Compostable materials for packaging food

Abstract

A compostable material for packaging food, comprising coffee-based granular material and at least one binder selected from methylcellulose, methylcellulose derivatives, and mixtures thereof.

Description

Technical Field

[0001] The present disclosure relates to compostable materials for packaging food products. Background Art

[0002] Compostable materials for packaging food products are currently known and available in different forms depending on the specific application. Growing interest is directed to identifying compostable materials for packaging food that can maintain their integrity even when subjected to, for example, thermal stress and pressure. In addition, the materials used to package food must meet requirements for being suitable for contact with food. However, the characteristics of compostability, degradation resistance, thermomechanical strength, suitability for contact with food may not be easily obtained in the same product simultaneously. Summary of the invention

[0003] It is an object of one or more embodiments of the present disclosure to provide a compostable material suitable for packaging food. In one or more embodiments, the compostable material is particularly suitable for producing capsules designed to contain doses of food substances.

[0004] According to one or more embodiments, the above objects are achieved by a compostable material having the features specified in the appended claims.

[0005] The claims form an integral part of the technical teaching provided herein in relation to the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] One or more embodiments will now be described, by way of non-limiting example only, with reference to the following drawings, in which:

[0007] - Figure 1 and Figure 2 shows a capsule made of a compostable material according to an embodiment of the present disclosure;

[0008] - Figure 3 and Figure 4 shows a capsule made of a compostable material according to an embodiment of the present disclosure;

[0009] - Figure 5 A block diagram showing steps relating to a method of producing a capsule according to an embodiment of the present disclosure;

[0010] - Figure 6 is a schematic diagram of the steps of a method of producing a capsule according to an embodiment of the present disclosure;

[0011] - Figure 7 A block diagram showing steps relating to a method of producing a capsule according to an embodiment of the present disclosure;

[0012] - Figure 8is a schematic diagram of the steps of a method of producing a capsule according to an embodiment of the present disclosure;

[0013] - Fig. 9 illustrates a histogram showing the results of migration experimental tests conducted on compostable materials according to embodiments of the present disclosure;

[0014] - Fig.10 A histogram showing the results of experimental testing conducted on compostable materials according to embodiments of the present disclosure is illustrated. DETAILED DESCRIPTION

[0015] In the following description, various specific details are shown to enable a deeper understanding of the examples of the embodiments of the present disclosure. These embodiments can be obtained without one or more of the specific details, or using other methods, components, materials, etc. In other cases, known structures, materials, or operations are not shown or described in detail so that various aspects of the embodiments will not be obscure.

[0016] Reference to "an embodiment" or "one embodiment" in the framework of the present disclosure is intended to indicate that a particular configuration, structure, or feature described with respect to that embodiment is included in at least one embodiment. Thus, phrases such as "in an embodiment" or "in one embodiment" that may appear in various places in this specification do not necessarily refer to the same embodiment. Furthermore, in one or more embodiments, particular configurations, structures, or features may be combined in any suitable manner.

[0017] The references used herein are provided for convenience only and therefore do not limit the scope of protection or the scope of the embodiments.

[0018] The compostable material forming the subject of the present disclosure comprises a coffee-based particulate material and at least one binder selected from methylcellulose, methylcellulose derivatives, and mixtures thereof.

[0019] The methylcellulose derivative may be selected from the group consisting of hydroxypropylmethylcellulose, carboxymethylcellulose, hydroxyethylmethylcellulose.Preferably, the binder is methylcellulose.

[0020] Compostable materials can be used for packaging food. One embodiment of the present disclosure provides a container for food, which comprises, preferably consists of, the disclosed compostable material. Preferably, the container is a capsule containing a dose of at least one food substance (which can preferably be used for the preparation of a liquid product). The capsule obtained is a fully compostable capsule that can be disposed of in wet waste after its use.

