Crystallized kestose

Abstract

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

Description

Technical Field

[0001] This application relates to crystalline kestose.

Background Art

[0002] Kestose is a type of fructooligosaccharide, and its enhancing effect on immunoglobulin A (IgA) antibodies, inhibitory effect on the production of immunoglobulin E (IgE) antibodies, growth activity effect on Bifidobacterium in the intestine, and improvement effect on atopic dermatitis in infants have been confirmed. In order to utilize the utility of being used as an allergy-suppressing composition, allergy-suppressing food, and allergy-suppressing agent using kestose, it is industrially useful to efficiently produce kestose.

[0003] However, kestose powder is amorphous, has very high hygroscopicity, is easily sticky, has low fluidity, is sensitive to ambient humidity, and easily solidifies like candy during storage, so it is very inconvenient to handle during product use. Therefore, there is a need for a technology that can produce crystalline kestose with low hygroscopicity, improved fluidity, and improved handling properties like sugar.

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of an example of this application is to provide kestose crystals having a specific particle size distribution and improved hygroscopicity and dissolution rate.

Means for Solving the Problems

[0005] An example of this 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 particles having a size of 70 μm or less are 35% or less.

[0006] Another example of this application relates to a method for producing crystalline kestose, comprising the steps of generating crystal nuclei at a temperature in which the degree of supersaturation of 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, is greater than 1 and less than or equal to 1; and growing crystals. [Effects of the Invention]

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

[0008] [Figure 1] This is a drawing showing an optical microscope image of a crystalline kestose according to an example of this application. [Figure 2] This graph shows the moisture absorption rate of crystalline kestose according to an example of this application. [Figure 3] This graph shows the dissolution rate of crystalline kestose according to an example of this application. [Modes for carrying out the invention]

[0009] The present application will be described in more detail below. The crystalline kestose according to this 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 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, aggregation between crystals occurs more frequently, leading to greater hygroscopicity and a slower dissolution rate, thus negatively impacting the quality of the product.

[0010] The crystalline kestose described in this application exhibits improved hygroscopicity and resistance to caking compared to the fine powder form, is stable during storage, easy to distribute and handle, has an improved dissolution rate for efficient product use, and possesses properties that make it suitable for a wide range of fields.

[0011] Specifically, a crystalline kestose according to an example of this application may have a particle size distribution in which the average particle size calculated from the volume of particles 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, a crystalline kestose according to an example of this application may have a particle size distribution in which 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 of particles having a size of 70 μm or less.

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

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

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

[0016] Specifically, a crystalline kestose according to an example of this application may have a particle size distribution in which 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 of particles having a size of 50 μm or less.

[0017] Specifically, a crystalline kestose according to an example of this application may have a particle size distribution in which 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 of particles having a size of 60 μm or less.

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

[0019] Specifically, a crystalline kestose according to an example of this application may have a particle size distribution in which 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 of particles having a size of 100 μm or less.

[0020] Specifically, a crystalline kestose according to an example of this 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 an 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 an 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 an example of the present application may have a particle size distribution in which particles having a size of 240 μm or less are 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] Crystalline kestose according to an example of the present application may also 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) A melting enthalpy (ΔH) of 120 ± 5 J / g or 120 ± 3 J / g, (3) A 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) Nistose content 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 this application relates to a method for producing crystalline kestose. The larger the average size of the kestose crystals, the better the physical properties and the greater the ease of use. To produce such large crystals, it is necessary to carry out both the seed crystal separation in the transfer process and the main crystallization process. However, the method for producing kestose crystals according to an example of this application can produce large kestose crystals in high yield in a single step.

[0026] A method for producing crystalline kestose according to one example of this application may 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 may be a kestose conversion reaction product obtained by performing kestose conversion. Specifically, the step of producing the kestose crystal stock solution may include the steps of performing a kestose conversion reaction from sugar; separating kestose from the kestose conversion reaction product with high purity; and performing selective filtration and / or ion purification operations.

