D-PSYCHOSAL CRYSTAL AND PREPARATION PROCEDURE THEREOF

Abstract

This disclosure relates to a preparation process for a D-psicose crystal containing 98% (w / w) or more D-psicose and 0.05% (w / w) or less ethanol, based on 100% (w / w) whole crystal. The preparation process includes a first step of mixing a solution containing D-psicose and an organic solvent, and a second step of adding a seed crystal to the mixed solution according to the first step, followed by cooling to obtain a baked mass containing the D-psicose crystal. It is therefore possible to increase the yield of D-psicose crystal from the D-psicose crystal solution and to prepare a D-psicose crystal of sufficient size and shape suitable for mass production without off-flavors or odors.

Description

D-PSYCHOSE CRYSTAL AND PREPARATION PROCEDURE THEREOF TECHNICAL FIELD OF THE INVENTION This disclosure relates to a high-yield D-psicose crystal preparation process from a D-psicose-containing solution. BACKGROUND OF THE INVENTION D-fructose epimer, D-psicose, is a rare saccharide and a type of functional saccharide. It is known to have a near-zero caloric value, even while exhibiting a high degree of sweetness—approximately 60% to 70% that of sugar—making it effective in the prevention and management of diabetes. Furthermore, D-psicose is known to have excellent solubility and has received attention for its potential use in food. Epimerization reaction solutions containing D-psicose have a solid content of approximately 20% (w / w) to 30% (w / w) with low purity. To prepare a 98% or higher purity D-psicose crystal formulation from these solutions, separation and purification techniques such as chromatography and crystallization are required.In general, procedures for crystallizing saccharides use the principle of inducing crystal growth within a metastable zone (the range between the saturated concentration and the lowest supersaturated concentration at which crystals spontaneously precipitate) in a supersaturated state. D-Psicose exhibits almost no change in crystal generation and crystal growth rates even within this supersaturated concentration range, and can therefore be classified as a saccharide with unfavorable particle size growth crystallization conditions. At concentrations within the metastable zone, crystallization phenomena such as crystal nucleation do not occur. However, when a new crystal is added from an external source, crystal growth takes place, and the crystal size increases. In other words, to generate crystals, when a seed crystal is added to a solution at or above its saturated concentration, the seed crystal grows in the metastable zone, resulting in crystal growth. Because D-psicose has a significantly lower crystal growth rate than sucrose, cooling crystallization procedures are generally applied, and the development of a highly economical technology is required for industrialization. A procedure for using a large amount of ethanol in the crystallization process of D-psicose has been reported (Kei T, et al., J. Biosci. Bioeng., 90(4), 453-455, 2000). However, according to this procedure, while crystal nucleation occurs, crystal growth does not. Specifically, a blocking phenomenon occurs during the crystallization process due to amorphous agglomerations, which lead to the generation of crystal particles. When this blocking occurs during the process, it becomes difficult to transfer the crystals to the outside of the crystallizer, and pulverization cannot be performed, thus reducing the production yield.Furthermore, in the saccharide crystallization industry, it is generally known that crystal particle size is an important factor. When crystals are produced in a mass production system, they are easily removed from the crystal centrifuge along with the mother liquor. The remaining particles from the separation process agglomerate between the crystals during drying and are excluded during sieving, thus reducing the packaging volume of the final product or affecting its marketability. Consequently, such crystal particles are unsuitable for mass production. Additionally, in saccharide crystallization using ethanol, a high concentration of the final ethanol can lead to unpleasant tastes and odors, further reducing the marketability of the saccharide crystal products. In light of the current situation, the present inventors have discovered that, by using a concentrated solution of D-psicose and an organic solvent within an operable range, the crystal recovery rate can be increased and the crystal particles can grow. Furthermore, they have developed a procedure for preparing high-purity D-psicose with a purity of 98% (w / w) or higher without bad taste / odor, which has a crystal particle size of MA 200 or more with better flowability in a crystallization process and better marketability as a product. BRIEF DESCRIPTION OF THE INVENTION Technical Problem An object of this disclosure is to provide a D-psicose crystal containing 98% (w / w) or more of D-psicose and 0.001% (w / w) to 0.05% (w / w) of ethanol based on 100% (w / w) of the whole crystal. Another object of this disclosure is to provide a preparation procedure for a D-psicose crystal that includes a first step of mixing a solution containing D-psicose and an organic solvent; and a second step of adding a seed crystal to the mixed solution according to the first step; 0Πί0ΠΠ / ί7Π7 / Β / ΥΙ subsequently, cooling of the same to obtain a cooked mass containing the D-psicose crystal. Technical solution The present disclosure will be described in more detail below. Meanwhile, each description and embodiment disclosed herein may also apply to the other description and embodiment. That is, all combinations of the various components disclosed herein fall within the scope of this disclosure. Furthermore, the specific description below may not limit the scope of this disclosure. Furthermore, those skilled in the art can recognize or determine a plurality of equivalents to specific embodiments of the disclosure described herein using only common experiments. Moreover, such equivalents are intended to be included in this disclosure. As one aspect of this disclosure to resolve the objects, this disclosure provides a D-psicose crystal containing 98% (w / w) or more of Dpsicose and 0.001% (w / w) to 0.05% (w / w) of ethanol based on 100% (w / w) of the whole crystal. In this disclosure, D-psicose is a low-calorie monosaccharide with the molecular formula C6H12O6 and the following structural formula. In addition to a chain-like structure, alpha- and beta-type hexagonal ring structures are also included within the scope of D-psicose. οηίοηη / ίζηζ / Β / γι In this disclosure, the D-psicose crystal is a solid in which the D-psicose molecules are arranged in a regularly repeating structure, which is different from an amorphous solid agglomeration without a repeating structure. The D-psicose crystal of this