Fragile capsule as well as preparation method and application of fragile capsule

Abstract

The invention provides a fragile capsule. A shell of the capsule contains a gel, a flexibilizer, an adhesive, an emulsifier and a pigment. During preparation, capsule shell liquid and core liquid are co-extruded into a condensation bath through capsule dripping equipment, wet capsules are collected from the condensation bath, then the wet capsules and oily adsorption substances are arranged in rotating cage equipment to be finished, the oily adsorption substances are oil absorption paper, cotton towels, plant fiber towels or artificial fiber fabrics, and then drying is conducted. A solution containing calcium or magnesium ions does not need to be used as a capsule shell reinforcing cross-linking agent, so that a divalent metal complexing agent capable of reacting with the calcium and magnesium ions does not need to be used in the capsule shell, and good physical properties can be obtained. On the other hand, the wet capsule is finished by adopting an oily adsorption substance and then is dried, so that the performance of the capsule is further improved. The invention provides a new way for preparing the fragile capsule.

Description

Technical Field

[0001] This invention relates to the field of capsule preparation, and particularly to a fragile seamless capsule, as well as a method for preparing the fragile capsule and its application. Background Technology

[0002] Fragile capsules (also known as flavored capsules) are an important carrier for flavoring and functionalization, widely used in tobacco products (such as filter sticks). Consumers can break the capsule by pressing it with their fingers during smoking, instantly releasing the flavoring, cooling agent, or other functional substances contained within. Existing tobacco capsules typically use natural polymer materials such as gelatin, gum arabic, and agar as the main components of the capsule shell, and are produced using a coaxial double-layer dropper co-extrusion process to obtain seamless capsules encapsulating liquid contents.

[0003] During the capsule extrusion process, the raw materials for the capsule shell contain a large amount of moisture, resulting in low strength of the wet capsules. These capsules are prone to breakage during subsequent drying, leading to contamination of other capsules and prolonged drying time, causing aroma loss. Chinese invention patent CN 101203213 B discloses a capsule preparation method where, after extruding the wet capsules, they are contacted with a solution of divalent metal ions, preferably calcium or magnesium ions, or with an organic acid solution. This allows the calcium and magnesium ions or organic acid to crosslink with the plant gum in the capsule shell raw material, forming a three-dimensional network structure to enhance the strength of the wet capsules and meet the strength requirements of the drying process. However, while this preparation process can improve the strength of the wet capsules, because it is achieved through washing or soaking steps, the uniformity of the contact between the solution and the wet capsules is difficult to achieve on an industrial scale. This results in differences in the strength of some wet capsules, and therefore, in industrial-scale production, some capsules still lack sufficient strength and break during drying.

[0004] On the other hand, the dripping process for seamless capsules involves co-extruding the capsule shell raw material liquid and core liquid into a condensation bath using a coaxial double-layer dripping device. The capsule spheres are cooled and shaped in the condensation bath, then collected and dried. This process results in capsules with an oily liquid adhering to their surface, which prolongs the drying time and causes aroma loss. Patent CN 101203148 B discloses methods for removing the oil from the capsule shell and further reinforcing the shell through washing and soaking, particularly through dehydration and osmotic equilibrium. During washing and soaking, due to concentration differences and osmotic pressure, some substances in the core liquid and capsule shell detach from the wet capsule through mass exchange, leading to fluctuations in the aroma and physical properties of the capsule product. Since the core liquid of capsules is often composed of highly volatile flavorings or cooling agents (such as menthol), existing capsule shell materials have poor barrier properties against these small molecules. Therefore, the core liquid slowly evaporates and migrates through the capsule shell as the capsule product is stored, causing "aroma decay" or "weakened cooling sensation." These factors cause the flavor of the capsules to decrease significantly later in their shelf life, even if the capsules are not crushed.

[0005] In view of the many technical defects of the existing technology, the inventors analyzed and summarized the existing technology and conducted a large number of experiments and analyses, and finally completed the present invention. Summary of the Invention

[0007] The present invention provides a fragile capsule, the capsule comprising a capsule shell and a core liquid, the capsule shell containing 1 to 10 parts by weight of a gelling agent, 1 to 5 parts by weight of a toughening agent, 0.5 to 3 parts by weight of an adhesive, 0.1 to 1 part by weight of an emulsifier and 0 to 1 part by weight of a pigment.