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

[0028] The kestose conversion reaction product can be produced using β-fructofuranosidase derived from the non-GMO Aspergillus niger. Specifically, sugar is dissolved in water, heated to 40-65°C, titrated with a 1.0-4.0N sodium hydroxide solution at pH 6.5-7.0, and then β-fructofuranosidase is added to proceed with the reaction. When the kestose content reaches 45% by weight or more, the pH is titrated to 7.6 or higher, for example at pH 8.0, and then heated to 70-90°C to inactivate the enzyme. Subsequently, the mixture is treated with activated carbon at a concentration of 0.5%-1.0% relative to the solid content and filtered to remove the color value. After the filtration process, ion purification is performed. While the general purification process involves passing the mixture through a K (cation)-A (anion)-MB (Mixed Bed: K:A=1:2) column, in the case of kestose, an A column is added at the end, such as a KA column or MB-A, MB-KA, or K-MB-A, to raise the pH of the reaction solution. This is to prevent the decomposition of fructooligosaccharide substances such as kestose and nystose during the manufacturing process. Subsequently, after adjusting the Brix to 50-60% by weight through concentration, kestose is separated with high purity using a high-purity chromatographic separation process called SMB (simulated moving bed). The resin used at this time is Na + Type and Ca 2+ A type of resin can be used. The separated stock solution is obtained with a kestose content of 80-98% by weight. The highly purified separated kestose undergoes another ion purification process, but the highly purified kestose-containing solution obtained after passing through the SMB passes through an ion purification column to have a pH of 5.0-8.0. After that, it can be concentrated to 70% by weight or more through a concentration process, and then a crystallization process can be carried out.

[0029] The kestose solution for crystallization may have a solid content of 60-90% by weight, 60-85% by weight, 65-90% by weight, 65-85% by weight, 70-90% by weight, 70-85% by weight, 75-90% by weight, 75-85% by weight, 78-90% by weight, 78-85% by weight, 80-90% by weight, or 80-85% by weight.

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

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

[0032] The kestose solution for crystallization may have a pH of 5-8, 5-7.5, 5.5-8, 5.5-7.5, 6-8, 6-7.5, 6.5-8, 6.5-7.5, 7-8, or 7.5-8. The lower the pH of the kestose crystallization composition, the more the fructooligosaccharides may decompose during the process, resulting in lower purity and adversely affecting the crystallization yield and crystal particles. Conversely, if the pH is excessively high, the solution may brown severely, turning yellow. Therefore, it is preferable to perform the crystallization at an appropriate pH.

[0033] A method for producing crystalline kestose according to one example of this application allows for crystallization 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 of the kestose solution or changing the concentration of the kestose solution. In one specific example of this application, the crystallization process can be monitored by taking samples at regular intervals during the crystallization step and observing them with the naked eye or under a microscope, or by analyzing the sugar concentration and crystal particle morphology of the supernatant obtained from centrifugation of the sample, and the temperature or kestose concentration can be adjusted based on the results. The crystal growth step may also include one or more additional steps of dissolving the fine crystals generated during the crystal growth stage.

[0034] The crystallization process can be carried out by various methods, including a cooling method in which the temperature is cooled to generate crystals in a supersaturated state, and / or an evaporation concentration method in which the concentration is increased by evaporating water to generate crystals.

[0035] One example of the aforementioned "cooling method" can also induce crystal growth through cooling rate and temperature control. For example, the cooling method can induce crystal growth through cooling rate and temperature control without performing vacuum concentration. For successful crystal growth, it is important to adjust the cooling rate so that the degree of supersaturation of the crystal stock solution concentration is kept constant during the cooling process. Therefore, in this application, the cooling process may include one or two intervals in which the temperature is kept constant during the cooling process, including cooling at a constant rate.

