Method for extracting sucralose-6-ethyl ester and application

Abstract

The invention discloses a method for extracting sucralose-6-ethyl ester and application, and belongs to the technical field of sucralose production, the method comprises the following steps: S1, concentrating an ester phase of sucralose-6-ethyl ester to obtain thick paste; s2, adding an organic solvent into the thick paste for dissolving to obtain a concentrated solution; and S3, crystallizing the concentrated liquid, and carrying out suction filtration to obtain the sucralose-6-ethyl ester. The organic solvent in the step S2 is an alkane solvent, and the addition amount of the organic solvent is as follows: the specific gravity of the concentrated solution is 1-1.15 by controlling the addition volume. The method has the advantages of low production cost, high yield, mild conditions, stable quality, simple equipment and the like. Especially under the condition that the components in the sucralose-6-ethyl ester solution are complex. The extraction efficiency of the method is far higher than that of other sucralose-6-ethyl ester extraction methods.

Description

Technical Field

[0001] The invention belongs to the technical field of sucralose production, and particularly relates to a method for extracting sucralose-6-ethyl ester and application thereof. Background Art

[0002] Sucralose is an artificial sweetener made from sucrose, which is 400-800 times sweeter than sucrose. It has a pure taste and does not participate in human metabolism. It is a "zero-calorie" sugar that can be used by diabetics, patients with cardiovascular and cerebrovascular diseases and the elderly. It also has the characteristics of good stability and high safety, and is widely used in many fields such as food, beverages, daily chemicals and medicine.

[0003] Currently, most manufacturers adopt the "monoester method" to produce sucralose, that is, first esterify sucrose to obtain sucrose 6-ethyl ester, then chlorinate to produce sucralose 6-ethyl ester, purify the resulting sucralose 6-ethyl ester, and then hydrolyze and deacetylate to produce sucralose.

[0004] The currently commonly used method for purifying sucralose-6-ethyl ester in industry is to crystallize sucralose using ethyl acetate as a crystallization solvent. However, this method also has the problems of long crystallization time and low one-time yield.

[0005] CN102807594A discloses a method for refining sucralose-6-ethyl ester, comprising the following steps: using an alcohol-ether mixed solvent to perform a primary refining on the concentrated sucralose-6-ethyl ester crude product to remove most impurities, and then using an ester-alkane mixed solvent to perform a secondary refining to remove trace impurities, thereby obtaining a high-purity sucralose-6-ethyl ester fine product.

[0006] CN109956983A discloses a method for extracting 6-ethyl sucralose, comprising: in the production process of preparing sucralose by the "monoester method", after the chlorination stage of preparing 6-ethyl sucralose by chlorinating 6-ethyl sucrose, neutralizing the obtained acidic material with an alkali, then adding a non-polar or low-polar solvent, stirring and then standing to allow the 6-ethyl sucralose to form a solid and precipitate, then performing solid-liquid separation to obtain a solid crude product of 6-ethyl sucralose, optionally, separating and recycling the liquid part after distillation, and recrystallizing the solid crude product of 6-ethyl sucralose.

[0007] The current extraction method has a low recovery rate, especially when the impurity content in the sucralose-6-ethyl ester solution system is high, the recovery efficiency of the above method is even lower. Summary of the invention

[0008] In view of the problems existing in the prior art, the present invention provides a method and application of extracting sucralose-6-ethyl ester with higher yield, simpler equipment and better product quality.

[0009] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0010] In a first aspect, the present invention provides a method for extracting sucralose-6-ethyl ester, comprising the following steps:

[0011] S1, concentrating the ester phase of sucralose-6-ethyl ester to obtain a thick paste;

[0012] S2, adding an organic solvent to the thick paste described in step S1 to dissolve it and obtain a concentrated solution;

[0013] S3, crystallizing the concentrated solution obtained in step S2, and filtering it with suction to obtain the sucralose-6-ethyl ester.

[0014] In some embodiments, the ester phase in step S1 includes sucralose-6-ethyl ester, sucralose, sucralose and inevitable impurities.

[0015] Preferably, the ester phase comprises, by weight percentage, 35-40% sucralose-6-ethyl ester, 12-18% sucralose, 35-40% sucralose and the balance inevitable impurities.

[0016] More preferably, the ester phase comprises, by weight percentage, 38.92% sucralose-6-ethyl ester, 15.52% sucralose, 38.84% sucralose and the remainder inevitable impurities.

[0017] In some embodiments, the concentration in step S1 is vacuum concentration. Preferably, the conditions for vacuum concentration are: 60-80° C., -0.08 to -0.12 MPa.

[0018] In some embodiments, the thick paste in step S1 is: no liquid is extracted by filtration at a vacuum degree of -0.04--0.03 MPa.

