Preparation system and method of erythritol and high-potency sweetener complex crystallization

Abstract

The present application relates to a kind of erythritol and high-fold sweetener complex crystallization preparation system and method thereof, system includes sequentially through pipeline communication's fermentation broth storage tank, ceramic membrane filtration system, nanofiltration system, first evaporator, first crystallization kettle, first centrifuge, dissolve sugar tank, decoloring tank, ion exchange column, blending tank, second evaporator, second crystallization kettle, second centrifuge, hot air drying tank, fluidized drying bed and finished product tank, also includes high-fold sweetener storage tank, primary mother liquor tank and secondary mother liquor tank, fermentation broth storage tank is equipped with the feed inlet of sterilized erythritol fermentation liquor, blending tank is equipped with the feed inlet of high-fold sweetener, first centrifuge is communicated with primary mother liquor tank, primary mother liquor tank is communicated with first evaporator, second centrifuge is communicated with secondary mother liquor tank, secondary mother liquor tank is communicated with blending tank, finished product tank stores the erythritol and high-fold sweetener complex crystallization product prepared by preparation.The complex crystallization particle size of the present application is concentrated and controllable, and the production cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of sugar alcohol preparation technology, and specifically relates to a preparation system and method for the crystallization of erythritol and a high-intensity sweetener. Background Technology

[0002] Erythritol is a natural sugar alcohol sweetener with many advantages, including pure sweetness, low calorie content, no tooth decay, and a refreshing taste. Its sweetness is 60-70% that of sucrose, but compared to sucrose, its sweetness is less pronounced, its texture is thinner, and it has a bitter aftertaste. Therefore, to mask these shortcomings of erythritol when used alone and to meet the demand for good taste and low calories, the industry often uses high-intensity sweeteners or other sugar alcohols in combination or co-crystallization with erythritol.

[0003] Existing processing methods utilize spray granulation technology, such as coating erythritol onto its surface or directly spray-granulating erythritol mixed with other high-intensity sweeteners. However, these methods suffer from issues like coating peeling and uneven texture. Other methods employ co-crystallization, using cooling or melt crystallization to obtain co-crystallized products from erythritol and other high-intensity sweeteners. For example, patent CN110179096A describes a solution-cooling crystallization method for co-crystallizing erythritol with inulin, steviol glycosides, and mogrosides, resulting in a compound sweetener with uniform particle size and a good taste. Patent CN103262972A describes a melt crystallization method for co-crystallizing erythritol and sucralose, yielding a co-crystallized product with good solubility and uniform sweetness. None of these methods, whether using cooling or melt crystallization, mention the possibility of controlling the particle size of the co-crystallized product. This is detrimental to producing products with different particle size specifications. If the particle size of the product is required, the above-mentioned product can only be screened to obtain the product with the required particle size, which increases the production cost. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a preparation system and method for compound crystallization of erythritol and high-intensity sweetener. The compound crystallization of erythritol and high-intensity sweetener is obtained by evaporation crystallization. By coordinating the particle size of the added erythritol seed crystals with the stirring speed, the particle size of the obtained compound crystals is concentrated and controllable, which is more conducive to the production of products with different particle size specifications, reduces production costs, and improves the undesirable flavor of erythritol, resulting in a uniform taste that is more in line with consumer preferences.

[0005] This invention provides a preparation system for the crystallization of erythritol and a high-intensity sweetener, comprising, in sequence via pipelines, a fermentation broth storage tank, a ceramic membrane filtration system, a nanofiltration system, a first evaporator, a first crystallization vessel, a first centrifuge, a sugar-dissolving tank, a decolorizing tank, an ion exchange column, a blending tank, a second evaporator, a second crystallization vessel, a second centrifuge, a hot air drying tank, a fluidized bed, and a finished product tank. It also includes a high-intensity sweetener storage tank, a primary mother liquor tank, and a secondary mother liquor tank. The fermentation broth storage tank is equipped with an inlet for sterilized erythritol fermentation broth, and the nanofiltration system is equipped with a permeate outlet, which is connected via pipelines to… The inlet of the first evaporator is connected, the sugar dissolving tank is equipped with a purified water inlet, the blending tank is equipped with a high-intensity sweetener inlet, the first centrifuge and the second centrifuge are respectively equipped with a solid discharge outlet and a liquid discharge outlet, the liquid discharge outlet of the first centrifuge is connected to the inlet of the primary mother liquor tank through a pipeline, the discharge outlet of the primary mother liquor tank is connected to the inlet of the first evaporator through a pipeline, the liquid discharge outlet of the second centrifuge is connected to the inlet of the secondary mother liquor tank through a pipeline, the discharge outlet of the secondary mother liquor tank is connected to one of the inlets of the blending tank through a pipeline, and the finished product tank stores the prepared erythritol and high-intensity sweetener compound crystallized product.