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

[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. If the cooling rate is low, the cocrystal formation time is long, which may result in low productivity, and if the cooling rate is high, crystals with small particle sizes may be formed, making crystal recovery difficult.

[0038] The method for producing the kestose crystals may include the steps of generating crystal nuclei from a high-purity kestose solution containing 85% by weight or more of kestose, with a solid content of 60-90% by weight, preferably 78-85% by weight, and a pH in the range of 6-8, preferably 6.5-7.5, at a temperature where the degree of supersaturation is greater than 1 and 1.4 or less, preferably 1.01-1.3, and growing crystals by cooling the temperature of the solution.

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

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

[0041] The amount of seed crystal added can be 0.01-5% by weight, 0.01-3% by weight, 0.01-2% by weight, 0.01-1.5% by weight, 0.01-1% by weight, 0.1-5% by weight, 0.1-3% by weight, 0.1-2% by weight, 0.1-1.5% by weight, 0.1-1% by weight, 0.5-5% by weight, 0.5-3% by weight, 0.5-2% by weight, 0.5-1.5% by weight, 0.5-1% by weight, 1-5% by weight, 1-3% by weight, 1-2% by weight, or 1-1.5% by weight relative to the solid content weight of the crystallization solution.

[0042] An example of the aforementioned "evaporation concentration method" may include the steps of generating crystal nuclei from a high-purity kestose solution containing 85% by weight or more of kestose, with a solid content of 60-90% by weight, preferably 65-85% by weight, and a pH in the range of 6-8, preferably 6.5-7.5, under vacuum conditions at a temperature where the degree of supersaturation is greater than 1 and 1.4 or less, preferably 1.01-1.3, and growing crystals while maintaining a degree of supersaturation of 1.1 under vacuum conditions and constant temperature conditions. To stably maintain the degree of supersaturation, the method may include the step of adding additional crystal stock solution. The step of adding additional crystal stock solution may be carried out under constant temperature conditions, that is, it may not involve a decrease in temperature. As the temperature of the kestose crystal stock solution is lowered, the viscosity of the crystal stock solution increases, which reduces the fluidity of the stock solution, and this may affect crystal growth by reducing intermolecular collisions. Also, as the viscosity increases, it may become very sticky, making it difficult to recover the crystals. Furthermore, if the viscosity of the mother liquor is high, separating the crystals from the mother liquor becomes difficult, requiring more washing steps, which ultimately negatively impacts the recovery rate. If even a small amount of mother liquor adheres to the crystals, the purity of the crystal particles may decrease, or the hygroscopic properties during storage may increase, causing them to harden or aggregate. Therefore, in one example of this application, the concentration may not involve an increase in the degree of supersaturation of the crystal stock solution.

[0043] Specifically, the method for producing kestose crystals may include the steps of: generating crystal nuclei by slowly stirring while adding a kestose-containing solution containing 85% by weight or more of kestose and a solid content of 60-90% by weight to a reactor at a temperature of 60-70°C until it reaches 20-50% of the reactor volume; and growing crystals while maintaining a vacuum and keeping the concentration constant at 60-90% by weight, 60-85% by weight, 60-83% by weight, 65-90% by weight, 65-85% by weight, 65-83% by weight, 70-90% by weight, 70-85% by weight, 70-83% by weight, 75-90% by weight, 75-85% by weight, 75-83% by weight, 80-90% by weight, 80-85% by weight, or 80-83% by weight. Maintaining a constant concentration may be achieved by adding additional kestose-containing solution. Specifically, the crystal growth process can be carried out by repeatedly adding the solution 1 to 4 times.

[0044] The method for producing the kestose crystal may additionally include a step of adding the seed crystal. The seed crystal is as described above.

[0045] In one specific example of this application, the method for producing crystalline kestose includes a step of secondary ion purification of the kestose fraction obtained in a high-purity separation step, a step of concentration of the ion-purified kestose fraction, and a step of crystallizing kestose from the concentrate to obtain kestose crystals, and may optionally include additional steps of recovering the kestose crystals, washing, and drying.