[0021] The inventors of the present application have noticed that, based on specific tests described below, the disclosed compostable material has the advantage of being useful for manufacturing food containers that do not alter the organoleptic properties of the food contained therein. In this regard, in order to test the suitability of the material for contact with food, a "migration" test is performed on it. Such a test consists in determining the amount of substances that migrate from the material itself into a liquid (also called "simulated liquid").

[0022] Migration tests have shown the suitability of the compostable material forming the subject of the present disclosure for contact with food. Furthermore, the compostable material described has proven to be particularly suitable for producing capsules containing doses of substances for producing liquid products.

[0023] The coffee-based material may consist of coffee in various forms, such as roast and ground coffee, spent ground coffee (SGC), mixtures thereof.

[0024] The coffee-based particulate material may include various forms of coffee, such as roasted and ground coffee, spent ground coffee (SGC) and mixtures thereof. In one or more embodiments, the coffee-based particulate material may include at least one of roasted and ground coffee, spent ground coffee, and preferably may consist of it.

[0025] Waste ground coffee (post-consumer coffee or post-use coffee) can be obtained as a by-product of industrial preparations (e.g., by-products in the production of instant coffee and / or coffee-based beverages). In addition, waste ground coffee can also come from the collection and recycling of waste generated by the preparation of coffee in restaurants and catering sectors (e.g., bars, restaurants) and households.

[0026] The binder is selected from methyl cellulose, methyl cellulose derivatives, and mixtures thereof.

[0027] The combination of a binder, preferably methylcellulose, with the coffee-based particulate material makes it possible to obtain a compostable material which is particularly suitable for producing capsules containing doses of food substances, for example capsules for producing liquid products such as coffee.

[0028] The specific combination of coffee-based granular material and adhesive (preferably methylcellulose) has advantages in tolerance and migration test of compostable materials. On the contrary, the experimental test of compostable materials comprising adhesives (such as alginate) different from methylcellulose or its derivatives presents non-optimal use characteristics. Such materials can cause the change of food organoleptic properties, and discoloration may occur, which is unpleasant from an aesthetic point of view. In addition, such materials are not easy to be molded, and their purposes may be limited to the spraying or dipping process of food to be packaged. The inventor has noticed that in order to be conducive to the moldability of such materials, particularly in order to produce capsules for dispensing coffee, it is necessary to add at least one plasticizer, such as glycerine, to such materials. However, the capsule obtained by the compostable material (combining coffee and alginate) comprising glycerine may burst in the beverage dispensing process.

[0029] On the contrary, the compostable material forming the subject of the present application retains rigid characteristics, thus enabling optimal dispensing without releasing any powder or residue in the prepared liquid product and / or in the machine used to prepare said liquid product. In particular, the capsules made of said material retain their shape, elasticity and leaktightness even when used in a machine for dispensing liquid products such as coffee by introducing water and / or steam at a temperature ranging from 50° C. to 100° C. and a pressure ranging from 1 bar to 30 bar.

[0030] Furthermore, the various parts of the capsule may be connected together only by an adhesive connection, without resorting to, for example, a glue connection, which may present critical aspects with regard to possible contact with food substances.

[0031] The compostable material may comprise coffee-based particulate material in an amount of 50% to 80% by weight (wt / wt) of the compostable material.

[0032] The binder may be included in the compostable material in an amount of 20% to 50% by weight (wt / wt) of the compostable material.

[0033] The weight ratio between the particulate material and the binder may be 1:1 to 4:1. Preferably, the weight ratio between the particulate material and the binder is equal to 4:1.

[0034] The above weight ratios allow obtaining a compostable material which is free of plasticizers, such as polyol compounds, and which is at the same time particularly suitable for molding.

[0035] In one or more embodiments, the compostable material consists of a coffee-based particulate material and a binder, preferably methylcellulose.

[0036] The compostable material forming the subject of the present disclosure may be produced by a first step of mixing the components, namely the coffee-based particulate material and the binder, preferably methylcellulose. Preferably, these components are mixed in the presence of water to obtain a homogeneous mixture. The weight ratio between the amount of water and the solid ingredients (coffee-based particulate material and binder) may be between 1.2 and 1.5.

