Crystalline kestose

Abstract

The present application relates to crystalline kestose and a method for producing the same.

Description

[Technical Field]

[0001] The present application relates to crystalline kestose. [Background technology]

[0002] Kestose is a type of fructooligosaccharide that has been shown to enhance immunoglobulin A (IgA) antibodies, inhibit the production of immunoglobulin E (IgE) antibodies, stimulate the proliferation of bihidobacteria in the gut, and improve atopic dermatitis in infants.Efficient production of kestose is therefore industrially useful in order to utilize its utility as an allergy-suppressing composition, allergy-suppressing food, and allergy-suppressing agent.

[0003] However, kestose powder is amorphous, highly hygroscopic, easily sticky, has low flowability, is sensitive to ambient humidity, and tends to harden like candy during storage, making it very inconvenient to handle when used as a product. Therefore, a technology is needed to produce crystalline kestose particles that have low hygroscopicity, improved flowability, and improved handleability like sugar. Summary of the Invention [Problem to be solved by the invention]

[0004] An object of one example of the present application is to provide kestose crystals having a specific particle size distribution and improved hygroscopicity and dissolution rate. [Means for solving the problem]

[0005] One example of the present application relates to crystalline kestose having a particle size distribution in which the average particle size represented by D(4,3) is 200 μm or more and the percentage of particles having a size of 70 μm or less is 35% or less.

[0006] Another example of the present application relates to a method for producing crystalline kestose, which includes the steps of generating crystal nuclei at a temperature at which the degree of supersaturation of a kestose solution having a nystose content of less than 10% by weight and a pH of 5 or higher, based on a solid content of 100% by weight, is greater than 1 and less than 1.4; and growing crystals. [Effects of the Invention]

[0007] One example of the present application is the provision of a kestose crystal form having a specific particle size distribution and a large average particle size, thereby improving the hygroscopicity and dissolution rate of the kestose crystals and increasing their storage stability. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing an optical microscope photograph of crystalline kestose according to an example of the present application. [Figure 2] 1 is a graph showing the moisture absorption rate of crystalline kestose according to an example of the present application. [Figure 3] 1 is a graph showing the dissolution rate of crystalline kestose according to an example of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present application will now be described in more detail. The crystalline kestose according to one embodiment of the present application has a low fine powder content and a uniform size distribution. The lower the fine powder content and the more uniform the size distribution of the crystals produced in the kestose crystallization process, the less aggregation occurs between the crystals, which reduces hygroscopicity and improves the dissolution rate. On the other hand, if the fine powder content is high and the size uniformity is low, the more aggregation occurs between the crystals, which increases hygroscopicity and slows the dissolution rate, adversely affecting product quality.

[0010] The crystalline kestose according to one example of the present application has improved hygroscopicity compared to fine powder, making it less prone to caking, stable during storage, easy to distribute and handle, and has an improved dissolution rate, making product use efficient and suitable for a wide range of applications.

[0011] Specifically, crystalline kestose according to one example of the present application may have a particle size distribution in which the average particle size calculated from the particle volume represented by D(4,3) is 200 μm or more, 250 μm or more, 280 μm or more, 300 μm or more, 340 μm or more, or 350 μm or more.

[0012] Specifically, crystalline kestose according to one example of the present application may have a particle size distribution in which particles having a size of 70 μm or less comprise 35% or less, 30% or less, 25% or less, 20% or less, 15% or less, 11% or less, 10% or less, 9% or less, 8% or less, 7% or less, 6% or less, or 5% or less.

[0013] Specifically, crystalline kestose according to one example of the present application may have a particle size distribution in which particles having a size of 50 μm or less are 20% or less, 15% or less, 10% or less, 7% or less, 5% or less, 4% or less, or 3% or less.

[0014] Specifically, crystalline kestose according to one example of the present application may have a particle size distribution in which particles having a size of 10 μm or less are 5.5% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1.5% or less, 1.3% or less, 1.1% or less, 1% or less, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, or 0.4% or less.

[0015] Specifically, crystalline kestose according to one example of the present application may have a particle size distribution in which particles having a size of 20 μm or less are 7.5% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2.5% or less, 2% or less, 1.5% or less, or 1% or less.

[0016] Specifically, crystalline kestose according to one example of the present application may have a particle size distribution in which particles having a size of 50 μm or less are 20% or less, 15% or less, 10% or less, 9% or less, 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, or 3% or less.

[0017] Specifically, crystalline kestose according to one example of the present application may have a particle size distribution in which particles having a size of 60 μm or less comprise 25% or less, 20% or less, 15% or less, 10% or less, 9% or less, 8% or less, 7% or less, 6% or less, 5% or less, or 4% or less.

[0018] Specifically, crystalline kestose according to one example of the present application may have a particle size distribution in which particles having a size of 80 μm or less are 42% or less, 40% or less, 35% or less, 30% or less, 25% or less, 20% or less, 15% or less, 14% or less, 13% or less, 12% or less, 11% or less, 10% or less, 9.5% or less, 9% or less, 8% or less, 7% or less, or 6% or less.