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

[0047] The crystallization yield of the method for producing crystalline kestose according to this application may 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] A crystalline kestose according to an example of this application may have improved hygroscopicity. For example, when the crystalline kestose is stored at 25°C and 75% relative humidity for 6 hours, its 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] The crystalline kestose according to one example of this application may have an improved dissolution rate. For example, the time required to dissolve the crystalline kestose 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 to dissolve in water may be the time required for the kestose crystals to completely dissolve after adding the crystalline kestose at a concentration of 10% by weight to water at a temperature of 25°C and stirring at a speed of 150 rpm.

[0050] The crystalline kestose described in this application is a type of oligosaccharide and has a lower sweetness than sugar, so it can be used in the manufacture of mixed sweeteners, solid mixed sweeteners, chocolate, chewing gum, instant juice, instant soup, granules, tablets, etc. Furthermore, the crystalline kestose can be contained and used in various compositions such as food and beverages, luxury goods, animal feed, cosmetics, and pharmaceuticals, and the method of incorporating the carbohydrates can be appropriately selected from known methods such as mixing, dissolving, melting, immersion, infiltration, spraying, coating, coating, atomizing, injection, crystallization, and solidification during the process until the product is completed.

[0051] Another example of this application is the provision of a sweetener composition containing the crystalline kestose. The sweetener composition may contain kestose crystals in various amounts and may additionally 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, erythorulose, galactose, idose, mannose, ribose, sorbose, tagatose, erythrose, fucrose, genthiobiose, genthiobiurose, isomaltose, isomaltulose, cozybiose, lactulose, allotrose, laminaribiose, arabinose, lucrose, fucose, rhamnose, sorbose, maltulose, mannobiose, mannosucrose, melezitose, melibiose, melibiurose, nigerose, raffinose, rutinose, rutinulose, stachyose, threose, trehalose, trehalulose, turanose, xylobiose, fructose, glucose, and allulose.

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

[0054] The aforementioned dietary fibers may be water-soluble dietary fibers, 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 aforementioned oligosaccharides may be one selected from the group consisting of fructooligosaccharides, isomaltoligosaccharides, maltooligosaccharides, breast milk oligosaccharides, and galactooligosaccharides.

[0056] The aforementioned 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, neotame, ribaudioside, monk fruit, mogroside, and monellin.

[0057] The present application will be described in more detail below based on the following embodiments. However, these embodiments are merely illustrative of the present application and do not limit the scope of the present application. [Examples]

[0058] Example 1: Preparation of kestose crystal stock solution After adding 45 kg of water heated to 55°C to a saccharification tank, 55 kg of sugar was added and stirred for 1 to 2 hours to completely dissolve the sugar crystals. Then, after titrating the pH to 6.5-7.0, β-fructofuranosidase derived from Aspergillus niger, an enzyme for producing kestose-rich syrup, was added and reacted for 24 to 48 hours according to the method disclosed in Korean Published Patent No. 10-2018-0078065. During this time, in the enzyme reaction section where 26% by weight of sugar remained, the pH was titrated to above 7.6 using 4N NaOH, and 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 produce a 75% by weight product. Subsequently, Na... + Using an SMB filled with type separation resin, high-purity separation was performed to obtain a stock solution for the crystallization process containing more than 85% kestose. <Analysis conditions for kestose content and sugar composition> -Analytical equipment: HPLC Agilent, 1100 Series - Column: Shodex Asahipak NH2P-50 4E -Injection volume: 10μl -Flow rate: 1ml / min - Column temperature: 30℃ - Mobile floor: Acetonitrile 70%

