A solid particle with long-lasting fragrance and biodegradable and its preparation and application

Abstract

The application provides a solid particle with long-lasting fragrance and biodegradability and preparation and application thereof. The biodegradable solid particle comprises a core material, a carrier wrapping the core material, and a shell layer covering the carrier. The core material comprises a fragrance compound, and the fragrance compound comprises at least one of a perfume or a precursor thereof, an essence or a precursor thereof. The core material comprises a fragrance compound with a molecular weight of 100-400 Dalton. The carrier comprises a first carrier, and the first carrier comprises a cyclodextrin composition. The cyclodextrin composition comprises alpha-cyclodextrin, beta-cyclodextrin, and gamma-cyclodextrin, and the mass percentage of alpha-cyclodextrin, beta-cyclodextrin, and gamma-cyclodextrin is 5-30%, 50-80%, and 5-15% respectively. The application is based on the specific fragrance performance of the fragrance compound, the molecular weight, and the molecular diameter. The mass ratio range of the cyclodextrin composition in the carrier can be flexibly adjusted, so that the size of the inclusion cavity of the cyclodextrin composition is more optimally matched with the spatial configuration and size characteristics of the target essence molecule.

Description

Technical Field

[0001] This invention belongs to the field of air freshener technology, and particularly relates to a long-lasting fragrance and biodegradable solid particle, its preparation and application. Background Technology

[0002] With the improvement of living standards, people's demand for various types of space fragrances has increased significantly. Fragrance products are now widely used in car environments, closets, bathrooms, and pet play areas. However, most mainstream liquid fragrance systems on the market currently contain volatile organic solvents. Long-term inhalation may not only have negative effects on human health but also release harmful substances into the environment. Furthermore, the fragrance essence in liquid fragrances often evaporates too quickly, typically being consumed within one or two weeks, requiring frequent replacements and incurring high costs. The release rate is also difficult to control effectively, often resulting in an overly strong initial scent that fades later. In addition, liquid products require sophisticated packaging design, further increasing manufacturing and usage costs. These unfavorable factors have prompted the industry to continuously focus on safer and more sustainable solid-form alternatives.

[0003] In many applications requiring long-lasting fragrance, such as shoe cabinets, wardrobes, restrooms, pet enclosures, toys, and clothing accessories, solid fragrance particles are gradually gaining traction. Currently, most common solid fragrance particles use ethylene-vinyl acetate copolymer resin (EVA resin) as the fragrance adsorption carrier. While this can achieve a certain degree of slow fragrance release, EVA resin itself has an extremely long degradation cycle, lasting up to hundreds of years. Furthermore, its degradation debris is a significant source of secondary microplastics, which, once released into the environment, persist and pose potential risks to ecosystems and human health. In addition, residual plasticizers and other substances in the resin matrix can easily mix into the fragrance, resulting in an unpleasant plastic odor and affecting the olfactory experience. Some products use fragrance beads, whose long-lasting fragrance release relies on a microencapsulated fragrance system with melamine as the wall material. This type of wall material is also difficult to degrade naturally, the microplastic problem remains prominent, and there is a risk of slow formaldehyde release during use, making the impact on the environment and human health even more complex. In addition, the aroma release curve is still not ideal. The high amount of evaporation in the early stage makes the aroma too strong, and after a period of time it quickly decays to almost no smell.

[0004] Therefore, there is an urgent need to develop an environmentally friendly wall material for effectively encapsulating fragrances, ideally in a solvent-free solid form, to reduce the burden on the ecological environment at the source and minimize potential harm to human and animal health. Currently, the industry faces several technical challenges and constraints in constructing biodegradable, low-hazard solid fragrance carriers, including how to balance the biodegradability and stable fragrance release performance of the wall material, how to achieve efficient fragrance loading and long-term controlled release under solvent-free conditions, and how to balance the feasibility of production costs with large-scale manufacturing processes. Summary of the Invention

[0005] In order to provide a biodegradable solid particle that also has the ability to stably release and efficiently load fragrance compounds, the present invention provides a long-lasting fragrance and biodegradable solid particle, as well as its preparation and application.

