Method for preparing psicose using recycling

Abstract

The present invention relates to a method for preparing psicose by effectively utilizing a psicose crystallization mother liquor obtained in a psicose crystallization process, and specifically, relates to a method of preparation of psicose by putting a psicose crystallization mother liquor obtained in a psicose crystallization process into one or more kinds of processes selected from the group consisting of activated carbon treatment, ion purification process, simulated moving bed chromatography separation process and concentration process of psicose fraction to recycle.

Claims

1. A method of preparation for psicose, comprising providing a psicose crystallization mother liquor into a psicose separation process to obtain psicose, wherein the psicose separation process comprises one or more of steps selected from the group consisting of activated carbon treatment, ion purification and simulated moving bed (SMB) chromatography separation, and wherein the psicose crystallization mother liquor is provided into the psicose separation process and mixed with a solution in the psicose separation process to produce a mixed solution such that the content of psicose in the mixed solution before being treated by the psicose separation process is 15% by weight to 50% by weight based on 100% by weight of the total solid content.

2. The method of preparation of claim 1, wherein the psicose crystallization mother liquor is obtained by performing SMB chromatography separation of psicose conversion product to produce a psicose fraction, ion purification and concentration of the psicose fraction to produce psicose concentrates, and crystallization of the concentrates to prepare a psicose crystal.

3. The method of preparation of claim 1, wherein the psicose crystallization mother liquor is treated by being putting into the psicose separation process.

4. The method of preparation of claim 1, wherein the psicose crystallization mother liquor is treated by the ion purification and SMB chromatography separation process in order, with being put into the ion purification step.

5. The method of preparation of claim 4, wherein the activated carbon treatment step is performed, before the ion purification step.

6. The method of preparation of claim 1, wherein the psicose crystallization mother liquor is treated by the activated carbon treatment, ion purification and simulated moving bed (SMB) chromatography separation process in order, with being put into the activated carbon treatment step.

7. The method of preparation of claim 1, wherein the psicose crystallization mother liquor comprises 80% by weight or higher of psicose content based on 100% by weight of the total solid content.

8. The method of preparation of claim 1, wherein the SMB chromatography process is carried out with a column chromatograph packed with cation exchange resin having calcium active group.

9. The method of preparation of claim 1, wherein the psicose content in the psicose fraction is 85% by weight or higher based on 100% by weight of the total solid content.

10. The method of preparation of claim 1, wherein the psicose crystallization mother liquor is obtained by converting a fructose-containing raw material into psicose to produce psicose conversion product, treating the psicose conversion product with ion purification and the simulated moving bed (SMB) chromatography process to produce psicose fraction, performing ion purification and concentration of the psicose fraction to produce psicose concentrate, and preparing psicose crystals from the concentrate.

11. The method of preparation of claim 10, wherein the psicose crystallization mother liquor is obtained by converting a fructose-containing raw material into psicose with using biological catalyst, to produce psicose conversion product, treating the psicose conversion product with activated carbon treatment, ion purification and the simulated moving bed (SMB) chromatography process to produce psicose fraction, performing ion purification and concentration of the psicose fraction to produce psicose concentrate, and preparing psicose crystals from the concentrate.

12. The method of preparation of claim 10, wherein the fructose content in fructose-containing raw material is 85% by weight or higher based on 100% by weight of the total solid content.

13. The method of preparation of claim 9, wherein the psicose conversion reaction is performed with a biological catalyst having 15% to 70% of the psicose conversion rate.

14. The method of preparation of claim 9, further comprising a step of treating fructose raffinate obtained in the SMB chromatography separation process with one or more steps selected from the group consisting of cooling, pH adjustment, ion purification and concentration processes, and recycling as a raw material of psicose conversion reaction.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a diagram showing one example of general SMB process.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(2) Hereinafter, the present invention will be described in more detail with the following examples. However, these examples are only for illustrative purpose, and the scope of the present invention is not limited by these examples.

Preparative Example 1. Preparation of Psicose Syrup

(3) A psicose syrup was prepared from a fructose substrate by the biological method substantially same with the preparation method disclosed in the Korean laid-open patent publication No. 2014-0054997.

