Packaged paper-based capsules

Abstract

The present invention relates to a packaged capsule comprising: (i) a capsule comprising cellulosic fibres, wherein the capsule is surface-coated with a lining which is (a) an inorganic coating; or (b) a natural polymer coating; the capsule is at least partially filled with an edible product suitable for human consumption; and the capsule is sealed with a membrane comprising cellulosic fibres, wherein the membrane is surface-coated with the same lining as the capsule; and (ii) a packaging comprising at least 80% wt of cellulosic fibres based upon the total weight of the packaging, a metallized polymer coating in contact with the cellulosic fibres, and a polymer coating in contact with the metallized polymer coating; wherein the capsule is placed within the packaging; to methods for the manufacture of the packaged capsule, and to a packet comprising a plurality of the packaged capsules.

Description

[0001] PACKAGED PAPER-BASED CAPSULES

[0002] Field of the invention

[0003] The present invention relates to packaged capsules and methods for their production.

[0004] Background of the invention

[0005] Aluminium-based coffee capsules for use in coffee capsule machines are well- established. The use of aluminium results in a capsule having extremely high barrier properties against water and oxygen, such that the shelf-life of the coffee contained within the capsule is long (e.g. over 18 months).

[0006] However, there is increasing consumer pressure to offer packaging that is more sustainable and environmentally-friendly. In particular, there is a desire to expand the use of paper packaging such that the packaging can be easily composted or recycled after use. Paper-based coffee capsules are known, but in order to achieve acceptable barrier properties against water and oxygen it is necessary to laminate the inner surface of the capsule with a plastic polymer. If a thin plastic polymer laminate is employed, capsules normally need to be stored in a high barrier bag (e.g. a plastic bag) that can help stabilise the shelf-life of the coffee until the bag is opened. Once opened, however, all of the capsules in the bag are subjected to environmental conditions and product degradation begins. A thicker plastic polymer laminate can be employed on the inner surface of the capsules, but this inevitably makes the packaging material less environmentally-friendly and risks losing consumer confidence in sustainability efforts.

[0007] Accordingly, there exists a need to provide capsules that have high barrier properties and a long shelf-life for the product contained within, which are also easily composted or recycled after use. The capsules also need to be able to withstand the harsh conditions applied during extraction in a coffee capsule machine. Summary of the invention

[0008] Viewed from a first aspect, the present invention relates to a packaged capsule comprising:

[0009] (i) a capsule comprising cellulosic fibres, wherein the capsule is surface-coated with a lining which is:

[0010] (a) an inorganic coating; or

[0011] (b) a natural polymer coating; the capsule is at least partially filled with an edible product suitable for human consumption; and the capsule is sealed with a membrane comprising cellulosic fibres, wherein the membrane is surface-coated with the same lining as the capsule; and

[0012] (ii) a packaging comprising at least 80% wt of cellulosic fibres based upon the total weight of the packaging, a metallized polymer coating in contact with the cellulosic fibres, and a polymer coating in contact with the metallized polymer coating; wherein the capsule is placed within the packaging.

[0013] Viewed from a further aspect, the present invention relates to a packet comprising a plurality of packaged capsules as hereinbefore described.

[0014] Viewed from a further aspect, the present invention relates to a method for manufacturing a packaged capsule, the method comprising the steps of: a) providing a capsule comprising cellulosic fibres; b) preparing a mixture comprising one or more alkoxy silane monomers and an acid catalyst in water; c) applying the mixture to said capsule; d) reacting the mixture with the cellulosic fibres of said capsule; e) subjecting the mixture to the sol-gel process to obtain a treated capsule; f) drying the treated capsule to obtain a capsule surface-coated with a lining; g) at least partially filling the capsule with an edible product suitable for human consumption; h) sealing the capsule with a membrane comprising cellulosic fibres, wherein the membrane is surface-coated with the same lining as the capsule; and i) placing the capsule in a packaging, wherein the packaging comprises at least 80% wt of cellulosic fibres based upon the total weight of the packaging, a metallized polymer coating in contact with the cellulosic fibres, and a polymer coating in contact with the metallized polymer coating.

[0015] Viewed from a further aspect, the present invention relates to a packaged capsule obtained by the method as hereinbefore described.

[0016] Viewed from a further aspect, the present invention relates to a method for manufacturing a packaged capsule, the method comprising the steps of: a) providing a capsule comprising cellulosic fibres; b) coating a natural polymer onto the capsule to obtain a treated capsule; c) drying the treated capsule to obtain a capsule surface-coated with a lining; d) at least partially filling the capsule with an edible product suitable for human consumption; e) sealing the capsule with a membrane comprising cellulosic fibres, wherein the membrane is surface-coated with the same lining as the capsule; and f) placing the capsule in a packaging, wherein the packaging comprises at least 80% wt of cellulosic fibres based upon the total weight of the packaging, a metallized polymer coating in contact with the cellulosic fibres, and a polymer coating in contact with the metallized polymer coating.

[0017] Viewed from a further aspect, the present invention relates to a packaged capsule obtained by the method as hereinbefore described. Brief description of the drawings

[0018] Additional features and advantages of the present invention are described in, and will be apparent from, the description of the presently preferred embodiments which are set out below with reference to the drawings in which:

[0019] Figure 1 is a photograph of a packaged capsule of the present invention, wherein the packaging has been opened and the capsule removed therefrom; and

[0020] Figure 2 is a photograph of the packaging of the present invention in both an open and closed arrangement.

