Pharmaceutical and edible gel confectionery in soft capsule form and method for preparing same

Abstract

This invention relates to the field of food processing technology, specifically disclosing a medicinal and edible homologous gel candy in soft capsule form and its preparation method. The gel candy's outer shell utilizes an interpenetrating network system constructed by first pre-gelatinizing glutinous rice flour to form a three-dimensional amylopectin network framework, and then adding gelatin to achieve a high proportion of medicinal and edible homologous functional powder loading with an oil leakage rate ≤1%. The core material uses a low water activity system thickened with roasted wheat flour to construct a moisture barrier at the core-shell interface. D-mannitol is added to the outer shell, and its migration and crystallization to the outer surface are driven by a three-stage gradient drying process, resulting in a sandy appearance. The outer shell thickness is 1.0–2.0 mm, and the final moisture content is 10%–15%; the D-mannitol is driven to migrate and crystallize through a three-stage gradient drying process (total time 8–22 hours). This invention systematically solves the constraints and conflicts between high powder loading, chewability, core material stability, and storage stability, making it suitable for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, and particularly relates to the formulation design and molding and drying process of soft capsule-type gel candies with a high proportion of medicinal and edible functional powder components loaded in the outer shell. Specifically, it relates to medicinal and edible gel candies with soft capsules as the excipient form and their preparation method. Background Technology

[0002] Soft capsules, using gelatin as the primary film-forming material, seal liquid or semi-solid contents within an elastic rubber shell, and are widely used in the pharmaceutical and health product industries. With the growing demand for diversified product forms in the functional food market, gel candies using soft capsules as the excipient form are gradually becoming a direction for product innovation. However, extending soft capsule technology to the gel candy field faces the following interrelated core technological contradictions:

[0003] Contradiction 1: The conflict between high solid powder loading and seam sealing. The health benefits of gelatinous candies require the outer shell to be loaded with medicinal and edible solid powders (such as jujube powder and ginger powder). However, the introduction of large amounts of solid particles interferes with the heat-sealing cross-linking of gelatin molecular chains in the seam area, leading to decreased sealing performance and increased leakage. Existing technologies typically address this problem by reducing the amount of solid powder added or transferring the powder into the core material. The essence is that traditional single-gelatin networks lack effective anchoring capabilities for solid particles. During the flow and pressing of the gelatin solution, particles easily aggregate towards the seam area, forming physical barriers across the seam interface (i.e., the phenomenon where solid particles act as rigid heterogeneous phases, blocking the thermal diffusion and cross-linking of gelatin molecular chains, which can be described as a particle bridging effect). This prevents the gelatin molecular chains from fully cross-linking and heat-sealing at the seam, and this effect intensifies with increasing powder loading.

[0004] Contradiction Two: The conflict between chewability and the traditional functional positioning of soft capsules. Traditional soft capsules are designed for swallowing, with a relatively hard outer shell and a moisture content typically not exceeding 8%; while gel candies require a soft, chewy texture, necessitating higher water content and specific elasticity. The introduction of a high proportion of solid powder further exacerbates the hardening of the outer shell. Traditional gelatin networks belong to a single thermally reversible gel system, where solid powder, as a rigid filler phase, acts as stress concentration points, increasing the matrix modulus and reducing elongation at break, making the outer shell tend to be hard and brittle rather than soft and chewy when chewed.

[0005] Contradiction 3: The contradiction between uniform dispersion of core components and long-term stability. When the core material contains oil carriers, solid powders (such as functional powders or thickening powders), and semi-solid components, the solid powders are prone to gravity sedimentation due to the density difference with the oil carriers (conforming to Stokes' sedimentation law). Semi-solid components (such as high-melting-point components in plant extracts) may precipitate or aggregate under temperature fluctuations, resulting in uneven product composition. Increasing the viscosity of the core material to prevent stratification and sedimentation will affect the granulation processability (the viscosity of soft capsule core materials usually needs to be controlled within a low range to ensure filling flowability). This contradiction is particularly prominent during storage. The lack of a stable three-dimensional suspension network in the core material will cause the components to slowly stratify or settle during the shelf life. The degree of stratification depends on multiple factors such as component density difference, particle size, medium viscosity, and the amplitude of storage temperature fluctuations. Under extreme conditions, the distribution of active ingredients between different particles may show significant differences.

[0006] Contradiction 4: The contradiction between molding drying rate and shell integrity. Soft capsules require drying and dehydration after molding. Too rapid drying leads to rapid surface hardening (i.e., surface hardening), preventing uniform moisture transfer from the interior. Differential shrinkage in the seam area causes stress concentration, leading to oil leakage and deformation. Too slow drying prolongs the production cycle, making the shell prone to collapse and deformation. This contradiction is particularly pronounced in thicker shells, where the difference in Biot number between the surface and core is greater, resulting in a more significant moisture gradient. Under constant temperature and humidity drying conditions, a gradient curing structure with a hard outer layer and a soft inner layer is easily formed, leading to mismatched shrinkage stress and causing warping, cracking, or seam failure.

[0007] Fifth contradiction: The contrast between the candy-like appearance and the smooth surface of soft capsules. Conventional soft capsules have a smooth, translucent appearance, far from the texture expected by candy consumers. Traditional candy re-crystallization processes (external powdering or cooling crystallization) have significant limitations in the already sealed soft capsule structure: the adhesion between the external dry powder coating and the gelatin surface is limited, making it prone to detachment during packaging and transportation; cooling crystallization relies on the surface crystallization process of sugar solution exposed to air, which is subject to stringent conditions in the closed system of soft capsules. While existing improvements such as sugar powder coating and granulated sugar coating have been implemented in industry, they still require systematic optimization in terms of uniformity, adhesion strength, and scalability.

[0008] Sixth contradiction: The threat of moisture migration at the core-skin interface to the long-term stability of the gelatin shell. During storage, soft capsules experience continuous moisture migration driven by water activity (Fick diffusion mechanism). When the water activity of the core is high, moisture permeates from the core to the shell, exerting a plasticizing effect on the gelatin network over time, leading to decreased mechanical strength and deterioration of seam sealing. This contradiction is more severe in chewable soft capsules with high water content, as higher initial shell water content means a narrower safety margin. Existing technologies include targeted measures such as hydrophobic coatings and low water activity core designs, but a comprehensive solution that systematically constructs a moisture barrier at the core-skin interface from the perspective of core formulation and synergistically optimizes it with the overall formulation system is still insufficient.

[0009] The six contradictions mentioned above are not independent but form a holistic constraint: increasing powder loading affects chewing texture and seam sealing; improving chewing texture requires increasing moisture content, which in turn affects storage stability; thick-walled designs can expand the powder-accommodating space but exacerbate the difficulty of drying control; drying process parameters simultaneously affect moisture control and appearance; the core material formulation not only concerns the uniformity and stability of the core material itself but also affects the long-term stability of the rubber through interfacial moisture exchange. Currently, there is a lack of technical solutions that can systematically and synergistically resolve the above-mentioned holistic constraint conflict. Summary of the Invention

[0010] This invention aims to solve the problems in existing soft capsule technology, such as the difficulty in adding a high proportion of medicinal and edible functional powders to the capsule shell, poor chewability, easy stratification and sedimentation of core components, easy oil leakage and deformation during the molding and drying process, lack of candy-like and grainy effect in product appearance, and the decline in long-term stability of the capsule shell due to moisture migration at the core-shell interface. The invention provides a soft capsule-type gel candy with excellent taste suitable for industrial production and its preparation method.

[0011] The specific objectives of this invention are: oil leakage rate of rubber sheet ≤1%; chewing sensory score ≥8.5 / 10; no obvious sedimentation of core material after 30 days of standing; final rubber sheet moisture content 10%~15%, deformation rate ≤2%; product surface exhibits uniform and delicate sandy appearance; oil leakage rate increases by ≤1% after 3 months of accelerated storage.

[0012] To achieve the above objectives, the present invention adopts the following technical solution:

[0013] A medicinal and edible gelatinous candy in the form of a soft capsule includes a shell and a core. The shell is made from the following raw materials in parts by weight: 60-100 parts gelatin, 30%-120% glycerin by weight of gelatin, 100-150 parts water, 5-15 parts glutinous rice flour, 20-40 parts medicinal and edible functional powder, 5-15 parts D-mannitol, and 30-60 parts brown sugar.

[0014] The core material is made from the following raw materials in parts by weight: 40-80 parts of medium-chain triglycerides, 2-10 parts of roasted wheat flour, 20-60 parts of medicinal and edible functional powder, and 1-5 parts of beeswax.

[0015] The glutinous rice flour contains ≥95% amylopectin; the glutinous rice flour and the medicinal and edible functional powder have a particle size of 80 mesh to 200 mesh; the rubber sheet thickness is 1.0 to 2.0 mm.

[0016] In the rubber sheet, glutinous rice flour is pregelatinized and then forms an interpenetrating network structure with gelatin. D-mannitol is dried in three stages to form a sand-returning layer on the outer surface of the rubber sheet.

[0017] Furthermore, the medicinal and edible functional powder is selected from one or more of the following: jujube powder, ginger powder, wolfberry powder, yam powder, mulberry powder, poria powder, astragalus powder, codonopsis powder, longan pulp powder, lily powder, hawthorn powder, kudzu root powder, honeysuckle powder, chrysanthemum powder, dandelion powder, coix seed powder, lotus seed powder, euryale seed powder, cassia seed powder, platycodon powder, licorice powder, cinnamon powder, amomum powder, clove powder, fennel powder, Sichuan pepper powder, galangal powder, lotus leaf powder, mulberry leaf powder, dendrobium officinale powder, American ginseng powder, ganoderma lucidum powder, gastrodia elata powder, ophiopogon japonicus powder, rehmannia glutinosa powder, angelica sinensis powder, polygonatum sibiricum powder, cistanche deserticola powder, eucommia ulmoides leaf powder, tangerine peel powder, saffron powder, cardamom powder, turmeric powder, raspberry powder, and jujube seed powder.

[0018] Furthermore, the final moisture content of the rubber sheet is 10% to 15%; the water activity of the roasted wheat flour is <0.3; and the overall water activity of the core material is <0.35.

[0019] Furthermore, the amount of gelatin is 85 parts, the amount of glycerin is 100% to 120% of the mass of gelatin, the amount of water is 120 parts, the amount of glutinous rice flour is 10 parts, the amount of D-mannitol is 10 parts, and the amount of brown sugar is 45 parts; the thickness of the gelatin sheet is 1.8 mm.

[0020] Furthermore, the glutinous rice flour and the medicinal and edible functional powder have a particle size of 120 mesh.

[0021] A method for preparing a medicinal and edible gel candy in the form of a soft capsule includes the following steps:

[0022] Step 1: Pre-gelatinization of glutinous rice flour: Mix glutinous rice flour with some water to form a slurry. Stir continuously at 70-100℃ until the glutinous rice flour is fully gelatinized. The slurry is a uniform, semi-transparent paste with no white particles remaining, thus obtaining amylopectin gelatinized liquid.

[0023] Step 2, Dissolving excipients: Add glycerol, D-mannitol and brown sugar to the gelling solution obtained in Step 1, and maintain the temperature at 70-85℃ while stirring until all components are completely dissolved and homogeneous to obtain a gelling solution containing excipients;

[0024] Step 3: Dispersion of medicinal and edible functional powder: Add the medicinal and edible functional powder to the gelling liquid containing excipients obtained in Step 2, and stir at medium speed for 15 to 20 minutes until the powder is evenly dispersed and there are no lumps or agglomerations, to obtain the gelling liquid containing the powder.

[0025] Step 4, Gelatin Sol and Degassing: After premixing and swelling the gelatin with the remaining water, add it to the gelling solution containing powder obtained in Step 3. Stir at 60-80℃ until the gelling solution is uniform and free of undissolved gelatin particles. Then degas at 60-80℃ under negative pressure for 30-45 minutes to obtain the gelling solution.

[0026] Step 5, Core Material Preparation: Mix roasted wheat flour with medium-chain triglycerides, medicinal and edible functional powders, and beeswax. Stir and cook continuously at 80°C for no less than 15 minutes until the system is uniformly thickened and there is no powder sedimentation. Cool to room temperature for later use.

[0027] Step 6, Shot Compression Molding: Using a rotary molding method, the adhesive liquid obtained in Step 4 and the core material obtained in Step 5 are respectively fed to a shot compression machine and pressed into shape to obtain soft capsule-type gel candy wet pellets with a rubber thickness of 1.0-2.0 mm.

[0028] Step 7, Three-stage gradient drying:

[0029] First stage: Temperature 18-22℃, relative humidity 40%-50%, drying for 1-4 hours;

[0030] Second stage: Temperature 23-25℃, relative humidity 35%-39%, drying for 5-10 hours;

[0031] Third stage: Temperature 26-30℃, relative humidity 25%-34%, drying for 2-8 hours;

[0032] Total drying time: 8–22 hours;

[0033] During the three-stage gradient drying process, D-mannitol migrates directionally from the inside of the rubber to the outer surface along with the moisture concentration gradient and crystallizes in a supersaturated manner on the outer surface, forming a return sand layer.

[0034] Furthermore, in step one, the water portion is 20% to 35% of the prescribed amount of water, the pregelatinization temperature is preferably 85°C, and the stirring time is 15 to 50 minutes.

[0035] Furthermore, in step five, the roasted wheat flour is obtained by dry roasting food-grade wheat at 160-200℃ for 10-15 minutes, followed by cooling and pulverizing, with a water activity of <0.3 after roasting.

[0036] Furthermore, in step six, the injection time for shot blasting is 0.25 to 0.35 seconds, the temperature of the glue box is 72 to 78°C, and the temperature of the spray body is 40 to 50°C.

[0037] Furthermore, in step seven, after the three-stage gradient drying is completed, the final moisture content of the rubber is 10% to 15%, and the product surface exhibits a uniform sandy appearance; during the drying process, the moisture difference between the inner and outer layers of the rubber is ≤1.5%.

[0038] The technical content, working mechanism, and coupling relationship between each module are described in turn below.

[0039] Module 1: IPN Rubber System

[0040] 1.1 Pregelatinization of glutinous rice flour—Construction of amylopectin-gelatin interpenetrating network structure

[0041] In the preparation of the gelatin solution, glutinous rice flour must first be mixed with a portion of water and allowed to fully gelatinize at 70–100°C to obtain amylopectin gelatinized solution. Then, gelatin is added to form a sol. The technical significance of this specific process sequence is as follows:

[0042] (a) Pregelation stage (70-100℃)

[0043] Glutinous rice starch granules absorb water, swell, and rupture, causing amylopectin molecules to unwind and unfold, forming a stable three-dimensional amylopectin network framework in the aqueous phase, with α-1,6 glycosidic bond branching points as network nodes. The amylopectin content in glutinous rice flour is typically ≥95%, far higher than that of ordinary starch (70%–80%). Its highly branched molecular topology endows the pregelatinized product with a denser and more uniform three-dimensional network. This characteristic is the material basis for choosing glutinous rice flour, rather than other starch sources, as a component of the IPN (Integrated Polymer Network).

[0044] (b) Gelatin sol stage (60-80℃)

[0045] Subsequently, gelatin sol is added, and the gelatin polypeptide chains unfold, intertwine, and entwine within the pores of the already formed three-dimensional amylopectin network. The two polymer networks interpenetrate to form an interpenetrating polymer network (IPN). In this IPN structure, the amylopectin network provides a rigid framework and anchoring points for solid particles, while the gelatin network provides elasticity and film-forming properties. Together, they endow the rubber with dual textural properties of both strength and flexibility.

[0046] (c) The irreplaceability of the process sequence

[0047] If glutinous rice flour and gelatin are mixed into a sol simultaneously (as shown in Comparative Example 6), the gelatin sol and starch gelatinization processes occur concurrently. The two compete for aqueous space, preventing amylopectin from forming an ordered three-dimensional network precursor, and gelatin from penetrating the pre-formed network, ultimately resulting in only a simple physical blend. The test data for Comparative Example 6 showed that the oil leakage rate increased from 0.6% to 3.5% (a difference of approximately 5.8 times), the rubber breakage rate increased from 0% to 8%, and the chewing score decreased from 9.2 to 6.2. Comparative Example 1, which did not add any glutinous rice flour, was even more severely affected: the oil leakage rate was 4.8%, the breakage rate was 12%, and the chewing score was 5.6. These two comparative examples, along with Example 1, constitute three progressively controlling sets, quantitatively demonstrating the non-obviousness and irreplaceability of the "gelatinization first, then addition" process sequence. The aforementioned amylopectin-gelatin interpenetrating network (IPN) structure can be verified using the following characterization method: Differential scanning calorimetry (DSC) analysis. The IPN system should exhibit independent thermal transition peaks in the gelatin gelation transition temperature range and the amylopectin retrogradation transition temperature range, rather than the fusion or disappearance of the two peaks in a simple blend system. The differences in the characterization data between Example 1 and Comparative Example 6 (simple blend) further corroborate the formation of IPN from a structural perspective.

