Sugar substitute chromogenic molecular device as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of sugar-substituted molecular design, and discloses a sugar-substituted chromogenic molecular device as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing a sucralose solution, an inorganic alkali solution and a urocanic acid solution, and reacting to obtain the sugar substitute chromogenic molecular device. According to the preparation method of the sugar substitute chromogenic molecular device, a one-step method is adopted, required raw materials mainly come from natural and industrial sugar substitutes, the price is controllable, the overall application and preparation cost is low, the device is suitable for large-scale chemical preparation, no complex preparation technology is adopted in the whole process, the final yield is high, and the process is relatively green and environmentally friendly; the method is typical natural product reconstruction and trans-boundary high-valued application in the food boundary.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sugar substitute molecule design, and particularly relates to a sugar substitute chromogenic molecule device and a preparation method and application thereof. BACKGROUND

[0002] Non-concentrated juice (NFC) solution is popular in the market because it is not concentrated, does not add water or preservatives in the production process, has a relatively short shelf life, and the flavor is closer to the actual fresh fruit. Generally, in the preparation process of NFC juice solution in the food industry, the dilution degree is closely related to the content of the thickening component added, which also affects the final drinking taste.

[0003] Micro-viscosity, as a property that can reflect the resistance of fluid to deformation or prevent the relative flow of adjacent fluid layers, has a deep connection with the apparent properties of NFC juice, such as flow, wetting, processing, and taste, as a physical parameter. For example, when the micro-viscosity of NFC juice solution is low, it has good flowability, can fully penetrate and mix various nutritional components, and can maintain good flow transmission during processing; when the micro-viscosity of NFC juice solution is high, it presents a paste-like state, and the flowability decreases significantly, making it difficult to fully flow and transport, but it can better retain and anchor various nutrients, forming a good nutrient filling layer. Therefore, the control of the dilution degree of NFC juice solution has a good promoting effect on subsequent processing and tasting. The change of micro-viscosity of NFC juice solution often occurs in the micro region. Traditional viscosity measurement is mostly designed for macro-viscosity and mainly relies on various types of viscometers (falling ball viscometer, rotary viscometer, vibration viscometer, etc.). The measurement has strong equipment dependence, requires a large amount of samples, and is not sensitive to the change of micro-viscosity, especially for NFC juice containing various oligomers (even polymer nutritional components), which has a significant shear thinning effect, making it difficult to measure the micro-viscosity at the molecular level and causing large measurement errors.

[0004] Sugar substitutes are common additives in NFC juice. Among them, sucralose is commonly used to sweeten NFC juice because of its high sweetness. Sucralose has a good reactive active site, which can provide a good possibility for further functionalization. At present, there are few sugar substitutes that introduce chromogenic devices to activate sugar molecules and improve their multiple functionalities. There are also few in-situ molecular-level micro-viscosity measurements for fine control of the dilution degree of NFC juice, which greatly improves the efficiency, convenience, and visualization.

[0005] Therefore, it is of great significance to obtain a sugar substitute chromogenic molecule device suitable for NFC juice solution and capable of measuring the change of micro-viscosity, and a preparation method and application thereof. SUMMARY

[0006] The present application aims to provide a sugar-substituted chromogenic molecular device, a preparation method and application thereof, so as to solve the problems of large measurement error and excessive dependence on viscometer in the prior art.

[0007] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions.

[0008] The present application provides a sugar-substituted chromogenic molecular device, the structural formula of which is shown in formula I:

[0009]

[0010] The present application also provides a preparation method of the sugar-substituted chromogenic molecular device, which comprises the following steps: mixing a chloro-sucrose solution, an inorganic alkali solution and a urocanic acid solution, and then reacting to obtain the sugar-substituted chromogenic molecular device.

[0011] Preferably, in the chloro-sucrose solution, the concentration of chloro-sucrose is 0.5-3 mol / L, and the solvent is a mixed solution of ethanol, methanol and ethylene glycol, and the volume ratio of the ethanol, methanol and ethylene glycol is 1-5:1-3:1.

[0012] Preferably, in the inorganic alkali solution, the ratio of the amount of inorganic alkali to the amount of solvent is 10-50 g:0.5 L, the inorganic alkali is one or more of sodium carbonate, sodium bicarbonate, cesium carbonate, potassium carbonate and potassium bicarbonate, and the solvent is a mixed solution of ethanol, methanol and ethylene glycol, and the volume ratio of the ethanol, methanol and ethylene glycol is 1-5:1-3:1.

[0013] Preferably, in the urocanic acid solution, the concentration of urocanic acid is 1-3 mol / L, and the solvent is a PBS buffer solution, and the pH value of the PBS buffer solution is 7-8.