[0008] In this invention, the gelling agent is selected from one or more combinations of agar, xanthan gum, carrageenan, konjac gum, gellan gum, or locust bean gum.

[0009] Gel agents are aqueous materials that are fluid in aqueous solutions at high temperatures but form gels upon cooling. They primarily serve as the skeleton of capsule shells, ensuring sufficient strength for the capsule product. After solidification, the three-dimensional network structure formed by the gel agent encapsulates the core fluid. As the drying process progresses, the moisture in the wet capsule shell evaporates, and the three-dimensional network structure gradually contracts, increasing the barrier properties of the capsule shell. Therefore, if the amount of gel agent is too low (less than 1 part), it will reduce the barrier properties and burst strength of the capsule shell. However, if too much gel agent is used (more than 10 parts), it will cause the capsule's strength to increase excessively, making it difficult to break and impacting the user experience.

[0010] The toughening agent is selected from one or more combinations of sorbitol, glycerol, triethyl citrate, or polyethylene glycol.

[0011] In this invention, the toughening agent effectively improves the toughness of the capsule shell, preventing the capsule from becoming too brittle and breaking during the manufacturing process. Therefore, if the amount of toughening agent is less than 1 part, the capsule shell will become too brittle and easily break during transportation and manufacturing, which will not only reduce the yield but also easily contaminate the manufacturing equipment. If the amount of toughening agent is greater than 5 parts, the toughening agent in the capsule shell will absorb moisture from the environment, thereby reducing the moisture resistance of the capsule.

[0012] The adhesive is selected from one or more combinations of sodium carboxymethyl cellulose, pullulan, or modified starch hydroxymethyl cellulose.

[0013] The main function of the adhesive in this invention is to fill the pores of the three-dimensional network structure formed by the gelling agent. As the adhesive dries, it crystallizes, increasing the density of the three-dimensional network structure and bonding the gelling agents together, thus increasing the cohesiveness between the gelling materials. Therefore, if the amount of adhesive is less than 0.5 parts, the density of the three-dimensional network structure of the gel will be reduced; if the amount of adhesive is too large, greater than 3 parts, the viscosity of the entire gel solution will increase, making it difficult to drip the capsules during the dripping process.

[0014] The emulsifier is selected from one or more combinations of Span, Tween, monoglycerides, sucrose fatty acid esters, or sodium octenyl succinate starch.

[0015] In this invention, the emulsifier reduces the interfacial tension between oil and water, ensuring that the core liquid is centered within the wet capsule shell, preventing the wet capsule from becoming eccentric and effectively improving capsule uniformity. However, if the emulsifier dosage is too high (more than 1 part), it can lead to core liquid eccentricity or the formation of core liquid satellite droplets within the capsule shell, affecting the physical properties of the capsule product.

[0016] The pigments used are food colorings, such as brilliant blue, amaranth, and tartrazine, which are common food colorings. These capsule shell liquid raw materials are all commercially available products.

[0017] Based on this, the present invention also provides a method for preparing fragile capsules, the method comprising the following steps:

[0018] (1) Preparation of capsule shell liquid

[0019] Weigh 1-10 parts of gelling agent, 1-5 parts of toughening agent, 0.5-3 parts of adhesive, 0.1-1 parts of emulsifier, 0-1 parts of pigment and 40-120 parts of purified water by weight, mix and stir until uniform to obtain capsule shell liquid, let stand to remove bubbles and set aside for later use.

[0020] (2) Drip

[0021] The capsule shell liquid and the core liquid are co-extruded into a condensation bath using a capsule dripping device, and wet capsules are collected from the condensation bath.

[0022] (3) Organize

[0023] The wet capsules and oily absorbent obtained in step (2) are placed in a rotating drum device for sorting. The oily absorbent is one or a combination of oil-absorbing paper, cotton towel, plant fiber towel or artificial fiber fabric. The initial weight of the oily absorbent is 1 to 10% of the weight of the wet capsule. The sorting time is 5 to 40 minutes and the rotating drum speed is 15 to 25 r / min.

