Flavored core-shell capsules film-coated with polyvinylidene chloride

Abstract

The present invention relates to a core-shell seamless breakable capsule, the shell of which comprises a hydrocolloid and the core of which comprises a flavouring and a lipophilic solvent, the shell being coated with a film coating layer which confers water resistance, the film coating layer comprising polyvinylidene chloride, an oral use pouch comprising said capsule, a consumable product comprising said capsule, a tobacco heating device comprising said consumable product, a method for producing said capsule, the use of said capsule as an additive for immediate sustained release of flavouring, and a method for flavouring an oral use pouch.

Description

[Technical field]

[0001] The present invention relates to a core-shell seamless breakable capsule, the shell of which comprises at least one hydrocolloid and which is coated with at least one layer of a polyvinylidene chloride film coating that confers water resistance, the capsule intended for incorporation into a tobacco heating device or product in an oral pouch. [Background technology]

[0002] Aromatic compounds are often sensitive and unstable molecules due to their physicochemical properties, making them difficult to use directly as flavorings. Encapsulation, which utilizes the film-forming, absorbing, and / or emulsifying properties of polymers to trap or coat sensitive compounds in microcapsules, is an increasingly used technique that meets several expectations. Indeed, the main purpose of encapsulation is to establish a barrier between a substance and its surrounding environment. In this case, the encapsulation of food flavorings is well known as a process to protect volatile flavoring substances from evaporation and from degradation that may be caused by contact with oxygen in the air, heat, humidity, or other compounds. There are two main types of capsule structure: matrix capsules, where the flavoring is dispersed in a support material, and core-shell capsules, where the flavoring is trapped in a shell (or membrane). In recent years, many applications of flavored capsules have been developed, especially in smoking devices such as cigarettes and cigars, tobacco heating devices, or oral use pouches (also called snus). For example, reference may be made to patent application WO 07-010407, which describes a smoking device in the form of a cigarette incorporating flavoured core-shell capsules in a filter, the capsules having hardness and deformation properties conferred by the amount of hydrocolloid added.

[0003] Patent applications WO2011042206 and WO2007037962 describe oral use pouches comprising capsules and / or microcapsules having a conventional matrix and / or core-shell structure.

[0004] Patent application WO2011054516 describes an oral use pouch comprising a capsule coated with two different coatings, a first coating based on a methacrylic acid polymer and a second coating based on paraffin wax.

[0005] Patent applications WO2017198876, WO2017198874 and WO2020089120 describe tobacco heating devices comprising at least one core-shell capsule encapsulating at least one flavoring. The capsules described in these documents have specific features regarding the compounds used in the core of said capsules in order to improve the quality of the aerosol formed.

[0006] However, despite these advantages, all these core-shell capsules of the prior art, whose shells are made of biopolymers, have a major drawback in that they are not waterproof, specifically when completely immersed in water. Because they are not waterproof, the prior art capsules cannot withstand the very high humidity found in tobacco heating devices or oral pouch products. Thus, the applications of flavored capsules listed above do not satisfy consumers. The traditional method of preventing capsule deterioration due to humidity is to add a film coating layer using a moisture-proofing agent such as wax, specifically carnauba wax, candelilla wax or beeswax, shellac (in alcoholic or aqueous solutions), ethyl cellulose, hydroxypropyl methylcellulose, hydroxypropyl cellulose, or polyvinyl alcohol. However, as their names suggest, these materials are moisture-proof layers or are called moisture-proof layers, which means that they allow the capsule to withstand a certain humidity for a certain period of time. However, after a while, the capsule will inevitably collapse.

[0007] Surprisingly, the applicant has discovered that adding a layer of polyvinylidene chloride-based film coating onto the capsule shell allows the capsule to withstand water and therefore become waterproof. The capsule according to the invention can withstand a 60°C immersion test for 6 minutes (conditions found in tobacco heating devices) or a 37°C dissolution test for 20 minutes carried out according to the USP, DAB, IP and EUR pharmacopoeias. In both cases, the polyvinylidene chloride-coated capsule does not disintegrate and retains its resistance to bursting and its ability to emit an audible popping sound upon rupture. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 07-010407 Brochure [Patent Document 2] International Publication No. 2011042206 Brochure [Patent Document 3] International Publication No. 2007037962 Brochure [Patent Document 4] International Publication No. 2011054516 Brochure [Patent Document 5] International Publication No. 2017198876 Brochure [Patent Document 6] International Publication No. 2017198874 Brochure [Patent Document 7] International Publication No. 2020089120 Brochure Summary of the Invention [Problem to be solved by the invention]

[0009] This disclosure improves the situation described above.

[0010] The present invention thus relates to a seamless breakable capsule comprising a shell encapsulating a lipophilic flavouring core, said capsule being suitable for incorporation into a consumer product intended for use in a tobacco heating device or an oral use pouch. [Means for solving the problem]

[0011] More precisely, the first object of the present invention is to A core-shell seamless breakable capsule, the shell of which comprises a hydrocolloid and the core of which comprises a flavoring and a lipophilic solvent, The shell is coated with a film coating layer that provides water resistance, the film coating layer comprising polyvinylidene chloride.

[0012] A second object of the invention relates to a pouch for oral use with immediate and sustained release of flavour, characterized in that it comprises one or more capsules containing a flavour according to the invention, said capsules being placed within said pouch.