[0014] Preferably, the molar ratio of chloro-sucrose, inorganic alkali and urocanic acid is 1-3:1-3:1.

[0015] Preferably, the mixing is first to stir and mix the chloro-sucrose solution and the inorganic alkali solution to obtain a mixed solution, and then to add the urocanic acid solution to the mixed solution.

[0016] Preferably, the rate of adding the urocanic acid solution is 5-10 mL / min.

[0017] The urocanic acid solution is added while being heated, and the heating rate to the reaction temperature is 1-5 ℃ / min.

[0018] Preferably, the reaction temperature is 70-95 ℃, and the reaction time is 3-12 h.

[0019] The application further provides application of the sugar-substituted color-producing molecular device in NFC juice micro-region viscosity detection.

[0020] Compared with the prior art, the application has the following beneficial effects:

[0021] The sugar-substituted color-producing molecular device can realize visual monitoring of the NFC juice modulation process, fills the blank of in-situ, real-time and convenient micro-region viscosity detection of traditional NFC juice, and avoids the shear thinning effect caused by a large amount of oligomers or even polymers in traditional NFC juice, that is, the sugar-substituted color-producing molecular device can be used as a molecular-level tool for regulating the concentration of NFC juice solution, and this method is very effective for monitoring and controlling the concentration of NFC juice solution, and can provide an effective reference for the development of multifunctional sugar-substituted tools.

[0022] The sugar-substituted color-producing molecular device has good pH stability and light stability, the released light signal intensity is consistent with the logarithmic function of the viscosity value of conventional NFC juice, and the viscosity sensitive coefficient reaches 0.80, indicating that the sensitivity to viscosity is high, and the sugar-substituted color-producing molecular device is suitable for measuring the viscosity of conventional NFC juice.

[0023] The apparent light signal of the sugar-substituted color-producing molecular device is bright blue, the visual sensitivity is high, the visual effect is good, and the Turn-on detection effect is good, the wavelength peak is 408nm, the emission wavelength range of violet light / ultraviolet light can be effectively avoided, the Stokes shift is more than 134nm, the interference of excitation light can be effectively avoided, and the signal-to-noise ratio is greatly improved.

[0024] The sugar-substituted color-producing molecular device is a modified compound of sugar substitute, has good solubility of sugar substitute, and has good rotatable characteristics, can be used as a functional modification layer of sugar substitute molecules, and provides the color-producing property of the sugar-substituted molecular device, and strengthens the comprehensive function of the sugar-substituted molecular device.

[0025] The application further provides a preparation method of the sugar-substituted color-producing molecular device, the method is prepared by one-step method, the required raw materials mainly come from nature and industrial sugar substitutes, the price is controllable, the overall application preparation cost is low, is suitable for large-scale chemical preparation, the whole process is simple, the final yield is high, the process is relatively green and environmentally friendly, is a typical reconstruction of natural products and cross-border high-value application in the food industry. BRIEF DESCRIPTION OF DRAWINGS

[0026] ​In order to make the technical solutions in the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description only aim at the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without any creative effort based on the provided drawings.

[0027] Figure 1 Schematic diagram of the mechanism of the sugar substitute chromogenic molecular device obtained in Example 1 for microviscosity detection;

[0028] Figure 2 High-resolution mass spectrum of the sugar substitute chromogenic molecular device obtained in Example 1;

[0029] Figure 3 Nuclear magnetic resonance spectrum of the sugar substitute chromogenic molecular device obtained in Example 1;

[0030] Figure 4 Emission spectrum of the sugar substitute chromogenic molecular device obtained in Example 1 in glycerol / water mixed solutions with different volume fractions;

[0031] Figure 5 Logarithmic function graph of the fluorescence intensity and viscosity value of the sugar substitute chromogenic molecular device obtained in Example 1;

[0032] Figure 6 Light stability test graph of the sugar substitute chromogenic molecular device obtained in Example 1 in glycerol and purified water, respectively;

[0033] Figure 7 Stokes shift spectrum of the sugar substitute chromogenic molecular device obtained in Example 1;

[0034] Figure 8 Emission spectrum of the sugar substitute chromogenic molecular device obtained in Example 1 in different commercial NFC juices;

[0035] Figure 9 Spectrum of the sugar substitute chromogenic molecular device obtained in Example 1 in NFC juices within 7 days of standing at room temperature (a) and fresh-keeping temperature (b). DETAILED DESCRIPTION

[0036] The present application provides a sugar substitute chromogenic molecular device, and a structural formula of the sugar substitute chromogenic molecular device is shown as formula I:

[0037]

[0038] The present application also provides a preparation method of the sugar substitute chromogenic molecular device, and the preparation method comprises the following steps: mixing a sucralose solution, an inorganic alkali solution and a urocanic acid solution, and then reacting to obtain the sugar substitute chromogenic molecular device.