[0048] (d) Anchoring mechanism of IPN for solid powder particles

[0049] The IPN structure provides physical anchoring for the solid powder particles (medicinal and edible functional powders and glutinous rice flour, 80-200 mesh) in the rubber. The two interconnected networks together wrap and fix the particles, which are embedded between the nodes of the two networks rather than simply suspended in a single network. This effectively prevents the particles from agglomerating in the joint area and forming bridging gaskets during the flow of the adhesive and the pressing process, thereby maintaining the joint seal under high powder load conditions.

[0050] (e) Contribution of IPN to chewing texture

[0051] The IPN dual-network gives the rubber a unique soft and chewy texture: the amylopectin network provides moderate resistance to deformation during chewing (preventing excessive collapse), while the gelatin network provides elastic recovery and adhesion. This textural property cannot be achieved with traditional single-gelatin rubbers or simple physical blends.

[0052] 1.2 Solid powder particle size control: 80 mesh ~ 200 mesh

[0053] The particle size of the medicinal and edible functional powders to be added to the rubber coating (including but not limited to jujube powder, ginger powder, wolfberry powder, yam powder, and glutinous rice flour) must be controlled between 80 and 200 mesh (corresponding to a particle size of approximately 75 to 180 μm). Particle size control has dual technical significance and forms a synergistic effect with the IPN structure:

[0054] The technical basis for the upper limit of particle size (80 mesh, about 180 μm): The particle size must be much smaller than the local thickness of the rubber in the joint area. The local thickness formed by the heat sealing and overlapping of two layers of rubber at the joint is usually 1 to 2 times the thickness of a single layer of rubber, that is, about 2.0 to 4.0 mm (calculated based on the thickness of a single layer of rubber of 1.0 to 2.0 mm in this invention). The ≥120 mesh particles (particle size ≤125 μm, that is, ≤0.125 mm) specified in this invention account for only 1 / 16 to 1 / 32 of this local thickness, which can effectively prevent particles from crossing the heat sealing interface at the joint and forming bridging gaskets that damage the sealing performance.

[0055] The technical basis for the lower limit of particle size (200 mesh, about 75μm): If the particles are too fine, the specific surface area will be too large, the amount of water adsorbed by the unit mass of powder will increase sharply, the free water in the adhesive system will decrease, the apparent viscosity will increase and the thixotropy will be enhanced, which will affect the uniform spreading of the adhesive and the full heat sealing of the joints during the shot blasting process.

[0056] Particle size-IPN structure matching effect: The pore size of the IPN dual network matches the particle size of 80-200 mesh. The particles can be effectively embedded and anchored between the dual network nodes. They are neither too large to break through the network constraints nor too small to penetrate the network pores, thus achieving structure matching anchoring.

[0057] 1.3 Plasticizer ratio control: Glycerin usage should be 30%–120% of the gelatin mass.

[0058] Food-grade glycerin is selected as the plasticizer, and its dosage is 30%–120% of the gelatin mass, preferably 100%–120%. The technical function and dosage limits of glycerin are set based on the following:

[0059] Glycerin molecules infiltrate the gelatin molecular chains, competing with and replacing some interchain hydrogen bonds through hydrogen bonding. This increases the intersegmental spacing and enhances the chain mobility, ensuring the flexibility and extensibility of the gelatin sheet. In the IPN system, sufficient glycerin also lubricates the interface between the branched starch network and the gelatin network, reducing interfacial stress and enabling the IPN to deform in a coordinated manner during chewing rather than de-adheding at the interface.

[0060] The technical basis for the lower limit of dosage (30%) is as follows: Under the synergistic effect of the IPN dual-network system, the amylopectin network itself can undertake part of the stress dispersion and water retention functions, and its dependence on glycerol plasticizer is lower than that of the traditional single gelatin system. When the amount of glycerol is reduced to 30% of the gelatin mass, although the viscosity of the gel increases and the chewing hardness increases, thanks to the structural advantages of the IPN network, the product can still achieve basic pelleting and acceptable chewing performance. Therefore, 30% is taken as the lower limit of the effective range of this invention; to obtain better taste and adaptability to production processes, it is preferred to be no less than 50%.

[0061] Technical basis for the upper limit of usage (120%): When the amount of glycerin exceeds 120%, the excess glycerin cannot be completely contained by the gelatin-IPN network. During long-term storage, it may migrate and seep out to the surface of the gelatin, affecting the product appearance and storage stability.

[0062] 1.4 D-Mannitol Reversion Mechanism—Gradient Drying-Driven Inner-to-Out Migration Crystallization

[0063] This invention incorporates D-mannitol as a sand-returning agent into the adhesive formulation. D-mannitol does not function independently; rather, it forms an inseparable coupling with Module Four (the three-stage gradient drying process) to jointly achieve a sand-returning mechanism involving crystallization from the inside out. The specific process is as follows:

[0064] (a) Initial state: D-mannitol is pre-dissolved and uniformly distributed in the aqueous phase of the IPN network adhesive system. The reason for choosing D-mannitol instead of other sugar alcohols (such as xylitol and sorbitol) is that D-mannitol has relatively low solubility in water (about 18 g / 100 mL, 25 °C) and has a clear tendency to crystallize and a narrow supersaturation crystallization window, which allows it to accurately reach supersaturation and uniformly crystallize on the outer surface as the water concentration changes during the gradient drying process; while xylitol and sorbitol have too high solubility and are not easy to crystallize, so they cannot achieve the directional migration and return sand effect.

[0065] (b) Gradient drying first stage (high humidity, low temperature): The evaporation rate of moisture on the outer surface of the rubber is inhibited by the high humidity environment, and a hardened shell layer is not formed. A mild and stable moisture concentration gradient (lower on the outside and higher on the inside) is established between the inside and outside. D-mannitol dissolved in the aqueous phase begins to be directionally enriched towards the outer surface of the rubber along with the direction of moisture migration.

[0066] (c) Gradient drying stages two and three (gradually increasing temperature and decreasing humidity): As the ambient humidity gradually decreases, the local concentration of D-mannitol in the outer surface area continues to increase and gradually exceeds the saturation point. Under the low humidity conditions of the third stage, D-mannitol crystallizes uniformly in situ on the outer surface, forming a fine and uniform granular surface, i.e., the sand-like effect.

[0067] (d) Crystal anchoring: At the end of the third stage, the IPN network completes the final gel solidification, permanently anchoring the D-mannitol crystals that have migrated to the surface and precipitated to the outer surface layer of the network, ensuring the long-term stability of the sand return effect.

[0068] (e) The essential difference from traditional sanding methods: In this mechanism, crystals dissolve in situ from the internal matrix of the rubber and migrate and accumulate outward along the moisture concentration gradient. After reaching supersaturation on the outer surface, they crystallize uniformly. The uniformity of distribution is controlled by the moisture field of gradient drying rather than by external spreading operations, resulting in a strong bond with the rubber and preventing detachment. If constant temperature and humidity drying is used (Comparative Example 5), the moisture concentration gradient cannot be established directionally, the migration path of D-mannitol is chaotic, the sanding effect is poor, and the distribution is inconsistent. The directional migration of D-mannitol from the inside of the rubber to the outer surface can be verified by the following method: slice the dried rubber along the thickness direction (approximately 1 / 3 thickness for the outer, middle, and inner layers), dissolve each layer separately, and determine the residual D-mannitol content of each layer using high-performance liquid chromatography (HPLC). If directional migration does occur, the concentration of D-mannitol in the outer layer should be significantly higher than that in the inner layer (the outer layer is enriched on the surface in the form of crystals), while the inner layer has the lowest residual concentration. In Example 1, the D-mannitol concentration in the outer layer of the product was measured to be approximately 3 to 5 times that of the inner layer, while in Comparative Example 5 (dried at constant temperature and humidity), the D-mannitol concentration in each layer did not differ significantly, thus verifying the mechanism of gradient drying driving directional migration.

[0069] 1.5 Rubber thickness: 1.0~2.0mm

[0070] By adjusting the pelleting process parameters (see Module 3 for details), the thickness of the capsule shell can be made to reach 1.0–2.0 mm, preferably 1.8 mm. Compared with traditional pharmaceutical soft capsules (typically 0.5–1.0 mm, intended for oral ingestion), the lower limit of the capsule shell thickness in this invention is extended to 1.0 mm, and the upper limit is extended to 2.0 mm. Within this wider thickness range, the capsule shell plays the following four irreplaceable technical functions in the system of this invention:

[0071] Firstly, the powder containment function: In the 1.0-2mm thick IPN matrix, 80-200 mesh particles can be dispersed in the rubber phase that is far from the heat-sealing surface of the joint, reducing the probability of particles migrating to the joint surface, and working together with the IPN anchoring effect to maintain the joint sealing performance.

[0072] Secondly, the migration and sanding path function: the spatial span of the moisture concentration gradient in thick-walled rubber is larger, the directional migration and enrichment efficiency of D-mannitol is higher, and the surface sanding is more uniform and delicate.

[0073] Third, the chewing texture function: During chewing, the tooth compression stroke increases, and the elastic recovery and stress dispersion effect of the IPN dual network are fully reflected, making the "soft and chewy" texture more pronounced.

[0074] Fourth, the stress dispersion function of the joint: During the drying and shrinkage process, the stress borne by the joint per unit area of ​​the thick-walled rubber is lower than that of the thin-walled rubber, which reduces the risk of joint cracking caused by the concentration of shrinkage stress.

[0075] Comparative Example 4 (thickness 0.8 mm, below the lower limit of 1.0 mm of this invention) shows that the oil leakage rate reaches 2.5% and the chewing score is 6.5 points when the solid powder content is 30%, which quantitatively proves the technical necessity of the film thickness not less than 1.0 mm. When the film thickness is ≥1.0 mm, the anchoring space of the IPN network for the powder, the directional migration path of D-mannitol, and the joint stress dispersion thickness can all meet the requirements of this invention.

[0076] In summary, this invention, through a complete gradient data chain of Comparative Example 4 (0.8mm, below the lower limit, severely excessive oil leakage rate, process failure) → Example 14 (1.0mm, lower limit, oil leakage rate 0.8%, chewing score 8.7, all indicators qualified) → Example 6 (1.5mm, middle section, excellent performance) → Example 1 (1.8mm, benchmark formula, optimal comprehensive performance, oil leakage rate 0.6%, chewing score 9.2) → Example 10 (2.0mm, upper limit, total drying time extended to 22h, all indicators qualified), confirms that the rubber thickness range of 1.0 to 2.0mm defined in the claims can be implemented in the entire range and the effect is predictable. Both the lower and upper limits were directly verified by the examples, and Comparative Example 4 conversely confirms the critical rationality of 1.0mm as the lower limit.

[0077] 1.6 Rubber Formulation

[0078] Table 1 lists the rubber formulation of the preferred embodiment 1: In this invention, unless otherwise specified, the amount of each component in the formulation is expressed in parts by weight.

[0079] Table 1. Rubber Formulation Composition (Preferred Scheme in Example 1)

[0080] Element Dosage (servings) Function gelatin 85 Film-forming base material, providing rubber skeleton glycerin 100 (approximately 118% of the gelatin weight) Plasticizers impart flexibility and lubricate the IPN interface. water 120 Dispersion medium Glutinous rice flour (120 mesh) 10 Pregelatinization forms a branched starch network, constructing IPN. Jujube powder (120 mesh) 20 Functional powders derived from both food and medicine Ginger powder (120 mesh) 10 Functional powders derived from both food and medicine D-Mannitol 10 Sand-returning agent (gradient drying-driven migration crystallization) brown sugar 45 Sweeteners improve taste

[0081] Table 1 above lists the specific formulations of the preferred embodiment of Example 1. Based on the verification results of each embodiment and comparative example, the effective range of each component in the rubber formulation of the present invention is summarized as follows:

[0082] Gelatin: 60-100 parts, preferably 80-90 parts.

[0083] Too little gelatin will result in insufficient film strength, while too much gelatin will lead to excessive viscosity of the adhesive, affecting the molding process.

[0084] Water: 100-150 parts, preferably 110-130 parts. Too little water will result in insufficient swelling of the gelatin and excessively high viscosity of the adhesive, affecting molding; too much water will result in an overly thin adhesive, making it difficult to control the film thickness and significantly prolonging the drying time.

[0085] Glutinous rice flour: 5-15 parts, preferably 8-12 parts. If the amount of glutinous rice flour is too low, the density of the IPN network skeleton will be insufficient and the anchoring effect will decrease; if the amount is too high, the viscosity of the glue system will be too high and the fluidity will be poor, affecting the uniformity of shot blasting.

[0086] Functional powders derived from both food and medicine: Total amount 20-40 parts, preferably 25-35 parts. The upper limit of this range is constrained by the particle capacity of the IPN network and the sealing performance of the seams, while the lower limit is determined by the functional attribute requirements of the product.

[0087] D-Mannitol: 5-15 parts, preferably 8-12 parts. If the amount is too low, the amount of crystallization on the outer surface will be insufficient and the sand-returning effect will be insignificant; if the amount is too high, the solute concentration in the adhesive system will be too high, and uncontrolled crystallization may occur in the early stage of drying.

[0088] Brown sugar: 30-60 parts, preferably 40-50 parts. Brown sugar mainly plays a role in sweetness regulation and has no significant impact on the IPN network structure. The dosage range is determined by taste design.

[0089] The effective ranges of each component in the core material formulation are summarized as follows:

[0090] Oil carrier: 40-80 parts, preferably 50-70 parts.

[0091] Roasted wheat flour: 2-10 parts, preferably 4-8 parts. Too little roasted wheat flour will result in insufficient thickening and suspending effect (the core material will settle within 30 days), while too much will lead to excessive viscosity of the core material, affecting the flowability of the filling. The gluten proteins (glutenin and prolamins) in wheat flour undergo partial thermal denaturation during roasting, but still retain a certain network-forming ability. Therefore, compared to roasted wheat flour, a lower amount can achieve an equivalent thickening and suspending effect.

[0092] Medicinal and edible functional powder: 20-60 parts, adjusted according to product function positioning. Increasing the amount of medicinal and edible functional powder increases the total amount of solid particles in the core material, correspondingly increasing the load-bearing capacity requirements of the suspension network. The three-dimensional suspension framework composed of the thermally denatured gluten protein network of roasted wheat flour and oils can effectively anchor a higher proportion of solid particles; within the above dosage range, the core material showed no significant settling after 30 days of standing. When the dosage exceeds 60 parts, the volume fraction of solid particles in the core material becomes too high, exceeding the limit of the suspension network's encapsulation and load-bearing capacity, significantly affecting injection flowability and pelletizing. The medicinal and edible functional powders mentioned are selected from substances listed in the "List of Substances That Are Traditionally Both Food and Chinese Medicinal Materials" published by the National Health Commission, including but not limited to 46 representative varieties such as ginger (powder), jujube (powder), wolfberry (powder), yam (powder), poria (powder), hawthorn (powder), coix seed (powder), kudzu root (powder), mulberry (powder), chrysanthemum (powder), tangerine peel (powder), longan (powder), lotus seed (powder), lily (powder), polygonatum (powder), Solomon's seal (powder), cassia seed (powder), and jujube seed (powder). The embodiments of this invention use ginger powder, jujube powder, wolfberry powder, and yam powder as representative raw materials for verification. Other medicinal and edible powders that conform to the above-mentioned list and meet the physical property requirements such as particle size (≤120 mesh) and moisture content (≤6%) specified in this invention can be implemented equivalently according to the technical solution of this invention without affecting the achievement of the purpose of this invention.

[0093] Beeswax: 1-5 parts, preferably 2-4 parts.

[0094] Module 2: Roasted Wheat Flour Thickening Low Moisture Activity Core Material System

[0095] Roasted wheat flour is added to the core material, mixed with oils and functional powders derived from both food and medicine, and then cooked at 75–85°C (preferably 80°C) for at least 15 minutes, before cooling to room temperature for later use. Roasted wheat flour plays the following three technical roles in the core material system:

[0096] 2.1 Thickening and anti-settling

[0097] During the roasting process, some starch in the roasted wheat flour undergoes pregelatinization (dry heat gelatinization), while the gluten protein undergoes partial thermal denaturation but retains residual network-forming ability. In the subsequent moist-heat cooking process at 80℃, the starch further gelatinizes and expands fully, and the thermally denatured gluten protein partially unfolds in the aqueous phase, forming auxiliary connection points. The gelatinized starch molecular chains, the thermally denatured gluten protein network, and the fatty acid chains in the oil together form a physically entangled network, constructing a three-dimensional suspension framework that uniformly encapsulates and suspends the medicinal and edible functional powders and insoluble solid components in the core material. Because the gluten protein network provides additional skeletal connection density, roasted wheat flour with a lower dosage (2-10 parts) can achieve an equivalent suspension effect to higher dosages, and this suspension framework has sufficient capacity to support higher proportions of medicinal and edible functional powders (20-60 parts). Example 1 showed no significant sedimentation after 30 days of standing, demonstrating the long-term effectiveness of this suspension network.

