Crystalline functional sweetener

Abstract

To provide a particular crystalline allulose, a method for producing the crystalline allulose with high yield and high purity, and, furthermore, sweeteners containing the crystalline allulose, various foods and beverages using the sweeteners, and the like.SOLUTION: There is provided an allulose crystal having an X-ray spectroscopic spectrum having peaks at diffraction angles (2θ)±0.2 of 15.24, 18.78, and 30.84. The allulose crystal of the present invention has better flowability than fine powders, are not easily caked and stable during storage, and are easy to distribute and handle.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a functional saccharide having specific crystallinity, a method for producing the same, and a functional sweetener containing the crystalline saccharide. [Background technology]

[0002] General sugars, represented by sugar and starch sugar, form the largest market worldwide, at approximately 65 trillion won. However, as consumer needs for health-conscious functional and premium products grow worldwide, the market for functional sweeteners, including sugar alcohols such as xylitol, oligosaccharides such as fructooligosaccharides, functional sugars such as crystalline fructose, and sweeteners such as sucralose and aspartame, is growing.

[0003] Sweeteners are a general term for seasonings and food additives that give a sweet taste. Of the many sweeteners, sugar, glucose, fructose, etc. are the most widely distributed as natural ingredients in foods and are also the most widely used in the manufacture of processed foods. However, as the negative aspects of "sugar" such as its ability to cause tooth decay, obesity, and diabetes have come to light, functional alternative sweeteners that can be used in place of sugar have been attracting attention worldwide.

[0004] Recently, allulose has been attracting attention as a saccharide that can replace sugar or fructose as a functional sweetener. Allulose can be produced by chemical or biological methods, but the allulose content in the product is low, so purification and concentration processes are required. However, concentrated syrups have limitations in their application, so there is a high demand for crystalline powder, but allulose has low crystallinity and is difficult to crystallize.

[0005] In addition, when allulose is produced by a biological method using an allulose converting enzyme or a strain that produces the enzyme, the conversion rate is low, so the purity of D-allulose must be increased before it is crystallized. For the purpose of industrial use of D-allulose, there are still unresolved issues in the purification process, purification yield, crystallization yield, etc. Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present invention is to provide a specific crystalline allulose and to provide a method for producing said crystalline allulose in high yield and high purity. Another object of the present invention is to provide a sweetener containing crystalline allulose, and various foods and beverages using the sweetener. [Means for solving the problem]

[0007] The present invention provides a specific crystalline form of allulose, a method for producing the crystalline allulose in high yield and high purity, and various uses of the specific crystalline allulose.

[0008] The allulose crystal according to one embodiment of the present invention may be an allulose crystal having an X-ray spectrum with peaks at diffraction angles (2θ) of 15.24, 18.78, and 30.84 ± 0.2 in the X-ray spectrum. In one embodiment of the present invention, the X-ray spectrum may be an allulose crystal having peaks at diffraction angles (2θ) of 15.24, 18.78, 30.84, and 28.37 ± 0.2 in the X-ray spectrum, at diffraction angles (2θ) of 15.24, 18.78, 30.84, and 31.87 ± 0.2, or at diffraction angles (2θ) of 15.24, 18.78, 30.84, and 47.06 ± 0.2. The peaks in the X-ray spectrum of the allulose crystal The diffraction angles indicated are the main peaks and morphology-specific peaks in the top (Relative Intensity%) of the X-ray diffraction analysis.

[0009] The allulose crystals according to one embodiment of the present invention may have a Tm temperature of 125.8°C±5°C or a melting enthalpy (ΔH) of 200 to 220 J / g by DSC analysis, and the Tm may be 125.8°C±3°C.

[0010] The ratio of the length (micrometers) of the major axis to the minor axis of the allulose crystal according to one embodiment of the present invention (=major axis / minor axis) may be 1.0 to 8.0.