[0013] A third object of the present application relates to a consumer product comprising a filter and tobacco, in particular intended for use in a tobacco heating device, characterized in that said filter comprises one or more capsules according to the invention.

[0014] A fourth object of the invention relates to a tobacco heating device, characterised in that it comprises a consumer product according to the invention.

[0015] A fifth object of the present invention is a method for producing a seamless breakable capsule comprising a shell and a core, comprising the steps of: (A) co-extruding a hydrophilic external liquid phase comprising 4% to 95% by weight of a hydrocolloid relative to the total dry weight of the shell and a lipophilic internal liquid phase comprising 5% to 70% by weight of a flavoring agent relative to the total weight of the core; Step (B) of solidifying and / or gelling the surface of the capsules obtained in step (A) by immersion in a fluid having a temperature between 1° C. and 25° C.; Step (C) of drying the capsules obtained in step (B); (D) film-coating the capsules obtained in step (C) by an air spray coating process using a film-coating solution comprising polyvinylidene chloride and water; and step (E) of recovering the capsules obtained in step (D).

[0016] A sixth object of the invention relates to the use of the capsule according to the invention as an additive for immediate sustained release of flavour, said capsule being placed in an oral use pouch or a consumer product comprising a filter and tobacco, in particular intended for use in a tobacco heating device.

[0017] A seventh object of the present invention is a method for a consumer to flavour a product contained in an oral use pouch according to the invention, comprising: a consumer placing the product contained in an oral pouch between the consumer's gums and cheek or upper lip, typically for 5 to 60 minutes; and at any time during consumption, the consumer bursts a capsule contained in the oral use pouch between the consumer's teeth to release flavor contained in the capsule into the consumer's mouth. [Brief description of the drawings]

[0018] Other features, details and advantages will become apparent upon reading the following detailed description and examining the accompanying drawings.

[0019] [Figure 1] 1 illustrates different compositions of the core-shell capsule according to the present invention before film coating. [Diagram 2] 1 illustrates different PVDC / TEC film coating solutions and different dry deposits applied to capsules according to the present invention. [Diagram 3] The results of capsule hardness, deformation, and audible popping before and after immersion and dissolution tests are described. [Figure 4] 1 illustrates different compositions of the core-shell capsule according to the present invention before film coating. [Diagram 5] 1 illustrates different formulations of PVDC / TEC film coating solution applied to capsules according to the present invention and different dry deposits. [Figure 6] The results of capsule hardness, deformation, and audible popping before and after immersion and dissolution tests are described. [Figure 7] 1 illustrates the results of dissolution testing performed on capsules in Example 3. [Figure 8] 1 illustrates the results of the immersion test carried out on the capsules in Example 3. [Figure 9] Explain the effect of capsule size on film coating thickness. [Figure 10] Explain the effect of capsule size on film coating thickness. [Figure 11] Explain the effect of capsule size on film coating thickness. [Figure 12]1 shows a photograph taken by a scanning electron microscope of a cross section of a capsule according to Example 1 in which the film coating layer is separated from the shell. [Figure 13] 1 shows a photograph taken by a scanning electron microscope of a cross section of a capsule according to Example 1 in which the film layer is not separated from the shell. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] In the present invention, the capsule is a core-shell seamless breakable capsule, the shell of which comprises a hydrocolloid and the core of which comprises a flavoring and a lipophilic solvent; The shell is coated with a film coating layer that provides water resistance, the film coating layer comprising polyvinylidene chloride.

[0021] In the present invention, the term "capsule" refers to a membrane encapsulation system of a composition, said capsule having a core-shell structure, in which the encapsulated composition constitutes a "core" that is enclosed within a shell (or envelope) made of a coating material.

[0022] Capsules according to the present invention differ from matrix systems, in which the composition is dispersed in a continuous matrix of material, commonly referred to by the term "microspheres."

[0023] The seamlessness of the capsule makes it possible to avoid the presence of a breaking point located in the seal between the two half shells forming the capsule, as is the case in so-called "softgel" capsules, and therefore has the advantage that leakage associated with seam rupture is avoided.

[0024] The term "breakable capsule" refers to a capsule as defined above whose shell can be broken by pressure applied to its exterior surface when the capsule is held between the fingers or teeth.

[0025] The capsules according to the present invention have the advantage of being water-resistant or waterproof. The term used herein is water-resistant rather than moisture-resistant, and the distinction between these two properties is clear. In fact, conventional capsules coated with additives such as ethyl cellulose, beeswax, or other such materials are moisture-resistant, meaning that these capsules of the prior art can withstand a certain environmental level of humidity for a certain period of time. However, after a certain period of time, these capsules of the prior art will begin to disintegrate. Under no circumstances can these capsules be immersed in warm water (37°C or 60°C for 20 minutes or 6 minutes, respectively) to retain their shape and resistance to bursting.

[0026] Polyvinylidene chloride, also called PVDC, is a vinyl polymer. It is made from the monomer vinylidene chloride by vinyl free radical polymerization. Polyvinylidene chloride copolymers are characterized by excellent chemical resistance and high impermeability to water vapor, gas, oil and grease. For these reasons, PVDC is commonly used in stretch films for protecting food. However, to the applicant's knowledge, PVDC has not been used as a film coating agent until now, especially in the specific case of encapsulation. When PVDC is used as a film coating agent, it allows the capsule according to the present invention to have water resistance when exposed to certain conditions.