[0037] Once a homogeneous mixture is obtained, it is molded to obtain the desired thickness of material, for example by extrusion or injection molding.

[0038] In one or more embodiments, films and sheets may also be obtained using techniques such as bubble film extrusion, starting from a suspension comprising a coffee-based material, at least one binder, preferably methylcellulose, and water.

[0039] The molding step can be carried out using a mold having the geometry of the container to be obtained. The mixture can then be placed under pressure to enable the material to take the shape of the mold. Next, the material can be dried, for example by exposure to a heat source (in an oven), microwave radiation, infrared radiation, drum drying, vacuum drying, freeze drying.

[0040] In one or more embodiments, after the molding and drying steps, the material can be subjected to a washing and subsequent drying step according to the methods outlined in the previous section. The washing step can help prevent trace amounts of coffee-based materials and binders from migrating from the material itself into the food contained therein. The washing step can be performed under cold conditions, at room temperature, or with hot (even boiling) water. Washing can be performed for intervals ranging from one second to one hour.

[0041] Compostable materials can advantageously be used to produce food containers, preferably capsules containing doses of substances that can be formed into liquid products by the introduction of water and / or steam.

[0042] The aforementioned materials may also be used to contain and protect a compressed dose of a substance, such as a compressed dose of coffee.One or more embodiments of the present disclosure provide a capsule containing a dose of at least one substance useful for preparing a liquid product, wherein the dose is a compressed dose of coffee.

[0043] The dose of the substance may be compressed by exerting pressure thereon or using a further compression procedure which envisages, for example, the use of freezing, exposure to infrared radiation or microwaves.

[0044] In various embodiments, the dose of the substance may be ground coffee or some other precursor of a liquid product, such as a beverage, tea, powdered or granulated chocolate, but may also be a product for preparing broths, soups, beverages and infusions of various natures: this list is to be understood as being provided by way of non-limiting examples. In the following, for the sake of simplicity, reference will be made to a capsule for preparing coffee, wherein the dose is understood to consist of ground coffee.

[0045] In one or more embodiments, the structure of the capsules containing the disclosed compostable materials can have different forms.

[0046] In one or more embodiments, for example Figure 1-4 As shown, the structure of the capsule 1 defines a chamber 2 for receiving a dose of a substance, and includes a first body portion 4 and a second body portion 6. Only one or both of the two body portions may include, and preferably may consist of, a compostable material as described herein. In one or more different embodiments, one of the two body portions may include a compostable material, for example selected from: paper, cellophane, cellulose and its derivatives, polymers extracted from biomass (e.g., polysaccharides such as starch and its derivatives); synthetic polymers (e.g., polylactic acid PLA derived from starch fermentation, polybutylene terephthalate adipate PBAT); polymers produced by microorganisms or genetically modified bacteria (e.g., polyhydroxyalkanoates, such as PHA, PHB, PHV, PHH); polymers from fossil monomers (e.g., polybutylene succinate-PBS, polycaprolactone-PCL); polyanhydrides, polyvinyl alcohol; this category may also include mixtures of the above compounds and / or the introduction of additives such as nanoparticles (e.g., talc, organosilicates (cloisite)).

[0047] Each body portion comprises an outer surface and an inner surface. The first body portion 4 and the second body portion 6 are connected in a manner that the respective outer surfaces face the outside of the capsule and the respective inner surfaces face each other and the inside of the capsule. At least one of the first and second body portions comprises a concave inner surface. Preferably, at least one of the first and second body portions may comprise a convex outer surface. At least one of the first and second body portions comprises, preferably consists of, a compostable material forming the subject matter of the present disclosure.