[0006] This invention is achieved by providing a method for preparing a compound crystallization of erythritol and a high-intensity sweetener. The method utilizes the aforementioned preparation system for the compound crystallization of erythritol and a high-intensity sweetener, and includes the following steps:

[0007] Step 1: The sterilized erythritol fermentation broth stored in the fermentation broth storage tank is sequentially transported through pipelines to a ceramic membrane filtration system for filtration, and then to a nanofiltration system for separation to obtain permeate. The permeate is then sequentially transported through pipelines to a first evaporator for concentration, a first crystallization vessel for crystallization, and a first centrifuge for centrifugation to obtain solid erythritol monocrystalline sugar and liquid primary mother liquor. The primary mother liquor is temporarily stored in a primary mother liquor tank and then returned to the first evaporator through pipelines for reuse. In this step, the erythritol content in the permeate after nanofiltration is ≥93%, and the light transmittance is ≥85%.

[0008] Step 2: Erythritol monocrystalline sugar is dissolved in a sugar-dissolving tank. The resulting solution is then decolorized in a decolorizing tank and purified by an ion exchange column. In a blending tank, it is mixed with a high-intensity sweetener solution from a high-intensity sweetener storage tank and a secondary mother liquor from a secondary mother liquor tank to obtain a blended solution. The blended solution is then sequentially introduced through pipelines into a second evaporator for concentration, a second crystallization kettle for crystallization, and a second centrifuge for centrifugation to obtain solid erythritol and high-intensity sweetener compound sugar, and liquid secondary mother liquor. The secondary mother liquor is temporarily stored in a secondary mother liquor tank and then returned to the blending tank for reuse. In this step, the transmittance of the ion exchange liquid after purification is ≥97%, and the conductivity is <30μs / cm. The refractive index of the blended concentrate after concentration in the second evaporator is 65-70%, the erythritol content is 95-99.9%, and the high-intensity sweetener content is 0.1-5%.

[0009] Step 3: The obtained erythritol and high-intensity sweetener compound molasses is passed through pipelines sequentially through a hot air drying tank and a fluidized bed for hot air drying, resulting in a crystalline product of erythritol and high-intensity sweetener temporarily stored in a finished product tank.

[0010] Compared with the prior art, the preparation system and method of erythritol and high-intensity sweetener compound crystallization of the present invention have the following characteristics:

[0011] 1. The particle size of the erythritol and high-intensity sweetener compound crystals obtained by this invention is concentrated and controllable.

[0012] 2. The morphology of the erythritol and high-intensity sweetener compound crystal obtained by the present invention is similar to that of erythritol crystals, and the crystal form is better.

[0013] 3. The sweetness of the erythritol and high-intensity sweetener crystals obtained by this invention can be adjusted, and is 0.7 to 2 times that of sucrose. The taste is uniform and superior to that of erythritol crystals. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a preferred embodiment of the preparation system for the compound crystallization of erythritol and a high-intensity sweetener of the present invention.

[0015] Figure 2 This is a schematic diagram showing the particle size distribution of the compound crystallized products of erythritol and high-intensity sweetener prepared in various embodiments of the present invention. Detailed Implementation

[0016] To make the technical problems, solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0017] Please refer to Figure 1 As shown, a preferred embodiment of the preparation system for the compound crystallization of erythritol and a high-intensity sweetener of the present invention includes, in sequence, a fermentation broth storage tank 1, a ceramic membrane filtration system 2, a nanofiltration system 3, a first evaporator 4, a first crystallization vessel 5, a first centrifuge 6, a sugar dissolving tank 7, a decolorizing tank 8, an ion exchange column 9, a blending tank 10, a second evaporator 11, a second crystallization vessel 12, a second centrifuge 13, a hot air drying tank 14, a fluidized bed drying bed 15, and a finished product tank 16. It also includes a high-intensity sweetener storage tank 17, a primary mother liquor tank 18, and a secondary mother liquor tank 19. The arrows in the figure indicate the flow direction of the materials in this system.

