chamber liquid in each chamber is 0.57 m / s. The electrodialysis system uses a stainless steel plate as the cathode and a tungsten plate as the anode.

[0059] (3) Use 1 mol / L NaOH solution to adjust the pH of the treated dilute chamber liquid to 9.0, and then perform nanofiltration washing and filtering treatment through a nanofiltration membrane module to obtain the washing and filtering permeate; the operating method adopted is cross-flow filtration, the washing and filtering method adopted is continuous washing and filtering, the nanofiltration membrane module is a plate-and-frame type membrane module, and a polyamide flat membrane with a cut-off molecular weight of 400 D is used in the module. The operating pressure difference of the cross-flow nanofiltration system is 0.6 MPa.

[0060] (4) Concentrate the washing and filtering permeate through a concentration membrane module. The operating method adopted by the concentration system is constant current dead-end nanofiltration. The nanofiltration membrane module is a plate-and-frame type membrane module, and a polyamide flat nanofiltration membrane with a cut-off molecular weight of 150 D is used in the module. The membrane flux in the constant current operation is 2 L / (m 2 ·h) to obtain the concentrated liquid, which is the fructose solution product.

[0061] Example 2

[0062] This example provides a method for separating, purifying, and concentrating an enzymatic fructose feed liquid, which is processed using the system shown in Figure 1 as follows:

[0063] (1) Ultrafilter the feed liquid to be treated through an ultrafiltration membrane module to obtain the ultrafiltration permeate; in this process, the operating method adopted is cross-flow filtration, the ultrafiltration membrane module is a spiral wound membrane module, and a polysulfone 1812 type spiral wound membrane with a cut-off molecular weight of 20000 D is used in the module. The operating pressure difference of the cross-flow filtration system is 0.4 MPa.

[0064] (2) Use the ultrafiltration permeate as the dilute chamber liquid, and perform electrodialysis treatment through an electrodialyzer to obtain the treated dilute chamber liquid; in this process, a pressure filter type electrodialyzer is used, the assembly form is one-stage and one-pass, the number of membrane stacks in the electrodialyzer is 4 pairs, that is, the membrane stack consists of 4 concentrated chambers and 4 dilute chambers. Select a sulfonic acid type homogeneous cation exchange membrane and a quaternary amine type homogeneous anion exchange membrane, and the effective membrane area of a single ion exchange membrane is 88.32 cm 2 . This electrodialysis system adopts an operation mode combining constant current circulation electrodialysis and constant pressure circulation electrodialysis. When operating at a constant current, the current density is 39 mA / cm 2 , and when operating at a constant pressure, the voltage is 9 V. The electrodialysis electrode chamber liquid is selected as a Na2SO4 solution with a concentration of 0.3 mol / L, the electrodialysis concentrated chamber liquid is selected as a sodium phosphate buffer solution (pH = 7.6) with a concentration of 0.05 mol / L, and the volumes of the dilute chamber liquid, concentrated chamber liquid, and electrode chamber liquid are all 1 L. The linear velocity of the dilute chamber liquid and the concentrated chamber liquid in each chamber is 0.57 m / s. The electrodialysis system uses a graphite plate as the cathode and a tungsten plate as the anode.

[0065] (3) Use 1 mol / L NaOH solution to adjust the pH of the treated dilute chamber liquid to 8.0, and then perform nanofiltration washing and filtering treatment through a nanofiltration membrane module to obtain the washing and filtering permeate; the operation mode adopted is cross-flow filtration, the washing and filtering method adopted is continuous washing and filtering, the nanofiltration membrane module is a spiral wound membrane module, and a polyamide 1812 type spiral wound membrane with a molecular weight cut-off of 300 D is used in the module. The operating pressure difference of the cross-flow nanofiltration system is 1.0 MPa.

[0066] (4) Concentrate the washing and filtering permeate through a concentration membrane module. The operation mode adopted by the concentration system is constant current dead-end nanofiltration. The nanofiltration membrane module is a spiral wound membrane module, and a polyamide spiral wound membrane with a molecular weight cut-off of 100 D is used in the module. The membrane flux in the constant current operation is 2 L / (m 2 ·h) to obtain the concentrated liquid, which is the fructose solution product.