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

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

[0061] Example 4: Production of kestose crystals using a cooling method (3) The same procedure as in Example 2 was used with the crystalline stock solution containing 91.4% by weight of kestose, 7.0% by weight of nystose, and 1.6% by weight of sugar, prepared in Example 1, but with the addition of 0.5% by weight of 300 μm seed crystals relative to the solid content weight, and the mixture was cooled at the same rate of -0.5°C / hour to 30°C. The purity of the produced kestose crystals was analyzed by HPLC using the same method as in Example 1. 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 the evaporation concentration method (1) Using the crystalline stock solution prepared in Example 1, which contained 91.4% by weight of kestose, 7.0% by weight of nystose, and 1.6% by weight of sugar, a kestose-containing solution with a solid content of 68% by weight and a pH of 7.5 was added under vacuum at a temperature of 60°C to 25% of the reactor volume, and the mixture was vacuum-concentrated in the reactor to a solid content of 82.5% by weight. Seed crystals were added to a stock solution with a supersaturation level of 1.1, and the mixture was slowly stirred to generate crystal nuclei. While maintaining the vacuum state, the same volume of stock solution was added to the initial solution, and the crystals were grown while concentrating the solution to maintain a constant solid content of 82.5% by weight and a constant supersaturation level. At this time, the solution was concentrated to a solid content of 82.5% by weight so that the supersaturation level of 1.1 could be maintained by adding the solution under constant temperature conditions without lowering the temperature. Since microcrystals can precipitate along with the crystals as they grow, a small amount of water was added to dissolve the microcrystals before adding the stock solution to prevent the microcrystals from inhibiting the growth of the crystal particles. The method of adding stock solution and adding water as described above was repeated a total of four times. After the kestose crystals produced were discharged from the reactor, the mother liquor was removed by centrifugal dehydration, and the crystals obtained by primary crystallization were washed with cooling water, dried, and recovered. The purity of the produced kestose crystals was analyzed by HPLC using the same method as in Example 1, and the purity of the produced kestose crystals was 99.7% by weight, with a crystal yield of 56.8%. In Examples 4 and 5, since the pH of the stock solution was 7.5, the kestose content did not decrease despite the crystallization process being carried out at high temperature for a long time. As the nystose content, which can act as an inhibitor of kestose crystal growth, was low at 7% by weight or less, it did not significantly affect the crystallization process.

[0063] Example 6: Production of kestose crystals using the evaporation concentration method (2) A stock solution containing 91.4% by weight kestose, 7.0% by weight nystose, and 1.6% by weight sugar, prepared in Example 1, was made, and its 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% by weight was added to the reactor at a temperature of 65°C to reach 25% of the reactor volume, and the solution was vacuum-concentrated in the reactor to a solid content of 82.5% by weight. Seed crystals were added to a supersaturated solution with a concentration of 1.1, and the mixture was slowly stirred to generate crystal nuclei. While maintaining the vacuum, the same volume of stock solution was added to the initial solution, and the crystals were grown while concentrating the solution to maintain a constant solid content of 82.5% by weight and a constant supersaturation level. However, the crystals in the stock solution did not grow well, and many microcrystals were present. In order to grow the microcrystals into larger crystals, a small amount of water was added to redissolve the microcrystals before adding the stock solution, but the crystals did not grow well. When the raw solution in the process of crystallization was sampled and its sugar composition was analyzed, it was found that the pH was less than 5, and the kestose and nystose components had been decomposed due to the prolonged high-temperature reaction, resulting in a slight decrease in the kestose content to 88.8%. It was determined that a composition containing 10% or more 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 determined that conditions with a pH of 5 or higher and a kestose 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 100 mesh 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 Kestose Crystal Form The morphology of the kestose crystals produced in Example 4 was observed using an optical microscope. Figure 1 is an optical microscope image of the kestose crystal particles produced in Example 3, measured at a magnification of X100. As shown in Figure 1, the kestose crystals produced according to this application were found to have a rectangular hexahedral morphology and exhibit high crystal uniformity and robustness.