disclosure may have a purity of 98% (w / w) or greater, specifically 98.5% (w / w) or greater, and more specifically 99% (w / w) or greater. In the preparation of the D-psicose crystal described in this disclosure, due to the addition of ethanol, the D-psicose crystal may contain a minimal amount of ethanol. The ethanol content may be 0.05% (w / w) or less, specifically 0.04% (w / w) or less, and more specifically 0.03% (w / w) or less. The ethanol content can be, for example, 0.001% (w / w) to 0.05% (w / w), 0.001% (w / w) to 0.04% (w / w), 0.001% (w / w) to 0.03% (w / w), 0.005% (w / w) to 0.05% (w / w), 0.005% (w / w) to 0.04% (w / w), 0.005% (w / w) to 0.03% (w / w), 0.01% (w / w) to 0.05% (w / w), 0.01% (w / w) to 0.04% (w / w), 0.01% (w / w) to 0.03% (w / w), 0.02% (w / w) to 0.05% (w / w), 0.02% (w / w) to 0.04% (w / w), or 0.02% (w / w) to 0.03% (w / w).According to an unlimited realization of this disclosure, when ethanol is contained in the above content, no unpleasant taste / odor appears, and therefore the D-psicose crystal can be used equivalently to a D-psicose crystal to which no ethanol has been added (Test Example 2). Because it contains a minimal amount of ethanol, the surface of the D-psicose crystal can be smooth, and the D-psicose crystal can be bright or lustrous compared to the D-psicose crystal to which no ethanol has been added (Test Example 3). Furthermore, when a minimal amount of ethanol is present, the fluidity of the D-psicose crystal increases, and a high yield and degree of crystallinity can be achieved according to the crystallization process when the seeds are dispersed.The fluidity of the crystal can be confirmed by measuring the fluidity and the angle of repose, where the angle of repose is the maximum inclined angle at which deposits that have not yet hardened can be deposited without flowing downhill when placed on a slope. The angle of repose can be obtained by measuring the angle of the top surface of a composition with a protractor after a D-psicosa crystal composition passes through a funnel installed on a horizontal surface at a predetermined speed (Figure 6). The % (w / w) can be used in combination with the % by weight. The % (w / w) can mean a crystal weight based on 100 parts by weight of the whole crystal, or a crystal weight based on 100 parts by weight of a solution containing a crystal. Specifically, the % (w / w) can mean a weight of a D-psicose crystal based on 100 parts by weight of the whole crystal, or a weight of a D-psicose crystal based on 100 parts by weight of a solution containing a crystal. The crystal may contain a dry solid (DS). Furthermore, the term "average crystal particle size" in this disclosure is a measurement representing an average crystal size. There is no limitation on procedures for measuring the crystal particle size of D-psicosa, and procedures generally used in the art may be employed. Limited examples of crystal particle size measurements include a comparison procedure (FGC), a cutting procedure (FGI), a flat capacity procedure (FGP), and similar procedures. The D-psicose crystal in this disclosure may be of average size 0Πί0ΠΠ / ί7Π7 / Β / ΥΙ of particle (MA: Area distribution average diameter) of the crystal of 60 pm or more, 100 pm or more, 150 pm or more, 200 pm or more, 230 pm or more, 250 pm or more, 300 pm or more, or 320 pm or more. For example, the average particle size can be 100 pm to 500 pm, 150 pm to 450 pm, 200 pm to 400 pm, 230 pm to 400 pm, 300 pm to 400 pm, 320 pm to 400 pm, or 320 pm to 390 pm. The d10 of the D-psicose crystal in this disclosure is a value corresponding to a lower 10% of the crystal's distribution and may be 100 pm or more, 110 pm or more, 130 pm or more, or 150 pm or more. For example, the d10 of the D-psicose crystal may be 100 pm to 200 pm, 100 pm to 180 pm, 110 pm to 180 pm, 110 pm to 160 pm, 130 pm to 180 pm, 130 pm to 160 pm, 150 pm to 180 pm, or 150 pm to 160 pm. The d50 of the D-psychose crystal in this disclosure is a value corresponding to the lower 50% of the crystal's distribution and can be used in combination with a median. It can be 100 pm or more, 150 pm or more, 200 pm or more, 230 pm or more, 250 pm or more, 300 pm or more, or 310 pm or more. For example, the d50 of the D-psychose crystal can be 100 pm to 500 pm, 150 pm to 450 pm, 200 pm to 400 pm, 230 pm to 400 pm, 300 pm to 400 pm, 320 pm to 400 pm, or 310 pm to 390 pm. The d90 of the D-psychose crystal in this disclosure is a value corresponding to the lower 90% of the crystal's distribution and may be 200 pm or higher, 250 pm or higher, 300 pm or higher, 330 pm or higher, 350 pm or higher, 400 pm or higher, or 500 pm or higher. For example, the d90 of the D-psychose crystal may be 200 pm to 800 pm, 250 pm to 700 pm, 300 pm to 650 pm, 330 pm to 600 pm, 350 pm to 600 pm, 400 pm to 600 pm, or 500 pm to 590 pm. The particle size distribution of the D-psicose crystal of the present disclosure can be confirmed by a relative standard deviation or relative particle size distribution. The relative standard deviation is a percentage value obtained by dividing a standard deviation by an average particle size and can be 30% to 60%, 35% to 55%, 37% to 50%, 38% to 48%, or 40% to 46%. The relative particle size distribution is a value obtained by dividing d50 by the difference between d90 and d10 and can be from 0.8 to 1.5, from 0.9 to 1.4, or from 1.0 to 1.3. As a result, a certain amount of the D-psicose crystal is lost along with the mother liquor in the crystal centrifuge to reduce aggregation between crystals. Consequently, the D-psicose crystal of the present disclosure, having the particle size specified, is suitable for mass production. οπίοπη / ίζηζ / Ε / γι As another aspect of the present disclosure to meet the object, the present disclosure provides a preparation procedure for a D-psicose crystal that includes a first step of concentrating a solution containing D-psicose; a second step of adding a seed crystal to the mixed solution according to the first step; and subsequently cooling the same to obtain a baked mass containing the D-psicose crystal. The solution containing D-psicose is not limited as long as it is a solution in which D-psicose is dissolved or dispersed. The solution containing D-psicose may be a solution containing D-psicose with a high purity of 90% (w / w) or greater, specifically 91% (w / w) or greater, 92% (w / w) or greater, 93% (w / w) or greater, 94% (w / w) or greater, or 95% (w / w) or greater, but this disclosure is not limited to these. The solution containing D-psicose can be obtained through an epimerization reaction by treating a substrate for D-psicose production with an enzyme, or it can be obtained by separating or purifying the solution. Examples of substrates and enzymes include fructose and D-psicose epimerases, as well as fructose-6-phosphate, D-psicose-6-phosphate epimerase, and D-psicose-6-phosphate