Alternative Allolose Crystallization Process

Abstract

Allulose crystals can be efficiently produced from allulose syrup by using seed crystals.

Description

Technical Field

[0001] Cross - reference to related applications This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 469,131, filed May 26, 2023, the entire content of which is incorporated herein by reference.

[0002] Field of the technology The present invention relates to the production of allulose crystals from allulose - containing syrup.

Background Art

[0003] Discussion of the prior art Many food and beverage products contain nutritive sweeteners such as sucrose (commonly referred to as “sugar” or “table sugar”), glucose, fructose, corn syrup, high - fructose corn syrup, etc. Even though they are desirable in terms of taste and functional properties, the over - consumption of nutritive sweeteners such as sucrose has long been associated with an increase in diet - related health problems such as obesity, heart disease, metabolic disorders, and dental problems. Due to such concerns, consumers have adopted a healthier lifestyle and become more aware of the importance of reducing the level of nutritive sweeteners in their diet.

[0004] In recent years, there has been a particular focus on the development of low - calorie or zero - calorie sweeteners, and the development of nutritive sweetener substitutes has been underway. One proposed substitute for nutritive sweeteners is allulose (also known as D - psicose). Allulose is known as a “rare sugar” because it exists naturally in extremely small amounts. Allulose is about 70% as sweet as sucrose but provides only about 5% of sucrose calories (about 0.2 kcal / g). Thus, allulose can be considered essentially a “zero - calorie” sweetener.

[0005] Given its scarcity in nature, the production of allulose relies on the epimerization of readily available fructose. Keose-3-epimerases can interconvert fructose and allulose, and various ketose-3-epimerases are known to carry out such conversions. Such epimerization reactions are usually carried out using an aqueous medium in which fructose is first dissolved, and the allulose-containing product obtained as a result of epimerization is in the form of an aqueous allulose solution. Further processing and purification of the reaction product can be carried out according to known procedures, thereby producing allulose syrup containing allulose of considerably high concentration and purity. Such allulose syrup can be used in many consumer products, including food and beverages, as a substitute for conventional "sugar" syrups such as glucose syrup and high-fructose corn syrup. [Overview of the project] [Problems that the invention aims to solve]

[0006] However, for other applications, it is preferable to use allulose in a "dry," free-flowing, crystalline form, i.e., a form generally similar to that of table sugar. Although several attempts have been reported to develop methods for producing crystalline allulose (see, for example, U.S. Patent No. 8,524,888 and WO2016 / 064087), allulose is generally recognized as a sugar that is difficult to crystallize in a controlled and efficient manner to ensure that crystals of the appropriate shape and size are reliably obtained in high yield. Therefore, improving methods for crystallizing allulose remains a matter of considerable interest. [Means for solving the problem]

[0007] Various embodiments of the present invention can be summarized as follows: Appearance 1: A method for producing allulose crystals, comprising the following steps: a) A step of cooling and stirring a first mixture consisting of a first portion of allulose syrup and allulose seed crystals to initiate the crystallization of allulose dissolved in the allulose syrup, thereby forming a first mother liquor containing allulose crystals and a first mother liquor containing residual dissolved allulose, wherein the cooling and stirring are continued until a pre-selected first target yield of allulose crystals is achieved; b) Optionally, a step of separating the first white substance into a first part (which may be subjected to further processing steps, such as separating the allulose crystals from the mother liquor and washing and / or drying the separated allulose crystals); c) Optionally, a step of combining the second portion of allulose syrup with the second portion of the first white syrup to form a second mixture; and d) Optionally, a step of cooling and stirring the second mixture to initiate the crystallization of allulose dissolved in the second portion of the allulose syrup, thereby forming a second white liquor containing allulose crystals and a second mother liquor containing residual dissolved allulose, wherein the cooling and stirring is continued until the allulose crystals achieve a pre-selected second target yield. The method, including the method described above.

[0008] In various embodiments of Embodiment 1, at least steps a) and b) are performed, at least steps a) to c) are performed, or at least steps a) to d) are performed.

[0009] Appearance 2: The method according to embodiment 1, wherein the above-mentioned first mixture is obtained by combining the first portion of the above-mentioned allulose syrup with dried allulose crystals.

[0010] Appearance 3: The method according to embodiment 1, wherein the above-mentioned first mixture is obtained by combining the first portion of the above-mentioned allulose syrup with a heel consisting of allulose crystals and mother liquor.

[0011] Appearance 4: The method according to any one of embodiments 1 to 3, wherein when step d) is performed, the first and second admixtures are stirred in steps a) and d) using a stirrer having a tip speed of 0.02 to 2 m / sec, respectively.

[0012] Appearance 5: a) The method according to any one of embodiments 1 to 4, wherein step further comprises blending the first admixture with at least one further portion of the allulose syrup after the crystallization of the allulose dissolved in the allulose syrup has commenced.

[0013] Appearance 6: The method according to any one of embodiments 1 to 5, wherein the cooling in step a) above includes the steps of lowering the temperature of the first admixture from within an initial temperature range to within a second temperature range and maintaining the temperature of the first admixture within the second temperature range for a certain period of time.

[0014] Appearance 7: The method according to any one of embodiments 1 to 6, wherein step d) is performed, and the cooling in step d) includes the steps of lowering the temperature of the second admixture from within an initial temperature range to within a second temperature range and maintaining the temperature of the second admixture within the second temperature range for a certain period of time.

[0015] Aspect 8: The method according to any one of embodiments 1 to 7, wherein the allulose syrup has a dry solid content of 70% to 95% by weight, 75% to 90% by weight, or 80% to 85% by weight.

[0016] Appearance 9: The method according to any one of embodiments 2 to 8, wherein the allulose syrup has an allulose purity of at least 70%, at least 75%, at least 80%, at least 85%, or at least 90%.

[0017] Appearance 10: The method according to any one of aspects 1 to 9, further comprising the step of separating allulose crystals from the first mother liquor in the first part below the first white.

[0018] Aspect 11: The method according to aspect 10, wherein the separation is at least partially carried out by one or more physical separation methods selected from the group consisting of centrifugation, filtration, decantation, membrane separation, and combinations thereof.

[0019] Aspect 12: The method according to aspect 10 or 11, wherein the allulose crystals separated from the first mother liquor are subjected to the steps of: i) washing with at least one of water, an organic solvent, a blend of organic solvents, a blend of water and (one or more) organic solvents, or an aqueous solution comprising at least one carbohydrate (e.g., allulose); ii) drying; or a combination thereof.

[0020] Aspect 13: The method according to any one of aspects 1 to 12, wherein steps b) to d) are carried out and repeated at least once.

[0021] Aspect 14: A method for producing allulose crystals, comprising the following steps: a). A step of passing a feed syrup / s recycled white blend (where the feed syrup / s recycled white blend is cooled within a first crystallization temperature range) consisting of: i) a feed syrup containing water and dissolved allulose, and ii) a recycled white below containing allulose crystals and a recycled white below mother liquor containing dissolved allulose, through a first step crystallization region, wherein the feed syrup / s recycled white blend is stirred, the feed syrup / s recycled white blend is maintained within the first crystallization temperature range, crystallization of allulose dissolved in the feed syrup and the recycled white below mother liquor is initiated, thereby forming a first white below containing allulose crystals and a first mother liquor containing residual dissolved allulose, and reaching a preselected first target yield. Step of discharging the first white substance that has reached the first step from the crystallization region; b) Optionally, the first white material discharged from the first step crystallization region is cooled to within the second crystallization temperature range, and the first white material is transferred to the second step crystallization region; c) Optionally, a step of passing the first white substrate through the second step crystallization region, wherein the first white substrate is stirred, the first white substrate is kept within the second crystallization temperature range, and crystallization of allulose dissolved in the first mother liquor is initiated, thereby forming a second white substrate containing allulose crystals and a second mother liquor containing residual dissolved allulose; and a step of discharging the second white substrate, which has achieved a pre-selected second target yield, from the second step crystallization region; and d) Optionally, repeat steps b and c at least once to obtain a final white base and final mother liquor containing allulose crystals. The method, including the method described above.

[0022] In various embodiments of the 14th model, at least steps a) and b) are performed, at least steps a) to c) are performed, or at least steps a) to d) are performed.

[0023] Appearance 15: The method according to embodiment 14, wherein steps a) to d) are performed, and further steps include separating at least some of the allulose crystals below the final white from the final mother liquor.

[0024] Appearance 16: The method according to embodiment 14 or 15, wherein steps a) to d) are performed and a portion of the final undercoat is used as the recycled undercoat.

[0025] Appearance 17: The method according to any one of embodiments 14 to 16, wherein the feed syrup / recycled white liquor mixture is obtained by the steps of mixing the feed syrup with the recycled white liquor, which consists of allulose crystals, and the recycled white liquor mother liquor containing dissolved allulose in a mixing container to provide the feed syrup / recycled white liquor mixture, and transferring the feed syrup / recycled white liquor mixture from the mixing container to the first step crystallization region.

[0026] Appearance 18: The method according to any one of embodiments 14 to 17, wherein the first and second admixtures described above are stirred in steps a) and c) using a stirrer having a tip speed of 0.02 to 2 m / sec, respectively, once step c) is performed.

[0027] Appearance 19: The method according to any one of embodiments 14 to 18, wherein the allulose syrup has a dry solid content of 70% to 95% by weight, 75% to 90% by weight, or 80% to 85% by weight.

[0028] Appearance 20: The method according to any one of embodiments 14 to 19, wherein the allulose syrup has an allulose purity of at least 70%, at least 75%, at least 80%, at least 85%, or at least 90%.

[0029] Appearance 21: The method according to embodiment 15, wherein the above separation is at least partially carried out by one or more physical separation methods selected from the group consisting of centrifugation, filtration, decantation, membrane separation, and combinations thereof.

[0030] Appearance 22: The method according to embodiment 15 or 21, wherein the allulose crystals separated from the final mother liquor are subjected to the steps of i) washing with at least one of the following: water, an organic solvent, a blend of organic solvents, a blend of water and (one or more) organic solvents, or an aqueous solution comprising at least one carbohydrate (e.g., allulose); ii) drying; or a combination thereof.

[0031] Appearance 23: The method according to any one of embodiments 14 to 22, wherein the feed syrup / recycled white substrate admixture passes through the first step crystallization region in a plug flow manner and / or steps b) and c) are performed, and the first white substrate passes through the second step crystallization region in a plug flow manner.

[0032] Appearance 24: The method according to any one of embodiments 1 to 23, wherein the method is performed continuously.

[0033] Appearance 25: Allulose crystals obtained by any of the methods described in Embodiments 1 to 24.

[0034] Appearance 26: A consumer product comprising or manufactured using allulose crystals and at least one further component other than allulose crystals according to embodiment 25.

[0035] Appearance 27: A method for producing a consumer product, comprising the step of using allulose crystals according to embodiment 25.

[0036] Appearance 28: Mother liquor obtained by any of the methods described in Embodiments 1 to 24.

[0037] Appearance 29: The mother liquor according to embodiment 28, wherein the mother liquor is suitable for use as a product consumable by humans or animals, or as an ingredient in a dosage form product consumable by humans or animals.

[0038] Appearance 30: A method for producing allulose crystals, comprising the following steps: a) Distilling off the feed allulose syrup at a first near-atmospheric pressure and a first temperature to produce a first supersaturated allulose syrup having a target allulose syrup saturation; b) A step of introducing seed crystals into a first supersaturated allulose syrup to crystallize allulose and produce a first white liquor containing allulose crystals and a first supersaturated mother liquor having a first target mother liquor saturation level higher than the target saturation level of the allulose syrup; c) Distilling off the first white base at a first near-atmospheric pressure and a first temperature to produce a second white base containing allulose crystals and a second supersaturated mother liquor having a second target saturation lower than the first target saturation; d) A step of increasing the first near-atmospheric pressure to the second near-atmospheric pressure and cooling the second base to the second temperature to produce a third base containing allulose crystals and a third supersaturated mother liquor having a target saturation of the third mother liquor; e) A step of producing a third whitening agent containing allulose crystals and a third mother liquor having a third target mother liquor saturation, by holding the second whitening agent at a second near-atmospheric pressure and a second temperature for a certain period of time; f) A step of increasing the pressure to atmospheric pressure and cooling the third whitening agent to a third temperature at a constant cooling rate to produce a fourth whitening agent containing allulose crystals and a fourth supersaturated mother liquor having a fourth target mother liquor saturation; g) A step of crystallizing the fourth white base over a crystallization time to produce a product white base containing product allulose crystals and product mother liquor in a target yield, wherein the product mother liquor has a target product mother liquor supersaturation; and h) A step of separating the product allulose crystals from the product supersaturated mother liquor to provide allulose crystals in a target yield. The method, including the method described above.