[0011] The allulose crystal according to one embodiment of the present invention may be an allulose crystal having one or more properties selected from the group consisting of (1) to (5) above: (1) A powder X-ray spectrum having peaks at diffraction angles (2θ) of 15.24, 18.78, and 30.84 ±0.2; (2) having a Tm temperature of 125.8°C ± 5°C by differential scanning calorimetry (DSC); (3) Having a melting enthalpy (△H) of 200 to 220 J / g as determined by differential scanning calorimetry; (4) having an average major axis of 350 μm or more, preferably 350 to 2,000 μm; and (5) The ratio of the major axis length (micrometers) to the minor axis length of the allulose crystal (= major axis / minor axis) is in the range of 1.0 to 8.0.

[0012] A further embodiment of the present invention relates to a sweetener composition comprising allulose crystals having one or more properties selected from the group consisting of (1) to (5) above. Other embodiments of the present invention include foods, beverages, feeds, medicines, or cosmetics comprising the allulose crystals.

[0013] The present invention will now be described in more detail. The allulose crystal according to one embodiment of the present invention may have one or more characteristics selected from the group consisting of the following (1) to (5): (1) A powder X-ray spectrum having peaks at diffraction angles (2θ) of 15.24, 18.78, and 30.84 ±0.2; (2) having a Tm temperature of 125.8°C ± 5°C by differential scanning calorimetry (DSC); (3) Having a melting enthalpy (△H) of 200 to 220 J / g as determined by differential scanning calorimetry; (4) Having an average major axis of 350 μm or more, 350 to 2000 μm, and (5) The ratio of the major axis length (micrometers) to the minor axis length of the allulose crystal (= major axis / minor axis) is in the range of 1.0 to 8.0.

[0014] The allulose crystals according to the present invention can be obtained by various crystallization methods, but the properties measured may be those of allulose crystals produced by a cooling method.

[0015] According to the powder X-ray spectroscopy analysis of the allulose crystals of the present invention, the crystals may have a powder X-ray spectroscopy spectrum with peaks at diffraction angles (2θ) of 15.24, 18.78, and 30.84 ± 0.2. Preferably, the crystals may have a powder X-ray spectroscopy spectrum with peaks at diffraction angles (2θ) of 15.24, 18.78, 30.84, and 28.37 ± 0.2, at diffraction angles (2θ) of 15.24, 18.78, 30.84, and 31.87 ± 0.2, or at diffraction angles (2θ) of 15.24, 18.78, 30.84, and 47.06 ± 0.2. More specifically, the X-ray spectroscopy spectrum may have peaks at diffraction angles (2θ) of 15.24, 18.78, 30.84, 27.37, 47.06 and 31.87 ±0.2 in an X-ray spectrum.

[0016] The diffraction peak value at the above-mentioned diffraction angle (2θ) may show a slight measurement error due to the measuring device or measuring conditions, etc. Specifically, the measurement error may be within the range of ±0.2, preferably ±0.1, and more preferably ±0.06.

[0017] The allulose crystal according to the present invention is analyzed by thermal analysis, specifically, differential scanning calorimetry (DSC). According to DSC analysis, the melting temperature (Tm) of the allulose crystal according to the present invention can be 125.8°C ± 5°C, preferably ± 3.0°C, more preferably ± 1.0°C. The allulose crystal may have a melting enthalpy (ΔH) of 200 to 220 J / g, for example, 212.7 J / g, according to DSC analysis. Differential scanning calorimetry (DSC) is operated by a temperature gradient and measures the energy provided to maintain the temperature increase of an allulose powder sample. In the DSC analysis of a crystal, the higher the heat capacity, the less easily it melts, and the higher the heat capacity and the narrower the width of the endothermic peak, the more uniform and hard the crystal is formed.

[0018] The allulose crystal according to the present invention may have an average short diameter of 50 to 1,000 μm, preferably 50 to 500 μm, and an average long diameter of 350 μm or more, preferably 350 to 2,000 μm, and more preferably 400 to 2,000 μm.

[0019] In addition, the ratio (micrometers) of the major axis length to the minor axis length (=major axis / minor axis) of the allulose 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, 2.0 to 5.5, or 2.0 to 5.0.

[0020] According to the results of powder XRD pattern analysis of the allulose crystals according to the present invention, the allulose crystals according to the present invention are pure crystalline particles and have a rectangular hexahedron or a structure close thereto. The closer the crystalline structure of the present invention is to a cubic system, the higher the uniformity and hardness of the crystals, which is more preferable.

