Novel dipeptide sweetening agent and synthesis method thereof

Abstract

The invention discloses a novel dipeptide sweetening agent and a synthesis method thereof. The sweetening agent disclosed by the invention is N-(N-(2, 3, 4, 5-tetrahydroxy) methyl-L-alpha-aspartyl)-L-phenylalanine-1-methyl ester, and is a product synthesized from aspartame and L-arabinose. The sweetening agent disclosed by the invention is pure in mouth feel and close to the mouth feel of cane sugar, the sweetness multiple is 800-1000 times of that of the cane sugar, the synthesis process is simple, the operation is convenient, the cost is relatively low, green development is met, industrialization is easy to realize, and the sweetening agent has very good use value and economic value in the field of food technology.

Description

Technical Field

[0001] The invention belongs to the technical field of food additives, and particularly relates to a novel dipeptide sweetener and a synthesis method thereof. Background Art

[0002] Sweeteners, as compounds that can provide sweetness, are widely used in various products such as food, beverages, and medicines to enhance the taste and flavor of the products. Among them, aspartame is a common sweetener. It is a dipeptide composed of aspartic acid and phenylalanine, and its sweetness is 180 to 220 times that of sucrose. L-arabinose is a naturally occurring sugar with a sweetness of about 0.5% of sucrose. It is often used as a food additive and has good sweetness and anti-caries effects. Developing new sweeteners that can replace sucrose with the advantages of high sweetness, safety, and low cost is one of the research and development goals in the field of food additives. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a novel dipeptide sweetener and a method for synthesizing the same, which has simple process operation, safety and relatively reasonable economic cost; the novel dipeptide sweetener is N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl]-L-phenylalanine-1-methyl ester, which is the reaction product of aspartame and L-arabinose, and has a sweetness 800-1000 times that of sucrose, greatly improving the sweetness and having a taste close to that of sucrose, without the lingering sweetness or false sweetness of common high-intensity sweeteners, and can replace sucrose or other sweeteners and be widely used in the food, beverage and pharmaceutical industries.

[0004] The first object of the present invention is to provide a dipeptide sweetener, which is N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester, the structural formula of which is shown in Formula I:

[0005]

[0006] A second object of the present invention is to provide a method for synthesizing N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl]-L-phenylalanine-1-methyl ester, comprising the following steps:

[0007] S1. Add ethanol, dehydrating agent, aspartame and L-arabinose into a reactor in sequence and heat until fully dissolved;

[0008] S2, adding palladium carbon catalyst to the dissolved solution and mixing thoroughly, replacing the air in the reaction system with protective gas, introducing hydrogen gas and pressurizing to carry out hydrogenation reduction reaction;

[0009] S3. After the reaction, the reaction solution is filtered under reduced pressure, the filtrate is collected, concentrated under reduced pressure, and the concentrated solution is recrystallized and purified to obtain N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester.

[0010] The corresponding synthesis reaction formula is as follows:

[0011]

[0012] Here, Me represents a methyl group.

[0013] Preferably, in step S1, the molar ratio of L-arabinose to aspartame is 0.5-4:1, the molar ratio of the dehydrating agent to aspartame is 1-10:1, the mass ratio of ethanol to aspartame is 5-20:1, and the mass ratio of the palladium-carbon catalyst to aspartame is 0.01-0.1:1.

[0014] More preferably, in step S1, the molar ratio of L-arabinose to aspartame is 1.8-4:1, the molar ratio of the dehydrating agent to aspartame is 1.9-5.9:1, the mass ratio of ethanol to aspartame is 7.5-14.5:1, and the mass ratio of the palladium-carbon catalyst to aspartame is 0.035:1.

[0015] The dehydrating agent is any one of anhydrous ferric chloride, anhydrous ferrous chloride, anhydrous magnesium chloride, anhydrous calcium chloride, anhydrous lithium chloride, anhydrous potassium chloride, anhydrous sodium chloride, anhydrous sodium bicarbonate, anhydrous potassium bicarbonate, anhydrous lithium bicarbonate, anhydrous potassium acetate, anhydrous sodium acetate, anhydrous lithium acetate, anhydrous calcium acetate, anhydrous magnesium acetate, anhydrous ferrous acetate, anhydrous sodium sulfate, anhydrous potassium sulfate, anhydrous magnesium sulfate, anhydrous lithium sulfate, anhydrous sodium dihydrogen phosphate, anhydrous disodium hydrogen phosphate, and anhydrous potassium hydrogen phosphate, or a combination of two or more thereof.