[0098] 2.2 Low water activity characteristics

[0099] During roasting, the Maillard reaction consumes reducing sugars and free amino acids, while high-temperature evaporation results in extremely low residual moisture in the roasted wheat flour (water activity typically <0.3). Furthermore, the thermal denaturation of gluten proteins exposes hydrophobic regions within their molecules, further reducing the protein's ability to bind water and helping to maintain a low water activity state. Together with an oil carrier (water activity <0.1), this constitutes a low water activity core material system (overall core material water activity <0.35), which is beneficial to the microbial stability of the core material itself.

[0100] 2.3 Core-skin interface moisture barrier function

[0101] A significant water activity difference is formed between the low water activity of the core material (<0.35) and the water activity of the rubber sheet (approximately 0.55–0.65 after gradient drying). The direction of the difference is from rubber sheet to core material, meaning that water tends to migrate slightly from the rubber sheet to the core material, rather than penetrating from the core material to the rubber sheet. This unidirectional water activity gradient forms a natural moisture barrier at the core-skin interface, effectively inhibiting the long-term softening and erosion of the rubber sheet's IPN network by moisture from the core material, and maintaining the structural integrity and mechanical strength of the IPN network.

[0102] This is one of the key reasons why the oil leakage rate increase was only about 0.4% after 3 months of accelerated storage in Example 1, which is in contrast to Comparative Example 5 (constant temperature and humidity drying caused the rubber to become too dry and the water activity to be abnormally low, which broke the core-skin interface balance, and the oil leakage rate rose to 3.5% after 3 months).

[0103] 2.4 Cross-module coupling of the three functions of roasting wheat flour

[0104] The three functions of roasted wheat flour do not operate independently, but rather are coupled across modules with the rubber IPN system (Module 1) and the gradient drying process (Module 4):

[0105] Thickening and anti-settling ensure the uniformity of the core material (module 2's own function);

[0106] Low water activity protects the rubber IPN for long-term stability through the interface barrier (Module 2 ↔ Module 1).

[0107] Gradient drying precisely controls the final moisture content of the rubber sheet within the range of 10% to 15%, ensuring that the water activity of the rubber sheet is within a range that forms a favorable interface gradient with the low water activity core material (Module 2 ↔ Module 4).

[0108] Module 3: Thick-walled shot blasting process

[0109] The key process parameters for the rotary molding process are as follows:

[0110] Injection time: 0.2 to 0.4 seconds (preferably 0.3 seconds);

[0111] Box temperature: 70~80℃ (preferably 75℃);

[0112] Spray temperature: 40-50℃ (preferably 45℃).

[0113] The technical significance of the above parameter combination is as follows:

[0114] Injection time 0.2–0.4 seconds: This controls the matching of the core material injection volume and injection rate, ensuring that the core material fills evenly without impacting the joint area that has not yet been fully heat-sealed. If the injection time is too short (<0.2 seconds), the instantaneous injection pressure will be too high, which may cause the adhesive at the joint to be pushed away and the seal to fail; if the injection time is too long (>0.4 seconds), the core material will not be filled sufficiently or the rubber will remain in the mold for too long and cool excessively, affecting the heat-sealing quality of the joint.

[0115] The optimal temperature range for the IPN adhesive system is 70–80°C. This temperature range ensures suitable fluidity and film-forming properties. Below 70°C, the gelatin begins to partially gel, resulting in insufficient fluidity and uneven spreading. Above 80°C, the amylopectin network may partially degrade at high temperatures, leading to a decrease in the strength of the IPN backbone.

[0116] Spray temperature 40-50℃: The core material maintains good fluidity and uniformity at this temperature (the roasted wheat flour thickening network maintains a three-dimensional structure without becoming excessively viscous in this temperature range), which facilitates accurate metering and injection.

[0117] The above parameter combination ensures that the rubber sheet has suitable heat-sealing temperature and pressure at the joint. Combined with the high joint strength of the IPN dual network, it ensures that the rubber sheet thickness reaches 1.0-2.0 mm (1.8 mm in Example 1), achieving stable and efficient industrial shot blasting production. The thick-walled design (1.0-2.0 mm) is more tolerant of shot blasting parameter errors compared to the traditional thin-walled design (0.5-1.0 mm). The thicker rubber sheet provides a wider heat-sealing contact area and a longer heat-sealing residence time at the joint, reducing the probability of joint defects caused by instantaneous parameter fluctuations. Supplementary explanation regarding equipment adaptability: Although the 1.0-2mm rubber thickness described in this invention exceeds the conventional wall thickness (0.5-1.0mm) of traditional pharmaceutical soft capsules, it can be achieved on existing rotary molding equipment in the following ways: (1) Adjust the spacing of the rubber spreading rollers (expand to the corresponding target rubber thickness), which is an adjustable parameter of the existing equipment; (2) Reduce the pelleting speed to match the heat sealing time requirements of thicker rubber tapes, usually by reducing the rotation speed to 60%-80% of the standard operating conditions; (3) Appropriately widen the heat sealing area of ​​the mold seam (expand from the standard 1mm to 1.0-2mm), which is a mold replacement rather than a modification of the main equipment. The above adjustments are all within the scope of process parameter adjustment or standard accessory replacement of existing soft capsule rotary molding equipment, and do not involve fundamental modifications to the main structure of the equipment. All pelleting in Examples 1-10 and Comparative Examples 1-6 were completed on the same commercial rotary molding soft capsule machine.

[0118] Module 4: Three-stage gradient drying process

[0119] This invention employs a three-stage gradient drying technology, controlling temperature and humidity in stages, with a total drying time of 8 to 22 hours, which can be flexibly adjusted within this range according to the thickness of the rubber sheet (1.0 to 2.0 mm) and the batch size.

[0120] Table 2. Three-stage gradient drying process parameters

[0121] stage Phase 1 Phase Two Phase Three temperature 18～22℃ 22～26℃ 26～30℃ relative humidity 40%～50% 35%～39% 25%～34% Time percentage 1～4h 5～10h 2～8h core role Surface shaping and crack prevention Main body dehydration, rate control Complete curing and drive crystallization

[0122] The total drying time is 8–22 hours, which can be flexibly adjusted within this range according to the rubber thickness (1.0–2.0 mm), batch size, and environmental conditions: when the rubber thickness is thin (1.0–1.5 mm) or the batch size is small, the lower limit of the time can be used for each stage, and the total time of about 8–14 hours can achieve the target moisture content; when the rubber thickness is thick (1.5–2.0 mm) or the batch size is large, the upper limit of the time should be used for each stage, and the total time should be extended to about 18–22 hours to ensure that the moisture inside the thick-walled rubber has sufficient time to diffuse outward and avoid a cliff-like difference in the moisture distribution between the inner and outer layers.

[0123] 4.1 Logical progression between stages

[0124] The first stage (high humidity, low temperature) – establishing a gradient rather than accelerating drying. High relative humidity (40%–50%) inhibits the evaporation rate of moisture on the outer surface of the rubber, preventing premature hardening and the formation of a dense shell (i.e., avoiding the casehardening effect). Under these conditions, moisture inside the rubber is slowly transferred outward through capillary forces and diffusion, establishing a gentle and stable moisture concentration gradient (lower on the outside, higher on the inside) from the core layer to the outer surface. This gradient not only controls the uniformity of moisture loss but also drives the directional migration of D-mannitol. D-mannitol molecules dissolved in the aqueous phase migrate in the same direction as the water diffusion, beginning to accumulate in the outer surface region.

[0125] The second stage (medium humidity and medium temperature) – smoothly advancing the gradient and initiating gel transition. The ambient humidity decreases from 40%–50% in the first stage to 35%–39%, and the temperature increases from 18–22℃ to 23–25℃. The rate of moisture loss moderately accelerates but remains controllable. This stage is the longest in the entire drying process (approximately 40%). Its design aims to ensure sufficient time for moisture diffusion from the thick-walled rubber (1.0–2 mm) to the outside, avoiding abrupt differences in moisture distribution between the inner and outer layers. Simultaneously, as the total moisture content of the rubber gradually decreases, the gelatin molecular chains in the IPN network begin to transform from a random coil conformation to a triple helix structure (gelation). The amylopectin network further shrinks and densifies due to reduced moisture, and the two networks enter a transitional stage of synergistic gelation and solidification. D-mannitol continues to accumulate on the outer surface during this stage, but has not yet reached the concentration required for crystallization.

[0126] The third stage (low humidity, high temperature) – completes curing, drives crystallization, and releases stress. Ambient humidity is reduced to 25%–34%, and temperature is raised to 26–30°C for 2–8 hours, further reducing the rubber's moisture content from approximately 18% to the target value of 10%–13%, maximizing the rate of moisture loss. This stage accomplishes three key tasks:

[0127] Task 1 (Final Dehydration): Remove bound water from the rubber to stabilize the final moisture content within the range of 10% to 15%. This moisture content range represents the optimal balance between chewability (≥10% to maintain softness) and storage stability (≤15% to prevent excessive softness and instability).

[0128] Task 2 (Crystallization and Sanding): Due to water loss, the concentration of D-mannitol on the outer surface increases sharply in some areas, exceeding its saturation solubility. This results in uniform in-situ crystallization, creating a fine, granular, sandy appearance. The IPN network completes its final gel solidification at this stage, permanently anchoring the D-mannitol crystals on the surface.

[0129] Task 3 (Stress Relief): The internal stress accumulated by the rubber during the drying and shrinking process (especially the stress in the joint area) is smoothly released through the relaxation of the gelatin chain segments under the moderate high temperature in the third stage, avoiding joint cracking or rubber warping caused by stress concentration.

[0130] 4.2 The Irreplaceability of Gradient Drying

[0131] Comparative Example 5 (constant temperature 25℃, constant humidity 40%, time 16 hours, same total drying time as Example 1) demonstrates from the opposite perspective that, under the same total drying time, the lack of temperature and humidity gradient control leads to surface hardening, a significant increase in the difference between internal and external moisture content, and a lack of sanding appearance. This further confirms the irreplaceable nature of three-stage gradient control compared to constant temperature and humidity drying: Under constant temperature and humidity conditions, a hardened shell forms on the outer surface of the rubber in the early stages of drying, hindering the transfer of internal moisture to the outside, resulting in a final moisture content of only 7.2% (far below the target lower limit of 10%); the feel is hard, with a chewing score of 5.1; more seriously, excessive drying causes excessive shrinkage and embrittlement of the gelatin network in the rubber, leading to stress-release cracking due to fluctuations in environmental temperature and humidity during long-term storage, and the oil leakage rate increases from 0 to 3.5% after 3 months. In addition, constant temperature and humidity drying cannot establish a directional moisture concentration gradient, resulting in disordered D-mannitol migration pathways and uneven surface sanding. The above comparison fully demonstrates that three-stage gradient drying cannot be replaced by constant temperature and humidity drying in terms of moisture control, sand return drive, and stress management.

[0132] 5. The synergistic coupling relationship of the four major technology modules

[0133] The four technical modules of this invention are tightly logically coupled. The absence or replacement of any module has been quantitatively proven, based on corresponding proportions, to lead to a significant decrease in overall performance. The coupling relationships between the modules are summarized as follows:

[0134] Module 1 (IPN Rubber) ↔ Module 3 (Thick-walled Design): The IPN dual network provides anchoring for the high proportion of solid powder in the thick-walled rubber, while the thick-walled design provides the IPN network with the space capacity to accommodate powder and D-mannitol migration.

[0135] Module 1 (IPN rubber) ↔ Module 4 (gradient drying): The gel curing kinetics of the IPN network determines the applicable range of temperature and humidity at each stage of gradient drying. Gradient drying controls the final moisture content and curing degree of the IPN network.

[0136] Module 4 (Gradient Drying) ↔ D-Mannitol Resettling: The directional moisture concentration gradient established by gradient drying is the sole driving force for the migration and crystallization of D-mannitol, and the two are inseparable.

[0137] Module 2 (Roasted Wheat Flour Core Material) ↔ Module 1 (IPN Sheet): The low water activity of the core material protects the long-term structural stability of the IPN network through the water barrier at the core-skin interface.

[0138] Module 2 (Roasted Wheat Flour Core Material) ↔ Module 4 (Gradient Drying): Gradient drying precisely controls the final moisture content of the rubber sheet, ensuring that the water activity of the rubber sheet is within a range that forms a favorable interface gradient with the low water activity core material.

[0139] The overall logic of the above coupling relationship can be summarized as follows: IPN construction lays the structural foundation → thick-wall design expands the functional space → roasted wheat flour core material builds an interface barrier → gradient drying achieves coordinated curing and sanding drive. The four links are interlinked and work together to achieve the simultaneous optimization of six objectives: high proportion of powder loading, excellent chewing texture, uniform and stable core material, candy-like sanding appearance, and storage stability.

[0140] The beneficial effects of this invention are as follows:

[0141] Effect 1: Significantly improved loading capacity of high proportion of solid powder

[0142] The total solid powder particles in the rubber sheet, including the medicinal and edible functional powders (20 parts jujube powder + 10 parts ginger powder, totaling 30 parts) and glutinous rice flour (10 parts), totaling 40 parts, account for approximately 47% of the mass of gelatin (85 parts), the main film-forming material of the rubber sheet, and approximately 14.3% of the mass of all non-aqueous components of the rubber sheet (85 parts gelatin + 100 parts glycerin + 10 parts glutinous rice flour + 20 parts jujube powder + 10 parts ginger powder + 10 parts D-mannitol + 45 parts brown sugar, totaling 280 parts). Among them, the medicinal and edible functional powders totaled 30 parts, accounting for approximately 35% of the gelatin mass. The oil leakage rate was only 0.6% (as shown in Comparative Example 1, the oil leakage rate of a traditional single gelatin network reached 4.8% under the same powder load), the rubber sheet breakage rate was 0%, and the production continuity was good. This effect is attributed to the physical anchoring of solid powder particles by the IPN dual network, the elimination of the bridging pad effect by the 80-200 mesh particle size control, and the guarantee of powder dispersion space by the 1.0-2 mm thick wall design, which work synergistically to achieve the desired effect.

[0143] Effect 2: Significantly improved chewing texture

[0144] The preferred embodiment in Example 1 achieved a chewiness score of 9.2 / 10 in a sensory evaluation panel of 20 people (consistent evaluation: soft, chewy, and easy to chew). All embodiments scored ≥8.5 / 10, significantly better than the comparative examples involving structural changes in the rubber sheet (range 4.2–7.2, comparative examples 1–6, 10). Comparative example 7 (without D-mannitol) and comparative example 9 (sorbitol substitution) had chewiness scores comparable to the embodiments, but failed to achieve the desired grainy appearance. The unique textural properties imparted by the IPN dual network—the amylopectin network providing moderate resistance to deformation, the gelatin network providing elastic recovery, and the glycerin lubricating the dual network interface—are unattainable by traditional single gelatin rubber sheets or simple physical blending systems.

[0145] Effect 3: Uniform and stable core material

[0146] The three-dimensional suspension network of gelatinized starch from roasted wheat flour ensures that the core material does not show obvious stratification or sedimentation after standing for 30 days. The content of medicinal and edible functional powders is uniform in each product, ensuring consistent efficacy.

[0147] Effect 4: The product's appearance gives it the appearance of an edible candy.

[0148] Driven by gradient drying, D-mannitol migrates and crystallizes directionally from the inside of the capsule to the outer surface, forming a uniform and delicate granular surface with a sandy appearance. This enhances the visual and tactile appeal of the product, creating a significant difference from the smooth appearance of traditional soft capsules and meeting the expectations of candy consumption scenarios.

[0149] Effect 5: Excellent storage stability

[0150] Gradient drying resulted in a final rubber moisture content of 12.5% ​​(within the midpoint of the target range of 10%–15%). Under accelerated storage conditions (40°C, 75% RH) for 3 months, the increase in oil leakage rate was only about 0.4% (from 0.6% to about 1.0%), significantly lower than the control group (comparative example 5, where the oil leakage rate increased from 0% to 3.5% after 3 months). This superior storage stability is attributed to: the uniform moisture distribution achieved by gradient drying avoiding localized stress concentrations, maintaining the long-term structural integrity of the IPN network; and the low moisture activity of the roasted wheat flour core forming a moisture barrier at the core-skin interface, inhibiting long-term erosion of the rubber by the core moisture.

[0151] Effect 6: Suitable for industrial production

[0152] The entire process is based on existing soft capsule rotary molding equipment. The only changes to the process involve adjusting the order of preparation of the gelatin solution (gelatinizing glutinous rice flour first and then adding gelatin), adding D-mannitol to the formula, adding roasted wheat flour to the core material for thickening and cooking, and setting the temperature and humidity parameters of the drying equipment in stages. No new special equipment or fundamental modifications to the production line are required. It is feasible for industrial implementation and suitable for large-scale continuous production.