phosphatase. Specifically, the D-psicose-containing solution can be obtained by purifying a solution obtained from an epimerization reaction between fructose and D-psicose. The fructose used as the substrate for the epimerization reaction can be dissolved in water at a concentration of 30 to 50 Brix at a temperature of 30 to 40 °C. In this disclosure, brix (%) means a percentage of a weight of D-psicose or fructose on the basis of the weight of the complete solution.In this document, the fructose can be subsequently mixed with a chromatographically separated fructose solution and can be used at a concentration of 30 Brix (%) to 50 Brix (%) at a temperature of 30 °C to 40 °C. In this document, the chromatographically separated fructose solution can use a fructose fraction with a purity of 70% (w / w) or higher, specifically 75% (w / w). The D-psicose epimerization reaction can be the production of D-psicose by epimerizing fructose in the presence of psicose epimerase, variants thereof, a strain that produces the enzyme, or a culture thereof. The D-psicose epimerase that may be used in this disclosure may be an enzyme or a variant derived from various donor microorganisms such as Agrobacterium tumefaciens, Flavonifractorplauti, and Clostridium hylemonae. The transformation strains are Escherichia coli, Corynebacterium, Bacillus, and Aspergillus, but are not limited to these strains. As strains transformed into Escheríchía coli, they include, for example, BL21(DE3) / pET24ATPE [Korean Patent Publication No. 10-211-0035805], BL21(DE3) / pET24-ATPE-2 [Korean Patent Registration No. 10-1203856], etc. Corynebacterium strains include Corynebacterium glutamicum ATCC13032 / pCJ-1-ATPE [No. Access Code KCCM11046 of Korean Patent Publication No.10-2011-0035805], Corynebacterium glutamicum ATCC13032 / pFIS-1-ATPE-2 [No. of Access KCCM11204P of Korean Patent Registration No. 10-1203856], Corynebacterium glutamicum CJ KY [No. of Access KCCM11403P of the Korean Patent Registry no. 10-1455759], Corynebacterium glutamicum ATCC13032 / pFIS-2-ATPE-2 [No. of Access KCCM11678P of Korean Patent Application no. 10-2015-0047111], etc., but the present disclosure is not limited to the same. As an example, the epimerization reaction can be carried out by immobilizing psicose epimerase, a variant thereof, a strain to produce the enzyme, or a culture of the enzyme in a carrier, such as sodium alginate, and filling an isomerization reaction apparatus, such as a column, with the immobilized enzyme. A fructose-containing solution can then be supplied to the filled column. The temperature in the apparatus can be maintained at 40 °C to 70 °C, for example, 40 °C to 55 °C, for the epimerization reaction. At this time, the temperature of the solution containing the supplied fructose increases, for example, from 5 °C to 20 °C per hour, to a temperature of 40 °C to 60 °C, for example, 50 °C, by means of a heat exchanger, and the solution passes at a space velocity (SV) [flow rate (L) / time (Hr) / amount of resin (L)] of 0.5 to 3.The purity of D-psicose produced by the epimerization reaction can be from approximately 15% (w / w) to approximately 35% (w / w), for example, from approximately 20% (w / w) to approximately 30% (w / w). The solution containing the epimerized D-psicose can be cooled. Cooling is carried out to the solution temperature or to room temperature within a range of 25°C to 45°C, specifically 30°C to 40°C. Specifically, cooling can be done slowly at a rate of 1°C to 10°C per hour, and a heat exchanger can be used for cooling. The solution containing D-psicose can be obtained by separating and / or purifying a crude solution containing D-psicose. That is, the preparation procedure for the D-psicose crystal described in this disclosure may include separating and / or purifying a crude solution containing D-psicose prior to the first step. οηίοηη / ίζηζ / Β / γι The solution containing D-psicose can be obtained by purifying the crude solution containing D-psicose. Specifically, purification can be carried out by at least one selected from the group consisting of decolorization by passing through a column packed with a decolorizing agent, desalting by ion-exchange resin chromatography, and continuous chromatography. Specifically, the solution containing epimerized D-psicose can be cooled and subsequently decolorized by passing it through a column packed with a decolorizing agent, and purified through a column packed with a strongly acidic cation-exchange resin and a weakly basic anion-exchange resin. When using a strongly basic anion-exchange resin, D-psicose denatures even at low temperatures of 25 °C to 45 °C, and therefore purity may deteriorate. Consequently, to prepare D-psicose in high yield, a weakly basic anion-exchange resin, and more specifically, a 100% weakly basic anion-exchange resin, can be used. For the effective removal of ionic components, the cation-exchange resin and the anion-exchange resin can be used simultaneously.In this case, the ratio of cation exchange resin to anion exchange resin can be from 1:0.5 to 1:3. During ion purification, a temperature of 25°C to 45°C is maintained, specifically from 30°C to 40°C, to prevent denaturation of the D-psicose. As a result, ionic components present as impurities in the D-psicose solution can be removed. After ion purification, the content of the ionic components can be 20 microsiemens or less, specifically 10 microsiemens or less per unit cm when measured using an electrical conduction system. The purity of the D-psicose in the ion-purified solution can be from approximately 10% (w / w) to approximately 35% (w / w).In this process, during cooling and ion purification, ethanol is removed from the mother liquor produced in a subsequent crystallization stage with D-psicose by distillation, and the mother liquor can then be reused. The solution containing purified D-psicose can be concentrated and cooled. Concentration is a process of raising the concentration of a solution containing purified D-psicose to a D-psicose concentration in the range of 50 Brix to 70 Brix, for example, 55 Brix to 65 Brix. Specifically, concentration can be achieved at a temperature of 50 °C to 80 °C, for example, 55 °C to 70 °C. During concentration, a low-temperature evaporator can be used to prevent denaturation of the D-psicose. After concentration, it is possible to... 0Πί0ΠΠ / ί7Π7 / Β / ΥΙ perform the cooling. When cooling is performed, it can be done so that the solution or ambient temperature reaches a temperature at least 10 °C lower than the temperature during concentration. For example, the cooling temperature can be in the range of 40 °C to 60 °C. Cooling can be carried out slowly at a cooling rate of 5 °C to 25 °C per hour, and a heat exchanger can be used for cooling. Currently, during concentration and cooling, the ethanol is removed from the mother liquor produced in a subsequent crystallization