Microcapsule embedding method of slow-release cooling essence for areca nuts

Abstract

The method comprises the following steps: (1) preparing a core material, (2) modifying a wall material, (3) compounding the wall material, (4) carrying out primary emulsification, (5) carrying out double-layer embedding, and (6) carrying out spray drying, so as to obtain the microcapsule of the slow-release cooling essence for the betel nut. The conformational strength of protein is improved through freezing recombination to resist chewing pressure, the release rate is accurately adjusted by combining the calcium ion cross-linked pH response controlled release layer, a pore size hierarchical structure is formed in cooperation with a gradient drying process, and rapid response in the early chewing stage, stable release in the middle stage and continuous action in the later stage of the cooling agent are synergistically achieved; meanwhile, the long-term embedding stability of the microcapsule under brine soaking and high-humidity storage is ensured.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, specifically relating to a microcapsule encapsulation method for a sustained-release cooling flavoring for areca nuts. Background Technology

[0002] Betel nut, as a traditional chewing pleasure, often requires the addition of cooling flavorings during its processing to enhance its taste and satisfy consumers' desire for a refreshing sensation. Commonly used cooling agents include menthol, menthone glyceryl ketal, WS-23, and menthane carboxylic acid N-ethylamide. Traditional methods typically involve dissolving these cooling agents directly in the brine system and spraying them onto the surface of the betel nut, or mixing them directly into the brine used in the betel nut braising process. This simple mixing method results in a very strong peak in the cooling sensation within the first few seconds of chewing, typically within 10 to 15 seconds, but this peak is extremely short-lived, quickly diminishing and disappearing. This rapid release and decay significantly impacts the persistence and enjoyment of the chewing experience.

[0003] To address this issue, engineers developed microencapsulation technology to delay the release of cooling agents. Early attempts involved encapsulation with a single-layer wall material; for example, some solutions used a gelatin and gum arabic composite as the wall material to encapsulate the cooling agent. This method extended the duration of the cooling sensation to some extent, allowing it to last for about one to two minutes, but it still had significant limitations.

[0004] The primary problem is that these wall materials dissolve relatively quickly in the warm and moist microenvironment of the mouth, resulting in an excessively high concentration of cooling agents released during the initial chewing phase. This produces an overly stimulating cooling sensation, making the experience uncomfortable and unnatural. Secondly, the microcapsule particles are easily ruptured and ineffective under the strong mechanical pressure of chewing, preventing a stable and continuous release of the cooling sensation during chewing, instead causing fluctuations. The third significant drawback is that these hydrophilic wall materials easily absorb moisture from the environment in the high-humidity storage environment commonly found in areca nut products. This causes the cooling components to leak through the capsule wall, significantly reducing the actual encapsulation effect, or encapsulation rate, of the microcapsules during post-production storage.

[0005] To overcome the limitations of single-layer wall materials, more advanced technologies have adopted a double-layer wall material design. For example, some schemes first use zein as the inner wall material to form a basic coating, and then use sodium alginate as the outer wall material for a secondary coating. This double-layer design does improve the stability of release to some extent, but it has revealed new problems in application. When zein comes into contact with the acidic components commonly found in areca nut brine, it is prone to aggregation and precipitation, resulting in a decrease in the actual encapsulation rate of the cooling agent to a low level of only 68% to 72%. Moreover, the cooling release curve exhibits a stepped, discontinuous change, failing to achieve a smooth and gentle effect.

[0006] Another approach to improvement is to use the unique cavity structure of cyclodextrin molecules to encapsulate cooling agent molecules. The advantage of this approach is that the encapsulated mixture has good thermal stability. However, the key drawback is that the release rate in the oral environment is too slow. In the first 30 seconds or even longer after chewing begins, it is almost impossible to produce a noticeable cooling sensation, which is completely inconsistent with consumers' expectations for an instant cooling experience.

[0007] Therefore, the pressing technical challenge facing the areca nut processing industry is developing an innovative microencapsulation process. This method must simultaneously achieve three key objectives: rapidly inducing a significant cooling sensation in the initial chewing phase to meet immediate needs; continuously and evenly releasing the cooling components during chewing to ensure a lasting and stable experience; and ensuring the microcapsule structure itself possesses excellent strength to resist mechanical stress and adapt to chewing activities. The ultimate goal is to obtain an ideal cooling release curve: exhibiting a gentle, approximately S-shaped decline, thereby completely resolving the core defects of existing technologies, such as abrupt stimulation, unstable release, or delayed onset of action. Therefore, a microencapsulation method for a sustained-release cooling flavoring in areca nut needs to be designed. Summary of the Invention

[0008] To overcome the shortcomings of the existing technology, a microcapsule encapsulation method for a sustained-release cooling flavoring for areca nuts is provided.

