阅读说明：本技术 生产功能性晶体甜味剂的方法 (Method for producing functional crystalline sweetener ) 是由 金*訚 金㚖訚 梁宰炅 柳京宪 朴成原 朴智远 崔垠修 于 2019-02-07 设计创作，主要内容包括：本发明涉及一种结晶的功能性甜味剂的制备方法,更具体地,涉及一种用于制备结晶的功能性甜味剂的方法,其通过控制杂质的含量或包含在用于制备晶体的溶液中的杂质的产生来提高结晶收率和增加粒径。(The present invention relates to a method for preparing a crystalline functional sweetener, and more particularly, to a method for preparing a crystalline functional sweetener, which improves a crystallization yield and increases a particle size by controlling the content of impurities or the generation of impurities contained in a solution for preparing crystals.)

1. A method for producing psicose crystals, comprising providing a psicose composition for crystallization containing psicose, and producing psicose crystals by cooling the psicose composition for crystallization,

wherein the step of providing the psicose composition for crystallization controls a content of the psicose-converting substance to 2% by weight or less based on a total solid content included in the psicose composition for crystallization.

2. The method according to claim 1, wherein the allulose conversion substance comprises a mass-to-charge ratio of 10-600m/z as measured by LC/MS analysis.

3. The method according to claim 1, wherein the psicose conversion substance comprises a substance having a maximum peak at an elution time of 31min ± 2min as measured by an HPLC analysis method.

4. The method according to claim 1, wherein the step of providing the psicose composition for crystallization provides the psicose composition for crystallization having a content of the psicose conversion substance of 2% by weight or less by adjusting one or more selected from pH conditions and temperature conditions of the psicose composition for crystallization,

wherein the pH condition is 4 to 7, and

wherein the temperature condition is 40 ℃ or more and 70 ℃ or less.

5. The method of claim 1, wherein the allulose conversion substance comprises a compound represented by the formula CxHyOz, wherein x is an integer from 3 to 15, y is an integer from 1 to 15, and z is an integer from 1 to 10.

6. The method of claim 1, wherein the psicose conversion substance comprises one or more selected from the group consisting of:

levulinic acid (4-oxopentanoic acid),

Furfural,

Hydroxymethylfurfural (HMF),

Gamma-hydroxypentanoic acid (GVB),

2, 5-dimethylfuran,

2, 5-Furanedicarboxylic acid (FDCA),

5-hydroxymethyl-2-furoic acid,

2, 5-formyl furan formic acid,

2, 5-furandicarboxaldehyde,

2, 5-bis- (hydroxymethyl) furan,

Bis (5-formyl-2-furfuryl) ether,

2-furoic acid,

3-furoic acid,

5-hydroxy furfural,

2, 5-dihydro-2, 5-dimethoxyfuran,

(2R) -5-oxotetrahydro-2-furancarboxylic acid,

2, 5-formyl furan formic acid,

5,5' -methylenebis (2-furoic acid) and

bis (5-methylfurfuryl) ether.

7. The method according to claim 1, wherein the psicose composition for crystallization comprises 90% by weight or more of psicose, based on the total solid content contained in the composition.

8. The method according to claim 1, wherein the step of preparing the psicose crystals comprises: forming a core crystal by stirring the allulose composition for crystallization at a temperature of 20-40 ℃, and growing the crystal by reducing the temperature of the solution.

9. The method of claim 8, wherein the step of preparing the psicose crystals comprises: a step of re-dissolving the crystals formed in the cooling one or more times by raising the temperature of the allulose composition for crystallization to a range of 30 ℃ to 35 ℃.

10. The method of claim 8, wherein the method further comprises adding a seed.

11. The method according to claim 1, wherein the yield of the psicose crystals is 45% or more.

12. The method according to claim 1, wherein the step of providing the psicose composition for crystallization is performed by treating a reaction solution containing psicose with an SMB chromatographic separation process and concentrating the obtained psicose fraction at a temperature of 40 ℃ to 70 ℃ or less.

13. The method of claim 12, wherein the concentration process is performed in at least two stages.

14. The method of claim 12, further comprising treating with activated carbon prior to the concentration process.

15. The method of claim 1, wherein the step of providing the psicose composition for crystallization is providing a solution of psicose crystals or powder dissolved in water.

16. The method according to claim 15, wherein the psicose crystals are crystals obtained by crystallizing a concentrate obtained by concentrating the psicose fraction from an SMB chromatographic separation process.

17. A composition for crystallizing psicose, comprising 90% by weight or more of psicose and 2% by weight or less of a psicose-converting substance (impurity-S), based on the total solid content of the composition.

18. The composition according to claim 17, wherein the composition for crystallizing psicose has a viscosity of 2cps to 200cps at a temperature of 45 ℃.

19. The composition according to claim 17, wherein the composition for crystallizing psicose has an electrical conductivity of 1000uS/cm or less.

20. The composition according to claim 17, wherein the psicose converting substance (impurity-S) is a substance having a mass-to-charge ratio of 10-600m/z as measured by LC/MS analysis.

21. The composition of claim 17, wherein the psicose conversion substance is a substance having a maximum peak at an elution time of 31min ± 2min as measured by HPLC analysis.

22. The composition of claim 17, wherein the psicose converting substance (impurity-S) comprises a psicose-modifying polymer having a molecular weight of 0.2 to 10 times the molecular weight of psicose.

23. A composition for crystallizing psicose according to claim 17, wherein the pH of the composition is 4-7.

24. The composition for crystallizing psicose according to claim 17, wherein the temperature of the composition is controlled below 70 ℃.

25. A method for controlling the content of an psicose-converting substance (impurity-S) contained in a composition for crystallizing psicose to 2% by weight or less based on a solid content.

26. The method according to claim 25, wherein the method is performed by controlling one or more selected from pH conditions and temperature conditions,

wherein the pH condition is 4 to 7, and

wherein the temperature condition is 40 ℃ or more and 70 ℃ or less.

27. The method of claim 25, wherein the allulose conversion substance comprises a compound of formula CxHyOz,

wherein x is an integer from 3 to 15, y is an integer from 1 to 15, and z is an integer from 1 to 10.