[0006] According to one aspect of the present invention, a long-lasting fragrance and biodegradable solid particle is provided, comprising a core material, a carrier encapsulating the core material, and a shell coating the carrier; wherein the core material comprises a fragrance compound, the fragrance compound comprising at least one of a fragrance or its precursor, a flavoring or its precursor; the core material comprises a fragrance compound with a molecular weight of 100 Daltons to 400 Daltons; the carrier comprises a first carrier, the first carrier comprising a cyclodextrin composition; the cyclodextrin composition comprises α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin, and the mass percentage of α-cyclodextrin:β-cyclodextrin:γ-cyclodextrin is 10% to 30%:50% to 80%:5% to 15%.

[0007] Traditional solid fragrance granules often face a certain degree of aroma profile deviation when restoring the original flavor of fragrance compounds. This is mainly because conventional adsorbent materials used in the solid matrix have a certain "screening" effect on aroma molecules of different sizes, meaning that some components are preferentially or excessively adsorbed, resulting in a deviation between the proportion of released aroma components and the original fragrance formula. This invention, however, flexibly adjusts the mass ratio range of α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin in the first carrier based on the molecular weight and diameter of the fragrance compound, allowing for a more precise match between the cavity size of the cyclodextrin composition and the spatial characteristics of the target aroma molecules. The technical solution provided by this invention helps to orderly accommodate different volatile components in the fragrance within a suitable microenvironment, avoiding the screening effect of traditional porous adsorbent materials while promoting a more balanced and stable volatilization of the aroma during room temperature release. Therefore, while maintaining the advantage of long-lasting fragrance, the solid granules can more completely present the original top, middle, and base notes of the fragrance compound, resulting in a more vivid and accurate olfactory experience. Furthermore, the solid particles provided by this invention also help improve the embedding stability and loading efficiency of the core material in the carrier, thereby making the aroma release curve more stable and lasting during use, and providing an effective adjustment method for solid particles to obtain a more harmonious olfactory experience in different application scenarios.

[0008] Preferably, the carrier further includes a second carrier, which includes hydrogenated lecithin.

[0009] Preferably, the core material includes fragrance compounds with a molecular weight higher than 400 Daltons.

[0010] Preferably, the carrier further includes a third carrier, which includes aluminum starch octylsuccinate.

[0011] Preferably, the core material includes fragrance compounds with a molecular weight of less than 100 Daltons.

[0012] To further optimize the capacity for containing fragrance compounds and the degree of fragrance reproduction, the inventors discovered through experiments that the hydrophobic cavity size of the cyclodextrin composition (cavity diameter approximately 0.45 nm to 1.00 nm, volume approximately 170 Å) 3 ~480 Å 3 It exhibits good matching and inclusion selectivity for fragrance molecules with molecular weights ranging from approximately 100 to 400 Daltons. However, some fragrance compounds have complex characteristics such as a wide molecular weight distribution and varying component volatility. Relying solely on cyclodextrin inclusion and secondary shell coating of solid particles still leaves room for optimization in terms of increasing the total loading of fragrance compounds and preserving the original aroma.

[0013] To further broaden the effective range of action of solid particles on fragrance compounds and more completely preserve the original olfactory characteristics of fragrances, this invention further introduces a second and / or a third carrier into the carrier structure. Hydrogenated lecithin, with its amphiphilic molecular arrangement, can interact with fragrance compounds with relatively large molecular weights to form a stable encapsulation structure, thereby improving the encapsulation efficiency of fragrance compounds over a wider molecular weight range. Meanwhile, aluminum octyl succinate, with its microporous structure and surface adsorption activity, effectively retains and regulates aroma components with smaller molecular weights and higher volatility. Through the combined action of the first, second, and third carriers, the entire carrier system achieves more comprehensive coverage and synergistic carrying capacity for fragrance components with different molecular sizes and physicochemical properties. This not only helps to increase the total loading of fragrance substances in the solid particles but also slows down the aroma profile shift caused by differences in the volatilization rates of various components during drying and storage. This allows the solid fragrance particles to more accurately reproduce the complete fragrance of the formula during subsequent use, thereby achieving further beneficial improvements in retention rate, stability, and olfactory experience.