[0021] Detailed description of the invention

[0022] As used herein, the phrase "is contact with" means that the material in question is near the other material, with or without any intervening material.

[0023] As used herein, the phrase "fibre" means a cellulosic fibre, which is generally extracted from plants, seeds or trees; such fibres contain not only cellulose molecules, but also hemi-cellulose as well as lignin.

[0024] As used herein, the term "natural polymer" means a polymer that occurs in nature, and which has not been processed or modified in any way that changes its chemical composition.

[0025] As used herein, the term "compostable" refers to a material that will biodegrade in a home composting system within six months.

[0026] As used herein, the term "shelf-life" means the period of time during which an edible product will remain suitable for human consumption following packaging it in a packaged capsule of the present invention. This is typically up to nine months from the date of packaging, but can be longer depending upon the nature of the edible product and the external environmental conditions.

[0027] Viewed from a first aspect, the present invention relates to a packaged capsule comprising: (i) a capsule comprising cellulosic fibres, wherein the capsule is surface-coated with a lining which is:

[0028] (a) an inorganic coating; or

[0029] (b) a natural polymer coating; the capsule is at least partially filled with an edible product suitable for human consumption; and the capsule is sealed with a membrane comprising cellulosic fibres, wherein the membrane is surface-coated with the same lining as the capsule; and

[0030] (ii) a packaging comprising at least 80% wt of cellulosic fibres based upon the total weight of the packaging, a metallized polymer coating in contact with the cellulosic fibres, and a polymer coating in contact with the metallized polymer coating; wherein the capsule is placed within the packaging.

[0031] In preferred packaged capsules of the present invention, the cellulosic fibres in the capsule are selected from cellulose fibres from wood, jut, bagasse, hemp, straw, bamboo and combinations thereof, preferably cellulose fibres from wood, jut, bagasse, hemp, and combinations thereof.

[0032] The capsules of the packaged capsules of the present invention are predominantly made of paper, meaning that they can easily be recycled. Thus, in preferred packaged capsules of the present invention, the capsule comprises at least 80% wt of cellulosic fibres based upon the total weight of the capsule, preferably at least 85% wt of cellulosic fibres based upon the total weight of the capsule, more preferably at least 90% wt of cellulosic fibres based upon the total weight of the capsule, even more preferably at least 95% wt of cellulosic fibres based upon the total weight of the capsule.

[0033] In the packaged capsules of the present invention, the lining provides hydrophobic properties (i.e. water barrier properties) and strength to the capsule, whilst maintaining a packaging solution that is plastic-free (i.e. the need to resort to plastic lamination of the capsule is avoided). The lining used in the packaged capsules of the present invention serves two purposes: (i) prior to use of the capsule, the lining acts as a water barrier and protects the edible product contained within from deteriorating in quality by minimising the amount of water that can come into contact with it; and (ii) during use of the capsule in a coffee capsule machine, the lining prevents the paper-based capsules from bursting during extraction, which involves them being filled with water at around 90 °C and under a pressure of around 19 bar. Preferably, the lining is present on both the inside and outside surfaces of the capsule.

[0034] In preferred packaged capsules of the present invention, the weight of the lining is 1 to 25% wt based upon the total weight of the capsule, preferably 5 to 10% wt based upon the total weight of the capsule.

[0035] In preferred packaged capsules of the present invention, the lining is an inorganic coating. Preferably, the inorganic coating is a polymer from a sol-gel process of a mixture of one or more alkoxy silane monomers and an acid catalyst in water.

[0036] In preferred packaged capsules of the present invention, the one or more alkoxy silane monomers are selected from tetraethyl orthosilicate, triethoxy methylsilane, triethoxy(methyl)alkoxy silane, triethoxy(ethyl)alkoxy silane, triethoxy(propyl)alkoxy silane, butyltriethoxyalkoxy silane, triethoxy(isopentyl)alkoxy silane, (3,3- dimethylbutyl)triethoxyalkoxy silane, triethoxy(vinyl)alkoxy silane, 3-

[0037] (triethoxysilyl)propan-l-amine, 3-(triethoxysilyl)propyl methacrylate, trimethoxy(methyl)alkoxy silane, trimethoxy(ethyl)alkoxy silane, trimethoxy(propyl)alkoxy silane, butyltrimethoxyalkoxy silane, trimethoxy(isopentyl)alkoxy silane, (3,3-dimethylbutyl)trimethoxyalkoxy silane, trimethoxy(vinyl)alkoxy silane, 3-(trimethoxysilyl)propan-l-amine, and 3- (trimethoxysilyl)propyl methacrylate. Preferably, the one or more alkoxy silane monomers are selected from tetraethyl orthosilicate and triethoxy methylsilane.

[0038] As the capsules are to be used for a food application, the acid catalyst used in the sol-gel process needs to be of food-grade. Thus, in preferred packaged capsules of the present invention, the acid catalyst is selected from hydrochloric acid, acetic acid, malic acid and lactic acid.