28. The method of claim 25, wherein the psicose conversion substance comprises one or more selected from the group consisting of:

levulinic acid (4-oxopentanoic acid),

Furfural,

Hydroxymethylfurfural (HMF),

Gamma-hydroxypentanoic acid (GVB),

2, 5-dimethylfuran,

2, 5-Furanedicarboxylic acid (FDCA),

5-hydroxymethyl-2-furoic acid,

2, 5-formyl furan formic acid,

2, 5-furandicarboxaldehyde,

2, 5-bis- (hydroxymethyl) furan,

Bis (5-formyl-2-furfuryl) ether,

2-furoic acid,

3-furoic acid,

5-hydroxy furfural,

2, 5-dihydro-2, 5-dimethoxyfuran,

(2R) -5-oxotetrahydro-2-furancarboxylic acid,

2, 5-formyl furan formic acid,

5,5' -methylenebis (2-furoic acid) and

bis (5-methylfurfuryl) ether.

29. The method according to claim 25, wherein the composition of the psicose solution is prepared by treating a reaction solution containing psicose with an SMB chromatographic separation process, and concentrating the obtained psicose fraction at a temperature of 40-70 ℃ or less.

30. The method of claim 29, wherein the concentration process is carried out in at least two stages, wherein the primary concentration of the psicose solution is carried out to 30-50Bx to obtain a primary concentrate, and the primary concentrate is subsequently concentrated to 60-85 Bx.

31. The method of claim 29, further comprising treating carbon with an activator prior to performing the concentration process.

32. The method of claim 25, wherein the psicose solution composition is provided in the form of a dissolved solution of psicose crystals or powder in water.

33. The method of claim 25, wherein the allulose solution composition has a conductivity of 1,000uS/cm or less.

34. An psicose crystal produced by cooling the produced psicose solution composition according to any one of claims 17-24,

wherein the X-ray spectrum of the psicose crystal has peaks at diffraction angles (2 θ) of 15.24 °, 18.78 ° and 30.84 ° ± 0.2 °.

35. An psicose crystal according to claim 34, having one or more characteristics selected from the following (1) to (4).

(1) Tm temperature according to Differential Scanning Calorimetry (DSC) of 125.8 ℃. + -. 5 ℃,

(2) according to differential scanning calorimetry analysis, the melting enthalpy (Delta H) is 200-220J/g,

(3) an average major diameter of 350 μm or more, 350-

(4) The ratio of the length of the long diameter (μm) to the short diameter (i.e., long diameter/short diameter) of the crystal is in the range of 1.0 to 8.0.

Technical Field

The present invention relates to a method for preparing a crystalline functional sweetener, and relates to a method for preparing psicose crystals by increasing the crystallization yield and increasing the particle size by controlling the content of impurities converted from psicose during the process of preparing a crystalline functional sweetener (e.g., psicose crystals).

Background

General sugars represented by sugar and amyloses constitute the largest market in the world, about 65 trillion won, but as consumer demand for health-oriented functional and advanced products increases worldwide, the market for functional sweeteners (e.g., sugar alcohols including xylitol, oligosaccharides including fructo-oligosaccharides, functional sugars including crystalline fructose, sweeteners including sucralose or aspartame, etc.) has increased.

Sweeteners are a general term for flavors and food additives that provide sweetness. Among many sweeteners, sugar, glucose, fructose, and the like are most widely distributed as natural ingredients and are most widely used for preparing processed foods. However, as negative aspects of sugar, such as tooth decay, obesity, diabetes, etc., become more prominent, alternative functional sweeteners for sugar have received worldwide attention.

Recently, there is psicose as an alternative sugar, which can replace sugar or fructose as a functional sweetener. Psicose may be produced by a chemical or biological method, but since the amount of psicose contained in the product is small, a process of purification and concentration is required. However, the demand for crystalline powders is high due to the limited use of concentrated syrups. It is difficult to crystallize psicose due to its low crystallinity.

Therefore, there is an urgent need for a method for preparing psicose crystals, which improves the crystallization yield and increases the particle size by minimizing the content of impurities contained in the psicose solution for crystallization or the generation of impurities during the preparation of psicose, and controlling the content of impurities resulting from the conversion of psicose.

Disclosure of Invention

[ problem ] to provide a method for producing a semiconductor device

The present invention relates to a method for preparing psicose crystals, which improves crystallization yield and increases particle size by controlling the content of impurities or the generation of impurities contained in a solution for preparing crystals.

Further, the present invention provides a method for producing psicose crystals, which can produce psicose having a uniform particle size by appropriately controlling the growth of crystal particles, thereby reducing loss during recovery and improving crystallization yield to achieve higher productivity.

Further, the present invention provides a composition for crystallizing psicose, in which the content of the psicose-converting substance (Impurity-S) is controlled within a specific content range, thereby increasing the crystallization yield, the particle size is uniform, and the loss during the recovery process is reduced.

[ technical solution ] A

The present invention relates to a composition for psicose crystallization for providing a uniform particle size and improving crystallization yield by reducing loss during recovery, wherein the content of psicose-converting substance (impurity-S) is controlled within a specific content range; and a method for producing allulose crystals using the composition. Further, the present invention relates to a method for preparing psicose crystals, which improves crystallization yield and increases particle size by controlling the content of impurities or the generation of impurities contained in a solution for preparing crystals.

Since psicose is more unstable, the content of psicose varies during actual production, particularly in the concentration step, when the pH is lower and the temperature is higher (fig. 2, fig. 3). This problem reduces the purity of high-purity psicose, thus largely affecting the crystallization step. It was confirmed that, since the content of psicose was actually reduced in the process, the content of an additionally produced psicose-converting substance (impurity) became higher, and the component largely affected the crystallization of psicose. The inventors found that when the content of impurity-S is contained in various psicose-converting substances, this may act as an inhibitor of the growth of psicose crystal particles, thereby largely affecting the particle size and crystallization yield of the crystal particles.