stage with D-psicose by distillation, and the mother liquor can then be reused. The solution containing D-psicose can be obtained by separating fructose from the D-psicose solution. Specifically, the fructose-containing solution can be separated by chromatography. Chromatography involves separating D-psicose by exploiting the weak bond strength between D-psicose and metal ions bound to the ion exchange resin. Continuous chromatography, for example, can be used. The ion exchange resin used for chromatography can be a strongly acidic cation exchange resin with bound K, Na, Ca, and Mg residues. Specifically, the ion exchange resin can be one capable of separating D-psicose and fructose, for example, K, Ca, or Na. The fructose-containing solution and the purified D-psicose-containing solution can be obtained by chromatography. The purified D-psicose-containing solution can be a D-psicose solution with a purity of 90% (w / w) or higher, for example, 95% (w / w) or higher. Specifically, the purity of D-psicose can range from 90% (w / w) to 99% (w / w) or higher. The solution containing fructose may be a solution containing fructose with a purity of 70% (w / w) or higher.The solution containing the separated fructose can be reused in the D-psicose epimerization reaction by chromatography. The fructose is denatured without separation and separated by chromatography, and subsequently reused in the D-psicose epimerization reaction to increase the overall yield. Before reuse, cooling to between 25°C and 45°C, or between 30°C and 40°C, can also be included. The D-psicose solution of this disclosure may be concentrated. For example, the purified D-psicose solution obtained with a purity of 95% (w / w) or higher may be concentrated to achieve a D-psicose concentration of 75 Brix (%) or higher, e.g., 80 Brix (%) or higher. Concentration may be achieved specifically at a temperature of 50°C to 80°C, e.g., 55°C to 70°C. During concentration, a low-temperature evaporator may be used to prevent denaturation of the D-psicose. The preparation procedure for the D-psicose crystal described herein includes a first step of mixing a solution containing D-psicose and an organic solvent. This allows the D-psicose to partially precipitate. Furthermore, the seed crystal addition and cooling described below can significantly contribute to high-yield crystal separation. The mixing in the first stage can be carried out at 20°C to 60°C. Specifically, it can be performed at 30°C to 60°C, or more precisely, at 40°C to 60°C. At lower temperatures, the state becomes supersaturated, exceeding the metastable region. This leads to the nucleation of new crystals instead of crystal growth, resulting in the suppression of crystal growth. At higher temperatures, the organic solvent volatilizes during the mixing process, creating a safety issue due to the decreased recovery rate and increased vapor generation. The organic solvent can be an alcohol, and specifically can include at least one selected from ethanol, methanol, and isopropyl alcohol. The organic solvent can be a mixture with a water:organic solvent ratio of 1:0.5 or higher, 1:0.7 or higher, or 1:1 or higher, and, for example, 1:0.5 to 1:10, 1:0.7 to 1:10, 1:1 to 1:10, 1:1 to 1:9, or 1:1 to 1:8. The preparation procedure for the D-psicose crystal described herein is a second step of adding a seed crystal to the mixed solution according to the first step and then cooling it to obtain a massecuite containing the D-psicose crystal. Herein, the massecuite means a suspension state in which the crystal and solution are mixed as the D-psicose seed begins the crystallization reaction. The most difficult aspect of preparing D-psicose crystals is controlling their size or shape. In this disclosure, this can be achieved using a crystallization procedure in which, after mixing the organic solvent into the D-psicose-containing solution, the seed crystal is added and the solution is slowly cooled. In this disclosure, D-psicose seed means a fine crystal consisting primarily of D-psicose, added while maintaining a uniform degree of supersaturation of D-psicose in the mixed organic solvent solution within the metastable region. The mixed organic solvent solution has low viscosity, allowing the added D-psicose seed to disperse readily. Under conditions of low viscosity and high dispersion, crystal growth can be excellent. The D-psicose seed can be a seed crystal of 100 pm or less, and specifically a seed crystal with a size of 40 pm to 100 pm. The D-psicose seed can be added at a weight percent of 0.01% (w / w) to 1% (w / w) based on the total weight of the mixed solution. In the preparation procedure described herein, when the D-psicose seed is not added, an amorphous D-psicose agglomeration is formed, and a D-psicose crystal of the desired size or shape is not produced. It is preferable to add the D-psicose seed to the mixed solution in dispersed form. After the seed is added, the crystal is grown by adjusting the cooling conditions. Regarding the cooling process, the temperature in the first mixing stage before cooling is the same as described above, and the final cooled temperature in the second stage can be 8°C to 30°C, 8°C to 25°C, 8°C to 20°C, 10°C to 30°C, 10°C to 25°C, or 10°C to 20°C. This temperature control suppresses the formation of new crystals, increasing crystal size and yield. If the final cooled temperature in the second stage is higher than the range described above, the D-psicosa crystal recovery rate is reduced. Furthermore, when the final temperature is lower than the above range, nucleation is induced, thus generating a large number of particles of less than 100 pm, which produces aggregation between crystals during drying and, as a result, reduces the packing volume of the final product or impairs its marketability. In this disclosure, the cooling rate is adjusted to control the growth rate of the D-psicose crystal. Specifically, cooling can be performed at a rate of 0.05 °C / hour to 1.4 °C / hour, 0.6 °C / hour to 1.4 °C / hour, 0.7 °C / hour to 1.3 °C / hour, 0.8 °C / hour to 1.2 °C / hour, or 0.9 °C / hour to 1.1 °C / hour. As another example, the cooling rate can be adjusted to cool within the metastable zone. When the cooling rate is faster than this range, the mixed solution quickly enters a supersaturated zone beyond the metastable zone, resulting in a large number of particles. Conversely, when the cooling rate is too low, the yield per unit of time is reduced, leading to inefficiencies in mass production. In the second stage, cooling and / or crystallization can be carried out for 20 to 70 hours or 30 to 70 hours. According to a non-limited realization of this disclosure, when the D-psicose crystal is prepared by using the organic solvent and controlling the rate 0Πί0ΠΠ / ί7Π7 / Β / ΥΙ of cooling, a block of structured D-psychose crystal can be generated. The procedure for preparing this