Microcapsule technology-based toothpaste essence and preparation method thereof

Abstract

The invention relates to toothpaste essence based on a microcapsule technology and a preparation method of the toothpaste essence. According to the essence, modified essence molecules are wrapped by a microcapsule technology, so that slow and controllable release of the essence is realized. Modified essence molecules are esterified with acetic acid, react with methyl isocyanate to introduce amino groups, react with ethanol to introduce carboxyl groups, and react with ethylamine to introduce aldehyde groups, so that the stability, durability and controlled release performance of the essence molecules are enhanced. Through a microcapsule wrapping technology, the essence can be kept for a long time, and rapid volatilization of the essence is avoided. According to the technology, the essence can be released for a longer time in the toothpaste essence, the stability and the oxidation resistance of the essence are improved, and the use experience of a user is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of oral care products, specifically to a toothpaste flavoring based on microcapsule technology and its preparation method. Background Technology

[0002] Toothpaste fragrance is a key ingredient in oral care products, and its sustained release significantly impacts the user experience. However, traditional toothpaste fragrance application methods typically rely on directly mixing fragrance molecules into the toothpaste base. This causes the fragrance to evaporate rapidly within a short time, failing to last and resulting in an unsatisfactory user experience. Rapid fragrance evaporation not only affects the breath-freshening effect but also significantly diminishes the consumer's overall experience.

[0003] To overcome this problem, microencapsulation technology, as an effective sustained-release technology, has been gradually applied to various fields. Microencapsulation technology encapsulates fragrance components in tiny particles, allowing for controlled release rates and achieving slow release of the fragrance. Although microencapsulation technology has been widely used in food and pharmaceuticals, its application in toothpaste fragrances remains relatively limited. Furthermore, existing technologies mainly focus on simple encapsulation of fragrance molecules, lacking innovative solutions for controlling the stability and persistence of fragrance molecules. In addition, traditional microencapsulation materials are mostly polymers, which, while offering some sustained-release effects, still have limitations regarding the long-term release and stability of fragrance molecules.

[0004] Therefore, improving microencapsulation technology to more effectively control the release rate of fragrance molecules and enhance their stability and durability has become a major challenge in toothpaste fragrance technology. Summary of the Invention

[0005] To overcome the aforementioned technical challenges, the present invention aims to provide a toothpaste fragrance capable of long-lasting fragrance release. This invention employs microencapsulation technology to encapsulate modified fragrance molecules and enhances the stability, persistence, and release control of the fragrance molecules through innovative modification methods. In this way, the release rate of the fragrance molecules is effectively controlled, avoiding the problem of rapid fragrance evaporation, thereby significantly extending the fragrance's duration and improving the user experience. The beneficial effects of this invention are significantly improved stability and persistence of the toothpaste fragrance release, resulting in enhanced oral freshness.

[0006] The objective of this invention can be achieved through the following technical solutions: A toothpaste fragrance based on microencapsulation technology, the fragrance comprising the following raw materials in parts by weight: 30-40 parts modified fragrance molecules; 20-30 parts polylactic acid; 10-15 parts melamine-formaldehyde resin; 5-10 parts polyvinyl alcohol; 0.5-1 part antioxidant; and 1-3 parts santalol; wherein the modified fragrance molecules are introduced by esterification with acetic acid, catalyzed by concentrated sulfuric acid, and by introducing amino groups through reaction with methyl isocyanate, introducing carboxyl groups through esterification with ethanol, and introducing aldehyde groups through reaction with ethylamine, thereby improving the stability, durability, and release control performance of the fragrance molecules.

[0007] Optionally, the modified fragrance molecule comprises the following raw materials in parts by weight: 30-40 parts benzyl acetate; 5-10 parts acetic acid; 1-3 parts concentrated sulfuric acid; 0.5-1.5 parts methyl isocyanate; 3-5 parts ethanol; and 2-4 parts ethylamine.