Therefore, the present invention can prevent the particle size of psicose from being reduced and provide psicose having a uniform particle size to perform a psicose crystallization process by controlling the content of the impurity (impurity-S) to be a specific content or less in a step before or after concentration after the high purity separation process. In addition, the growth of particles having a uniform particle size can reduce loss during the recovery process and increase the crystallization yield, thereby improving productivity.

In the allulose syrup as a raw material used in the allulose crystallization process, various allulose conversion substances, which are impurities other than allulose produced in the process of preparing allulose, may be included. Alternatively, the psicose-converting substance may be produced during the crystallization of psicose. By adjusting (controlling) a specific conversion substance (hereinafter referred to as impurity-S) in the conversion substance to be lower than a specific amount, for example, lower than 2% by weight, the shape, structure and size of the psicose crystal particles, crystal purity, crystal yield and crystallization yield can be improved. The impurity-S acts as an inhibitor, preventing the growth of allulose crystal particles, thus reducing the crystallization yield. In the present invention, a method for increasing the particle size and yield of psicose crystals can be achieved by controlling the production process of psicose to be carried out under conditions where the psicose-converting substance is not produced.

The psicose-converting substance (impurity-S) may have a mass-to-charge ratio of 10-600m/z, 10-550m/z, 10-500m/z, 10-450m/z, 10-400m/z, 20-600m/z, 20-550m/z, 20-500m/z, 20-450m/z, 20-400m/z, 30-600m/z, 30-550m/z, 30-500m/z, 30-450m/z, 30-400m/z, 40-600m/z, 40-550m/z, 40-500m/z, 40-450m/z, 40-400m/z, 50-600m/z, 50-550m/z, 50-500m/z, 50-450m/z or 50-400m/z, or a substance having a maximum peak at an elution time of 31+ -2 min as measured by HPLC analysis. The LC/MS analysis is an analysis of a substance obtained by separating a substance having the largest peak at an elution time of 31 ± 2min as measured by HPLC analysis.

Further, the psicose-converting substance (impurity-S) may be a denatured product of psicose, a polymer of the denatured product of psicose, or an intermediate substance generated or converted during degradation of psicose. The lower limit of the molecular weight of the psicose conversion substance (impurity-S) may be 0.2 times or more, 0.3 times or more, 0.4 times or more, 0.5 times or more, 0.6 times or more, 0.7 times or more, 0.8 times or more, 0.9 times or more, 1 times or more, 1.1 times or more, 1.2 times or more, 1.3 times or more, 1.4 times or more, 1.5 times or more, 1.6 times or more, 1.7 times or more, 1.8 times or more, 1.9 times or more, or 2 times or more of the molecular weight of psicose. The upper limit of the molecular weight of the psicose conversion substance (impurity-S) may be 10 times or less, 9 times or less, 8 times or less, 7 times or less, 6 times or less, 5 times or less, 4 times or less, 3 times or less, 2 times or less, less than 1.5 times, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, 1 times or less, 0.9 times or less, 0.8 times or less, 0.7 times or less, 0.6 times or less, 0.5 times or less, 0.4 times or less, 0.3 times or less, 0.2 times or less of the molecular weight of psicose. The molecular weight of the psicose-converting substance (impurity-S) may be within a range set by a combination of a lower limit value and an upper limit value. For example, the molecular weight of the psicose-converting substance (impurity-S) may be 0.4 or more and 10 times, 0.5 or more and 10 times, 0.53 or more and 10 times, 0.4 or more and 9 times, 0.5 or more and 9 times, 0.53 or more and 9 times, 0.4 or more and 8 times, 0.5 or more and 8 times, 0.53 or more and 8 times, 0.4 or more and 7 times, 0.4 or more and 6 times, 0.4 or more and 5 times, 0.4 or more and 4 times, 0.4 or more and 3 times, 0.4 or more and 2 times, 0.4 or more and less than 1.5 times, 0.4 or more and 1.4 times, 0.4 or more and 1.3 times, 0.4 or more and 1.2 times, 0.4 or more and less, 0.4 or more and 1.5 times, 0.4 or more and 0.4 times, 0.4 or more and 0.4 times, 0.4 times or more and 0.5 times, 0.4 times or more and 1.5 times, 0.4 times or more and 0.4, 0.5 to 7 times, 0.53 to 7 times, 0.4 to 6 times, 0.5 to 5 times, 0.5 to 4 times, 0.5 to 3 times, 0.5 to 2 times, 0.5 to less than 1.5 times, 0.5 to 1.4 times, 0.5 to 1.3 times, 0.5 to 1.2 times, 0.5 to 1.1 times, 0.5 to 1 time, 0.5 to 0.9 times, 0.5 to 0.8 times, 0.5 to 0.7 times, 0.5 to 0.6 times, 0.53 to 6 times, 0.4 to 5 times, 0.5 to 5 times, 0.53 to 4 times, 4 to 10 times, and the modified product of allulose, the modified product of which the modified product is 0.5 to 6 times or more, 0.5 to 7 times, 0.53 to 4 times, 0.5 to 4 times, 5 times or more to 10 times, and the modified product of allulose, Or intermediates generated or converted during degradation of psicose.

In one embodiment, the psicose-modifying polymer as the psicose-converting substance (impurity-S) may be converted into a psicose-modifying polymer (tetramer analog of psicose) having a molecular weight similar to that of a dimer due to continuous exposure of the psicose-converting substance (impurity-S) under an external stress (stress), for example, high temperature or acidic condition. This is because psicose or a psicose-converting substance repeats dehydration and condensation reactions at random due to a mechanism by which it is converted into a denatured polymer since psicose is easily denatured by external stress. Alternatively, the psicose-converting substance (impurity-S) may be an intermediate substance produced or converted during the degradation of psicose.

