A solvent-free method for preparing eutectic sustained-release fragrances

Abstract

This invention belongs to the field of tobacco flavorings and provides a solvent-free method for preparing eutectic sustained-release flavorings. The method includes: mixing cyclodextrin and flavoring in a certain proportion, stirring and heating to a preset temperature until completely dissolved, and allowing to cool at room temperature to obtain a sustained-release flavoring solid. Depending on the requirements, the sustained-release flavoring solid can be processed into blocks, granules, or powder. Using cyclodextrin as a hydrogen bond acceptor and flavoring as a hydrogen bond donor, a homogeneous and transparent liquid is formed under a certain ratio and reaction temperature. Cooling at room temperature yields the sustained-release flavoring solid. The cyclodextrin and flavoring form a homogeneous and stable complex, improving the stability and sustained-release performance of the flavoring. This method is simple, uses safe and environmentally friendly materials, does not introduce additional impurities, and has a high flavoring utilization rate, showing great application prospects in the food, tobacco, and cosmetic industries.

Description

Technical Field

[0001] This invention belongs to the field of tobacco flavorings, and specifically relates to a solventless method for preparing eutectic slow-release flavorings. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Fragrances possess various functions such as flavor enhancement, deodorization, calming, sterilization, mosquito repellency, and health benefits, and are widely used in food, medical, daily chemical, tobacco, and textile industries. Based on the different functional groups in the fragrance molecule, fragrances are mainly highly volatile aliphatic, aromatic, terpene, and heterocyclic substances such as alkanes, alkenes, alcohols, ethers, aldehydes, and ketones. Due to their structural characteristics, fragrances have low boiling points, are easily volatile under natural conditions, and are unstable under the influence of light and heat. To improve the stability of fragrances and expand their application range, fragrance sustained-release technology is an effective means to slow down fragrance loss, improve fragrance stability, and achieve sustained fragrance release. There are four main loading forms for fragrance sustained-release technology: adsorption type, encapsulation type, matrix type, and hybrid type. Hybrid types typically involve mixing fragrances with one or more fragrance carriers in a certain proportion and method, and then processing the mixture to obtain a composite sustained-release fragrance material. The commonly used mixing method is solvent mixing. However, issues such as organic solvent evaporation, encapsulation efficiency, and sustained-release performance still need to be improved. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a solvent-free method for preparing eutectic sustained-release fragrances. This invention uses cyclodextrin as a hydrogen bond acceptor and fragrance as a hydrogen bond donor. Under specific ratios and reaction temperatures, a homogeneous, transparent liquid is formed, which, upon cooling at room temperature, yields a sustained-release fragrance solid. The cyclodextrin and fragrance form a homogeneous and stable complex, improving the fragrance's stability and sustained-release properties. This method is simple, uses safe and environmentally friendly materials, and does not introduce additional solvents, showing promising application prospects in the food, tobacco, and cosmetics industries.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A first aspect of the present invention provides a solvent-free method for preparing eutectic sustained-release fragrances, comprising:

[0007] Solid cyclodextrin and solid flavoring are mixed in a certain proportion, heated to a preset temperature to completely melt them, and then allowed to cool to obtain eutectic slow-release flavoring.

[0008] Eutectic solvents (DES) are a novel class of ionic solvent systems, mostly binary or ternary mixtures consisting of one or more quaternary ammonium salts or zwitterions as hydrogen bond acceptors (HBA) and at least one alcohol, amine, carboxylic acid, etc., as a hydrogen bond donor (HBD). Their freezing points are significantly lower than the melting points of their individual components. DES have applications in gas absorption, extraction and separation, nanomaterial synthesis, drug sustained release, and electrolytes.

[0009] This invention uses a eutectic method to prepare a mixed-type sustained-release fragrance, which can achieve 100% utilization of the fragrance under solvent-free conditions, while also providing better sustained-release performance.

[0010] In some embodiments, the mass ratio of the solid cyclodextrin to the solid flavor is 9:1 to 1:9.

[0011] In some embodiments, the cyclodextrin is at least one of β-cyclodextrin, γ-cyclodextrin, and hydroxypropyl-β-cyclodextrin.

[0012] In some embodiments, the solid fragrance is a hydroxyl-containing aromatic / aliphatic solid fragrance.

[0013] In some embodiments, the solid flavor is at least one of vanillin, maltol, ethyl maltol, and cinnamic acid.

[0014] In some embodiments, the melting point of the hydroxyl-containing aromatic / aliphatic solid fragrance is a℃, and the preset melting temperature is 0.5a~1a℃;

[0015] In some preferred embodiments, the preset temperature is 60-120℃ and the heating time is 0.5-2h.

[0016] In some implementations, the resting condition is to leave it at room temperature for 10 to 16 hours.