[0067] Example 3

[0068] This example provides a method for separating, purifying, and concentrating an enzymatic fructose feed liquid, which is processed using the Figure 1 shown system. The specific operation is only different from that of Example 1 in that the polyethersulfone flat membrane with a molecular weight cut-off of 10000 D is replaced with a polyacrylonitrile flat membrane with a molecular weight cut-off of 10000 D, and other conditions remain unchanged.

[0069] Example 4

[0070] This example provides a method for separating, purifying, and concentrating an enzymatic fructose feed liquid, which is processed using the Figure 1The system shown is processed. The specific operation is only different from that of Example 1 in that the polyethersulfone flat membrane with a molecular weight cut-off of 10,000 D is replaced by a cellulose acetate flat membrane with a molecular weight cut-off of 10,000 D, and other conditions remain unchanged.

[0071] Example 5

[0072] This example provides a method for separating, purifying and concentrating an enzymatic fructose feed solution, using Figure 1 the system shown is processed. The specific operation is only different from that of Example 1 in that the polyethersulfone flat membrane with a molecular weight cut-off of 10,000 D is replaced by a polyethersulfone flat membrane with a molecular weight cut-off of 40,000 D, and other conditions remain unchanged.

[0073] Example 6

[0074] This example provides a method for separating, purifying and concentrating an enzymatic fructose feed solution, using Figure 1 the system shown is processed. The specific operation is only different from that of Example 1 in that the polyethersulfone flat membrane with a molecular weight cut-off of 10,000 D is replaced by a polyethersulfone flat membrane with a molecular weight cut-off of 3,000 D, and other conditions remain unchanged.

[0075] Example 7

[0076] This example provides a method for separating, purifying and concentrating an enzymatic fructose feed solution, using Figure 1 the system shown is processed. The specific operation is only different from that of Example 1 in that the sulfonic acid type homogeneous cation membrane and the quaternary amine type homogeneous anion membrane are replaced by the sulfonic acid type homogeneous cation membrane and the tertiary amine type homogeneous anion membrane, and other conditions remain unchanged.

[0077] Example 8

[0078] This example provides a method for separating, purifying and concentrating an enzymatic fructose feed solution, using Figure 1 the system shown is processed. The specific operation is only different from that of Example 1 in that the sulfonic acid type homogeneous cation membrane and the quaternary amine type homogeneous anion membrane are replaced by the phosphoric acid type homogeneous cation membrane and the quaternary amine type homogeneous anion membrane, and other conditions remain unchanged.

[0079] Example 9

[0080] This example provides a method for separating, purifying and concentrating an enzymatic fructose feed solution, using Figure 1 the system shown is processed. The specific operation is only different from that of Example 1 in that the sulfonic acid type homogeneous cation membrane and the quaternary amine type homogeneous anion membrane are replaced by the carboxylic acid type homogeneous cation membrane and the secondary amine type homogeneous anion membrane, and other conditions remain unchanged.

[0081] Example 10

[0082] This example provides a method for separating, purifying and concentrating an enzymatic fructose feed solution, usingFigure 1 The system shown is processed. The specific operation is only different from that of Example 1 in that the polyamide flat membrane with a molecular weight cut-off of 400 D is replaced by a polyethersulfone flat membrane with a molecular weight cut-off of 400 D, and other conditions remain unchanged.

[0083] Example 11

[0084] This example provides a method for separating, purifying, and concentrating an enzymatic fructose solution. It is processed using the Figure 1 system shown. The specific operation is only different from that of Example 1 in that the polyamide flat membrane with a molecular weight cut-off of 400 D is replaced by a polysulfone flat membrane with a molecular weight cut-off of 400 D, and other conditions remain unchanged.