[0024] (4) Drying

[0025] The prepared capsules are dried at 15-40℃ and 30-70% humidity to obtain fragile capsules.

[0026] In this invention, the gelling agent is selected from one or more combinations of agar, xanthan gum, carrageenan, konjac gum, gellan gum, or locust bean gum;

[0027] The toughening agent is selected from one or more combinations of sorbitol, glycerin, triethyl citrate or polyethylene glycol;

[0028] The adhesive is selected from one or more combinations of sodium carboxymethyl cellulose, pullulan, or modified starch hydroxymethyl cellulose;

[0029] The emulsifier is selected from one or more combinations of Span, Tween, mono-fatty acid glycerides, sucrose fatty acid esters or sodium octenyl succinate starch.

[0030] The pigment is an edible pigment.

[0031] In this invention, the core fluid is an oily liquid.

[0032] Preferably, the wet capsules obtained in step (2) have a burst strength greater than 0.5N, and the pressure value of the dried capsule product is 8~22N, with a compression ratio of 15~60%.

[0033] In this invention, the pressure value of the finished capsule is the maximum stress experienced when the capsule ruptures, and the compression ratio is the ratio of the distance the capsule is compressed when it breaks to the initial diameter of the capsule.

[0034] The burst strength, pressure value, and compression ratio of capsules can be tested using a bursting bead strength tester (model CTS-Ⅲ, manufactured by Chengdu Ruituo Technology Co., Ltd.). If the strength of the wet capsule is less than 0.5N, it is prone to bursting during the drying process, leading to prolonged drying time and potentially affecting the quality of other capsule products.

[0035] In this invention, the maximum stress of the gel after freezing the capsule shell liquid is greater than 5.0 N. The maximum stress test method for the gel is as follows: the capsule shell liquid is thoroughly mixed in a water bath at a temperature of 80-90°C, a stirring speed of 200-500 r / min, and a stirring time of 1-3 hours. Then, about 105 ml of the hot gel solution is poured into a standard gel freezing bottle, the bottle is capped, and the bottle is placed in a constant temperature water bath at 10.0±0.1°C for cooling and aging for 17 hours to complete gelation. Then, the gel is tested using a texture analyzer (model SNZGY-1 manufactured by Dongguan Bolide Instrument Equipment Co., Ltd.) according to the GB 6783-2013 testing standard.

[0036] The surface tension of the capsule shell liquid in this invention was measured to be 30~60 mN / m at 85°C using a surface tension meter (such as the ST-2000 manufactured by Shanghai Fangrui Instruments Co., Ltd.) (in a constant temperature water bath at 90°C). If the surface tension is less than 30 mN / m, the capsule shell liquid may not be able to completely encapsulate the core liquid; if the surface tension is greater than 60 mN / m, the liquid may fail to break apart under shear force in the condensation bath to form spherical capsules, resulting in an incorrect morphology where micelles encapsulate the core liquid bundles.

[0037] In this invention, oil-absorbing paper, cotton towels, plant fiber towels, or synthetic fiber fabrics are all soft materials with absorbent properties for oily substances, and will not directly damage the wet capsules. The inventors discovered in experiments that if a small number of wet capsules are damaged by these soft materials during the tumble drying process, it is usually due to defects such as core-liquid misalignment, resulting in localized low strength (for example, core-liquid misalignment is prone to occur when the emulsifier dosage is too low). Therefore, during the finishing stage, these few defective wet capsules are destroyed and removed, and are not further transported to the subsequent drying step.

[0038] These soft materials, which have the ability to adsorb oily substances, are fed into the rotary drum along with the wet capsules, and the finishing time is 5 to 40 minutes. If the finishing time is too short, it may not be able to completely remove the residual condensate on the capsule surface, thus prolonging the subsequent drying time and affecting production efficiency; if the finishing time is too long, greater than 40 minutes, the repeated friction between the capsule surface and the adsorbent material may affect the stability of the capsule shell.