[0039] Appearance 31: The method according to embodiment 30, wherein the target yield is 40% or more.

[0040] Appearance 32: The method according to embodiment 30 or embodiment 31, wherein the feed allulose syrup has a total dry solid content of 50% to 80% by weight.

[0041] Appearance 33: The method according to any one of embodiments 30 to 32, wherein the allulose in the feed allulose syrup is at least 80% pure by weight on a dry solid basis.

[0042] Appearance 34: The method according to any one of embodiments 30 to 33, wherein the pH of the feed allulose syrup is 2.5 to 6.0.

[0043] Appearance 35: The method according to any one of embodiments 30 to 34, wherein the feed allulose syrup is at least 95% pure by weight on a dry solid basis.

[0044] Appearance 36: The method according to any one of embodiments 30 to 35, wherein the feed allulose syrup is at least 98% pure by weight on a dry solid basis.

[0045] Appearance 37: The method according to any one of embodiments 30 to 36, wherein the seed crystal is contained in an amount of 0.0001% to 5% by weight of feed allulose syrup.

[0046] Appearance 38: The method according to any one of embodiments 30 to 37, wherein the seed crystal has an average particle size of 75 microns (μm) or less.

[0047] Appearance 39: The method according to any one of embodiments 30 to 38, wherein the seed crystal has an average grain size of 5 to 250 microns (μm).

[0048] Phenomenon 40: The method according to any one of embodiments 30 to 39, wherein the first temperature is 35 to 50°C.

[0049] Appearance 41: The method according to any one of embodiments 30 to 40, wherein the first target mother liquor saturation is 1.05 to 1.15.

[0050] Appearance 42: The method according to any one of embodiments 30 to 41, wherein the first supersaturated mother liquor contains 85 to 90 wt% allulose on a dry solid basis.

[0051] Appearance 43: The method according to any one of embodiments 30 to 42, wherein the second temperature is 22 to 35°C.

[0052] Aspect 44: The method according to any one of embodiments 30 to 43, wherein the second target mother liquor saturation is 1.05 supersaturation or less.

[0053] Appearance 45: The method according to any one of embodiments 30 to 44, wherein the second supersaturated mother liquor contains 80 to 95 wt% allulose on a dry solid basis.

[0054] Appearance 46: The method according to any one of embodiments 30 to 45, wherein the third temperature is 20 to 25°C.

[0055] Appearance 47: The method according to any one of embodiments 30 to 46, wherein the third target mother liquor saturation is 1.1 to 1.2 supersaturated.

[0056] Aspect 48: The method according to any one of embodiments 30 to 47, wherein the fourth target mother liquor saturation is 1.05 to 1.2 supersaturated.

[0057] Appearance 49: The method according to any one of embodiments 30 to 48, wherein the separation is performed at least partially by one or more physical separation methods selected from the group consisting of centrifugation, filtration, decantation, membrane separation, and combinations thereof.

[0058] Appearance 50: The method according to any one of embodiments 30 to 49, wherein the allulose crystals separated from the final mother liquor are subjected to the steps of i) washing with at least one of water, an organic solvent, a blend of organic solvents, a blend of water and (one or more) organic solvents, or an aqueous solution comprising at least one carbohydrate; ii) drying; or a combination thereof.

[0059] Appearance 51: Allulose crystals obtained by the method described in any of embodiments 30 to 50.

[0060] Appearance 52: A consumer product comprising allulose crystals and at least one additional component other than allulose crystals according to any of embodiments 30 to 51, or prepared using them.

[0061] Appearance 53: A method for producing a consumer product, comprising the step of using allulose crystals according to any one of embodiments 30 to 51.

[0062] Appearance 54: A mother liquor, which is a product mother liquor obtained by the method described in any of embodiments 30 to 53.

[0063] Appearance 55: A mother liquor obtained by the method described in any of embodiments 30 to 54, which is suitable for use as a product consumable by humans or animals, or as a component in a dosage form product consumable by humans or animals.

[0064] Appearance 56: Allulose crystal product having an average particle size of 100-500 microns (μm) and a d10 of 10-100 microns (μm) as measured by laser diffraction.

[0065] Appearance 57: The allulose crystal product according to embodiment 56, having a d90 of 300 to 1000 microns (μm) on a volume basis as measured by laser diffraction.

[0066] Appearance 58: An allulose crystal product according to embodiment 56 or embodiment 57, having a median particle size of 50 to 250 microns (μm) on a volume basis as measured by laser diffraction.

[0067] Appearance 59: The bulk density of the aforementioned product is at least 30 lb / ft 3 The allulose crystal product according to any one of embodiments 56 to 58.

[0068] Appearance 60: A consumer product comprising an allulose crystal product according to any one of embodiments 56 to 59, and at least one additional component other than allulose crystals.

[0069] Appearance 61: A method for producing allulose crystals, comprising the following steps: a) Distilling off the feed allulose syrup at a first near-atmospheric pressure and a first temperature to produce a first supersaturated allulose syrup having a target allulose syrup saturation; b) A step of introducing seed crystals into a first supersaturated allulose syrup and crystallizing allulose at a constant crystallization rate to produce a first white liquor containing allulose crystals and a first supersaturated mother liquor having a first target mother liquor saturation level higher than the target saturation level of the allulose syrup; c) Distilling off the first white base at a first near-atmospheric pressure and a second temperature lower than the first temperature to produce a second white base containing allulose crystals and a second supersaturated mother liquor having a second mother liquor target saturation lower than the first mother liquor target saturation; d) A step of producing a third white liquor containing allulose crystals and a third supersaturated mother liquor having a third target mother liquor saturation; e) A step of crystallizing the third white base over a crystallization time to produce a product white base containing product allulose crystals and product mother liquor in a target yield, wherein the product mother liquor has a target product mother liquor supersaturation; and f) A step of separating the product allulose crystals from the product supersaturated mother liquor to provide allulose crystals in a target yield. The method, including the method described above.

[0070] Appearance 62: The method according to embodiment 61, wherein the target allulose syrup saturation is 1.05 to 1.20.

[0071] Appearance 63: The method according to embodiment 61 or embodiment 62, wherein the first target mother liquor saturation is 1.10 to 1.35.

[0072] Appearance 64: The method according to any one of embodiments 61 to 63, wherein the supersaturated allulose syrup has a total dry solid content of 78% to 90% by weight.

[0073] Appearance 65: The method according to any one of embodiments 61 to 64, wherein the target yield is 40% or more.

[0074] Appearance 66: The method according to any one of embodiments 61 to 65, wherein the yield of allulose crystals in step c) is 5 to 20% by weight.

[0075] Appearance 67: The method according to any one of embodiments 61 to 66, wherein the crystallization rate of allulose in step c) is 1 to 5 wt% per hour.

[0076] Appearance 68: The method according to any one of embodiments 61 to 67, wherein the crystallization time in step e) is 5 to 50 hours.

[0077] Appearance 69: The method according to any one of embodiments 61 to 68, wherein the feed allulose syrup has a total dry solid content of 50% to 80% by weight.

[0078] Appearance 70: The method according to any one of embodiments 61 to 69, wherein the allulose in the feed allulose syrup is at least 80% pure by weight on a dry solid basis.

[0079] Appearance 71: The method according to any one of embodiments 61 to 70, wherein the pH of the feed allulose syrup is 2.5 to 6.0.

[0080] Appearance 72: The method according to any one of embodiments 61 to 71, wherein the feed allulose syrup is at least 95% pure by weight on a dry solid basis.

[0081] Appearance 73: The method according to any one of embodiments 61 to 72, wherein the feed allulose syrup is at least 98% pure by weight on a dry solid basis.

[0082] Appearance 74: The method according to any one of embodiments 61 to 73, wherein the seed crystal is contained in an amount of 0.0001% to 5% by weight of feed allulose syrup.

[0083] Appearance 75: The method according to any one of embodiments 61 to 74, wherein the seed crystal has an average particle size of 75 microns (μm) or less.

[0084] Appearance 76: The method according to any one of embodiments 61 to 75, wherein the seed crystal has an average particle size of 5 to 250 microns (μm).

[0085] Appearance 77: The method according to any one of embodiments 61 to 76, wherein the first temperature is 30 to 70°C.

[0086] Appearance 78: The method according to any one of embodiments 61 to 77, wherein the first target mother liquor saturation is 1.10 to 1.15.

[0087] Appearance 79: The method according to any one of embodiments 61 to 78, wherein the first supersaturated mother liquor contains 85 to 90 wt% allulose on a dry solid basis.

[0088] Appearance 80: The method according to any one of embodiments 61 to 79, wherein the second temperature is 25 to 50°C.

[0089] Appearance 81: The method according to any one of embodiments 61 to 80, wherein the aforementioned near-atmospheric pressure is 25 to 55 millibars.

[0090] Appearance 82: The method according to any one of embodiments 61 to 81, wherein the third temperature is 5 to 50°C.

[0091] Appearance 83: The method according to any one of embodiments 61 to 82, wherein the second target mother liquor saturation is 1.05 supersaturation or less.

[0092] Aspect 84: The method according to any one of embodiments 61 to 83, wherein the second supersaturated mother liquor contains 80 to 95 wt% allulose on a dry solid basis.

[0093] Appearance 85: The method according to any one of embodiments 61 to 84, wherein the third target mother liquor saturation is 1.05 to 1.2 supersaturated.

[0094] Appearance 86: The method according to any one of embodiments 61 to 85, wherein the separation is performed at least partially by one or more physical separation methods selected from the group consisting of centrifugation, filtration, decantation, membrane separation, and combinations thereof.

[0095] Appearance 87: The method according to any one of embodiments 61 to 86, wherein the allulose crystals separated from the final mother liquor are subjected to the steps of i) washing with at least one of water, an organic solvent, a blend of organic solvents, a blend of water and (one or more) organic solvents, or an aqueous solution comprising at least one carbohydrate; ii) drying; or a combination thereof.

[0096] Feature 88: Allulose crystals obtained by the method described in any of embodiments 61 to 87.

[0097] Appearance 89: A consumer product comprising allulose crystals and at least one additional component other than allulose crystals according to any of embodiments 61 to 87, or prepared using them.

[0098] Appearance 90: A method for producing a consumer product, comprising the step of using allulose crystals obtained by the method described in any of embodiments 61 to 87.

[0099] Appearance 91: A mother liquor, which is a product mother liquor obtained by the method described in any of embodiments 61 to 87.

[0100] Appearance 92: A mother liquor obtained by the method described in any of embodiments 61 to 87, which is suitable for use as a product consumable by humans or animals, or as a component in a dosage form product consumable by humans or animals. [Brief explanation of the drawing]

[0101] [Figure 1] Figure 1 illustrates a diagrammatic representation of a crystallization system and process according to one embodiment of the present invention.

[0102] [Figure 2] Figure 2 illustrates a diagrammatic representation of a crystallization system and process according to another embodiment of the present invention.

[0103] [Figure 3] Figure 3 is a microscopic image of a white background containing allulose crystals produced according to one embodiment of the present invention.

[0104] [Figure 4] Figure 4 shows a photograph of a crystallization apparatus according to one embodiment of the present invention described in Example 2.

[0105] [Figure 5] Figure 5 shows the grain size distribution of a seed crystal according to one embodiment of the present invention described in Example 2.

[0106] [Figure 6] Figure 6 shows a microscopic image of an allulose crystal during the crystallization process according to one embodiment of the present invention, immediately after adding the seed crystal described in Example 2.

[0107] [Figure 7] Figure 7 shows a microscopic image of allulose crystals during a crystallization process according to one embodiment of the present invention, several hours after adding the seed crystal described in Example 2.

[0108] [Figure 8] Figure 8 shows a microscopic image of the allulose crystal product after the crystallization process according to one embodiment of the present invention described in Example 2 is completed.