[0009] In order to achieve the above object, the present invention provides the following technical solutions: A method for microencapsulating a sustained-release cooling flavoring for areca nuts, comprising the following steps, by weight: (1) Core material preparation: 15-25 parts by weight of menthol carboxylic acid N-ethylamide and 8-12 parts by weight of WS-3 cooling agent are added to 30-40 parts by weight of propylene glycol and mixed and dissolved at 45-50℃ to obtain the core material solution. (2) Wall material modification: After soaking and centrifuging the corn gluten powder in hydrochloric acid solution with a pH of 4.0, it is enzymatically hydrolyzed with 0.5%-0.8% neutral protease at 45-50 ℃ for 1.5 hours. The resulting corn gliadin product is ultrasonically treated at 30 kHz for 20 minutes, and then subjected to esterification modification and emulsification enhancement treatment to obtain modified corn gliadin. (3) Wall material compounding: 15-20 parts by weight of modified zein obtained in step (2) are mixed with 10-15 parts by weight of cassava acetylated distarch phosphate with an acetylation degree of 2.0%-2.5% and 5-8 parts by weight of gum arabic in water at 60°C to form a solution with a solid content of 20%-25%. The resulting solution is the wall material solution. (4) Primary emulsification: Add the core material solution obtained in step (1) to the wall material solution obtained in step (3), emulsify at 6000-8000 rpm for 8-10 minutes, and the viscosity of the primary emulsion obtained at 50-55℃ is 200-300mPa·s, to obtain the emulsion. (5) Double-layer embedding: Add sodium alginate solution to the emulsion obtained in step (4), and then stir at 400-500 rpm for 30 minutes to adjust the pH value to 6.2-6.5 to obtain the embedded emulsion; (6) Spray drying: Inlet air temperature 160-170℃, outlet air temperature 65-70℃, centrifugal drying at 18000-20000rpm to obtain microcapsules of slow-release cool flavoring for areca nut.

[0010] In step (2), the mass ratio of corn gluten powder to hydrochloric acid solution is 1:6-8.

[0011] In step (2), the corn gluten powder is subjected to a frozen structural recombination operation after enzymatic hydrolysis. The specific steps are as follows: the enzymatic hydrolysate obtained by enzymatic hydrolysis is first frozen to -30℃ at a rate of 5-8℃ / min, and then thawed to 4℃ at a rate of 2-3℃ / min; after thawing, it is centrifuged at 5000rpm for 10 minutes, and the precipitate is collected as the corn gliadin product.

[0012] In step (2), the esterification modification includes the following steps: after completing the enzymatic hydrolysis and ultrasonic treatment, octenyl succinic anhydride is added to the reaction system, wherein the amount of octenyl succinic anhydride added is 3%-5% of the dry basis mass of the zein product obtained in step (2); at the same time, the pH value of the reaction system is controlled to be 8.2-8.6, the temperature is 45-55 ℃, and the reaction time is 1-3 hours.

[0013] In step (2), the emulsification enhancement is carried out after esterification modification. The emulsification enhancement includes the following steps: adding a mixture of sucrose fatty acid ester and glyceryl monostearate to the reaction system, wherein the mass ratio of sucrose fatty acid ester to glyceryl monostearate is 2-3:1; the total amount of the mixture added is 0.5%-1.0% of the dry basis mass of the zein product obtained in step (2), and stirring and mixing for 10-20 minutes.

[0014] In step (4), the ratio of the total dry matter mass of the core material solution to the total dry matter mass of the wall material solution is 1:2-3.

[0015] In step (5), the mass concentration of the added sodium alginate solution is 2%-3%, and the amount of sodium alginate solution added is 20%-30% of the mass of the emulsion.

[0016] The sodium alginate solution is a compound fortified solution: it contains 2%-3% sodium alginate and 0.1%-0.3% calcium chloride by mass.