[0021] In addition, the more uniform the crystals produced in the crystallization process of allulose are, the stronger the crystals will be, and the more uniform the particle size distribution will be as the particle cracking is minimized, thereby improving flowability.On the other hand, if the degree of uniformity is low, the crystal particles will be broken down into fine powder during the drying and transport stages, and will be relatively easy to dissolve, adversely affecting product quality.

[0022] In the present invention, "purity of crystal" refers to the purity of allulose crystal.The physical properties including the purity of the crystal of the present invention can be determined by, for example, X-ray powder diffraction analysis, differential scanning calorimetry (DSC) analysis, infrared spectroscopy (FTIR) analysis, HPLC analysis, LC / MS analysis, etc., and the purity can be specifically analyzed by HPLC chromatography.

[0023] The purity of the crystalline form of the present invention may be 70% by weight or more, preferably 80% by weight or more, more preferably 90% by weight or more, even more preferably 95% by weight or more, and most preferably 98% by weight or more. A purity within this range is preferred for quality assurance.

[0024] The allulose crystal of the present invention has a good flowability compared to fine powder, is stable during storage without easy caking, and has the characteristics of easy distribution and handling.In addition, the allulose powder has a lower calorie content than sugar and has sweetness similar to that of sugar, so that it can be easily and advantageously manufactured mixed sweeteners, solid mixed sweeteners, chocolate, chewing gum, instant juice, instant soup, granules, tablets, etc.In addition, the allulose crystal powder can be used by being contained in various compositions such as food and beverage products, luxury items, feed, cosmetics, and medicines, and the method of containing carbohydrates can be appropriately selected from known methods such as mixing, dissolving, melting, immersing, penetrating, scattering, coating, covering, spraying, injection, crystallization, and solidification in the process until the product is completed.

[0025] A specific example of the present invention provides a sweetener composition containing the allulose crystalline powder. The sweetener composition may contain various amounts of allulose crystalline powder, and may further contain one or more selected from the group consisting of high-sweetness sweeteners, monosaccharides other than allulose, disaccharides, sugar alcohols, dietary fibers, and oligosaccharides.

[0026] For example, the monosaccharides and disaccharides may be one or more selected from the group consisting of allose, deoxyribose, erythrulose, galactose, idose, mannose, ribose, sorbose, tagatose, erythrose, fuculose, gentiobiose, gentiobiulose, isomaltose, isomaltulose, kojibiose, lactulose, altrose, laminaribiose, arabinose, leucrose, fucose, rhamnose, sorbose, maltulose, mannobiose, mannosucrose, melezitose, melibiose, melibiulose, nigerose, raffinose, rutinose, rutinulose, stachyose, threose, trehalose, trehalulose, turanose, xylobiose, fructose, glucose, and allulose.

[0027] The sugar alcohol may be one or more selected from the group consisting of xylitol, maltitol, erythritol, mannitol, lactitol, inositol and sorbitol. The dietary fiber may be water-soluble dietary fiber, and the water-soluble dietary fiber may be one or more selected from the group consisting of polydextrose, indigestible maltodextrin and pectin. The oligosaccharide may be one or more selected from the group consisting of fructooligosaccharide, isomaltooligosaccharide, maltooligosaccharide and galactooligosaccharide.

[0028] The high-intensity sweetener may be one or more selected from the group consisting of aspartame, acesulfame potassium, sodium cyclamate, sodium saccharin, sucralose, stevia sweetener (steviol glycoside, enzyme-treated stevia), dulcin, thaumatin, tomatine, neotame, rebaudioside, and monellin.

[0029] The method for producing allulose crystals according to the present invention can be carried out in various ways, and preferably by cooling. One example of the cooling method according to the present invention can include a step of slowly stirring an allulose solution containing 90% by weight or more of allulose and having a Brix of 60 to 85 at a temperature of 20 to 40°C, or 30 to 40°C, for example, 35°C, to generate crystal nuclei, and a step of cooling the temperature of the solution to 10°C to grow crystals. For example, the allulose solution can be cooled to a temperature of 35 to 10°C to induce a supersaturated state to generate crystals. The cooling rate is preferably maintained at 0.01 to 20°C / min. If the cooling rate is low, the cocrystal formation time is long and the productivity is reduced, and if the cooling rate is high, crystals with small particle sizes are formed, making it difficult to recover the crystals.