[0019] Specifically, crystalline kestose according to one example of the present application may have a particle size distribution in which particles having a size of 100 μm or less are 45% or less, 40% or less, 35% or less, 30% or less, 25% or less, 20% or less, 15% or less, 13% or less, 12.5% ​​or less, 12% or less, 11% or less, 10% or less, 9% or less, or 8% or less.

[0020] Specifically, crystalline kestose according to one example of the present application may have a particle size distribution in which particles having a size of 140 μm or less account for 55% or less, 50% or less, 45% or less, 40% or less, 35% or less, 30% or less, 29% or less, 28% or less, 27% or less, 26% or less, 25% or less, 24% or less, 23% or less, 22% or less, 21% or less, 20% or less, 19% or less, 18% or less, 17% or less, or 16.5% or less.

[0021] Specifically, crystalline kestose according to one example of the present application may have a particle size distribution in which particles having a size of 180 μm or less are 60% or less, 55% or less, 50% or less, 45% or less, 42% or less, 40% or less, 39% or less, 38% or less, 37% or less, 36% or less, 35% or less, 30% or less, 29% or less, 28% or less, 27% or less, 26.5% or less, 26% or less, 25.5% or less, or 25% or less.

[0022] Specifically, crystalline kestose according to one example of the present application may have a particle size distribution in which particles having a size of 200 μm or less are 65% or less, 60% or less, 55% or less, 54% or less, 53% or less, 52% or less, 51% or less, 50% or less, 49% or less, 48% or less, 47% or less, 46% or less, 45% or less, 44% or less, 43% or less, 42% or less, 41% or less, 40% or less, 39% or less, 38% or less, 37% or less, 36% or less, 35% or less, 34% or less, 33% or less, 32% or less, 31.5% or less, 31% or less, or 30.5% or less.

[0023] Specifically, crystalline kestose according to one example of the present application may have a particle size distribution in which particles having a size of 240 μm or less account for 78% or less, 75% or less, 70% or less, 69% or less, 68% or less, 67% or less, 66% or less, 65% or less, 60% or less, 55% or less, 50% or less, 49% or less, 45% or less, 40% or less, 39% or less, 38% or less, 37% or less, or 36% or less.

[0024] The crystalline kestose according to one example of the present application may have one or more properties selected from the group consisting of the following (1) to (4): (1) a melting temperature (Tm) of 206±5°C or 206±3°C; (2) enthalpy of fusion (△H) of 120±5 J / g or 120±3 J / g; (3) Purity of 70% by weight or more, 80% by weight or more, 85% by weight or more, 90% 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; and (4) Nystose content is less than 1.4% by weight, 1% by weight or less, 0.9% by weight or less, 0.8% by weight or less, 0.7% 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, 0.25% by weight or less, or 0.2% by weight or less.

[0025] Another example of the present application relates to a method for producing crystalline kestose. The larger the average size of kestose crystals, the better the physical properties and the greater the ease of use. To produce such large crystals, a seed crystal separated by a transfer process and a main crystallization process must all be carried out. However, the method for producing kestose crystals according to this example of the present application can produce large kestose crystals in a high yield even in a single process.

[0026] A method for producing crystalline kestose according to one embodiment of the present application can include the steps of producing a kestose crystal stock solution, adjusting the degree of supersaturation of the kestose crystal stock solution to generate crystal nuclei, and growing crystals. The kestose crystal stock solution can be a kestose conversion reaction product obtained by kestose conversion. Specifically, the step of producing the kestose crystal stock solution can include the steps of performing a kestose conversion reaction from sugar, separating kestose from the kestose conversion reaction product at a high purity, and optionally performing a filtration operation and / or an ion purification operation.

[0027] A specific example of the method for producing crystalline kestose may include primary ion purification, SMB chromatographic separation, secondary ion purification, concentration, and crystallization steps, and optionally, the kestose conversion reaction product may be subjected to an activated carbon treatment step, an ion purification step, or both the activated carbon treatment step and the ion purification step.

[0028] The kestose conversion reaction product can be produced using β-fructofuranosidase derived from non-GMO Aspergillus niger. Specifically, sugar is dissolved in water, heated to 40-65°C, and titrated to pH 6.5-7.0 using 1.0-4.0N sodium hydroxide solution. β-fructofuranosidase is then added and allowed to react. When the kestose content reaches 45% by weight or more, the pH is adjusted to 7.6 or higher, e.g., pH 8.0, and the enzyme is inactivated by heating to 70-90°C. The mixture is then filtered using activated carbon (0.5%-1.0% of the solids) to remove color. After the filtration process, ion purification is carried out. While the general purification process involves passing the mixture through a K (cation)-A (anion)-MB (mixed bed: K:A=1:2) system, in the case of kestose, a KA tower or an A tower such as MB-A, MB-KA, or K-MB-A is installed at the end to raise the pH of the reaction solution. This is to prevent the decomposition of fructooligosaccharides such as kestose and nystose during the manufacturing process. After that, the Brix is ​​adjusted to 50-60% by weight through concentration, and kestose is separated at a high purity using a simulated moving bed (SMB), a chromatographic high-purity separation process. The resin used in this process is Na + Type and Ca 2+ A type resin can be used. The separated raw solution has a kestose content of 80 to 98% by weight. The highly purified kestose is again subjected to an ion purification process, and the highly purified kestose-containing solution obtained through SMB passes through an ion purification column and has a pH of 5.0 to 8.0. It is then concentrated to 70% by weight or more through a concentration process, after which it can be subjected to a crystallization process.