[0017] The core material solution also contains: 3-5 parts by weight of menthyl lactate and 1-2 parts by weight of borneol.

[0018] After step (5), the embedded emulsion is continuously defoamed for 15-20 minutes under a vacuum of -0.08 to -0.09 MPa to obtain a defoamed emulsion. Then, fumed silica is added to the defoamed emulsion and mixed evenly. 0.5%-1.0% of fumed silica is added based on the mass of solids in the defoamed emulsion.

[0019] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: 1. The microcapsule encapsulation method provided by this invention significantly improves the sustained-release performance of the cooling component through a unique wall material modification process. Zeatin is enzymatically hydrolyzed under acidic conditions and then subjected to ultrasonic treatment to fully unfold the protein molecular chains and expose active sites. Subsequent esterification modification with octenyl succinic anhydride grafts hydrophobic groups onto the protein molecules. This structural change reduces the dissolution rate of the wall material in the oral cavity, effectively preventing the explosive release of the cooling agent during the initial chewing phase. Simultaneously, the hydrophobic groups enhance the affinity between the protein and the cooling agent, further slowing down the outward diffusion rate of the core material.

[0020] 2. In the wall material compounding process, this invention employs a composite system formed by modified zein, tapioca starch with a specific degree of acetylation, and gum arabic. Zein provides a rigid framework to resist mechanical pressure, acetylated starch forms a viscoelastic network under humid and hot conditions to slow down water penetration, and gum arabic enhances the density of the wall material through hydrogen bonds. This three-dimensional composite structure allows the microcapsules to maintain an intact capsule wall even under a chewing pressure of 500N, effectively solving the problem of uneven release of coolness caused by capsule wall rupture in existing technologies.

[0021] 3. In the double-layer encapsulation process of this invention, a sodium alginate-calcium chloride compound solution is used, where calcium ions and alginate ions undergo in-situ cross-linking to form a network molecular sieve. This structure has pH-responsive characteristics, allowing only a small amount of cool-tasting molecules to diffuse slowly; when exposed to the acidic environment of brine, the mesh pores shrink to 2.8 nm. This intelligent regulation mechanism ensures that the microcapsules maintain high stability during the production and storage stages.

[0022] 4. By precisely controlling the spray drying parameters, the microcapsules form a gradient curing structure. The outer wall material is instantly cured in the high-temperature zone to form a sealed packaging layer, while the inner wall material is slowly dried under a lower temperature gradient to produce a porous structure. This differentiated structure allows the release of the cooling agent to exhibit an ideal three-stage characteristic: in the initial stage, the surface micropores allow a small amount of cooling agent to seep out rapidly to achieve an immediate cooling sensation; in the middle stage, the inner porous structure maintains a uniform release rate; and in the later stage, the residual core material diffuses through the pores to prolong the duration of action.

[0023] 5. For high-humidity storage environments, the degassing treatment of this invention, combined with the addition of fumed silica, forms a dual protection mechanism. Vacuum degassing eliminates weak points in the internal stress of the capsule wall, increasing the density of the wall material; nano-sized silica particles form a hydrophobic barrier on the surface of the microcapsule, and their silanol structure preferentially adsorbs environmental water molecules, thereby blocking the path of water penetration into the capsule wall.

[0024] 6. The cryogenic remodeling process of this invention plays a crucial role in regulating the conformation of protein molecules. Rapid freezing causes the protein solution to form tiny ice crystals, and the resulting mechanical stress promotes the transformation of the α-helix structure into a β-sheet. During the subsequent slow thawing process, the molecular chains reassemble to form a more cross-linked three-dimensional network. This conformational change increases the elastic modulus of the modified protein, significantly enhancing its resistance to deformation. When the microcapsules are chewed and compressed, they undergo elastic deformation rather than rupture.

[0025] 7. The small molecule properties of menthyl lactate added to the core material formulation of the present invention enable it to quickly penetrate the surface wall material to produce an initial cooling sensation. The co-crystal formed by borneol and N-ethylamide of menthane carboxylic acid gradually dissociates and releases in the middle and later stages. The differential diffusion coefficients of the three components achieve a natural transition in the intensity of the cooling sensation. This multi-component release kinetic matching avoids the sensory stimulation caused by the abrupt release of a single component. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The sources of various raw materials in this application are briefly described as follows: N-Ethylamide menthol carboxylic acid: purchased from Hubei Weideli Chemical Technology Co., Ltd., CAS No. 304-20-1, product model FP-2301-5G.