[0019] In some embodiments, the organic solvent in step S2 is an alkane solvent, and the amount of the organic solvent added is: the added volume is controlled so that the specific gravity of the concentrated solution is 1-1.15 (60°C); preferably 1.02-1.10 (60°C); further preferably 1.05-1.08 (60°C); further preferably 1.05-1.06 (60°C).

[0020] In some embodiments, the alkane solvent in step S2 is diethoxymethane.

[0021] In some embodiments, the alkane solvent in step S2 further includes an ester solvent, and the ester solvent includes at least one of ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and acetone; preferably acetone.

[0022] In some embodiments, the volume ratio of the alkane solvent to the ester solvent is 1:0.5-3.

[0023] In some embodiments, the dissolving temperature in step S2 is 50-80°C.

[0024] In some embodiments, the crystallization in step S3 is: stirring crystallization at -5-30°C for 10-24h; preferably stirring crystallization at 0-25°C for 12-18h; further preferably stirring crystallization at 15-20°C for 15h.

[0025] In some embodiments, the filtration in step S3 is: the vacuum degree is -0.04-0.03 MPa until no liquid is extracted and then increased to -0.09-0.1 MPa to dry.

[0026] In a second aspect, the present invention provides application of the above method in producing sucralose.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] Compared with the reported sucralose-6-ethyl ester crystallization process, the present invention has the advantages of low production cost, high yield, mild conditions, stable quality, simple equipment, etc. Especially when the components in the sucralose-6-ethyl ester solution are complex, its extraction efficiency is much greater than other sucralose-6-ethyl ester extraction methods. DETAILED DESCRIPTION

[0029] The present invention is described below through specific embodiments to make the technical solution of the present invention easier to understand and grasp, but the present invention is not limited thereto, and the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0030] The endpoints and any value of the scope disclosed in this article are not limited to the accurate scope or value, and these scopes or values ​​should be understood to include values ​​close to these scopes or values. For numerical ranges, between the endpoint values ​​of each scope, between the endpoint values ​​of each scope and a separate point value, and between separate point values, one or more new numerical ranges can be combined with each other, and these numerical ranges should be considered as specifically disclosed in this article. Unless the context clearly indicates otherwise, the singular form "one", "a kind of" and "described" as used herein include singular and plural indicators. The numerical range described by the endpoint is included in all numerical values ​​and fractions within the corresponding range, as well as the described endpoint.

[0031] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should belong to the scope of protection of the present invention. The experimental methods described in the following embodiments are conventional methods unless otherwise specified. The reagents and materials, unless otherwise specified, can be obtained from commercial channels. The following reagent source information is illustrative and should not be used to limit the present invention.

[0032] The composition of the layered ester phase containing sucralose-6-ethyl ester in this example is shown in Table 1 (weight percentage %).

[0033] Table 1

[0034]

[0035] The "no solution dripping out" in the present invention means that no liquid is extracted during filtration at a vacuum degree of -0.04 to -0.03 MPa.

[0036] Example 1 Method for extracting sucralose-6-ethyl ester

[0037] Take 500 mL of the layered ester phase containing sucralose-6-ethyl ester and concentrate until no solution drips out. Add 185 mL of diethoxymethane (specific gravity: 1.06, 60°C) and stir to dissolve. Stir and crystallize at 15-20°C for 16 hours and then filter. Vacuum at -0.04-0.03Mpa until no liquid is extracted and then add to -0.09Mpa to dry. Weigh the crystals, the volume of the mother liquor, and the content of sucralose-6-ethyl ester.

[0038] Example 2 Method for extracting sucralose-6-ethyl ester

[0039] Take 500 mL of the layered ester phase containing sucralose-6-ethyl ester and concentrate until no solution drips out. Add 185 mL of a mixture of diethoxymethane and acetone (volume ratio 1:0.5) and stir to dissolve (specific gravity: 1.06, 60°C). Stir and crystallize at 15-20°C for 16 hours and then filter. The vacuum degree is -0.04--0.03Mpa until no liquid is extracted and then added to -0.09Mpa to dry, weigh the crystals, the volume of the mother liquor, and the content of sucralose-6-ethyl ester.

[0040] Example 3 Method for extracting sucralose-6-ethyl ester

[0041] Take 500 mL of the layered ester phase containing sucralose-6-ethyl ester and concentrate until no solution drips out. Add 185 mL of a mixture of diethoxymethane and acetone (volume ratio 1:3) and stir to dissolve (specific gravity: 1.08, 60°C). Stir and crystallize at 15-20°C for 16 hours and then filter. The vacuum degree is -0.04--0.03Mpa until no liquid is extracted and then added to -0.09Mpa to dry, weigh the crystals, the volume of the mother liquor, and the content of sucralose-6-ethyl ester.