[0153] Furthermore, by optimizing the three-stage gradient drying process parameters, this invention further reduces the total drying time from the conventional 20-28 hours to 8-22 hours. While ensuring product moisture uniformity (moisture difference between inner and outer layers ≤1.5%) and the appearance of the returned sand, it significantly improves the production line turnover efficiency, reduces the energy consumption and occupation cost of drying equipment, and further enhances the economic viability of industrialization. Detailed Implementation

[0154] The raw materials involved in this invention shall meet the following quality standards:

[0155] (1) Rubber system raw materials

[0156] Gelatin: Food-grade gelatin (compliant with GB6783 "National Food Safety Standard for Food Additives Gelatin") is selected. The gel strength (Bloom value) is 150–250 g, preferably 200 g; viscosity (6.67% solution, 60℃) is 2.0–5.0 mPa·s; moisture content ≤14%; ash content ≤2.0%; sulfur dioxide residue ≤30 mg / kg; heavy metals (as Pb) ≤1.5 mg / kg; microbiological indicators: total bacterial count ≤10000 CFU / g, coliform bacteria ≤30 MPN / 100g, pathogenic bacteria (Salmonella, Staphylococcus aureus) must not be detected. A Bloom value that is too low (<150 g) will result in insufficient film strength and reduced heat-sealing properties of the IPN rubber system; a Bloom value that is too high (>250 g) will cause excessive viscosity of the adhesive solution, uneven spreading, and affect the uniformity of shot blasting.

[0157] Glycerin (glycerol): Food-grade glycerin (compliant with GB29950 "National Food Safety Standard for Food Additives Glycerin") is selected, with a content ≥99.0%; moisture ≤5.0%; density (20℃) 1.257~1.261g / mL; and residue on ignition ≤0.01%. When the glycerin purity is lower than 99.0%, impurities (such as acrolein, fatty acids, etc.) may interfere with the plasticizing effect of gelatin molecular chains and produce off-odors.

[0158] Glutinous rice flour: Food-grade glutinous rice flour (glutinous variety) conforming to relevant national, industry, or enterprise standards; moisture content ≤14%; amylopectin content ≥95% (requirement for glutinous varieties); particle size passing through a 120-mesh sieve (residue ≤5%); ash content ≤1.0%; fat content ≤2.0%. Amylopectin content is the material basis for constructing the IPN interpenetrating network; below 95% will lead to insufficient 3D network density after pregelatinization and a decrease in IPN anchoring effect. Upon arrival at the factory, the glutinous rice flour should be accompanied by a variety certificate (confirming it as a glutinous variety) and batch inspection report provided by the supplier.

[0159] Jujube powder: Made from jujubes that meet the quality requirements of GB / T5835 "Dried Jujubes" or GB / T26150 "Unwashed Jujubes," food-grade jujube powder is produced through drying and pulverizing. It can also be a food-grade product conforming to the corresponding enterprise standards. Moisture content ≤8%; particle size passing through a 120-mesh sieve (residue ≤5%); total sugar content ≥55% (dry basis); sulfur dioxide residue ≤50mg / kg (according to GB2760); total bacterial count ≤1000CFU / g. A moisture content exceeding 8% in the jujube powder will increase uncontrollable moisture variables in the gel system, affecting the construction of the IPN network and the precise control of D-mannitol solubilization and crystallization.

[0160] Ginger powder (fresh ginger powder): Food-grade ginger powder processed in accordance with GB / T30383 "Ginger" or equivalent food standards; moisture content ≤12%; particle size passing through a 120-mesh sieve (sieve residue ≤5%); volatile oil content ≥0.8% (on a dry basis); ash content ≤7.0%; total bacterial count ≤10000 CFU / g. The cellulose component in ginger powder can form auxiliary entanglements with the amylopectin network in the IPN network, but excessively high fiber content (indirectly reflected by high ash content) will increase particle rigidity and affect chewing texture.

[0161] Goji berry powder (used in alternative schemes such as Example 7): Food-grade goji berry powder is made from goji berries that meet the quality requirements of GB / T18672 "Goji Berry"; moisture content ≤10%; particle size passes through a 120-mesh sieve (residue ≤5%); polysaccharide content ≥1.8% (on a dry basis); total bacterial count ≤1000 CFU / g.

[0162] Yam powder (used in alternative schemes such as Example 7): Food-grade yam powder that meets the corresponding food standards is selected; moisture content ≤10%; particle size passes through a 120-mesh sieve (residue ≤5%); starch content ≥60% (on a dry basis); total bacterial count ≤1000 CFU / g.

[0163] D-Mannitol: Food-grade D-mannitol (compliant with GB1886.181 "National Food Safety Standard for Food Additives D-Mannitol"), content ≥98.0%; melting point 165~170℃; specific rotation [α] 20 D = +137°~+145° (measured using a saturated borax solution as solvent); moisture ≤0.3%; reducing sugar (calculated as glucose) ≤0.3%. D-Mannitol has a solubility of approximately 18 g / 100 mL in water at 25°C. This physicochemical parameter is the key characteristic basis for its directional migration crystallization and sand return during gradient drying. It should be ensured that the product crystallization morphology is β-type (the most stable crystal form), and amorphous or δ-type mannitol should be avoided (crystallization behavior is uncontrollable).

[0164] Brown sugar: Food-grade brown sugar conforming to GB / T35885 "Brown Sugar" or GB13104 "National Food Safety Standard for Sugar" is selected; total sugar content ≥85% (calculated as sucrose); moisture ≤5.0%; water-insoluble impurities ≤0.15%. The reducing sugars and mineral components in brown sugar can participate in the Maillard reaction during the cooking process of the gum, giving the gum its characteristic flavor and color.

[0165] (2) Raw materials for the core material system

[0166] Medium-chain triglycerides (MCT oil): Food-grade medium-chain triglycerides (compliant with GB1886.180 "National Food Safety Standard for Food Additives: Medium-chain Fatty Acid Triglycerides") are selected, with C8 and C9... 10 The total fatty acid content should be ≥95%; acid value ≤0.5 mg KOH / g; peroxide value ≤5.0 mmol / kg; iodine value ≤1.0 g I2 / 100g; moisture content ≤0.1%; water activity (Aw) <0.1. MCT oil, as the core material's oil carrier, possesses low water activity, a fundamental condition for constructing a moisture barrier at the core-skin interface. MCT oil is chosen over vegetable oils (such as soybean oil) because its oxidative stability is superior to vegetable oils with higher unsaturated fatty acid content, making it more suitable for long-term storage of functional foods. If alternative oils are used, first-grade refined soybean oil (compliant with GB / T1535, acid value ≤0.2 mg KOH / g, peroxide value ≤5.0 mmol / kg) can be selected, but its oxidative stability during storage needs to be additionally assessed. Use within 7 days of opening.

[0167] Wheat flour: Food-grade wheat flour (medium or high gluten) conforming to GB / T1355 "Wheat Flour" or corresponding food standards is selected. After cleaning and drying, it is dry-roasted at 160-200℃ (preferably 180℃) for 10-15 minutes until the surface is uniformly golden and has a caramelized aroma. After cooling, it is pulverized through an 80-mesh sieve. The roasted wheat flour should meet the following quality requirements: moisture content ≤5%; water activity (Aw) <0.3; starch content ≥55% (on a dry basis, of which pregelatinized starch accounts for ≥30%, and dry-roasting causes some starch to undergo α-transformation); gluten protein content (on a dry basis) ≥8% (the raw wheat flour wet gluten content is ≥22%, and after roasting, the gluten protein undergoes partial thermal denaturation but the total protein content remains basically unchanged); sensory requirements: uniform golden color, caramelized aroma, and no burnt or bitter taste. The Maillard reaction during roasting consumes reducing sugars and free amino acids, which is the key chemical basis for achieving low water activity in roasted wheat flour. Partial thermal denaturation of gluten proteins allows it to retain residual network-forming ability, providing the protein chemical basis for achieving efficient thickening with low dosage. Insufficient roasting (lighter color, insufficient pregelatinization, inadequate gluten protein denaturation) will affect the thickening effect and protein-assisted suspension during subsequent cooking at 80℃; over-roasting (burnt) will produce bitter substances and lead to excessive starch degradation and complete carbonization of gluten proteins, resulting in loss of thickening ability. Use within 24 hours of opening.

[0168] Beeswax: Food-grade white beeswax (compliant with GB1886.87 "National Food Safety Standard for Food Additives: Beeswax") is selected, with a melting point of 62-67℃; acid value of 17-24 mgKOH / g; and saponification value of 87-104 mgKOH / g. Beeswax plays a role in consistency regulation and auxiliary suspension in the core material. The microcrystalline network formed by its curing at room temperature assists the gelatinized starch-thermally denatured gluten protein complex network of roasted wheat flour in maintaining the suspension of solid particles.

[0169] (3) Acceptance procedures for each raw material upon arrival at the factory

[0170] Upon arrival of each raw material, the quality management department verifies the supplier's certificate of conformity, product inspection report, and factory certificate of conformity. For key raw materials (gelatin, glycerin, glutinous rice flour, D-mannitol, MCT oil, and roasted wheat flour), samples should be taken from each batch for testing. Testing items must include at least sensory evaluation, moisture content, and mandatory testing items stipulated by relevant national standards. Only materials that pass the tests can be stored and used. Samples of each batch of raw materials should be retained, with a sample size no less than twice the normal testing quantity. The retention period for these samples should extend at least six months after the expiration date of the final product manufactured from that batch of raw materials.

[0171] (4) Raw material storage

[0172] Gelatin: Store in a dry warehouse at a temperature of 15–25℃ and a relative humidity of ≤60%. Gelatin has strong hygroscopic properties; when the ambient humidity exceeds 60%, the surface absorbs moisture and clumps, which will seriously affect the uniformity and rate of the subsequent sol-gel process, resulting in undissolved gelatin particles in the solution, affecting the uniform construction of the IPN network and the quality of shot sizing. Once opened, the gelatin should be used within 24 hours. Any unused gelatin should be resealed and temporarily stored in a sealed, dry container within 2 hours.

[0173] Powdered raw materials such as glutinous rice flour, jujube powder, ginger powder, goji berry powder, and yam powder: Store in a sealed container in a cool, dry place at a temperature ≤25℃ and a relative humidity ≤50%. Each powdered raw material has been sieved to the target particle size (80-200 mesh, preferably 120 mesh) as required. Once opened, it should be used within 48 hours to avoid moisture absorption, which would increase the moisture content (affecting the accuracy of the water content in the adhesive system) and cause changes in particle size due to clumping (affecting the IPN anchoring effect and joint sealing).

[0174] D-Mannitol: Store in a sealed container in a low-humidity environment with a temperature of 15–25°C and a relative humidity of ≤40%. D-Mannitol is a crystalline solid and does not easily absorb moisture, but under high humidity conditions, trace amounts of dissolution and recrystallization may occur on the surface, leading to clumping, which affects weighing accuracy and the uniformity of dissolution in the adhesive.

[0175] Glycerin: Store in a sealed container at a temperature of 15–25°C. Glycerin is highly hygroscopic; once opened, it should be sealed as soon as possible to avoid prolonged exposure to air and absorption of moisture (which can lead to increased moisture content and affect the precise control of moisture in the adhesive formulation).

[0176] Brown sugar: Store in a sealed container in a cool, dry place at a temperature ≤25℃ and a relative humidity ≤60%. Although brown sugar has a low moisture content (≤5%), its high sugar content makes it prone to absorbing moisture and clumping in high humidity environments, so it should be kept away from moisture.

[0177] MCT oil: Store in a sealed container away from light at a temperature of 15–25°C. Although MCT oil has good oxidation stability, prolonged exposure to light and high temperatures should still be avoided. Use within 7 days of opening. Before use, visually inspect the color and transparency of the oil; discard it if it becomes cloudy or has an unusual odor.

[0178] Roasted wheat flour: Store in a sealed container in a cool, dry place at a temperature ≤25℃ and relative humidity ≤40%. Roasted wheat flour itself has extremely low water activity (Aw<0.3), but its loose, porous structure makes it absorb moisture quickly. Rapid moisture absorption under high humidity conditions will lead to an increase in water activity, weakening its function of building a low water activity barrier in the core material. It may also cause heat-denatured gluten proteins to absorb water and rebound, affecting the consistency of subsequent thickening effects. Use within 24 hours after opening. If roasting is done on-site, after roasting, it should be fully cooled to room temperature (25±2℃) before sealing and packaging or directly transferred to the weighing process to avoid condensation caused by hot packaging.

[0179] Beeswax: Store in a dark place at a temperature of 15-25℃, away from heat sources. Beeswax has a melting point of 62-67℃ and may soften and deform under high temperatures.

[0180] Ginger powder and other raw materials should be stored separately according to variety and batch, with clear labeling (product name, batch number, date of receipt, and expiration date), following the first-in, first-out (FIFO) principle. The warehouse should regularly (at least once a month) check temperature and humidity records and the condition of the raw materials.

[0181] (5) Weighing raw materials

[0182] Weighing System: A dual-verification system is adopted. The operator accurately weighs each component according to the production batch's formula and process sheet. The verifier checks each item against the raw material name, batch number, weighed mass, and theoretical usage. Both parties sign off after confirming that everything is correct. Weighing deviation should be controlled within ±1%.

[0183] Weighing equipment: For solid powder raw materials (gelatin, glutinous rice flour, jujube powder, ginger powder, D-mannitol, brown sugar, roasted wheat flour, etc.), use an electronic balance or scale with an accuracy of not less than ±0.1g (when the amount used is ≤500g) or an electronic scale with an accuracy of not less than ±1g (when the amount used is >500g); for liquid raw materials (glycerol, MCT oil, water), use a graduated cylinder with an accuracy of not less than ±1mL or an electronic balance with an accuracy of not less than ±0.1g for volumetric or gravimetric weighing. Weighing equipment should be calibrated regularly according to metrological management requirements (at least once every six months) and zero-point calibration should be performed before each use.

[0184] Grouping and Temporary Storage: After weighing, each raw material is temporarily stored separately in clean, airtight stainless steel containers or food-grade plastic sealed buckets according to the following groups: the outer layer group (gelatin, glycerin, water, glutinous rice flour, jujube powder / ginger powder / goji berry powder / yam powder and other medicinal and edible functional powders, D-mannitol, brown sugar) and the core material group (MCT oil, roasted wheat flour, medicinal and edible functional powders, beeswax). The containers are labeled with the product name, batch number, date, and operator's name. Glutinous rice flour should be stored separately in a container labeled "Step 1 - Pre-gelatinization Dedicated," physically isolated from other outer layer group raw materials to prevent accidental addition of glutinous rice flour and gelatin during the feeding process (incorrect process sequence will prevent IPN formation, see the serious consequences in Comparative Example 6). Weighed raw materials should be transferred to the next process (Step 1 glutinous rice flour pre-gelatinization or Step 5 core material preparation) within 2 hours to avoid prolonged exposure leading to moisture absorption and deterioration.

[0185] Special Notes:

[0186] Weighing water: The prescribed amount of water (e.g., 120 parts in Example 1) needs to be properly allocated between step 1 (30-40 parts of water for pregelatinization of glutinous rice flour) and step 4 (80-90 parts of water for gelatin sol). When weighing, it should be weighed in two portions and labeled separately for the water used in step 1 and step 4 to avoid confusion between the water amounts in the steps, which could lead to insufficient pregelatinization or abnormal gelatin sol concentration.

[0187] Confirmation of particle size for functional powders derived from both food and medicine: Before weighing, confirm that each powder raw material has passed through a sieve of the target particle size (80-200 mesh, preferably 120 mesh). If the raw material supplier only provides coarse powder, the preparation personnel must sieve it using a standard test sieve of the corresponding mesh size before weighing. Collect the undersize material as the usable material, and return or process the oversize material separately. The sieving operation should be carried out under dust-free and low-humidity conditions, and the sieving yield should be recorded.

[0188] The present invention will be described in detail below with reference to embodiments and comparative examples. The detection indicators involved in each embodiment and comparative example were measured according to the following methods:

[0189] (1) Oil leakage rate: 24 hours after the capsules are pressed, 200 capsules are randomly sampled. Each soft capsule is placed on white oil-absorbing paper and left to stand for 2 hours at 25±2℃ and 50±5% relative humidity. The oil-absorbing paper is visually inspected for oil stains and diffusion marks. At the same time, the capsule seam area is gently pressed to observe whether there is oil seepage. The oil leakage rate (%) is calculated as the percentage of capsules with oil stains or seam seepage out of the total number of samples. Each batch is sampled and tested 3 times, and the average value is taken.