[0039] In the present application, the concentration of sucralose in the sucralose solution is preferably 0.5-3 mol / L, further preferably 1-2.5 mol / L, more preferably 1.5-2 mol / L, and the solvent is preferably a mixed solution of ethanol, methanol and ethylene glycol, and the volume ratio of the ethanol, methanol and ethylene glycol is preferably 1-5:1-3:1, further preferably 2-4:1.5-2.5:1, and more preferably 3-3.5:2-2.2:1.

[0040] In the present application, the preparation method of the sucralose solution is as follows: sucralose is mixed with a solvent by stirring to obtain a sucralose solution.

[0041] The stirring rate is preferably 600-1600 rpm, further preferably 800-1400 rpm, and more preferably 1000-1200 rpm, the stirring time is preferably 0.3-1.2 h, further preferably 0.5-1 h, and more preferably 0.6-0.8 h, and the stirring temperature is preferably 20-30℃, further preferably 22-26℃, and more preferably 24-25℃.

[0042] In the present application, the amount ratio of the inorganic base to the solvent in the inorganic base solution is preferably 10-50 g:0.5 L, further preferably 20-40 g:0.5 L, and more preferably 30-35 g:0.5 L, the inorganic base is preferably one or more of sodium carbonate, sodium bicarbonate, cesium carbonate, potassium carbonate and potassium bicarbonate, and the solvent is preferably a mixed solution of ethanol, methanol and ethylene glycol, and the volume ratio of the ethanol, methanol and ethylene glycol is preferably 1-5:1-3:1, further preferably 2-4:1.5-2.5:1, and more preferably 3-3.5:2-2.2:1.

[0043] In the present application, the concentration of the uric acid in the uric acid solution is preferably 1-3 mol / L, further preferably 1.5-2.5 mol / L, and more preferably 1.8-2 mol / L, the solvent is preferably a PBS buffer solution, the pH value of the PBS buffer solution is preferably 7-8, further preferably 7.2-7.8, and more preferably 7.4-7.6, and the PBS buffer solution is preferably a mixed solution of sodium monobasic phosphate and sodium dihydrogen phosphate.

[0044] In the present application, the preparation method of the uric acid solution is as follows: uric acid is mixed with a solvent by stirring to obtain a uric acid solution.

[0045] The stirring mixing rate is preferably 1000-1600 rpm, further preferably 1100-1500 rpm, more preferably 1200-1400 rpm, the stirring mixing time is preferably 0.5-1.5 h, further preferably 0.7-1.3 h, more preferably 0.8-1 h, and the stirring mixing temperature is preferably 40-75℃, further preferably 50-70℃, more preferably 60-65℃.

[0046] In the present application, the molar ratio of sucralose, inorganic base and urocanic acid is preferably 1-3:1-3:1, further preferably 1.5-2.5:1.5-2.5:1, more preferably 1.8-2:2-2.2:1.

[0047] In the present application, the mixing is preferably first stirring and mixing the sucralose solution and the inorganic base solution to obtain a mixed solution, and then adding the urocanic acid solution to the mixed solution.

[0048] In the present application, the stirring mixing rate is preferably 600-1200 rpm, further preferably 700-1000 rpm, further preferably 800-900 rpm, the stirring mixing time is preferably 0.5-1.5 h, further preferably 0.8-1.4 h, more preferably 1-1.2 h, and the stirring mixing temperature is preferably 20-30℃, further preferably 22-28℃, more preferably 25-26℃.

[0049] In the present application, the rate of adding the urocanic acid solution is preferably 5-10 mL / min, further preferably 6-9 mL / min, more preferably 7-8 mL / min;

[0050] The temperature is preferably raised at the same time as the addition of the urocanic acid solution, and the temperature raising rate to the reaction temperature is preferably 1-5℃ / min, further preferably 2-4℃ / min, more preferably 3-3.5℃ / min.

[0051] In the present application, the reaction temperature is preferably 70-95℃, further preferably 75-90℃, more preferably 80-85℃, and the reaction time is preferably 3-12 h, further preferably 5-10 h, more preferably 6-8 h.

[0052] In the present application, the temperature raising process and the reaction are both carried out under ultrasonic stirring;

[0053] The ultrasonic power is preferably 100-500 W, further preferably 200-400 W, more preferably 300-350 W;

[0054] The rotation speed of the stirring is preferably 1200-2000 rpm, further preferably 1400-1800 rpm, and more preferably 1500-1600 rpm.

[0055] In the present application, the cooling, the reduced pressure distillation, the filtration and the drying are sequentially performed after the reaction;

[0056] The temperature of the cooling is preferably 20-30℃, further preferably 22-28℃, and more preferably 24-25℃.