[0016] The amount of the dehydrating agent used is calculated and determined based on the water content of the reaction system and the dehydrating capacity of the dehydrating agent. For example, the total amount of water in the solvent and reagent is A, and the dehydrating capacity of the dehydrating agent is B, and B is always required to be greater than A. The purpose of adding a dehydrating agent to the reaction is mainly to combine the water in the reaction system, including the water brought in by the reactants and the water generated by the reaction, so as to promote the condensation reaction to proceed fully. Therefore, the amount of the dehydrating agent added to the reaction system is usually more than the total amount of water in the reaction system.

[0017] The palladium-carbon catalyst has a water content of 40%-60%, and the mass ratio of palladium excluding water is 5%-10%. Before use, it is washed with methanol or ethanol to remove more than 90% of the water, and then used for catalytic reaction.

[0018] Preferably, the palladium-carbon catalyst has a water content of 50%, a palladium mass ratio other than water content of 10%, and is washed with ethanol to remove more than 90% of water before use, and then used for catalytic reaction. The amount of the palladium-carbon catalyst referred to in the reaction is based on the mass of the palladium-carbon catalyst before removing water (i.e., the water content is 50%).

[0019] Preferably, the heating temperature in step S1 is 30°C-45°C.

[0020] Preferably, the step S2 of adding the palladium-carbon catalyst to the solution and mixing them thoroughly is a mixing reaction for 0.5-2h. The purpose is to allow the palladium-carbon catalyst to mix thoroughly with the solution to facilitate subsequent catalytic reactions. The protective gas is nitrogen or an inert gas.

[0021] Preferably, the step S2 of introducing hydrogen and pressurizing for the hydrogenation reduction reaction is to introduce hydrogen, control the hydrogen pressure to 8.5-10 atm, react at a temperature of 30°C-50°C, and react for 10-16 hours. When the reaction pressure is low, the reaction time is prolonged; when the pressure is too high, the by-products increase. The time of the hydrogenation reduction reaction is determined according to the HPLC test results, and is determined by comprehensive economic cost and the yield of the synthetic product.

[0022] Preferably, the concentrated solution recrystallization purification in step S3 is performed by adding 50% by volume ethanol aqueous solution into the concentrated solution to dissolve and precipitate crystals.

[0023] Preferably, the step S3 is: adding an appropriate amount of water to the reaction solution after the reaction, filtering under reduced pressure, collecting the filtrate, recovering the palladium-carbon catalyst and washing it with ethanol, collecting the washing solution and merging the filtrate, concentrating under reduced pressure, and purifying the concentrated solution by recrystallization to obtain N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester. That is, step S3 can also include the step of recovering the palladium-carbon catalyst to achieve the recycling of the palladium-carbon catalyst.

[0024] The third object of the present invention is to provide the use of N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester in the preparation of products containing sweeteners.

[0025] Preferably, the product containing the sweetener is food, beverage or medicine.

[0026] The present invention has the following beneficial effects:

[0027] The present invention uses aspartame and L-arabinose for synthesis reaction, and the product is N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester; the product has a pure taste, close to the taste of sucrose, and a sweetness multiple of 800-1000 times that of sucrose, and has a significant difference in taste from high-multiple sweeteners such as advantame, neotame, and stevioside. The synthesis process of the present invention is simple, easy to operate, relatively low in cost, in line with green development, easy to realize industrialization, and has good use value and economic value in the field of food technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a chromatogram of N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester.

[0029] Figure 2 This is the mass spectrum of N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester.

[0030] Figure 3 It is a radar chart of the sensory flavor profile of sweeteners. DETAILED DESCRIPTION

[0031] The following examples are provided to further illustrate the present invention, rather than to limit the present invention.