Specifically, the component detected in the molecular weight of 341m/z is a component whose content is increased because the psicose-containing crystallization starting material is strictly treated and the substance of the dimer-like structure of the psicose is denatured by dehydration or condensation reaction. As a result of the structure being deduced by LC-MS analysis, it can be predicted that the substance has the chemical formula C12H22O11, and is a psicose-denatured polymer. It was confirmed that, as the heat treatment proceeded, the psicose-modifying polymer (tetramer analog of psicose) C25H28O11, C24H42O21 or C24H44O22 having a molecular weight similar to that of the dimer of the psicose-modifying polymer increased together with the substance of the dimer-like structure of psicose. It is considered that psicose is easily denatured by external stress (e.g., heat treatment), and psicose or a psicose-converting substance is converted into the above-mentioned substance by repeating dehydration and condensation reactions at random.

Specifically, as a result of the LC-MS analysis, the components detected in the psicose conversion substance (impurity-S) may include an intermediate substance (furan aldehyde intermediate) produced in the degradation process of hexose (e.g., psicose is decomposed into HMF by dehydration reaction), Na⁺Ionically bonded to psicose [ C₆H₁₂O₆+Na]⁺Or Na⁺Ionically bonded to psicose dimer molecule [ C₆H₁₂O₆+Na]⁺)。

Further, as a result of inferring the chemical structure by LC-MS analysis, the psicose conversion substance may comprise a compound having the formula CxHyOz, wherein x may be an integer of 3-15, 3-14, 3-13, 3-12, 4-15, 4-14, 4-13, 4-12, 5-15, 5-14, 5-13 or 5-12, y may be an integer of 1-15, 1-14, 1-13, 1-12, 2-15, 2-14, 2-13, 2-12, 3-15, 3-13, 3-12, 4-15, 4-14, 4-13 or 4-12, and z can be an integer from 1-10, 1-9, 1-8, 1-7, or 1-6.

For example, the psicose-converting substance may comprise a compound having the formula C₅H₄O₃、C₅H₆O₄、C₅H₈O₃、C₅H₄O₂、C₅H₁₀O₃、C₆H₄O₅、C₆H₁₀O₃、C₆H₄O₄、C₆H₆O₃、C₆H₈O、C₆H₄O₅、C₆H₆O₄、C₆H₄O₄、C₆H₄O₃、C₆H₈O₃、C₁₁H₈O₆、C₁₂H₁₂O₅Or C₁₂H₁₀O₅The compound of (1).

In particular, the allulose conversion substance may comprise one or more compounds selected from the group consisting of: levulinic acid (4-oxopentanoic acid), furfural, Hydroxymethylfurfural (HMF), gamma-hydroxyvaleric acid (GVB), 2, 5-dimethylfuran, 2, 5-furandicarboxylic acid (FDCA), 5-hydroxymethyl-2-furoic acid, 2, 5-formylfurancarboxylic acid, 2, 5-furandicarboxaldehyde, 2, 5-bis- (hydroxymethyl) furan, bis (5-formyl-2-furfuryl) ether, 2-furoic acid, 3-furoic acid, 5-hydroxyfurfural, 2, 5-dihydro-2, 5-dimethoxyfuran, (2R) -5-oxotetrahydro-2-furancarboxylic acid, 2, 5-formylfurancarboxylic acid, 5' -methylenebis (2-furoic acid), and bis (5-methylfurfuryl) ether.

According to the present invention, there is provided a method for removing or reducing the content of a conversion substance (impurity-S) contained in allulose slurry used as a raw material for allulose crystallization process by performing the allulose production, separation and/or purification process without producing the allulose conversion substance, and thus, by reducing the content of impurity-S in the crystallization raw material and reducing the content of impurities that inhibit crystal growth, it is possible to improve the crystal shape and increase the crystallization yield.

Specifically, the content of the conversion substance (impurity-S) can be controlled by a method for preventing or reducing the production of the impurity-S, or removing or reducing the produced impurity-S. In one embodiment of the present invention, due to the method of controlling the production process of psicose under the condition of suppressing or reducing the production of the psicose conversion substance, the particle size of the psicose crystals may be increased, and the crystals may be formed into a shape close to a quadrangle, and the yield of psicose may be increased. More specifically, when the content of the psicose conversion substance (impurity-S) component in the crystallization undiluted solution is 2% by weight or less, the growth and yield of the psicose crystal particles can be improved.

The method of suppressing or reducing the production of impurity-S can be achieved by controlling the conditions under which no psicose-converting substance is produced, particularly the conditions (e.g., control of pH, temperature, conductivity) of the production process of psicose in the concentration process. Further, a method for removing or reducing the produced impurity-S may use a method of performing activated carbon treatment or a method of secondary crystallization by re-dissolving crystals obtained in the primary crystallization, or the like, and a method of removing impurities in allulose slurry may be used.

Specifically, the method of controlling the generation or content of impurities may be performed in one or more of the following methods.

As an embodiment, an embodiment of the method for inhibiting or reducing the production of the psicose conversion substance (impurity-S) during the psicose production process may be a method of performing the psicose production process at a temperature of pH 4 or more and/or 70 ℃ or less. Specifically, since psicose is relatively stable under conditions of pH 4 to 7 or pH 4 to 6 and a temperature of 70 ℃ or less, preferably 60 ℃ or less, it is preferable to always control it from the influence of external stress by controlling the temperature of the reaction solution to 70 ℃ or less, preferably 60 ℃ or less, particularly by dividing the concentration process into two or more steps in the psicose production process (e.g., decoloring, ion purification, high purity separation, etc.).

In order to suppress or reduce the production of impurity-S during the production of psicose, the psicose production may be performed on the psicose fraction obtained during the SMB chromatographic separation under the temperature condition of 40-70 ℃ or lower, and optionally, the concentration process may be divided into at least two or more steps. For example, when the concentration process is performed in two steps, the psicose syrup may be concentrated to a concentration of 30-50Bx, and then the primary concentrate may be concentrated again to a concentration of 60-85Bx, and preferably an activated carbon treatment process may be further included between the primary concentration process and the secondary concentration process, thereby removing or reducing the content of impurity-S contained in the concentrate.

In another embodiment, a method for removing or reducing the content of the conversion substance (impurity-S) contained as an impurity in the psicose syrup as a raw material for the psicose crystal is to remove it by activated carbon treatment, or by adsorbing a high-or small-molecular organic substance, a colored ionic material, a protein or the like, each of which causes denaturation of psicose.