[0057] The reduced pressure distillation is used to remove the solvent, and the pressure of the reduced pressure distillation is preferably -0.07 to -0.09 MPa, further preferably -0.075 to -0.085 MPa, and more preferably -0.078 to -0.08 MPa, and the rotation speed is preferably 50-300 rpm, further preferably 100-250 rpm, and more preferably 150-200 rpm.

[0058] The filtration is performed by mixing the crude product obtained by the reduced pressure distillation with a solvent and then standing until crystals are precipitated, and the solvent is preferably a mixed solution of anhydrous ethanol and water, and the volume ratio of anhydrous ethanol to water is preferably 1:1-5, further preferably 1:2-4, and more preferably 1:3-3.5, and the ratio of the use amount of the crude product to the solvent is preferably 2-6 mg:1 mL, further preferably 3-5 mg:1 mL, and more preferably 4-4.5 mg:1 mL, and the standing temperature is preferably 1-10℃, further preferably 3-7℃, and more preferably 5-6℃, and the standing time is preferably 12-28 h, further preferably 16-24 h, and more preferably 18-22 h, and the filter paper used for the filtration is preferably a medium-speed filter paper or a fast filter paper, the number of filter paper layers used for the filtration is preferably 1-3 layers, further preferably 2 layers, the flow rate of the filtration is preferably 0.2-1 mL / s, further preferably 0.4-0.8 mL / s, and more preferably 0.5-0.6 mL / s, the vacuum degree of the filtration is preferably -0.1 to -0.08 MPa, further preferably -0.095 to -0.085 MPa, and more preferably -0.09 to -0.088 MPa, and the solution used for the filtration is preferably a mixed solution of anhydrous ethanol and water, and the volume ratio of anhydrous ethanol to water is preferably 1:1-10, further preferably 1:2-8, and more preferably 1:3-5, and the flow rate of the mixed solution is preferably 0.2-1 mL / s, further preferably 0.4-0.8 mL / s, and more preferably 0.5-0.6 mL / s, and the number of repetitions of the filtration is preferably 1-4 times, further preferably 2-3 times.

[0059] The drying is preferably freeze-drying, the temperature of the freeze-drying is preferably -40 to -5 DEG C, further preferably -30 to -10 DEG C, more preferably -20 to -15 DEG C, and the time of the freeze-drying is preferably 24 to 72 hours, further preferably 36 to 54 hours, more preferably 42 to 48 hours.

[0060] In the present application, the sugar substitute chromogenic molecular device is based on the reconstruction of conventional sugar substitutes and natural products, and the obtained product is a light yellow powder, which is easily soluble in ethanol, methanol and ethylene glycol, and aqueous solutions of the above organic solvents, and is suitable for large-scale use in the food industry. The uric acid in the sugar substitute chromogenic molecular device has a good flexible conjugated structure, and there is a freely rotatable conjugated single bond in the molecular structure, which shows typical flexible intramolecular rotation characteristics. The conjugated structure can freely rotate in the food dilute solution, and the apparent light signal is weak. When in the food thick solution, the free rotation phenomenon is limited, and the apparent released light signal is strong. Therefore, it can be used as a sugar substitute molecular tool for monitoring the dilution change of food NFC solution, and can provide real-time, non-destructive and visual detection support for the process development of food NFC juice solution preparation. In addition, the overall chemical structure is stable and suitable for long-term storage, and the light stability is good, and the light bleaching phenomenon is not easy to occur.

[0061] The sugar substitute chromogenic molecular device can also be used for the visual detection of the deterioration of various types of flow state food, further strengthening the multiple functional performance of the sugar substitute molecular tool.

[0062] The present application also provides the application of the sugar substitute chromogenic molecular device in NFC juice micro-viscosity detection.

[0063] The technical solutions provided by the present application will be described in detail below in combination with the embodiments, but they should not be understood as limiting the scope of protection of the present application.

[0064] In the present application, NFC juice 1 is lemon juice, NFC juice 2 is apple juice, and NFC juice 3 is roxburgh rose juice.

[0065] Example 1

[0066] 795.2g of sucralose was mixed with a mixed solution of anhydrous ethanol, methanol and ethylene glycol in a volume ratio of 3:2:1 at a speed of 900rpm at 25 DEG C for 54min to obtain a sucralose solution with a concentration of 2mol / L;

[0067] 168g of sodium bicarbonate was mixed with 2.8L of solvent (a mixed solution of ethanol, methanol and ethylene glycol in a volume ratio of 3:2:1) to obtain an inorganic alkali solution;

[0068] 138.1g of uric acid was mixed with PBS solution with a pH of 7.5 at 1300rpm at 60℃ for 1h to obtain a uric acid solution with a concentration of 2mol / L.