[0039] In alternative preferred packaged capsules of the present invention, the lining is a natural polymer coating, which is preferably cellophane. Natural polymer coatings, such as cellophane, are able to provide thermoplastic properties to the capsule in addition to hydrophobic properties (i.e. water barrier properties) and strength. That the natural polymer coatings have thermoplastic properties means that the need for a glue when sealing the capsule with a membrane can be avoided.

[0040] In preferred packaged capsules of the present invention, the edible product is selected from coffee, milk, tea, chocolate, or emulsified fat (e.g. a creamer). Preferably, the edible product is coffee, more preferably ground coffee.

[0041] In preferred packaged capsules of the present invention, the shelf-life of the edible product in the capsule is at least one month, preferably at least two months, more preferably at least three months, more preferably at least six months, even more preferably at least nine months.

[0042] In preferred packaged capsules of the present invention, the cellulosic fibres in the membrane are selected from cellulose fibres from wood, jut, bagasse, hemp, straw, bamboo and combinations thereof, preferably cellulose fibres from wood, jut, bagasse, hemp, and combinations thereof.

[0043] The membrane of the packaged capsules of the present invention is predominantly made of paper, meaning that it can easily be recycled. Thus, in preferred packaged capsules of the present invention, the membrane comprises at least 80% wt of cellulosic fibres based upon the total weight of the membrane, preferably at least 85% wt of cellulosic fibres based upon the total weight of the membrane, more preferably at least 90% wt of cellulosic fibres based upon the total weight of the membrane, even more preferably at least 95% wt of cellulosic fibres based upon the total weight of the membrane.

[0044] In preferred packaged capsules of the present invention, the membrane is sealed to the capsule by a glue, preferably a lignin-based glue. This is usually the case when the lining of the capsules is an inorganic coating, as the inorganic coating does not have thermoplastic properties.

[0045] In alternative preferred packaged capsules of the present invention, the membrane is sealed to the capsule by a thermoplastic seal. This is usually the case when the lining of the capsules is a natural polymer coating, as such a material does have thermoplastic properties.

[0046] In preferred packaged capsules of the present invention, the capsule is plastic- free, e.g. as defined by the EU Single-Use Plastics Directive.

[0047] In preferred packaged capsules of the present invention, the capsule is compostable.

[0048] The packaging of the packaged capsules of the present invention is predominantly made of paper, meaning that it can easily be recycled. Thus, in the packaged capsules of the present invention, the packaging comprises at least 80% wt of cellulosic fibres based upon the total weight of the packaging. In preferred packaged capsules of the present invention, the packaging comprises at least 85% wt of cellulosic fibres based upon the total weight of the packaging, preferably at least 90% wt of cellulosic fibres based upon the total weight of the packaging, more preferably at least 95% wt of cellulosic fibres based upon the total weight of the packaging.

[0049] In preferred packaged capsules of the present invention, the packaging is recyclable, preferably recyclable in paper recycling.

[0050] In preferred packaged capsules of the present invention, the packaging is plastic-free, e.g. as defined by the EU Single-Use Plastics Directive.

[0051] The packaged capsules of the present invention comprise a packaging comprising a metallized polymer coating. Preferably, the metallized polymer coating of the packaging comprises a polymer layer and a barrier layer. The polymer layer serves to provide barrier properties to the packaging against water, oxygen and other gases. The barrier layer serves to enhance these barrier properties, particularly the barrier properties against water. In preferred packaged capsules of the present invention, the polymer layer of the metallized coating layer comprises at least one polymer selected from a polyolefin, a polyester, and combinations thereof. Preferably, the polymer layer comprises at least one polymer selected from low-density polyethylene, high-density polyethylene, polypropylene, polybutylene, polyisobutylene, polyethylene tetraphthalate, ethylene vinyl alcohol, polylactic acid, and combinations thereof. More preferably, the polymer layer comprises polypropylene. Even more preferably, the polymer layer consists of polypropylene.

[0052] In preferred packaged capsules of the present invention, the barrier layer of the metallized coating layer comprises a metal, preferably aluminium.

[0053] The polymer coating of the packaging enables the packaging to be sealed closed, e.g. during a sealing process.

[0054] In preferred packaged capsules of the present invention, the packaging is tetrahedrally-shaped. A tetrahedrally-shaped packaging has a reduced number of triple points versus a conventional sachet-shaped packaging, meaning there is less strain on the structure and a reduced risk of the packaging cracking which would negatively impact on the barrier properties of the packaging. Additionally, a tetrahedral structure is easier to stack, which aids in the recycling of the packaging.

[0055] In preferred packaged capsules of the present invention, the capsule is sealed within the packaging.

[0056] Viewed from a further aspect, the present invention relates to a packet comprising a plurality of packaged capsules as hereinbefore described.

[0057] Viewed from a further aspect, the present invention relates to a method for manufacturing a packaged capsule, the method comprising the steps of: a) providing a capsule comprising cellulosic fibres; b) preparing a mixture comprising one or more alkoxy silane monomers and an acid catalyst in water; c) applying the mixture to said capsule; d) reacting the mixture with the cellulosic fibres of said capsule; e) subjecting the mixture to the sol-gel process to obtain a treated capsule; f) drying the treated capsule to obtain a capsule surface-coated with a lining; g) at least partially filling the capsule with an edible product suitable for human consumption; h) sealing the capsule with a membrane comprising cellulosic fibres, wherein the membrane is surface-coated with the same lining as the capsule; and i) placing the capsule in a packaging, wherein the packaging comprises at least 80% wt of cellulosic fibres based upon the total weight of the packaging, a metallized polymer coating in contact with the cellulosic fibres, and a polymer coating in contact with the metallized polymer coating.