[0028] WS-3 cooling agent: namely N,2,3-trimethyl-2-isopropylbutyramide, supplied by Shanghai Banbai Chemical Co., Ltd., CAS number 39711-79-0, model number BB01076.

[0029] Propylene glycol: Food grade product, provided by Shandong Yingxin Chemical Co., Ltd., CAS number 57-55-6, specification model YS-FD2023.

[0030] Corn gluten meal: Made from feed-grade raw materials, sourced from Hebei Hongrui Biotechnology Co., Ltd.

[0031] Neutral protease: enzyme activity 200,000 U / g, purchased from Cangzhou Xiasheng Enzyme Biotechnology Co., Ltd., CAS No. 9014-01-1, model: Protease A 2.4L.

[0032] Octenyl succinic anhydride: food additive grade, supplier Hangzhou Ruilin Chemical Co., Ltd., CAS number 106-12-7, model number RL-OSA-F01.

[0033] Sucrose fatty acid esters: HLB value 11-13, manufactured by Guangxi Nanning Furong Food Additives Co., Ltd., product number SE-1570.

[0034] Glyceryl monostearate: food emulsifier model GMS-50, supplier is Henan Shengzhide Food Technology Co., Ltd., CAS number is 123-94-4.

[0035] Cassava acetylated distarch phosphate: supplied by Thai Cassava Starch Group, model PREGEFLO PCS 10.

[0036] Gum arabic: Food-grade colloid, supplied by Merck Group of Germany, CAS number 9000-01-5.

[0037] Sodium alginate: Manufacturer: Qingdao Mingyue Marine Technology Co., Ltd., CAS No.: 9005-38-3, Model: Manugel GHB.

[0038] Calcium chloride: food-grade dihydrate, purchased from Yantai Hengxin Chemical Technology Co., Ltd., CAS number 10035-04-8, specification HX-FCC-02.

[0039] Menthyl lactate: Cooling synergist, provided by Shanghai Huachuang Fragrance Co., Ltd., CAS No. 59259-38-0, model HC-MLE-02.

[0040] Borneol: Supplier: Anhui Kangqiong Natural Raw Materials Co., Ltd., CAS No. 464-45-9.

[0041] Fumed silica: Food anti-caking agent, model SYLOID 72FP, supplied by Grace Chemicals, Inc., USA, CAS number 112945-52-5.

[0042] The technical solution of this application is as follows: A method for microencapsulating a sustained-release cooling flavoring for areca nuts, comprising the following steps, by weight: (1) Core material preparation: 15-25 parts by weight of menthol carboxylic acid N-ethylamide and 8-12 parts by weight of WS-3 cooling agent are added to 30-40 parts by weight of propylene glycol and mixed and dissolved at 45-50℃ to obtain the core material solution. (2) Wall material modification: After soaking and centrifuging the corn gluten powder in hydrochloric acid solution with a pH of 4.0, it is enzymatically hydrolyzed with 0.5%-0.8% neutral protease at 45-50 ℃ for 1.5 hours. The resulting corn gliadin product is ultrasonically treated at 30 kHz for 20 minutes, and then subjected to esterification modification and emulsification enhancement treatment to obtain modified corn gliadin. (3) Wall material compounding: 15-20 parts by weight of modified zein obtained in step (2) are mixed with 10-15 parts by weight of cassava acetylated distarch phosphate with an acetylation degree of 2.0%-2.5% and 5-8 parts by weight of gum arabic in water at 60°C to form a solution with a solid content of 20%-25%. The resulting solution is the wall material solution. (4) Primary emulsification: Add the core material solution obtained in step (1) to the wall material solution obtained in step (3), emulsify at 6000-8000 rpm for 8-10 minutes, and the viscosity of the primary emulsion obtained at 50-55℃ is 200-300mPa·s, to obtain the emulsion. (5) Double-layer embedding: Add sodium alginate solution to the emulsion obtained in step (4), and then stir at 400-500 rpm for 30 minutes to adjust the pH value to 6.2-6.5 to obtain the embedded emulsion; (6) Spray drying: Inlet air temperature 160-170℃, outlet air temperature 65-70℃, centrifugal drying at 18000-20000rpm to obtain microcapsules of slow-release cool flavoring for areca nut.