(4) Specifically, the encoding gene of psicose epimerase derived from Clostridiuim scindens (Clostridiuim scindens ATCC 35704) (DPE gene; Gene bank: EDS06411.1) was introduced into a recombinant vector (pCES_sodCDPE), and Corynebacterium glutaricum was transformed by using the prepared recombinant vector (pCES_sodCDPE) plasmid with electroporation. A bead including the transformed Corynebacterium glutaricum cell was prepared and packed into an immobilization reaction column, and a psicose syrup was prepared from 40 bix of 88% by weight of fructose or 95% by weight of fructose. That is, the psicose syrup of 21-23 (w/w) % of which solid mixture weight ratio of glucose:fructose:psicose:oligosaccharide is 41:39:15:5 from 88% by weight of fructose-containing substrate (psicose syrup A), and the psicose syrup of 24-26 (w/w) % of which glucose:fructose:psicose:oligosaccharide=6:67:25:2 from the raw material comprising 95% by weight of fructose content (psicose syrup B).

Preparative Example 2: Preparation of Psicose Crystallization Mother Liquor

(5) In order to remove impurities such as colored and ion components, etc in two kinds of psicose syrups obtained in Preparative Example 1, after desalting by passing solution at the rate of twice (1-2 times) volumes of ion exchange resin per hour into the column at room temperature packed with cation exchange resin, anion exchange resin and resin in which cation exchange resin and anion exchange resin are mixed, the high purity of psicose solution was separated and collected by using a chromatography packed with calcium (Ca.sup.2+) type of ion exchange resin. The psicose fraction comprised the psicose content of 95 to 98% by weight and the fructose raffinate comprised the fructose 85 to 95% by weight, glucose 1 to 10% by weight and reducing sugar 1 to 5% by weight, which were collected from the psicose syrup obtained from the raw material of fructose content of 88% by weight (psicose syrup A). The psicose fraction comprised the psicose content of 95 to 98% by weight and the fructose raffinate comprised the fructose 88 to 97% by weight, glucose 1 to 8% by weight and reducing sugar 1 to 4% by weight, which were collected from the psicose syrup obtained from the raw material of fructose content of 95% by weight (psicose syrup B).

(6) The psicose fraction was concentrated at the concentration of 82Bx (%, w/w) (80-83Bx), and cooled slowly from the temperature of 35° C. (35-40° C.) at which it became supersaturated up to the temperature of 10° C. (10-15° C.), thereby generating crystals. Then the psicose seed crystals were not added, and the psicose crystals collected in the crystallization step were centrifugally dehydrated, thereby obtaining the psicose crystallization mother liquor and crystals. After the psicose crystals were washed with cooling water, they were dried and collected. The psicose crystallization mother liquor comprised the psicose content of 88 to 92% by weight. The average particle size of obtained psicose crystal powder was 237 μm, and its particle diameter range was distributed in 74-428 μm, and it had a long rectangular shape of crystal structure rhombic system.

Example 1: Production of Psicose Using Recycling of Psicose Crystallization Mother Liquor

(7) To produce 10 tons of solids of 95% by weight of psicose content by using the fructose-containing raw material solution of 88% by weight of fructose content obtained in Preparative Example 1, the psicose conversion process and separation process were carried out at flow rate 3.8 m.sup.3/hr. The psicose content of reactants collected through the psicose conversion process was 20 to 24% by weight, and they passed through the separation process at a concentration of 45 to 50% by weight after ion purification. The psicose content of psicose fraction obtained by separating it using Ca+ type separation resin was 95 to 98% by weight, and the total solids were 5 to 9% by weight. The psicose fraction was used for the crystallization process through ion purification and concentration. The psicose solution put into the crystallization process had the psicose content of 80 to 82% by weight, and it was crystallized through cooling crystallization generally used for the crystallization process. After the crystallization reaction, crystals and mother liquor which was not crystallized were separated by a dehydrator. Then the yield of crystallization was 45 to 60%. The psicose conversion reaction and crystallization method were carried out by the substantially same method with Preparative Examples 1 and 2.