[0030] The method for producing allulose crystals comprises: The method may include a step of generating crystal nuclei in an allulose solution having a brix of 1,000 uS / cm or less and an electrical conductivity of 1,000 uS / cm or less, and a step of growing crystals by cooling the temperature of the solution. Specifically, the method for producing allulose crystals may include a step of generating crystal nuclei by slowly stirring an allulose solution containing 90% by weight or more of allulose and having a Brix of 80 to 83 at a temperature of 35°C, and a step of growing crystals by cooling the temperature of the solution to 10°C. The method may additionally include one or more steps of increasing the temperature of the solution to a range of 20 to 40°C, preferably 30 to 35°C, and redissolving the fine crystals generated during the cooling. The method for producing allulose crystals may additionally include a step of adding the seed crystals. The seed crystal addition step and the redissolution step may be selectively included in the method for producing allulose crystals, or both of the two steps may be included.

[0031] The allulose solution for crystallization may be a high-purity allulose solution containing allulose at a content of 90% by weight or more, for example, 95% by weight or more. The viscosity of the composition may be 2 cps to 200 cps at a temperature of 45°C, and the electrical conductivity may be 1000uS / cm or less, for example, 0.01 to 1000uS / cm, preferably 30uS / cm or less, for example, 0.1 to 30uS / cm. The lower the electrical conductivity of the allulose crystallization composition, the more favorable it is for crystallization. The allulose solution for crystallization may have a solid content of 60 to 85 Brix, for example, more than 60 Brix to 80 Brix, 65 to 85 Brix, 65 to 80 Brix, or 68 to 85 Brix.

[0032] Generally, it is known that the larger the size of allulose crystals, the better the physical properties and the more convenient their use. In order to produce such large crystals, a seed crystal separated into a transfer process and a main crystallization process must all be carried out. However, the crystallization process of the present invention can easily produce relatively large crystals in a high yield even in a single process.

[0033] In addition, the crystallization step may include a step of dissolving the fine crystals generated during cooling in the crystal growth step by increasing the temperature of the solution to 30 to 35° C. In the crystallization step according to the present invention, the crystal growth step and the fine crystal dissolving step may be repeated at least once.

[0034] In the process of producing the crystals, seeds may be added to increase the crystal growth rate and size.

[0035] In a specific example according to the present invention, allulose crystals are produced by stirring an allulose solution containing 90% or more by weight of allulose on a solid basis and having a total solid content of 60 to 85 Brix at a temperature of 20 to 40°C, preferably 30 to 40°C, for example 35°C, to generate a small amount of crystal nuclei, and then cooling the solution to a temperature of 10°C by decreasing the temperature by 1°C per hour to grow the crystals. Optionally, in order to re-dissolve the fine crystals generated during cooling, the temperature of the solution is increased to 30 to 35°C, and the process of dissolving the fine crystals is repeated at least once to produce allulose crystals.

[0036] In one embodiment of the present invention, a method for producing allulose crystals includes a step of subjecting an allulose fraction obtained in an SMB chromatography separation process to secondary ion purification, a step of concentrating the ion-purified allulose fraction, and a step of crystallizing allulose from the concentrate to obtain allulose crystals, and may optionally further include a step of recovering, washing, and drying the allulose crystals.

[0037] A specific example of the method for producing allulose crystals may include a first ion purification, SMB chromatographic separation, a second ion purification, concentration and crystallization process, and optionally allulose conversion. The exchange reaction product may be subjected to a carbon treatment step, an ion purification step, or both of the carbon treatment step and the ion purification step.

[0038] In the method for producing allulose crystals according to the present invention, the temperature and concentration of the allulose concentrate solution can be adjusted to crystallize, and specifically, the supersaturated state required for crystallization can be maintained by lowering the temperature of the allulose solution or by changing the concentration of D-allulose in the D-allulose solution. In one embodiment of the present invention, the progress of crystallization can be monitored by collecting samples at regular intervals during the crystallization step and observing them with the naked eye or a microscope, or by analyzing the sugar concentration in the supernatant obtained by centrifuging the sample, and the temperature or the concentration of D-allulose can be adjusted according to the results. When the allulose concentrate solution is cooled to crystallize in order to produce allulose crystals, it can be rapidly cooled to a temperature range of 10 to 25 ° C. using a heat exchanger, and then repeatedly heated and cooled to induce crystal growth.