[0069] Sucralose solution and inorganic alkali solution were mixed at 900 rpm and 25°C for 1 h to obtain a mixed solution. Uric acid solution was added to the mixed solution at a rate of 8 mL / min, and the temperature was increased at a rate of 3°C / min during the addition. After the addition was completed, the mixture was reacted at 85°C for 6 h to obtain the reaction solution. The above addition process and reaction process were carried out in a stirring and ultrasonic environment. The stirring rate was 1600 rpm and the ultrasonic power was 300 W.

[0070] After cooling the reaction solution to 25°C, the solvent was removed by vacuum distillation at a pressure of -0.08 MPa and a speed of 250 rpm to obtain the crude product.

[0071] The crude product was mixed with an ethanol-water solution at a volume ratio of 1:3 to obtain a solution with a solid content of 4 mg / L. The solution was allowed to stand at 5 °C for 18 h to precipitate crystals. The crystals were then filtered using an ethanol-water solution at a flow rate of 0.5 mL / s and a volume ratio of 1:5. Fast filter paper with two layers was used for filtration. The filtration operation was repeated twice. The resulting solid was then freeze-dried at -20 °C for 48 h to obtain 468 g of sucralose-based urea ester powder, i.e., a sugar substitute color-forming molecule device, denoted as "BDTCDA". The yield was calculated to be 90.4%.

[0072] Example 2

[0073] 397.6 g of sucralose was mixed with a mixture of anhydrous ethanol, methanol and ethylene glycol in a volume ratio of 1:1:1 at 25 °C for 72 min at a speed of 600 rpm to obtain a sucralose solution with a concentration of 1 mol / L.

[0074] 84g of sodium bicarbonate was mixed with 4.2L of solvent (a mixed solution of ethanol, methanol and ethylene glycol in a volume ratio of 1:1:1) to obtain an inorganic alkaline solution.

[0075] 138.1 g of uric acid was mixed with PBS solution with a pH of 7.5 at 1000 rpm at 40 °C for 1.5 h to obtain a uric acid solution with a concentration of 1 mol / L.

[0076] Sucralose solution and inorganic alkali solution were mixed at 600 rpm and 25°C for 1.5 h to obtain a mixed solution. Uric acid solution was added to the mixed solution at a rate of 5 mL / min, and the temperature was increased at a rate of 1°C / min during the addition. After the addition was completed, the mixture was reacted at 70°C for 12 h to obtain the reaction solution. The above addition process and reaction process were carried out in a stirring and ultrasonic environment. The stirring rate was 2000 rpm and the ultrasonic power was 100 W.

[0077] After cooling the reaction solution to 25°C, the solvent was removed by vacuum distillation at a pressure of -0.07 MPa and a rotation speed of 200 rpm to obtain the crude product.

[0078] The crude product was mixed with an ethanol-water solution at a volume ratio of 1:1 to obtain a solution with a solid content of 2 mg / L. The solution was allowed to stand at 1 °C for 12 h to precipitate crystals. The crystals were then filtered using an ethanol-water solution at a flow rate of 0.2 mL / s and a volume ratio of 1:1. Medium-speed filter paper was used for filtration, and one layer of filter paper was used. The filtration operation was repeated once. The resulting solid was then freeze-dried at -40 °C for 24 h to obtain 453.5 g of sucralose-based urea ester powder, which is a sugar substitute color-generating molecular device. The calculated yield was 87.6%.

[0079] Example 3

[0080] 1192.8g of sucralose was mixed with a mixture of anhydrous ethanol, methanol and ethylene glycol in a volume ratio of 5:3:1 at 1600rpm at 25℃ for 18min to obtain a sucralose solution with a concentration of 3mol / L.

[0081] 84g of sodium bicarbonate was mixed with 0.84L of solvent (a mixed solution of ethanol, methanol and ethylene glycol in a volume ratio of 5:3:1) to obtain an inorganic alkaline solution.

[0082] 138.1 g of uric acid was mixed with a PBS solution with a pH of 7.5 at 1600 rpm at 75°C for 0.5 h to obtain a uric acid solution with a concentration of 3 mol / L.

[0083] Sucralose solution and inorganic alkali solution were mixed at 1200 rpm at 25°C for 0.5 h to obtain a mixed solution. Uric acid solution was added to the mixed solution at a rate of 10 mL / min, and the temperature was increased at a rate of 5°C / min during the addition. After the addition was completed, the mixture was reacted at 95°C for 3 h to obtain the reaction solution. The above addition process and reaction process were carried out in a stirring and ultrasonic environment. The stirring rate was 1200 rpm and the ultrasonic power was 500 W.