(8) The generated psicose crystallization mother liquor was recovered all and mixed with the psicose conversion reactant syrup of psicose content 20 to 24% by weight which passed the psicose conversion process, thereby maintaining the psicose content of mixture to 30% by weight. The psicose mixture with the psicose content of 30% by weight was passed through SMB chromatography separation process via ion purification. The mixture and the composition of saccharides of fructose raffinate by each process we analyzed and shown in the following Table 1.

(9) The yield shown in the following Table 1 represented the solid content comprised in result obtained after treating the corresponding process as % by weight based on 100% by weight of solid content of input provided for the corresponding process. The content of raw material before treatment and result after treatment by each process of the following Table 1 represented the content of each compositional component as % by weight based on 100% by weight of the total solid content comprised in input or result of corresponding process.

(10) TABLE-US-00001 TABLE 1 Saccharides including disaccharides or higher degree of Reducing Classification polymerization Glucose Fructose Psicose sugar Yield Fructose raw material 1.1% 5.0% 88.1% 0.0% 5.8% — Psicose conversion 1.1% 5.0% 65.2% 22.9% 5.8% — reaction solution Mixed solution of 0.6% 3.5% 61.8% 30.2% 3.9% — psicose conversion reaction and crystallization mother liquor Reaction solution after 0.6% 3.5% 61.8% 30.2% 3.9% — purification/concentration Psicose fraction after 0.0% 0.0% 0.6% 98.0% 1.4% 28.5% SMB high purity separation Fructose raffinate after 1.2% 6.3% 86.9% 1.3% 4.3% 81.5% SMB high purity separation Purification/concentration 0.0% 0.0% 0.6% 98.0% 1.4% — of psicose fraction Psicose crystal 0.0% 0.0% 0.1% 99.9% 0.0% 55.2% Cyrstallization 0.0% 0.0% 5.5% 91.2% 3.3% 44.8% motherliquor

(11) As shown in the Table 1, when the psicose preparation process was operated by using 88 wt % of fructose content of fructose raw material by weight based on 100% by weight of total content of solids, the psicose conversion rate represented about 23%. When the process was operated by mixing the crystallization mother liquor and setting the psicose 30% by weight, the psicose fraction obtained after conducting SMB high-purity separation had the psicose content of 95% by weight or higher. It was demonstrated that the production of high purity psicose was increased by increasing the separation yield according to raising the psicose content of raw material before treatment which was put into the SMB high purity process by recycling the psicose crystallization mother liquor.

Example 2: Production of Psicose Using Recycling of Psicose Crystallization Mother Liquor

(12) To produce 10 tons of solids of 95% by weight of psicose content by using the fructose-containing raw material solution of 88% by weight of fructose content obtained in Preparative Example 1, the psicose conversion process and separation process were carried out at flow rate 3.8 m.sup.3/hr. The psicose content of reactants collected through the psicose conversion process was 20 to 24% by weight, and they passed through the separation process at a concentration of 45 to 50% by weight after ion purification. The psicose content of psicose fraction obtained by separating it using Ca.sup.2+ type separation resin was 95 to 98% by weight, and the total solids were 5 to 9% by weight. The psicose fraction was used for the crystallization process through ion purification and concentration. The psicose solution put into the crystallization process had the psicose content of 80 to 82% by weight, and it was crystallized through cooling crystallization generally used for the crystallization process. After the crystallization reaction, crystals and mother liquor which was not crystallized were separated by a dehydrator. Then the yield of crystallization was 45 to 60%. The psicose conversion reaction and crystallization method were carried out by the substantially same method with Preparative Examples 1 and 2.

(13) The produced psicose crystallization mother liquor was recovered as a whole and mixed with the psicose conversion product syrup of psicose content 20 to 24% by weight which passed the psicose conversion process, thereby maintaining the psicose content of mixture to 40% by weight. The psicose mixture with the psicose content of 40% by weight was passed through SMB chromatography separation process after ion purification. The saccharides composition of the mixture and fructose raffinate obtained by each process were analyzed and shown in the following Table 2. The yield and content indication criteria in the following Table 2 were the same those defined in the Table 1.