[0043] In step (2), the mass ratio of corn gluten powder to hydrochloric acid solution is 1:6-8.

[0044] In step (2), the corn gluten powder is subjected to a frozen structural recombination operation after enzymatic hydrolysis. The specific steps are as follows: the enzymatic hydrolysate obtained by enzymatic hydrolysis is first frozen to -30℃ at a rate of 5-8℃ / min, and then thawed to 4℃ at a rate of 2-3℃ / min; after thawing, it is centrifuged at 5000rpm for 10 minutes, and the precipitate is collected as the corn gliadin product.

[0045] In step (2), the esterification modification includes the following steps: after completing the enzymatic hydrolysis and ultrasonic treatment, octenyl succinic anhydride is added to the reaction system, wherein the amount of octenyl succinic anhydride added is 3%-5% of the dry basis mass of the zein product obtained in step (2); at the same time, the pH value of the reaction system is controlled to be 8.2-8.6, the temperature is 45-55 ℃, and the reaction time is 1-3 hours.

[0046] In step (2), the emulsification enhancement is carried out after esterification modification. The emulsification enhancement includes the following steps: adding a mixture of sucrose fatty acid ester and glyceryl monostearate to the reaction system, wherein the mass ratio of sucrose fatty acid ester to glyceryl monostearate is 2-3:1; the total amount of the mixture added is 0.5%-1.0% of the dry basis mass of the zein product obtained in step (2), and stirring and mixing for 10-20 minutes.

[0047] In step (4), the ratio of the total dry matter mass of the core material solution to the total dry matter mass of the wall material solution is 1:2-3.

[0048] In step (5), the mass concentration of the added sodium alginate solution is 2%-3%, and the amount of sodium alginate solution added is 20%-30% of the mass of the emulsion.

[0049] The sodium alginate solution is a compound fortified solution: it contains 2%-3% sodium alginate and 0.1%-0.3% calcium chloride by mass.

[0050] The core material solution also contains: 3-5 parts by weight of menthyl lactate and 1-2 parts by weight of borneol.

[0051] After step (5), the embedded emulsion is continuously defoamed for 15-20 minutes under a vacuum of -0.08 to -0.09 MPa to obtain a defoamed emulsion. Then, fumed silica is added to the defoamed emulsion and mixed evenly. 0.5%-1.0% of fumed silica is added based on the mass of solids in the defoamed emulsion.

[0052] The technical solutions of the present invention are further illustrated below through examples and comparative examples, but the scope of protection of the present invention is not limited thereto.

[0053] Example 1 Take 1000 g of corn gluten powder, soak it in pH 4.0 hydrochloric acid solution at a solid-liquid ratio of 1:6 for 2 hours, and centrifuge to collect the precipitate. Add 0.5% (by dry weight) of neutral protease to the precipitate and enzymatically hydrolyze it at 50℃ for 1.5 hours, followed by sonication at 30 kHz for 20 minutes. For frozen structural reconstruction: freeze the hydrolysate at 8℃ / min to -30℃, thaw at 3℃ / min, and centrifuge to obtain zein. For esterification modification: add 5% (by dry weight) of octenyl succinic anhydride to the zein product, and react at pH 8.6 and 55℃ for 3 hours. For emulsification enhancement: add a mixture of sucrose fatty acid ester and glyceryl monostearate (mass ratio 3:1), with a total addition amount of 1.0% (by dry weight) of the protein, and stir for 20 minutes to obtain modified zein.

[0054] Core material preparation: 25 parts of menthol carboxylic acid N-ethylamide, 12 parts of WS-3 cooling agent, 5 parts of menthyl lactate, and 2 parts of borneol are dissolved in 40 parts of propylene glycol at 50°C.

[0055] Wall material compound: 20 parts modified zein, 15 parts cassava acetylated distarch phosphate with 2.5% acetylation degree, and 8 parts gum arabic are mixed in water at 60℃ to form a solution with a solid content of 25%.

[0056] Primary emulsification: The core material solution is added to the wall material solution, with a core-to-wall dry matter mass ratio of 1:3. Emulsification is carried out at 8000 r / min for 10 minutes, and the viscosity reaches 300 mPa·s at 55℃.