[0018] Fermentation broth storage tank 1 is equipped with an inlet for sterilized erythritol fermentation broth, and nanofiltration system 3 is equipped with a permeate outlet, which is connected to the inlet of the first evaporator 4 via a pipeline. Sugar dissolving tank 7 is equipped with a purified water inlet, and blending tank 10 is equipped with a high-concentration sweetener inlet.

[0019] The first centrifuge 6 and the second centrifuge 13 are respectively equipped with a solid discharge port and a liquid discharge port. The liquid discharge port of the first centrifuge 6 is connected to the inlet of the primary mother liquor tank 18 via a pipeline, and the discharge port of the primary mother liquor tank 18 is connected to the inlet of the first evaporator 4 via a pipeline. The liquid discharge port of the second centrifuge 13 is connected to the inlet of the secondary mother liquor tank 19 via a pipeline, and the discharge port of the secondary mother liquor tank 19 is connected to one inlet of the blending tank 10 via a pipeline. The finished product tank stores the prepared erythritol and high-intensity sweetener compound crystallized product.

[0020] After sterilization, the erythritol fermentation broth enters the fermentation broth storage tank 1 through the feed inlet for temporary storage. After sterilization, the erythritol fermentation broth is filtered and separated by the ceramic membrane filtration system 2 and the nanofiltration system 3 to remove most of the impurities. Then, it is sequentially subjected to evaporation and concentration treatment in the first evaporator 4, crystallization treatment in the first crystallization kettle 5, and centrifugation separation treatment in the first centrifuge 6 to obtain erythritol monocrystalline sugar and primary mother liquor. Erythritol monocrystalline sugar is transported to the sugar dissolving tank 7 through pipelines for dissolution. The resulting solution is then subjected to decolorization treatment in the decolorization tank 8 and ion exchange treatment in the ion exchange column 9. The high-intensity sweetener solution transported in the blending tank 10 and the secondary mother liquor transported in the secondary mother liquor tank 19 are mixed to obtain a blended solution. The blended solution is then subjected to concentration treatment in the second evaporator 11, crystallization treatment in the second crystallization kettle 12, centrifugal separation treatment in the second centrifuge 13, hot air drying treatment in the hot air drying tank 14, and cold air drying treatment in the fluidized bed drying bed 15 to obtain a compound crystallized product of erythritol and high-intensity sweetener.

[0021] The high-intensity sweetener is at least one of steviol glycosides, mogrosides, sucralose, acesulfame potassium, and aspartame.

[0022] This invention also discloses a method for preparing erythritol and a high-intensity sweetener compound crystallization, wherein the preparation method uses the preparation system for erythritol and high-intensity sweetener compound crystallization as described above, and the preparation method includes the following steps:

[0023] Step 1: The sterilized erythritol fermentation broth stored in fermentation broth storage tank 1 is sequentially transported through pipelines to ceramic membrane filtration system 2 for filtration, and nanofiltration system 3 for separation to obtain permeate. The permeate is then sequentially transported through pipelines to first evaporator 4 for concentration, first crystallization vessel 5 for crystallization, and first centrifuge 6 for centrifugation to obtain solid erythritol monocrystalline sugar and liquid primary mother liquor. The primary mother liquor is temporarily stored in primary mother liquor tank 18 and then returned to first evaporator 4 for reuse. In this step, the erythritol content in the permeate after nanofiltration is ≥93%, and the light transmittance is ≥85%.

[0024] Step 2: Erythritol monocrystalline sugar is dissolved in dissolving tank 7. The resulting solution is then decolorized in decolorizing tank 8 and purified by ion exchange column 9. In blending tank 10, it is mixed with a high-intensity sweetener solution from high-intensity sweetener storage tank 17 and a secondary mother liquor from secondary mother liquor tank 19 to obtain a blended solution. This blended solution is then piped to a second evaporator 11 for concentration, a second crystallizer 12 for crystallization, and a second centrifuge 13 for centrifugation to obtain solid erythritol and high-intensity sweetener compound sugar, and liquid secondary mother liquor. The secondary mother liquor is temporarily stored in secondary mother liquor tank 19 and then piped back to blending tank 10 for reuse. In this step, the transmittance of the ion exchange solution after purification is ≥97%, and the conductivity is <30μs / cm. The concentrated liquid after the second evaporator 11 has a refractive index of 65-70%, an erythritol content of 95-99.9%, and a high-intensity sweetener content of 0.1-5%.