[0048] exist Figure 1 and 2 In the example shown, the capsule may include a first body portion 4 formed on a side wall 8 and a first end wall 10. A second body portion 6 is formed only on a second end wall 12. For example, the first end wall 10 and the second end wall 12 may be transverse walls - also defined herein as "bottom wall" and "closure wall" for simplicity only. Figure 2In the example shown, the capsule 1 is a sealed capsule, the end wall of which has no openings. The end wall 10 and the side wall 8 are made of a single piece.

[0049] The second end wall (or closing wall) 12 is secured to the side wall 8 at the peripheral edge 9 by means of the peripheral edge 11. The adhesion is ensured simply by wetting and joining the mouth portion of the first body portion 4.

[0050] The first body portion 4 may have a cup-like or tray-like shape diverging from the bottom 10 to the end closed by the closed wall 12. This diverging shape may be a truncated cone. The capsule 1 may have different shapes, such as substantially cylindrical or substantially hemispherical or cup-shaped. The bottom wall 10 may have a structure of a concave dome, with the concave surface of the dome facing the outside of the capsule 1. Also in this case, the choice of this structure is not restrictive, for example the capsule 1 may have a dome-shaped bottom wall 10 with the concave surface facing the inside of the capsule 1, or a flat or substantially flat bottom wall 10. In one or more embodiments, the bottom wall 10 may have a protrusion extending to a certain height inside the capsule, which height makes it possible to be arranged to contact the closed wall 12.

[0051] The structure of the end walls 10 and 12 of the two body parts may be rendered symmetrical so as to be able to dispense the beverage independently on one side or the other of the capsule, a choice which is a useful distinction for the design of the device for dispensing liquid products.

[0052] In one or more embodiments, at least one of the end wall 10, the side wall 8 and the closing wall 12 of the capsule may include, preferably may consist of, a compostable material forming the subject matter of the present disclosure. The capsule may also include at least one of the end wall 10, the side wall 8 and the closing wall 12 made of a compostable material selected from paper, cellophane, cellulose and its derivatives, polymers extracted from biomass (e.g., polysaccharides such as starch and its derivatives); synthetic polymers (e.g., polylactic acid PLA, polybutylene terephthalate adipate PBAT derived from starch fermentation); polymers produced by microorganisms or genetically modified bacteria (e.g., polyhydroxyalkanoates, such as PHA, PHB, PHV, PHH); polymers from fossil monomers (e.g., polybutylene succinate – PBS, polycaprolactone – PCL); polyanhydrides, polyvinyl alcohol; this category may also include mixtures of the above compounds and / or the introduction of additives such as nanoparticles (e.g., talc, organosilicates).

[0053] exist Figure 3 and 4In the example shown in , the capsule 1 has a first body part 4 and a second body part 6, both of which have a lens-like (or shell-like) shape. The two parts 4 and 6 are connected at respective peripheral edges 9, 11. Its inner surface faces and defines a chamber 2 for receiving a dose of a substance. The peripheral edges 9, 11 can extend toward the outside of the capsule, in particular toward the outside of the first and second body parts.

[0054] In the embodiment considered herein by way of example, it is envisaged that at least one of the first and second body portions of the capsule may be perforated by a tip of a machine for dispensing coffee, so as to enable the liquid product to flow out of the sleeve 1 through said portion.

[0055] In other embodiments, at least one between the first body portion 4 and the second body portion 6 may have a structure including at least one hole (eg, a porous structure) through which the liquid product may flow out of the capsule 1 .

[0056] In one or more embodiments, when the first body portion 4 includes the side wall 8 and the first end wall 10 and the second body portion 6 includes only the second end wall 12, at least one of the side wall 8, the first end wall 10 and the second end wall may include a structure (e.g., a porous structure) including at least one hole through which the aforementioned liquid product can flow out of the capsule 1.

[0057] Furthermore, the present disclosure provides a method for producing a capsule 1 containing a dose of at least one substance, preferably a substance for preparing a liquid product by liquid and / or steam introduced into the capsule 1. The method may comprise the following steps:

[0058] - a first body portion 4 is provided for containing a dose of food substance;

[0059] - arranging the dose in the first body portion 4;

[0060] - Closing the capsule 1 with a second body portion 6 which serves to close said first body portion 4 at respective peripheral edges 9, 11.