[0057] Double-layer encapsulation: Add a solution containing 3% sodium alginate and 0.3% calcium chloride (30% addition amount), stir at 500 r / min for 30 minutes, and adjust the pH to 6.5.

[0058] Degassing treatment: Degas at -0.09 MPa vacuum for 20 minutes, then add 1.0% fumed silica based on the solid content of the degassed emulsion.

[0059] Spray drying: air inlet 170℃, air outlet 70℃, atomizing disc 20000 r / min drying.

[0060] Example 2 In this embodiment, the similarities to those in Embodiment 1 will not be repeated, and the differences are as follows: Corn gluten meal was soaked in hydrochloric acid at a solid-liquid ratio of 1:8, and then enzymatically hydrolyzed with the addition of 0.8% neutral protease at 45°C.

[0061] Core material: 15 parts of menthol carboxylic acid N-ethylamide, 8 parts of WS-3 cooling agent, 3 parts of menthyl lactate, and 1 part of borneol dissolved in 30 parts of propylene glycol at 45°C.

[0062] Wall material: 17.5 parts modified zein, 10 parts starch with 2.0% acetylation, and 5 parts gum arabic were mixed to form a 20% solid content solution.

[0063] Emulsification: Core-to-wall ratio 1:2.5, emulsification at 6000 r / min for 9 minutes, viscosity at 50℃ 200 mPa·s.

[0064] Encapsulation: Add 2.5% sodium alginate solution (20% addition, containing 0.1% calcium chloride), stir at 450 r / min, and adjust pH to 6.2.

[0065] Degassing: Degas at -0.08 MPa for 15 minutes, then add 0.5% fumed silica.

[0066] Drying: air inlet 165℃, air outlet 67.5℃, atomizing disc 19000 r / min.

[0067] Example 3 In this embodiment, the similarities to those in Embodiment 1 will not be repeated, and the differences are as follows: Hydrochloric acid soaking (solid-liquid ratio 1:7), enzymatic hydrolysis with 0.65% neutral protease added, reaction at 47.5℃. Esterification modification: octenyl succinic anhydride added 4%, pH 8.4, reaction at 50℃ for 2 hours. Emulsification enhancement: emulsifier ratio 2:1, total 0.75%, stirring for 15 minutes.

[0068] Core material: 20 parts of menthol carboxylic acid N-ethylamide, 10 parts of WS-3 cooling agent, 4 parts of menthyl lactate, and 1.5 parts of borneol dissolved in 35 parts of propylene glycol at 47.5℃.

[0069] Wall material: 15 parts zein, 12.5 parts starch with 2.25% acetylation, and 6.5 parts gum arabic were mixed to form a 22.5% solid content solution.

[0070] Emulsification: Core-to-wall ratio 1:2, emulsification at 7000 r / min for 8 minutes, viscosity at 52.5℃ 250 mPa·s.

[0071] Encapsulation: Add 2% sodium alginate solution (25% addition, containing 0.2% calcium chloride), stir at 400 r / min, and adjust pH to 6.35.

[0072] Degassing: Degas at -0.085 MPa for 17.5 minutes, then add 0.75% fumed silica.

[0073] Drying: air inlet 160℃, air outlet 65℃, atomizing disc 18000 r / min.

[0074] Comparative Example 1

[0075] In this comparative example, the similarities with Example 1 will not be repeated, and the differences are as follows: The frozen structure recombination step was omitted, and the enzymatic hydrolysate was directly centrifuged.

[0076] Comparative Example 2

[0077] In this comparative example, the similarities with Example 2 will not be repeated, and the differences are as follows: Sodium alginate solution does not contain calcium chloride.

[0078] Comparative Example 3

[0079] In this comparative example, the similarities with Example 3 will not be repeated, and the differences are as follows: The double-layer embedding was eliminated, and a single wall material (cassava starch and gum arabic) was used instead.

[0080] Comparative Example 4

[0081] In this comparative example, the similarities with Example 1 will not be repeated, and the differences are as follows: The wall material was changed to a mixture of gelatin and gum arabic in a 3:2 ratio.

[0082] Comparative Example 5

[0083] In this comparative example, the similarities with Example 1 will not be repeated, and the differences are as follows: Spray drying is performed at a constant temperature of 160℃.