[0008] Optionally, the method for preparing modified flavor molecules includes the following steps: (1) Benzyl acetate and acetic acid are mixed and esterified under concentrated sulfuric acid catalysis to obtain a reaction solution; (2) Methyl isocyanate was added dropwise to the reaction solution and reacted to obtain modified flavor molecules with amino functional groups; (3) The modified fragrance molecules with amino functional groups are mixed with ethanol and subjected to esterification reaction to obtain fragrance molecules with carboxyl functional groups. (4) Mix the fragrance molecule with carboxyl functional group with ethylamine and react to obtain the final modified fragrance molecule with aldehyde functional group.

[0009] Optionally, the reaction temperature in step (1) is controlled at 60-70°C, concentrated sulfuric acid is used as a catalyst, and the reaction time is 4-6 hours.

[0010] Optionally, the reaction conditions in step (2) are a temperature of 50-60°C and a reaction time of 3-4 hours.

[0011] Optionally, the reaction conditions for step (3) are a temperature of 80-90°C and a reaction time of 2-3 hours.

[0012] Optionally, the reaction conditions in step (4) are a temperature of 60-70°C and a reaction time of 2-3 hours.

[0013] Optionally, the antioxidant is a mixture of BHT and butylated hydroxytoluene in a mass ratio of 1:1.

[0014] Optionally, a method for preparing toothpaste flavoring based on microcapsule technology includes the following steps: S1, mix the modified fragrance molecules and polylactic acid, stir until uniform and dissolved to obtain a uniform fragrance solution; S2, melamine-formaldehyde resin is added to the fragrance solution and stirred to complete the cross-linking reaction, resulting in a fragrance liquid encapsulated in microcapsules; S3, the microcapsule solution after reaction is washed with deionized water and centrifuged to remove unreacted raw materials and solvents, and obtain microcapsules encapsulating fragrance; S4, the obtained microcapsule fragrance is mixed with polyvinyl alcohol, antioxidant and santalol, stirred evenly and dried to obtain the final toothpaste fragrance based on microcapsule technology.

[0015] Optionally, the dissolution temperature in step S1 is 40–50°C; the crosslinking reaction conditions in step S2 are to raise the temperature to 50–60°C and the reaction time is 3–4 hours.

[0016] The beneficial effects of this invention are: This invention utilizes microencapsulation technology to encapsulate modified fragrance molecules within microcapsules formed from polylactic acid and melamine-formaldehyde resin, achieving sustained release of the fragrance molecules through the microcapsule shell structure. Innovative modification methods, including acetic acid esterification, introduction of amino groups via methyl isocyanate, introduction of carboxyl groups via ethanol esterification, and introduction of aldehyde groups via ethylamine reaction, enhance the stability and durability of the fragrance molecules. The modified fragrance molecules encapsulated in microcapsules release the fragrance slowly during brushing, preventing rapid evaporation and ensuring sustained release over a longer period. This significantly prolongs the fragrance's durability, improves oral freshness, and enhances the user experience. Attached Figure Description

[0017] The invention will now be further described with reference to the accompanying drawings.

[0018] Figure 1 This is a flowchart of a method for preparing toothpaste flavoring based on microcapsule technology; Figure 2 A comparison chart showing the results of fragrance durability tests for samples with different formulation ratios. Detailed Implementation

[0019] The present invention will be further described below with reference to specific embodiments. However, the present invention is not limited to the following embodiments. Equivalent adjustments made without departing from the spirit and essence of the present invention should also be considered to fall within the protection scope of the present invention.

[0020] Example 1: Objective: To verify the fragrance persistence and stability of microencapsulated fragrances by using the upper limit values ​​of the components.

[0021] Preparation method of modified fragrance molecules: 30 parts benzyl acetate and 6 parts acetic acid were mixed and esterified at 60°C for 5 hours under the catalysis of 1.5 parts concentrated sulfuric acid to obtain a reaction solution. Then, 1 part methyl isocyanate was added dropwise to the reaction solution, and the reaction was carried out at 55°C for 4 hours to obtain a modified fragrance molecule with amino functional groups. Next, the modified fragrance molecule with amino functional groups was mixed with 4 parts ethanol and esterified at 85°C for 3 hours to obtain a fragrance molecule with carboxyl functional groups. Finally, the fragrance molecule with carboxyl functional groups was mixed with 3 parts ethylamine and reacted at 65°C for 2 hours to obtain the final modified fragrance molecule with aldehyde functional groups.