[0084] After cooling the reaction solution to 25°C, the solvent was removed by vacuum distillation at a pressure of -0.09 MPa and a speed of 250 rpm to obtain the crude product.

[0085] The crude product was mixed with an ethanol-water solution at a volume ratio of 1:5 to obtain a solution with a solid content of 6 mg / L. The solution was allowed to stand at 10 °C for 28 h to precipitate crystals. The crystals were then filtered using an ethanol-water solution at a flow rate of 1 mL / s and a volume ratio of 1:10. Medium-speed filter paper with 3 layers was used for filtration. The filtration operation was repeated 4 times. The resulting solid was then freeze-dried at -5 °C for 72 h to obtain 462.3 g of sucralose-based urea ester powder, which is a sugar substitute color-generating molecular device. The yield was calculated to be 89.3%.

[0086] A schematic diagram of the mechanism of micro-area viscosity detection by the sugar substitute chromogenic molecular device obtained in Example 1 is shown below. Figure 1 As shown. By Figure 1 As can be seen, BDTCDA contains a freely rotatable single and double bond conjugated structure. This type of conjugated structure exhibits certain flexibility and intramolecular rotational properties. In low-viscosity NFC juice solutions, it can rotate freely and dissipate excited-state energy through non-radiative transitions, resulting in weak color formation. In high-viscosity NFC juice solutions, it is difficult to rotate, and excited-state energy is dissipated through radiative transitions, resulting in a significant difference in light signal intensity. The viscosity of the NFC juice solution can be judged based on the light signal intensity, and the sensitivity coefficient to micro-region viscosity is high (x = 0.80). In addition, the sugar substitute color-forming molecule device obtained in this invention has a stable chemical structure, good photostability, and good pH tolerance. Even under prolonged irradiation, it can maintain a good light signal intensity and also has a large Stokes shift.

[0087] The high-resolution mass spectrum of the sugar substitute chromogenic molecular device obtained in Example 1 is shown below. Figure 2 As shown. By Figure 2 It can be seen that the relative molecular mass of BDTCDA is 517.7514, and the molecular formula is C. 18 H 23 Cl3N2O9 has a theoretical relative mass estimate of 517.7470, which means that the product obtained in Example 1 is consistent with the target product in terms of relative molecular mass.

[0088] The nuclear magnetic resonance spectrum of the sugar substitute chromogenic molecule device obtained in Example 1 is shown below. Figure 3 As shown. By Figure 3 As can be seen, the carbon spectrum of BDTCDA is 13C NMR (101MHz, DMSO-d6) δ 167.5, 137.4, 136.2, 134.3, 128.9, 117.8, 115.2, 96.9, 87.8, 81.1, 79.5, 70.9, 70.1, 65.5, 64.1, 62.8, 45.1, 44.5. The carbon skeleton shift in its molecular structure was confirmed, and it can be identified as the target product, sucralose urea ester.

[0089] The following performance tests were performed on the sugar substitute chromogenic molecular device obtained in Example 1:

[0090] 1. Viscosity response test

[0091] According to Table 1, six groups of glycerol aqueous solutions with different viscosities were prepared. BDTCDA was added to each of the six groups of glycerol aqueous solutions to obtain glycerol solutions with a BDTCDA concentration of 10 μM. The external excitation wavelength was controlled at 350 nm, and the tests were conducted at room temperature. The obtained spectra are shown below. Figure 4 As shown.

[0092] Table 1. Relationship between solution viscosity and glycerol content in the solution

[0093] Glycerol volume fraction (%) 0 10 30 50 70 99 Viscosity (cP) 1.00 1.74 3.72 10.72 58.89 956.00

[0094] The emission spectra of the sugar substitute chromogenic molecular device obtained in Example 1 in glycerol / water mixed solutions of different volume fractions are shown below. Figure 4 As shown. By Figure 4 It is evident that as the viscosity of the micro-regions of the mixed solution gradually increases, the intensity of the emitted light signal also gradually increases. In particular, when the volume fraction of glycerol exceeds 70%, the viscosity of the mixed system increases more significantly, and its light signal intensity increases dramatically, reaching a maximum increase of 151.3 times compared to the solution system without added glycerol.

[0095] The logarithmic function of the optical signal intensity of the mixed solution and the viscosity of the solution can be fitted to a straight line, as shown below. Figure 5 As shown.

[0096] The logarithmic function of fluorescence intensity versus viscosity of the sugar substitute chromogenic molecular device obtained in Example 1 is shown in the figure below. Figure 5 As shown. By Figure 5 It is evident that BDTCDA releases a stronger light signal as the viscosity increases, and... The relationship is consistent, showing that BDTCDA has a viscosity sensitivity coefficient of 0.80 and a coefficient of determination of 0.96. The test results indicate that BDTCDA has good detection sensitivity for the micro-region viscosity of solutions and can be used as supporting data for the micro-region viscosity (thickness) adjustment process of NFC juice solutions. Specific logarithmic function values ​​are shown in Table 2.