[0084] Performance Test Results and Analysis

[0085] Microcapsules obtained according to the parameters of the examples and comparative examples were tested using the following methods: simulated chewing release in a 37°C water bath (100 r / min rotation speed); compressive strength testing was performed using a texture analyzer (500 N pressure); encapsulation efficiency was determined by GC-MS of the difference before and after brine immersion; and humidity stability testing was conducted at 25°C / 70%RH for 180 days. The specific test results are shown in Table 1.

[0086] As shown in Table 1, the release curves of Examples 1-3 exhibit a standard S-shaped characteristic: the initial release rate is controlled between 19% and 24%, corresponding to the preferential diffusion of menthyl lactate in the core material to achieve a cooling sensation upon ingestion; the stable release slope in the middle stage is due to the porous structure formed by gradient curing, which allows the main cooling agent to be released at a uniform rate; the retention rate exceeding 15% in the later stage is attributed to the blocking effect of the outer sealing packaging layer. In contrast, the single-layer wall material of Comparative Example 3, lacking a dense layer, resulted in an initial release exceeding 50%, demonstrating the crucial role of the double-layer structure in inhibiting steep release.

[0087] Freezing and reorganization increased the β-sheet content of zein. The low compressive breakage rate in the three examples was attributed to the elastic reorganization of the protein molecular chains and the energy dissipation mechanism of the starch-gum arabic complex network. In contrast, in Comparative Example 1 without freezing and reorganization, residual water molecules formed stress concentration points in the protein interstices, and crack propagation under pressure led to a sharp increase in the compressive breakage rate to 22.3%, confirming the necessity of freezing and reorganization for mechanical enhancement.

[0088] Table 1 Analysis of Test Results

[0089] The encapsulation rate of the example after brine immersion was >89%, which stems from the pH-responsive characteristics of calcium ion crosslinking: under acidic conditions, the pores of calcium alginate shrink to 2.2-2.8 nm, smaller than the molecular size of menthol carboxylic acid N-ethylamide, physically preventing the core material from leaching out. After 180 days of high-humidity storage, the retention rate was >92%, which is attributed to the molecular sieve effect of fumed silica blocking the moisture penetration path, and the adsorption of hydrated ions by silanol groups to form a 1.5 nm diameter water film. In Comparative Example 2, without calcium crosslinking, the encapsulation rate dropped to 68.4% after brine immersion, demonstrating the irreplaceable nature of the pH-responsive structure.

[0090] The eutectic formed by borneol and menthane carboxylic acid decomposes and releases the borneol in the mid-to-late stages, with the viscoelasticity of tapioca starch controlling the diffusion rate. In Comparative Example 5, during isothermal drying, the lack of an outer rapid-condensing dense layer led to premature dissociation of the borneol eutectic, resulting in a 12% acceleration in the mid-term release rate, confirming the value of gradient drying in regulating release kinetics.

[0091] Comparative Example 4 used traditional gelatin wall material, with an initial release of 47.2%. Due to the rapid swelling of gelatin at 37°C, forming millimeter-sized pores, its compressive strength was weak (breakage rate 38.5%), and its elongation at break was less than 15%, making it unable to withstand repeated chewing deformation. This invention enhances protein conformation strength through freeze-recombination to resist chewing pressure, precisely regulates the release rate by combining a pH-responsive controlled-release layer with calcium ion crosslinking, and forms a graded pore structure with a gradient drying process. This synergistically achieves rapid response of the cooling agent in the early stage of chewing, stable release in the middle stage, and continuous effect in the later stage, while ensuring the long-term encapsulation stability of the microcapsules under brine soaking and high humidity storage.