[0109] [Figure 9] Figure 9 shows the particle size distribution, expressed as a volume percentage of the final white area, measured by laser light scattering, after the crystallization process according to one embodiment of the present invention described in Example 2 is completed. [Modes for carrying out the invention]

[0110] Detailed Description of Specific Embodiments of the Invention Feed Allulose Syrup The present invention utilizes at least one allulose syrup, i.e., a feed allulose syrup, as a starting material for a crystallization process, wherein allulose present in a soluble form within the syrup is converted to a crystalline form. Methods for obtaining feed allulose syrup are well known in the art and are described, for example, in the following patent documents: WO 2016 / 135458; US 2015 / 0210996; US 5,411,880; US 8,735,106; US 8,030,035; and 11,653,688, the respective disclosures of which are incorporated herein by reference in whole for all purposes.

[0111] For example, feed allulose syrup can be produced by a process comprising the steps of contacting an aqueous fructose solution with the enzyme allulose (D-psicose) epimerase under conditions effective in converting at least a portion of fructose to allulose, purifying the resulting reaction product, and then concentrating the purified reaction product to a desired dry solid content. The purification step may include removing impurities from the reaction product using one or more techniques such as deproteinization, decolorization (treatment with one or more decolorizing agents), decontamination, ion exchange chromatography (using one or more ion exchange resins such as anion exchange resins and cation exchange resins), column chromatography, and fractionation.

[0112] The feed allulose syrup should have a dry solids content that is sufficiently effective to crystallize allulose when the syrup is cooled in the presence of a seed crystal, as described in more detail below. For example, in various embodiments, the dry solids content of the feed allulose syrup may be at least 50% by weight, at least 55% by weight, at least 60% by weight, at least 65% by weight, at least 70% by weight, at least 75% by weight, at least 80% by weight, or at least 85% by weight. However, it is generally preferable that the dry solids content of the allulose be sufficiently low so that the syrup exists as a free-flowing solution without the seed crystal at the temperature at which the syrup is held before crystallization is initiated by the introduction of the seed crystal. Therefore, in various embodiments of the present invention, the feed allulose syrup has a dry solids content not exceeding 90% or not exceeding 85%. The desired dry solids content can be achieved by distillation or concentration of the diluted solution of allulose, in which case volatile components (e.g., water) are removed from the solution, leaving only a more concentrated syrup. The above distillation / concentration conditions may be advantageously selected to minimize or reduce the degree to which allulose is denatured; for example, a relatively low evaporation temperature may be employed.

[0113] According to some embodiments, the allulose feed syrup has a total dry solid content of 50% to 80% by weight and contains at least 80% by weight of allulose on a dry solid basis, wherein the pH of the feed syrup is 2.5 to 6.0.

[0114] According to another embodiment, the feed allulose syrup has a total dry solid content of 70% to 80% by weight and contains at least 90% by weight of allulose on a dry solid basis, wherein the pH of the syrup is 3.0 to 5.0.

[0115] The total dry solids content of feed allulose syrup is 50% to 80% by weight. For example, the total dry solids content may be 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, or 80%, as well as all intermediate values.

[0116] In one embodiment, the total dry solid content of feed allulose syrup is 70% to 80% by weight. For example, the total dry solid content may be 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, or 80%, as well as all intermediate values. In one embodiment, the total dry solid content of feed allulose syrup is 71% to 78% by weight. In another embodiment, the total dry solid content of feed allulose syrup is 71% to 73% by weight. In yet another embodiment, the total dry solid content of feed allulose syrup is 76% to 78% by weight. In yet another embodiment, the total dry solid content of feed allulose syrup is 50% to 70% by weight.

[0117] The pH of feed allulose syrup is between 2.5 and 6.0. For example, the pH of the syrup may be 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, or 6.0, as well as all intermediate values.

[0118] In one embodiment, the pH of the feed allulose syrup is 3.0 to 5.0. For example, the pH of the syrup may be 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, or 5.0, as well as all intermediate values. In one embodiment, the pH of the feed allulose syrup is 3.5 to 4.5. For example, the pH of the syrup may be 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, or 4.5, as well as all intermediate values. In one embodiment, the pH of the feed allulose syrup is 3.8 to 4.2. In one embodiment, the pH of the feed allulose syrup is approximately 4.0. Feed allulose syrup contains at least 80% by weight of allulose on a dry solid basis (i.e., at least 80% by weight of the total dry solids present in the feed allulose syrup is allulose). For example, feed allulose syrup may contain allulose in amounts of 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% by weight, as well as all intermediate amounts, on a dry solid basis.

[0119] In one embodiment, the feed allulose syrup contains at least 90% by weight of allulose on a dry solid basis (i.e., at least 90% by weight of the total dry solid present in the feed allulose syrup is allulose). For example, the allulose syrup may contain amounts of 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% by weight, as well as all intermediate values, on a dry solid basis. In one embodiment, the feed allulose syrup contains at least 95% by weight of allulose on a dry solid basis. In one embodiment, the feed allulose syrup contains less than 1000 ppm of HMF (hydroxymethylfurfural). For example, feed allulose syrup may contain HMF in amounts less than 900 ppm, less than 800 ppm, less than 700 ppm, less than 600 ppm, less than 500 ppm, less than 400 ppm, less than 300 ppm, less than 200 ppm, or less than 100 ppm. In certain embodiments, allulose syrup contains HMF (hydroxymethylfurfural) in amounts greater than 0.1 ppm and less than 1000 ppm, for example, greater than 0.1 ppm and less than 900 ppm, greater than 0.1 ppm and less than 800 ppm, greater than 0.1 ppm and less than 700 ppm, greater than 0.1 ppm and less than 600 ppm, greater than 0.1 ppm and less than 500 ppm, greater than 0.1 ppm and less than 400 ppm, greater than 0.1 ppm and less than 300 ppm, greater than 0.1 ppm and less than 200 ppm, or greater than 0.1 ppm and less than 100 ppm.

[0120] In one embodiment, the feed allulose syrup contains 0.1 to 20 ppm of sulfur dioxide. In another embodiment, the feed allulose syrup contains 1 to 15 ppm of sulfur dioxide. In another embodiment, the feed allulose syrup contains less than 10 parts per billion of isovaleraldehyde. In another embodiment, the feed allulose syrup contains less than 2 parts per billion of 2-aminoacetophenone. In another embodiment, the feed allulose syrup further comprises one or more additives. In another embodiment, one or more additives may encompass one additive. In another embodiment, one or more additives may encompass antioxidants. In another embodiment, one or more additives may encompass a buffer. Incorporation of a buffer into the feed allulose syrup maintains the pH of the feed allulose syrup within the desired range for a longer period of time. In another embodiment, the additive is present in an amount of about 0.01 to 2.0% by weight based on the total weight of the feed allulose syrup. In one embodiment, the additive may be selected from the group consisting of ascorbic acid and its salts; isoascorbic acid (erythorbate) and its salts; citric acid and its salts; acetic acid and its salts; and bisulfites and metabisulfites; and tocopherol acetate. In the case of salts, preferred salts include alkali metal salts, particularly sodium and potassium salts, and especially sodium salts. Specific examples of additives useful in the present invention include ascorbic acid, isoascorbic acid, sodium citrate, sodium acetate, tocopherol acetate, and metabisulfites. In one embodiment, the stability-enhancing additive is present in an amount of about 0.2% by weight based on the total weight of the feed allulose syrup, in the case of ascorbic acid or its salts; isoascorbic acid (erythorbate) or its salts; citric acid or its salts; acetic acid or its salts; and tocopherol acetate. In one embodiment, the stability-enhancing additive is present in an amount of about 0.02% by weight based on the total weight of the feed allulose syrup, in the case of bisulfites or metabisulfites.

[0121] The concentration of the buffer in feed allulose syrup may be approximately 0.01 to 2.0% by weight based on the total weight of feed allulose syrup. In the case of ascorbic acid or its salts; isoascorbic acid (erythorbate) or its salts; citric acid or its salts; acetic acid or its salts; and tocopherol acetate, the concentration of the buffer in feed allulose syrup may be approximately 0.2% by weight based on the total weight of feed allulose syrup. In the case of bisulfite or metabisulfite, the concentration of the buffer in feed allulose syrup may be approximately 0.02% by weight based on the total weight of feed allulose syrup.

[0122] According to some embodiments, the dry solid content range in allulose feed syrup is 60-80%, 70-80%, 71-78%, 71-73%, or 76-78%. According to some embodiments, the pH range of allulose feed syrup is 3.5-4.5 or 3.8-4.2. The purity of allulose in feed allulose syrup can be more than 95% allulose on a dry solid basis. Feed allulose syrup contains the following compounds in certain limit amounts: less than 1000 ppm of hydroxymethylfurfural (HMF); less than 20 parts per million of sulfur dioxide; less than 10 parts per billion of isovaleraldehyde at a measured concentration; and less than 2 parts per billion of 2-aminoacetophenone. Optionally, feed allulose syrup may contain, alone or in combination thereof, one or more of the following stability-enhancing compounds: 1) ascorbic acid or a salt thereof, 2) isoascorbic acid (erythorbate) or a salt thereof, 3) citric acid or a salt thereof, 4) acetic acid or a salt thereof, 5) bisulfite or metabisulfite, and / or 6) tocopherol acetate. Feed allulose syrup may have a concentration greater than 90% (e.g., greater than 95%).

[0123] The purity of allulose syrup can vary, but it is generally preferable that allulose constitutes the majority (by weight) of the nonvolatile substances present in the allulose syrup. Therefore, the allulose purity of the syrup may be at least 60% by weight, at least 65% by weight, at least 70% by weight, at least 75% by weight, at least 80% by weight, at least 85% by weight, or at least 90% by weight, or at least 95% by weight, or at least 96, 97, 98, or at least 99% by weight, or 100% by weight. As used herein with respect to allulose syrup, the term "allulose purity" means the weight percentage of allulose in the syrup based on the total weight of the dry solids in the syrup.

[0124] Arlos seed crystal The present invention employs allulose seed crystals to assist in promoting the initiation of further allulose crystallization from a solution (e.g., in the form of allulose-containing solid crystals previously present in a solution in allulose syrup, mother liquor, or similar). In certain embodiments, the allulose seed crystals exist in a dry form (e.g., dry crystals of allulose recovered from previously performed crystallization) and / or in the form of a heel, such as a portion of the white base consisting of allulose crystals and mother liquor. The amount of allulose seed may be used, for example, in an amount accounting for about 0.0001 to about 5% of the total amount of allulose present in the crystallization vessel or crystallization region, which will be described in more detail below. Generally speaking, it is preferable to use allulose seed crystals of relatively high purity; for example, in various embodiments of the present invention, allulose seed crystals can have an allulose purity of at least 90%, at least 95%, or at least 99% by weight. The term "allulose purity" as used herein for allulose crystals means the weight percentage of allulose in the crystal, based on the total weight of the dry solid in the crystal.

[0125] According to some embodiments, the seed crystal has an average grain size of 75 microns (μm) or less. For example, the seed crystal may have an average grain size of 1 to 250 microns (μm), or 1 to 75 microns (μm). The average grain size can be measured by laser diffraction, i.e., laser light scattering.

[0126] According to some embodiments, the seed crystal may exist in a dry form and, when measured by laser diffraction, may have an average particle size of 75 microns (μm) or less. According to some embodiments, the seed crystal may have an average particle size of 5 to 250 microns (μm). For example, the seed crystal may have an average particle size of at least 0.1, 0.5, 1, 1.5, 2, 2.5, 5, 25, 50, 75, 100, 125, 150, 175, or at least 250 microns (μm). The particle size distribution of the seed crystal may have an effect on the efficiency of crystallization and on the size of the final dried allulose product. According to some embodiments, the seed crystal may have an average grain size of at most 250, 200, 175, 150, 125, 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 10, or at most 5 microns (μm) on a volume basis as measured by laser diffraction. The average grain size of the seed crystal may be 5-75 μm, 5-60, 5-50, 5-40, 5-30, 5-25, 5-20, or 5-15 microns (μm). The median grain size (d50) of the seed crystal, when measured on a volume basis by laser light scattering, may be 5-75 μm, 5-60, 5-50, 5-40, 5-30, 5-25, 5-20, or 5-15 microns (μm). The d10 of the seed crystal can range from 0.01 to 25 microns (μm) on a volume basis, as measured by laser light scattering. The d10 of the seed crystal, as measured by laser light scattering on a volume basis, can range from 0.01 to 20, 0.05 to 15, 0.1 to 10, 0.5 to 5, and 0.5 to 5 microns (μm). The d90 of the seed crystal, as measured by laser light scattering on a volume basis, can range from 5 to 100 microns (μm). The d90 of the seed crystal, as measured by laser light scattering on a volume basis, can range from 5 to 90, 5 to 80, 5 to 75, 10 to 70, 10 to 65, 10 to 50, 15 to 50, 15 to 45, and 20 to 40 microns (μm).