[0027] The capsule according to the present invention has a burst resistance (also called hardness or burst strength) of 0.5 kgf to 20 kgf (1 kilogram weight corresponds to 9.81 Newtons).

[0028] The burst resistance is measured by the crushing force required to break the capsule. More preferably, the capsule has a burst resistance of 1 kgf to 8 kgf, or more preferably, a burst resistance of 1 kgf to 4 kgf. The burst resistance of the capsule is measured by a TA.XT+ texture analyzer using a P0.5 piston at a speed of 0.50 mm / s for 20 capsules.

[0029] When the capsule is broken, a deformation phenomenon occurs. In order for the capsule to burst with an audible popping sound, it must be deformed to a certain limit, beyond which it will not burst (it will collapse on itself). For this, the capsule according to the invention must have a deformation percentage of less than 66%. This percentage corresponds to the ratio of the final diameter of the capsule when pressed to the breaking limit to the initial diameter of the capsule, multiplied by 100.

[0030] In particular, the capsules according to the invention retain their resistance to bursting when subjected to an immersion test carried out for 6 minutes in demineralised water at 60° C. with stirring at 500 rpm. "Retaining resistance to bursting" is understood to mean that the resistance to bursting of the capsule does not change by more than ±15% compared to the value of the resistance to bursting before the immersion test.

[0031] The capsule according to the invention therefore allows for a very wide range of applications where water resistance is required.

[0032] Moreover, the capsules according to the invention retain their burst resistance when subjected to a dissolution test in water at 37°C for 20 minutes. In this specification, "retains burst resistance" is understood to mean that the burst resistance of the capsule does not change by more than ±15% compared to the burst resistance value before the dissolution test. Indeed, surprisingly, the applicant has also discovered that the capsules according to the invention retain their burst resistance quality when subjected to dissolution tests according to the USP, DAB, IP and EUR pharmacopoeias. In fact, the capsules do not dissolve after being subjected to said test at 37°C for 20 minutes, retain their spherical shape, and retain their burst resistance and ability to emit an audible popping sound upon bursting.

[0033] Therefore, to obtain these specific burst resistance values ​​under such conditions (60°C, 6 min water immersion test and 37°C, 20 min water dissolution test), the capsule is coated with a layer containing polyvinylidene chloride. Preferably, the amount of polyvinylidene chloride is 50%-100% by weight, specifically 60%-99%, specifically 70%-98%, more specifically 80%-97%, and even more specifically 90%-96%, based on the total dry weight of the film coating layer. Polyvinylidene chloride is applied by a process of film coating by air spraying (also called "pneumatic spray") the capsule with a solution containing polyvinylidene chloride diluted in water as a solvent.

[0034] In a first embodiment, polyvinylidene chloride is used alone.

[0035] In a second embodiment, polyvinylidene chloride is used in a mixture with at least one plasticizer to compensate for the fact that PVDC can be brittle under some conditions. The plasticizer can be chosen from triethyl citrate (TEC), sugar alcohols such as glycerol, sorbitol and maltitol, polyvinyl alcohol, monosaccharides, disaccharides, oligosaccharides, triacetin, polyethylene glycol, or mixtures thereof. Advantageously, triethyl citrate is used as the plasticizer mixed with polyvinylidene chloride.

[0036] The plasticizer may be used in an amount of 0% to 20% by weight, based on the total dry weight of the film coating layer.

[0037] Advantageously, the thickness of the film coating layer is between 1 μm and 200 μm, preferably between 3 μm and 100 μm, and even more preferably between 3 μm and 50 μm.

[0038] One advantage of the capsules of the present invention is that they emit an audible popping sound upon rupture, allowing the consumer to "know" that the capsule has actually burst, if desired.

[0039] Advantageously, the shell of the capsule according to the invention comprises a hydrocolloid. Preferably, the hydrocolloid according to the invention is a biobased polymer. A biobased polymer is understood to mean a synthetic polymer obtained partially (generally >20%) or entirely from derivatives of biomass origin. The biobased nature of a polymer can be determined according to the ASTM D6866 standard, in particular from the C14 content of the polymer.

[0040] The hydrocolloid in the capsule shell is selected from gellan gum, gelatin (animal or biotechnological origin), collagen, alginates, carrageenan, agar, chitosan and its derivatives, pectin, gum arabic, gum ghatti, pullulan gum, mannan gum, vegetable proteins, or mixtures thereof. The amount of said hydrocolloid(s) present in the shell is between 4% and 95% by weight, preferably between 4% and 75% by weight, and even more preferably between 20% and 50% by weight, based on the total dry weight of the shell. In a preferred embodiment, the hydrocolloid selected is gellan gum, used alone or in combination with gelatin. In another preferred embodiment, the hydrocolloid is selected from carrageenan.

[0041] Bulking agents may also be included in the composition of the shell, which is understood to mean any suitable material capable of increasing the percentage of dry matter in the external liquid phase and thus the dry matter after co-extrusion into the shell of the resulting capsule. Increasing the amount of dry matter in the capsule shell solidifies said shell and makes it more physically resistant. Preferably, the bulking agent is selected from the group comprising starch derivatives such as dextrin, maltodextrin, cyclodextrin (alpha, beta or gamma), hydroxypropyl starch derivatives or cellulose derivatives such as hydroxypropylmethylcellulose (HPMC), hydroxypropylcellulose (HPC), methylcellulose (MC), carboxymethylcellulose (CMC), polyvinyl alcohols, polyols or mixtures thereof. Dextrin is the preferred bulking agent. The amount of bulking agent in the shell is up to 98.5% by weight, preferably between 25% and 95% by weight, more preferably between 40% and 80% by weight, even more preferably between 50% and 60% by weight, based on the total dry weight of the shell.