[0025] Step 3: The obtained erythritol and high-intensity sweetener compound molasses is passed through pipelines sequentially through hot air drying tank 14 and cold air drying bed 15 to obtain the erythritol and high-intensity sweetener compound crystallized product temporarily stored in finished product tank 16.

[0026] Specifically, in step one, the erythritol concentrate obtained after concentration treatment in the first evaporator 4 has a refractive index of 55-60%, and the crystallization temperature in the first crystallization vessel 5 is 60-65℃.

[0027] Specifically, in step two, during the crystallization process in the second crystallization vessel 12, the stirring speed is set to 50–100 rpm and the crystallization temperature to 60–65°C. Erythritol seed crystals are added, and after the seed crystals are evenly dispersed in the sugar solution, the temperature and stirring speed are maintained constant for 0.5–2 hours of crystal growth. After crystal growth is complete, the pressure in the second crystallization vessel 12 is set to 150–220 mbar, and evaporation crystallization is carried out while stirring. Crystallization is stopped and the product is discharged from the vessel after 2–6 hours. The addition ratio of erythritol seed crystals is 1–5%, and the seed crystal particle size is 60–120 mesh.

[0028] Specifically, in step three, the hot air temperature in the hot air drying tank 14 is selected to be 90-100℃, and the cold air temperature in the fluidized bed 15 is 15-30℃.

[0029] The preparation system and method of the compound crystallization of erythritol and high-intensity sweetener of the present invention are further illustrated below through specific embodiments.

[0030] Example 1

[0031] The first embodiment of the preparation method of the present invention, which involves the compound crystallization of erythritol and a high-intensity sweetener, includes the following steps:

[0032] (11) The sterilized erythritol fermentation broth is sequentially passed through a ceramic membrane filtration system 2 and a nanofiltration system 3 to remove bacteria and other impurities, resulting in a nanofiltration solution with an erythritol content of 93% and a transmittance of 85%. The nanofiltration solution is then concentrated in a first evaporator 4 to obtain an erythritol concentrate with a refractive index of 55%. The erythritol concentrate is evaporated and crystallized in a first crystallization vessel 5 to obtain erythritol sugar paste at a crystallization temperature of 60°C. The erythritol sugar paste is centrifuged in a first centrifuge 6 to obtain erythritol monocrystalline sugar and a first centrifugation mother liquor. The first centrifugation mother liquor is returned to the nanofiltration system for reuse.

[0033] (12) Erythritol monocrystalline sugar is introduced into sugar dissolving tank 7 to dissolve. The resulting solution is passed through decolorizing tank 8 and ion exchange column 9 in sequence to obtain a decolorized ion exchange solution with a transmittance of 98% and a conductivity of 18 μs / cm. The decolorized ion exchange solution is mixed with steviol glycoside solution in blending tank 10 in proportion to obtain blending solution. The blending solution contains 99.84% erythritol and 0.1% steviol glycoside. The blending solution is introduced into second evaporator 11 for concentration treatment to obtain blended concentrated solution with 66% erythritol steviol glycoside refractive index.

[0034] (13) The concentrated liquid was poured into the second crystallization vessel 12. The stirring speed was set to 60 rpm and the temperature to 65°C. Erythritol seed crystals were added at a ratio of 2% with a particle size of 60-80 mesh. After the erythritol seed crystals were evenly dispersed in the sugar solution, the temperature and stirring speed were maintained for 1 hour to allow crystals to grow. After crystal growth, the pressure of the second crystallization vessel 12 was set to 18 MPa. Evaporation and crystallization were carried out while stirring. After evaporation and crystallization for 4 hours, crystallization was stopped and the mixture was removed from the vessel to obtain erythritol steviol glycoside compound crystalline sugar paste.

[0035] (14) The erythritol and steviol glycoside compound crystalline sugar paste is separated by a second centrifuge 13 to obtain erythritol and steviol glycoside compound crystals and secondary mother liquor. The compound crystals are dried with hot air at 90°C and cold air at 30°C to obtain the erythritol and steviol glycoside compound crystalline product. The secondary centrifugation mother liquor is returned to the mixing tank 10 for reuse.