[0127] Percentage of dry solids in allulose syrup when seed crystals are added According to some embodiments of the present invention, seed crystals may be added when increasing the dry solid content, expressed as weight percent dry solid (%ds) in the feed syrup, to 83.5% to 86%ds. For example, when seed crystals are added, the %ds of the syrup may be 75 to 90%ds. When feed crystals are added, the %ds of the syrup may be at least 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, and 90%ds. When feed crystals are added, the %ds of the syrup may be at most 95, 94, 93, 92, 91, 90, 89, 88, and 87%ds.

[0128] Description of various exemplary embodiments of the crystallization process In one embodiment of the invention, batch crystallization of allulose can be carried out in a jacketed vessel equipped with a stirrer by lowering the temperature of the cooling medium (e.g., water or other heat transfer liquid) in the jacket to induce crystallization. The following series of steps may be performed: 1. The container is partially filled with the appropriate allulose syrup. 2. Set the temperature of the cooling medium to the desired initial temperature. 3. Operate the agitator and set it to an effective RPM to provide the desired tip speed. 4. The temperature of the allulose syrup in the container is lowered to the desired temperature by appropriately changing the temperature of the cooling medium. 5. Add the desired amount of seed crystals (e.g., dried seed crystals) to the container (this addition can be done before the time it takes for the allulose syrup to reach the temperature set in step 2). 6. Mix the seed crystal and allulose syrup using an appropriate stirrer tip speed. The stirrer tip speed may be selected to minimize or avoid damage to the seed crystal as well as to the allulose crystals that subsequently form during crystallization. In certain embodiments, the stirrer tip speed is faster when proceeding with the initial mixing of the seed crystal and allulose syrup than when proceeding with the subsequent (one or more) crystallization steps.

[0129] 7. Next, the temperature of the allulose syrup / seed crystal mixture is lowered to a desired temperature that is effective in achieving the crystallization of a portion of the allulose dissolved in the allulose syrup. This temperature may vary depending on, for example, the concentration of allulose in the syrup, but will usually not exceed about 40°C and will not be lower than about 0°C. 8. Crystallization can be continued with appropriate stirring until the desired yield of allulose crystals is achieved (this can be confirmed by periodically taking a sample from the container and measuring the dry solid content of the mother liquor). 9. To achieve the desired yield of allulose crystals, the temperature under the white layer may be continuously or continuously in one or more steps.

[0130] 10. Once the desired yield of allulose crystals is achieved, the white mixture is combined with the remaining allulose syrup (for example, filling the container). Then, steps 7-9 are repeated. 11. After introducing the additional allulose syrup portion into the container, once the desired yield of allulose crystals is achieved, a portion of the whitening (e.g., about 1 / 4 to 3 / 4) is removed from the container, while the remaining whitening portion is retained in the container to serve as a seed crystal source for subsequent batches of whitening. In this manner, multiple batches of whitening can be produced.

[0131] 12. The white (one or more) portions removed from the container may be subjected to one or more desired processing steps, such as separating the allulose crystals from the mother liquor by one or more physical separation methods selected from the group consisting of centrifugation, filtration, decantation, membrane separation, and combinations thereof, and then washing and / or drying the separated allulose crystals.

[0132] In another embodiment of the present invention, crystallization can be carried out in a sequential manner comprising multiple steps (e.g., 3 or 4 steps). Such a process is shown schematically in Figure 1 and may be carried out using a system further described in more detail below.

[0133] Allulose syrup of appropriate purity is introduced into evaporator 2 via line 1, where the dry solids content of the syrup is increased to a desired level. The allulose syrup is then pumped via line 4 (using pump 3) into allulose syrup feed tank 5. From tank 5, the allulose syrup is pumped via line 7 (using pump 6) into heat exchanger 8, where the temperature of the allulose syrup is adjusted to a desired value before being supplied to mix tank 10 via line 9. In mix tank 10, the allulose syrup is compounded vigorously with white powder from crystallization region 22, which is supplied to mix tank 10 via line 25. The mixture of allulose syrup and white powder (which serves as a source of seed crystals) is discharged from mix tank 10 and introduced into crystallization region 12. Crystallization region 12 may be located inside a suitable tank or other container equipped with a stirrer. Any type of agitator known in the art may be used; in particular, the agitator may be any type of mechanical device recognized as useful for stirring the solution / seed crystal mixture that may be used in the crystallization process. In one embodiment, the agitator in the crystallization region can induce its stirring effect horizontally but not vertically. It may be preferable that the stirring proceeds at a low speed to prevent or reduce turbulence and crystal breakage / fragmentation that may occur during crystallization. The agitator may be arranged and operated to prevent allulose crystals from adhering to the walls and / or bottom of the (one or more) containers constituting the crystallization region 12. According to one aspect of the present invention, the allulose syrup and white mixture do not undergo concentration in the crystallization region 12. The allulose syrup / white mixture can be moved through the crystallization region 12 in a plug-flow manner, in which case the tip speed of the agitator is appropriately adjusted to promote the crystallization of allulose dissolved in the liquid-phase mixture and to produce allulose crystals of the desired size and shape. In one embodiment, the process parameters are controlled so that the allulose syrup / white mixture flows in a descending continuous flow through a container containing a crystallization region 12.The flow rate of the admixture passing through the crystallization region 12 and the resulting residence time of the admixture in the crystallization region 12 are controlled so that the admixture leaving the crystallization region 12 via line 14 has a desired content of allulose crystals (i.e., the desired yield of allulose crystals is achieved by the time the admixture is discharged from the crystallization region 12). In one embodiment, the temperature of the allulose syrup / white admixture is kept constant or essentially constant as the admixture passes through the crystallization region 12. For example, the temperature of the admixture can be controlled so that the temperature of the admixture at the time it is introduced into the crystallization region 12 differs from the temperature of the admixture at the time it leaves or is discharged from the crystallization region 12 by less than 5°C, less than 4°C, less than 3°C, less than 2°C, or less than 1°C.

[0134] The white substrate obtained from the crystallization region 12 is further cooled to a desired temperature using a heat exchanger 15 (for example, about 1°C to about 10°C lower than the temperature at which the white substrate leaves the crystallization region 12) and introduced into the crystallization region 17 via line 16. According to one embodiment of the present invention, the white substrate obtained from the crystallization region 12 is not concentrated before or after being introduced into the crystallization region 17. The crystallization region 17 may be located inside a suitable tank or other container equipped with a stirrer. The white substrate can be moved through the crystallization region 17 in a plug-flow manner, in which case the tip speed of the stirrer is appropriately adjusted to promote the crystallization of allulose still dissolved in the liquid phase (mother liquor) of the white substrate. The flow rate of the admixture passing through the crystallization region 17 and the resulting residence time of the admixture within the crystallization region 17 are controlled so that the admixture leaving the crystallization region 17 via line 18 has a desired content of allulose crystals (i.e., the desired yield of allulose crystals is achieved by the time the admixture is discharged from the crystallization region 17), but the desired content of allulose crystals is higher than the content of the white substance discharged from the crystallization region 12. According to one embodiment of the present invention, the white substance in the crystallization region 17 does not undergo concentration.

[0135] The white substrate obtained from the crystallization region 17 is further cooled to a desired temperature using a heat exchanger 20 (for example, about 1°C to about 10°C lower than the temperature at which the white substrate leaves the crystallization region 17) and introduced into the crystallization region 22 via line 21. According to one embodiment of the present invention, the white substrate obtained from the crystallization region 17 is not concentrated before or after being introduced into the crystallization region 22. The crystallization region 22 may be located inside a suitable tank or other container equipped with a stirrer. The white substrate can be moved through the crystallization region 22 in a plug-flow manner, in which case the tip speed of the stirrer is appropriately adjusted to promote the crystallization of allulose still dissolved in the liquid phase (mother liquor) of the white substrate. The flow rate of the admixture passing through the crystallization region 22 and the resulting residence time of the admixture within the crystallization region 22 are controlled so that the admixture leaving the crystallization region 22 via line 23 has a desired content of allulose crystals (i.e., the desired yield of allulose crystals is achieved by the time the admixture is discharged from the crystallization region 22), but the desired content of allulose crystals is higher than the content of the white substance discharged from the crystallization region 17. The white substance within the crystallization region 22 does not undergo concentration according to one embodiment of the present invention.

[0136] If so desired, one or more further crystallization regions (not shown) can be introduced, operating in a manner similar to that of crystallization regions 12, 17, and 22, in which the white substrate detaches from crystallization region 22 and undergoes further cooling and crystallization. According to a particular embodiment of the present invention, such further processes are carried out without any concentration of the white substrate.

[0137] Once a white liquor with the desired final target yield of allulose crystals is produced, a portion of it can be recycled and used as a source of seed crystals as described above (transported to the mix tank 10 via line 25), and the remaining portion can pass through the heat exchanger 27 and be supplied to the white liquor storage tank 29 via line 28. From the white liquor storage tank 29, the white liquor can be separated from the mother liquor using centrifugation 30, and the resulting cake of allulose crystals is washed before being dried in a rotary dryer 31.

[0138] In another embodiment of the present invention shown in Figure 2, crystallization of allulose from feed syrup may be carried out in an evaporator 102 equipped with a vacuum device 106, in contact with a suitable heat transfer medium 104. The vacuum device 106 may be configured and arranged to reduce the pressure relative to the feed syrup. The evaporator 102 may be constructed or arranged to heat or cool the feed syrup, either alone or in combination with the vacuum device 106, to reduce the liquid content in the feed syrup and thereby increase the solid content in the feed syrup. The evaporator 102 may also be configured or arranged to receive seed crystals. According to one embodiment, the evaporator 102 may be fluidly coupled to a crystallization apparatus unit 110, as shown in Figure 2. According to another embodiment, the crystallization apparatus unit 110 may be a separate unit. According to another embodiment, a valve and / or pump 112 may be inserted between the evaporator 106 and the crystallization apparatus unit 110, as shown in Figure 2. The crystallization apparatus unit 110 may be configured and arranged to cool the white substrate. According to several embodiments, the crystallization apparatus unit 116 may be a batch unit or a continuous crystallization apparatus. The crystallization apparatus unit 110 may be equipped with a stirrer. Any type of stirrer known in the art may be used; in particular, the stirrer may be any type of mechanical device recognized as useful for stirring the solution / seed crystal mixture in the crystallization process. In one embodiment, the stirrer of the crystallization unit 110 may provide its stirring effect horizontally rather than vertically. To prevent or reduce turbulence and the fracture / breakage of crystals formed during crystallization, stirring may preferably be performed at a low speed. The stirrer may be configured and operated to prevent allulose crystals from adhering to the (one or more) walls and / or bottom of the vessel causing crystallization. As shown in Figure 2, the crystallization apparatus unit 110 may be fluidly coupled to a centrifuge 116, or the centrifuge 116 may be a separate unit. The centrifuge 114 shown in Figure 2 may be coupled to a dryer 118. The centrifuge 116 (118) may be configured and arranged to separate the mother liquor bulk and allulose crystals in the white substrate.According to one embodiment, the allulose crystals may be washed before being sent to the dryer 118. According to one embodiment, the dryer 118 may be a separate unit. In some embodiments, the dryer 118 is configured and arranged to remove moisture from the allulose crystals. For example, the dryer may be a rotary dryer.

[0139] The following series of steps can be performed in the apparatus shown in Figure 2: 1. Fill the evaporator 102 with a suitable feed allulose syrup. 2. Set the temperature of the heat transfer medium 104 to the desired initial temperature. This temperature may be 35°C to 55°C or 45°C to 50°C. 3. Set the vacuum device 106 of the evaporator 102 to the desired level. Thus, the pressure in the evaporator 102 is below atmospheric pressure. 4. During the distillation process, when the syrup in the evaporator reaches the desired dry solids weight %, a desired amount of crystalline allulose is seeded into the evaporator 102. The amount of seed crystals can be 0.0001% by weight to a maximum of 5% by weight based on the weight of the syrup in the evaporator unit. According to some embodiments, the amount of seed crystals is based on the weight of the syrup in the evaporator unit 102 It may be 0.0001 to 5% by weight, 0.05 to 0.5% by weight, or 0.2 to 1.2% by weight.