[0014] Preferably, the shell layer comprises a polysaccharide compound, which includes at least one of chitosan and sodium alginate.

[0015] Preferably, the solid particles comprise 10% to 40% core material, 50% to 80% carrier, and 5% to 20% shell layer by mass percentage.

[0016] Preferably, the carrier includes at least one of a first carrier, a second carrier, and a third carrier.

[0017] Preferably, the mass percentage of the first carrier in the carrier is 60% to 100%.

[0018] Preferably, the mass percentage of the second carrier in the carrier is 0% to 10%.

[0019] Preferably, the mass percentage of the third carrier in the carrier is 0% to 40%.

[0020] Preferably, the particle size of the solid particles is 1 mm to 5 mm.

[0021] A second aspect of the present invention provides a method for preparing solid particles as described above, comprising the following steps: S1. Preparing a fragrance compound, a first carrier reactant, and a shell reactant respectively; wherein the first carrier reactant comprises a cyclodextrin composition; S2. Adding a surfactant to the first carrier reactant, followed by adding a fragrance compound to obtain a first emulsion; S3. Mixing the first emulsion with the shell reactant to obtain a second emulsion; S4. Mixing the second emulsion with a crosslinking agent to form a gel, and obtaining solid particles after post-treatment.

[0022] Preferably, the above preparation method includes the following steps: S1. Preparing a fragrance compound, a first carrier reactant, a second carrier reactant, a third carrier reactant, and a shell reactant respectively; wherein, the first carrier reactant includes a cyclodextrin composition, the second carrier reactant includes hydrogenated lecithin, and the third carrier reactant includes aluminum octyl succinate; S2. Adding the second carrier reactant and a surfactant to the first carrier reactant, followed by adding the fragrance compound to obtain a first emulsion; S3. Mixing the first emulsion with the third carrier reactant, and then adding the shell reactant to mix, to obtain a second emulsion; S4. Mixing the second emulsion with a crosslinking agent to form a gel, and obtaining solid particles after post-treatment.

[0023] Preferably, after mixing the cyclodextrin composition with the organic solvent, the organic solvent is removed by evaporation. The cyclodextrin composition does not dissolve during mixing with the organic solvent. This operating condition helps the cyclodextrin molecules to exhibit a more open conformation in the solution environment, fully exposing their hydrophobic cavity regions. This structural change provides favorable conditions for fragrance compound molecules to enter the cyclodextrin cavity and form stable inclusion complexes, thereby improving the binding efficiency and encapsulation stability between the core material and the carrier during subsequent inclusion processes, resulting in better aroma loading capacity and release regulation performance for the solid particles.

[0024] Preferably, the organic solvent includes at least one of ethanol, propylene glycol, butanediol, and dipropylene glycol.

[0025] Preferably, the surfactant includes at least one of Tween 20, Tween 60, and Tween 80.

[0026] Preferably, the crosslinking agent includes at least one of soluble calcium salt and magnesium salt.

[0027] Preferably, when a soluble calcium salt is used as a crosslinking agent, the mass concentration of the calcium salt is 0.3% to 3%.

[0028] Preferably, the post-processing includes drying.

[0029] A third aspect of the present invention provides a consumer product comprising solid particles as described above, or solid particles prepared by the preparation method described above.

[0030] Preferably, the consumer product is any one of the following: personal care products, household care products, cleaning products, food, air purifiers, air deodorizers, room fragrances, and sleep-aid fragrance products. Among them, air purifiers, air deodorizers, and room fragrances are used to purify, remove, or neutralize odors in various spaces, which can be enclosed spaces, open spaces, or mobile spaces, and can be used in specific application scenarios such as wardrobes, cabinets, shoe cabinets, kitchens, bathrooms, living rooms, bedrooms, offices, shopping malls, car interiors, product packaging (such as clothing, shoes, accessories, toys, etc.), storage spaces, or pet spaces.