[0097] Table 2. Logarithmic values ​​of viscosity and fluorescence intensity

[0098] Logarithm of viscosity (log η) 0.01 0.24 0.57 1.03 1.77 2.99 Logarithm of fluorescence intensity (log I) 1.80 1.99 2.40 2.88 3.41 3.98

[0099] 2. Light stability test

[0100] 1.04 mg of BDTCDA was dissolved in a 1:5 volume ratio ethanol-water solution to control the BDTCDA concentration at 2 mM. For subsequent testing, the solution was diluted to 10 μM using a 1:5 volume ratio ethanol-water solution and added to solutions of different viscosities (water and glycerol). The solutions were continuously excited under a 320 nm excitation source for 60 min, and the changes in optical signal intensity were measured. The test results are as follows: Figure 6 As shown in Table 3, the obtained data are presented in the table below.

[0101] Table 3 Fluorescence intensity test results

[0102] Time / min 0 10 20 30 60 Fluorescence intensity in purified water / a.u. 63.11 63.05 62.98 62.54 61.88 Fluorescence intensity in glycerol / a.u. 9549.8 9540.2 9451.3 9412.3 9367.2

[0103] The photostability test results of the sugar substitute chromogenic molecular device obtained in Example 1 in glycerol and purified water are shown in the figure below. Figure 6 As shown. By Figure 6 As shown in Table 3, BDTCDA exhibits good photostability and can release stable light signals under prolonged excitation light source irradiation.

[0104] 3. Stokes displacement test

[0105] 1.55 mg of BDTCDA was dissolved in an ethanol-water solution with a volume ratio of 1:5 to control the concentration of BDTCDA at 3 mM. For testing, the solution was further diluted to 10 μM with an ethanol-water solution with a volume ratio of 1:5, and then added to purified water to measure its absorption and emission spectra. The Stokes shift was also measured. All tests were conducted at room temperature, and the results are as follows: Figure 7 As shown.

[0106] The Stokes shift spectrum of the chromogenic molecule device obtained in Experiment Example 1 is as follows: Figure 7 As shown. By Figure 7 As can be seen, the Stokes shift of BDTCDA is 134 nm, indicating that it is not easily affected by the excitation wavelength and can effectively improve the signal-to-noise ratio.

[0107] Application Example 1

[0108] 2.07 mg of BDTCDA was dissolved in a 4:1 water-ethanol solution to control the BDTCDA concentration at 4 mM. During testing, this solution was further diluted to 10 μM using the same 4:1 water-ethanol solution. Three commercially available NFC juice solutions were selected as test subjects. The 10 μM BDTCDA solution was added to each of these three NFC juice solutions, and the test was conducted at room temperature with an external light source excitation wavelength of 320 nm. The test results are as follows. Figure 8 As shown.

[0109] The emission spectra of the sugar substitute color-producing molecular device obtained in Example 1 in different commercially available NFC juices are shown below. Figure 8 As shown. By Figure 8 As can be seen, the light signal release intensities of the three NFC juice solutions differ, indicating a certain viscosity difference. This may be related to the different types and components of the NFC juice solutions. The different components in the three NFC juice solutions will greatly affect their flow, adhesion, wetting, and taste. The final test results show that NFC juice 1 is a low-viscosity NFC juice solution, exhibiting a relatively thin appearance, with better flowability and smoothness in the mouth; NFC juice 2 is a medium-viscosity NFC juice solution, with a medium consistency; and NFC juice 3 is a high-viscosity NFC juice solution, exhibiting good viscosity, with better plasticity and body. These test results show that BDTCDA can fully sense the changes in viscosity in the micro-regions of NFC juice solutions and release them through visualized light signals. This is of great significance for studying the thickening process of different types of NFC juice solutions and can help develop more products that meet the needs of different customers.

[0110] Application Example 2

[0111] 2.59 mg of BDTCDA was dissolved in a 3:1 water-fructose corn syrup solution to control the BDTCDA concentration at 5 mM. During testing, this solution was further diluted to 10 μM using the 3:1 water-fructose corn syrup solution. NFC juice 1 was selected as the test subject. The 10 μM BDTCDA solution was added to NFC juice 1, and the mixture was left to stand for 7 days at room temperature (25°C) and at a preservation temperature (5°C). The light signal intensity was measured on days 0, 2, 5, and 7. The excitation wavelength of the external light source was controlled at 320 nm. The test results are as follows: Figure 9 As shown.