[0085] Example 12

[0086] This example provides a method for separating, purifying, and concentrating an enzymatic fructose solution. It is processed using the Figure 1 system shown. The specific operation is only different from that of Example 1 in that the polyamide flat membrane with a molecular weight cut-off of 400 D is replaced by a polyamide flat membrane with a molecular weight cut-off of 600 D, and other conditions remain unchanged.

[0087] Example 13

[0088] This example provides a method for separating, purifying, and concentrating an enzymatic fructose solution. It is processed using the Figure 1 system shown. The specific operation is only different from that of Example 1 in that the polyamide flat membrane with a molecular weight cut-off of 400 D is replaced by a polyamide flat membrane with a molecular weight cut-off of 150 D, and other conditions remain unchanged.

[0089] Example 14

[0090] This example provides a method for separating, purifying, and concentrating an enzymatic fructose solution. It is processed using the Figure 1 system shown. The specific operation is only different from that of Example 1 in that in step (3), the pH of the treated dilute chamber solution is adjusted to 7.0 using 1 mol / L NaOH solution, and other conditions remain unchanged.

[0091] Test Example

[0092] The fructose solution products prepared in Examples 1 - 14 are tested for BSA, HEPES, Cl - , PO4 3- , and fructose content. The test results of each group are shown in Table 1:

[0093] Table 1

[0094]

[0095]

[0096] As can be seen from the data in Table 1, the separation, purification and concentration system and method involved in the present invention can ultimately achieve the retention and recycling of enzyme proteins in the fructose feed solution, the removal of phosphates, chlorides and buffer salts, and the concentration of fructose products, and finally obtain a fructose solution product with high purity and concentration. Moreover, the membrane type and molecular retention volume of the ultrafiltration membrane module, the membrane type and molecular retention volume of the nanofiltration membrane module, the membrane type of electrodialysis, etc. all affect the above technical effects.

[0097] The applicant declares that the present invention uses the above embodiments to illustrate the technical solutions of the present invention, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc. all fall within the protection scope and the disclosure scope of the present invention.

[0098] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0099] In addition, it should be noted that, in the case of no contradiction, the various specific technical features described in the above specific embodiments can be combined in any appropriate manner. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

Claims

1. A system for separating, purifying and concentrating a fructose feed solution obtained by an enzymatic method, characterized in that, The system for obtaining fructose feed liquid by separation, purification and concentration through enzymatic method comprises an ultrafiltration membrane module, an electrodialyzer, a nanofiltration membrane module and a concentration membrane module which are connected in sequence.

2. The system for obtaining a fructose feed solution by separation, purification and concentration using an enzymatic method according to claim 1, wherein The components of the fructose feed liquid obtained by enzymatic method include: enzyme protein, phosphate, chloride, fructose and optionally non-phosphate buffer salts.

3. The system for obtaining a fructose feed solution by separation, purification and concentration using an enzymatic method according to claim 1, characterized in that, The ultrafiltration membrane module is selected from plate-and-frame membrane module, tubular membrane module, spiral-wound membrane module or hollow fiber membrane module; Preferably, the operation mode of the ultrafiltration membrane module is selected from dead-end filtration or cross-flow filtration; Preferably, the membrane material of the ultrafiltration membrane module includes any one or a combination of at least two of polyethersulfone, polysulfone, polyacrylonitrile, regenerated cellulose or cellulose acetate; more preferably polyethersulfone and / or polysulfone; Preferably, the molecular weight cut-off of the membrane of the ultrafiltration membrane module is 5000 - 30000D; Preferably, the operation pressure difference of the ultrafiltration membrane module is 0.1 - 1MPa.

4. The system for obtaining fructose liquor by separation, purification and concentration through enzymatic method according to claim 1, wherein, The electrodialyzer is selected from pressure filter type electrodialyzer or spiral-wound electrodialyzer; Preferably, the assembly form of the electrodialyzer includes parallel assembly of one-stage one-pass, parallel assembly of multi-stage one-pass, series assembly of one-stage multi-pass, series assembly of multi-stage multi-pass; Preferably, the electrode material of the electrodialyzer includes any one or a combination of at least two of stainless steel, graphite, ruthenium or its oxide, lead or its oxide, platinum or its oxide, titanium or its oxide, iridium or its oxide, tantalum or its oxide, tungsten or its oxide; Preferably, the operation mode of the electrodialyzer includes constant current electrodialysis and / or constant voltage electrodialysis.