[0032] The following reagents were used: ethanol was anhydrous ethanol purchased from Jinan Century Tongda Chemical Co., Ltd., purity specification: 99.9%; anhydrous sodium chloride was purchased from AP Science, model: B1017, purity: ≥99.5%; aspartame was purchased from Jiangsu Hanguang Sweetener Co., Ltd., model: Hanguang Aspartame, purity: ≥99.5%; L-arabinose was purchased from Jiangsu Dongju Biotechnology Co., Ltd., model: food grade, purity: 99%; palladium carbon catalyst was purchased from Sigma-Aldrich (China), model: palladium carbon (10%).

[0033] The following instruments were used: 400 MHz nuclear magnetic resonance spectrometer, manufacturer: Bruker, Switzerland, model: AVANCE NEO400 MHz NMR SPECTROMETER NANO; Agilent liquid chromatography / quadrupole-time of flight mass spectrometry (LC / Q-TOF); Agilent liquid chromatography (HPLC) 1260 Infinity I.

[0034] Example 1

[0035] A method for synthesizing a new sweetener comprises the following steps.

[0036] S1. Add 180 mL of ethanol, 11.7 g of anhydrous sodium chloride, 10 g of aspartame and 20 g of L-arabinose into a reactor, heat to 45°C and fully dissolve;

[0037] S2, take 0.35g of palladium carbon catalyst (the water content of palladium carbon catalyst is 50%, and the mass ratio of palladium excluding water is 10%), wash it twice with 20mL of ethanol to remove more than 90% of the water, then add it to the solution prepared in step S1, mix and react for 2h, and then proceed to step S3;

[0038] S3, replace the air in the kettle with nitrogen, and then replace the nitrogen in the kettle with hydrogen, control the hydrogen pressure to 10atm, the reaction temperature to 50°C, and carry out hydrogenation reduction reaction. After the reaction for 16h, the reaction liquid enters step S4;

[0039] S4. After the reaction is completed, the reaction pressure is released and replaced with nitrogen. 10 mL of water is added to the reaction solution, and the reaction solution is filtered under reduced pressure. The filtrate is collected, the palladium carbon catalyst is recovered and washed with ethanol, the washing solution is collected and combined with the filtrate, and the mixture is concentrated under reduced pressure to a slurry to obtain a crude product (i.e., a concentrated solution); then, a 50% by volume ethanol aqueous solution is added to the concentrated solution to dissolve and crystallize to obtain a new sweetener.

[0040] After NMR spectroscopy and mass spectrometry analysis, it was confirmed that the sweetener in the product was N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester. The chromatogram of N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester is shown in the figure below. Figure 1 As shown. After HPLC analysis, the purity of N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester in the crude product reached 78.09%; 11.5 g of the new sweetener was obtained, of which the purity of N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester was 85.4%, and the yield (actual yield divided by theoretical yield) was 82.1%.

[0041] The N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl]-L-phenylalanine-1-methyl ester prepared in Example 1 has the following NMR spectral characteristics: 13C NMR (100 MHz, CD3Cl): 175.1, 173.2, 171.7, 136.6, 128.6, 128.6, 127.7, 127.7, 125.9, 72.8, 72.1, 72.0, 64.4, 61.2, 56.7, 51.9, 49.9, 40.6, 36.8. The mass spectrum of the obtained N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl]-L-phenylalanine-1-methyl ester is as follows: Figure 2 As shown, the mass spectrometry data are as follows: MS (ESI, m / z) 427.17 (MH + ); The theoretical calculation data of high-resolution electrospray ionization mass spectrometry is [C 19 H 28 N2O9]-(MH + )427.1717, the actual measured value is 427.1737.