[0066] Test Example 2: Analysis of the particle size distribution of kestose crystals To confirm the particle size distribution of the kestose crystals produced in Examples 2-5 and Comparative Example 1, a laser diffraction-based particle size analysis system was used. The results of analyzing the particle size distribution by repeating the analysis of the samples several times are shown in Table 1. <Analysis conditions> Analytical instrument: Mastersizer2000 (MALVERN Instrument) Accessory equipment 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, it was observed that the particle size distribution of the final kestose crystal particles increased as larger seed crystals were introduced. This indicates that seed crystal size is an important factor in kestose crystal growth. Furthermore, the growth pattern of kestose crystals could be controlled by adjusting the amount of seed crystals introduced and the cooling rate. Therefore, it was confirmed that the amount of seed crystals introduced, the size of the seed crystals introduced, and the cooling rate are factors that influence kestose crystallization.

[0069] Test Example 4: Differential Scanning Calorimeter (DSC) Analysis DSC analysis was performed on the kestose crystals produced in Example 4, and a fructooligosaccharide powder containing 85% kestose, produced by CVD drying, was used as a control group. The specific DSC analysis conditions were as follows: - Equipment name: DSC [differential scanning calorimetry] - Manufacturer: Perkin Elmer -Method: Heating from 30 to 250°C at a rate of 10°C / min, N2 gas purge (reference method: ASTM D 3418). The DSC analysis results of the kestose crystals are shown in Table 2.

[0070] [Table 2]

[0071] DSC analysis revealed that, compared to amorphous powder produced immediately by spray drying or convection drying (CVD) without crystallization, the kestose crystals produced according to this application example had relatively higher Tm values ​​and higher heat capacity. In DSC analysis of crystals, a higher heat capacity indicates that the crystal is less easily dissolved, and a higher heat capacity and a narrower endothermic peak width predict that the crystal is uniformly and firmly formed. Therefore, it was confirmed that by producing crystalline particles through crystallization, kestose is formed more uniformly and firmly than the amorphous powder form, making it more stable for use.

[0072] Test Example 5: Measurement of the hygroscopicity of kestose crystals A comparative hygroscopic test was conducted on the kestose crystals obtained in Examples 2-5 and Comparative Example 1. Specifically, a constant temperature and humidity chamber set to 25°C and 75% relative humidity was used to quickly compare the effect on hygroscopicity. Each sample was accurately weighed in 10g increments and stored at different times under constant temperature and humidity conditions. The increase in weight from the total weight of the dish containing the initial sample was measured, and it was determined that moisture had been absorbed by the amount of the increase in weight. The increase in weight was then calculated as a percentage based on the initial weight of the dish and sample combined. A comparative graph of the hygroscopicity of each sample is shown in Figure 2, and the percentage increase in moisture absorption weight (%) for each sample is shown in Table 3. As shown in Table 3, the kestose crystals of Examples 2 and 3 showed weight increases of 1.8% and 1.6%, respectively, after a 6-hour storage period, while the kestose crystals of Examples 4 and 5 showed a weight increase of approximately 1.5%. On the other hand, the kestose crystal of Comparative Example 1 showed a high weight increase of over 2%. From these results, it was confirmed that the hygroscopic properties of kestose can be greatly improved by growing the crystal particles.

[0073] [Table 3]