[0039] The method for producing allulose crystals according to the present invention may further include recovering the allulose crystals obtained in the crystallization step by various solid-liquid separation methods, for example, centrifugation, washing with deionized water, and drying. The drying step is carried out in a fluidized bed dryer or a vacuum dryer, but is not limited thereto. The allulose contained in the allulose crystals may be 94% by weight or more, 95% by weight or more, 96% by weight or more, 97% by weight or more, 98% by weight or more, or 99% by weight or more based on the total solid content of 100% by weight. Effect of the Invention

[0040] The allulose crystals and the method for producing the same according to the present invention can produce allulose crystals with high yield and purity, and the produced crystals can be used in various foods and beverages by incorporating them into sweeteners. [Brief description of the drawings]

[0041] [Figure 1] 1 is an optical microscope photograph of the allulose powder obtained in Example 1 of the present invention, measured at a magnification of ×100. [Diagram 2]1 is an optical microscope photograph of the allulose powder obtained in Example 2 of the present invention, measured at a magnification of ×100. [Diagram 3] 1 is an optical microscope photograph of the allulose powder obtained in Example 3 of the present invention, measured at a magnification of ×100. [Figure 4] 1 is a scanning electron microscope (SEM) photograph of the allulose powder obtained in Example 1 of the present invention, measured at a magnification of ×50. [Diagram 5] 1 is a scanning electron microscope (SEM) photograph of the allulose powder obtained in Example 2 of the present invention, measured at a magnification of ×50. [Figure 6] 1 is a scanning electron microscope (SEM) photograph of the allulose powder obtained in Example 3 of the present invention, measured at a magnification of ×50. [Figure 7] 1 is an infrared spectroscopic (IR) spectrum of the allulose crystals obtained in Examples 1 to 3 of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] The present invention will be described in more detail with reference to the following examples, but the following examples are merely preferred examples of the present invention and are not intended to limit the present invention.

[0043] Example 1: Production of allulose crystals High-purity allulose syrup containing 94.6% by weight of allulose based on 100% solid content was concentrated to a concentration of 82.6Bx (w / w%) and had an electrical conductivity of 8uS / cm. The allulose syrup for crystallization having the above composition was prepared. The allulose syrup for crystallization was gradually cooled from 35°C, at which the temperature was supersaturated, to 10°C to grow crystals. At this time, allulose seed crystals were added, and the mixture was slowly stirred at 35°C to generate a small amount of crystal nuclei, and the temperature was reduced by 1°C per hour to grow crystals. In order to redissolve the fine crystals generated during the cooling process in the crystal growth process, the temperature of the solution was increased to 30-35°C to dissolve the fine crystals. The crystal growth process and the fine crystal dissolution process were repeated at least once to perform crystallization. The allulose crystals produced here were centrifuged to remove the mother liquor, and the crystals obtained in the primary crystallization were washed with cooling water, dried, and collected. The obtained primary crystals were dissolved in water to prepare allulose solution 81.6Bx containing 99.5% allulose based on 100% solid content by weight. The allulose solution thus prepared was subjected to a secondary crystallization process in a manner substantially similar to that of the primary crystallization process. The allulose crystals thus prepared were centrifuged to remove the mother liquor, and the final crystals obtained by the secondary crystallization were washed with cooling water, dried, and then collected. The purity of the prepared allulose crystals was determined by HPLC analysis under the following conditions. Analytical column: Biolad Aminex HPX-87C column Mobile phase: water Flow rate: 0.6ml / min Column temperature: 80℃ Detector: RI detector As a result of the HLPC analysis, the purity of allulose in the allulose crystals prepared in Example 1 was 99.8% by weight, and the crystal yield was 62.5%. The crystal yield is expressed as a percentage of the weight of the recovered allulose crystal powder relative to the solid weight of the raw material allulose syrup for crystallization.