[0042] Comparative Example 1 Method for Extracting Sucralose-6-Ethyl Ester

[0043] Take 500mL of the layered ester phase containing sucralose-6-ethyl ester and concentrate until no solution drips out. Add 185mL of a mixture of dichloromethane and acetone (volume ratio 1:3) and stir to dissolve (specific gravity: 1.06, 60°C). Stir and crystallize at 15-20°C for 16 hours and then filter. Vacuum at -0.04--0.03Mpa until no liquid is extracted and then add to -0.09Mpa to dry, weigh the crystals, the volume of the mother liquor, and the content of sucralose-6-ethyl ester.

[0044] Comparative Example 2 Method for Extracting Sucralose-6-Ethyl Ester

[0045] Take 500 mL of the layered ester phase containing sucralose-6-ethyl ester and concentrate until no solution drips out. Add 185 mL of cyclohexane (specific gravity: 1.06, 60°C) and stir to dissolve. Stir and crystallize at 15-20°C for 16 hours and then filter. Vacuum at -0.04-0.03Mpa until no liquid is extracted and then add to -0.09Mpa to dry. Weigh the crystals, the volume of the mother liquor, and the content of sucralose-6-ethyl ester.

[0046] Blank experiment

[0047] Take 500 mL of the layered ester phase containing sucralose-6-ethyl ester and concentrate to a specific gravity of 1.15. Stir and crystallize at 8°C for 24 hours and then filter. Vacuum at -0.04-0.03Mpa until no liquid is extracted and then increase to -0.09Mpa to dry. Weigh the crystals, measure the volume of the mother liquor, and sample the sucralose-6-ethyl ester content.

[0048] The results are shown in Table 2.

[0049] Table 2 Comparison of recovery effects of sucralose-6-ethyl ester

[0050]

[0051] The results show that the yield of sucralose-6-ethyl ester in the extraction method of Examples 1-3 is above 88.5%, and compared with the blank test, the yield of sucralose-6-ethyl ester is increased by about 43%, indicating that the extraction method of the present invention can significantly increase the yield of sucralose-6-ethyl ester.

[0052] Compared with Comparative Examples 1 and 2, it can be seen that the yield of sucralose-6-ethyl ester extracted by using dichloromethane, acetone and cyclohexane as organic solvents for dissolution and crystallization is 71.28-75.58%, and the yield of sucralose-6-ethyl ester is increased by about 14-21% compared with the blank test. It shows that in the technical solution claimed by the present invention, the use of conventional organic solvents for dissolution and crystallization has little effect on the yield of sucralose-6-ethyl ester extracted. Combined with Examples 1-3, it can be seen that the specific organic solvent of the present invention can significantly increase the yield of sucralose-6-ethyl ester, and achieve unexpected technical effects.

[0053] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A method for extracting sucralose-6-ethyl ester, characterized in that: The steps include: S1, concentrating the ester phase of sucralose-6-ethyl ester to obtain a thick paste; S2, adding an organic solvent to the thick paste described in step S1 to dissolve it and obtain a concentrated solution; S3, crystallizing the concentrated solution obtained in step S2, and filtering it with suction to obtain the sucralose-6-ethyl ester; In step S2, the organic solvent is an alkane solvent, and the amount of the organic solvent added is: the added volume is controlled so that the specific gravity of the concentrated solution is 1-1.

15.

2. The method according to claim 1, characterized in that: The amount of the organic solvent added is: the added volume is controlled so that the specific gravity of the concentrated solution is 1.05-1.

08.

3. The method according to claim 1, characterized in that: The ester phase in step S1 includes, by weight percentage, 35-40% sucralose-6-ethyl ester, 12-18% sucralose, 35-40% sucralose and the remainder of inevitable impurities.

4. The method according to claim 1, characterized in that: The thick paste in step S1 is: no liquid is extracted by filtration at a vacuum degree of -0.04 to -0.03 MPa.

5. The method according to claim 1, characterized in that: The alkane solvent in step S2 is diethoxymethane.

6. The method according to claim 1, characterized in that: The alkane solvent in step S2 further includes an ester solvent, and / or; The ester solvent includes at least one of ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and acetone.

7. The method according to claim 6, characterized in that: The volume ratio of the alkane solvent to the ester solvent is 1:0.5-3.

8. The method according to claim 1, characterized in that: The crystallization in step S3 is: stirring the crystallization at -5-30°C for 10-24h.

9. The method according to claim 1, characterized in that: The filtration in step S3 is as follows: the vacuum degree is between -0.04 and -0.03 MPa until no liquid is extracted, and then increased to -0.09 to -0.1 MPa to dry.

10. Use of the method according to any one of claims 1 to 9 in the production of sucralose.

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