disclosure may also include a third step of separating and drying the D-psicose crystal from the massecuite. Specifically, the D-psicose crystal containing an excess of organic solvent may be separated from the massecuite obtained in the first and second steps. In separating the D-psicose crystal from the massecuite, any procedure capable of separating the crystal may be used without limitation, but, for example, a centrifugal dehydrator may be used. The separated crystal may contain 0.07% (w / w) or more, 0.1% (w / w) or more, and 0.13% (w / w) or more organic solvent, for example, 0.07% (w / w) to 0.5% (w / w), 0.1% (w / w) to 0.3% (w / w), or 0.13% (w / w) to 0.2% (w / w), based on 100% (w / w) of the total crystal. The D-psicose crystal containing an excessive amount of organic solvent is dried to obtain a D-psicose crystal containing 98% (w / w) or more D-psicose and 0.05% (w / w) or less organic solvent based on 100% (w / w) of the total crystal. The description of the resulting D-psicose crystal is the same as above. The procedure for preparing this disclosure may also include a fourth step of recovering the organic solvent from a crystal mother liquor in which the D-psicose crystal is separated according to the third step and subsequently reusing the recovered organic solvent as the organic solvent of the first step. In addition, the procedure for preparing this disclosure may also include a fifth step of reusing the crystal mother liquor in which the organic solvent is removed in accordance with the fourth step in preparing a D-psicose solution in the first step. The yield according to the preparation procedure of the present disclosure, i.e., a weight percent of the D-psicose crystal finally obtained compared to the weight of the D-psicose existing in the D-psicose-containing solution in the first stage, may be 65% (w / w) or greater, 70% (w / w) or greater, 75% (w / w) or greater, or 80% (w / w) or greater. In other words, in this disclosure, performance can be represented by the following formula. [Formula 1] Yield (%) = (weight of dehydrated and dried D-psicose crystal / weight of D-psicose in crude solution before crystallization) * 100 When calculating the yield, the weight of D-psicose in the crude solution before crystallization is measured with D-psicose g / L in the crude solution through HPLC analysis, and subsequently the measured D-psicose g / L is substituted according to a previously measured amount of crude crystallization solution (L) to calculate a weight (g) of D-psicose included in a specific amount of crude solution (L). Furthermore, the mother liquor separated during crystallization—that is, a dehydrated supernatant from the massecuite—can be reused in the first stage of organic solvent recovery by distillation. The recovered organic solvent can then be blended with the D-psicose solution. The D-psicose solution, from which the organic solvent is removed after distillation, is cooled to 30 °C and can be recirculated in a column where a strongly acidic cation-exchange resin is replaced with a hydrogen group and a weakly acidic anion-exchange resin is replaced with a hydroxyl group. Alternatively, it can be recirculated by continuous chromatography or in the first stage. The mother liquor generated during D-psicose crystallization can be a fraction containing D-psicose with a purity of 75% (w / w) or higher, 85% (w / w) or higher, or 95% (w / w) or higher. Advantageous effects In the preparation procedure for the D-psicose crystal of the present disclosure, by the crystallization procedure of mixing the organic solvent in the solution containing D-psicose, adding the seed and subsequently slowly cooling the mixture, it is possible to increase the yield of D-psicose crystal from the D-psicose solution and prepare D-psicose crystal in a size sufficient and shape suitable for use in mass production without bad taste / odor. BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a micrograph of a D-psicose crystal prepared in Example 1. Figure 2 is a result of the particle size analysis of the Dpsicosa crystal prepared in Example 1. Figure 3 is a result of the particle size analysis of a D-psicose crystal composition prepared in Example 2. Figure 4 is a diagram illustrating a shape of a Dpsicosa crystal cake prepared in Example 6. Figure 5A is a scanning electron micrograph (SEM) of a surface of the 0Πί0ΠΠ / ί7Π7 / Β / ΥΙ crystal of D-psicose prepared in Example 1. Figure 5B is a scanning electron micrograph (SEM) of a surface of a D-psicose crystal prepared in the Comparative Example. Figure 6 is a diagram that illustrates a procedure for measuring an angle of repose. Mode for the invention This disclosure will be described in greater detail hereafter with reference to the following Examples. However, the following Examples are merely illustrative of this disclosure, and its scope is not limited to them. Example 1: Preparation of high-purity D-psicose crystal composition with purity of 98% (w / w) or higher and containing 0.05% (w / w) or less of ethanol (1) Production of low-purity D-psicose solution using microorganisms A fructose solution of 50 brix (%) (enzyme reaction substrate solution) was prepared with a purity of 95% (w / w) or higher. As in the enzymatic epimerization reaction disclosed in Korean Patent Publication No. KR 102011-0035805 A (Korean Patent Application No. 10-2009-0118465), in which a D-psicose epimerase separated from a strain of Corynebacterium glutamicum KCCM 11046P was immobilized to a sodium alginate carrier and filled into an isomerization apparatus (isomerization tower, HANJOO Machine Industrial Co., Ltd.), and subsequently the prepared enzyme reaction substrate solution was passed through a heat exchanger at space velocity (SV) [flow rate (L) / time (Hr) / amount of resin (L)] by raising the temperature to 50 °C at a rate of 5 °C to 20 °C per hour to obtain an epimerized D-psicose solution. At this time, the purity of D-psicose was approximately 24% (w / w). (2) Purification of the D-psicose solution The epimerized D-psicose solution was first cooled to 30–40 °C at a rate of 5–10 °C per hour using a heat exchanger. It was then passed through a column loaded with a decolorizing agent (SV3) for decolorization, and subsequently through a column loaded with a strongly acidic cation-exchange resin substituted with a hydrogen group and a weakly acidic anion-exchange resin substituted with a hydroxyl group for desalting. The final ionic composition was adjusted to 10 microsiemens or less per unit cm² by measurement using an electrical conduction system, and the purity of the D-psicose in the desalted enzyme reaction solution was maintained at 24% (w / w). (3) Separation of the high-purity D-psicose solution using chromatography The ion-purified D-psicose-containing solution was added to a low-temperature evaporator (forced thin-film evaporator, WELCRON Hantec), concentrated