[0017] In some embodiments, the method further includes: pulverizing the obtained eutectic slow-release fragrance, sieving it, and obtaining hydroxypropyl-β-cyclodextrin / solid fragrance eutectic powder.

[0018] More specifically, the process includes the following steps: mixing solid flavor powder and hydroxypropyl-β-cyclodextrin powder at a certain mass ratio, stirring and heating to a preset temperature until completely melted, and allowing to cool to obtain a hydroxypropyl-β-cyclodextrin / solid flavor eutectic. The obtained eutectic is then pulverized using a mortar and pestle and sieved to obtain hydroxypropyl-β-cyclodextrin / solid flavor eutectic powder.

[0019] In some embodiments, the stirring rate is 500–2000 r / min.

[0020] In a second aspect, the present invention provides a eutectic slow-release fragrance prepared by the above-described method.

[0021] A third aspect of the present invention provides the application of the above-mentioned eutectic slow-release flavoring in the fields of food, tobacco, and cosmetics.

[0022] Beneficial effects of the present invention

[0023] (1) This invention uses hydroxypropyl-β-cyclodextrin as the hydrogen bond acceptor in the preparation of DES (Diethylsaturated Ester) and solid flavor as the hydrogen bond donor. A homogeneous, transparent liquid can be formed at a relatively low temperature, and a solid can be formed upon cooling to room temperature. Compared with solvent-based methods for preparing composite sustained-release flavor materials, the solid flavor forms a stable complex with hydroxypropyl-β-cyclodextrin, which improves the stability and sustained-release performance of the solid flavor. This invention is simple, has a short reaction time, and uses safe and environmentally friendly materials, showing great promise for application in the food, tobacco, and cosmetic industries.

[0024] (2) The only substances involved in the reaction in the method of the present invention are fragrance and fragrance carrier, without the introduction of solvents and other reactants, requiring no subsequent treatment and generating no additional pollution.

[0025] (3) The raw materials and products in this invention are all food grade, which is safe and environmentally friendly.

[0026] (4) The present invention has a high fragrance utilization rate. Since hydroxypropyl-β-cyclodextrin is completely mixed and melted with the fragrance, the fragrance utilization rate is 100%. Attached Figure Description

[0027] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. Exemplary embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0028] Figure 1 Thermogravimetric curves of vanillin, hydroxypropyl-β-cyclodextrin, and the hydroxypropyl-β-cyclodextrin / vanillin sustained-release flavor prepared in Example 1;

[0029] Figure 2 GC / MS image of vanillin release gas at 45°C for the hydroxypropyl-β-cyclodextrin / vanillin sustained-release flavor prepared in Example 1;

[0030] Figure 3 GC / MS images of the gas released by hydroxypropyl-β-cyclodextrin / vanillin sustained-release flavor prepared in Example 1 at (a) 45°C, (b) 75°C, (c) 120°C, and (d) 230°C.

[0031] Figure 4The image shows the DSC analysis chromatogram for Example 5. The melting point of the eutectic formed by vanillin and hydroxypropyl-β-cyclodextrin is 78.59°C.

[0032] Figure 5 The image shows the DSC analysis chromatogram for Example 6. The melting point of the eutectic formed by maltol and hydroxypropyl-β-cyclodextrin is 146.67°C.

[0033] Figure 6 The image shows the DSC analysis chromatogram for Example 7. The melting point of the eutectic formed by ethyl maltol and hydroxypropyl-β-cyclodextrin is 83.79°C.

[0034] Figure 7 The graph shows the release test results of the hydroxypropyl-β-cyclodextrin / solid flavor eutectic and the hydroxypropyl-β-cyclodextrin and solid flavor mixture of Example 5.

[0035] Figure 8 The graph shows the release test results of the hydroxypropyl-β-cyclodextrin / solid flavor eutectic and the hydroxypropyl-β-cyclodextrin and solid flavor mixture of Example 6.

[0036] Figure 9 The hydroxypropyl-β-cyclodextrin / solid flavor eutectic and hydroxypropyl-β-cyclodextrin and solid flavor are from Example 7. Detailed Implementation

[0037] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0038] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are explanations of the present invention and not limitations thereof.

[0039] Example 1: Preparation of Hydroxypropyl-β-Cyclodextrin / Vanillin Sustained-Release Flavor

[0040] 7g of hydroxypropyl-β-cyclodextrin powder was mixed with 3g of vanillin powder and heated and stirred in a water bath at 90°C for 2 hours to form a homogeneous and transparent solution. The solution was then cooled to room temperature and further cooled at room temperature for 12 hours to obtain a sustained-release hydroxypropyl-β-cyclodextrin / vanillin eutectic fragrance. (Because the hydroxypropyl-β-cyclodextrin and fragrance were completely mixed and eutectic, the fragrance utilization rate was 100%).