[0074] Test Example 6: Measurement of the dissolution rate of kestose crystals A comparative dissolution rate test was conducted on the kestose crystals produced in Examples 2-5 and Comparative Example 1. Specifically, the time it took for 20g of the sample to completely dissolve in 180g of water was measured. The sample was stirred at a constant speed of 150rpm at 25°C, and the solid content of the supernatant was measured. The solubility until the final dissolution concentration was reached was calculated as a percentage, and the point at which complete dissolution occurred was confirmed. A comparative graph of the dissolution rates of each sample is shown in Figure 3, and the solubility percentage (%) of each sample is shown in Table 4. The kestose crystals in Examples 2 and 3 took 180 seconds and 135 seconds, respectively, to completely dissolve, while the kestose crystals in Examples 4 and 5 took 108 seconds and 110 seconds, respectively, to completely dissolve. On the other hand, the kestose crystals in Comparative Example 1 took the longest time to completely dissolve, at 280 seconds. Generally, larger crystals dissolve more slowly. However, the kestose crystals according to this application, despite having a large average particle size, dissolved quickly and completely in a short time. Furthermore, the kestose crystals according to this application dissolved even faster as their size increased. This is a characteristic different from that of typical crystals. Kestose crystals are trisaccharide crystals with high viscosity in the raw material and are prone to agglomeration during the crystallization process. However, the kestose crystals according to this application were found to dissolve quickly because of their large average particle size and low distribution ratio of fine crystals prone to agglomeration. Therefore, this application can provide kestose in which the aggregation phenomenon between crystals is reduced during dissolution, resulting in an improved dissolution rate.

[0075] [Table 4]

Claims

1. The average particle size represented by D(4,3) is 200 μm or larger, and The particle size distribution has such that 35% or less of the particles are 70 μm or smaller in size. A crystalline kestose with a melting temperature (Tm) of 206 ± 5°C.

2. The average particle size, represented by D(4,3), is 200 μm or larger. Particles with a size of 50 μm or less make up 20% or less, The crystalline kestose according to claim 1, having a particle size distribution in which 35% or less of the particles have a size of 70 μm or less.

3. Furthermore, the crystalline kestose according to claim 1 has one or more particle size distributions selected from the group consisting of (1) to (10) below: (1) Particles with a size of 10 μm or less make up 5.5% or less. (2) Particles with a size of 20 μm or less make up 7.5% or less. (3) Particles with a size of 50 μm or less make up 20% or less. (4) Particles with a size of 60 μm or less make up 25% or less. (5) 42% or less of particles have a size of 80 μm or less. (6) 45% or less of the particles have a size of 100 μm or less. (7) 55% or less of the particles have a size of 140 μm or less. (8) 60% or less of the particles are 180 μm or smaller in size. (9) 65% or less of the particles are 200 μm or smaller in size, (10) 78% or less of the particles are 240 μm or smaller in size.

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

5. The crystalline kestose according to claim 1, wherein the crystalline kestose has a purity of 70% by weight or more.

6. The crystalline kestose according to claim 1, wherein the crystalline kestose contains less than 1.4% by weight of nitose.

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

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

9. A fructooligosaccharide composition comprising the crystalline kestose described in any one of claims 1 to 8.

10. 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 where the degree of supersaturation is greater than 1 and less than or equal to 1.4; and A method for producing crystalline kestose according to any one of claims 1 to 8, comprising the step of growing crystals.

11. The method according to claim 10, wherein the kestose content of the kestose solution is 80% by weight or more, based on a solid content of 100% by weight.

12. The method according to claim 10, wherein the step of growing the crystal is to cool the kestose solution to grow the crystal.

13. The method according to claim 12, wherein the cooling does not involve reduced pressure concentration.

14. The method according to claim 12, wherein the cooling is performed at a rate of 5°C or less per hour.

15. The method according to claim 12, wherein the kestose solution is cooled to a temperature of 30 to 75°C.

16. The method according to claim 10, wherein the step of growing the crystals involves concentrating the kestose-containing crystalline stock solution and growing the crystals.

17. The method according to claim 16, wherein the kestose-containing crystalline stock solution is concentrated to a solid content of 60 to 90% by weight.

18. The method according to claim 16, wherein the concentration is performed without a decrease in temperature.

19. The method according to claim 10, wherein the step of growing the crystal further includes one or more additional steps of dissolving the microcrystals generated during the crystal growth stage.

20. The method according to claim 10, further comprising the step of adding a seed crystal.

21. The method according to claim 10, wherein the crystallization yield of the method is 40% or more.

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