[0061] The method includes:

[0062] - at least one between said first body portion 4 and said second body portion 6 is made of a compostable material forming the subject of the present disclosure, said compostable material comprising, optionally consisting of, a coffee-based granular material and a binder (selected from methylcellulose, its derivatives, mixtures thereof);

[0063] - wetting at least one between said first body portion 4 and said second body portion 6 at the respective peripheral edges 9, 11;

[0064] - bringing said first body portion 4 and said second body portion 6 of the capsule into contact at their respective peripheral edges 9, 11;

[0065] - Optionally drying the capsule 1 .

[0066] In one or more embodiments, the wetting step can be performed with water and / or an aqueous solution comprising methylcellulose in an amount preferably from 0.01 wt % to 10 wt %.

[0067] Figure 5 A block diagram showing a method for producing the compostable material forming the subject of the present application and capsules obtained with said material, for example Figure 1 and 2 Capsules shown. Figure 6 Schematic diagram of the production steps of the capsule body part, ie, the body part 4 including the bottom wall 10 and the side wall 8.

[0068] like Figure 5 As shown, coffee, methylcellulose and water are mixed to form a homogeneous mixture. The mixture is divided into two parts: the first part is used to produce the main body part 6 formed only on the end wall (or closing wall) 12; and the second part is used to produce the main body part 4 of the capsule, which has a cup shape and includes the end wall (or bottom wall 10) and the side wall 8.

[0069] In the case of producing the end wall (or closing wall) 12, the mixture undergoes a molding step, for example a rotational molding step, to form a film. After a drying step, for example in a paternoster oven, the closing wall 12 of the capsule 1 is obtained from the film material.

[0070] The portion of the mixture used to produce the capsule body 4 comprising the bottom wall 10 and the side wall 8 is transferred to a doser and distributed in a multi-cavity mould. After the drying step, the body of the capsule is filled with a dose of substance (e.g. coffee) and then closed by adhering the closing wall 12.

[0071] Figure 6 Reference numeral 20 in the figure denotes a dosing device for the mixture, and reference numeral 22 denotes a mold having a plurality of cup-shaped cavities 23. The pressure applied by the punch 24 causes the material to be molded and formed into a cup shape. The material molded in this way is preferably dried in a paternoster oven 26 at a temperature of 15° C. to 105° C. After coming out of the oven 26, the punch 24 is removed from the mold 22, followed by a step of extracting the compostable material through a specially provided extractor 28. The compostable material, which has assumed a cup shape, undergoes a step of dosing a filling substance (e.g., coffee).

[0072] The capsule is then closed by connecting the closing wall 12 to the side wall 8 of the body 4 of the capsule 1 at the respective peripheral edges 9, 11.

[0073] Advantageously, the closing wall 12 can be connected to the body part 4, in particular to the side wall 8, without using any adhesive substance, glue, welding; in fact, the bonding of the two parts can be obtained by wetting the areas to be in contact. The wetting of the parts to be in contact can be obtained by techniques such as coating, spraying, applying with a paintbrush water or an aqueous solution containing methylcellulose (in a concentration of 0.01% to 10% by weight).

[0074] On the parts arranged in contact, pressure may be applied to promote their bonding.

[0075] Optionally, a drying step may then be carried out, for example in a paternoster oven as described above.

[0076] The capsule thus obtained, in which the first body portion 4 is connected to the second body portion 6 by contact bonding, advantageously does not envisage the use of synthetic bonding substances.

[0077] Figure 7 The present invention shows a method for producing compostable materials and methods such as Figure 3 and 4 Schematic diagram of the method steps of the capsule shown. In particular, coffee, methylcellulose and water are mixed to form a homogeneous mixture. The mixture is extruded to obtain a film.