[0042] Advantageously, the shell may contain a coloring agent that can make the capsule containing the flavor composition more attractive. The coloring agent is preferably selected from food-derived dyes and pigments. The coloring may be within the body of the shell or may be applied by an additional coating process.

[0043] In one embodiment, the dry weight of the shell is from 5% to 70% by weight, preferably from 8% to 50% by weight, more preferably from 8% to 20% by weight, based on the total dry weight of the capsule.

[0044] Preferably, the capsule has a diameter of 1 mm to 6 mm, more preferably, the capsule has a diameter of 2.5 mm to 5 mm.

[0045] Advantageously, the shell thickness of the capsule (without film coating) is between 10 μm and 300 μm, preferably between 20 μm and 200 μm, and even more preferably between 30 μm and 150 μm.

[0046] There is a relationship between the thickness of the film-coating layer, the diameter of the capsule, and the burst resistance of the film-coated capsule. In fact, the applicant has demonstrated that a certain ratio of the thickness of the film-coating layer to the diameter of the capsule can ensure that the film-coated capsule has the required burst resistance.

[0047] Ratio (R) = (thickness of film coat layer x 2) / capsule diameter.

[0048] Advantageously, said ratio is greater than or equal to 0.18, advantageously greater than or equal to 0.2, more advantageously greater than or equal to 0.3, even more preferably greater than or equal to 0.4.

[0049] The capsule core comprises one or more lipophilic solvents commonly used in the food industry.

[0050] In a preferred embodiment, these lipophilic solvents may be triglycerides, in particular medium-chain triglycerides (MCT), in particular caprylic and capric triglycerides, or mixtures of triglycerides such as vegetable oils, olive oil, sunflower oil, corn oil, peanut oil, grapeseed oil, wheat germ oil, mineral oil and silicone oil, or mixtures thereof.

[0051] The amount of lipophilic solvent in the core of the capsule according to the present invention is about 0.01% to 90%, preferably 25% to 75%, of the total weight of the capsule.

[0052] The core may also contain a perfume comprising one or more perfume molecules as are commonly used in the formulation of perfume compositions. Such perfume materials are described, for example, in "Common Fragrance and Flavor Materials", Wiley-VCH, Weinheim, 2006.

[0053] Fragrance substances may in particular include aromatic, terpene and / or sesquiterpene hydrocarbons, more particularly essential oils, alcohols, aldehydes, phenols, various forms of carboxylic acids, aromatic acetals or ethers, nitrogen heterocycles which may be aromatic or non-aromatic, ketones, sulfides, disulfides, and mercaptans.

[0054] The core may also contain one or more fillers, such as those used in perfume emulsions. Examples include dammar gum, wood resins of the ester gum type, sucrose acetate isobutyrate (SAIB), or brominated vegetable oils. The function of these fillers is to adjust the density of the liquid core.

[0055] The core may also include one or more sweeteners, which may be in the form of an ethanol solution or suspension. Examples of suitable sweeteners may include, but are not limited to, aspartame, saccharin, NHDC, sucralose, acesulfame, neotame, stevia and its derivatives. The core may also include one or more "sensory" flavoring agents that provide either a cooling or warming effect in the mouth. Suitable cooling agents may include, but are not limited to, menthyl succinate and its derivatives, specifically Physcool®. Suitable warming agents may include, but are not limited to, vanillyl ethyl ether or gold root.

[0056] Examples of suitable complex flavors include vanilla, coffee, chocolate, cinnamon, mint, and the like.

[0057] When the capsule core contains several flavors, the total amount of the flavor mixture is 5% to 60% by weight, based on the total weight of the capsule core.

[0058] A second object of the present invention relates to an oral use pouch with immediate and sustained release of flavour, characterized in that it comprises one or more capsules containing said flavour as defined above, said capsules being placed in the oral use pouch. One application of the capsules according to the invention is their use to flavour porous oral pouches, also called snus, with or without tobacco. The main advantage of using capsules in these snus products is to provide flavour by releasing the flavour immediately and sustained in the form of a "burst". Another advantage is that the consumer can choose the exact moment when the flavoured capsule contained in the pouch can burst to release the flavouring agent. In fact, snus consumers are accustomed to holding said pouch in their mouth for up to an hour. It is therefore important that the capsules of the present invention can be burst by the consumer experiencing both an audible pop and the sensation of bursting said capsule between the teeth. As a result, the capsule must be able to withstand being left for a long period of time (average 1 hour) in the temperature and humidity environment (37°C, pH 6.8 to 7.5) created by saliva, while maintaining sufficient hardness and deformation characteristics.

[0059] In a first embodiment, the pouch according to the invention contains tobacco in the form of leaves or in the form of tobacco powder. This type of product contained in an oral use pouch corresponds to conventional snus in the sense that it contains tobacco. The tobacco present in the pouch has a very high humidity level, which makes the water resistance of the capsule important. In fact, taking into account a tobacco humidity of about 40%, the humidity due to saliva when the pouch is placed in the mouth, and the temperature in the mouth, the overall humidity level can reach 95%.