[0041] Example 2: Preparation of Hydroxypropyl-β-Cyclodextrin / Maltol Sustained-Release Flavor

[0042] 6g of hydroxypropyl-β-cyclodextrin powder and 4g of maltol powder were mixed together and heated and stirred in a water bath at 80°C for 1 hour to make it a homogeneous and transparent solution. The solution was then cooled to room temperature and cooled at room temperature for another 10 hours to obtain a hydroxypropyl-β-cyclodextrin / maltol eutectic slow-release flavor.

[0043] Example 3: Preparation of Hydroxypropyl-β-Cyclodextrin / Ethyl Maltol Sustained-Release Flavor

[0044] 5g of hydroxypropyl-β-cyclodextrin powder and 5g of ethyl maltol powder were mixed together and heated and stirred in a water bath at 60°C for 1.5h to make it a homogeneous and transparent solution. The solution was then cooled to room temperature and cooled at room temperature for another 8h to obtain a hydroxypropyl-β-cyclodextrin / ethyl maltol eutectic slow-release flavoring.

[0045] Example 4: Preparation of Hydroxypropyl-β-Cyclodextrin / Cinnamic Acid Sustained-Release Flavor

[0046] 4g of hydroxypropyl-β-cyclodextrin powder and 6g of cinnamic acid powder were mixed together and heated and stirred in an oil bath at 120°C for 0.5h to make it a homogeneous and transparent solution. The solution was then cooled to room temperature and cooled at room temperature for another 15h to obtain a hydroxypropyl-β-cyclodextrin / cinnamic acid eutectic sustained-release flavor.

[0047] Example 5: Preparation of cyclodextrin / vanillin eutectic

[0048] 3g of vanillin powder and 7g of hydroxypropyl-β-cyclodextrin powder were mixed together and heated and stirred at 80℃ for 1h to obtain a homogeneous and transparent solution at a stirring rate of 1000r / min. The mixture was then cooled at room temperature for 12h to obtain a hydroxypropyl-β-cyclodextrin / vanillin eutectic. The obtained eutectic was pulverized in a mortar and sieved to obtain hydroxypropyl-β-cyclodextrin / vanillin eutectic powder.

[0049] Example 6: Preparation of cyclodextrin / maltol eutectic

[0050] 4g of maltol powder and 6g of hydroxypropyl-β-cyclodextrin powder were mixed together and heated and stirred at 130℃ for 1h to form a homogeneous and transparent solution at a stirring rate of 1000r / min. The mixture was then cooled at room temperature for 12h to obtain a hydroxypropyl-β-cyclodextrin / maltol eutectic. The obtained eutectic was pulverized in a mortar and sieved to obtain hydroxypropyl-β-cyclodextrin / maltol eutectic powder.

[0051] Example 7: Preparation of cyclodextrin / ethyl maltol eutectic

[0052] 5g of ethyl maltol powder and 5g of hydroxypropyl-β-cyclodextrin powder were mixed together and heated and stirred at 80℃ for 1h to form a homogeneous and transparent solution at a stirring rate of 1000r / min. The mixture was then cooled at room temperature for 12h to obtain a hydroxypropyl-β-cyclodextrin / ethyl maltol eutectic. The obtained eutectic was pulverized in a mortar and sieved to obtain hydroxypropyl-β-cyclodextrin / ethyl maltol eutectic powder.

[0053] Performance testing:

[0054] I. Thermogravimetric analysis and GC / MS analysis of released gases were performed on the hydroxypropyl-β-cyclodextrin / vanillin prepared in Example 1:

[0055] 1. Thermogravimetric analysis

[0056] Thermogravimetric analysis (TGA) was performed on vanillin, hydroxypropyl-β-cyclodextrin, and hydroxypropyl-β-cyclodextrin / vanillin, respectively. Analytical methods: TGA temperature range: 40-900℃; heating rate: 10℃ / min; reaction atmosphere: N2; sample amount: 10 mg.

[0057] Figure 1 These are the thermogravimetric curves (TGA) of vanillin, hydroxypropyl-β-cyclodextrin, and hydroxypropyl-β-cyclodextrin / vanillin. It can be seen that vanillin experiences a rapid decrease in mass during heating, and the reaction is essentially complete by 200℃, indicating poor thermal stability. The hydroxypropyl-β-cyclodextrin / vanillin eutectic slow-release flavor exhibits a slow decrease in mass below 400℃, demonstrating significantly improved thermal stability compared to vanillin.