[0039] Furthermore, the flavor retention capacity of flavor compounds within a capsule is primarily determined by the capsule shell. At a microscopic level, there are two distinct relationships between the core liquid and the capsule shell: the mutual diffusion of the two substances and the barrier effect of the capsule shell on the core liquid. Therefore, improving the diffusion and barrier properties of the capsule shell can, to some extent, extend the stability of the capsule's flavor and its shelf life.

[0040] In this invention, the oxygen permeability of the capsule shell is less than 0.300 cm³ / m²·24h·0.1 MPa. The test was conducted using a C101H gas permeability testing system manufactured by Jinan Langguang Electromechanical Technology Co., Ltd., according to GB-1038. If the oxygen permeability of the capsule shell is high, it may cause oxidation of the flavor components in the core liquid, leading to changes in flavor and spoilage.

[0041] The diffusion rate of the core liquid to the capsule shell is less than 0.02%. Utilizing the Franz diffusion cell principle, the supply chamber contains the core liquid, the receiving chamber contains pure MCT, and a rubber membrane lies between the two chambers. The system is placed in an environment with a temperature of 22±1℃ and a humidity of 60±5%. Samples are taken from the receiving chamber every week for GC / MS analysis to detect whether flavor components have diffused into the MCT within the receiving chamber. If the rubber membrane has good diffusion properties, it may lead to continuous evaporation of the core liquid, affecting the flavor profile and causing bubbles to form in the capsule, thus impacting physical properties and machine adaptability.

[0042] The preparation method of this invention eliminates the need for solutions containing calcium or magnesium ions (typically calcium salts such as calcium chloride or other magnesium salts) as wet rubber reinforcing crosslinking agents. Therefore, it also eliminates the need for divalent metal complexing agents (typically metal salts such as trisodium citrate, trisodium phosphate, tetrasodium pyrophosphate, sodium hexametaphosphate, alginate, etc.) that can react with calcium and magnesium ions in the capsule shell, while still achieving good physical properties. This provides a new approach for the preparation of fragile capsules. Detailed Implementation

[0043] The following examples are used to explain the technical solutions of the present invention in a non-limiting manner.

[0044] In this invention, unless otherwise specified, "%" for concentration refers to weight percentage and ":" refers to weight ratio.

[0045] All raw materials used in this invention are food-grade raw materials that are available on the market.

[0046] Example 1

[0047] Weigh the following raw materials by weight and stir thoroughly to obtain capsule shell liquid, a total of 7 groups.

[0048] Table 1. Proportions of adhesive solutions for different samples

[0049]

[0050] The capsule shell liquid and core liquid were co-extruded into a medium-chain glycerol ester condensation bath using a capsule dripping device, and the wet capsules 1-7 were collected from the condensation bath.

[0051] Oil-absorbing paper was cut into strips, with the amount of paper used being 10% of the total weight of the wet capsules. The strips of oil-absorbing paper and the wet capsules were placed together in a rotating drum and rotated at 19 r / min for 20 minutes to absorb any residual condensate from the wet capsules onto the oil-absorbing paper. The capsules were then dried under room temperature conditions to obtain fragile capsule samples 1-4 and reference standards 1-3. Reference standard 1 used the same formulation as sample 1, but without an emulsifier. Reference standard 2 used the same formulation as sample 2, but without a binder.

[0052] On the other hand, wet capsule samples 1 and 2 were soaked in pure water for 5 minutes, and after filtering off the water on the surface of the capsules, they were dried under the same indoor conditions to obtain reference standards 4 and 5, respectively.

[0053] The performance of each sample was determined using the methods described above, as shown in Table 2.

[0054] Table 2 Physical performance indicators of different samples

[0055]

[0056] Comparative results show that, while ensuring good strength, the capsules prepared by the method of this invention have an oxygen permeability of less than 0.300 cm³ / m²·24h·0.1 MPa, which effectively prevents the oxidation of flavor components in the core liquid, thereby extending the product's shelf life and preventing changes in capsule flavor. For products with long transportation periods, it effectively prevents flavor changes in the capsule products during extended transportation. Furthermore, due to the low diffusion rate of the core liquid to the capsule shell (less than 0.02%), core liquid evaporation is prevented, ensuring the flavor profile of the core liquid while maintaining the physical properties and machine adaptability of the capsule shell.