[0078] The film of compostable material thus obtained is shaped, cut (dinking) and dried in a lens-shaped mold. The part of the excess material is collected and used for a new cycle. After drying, a predetermined dose of coffee is placed in one of the two lens-shaped body parts. The second body part is positioned on the first body part at the corresponding peripheral edges 9, 11 so as to obtain the closure of the capsule. In this case as well, in order to obtain adhesion of the two parts, it is sufficient to wet the peripheral edge parts to be in contact. On the parts set in contact, pressure can be applied to promote their adhesion. Optionally, a drying step can then be carried out, for example in a paternoster oven as described above.

[0079] The capsule thus obtained, in which the first body portion 4 is connected to the second body portion 6 by contact bonding, advantageously does not envisage the use of synthetic bonding substances.

[0080] Figure 8 The extruder 30 is shown from which a film of compostable material is obtained, which is placed on a multi-cavity die 32 comprising cavities 33 having a lens shape. The pressure applied by a rotating punch 34 will enable the material to assume a lens shape. A rotating cutter 36 cuts and divides the obtained portions. The excess portion is collected and returned to the extruder 30. Figure 8The paternoster oven in which the material is dried is shown. After exiting the oven 38, the step of extracting the compostable material from the mold 32 is then followed by an extractor 28 provided specifically for this purpose.

[0081] The resulting capsules can generally be considered compostable according to the UNI EN 13432 standard.

[0082] In various embodiments, the order of use of the capsules may correspond substantially to the order of use of the capsules described in EP-A-0 507 905 or WO 2012 / 077066 A1, which makes any repetition of the corresponding description superfluous herein. This order of use (which should be understood to be provided only by way of example and allows for different variants) is considered to be known per se, which makes a more detailed description thereof superfluous.

[0083] Thus, the compostable material forming the subject of the present disclosure has the advantage of being useful for containing food products, providing a heat and pressure resistant support, and being perforated by the perforating tip of a machine for dispensing liquid products such as coffee, and then being disposable as a compostable material.

[0084] In the applications considered herein, i.e. in the case where the compostable material is used for packaging food, which food will be heated at a temperature ranging from 50° C. to 100° C. and a pressure ranging from 1 bar to 30 bar and water and / or steam will be introduced, the compostable material may undergo phenomena of softening, melting, altering the food contained therein, which is essentially due to the fact that the material is of natural origin.

[0085] The compostable material forming the subject of the present disclosure is able to overcome said drawbacks, since the specific combination of coffee-based particulate material and binder, preferably methylcellulose, in the indicated quantitative ratios presents rigid properties, thereby facilitating the retention of structural properties under the temperature and pressure conditions of beverage dispensing.

[0086] The specific combination of the composite components in specific weight ratios imparts thermomechanical strength to the material, for example when the material is subjected to a process of vacuum packaging or packaging in a modified atmosphere.

[0087] Thus, one or more embodiments make it possible to provide a material having compostable properties, which has a particular stability and strength with respect to mechanical and thermal stresses and pressures, and which can be used in machines for dispensing coffee.

[0088] Example

[0089] Comparative experimental tests were conducted in the following areas:

[0090] - a compostable material forming the subject matter of the present disclosure comprising a coffee-based particulate material and methylcellulose, with and without glycerol as a plasticizer; and

[0091] - Compostable material comprising coffee-based particulate material and alginate as binder, with and without glycerol as plasticizer.

[0092] These materials were tested for migration using a standard protocol for evaluating total dissolved solids (TDS).

[0093] The first set of experiments

[0094] Migration testing is performed by immersing the compostable material in hot water at a temperature of 80°C to 90°C, keeping the aqueous solution agitated, and evaluating the change in the solution's color after a few minutes (usually two minutes).