In detail, the content of the conversion substance (impurity-S) may be removed or reduced by performing a process of activated carbon treatment before concentrating the psicose fraction obtained by performing an SMB chromatographic separation process on the psicose reaction solution obtained from the substrate. After performing an ion purification process of the psicose fraction obtained in the SMB chromatographic separation process, an activated carbon treatment may be additionally performed.

The activated carbon treatment may be to subject the reaction solution containing activated carbon to a solid-liquid separation process after contacting activated carbon to the psicose solution and reacting them at a temperature of 40-50 ℃ for 0.5 to 5 hours, thereby collecting the residue, and impurities may be removed as a filtration residue. The filtration can be performed by using a filtration apparatus such as a filter press.

During the activated carbon reaction, stirring may be optionally performed, and the stirring rate of the reaction solution may be 5 to 500rpm, preferably 50 to 300 rpm. The stirring speed may be appropriately selected in consideration of the degree of dispersion of the activated carbon and the stirring cost. The contact time of the activated carbon with the reaction solution may be appropriately selected in consideration of the degree of dispersion of the activated carbon, the impurity removal efficiency, and the like, and may be, for example, 0.5 to 5 hours, preferably 0.5 to 2 hours. If the contact time is short, impurities cannot be sufficiently removed, for example, discoloration cannot be sufficiently attained, and if the contact time is long, destruction of main components and browning may be caused.

The activated carbon used in the activated carbon treatment process may be derived from a stone carbon system (carboniferousystem) or a lignocellulose system (Lignocellulosic system), and impurities may be selectively removed according to the pore size of the activated carbon.

As other embodiments, the method for inhibiting or reducing the production of the psicose conversion substance (impurity-S) of the psicose crystal composition is to perform recrystallization. The psicose solution subjected to the high-purity separation and concentration process is subjected to primary crystallization, and the psicose crystals recovered by removing the supernatant from the dehydrated primary crystallization undiluted solution are dissolved again in water and input to the secondary crystallization process, so that the content of the psicose-converting substance (impurity-S) in the primary crystallization process can be removed or reduced.

Accordingly, one embodiment of the present invention provides a method of controlling the content of the psicose conversion substance (impurity-S) contained in the psicose composition for crystallization to 2% by weight or less, based on the solid content of the composition.

The method may be performed by controlling one or more conditions selected from pH conditions and temperature conditions, and the pH conditions may be in the range of pH 4 to 7, or the temperature conditions may be below 70 ℃.

The psicose composition for crystallization may be prepared by treating a reaction solution containing psicose with an SMB chromatographic separation process and concentrating the resulting psicose solution at a temperature of 40-70 ℃ or less. The concentration process can be divided into at least two steps, and the primary concentration of the allulose solution can be carried out to 30-50Bx, and the secondary concentration of the primary concentrate can be carried out to 60-85 Bx. The activated carbon treatment process may be further performed before the concentration process is performed.

Another embodiment of the present invention relates to a composition for crystallizing psicose, comprising 2 wt% or less, 1.9 wt% or less, 1.8 wt% or less, 1.7 wt% or less, 1.6 wt% or less, 1.5 wt% or less, 1.4 wt% or less, 1.3 wt% or less, 1.2 wt% or less, 1.1 wt% or less, 1.0 wt% or less, 0.9 wt% or less, 0.8 wt% or less, 0.7 wt% or less, 0.65 wt% or less, 0.6 wt% or less, 0.5 wt% or less, 0.4 wt% or less, 0.3 wt% or less, 0.2 wt% or less, 0.1 wt% or less, preferably 1.0 wt% or less of an psicose-converting substance (impurity-S) based on 100 wt% of the total solid content of the composition, more preferably it does not comprise impurities.

Preferably, the composition for crystallizing psicose may comprise 90 wt% or more, 91 wt% or more, 92 wt% or more, 93 wt% or more, 94 wt% or more, or 95 wt% or more of psicose, based on 100 wt% of the total solid content of the composition.

The psicose composition for crystallization may have a viscosity of 2cps to 200cps and a conductivity of 1,000uS/cm or less, for example 0.01 to 1,000uS/cm, preferably 30uS/cm or less, for example 0.1 to 30uS/cm, at a composition temperature of 45 ℃. The conductivity of the composition for crystallizing psicose is preferably low. The conductivity of the allulose pulp was a value measured based on a solid content of 30 Bx.

The allulose solution used for crystallization may have a solids content of 60 or more and 85Bx or less, for example, above 60Bx to 80Bx, 65 to 85Bx, 65 to 80Bx, or 68 to 85 Bx.

An embodiment of the present invention relates to a method for preparing psicose crystals by using a psicose solution for crystallization, more specifically, a method for preparing psicose crystals, the method comprising the steps of: provided are a composition for crystallizing psicose, comprising 2% by weight or less, 1.9% by weight or less, 1.8% by weight or less, 1.7% by weight or less, 1.6% by weight or less, 1.5% by weight or less, 1.4% by weight or less, 1.3% by weight or less, 1.2% by weight or less, 1.1% by weight or less, 1.0% by weight or less, 0.9% by weight or less, 0.8% by weight or less, 0.7% by weight or less, 0.65% by weight or less, 0.6% by weight or less, 0.5% by weight or less, 0.4% by weight or less, 0.3% by weight or less, 0.2% by weight or less, 0.1% by weight or less, preferably 1.0% by weight or less of an psicose-converting substance (impurity-S) based on 100% by weight of the total solid content of the composition, and a step of preparing psicose crystals by cooling an aqueous solution of psicose.

In a specific embodiment of the present invention, a method for preparing psicose crystals may comprise: a step of performing secondary ion purification on the psicose fraction obtained in the SMB chromatographic separation process, and a step of concentrating the ion-purified psicose fraction; and a step of obtaining the psicose crystals and a mother liquor for the psicose crystallization by crystallizing the psicose from the concentrate, optionally, a recovery process, a washing process and a drying process of the psicose crystals may be further included.