[0029] The kestose solution for crystallization may have a solids content of 60 to 90 wt%, 60 to 85 wt%, 65 to 90 wt%, 65 to 85 wt%, 70 to 90 wt%, 70 to 85 wt%, 75 to 90 wt%, 75 to 85 wt%, 78 to 90 wt%, 78 to 85 wt%, 80 to 90 wt%, or 80 to 85 wt%.

[0030] The kestose solution for crystallization may be a high-purity kestose solution containing kestose in an amount of 85% by weight or more, for example, 90% by weight or more, based on a solid content of 100% by weight.

[0031] The kestose solution for crystallization may have a nystose content of 10 wt% or less, less than 10 wt%, 9 wt% or less, 8 wt% or less, 7 wt% or less, 6 wt% or less, 5 wt% or less, 4 wt% or less, 3 wt% or less, 2 wt% or less, or 1 wt% or less, based on a solids content of 100 wt%.

[0032] The kestose solution for crystallization may have a pH of 5 to 8, pH 5 to 7.5, pH 5.5 to 8, pH 5.5 to 7.5, pH 6 to 8, pH 6 to 7.5, pH 6.5 to 8, pH 6.5 to 7.5, pH 7 to 8, or pH 7.5 to 8. The lower the pH of the kestose crystallization composition, the more likely it is that fructooligosaccharides will be decomposed during the process, resulting in a lower purity and adversely affecting the crystallization yield and crystal particles. On the other hand, if the pH is too high, the solution may turn yellow and brown more severely, and therefore, it is preferable to perform crystallization at an appropriate pH.

[0033] In a method for producing crystalline kestose according to one embodiment of the present application, crystallization can be achieved by adjusting the temperature and / or concentration of the kestose concentrate solution. Specifically, the supersaturated state required for crystallization can be maintained by lowering the temperature or changing the concentration of the kestose solution. In one embodiment of the present application, the progress of crystallization can be monitored by collecting samples at regular intervals during the crystallization process and observing them with the naked eye or a microscope, or by analyzing the sugar concentration and crystal particle morphology of the supernatant obtained by centrifugation of the sample, and the temperature or kestose concentration can be adjusted based on the results. In addition, the crystal growth process can include one or more additional steps of dissolving the fine crystals produced during the crystal growth step.

[0034] The crystallization process can be carried out in various ways, including a cooling method in which crystals are formed in a supersaturated state by cooling the temperature, and / or an evaporation concentration method in which water is evaporated to increase the concentration and form crystals.

[0035] An example of the "cooling method" is to induce crystal growth by adjusting the cooling rate and temperature. For example, the cooling method can induce crystal growth by adjusting the cooling rate and temperature without vacuum concentration. To ensure good crystal growth, it is important to adjust the cooling rate so that the supersaturation of the crystallization solution concentration is maintained constant during the cooling process. Therefore, in this application, the method may include cooling the temperature at a constant rate, or may include one or two periods during the cooling process where the temperature is kept constant.

[0036] For example, the cooling method can involve cooling the kestose solution to a temperature of 75 to 30°C, 70 to 30°C, 65 to 30°C, 60 to 30°C, 55 to 30°C, 50 to 30°C, 45 to 30°C, 40 to 30°C, or 35 to 30°C to induce a supersaturated state and produce crystals.

[0037] The cooling rate can be -0.1 to -5°C / hour, -0.1 to -3°C / hour, -0.1 to -2°C / hour, -0.1 to -1.5°C / hour, -0.5 to -5°C / hour, -0.5 to -3°C / hour, -0.5 to -2°C / hour, -0.5 to -1.5°C / hour, -1 to -5°C / hour, -1 to -3°C / hour, -1 to -2°C / hour, or -1 to -1.5°C / hour. A slow cooling rate can result in low productivity due to a long formation time of the co-crystal, while a fast cooling rate can result in the formation of small particle size crystals that are difficult to recover.

[0038] The method for producing kestose crystals includes a step of generating crystal nuclei from a high-purity kestose solution containing 85% by weight or more kestose, having a solids content of 60 to 90% by weight, preferably 78 to 85% by weight, and having a pH in the range of 6 to 8, preferably 6.5 to 7.5, at a temperature where the degree of supersaturation is greater than 1 and not more than 1.4, preferably 1.01 to 1.3, and a step of cooling the temperature of the solution to grow crystals.