(14) TABLE-US-00002 TABLE 2 Saccharides including disaccharides or higher degree of Reducing Classification polymerization Glucose Fructose Psicose sugar Yield Fructose raw material 1.1% 5.0% 88.1% 0.0% 5.8% — Psicose conversion 1.1% 5.0% 65.2% 22.9% 5.8% — reaction solution Mixed solution of 0.3% 2.3% 54.7% 40.6% 2.1% — psicose conversion reaction and crystallization mother liquor Reaction solution after 0.3% 2.3% 54.7% 40.6% 2.1% — purification/concentration Psicose fraction after 0.0% 0.0% 0.1% 97.6% 2.3% 38.4% SMB high purity separation Fructose raffinate after 1.2% 8.6% 84.4% 2.2% 3.6% 61.6% SMB high purity separation Purification/concentration 0.0% 0.0% 0.1% 97.6% 2.3% — of psicose fraction Psicose crystal 0.0% 0.0% 0.1% 99.9% 0.0% 56.6% Cyrstallization 0.0% 0.0% 6.8% 90.3% 2.9% 43.4% motherliquor

(15) As shown in the Table 2, when the psicose preparation process was operated by using 88 wt % of fructose content of fructose raw material by weight based on 100% by weight of total content of solids, the psicose conversion rate represented about 23%, and the psicose fraction obtained after conducting SMB high purity separation by mixing the crystallization mother liquor and setting the psicose 40% by weight had the psicose content of 95% by weight or higher. It was demonstrated that the production of high purity psicose was increased by increasing the separation yield according to raising the psicose content of raw material before treatment which was put into the SMB high purity process by recycling the psicose crystallization mother liquor.

Example 3: Production of Psicose Using Recycling of Psicose Crystallization Mother Liquor

(16) To produce 10 tons of solids of 95% by weight of psicose content by using the fructose-containing raw material solution of 95% by weight of fructose content obtained in Preparative Example 1, the psicose conversion process and separation process were carried out at flow rate 3.8 m.sup.3/hr. The psicose content of reactants collected through the psicose conversion process was 24 to 27% by weight, and they passed through the separation process at a concentration of 45 to 50% by weight after ion purification. The psicose content of psicose fraction obtained by separating it using Ca+ type separation resin was 95 to 98% by weight, and the total solids were 5 to 9% by weight. The psicose fraction was used for the crystallization process through ion purification and concentration. The psicose solution put into the crystallization process had the psicose content of 80 to 82% by weight, and it was crystallized through cooling crystallization generally used for the crystallization process. After the crystallization reaction, crystals and mother liquor which was not crystallized were separated by a dehydrator. Then the yield of crystallization was 45 to 60%. The psicose conversion reaction and crystallization method were carried out by the substantially same method with Preparative Examples 1 and 2.

(17) The generated psicose crystallization mother liquor was recovered all and mixed with the psicose conversion reactant syrup of psicose content 24 to 27% by weight which passed the psicose conversion process, thereby maintaining the psicose content of mixture to 30% by weight. The psicose mixture with the psicose content of 30% by weight was passed through SMB chromatography separation process via ion purification. The saccharides composition of the mixture and fructose raffinate obtained by each process were analyzed and shown in the following Table 3. The yield and content indication criteria in the following Table 3 were the same those defined in the Table 1.

(18) TABLE-US-00003 TABLE 3 Saccharides including disaccharides or higher degree of Reducing Classification polymerization Glucose Fructose Psicose sugar Yield Fructose raw material 0.6% 2.6% 95.2% 0.0% 1.6% — Psicose conversion 0.6% 2.5% 67.4% 26.4% 2.5% — reaction solution Mixed solution of 0.5% 2.2% 67.4% 30.2% 2.2% — psicose conversion reaction and crystallization mother liquor Reaction solution after 0.5% 2.2% 67.4% 30.2% 2.2% — purification/concentration Psicose fraction after 0.0% 0.0% 1.2% 96.2% 2.3% 28.5% SMB high purity separation Fructose raffinate after 1.2% 4.6% 89.6% 1.4% 3.2% 81.5% SMB high purity separation Purification/concentration 0.0% 0.0% 0.6% 98.0% 1.4% — of psicose fraction Psicose crystal 0.0% 0.0% 0.1% 99.9% 0.0% 53.5% Cyrstallization 0.0% 0.0% 6.3% 89.8% 3.9% 46.5% motherliquor