[0058] The method of the present invention involves a sol-gel process. The sol-gel process enables the synthesis of solid materials from small molecules, which involves the formation of silanols and then polysiloxanes from an alkoxy silane. Initially, a sol is formed, which is a colloidal solution of alkoxy silane particles. These particles begin to aggregate, forming a macrostructure. This process leads to gel formation, which is a biphasic system comprising both a liquid and a solid phase. It involves several steps to transform the sol into a gel and eventually into a solid material, as outlined below.

[0059] • Sol Formation

[0060] A precursor solution, called a sol, is prepared by dissolving alkoxy silanes in a solvent. The precursor solution may also contain organic compounds or polymers.

[0061] • Gelation

[0062] The sol undergoes gelation, forming a three-dimensional network of interconnected particles or polymers. This is achieved through a number of chemical steps, such as hydrolysis (Journal of Applied Polymer Science 108, 1958-1968) and condensation.

[0063] In accordance with the method of the present invention, this is achieved with the hydrolysis of the alkoxy function in the alkoxy silane monomer by the acid catalyst, leading to a silanol, followed by the polycondensation of the silanol with itself and with the cellulosic capsule. • Aging

[0064] The gel is allowed to age or undergo further chemical reactions, which leads to the strengthening and stabilization of the gel structure. This step can take place at ambient or elevated temperatures, depending on the desired properties of the final material.

[0065] In accordance with the method of the present invention, the aging of the gel structure is preferably done at room temperature or in a cold environment, i. e. provided by an ice bath. In each case, the rate of formation of the gel is affected by the temperature.

[0066] • Drying

[0067] The wet gel is subjected to drying to remove the solvent from the gel structure. This can be done by evaporation, supercritical drying, or other drying techniques. The drying process is essential for converting the gel into a solid material while preserving its structure.

[0068] In preferred methods of the present invention, the cellulosic fibres in the capsule are selected from cellulose fibres from wood, jut, bagasse, hemp, straw, bamboo and combinations thereof, preferably from cellulose fibres from wood, jut, bagasse, hemp, and combinations thereof.

[0069] The capsules of the packaged capsules of the present invention are predominantly made of paper, meaning that they can easily be recycled. Thus, in preferred methods of the present invention, the capsule comprises at least 80% wt of cellulosic fibres based upon the total weight of the capsule, preferably at least 85% wt of cellulosic fibres based upon the total weight of the capsule, more preferably at least 90% wt of cellulosic fibres based upon the total weight of the capsule, even more preferably at least 95% wt of cellulosic fibres based upon the total weight of the capsule.

[0070] In preferred methods of the present invention, the capsule comprising cellulosic fibres is provided in step (a) via a moulded pulp method or a paper stretching method. In preferred methods of the present invention, the one or more alkoxy silane monomers in step (b) are selected from tetraethyl orthosilicate, triethoxy methylsilane, triethoxy(methyl)alkoxy silane, triethoxy(ethyl)alkoxy silane, riethoxy(propyl)alkoxy silane, butyltriethoxyalkoxy silane, triethoxy(isopentyl)alkoxy silane, (3,3-dimethylbutyl)triethoxyalkoxy silane, triethoxy(vinyl)alkoxy silane, 3-

[0071] (triethoxysilyl)propan-l-amine, 3-(triethoxysilyl)propyl methacrylate, trimethoxy(methyl)alkoxy silane, trimethoxy(ethyl)alkoxy silane, trimethoxy(propyl)alkoxy silane, butyltrimethoxyalkoxy silane, trimethoxy(isopentyl)alkoxy silane, (3,3-dimethylbutyl)trimethoxyalkoxy silane, trimethoxy(vinyl)alkoxy silane, 3-(trimethoxysilyl)propan-l-amine, and 3- (trimethoxysilyl)propyl methacrylate. Preferably, the one or more alkoxy silane monomers are selected from tetraethyl orthosilicate and triethoxy methylsilane.

[0072] As the capsules are to be used for a food application, the acid catalyst used in the sol-gel process needs to be of food-grade. Thus, in preferred methods of the present invention, the acid catalyst in step (b) is selected from hydrochloric acid, acetic acid, malic acid and lactic acid.

[0073] Applying the acid catalyst to the alkoxy silane monomers just before reacting with cellulose enhances the grafting to cellulose, as evidenced by reduced leaching. The preferred timing for applying the acid catalyst is a few minutes before reacting with the capsule comprising cellulosic fibres, but no more than two hours before. Beyond that timeframe, improper grafting occurs due to significant advancement of the sol-gel process, which hinders proper grafting to the hydroxyl groups of cellulose, mainly due to steric hindrance. Additionally, cooling the alkoxy silane monomers in solution with the acid catalyst extends the application time, providing a longer window before improper grafting takes place.

[0074] The level of silicon-to-cellulose grafting is crucial for achieving the desired modifications in the physicochemical properties of the capsule comprising cellulosic fibres. The purpose of the treatment of the present invention is to enhance the hydrophobicity of the capsule comprising cellulosic fibres through the sol-gel process. This modification enables its application in moisture-protective paper-based capsules for coffee machines.