[0039] Specifically, the method for producing kestose crystals can include a step of generating crystal nuclei by slowly stirring a kestose-containing solution containing 85% or more by weight of kestose and having a solid content of 78 to 83% by weight at a temperature of 50 to 70°C, and a step of growing crystals by cooling the temperature of the solution to 25 to 35°C. The method for producing kestose crystals can additionally include a step of adding seed crystals.

[0040] The size of the seed crystals is 50 to 500 μm, 50 to 450 μm, 50 to 400 μm, 50 to 350 μm, 50 to 300 μm, 100 to 500 μm, 100 to 450 μm, 100 to 400 μm, 100 to 350 μm, 100 to 300 μm, 150 to 500 μm, 150 to 450 μm, 150 to 400 μm, 150 to 350 μm, 150 to 30 The thickness may be 0 μm, 200 to 500 μm, 200 to 450 μm, 200 to 400 μm, 200 to 350 μm, 200 to 300 μm, 250 to 500 μm, 250 to 450 μm, 250 to 400 μm, 250 to 350 μm, 250 to 300 μm, 300 to 500 μm, 300 to 450 μm, 300 to 400 μm, or 300 to 350 μm.

[0041] The amount of the seed crystals added may be 0.01 to 5 wt%, 0.01 to 3 wt%, 0.01 to 2 wt%, 0.01 to 1.5 wt%, 0.01 to 1 wt%, 0.1 to 5 wt%, 0.1 to 3 wt%, 0.1 to 2 wt%, 0.1 to 1.5 wt%, 0.1 to 1 wt%, 0.5 to 5 wt%, 0.5 to 3 wt%, 0.5 to 2 wt%, 0.5 to 1.5 wt%, 0.5 to 1 wt%, 1 to 5 wt%, 1 to 3 wt%, 1 to 2 wt%, or 1 to 1.5 wt% based on the solid content weight of the crystallization solution.

[0042] An example of the "evaporative concentration method" includes the steps of generating crystal nuclei from a high-purity kestose solution containing 85% or more by weight, having a solids content of 60-90% by weight, preferably 65-85% by weight, and having a pH in the range of 6-8, preferably 6.5-7.5, under vacuum at a temperature where the degree of supersaturation is greater than 1 and less than 1.4, preferably 1.01-1.3, and growing crystals under vacuum and at a constant temperature while maintaining the degree of supersaturation at 1.1. To maintain the degree of supersaturation stably, the method can include the step of adding additional crystal stock solution. The step of adding additional crystal stock solution may be performed under constant temperature conditions, i.e., without temperature reduction. When the temperature of the kestose crystal stock solution is lowered, the viscosity of the crystal stock solution increases, reducing the fluidity of the stock solution, which may reduce intermolecular collisions and affect crystal growth. Furthermore, as the viscosity increases, the solution becomes more sticky, making the crystal recovery process more difficult. Furthermore, if the crystallization mother liquor has a high viscosity, it becomes difficult to separate the crystals from the mother liquor, requiring more washing steps, which ultimately negatively affects the recovery rate. If even a small amount of mother liquor is present on the crystals, the purity of the crystal particles may decrease, or the crystals may harden or aggregate due to increased hygroscopicity during storage. Therefore, in one example of the present application, the concentration may not be accompanied by an increase in the supersaturation of the crystallization raw solution.

[0043] Specifically, the method for producing kestose crystals includes the steps of: adding a kestose-containing solution containing 85% or more by weight of kestose and having a solids content of 60 to 90% by weight to a reactor at a temperature of 60 to 70°C so that the solution occupies 20 to 50% of its volume; and slowly stirring the solution to generate crystal nuclei; and growing crystals while maintaining a vacuum and maintaining the concentration at a constant value of 60 to 90% by weight, 60 to 85% by weight, 60 to 83% by weight, 65 to 90% by weight, 65 to 85% by weight, 65 to 83% by weight, 70 to 90% by weight, 70 to 85% by weight, 70 to 83% by weight, 75 to 90% by weight, 75 to 85% by weight, 75 to 83% by weight, 80 to 90% by weight, 80 to 85% by weight, or 80 to 83% by weight. Maintaining the concentration constant can be achieved by adding additional kestose-containing solution to maintain the concentration. Specifically, the crystal growth step can be carried out by repeatedly adding the solution 1 to 4 times.

[0044] The method for producing kestose crystals may further include the step of adding the seed crystals. The seed crystals are as described above.

[0045] In one embodiment of the present application, the method for producing crystalline kestose includes a step of secondary ion-purifying the kestose fraction obtained in the high-purity separation step, a step of concentrating the ion-purified kestose fraction, and a step of crystallizing kestose from the concentrate to obtain kestose crystals, and may optionally additionally include a step of recovering the kestose crystals, a washing step, and a drying step.