[0031] A fourth aspect of the present invention provides solid particles as described above, solid particles prepared by the preparation method described above, or consumer products as described above, for use in the consumer field. Attached Figure Description

[0032] Figure 1 Comparison of fragrance loading rates of solid particles provided in each embodiment and comparative example; Figure 2 The solid particles and original flavorings provided in each embodiment and comparative example have similarity scores. Figure 3 The duration of aroma of the solid particles provided in Example 7 was compared in exposed air and in a confined space. Detailed Implementation

[0033] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0034] Example 1 1. Raw materials required for biodegradable solid particles In this embodiment, the raw materials required for preparing biodegradable solid particles were weighed according to the formulation shown in Table 1. The fragrance compounds used included ethyl acetate (molecular weight 88.106), vanillin (molecular weight 154.165), methyl cedryone (molecular weight 246.39), sweet orange oil (molecular weight 244.35), and ambergris (molecular weight 428.73). In the cyclodextrin composition, the mass percentage ratio of α-cyclodextrin:β-cyclodextrin:γ-cyclodextrin was 10%:80%:10%. In the polysaccharide compound, the mass ratio of chitosan:sodium alginate was 2:8, and a polysaccharide compound solution with a mass concentration of 1.5% was prepared. The surfactant was a 1% Tween solution (a mixture of Tween 20 and Tween 80 in a 1:1 ratio), and the crosslinking agent was a calcium chloride solution with a mass concentration of 0.3%~1.0%.

[0035] Table 1. Formula provided in Example 1

[0036] 2. Preparation method of biodegradable solid particles S1. Prepare fragrance compounds, first carrier reactants, and polysaccharide compounds respectively; wherein, the first carrier reactant includes a cyclodextrin composition, and the cyclodextrin composition is mixed with 15 parts of anhydrous ethanol and stirred for 2 hours, and then the ethanol is evaporated to remove it; S2. Add a surfactant to the first carrier reactant, then slowly add the fragrance compound to be encapsulated, heat to 40℃~60℃ and stir thoroughly until homogenized to form the first emulsion; S3. After heating the first emulsion to 40℃~60℃ and stirring for 4 hours to encapsulate it, it is mixed with the polysaccharide compound and stirred for 2 hours to obtain the second emulsion; S4. The second emulsion is uniformly added dropwise to the crosslinking agent to form a uniform three-dimensional gel, which is then dried to obtain dry, biodegradable solid particles.

[0037] Example 2 This embodiment prepares biodegradable solid particles using the formulation and method provided in Example 1. The difference from Example 1 is that, in preparing the biodegradable solid particles in this embodiment, the cyclodextrin composition used is calculated by mass ratio: α-cyclodextrin:β-cyclodextrin:γ-cyclodextrin = 30%:55%:15%. Apart from the above differences, the operational steps for preparing the biodegradable solid particles in this embodiment are strictly consistent with those in Example 1.

[0038] Example 3 This embodiment prepares solid particles with reference to the formula and method provided in Embodiment 1. The difference between this embodiment and Embodiment 1 is that the formula provided for preparing solid particles is shown in Table 2.

[0039] Table 2. Formula provided in Example 3

[0040] The method for preparing solid particles in this embodiment is as follows: S1 shall be performed strictly in accordance with the steps provided in Example 1; S2. Add hydrogenated lecithin and surfactant to the first carrier reactant, then slowly add the fragrance compound to be encapsulated, heat to 40℃~60℃ and stir thoroughly until homogenized to form the first emulsion; S3~S4. Strictly follow the steps provided in Example 1.

[0041] Example 4 This embodiment prepares biodegradable solid particles using the formula and method provided in Example 3. The difference from Example 3 is that 0.6 parts of hydrogenated lecithin are used in this embodiment when preparing the biodegradable solid particles. Apart from the above differences, the operational steps for preparing the biodegradable solid particles in this embodiment are strictly consistent with those in Example 3.

[0042] Example 5 This embodiment prepares biodegradable solid particles using the formulation and method provided in Example 3. The difference from Example 1 is that the amount of hydrogenated lecithin used in this embodiment is 1.0 part. Apart from the above differences, the operational steps for preparing the biodegradable solid particles in this embodiment are strictly consistent with those in Example 1.