[0140] 5. Distillation in the evaporator 102 is continued until a white base is formed, where a desired weight percentage of the crystal content in the white base is achieved in the evaporator. The white base contains the mother liquor and allulose crystals. The mother liquor may be supersaturated. According to some embodiments, the mother liquor may be 1.01, 1.02, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, or 1.5 supersaturated. According to some embodiments, the amount of crystals may be 20-90% by weight, 40-80% by weight, 50-75% by weight, or 60-70% by weight of the white base in the evaporator 102.

[0141] 6. Optionally, the temperature of the mother liquor in the evaporator 102 may be lowered to increase the supersaturation of the mother liquor, and this lower temperature may be maintained for a desired time to further complete crystallization and obtain additional crystal yields. In some embodiments, the temperature may be lowered by 2, 5, 10, 15°C or 20°C from the initial temperature. According to some embodiments, the supersaturation of the mother liquor may be 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, or 1.5 supersaturation. 7. Next, the white substrate can be dropped into, pumped into, or transferred to the cooling crystallization unit 110 (by opening or using the valve and / or pump 112). 8. The cooling crystallization apparatus unit 110 may be in batch or continuous configuration.

[0142] 9. The temperature of the coolant 114 in the cooling crystallization apparatus unit 110 is set to a desired initial temperature. According to some embodiments, this initial temperature may be the same as or lower than the initial or cooling temperature of the evaporator 102. According to some embodiments, the temperature of the white substrate in the crystallization apparatus unit 110 may vary depending on, for example, the concentration of allulose in the syrup, but is typically about 40°C or less and about 0°C or more. According to some embodiments, the temperature of the white substrate in the crystallization apparatus unit 110 may be 15°C or more, or 10°C or more.

[0143] 10. The stirrer of the cooling crystallization apparatus unit 110 is started and set to an RPM effective in providing the desired tip velocity. According to some embodiments, the tip velocity may be 0.2 to 2 m / s. 11. The temperature of the white substrate in the crystallization apparatus unit 110 is lowered to a desired temperature by appropriately changing the temperature of the coolant 114. This white substrate temperature varies depending on, for example, the concentration of allulose in the mother liquor of the white substrate, but is typically about 40°C or less and about 0°C or more. According to some embodiments, the white substrate temperature may be 10°C to 35°C or 20°C to 30°C.

[0144] 12. Crystallization may be continued with a suitable degree of stirring until the desired yield of allulose crystals is achieved. The yield can be confirmed by periodically withdrawing a sample from the crystallization unit 110 and measuring the dry solid content of the mother liquor. 13. To achieve the desired yield of allulose crystals, the temperature of the white substrate in the crystallization apparatus unit 110 may be continuously lowered or in one or more stages.

[0145] 14. Once the desired yield of allulose crystals is achieved, the white substrate may be subjected to one or more desired processing steps, such as separating the allulose crystals from the mother liquor by one or more physical separation methods, such as centrifugation, filtration, decantation, membrane separation, or a combination thereof, and then washing and / or drying the separated allulose crystals. As shown in Figure 2, the white substrate in the crystallization apparatus unit 110 can be separated into allulose crystals and mother liquor using a centrifuge 116. The allulose crystals may be washed in the centrifuge 116 or in a separate unit. The allulose crystals from the centrifuge 116 are then sent to a dryer 118, where any remaining moisture is removed.

[0146] Therefore, a method for producing allulose crystals is provided by one embodiment. The method includes the following steps.

[0147] The first step is to distill off the feed allulose syrup at a first near-atmospheric pressure and a first temperature to produce a first supersaturated allulose syrup having a target allulose syrup saturation. According to some embodiments, the feed syrup may already be supersaturated, thereby helping this step to further saturate the allulose syrup. The concentration of allulose in the supersaturated syrup can conveniently be measured by measuring the refractive index. Next, seed crystals are introduced into the first supersaturated allulose syrup to crystallize allulose and produce a first white liquor containing allulose crystals and a first supersaturated mother liquor having a first target mother liquor saturation. This target mother liquor saturation is higher than the target allulose syrup saturation. The first white liquor is distilled off at a first near-atmospheric pressure and a first temperature to produce a second white liquor containing allulose crystals and a second supersaturated mother liquor having a second target mother liquor saturation lower than the first target mother liquor saturation. The pressure is increased from the first near-atmospheric pressure to the second near-atmospheric pressure, and the second whitening is cooled to the second temperature to produce the third whitening containing allulose crystals and a third supersaturated mother liquor having the third target saturation. At this point, the second whitening is held at the second near-atmospheric pressure and the second temperature for a certain period of time to produce the third whitening containing allulose crystals and a third mother liquor having the third target saturation. This period may be 10 to 1 hour, 2 hours, 3 hours, 4 hours, or up to 6 hours. Next, the vacuum device is released, and the pressure rises to atmospheric pressure. This third whitening is cooled to the third temperature at a constant cooling rate to produce the fourth whitening containing allulose crystals and a fourth supersaturated mother liquor having the fourth target saturation. The cooling rate may be 0.5°C / hour to 1.25°C / hour or 0.1°C / hour to 0.6°C / hour. Once the third temperature is reached, the fourth white liquor is crystallized over the crystallization time to produce a product white liquor containing product allulose crystals and product mother liquor in the target yield, wherein the product mother liquor has the target degree of supersaturation. The crystallization time may be 10 minutes to 1 hour, 2 hours, 3 hours, or 4 hours, or up to 6 hours, or as long as necessary to reach the target yield. Next, the product allulose crystals are separated from the product supersaturated mother liquor to provide allulose crystals in the target yield.

[0148] According to one embodiment, a vacuum evaporator may be used in the process of distilling the allulose syrup from an initial dry solids (%ds) content to a dry solids content suitable for sowing, sowing the syrup, and subsequently crystallizing the allulose to form a final crystalline allulose product. According to some embodiments, the feed syrup may be 70% to 72%ds. According to some embodiments, the feed syrup may be at least 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, or at least 80%ds of allulose. According to some embodiments, the feed syrup may be at most 85, 84, 83, 82, 81, 80, 79, 78, 77, 76, 75, 74, 73, 72, 71, or at most 70%ds by weight of allulose. According to some embodiments, the feed syrup may be 65-80, 65-75, or 68-74%ds by weight of allulose. According to one embodiment, the %ds of allulose may be 83.5-86%ds when sowing is performed. When it is sowed, the weight %ds of allulose in the syrup may be at least 80, 81, 82, 86, 84, 85, 86, 87, 88, 89, 90, 91, 92, or 93.5%ds by weight. When it is sowed, the weight %ds of the syrup may be at most 95, 94, 93, 92, 91, 90, 89, 88, 87, 86, 85, or 84%ds by weight of allulose. The weight %ds of allulose in syrup can be 75–95, 80–90, 82–88, or 82–87 weight %ds of allulose in syrup when it is sown.

[0149] Generally speaking, high allulose crystal concentrations tend to result in high viscosity and, consequently, a whitening that can complicate further processing. Therefore, it is preferable to control the crystallization conditions so that the final whitening (i.e., the whitening from which allulose crystals are recovered, including separation from the mother liquor components of the whitening) does not have an excessively high allulose crystal content. Accordingly, in various embodiments of the present invention, the allulose crystal yield in the final whitening is 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, 65% or less, 60% or less, 55% or less, 50% or less, or 45% or less. At the same time, it is preferable that the allulose crystal yield achieved in the final whitening is sufficiently high in order to reduce manufacturing costs. Accordingly, in various embodiments, the allulose crystal yield in the final whitening is at least 20%, at least 25%, at least 30%, at least 35%, or at least 40%.

[0150] The mother liquor (one or more) separated from allulose crystals according to various embodiments of the present invention can be further processed and / or used in different ways. For example, the mother liquor recovered from the separation step can be used to manufacture consumer products or can be used directly (e.g., in solution or syrup form) as an allulose source in dosage formulation. If so desired, the mother liquor can undergo one or more processing steps, such as concentration (distillation) and / or treatment to remove impurities (using an adsorbent or similar). In yet another embodiment, the recovered mother liquor can be recycled back into the type of crystallization process described herein and thus act as a (whole or partial) source of allulose syrup starting material. Prior to such recycling, the mother liquor can undergo one or more processing steps, such as concentration and / or purification.

[0151] According to one embodiment, a method for producing allulose crystals is provided. The method includes the following steps. a) A step of producing a first supersaturated allulose syrup having a target allulose syrup saturation by distilling off the feed allulose syrup at a first near-atmospheric pressure and a first temperature. b) A step of introducing seed crystals into a first supersaturated allulose syrup and crystallizing allulose at a constant crystallization rate to produce a first white liquor containing allulose crystals and a first supersaturated mother liquor having a first target mother liquor saturation higher than the target saturation of the allulose syrup. c) A step of producing a second white base by distilling off the first white base at a first near-atmospheric pressure and a second temperature lower than the first temperature, thereby producing an allulose crystal and a second supersaturated mother liquor having a second mother liquor target saturation lower than the first mother liquor target saturation. d) A step of producing a third white base containing allulose crystals and a third supersaturated mother liquor having a third target mother liquor saturation. e) A step of crystallizing a third white base over a crystallization time to produce a product white base containing product allulose crystals and product mother liquor in a target yield, wherein the product mother liquor has a target degree of product mother liquor supersaturation. f) A step of separating the product allulose crystals from the product supersaturated mother liquor to provide allulose crystals in a target yield.

[0152] According to one embodiment, a vacuum evaporator may be used in the process to carry out steps a) to c). At that point, the second matrix, containing allulose crystals and a second supersaturated mother liquor having a second mother liquor target saturation lower than the first mother liquor target saturation, is transferred to a crystallizer to complete the crystallization process at atmospheric pressure, achieving a yield of at least 40%. The overall yield may be 40-85%, 40-80%, 45-70%, 45-65%, 50-75%, or 50-85%. Steps a) and c) may take 1-5 hours to achieve an intermediate yield of 10-15% at the end of step c). The remaining steps d)-f) may then take 15-40 hours to achieve an overall final yield of 40-85%. This results in significant time savings compared to other allulose crystallization processes. According to some embodiments, the conditions (temperature and pressure) in step c) are selected to achieve a crystallization rate of 1-5%, 1-4%, 1-3%, 2-5%, 2-4%, or 2-3% yield per hour. These conditions may be temperatures of 25-50°C, 25-45°C, 25-40°C, 30-50°C, 30-45°C, 30-40°C, 35-50°C, 35-45°C, or 30-40°C.

[0153] According to some embodiments, the feed syrup may be 70% to 72% ds. According to some embodiments, the feed syrup may be at least 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, or at least 80% ds of allulose. According to some embodiments, the feed syrup may be at most 85, 84, 83, 82, 81, 80, 79, 78, 77, 76, 75, 74, 73, 72, 71, or at most 70% ds by weight of allulose. According to some embodiments, the feed syrup may be 65 to 80, 65 to 75, or 68 to 74% ds by weight of allulose. According to one embodiment, the % ds of allulose may be 83.5% to 86% ds when sowing is performed. When it is sown, the weight %ds of allulose in the syrup may be at least 80, 81, 82, 86, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93.5 weight %ds. When it is sown, the weight %ds of allulose in the syrup may be at most 95, 94, 93, 92, 91, 90, 89, 88, 87, 86, 85, 84 weight %ds. The weight %ds of allulose in the syrup may be 75-95, 80-90, 82-88, or 82-87 weight %ds of allulose in the syrup when it is sown.

[0154] According to some embodiments, the first target mother liquor may be saturated to 1.10–1.35 when measured by refractive index. According to some embodiments, the first target mother liquor may be at least 1.10, 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.18, 1.20, 1.21, 1.22, 1.23, 1.24, 1.25, 1.26, 1.27, 1.28, or at least 1.29 when measured by refractive index. According to some embodiments, the first target mother liquor, when measured by refractive index, may be at most 1.35, 1.34, 1.33, 1.32, 1.31, 1.30, 1.29, 1.28, 1.27, 1.26, 1.25, 1.24, 1.23, 1.22, 1.21, 1.20, 1.19, 1.18, 1.17, 1.16, or at most 1.15.