[0046] The method for producing kestose crystals according to the present application may further include recovering the kestose crystals obtained in the crystallization step using various solid-liquid separation methods, such as centrifugation, washing the crystals with deionized water, and drying the crystals. The drying step may be carried out using, but is not limited to, a fluidized bed dryer or a vacuum dryer.

[0047] The crystallization yield of the method for producing crystalline kestose according to the present application can be 40% or more, 45% or more, 46% or more, 47% or more, 48% or more, 49% or more, 50% or more, 51% or more, 52% or more, 53% or more, 54% or more, 55% or more, or 56% or more.

[0048] Crystalline kestose according to one example of the present application may have improved hygroscopicity. For example, when the crystalline kestose is stored at 25° C. and 75% relative humidity for 6 hours, the hygroscopicity may be 2% or less, 1.95% or less, 1.9% or less, 1.85% or less, 1.8% or less, 1.75% or less, 1.7% or less, 1.65% or less, 1.6% or less, 1.55% or less, or 1.5% or less.

[0049] Crystalline kestose according to one example of the present application may have an improved dissolution rate. For example, the time required for the crystalline kestose to dissolve in water at a concentration of 10% (w / w) may be 250 seconds or less, 240 seconds or less, 230 seconds or less, 220 seconds or less, 210 seconds or less, 200 seconds or less, 190 seconds or less, 180 seconds or less, 170 seconds or less, 160 seconds or less, 150 seconds or less, 140 seconds or less, 130 seconds or less, 120 seconds or less, or 110 seconds or less. The time required for dissolution in water may be the time required for the kestose crystals to completely dissolve after adding crystalline kestose to water at a concentration of 10% by weight at 25°C while stirring at 150 rpm.

[0050] Crystalline kestose according to one example of the present application is a type of oligosaccharide and has a sweetness lower than that of sugar, and therefore can be used in the production of mixed sweeteners, solid mixed sweeteners, chocolate, chewing gum, instant juice, instant soup, granules, tablets, etc. Furthermore, the crystalline kestose can be incorporated into various compositions such as foods and beverages, luxury goods, feed, cosmetics, and pharmaceuticals, and the method for incorporating the carbohydrate can be appropriately selected from known methods, such as blending, mixing, dissolving, melting, immersing, permeating, scattering, applying, covering, spraying, injecting, crystallizing, and solidifying, in the process leading up to the completion of the product.

[0051] Another example of the present application provides a sweetener composition containing the crystalline kestose. The sweetener composition may contain kestose crystals in various amounts and may further contain one or more selected from the group consisting of high-intensity sweeteners, monosaccharides, disaccharides, sugar alcohols, dietary fibers, and oligosaccharides.

[0052] For example, the monosaccharides and disaccharides may be at least one 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, luculose, fucose, rhamnose, sorbose, maltulose, mannobiose, mannosucrose, melezitose, melibiose, melibiulose, nigerose, raffinose, rutinose, rutinulose, stachyose, threose, trehalose, trehalulose, turanose, xylobiose, fructose, glucose, and allulose.

[0053] The sugar alcohol may be one selected from the group consisting of xylitol, maltitol, erythritol, mannitol, lactitol, inositol, and sorbitol.

[0054] The dietary fiber may be water-soluble dietary fiber, and the water-soluble dietary fiber may be one selected from the group consisting of polydextrose, indigestible maltodextrin, inulin, carrageenan, guar gum, alginic acid, agar, and pectin.

[0055] The oligosaccharides may be one selected from the group consisting of fructooligosaccharides, isomaltooligosaccharides, maltooligosaccharides, human milk oligosaccharides, and galactooligosaccharides.

[0056] The high-intensity sweetener may be one or more selected from the group consisting of aspartame, acesulfame potassium, sodium cyclamate, sodium saccharin, sucralose, stevia sweeteners (steviol glycosides, enzyme-treated stevia), dulcin, thaumatin, neotame, rebaudioside, swingle fruit, mogroside, and monellin.

[0057] The present application will be described in more detail below with reference to the following examples, but these examples are merely illustrative of the present application and do not limit the scope of the present application. [Example]

[0058] Example 1: Preparation of kestose crystal stock solution 45 kg of water heated to 55°C was added to the saccharification tank, and 55 kg of sugar was added and stirred for 1-2 hours to completely dissolve the sugar crystals. The pH was then adjusted to 6.5-7.0, and β-fructofuranosidase derived from Aspergillus niger, an enzyme used to produce kestose-rich syrup, was added. The reaction was allowed to proceed for 24-48 hours according to the method disclosed in Korean Patent Publication No. 10-2018-0078065. In the enzyme reaction section, where 26% by weight of sugar remained, the pH was titrated to above 7.6 using 4N NaOH, while the mixture was heated at 80°C for 2 hours to induce enzyme inactivation. Once enzyme inactivation was complete, the mixture was decolorized, filtered, purified, and concentrated to a concentration of 75% by weight. NaOH was then added. + High-purity separation was performed using an SMB filled with a type separation resin, and a stock solution containing more than 85% kestose was obtained for the crystallization process. <Analysis conditions for kestose content and sugar composition> -Analysis equipment: HPLC Agilent, 1100 Series -Column: Shodex Asahipak NH2P-50 4E -Injection volume: 10μl -Flow rate: 1ml / min -Column temperature: 30℃ -Moving bed: Acetonitrile 70%