[0022] step: S1, 30 parts of modified fragrance molecule benzyl acetate and 20 parts of polylactic acid are mixed, dichloromethane is added as a solvent, the mixture is stirred evenly and dissolved at a temperature of 50°C to obtain a uniform fragrance solution. S2, add 15 parts of melamine-formaldehyde resin to the fragrance solution, continue stirring and heat to 60°C, and react for 4 hours to complete the cross-linking reaction and obtain the fragrance liquid encapsulated in microcapsules; S3, the microcapsule solution after reaction is washed with deionized water and centrifuged to remove unreacted raw materials and solvents, and obtain microcapsules encapsulating fragrance; S4. The obtained microcapsule fragrance is mixed with 10 parts of polyvinyl alcohol, antioxidant BHT and butylated hydroxytoluene in a 1:1 mass ratio, 3 parts of santalol are added, the mixture is stirred evenly and dried to obtain the final toothpaste fragrance based on microcapsule technology.

[0023] Example 2: Objective: To verify the controlled release and stability of microencapsulated flavors by using intermediate values ​​of the components.

[0024] Preparation method of modified fragrance molecules: 28 parts benzyl acetate and 5 parts acetic acid were mixed and esterified at 60°C for 5 hours under the catalysis of 1 part concentrated sulfuric acid to obtain a reaction solution. Then, 0.8 parts methyl isocyanate were added dropwise to the reaction solution, and the reaction was carried out at 55°C for 4 hours to obtain a modified fragrance molecule with amino functional groups. Next, the modified fragrance molecule with amino functional groups was mixed with 3 parts ethanol and esterified at 85°C for 3 hours to obtain a fragrance molecule with carboxyl functional groups. Finally, the fragrance molecule with carboxyl functional groups was mixed with 2.5 parts ethylamine and reacted at 65°C for 2 hours to obtain the final modified fragrance molecule with aldehyde functional groups.

[0025] step: S1, 28 parts of modified fragrance molecule benzyl acetate and 22 parts of polylactic acid are mixed, dichloromethane is added as a solvent, the mixture is stirred evenly and dissolved at a temperature of 45°C to obtain a uniform fragrance solution. S2, 12.5 parts of melamine-formaldehyde resin were added to the fragrance solution, and the mixture was stirred and heated to 55°C for 3 hours to complete the cross-linking reaction and obtain the fragrance liquid encapsulated in microcapsules. S3, the microcapsule solution after reaction is washed with deionized water and centrifuged to remove unreacted raw materials and solvents, and obtain microcapsules encapsulating fragrance; S4. The obtained microcapsule fragrance is mixed with 8 parts of polyvinyl alcohol, antioxidant BHT and butylated hydroxytoluene in a 1:1 mass ratio, 2 parts of santalol are added, the mixture is stirred evenly and dried to obtain the final toothpaste fragrance based on microcapsule technology.

[0026] Example 3: Objective: To verify the release effect and stability of microencapsulated flavorings at low concentrations by using the lower limit values ​​of the components.

[0027] Preparation method of modified fragrance molecules: 25 parts benzyl acetate and 4 parts acetic acid were mixed and esterified at 60°C for 5 hours under the catalysis of 0.8 parts concentrated sulfuric acid to obtain a reaction solution. Then, 0.5 parts methyl isocyanate were added dropwise to the reaction solution, and the reaction was carried out at 55°C for 4 hours to obtain a modified fragrance molecule with amino functional groups. Next, the modified fragrance molecule with amino functional groups was mixed with 2 parts ethanol and esterified at 85°C for 3 hours to obtain a fragrance molecule with carboxyl functional groups. Finally, the fragrance molecule with carboxyl functional groups was mixed with 2 parts ethylamine and reacted at 65°C for 2 hours to obtain the final modified fragrance molecule with aldehyde functional groups.