Further, before the concentration step, the content of the psicose conversion substance (impurity-S) may be reduced or removed by treating a solution of the psicose fraction itself obtained in the SMB chromatographic separation process or a solution of the ion-purified psicose fraction with activated carbon. Further, the content of the psicose conversion substance (impurity-S) may be reduced or removed by performing primary crystallization after concentrating the psicose solution for crystallization and performing secondary crystallization by dissolving the obtained crystals.

In a specific embodiment of the present invention, a method for preparing psicose crystals may comprise: a step of subjecting the psicose fraction to secondary ion purification, wherein the psicose fraction is obtained by treating an psicose-containing reaction solution prepared from a substrate using an SMB chromatographic separation process; and a step of concentrating the ion-purified psicose fraction, or may include a process of ion-purifying the psicose fraction obtained by the SMB chromatographic separation process, an activated carbon treatment process, or both the activated carbon treatment process and the ion-purification process.

The step of providing the psicose composition for crystallization relates to a method of preparing psicose crystals, based on the total solid content contained in the composition for crystallization, the psicose composition for crystallization contains 2 wt% or less, 1.9 wt% or less, 1.8 wt% or less, 1.7 wt% or less, 1.6 wt% or less, 1.5 wt% or less, 1.4 wt% or less, 1.3 wt% or less, 1.2 wt% or less, 1.1 wt% or less, 1.0 wt% or less, 0.9 wt% or less, 0.8 wt% or less, 0.7 wt% or less, 0.65 wt% or less, 0.6 wt% or less, 0.5 wt% or less, 0.4 wt% or less, 0.3 wt% or less, 0.2 wt% or less, 0.1 wt% or less, preferably 1.0 wt% or less of an psicose converting substance (impurity-S), or contains no psicose converting substance (impurity-S).

The method for producing psicose crystals according to the present invention may have a crystallization yield of psicose of 45% or more, preferably 48% or more, 50% or more, 53% or more, 54% or more, more preferably 55% or more, 56% or more, 57% or more, 58% or more, 59% or more, or 60% or more.

The content of the psicose conversion substance may be controlled by controlling one or more selected from the group consisting of pH conditions and the temperature of the psicose solution, and the pH control may be achieved in the range of pH 4-7, pH 4.5-7, and the temperature control may be performed in the range of 80 ℃ or less, 75 ℃ or less, 70 ℃ or less, preferably 30-70 ℃ or less, 30-69 ℃, 30-65 ℃ or 30-60 ℃.

Since psicose is unstable at a low pH and a high temperature, the content of psicose varies in the concentration step in the actual production process. This problem reduces the purity of high-purity psicose, thus largely affecting the crystallization step. It was confirmed that, in this process, a specific psicose-converting substance (impurity) was produced while the content of psicose was reduced, and the ingredient largely affected the crystallization of psicose. It was confirmed that when the content of the impurity-S component in each impurity-converted substance exceeds 2%, it may become a major hindrance to the growth of impurity crystal particles, thereby largely affecting the particle diameter of crystal particles and the crystal yield.

Specifically, as shown in fig. 1 and 2, as the storage temperature increases, the content of psicose decreases, and the content of the psicose-converting substance (impurity-S) increases. As shown in fig. 3 and 4, as the pH value decreases at a temperature of 70 ℃, the content of psicose decreases and the production of the psicose-converting substance increases.

The psicose composition for crystallization according to the present invention may be a reactant containing psicose obtained by a biological or chemical method, a psicose fraction obtained by separating the reactant by SMB chromatography, or a concentrate of the psicose-concentrated fraction. The concentration process for preparing the psicose concentrate may be further subjected to an ion purification and/or activated carbon treatment process before being performed, and the concentration process may be performed in at least two steps. The psicose-containing reactant may be obtained from a fructose substrate by a biological or chemical method, and as a biological method, it is preferable that the psicose-containing reactant may be produced by using a psicose-converting enzyme or a microorganism producing the enzyme.

For the psicose reaction solution, the separation process of the psicose conversion reactant includes ion purification and Simulated Moving Bed (SMB) chromatographic separation processes. In a specific embodiment, the psicose conversion reactant is separated into a psicose fraction having a higher psicose content than the converted reactant and the fructose residue by performing an ion purification and SMB chromatographic separation process, and the psicose fraction is input to the crystallization process by a psicose concentration process.

The content of the psicose in the psicose solution from which the psicose crystals are collected should be a high concentration in a supersaturated state, but since the psicose conversion reactant has a low content of psicose, crystallization cannot be directly performed, and in order to increase the content of psicose before the crystallization step, a desired level of purification and concentration process should be performed.

The method for obtaining the composition may be a concentration treatment of the high purity allulose solution at a temperature of 90 ℃ or less, 85 ℃ or less, 80 ℃ or less, 75 ℃ or less, 70 ℃ or less, less than 70 ℃, for example, 40 to 70 ℃ or less, and specifically concentration by using a thin film evaporator or a multiple effect evaporator. In a specific embodiment of the present invention, the step of concentrating the purified allulose solution may be performed under a temperature condition of 40 to 70 ℃ or lower. When the temperature of the concentrate is higher than 70 deg.c, thermal denaturation of D-psicose is caused, and thus, the psicose-converting substance (impurity-S) according to the present invention may be generated or increased. In addition, since the temperature of the reactant is rapidly increased by the heat of vaporization as the concentration proceeds, the temperature of the concentrate should be maintained below 70 ℃ to rapidly concentrate.

Specifically, the concentration process of the psicose fraction obtained in the SMB chromatographic separation process may be performed by various methods, and may be performed in such a manner that the solid content of the concentrate is 70Brix or more. For example, the allulose fraction obtained by the simulated moving bed separation process (e.g., 20-30% by weight solids content) may be concentrated by a concentration process at a solids content of 60Brix or greater. The composition for crystallizing psicose according to the present invention may have a solid content of 60-85Bx or less, for example, above 60Bx to 85Bx, 65-85Bx, 70-85Bx, 75-85Bx, above 60Bx-83.5Bx, 65-83.5Bx, 70-83.5Bx, or 75-83.5 Bx.