[0190] (2) Rubber breakage rate: In the continuous production process of shot blasting, each 1000 pellets is used as a statistical unit to record the total number of rubber breakages (including waste pellets caused by tape breakage during shot blasting and products with rubber cracks within 24 hours after molding). The rubber breakage rate (%) is calculated as the percentage of the number of broken pellets to the total number of pellets in the statistical unit. At least 3 statistical units are continuously counted for each batch, and the average value is taken.

[0191] (3) Sensory evaluation of chewing performance: A blind evaluation was conducted by a 20-person sensory evaluation team. Evaluators chewed one finished soft capsule in their mouths at 25±2℃, evaluating it comprehensively from five dimensions: softness, elasticity, granular texture, stickiness, and overall chewing pleasure. A 10-point scale was used (10 being the best score). Each evaluator scored independently, and the arithmetic mean of the remaining 18 scores was taken after removing the highest and lowest scores. Scoring criteria: 9.0–10.0 points indicate softness and easy chewing with excellent taste; 7.0–8.9 points indicate good taste but slight deficiencies in one dimension; 5.0–6.9 points indicate average taste with obvious defects (such as being too hard or having a granular texture); below 5.0 points indicates poor taste and unacceptable quality.

[0192] (4) Core material sedimentation stability: Take about 10 mL of the prepared core material (after cooling to room temperature in step 5), put it into a glass test tube with an inner diameter of 15 mm, seal the tube opening, and let it stand at 25±2℃. Observe and record the appearance of the core material on day 1, day 7, day 14, and day 30, including whether there is stratification, oil separation in the upper layer, or sedimentation at the bottom. At the same time, take about 1 mL of sample from the top, middle, and bottom of the test tube on day 30. Based on the characteristics of the medicinal and edible functional powder in the core material, use ultraviolet-visible spectrophotometry (suitable for components with characteristic absorption) or high-performance liquid chromatography (HPLC, suitable for situations where the content of specific active ingredients needs to be quantitatively determined) to determine the content of functional components in each layer, and calculate the relative standard deviation (RSD) of the content of the three layers. If the functional components in the core material lack clear UV characteristic absorption, the content of solids in each layer can be determined by weighing as an alternative evaluation index. Judgment criteria: If no obvious stratification or bottom sedimentation is observed after standing for 30 days, and the RSD of the three layers is ≤10%, it is judged as having no obvious sedimentation.

[0193] (5) Final moisture content of the rubber: After drying, take 5 samples, carefully cut open the capsules, remove the core material, absorb the residual grease on the inner surface of the rubber with oil-absorbing paper, cut the rubber into pieces, and determine the moisture content using the constant weight method at 105℃ (refer to GB5009.3 "National Food Safety Standard - Determination of Moisture in Food"). That is, place the rubber sample in a pre-weighed weighing bottle and dry it in a drying oven at 105±2℃ until constant weight (the difference between two adjacent weighings ≤2mg). Calculate the moisture content (%) as the percentage of weight loss relative to the original rubber mass. Take the average value of 5 samples.

[0194] (6) Deformation rate: After drying, 100 particles were randomly sampled and visually inspected one by one and compared with the shape of the standard ellipsoidal mold. The number of particles with obvious deformation (including warping, dents, surface wrinkles, asymmetrical expansion, and other deviations from the standard shape) was recorded. The deformation rate (%) was calculated as the percentage of deformed particles to the total number of samples. Each batch was sampled and tested three times, and the average value was taken.

[0195] (7) Appearance of surface sand return: After drying, take 20 samples and observe them visually under natural light and touch the surface of the capsules with your fingers to evaluate the uniformity, fineness and firmness of the sand return. The judgment criteria are divided into three levels: uniform and fine, that is, the surface is fully covered with fine white sand-like crystals, which are evenly distributed and do not fall off when lightly rubbed with your fingers; basically uniform, that is, most areas of the surface are covered with sand return, but some areas are slightly thin or slightly uneven; uneven, that is, there are obvious areas without sand return and clusters of coarse crystals coexisting, or the crystals are easy to fall off.

[0196] (8) Accelerated storage stability (oil leakage rate increment): Take 200 finished products that have passed the initial test after drying and place them in sealed aluminum foil bags (50 capsules per bag). Store them for 3 months under accelerated storage conditions (temperature 40±2℃, relative humidity 75±5%RH). Take one bag (50 capsules) each month and check for oil leakage according to the above oil leakage rate test method. The difference between the oil leakage rate in the 3rd month and the initial oil leakage rate is taken as the oil leakage rate increment (%) to evaluate the long-term storage stability.

[0197] (9) Apparent viscosity of the adhesive solution: A rotational viscometer (Brookfield type or equivalent precision device) was used, with a No. 4 rotor and a rotation speed of 30 rpm. The viscosity was measured at the actual shot-pressing temperature of the adhesive solution. The specific temperature was set according to the adhesive box temperature of each example / comparative example (usually within the range of 70-80℃). The temperature deviation of the constant temperature water bath during measurement was controlled within ±1℃. The viscosity measurement temperature of the adhesive solution in each example and comparative example should be marked in the test results to ensure the comparability of the data. Take about 200 mL of the adhesive solution into a 500 mL beaker, insert the rotor after the constant temperature water bath reaches the target temperature, and read the apparent viscosity value (mPa·s) after the reading stabilizes. Three measurements were taken for each batch, and the average value was taken.

[0198] (10) Elongation at break of rubber: Take the dried finished capsule, carefully cut it open and remove the rubber, cut it into dumbbell-shaped specimens (gauge length 20 mm, width 4 mm, thickness is the actual rubber thickness), equilibrate for 24 hours at 25±2℃ and relative humidity 50±5%, and then perform uniaxial tensile testing using a universal testing machine at a tensile rate of 50 mm / min. Record the elongation at break of the specimen, and express the elongation at break (%) as the percentage of the elongation at break to the original gauge length. Take 5 specimens for each sample and take the average value.

[0199] (11) Production efficiency and screen adhesion rate: In the continuous production process of shot blasting, the number of defective shot due to the shot sticking to the molding screen and being unable to be demolded normally is recorded in every 1000 shot units. The screen adhesion rate (%) is calculated as the percentage of defective shot sticking to the screen relative to the total number of shot produced in that statistical unit. Production efficiency is expressed as the ratio (%) of the output of qualified products per unit time (hour) to the standard output under normal working conditions.

[0200] (12) Shot pressing molding qualification rate: In the continuous production process, every 1000 pellets is a statistical unit. The number of qualified products with complete appearance, no oil leakage, no obvious deformation, and weight within the standard deviation range (within ±5%) is counted. The molding qualification rate (%) is calculated as the percentage of qualified products to the total number of pellets produced.

[0201] (13) Moisture difference between inner and outer layers of rubber: For thick-walled rubber (thickness ≥ 1.5 mm), after drying, take 5 samples, cut open the capsules and take out the rubber. Use a scalpel to divide the rubber into an outer layer (about 1 / 3 of the thickness near the outer surface) and an inner layer (about 1 / 3 of the thickness near the core material) along the thickness direction. The moisture content of each layer is determined by constant weight method at 105℃. The absolute value of the difference between the moisture content of the outer layer and the inner layer is used to express the moisture difference between the inner and outer layers of the rubber (%). The average value of 5 samples is taken.

[0202] Example 1 (Preferred embodiment of the present invention)

[0203] Rubber formulation: Same as the preferred formulation of Example 1 listed in Table 1.

[0204] Table 3 lists the core material formulations:

[0205] Table 3 Core Material Formulation

[0206] Element Dosage (servings) Function Medium-chain triglycerides (MCT oil) 60 Oil carrier Roasted wheat flour 6 Thickening and anti-settling, low water activity barrier Ginger powder 40 Functional powders derived from both food and medicine beeswax 3 Consistency adjustment to assist in suspension

[0207] Preparation method:

[0208] Step 1 (Pregelatinization of glutinous rice flour): Take 10 parts of glutinous rice flour and mix it with some water (30-40 parts of the 120 parts of the prescription water) to form a slurry. Place the slurry in a stirring and heating container, heat it to 85°C, and stir continuously for 20-30 minutes until the slurry is a uniform, semi-transparent paste with no white particles remaining. This indicates that the slurry is completely gelatinized and the amylopectin gelatinized liquid is obtained.

[0209] Step 1a (Online monitoring steps for IPN network formation):

[0210] The amylopectin gelling solution obtained in step 1 was sampled, and its blue value (BV) was determined using the iodine-starch colorimetric method. The specific procedure is as follows: Take 1.0 g of the gelling solution sample, dilute it to 50 mL with deionized water, add 0.5 mL of iodine solution (0.2% I₂ + 2% KI aqueous solution), shake to mix, and let stand for 5 minutes. Measure the absorbance at 600 nm using a UV-Vis spectrophotometer, and record this value as BV. 600 .

[0211] Judgment criteria: BV 600 When the concentration is ≥0.35, the amylopectin is considered to have fully gelled and expanded, and the three-dimensional network precursor has been sufficiently formed, allowing proceeding to step 2. 600 If the value is less than 0.35, the heating and stirring time in step 1 should be extended or the temperature should be appropriately increased (not exceeding 95°C) until the BV reaches 0.35. 600 Only after reaching a value of 0.35 or higher can you proceed to the next step.

[0212] Technical principle: During the pregelatinization process, amylopectin granules swell, amylose dissolves, and amylopectin branches unfold. Iodine molecules embed into the unfolded amylopectin helical cavities, forming a blue complex. (BV) 600 The value reflects the degree of expansion of amylopectin molecular chains and the density of helical cavities in solution that can accommodate iodine molecules, indirectly characterizing the skeletal density of the three-dimensional network precursor. 600 ≥0.35 corresponds to the typical fully expanded state of glutinous rice amylopectin under the condition of treatment at 85℃ for more than 20 minutes. At this time, the amylopectin network density is sufficient to form an effective IPN structure when it interpenetrates with gelatin polypeptide chains.

[0213] Step 2 (Dissolving excipients): Add 100 parts of glycerin, 10 parts of D-mannitol, and 45 parts of brown sugar to the glutinous rice gelatinized liquid obtained in Step 1. Maintain the temperature at 80°C and continue stirring until all components are completely dissolved and homogeneous to obtain a gelatinized liquid containing excipients.

[0214] Step 3 (Dispersion of functional powder containing both food and medicine): Add 20 parts of jujube powder and 10 parts of ginger powder (both 120 mesh) to the gelling liquid obtained in Step 2, and stir at medium speed for 15 to 20 minutes until the powder is evenly dispersed without lumps or agglomeration, to obtain a gelling liquid containing powder.

[0215] Step 4 (Gelatin Sol and Degassing): Premix 85 parts of gelatin with the remaining water (approximately 80-90 parts remaining after deducting the amount used in Step 1 from 120 parts) until it expands. Then add it to the gelling solution obtained in Step 3 and stir to dissolve at 70°C until the solution is uniform and free of undissolved gelatin particles. After that, degas at 70°C under negative pressure for 30-45 minutes to obtain the gelling solution for pellet pressing.

[0216] Step 4a (Quantitative verification of IPN interpenetrating network structure):

[0217] The adhesive solution obtained in step 4 was sampled, and the thermal transformation behavior of the adhesive solution film was determined by differential scanning calorimetry (DSC). The specific operation is as follows: An appropriate amount of adhesive solution was coated onto a glass slide and allowed to dry naturally at 25℃ and 50%RH until constant weight, resulting in a film sample with a thickness of approximately 0.3 mm. 5–10 mg of the sample was sealed in a DSC aluminum crucible, and the temperature was increased from 25℃ to 250℃ at a heating rate of 10℃ / min. The DSC heat flow curve was recorded.

[0218] IPN structure determination criteria:

[0219] (i) If a single, broadened endothermic peak (half-width ≥ 15°C) appears on the DSC curve in the 100–130°C range, and this peak temperature shifts to a higher temperature (≥ 8°C) relative to the helical-coil transition peak temperature of pure gelatin film (typically around 95–105°C), then the IPN interpenetrating network structure is considered to have been successfully formed. A shift of ≥ 8°C indicates that the physical constraint (topological interlocking) of the amylopectin network on the gelatin polypeptide chain significantly restricts the conformational freedom of the polypeptide chain, requiring higher thermal energy to complete the helical-coil transition. This is direct thermodynamic evidence for the existence of the IPN structure.

[0220] (ii) If two independent endothermic peaks appear on the DSC curve in the ranges of 90–105℃ and 150–170℃ (corresponding to the independent thermal transitions of gelatin and starch, respectively), it is determined to be a simple physical blend structure rather than an IPN structure. You need to return to step 1 to check the pregelatinization quality or adjust the process parameters.

[0221] Technical significance: DSC thermal transition behavior is one of the most classic methods for determining the structure of polymer interpenetrating network (IPN). In a true IPN structure, the two polymer networks interpenetrate and interlock at the molecular scale, resulting in the mutual coupling and constraint of the chain segment movements of each component, manifested as a single peak in the glass transition temperature (Tg) or thermal transition peak temperature and a shift towards higher temperatures. Conversely, in simple physical blends, the two components maintain independent thermal transition behaviors, exhibiting a bimodal characteristic. The quantitative determination method provided in this step can be used for: (1) quality control during the production process to ensure that each batch of products achieves an effective IPN structure; (2) providing objective physicochemical characterization evidence for the existence of the IPN structure of this invention.

[0222] Step 5 (Core Material Preparation): Mix 15 parts of roasted wheat flour (dry roasted at 180℃ for 12 minutes after drying) with 60 parts of medium-chain triglycerides, 10 parts of ginger powder, and 3 parts of beeswax. Place the mixture in a stirring and heating container, heat to 80℃, and continue stirring and cooking for more than 15 minutes until the system is uniformly thickened and there is no powder sediment. Cool to room temperature (25±2℃) and set aside.

[0223] Step 6 (Shot Pressing): Using a rotary molding method, the adhesive liquid obtained in Step 4 and the core material obtained in Step 5 are respectively fed to the shot press machine. The injection time is set to 0.3 seconds, the glue box temperature is 75℃, and the spray temperature is 45℃. The mixture is pressed and molded to obtain soft capsule-type gel candy wet pellets with a glue thickness of 1.8mm.

[0224] Step 7 (Three-stage gradient drying):

[0225] First stage: Place the shaped soft capsules in a constant temperature and humidity drying room, set the temperature to 20℃, the relative humidity to 45%, and the drying time to 3 hours;

[0226] Second stage: Adjust the drying chamber parameters to 25℃ and 35% relative humidity, and dry for 8 hours;

[0227] Third stage: Adjust the drying chamber parameters to 30℃ temperature, 25% relative humidity, and 5 hours drying time.

[0228] The total drying time was 16 hours. After drying, samples were taken for testing, and the final moisture content of the rubber was 12.5%. The product surface exhibited a uniform, fine, white, sandy texture with a grainy appearance.

[0229] Table 4 lists the test results of Example 1:

[0230] Table 4 Detection results of Example 1

[0231] detection indicators Measured value target value Does it meet the standard? Oil leakage rate 0.6% ≤1% Meets standards Rubber breakage rate 0% 0% Meets standards Chewing score 9.2 / 10 ≥9.0 / 10 Meets standards Core material settling (after 30 days of settling) No obvious settlement No obvious settlement Meets standards Final rubber moisture 12.5% 10%～15% Meets standards Deformation rate <0.9% ≤2% Meets standards Surface sanding appearance Even and delicate Uniform sand return Meets standards Accelerated oil leakage rate increase after 3 months of storage Approximately 0.4% ≤1% Meets standards IPN structure DSC verification A single broadened peak with a peak temperature of 118℃ (offset of approximately 16℃) and a full width at half maximum (FWHM) of 22℃. If a single, broadened endothermic peak (half-width ≥ 15℃) appears in the 100–130℃ range, and this peak temperature shifts to a higher temperature (≥ 8℃) relative to the helix-coil transition peak temperature of pure gelatin film (typically around 95–105℃), then the IPN interpenetrating network structure is considered to have been successfully formed. Achieved (IPN structure formed)

[0232] Example 2 (Scheme with a gelatinization temperature of 70℃ for glutinous rice flour)

[0233] Rubber formulation: Same as in Example 1.

[0234] Preparation method: Basically the same as in Example 1, except that in step 1, the gelatinization temperature of glutinous rice flour is 70℃ (lower limit of the range of this invention), and the stirring time is extended to 40-50 minutes to ensure full gelatinization. The remaining steps are the same as in Example 1.

[0235] Table 5 lists the detection results of Example 2:

[0236] Table 5 Detection results of Example 2

[0237] detection indicators Measured value Oil leakage rate 0.9% Rubber breakage rate 0% Chewing score 8.8 / 10 Core material settling (after 30 days of settling) No obvious settlement Final rubber moisture 12.8% Deformation rate 1.1%

[0238] Note: At a gelatinization temperature of 70℃, the degree of gelatinization of glutinous rice starch granules is slightly lower than that at 85℃, and the uniformity of the three-dimensional network of amylopectin is slightly worse, but it is still within the effective range of this invention, and all indicators meet the standards.