[0075] Water plays a crucial role in the sol-gel process as it initiates hydrolysis and triggers polycondensation. The stoichiometric quantity of water required for full hydrolysis depends on the precursor's structure (the number of alkoxy groups), and when provided, it ensures complete hydrolysis of the reagent throughout the reaction. With a water ratio lower than stoichiometric, the reaction may be hindered, allowing only a portion of the overall moieties to be available for polymerization. A reaction limited cluster aggregation of this kind is described e.g. by Roucher, A., Biofunctional materials made by integrative chemistry, Elaboration de materiaux biofonctionnels par chimie integrative, Universite de Bordeaux, (2018).

[0076] On the other hand, employing a water ratio greater than stoichiometric may appear to speed up both hydrolysis and polycondensation reactions. However, it should be emphasized that the process of polycondensation is constrained by diffusion, and a reduced concentration of reactants decelerates this process (diffusion limited cluster aggregation).

[0077] Thus, in preferred methods of the present invention, the alkoxy silane-to-water molecular ratio in step (b) is 1:1.

[0078] In preferred methods of the present invention, the alkoxy silane-to-cellulose molecular ratio in step (c) is in the range of 2:1 to 0.5:1, preferably 3:1.

[0079] In preferred methods of the present invention, the mixture is applied to the capsule in step (c) via a dipping method or a spray method. Preferably, the mixture is applied to both the inside and outside surfaces of the capsule.

[0080] In step (d) of the method of the present invention, the mixture formed in step (b) is reacted with the cellulosic fibres of the capsule. The bonding occurs by grafting the alkoxy silane monomers to the hydroxyl groups of the cellulosic capsule (i.e. to the hydroxyl groups on C2, C3 and C6 of the glucose monomers of the cellulose). In preferred methods of the present invention, reacting the mixture with the cellulosic fibres of the capsule in step (d) is performed for a time of from 2 minutes to

[0081] 2 hours.

[0082] In preferred methods of the present invention, reacting the mixture with the cellulosic fibres of the capsule in step (d) is performed at a temperature of 21 °C or below.

[0083] The catalytic effect can enhance the hydrolysis and polycondensation rates, leading to a faster reaction. It is important to note that a catalyst cannot only alter the rate but also the final structure of the solid. There are two options: adding an acid, such as HCI, acetic acid, or citric acid, or a base, such as different hydroxides (e.g., NaOH, KOH). Acidic catalysis accelerates hydrolysis more than basic catalysis, and polycondensation occurs after this initial process. The primary difference between the two cases is the reaction mechanism; under acidic conditions, the driving force is the good leaving group generated upon protonation of the hydroxyl, while the key factor under basic conditions is the nucleophilicity of the deprotonated hydroxyl group in silica.

[0084] The isoelectric point of silica, measured at approximately 2.1 (Chemical Reviews 65, 177-198), is of utmost importance in understanding the overall charge of the forming structure. At values below or above this point, the particles will be positively or negatively charged and will repel each other, inhibiting cluster aggregation. By maintaining a pH between 7 and 10, it is possible to impede gel formation and promote particle growth until flocculation occurs. Thus, in preferred methods of the present invention, reacting the mixture with the cellulosic fibres of the capsule in step (d) is performed at a pH between 7 and 10.

[0085] In preferred methods of the present invention, drying the treated capsule to obtain the capsule surface-coated with a lining in step (f) is done at a temperature of from 100 °C to 150 °C, preferably at a temperature of 120 °C. Temperatures higher than 150°C should be avoided as they can lead to the degradation of the cellulosic capsule. In preferred methods of the present invention, drying the treated capsule to obtain the capsule surface-coated with a lining in step (f) is done over a period of time from 1 minute to 10 minutes, preferably over a period of time of 5 to 10 minutes. When step (f) is conducted in a static environment (e.g. an oven), the drying is preferably done over a period of time of 2 minutes. When step (f) is conducted in a dynamic environment (continuous coating), the drying is preferably done over a period of up to 30 seconds, most preferably 3 to 5 seconds.

[0086] In preferred methods of the present invention, drying the treated capsule to obtain the capsule surface-coated with a lining in step (f) is done by an evaporation process or a supercritical drying process.

[0087] In preferred methods of the present invention, the weight of the lining formed in step (f) is 1 to 25% wt based upon the total weight of the capsule, preferably 5 to 10% wt based upon the total weight of the capsule.

[0088] In preferred methods of the present invention, the edible product used in step (g) is selected from coffee, milk, tea, chocolate, or emulsified fat (e.g. a creamer). Preferably, the edible product used in step (g) is coffee, more preferably ground coffee.

[0089] In preferred methods of the present invention, the shelf-life of the edible product in the capsule is at least one month, preferably at least two months, more preferably at least three months, more preferably at least six months, even more preferably at least nine months

[0090] In preferred methods of the present invention, the cellulosic fibres in the membrane are selected from cellulose fibres from wood, jut, bagasse, hemp, straw, bamboo and combinations thereof, preferably from cellulose fibres from wood, jut, bagasse, hemp, and combinations thereof.