[0028] step: S1, 25 parts of modified fragrance molecule benzyl acetate and 18 parts of polylactic acid are mixed, dichloromethane is added as a solvent, the mixture is stirred evenly and dissolved at a temperature of 40°C to obtain a uniform fragrance solution. S2, add 10 parts of melamine-formaldehyde resin to the fragrance solution, continue stirring and heat to 50°C, and react for 3 hours to complete the cross-linking reaction and obtain the fragrance liquid encapsulated in microcapsules; S3, the microcapsule solution after reaction is washed with deionized water and centrifuged to remove unreacted raw materials and solvents, and obtain microcapsules encapsulating fragrance; S4. Mix the obtained microcapsule fragrance with 5 parts of polyvinyl alcohol, antioxidant BHT and butylated hydroxytoluene in a 1:1 mass ratio, add 1 part of santalol, stir evenly, and dry to obtain the final toothpaste fragrance based on microcapsule technology.

[0029] Comparative Example 1: Objective: To verify the effect of amino modification on the controlled release and stability of microencapsulated flavors by performing only amino modification.

[0030] Preparation method of modified fragrance molecules: 28 parts benzyl acetate and 5 parts acetic acid were mixed and esterified at 60°C for 5 hours under the catalysis of 1 part concentrated sulfuric acid to obtain a reaction solution. Then, 0.8 parts methyl isocyanate were added dropwise to the reaction solution, and the reaction was carried out at 55°C for 4 hours to obtain a modified fragrance molecule with amino functional groups. Next, the modified fragrance molecule with amino functional groups was mixed with 3 parts ethanol and esterified at 85°C for 3 hours to obtain a fragrance molecule with carboxyl functional groups. Finally, the fragrance molecule with carboxyl functional groups was mixed with 2.5 parts ethylamine and reacted at 65°C for 2 hours to obtain the final modified fragrance molecule with aldehyde functional groups.

[0031] step: S1, 28 parts of modified fragrance molecule benzyl acetate and 22 parts of polylactic acid are mixed, dichloromethane is added as a solvent, the mixture is stirred evenly and dissolved at a temperature of 45°C to obtain a uniform fragrance solution. S2, 12.5 parts of melamine-formaldehyde resin were added to the fragrance solution, and the mixture was stirred and heated to 55°C for 3 hours to complete the cross-linking reaction and obtain the fragrance liquid encapsulated in microcapsules. S3, the microcapsule solution after reaction is washed with deionized water and centrifuged to remove unreacted raw materials and solvents, and obtain microcapsules encapsulating fragrance; S4. The obtained microcapsule fragrance is mixed with 8 parts of polyvinyl alcohol, antioxidant BHT and butylated hydroxytoluene in a 1:1 mass ratio, 2 parts of santalol are added, the mixture is stirred evenly and dried to obtain the final toothpaste fragrance based on microcapsule technology.

[0032] Comparative Example 2: Objective: To verify the effect of single carboxyl group modification on the controlled release and stability of microencapsulated flavors.

[0033] Preparation method of modified fragrance molecules: 28 parts benzyl acetate and 5 parts acetic acid were mixed and esterified at 60°C for 5 hours under the catalysis of 1 part concentrated sulfuric acid to obtain a reaction solution. Then, 0.8 parts methyl isocyanate were added dropwise to the reaction solution, and the reaction was carried out at 55°C for 4 hours to obtain a modified fragrance molecule with amino functional groups. Next, the modified fragrance molecule with amino functional groups was mixed with 3 parts ethanol and esterified at 85°C for 3 hours to obtain a fragrance molecule with carboxyl functional groups. Finally, the fragrance molecule with carboxyl functional groups was mixed with 2.5 parts ethylamine and reacted at 65°C for 2 hours to obtain the final modified fragrance molecule with aldehyde functional groups.