[0044] Example 2: Production of allulose crystals High-purity allulose syrup containing 94.6% by weight of allulose based on a solid content of 100% by weight was concentrated to a concentration of 82.6Bx to produce an allulose syrup for crystallization having an electrical conductivity of 16uS / cm. The allulose syrup for crystallization produced was gradually cooled from a temperature of 35°C, at which the temperature was supersaturated, to a temperature of 10°C to grow crystals. At this time, allulose seed crystals were added, and the mixture was slowly stirred at a temperature of 35°C to generate a small amount of crystal nuclei, and the temperature was reduced by 1°C per hour to grow crystals. In order to redissolve the fine crystals generated during the cooling in the crystal growth process, the temperature of the solution was increased to 30-35°C to dissolve the fine crystals. The crystal growth process and the fine crystal dissolution process were repeated at least once to perform crystallization. The mother liquor was removed from the allulose crystals produced here by centrifugal dehydration, and the crystals were washed with cooling water and then dried and collected. The purity of the allulose crystals produced was analyzed by HPLC in the same manner as in Example 1, and the purity of the allulose crystals produced in Example 2 was 99.6% by weight, and the crystal yield was 52.8%.

[0045] Example 3: Production of allulose crystals High-purity allulose syrup containing 91.5% by weight of allulose based on a solid content of 100% by weight was concentrated to a concentration of 81.2Bx to produce allulose syrup for crystallization having an electrical conductivity of 21uS / cm. The allulose syrup for crystallization produced was gradually cooled from a temperature of 35°C, at which the temperature was supersaturated, to a temperature of 10°C to grow crystals. At this time, allulose seed crystals were added, and the mixture was slowly stirred at a temperature of 35°C to generate a small amount of crystal nuclei, and the temperature was reduced by 1°C per hour to grow crystals. In order to redissolve the fine crystals generated during the cooling process in the crystal growth process, the temperature of the solution was increased to 30-35°C to dissolve the fine crystals. The crystal growth process and the fine crystal dissolution process were repeated for at least 1 hour. The allulose crystals produced here were centrifuged to remove the mother liquor, and the crystals were washed with cooling water, dried, and then collected. The purity of the allulose crystals produced was analyzed by HPLC in the same manner as in Example 1, and the purity of the allulose crystals produced in Example 3 was 99.6% by weight, and the crystal yield was 34%.

[0046] According to the production of allulose crystals in Examples 1 to 3, the lower the purity of the crystallization raw material allulose, the more components other than allulose act as impurities that hinder the crystal growth of pure allulose, and the difference in crystal yield occurs depending on the purity of allulose in the crystallization stock solution.Specifically, in Example 1, the crystals obtained by two crystallization steps of allulose syrup have higher purity and crystal yield of allulose crystals than Example 2, which performed one crystallization step.Examples 1 and 2, which have high purity of allulose in the crystallization stock solution, have higher purity and crystal yield of allulose crystals than Example 3, which uses a crystallization stock solution with a relatively low purity.

[0047] Example 4: Characterization of allulose crystals 4-1: Analysis of crystal grain size distribution The particle size distribution of the allulose crystals obtained in Examples 1 and 3 was confirmed using standard mesh sieves for each mesh. The mesh sizes of the standard mesh sieves used were 20, 30, 40, 60, 80, and 100 mesh, and the size distribution of the crystal particles was measured for the hole size of the standard mesh sieve. The pore sizes of the standard mesh sieves for each mesh are 850, 600, 425, 250, 180, and 150 μm. A 100 g weight of each sample was taken and placed in the standard mesh sieve for each mesh size, and the sample was allowed to pass through the standard mesh sieve by vibrating for 3 minutes. The weight of the sample remaining on the sieve for each mesh size was measured, and the percentage values ​​are shown in Table 1. In Table 1 below, the particle size distribution for each mesh is expressed as a numerical value in terms of the weight % of the particles.