(19) As shown in the Table 3, when the psicose preparation process was operated by using 95.2 wt % of fructose content of fructose raw material by weight based on 100% by weight of total content of solids, the psicose conversion rate represented about 26.4%, and the psicose fraction obtained after conducting SMB high purity separation by mixing the crystallization mother liquor and setting the psicose 30% by weight had the psicose content of 95% by weight or higher. It was demonstrated that the production of high purity psicose was increased by increasing the separation yield according to raising the psicose content of raw material before treatment which was put into the SMB high purity process by recycling the psicose crystallization mother liquor.

Example 4: Production of Psicose Using Recycling of Psicose Crystallization Mother Liquor

(20) To produce 10 tons of solids of 95% by weight of psicose content by using the fructose-containing raw material solution of 95% by weight of fructose content obtained in Preparative Example 1, the psicose conversion process and separation process were carried out at flow rate 3.8 m.sup.3/hr. The psicose content of reactants collected through the psicose conversion process was 24 to 27% by weight, and they passed through the separation process at a concentration of 45 to 50% by weight after ion purification. The psicose content of psicose fraction obtained by separating it using Ca+ type separation resin was 95 to 98% by weight, and the total solids were 5 to 9% by weight. The psicose fraction was used for the crystallization process through ion purification and concentration. The psicose solution put into the crystallization process had the psicose content of 80 to 82% by weight, and it was crystallized through cooling crystallization generally used for the crystallization process. After the crystallization reaction, crystals and mother liquor which was not crystallized were separated by a dehydrator. Then the yield of crystallization was 45 to 60%. The psicose conversion reaction and crystallization method were carried out by the substantially same method with Preparative Examples 1 and 2.

(21) The generated psicose crystallization mother liquor was recovered all and mixed with the psicose conversion reactant syrup of psicose content 24 to 27% by weight which passed the psicose conversion process, thereby maintaining the psicose content of mixture to 40% by weight. The psicose mixture with the psicose content of 40% by weight was passed through SMB chromatography separation process via ion purification. The saccharides composition of the mixture and fructose raffinate obtained by each process were analyzed and shown in the following Table 4. The yield and content indication criteria in the following Table 4 were the same those defined in the Table 1.

(22) TABLE-US-00004 TABLE 4 Saccharides including disaccharides or higher degree of Reducing Classification polymerization Glucose Fructose Psicose sugar Yield Fructose raw material 0.6% 2.6% 95.2% 0.0% 1.6% — Psicose conversion 0.6% 2.5% 67.4% 26.4% 2.5% — reaction solution Mixed solution of 0.3% 1.6% 56.3% 40.1% 1.7% — psicose conversion reaction and crystallization mother liquor Reaction solution after 0.3% 1.6% 56.3% 40.1% 1.7% — purification/concentration Psicose fraction after 0.0% 0.0% 0.8% 97.1% 2.1% 37.8% SMB high purity separation Fructose raffinate after 1.0% 4.1% 88.6% 3.6% 2.7% 62.2% SMB high purity separation Purification/concentration 0.0% 0.0% 0.8% 97.1% 2.1% — of psicose fraction Psicose crystal 0.0% 0.0% 0.1% 99.9% 0.0% 53.2% Cyrstallization 0.0% 0.0% 6.9% 88.6% 4.5% 46.8% motherliquor

(23) As shown in the Table 4, when the psicose preparation process was operated by using 95.2 wt % of fructose content of fructose raw material by weight based on 100% by weight of total content of solids, the psicose conversion rate represented about 26.4%, and the psicose fraction obtained after conducting SMB high purity separation by mixing the crystallization mother liquor and setting 40% by weight of psicose had 95% by weight or higher of the psicose content. It was demonstrated that the production of high purity psicose was increased by increasing the separation yield according to raising the psicose content of raw material before treatment which was put into the SMB high purity process by recycling the psicose crystallization mother liquor.