As an embodiment, the composition for crystallization may be an psicose fraction obtained by performing a Simulated Moving Bed (SMB) chromatographic separation process by using a column chromatograph packed with a cation exchange resin to which a calcium active group is attached, and specifically, may be an psicose fraction obtained by: a fructose-containing feedstock is converted to psicose using a biocatalyst to obtain a psicose conversion reactant, which is subjected to an activated carbon treatment, ion purification, and Simulated Moving Bed (SMB) chromatographic separation process. The psicose fraction may be obtained in the SMB chromatographic separation process itself, or may be collected by an ion purification process. The fructose content in the fructose-containing raw material is 85% by weight or more based on 100% by weight of the total content of solids, and a biocatalyst having an psicose conversion rate of the psicose conversion reaction of 15% to 70% may be used.

For the psicose fraction obtained in the SMB chromatographic separation process, before the concentration process, an ion purification and/or an activated carbon treatment process may be further performed.

The method for preparing psicose crystals according to the present invention may control the temperature of the psicose concentrate and the concentration of the solution to crystallize psicose, and in particular, may maintain the supersaturation conditions required for crystallization by lowering the temperature of the psicose solution or changing the concentration of D-psicose in the D-psicose solution. In a particular embodiment of the present invention, the crystallization process can be monitored by observing samples taken at constant intervals during the crystallization step with the naked eye or a microscope, or analyzing the concentration of sugar in the supernatant collected by centrifuging the samples. According to the result, the temperature or concentration of D-psicose can be controlled. To prepare the psicose crystals, when a solution of the psicose concentrate is cooled and crystallized, after being rapidly cooled in a temperature range of 10-25 ℃ by a heat exchanger, crystal growth may be induced by repeatedly performing temperature elevation and cooling.

The method for preparing psicose crystals according to the present invention may control the temperature of the psicose concentrate and the concentration of the solution to crystallize the psicose crystals, and in particular, may maintain the supersaturation conditions required for crystallization by reducing the temperature of the psicose solution or changing the concentration of D-psicose in the D-psicose solution. The method for producing psicose crystals according to the present invention may be performed by various methods, preferably by a cooling method. An embodiment of the cooling method according to the present invention may generate crystals by inducing a supersaturated state by cooling the allulose solution to a temperature in the range of 35 ℃ to 10 ℃. It is desirable to maintain the cooling rate at 0.01 to 20 c/min, and when the cooling rate is low, the time for forming crystals is long, and thus productivity may be reduced, while when the cooling rate is high, crystals having a small particle size are formed, and thus it may be difficult to recover the crystals.

The method for producing the psicose crystal may include: a step of generating crystal nuclei in an psicose solution containing 90% by weight or more of psicose and having a conductivity of 60-85Brix and 1000uS/cm or less, and a step of growing crystals by lowering the solution temperature.

Specifically, the preparation method of the psicose crystal may include: a step of generating crystal nuclei by slowly stirring an psicose solution containing 90 wt% or more of psicose and having 60-85Brix at a temperature of 20-40 ℃ or 30-40 ℃ (e.g., 35 ℃), and a step of growing crystals by lowering the solution temperature. The method may further comprise: a step of re-dissolving the crystallites produced during cooling one or more times by raising the temperature of the solution to a range of 30-35 ℃. The method for preparing the psicose crystal may further include a process of adding a seed. The seed addition step and the re-dissolution step may be selectively included in the method for producing psicose crystals, respectively, or both steps may be included in the method for producing psicose crystals.

It is generally known that the larger the size of the psicose crystal, the better the performance, the higher the convenience of use, and in order to prepare the large-sized crystal, the seed crystals classified by the transfer process and the main crystallization process should be all performed, but the crystallization process according to the present invention can easily prepare the large-sized crystal in a high yield through only one step.

In addition, the crystallization process may perform a process of dissolving the microcrystals by raising the temperature of the solution to the range of 30-35 ℃ to re-dissolve microcrystals formed in the cooling of the crystal growth process. In the crystallization process according to the present invention, the crystal growth process and the crystallite dissolution process may be repeated one or more times.

In the method of preparing crystals, a seed crystal may be further added to increase the production rate and size of the crystals.

In a specific embodiment of the present invention, the psicose crystals may be prepared by the following method: after a small amount of crystal nuclei are generated by stirring an psicose solution containing 90% by weight or more of psicose and having a total solid content of 60-85Brix at a temperature of 35 ℃, crystals are grown by cooling the temperature to 10 ℃ at a rate of decreasing the temperature by 1 ℃ per hour, and optionally, further comprising a step of dissolving microcrystals generated during cooling at least once or more by increasing the temperature of the solution to 30-35 ℃ to re-dissolve the microcrystals, to prepare psicose crystals.

The method for preparing psicose crystals according to the present invention may further comprise: a step of recovering the allose crystals collected in the crystallization step using various solid-liquid separation methods (e.g., centrifugal separation), a step of washing with deionized water, and a step of drying. The drying step may be performed in a fluidized bed dryer or a vacuum dryer, but is not limited thereto.

The psicose crystals may be prepared by a method of cooling the psicose composition for crystallization according to the present invention. The allulose composition used for crystallization is the same as described above.

The psicose may be contained at 94 wt% or more, 95 wt% or more, 96 wt% or more, 97 wt% or more, 98 wt% or more, or 99 wt% or more in the psicose crystals with respect to 100 wt% of the total solid content.

Here, "crystal purity" refers to the purity of allulose crystals. The properties including purity of the crystal comprising the present invention can be obtained by methods such as X-ray powder diffraction analysis, Differential Scanning Calorimetry (DSC) analysis, infrared spectroscopy (FTIR) analysis, HPLC analysis, LC/MS analysis, and the like, and the purity can be specifically analyzed by HPLC chromatography.