[0048] [Table 1]

[0049] As shown in Table 1, the allulose crystals of Example 1 showed a very narrow particle distribution with a concentration of 90.2 wt%, while the allulose crystals of Example 3 showed the most abundant distribution at 40↑, but were evenly distributed at 80↑, 60↑, 40↑, and 30↑, showing a wide particle distribution. As in Example 1, it was confirmed that the smaller the major axis / minor axis ratio and the harder the crystal particles, the lower the fine powder content of the product and the more uniform the particle size distribution. In addition, the larger the major axis / minor axis ratio and the lower the uniformity of the particles, the more likely they are to be pulverized due to particle cracking during drying and transportation, resulting in non-uniform particle sizes and a wide range of particle size distribution.

[0050] 4-2: Analysis of crystal morphology and crystal particle size Optical microscope photographs of the allulose crystals obtained in Examples 1 to 3 measured at a magnification of ×100 are shown in Figures 1 to 3. Scanning electron microscope (SEM) photographs of the allulose crystals obtained in Examples 1 to 3 measured at a magnification of ×100 are shown in Figures 4 to 6. In addition, the major axis (vertical) and minor axis (horizontal) were measured for the nine samples of allulose crystals obtained in Examples 1 to 3, and the particle size ratio (= major axis / minor axis) was obtained and shown in the following Table 1. Specifically, for five crystals, the ratio of the major axis length (μm) was shown with the minor axis length (μm) as 1 standard.

[0051] [Table 2]

[0052] As shown in Figures 4 to 6, the allulose crystal according to the present invention has a rectangular hexahedron or a crystal structure close thereto. The ratio of the major axis length (μm) of the crystals shown in Table 2 based on the minor axis length (μm) is 1 on average for Example 1, 4.3 on average for the crystals of Example 2, and 7.6 on average for the crystals of Example 3. In comparison, the crystals of Example 1 have more uniformly grown crystal faces than the crystals of Examples 2 and 3, forming an orthorhombic crystal form close to a square. It was also confirmed that the more uniformly grown the crystal faces, the smaller the major axis / minor axis ratio tends to be. This is interpreted as the lower the purity of the allulose used as the crystallization raw material, the more components other than allulose act as impurities that hinder the crystal growth of pure allulose, thereby affecting the shape of the crystals.

[0053] Example 5: Differential Scanning Calorimetry (DSC) Analysis The allulose crystals obtained in Examples 1 to 3 were subjected to DSC analysis, and the specific DSC analysis conditions were as follows. Equipment name: DSC [differential scanning calorimetry] Manufacturer: Perkin Elmer Method: 30~250℃, 10℃ / min temperature increase, N2 gas purge (standard method: see ASTM D 3418) The results of the DSC analysis of the allulose crystals are shown in Table 3 below.

[0054] [Table 3]

[0055] As a result of the DSC analysis, the crystals of Example 1 were measured to have the highest Tm value and the highest heat capacity. In the DSC analysis of crystals, it can be predicted that the higher the heat capacity, the less easily they melt, and that the higher the heat capacity and the narrower the width of the endothermic peak, the more uniform and hard the crystals are formed. Considering the heat capacity and enthalpy values ​​of the endothermic peaks of Examples 1 to 3, Example 1 It was confirmed that the crystals of SiO2 were relatively more uniform and harder.

[0056] Example 6: Infrared absorption (IR) spectroscopy In order to confirm the allulose crystals produced, infrared absorption (IR) spectrum analysis was performed on the crystals of Examples 1 to 3 under the following measurement conditions. Analytical equipment: TENSOR II with Platinum ATR, Manufacturer: Bruker (German) Detector: highly sensitive photovoltaic MCT detector with liquid nitrogen cooling Scan count: 64 scans at 20kHz Scan range: 800-4,000cm -1 and averaged at 4cm -1 resolution According to the results of infrared absorption (IR) spectroscopy of the allulose crystals of the present invention, it was confirmed that the allulose molecular structure is composed of functional groups -OH and COC, CC, C-OH, etc., and has structural characteristics unique to allulose molecules, and therefore it was confirmed that the crystals of Examples 1 to 3 are the same allulose crystals. The IR analysis spectrum is shown in Figure 7.