to a concentration of 60 brix (%) for a short time of 10 to 15 minutes at a temperature of 55 °C to 70 °C, and then cooled again at a rate of 5 °C to 25 °C per hour through the heat exchanger to separate into a purified D-psicose solution having a D-psicose purity of 95% (w / w) or higher and a fructose-containing solution having a fructose purity of 70% (w / w) or higher by continuous chromatography on a column loaded with a strongly acidic cation exchange resin with a calcium-bonded active group at 50 °C to 60 °C. The fructose-containing solution having a purity of 70% (w / w) or higher, separated by continuous chromatography, was recovered and cooled at a rate of 20°C to 30°C per hour for recirculation in a fructose epimerization process at 30°C. (4) Crystallization by concentration, treatment with organic solvent, and cooling of the D-psicose solution The purified D-psicose solution having a purity of 95% (w / w) or greater, separated by continuous chromatography, was concentrated at a temperature of 55 °C to 70 °C to adjust to a concentration of 85.0 brix (%). The concentrated D-psicose solution having a purity of 95% (w / w) or greater was rapidly cooled to a temperature of 40 °C at a rate of 5 °C to 20 °C per hour through the heat exchanger, and subsequently mixed with ethanol corresponding to a water:ethanol weight ratio = 1:1.13 compared to the water content, excluding solids. An appropriate amount of seed was added to the D-psicose solution mixed with ethanol cooled to 40 °C, and subsequently cooled to a final temperature of 10 °C. QnLQnn / Lznz / E / Yii was cooled at a rate of 1 °C per hour and crystallized for 30 hours to obtain a mass bake containing the D-psicose crystal. The cooked mass containing the D-psicose crystal was added to a high-speed centrifugal dehydrator and centrifuged at 4,000 rpm for 10 minutes. A supernatant was then discharged to obtain a D-psicose crystal containing an excessive amount of ethanol. The residual supernatant was washed by spraying with deionized water or ethanol, and the ethanol concentration in the resulting D-psicose crystal was approximately 0.15% (w / w). The recovered D-psicose crystal containing an excess of ethanol was transferred to a fluidized bed dryer or vacuum dryer and dried for 1 to 2 hours to remove excess ethanol and obtain D-psicose crystals with a purity of 98% (w / w) or higher and containing 0.03% (w / w) ethanol. The amount of D-psicose crystal obtained after drying was 2.252 g, which was recovered at a rate of approximately 81% compared to the 2.780 g present in the D-psicose solution separated and concentrated by continuous chromatography, and the crystal size was MA 336 (Figures 1 and 2). Furthermore, the mother liquor separated during crystallization—that is, a dehydrated supernatant from the massecuite—can be reused in the ethanol recovery stage by distillation, and the recovered ethanol can be blended with the D-psicose solution. The D-psicose solution, from which the ethanol is removed after distillation, is cooled to 30 °C and can be recirculated in a column loaded with strongly acidic cation-exchange resin substituted with a hydrogen group and weakly acidic anion-exchange resin substituted with a hydroxyl group, or it can be recirculated by continuous chromatography. Example 2: Preparation of a high-purity D-psicose crystal composition with a purity of 98% (w / w) or greater and containing 0.05% (w / w) or less of ethanol In Example 1 above, except that the solution containing D-psicosa concentrated to 80.0 brix (%) was cooled to 50 °C, the corresponding ethanol was mixed in a water:ethanol weight ratio of 1:9 compared to the water content, excluding solids, the cooling rate was 0.5 °C per hour, and a final temperature was up to 20 °C for 60 hours, the high-purity D-psicosa crystal composition with a purity of 98% (w / w) or greater and 0.05% (w / w) or less of ethanol was prepared in the same manner as in Example 1. οηίοηη / ίζηζ / Β / γι The amount of D-psicose crystal obtained with a purity of 98% (w / w) or higher and containing 0.05% (w / w) or less of ethanol was 2,307 g, which was recovered at a rate of approximately 83% compared to 2,780 g of D-psicose initially dissolved, and the crystal size was MA 241 (Figure 3). Example 3: Crystal preparation of a D-psicose composition having a purity of 98% (w / w) or higher and containing 0.05% (w / w) ethanol, In Example 1 above, except that the drying time was 30 minutes to 1 hour, a high-purity D-psicose crystal composition with a purity of 98% (w / w) or higher was prepared in the same manner as in Example 1. The D-psicose crystal obtained contained 0.05% (w / w) ethanol, and the purity was 98% (w / w) or higher Example 4: Preparation of D-psicose crystal composition having a purity of 98% (w / w) or higher and containing 0.06% (w / w) ethanol In Example 1 above, except that the drying time was 10 minutes to 20 minutes, a high-purity D-psicose crystal composition with a purity of 98% (w / w) or higher was prepared in the same manner as in Example 1. The D-psicose crystal obtained contained 0.06% (w / w) ethanol, and the purity was 98% (w / w) or higher. Example 5: Preparation of high-purity D-psicose crystal by changing the type of mixed organic solvent In Example 1 above, except that methanol and isopropyl alcohol were mixed into the concentrated solution containing D-psicose, a high-purity D-psicose crystal with a purity of 98% (w / w) or higher was prepared in the same manner as in Example 1. When methanol was used, the yield of the D-psicose crystal obtained was 33%, and an average particle size was MA 109. When isopropyl alcohol was used, the yield of D-psicose crystal obtained was 32%, and an average particle size was MA 61. Example 6: Preparation of high-purity D-psicose crystal composition using an organic solvent without cooling rate control In Example 2 above, except that the ethanol corresponding to a water:ethanol weight ratio of 1:4 was mixed with the water content, excluding solids in the concentrated solution containing D-psicose, and a seed was added and subsequently crystallized by cooling for 30 hours to a final temperature of 20 °C in 30 minutes to 1 hour without controlling the cooling rate, a high-purity D-psicose crystal composition having a purity of 98% (w / w) or greater and containing 0.05% (w / w) or less of ethanol was prepared in the same manner as in Example 2. The amount of D-psicose crystal obtained was 1.056 g, which was recovered at a rate of approximately 38% compared to the D-psicose initially dissolved, and the D-psicose crystal block generated was 1.084 g and was confirmed to have been recovered at a rate of 39%. Comparative Example: Preparation of high-purity D-psicose crystal by cooling crystallization procedure without using organic solvent In Example 2 above, except that the concentrated solution containing D-psicose was cooled to an initial temperature