[0042] Example 2

[0043] A method for synthesizing a new sweetener comprises the following steps:

[0044] S1. Add 140 mL of ethanol, 7.8 g of anhydrous sodium chloride, 10 g of aspartame and 20 g of L-arabinose into a reactor, heat to 35°C and fully dissolve;

[0045] S2, take 0.35g of palladium carbon catalyst (the water content of palladium carbon catalyst is 50%, and the mass ratio of palladium excluding water is 10%), wash it twice with 20mL of ethanol to remove more than 90% of the water, then add it to the solution prepared in step S1, react for 1h and proceed to step S3;

[0046] S3, replace the air in the kettle with nitrogen, and then replace the nitrogen in the kettle with hydrogen, control the hydrogen pressure to 8.5atm, mix and react at 40°C, perform hydrogenation reduction reaction, and after 13h of reaction, the reaction liquid enters step S4;

[0047] S4. After the reaction is completed, the reaction pressure is released and replaced with nitrogen. 10 mL of water is added to the reaction solution, and the reaction solution is filtered under reduced pressure. The filtrate is collected, the palladium carbon catalyst is recovered and washed with ethanol, the washing solution is collected and combined with the filtrate, and the mixture is concentrated under reduced pressure to a slurry to obtain a crude product (i.e., a concentrated solution); then, a 50% by volume ethanol aqueous solution is added to the concentrated solution to dissolve and crystallize to obtain a new sweetener.

[0048] After HPLC detection and analysis, the purity of N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester in the crude product reached 77.91%; 10.8 g of the new sweetener was obtained, of which the purity of N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester was 83.1%, and the yield was 77.1%.

[0049] Example 3

[0050] A method for synthesizing a new sweetener comprises the following steps:

[0051] S1. Add 100 mL of ethanol, 3.9 g of anhydrous sodium chloride, 10 g of aspartame and 10 g of L-arabinose into a reactor, heat to 30°C and fully dissolve;

[0052] S2, take 0.35g of palladium carbon catalyst (the water content of palladium carbon catalyst is 50%, and the mass ratio of palladium excluding water is 10%), wash it twice with 20mL of ethanol to remove more than 90% of the water, then add it to the solution prepared in step S1, mix and react for 0.5h, and then proceed to step S3;

[0053] S3, replace the air in the kettle with nitrogen, and then replace the nitrogen in the kettle with hydrogen, control the hydrogen pressure to 8.5atm, the reaction temperature to 30°C, and carry out hydrogenation reduction reaction. After the reaction for 10h, the reaction liquid enters step S4;

[0054] S4. After the reaction is completed, the reaction pressure is released and replaced with nitrogen. 10 mL of water is added to the reaction solution, and the reaction solution is filtered under reduced pressure. The filtrate is collected, the palladium carbon catalyst is recovered and washed with ethanol, the washing solution is collected and combined with the filtrate, and the mixture is concentrated under reduced pressure to a slurry to obtain a crude product (i.e., a concentrated solution); then, a 50% by volume ethanol aqueous solution is added to the concentrated solution to dissolve and crystallize to obtain a new sweetener.

[0055] After HPLC detection and analysis, the purity of N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester in the crude product reached 66.35%; 6.995 g of the new sweetener was obtained, of which the purity of N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester was 72.6%, and the yield was 67.8%.

[0056] Example 4: Evaluation of new sweeteners

[0057] 1. Sweetness Evaluation

[0058] The new sweetener prepared in Example 1 was taken and the relative sweetness was measured by the calibration test method.

[0059] Prepare 10 gradient concentrations of sucrose solutions of 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 6.0%, 7.0%, 8.0%, 9.0%, and 10% (w / w) as references. Since the sweetness of the new sweetener prepared in Example 1 is too high, it cannot be evaluated normally; therefore, the new sweetener is first diluted 1000 times with pure water to prepare a thousand-fold dilution, and then the thousand-fold dilution is taken as the mother liquor to be diluted to prepare 2% and 5% new sweetener thousand-fold dilutions (that is, the mass proportion of the new sweetener component in the 2% new sweetener thousand-fold dilution is 2%*1‰, and the mass proportion of the new sweetener component in the 5% new sweetener thousand-fold dilution is 5%*1‰) as test samples.

[0060] All experimental sample solutions were prepared using purified water and placed at room temperature (22±1°C) in advance. Each solution was prepared based on the mass ratio (w / w). The sample solution was placed in a 50 mL tasting cup.