[0155] According to one embodiment, the target allulose syrup saturation may be 1.05 to 1.20. When measured by refractive index, the target allulose syrup saturation may be at least 1.05, 1.06, 1.07, 1.08, 1.09, 1.10, 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, or at least 1.19. According to one embodiment, when measured by refractive index, the target allulose syrup saturation may be at most 1.20, 1.19, 1.18, 1.17, 1.16, 1.15, 1.14, 1.13, 1.12, 1.11, 1.10, 1.09, 1.08, 1.07, or at most 1.06. According to one embodiment, the supersaturated allulose syrup may have a total dry solids content of 78% to 90% by weight. As previously stated, this is the dry solids content based on the weight of the supersaturated allulose syrup when seed allulose crystals are added. According to one embodiment, the supersaturated allulose syrup may have a total dry solids content of at least 78, 78.5, 79, 79.5, 80, 80.5, 81, 81.5, 82, 82.5, 83, 83.5, 84, 84.5, 85, 85.5, 86, 86.5, 87, 87.5, 88, 88.5, or at least 89% by weight of the supersaturated allulose syrup. According to one embodiment, the supersaturated allulose syrup may have a total dry solid content of at most 90, 89.5, 89, 88.5, 88, 87.5, 87, 86.5, 86, 85.5, 85, 84.5, 84, 83.5, 83, 82.5, 82, 81.5, 81, 80.5, 80, 79.5, or at most 79% by weight.

[0156] As mentioned earlier, according to one embodiment, the overall target yield is 40% or more. According to several embodiments, the overall yield may be at least 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, or at least 85%. According to some embodiments, the overall yield may be up to 100%, or up to 99%, 98%, 97%, 96%, 95%, 94%, 93%, 92%, 91%, 90%, 89%, 88%, 87%, 86%, 85%, 84%, 83%, 82%, 81%, 79%, 78, 77, 76, 75%, 74%, 73%, 72%, 71%, 70%, 69%, 68, 67, 66%, or up to 65%. As mentioned earlier, the yield of allulose crystals in step c) may be 5–20% by weight. The yield of allulose crystals in step c) may be 5–15% by weight, 5–10% by weight, 10–20% by weight, 15–20% by weight, or 10–15% by weight. As mentioned earlier, the crystallization rate of allulose in step c) may be 1-5 wt%, 1-7 wt%, 1-3 wt%, or 1-2 wt% per hour. The crystallization time in step c) may be 1-7 hours, 1-5 hours, 1-3 hours, 1-2 hours, 2-5 hours, 2-7 hours, 2-3 hours, 2-5 hours, 3-7 hours, or 3-5 hours. The crystallization time in step e) may be 15-40 hours. The crystallization time in step e) may be 20-40, 25-35, or 28-32 hours. In this process, there may be no waiting time between step c) and step d), that is, the white powder in step c) crystallizes immediately at atmospheric pressure. The crystallization time in step e) may be at least 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 3, 0, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, or at least 48 hours.The crystallization time in step e) may be at most 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, or at most 20 hours.

[0157] As mentioned earlier, the conditions in step c) can be selected to provide a constant crystallization rate. These conditions may be a pressure of 25–55 millibars and a temperature of 25–50°C. The pressure in step c) may be at least 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, or at least 54 millibars. The pressure in step c) may be at most 55, 54, 53, 52, 5150, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, or at most 26 millibars. The temperature in step c), i.e., the second temperature, may be at least 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, or at least 48°C. The temperature in step c) may be at most 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, or at most 26°C.

[0158] According to some embodiments, feed allulose syrup may have a total dry solid content of 50% to 80% by weight. According to some embodiments, the allulose in feed allulose syrup is at least 80% pure by weight on a dry solid basis. According to some embodiments, the pH of feed allulose syrup is 2.5 to 6.0. According to some embodiments, feed allulose syrup may be at least 95% pure by weight on a dry solid basis. According to some embodiments, feed allulose syrup may be at least 98% pure by weight on a dry solid basis. According to some embodiments, seed crystals may be contained in feed allulose syrup at a concentration of 0.0001% to 5% by weight. For example, seed crystals may be added in amounts of at least 0.0001%, 0.0003, 0.0005, 0.001, 0.003, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, or at least 5 wt% by weight of feed allulose syrup. Seed crystals may be added in amounts of at most 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5, 1, 0.5, 0.1, 0.05, 0.01, 0.005, 0.003, 0.001, 0.0005, or at most 0.0003 wt% by weight of feed allulose syrup. According to some embodiments, seed crystals may have an average particle size of 75 microns (μm) or less. According to some embodiments, the seed crystal may have an average grain size of 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, or 10 microns (μm) or less, based on volume measured by laser diffraction. According to some embodiments, the average grain size of the seed crystal may be 1 micron (μm) or more, or 2, 3, 4, 5, 6, 7, 8, 9, or 10 microns (μm) or more, but may be 30, 25, 20, or 15 microns (μm) or less, based on volume measured by laser diffraction. According to some embodiments, the seed crystal may have an average grain size of 5 to 250 microns (μm).

[0159] Arlos seed crystal Therefore, the present invention employs allulose seed crystals to assist in promoting the initiation of further allulose crystallization from a solution (e.g., in the form of allulose-containing solid crystals previously present in solution in allulose syrup, mother liquor, or similar). In certain embodiments, the allulose seed crystals exist in a dry form (e.g., dry crystals of allulose recovered from previously performed crystallization) and / or in the form of a heel, such as a portion of the white base consisting of allulose crystals and mother liquor. The amount of allulose seed may be, for example, an amount accounting for about 0.0001 to about 5% of the total amount of allulose present in the crystallization vessel or crystallization region, which will be described in more detail below. Generally speaking, it is preferable to use allulose seed crystals of relatively high purity; for example, in various embodiments of the present invention, allulose seed crystals can have an allulose purity of at least 90%, at least 95%, or at least 99% by weight. The term "allulose purity" as used herein for allulose crystals means the weight percentage of allulose in the crystal based on the total weight of the dry solid in the crystal.

[0160] According to some embodiments, the seed crystal may have an average grain size of 75 microns (μm) or less. For example, the seed crystal may have an average grain size of 1 to 250 microns (μm), or 1 to 75 microns (μm). The average grain size can be measured by laser diffraction, i.e., laser light scattering.

[0161] According to some embodiments, the seed crystal may exist in a dry form and, when measured by laser diffraction, may have an average particle size of 75 microns (μm) or less. According to some embodiments, the seed crystal may have an average particle size of 5 to 250 microns (μm). For example, the seed crystal may have an average particle size of at least 0.1, 0.5, 1, 1.5, 2, 2.5, 5, 25, 50, 75, 100, 125, 150, 175, or at least 250 microns (μm). The particle size distribution of the seed crystal may have an effect on the efficiency of crystallization and on the size of the final dried allulose product. According to some embodiments, the seed crystal may have an average grain size of at most 250, 200, 175, 150, 125, 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 10, or at most 5 microns (μm) on a volume basis as measured by laser diffraction. The average grain size of the seed crystal may be 5-75 μm, 5-60, 5-50, 5-40, 5-30, 5-25, 5-20, or 5-15 microns (μm). The median grain size (d50) of the seed crystal, when measured on a volume basis by laser light scattering, may be 5-75 μm, 5-60, 5-50, 5-40, 5-30, 5-25, 5-20, or 5-15 microns (μm). The d10 of the seed crystal can range from 0.01 to 25 microns (μm) on a volume basis, as measured by laser light scattering. The d10 of the seed crystal, as measured by laser light scattering on a volume basis, can range from 0.01 to 20, 0.05 to 15, 0.1 to 10, 0.5 to 5, and 0.5 to 5 microns (μm). The d90 of the seed crystal, as measured by laser light scattering on a volume basis, can range from 5 to 100 microns (μm). The d90 of the seed crystal, as measured by laser light scattering on a volume basis, can range from 5 to 90, 5 to 80, 5 to 75, 10 to 70, 10 to 65, 10 to 50, 15 to 50, 15 to 45, and 20 to 40 microns (μm).

[0162] As previously stated, according to some embodiments of the present invention, seed crystals may be added when increasing the dry solid content, expressed as weight percent dry solid (%ds) in the feed syrup, to 83.5% to 86%ds. For example, when seed crystals are added, the %ds of the syrup may be 75 to 90%ds. When feed crystals are added, the %ds of the syrup may be at least 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, and 90%ds. When feed crystals are added, the %ds of the syrup may be at most 95, 94, 93, 92, 91, 90, 89, 88, and 87%ds.

[0163] According to some embodiments, the first temperature may be 30 to 70°C. For example, the first temperature may be at least 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, or at least 67°C. According to some embodiments, the first temperature may be at most 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60, 59, 58, 57, 56, 55, 54, 53, 52, 51, 50, 79, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, or at most 32°C.

[0164] According to some embodiments, the first target mother liquor saturation may be 1.10 to 1.15. When the first target mother liquor saturation is measured by refractive index, it may be at least 1.10, 1.11, 1.12, 1.13, or at least 1.14. When the first target mother liquor saturation is measured by refractive index, it may be at most 1.15, 1.14, 1.13, 1.12, or at most 1.11. According to some embodiments, the first supersaturated mother liquor may contain 85 to 90 wt% allulose on a dry solid basis. The first supersaturated mother liquor may contain at least 85, 86, 87, 88, or at least 89 wt% allulose on a dry solid basis. The first supersaturated mother liquor may contain at most 90, 89, 88, 87, or at most 85 wt% allulose on a dry weight basis.

[0165] According to some embodiments, the third temperature, i.e., the temperature of steps d) and / or e) for cooling the crystallization, can be 10 to 50°C. The third temperature can be at least 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, or at least 50°C. The third temperature may be at most 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, or at most 10°C. According to some embodiments, the temperature in steps d) and / or e) may be lowered over a period of 5 to 50 hours until the final yield is achieved. For example, the temperature during step d) and / or e) may be lowered for at least 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 40, 41, 42, 43, 44, 45, 46, 47, or at least 48 hours. The temperature in steps d) and / or e) may be lowered over a period of at most 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 34, 30, 28, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, or at most 7 hours. The temperature reduction may be carried out regularly or as one or more step changes to the temperature control medium. Therefore, it must be understood that the temperature in steps d) and / or e) starts at a higher temperature and is then lowered to a lower temperature to act on further crystallization beyond the crystallization in step c).

[0166] According to one embodiment, the second target mother liquor saturation may be 1.05 or less supersaturated. According to several embodiments, the second target mother liquor saturation may be 1.4, 1.35, 1.3, 1.25, 1.2, 1.15, 1.1 or less. According to several embodiments, the second supersaturated mother liquor may contain 80-95 wt% allulose on a dry solid basis. The second supersaturated mother liquor may contain at least 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, or at least 93 wt% allulose on a dry solid basis. The second supersaturated mother liquor may contain at most 94, 93, 92, 91, 90, 89, 88, 87, 86, 85, 84, 83, or at most 82 wt% allulose on a dry weight basis.

[0167] According to some embodiments, the third target mother liquor saturation may be 1.05 to 1.2 supersaturated. The third target mother liquor saturation may be at least 1.06, 1.07, 1.08, 1.09, 1.1, 1.00, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, or at least 1.18 supersaturated. The third target mother liquor saturation may be at most 1.19, 1.18, 1.17, 1.16, 1.15, 1.14, 1.13, 1.12, 1.11, 1.10, 1.09, 1.08, or at most 1.07 supersaturated.

[0168] According to some embodiments, separation can be carried out at least in part by one or more physical separation methods selected from the group consisting of centrifugation, filtration, decantation, membrane separation, and combinations thereof. According to some embodiments, allulose crystals separated from the final mother liquor can be subjected to the following steps: i) washing with at least one of water, an organic solvent, a blend of organic solvents, a blend of water and (one or more) organic solvents, or an aqueous solution consisting of at least one carbohydrate; ii) drying; or a combination thereof.

[0169] Allulose crystals obtained by the methods disclosed herein are also provided. Consumer products consisting of or prepared using allulose crystals and at least one additional component other than allulose crystals, prepared by any of the methods disclosed herein, are also provided.