5. The system for obtaining a fructose solution by separation, purification and concentration using an enzymatic method according to any one of claims 1-4, characterized in that, The ion exchange membranes of the electrodialyzer are alternately arranged anion exchange membranes and cation exchange membranes; Preferably, the active group of the cation exchange membrane includes any one of sulfonic acid group, phosphoric acid group, carboxylic acid group, more preferably sulfonic acid group; Preferably, the active group of the anion exchange membrane includes any one of quaternary amine group, tertiary amine group, secondary amine group, primary amine group, more preferably quaternary amine group.

6. The system for obtaining a fructose feed solution by separation, purification and concentration using an enzymatic method according to claim 1, wherein The operation mode of the nanofiltration membrane module is cross-flow filtration; Preferably, the washing and filtering method of the nanofiltration membrane module includes continuous washing and filtering or discontinuous washing and filtering; Preferably, the nanofiltration membrane module includes plate-and-frame membrane module, tubular membrane module, spiral-wound membrane module or hollow fiber membrane module; Preferably, the membrane material of the nanofiltration membrane module includes any one or a combination of at least two of polyethersulfone, polysulfone, cellulose acetate, polyamide or polyvinyl alcohol; more preferably polyamide; Preferably, the molecular weight cut-off of the membrane of the nanofiltration membrane module is 250 - 400D; Preferably, the operation pressure difference of the nanofiltration membrane module is 0.6 - 4MPa.

7. The system for obtaining fructose liquor by separation, purification and concentration through enzymatic method according to claim 1, characterized in that, The operation mode of the concentration membrane module is cross-flow filtration or dead-end filtration; Preferably, the concentration membrane module includes plate-and-frame membrane module, tubular membrane module, spiral-wound membrane module or hollow fiber membrane module; Preferably, the membrane material of the concentration membrane module includes any one or a combination of at least two of polyethersulfone, polysulfone, cellulose acetate, polyamide or polyvinyl alcohol; more preferably polyamide; Preferably, the molecular weight cut-off of the membrane of the concentration membrane module is less than 150D; Preferably, the operation pressure difference of the concentration membrane module is 0.6 - 4MPa.

8. A method for separating, purifying and concentrating a fructose feed solution obtained by an enzymatic method, characterized in that, The method is carried out using the system for obtaining fructose feed liquid by the separation, purification and concentration enzymatic method described in any one of claims 1-7, and specifically includes the following steps: (1) Subjecting the fructose feed liquid obtained by the enzymatic method to ultrafiltration treatment through an ultrafiltration membrane module to obtain an ultrafiltration permeate; (2) Using the ultrafiltration permeate as the dilute chamber liquid and subjecting it to electrodialysis treatment through an electrodialyzer to obtain the treated dilute chamber liquid; (3) Adjusting the pH of the treated dilute chamber liquid, and then subjecting it to nanofiltration washing filtration treatment through a nanofiltration membrane module to obtain a washing filtration permeate; (4) Concentrating the washing filtration permeate through a concentration membrane module to obtain a concentrate.

9. The method for obtaining a fructose feed solution by separation, purification and concentration using an enzymatic method according to claim 8, characterized in that, The components of the fructose feed liquid obtained by the enzymatic method include: enzyme protein, phosphate, chloride, fructose and optionally non-phosphate buffer salts; Preferably, the pH in step (3) is adjusted to 8.0-9.

0.

10. Use of the system for obtaining fructose feed liquid by the separation, purification and concentration enzymatic method described in any one of claims 1-7 and / or the method for obtaining fructose feed liquid by the separation, purification and concentration enzymatic method described in any one of claims 8-9 in the preparation of fructose products.

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