[0061] Ten senior perfumers with more than five years of experience were invited to serve as testers to evaluate the sweetener. Each tester was provided with 10 sucrose solution references with gradient concentrations and two new sweetener test samples with different concentrations for testing. The sample with the sweetness closest to that of the test sample was selected. The test results are shown in Table 1.

[0062] Table 1 Sweetness test results

[0063]

[0064]

[0065] The test results show that the sweetness of the new sweetener prepared in Example 1 is 800 to 1000 times that of sucrose, and as the concentration of the new sweetener increases, its sweetness relative to sucrose tends to decrease.

[0066] 2. Sweetness Evaluation

[0067] Ten senior perfumers with more than 5 years of experience were invited as evaluators to evaluate the sensory flavor characteristics of different sweetener products. Six flavor characteristic indicators of "sugar sweetness, sugar substitute, peculiar taste, metallic taste, mouthfeel, and aftersweetness" were determined through screening, and the sucrose flavor characteristics were used as a reference. After preliminary testing, a series of stevioside, sucralose, aspartame, neotame and the new sweetener samples prepared in Example 1 with equal sweetness were prepared with 5% sucrose sweetness as the standard. The concentrations of each sweetener (Table 2) are explained as follows:

[0068] Sample No. 1 is a sucrose aqueous solution prepared with sucrose at a mass fraction of 5%, which is then used for tasting evaluation.

[0069] Sample No. 2 was prepared by diluting stevioside 100 times as a stevioside mother solution (i.e., stevioside was prepared into a 1% by mass stevioside aqueous solution as a stevioside mother solution). Then, 10 mL of the stevioside mother solution was taken, made up to 1000 mL with water and diluted and mixed (i.e., prepared into a 1% concentration of the stevioside mother solution), and then used for tasting evaluation.

[0070] Sample No. 3 was prepared by diluting sucralose 100 times as a sucralose mother liquor (i.e., preparing sucralose into a 1% by mass sucralose aqueous solution as the sucralose mother liquor), then taking 8 mL of the sucralose mother liquor, adding water to make up to 1000 mL and diluting and mixing (i.e., preparing a 0.8% concentration of the sucralose mother liquor), and then using it for tasting evaluation.

[0071] Sample No. 4 is prepared by diluting aspartame 100 times as aspartame mother liquor (i.e., preparing aspartame into a 1% by mass aspartame aqueous solution as aspartame mother liquor), then taking 25 mL of aspartame mother liquor, adding water to make up to 1000 mL and diluting and mixing (i.e., preparing into 2.5% concentration of aspartame mother liquor), and then using it for tasting evaluation.

[0072] Sample No. 5 was prepared by diluting neotame 1000 times as a neotame mother liquor (i.e., preparing a neotame aqueous solution with a mass fraction of 0.1% as a neotame mother liquor), then taking 6 mL of the neotame mother liquor, adding water to make up to 1000 mL and diluting and mixing (i.e., preparing a 0.6% concentration of the neotame mother liquor), and then using it for tasting evaluation.

[0073] Sample No. 6 is prepared by diluting the new sweetener 1000 times as the new sweetener mother liquor (i.e., preparing the new sweetener into a new sweetener aqueous solution with a mass fraction of 0.1% as the new sweetener mother liquor), then taking 40 mL of the new sweetener mother liquor, adding water to make up to 1000 mL and diluting and mixing (i.e., preparing it into a 4% concentration of the new sweetener mother liquor), and then using it for tasting evaluation.

[0074] Use purified water to prepare all experimental sample solutions, and place the sample solutions at room temperature (22±1℃) in advance. Each solution is prepared based on the mass ratio (w / w). The sample solution is placed in a 50mL tasting cup and the evaluator is asked to evaluate it.

[0075] Using sucrose as the standard sample, the test results are shown in Table 2. The numerical results in Table 2 are scored on a scale of 1-5, with a higher score indicating a more significant indicator.

[0076] Table 2 Sweetness test results

[0077]

[0078] A radar chart is drawn based on the intensities of the above six sensory characteristic indicators corresponding to each sample in Table 2 to determine the flavor characteristics of each sweetener. The radar chart shows the results as follows: Figure 3 shown.