[0170] A method for producing a consumer product is also provided, the method comprising the step of using allulose crystals prepared by any of the methods disclosed herein. A mother liquor is also provided, which is a product mother liquor obtained by any of the methods disclosed herein. The mother liquor may be suitable for use as a product consumable by humans or animals, or as a component in a dosage form product consumable by humans or animals.

[0171] Further processing of allulose crystals In various embodiments of the present invention, any method disclosed herein may include one or more further steps, wherein the allulose crystals present in the white base undergo further processing after separation from the mother liquor portion of the white base by centrifugation, filtration, decantation, membrane separation, or other such physical separation methods. For example, allulose crystals separated from the mother liquor generally have some mother liquor on the outer surface of the crystals. Since the mother liquor generally contains some impurities (substances other than allulose), the purity of the recovered crystals can be improved by performing one or more washing steps in which the separated allulose crystals are washed using one or more volumes of a suitable liquid. The washing steps (one or more) can be performed in any suitable manner using techniques known in the art, such as passing the washing liquid through a bed of allulose crystals, or slurring the separated allulose crystals with a predetermined volume of washing liquid, and then performing physical separation steps such as centrifugation, decantation, membrane separation, and / or filtration to recover the washed allulose crystals from the washing liquid. Any suitable washing solution may be used, such as an aqueous solution consisting of water, an organic solvent (e.g., alcohol such as ethanol), a blend of water and one or more organic solvents, a blend of two or more organic solvents, and / or at least one carbohydrate (e.g., allulose). In one embodiment, the allulose crystals are washed with allulose syrup or even a recovered mother liquor having a higher purity (relative to allulose) than the purity of the residual mother liquor initially present in the crystals being washed.

[0172] The allulose crystals separated from the mother liquor can be subjected to a drying step to reduce the water content of the crystals. The drying step can be carried out, for example, after a washing step or a series of washing steps. Drying of the crystals can be carried out in a fluidized bed dryer, rotary dryer, vacuum dryer or other such apparatus. For example, in the drying step, the allulose crystals can be dried for about 20 minutes to about 24 hours, more preferably about 20 minutes to about 6 hours, using an air temperature not exceeding a maximum of about 100°C, preferably 80°C.

[0173] Compared to conventionally known allulose crystallization processes, this invention allows for the production of relatively large, dry, free-flowing allulose crystals at a lower manufacturing cost (with better equipment utilization). Such larger crystals have a better appearance than smaller allulose crystals that appear powdery and cottony. Larger crystals have fewer fine particles, which ultimately reduces dusting. While fine particles (i.e., smaller crystals) can fill the spaces between larger crystals, this likely leads to solidification problems as well as poor flow properties. Furthermore, smaller allulose crystals have a larger surface area compared to larger crystals; this results in faster moisture absorption, which can also contribute to solidification. The types of dry, free-flowing allulose crystals that can be economically produced using this invention do not require special handling equipment and can be handled by customers (e.g., food manufacturers).

[0174] The process according to the present invention can produce allulose crystal products having an average particle size of, for example, at least 100 microns (μm), at least 150 microns (μm), at least 200 microns (μm), or at least 250 microns (μm), or larger (e.g., 250-350 microns (μm)) in various embodiments of the present invention. The average particle size can be determined using a laser diffraction particle size analyzer, such as the LS 13 320 model manufactured by Beckman Coulter. According to a particular aspect of the present invention, less than 25% of the obtained allulose crystal products have a size less than 75 microns (μm). According to some embodiments, the average particle size is at least 275 microns (μm), at least 300 microns (μm), at least 325 microns (μm), at least 350 microns (μm), at least 375 microns (μm), at least 400 microns (μm), at least 425 microns (μm), at least 450 microns (μm), at least 475 microns (μm), or up to 500 microns (μm). According to some embodiments, the average crystal size of allulose particles produced by any method of the present disclosure may be 100-500 microns (μm), 150-450, 150-400, 150-350, 150-300, 150-250, or 200-250 microns (μm), as measured by laser diffraction. Based on volume measurement by laser diffraction, the d50 (median) particle size of the product crystalline allolose particles may be 50-250 microns (μm), 60-225 microns (μm), 70-200 microns (μm), 80-190q, 100-200 microns (μm), or 125-175 microns (μm). Based on volume measurement by laser diffraction, the d10 particle size of the product crystalline allolose particles may be 10-100 microns (μm), 15-90, 20-80, 25-75, 30-65, or 45-55 microns (μm).Based on volume measurements by laser diffraction, the d90 particle size of product crystalline allolose particles can range from 300 to 1000 microns (μm), 325 to 900, 325 to 800, 325 to 700, 325 to 600, 300 to 600, 300 to 550, and 400 to 500 microns (μm).

[0175] The present invention can be carried out to obtain allulose crystals having a preferred morphology having a clearly defined three-dimensional shape rather than the shape of needles or flat sheets. Figure 3 is a micrograph image of an allulose crystal having such a preferred morphology. The crystal may have triangular fragments.

[0176] Allulose crystals produced according to at least specific embodiments of the present invention may have a density of, for example, 30 lb / ft 3 Exceeding, more preferably 35 lb / ft 3 Having an excess bulk density can be advantageous. According to some embodiments, the bulk density is at least 20, 25, 30, 35, 40, 45, 50, 55 or at least 60 lb / ft 3 It is possible.

[0177] Uses of allulose crystals Allulose crystals produced by the method of the present invention can be used in products for human and / or animal consumption. Such applications are particularly beneficial for products with low moisture content. In some embodiments, the product may be a food, beverage product, pharmaceutical, nutritional product, sports product, or cosmetic. For example, if the product is a food, it can be selected from the group consisting of confectionery products (including chocolate products), dessert products, cereal products, baked goods, frozen dairy products (e.g., ice cream), meats, dairy products (e.g., yogurt), condiments, snack bars, energy bars, nutrition bars, soups, dressings, mixes, prepared foods, baby food, diet formulations, syrups, food coatings, dried fruits, sauces, gravies, and jams / jelly. In some embodiments, the food may contain allulose crystals produced by the method of the present invention in the form of a coating or frosting formed on the surface of the product. Alternatively, if the product is a beverage product, it can be selected from the group consisting of carbonated drinks, non-carbonated drinks, fruit-flavored drinks, fruit juices, tea, milk, coffee, etc. Foods containing allulose crystals produced according to the present invention can also be table sweeteners.

[0178] Allulose crystals produced in accordance with the present invention can be used in combination with one or more other food or beverage ingredients, including any food and beverage ingredients known in the art. Such further food and beverage ingredients are not limited to, but include, flavorings, colorings, etc. (Other carbohydrates such as sucrose, fructose, allose, tagatose and other rare carbohydrates, high-efficacy synthetic sweeteners such as sucralose, acesulfame K, saccharin, aspartame, stevia and monk fruit extract sweeteners and terpene glycosides present therein (e.g., rebaudioside A, rebaudioside B, rebaudioside C, rebaudioside D, rebaudioside E, rebaudioside F, rebaudioside G, rebaudioside H, rebaudioside I, rebaudioside J, rebaudioside K, rebaudioside L, rebaudioside M (also known as rebaudioside X), rebaudioside N, rebaudioside O, stevioside, steviol monoside, steviol bioside, z This product contains high-potency natural sweeteners such as steviol glycosides and mogrosides, including but not limited to combinations thereof, including Glucoside A, Glucoside B, Rubusoside, Glycosylated Steviol Glycosides, Enzyme-Modified Steviol Glycosides, Mogroside IIA, Mogroside IIB, 7-Oxomogroside IIE, 11-Oxomogroside A, Mogroside IIIA2, 11-Deoxymogroside III, 11-Oxomogroside IVA, 7-Oxomogroside V, 11-Oxomogroside V, Mogroside V, Mogroside VI and similar, as well as steviol glycosides and mogrosides; dietary fiber (including soluble dietary fiber such as soluble corn fiber and polydextrose); sweeteners other than allulose; acidulants; water; and so on. Allulose crystals may be mixed or blended with such other ingredients in a dried form. In other embodiments, the allulose crystals may be coated with one or more other components; for example, a solution containing one or more other components (such as a high-potency sweetener, a high-potency sweetener, and / or a combination of one or more other carbohydrates) may be applied to the allulose crystals by spraying or other such procedure and then dried.

[0179] While embodiments have been described herein in order to provide a clear and concise specification, it is intended and will be understood that embodiments can be combined and separated in various ways without departing from the present invention. For example, it will be understood that all preferred features described herein are applicable to all aspects of the present invention described herein. In some embodiments, the present invention described herein can be interpreted as excluding elements or process steps that do not substantially affect the basic and novel properties of the composition or process. Furthermore, in some embodiments, the present invention can be interpreted as excluding elements or process steps not expressly expressed herein. While the present invention has been illustrated and described herein with reference to specific embodiments, the present invention is not intended to be limited to the details shown. Rather, various modifications to the details can be made within the scope and range of equivalent claims without departing from the present invention. [Examples]

[0180] Example 1 Allulose syrup, Dolcia Prima® LS (Tate & Lyle), is introduced into an evaporator and can be distilled under reduced pressure at 100-120°F (37.8-48.9°C) until the dry solid content reaches 87-88%. During distillation, when the syrup saturates to approximately 1.13, i.e., when the syrup exceeds 100% saturation by 13%, the syrup can be seeded with ultrafinely ground crystalline allulose seeds. The particle size of the ground seeds may vary, but the preferred particle size distribution of the final product is an average particle size of 75 microns (μm) or less. The particle size of the seeds can vary from 5 microns (μm) to 250 microns (μm). The amount of ground seeds can range from a minimum of 0.0001% to a maximum of 5%. Distillation can be continued until the mother liquor saturates to 1.05 or less.

[0181] The temperature may be lowered, and the evaporator is suctioned into the vacuum device until the temperature falls below 10°F (6°C), and then held for approximately 1 to 4 hours until the mother liquor saturates again to below 1.05.

[0182] Crystalline white liquor can be dropped into a cooling crystallizer. The batch may be crystallized by cooling the white liquor to a saturation of 1.2-1.3, and it can be crystallized to a minimum saturation of 1.05-1.16. The cooling step can be repeated until a yield of 50-60% of allulose crystals is achieved, or until the white liquor becomes too concentrated to handle. For example, the white liquor may have a viscosity of about 40,000 cP at this point. The white liquor may have a viscosity of 80,000 cP or less at this point. At this point, the refractive index of the mother liquor may be 1.4695 or less.

[0183] The temperature and details of the allulose syrup during the above process, along with the wt% yield of allulose, can be shown as described in Table 1. The yield can be calculated as follows: (mass of crystallized allulose from syrup) / (mass of allulose in feed syrup) × 100

[0184] [Table 1]

[0185] Example 2 The crystallization unit 200 shown in Figure 4 was filled with 1 to 3 liters of allulose syrup. A water bath 204 was placed over the crystallizer 202. A vacuum was introduced through the port 206 on the lid 208 of the crystallizer 202. The entire container was tightly sealed to prevent any leakage. The crystallizer was equipped with a stirrer 210. Crystallization by distillation may be carried out in separate containers, and the resulting material may then be transferred to a cooling crystallizer similar to the glass crystallizer shown in Figure 4, but without a vacuum.

[0186] Preparation for sowing: The feed syrup contained 70-72% allulose (dry solid content by weight of feed syrup). The feed syrup was distilled off in a crystallizer to 83.5-86% allulose, and then seeding was performed. This was done by heating the crystallizer to 50°C-57°C and maintaining a vacuum of 30-50 mbar.

[0187] When the syrup was at the desired %ds, seed crystals were added at a concentration of 0.2% to 0.5 wt% based on the total weight of the syrup and seeds at the time of seed addition. The seeds were ground to the desired particle size range using a coffee grinder. The average particle size of the seeds was approximately 10 microns (μm).

[0188] The particle size distribution of species by volume was measured by laser light scattering and is shown in Figure 5. The data describing the particle size distribution is shown in microns (μm) in Table 2. d10, d50, and d90 are in μm units, depending on the volume.

[0189] [Table 2]

[0190] Sowing and crystallization: At the target seeding %ds, the water bath temperature was lowered so that the saturation of the bulk feed, measured by refractive index, was 1.05-1.2. At this point, the seeds were introduced into a vacuum crystallizer. On a commercial scale, the seeds are introduced into a vacuum chamber.