[0036] The erythritol steviol glycoside complex crystal product obtained in this embodiment was screened, and the particle size distribution of the product is shown in Table 1 below.

[0037] Table 1. Particle size distribution of the erythritol and steviol glycoside compound crystallized product of Example 1

[0038] granularity 10~20 mesh 20~30 mesh 30~40 mesh 40~50 mesh 50~60 mesh Under 60 items Percentage / % 42.68 28.01 17.43 8.38 1.49 2.01

[0039] Table 1 shows that 70.69% of the erythritol and steviol glycoside compound crystal products have a particle size between 10 and 30 mesh.

[0040] Example 2

[0041] A second embodiment of the preparation method of the compound crystallization of erythritol and a high-intensity sweetener of the present invention includes the following steps:

[0042] (21) The sterilized erythritol fermentation broth is sequentially passed through a ceramic membrane filtration system 2 and a nanofiltration system 3 to remove bacteria and other impurities, resulting in a nanofiltration solution with an erythritol content of 96% and a transmittance of 87%. The nanofiltration solution is then concentrated in a first evaporator 4 to obtain an erythritol concentrate with a refractive index of 60%. The erythritol concentrate is then evaporated and crystallized in a first crystallization vessel 5 to obtain erythritol sugar paste at a crystallization temperature of 60°C. The erythritol sugar paste is then centrifuged in a first centrifuge 6 to obtain erythritol monocrystalline sugar and a first centrifugation mother liquor. The first centrifugation mother liquor is returned to the nanofiltration system for reuse.

[0043] (22) Erythritol monocrystalline sugar is introduced into sugar dissolving tank 7 to dissolve. The resulting solution is passed through decolorizing tank 8 and ion exchange column 9 in sequence to obtain a decolorized ion exchange solution with a transmittance of 99% and a conductivity of 25 μs / cm. The decolorized ion exchange solution is mixed with steviol glycoside solution in blending tank 10 in a certain proportion to obtain a blending solution. The blending solution contains 99.11% erythritol, 0.64% steviol glycoside, and 0.25% mogroside. The blending solution is introduced into the second evaporator 11 for concentration treatment to obtain a blended concentrated solution with 70% erythritol steviol glycoside refractive index.

[0044] (23) The concentrated liquid was poured into the second crystallization vessel 12. The stirring speed was set to 100 rpm and the temperature to 64°C. Erythritol seed crystals were added at a ratio of 5% and a particle size of 100-120 mesh. After the erythritol seed crystals were evenly dispersed in the sugar solution, the temperature and stirring speed were kept constant for 0.5 h. After the crystallization was completed, the pressure of the second crystallization vessel 12 was set to 20 MPa. Evaporation and crystallization were carried out while stirring. After evaporation and crystallization for 6 h, the crystallization was stopped and the mixture was removed from the vessel to obtain erythritol steviol glycoside compound crystalline sugar paste.

[0045] (24) The erythritol and steviol glycoside compound crystalline sugar paste was separated by a second centrifuge 13 to obtain erythritol and steviol glycoside compound crystals and a secondary mother liquor. The compound crystals were dried with hot air at 95°C and cold air at 22°C to obtain the erythritol and steviol glycoside compound crystalline product. The secondary centrifugation mother liquor was returned to the mixing tank 10 for reuse.

[0046] The erythritol steviol glycoside complex crystal product obtained in this embodiment was screened, and the particle size distribution of the product is shown in Table 2 below.

[0047] Table 2. Particle size distribution of the erythritol and steviol glycoside compound crystal products of Example 2

[0048] granularity 10~20 mesh 20~30 mesh 30~40 mesh 40~50 mesh 50~60 mesh Under 60 items Percentage / % 1.5 3.68 18.62 38.83 23.24 14.12

[0049] Table 2 shows that 76.2% of the erythritol and steviol glycoside compound crystal products have a particle size of less than 40 mesh.