[0239] Example 3 (Scheme for glutinous rice flour gelatinization temperature of 100℃)

[0240] Rubber formulation: Same as in Example 1.

[0241] Preparation method: Basically the same as in Example 1, except that the gelatinization temperature of glutinous rice flour in step 1 is 100℃ (the upper limit of the range of this invention), and the stirring time is shortened to 15-20 minutes (the gelatinization speed is accelerated at high temperature). The remaining steps are the same as in Example 1.

[0242] Table 6 lists the detection results of Example 3:

[0243] Table 6 Detection Results of Example 3

[0244] detection indicators Measured value Oil leakage rate 0.8% Rubber breakage rate 0% Chewing score 9.0 / 10 Core material settling (after 30 days of settling) No obvious settlement Final rubber moisture 12.3% Deformation rate 1.0%

[0245] Note: At a gelatinization temperature of 100℃, the glutinous rice starch granules gelatinize very thoroughly, and the amylopectin network is fully developed. However, some amylopectin undergoes slight degradation due to the high temperature (a slight decrease in molecular weight), resulting in a slight decrease in the elastic modulus of the network skeleton. The chewing score is slightly lower than the optimal solution at 85℃, but still meets the standard. Taking all factors into consideration, 85℃ is the optimal gelatinization temperature.

[0246] Example 4 (50% glycerin dosage)

[0247] Table 7 lists the rubber formulations:

[0248] Table 7 Rubber Formulation Composition

[0249] Element Dosage (servings) gelatin 85 glycerin 42.5 (50% of the gelatin weight) water 120 Glutinous rice flour (120 mesh) 10 Jujube powder (120 mesh) 20 Ginger powder (120 mesh) 10 D-Mannitol 10 brown sugar 45

[0250] Preparation method: Same as in Example 1, except that the amount of glycerol is adjusted to 42.5 parts.

[0251] Table 8 lists the detection results of Example 4:

[0252] Table 8 Detection Results of Example 4

[0253] detection indicators Measured value Oil leakage rate 0.9% Rubber breakage rate 0% Chewing score 8.5 / 10 Core material settling (after 30 days of settling) No obvious settlement Final rubber moisture 11.8% Deformation rate 1.3% Production efficiency Normal (no significant decrease)

[0254] Note: When the glycerol content is 50% of that in this invention, the flexibility of the capsule is reduced, and the chewing score decreases from 9.2 to 8.5 (still within the easy-to-chew range). During production, the capsule and the mesh can separate normally, and all indicators are within the acceptable range. Compared with Comparative Example 3 (glycerol 20%, chewing score 3.5, production efficiency decreased by more than 60%), the preferred lower limit of 50% glycerol in this invention can still ensure good chewing texture (score 8.5 / 10) and normal production efficiency. Furthermore, combined with the data from Example 13 (glycerol 30%, score 7.2 / 10), Example 1 (glycerol approximately 118%, score 9.2 / 10), and Example 8 (glycerol 120%, score 8.8 / 10), a complete effective range of glycerol content from 30% to 120% is defined, and a reasonable trend of chewing score first increasing and then decreasing with the amount of glycerol is presented. 50% to 120% is the preferred range, and 100% to 120% is the optimal range.

[0255] Example 5 (80 mesh particle size scheme)

[0256] Rubber formulation: Same as in Example 1, but the particle size of jujube powder, ginger powder, and glutinous rice powder is adjusted to 80 mesh (approximately 180 μm).

[0257] Preparation method: Same as in Example 1.

[0258] Table 9 lists the detection results of Example 5:

[0259] Table 9 Detection Results of Example 5

[0260] detection indicators Measured value Oil leakage rate 0.9% Rubber breakage rate 0% Chewing performance rating (20-person group) 8.6 / 10 Rubber appearance There are no obvious granular protrusions at the seam. Final rubber moisture 12.6% Deformation rate 1.2%

[0261] Note: 80 mesh (approximately 180 μm) is the upper limit of the particle size in this invention. At this particle size, particles can still be fully wrapped and anchored by the IPN network, no bridging gasket effect appears at the joints, and the oil leakage rate remains below 1%. Compared with Comparative Example 2 (40 mesh, approximately 420 μm, oil leakage rate 3.2%, with obvious particle protrusions visible at the joints), 80 mesh constitutes the critical particle size threshold at which particles can be effectively managed by the IPN network.

[0262] Example 6 (1.5mm rubber thickness scheme)

[0263] Rubber formulation: Same as in Example 1.

[0264] Preparation method: Same as in Example 1, but in step 6, the rubber thickness is 1.5 mm by adjusting the injection time to 0.25 seconds and the glue box temperature to 78°C.

[0265] Table 10 lists the detection results of Example 6:

[0266] Table 10 Detection results of Example 6

[0267] detection indicators Measured value Oil leakage rate 0.9% Rubber breakage rate 0% Chewing score 8.7 / 10 Surface sanding appearance Uniform but the return sand layer is slightly thin Final rubber moisture 12.0% Deformation rate 1.4%

[0268] Note: When the rubber thickness is 1.5mm, the powder containment space and the migration path of D-mannitol are slightly shortened, and the thickness of the return sand layer is slightly thinner than that of Example 1 (1.8mm), but all indicators are within the acceptable range.

[0269] Example 7 (Schemes for different types of functional powders that are both medicinal and edible)

[0270] Table 11 lists the rubber formulations:

[0271] Table 11 Rubber Formulation Composition

[0272] Element Dosage (servings) gelatin 85 glycerin 100 water 120 Glutinous rice flour (120 mesh) 10 Goji berry powder (120 mesh) 15 Yam powder (120 mesh) 15 D-Mannitol 10 brown sugar 45

[0273] Core material formula: 60 parts medium-chain triglycerides, 6 parts roasted wheat flour, 40 parts wolfberry powder, and 3 parts beeswax.

[0274] Preparation method: Same as in Example 1, except that the medicinal and edible functional powder is replaced with wolfberry powder and yam powder instead of jujube powder and ginger powder, and the total amount of powder remains unchanged at 30 parts.

[0275] Table 12 lists the detection results of Example 7:

[0276] Table 12 Detection Results of Example 7

[0277] detection indicators Measured value Oil leakage rate 0.7% Rubber breakage rate 0% Chewing score 9.0 / 10 Core material settling (after 30 days of settling) No obvious settlement Final rubber moisture 12.4% Deformation rate 0.9% Surface sanding appearance Even and delicate

[0278] Note: After replacing the medicinal and edible functional powders with wolfberry powder and yam powder, the technical indicators are comparable to those in Example 1, indicating that the IPN rubber system of the present invention has good universal adaptability to medicinal and edible powders and the technical solution is not limited by specific powder varieties.

[0279] Supplementary explanation regarding the range of glutinous rice flour usage: The range of glutinous rice flour usage in this invention is 5–15 parts. When the amount of glutinous rice flour is less than 5 parts, the density of the amylopectin network backbone formed after pregelatinization is insufficient to construct an effective IPN structure, and the anchoring effect of the solid powder particles is close to that of Comparative Example 1 (without added glutinous rice flour). When the amount of glutinous rice flour is greater than 15 parts, the viscosity of the high-concentration starch paste formed in the pregelatinization stage is too high. After adding gelatin, the overall viscosity of the adhesive exceeds the operable upper limit of the pelletizing process, resulting in uneven spreading and a decrease in the heat-sealing quality of the joints. Example 1 uses 10 parts as the preferred amount, achieving the optimal balance between IPN network density, adhesive viscosity, and process operability. Examples 11 (5 parts glutinous rice flour, 60 parts gelatin) and 12 (15 parts glutinous rice flour, 100 parts gelatin) respectively verified the feasibility of the endpoint of the glutinous rice flour usage range under different gelatin usage conditions.

[0280] Example 8 (120% glycerin dosage scheme)

[0281] Table 13 lists the rubber formulations:

[0282] Table 13 Rubber Formulation Composition

[0283] Element Dosage (servings) gelatin 85 glycerin 102 (120% of the gelatin weight) water 120 Glutinous rice flour (120 mesh) 10 Jujube powder (120 mesh) 20 Ginger powder (120 mesh) 10 D-Mannitol 10 brown sugar 45

[0284] Preparation method: Same as in Example 1, except that the amount of glycerol is adjusted to 102 parts.

[0285] Table 14 lists the detection results of Example 8:

[0286] Table 14 Detection Results of Example 8

[0287] detection indicators Measured value Oil leakage rate 0.7% Rubber breakage rate 0% Chewing score 8.8 / 10 Core material settling (after 30 days of settling) No obvious settlement Final rubber moisture 13.0% Deformation rate 1.0% Oil seepage on the surface after 3 months of accelerated storage Very slight oil seepage, overall acceptable.

[0288] Note: When the glycerin content is at the upper limit of 120% in this invention, the rubber has sufficient flexibility and a chewing score of 8.8 (soft and chewy, but slightly softer than the 9.2 score in Example 1). All indicators are still within the acceptable range. After 3 months of accelerated storage, very slight signs of surface oil seepage appeared, indicating that 120% is close to the critical upper limit for glycerin to be stably accommodated by the IPN network. Further increasing the glycerin content will exacerbate the risk of oil seepage and should not exceed this ratio.

[0289] Example 9 (200 mesh particle size scheme)

[0290] Rubber formulation: Same as in Example 1, but the particle size of jujube powder, ginger powder, and glutinous rice powder is adjusted to 200 mesh (approximately 75 μm).

[0291] Preparation method: Same as in Example 1.

[0292] Table 15 lists the detection results of Example 9:

[0293] Table 15 Detection Results of Example 9

[0294] detection indicators Measured value Oil leakage rate 0.7% Rubber breakage rate 0% Chewing score 8.8 / 10 Rubber appearance The seams are smooth and free of bumps or particles. Final rubber moisture 12.4% Deformation rate 1.0% Apparent viscosity of the adhesive (60℃) The temperature is about 15% higher than in Example 1, but it does not affect normal shot blasting. Shot press molding pass rate 96%

[0295] Note: 200 mesh (approximately 75 μm) is the lower limit of the particle size in this invention. At this particle size, the increased specific surface area of ​​the powder leads to a slight increase in the viscosity of the adhesive, but it is still within the acceptable range for shot blasting, and the molding qualification rate is 96%. All product performance indicators meet the standards. This example, together with Example 5 (upper limit 80 mesh), verifies the complete effectiveness of the 80-200 mesh particle size range.

[0296] Example 10 (2.0mm rubber thickness scheme)

[0297] Rubber formulation: Same as in Example 1.

[0298] Preparation method: Same as in Example 1, but in step 6, the rubber sheet thickness is adjusted to 2.0 mm (the upper limit of the scope of this invention) by adjusting the injection time to 0.35 seconds and the glue box temperature to 72°C. In step 7, the total time for the three-stage gradient drying is extended to 22 hours (4 hours for the first stage, 10 hours for the second stage, and 8 hours for the third stage).

[0299] Table 16 lists the test results of Example 10:

[0300] Table 16 Detection Results of Example 10

[0301] detection indicators Measured value Oil leakage rate 0.5% Rubber breakage rate 0% Chewing score 9.0 / 10 Surface sanding appearance Even and delicate Final rubber moisture 12.2% Deformation rate 0.8% Moisture difference between the inner and outer layers of the rubber ≤1.5% (good uniformity) Total time for gradient drying 22 hours

[0302] Note: With a rubber thickness of 2.0 mm, there is more space for powder to be contained, the effective sealing layer of IPN in the joint area is thicker, and the oil leakage rate is further reduced to 0.5%. The migration path of D-mannitol is increased, and the thickness and uniformity of the return sand layer are both good. The total drying time is set to 22 hours (near the upper limit of the 8-22 hour process range of this invention) to ensure uniform moisture loss from the inner and outer layers of the thick-walled rubber. Further thickening to more than 2.5 mm will result in a drying time that exceeds the acceptable range and a significant deterioration in the moisture uniformity of the inner and outer layers, which is not within the recommended range of this invention.

[0303] Example 11 (Verification scheme for lower limit combination of formulation parameters)

[0304] Table 17 lists the rubber formulations:

[0305] Table 17 Rubber Formulation Composition

[0306] Element Dosage (servings) gelatin 60 glycerin 60 (approximately 100% of the gelatin weight) water 100 Glutinous rice flour (120 mesh) 5 Jujube powder (120 mesh) 15 Ginger powder (120 mesh) 5 D-Mannitol 5 brown sugar 30

[0307] Core material formula: 40 parts medium-chain triglycerides, 2 parts roasted wheat flour, 20 parts ginger powder, and 1 part beeswax.

[0308] Preparation method: Same as in Example 1, except that the amount of glutinous rice flour in step 1 is adjusted to 5 parts, which is mixed with some water (20-25 parts out of the prescribed 100 parts of water) for pre-gelatinization. Step 7 involves a three-stage gradient drying process with a total time of 14 hours (2 hours for the first stage, 7 hours for the second stage, and 5 hours for the third stage). The parameters for the remaining steps are the same as in Example 1.

[0309] Table 18 lists the test results of Example 11:

[0310] Table 18 Detection Results of Example 11

[0311] detection indicators Measured value Oil leakage rate 0.9% Rubber breakage rate 0% Chewing score 8.5 / 10 Core material settling (after 30 days of settling) No obvious settlement Final rubber moisture 11.5% Deformation rate 1.5% Surface sanding appearance It is basically uniform, but the return sand layer is relatively thin.

[0312] Note: When the amounts of gelatin (60 parts), glutinous rice flour (5 parts), and D-mannitol (5 parts) are all taken at the lower limit of the scope of this invention, although the IPN network backbone density is lower than that of Example 1 (10 parts glutinous rice flour), an effective interpenetrating network structure can still be constructed, and all indicators are within the acceptable range. The 5 parts D-mannitol represents the effective lower limit for the sanding effect; the sanding layer is thinner than in Example 1 but still has a identifiable granular appearance. The core material, consisting of 2 parts roasted wheat flour, 40 parts MCT oil, and 1 part beeswax, provides sufficient thickening and suspension effects, with no significant sedimentation within 30 days. This example verifies the feasibility of the lower limit combination of formulation parameters.

[0313] Example 12 (Verification scheme for upper limit combination of formula parameters)

[0314] Table 19 lists the rubber formulations:

[0315] Table 19 Rubber Formulation Composition

[0316] Element Dosage (servings) gelatin 100 glycerin 110 (approximately 110% of the gelatin weight) water 150 Glutinous rice flour (120 mesh) 15 Jujube powder (120 mesh) 25 Ginger powder (120 mesh) 15 D-Mannitol 15 brown sugar 60

[0317] Core material formula: 80 parts medium-chain triglycerides, 10 parts roasted wheat flour, 60 parts ginger powder, and 5 parts beeswax.

[0318] Preparation method: Same as in Example 1, except that in step 1, the amount of glutinous rice flour is adjusted to 15 parts, which is mixed with some water (45-50 parts out of the prescribed 150 parts of water) for pre-gelatinization. In step 4, 100 parts of gelatin are pre-mixed with the remaining water (approximately 100-105 parts) and added after expansion. In step 7, the total drying time for the three-stage gradient is 20 hours (4 hours for the first stage, 10 hours for the second stage, and 6 hours for the third stage). The parameters for the remaining steps are the same as in Example 1.

[0319] Table 20 lists the test results of Example 12:

[0320] Table 20 Detection Results of Example 12

[0321] detection indicators Measured value Oil leakage rate 0.8% Rubber breakage rate 0% Chewing score 8.8 / 10 Core material settling (after 30 days of settling) No obvious settlement Final rubber moisture 13.2% Deformation rate 1.2% Surface sanding appearance Even and delicate Apparent viscosity of the adhesive (60℃) The speed is about 20% higher than in Example 1, and the shot blasting speed is reduced to 65% of the standard operating conditions, but normal continuous production is still possible.

[0322] Note: When the amounts of gelatin (100 parts), glutinous rice flour (15 parts), and medicinal and edible functional powders (totaling 40 parts, including jujube powder (25 parts) and ginger powder (15 parts)) and D-mannitol (15 parts) are all taken at the upper limit of the scope of this invention, the viscosity of the glue solution is relatively high. The pelletizing speed needs to be appropriately reduced to ensure molding quality, but normal continuous production is still possible. The high-density amylopectin network formed by the pre-gelatinization of the 15 parts of glutinous rice flour provides sufficient anchoring ability for the 40 parts of solid powder, with an oil leakage rate of 0.8%, and all indicators are within the acceptable range. The 15 parts of D-mannitol form a thick and uniform return sand layer after gradient drying. The core material, consisting of 10 parts of roasted wheat flour, 80 parts of MCT oil, and 5 parts of beeswax, provides sufficient thickening effect. The core material injection viscosity is slightly high, but it can be filled normally under the condition of an injection time of 0.35 seconds. This example verifies the feasibility of the upper limit combination of formula parameters and also shows that when the amount of glutinous rice flour and solid powder is close to the upper limit, it has a certain impact on the production speed, but does not constitute a process obstacle.