[0059] Example 2: Kestose crystallization using the cooling method (1) The crystallization process was carried out by using the crystallization stock solution containing 91.4 wt % kestose, 7.0 wt % nystose, and 1.6 wt % sugar prepared in Example 1 and gradually cooling the temperature to precipitate crystals. Specifically, 150 μm seed crystals were added at 1 wt% of the solid content to a crystallization solution with an initial temperature of 60°C, pH 7.5, and a solid content of 82.5 wt%. The degree of supersaturation was 1.1, and the solution was cooled to 30°C at a rate of -1°C / h. The mother liquor was removed by centrifugal dehydration, and the crystals obtained in the primary crystallization were washed with cooled water and then dried to recover kestose crystals. The purity of the produced kestose crystals was analyzed by HPLC in the same manner as in Example 1, and the purity of the produced kestose crystals was 99.3 wt % and the crystal yield was 48.4%.

[0060] Example 3: Production of kestose crystals using the cooling method (2) The crystallization process was carried out in the same manner as in Example 2 using the crystallization stock solution containing 91.4 wt% kestose, 7.0 wt% nystose, and 1.6 wt% sugar produced in Example 1, but using 300 μm-sized seed crystals. The purity of the produced kestose crystals was analyzed by HPLC in the same manner as in Example 1, and the purity of the produced kestose crystals was 99.4 wt % and the crystal yield was 46.6%.

[0061] Example 4: Production of kestose crystals using the cooling method (3) The same procedure as in Example 2 was carried out using the crystal stock solution containing 91.4 wt% kestose, 7.0 wt% nystose, and 1.6 wt% sugar produced in Example 1, except that 300 μm-sized seed crystals were added at 0.5 wt% of the solid content, and the cooling rate was -0.5°C / hour to 30°C at the same rate. The purity of the produced kestose crystals was analyzed by HPLC in the same manner as in Example 1, and the purity of the produced kestose crystals was 99.7% by weight, and the crystal yield was 51.6%.

[0062] Example 5: Production of kestose crystals using evaporation concentration method (1) Using the crystallization stock solution containing 91.4 wt% kestose, 7.0 wt% nystose, and 1.6 wt% sugar prepared in Example 1, a kestose-containing solution with a solid content of 68 wt% and a pH of 7.5 was added to a reactor under vacuum at a temperature of 60°C to fill 25% of the reactor volume, and the solution was concentrated under vacuum in the reactor to a solid content of 82.5 wt%. Seed crystals were added to a stock solution concentration with a supersaturation of 1.1 and slowly stirred to form crystal nuclei. While maintaining the vacuum, additional stock solution was added at the same volume as the initial solution, and crystals were grown while concentrating to maintain a constant solids content of 82.5 wt% and supersaturation. The solution was added at a constant temperature without lowering the temperature, and concentrated to a solids content of 82.5 wt% to maintain a supersaturation of 1.1. Since fine crystals may precipitate as the crystals grow, adding a small amount of water to dissolve the fine crystals before adding the stock solution prevented the fine crystals from inhibiting the growth of crystal particles. The stock solution addition and water addition methods were repeated a total of four times in the same manner as described above. The kestose crystals thus produced were discharged from the reactor, and the mother liquor was removed by centrifugal dehydration. The crystals obtained in the primary crystallization were washed with cooling water, dried, and then recovered. The purity of the kestose crystals thus produced was analyzed by HPLC in the same manner as in Example 1. The purity of the kestose crystals thus produced was 99.7 wt % and the crystal yield was 56.8%. In Examples 4 and 5, the pH of the raw solution was 7.5, so the kestose content did not decrease even though the crystallization process was carried out at high temperature for a long time, and the content of nystose, which can act as an inhibitor of kestose crystal growth, was low at less than 7% by weight, so it did not have a significant impact on the crystallization process.

[0063] Example 6: Production of kestose crystals using evaporation concentration method (2) A crystallization stock solution containing 91.4 wt% kestose, 7.0 wt% nystose, and 1.6 wt% sugar was prepared as in Example 1, and the pH was adjusted to 4.3 using 1N HCl. In the same manner as in Example 5, a kestose-containing solution with a solid content of 68 wt% was added to a reactor at 65°C under vacuum to a volume of 25%. The reactor was then vacuum concentrated to a solid content of 82.5 wt%. Seed crystals were added at a supersaturation level of 1.1 and slowly stirred to generate crystal nuclei. While maintaining the vacuum, the same volume of stock solution as the initial solution was added, and crystals were grown while concentrating to maintain a constant solids content of 82.5 wt% and supersaturation. However, the crystals in the crystal stock solution did not grow well, and many fine crystals were present. To grow the fine crystals into larger crystals, a small amount of water was added to redissolve the fine crystals before adding the stock solution, but crystal growth was poor. When the raw solution was sampled during the crystallization and the sugar composition was analyzed, it was found that the kestose and nystose components were decomposed due to the long-term high-temperature reaction at a pH of less than 5, resulting in a slight decrease in the kestose content to 88.8%. It was determined that a composition containing 10% or more of nystose components was at a level that would hinder the growth of kestose crystals. Therefore, kestose crystals could not be recovered in Example 6. Therefore, it was concluded that a pH of 5 or higher and a nystose content of 10% or less of the total sugar composition are necessary for kestose crystallization.