[0058] 2. GC / MS analysis of released gases

[0059] Thermogravimetric analysis (TG)-gas chromatography (GC) / mass spectrometry (MS) was used to detect gases released from fragrances under different temperature conditions. TG experimental conditions: TG temperature range: 40-300℃; heating rate: 10℃ / min; reaction atmosphere: N2; sample volume: 10 mg. GC experimental conditions: Column: DB-5MS capillary column (30m × 0.25mm ID × 0.25μm df); split ratio: 10:1; carrier gas: He, constant flow mode, flow rate 1.0 ml / min; temperature program: 50℃ for 1 min, then ramped at 5℃ / min to 260℃ and held for 5 min. MS operating conditions: transfer line temperature: 250℃; EI ion source temperature: 230℃; ionization energy: 70 eV; scan range: 45-450 amu. Qualitative analysis was performed using the NIST standard spectral library. The gas emitted from the sample under thermogravimetric analysis at a certain temperature is collected and analyzed by gas chromatography / mass spectrometry.

[0060] Figure 2This is a GC / MS total ion chromatogram of vanillin gas escaping at 45°C. It can be observed that a large amount of vanillin is released from the vanillin monomer at 45°C. Figure 2 The figures show the GC / MS total ion chromatograms of the gas escaping from hydroxypropyl-β-cyclodextrin / vanillin at 45℃, 75℃, 120℃, and 230℃. It can be seen that vanillin was not detected at 45℃, indicating that the eutectic mixture flavoring is relatively stable at this temperature and no significant release occurred. Vanillin was detected from 75℃ to 230℃, indicating that the eutectic mixture flavoring begins to release aroma components starting at 75℃, and the amount of vanillin released increases relatively with increasing temperature, suggesting that the release amount of the eutectic mixture flavoring can be temperature-controlled. Figure 1 Thermogravimetric curves show that vanillin monomers were basically pyrolyzed at 200℃, but the eutectic blend flavor still released a large amount at 230℃, indicating that the eutectic blend flavor significantly improved the thermal stability of vanillin and achieved a gradual release process.

[0061] II. DSC analysis and release tests were performed on the cyclodextrin / solid flavor eutectic compounds prepared in Examples 5, 6, and 7.

[0062] Depend on Figure 7 , Figure 8 , Figure 9 The graph shows the release test results for hydroxypropyl-β-cyclodextrin / solid fragrance eutectic and hydroxypropyl-β-cyclodextrin and solid fragrance mixtures. The retention rate of the DES eutectic is higher than that of the hydroxypropyl-β-cyclodextrin and solid fragrance mixture, indicating that the eutectic can better retain the aroma and has good application prospects.

[0063] Table 1 shows the melting points of solid fragrances, hydroxypropyl-β-cyclodextrin, and eutectic compounds.

[0064]

[0065] The results in Table 1 show that the melting point of the hydroxypropyl-β-cyclodextrin / solid fragrance eutectic is lower than that of the solid fragrance and the hydroxypropyl-β-cyclodextrin, proving the successful synthesis of the eutectic.

[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for solvent-free preparation of a eutectic slow-release fragrance, characterized by, The application relates to a method for preparing a low-eutectic slow-release fragrance. The solid cyclodextrin and the hydroxyl-containing aromatic / aliphatic solid fragrance are mixed in a certain proportion, heated to a preset temperature to completely melt the two, and cooled to obtain a low-eutectic slow-release fragrance. The cyclodextrin is hydroxypropyl-beta-cyclodextrin. The hydroxyl-containing aromatic / aliphatic solid fragrance is at least one of vanillin, maltol, ethyl maltol and cinnamic acid. The mass ratio of the solid cyclodextrin and the hydroxyl-containing aromatic / aliphatic solid fragrance is 9:1-1:

9.

2. The method for preparing the solvent-free eutectic sustained-release fragrance of claim 1, wherein the solvent-free eutectic sustained-release fragrance is prepared by mixing the first and second components in a weight ratio of 1:1 to 1:

3. The melting point of the hydroxyl-containing aromatic / aliphatic solid fragrance is a degrees Celsius, and the preset temperature is 0.5a-1a degrees Celsius.

3. The method for preparing the solvent-free eutectic slow-release fragrance of claim 1, wherein the solvent-free eutectic slow-release fragrance is prepared by mixing the first and second components in a weight ratio of 1:1 to 1:

3. The preset temperature is 60-120 degrees Celsius, and the heating time is 0.5-2 hours.

4. The method of claim 1, wherein the solvent-free preparation of the eutectic time- release fragrance is characterized by, The standing condition is to place at normal temperature for 10-16 hours.

5. The method of claim 1, wherein the solvent-free preparation of the eutectic time- release fragrance is characterized by, The application further relates to a method for preparing a low-eutectic slow-release fragrance. The low-eutectic slow-release fragrance is crushed and sieved to obtain a low-eutectic powder.

6. The low-eutectic slow-release fragrance prepared by the method in any one of claims 1-5.

7. The low-eutectic slow-release fragrance in claim 6 is applied in the field of tobacco and cosmetics.

Images