[0112] The spectra of NFC juice obtained from the sugar substitute color-producing molecular device in Example 1 after standing for 7 days at room temperature (a) and preservation temperature (b) are shown below. Figure 9 As shown. By Figure 9It is evident that the apparent light signal enhancement of NFC juice that has been left to stand at room temperature for 7 days (23.1%) is much greater than that of NFC juice that has been left to stand at the preservation temperature for 7 days (9.2%). This is because the rate and extent of spoilage of NFC juice after standing at room temperature for 7 days is greater than that at the preservation temperature. This spoilage process can be monitored by the sugar substitute color-producing molecule device provided by this invention, achieving better visualization and thus quickly determining the degree of spoilage of NFC juice.

[0113] As can be seen from the above embodiments, the sugar substitute chromogenic molecular device provided by the present invention has a flexible conjugated structure, which can exhibit different rotational states in environments with different micro-viscosities. Changes in the micro-viscosity of NFC juice solutions can be converted into apparent optical signals, achieving effective detection of the physical indicator of micro-viscosity of NFC juice solutions from a completely new molecular-level perspective. Various test results show that the sugar substitute chromogenic molecular device can maintain good optical signal intensity even under long-term irradiation, with an apparent blue color and high visual sensitivity. Its viscosity sensitivity coefficient is x = 0.80, making it suitable for detecting the micro-viscosity of NFC juice solutions in complex liquid environments containing multiple components. Its Stokes shift exceeds 134 nm, effectively avoiding interference caused by the excitation wavelength and significantly improving the signal-to-noise ratio. The sugar substitute chromogenic molecular device itself is also an improved sugar substitute molecule tool. Containing a rotatable flexible conjugated structure, it can not only serve as an in-situ testing tool for the viscosity of natural juices but also provide the possibility of visual detection for monitoring juice spoilage, effectively enhancing its multifunctionality as a sugar substitute chromogenic molecular device. Furthermore, the color-producing device rotor modified by natural products is prepared in one step. The preparation process is green and environmentally friendly, and the final yield is also high. The raw materials required are derived from natural products, which are inexpensive, easy to obtain, and have low preparation costs. The post-processing process is also simple and easy to carry out. Overall, it is low-carbon and environmentally friendly, cost-effective, and only requires milligram-level applications, making it suitable for large-scale industrial applications.

[0114] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A color-generating molecular device for sugar substitutes, characterized in that, The structural formula of the sugar substitute color-generating molecular device is shown in Formula I:

2. The method for preparing a sugar substitute color-generating molecular device according to claim 1, characterized in that, The preparation method includes the following steps: mixing sucralose solution, inorganic alkaline solution and uric acid solution and reacting them to obtain a sugar substitute color-generating molecular device.

3. The method for preparing a sugar substitute color-generating molecular device according to claim 2, characterized in that, The sucralose solution has a concentration of 0.5–3 mol / L and is a mixed solution of ethanol, methanol, and ethylene glycol in a volume ratio of 1–5:1–3:

1.

4. The method for preparing a sugar substitute color-generating molecular device according to claim 3, characterized in that, In the inorganic alkali solution, the ratio of inorganic alkali to solvent is 10-50 g: 0.5 L. The inorganic alkali is one or more of sodium carbonate, sodium bicarbonate, cesium carbonate, potassium carbonate, and potassium bicarbonate. The solvent is a mixed solution of ethanol, methanol, and ethylene glycol, and the volume ratio of ethanol, methanol, and ethylene glycol is 1-5:1-3:

1.

5. The method for preparing a sugar substitute color-generating molecular device according to claim 4, characterized in that, The concentration of uric acid in the uric acid solution is 1-3 mol / L, the solvent is PBS buffer solution, and the pH value of the PBS buffer solution is 7-8.

6. The method for preparing a sugar substitute color-generating molecular device according to any one of claims 3 to 5, characterized in that, The molar ratio of sucralose, inorganic base, and uric acid is 1–3:1–3:

1.

7. The method for preparing a sugar substitute color-generating molecular device according to claim 2, characterized in that, The mixing process involves first stirring and mixing a sucralose solution with an inorganic alkaline solution to obtain a mixed solution, and then adding a uric acid solution to the mixed solution.

8. The method for preparing a sugar substitute color-generating molecular device according to claim 7, characterized in that, The uric acid solution is added at a rate of 5–10 mL / min; The temperature is increased simultaneously with the addition of uric acid solution, and the heating rate to the reaction temperature is 1-5℃ / min.

9. The method for preparing a sugar substitute color-generating molecular device according to claim 7 or 8, characterized in that, The reaction temperature is 70–95°C, and the reaction time is 3–12 hours.

10. The application of the sugar substitute color-generating molecule device according to claim 1 in NFC juice micro-area viscosity detection.

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