[0091] The membrane of the packaged capsules of the present invention is predominantly made of paper, meaning that it can easily be recycled. Thus, in preferred methods of the present invention, the membrane comprises at least 80% wt of cellulosic fibres based upon the total weight of the membrane, preferably at least 85% wt of cellulosic fibres based upon the total weight of the membrane, more preferably at least 90% wt of cellulosic fibres based upon the total weight of the membrane, even more preferably at least 95% wt of cellulosic fibres based upon the total weight of the membrane.

[0092] In step (h) of the method of the present invention, the capsule is sealed with a membrane comprising cellulosic fibres, wherein the membrane is surface-coated with the same lining as the capsule. Preferred features of the process for surface-coating the membrane are as described above for the capsule.

[0093] In preferred methods of the present invention, the membrane is sealed to the capsule in step (h) by a glue, preferably a lignin-based glue. This is because the inorganic coating formed on the surfaces of the capsule and the membrane does not have thermoplastic properties.

[0094] In preferred methods of the present invention, the capsule is plastic-free, e.g. as defined by the EU Single-Use Plastics Directive.

[0095] In preferred methods of the present invention, the capsule is compostable.

[0096] The packaging of the packaged capsules of the present invention is predominantly made of paper, meaning that it can easily be recycled. Thus, in the methods of the present invention, the packaging used in step (i) comprises at least 80% wt of cellulosic fibres based upon the total weight of the packaging. In preferred methods of the present invention, the packaging used in step (i) comprises at least 85% wt of cellulosic fibres based upon the total weight of the packaging, preferably at least 90% wt of cellulosic fibres based upon the total weight of the packaging, more preferably at least 95% wt of cellulosic fibres based upon the total weight of the packaging.

[0097] In preferred methods of the present invention, the packaging is recyclable, preferably recyclable in paper recycling.

[0098] In preferred methods of the present invention, the packaging is plastic-free, e.g. as defined by the EU Single-Use Plastics Directive.

[0099] The packaged capsules of the present invention comprise a packaging comprising a metallized polymer coating. Preferably, the metallized polymer coating of the packaging comprises a polymer layer and a barrier layer. The polymer layer serves to provide barrier properties to the packaging against water, oxygen and other gases. The barrier layer serves to enhance these barrier properties, particularly the barrier properties against water.

[0100] In preferred methods of the present invention, the polymer layer of the metallized coating layer comprises at least one polymer selected from a polyolefin, a polyester, and combinations thereof. Preferably, the polymer layer comprises at least one polymer selected from low-density polyethylene, high-density polyethylene, polypropylene, polybutylene, polyisobutylene, polyethylene tetraphthalate, ethylene vinyl alcohol, polylactic acid, and combinations thereof. More preferably, the polymer layer comprises polypropylene. Even more preferably, the polymer layer consists of polypropylene.

[0101] In preferred methods of the present invention, the polymer layer is laminated onto the cellulosic fibres of the packaging using a dry bond lamination process, a wet bond lamination process, or a heat lamination process.

[0102] In preferred methods of the present invention, the barrier layer of the metallized coating layer comprises a metal, preferably aluminium.

[0103] In preferred methods of the present invention, the barrier layer is applied to the polymer layer using a physical vapour deposition process, a chemical vapour deposition process or a sputtering process.

[0104] The polymer coating of the packaging enables the packaging to be sealed closed, e.g. during a sealing process. Preferred methods of the present invention further comprise the step of sealing the capsule in the packaging, preferably by a heat sealing process or an ultrasonic sealing process.

[0105] Viewed from a further aspect, the present invention relates to a packaged capsule obtained by the method as hereinbefore described.

[0106] Viewed from a further aspect, the present invention relates to a method for manufacturing a packaged capsule, the method comprising the steps of: a) providing a capsule comprising cellulosic fibres; b) coating a natural polymer onto the capsule to obtain a treated capsule; c) drying the treated capsule to obtain a capsule surface-coated with a lining; d) at least partially filling the capsule with an edible product suitable for human consumption; e) sealing the capsule with a membrane comprising cellulosic fibres, wherein the membrane is surface-coated with the same lining as the capsule; and f) placing the capsule in a packaging, wherein the packaging comprises at least 80% wt of cellulosic fibres based upon the total weight of the packaging, a metallized polymer coating in contact with the cellulosic fibres, and a polymer coating in contact with the metallized polymer coating.

[0107] In preferred methods of the present invention, the cellulosic fibres in the capsule are selected from cellulose fibres from wood, jut, bagasse, hemp, straw, bamboo and combinations thereof, preferably from cellulose fibres from wood, jut, bagasse, hemp, and combinations thereof.

[0108] The capsules of the packaged capsules of the present invention are predominantly made of paper, meaning that they can easily be recycled. Thus, in preferred methods of the present invention, the capsule comprises at least 80% wt of cellulosic fibres based upon the total weight of the capsule, preferably at least 85% wt of cellulosic fibres based upon the total weight of the capsule, more preferably at least 90% wt of cellulosic fibres based upon the total weight of the capsule, even more preferably at least 95% wt of cellulosic fibres based upon the total weight of the capsule.

[0109] In preferred methods of the present invention, the capsule comprising cellulosic fibres is provided in step (a) via a moulded pulp method or a paper stretching method.