[0191] In the laboratory crystallizer, the vacuum was released to add seed crystals, and the seeds were introduced through a port on the lid. Upon introduction of the seeds, the stirrer RPM was increased to 50-70 RPM for 15 minutes to ensure that the seeds were thoroughly mixed during feeding. Once the seeds were sufficiently mixed, the stirrer RPM was reduced to 20-30 RPM. After introducing the seeds into the crystallizer, a vacuum of 30-50 mbar was reintroduced, and the temperature was maintained at 35-50°C.

[0192] The water bath temperature and vacuum were selected so that the water in the feed would continue to boil. Due to the boiling point elevation caused by allulose dissolved in the water, this was 10°C to 15°C higher than the boiling point of water at that vacuum level. There is a temperature limit due to the risk of allulose dissolution if the saturation level falls below 1. The white water was analyzed for %ds due to the refraction of the mother liquor over time, the distilled water was concentrated and weighed, the distillation rate was measured, and the water was weighed to complete the mass balance.

[0193] If the distillation of the white substrate appeared to be faster than the pressure release (i.e., crystallization slowed down or stopped, reaching a saturation point), the energy (water bath temperature) was reduced to delay the evaporation step. If the pressure release of the white substrate was faster than the distillation, the vacuum was further reduced to increase the distillation rate. Distillation was continued for 4-6 hours at a temperature and pressure effective for maintaining a constant crystallization rate, at which point a yield of approximately 10-25% was obtained from the crystallizer. The goal was to have a stable crystallization rate of approximately 1-5% per hour during this stage.

[0194] At this point, the vacuum was released, and the process was switched to cooling crystallization at atmospheric pressure. The temperature was started at 40°C and then lowered to 12-16°C over 45 hours. The white substrate was allowed to cool until a yield of 45-60% was obtained.

[0195] The viscosity of the final white substrate ranged from 40,000 cP to 80,000 cP. This may be measured using a Brookfield viscometer with a helipas motor and a B-92 T-bar spindle. The RPM can be adjusted to maintain torque on the unit spring within the range of 20–100%, but typically 50–60%. The RPM for most viscosity measurements was 10–20 RPM.

[0196] Microscopic images of allulose crystals obtained when crystallization was continued are shown in Figure 6, 1 hour after sowing, and in Figure 7, 4-5 hours after sowing. Figure 8 shows a microscopic image of the final crystallized allulose product.

[0197] Figure 9 shows the particle size distribution of the final white substrate before removal of the mother liquor. Statistical data on the particle size distribution are shown in Table 3 below. The particles ranged from 0.375 μm to 2000 μm. In Table 3, the statistical data is based on 100% volume.

[0198] [Table 3]

Claims

1. A method for producing allulose crystals, comprising the following steps: a) Distilling off the feed allulose syrup at a first near-atmospheric pressure and a first temperature to produce a first supersaturated allulose syrup having a target allulose syrup saturation; b) A step of introducing seed crystals into a first supersaturated allulose syrup to crystallize allulose and produce a first white liquor containing allulose crystals and a first supersaturated mother liquor having a first target mother liquor saturation higher than the target saturation of the allulose syrup; c) Distilling off the first white base at a first near-atmospheric pressure and a first temperature to produce a second white base containing allulose crystals and a second supersaturated mother liquor having a second target saturation lower than the first target saturation; d) A step of increasing the first near-atmospheric pressure to the second near-atmospheric pressure and cooling the second base to the second temperature to produce a third base containing allulose crystals and a third supersaturated mother liquor having a target saturation of the third mother liquor; e) A step of producing a third white base containing allulose crystals and a third mother liquor having a third target mother liquor saturation, by holding the second white base at a second near-atmospheric pressure and a second temperature for a certain period of time; f) A step of increasing the pressure to atmospheric pressure and cooling the third whitening agent to a third temperature at a constant cooling rate to produce a fourth whitening agent containing allulose crystals and a fourth supersaturated mother liquor having a fourth target mother liquor saturation; g) A step of crystallizing the fourth white base over a crystallization time to produce a product white base containing product allulose crystals and product mother liquor in a target yield, wherein the product mother liquor has a target product mother liquor supersaturation; and h) A step of separating the product allulose crystals from the product supersaturated mother liquor to provide allulose crystals in a target yield. The method, including the method described above.

2. The method according to claim 1, wherein the target yield is 40% or more.

3. The method according to claim 1, wherein the feed allulose syrup has a total dry solid content of 50% to 80% by weight.

4. The method according to claim 1, wherein the allulose in the feed allulose syrup is at least 80% pure by weight on a dry solid basis.

5. The method according to claim 1, wherein the pH of the feed allulose syrup is 2.5 to 6.

0.

6. The method according to claim 1, wherein the feed allulose syrup is at least 95% pure by weight on a dry solid basis.

7. The method according to claim 1, wherein the feed allulose syrup is at least 98% pure by weight on a dry solid basis.

8. The method according to claim 1, wherein the seed crystal is contained in an amount of 0.0001% to 5% by weight of feed allulose syrup.

9. The method according to claim 1, wherein the seed crystal has an average particle size of 75 microns (μm) or less.

10. The method according to claim 1, wherein the seed crystal has an average particle size of 5 to 250 microns (μm).

11. The method according to claim 1, wherein the first temperature is 35 to 50°C.

12. The method according to claim 1, wherein the first target mother liquor saturation is 1.05 to 1.

15.

13. The method according to claim 1, wherein the first supersaturated mother liquor contains 85 to 90 wt% allulose on a dry solid basis.

14. The method according to claim 1, wherein the second temperature is 22 to 35°C.

15. The method according to claim 1, wherein the second target mother liquor saturation is 1.05 supersaturation or less.

16. The method according to claim 1, wherein the second supersaturated mother liquor contains 80 to 95 wt% allulose on a dry solid basis.

17. The method according to claim 1, wherein the third temperature is 20 to 25°C.

18. The method according to claim 1, wherein the third target mother liquor saturation is 1.1 to 1.2 supersaturated.

19. The method according to claim 1, wherein the fourth target mother liquor saturation is 1.05 to 1.2 supersaturated.

20. The method according to claim 1, wherein the separation is at least partially carried out by one or more physical separation methods selected from the group consisting of centrifugation, filtration, decantation, membrane separation, and combinations thereof.

21. The method according to claim 1, wherein the allulose crystals separated from the final mother liquor are subjected to the steps of i) washing with at least one of water, an organic solvent, a blend of organic solvents, a blend of water and (one or more) organic solvents, or an aqueous solution comprising at least one carbohydrate; ii) drying; or a combination thereof.

22. Allulose crystals obtained by the method described in claim 1.

23. A consumer product comprising allulose crystals according to claim 1 and at least one additional component other than allulose crystals, or prepared using them.

24. A method for producing a consumer product, comprising the step of using allulose crystals according to claim 1.

25. A mother liquor, which is a product mother liquor obtained by the method described in claim 1.

26. A mother liquor obtained by the method described in claim 1, which is suitable for use as a product consumable by humans or animals, or as a component in a dosage form product consumable by humans or animals.

27. Allulose crystal product having an average particle size of 100 to 500 microns (μm) on a volume basis as measured by laser diffraction, and a d10 of 10 to 100 microns (μm).

28. The allulose crystal product according to claim 27, having a d90 of 300 to 1000 microns (μm) on a volume basis as measured by laser diffraction.

29. The allulose crystal product according to claim 27, having a median particle size of 50 to 250 microns (μm) on a volume basis as measured by laser diffraction.

30. The bulk density of the aforementioned product is at least 30 lb / ft ３ The allulose crystal product according to claim 27.

31. A consumer product comprising the allulose crystal product according to claim 27, and at least one additional component other than allulose crystals.

32. A method for producing allulose crystals, comprising the following steps: a) Distilling off the feed allulose syrup at a first near-atmospheric pressure and a first temperature to produce a first supersaturated allulose syrup having a target allulose syrup saturation; b) A step of introducing seed crystals into a first supersaturated allulose syrup and crystallizing allulose at a constant crystallization rate to produce a first white liquor containing allulose crystals and a first supersaturated mother liquor having a first target mother liquor saturation level higher than the target saturation level of the allulose syrup; c) Distilling off the first white base at a first near-atmospheric pressure and a second temperature lower than the first temperature to produce a second white base containing allulose crystals and a second supersaturated mother liquor having a second mother liquor target saturation lower than the first mother liquor target saturation; d) A step of producing a third white liquor containing allulose crystals and a third supersaturated mother liquor having a third target mother liquor saturation; e) A step of crystallizing the third white base over a crystallization time to produce a product white base containing product allulose crystals and product mother liquor in a target yield, wherein the product mother liquor has a target product mother liquor supersaturation; and f) A step of separating the product allulose crystals from the product supersaturated mother liquor to provide allulose crystals in a target yield. The method, including the method described above.

33. The method according to claim 32, wherein the target allulose syrup saturation is 1.05 to 1.

20.

34. The method according to claim 32, wherein the first target mother liquor saturation is 1.10 to 1.

35.

35. The method according to claim 32, wherein the supersaturated allulose syrup has a total dry solid content of 78% to 90% by weight.

36. The method according to claim 32, wherein the target yield is 40% or more.

37. The method according to claim 32, wherein the yield of allulose crystals in step c) is 5 to 20% by weight.

38. The method according to claim 32, wherein the crystallization rate of allulose in step c) is 1 to 5 wt% per hour.

39. The method according to claim 32, wherein the crystallization time in step e) is 5 to 50 hours.

40. The method according to claim 32, wherein the feed allulose syrup has a total dry solid content of 50% to 80% by weight.

41. The method according to claim 32, wherein the allulose in the feed allulose syrup is at least 80% pure by weight on a dry solid basis.

42. The method according to claim 32, wherein the pH of the feed allulose syrup is 2.5 to 6.

0.

43. The method according to claim 32, wherein the feed allulose syrup is at least 95% pure by weight on a dry solid basis.

44. The method according to claim 32, wherein the feed allulose syrup is at least 98% pure by weight on a dry solid basis.

45. The method according to claim 32, wherein the seed crystal is contained in an amount of 0.0001% to 5% by weight of feed allulose syrup.

46. The method according to claim 32, wherein the seed crystal has an average particle size of 75 microns (μm) or less.

47. The method according to claim 32, wherein the seed crystal has an average particle size of 5 to 250 microns (μm).

48. The method according to claim 32, wherein the first temperature is 30 to 70°C.

49. The method according to claim 32, wherein the first target mother liquor saturation is 1.10 to 1.

15.

50. The method according to claim 32, wherein the first supersaturated mother liquor contains 85 to 90 wt% allulose on a dry solid basis.

51. The method according to claim 32, wherein the second temperature is 25 to 50°C.

52. The method according to claim 32, wherein the aforementioned near-atmospheric pressure is 25 to 55 millibars.

53. The method according to claim 32, wherein the third temperature is 5 to 50°C.

54. The method according to claim 32, wherein the second target mother liquor saturation is 1.05 supersaturation or less.

55. The method according to claim 32, wherein the second supersaturated mother liquor contains 80 to 95 wt% allulose on a dry solid basis.

56. The method according to claim 32, wherein the third target mother liquor saturation is 1.05 to 1.2 supersaturated.

57. The method according to claim 32, wherein the separation is carried out at least partially by one or more physical separation methods selected from the group consisting of centrifugation, filtration, decantation, membrane separation, and combinations thereof.

58. The method according to claim 32, wherein the allulose crystals separated from the final mother liquor are subjected to the steps of i) washing with at least one of water, an organic solvent, a blend of organic solvents, a blend of water and (one or more) organic solvents, or an aqueous solution comprising at least one carbohydrate; ii) drying; or a combination thereof.

59. Allulose crystals obtained by the method described in claim 32.

60. A consumer product comprising allulose crystals and at least one additional component other than allulose crystals according to claim 32, or prepared using them.

61. A method for producing a consumer product, comprising the step of using allulose crystals obtained by the method described in claim 32.

62. A mother liquor, which is a product mother liquor obtained by the method described in claim 32.

63. A mother liquor obtained by the method described in claim 32, which is suitable for use as a product consumable by humans or animals, or as a component in a dosage form product consumable by humans or animals.

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