[0095] The first set of experiments was conducted on a compostable material with a thickness of 2.5 mm, comprising coffee, methylcellulose and optionally glycerol in the following quantitative ratios:

[0096] - Coffee and methylcellulose in a weight ratio of 4:1 ( Fig. 9 4:1C:CMC in the figure);

[0097] - coffee and methylcellulose in a weight ratio of 4:1, and glycerol in an amount equal to 20% by weight ( Fig. 9 4:1 20% glycerol in the figure);

[0098] - coffee and methylcellulose in a weight ratio of 4:1, and glycerol in an amount equal to 15% by weight of the material ( Fig. 9 4:1 15% glycerol in the figure);

[0099] - coffee and methylcellulose in a weight ratio of 9:1, and glycerol in an amount equal to 20% by weight ( Fig. 9 9:1 ​​20% glycerol in the figure); and

[0100] - coffee and methylcellulose in a weight ratio of 7:3, and glycerol in an amount equal to 20% by weight ( Fig. 9 7:3 20% glycerol in the figure).

[0101] A control test was conducted using water only.

[0102] The results of the migration tests showed that glycerol helped reduce the amount of total dissolved solids (TDS) when combined with coffee and methylcellulose at a specific weight ratio of 4:1.

[0103] However, these materials suffer from discoloration, which can be observed in particular during the drying step at 60° C. for 5 hours and when the material is subjected to a pressure of about 250 Pa. Furthermore, this material has the disadvantage that, during its production, optimal surface adhesion between the contact parts of the capsule arrangement is not guaranteed.

[0104] The second set of experiments

[0105] Compostable materials comprising coffee, sodium alginate and glycerol as a binder were tested. The obtained material did not show satisfactory properties, especially in the production process of capsules. In addition, the method for producing the material requires acidic pH conditions in the alginate cross-linking process in the presence of glycerol to obtain sufficiently soft and processable materials. However, acidic pH causes color changes in the obtained compostable material, so from an aesthetic point of view, the capsule has an unsatisfactory appearance. In addition, migration tests have demonstrated the tendency of glycerol to migrate from the compostable material.

[0106] The third group of experiments

[0107] Migration tests were performed on compostable materials in the form of disks with a diameter of 50 mm and a thickness of 1.5 mm, containing different combinations of components, after soaking in deionized water (DI water) and boiling for 30 minutes. In particular, the following results were obtained:

[0108] - a disc of material comprising coffee and methylcellulose in a weight ratio of 80:20;

[0109] - a disc of material comprising spent ground coffee (SGC) and methylcellulose in a weight ratio of 80:20;

[0110] - a disc of material comprising coffee and methylcellulose in a weight ratio of 50:50; and

[0111] - A disc of material comprising spent ground coffee (SGC) and methylcellulose in a 50:50 weight ratio.

[0112] Fig.10 The results of the graph show that the migration of the disc containing spent ground coffee instead of coffee was reduced. In addition, cleaning the disc before experimental testing was shown to help further reduce migration.

[0113] The disks tested for migration were also analyzed from a dimensional perspective. The analysis showed that the step of washing the disks, while beneficial in reducing migration, resulted in shrinkage of the disks.

[0114] For example, the diameter of the discs containing coffee and methylcellulose in a weight ratio of 80:20 showed a variation from 50 mm to 46.9 mm. The discs containing spent ground coffee and methylcellulose in a weight ratio of 50:50 showed a variation from 50 mm to 40.2 mm. The discs containing spent ground coffee and methylcellulose in a weight ratio of 80:20 showed a variation from 50 mm to 47.2 mm.

[0115] The fourth experiment

[0116] Further migration tests were carried out by adding food coloring agents to the mixture. In particular, a blue coloring agent (GNT ExBerry Shade Blue) was used in an amount equal to 0.5 ml for 20 g of a mixture used to obtain a compostable material comprising coffee and methylcellulose in a weight ratio of 80:20; a disk having a diameter of 50 mm and a thickness of 1.5 mm was obtained.

[0117] The tests were carried out in cold deionized water at room temperature and also in deionized water at a temperature of about 90°C.