[0323] Example 13 (30% Glycerin Usage Scheme—Verification of Plasticizer Lower Limit)

[0324] Rubber formulation: 25.5 parts glycerin (30% of the mass of 85 parts gelatin), the rest is the same as in Example 1.

[0325] Preparation method: Same as in Example 1, except that the amount of glycerol is adjusted to 25.5 parts. In step 4, the gelatin sol stage, the stirring time is appropriately extended until the gel is completely dissolved and uniform; in step 6, the pelletizing stage, the temperature of the glue box is increased to 78°C to reduce the apparent viscosity of the glue, and the injection time is adjusted to 0.35 seconds to meet the spreading requirements of the higher viscosity glue.

[0326] Table 21 lists the test results of Example 13:

[0327] Table 21 Detection Results of Example 13

[0328] detection indicators Measured value Example 1 Comparison illustrate Oil leakage rate Approximately 1.0% 0.6% Still meets the ≤1% target Rubber breakage rate ≤1% 0% Basically equivalent Chewing score 7.2 / 10 9.2 / 10 Slightly firm but acceptable, still within a good range Core material settling (after 30 days of settling) No obvious settlement No obvious settlement Indifference Final rubber moisture Approximately 11.0% 12.5% Slightly low (decreased water retention capacity of glycerol) Deformation rate Approximately 1.8% ≤1% Slight increase but still ≤2% Accelerated oil leakage rate increase after 3 months of storage Approximately 0.6% Approximately 0.4% Basically equivalent Production efficiency It is approximately 80% of that of Example 1 (can be produced continuously under normal conditions, with a screen sticking rate of approximately 4%). Benchmark 100% Slight decline but industrialization is feasible

[0329] Note: When the glycerol content is at the lower limit of 30% in this invention, the rubber's flexibility is lower than that of Example 1 (glycerol approximately 118%) and Example 4 (glycerol 50%), with a chewing score of approximately 7.2, falling into the category of good taste but slightly insufficient softness. Utilizing the IPN dual-network structure (branched starch network sharing stress, gelatin network providing elasticity), even with low glycerol content, seam sealing (oil leakage rate ≤1%) and production operability can still be maintained. This is a unique advantage of the IPN system of this invention compared to traditional single-gelatin rubber. This example, together with Example 4 (glycerol 50%, score 8.5), Example 1 (glycerol approximately 118%, score 9.2), and Example 8 (glycerol 120%, score 8.8), defines the complete effective range of glycerol content from 30% to 120%.

[0330] Example 14 (Verifying the feasibility of a minimum rubber thickness of 1.0 mm)

[0331] Rubber formulation: Same as in Example 1.

[0332] Preparation method: Same as Example 1, but the rubber thickness in step 6 is 1.0 mm. Step 7 (three-stage gradient drying): First stage: 20℃ / 45%RH / 1h; Second stage: 24℃ / 37%RH / 5h; Third stage: 28℃ / 30%RH / 4h. Total drying time: 16 hours.

[0333] Table 22 lists the test results of Example 10:

[0334] Table 22 Detection Results of Example 14

[0335] detection indicators Measured value Oil leakage rate 0.8% Rubber breakage rate ≤1% Chewing score 8.7 / 10 Core material settling (after 30 days of settling) No obvious settlement Final rubber moisture 11.8% Moisture difference between the inner and outer layers of the rubber Approximately 1.2% Deformation rate Approximately 1.5% Surface sanding appearance Even and delicate Accelerated oil leakage rate increase after 3 months of storage Approximately 0.6%

[0336] Technical Analysis: When the rubber sheet thickness is reduced to the lower limit of 1.0 mm, the total drying time can be shortened from the baseline of 16 h to 10 h due to the shortening of the moisture diffusion path by about 44% (relative to 1.8 mm), while still achieving the target moisture content (10%~15%). The oil leakage rate (0.8%) is slightly higher than the baseline but still meets the requirement of ≤1%. This is mainly because the safety margin of the local thickness of the joint (about 2.0 mm) relative to the powder particle size (≤125 μm) is narrowed under thin-wall conditions. However, the particle bridging effect can still be effectively suppressed by the anchoring effect of the glutinous rice flour amylopectin network on the powder particles. The chewing score (8.7) is slightly lower than the baseline (9.2), mainly because the overall thickness of the thin-wall structure is weakened. However, the soft and elastic texture provided by the IPN double network structure can still be maintained, achieving the target of ≥8.5. The core technical effects such as the appearance of D-mannitol return sand and the long-term stability of the core material are all maintained under the lower thickness condition.

[0337] Comparative Example 1 (no glutinous rice flour added, no IPN structure)

[0338] Rubber sheet formulation: Contains no glutinous rice flour (i.e., removes 10 parts of glutinous rice flour from the formulation of Example 1), otherwise the same as in Example 1.

[0339] Preparation method: 85 parts of gelatin and 120 parts of water were premixed and swelled. Then, 100 parts of glycerin, 10 parts of D-mannitol, and 45 parts of brown sugar were added. The mixture was stirred at 70°C until all components were completely dissolved. Then, 20 parts of jujube powder and 10 parts of ginger powder (both 120 mesh) were added. The mixture was stirred at medium speed for 15-20 minutes until the powder was evenly dispersed. After that, the mixture was degassed at 70°C under negative pressure for 30-45 minutes to obtain the gel solution. The remaining steps (core material preparation, pelletizing parameters, gradient drying parameters) were the same as in Example 1.

[0340] Table 23 lists the detection results of Comparative Example 1:

[0341] Table 23 Detection results of Comparative Example 1

[0342] detection indicators Measured value Example 1 Comparison Deterioration level Oil leakage rate 4.8% 0.6% 8 times Rubber breakage rate 12% 0% Significant deterioration Chewing score 5.6 / 10 9.2 / 10 Significant deterioration IPN structure DSC verification Single peak, peak temperature 98℃, no shift A single broadened peak with a peak temperature of 118℃ (offset of approximately 16℃) and a full width at half maximum (FWHM) of 22℃. No IPN structure

[0343] Technical Analysis: Without the addition of glutinous rice flour, the gelatin system is a single gelatin network. In the presence of a high proportion of solid powder (30 parts total of jujube powder and ginger powder), the solid particles cause steric hindrance at the triple-helix cross-linking nodes of the gelatin molecular chains, reducing the entanglement density of gelatin segments in the heat-sealing area of ​​the joint and resulting in insufficient joint strength. Specifically, this manifests as frequent gelatin breakage during production (breakage rate 12%), and an oil leakage rate of 4.8% within 24 hours after pelleting. In terms of chewing texture, the lack of elastic buffering and water retention assistance from the branched-chain starch network results in a hard and brittle texture. This comparative example quantitatively demonstrates, from the opposite perspective, the decisive role of glutinous rice flour pregelatinization in forming an IPN network in maintaining joint sealing and chewing texture under high powder loads.

[0344] Comparative Example 2 (Solid powder particle size too large: 40 mesh)

[0345] Rubber formulation: The solid powders (jujube powder, ginger powder, and glutinous rice powder) all have a particle size of 40 mesh (approximately 420 μm), and the remaining formulations and dosages are the same as in Example 1.

[0346] Preparation method: Same as in Example 1 (including pregelatinization of glutinous rice flour), only the powder particle size is different.

[0347] Table 24 lists the detection results of Comparative Example 2:

[0348] Table 24 Detection results of Comparative Example 2

[0349] detection indicators Measured value Example 1 Comparison Deterioration level Oil leakage rate 3.2% 0.6% 5.3 times Rubber breakage rate 2% 0% Deterioration Rubber appearance Obvious raised particles are visible at the seams, and some oil is leaking. The seams are smooth and without protrusions. Significant deterioration Chewing score 6.8 / 10 9.2 / 10 Significant deterioration Final rubber moisture 12.6% 12.5% Basically equivalent Deformation rate 1.8% <0.9% Slightly degraded

[0350] Technical Analysis: The 40-mesh powder (particle size approximately 420 μm) is significantly larger than the 80-mesh upper limit of this invention (approximately 180 μm). The particles cannot be fully encapsulated by the IPN network in the joint area. These large particles cross the joint surface, forming bridging gaskets. In other words, the particles physically block the heat-sealing contact of the adhesive on both sides of the joint, resulting in localized unsealing and oil leakage. Visual inspection reveals obvious particle protrusions at the joint, and a rough, granular feel when chewed. This comparative example quantitatively demonstrates the technical necessity of the particle size control upper limit (80 mesh): the particle size must be smaller than the critical value of the IPN network pore size and the local thickness of the joint to avoid the bridging gasket effect.

[0351] Comparative Example 3 (Plasticizer ratio too low: Glycerin content is 20% of gelatin mass)

[0352] Rubber formulation: 17 parts glycerin (20% of the mass of 85 parts gelatin), the rest is the same as in Example 1.

[0353] Preparation method: Same as in Example 1, only the amount of glycerol was adjusted.

[0354] Table 25 lists the detection results of Comparative Example 3:

[0355] Table 25 Detection results of Comparative Example 3

[0356] detection indicators Measured value Example 1 Comparison Deterioration level Production efficiency The rate decreased by more than 60% (due to frequent adhesion of the glue to the screen, with a screen adhesion rate of about 30%). Normal (stickiness < 2%) Severe deterioration Oil leakage rate 2.5% 0.6% 3 times Chewing score 3.5 / 10 9.2 / 10 Severe deterioration elongation at break of rubber Approximately 45% Approximately 250% Severe deterioration Final rubber moisture 10.5% 12.5% Low but within the range

[0357] Technical Analysis: The core function of glycerol as a plasticizer is to embed between gelatin polypeptide chains, increasing the intersegmental spacing through hydrogen bond competition, improving the freedom of chain movement, and lowering the glass transition temperature of the gelatin network, thus maintaining the softness and elasticity of the gelatin shell at room temperature. When the glycerol content is only 20% of the gelatin mass, which is lower than the 30% lower limit of this invention, the intersegmental spacing of the gelatin chains is insufficient, and the movement of molecular chains is restricted. This manifests as: excessively high viscosity of the gelatin solution, extremely poor shell flexibility, and the adhesion between the capsules and the molding mesh exceeding the cohesive force of the shell itself, preventing normal demolding and reducing production efficiency by more than 60%. The finished shell is hard and brittle (elongation of only about 45%), with a chewing score of only 3.5 (too hard and difficult to chew). In the IPN system, insufficient glycerol also leads to insufficient lubrication at the interface between the amylopectin network and the gelatin network. During chewing deformation, the two networks experience interfacial debonding rather than coordinated deformation, further deteriorating the taste. This comparative example, together with Example 4 (50% glycerol, score 8.5, normal production), constitutes a critical boundary control, quantitatively demonstrating the dual necessity of the lower limit of plasticizer (30% gelatin mass) for both production operability and product taste.

[0358] Comparative Example 4 (Conventional thin-walled rubber: 0.8mm)

[0359] Rubber formulation: Same as in Example 1.

[0360] Preparation method: Same as in Example 1, but in step 6, the thickness of the capsule shell is adjusted to 0.8 mm (the conventional thickness of a soft capsule) by adjusting the injection time to 0.15 seconds and the capsule temperature to 80°C. The remaining steps are the same as in Example 1.

[0361] Table 26 lists the detection results of Comparative Example 4:

[0362] Table 26 Detection results of Comparative Example 4

[0363] detection indicators Measured value Example 1 Comparison Deterioration level Oil leakage rate 2.5% 0.6% 4.2 times Chewing score 6.5 / 10 9.2 / 10 Significant deterioration Surface sanding appearance The sand layer is extremely thin, with some areas showing no obvious sand return, making it easy for crystals to detach. Even and delicate Significant deterioration

[0364] Technical Analysis: With a rubber thickness of 0.8mm and 30 parts solid powder (approximately 35% of gelatin mass), the effective matrix thickness of the IPN network (total rubber thickness minus the space occupied by powder particles) is significantly reduced. Powder particles are compressed into a very limited space in the thickness direction, and some particles inevitably approach or even enter the heat-sealed seam area, forming a bridging gasket effect, increasing the oil leakage rate to 2.5%. In terms of chewing texture, the thin-walled rubber has insufficient tooth compression stroke, and the elastic recovery and stress dispersion effect of the IPN dual network cannot be fully realized, resulting in a thin texture rather than a soft and full-bodied one, scoring only 6.5 points. Regarding the graininess, the migration path of D-mannitol from the inside to the outside of the 0.8mm thick rubber is too short, and the total amount of D-mannitol available for enrichment and crystallization on the outer surface is insufficient. The graininess layer is thin and has a shallow intercalation depth with the rubber matrix, making it prone to detachment. This comparative example, together with Example 14 (1.0 mm, all standards met), constitutes a critical thickness control, quantitatively demonstrating the technical necessity of the 1.0–2.0 mm thick wall design from four dimensions: powder containment, joint sealing, chewing texture, and sand return effect.

[0365] Comparative Example 5 (Gradient-free drying: constant temperature and humidity drying)

[0366] Rubber formulation and preparation method: Same as in Example 1 (steps 1 to 6 are exactly the same), only the drying method in step 7 is different.

[0367] Drying conditions: constant temperature 25°C, constant humidity 40%RH, time 16 hours (same as the total time in Example 1).

[0368] Table 27 lists the detection results of Comparative Example 5:

[0369] Table 27 Detection results of Comparative Example 5

[0370] detection indicators Measured value Example 1 Comparison Deterioration level Final rubber moisture 7.2% 12.5% Excessively dry (below the lower limit of the target of 10%) Appearance and Touch Hard, with visible shrinkage wrinkles on the surface. Soft and elastic, with a smooth surface Severe deterioration Chewing score 5.1 / 10 9.2 / 10 Severe deterioration Sand-returned appearance The distribution is uneven, with localized clustered crystals coexisting with large areas of areas without sand return. Even and delicate Significant deterioration Oil leakage rate (initial 24h) 0% 0.6% Initial anti-optimization (mechanism analyzed below) Accelerate oil leakage rate after 3 months of storage 3.5% (from 0 to 3.5%) Approximately 1.0% (increased from 0.6% to approximately 1.0%) Severe deterioration

[0371] Technical Analysis:

[0372] Under constant temperature and humidity drying conditions, none of the three key technical objectives could be achieved:

[0373] (1) Moisture control failure. In the early stage of drying, the moisture evaporation rate of the outer surface of the rubber is relatively fast under a constant 40%RH condition, which quickly forms a dense hardened shell layer (case hardening) and hinders the uniform mass transfer of internal moisture to the outside. However, the internal moisture continues to slowly seep out throughout the 24-hour drying cycle. In addition, the hardened outer shell limits the mass transfer area rather than completely blocking the mass transfer, which ultimately leads to excessive dehydration of the rubber as a whole (moisture content of 7.2%, far below the target lower limit of 10%). The rubber enters the glassy state, feels hard and brittle to the touch, and has a chewing score of only 5.1 points.

[0374] (2) Failure of sand return drive. Under constant temperature and humidity conditions, it is impossible to establish a directional, continuous, and gradient moisture concentration field from the inside of the rubber to the outer surface. After the outer surface hardens prematurely, the migration channels of D-mannitol molecules are blocked, and they can only crystallize randomly inside the rubber or in local cracks, resulting in extremely uneven distribution of sand return on the surface. Locally, clusters of coarse crystals appear, while large areas are not covered by sand return.

[0375] (3) Stress management failure and long-term stability deterioration. It is worth noting that the initial oil leakage rate of this comparative example was 0%, which was lower than the 0.6% of Example 1. This seemingly contradictory phenomenon reveals the essential defect of constant temperature and humidity drying: excessive dehydration (moisture content only 7.2%) puts the rubber in a glassy, ​​compressed state, and the joints are mechanically compressed, resulting in a temporary high sealing degree. However, this compressed seal caused by excessive drying is brittle and unsustainable. Under subsequent accelerated storage conditions (40°C, 75%RH), the over-dried rubber absorbs moisture from the environment, causing repeated cycles of moisture absorption and dehydration, and the IPN network gradually fatigues and cracks in the stress concentration area of ​​the joints. After 3 months, the oil leakage rate rose sharply from 0 to 3.5%. In contrast, the gradient drying in Example 1 stabilized the rubber moisture content at 12.5% ​​(elastic gel state). Although there was a very small amount of leakage (0.6%) initially, the IPN network was in a flexible elastic state and had the ability to resist stress fluctuations over a long period of time. After 3 months, the oil leakage rate only increased by about 0.4%, demonstrating inherently better long-term sealing reliability.

[0376] This comparative example comprehensively demonstrates the irreplaceable nature of the three-stage gradient drying process from three independent dimensions: moisture control, sand return drive, and stress management.

[0377] Comparative Example 6 (glutinous rice flour was added directly without pre-gelatinization)

[0378] Rubber sheet formula: Same as Example 1 (containing 10 parts glutinous rice flour).