[0064] Comparative Example 1: Separation of Kestose Crystal Particles The kestose crystals produced in Example 2 were sieved and the crystals that passed through a 100 mesh sieve were mixed with the crystals obtained in Example 4 in a ratio of 7.7:2.3 to produce a kestose crystal sample with an average particle size of approximately 200 μm and a high fine powder content.

[0065] Test Example 1: Observation of the crystal form of kestose The morphology of the kestose crystals produced in Example 4 was observed using an optical microscope. Figure 1 is an optical microscope photograph of the kestose crystal particles produced in Example 3, measured at a magnification of 100x. As shown in Figure 1, the kestose crystals according to the present application were found to have a rectangular hexahedral morphology and high crystal uniformity and robustness.

[0066] Test Example 2: Analysis of particle size distribution of kestose crystals A laser diffraction particle size analyzer was used to confirm the particle size distribution of the kestose crystals produced in Examples 2 to 5 and Comparative Example 1. The particle size distribution was analyzed by repeating the sample several times, and the results are shown in Table 1. <Analysis conditions> Analytical instrument: Mastersizer2000 (MALVERN Instrument) Accessory name: Hydro 2000MU(A) Dispersant: Isopropyl alcohol

[0067] [Table 1]

[0068] As shown in Table 1, when producing kestose crystals by the cooling crystallization method, the larger the size of the seed crystals added, the larger the particle size distribution of the final kestose crystal particles, indicating that seed size is an important factor in kestose crystal growth. Furthermore, the growth mode of kestose crystals could be controlled by adjusting the amount of seed crystals added and the cooling rate. Therefore, it was confirmed that the amount of seed crystals added, the size of the added seed crystals, and the cooling rate are factors that affect kestose crystallization.

[0069] Test Example 4: Differential Scanning Calorimetry (DSC) Analysis DSC analysis was performed on the kestose crystals prepared in Example 4. As a control, a fructooligosaccharide powder containing 85% kestose prepared by the CVD drying method was used. 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 (reference method: ASTM D 3418) The results of DSC analysis of the kestose crystals are shown in Table 2.

[0070] [Table 2]

[0071] DSC analysis showed that kestose crystals according to one example of the present application had a relatively high Tm value and a high heat capacity compared to amorphous powders prepared directly using a spray dryer or CVD method without crystallization. In DSC analysis of crystals, the higher the heat capacity, the less easily they melt, and the higher the heat capacity and the narrower the endothermic peak, the more uniformly and firmly the crystals are formed. Therefore, it was confirmed that by preparing crystalline particles through crystallization, kestose is formed more uniformly and firmly than products in the form of amorphous powder, making it more stable for use.

[0072] Test Example 5: Measurement of hygroscopicity of kestose crystals A comparative hygroscopicity test was conducted on the kestose crystals obtained in Examples 2 to 5 and Comparative Example 1. Specifically, to rapidly compare the effects on hygroscopicity, a thermo-hygrostat set at 25°C and 75% relative humidity was used. Each sample was weighed accurately (10 g) and stored under constant temperature and humidity conditions for various time periods. The weight increase from the total weight of the dish containing the initial sample was measured, and the increased weight was determined as the amount of moisture absorbed. The increased weight was calculated as a percentage of the initial weight of the dish and sample combined. A graph comparing the hygroscopicity of each sample is shown in Figure 2, and the weight increase (%) of each sample due to moisture absorption is shown in Table 3. As shown in Table 3, the kestose crystals of Examples 2 and 3 showed weight gains of 1.8% and 1.6%, respectively, during a 6-hour storage period, while the kestose crystals of Examples 4 and 5 showed a weight gain of approximately 1.5%. In contrast, the kestose crystals of Comparative Example 1 showed a high weight gain of over 2%. These results confirm that the more the kestose crystal particles grow, the more kestose with significantly improved hygroscopicity can be provided.