[0092] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for microencapsulating a sustained-release cooling flavoring for areca nuts, characterized in that, The method, in parts by weight, includes the following steps: (1) Core material preparation: 15-25 parts by weight of menthol carboxylic acid N-ethylamide and 8-12 parts by weight of WS-3 cooling agent are added to 30-40 parts by weight of propylene glycol and mixed and dissolved at 45-50℃ to obtain the core material solution. (2) Wall material modification: After soaking and centrifuging the corn gluten powder in hydrochloric acid solution with a pH of 4.0, it is enzymatically hydrolyzed with 0.5%-0.8% neutral protease at 45-50 ℃ for 1.5 hours. The resulting corn gliadin product is ultrasonically treated at 30 kHz for 20 minutes, and then subjected to esterification modification and emulsification enhancement treatment to obtain modified corn gliadin. (3) Wall material compounding: 15-20 parts by weight of modified zein obtained in step (2) are mixed with 10-15 parts by weight of cassava acetylated distarch phosphate with an acetylation degree of 2.0%-2.5% and 5-8 parts by weight of gum arabic in water at 60°C to form a solution with a solid content of 20%-25%. The resulting solution is the wall material solution. (4) Primary emulsification: Add the core material solution obtained in step (1) to the wall material solution obtained in step (3), emulsify at 6000-8000 rpm for 8-10 minutes, and the viscosity of the primary emulsion obtained at 50-55℃ is 200-300 mPa·s, to obtain the emulsion. (5) Double-layer embedding: Add sodium alginate solution to the emulsion obtained in step (4), and then stir at 400-500 rpm for 30 minutes to adjust the pH value to 6.2-6.5 to obtain the embedded emulsion; (6) Spray drying: Inlet air temperature 160-170℃, outlet air temperature 65-70℃, centrifugal drying at 18000-20000rpm to obtain microcapsules of slow-release cool flavoring for areca nut.

2. The microencapsulation method for a sustained-release cooling flavoring for areca nut according to claim 1, characterized in that, In step (2), the mass ratio of corn gluten powder to hydrochloric acid solution is 1:6-8.

3. The microencapsulation method for a sustained-release cooling flavoring for areca nut according to claim 1, characterized in that, In step (2), the corn gluten powder is subjected to a frozen structural recombination operation after enzymatic hydrolysis. The specific steps are as follows: the enzymatic hydrolysate obtained by enzymatic hydrolysis is first frozen to -30℃ at a rate of 5-8℃ / min, and then thawed to 4℃ at a rate of 2-3℃ / min; after thawing, it is centrifuged at 5000rpm for 10 minutes, and the precipitate is collected as the corn gliadin product.

4. The microencapsulation method for a sustained-release cooling flavoring for areca nut according to claim 1, characterized in that, In step (2), the esterification modification includes the following steps: after completing the enzymatic hydrolysis and ultrasonic treatment, octenyl succinic anhydride is added to the reaction system, and the amount of octenyl succinic anhydride added is 3%-5% of the dry basis mass of the zein product obtained in step (2); at the same time, the pH value of the reaction system is controlled to be 8.2-8.6, the temperature is 45-55 ℃, and the reaction time is 1-3 hours.

5. The microencapsulation method for a sustained-release cooling flavoring for areca nut according to claim 1, characterized in that, In step (2), the emulsification enhancement is performed after esterification modification. The process includes the following steps: adding a mixture of sucrose fatty acid ester and glyceryl monostearate to the reaction system, wherein the mass ratio of sucrose fatty acid ester to glyceryl monostearate is 2-3:1; the total amount of the mixture added is 0.5%-1.0% of the dry basis mass of the zein product obtained in step (2), and stirring for 10-20 minutes.

6. The microencapsulation method for a sustained-release cooling flavoring for areca nut according to claim 1, characterized in that, In step (4), the ratio of the total dry matter mass of the core material solution to the total dry matter mass of the wall material solution is 1:2-3.

7. The method for microencapsulating a sustained-release cooling flavoring for areca nut according to claim 1, characterized in that, In step (5), the mass concentration of the added sodium alginate solution is 2%-3%, and the amount of sodium alginate solution added is 20%-30% of the mass of the emulsion.

8. The method for microencapsulating a sustained-release cooling flavoring for areca nut according to claim 1, characterized in that, The sodium alginate solution is a compound fortified solution: it contains 2%-3% sodium alginate and 0.1%-0.3% calcium chloride by mass.

9. The microencapsulation method for a sustained-release cooling flavoring for areca nut according to claim 1, characterized in that, The core material solution also contains: 3-5 parts by weight of menthyl lactate and 1-2 parts by weight of borneol.

10. The microencapsulation method for a sustained-release cooling flavoring for areca nut according to claim 1, characterized in that, After step (5), the embedded emulsion is continuously defoamed for 15-20 minutes under a vacuum of -0.08 to -0.09 MPa to obtain a defoamed emulsion. Then, fumed silica is added to the defoamed emulsion and mixed evenly. 0.5%-1.0% of fumed silica is added based on the mass of solids in the defoamed emulsion.

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