[0060] In a second embodiment, the oral use pouch according to the invention does not contain tobacco. In this embodiment, the tobacco is replaced by a mixture containing cellulose acetate fibers, a large amount of humectant, and a pH adjuster, with or without nicotine. This new type of product has been developed in recent years to circumvent the regulations that prohibit snus containing tobacco. However, these products that reproduce the effect of traditional snus have the same drawbacks as traditional tobacco-containing snus, in the sense that the humidity level is high due to the humectant present in the pouch. Also, the pouches, whether they contain tobacco or not, are packed in small boxes with very high humidity, due to the need to ensure the quality of the product before consumption.

[0061] The pouch according to the present invention contains one or more capsules.

[0062] In one embodiment, the pouch according to the present invention further comprises vegetable fiber, and / or encapsulated or non-encapsulated flavoring agents, and / or fillers, and / or humectants disposed within the pouch.

[0063] The oral use pouch may also contain other flavouring agents present in various forms, specifically encapsulated or non-encapsulated.

[0064] A third object of the invention relates to a consumer product comprising a part containing a filter and another part containing tobacco, characterized in that the filter contains one or more capsules according to the invention.

[0065] Faced with declining cigarette sales, the tobacco industry is developing new products known as "reduced harm" products. These "reduced harm" products include tobacco heating devices that can electrically heat tobacco in "mini-cigarettes" or "capsules" to 180°-350° (600°-900° for combustible cigarettes) to release an aerosol. These devices heat tobacco without burning it, dispersing nicotine by aerosolizing it without combustion or smoke.

[0066] One application of the capsules of the present invention is for use in flavoring the aerosol (or "smoke") formed when used in a tobacco heating device. When a tobacco heating device is used, the aerosol formed has a high moisture content and can reach temperatures of 50°C to 70°C. The capsules are ideal candidates for this application, as they can withstand a water immersion test at 60°C for 6 minutes (corresponding to the duration of the device's consumption) while remaining burst-resistant.

[0067] The capsule according to the invention can be incorporated into a consumer product comprising one part containing a filter (made of cellulose acetate, like conventional cigarettes) and another part containing tobacco. In this way, the capsule according to the invention, placed in the filter, can be burst at any time by the consumer while retaining the required properties of hardness and deformation, so that said consumer knows exactly when to burst said capsule to release its flavouring contents into the filter.

[0068] The consumable product comprises one or more capsules according to the invention.

[0069] Advantageously, the consumer product according to the invention is disposable and intended to be used as a tobacco refill for a tobacco heating device.

[0070] A fourth object of the invention relates to a tobacco heating device, characterized in that it comprises a consumer product according to the invention. As the name suggests, a tobacco heating device heats tobacco to a temperature between 30°C and 300°C, which is different from a conventional cigarette, which burns the tobacco and reaches a temperature between 700°C and 800°C. In this type of device, the heated tobacco triggers the formation of an aerosol that can be flavored, specifically by the capsule according to the invention. The consumer product according to the invention is inserted into a smoking device. When the consumer switches on the device, the tobacco is heated by the device. The consumer can at any time break the capsule of the invention, which is located in the filter of the consumer product, so that the aerosol formed by heating the tobacco can be flavored.

[0071] A fifth object of the present invention is a method for producing a seamless breakable capsule comprising a shell and a core, comprising the steps of: (A) co-extruding a hydrophilic external liquid phase comprising 4% to 95% by weight of a hydrocolloid relative to the total dry weight of the shell and a lipophilic internal liquid phase comprising 5% to 70% by weight of a flavoring agent relative to the total weight of the core; Step (B) of solidifying and / or gelling the surface of the capsules obtained in step (A) by immersion in a fluid having a temperature between 1° C. and 25° C.; Step (C) of drying the capsules obtained in step (B); (D) film-coating the capsules obtained in step (C) by an air spray coating process using a film-coating solution comprising polyvinylidene chloride and water; and step (E) of recovering the capsules obtained in step (D).

[0072] The co-extrusion process is the simultaneous extrusion of two liquids, a hydrophilic external liquid phase and a lipophilic internal liquid phase. The co-extrusion process includes three main stages: droplet formation, shell solidification, and capsule collection. The capsules of the present invention may be produced by any suitable co-extrusion process. Preferably, the capsules are produced by the apparatus and method described in EP 513603.

[0073] In one embodiment of the present invention, after the co-extrusion step, a solidification step is carried out while the capsules are kept at low temperature, for example by contacting them with a cold fluid, in order to ensure good gelation of the shell. The cold fluid is preferably a cold oil. Within the meaning of the present invention, low temperature is understood to mean a temperature between 1° C. and 25° C., preferably between 2° C. and 10° C., more preferably between 4° C. and 6° C. The capsules are then centrifuged to remove excess oil, optionally washed with an organic solvent, also to remove excess oil, and dried. In one embodiment of the present invention, after the co-extrusion step and optionally after the solidification step, the capsules are centrifuged.

[0074] In another embodiment of the invention, the capsules are co-extruded, centrifuged, and optionally immersed in a solution or emulsion containing additives or chelating agents capable of hardening the capsule shell.

[0075] The chelating agent may be ethanol or any other anhydrous organic solvent maintained at a temperature between 0°C and 25°C, more specifically between 10°C and 20°C.