[0073] [Table 3]

[0074] Test Example 6: Measurement of the dissolution rate of kestose crystals A dissolution rate comparison test was conducted for the kestose crystals produced in Examples 2 to 5 and Comparative Example 1. Specifically, 20 g of sample was placed in 180 g of water and the time required for complete dissolution was measured. The sample was stirred at a constant speed of 150 rpm at 25°C, and the solids content of the supernatant was measured. The solubility was calculated as a percentage until the final dissolved concentration was reached, and the time at which the sample was completely dissolved was determined. A graph comparing the dissolution rates of each sample is shown in Figure 3, and the solubility percentages (%) of each sample are shown in Table 4. The times required for the kestose crystals of Examples 2 and 3 to completely dissolve were 180 seconds and 135 seconds, respectively, and the times required for the kestose crystals of Examples 4 and 5 to completely dissolve were 108 seconds and 110 seconds, respectively. In contrast, the kestose crystals of Comparative Example 1 took the longest time to completely dissolve, at 280 seconds. Generally, the larger the crystal size, the slower the dissolution rate. However, the kestose crystals according to one example of the present application exhibited a fast dissolution rate, with a short time to complete dissolution, despite their large average particle size. Furthermore, the larger the size of the kestose crystals according to one example of the present application, the faster the dissolution rate. This is a characteristic different from that of typical crystals. Kestose crystals are trisaccharide crystals, and the viscosity of the crystal stock solution is high, making them prone to agglomeration during the crystallization process. However, the kestose crystals according to one example of the present application were found to have a fast dissolution rate due to their large average particle size and low distribution of fine crystals that are prone to agglomeration. Therefore, one example of the present application can provide kestose that reduces the aggregation phenomenon between crystals during dissolution, thereby improving the dissolution rate.

[0075] [Table 4]

Claims

1. The average particle size represented by D(4,3) is 200 μm or more, and Crystalline kestose having a particle size distribution in which 35% or less of particles have a size of 70 μm or less.

2. The average particle size represented by D(4,3) is 200 μm or more, 20% or less of particles have a size of 50 μm or less, and 2. Crystalline kestose according to claim 1, having a particle size distribution in which particles having a size of 70 μm or less account for 35% or less.

3. The crystalline kestose according to claim 1, further having one or more particle size distributions selected from the group consisting of the following (1) to (10): (1) 5.5% or less of particles having a size of 10 μm or less; (2) 7.5% or less of particles having a size of 20 μm or less; (3) 20% or less of particles have a size of 50 μm or less; (4) 25% or less of particles having a size of 60 μm or less; (5) 42% or less of particles having a size of 80 μm or less; (6) 45% or less of particles having a size of 100 μm or less; (7) 55% or less of particles have a size of 140 μm or less; (8) 60% or less of particles have a size of 180 μm or less; (9) 65% or less of particles have a size of 200 μm or less; and (10) 78% or less of particles have a size of 240 μm or less.

4. The crystalline kestose according to claim 1, wherein the crystalline kestose has a melting temperature (Tm) of 206±5°C.

5. 2. The crystalline kestose according to claim 1, wherein the crystalline kestose has a melting enthalpy (ΔH) of 120±5 J / g.

6. 2. The crystalline kestose according to claim 1, wherein the purity of the crystalline kestose is 70% by weight or more.

7. 2. The crystalline kestose of claim 1, wherein the crystalline kestose contains less than 1.4% by weight of nystose.

8. 2. The crystalline kestose according to claim 1, wherein the hygroscopicity of the crystalline kestose is 2% or less when stored at 25°C and 75% relative humidity for 6 hours.

9. 2. The crystalline kestose according to claim 1, wherein the time required for the crystalline kestose to dissolve in water at a concentration of 10% (w / w) is 250 seconds or less.

10. A fructooligosaccharide composition comprising the crystalline kestose according to any one of claims 1 to 9.

11. A step of generating crystal nuclei in a kestose solution having a nystose content of less than 10% by weight based on a solid content of 100% by weight and a pH of 5 or higher at a temperature at which the degree of supersaturation is greater than 1 and less than 1.4; and A method for producing crystalline kestose according to any one of claims 1 to 9, comprising a step of growing crystals.

12. The method according to claim 11, wherein the kestose content of the kestose solution is 80% by weight or more, based on a solid content of 100% by weight.

13. The method according to claim 11, wherein the step of growing crystals comprises cooling the kestose solution to grow crystals.

14. 14. The method of claim 13, wherein the cooling is not accompanied by vacuum concentration.

15. 14. The method of claim 13, wherein the cooling is at a rate of 5°C per hour or less.

16. The method according to claim 13, wherein the kestose solution is cooled to a temperature of 30 to 75°C.

17. The method according to claim 11, wherein the step of growing crystals comprises concentrating the kestose-containing crystal stock solution to grow crystals.

18. The method according to claim 17, wherein the kestose-containing crystal stock solution is concentrated to a solid content of 60 to 90% by weight.

19. 18. The method of claim 17, wherein the concentration is not accompanied by a temperature reduction.

20. 12. The method of claim 11, wherein the step of growing the crystals comprises one or more additional steps of dissolving the microcrystals produced in the crystal growing step.

21. 12. The method of claim 11, wherein the method further comprises the step of adding seeds.

22. 12. The method of claim 11, wherein the crystallization yield of the method is 40% or greater.

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