[0110] In preferred methods of the present invention, the natural polymer used in step (b) is cellophane. Natural polymer coatings, such as cellophane, are able to provide thermoplastic properties to the capsule in addition to hydrophobic properties (i.e. water barrier properties) and strength. That the natural polymer coatings have thermoplastic properties means that the need for a glue when sealing the capsule with a membrane can be avoided.

[0111] In preferred methods of the present invention, the natural polymer is coated onto the capsule in step (b) via a dipping method or a spray method. Preferably, the natural polymer is coated onto both the inside and outside surfaces of the capsule.

[0112] In preferred methods of the present invention, drying the treated capsule to obtain the capsule surface-coated with a lining in step (c) is done by an evaporation process or a supercritical drying process.

[0113] In preferred methods of the present invention, the weight of the lining formed in step (c) is 1 to 25% wt based upon the total weight of the capsule, preferably 5 to 10% wt based upon the total weight of the capsule.

[0114] In preferred methods of the present invention, the edible product used in step (d) is selected from coffee, milk, tea, chocolate, or emulsified fat (e.g. a creamer). Preferably, the edible product used in step (d) is coffee, more preferably ground coffee.

[0115] In preferred methods of the present invention, the shelf-life of the edible product in the capsule is at least one month, preferably at least two months, more preferably at least three months, more preferably at least six months, even more preferably at least nine months.

[0116] In preferred methods of the present invention, the cellulosic fibres in the membrane are selected from cellulose fibres from wood, jut, bagasse, hemp, straw, bamboo and combinations thereof, preferably from cellulose fibres from wood, jut, bagasse, hemp, and combinations thereof.

[0117] The membrane of the packaged capsules of the present invention is predominantly made of paper, meaning that it can easily be recycled. Thus, in preferred methods of the present invention, the membrane comprises at least 80% wt of cellulosic fibres based upon the total weight of the membrane, preferably at least 85% wt of cellulosic fibres based upon the total weight of the membrane, more preferably at least 90% wt of cellulosic fibres based upon the total weight of the membrane, even more preferably at least 95% wt of cellulosic fibres based upon the total weight of the membrane.

[0118] In step (e) of the method of the present invention, the capsule is sealed with a membrane comprising cellulosic fibres, wherein the membrane is surface-coated with the same lining as the capsule. Preferred features of the process for surface-coating the membrane are as described above for the capsule.

[0119] In preferred methods of the present invention, the membrane is sealed to the capsule in step (e) by a thermoplastic seal. This is because the natural polymer coating has thermoplastic properties.

[0120] In preferred methods of the present invention, the capsule is plastic-free, e.g. as defined by the EU Single-Use Plastics Directive.

[0121] In preferred methods of the present invention, the capsule is compostable.

[0122] The packaging of the packaged capsules of the present invention is predominantly made of paper, meaning that it can easily be recycled. Thus, in the methods of the present invention, the packaging used in step (f) comprises at least 80% wt of cellulosic fibres based upon the total weight of the packaging. In preferred methods of the present invention, the packaging used in step (f) comprises at least 85% wt of cellulosic fibres based upon the total weight of the packaging, preferably at least 90% wt of cellulosic fibres based upon the total weight of the packaging, more preferably at least 95% wt of cellulosic fibres based upon the total weight of the packaging.

[0123] In preferred methods of the present invention, the packaging is recyclable, preferably recyclable in paper recycling.

[0124] In preferred methods of the present invention, the packaging is plastic-free, e.g. as defined by the EU Single-Use Plastics Directive.

[0125] The packaged capsules of the present invention comprise a packaging comprising a metallized polymer coating. Preferably, the metallized polymer coating of the packaging comprises a polymer layer and a barrier layer. The polymer layer serves to provide barrier properties to the packaging against water, oxygen and other gases. The barrier layer serves to enhance these barrier properties, particularly the barrier properties against water.

[0126] In preferred methods of the present invention, the polymer layer of the metallized coating layer comprises at least one polymer selected from a polyolefin, a polyester, and combinations thereof. Preferably, the polymer layer comprises at least one polymer selected from low-density polyethylene, high-density polyethylene, polypropylene, polybutylene, polyisobutylene, polyethylene tetraphthalate, ethylene vinyl alcohol, polylactic acid, and combinations thereof. More preferably, the polymer layer comprises polypropylene. Even more preferably, the polymer layer consists of polypropylene.

[0127] In preferred methods of the present invention, the polymer layer is laminated onto the cellulosic fibres of the packaging using a dry bond lamination process, a wet bond lamination process, or a heat lamination process.

[0128] In preferred methods of the present invention, the barrier layer of the metallized coating layer comprises a metal, preferably aluminium.

[0129] In preferred methods of the present invention, the barrier layer is applied to the polymer layer using a physical vapour deposition process, a chemical vapour deposition process or a sputtering process.

[0130] The polymer coating of the packaging enables the packaging to be sealed closed, e.g. during a sealing process. Preferred methods of the present invention further comprise the step of sealing the capsule in the packaging, preferably by a heat sealing process or an ultrasonic sealing process.

[0131] Viewed from a further aspect, the present invention relates to a packaged capsule obtained by the method as hereinbefore described.