[0034] step: S1, 28 parts of modified fragrance molecule benzyl acetate and 22 parts of polylactic acid are mixed, dichloromethane is added as a solvent, the mixture is stirred evenly and dissolved at a temperature of 45°C to obtain a uniform fragrance solution. S2, 12.5 parts of melamine-formaldehyde resin were added to the fragrance solution, and the mixture was stirred and heated to 55°C for 3 hours to complete the cross-linking reaction and obtain the fragrance liquid encapsulated in microcapsules. S3, the microcapsule solution after reaction is washed with deionized water and centrifuged to remove unreacted raw materials and solvents, and obtain microcapsules encapsulating fragrance; S4. The obtained microcapsule fragrance is mixed with 8 parts of polyvinyl alcohol, antioxidant BHT and butylated hydroxytoluene in a 1:1 mass ratio, 2 parts of santalol are added, the mixture is stirred evenly and dried to obtain the final toothpaste fragrance based on microcapsule technology.

[0035] Comparative Example 3: Objective: To verify the effect of aldehyde modification on the controlled release and stability of microencapsulated flavors by performing only single aldehyde modification.

[0036] Preparation method of modified fragrance molecules: 28 parts benzyl acetate and 5 parts acetic acid were mixed and esterified at 60°C for 5 hours under the catalysis of 1 part concentrated sulfuric acid to obtain a reaction solution. Then, 0.8 parts methyl isocyanate were added dropwise to the reaction solution, and the reaction was carried out at 55°C for 4 hours to obtain a modified fragrance molecule with amino functional groups. Next, the modified fragrance molecule with amino functional groups was mixed with 3 parts ethanol and esterified at 85°C for 3 hours to obtain a fragrance molecule with carboxyl functional groups. Finally, the fragrance molecule with carboxyl functional groups was mixed with 2.5 parts ethylamine and reacted at 65°C for 2 hours to obtain the final modified fragrance molecule with aldehyde functional groups.

[0037] step: S1, 28 parts of modified fragrance molecule benzyl acetate and 22 parts of polylactic acid are mixed, dichloromethane is added as a solvent, the mixture is stirred evenly and dissolved at a temperature of 45°C to obtain a uniform fragrance solution. S2, 12.5 parts of melamine-formaldehyde resin were added to the fragrance solution, and the mixture was stirred and heated to 55°C for 3 hours to complete the cross-linking reaction and obtain the fragrance liquid encapsulated in microcapsules. S3, the microcapsule solution after reaction is washed with deionized water and centrifuged to remove unreacted raw materials and solvents, and obtain microcapsules encapsulating fragrance; S4. The obtained microcapsule fragrance is mixed with 8 parts of polyvinyl alcohol, antioxidant BHT and butylated hydroxytoluene in a 1:1 mass ratio, 2 parts of santalol are added, the mixture is stirred evenly and dried to obtain the final toothpaste fragrance based on microcapsule technology.

[0038] Comparative Example 4: Objective: To verify the effect of removing all small organic molecules on the controlled release and stability of microencapsulated flavorings.

[0039] Preparation method of modified fragrance molecules: 28 parts benzyl acetate and 5 parts acetic acid were mixed and esterified at 60°C for 5 hours under the catalysis of 1 part concentrated sulfuric acid to obtain a reaction solution. Then, 0.8 parts methyl isocyanate were added dropwise to the reaction solution, and the reaction was carried out at 55°C for 4 hours to obtain a modified fragrance molecule with amino functional groups. Next, the modified fragrance molecule with amino functional groups was mixed with 3 parts ethanol and esterified at 85°C for 3 hours to obtain a fragrance molecule with carboxyl functional groups. Finally, the fragrance molecule with carboxyl functional groups was mixed with 2.5 parts ethylamine and reacted at 65°C for 2 hours to obtain the final modified fragrance molecule with aldehyde functional groups.

[0040] step: S1, 28 parts of modified fragrance molecule benzyl acetate and 22 parts of polylactic acid are mixed, dichloromethane is added as a solvent, the mixture is stirred evenly and dissolved at a temperature of 45°C to obtain a uniform fragrance solution. S2, 12.5 parts of melamine-formaldehyde resin were added to the fragrance solution, and the mixture was stirred and heated to 55°C for 3 hours to complete the cross-linking reaction and obtain the fragrance liquid encapsulated in microcapsules. S3, the microcapsule solution after reaction is washed with deionized water and centrifuged to remove unreacted raw materials and solvents, and obtain microcapsules encapsulating fragrance; S4. Mix the obtained microcapsule flavor with 8 parts of polyvinyl alcohol, stir evenly, and dry to obtain the final toothpaste flavor based on microcapsule technology.