[0043] Example 6 This embodiment refers to the formula and method provided in Embodiment 1 to prepare solid particles. The difference between this embodiment and Embodiment 1 is that the formula provided in this embodiment for preparing solid particles is shown in Table 3.

[0044] Table 3. Formula provided in Example 6

[0045] The method for preparing solid particles in this embodiment is as follows: S1~S2. Strictly follow the steps provided in Example 1; S3. The first emulsion was stirred and encapsulated with aluminum octyl succinate starch for 2 hours, then heated to 40℃~60℃ and stirred and encapsulated for 4 hours, and then mixed and stirred with polysaccharide compound for 2 hours to obtain the second emulsion; S4. Strictly follow the steps provided in Example 1.

[0046] Example 7 This embodiment prepares biodegradable solid particles using the formula and method provided in Example 6. The difference from Example 6 is that in this embodiment, 10 parts of aluminum octyl succinate starch are used in the preparation of the biodegradable solid particles. Apart from the above differences, the operational steps for preparing the biodegradable solid particles in this embodiment are strictly consistent with those in Example 6.

[0047] Example 8 This embodiment prepares solid particles with reference to the formula and method provided in Embodiment 1. The difference between this embodiment and Embodiment 1 is that the formula provided for preparing solid particles is shown in Table 4.

[0048] Table 4. Formula provided in Example 8

[0049] The method for preparing solid particles in this embodiment is as follows: S1. Prepare fragrance compounds, first carrier reactants, second carrier reactants, third carrier reactants, and shell reactants respectively; the first carrier reactant includes a cyclodextrin composition, which is mixed with 15 parts of anhydrous ethanol and stirred for 2 hours, and then the ethanol is evaporated to remove it; S2. Add hydrogenated lecithin and surfactant to the first carrier reactant, then slowly add the fragrance compound to be encapsulated, heat to 40℃~60℃ and stir thoroughly until homogenized to form the first emulsion; S3. The first emulsion was stirred and encapsulated with aluminum octyl succinate starch for 2 hours, then heated to 40℃~60℃ and stirred and encapsulated for 4 hours, and then mixed and stirred with polysaccharide compound for 2 hours to obtain the second emulsion; S4. The second emulsion is uniformly added dropwise to the crosslinking agent to form a uniform three-dimensional gel, which is then dried to obtain dry, biodegradable solid particles.

[0050] Example 9 This embodiment prepares biodegradable solid particles using the formulation and method provided in Example 8. The difference from Example 8 is that in this embodiment, one part of hydrogenated lecithin is used in the preparation of the biodegradable solid particles. Apart from the above differences, the operational steps for preparing the biodegradable solid particles in this embodiment are strictly consistent with those in Example 8.

[0051] Example 10 This embodiment prepares biodegradable solid particles using the formula and method provided in Example 1. The difference from Example 1 is that the fragrance compounds used in this embodiment are vanillin (molecular weight 154.165), methyl cedryone (molecular weight 246.39), and sweet orange oil (molecular weight 244.35). Apart from the above differences, the operational steps for preparing the biodegradable solid particles in this embodiment are strictly consistent with those in Example 1.

[0052] Comparative Example 1 This comparative example prepares solid particles according to the formulation and method provided in Example 1. The difference between this comparative example and Example 1 is that, in preparing solid particles, an equal mass fraction of β-cyclodextrin is used instead of the cyclodextrin composition. Apart from the above differences, the operation steps for preparing biodegradable solid particles in this comparative example are strictly consistent with those in Example 1.

[0053] Comparative Example 2 This comparative example prepares solid particles using the formulation and method provided in Example 1. The difference between this comparative example and Example 1 is that, in preparing solid particles, an equal mass fraction of α-cyclodextrin is used instead of the cyclodextrin composition. Apart from the above differences, the operating steps for preparing biodegradable solid particles in this comparative example are strictly consistent with those in Example 1.

[0054] Comparative Example 3 This comparative example prepares solid particles according to the formulation and method provided in Example 1. The difference between this comparative example and Example 1 is that, in preparing solid particles, an equal mass fraction of γ-cyclodextrin is used instead of the cyclodextrin composition. Apart from the above differences, the operation steps for preparing biodegradable solid particles in this comparative example are strictly consistent with those in Example 1.