[0050] Example 3

[0051] A second embodiment of the preparation method of the compound crystallization of erythritol and a high-intensity sweetener of the present invention includes the following steps:

[0052] (31) The sterilized erythritol fermentation broth is sequentially passed through a ceramic membrane filtration system 2 and a nanofiltration system 3 to remove bacteria and other impurities, resulting in a nanofiltration solution with an erythritol content of 95% and a transmittance of 90%. The nanofiltration solution is then concentrated in a first evaporator 4 to obtain an erythritol concentrate with a refractive index of 58%. The erythritol concentrate is evaporated and crystallized in a first crystallization vessel 5 to obtain erythritol sugar paste at a crystallization temperature of 65°C. The erythritol sugar paste is centrifuged in a first centrifuge 6 to obtain erythritol monocrystalline sugar and a first centrifugation mother liquor. The first centrifugation mother liquor is returned to the nanofiltration system for reuse.

[0053] (32) Erythritol monocrystalline sugar is introduced into sugar dissolving tank 7 for dissolution. The resulting solution is passed through decolorizing tank 8 and ion exchange column 9 in sequence to obtain a decolorized ion exchange solution with a transmittance of 99% and a conductivity of 20 μs / cm. The decolorized ion exchange solution is mixed with steviol glycoside solution in blending tank 10 in a certain proportion to obtain a blending solution. The blending solution contains 95.00% erythritol, 0.88% sucralose, 1.12% steviol glycoside, and 3.0% mogroside. The blending solution is introduced into the second evaporator 11 for concentration treatment to obtain a blended concentrated solution with a refractive index of 68% erythritol steviol glycoside.

[0054] (33) The concentrated liquid was poured into the second crystallization vessel 12. The stirring speed was set to 85 rpm and the temperature to 65°C. Erythritol seed crystals were added at a ratio of 1% with a particle size of 80-100 mesh. After the erythritol seed crystals were evenly dispersed in the sugar solution, the temperature and stirring speed were maintained for 2 hours to allow crystals to grow. After crystal growth, the pressure of the second crystallization vessel 12 was set to 15 MPa. Evaporation and crystallization were carried out while stirring. After evaporation and crystallization for 2 hours, crystallization was stopped and the mixture was removed from the vessel to obtain erythritol steviol glycoside compound crystalline sugar paste.

[0055] (34) The erythritol and steviol glycoside compound crystalline sugar paste is separated by a second centrifuge 13 to obtain erythritol and steviol glycoside compound crystals and secondary mother liquor. The compound crystals are dried with hot air at 100°C and cold air at 15°C to obtain the erythritol and steviol glycoside compound crystalline product. The secondary centrifugation mother liquor is returned to the mixing tank 10 for reuse.

[0056] The erythritol steviol glycoside complex crystal product obtained in this embodiment was screened, and the particle size distribution of the product is shown in Table 3 below.

[0057] Table 3. Particle size distribution of the erythritol and steviol glycoside compound crystal products of Example 3

[0058] granularity 20 mesh 20~30 mesh 30~40 mesh 40~50 mesh 50~60 mesh Under 60 items Percentage / % 2.42 5.76 27.92 40.01 8.49 15.40

[0059] Table 3 shows that 67.93% of the erythritol and steviol glycoside compound crystal products have a particle size between 30 and 50 mesh.

[0060] The particle size distribution of the erythritol and steviol glycoside complex crystal products prepared in Examples 1-3 was analyzed to obtain... Figure 2 The particle size distribution diagram shown.

[0061] The erythritol and steviol glycoside compound crystal products obtained in each embodiment were subjected to taste tests. Taste comparison tests were also conducted with sucrose and steviol glycoside products. Both sucrose and steviol glycosides were prepared with a 7% sugar solution, where the default sweetness of 7% sucrose was 7. Taste intensity was divided into 7 levels: 1 – very weak, 2 – weak, 3 – somewhat weak, 4 – average, 5 – somewhat strong, 6 – strong, 7 – very strong. The test results are shown in Table 4.

[0062] Table 4. Taste test results for each product

[0063]

[0064]