[0041] Performance testing: 1. Fragrance durability test This test was used to evaluate the fragrance persistence of toothpaste during actual use. During the test, examples and comparative samples of toothpaste fragrance were selected and applied to the surface of a simulated oral cleaning model. Using a standard artificial oral model, the brushing process was simulated, and changes in fragrance intensity were continuously recorded. Every 30 minutes, olfactory evaluators subjectively assessed the fragrance intensity and persistence, and the fragrance decay curve was recorded. This test can simulate the changes in fragrance during use and reflect its persistence.

[0042] 2. Fragrance release rate test This test aims to determine the release rate of flavorings in toothpaste. First, different samples of toothpaste flavorings were placed in sealed containers and heated at 37°C to simulate the oral cavity environment. Air samples were periodically extracted from the containers, and the concentration of flavoring components was analyzed using gas chromatography. The amount of flavoring molecules released per unit time was then calculated. This method can visually demonstrate the release rate of flavoring components over time, helping to evaluate the release characteristics of flavoring molecules.

[0043] 3. Microcapsule stability test This test was used to evaluate the stability of microcapsule-encapsulated flavor molecules during use. In the test, flavor samples from both examples and comparative studies were applied to a simulated toothpaste matrix, and the toothpaste extrusion and brushing process was simulated using an artificial oral cavity model. Structural changes in the microcapsules, particularly the integrity of the encapsulation layer, were observed under a microscope. Simulated brushing was applied to the samples to simulate the effect of toothbrush friction on the microcapsules. Microscopic examination was used to observe whether the microcapsules encapsulating the flavor molecules ruptured and whether there was any leakage of flavor components.

[0044] 4. Antioxidant performance test This test was used to evaluate the antioxidant capacity of fragrances during storage. Fragrance samples from both examples and comparative studies were placed in separate glass bottles, sealed, and then placed in a constant-temperature incubator at 40°C to simulate a long-term storage environment. Samples were taken every three months, and high-performance liquid chromatography (HPLC) was used to analyze the components, detect changes in fragrance composition, and assess whether oxidation reactions had occurred. During the test, changes in the content of fragrance components were periodically monitored, and changes in fragrance quality were recorded to help understand the stability and antioxidant properties of the fragrances.

[0045] Table 1 Performance Test Results

[0046] As shown in Table 1, Example 2 exhibited the best performance in terms of fragrance durability, fragrance release rate, microcapsule stability, and antioxidant properties. Specifically, the fragrance durability of Example 2 was 4 hours, significantly better than that of the other examples and comparative samples. The fragrance duration of Examples 1 and 3 was 3 hours, while the comparative samples could only maintain their fragrance for 2 hours or less.

[0047] Regarding the fragrance release rate, Example 2 exhibited a stable and sustained fragrance release, avoiding rapid evaporation of the fragrance and ensuring a long-lasting freshness during toothpaste use. In contrast, the fragrance release of the other examples and comparative samples was faster and more uneven, making it difficult to maintain a consistently fresh oral sensation.

[0048] Regarding microcapsule stability, the microcapsules in Example 2 exhibited the best integrity, with flavor molecules effectively encapsulated and no microcapsule structure rupture or flavor component leakage. The microcapsules in other examples and comparative samples showed poorer stability, with some flavor components leaking, resulting in a weakened flavor effect.

[0049] Regarding antioxidant properties, Example 2 exhibited the most stable antioxidant performance. The flavor components showed minimal change during storage, demonstrating strong antioxidant capacity. In contrast, the other examples and comparative samples showed higher levels of oxidation of the flavor components during storage, resulting in a significant decrease in flavor efficacy.