[0057] Drying methods are of great significance for reducing the oxygen permeability of capsules and the diffusion rate of the core liquid to the capsule shell. After treating wet capsules with oily adsorbents, the subsequent drying time (under the same temperature conditions) is shorter, the time required for the capsule shell to be completely shaped is shortened, and the migration between the core liquid and the capsule shell material is further avoided, thereby improving the performance of the capsule shell.

[0058] In summary, this invention does not use solutions containing calcium or magnesium ions as reinforcing cross-linking agents for the capsule shell. Therefore, it also eliminates the need for divalent metal complexing agents (typically metal salts such as trisodium citrate, trisodium phosphate, tetrasodium pyrophosphate, sodium hexametaphosphate, alginate, etc.) that react with calcium and magnesium ions in the capsule shell, while still achieving good physical properties. Furthermore, by treating the wet capsules with an oily adsorbent before drying, the capsule's performance is further improved. This invention provides a new approach for the preparation of fragile capsules.

Claims

1. A fragile capsule, said capsule comprising a capsule shell and a core liquid, characterized in that... The capsule shell contains, by weight, 1 to 10 parts gelling agent, 1 to 5 parts toughening agent, 0.5 to 3 parts adhesive, 0.1 to 1 part emulsifier and 0 to 1 part pigment.

2. The fragile capsule according to claim 1, characterized in that... The gelling agent is selected from one or more combinations of agar, xanthan gum, carrageenan, konjac gum, gellan gum, or locust bean gum; The toughening agent is selected from one or more combinations of sorbitol, glycerin, triethyl citrate or polyethylene glycol; The adhesive is selected from one or more combinations of sodium carboxymethyl cellulose, pullulan, or modified starch hydroxymethyl cellulose; The emulsifier is selected from one or more combinations of Span, Tween, mono-fatty acid glycerides, sucrose fatty acid esters or sodium octenyl succinate starch. The pigment is an edible pigment.

3. A method for preparing a fragile capsule, the method comprising the following steps: (1) Preparation of capsule shell liquid Weigh 1-10 parts of gelling agent, 1-5 parts of toughening agent, 0.5-3 parts of adhesive, 0.1-1 parts of emulsifier, 0-1 parts of pigment and 40-120 parts of purified water by weight, mix and stir until uniform to obtain capsule shell liquid, let stand to remove bubbles and set aside for later use. (2) Drip The capsule shell liquid and the core liquid are co-extruded into a condensation bath using a capsule dripping device, and wet capsules are collected from the condensation bath. (3) Organize The wet capsules and oily absorbent obtained in step (2) are placed in a rotating drum device for sorting. The oily absorbent is one or a combination of oil-absorbing paper, cotton towel, plant fiber towel or artificial fiber fabric. The initial weight of the oily absorbent is 1 to 10% of the weight of the wet capsule. The sorting time is 5 to 40 minutes and the rotating drum speed is 15 to 25 r / min. (4) Drying The prepared capsules are dried at 15-40℃ and 30-70% humidity to obtain fragile capsules.

4. The preparation method according to claim 3, characterized in that... The gelling agent is selected from one or more combinations of agar, xanthan gum, carrageenan, konjac gum, gellan gum, or locust bean gum; The toughening agent is selected from one or more combinations of sorbitol, glycerin, triethyl citrate or polyethylene glycol; The adhesive is selected from one or more combinations of sodium carboxymethyl cellulose, pullulan, or modified starch hydroxymethyl cellulose; The emulsifier is selected from one or more combinations of Span, Tween, mono-fatty acid glycerides, sucrose fatty acid esters or sodium octenyl succinate starch. The pigment is an edible pigment.

5. The preparation method according to claim 3, characterized in that... The core fluid is an oily liquid.

6. The production method according to claim 1, characterized in that... The wet capsules obtained in step (2) have a burst strength greater than 0.5N, a pressure value of 8~22N, and a compression ratio of 15~60%.

7. The production method according to claim 1, characterized in that... In step (2), the condensation bath uses one or more combinations of medium-chain glycerides, soybean oil, olive oil, and peanut oil.

8. The use of the fragile capsule of claim 1 in tobacco products.

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