of 40 °C and subsequently cooled to 20 °C for 80 hours without mixing in ethanol, a high-purity D-psicose crystal having a purity of 98% (w / w) or higher was prepared in the same manner as in Example 2. The yield of the D-psicose crystal obtained was 53%, and the average particle size was MA 374. Example Test 1: Confirmation of the residual ethanol removal effect The high-purity D-psicose crystals in Example 1 (containing 0.03% (w / w) or less of residual ethanol), the Comparative Example, Example 4, and Example 3 were consumed by a subject in a predetermined amount in powder form, and a 3-point test was subsequently conducted to assess whether a difference could be discerned. Two test groups were set up with three options, and an evaluator consumed all three options sequentially without knowing the order in order to select which one tasted different. The test was performed by 20 evaluators three times, and the difference was assessed according to the correct response rate out of the total number of tests. The D-psicose crystal and the % residual ethanol concentration (w / w) used in the evaluation are shown in Table 1, and the evaluation results are shown in Table 2.The evaluation was performed by counting the number of correct answers, comparing the total number of responses and the number of correct answers with a significance test table, and determining whether there was statistical significance. When the test was performed 60 times, if the number of correct answers was 27 or more, it was determined that there was a significant difference in quality. οηίαηη / ίζηζ / Ε / γι Table 1 Example 3 Example 1 Example 4 Comparative Example Residual concentration of ethanol (%, w / w) 0.05 0.03 0.06 0 Table 2 Comparative Group Number of Test Times Number of Correct Responses Correct Response Rate Test Results % Presence / Absence of Difference Comparative Example Example 4 60 48 80.0 Presence Comparative Example Example 3 60 22 36.7 Absence Comparative Example Example 1 60 12 20.0 Absence Example 4 Example 3 60 43 71.7 Presence Example 4 Example 1 60 46 76.7 Presence Example 3 Example 1 60 11 18.3 Absence It was confirmed that there was no functional difference between D-psicose crystals (Examples 1 and 3) containing 0.05% (w / w) or less of residual ethanol compared to a D-psicose crystal (Comparative Example) prepared by a procedure without using an organic solvent. From this, it can be observed that when the residual ethanol is adjusted below a predetermined concentration, a flavor equivalent to that of the original D-psicose crystal is achieved. Example Test 2: Confirmation of the effect of reducing the intensity of bad taste / odor by removing residual ethanol In the preceding Test Example 1, the intensity of the off-flavor / odor was evaluated for the same test group (Table 1) used in the trial. Twenty evaluators consumed the D-psicose crystal, and the intensity of the off-flavor / odor was subsequently expressed as a level (5 points indicated a case where the off-flavor / odor intensity was at its maximum), with the evaluation results shown in Table 3. It was confirmed that there were no differences in off-flavor / odor in D-psicose crystals (Examples 1 and 3) containing 0.05% (w / w) or less of residual ethanol compared to a D-psicose crystal (Comparative Example) prepared by a procedure without the use of an organic solvent. From this, it can be observed that when the residual ethanol is removed below a predetermined concentration, the off-flavor / odor is equivalent to that of the original D-psicose crystal. οηίαηη / ίζηζ / Ε / γι Table 3 Comparative Example Example 4 Example 3 Example 1 1.9 ± 0.8 3.0 ± 0.4 2.0 ± 0.9 1.9 ± 0.7 Example Test 3: Confirmation of the smooth surface effect when containing ethanol The surfaces of the high-purity D-psicose crystals in Example 1 (containing 0.03% (w / w) or less of residual ethanol) and the Comparative Example were examined by SEM. The results are shown in Figure 5. It was confirmed that, compared to the D-psicose crystal (Figure 5B) without the addition of ethanol in the Comparative Example, the surface of the D-psicose crystal (Figure 5A) with the addition of ethanol in Example 1 was smooth. From this, it can be observed that the smoothness of the D-psicose crystal surface increases with the addition of ethanol, and therefore its surface is lustrous or shiny. Example Test 4: Confirmation of the effect of increasing crystal fluidity when containing ethanol Example Test 4.1: Flow Measurement The flowability of D-psicose crystals (Example 1) containing 0.03% (w / w) or less of residual ethanol was compared to that of D-psicose crystals (Comparative Example) prepared by a procedure without using an organic solvent and was evaluated. A flowability meter was used for the evaluation of flowability. Table 4 Inlet diameter 1.5 cm Tray diameter 5.0 cm Space between inlet and tray 15 cm Quantity added 30 g 0Πί0ΠΠ / ί7Π7 / E / ΥΙ Table 4 above is a table showing the measurement conditions of the flow meter. Flowability = [(weight of added powder - weight of residual powder in the tray) / weight of added powder x 100)] As the resulting value calculated according to the formula increases, the fluidity of the crystal increases. Example Test 4.2: Measuring the Angle of Repose Furthermore, the effect of increased fluidity from the addition of ethanol was confirmed by measuring the angle of repose. The angle of repose refers to the maximum inclined angle at which deposits that have not yet hardened can be laid down without flowing downwards when deposited on a slope, and the smaller the angle of repose, the greater the crystal fluidity (Figure 6). The angle of repose was obtained by measuring an angle of the top surface of a composition with a protractor after a D-psicose crystal composition passes through a funnel installed on a horizontal surface at a predetermined speed. Table 5 Flow Angle of repose Example 1 59.7 35 Comparative Example 48 45 Table 5 above shows the flowability and angle of repose measurement results. Table 5 confirms that flowability increased for D-psicose with added ethanol. This suggests that because ethanol-containing D-psicose has low viscosity, crystallization continues as the seed disperses, thus providing a high yield and degree of crystallization. Those skilled in the art will appreciate that the present disclosure, as described above, can be implemented in other specific forms without departing from its technical spirit or essential features. It should therefore be appreciated that the embodiments described above are intended to be illustrative in all respects and not restrictive. The scope of this disclosure is represented by the claims described below rather than a detailed description, and the meaning and scope of the claims and all changes or modifications derived from their equivalents should be construed as falling within the scope of this disclosure.