[0379] Preparation method: The difference from Example 1 is that the pre-gelatinization treatment in step 1 is omitted. 10 parts of glutinous rice flour in dry powder form and 85 parts of gelatin are simultaneously added to water in step 4, and the mixture is stirred at 70°C to form a sol, allowing the gelatinization of the glutinous rice flour and the gelatin sol to proceed simultaneously. The dissolution of excipients and the dispersion of the medicinal and edible functional powders in steps 2 and 3 are carried out after the gelatin-glutinous rice flour mixture sol is completed. The remaining steps (including core material preparation, pelleting parameters, and gradient drying parameters) are the same as in Example 1.

[0380] Table 28 lists the detection results of Comparative Example 6:

[0381] Table 28 Detection results of Comparative Example 6

[0382] detection indicators Measured value Example 1 Comparison Deterioration level Oil leakage rate 3.5% 0.6% 5.8 times Rubber breakage rate 8% 0% Significant deterioration Chewing score 6.2 / 10 9.2 / 10 Significant deterioration Final rubber moisture 12.0% 12.5% Basically equivalent Deformation rate 2.5% <0.9% Significant deterioration Surface sanding appearance Generally uniform but slightly rough Even and delicate Slightly degraded IPN structure DSC verification The two peaks are located at 101℃ and 158℃ respectively. A single broadened peak with a peak temperature of 118℃ (offset of approximately 16℃) and a full width at half maximum (FWHM) of 22℃. Simple blending structure, non-IPN

[0383] Technical Analysis: This comparative example is key evidence demonstrating the decisive role of the "pregelatinization process sequence." Although the amount of glutinous rice flour added was the same (10 parts), the simultaneous mixing of unpregelatinized glutinous rice flour and gelatin at 70℃ triggered two unfavorable processes: First, the gelatin sol and glutinous rice flour gelatinization occurred simultaneously, competing for aqueous space. The sol unfolding of gelatin polypeptide chains and the granular swelling of amylopectin interfered with each other in the same aqueous phase, preventing amylopectin from independently forming an ordered three-dimensional network precursor in the free aqueous phase. Second, although 70℃ is close to the gelatinization temperature of glutinous rice starch, the aqueous phase was already largely occupied by gelatin, leaving insufficient available free water. The glutinous rice flour particles were not fully gelatinized in the high-viscosity gelatin sol, with some remaining as unexpanded particle aggregates in the gelatin coating, becoming stress concentration defects and weak sealing areas. Ultimately, a simple physical blend was formed rather than an interpenetrating network structure.

[0384] The test results showed an oil leakage rate of 3.5%, which falls between Comparative Example 1 (no glutinous rice flour added, 4.8%) and Example 1 (added after pre-gelatinization, 0.6%). This indicates that adding glutinous rice flour without pre-gelatinization has a very limited improvement effect and cannot replace the pre-gelatinized IPN process. This comparative example, along with Comparative Example 1 (no glutinous rice flour added) and Example 1 (added after pre-gelatinization), constitutes three progressive control groups: Comparative Example 1 (4.8%) → Comparative Example 6 (3.5%) → Example 1 (0.6%). This quantitatively and rigorously demonstrates the irreplaceable nature of the "gelatinization first, then addition" process sequence in forming an effective IPN structure, and the decisive impact of whether or not an IPN structure is formed on the core performance of the product.

[0385] Comparative Example 7 (without D-mannitol)

[0386] Rubber formulation: Remove 10 parts of D-mannitol from the formulation of Example 1, and increase the brown sugar to 55 parts to keep the total solids content close (the rest is the same as in Example 1).

[0387] Preparation method: Same as in Example 1 (steps 1 to 7 are exactly the same, including three-stage gradient drying).

[0388] Table 29 lists the detection results of Comparative Example 7:

[0389] Table 29 Detection results of Comparative Example 7

[0390] detection indicators Measured value Example 1 Comparison illustrate Oil leakage rate 0.7% 0.6% Basically equivalent Rubber breakage rate 0% 0% Indifference Chewing score 9.0 / 10 9.2 / 10 Basically equivalent Surface sanding appearance No sand return, smooth surface Even and delicate sand return Significant differences Final rubber moisture 12.3% 12.5% Basically equivalent Accelerated oil leakage rate increase after 3 months of storage Approximately 0.5% Approximately 0.4% Basically equivalent

[0391] Technical Analysis: Without D-mannitol, the structural integrity, seam sealing, and chewing texture of the IPN capsule system are not significantly affected, proving that the core function of D-mannitol in this invention is to achieve a candied, grainy appearance, rather than contributing to structure or sealing. Products without D-mannitol exhibit the smooth appearance of traditional soft capsules, lacking the grainy visual effect and granular texture required for candy consumption scenarios, and thus failing to achieve the technical goal of achieving a candied appearance as described in this invention. This comparative example positively demonstrates the functional independence and irreplaceability of D-mannitol in the formulation (regarding the grainy appearance goal).

[0392] Comparative Example 8 (core material does not contain roasted wheat flour)

[0393] Rubber formulation: Same as in Example 1.

[0394] Core formulation: Remove 6 parts of roasted wheat flour and increase medium-chain triglycerides to 75 parts (the rest is the same as the core formulation in Example 1).

[0395] Preparation method: Same as in Example 1. When preparing the core material, only 75 parts of MCT oil, 40 parts of ginger powder, and 3 parts of beeswax are mixed, stirred at 80°C for 15 minutes, and then cooled to room temperature.

[0396] Table 30 lists the detection results of Comparative Example 8:

[0397] Table 30 Detection results of Comparative Example 8

[0398] detection indicators Measured value Example 1 Comparison Deterioration level Oil leakage rate (initial 24h) 0.6% 0.6% Indifference Core material settling (after 30 days of settling) On the 7th day, obvious bottom sedimentation and oil separation in the upper layer appeared. No significant settlement after 30 days Significant deterioration Core material three-layer content RSD (30 days) Approximately 35% ≤10% Severe deterioration Accelerated oil leakage rate increase after 3 months of storage Approximately 1.2% Approximately 0.4% Significant deterioration Accelerate the change in rubber feel after 3 months of storage Localized softening and decreased elasticity No significant changes Significant deterioration

[0399] Technical Analysis: Without roasted wheat flour, the beeswax microcrystalline network in the core material provides only limited suspension, insufficient to maintain the uniform dispersion of the medicinal and edible functional powder in the long term, and stratification occurs as early as day 7. More importantly, after removing the roasted wheat flour, the core material system lacks a low water activity starch matrix barrier. Although the overall water activity of the core material remains low (MCT oil itself has a water activity of <0.1), trace amounts of water in the core material are more likely to migrate to the outer skin during long-term storage (due to the lack of adsorption and locking effect of the gelatinized starch network of roasted wheat flour on water molecules). After 3 months, the outer skin shows local softening, and the oil leakage rate increases by 1.2% (3 times that of Example 1), confirming the irreplaceable role of roasted wheat flour in constructing the core-skin interface water barrier. This comparative example quantitatively verifies the technical necessity of roasted wheat flour in the core material for both thickening and anti-settling functions as an interface water barrier.

[0400] Comparative Example 9 (using sorbitol instead of D-mannitol)

[0401] Rubber formulation: Replace 10 parts of D-mannitol in the formulation of Example 1 with 10 parts of sorbitol, and the rest are the same as in Example 1.

[0402] Preparation method: Same as in Example 1 (steps 1 to 7 are exactly the same, including three-stage gradient drying).

[0403] Table 31 lists the detection results of Comparative Example 9:

[0404] Table 31 Detection results of Comparative Example 9

[0405] detection indicators Measured value Example 1 Comparison illustrate Oil leakage rate 0.7% 0.6% Basically equivalent Chewing score 9.0 / 10 9.2 / 10 Basically equivalent Surface sanding appearance No sand return, smooth surface with a slightly sticky feel. Even and delicate sand return Significant differences Final rubber moisture 13.5% 12.5% High

[0406] Technical Analysis: Sorbitol has a solubility of approximately 235 g / 100 mL in water at 25°C, significantly higher than D-mannitol (approximately 18 g / 100 mL). Furthermore, sorbitol is amorphous and extremely difficult to crystallize under normal conditions. During gradient drying, even though the moisture concentration gradient enriches sorbitol on the outer surface, its local concentration in the outer surface region is far from reaching saturation solubility, preventing crystallization and the formation of a sandy layer. In addition, sorbitol's strong hygroscopicity results in a higher final moisture content (13.5%) in the rubber, giving it a sticky feel rather than the desired gritty texture. This comparative example quantitatively demonstrates, from the opposite perspective, the specificity of D-mannitol (low solubility + strong crystallization tendency + narrow supersaturated crystallization window) for the gradient drying-driven directional migration sandy layer mechanism, and that this specificity cannot be replaced by other common sugar alcohols.

[0407] Comparative Example 10 (using regular cornstarch instead of glutinous rice flour)

[0408] Rubber sheet formulation: Replace 10 parts of glutinous rice flour in the formulation of Example 1 with 10 parts of ordinary corn starch, and the rest is the same as in Example 1. The amylopectin content of ordinary corn starch is about 72% to 78% (far lower than ≥95% of glutinous rice flour).

[0409] Preparation method: Same as in Example 1, except that in step 1, 10 parts of ordinary corn starch are mixed with some water and stirred at 85°C until fully gelatinized. The remaining steps are the same as in Example 1.

[0410] Table 32 lists the detection results of Comparative Example 10:

[0411] Table 32 Detection results of Comparative Example 10

[0412] detection indicators Measured value Example 1 Comparison Deterioration level Oil leakage rate 2.1% 0.6% 3.5 times Rubber breakage rate 3% 0% Significant deterioration Chewing score 7.2 / 10 9.2 / 10 Significant deterioration Rubber touch It's rather stiff and has poor elasticity. Soft and elastic Significant deterioration

[0413] Technical Analysis: Ordinary corn starch contains approximately 22%–28% amylose. After pregelatinization, amylose molecules tend to align linearly and rapidly retrograde to form dense, rigid crystalline microregions, rather than the uniform, flexible three-dimensional network formed by the highly branched structure of amylopectin. These retrograded crystalline microregions of amylose, acting as rigid defect points inserted into the gelatin network, not only fail to construct an effective interpenetrating network structure but also create localized stress concentrations at the seams, leading to an oil leakage rate of 2.1% and a breakage rate of 3%. In terms of chewing texture, the retrograde crystallization of amylose increases the overall hardness and decreases the elasticity of the gelatin, resulting in a harder texture. This comparative quantitative analysis demonstrates the irreplaceable material basis for constructing an effective IPN network in glutinous rice flour (≥95% amylopectin content). Ordinary starch (approximately 72%–78% amylopectin content) cannot replace glutinous rice flour to achieve the technical effects of this invention.

Claims

1. A medicinal and edible gel candy in the form of a soft capsule, comprising a shell and a core material, characterized in that: The gelatinous material is made from the following raw materials in parts by weight: 60-100 parts gelatin, 30%-120% glycerin by weight of gelatin, 100-150 parts water, 5-15 parts glutinous rice flour, 20-40 parts medicinal and edible functional powder, 5-15 parts D-mannitol, and 30-60 parts brown sugar. The core material is made from the following raw materials in parts by weight: 40-80 parts of medium-chain triglycerides, 2-10 parts of roasted wheat flour, 20-60 parts of medicinal and edible functional powder, and 1-5 parts of beeswax. The glutinous rice flour contains ≥95% amylopectin; the glutinous rice flour and the medicinal and edible functional powder have a particle size of 80 mesh to 200 mesh; the rubber sheet thickness is 1.0 to 2.0 mm. In the rubber sheet, glutinous rice flour is pregelatinized and then forms an interpenetrating network structure with gelatin. D-mannitol is dried in three stages to form a sand-returning layer on the outer surface of the rubber sheet.

2. The gel candy according to claim 1, characterized in that, The medicinal and edible functional powders are selected from one or more of the following: jujube powder, ginger powder, wolfberry powder, yam powder, mulberry powder, poria powder, astragalus powder, codonopsis powder, longan pulp powder, lily powder, hawthorn powder, kudzu root powder, honeysuckle powder, chrysanthemum powder, dandelion powder, coix seed powder, lotus seed powder, euryale seed powder, cassia seed powder, platycodon powder, licorice powder, cinnamon powder, amomum powder, clove powder, fennel powder, Sichuan pepper powder, galangal powder, lotus leaf powder, mulberry leaf powder, dendrobium officinale powder, American ginseng powder, ganoderma lucidum powder, gastrodia elata powder, ophiopogon japonicus powder, rehmannia glutinosa powder, angelica sinensis powder, polygonatum sibiricum powder, cistanche deserticola powder, eucommia ulmoides leaf powder, tangerine peel powder, saffron powder, cardamom powder, turmeric powder, raspberry powder, and jujube seed powder.

3. The gel candy according to claim 1, characterized in that, The final moisture content of the rubber sheet is 10% to 15%; the water activity of the roasted wheat flour is <0.3; and the overall water activity of the core material is <0.

35.

4. The gel candy according to claim 1, characterized in that, The gelatin is 85 parts, the glycerin is 100% to 120% of the gelatin mass, the water is 120 parts, the glutinous rice flour is 10 parts, the D-mannitol is 10 parts, and the brown sugar is 45 parts; the thickness of the gelatin sheet is 1.8 mm.

5. The gel candy according to claim 1, characterized in that, The glutinous rice flour and the medicinal and edible functional powder have a particle size of 120 mesh.

6. A method for preparing a medicinal and edible gel candy in the form of a soft capsule as described in any one of claims 1 to 5, characterized in that, Includes the following steps: Step 1: Pre-gelatinization of glutinous rice flour: Mix glutinous rice flour with some water to form a slurry. Stir continuously at 70-100℃ until the glutinous rice flour is fully gelatinized. The slurry is a uniform, semi-transparent paste with no white particles remaining, thus obtaining amylopectin gelatinized liquid. Step 2, Dissolving excipients: Add glycerol, D-mannitol and brown sugar to the gelling solution obtained in Step 1, and maintain the temperature at 70-85℃ while stirring until all components are completely dissolved and homogeneous to obtain a gelling solution containing excipients; Step 3: Dispersion of medicinal and edible functional powder: Add the medicinal and edible functional powder to the gelling liquid containing excipients obtained in Step 2, and stir at medium speed for 15 to 20 minutes until the powder is evenly dispersed and there are no lumps or agglomerations, to obtain the gelling liquid containing the powder. Step 4, Gelatin Sol and Degassing: After premixing and swelling the gelatin with the remaining water, add it to the gelling solution containing powder obtained in Step 3. Stir at 60-80℃ until the gelling solution is uniform and free of undissolved gelatin particles. Then degas at 60-80℃ under negative pressure for 30-45 minutes to obtain the gelling solution. Step 5, Core Material Preparation: Mix roasted wheat flour with medium-chain triglycerides, medicinal and edible functional powders, and beeswax. Stir and cook continuously at 80°C for no less than 15 minutes until the system is uniformly thickened and there is no powder sedimentation. Cool to room temperature for later use. Step 6, Shot Compression Molding: Using a rotary molding method, the adhesive liquid obtained in Step 4 and the core material obtained in Step 5 are respectively fed to a shot compression machine and pressed into shape to obtain soft capsule-type gel candy wet pellets with a rubber thickness of 1.0-2.0 mm. Step 7, Three-stage gradient drying: First stage: Temperature 18-22℃, relative humidity 40%-50%, drying for 1-4 hours; Second stage: Temperature 23-25℃, relative humidity 35%-39%, drying for 5-10 hours; Third stage: Temperature 26-30℃, relative humidity 25%-34%, drying for 2-8 hours; Total drying time: 8–22 hours; During the three-stage gradient drying process, D-mannitol migrates directionally from the inside of the rubber to the outer surface along with the moisture concentration gradient and crystallizes in a supersaturated manner on the outer surface, forming a return sand layer.

7. The preparation method according to claim 6, characterized in that, In step one, the water portion is 20% to 35% of the prescribed amount of water, the pregelatinization temperature is preferably 85°C, and the stirring time is 15 to 50 minutes.

8. The preparation method according to claim 6, characterized in that, In step five, the roasted wheat flour is made by dry roasting food-grade wheat at 160-200℃ for 10-15 minutes, followed by cooling and pulverizing. The water activity after roasting is <0.

3.

9. The preparation method according to claim 6, characterized in that, In step six, the injection time for shot blasting is 0.25 to 0.35 seconds, the temperature of the glue box is 72 to 78°C, and the temperature of the spray body is 40 to 50°C.

10. The preparation method according to claim 6, characterized in that, In step seven, after the three-stage gradient drying is completed, the final moisture content of the rubber is 10% to 15%, and the product surface exhibits a uniform sandy appearance; the moisture difference between the inner and outer layers of the rubber during the drying process is ≤1.5%.