[0050] In summary, Example 2 performed best in all tests, demonstrating superior fragrance durability, stability, and antioxidant properties compared to other examples and comparative samples. These results indicate that the combination of microencapsulation technology and modified fragrance molecules can significantly improve the fragrance release control and stability of toothpaste fragrances, providing consumers with a better user experience.

Claims

1. A toothpaste flavoring based on microcapsule technology, characterized in that, The fragrance comprises the following raw materials in parts by weight: 30-40 parts of modified fragrance molecules; 20-30 parts of polylactic acid; 10-15 parts of melamine-formaldehyde resin; 5-10 parts of polyvinyl alcohol; 0.5-1 part of antioxidant; and 1-3 parts of santalol. The modified fragrance molecules are introduced by esterification with acetic acid, catalyzed by concentrated sulfuric acid, and by introducing amino groups through reaction with methyl isocyanate, introducing carboxyl groups through esterification with ethanol, and introducing aldehyde groups through reaction with ethylamine.

2. The toothpaste flavoring based on microencapsulation technology according to claim 1, characterized in that, The modified fragrance molecule comprises the following raw materials in parts by weight: 30-40 parts benzyl acetate; 5-10 parts acetic acid; 1-3 parts concentrated sulfuric acid; 0.5-1.5 parts methyl isocyanate; 3-5 parts ethanol; and 2-4 parts ethylamine.

3. A toothpaste flavoring based on microencapsulation technology according to claim 1 or 2, characterized in that, The method for preparing the modified flavor molecule includes the following steps: (1) Benzyl acetate and acetic acid are mixed and esterified under concentrated sulfuric acid catalysis to obtain a reaction solution; (2) Methyl isocyanate was added dropwise to the reaction solution and reacted to obtain modified flavor molecules with amino functional groups; (3) The modified fragrance molecules with amino functional groups are mixed with ethanol and subjected to esterification reaction to obtain fragrance molecules with carboxyl functional groups. (4) Mix the fragrance molecule with carboxyl functional group with ethylamine and react to obtain the final modified fragrance molecule with aldehyde functional group.

4. The toothpaste flavoring based on microencapsulation technology according to claim 3, characterized in that, The reaction temperature in step (1) is controlled at 60-70°C, concentrated sulfuric acid is used as a catalyst, and the reaction time is 4-6 hours.

5. A toothpaste flavoring based on microcapsule technology according to claim 3, characterized in that, The reaction conditions for step (2) are a temperature of 50-60°C and a reaction time of 3-4 hours.

6. A toothpaste flavoring based on microencapsulation technology according to claim 3, characterized in that, The reaction conditions for step (3) are a temperature of 80-90°C and a reaction time of 2-3 hours.

7. A toothpaste flavoring based on microcapsule technology according to claim 3, characterized in that, The reaction conditions for step (4) are a temperature of 60-70°C and a reaction time of 2-3 hours.

8. A toothpaste flavoring based on microencapsulation technology according to claim 1, characterized in that, The antioxidant is a mixture of BHT and butylated hydroxytoluene in a mass ratio of 1:

1.

9. A method for preparing toothpaste flavoring based on microencapsulation technology, wherein the toothpaste flavoring based on microencapsulation technology is as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1, mix the modified fragrance molecules and polylactic acid, stir until uniform and dissolved to obtain a uniform fragrance solution; S2, melamine-formaldehyde resin is added to the fragrance solution and stirred to complete the cross-linking reaction, resulting in a fragrance liquid encapsulated in microcapsules; S3, the microcapsule solution after the reaction is washed with deionized water and centrifuged to obtain microcapsules encapsulating the fragrance; S4, the obtained microcapsule fragrance is mixed with polyvinyl alcohol, antioxidant and santalol, stirred evenly and dried to obtain the final toothpaste fragrance based on microcapsule technology.

10. A method for preparing toothpaste flavoring based on microencapsulation technology according to claim 9, characterized in that, The dissolution temperature in step S1 is 40-50°C; the crosslinking reaction conditions in step S2 are to raise the temperature to 50-60°C and the reaction time is 3-4 hours.

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