[0055] Comparative Example 4 This comparative example prepares solid particles using the formulation and method provided in Example 1. The difference from Example 1 is that, in preparing the solid particles in this comparative example, the cyclodextrin composition used is calculated by mass ratio: α-cyclodextrin:β-cyclodextrin:γ-cyclodextrin = 50:20:30. Apart from the above differences, the operational steps for preparing biodegradable solid particles in this comparative example are strictly consistent with those in Example 1.

[0056] Comparative Example 5 This comparative example prepares solid particles using the formulation and method provided in Example 7. The difference from Example 7 is that no cyclodextrin composition is added during the preparation of the solid particles in this comparative example. Apart from the above differences, the operational steps for preparing biodegradable solid particles in this comparative example are strictly consistent with those in Example 7.

[0057] Comparative Example 6 This comparative example prepares solid particles using the formulation and method provided in Example 6. The difference from Example 6 is that no cyclodextrin composition is added during the preparation of the solid particles in this comparative example. Apart from the above differences, the operational steps for preparing biodegradable solid particles in this comparative example are strictly consistent with those in Example 6.

[0058] Test case 1. Test Object The biodegradable solid particles prepared in Examples 1-10 and Comparative Examples 1-6 were used as test samples.

[0059] 2. Testing Methods (1) Test of fragrance carrying capacity of solid particles The test can be conducted using either an oven drying method or a solvent washing method. Generally, the oven drying method is used for simple laboratory testing, while the solvent washing method is used to accurately determine the fragrance loading rate of the solid particles.

[0060] The operation steps of the oven drying method are as follows: weigh the mass of the sample to be tested to obtain M1, adjust the oven to 135℃, dry the sample to constant weight and weigh it to obtain M2, and the aroma carrying rate (%) = (M1-M2)*100% / M1.

[0061] The solvent washing method involves two steps: measuring the total fragrance content and the free fragrance content. First, a sample of mass M is weighed and added to a specific volume of ethanol-water solution. High-speed homogenization is used to completely break down the shell of the carrier, allowing all the fragrance compounds inside the sample to dissolve in the ethanol-water solution. After adjusting the volume, the total concentration of fragrance compounds (Ct) is measured using gas chromatography. Next, another sample of mass m is taken and gently shaken with ethanol for 30-60 seconds to elute only the free fragrance on the surface without breaking down the carrier shell. Then, centrifugation is performed, and the supernatant (containing unencapsulated free fragrance compounds) is collected. This process is repeated two or three times, and all supernatants are combined. The combined washing solution is then adjusted to a specific volume (Vs), and the fragrance concentration (Cs) in this washing solution is measured using gas chromatography. The mass of total fragrance compounds = Ct * Vt; the mass of surface fragrance compounds = Cs * Vs; the mass of encapsulated fragrance compounds = the mass of total fragrance compounds - the mass of surface fragrance; the fragrance carrying capacity (%) = the mass of encapsulated fragrance compounds * 100% / the mass of total fragrance compounds.

[0062] This invention uses an oven drying method to test the aroma carrying capacity of solid particles.

[0063] (2) Aroma integrity test Five professionals evaluated the solid fragrance granules and the original liquid fragrance, comparing their scent similarity to assess the fragrance integrity of the solid fragrance granules. A score of 3-5 indicates a significant deviation from the original fragrance, 5-7 indicates some deviation, and 7-10 indicates a high degree of fidelity to the original fragrance.

[0064] (3) Monitoring of aroma release time A certain amount of test sample was fully exposed to the air, and the fragrance release time was monitored at regular intervals. Another equal amount of test sample was placed in a sealed container, and the fragrance release time and fragrance concentration were monitored at the same intervals as the air-exposed group. The release time and fragrance concentration of the two methods were compared, and the lasting fragrance time of the solid fragrance particles was obtained by combining the scores of 5 professionals.