[0076] The chelating agent may be a calcium ion bath, such as a calcium chloride, dicalcium phosphate, or calcium sulfate bath, having a pH of 5 to 8. The temperature of the calcium ion bath is preferably 0°C to 25°C, preferably 10°C to 20°C.

[0077] After the immersion step (B), the capsules are dried (step (C)), for example in an air stream of controlled temperature and humidity. The drying air has a relative humidity of 20% to 60%, preferably 30 to 50%, and a temperature of 15° C. to 60° C., preferably 35° C. to 50° C. If necessary, surface oils can be removed using adsorbents such as silica or starch (0.1 to 5%, preferably 0.1 to 2%) added during drying.

[0078] Step (D) is the key step of film-coating the capsules, during which the capsules are provided with an outer polyvinylidene chloride layer. "Film-coating" is understood to mean a process by which a thin layer of film-coating agent can be deposited on a support. In this case, the film-coating process is carried out by a process of air-spraying a solution of the film-coating agent (in the present invention, polyvinylidene chloride) in order to transport the generated microdroplets onto the support (in the present invention, the capsules). For these reasons, the film-coating process is clearly distinguished from coating processes that make it possible to cover a support with a thick layer by processes other than spraying without the use of a carrier fluid (and thus without the use of air).

[0079] The film coating step is carried out by an air spray process using a solution containing at least polyvinylidene chloride and water. In a first embodiment, polyvinylidene chloride is used as a 8% to 50% by weight solution diluted in water.

[0080] Preferably, the film coating solution comprises polyvinylidene chloride, water and at least one plasticizer selected from triethyl citrate, glycerol, polyhydric alcohols such as sorbitol and maltitol, polyvinyl alcohol, monosaccharides, disaccharides, oligosaccharides, triacetin and polyethylene glycol.

[0081] The capsules produced by the process of the present invention are essentially or perfectly spherical and uniform in size.

[0082] A sixth object of the invention relates to the use of the capsule according to the invention as an additive for immediate sustained release of flavouring, said capsule being placed in an oral use pouch or a consumer product comprising a filter and tobacco, in particular intended for use in a tobacco heating device. In this embodiment, the capsule, when broken in the oral use pouch or consumer product, bursts with an audible popping sound and releases the flavouring contained therein.

[0083] A seventh object of the present invention is a method for a consumer to flavour a product contained in an oral use pouch according to the invention, comprising: A consumer places the oral pouch between the consumer's gums and cheek or upper lip, typically for 5 to 60 minutes; and a consumer bursting a capsule contained in the oral pouch between the consumer's teeth to release flavor contained in the capsule into the consumer's mouth.

[0084] The invention will now be illustrated by the following examples which should not be considered as limiting the scope of the invention but which should be read with reference to the drawings. EXAMPLES

[0085] Example 1 1. Composition of capsules before film coating (Table 1) Percentages are expressed by weight. [Table 1] F = Ingredients contained in capsule fragrance S = Ingredients contained in the capsule shell

[0086] Preparation of capsule films: Weigh the water, sodium citrate, glycerin and sorbitol into a beaker and stir and heat the mixture to 85°C. Weigh out the gellan gum and add it to a beaker. Weigh out the gelatin, dextrin, starch and colorant and add them to a beaker. The mixture is stirred until the ingredients are dissolved and then degassed.

[0087] Co-extrusion steps: The film solution was pumped through a concentric nozzle at 85°C. A flavored liquid base solution consisting of menthol, mint essential oil, and aroma molecules in MCT is separately pumped into the concentric nozzle at room temperature; The two solutions were simultaneously extruded through a coaxial nozzle into cold (approximately 10°C) MCT, and the coextrusion instantly formed two droplets, called the core and the shell, in a ratio of approximately 90 / 10, one inside the other. The drop in temperature causes the outer shell solution to gel around the fragrance core, The gelled wet capsules were collected in cold MCT and allowed to solidify for 1 hour at 4°C. Remove MCT by centrifugation. After mixing, the capsules are dried in a dryer using hot air (about 45°C) and a drying aid (silica). The dried capsules are collected and sieved.

[0088] 2. Preparation of film coating solution (Table 2) Percentages are expressed by weight. [Table 2]

[0089] procedure: Weigh out water into a beaker, Weigh out the polymer (PVDC) and plasticizer (TEC). The polymer solution and plasticizer are added while stirring, and the mixture is left at room temperature for 15 minutes. Controlled agitation to avoid foam formation, Maintain gentle agitation during the film coating process.

[0090] Table 3 below shows the characteristics of the film coating solutions. [Table 3]

[0091] 3. Film coating process: The capsules obtained after coextrusion are introduced into a film coating turbine, The film coating solution was weighed on a balance. Installing the desired spray nozzles, pre-filled and purged with the film coating material, into the film coating turbine; Rotating the turbine at a desired rotational speed; Preheat the incoming air to 40°C at the desired flow rate, Once the temperature of the capsules to be coated (approximately 26°C) is reached, spraying of the polymer solution begins. When the desired percentage of dry deposit is reached (i.e., the desired weight of the film coating solution applied is reached), spraying is stopped; A stabilization step is carried out by reducing the temperature of the inlet air (approximately 20 min).