[0079] The test results show that the new sweetener prepared in Example 1 has a sweetness and flavor index close to that of sucrose, and has certain advantages over stevioside, sucralose, aspartame, and neotame. This experiment verifies the taste and flavor characteristics of the new sweetener, and in the future it can be considered to replace sucrose or other sweeteners and be widely used in the food, beverage, and pharmaceutical industries.

Claims

1. A dipeptide sweetener, characterized in that: It is N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester, and its structural formula is shown in Formula I:

2. A method for synthesizing N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester, characterized in that it comprises the following steps: S1. Add ethanol, dehydrating agent, aspartame and L-arabinose into a reactor in sequence and heat until fully dissolved; S2, adding palladium carbon catalyst to the dissolved solution and mixing thoroughly, replacing the air in the reaction system with protective gas, introducing hydrogen gas and pressurizing to carry out hydrogenation reduction reaction; S3. After the reaction, the reaction solution is filtered under reduced pressure, the filtrate is collected, concentrated under reduced pressure, and the concentrated solution is recrystallized and purified to obtain N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester.

3. The synthesis method according to claim 2, characterized in that In the step S1, the molar ratio of L-arabinose to aspartame is 0.5-4:1, the molar ratio of the dehydrating agent to aspartame is 1-10:1, the mass ratio of ethanol to aspartame is 5-20:1, and the mass ratio of the palladium carbon catalyst to aspartame is 0.01-0.1:

1.

4. The synthesis method according to claim 3, characterized in that In the step S1, the molar ratio of L-arabinose to aspartame is 1.8-4:1, the molar ratio of the dehydrating agent to aspartame is 1.9-5.9:1, the mass ratio of ethanol to aspartame is 7.5-14.5:1, and the mass ratio of the palladium carbon catalyst to aspartame is 0.035:

1.

5. The synthesis method according to claim 2, characterized in that The dehydrating agent is any one of anhydrous ferric chloride, anhydrous ferrous chloride, anhydrous magnesium chloride, anhydrous calcium chloride, anhydrous lithium chloride, anhydrous potassium chloride, anhydrous sodium chloride, anhydrous sodium bicarbonate, anhydrous potassium bicarbonate, anhydrous lithium bicarbonate, anhydrous potassium acetate, anhydrous sodium acetate, anhydrous lithium acetate, anhydrous calcium acetate, anhydrous magnesium acetate, anhydrous ferrous acetate, anhydrous sodium sulfate, anhydrous potassium sulfate, anhydrous magnesium sulfate, anhydrous lithium sulfate, anhydrous sodium dihydrogen phosphate, anhydrous disodium hydrogen phosphate, and anhydrous potassium hydrogen phosphate, or a combination of two or more thereof; the palladium-carbon catalyst has a water content of 50%, a palladium mass ratio excluding water of 10%, and is washed with ethanol to remove more than 90% of water before use, and then used for catalytic reaction.

6. The synthesis method according to claim 2, characterized in that The heating temperature of step S1 is 30°C-45°C; the palladium carbon catalyst is added to the dissolved solution and mixed thoroughly in step S2, and the mixing reaction is carried out for 0.5-2h, and the protective gas is nitrogen or an inert gas; the hydrogen is introduced and pressurized for hydrogenation reduction reaction in step S2, and hydrogen is introduced, the hydrogen pressure is controlled to be 8.5-10atm, the reaction temperature is 30°C-50°C, and the reaction is carried out for 10-16h.

7. The synthesis method according to claim 2, characterized in that The concentrated solution recrystallization purification in step S3 is to add 50% by volume ethanol aqueous solution into the concentrated solution to dissolve and precipitate crystals.

8. The synthesis method according to claim 2, characterized in that The step S3 is as follows: adding an appropriate amount of water to the reaction solution after the reaction, filtering under reduced pressure, collecting the filtrate, recovering the palladium-carbon catalyst and washing it with ethanol, collecting the washing solution and combining the filtrate, concentrating under reduced pressure, and recrystallizing and purifying the concentrated solution to obtain N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester.

9. Use of N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester in the preparation of products containing sweeteners.

10. The use according to claim 9, characterized in that: The products containing sweeteners are food, beverages and medicines.

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