[0065] 3. Test Results and Analysis The test results for this test example are shown in Table 5. Data from Examples 1-2 and Comparative Examples 1-4 show that in Examples 1-2, the proportion of the cyclodextrin composition falls within the defined range, resulting in a precise match between the cavity size and the molecular size of the fragrance compound, avoiding the screening effect, and achieving high fragrance loading and high top, middle, and base note restoration. In contrast, Comparative Examples 1-3 used only a single cyclodextrin, leading to a mismatch between the cavity and multiple sizes of fragrance molecules, resulting in a sharp decrease in fragrance loading and fragrance shift. Comparative Example 4 deviated from the range, with a low proportion of β-cyclodextrin, causing a lack of the cyclodextrin inclusion framework, resulting in a large amount of fragrance being released and layering occurring during fragrance evaporation. This further confirms that deviating from this proportion range leads to a simultaneous and significant decrease in both fragrance loading and fragrance integrity. This demonstrates that the biodegradable solid particles provided by this invention allow for adjustments to the proportion of the cyclodextrin composition based on the molecular weight distribution of the fragrance compound and the actual fragrance effect of the encapsulated fragrance.

[0066] After adding an appropriate amount of hydrogenated lecithin to the cyclodextrin composition of Example 1, the fragrance carrying capacity and aroma integrity of Examples 3 and 4 were further improved. In Example 5, the content of hydrogenated lecithin was further increased, and although the aroma integrity remained unchanged, the fragrance carrying capacity was further improved. Hydrogenated lecithin, with its spontaneously formed vesicles and bilayer structure (vesicle diameters ranging from a few nanometers to hundreds of nanometers), can supplementarily encapsulate and emulsify fragrance components with larger molecular weights that are difficult to efficiently accommodate in the cyclodextrin cavity. This synergistic effect broadens the coverage range of the carrier for larger aroma molecules. After adding an appropriate amount of aluminum octyl succinate to the composition of Example 1, the fragrance carrying effect of Examples 6 and 7 was enhanced to some extent. Aluminum octyl succinate possesses a unique physicochemical structure of modified starch. Aluminum ion crosslinking creates a rigid framework, maintaining structural integrity. The introduction of hydrophobic octyl chains and the entanglement of starch molecular chains, after drying, form a porous carrier with numerous irregular pores and channels, exhibiting excellent adsorption and encapsulation capabilities. Its large specific surface area allows it to adsorb various fragrance molecules of different sizes. Through the synergistic effect of cyclodextrin composition and inclusion and porous adsorption, the carrier system can cover a wider range of aroma substances by molecular weight, reducing aroma shift caused by differences in evaporation rates, thereby increasing the total fragrance loading and better preserving the original fragrance characteristics. In Comparative Example 5, the solid particles prepared using only hydrogenated lecithin and ASO exhibited problems such as fragrance product precipitation and rapid aroma release, indicating that the cyclodextrin composition has a good encapsulation effect on fragrances. In Comparative Example 6, the addition of only starch octyl succinate aluminum could not completely encapsulate the fragrance substances, and the fragrance evaporated quickly, indicating that starch octyl succinate aluminum only has an adsorption effect, thus verifying the importance of the cyclodextrin composition.

[0067] Furthermore, in Examples 8 and 9, by simultaneously using the cyclodextrin complex, hydrogenated lecithin, and aluminum octylsuccinate, the hydrogenated lecithin forms vesicles and bilayer structures to supplement the encapsulation of larger molecular weight fragrance components. Aluminum octylsuccinate, with its microporous structure and large specific surface area, adsorbs and regulates small molecules and highly volatile top notes that are difficult to retain efficiently in the cyclodextrin cavities. The synergistic effect of these three components allows the carrier system to cover a wider range of fragrance components by molecular weight, significantly reducing aroma profile shifts caused by differences in evaporation rates while increasing the total loading and encapsulation efficiency, thus preserving the original fragrance more completely.

[0068] In Example 10, the molecular weight and diameter of the fragrance fall within the optimal matching range of the cyclodextrin composition cavity. The hydrophobic cavity can precisely encapsulate each component, avoiding free loss due to molecules that are too large to enter or too small to bind properly. Therefore, the fragrance loading rate and aroma integrity are significantly better than in Example 1, which has a wider molecular distribution. This demonstrates that for fragrance compounds with a molecular weight of 100 Daltons to 400 Daltons, the cyclodextrin composition provided by this invention alone can achieve excellent fragrance loading rate and aroma integrity. Therefore, hydrogenated lecithin or aluminum octylsuccinate can be added as needed, depending on the actual molecular weight of the fragrance compound and the product's requirements for fragrance loading rate and aroma.