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a compound crystallized product of erythritol and a high-intensity sweetener, characterized in that, The preparation method uses a preparation system for the compound crystallization of erythritol and a high-intensity sweetener. This preparation system is characterized by comprising, sequentially connected by pipelines, a fermentation broth storage tank, a ceramic membrane filtration system, a nanofiltration system, a first evaporator, a first crystallization vessel, a first centrifuge, a sugar-dissolving tank, a decolorizing tank, an ion exchange column, a blending tank, a second evaporator, a second crystallization vessel, a second centrifuge, a hot air drying tank, a fluidized bed, and a finished product tank. It also includes a high-intensity sweetener storage tank, a primary mother liquor tank, and a secondary mother liquor tank. The fermentation broth storage tank is equipped with an inlet for the sterilized erythritol fermentation broth, and the nanofiltration system is equipped with a permeate outlet. The liquid outlet is connected to the inlet of the first evaporator via a pipeline. The sugar dissolving tank is equipped with a purified water inlet, and the blending tank is equipped with a high-intensity sweetener inlet. The first centrifuge and the second centrifuge are respectively equipped with a solid discharge outlet and a liquid discharge outlet. The liquid discharge outlet of the first centrifuge is connected to the inlet of the primary mother liquor tank via a pipeline. The discharge outlet of the primary mother liquor tank is connected to the inlet of the first evaporator via a pipeline. The liquid discharge outlet of the second centrifuge is connected to the inlet of the secondary mother liquor tank via a pipeline. The discharge outlet of the secondary mother liquor tank is connected to one of the inlets of the blending tank via a pipeline. The finished product tank stores the prepared erythritol and high-intensity sweetener compound crystallized product. The preparation method includes the following steps: Step 1: The sterilized erythritol fermentation broth stored in the fermentation broth storage tank is sequentially transported through pipelines to a ceramic membrane filtration system for filtration, and then to a nanofiltration system for separation to obtain permeate. The permeate is then sequentially transported through pipelines to a first evaporator for concentration, a first crystallization vessel for crystallization, and a first centrifuge for centrifugation to obtain solid erythritol monocrystalline sugar and liquid primary mother liquor. The primary mother liquor is temporarily stored in a primary mother liquor tank and then returned to the first evaporator through pipelines for reuse. In this step, the erythritol content in the permeate after nanofiltration is ≥93%, and the light transmittance is ≥85%. Step 2: Erythritol monocrystalline sugar is dissolved in a sugar-dissolving tank. The resulting solution is then decolorized in a decolorizing tank and purified by an ion exchange column. In a blending tank, it is mixed with a high-intensity sweetener solution from a high-intensity sweetener storage tank and a secondary mother liquor from a secondary mother liquor tank to obtain a blended solution. This blended solution is then sequentially piped into a second evaporator for concentration, a second crystallization vessel for crystallization, and a second centrifuge for centrifugal separation, yielding solid erythritol and high-intensity sweetener compound sugar, and liquid secondary mother liquor. The secondary mother liquor is temporarily stored in a secondary mother liquor tank and then piped back to the blending tank for reuse. In this step, the transmittance of the ion exchange liquid after purification is ≥97%, and the conductivity is <30μs / cm. The refractive index of the blended concentrate after concentration in the second evaporator is 65-70%, the erythritol content is 95-99.9%, and the high-intensity sweetener content is 0.1-5%. Step 3: The obtained erythritol and high-intensity sweetener compound molasses is passed through pipelines sequentially through a hot air drying tank and a fluidized bed for hot air drying, resulting in a crystalline product of erythritol and high-intensity sweetener temporarily stored in a finished product tank.

2. The preparation method of erythritol and high-intensity sweetener compound crystallization as described in claim 1, characterized in that, In step one, the erythritol concentrate obtained after the first evaporator concentration treatment has a refractive index of 55-60%, and the crystallization temperature of the first crystallizer is 60-65℃.

3. The preparation method of erythritol and high-intensity sweetener compound crystallization as described in claim 1, characterized in that, In step two, during the crystallization process in the second crystallization vessel, the stirring speed is set to 50-100 rpm and the crystallization temperature is set to 60-65℃. Erythritol seed crystals are added, and after the seed crystals are evenly dispersed in the sugar solution, the temperature and stirring speed are maintained constant for 0.5-2 hours of crystal growth. After crystal growth is completed, the pressure of the second crystallization vessel is set to 150-220 mbar, and evaporation crystallization is carried out while stirring. When the crystallization process takes 2-6 hours, the crystallization is stopped and the product is discharged from the vessel. The addition ratio of erythritol seed crystals is 1-5%, and the seed crystal particle size is 60-120 mesh.

4. The preparation method of erythritol and high-intensity sweetener compound crystallization as described in claim 1, characterized in that, In step three, the hot air temperature in the hot air drying tank is selected to be 90~100℃, and the cold air temperature in the fluidized bed is 15~30℃.

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