The psicose crystal according to an embodiment of the present invention may be a psicose crystal having an X-ray spectrum as described below: it has peaks in the X-ray spectrum at diffraction angles (2. theta.) of 15.24, 18.78 and 30.84 + -0.2 deg.. In one embodiment of the invention, the X-ray spectrum may be psicose crystals with X-ray spectroscopy as described below: it has peaks at diffraction angles (2 θ) of 15.24, 18.78, 30.84 and 28.37 ± 0.2 °, diffraction angles (2 θ) of 15.24, 18.78, 30.84 and 31.87 ± 0.2 °, or diffraction angles (2 θ) of 15.24, 18.78, 30.84 and 47.06. The diffraction angle having a peak in the X-ray spectrum of the psicose crystal is the result of X-ray diffraction analysis by selecting and expressing the upper (relative intensity%) main peak and the morphology-specific peak.

The psicose crystal according to the present invention can be obtained by various crystallization methods, but the characteristics can be measured with the psicose crystal produced by a cooling method.

According to DSC analysis, the psicose crystal according to the present invention may have a Tm temperature of 125.8 ℃. + -. 5 ℃ or a melting enthalpy (. DELTA.H) of 200-220J/g, and the Tm may be 125.8 ℃. + -. 3 ℃. Differential Scanning Calorimetry (DSC) operates on a temperature gradient and measures the energy supplied to keep the temperature of the allulose powder sample elevated. It is expected that, in the DSC analysis, the higher the heat capacity of the crystal, the less soluble it is, and the higher the heat capacity, the narrower the width of the endothermic peak, the more uniformly and more rigid the crystal is formed.

Another embodiment of the present invention is an psicose crystal produced using the composition for psicose crystallization, and may be psicose having one or more characteristics selected from the following (1) to (5):

(1) an X-ray spectrum having peaks at diffraction angles (2 theta) of 15.24, 18.78 and 30.84 + -0.2 DEG in the X-ray spectrum,

(2) tm temperature according to Differential Scanning Calorimetry (DSC) of 125.8 ℃. + -. 5 ℃,

(3) according to differential scanning calorimetry analysis, the melting enthalpy (Delta H) is 200-220J/g,

(4) an average major diameter of 350 μm or more, preferably 350-2,000 μm, and

(5) the ratio of the length of the long diameter (μm) to the short diameter (i.e., long diameter/short diameter) of the crystal is in the range of 1.0 to 8.0.

According to the psicose crystal of the present invention, the average short diameter (small diameter) of the crystal may be 50 to 1,000 μm, preferably 50 to 500 μm, and the average long diameter (large diameter) may be 350 μm or more, preferably 350-2,000 μm, more preferably 400 μm or more to 2,000 μm.

Further, the ratio of the length of the long diameter (μm) to the short diameter (═ long diameter/short diameter) of the psicose crystal according to the present invention may be 1.0 to 8.0, 1.0 to 6.9, 1.0 to 6.0, 1.0 to 5.5, 1.0 to 5.0, 1.1 to 8.0, 1.1 to 6.9, 1.1 to 6.0, 1.1 to 5.5, 1.1 to 5.0, 1.3 to 8.0, 1.3 to 6.9, 1.3 to 6.0, 1.3 to 5.5, 1.3 to 5.0, 1.5 to 8.0, 1.1 to 6.9, 1.5 to 6.0, 1.5 to 5.5, 1.5 to 5.0, 2.0 to 8.0, 2.0 to 6.9, 2.0 to 6.0, 2.5 to 5.0, or 2.5 to 5 to 5.0.

As a result of XRD pattern analysis of the powder of the psicose crystal according to the present invention, the psicose crystal according to the present invention is a pure crystal particle and has a rectangular hexahedral or nearly hexahedral structure. More preferably, because the uniformity and robustness of the crystal increases as the crystal structure of the present invention approaches the cubic system.

Further, since the crystals prepared during the crystallization of psicose are uniform, the strength of the crystals is increased and particle breakage is minimized, and thus the particle size distribution becomes uniform, and thus the flowability can be enhanced. On the other hand, when the uniformity is low, it may be micronized by breakage of crystal particles in the drying and transferring stages, and may be relatively easily dissolved, thus negatively affecting the product quality.

Compared to micronized powders, the allulose crystals of the present invention have better flowability, are stable during storage due to their low tendency to agglomerate, and are characterized by ease of distribution and handling. In addition, allulose powder is less caloric than sugar and has a sweetness similar to sugar, and thus can be conveniently and advantageously used in the preparation of mixed sweeteners, solid mixed sweeteners, chocolate, chewing gum, instant juice, instant soup, granules, tablets, and the like. Further, the psicose crystal powder may be included in various compositions for use, such as foods and beverages, favorite catenaries, feeds, cosmetics, pharmaceuticals, and the like.

[ Effect of the invention ]

The method for preparing psicose crystals according to the present invention can prevent the reduction of the particle size of psicose by controlling the content of the psicose-converting substance (impurity-S) contained in the solution for preparing crystals, and can produce psicose having uniform particles by appropriately controlling the growth of crystal particles. Further, by growing the particles to a uniform size, loss in the recovery process can be reduced and the crystallization yield can be improved, thereby improving productivity.

Drawings

Fig. 1 is a graph showing the change in allulose content with temperature when allulose syrup at pH 5 and a concentration of 70Brix is stored.

Fig. 2 is a graph showing the change in the content of psicose-converting substance with temperature when psicose syrup of pH 5 and a concentration of 70Brix was stored.

Fig. 3 is a graph showing changes in the content of psicose when psicose syrups of different pH and a concentration of 70Brix were stored at a temperature of 70 ℃.

Fig. 4 is a graph showing the change in the content of the psicose-converting substance when psicose syrups of different pH and a concentration of 70Brix were stored at a temperature of 70 ℃.

Fig. 5 is an optical microscope photograph of the psicose powder obtained in example 5, measured at magnification X100.

Fig. 6 is a Scanning Electron Microscope (SEM) photograph of the psicose powder obtained in example 5, measured at magnification X50.

Fig. 7 is an infrared spectrum (IR) spectrum of the psicose crystal obtained in example 5.

Detailed Description

The present invention will be described in more detail by the following examples. However, the following embodiments are desirable embodiments of the present invention, and the present invention is not limited thereto.