[0092] 4. Analysis of capsules before and after film coating, immersion test and dissolution test (Table 4) The film-coated capsules are subjected to a water immersion test at 60° C. for 6 minutes according to the following protocol. Preparation: Preheat the water used in the test, Count 200 capsules using a counting plate, To remove residual oil or other trace impurities, the capsules are immersed in 200 ml of demineralized water for 20 seconds while stirring at room temperature (250 RPM); The capsules are collected using a sieve and lightly dried on cotton wool.

[0093] Immersion test: Start a water bath and set the temperature to 60 °C so that the internal temperature of the beaker is 60 °C ± 1 °C. Weigh 200g of demineralized water into a beaker. Place the beaker in the water bath, insert the magnetic bar and begin stirring at 500 rpm. Put the capsule into the beaker. The duration is 6 minutes. After 6 minutes, record the color of the water, count the number of capsules that have burst or floated to the surface, and record any odor (corresponding to flavorings). The capsules are collected on a sieve, spread on cotton wool and allowed to dry. The appearance of the capsule is observed and an analysis is performed.

[0094] The film-coated capsules are subjected to a dissolution test in water at 37° C. for 20 minutes according to the following protocol. Heat the water bath's water tank to 39°C. Water filtered by reverse osmosis is introduced into the test beaker; Once the water has reached 37°C, measure the pH and it should be between 6.8 and 7.5. 21 capsules were introduced into the wells, Set the timer for 20 minutes.

[0095] Get started with the steps below: The well is lowered 55 mm at a rate of 30 strokes per minute. The capsules are kept completely immersed in water at 37°C. After 20 minutes the capsule is removed, wiped lightly with cotton wool and the analysis is carried out.

[0096] Analytical results of capsules before and after film coating, and after immersion and dissolution tests (Table 4) [Table 4]

[0097] Analysis of capsules before and after film coating, after immersion test and dissolution test (Table 4)

[0098] As can be seen from Example 1, the film-coated capsules according to the present invention: Burst resistance (hardness) equivalent to that measured before the immersion test and dissolution test, The material retains both the ability to emit an audible popping sound (greater than 80db) equivalent to that measured prior to the immersion test and the dissolution test.

[0099] Example 2 Effects of "dry deposits": Dry weight is a factor that reflects the thickness of the film coating layer. It is calculated by taking the ratio ((final capsule weight-initial capsule weight) / initial capsule weight).

[0100] In Example 2, capsules of similar diameter (approximately 3.5 mm) were produced with varying dry deposits to evaluate the effect of dry deposits on capsule properties.

[0101] The table in Figure 1 illustrates the different compositions of the core / shell capsules before film coating.

[0102] The table in FIG. 2 illustrates different PVDC / TEC film coating solutions and different dry deposits applied to the capsules in the table in FIG.

[0103] The table in FIG. 3 illustrates the results of capsule hardness, deformation, and audible popping before and after the immersion test and dissolution test.

[0104] As can be seen from these tests, capsules with a diameter of 3.5 mm having a dry sediment of less than 1% (reference capsule 16030 / AK3 1%) do not withstand a water immersion test at 60° C. for 6 minutes or a dissolution test in water at 37° C. for 20 minutes.

[0105] Example 3 The capsules are manufactured according to Example 1. The table in Figure 4 illustrates different formulations of the core-shell capsules.

[0106] In a second step, the capsules are film-coated according to Example 1. The table in Figure 5 illustrates different formulations of film-coating solutions using different film-coating agents and with different dry deposit values.

[0107] The film-coated capsules are subjected to a water immersion test at 60° C. for 6 minutes and a water dissolution test at 37° C. for 20 minutes according to the protocol described in Example 1. Analysis of the capsules before film coating, after the immersion test and the dissolution test is performed as described in Example 1. The results are summarized below in Tables 5, 6 and FIG.

[0108] Figures 7 and 8 are graphical representations of the results reported in Tables 5 and 6, illustrating all hardness results after immersion and dissolution testing depending on the film coating used. [Table 5] G=gelatin V=Carrageenan or gellan gum

[0109] [Table 6] G=gelatin V=Carrageenan or gellan gum

[0110] Furthermore, all capsules coated with polymers other than PVDC cannot withstand a water immersion test at 60°C for 6 minutes.

[0111] It should be noted that in the case of ethyl cellulose (EC), the capsule (reference number 10042 / F1) survived the immersion test, but the sound emitted when the capsule broke was much lower (49db) than 80db. This relative resistance is not due to the ethyl cellulose providing this property, but due to the large amount of ethyl cellulose used (15% dry deposit, see table in Figure 5).

[0112] PVDC (used in the present invention in a mixture with TEC) is the only film coating agent that allows the capsules to withstand immersion and dissolution tests.

[0113] Example 4 G=gelatin Effect of capsule size on film thickness. Relationship between film coating thickness, dry deposit, and determination of the ratio ((film coating layer thickness) x 2 / capsule diameter).

[0114] In Example 4, capsules of different diameters are film-coated with PVDC or ethylcellulose according to Example 1.

[0115] The tables in Figures 9-11 summarize the film coating characteristics.

[0116] At the same dry load value, the thickness of the film-coating layer varies depending on the capsule size: as the dry load increases, the thickness of the film-coating layer increases with the capsule size.

[0117] For example, a 3% dry deposit on a 3.5 mm diameter capsule and a 3% dry deposit on a 5 mm diameter capsule have different effects on the film coating layer thickness: 10.059 μm and 14.364 μm, respectively.

[0118] The ratio ((film coating layer thickness)×2 / capsule diameter) remains the same regardless of the capsule size, which in the context of the above example is R=0.575.