Claims

1. A D-psicose crystal comprising: 98% (w / w) or more of D-psicose and from 0.001% (w / w) to 0.05% (w / w) of ethanol based on 100% (w / w) of the whole crystal.

2. The D-psicose crystal according to claim 1, wherein an average particle size (APS) is 200 pm or more.

3. A preparation process for a D-psicose crystal comprising: a first step of mixing a solution containing D-psicose and an organic solvent; and a second step of adding a seed to the mixed solution according to the first step and subsequently cooling the same to obtain a baked mass containing the D-psicose crystal.

4. The preparation process according to claim 3, wherein the first stage mixing is carried out at 40°C to 60°C, and a final cooled temperature according to the second stage is 10°C to 20°C.

5. The preparation method according to claim 3, wherein, in the second stage, the seed is grown in a metastable zone by adjusting a cooling rate.

6. The preparation process according to claim 5, wherein, in the second stage, the cooling rate is from 0.05 “C / hour to 1.4 “C / hour.

7. The preparation process according to claim 3, wherein, in the second stage, cooling and crystallization are carried out for 20 to 70 hours.

8. The preparation process according to claim 3, wherein the solution containing D-psicose contains 95% (w / w) or more of D-psicose.

9. The preparation process according to claim 3, wherein a weight percent of a D-psicose crystal finally obtained compared to the D-psicose content existing in the D-psicose-containing solution in the first stage is 65% (w / w) or more.

10. The preparation process according to claim 3, wherein the organic solvent is an alcohol.

11. The preparation process according to claim 3, wherein the organic solvent includes at least one selected from ethanol, methanol and propyl alcohol.

12. The preparation process according to claim 3, wherein the organic solvent is a mixture with a water:organic solvent ratio of 1:0.5 or more in the solution containing D-psicose.

13. The preparation process according to claim 3, wherein in the solution containing D-psicose, a concentration of D-psicose is from 80 brix to 85 brix.

14. The preparation process according to claim 3, further comprising: a third step of separating and drying the D-psicose crystal from the baked mass.

15. The preparation process according to claim 14, further comprising: a fourth step of recovering the organic solvent from a crystal mother liquor in which the D-psicose crystal is separated according to the third step and subsequently reusing the recovered organic solvent as the organic solvent of the first step.

16. The preparation process according to claim 14, further comprising: a fifth step of removing the organic solvent from a crystal mother liquor in which the D-psicose crystal is separated according to the third step, and subsequently reusing the crystal mother liquor in the preparation of a solution containing D-psicose.

17. The preparation process according to claim 14, wherein a concentration of the organic solvent in the D-psicose crystal is adjusted to 0.05% (w / w) or less by drying.