[0069] Therefore, this invention can flexibly adjust the compound ratio of cyclodextrin according to the molecular weight distribution of fragrance and selectively introduce hydrogenated lecithin and aluminum octyl succinate of starch. While controlling costs, it can effectively broaden the range of fragrance molecules covered by the carrier, reduce the fragrance shift caused by volatilization differences, and make the total loading and original fragrance restoration reach the ideal state.

[0070] Table 5. Test Results

[0071] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A long-lasting fragrance and biodegradable solid granule, characterized in that, It includes a core material, a carrier enclosing the core material, and a shell covering the carrier; The core material includes fragrance compounds, which include at least one of fragrances or their precursors, and flavorings or their precursors. The core material includes the fragrance compound with a molecular weight of 100 Daltons to 400 Daltons; The carrier includes a first carrier, the first carrier comprising a cyclodextrin composition; The cyclodextrin composition comprises α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin, and is calculated by mass percentage as follows: α-cyclodextrin:β-cyclodextrin:γ-cyclodextrin = 10%~30%:50%~80%:5%~15%.

2. The solid particles as described in claim 1, characterized in that, The carrier also includes a second carrier, which comprises hydrogenated lecithin.

3. The solid particles as described in claim 1, characterized in that, The carrier also includes a third carrier, which comprises aluminum starch octylsuccinate.

4. The solid particles as described in claim 1, characterized in that, The shell layer comprises a polysaccharide compound, which includes at least one of chitosan and sodium alginate.

5. The solid particles according to any one of claims 1 to 4, characterized in that, The solid particles comprise, by mass percentage, 10% to 40% of the core material, 50% to 80% of the carrier, and 5% to 20% of the shell layer; And / or, the carrier includes at least one of a first carrier, a second carrier, and a third carrier; And / or, in the carrier, the mass percentage of the first carrier is 60% to 100%; And / or, in the carrier, the mass percentage of the second carrier is 0% to 10%; And / or, in the carrier, the mass percentage of the third carrier is 0% to 40%.

6. A method for preparing solid particles as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1. Prepare fragrance compounds, a first carrier reactant, and a shell reactant respectively; wherein, the first carrier reactant includes the cyclodextrin composition; S2. A surfactant is added to the first carrier reactant, followed by the fragrance compound, to obtain a first emulsion; S3. Mix the first emulsion with the shell reactant to obtain the second emulsion; S4. The second emulsion is mixed with a crosslinking agent to form a gel, and the solid particles are obtained after post-treatment.

7. The preparation method according to claim 6, characterized in that, Includes the following steps: S1. Prepare fragrance compounds, a first carrier reactant, a second carrier reactant, a third carrier reactant, and a shell reactant respectively; wherein, the first carrier reactant includes the cyclodextrin composition, the second carrier reactant includes hydrogenated lecithin, and the third carrier reactant includes aluminum starch octylsuccinate; S2. Add the second carrier reactant and surfactant to the first carrier reactant, and then add the fragrance compound to obtain the first emulsion; S3. After mixing the first emulsion with the third carrier reactant, the shell reactant is added and mixed to obtain the second emulsion; S4. The second emulsion is mixed with a crosslinking agent to form a gel, and the solid particles are obtained after post-treatment.

8. A consumer product, characterized in that, The consumer product includes the solid particles as described in any one of claims 1 to 5, or the solid particles prepared by the preparation method as described in any one of claims 6 to 7.

9. The consumer product as described in claim 8, characterized in that, The consumer products mentioned are any one of the following: personal care products, household care products, cleaning products, food, air purifiers, air deodorizers, room fragrances, and sleep-aid fragrance products.

10. The solid particles as described in any one of claims 1 to 5, the solid particles prepared by the preparation method as described in claim 6 or 7, or the consumer product as described in claim 8 or 9, in the consumer field.

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