Claims

1. A core-shell type seamless breakable capsule in which the shell contains a hydrophilic colloid and the core contains a fragrance and a lipophilic solvent, wherein the shell is coated with a film coating layer that imparts water resistance, and the film coating layer contains polyvinylidene chloride, and the breakable capsule is characterized by this.

2. The breakable capsule according to claim 1, which retains its burst resistance even when subjected to an immersion test at 60°C for 6 minutes.

3. The breakable capsule according to claim 1, wherein the burst resistance after undergoing a water elution test at 37°C for 20 minutes is 0.5 to 20 kgf.

4. The breakable capsule according to claim 1, wherein the amount of polyvinylidene chloride is 50% to 100% by weight based on the total dry weight of the film coating layer.

5. The breakable capsule according to claim 1, wherein the film coating layer further contains a plasticizer.

6. The plasticizer is selected from triethyl citrate, polyhydric alcohols such as glycerol, sorbitol and maltitol, polyvinyl alcohol, monosaccharides, disaccharides, oligosaccharides, triacetin, polyethylene glycol, or mixtures thereof. The breakable capsule according to claim 5.

7. The breakable capsule according to claim 1, wherein the thickness of the film coating layer is 1 μm to 200 μm.

8. The breakable capsule according to claim 1, which makes an audible popping sound when broken.

9. The shell of the breakable capsule according to claim 1 contains a hydrophilic colloid selected from gellan gum, gelatin, collagen, alginate, carrageenan, agar, chitosan and its derivatives, pectin, gum arabic, gutti gum, pullulan gum, mannan gum, vegetable protein, or mixtures thereof.

10. The breakable capsule according to claim 9, wherein the hydrophilic colloid is gellan gum used alone or in combination with gelatin.

11. The breakable capsule according to claim 9, wherein the hydrophilic colloid is selected from carrageenan.

12. The breakable capsule according to claim 1, having a diameter of 1 mm to 6 mm.

13. The breakable capsule according to claim 1, wherein the thickness of the shell is 10 μm to 300 μm.

14. The amount of polyvinylidene chloride is 50% by weight to 100% by weight based on the total dry weight of the film coating layer, the film coating layer further contains a plasticizer selected from triethyl citrate, polyhydric alcohols such as glycerol, sorbitol and maltitol, polyvinyl alcohol, monosaccharides, disaccharides, oligosaccharides, triacetin, polyethylene glycol, or mixtures thereof, the thickness of the film coating layer is 1 μm to 200 μm The breakable capsule according to claim 1.

15. The shell contains a hydrocolloid selected from gellan gum, gelatin, collagen, alginate, carrageenan, agar, chitosan and its derivatives, pectin, gum arabic, gutti gum, pullulan gum, mannan gum, vegetable protein, or mixtures thereof, the diameter of the breakable capsule is 1 mm to 6 mm, the thickness of the shell is 10 μm to 300 μm The breakable capsule according to claim 14.

16. An oral-use pouch that immediately and continuously releases a fragrance, comprising one or more capsules containing the fragrance according to any one of claims 1 to 15, wherein the capsules are disposed within the pouch. The oral-use pouch is characterized by this.

17. The oral-use pouch according to claim 16, further comprising tobacco in the form of leaves or ground tobacco disposed within the pouch.

18. The oral-use pouch according to claim 16, which does not contain tobacco disposed within the pouch.

19. The oral-use pouch according to claim 16, further comprising plant fibers, and / or encapsulated or non-encapsulated fragrance agents, and / or fillers, and / or humectants disposed within the pouch.

20. A consumer product comprising a portion containing a filter and another portion containing tobacco, wherein the filter contains one or more capsules according to any one of claims 1 to 15. The consumer product is characterized by this.

21. The consumer product according to claim 20, which is disposable and intended to be used as a tobacco refill for a tobacco heating device.

22. A tobacco heating device characterized by comprising the consumer product according to claim 20.

23. A method for manufacturing a seamless breakable capsule comprising a shell and a core, Step (A) of co-extruding a hydrophilic external liquid phase containing 4% to 95% by weight of a hydrophilic colloid based on the total dry weight of the shell and a lipophilic internal liquid phase containing 5% to 70% by weight of a fragrance agent based on the total weight of the core; Step (B) of solidifying and / or gelling the surface of the capsule obtained in step (A) by immersing it in a fluid at a temperature of 1°C to 25°C; Step (C) of drying the capsule obtained in step (B); Step (D) of film-coating the capsule obtained in step (C) by an air spray coating process using a film coating solution containing polyvinylidene chloride and water; Step (E) of recovering the capsule obtained in step (D), a method comprising.

24. The method according to claim 23, wherein the film coating solution further comprises a plasticizer selected from triethyl citrate, polyhydric alcohols such as glycerol, sorbitol and maltitol, polyvinyl alcohol, monosaccharides, disaccharides, oligosaccharides, triacetin, polyethylene glycol, or mixtures thereof.

25. Use of the capsule according to any one of claims 1 to 15 as an additive for immediate and sustained release of a fragrance, wherein the capsule is placed in a product contained in an oral use pouch, or a consumer product containing a filter and tobacco, specifically a consumer product intended for use in a tobacco heating device.

26. The use according to claim 25, wherein the capsule emits an audible "pop" sound to release the fragrance when broken within the oral use pouch or the consumer product.

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