Claims

Claims1. A packaged capsule comprising:(i) a capsule comprising cellulosic fibres, wherein the capsule is surface-coated with a lining which is:(a) an inorganic coating; or(b) a natural polymer coating; the capsule is at least partially filled with an edible product suitable for human consumption; and the capsule is sealed with a membrane comprising cellulosic fibres, wherein the membrane is surface-coated with the same lining as the capsule; and(ii) a packaging comprising at least 80% wt of cellulosic fibres based upon the total weight of the packaging, a metallized polymer coating in contact with the cellulosic fibres, and a polymer coating in contact with the metallized polymer coating; wherein the capsule is placed within the packaging.

2. A packaged capsule as claimed in claim 1, wherein the cellulosic fibres in the capsule and / or the membrane are selected from cellulose fibres from wood, jut, bagasse, hemp, straw, bamboo and combinations thereof, preferably cellulose fibres from wood, jut, bagasse, hemp, and combinations thereof.

3. A packaged capsule as claimed in claim 1 or claim 2, wherein the inorganic coating is a polymer from a sol-gel process of a mixture of one or more alkoxy silane monomers and an acid catalyst in water.

4. A packaged capsule as claimed in claim 3, wherein the one or more alkoxy silane monomers are selected from tetraethyl orthosilicate, triethoxy methylsilane, triethoxy(methyl)alkoxy silane, triethoxy(ethyl)alkoxy silane, triethoxy(propyl)alkoxysilane, butyltriethoxyalkoxy silane, triethoxy(isopentyl)alkoxy silane, (3,3- dimethylbutyl)triethoxyalkoxy silane, triethoxy(vinyl)alkoxy silane, 3- (triethoxysilyl)propan-l-amine, 3-(triethoxysilyl)propyl methacrylate, trimethoxy(methyl)alkoxy silane, trimethoxy(ethyl)alkoxy silane, trimethoxy(propyl)alkoxy silane, butyltrimethoxyalkoxy silane, trimethoxy(isopentyl)alkoxy silane, (3,3-dimethylbutyl)trimethoxyalkoxy silane, trimethoxy(vinyl)alkoxy silane, 3-(trimethoxysilyl)propan-l-amine, and 3- (trimethoxysilyl)propyl methacrylate, preferably selected from tetraethyl orthosilicate and triethoxy methylsilane.

5. A packaged capsule as claimed in claim 3 or claim 4, wherein the acid catalyst is selected from hydrochloric acid, acetic acid, malic acid and lactic acid.

6. A packaged capsule as claimed in claim 1 or claim 2, wherein the natural polymer coating is cellophane.

7. A packaged capsule as claimed in any one of claims I to 6, wherein the edible product is selected from coffee, milk, tea, chocolate, or emulsified fat (e.g. a creamer), preferably coffee, more preferably ground coffee.

8. A packaged capsule as claimed in any one of claims 1 to 7, wherein the metallized polymer coating of the packaging comprises a polymer layer and a barrier layer.

9. A packaged capsule as claimed in claim 8, wherein the polymer layer comprises at least one polymer selected from a polyolefin, a polyester, and combinations thereof, preferably wherein the polymer layer comprises at least one polymer selected from low-density polyethylene, high-density polyethylene, polypropylene, polybutylene, polyisobutylene, polyethylene tetraphthalate, ethylene vinyl alcohol, polylactic acid,and combinations thereof, more preferably wherein the polymer layer comprises polypropylene.

10. A packaged capsule as claimed in claim 8 or claim 9, wherein the barrier layer of the metallized polymer coating comprises a metal, preferably aluminium.

11. A packaged capsule as claimed in any one of claims 1 to 10, wherein the capsule is compostable and / or the packaging is recyclable.

12. A packet comprising a plurality of packaged capsules as claimed in any one of claims I to 11.

13. A method for manufacturing a packaged capsule, the method comprising the steps of: a) providing a capsule comprising cellulosic fibres; b) preparing a mixture comprising one or more alkoxy silane monomers and an acid catalyst in water; c) applying the mixture to said capsule; d) reacting the mixture with the cellulosic fibres of said capsule; e) subjecting the mixture to the sol-gel process to obtain a treated capsule; f) drying the treated capsule to obtain a capsule surface-coated with a lining; g) at least partially filling the capsule with an edible product suitable for human consumption; h) sealing the capsule with a membrane comprising cellulosic fibres, wherein the membrane is surface-coated with the same lining as the capsule; and i) placing the capsule in a packaging, wherein the packaging comprises at least 80% wt of cellulosic fibres based upon the total weight of the packaging, a metallized polymer coating in contact with the cellulosic fibres, and a polymer coating in contact with the metallized polymer coating.

14. A method for manufacturing a packaged capsule, the method comprising the steps of: a) providing a capsule comprising cellulosic fibres; b) coating a natural polymer onto the capsule to obtain a treated capsule; c) drying the treated capsule to obtain a capsule surface-coated with a lining; d) at least partially filling the capsule with an edible product suitable for human consumption; e) sealing the capsule with a membrane comprising cellulosic fibres, wherein the membrane is surface-coated with the same lining as the capsule; and f) placing the capsule in a packaging, wherein the packaging comprises at least 80% wt of cellulosic fibres based upon the total weight of the packaging, a metallized polymer coating in contact with the cellulosic fibres, and a polymer coating in contact with the metallized polymer coating.

15. A packaged capsule obtained by the method of claim 13 or claim 14.

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