[0057] Example 7: X-ray Diffraction (XRD) Analysis The allulose crystals obtained in Examples 1 to 3 were subjected to X-ray diffraction analysis under the specific analytical conditions described below, and the results of the X-ray diffraction analysis of the allulose crystals obtained in Examples 1 to 3 were shown in Table 4, with the top five peaks (Relative Intensity%) and form-specific peaks selected. Analytical equipment: D / MAX-2200 Ultima / PC Manufacturer: Rigaku International Corporation(Japan) X-ray sauce system target: sealed tube Cu Tube voltage: 45kV / Tube current: 200mA Scan range: 5~80°2θ Step size: 0.01° Scan speed: 5° / min

[0058] [Table 4]

[0059] As shown in Table 4, the allulose crystals obtained in Example 1 were confirmed to have specific peaks at 2θ values ​​of 15.24, 18.78, and 30.84; 15.24, 18.78, 30.84, and 28.37; or 15.24, 18.78, 30.84, and 31.87; in the powder X-ray spectroscopy spectrum. In the X-ray spectroscopy, the crystals of Examples 1 to 3 are in the same range of Angle 2-T It was confirmed that they had the same crystal lattice structure based on the heta degree values. However, it can be inferred that the crystal of Example 1 has a slightly different external crystal morphology from the crystals of Examples 2 and 3, which may lead to differences in the crystal lattice orientation, resulting in differences in the Intensity% values.

[0060] Example 8: Measurement of flowability of allulose crystals In order to analyze the flowability of allulose crystals, the angles of repose of the crystal powders of Examples 1 and 3 were measured. Specifically, a certain volume of the crystalline powders of Examples 1 and 3 was passed through a funnel fixed at a certain height of 20 cm on a perfectly flat reference plate, and the angle of repose was measured at three different points based on the horizontal plane and the inclined plane that was piled up like a mountain and could not slide down. The repose angles of the crystals obtained in Example 1 were 42.6°, 43.3°, and 42.2°±0.2°, with an average value of 42.7±0.2°, and the repose angles of the crystals obtained in Example 3 were 46.0°, 45.3°, and 46.2°±0.2°, with an average value of 45.8°±0.2°. The repose angle is the shape created by the natural fall of the powder on a horizontal surface, which has a great influence on the flowability. In general, if the repose angle is small, it can be judged that the flowability of the powder is good. The repose angles of sugar (average particle size 420 μm) and crystalline fructose (average particle size 341 μm) were measured by the same method as the method for measuring the repose angle of allulose crystals, and as a result, the average value of the repose angle of sugar was 41.2°±0.2°, and the average value of the repose angle with the crystals was 41.8°±0.2°. When comparing the angles of repose of sugar and crystalline fructose, it was confirmed that allulose crystalline fructose has powder flowability comparable to these.

Claims

1. Having an X-ray spectral spectrum having four peaks with the highest relative intensity at diffraction angles (2θ) ±0.2° of 15.24, 18.78, 28.37, and 30.84 in X-ray diffraction analysis, Differential scanning calorimetry (DSC) analysis revealed that it has a melting temperature (Tm) of 125.8°C ± 5°C. D-allulose crystals with an average major axis of 350 to 2,000 μm or more.

2. The D-allose crystal according to Claim 1, wherein the mean angle of repose is 42.7 ± 0.2°.

3. The D-allose crystal according to Claim 1, having an X-ray spectral spectrum with peaks at diffraction angles (2θ) ±0.2° of 15.24, 18.78, 28.37, 30.84, 31.87, and 47.06 in X-ray diffraction analysis.

4. The D-allose crystal according to Claim 1, having a melting enthalpy (ΔH) of 200 to 220 J / g as determined by differential scanning calorimeter (DSC) analysis.

5. The D-allose crystal according to any one of claims 1 to 4, wherein the ratio of the length of the major axis (micrometers) to the minor axis of the crystal (major axis / minor axis) is in the range of 1.0 to 8.

0.

6. The D-allulose crystal according to any one of claims 1 to 5, wherein the average short diameter of the crystal is 50 to 1,000 μm.

7. The D-allulose crystal according to claim 1, wherein the allulose purity of the crystal is 70% by weight or more.

8. A sweetener composition comprising D-allulose crystals according to any one of claims 1 to 7.

9. The sweetener composition according to claim 8, further comprising one or more selected from the group consisting of high-intensity sweeteners, monosaccharides excluding D-allulose, disaccharides, sugar alcohols, dietary fiber, and oligosaccharides.

Images