[0118] No migration of the dye into aqueous solution was observed, thus demonstrating that the materials forming the subject matter of the present disclosure are suitable for packaging food products.

[0119] The fifth experiment

[0120] Compostable materials containing different quantitative ratios of coffee and methylcellulose were analyzed at various steps of material production and processing.

[0121] In particular, the analyzed compostable materials contained quantitative ratios between coffee and methylcellulose equal to 80:20, 50:50, 30:70.

[0122] The above compostable material is obtained from a mixture comprising water in an amount of about 55 to 60 wt % relative to the total weight of the mixture.

[0123] The compostable material with a weight ratio of coffee to methylcellulose of 80:20 (80:20) was obtained from a soft mixture that was easy to mix; the compostable material with a weight ratio of coffee to methylcellulose of 50:50 (50:50) was obtained from a medium-hard mixture, and the compostable material with a ratio of coffee to methylcellulose of 30:70 (30:70) was obtained from a mixture that required a long mixing time and was difficult to process.

[0124] In the molding step of the material, the materials 20:80 and 50:50 have good surface adhesion and are easy to mold without causing tearing. In addition, the material 50:50 is suitable for producing thin sheets.

[0125] Furthermore, the material 80:20 has the advantage that during the production step the mixture can even be dried at low temperatures for a period of about two / three hours without structural changes occurring. With increasing amounts of methylcellulose (material 30:70), shrinkage phenomena can occur during the drying process, i.e. phenomena that can generate stresses and lead to material failure.

[0126] The materials containing coffee and methylcellulose in weight ratios of 80:20 and 50:50 can be easily removed from the mold cavity with little or no surface defects. In addition, the material 80:20 has a light color, while the materials 50:50 and 30:70 have a darker color.

[0127] The results obtained in various sets of experimental tests show that compostable materials comprising coffee-based materials and a binder, preferably cellulose, have advantages over compostable materials comprising other binders and coffee. Compostable materials comprising coffee and alginate as a binder, possibly in the presence of glycerol, have not proven suitable for the production of food containers, in particular rigid containers, such as capsules containing doses of substances for the production of liquid products.

[0128] The presence of glycerol as a plasticizer does not provide a clear advantage for compostable materials and migration may occur.

[0129] A specific amount of binder, preferably methylcellulose, preferably 20 to 50% by weight of the compostable material, gives the material optimal properties in terms of the capsule production process.

[0130] Furthermore, the use of spent ground coffee in combination with a binder, preferably methylcellulose, proves to be advantageous both in terms of cost and transport.

[0131] Without prejudice to the essential principles and without departing from the scope of protection of the present invention, the details of construction and embodiment may vary, even significantly, with respect to what is described herein merely by way of non-limiting example, which scope is defined by the appended claims.

Claims

1. A compostable material for food packaging, the compostable material consisting of a coffee-based granular material and methylcellulose as a binder, wherein the coffee-based particulate material comprises at least one of roast and ground coffee, spent ground coffee, and mixtures thereof, The weight ratio between the coffee-based particulate material and the binder is 1:1 to 4:

1.

2. The compostable material according to claim 1, wherein the weight ratio between the coffee-based particulate material and the binder is equal to 4:

1.

3. Capsule (1) suitable for containing a dose of at least one food substance, said capsule comprising a compostable material according to claim 1 or 2.

4. The capsule (1) according to claim 3, wherein the capsule (1) contains a dose of at least one food substance for preparing a liquid product, the capsule (1) comprising a first body portion (4) and a second body portion (6), wherein each of the first body portion (4) and the second body portion (6) comprises an outer surface and an inner surface, wherein the first main body portion (4) and the second main body portion (6) are connected in such a way that their respective outer surfaces face the outside of the capsule and their respective inner surfaces face each other and the inside of the capsule, wherein at least one of the first body portion (4) and the second body portion (6) comprises a concave inner surface, At least one of the first body portion (4) and the second body portion (6) comprises a compostable material according to any one of claims 1 or 2.

5. Capsule (1) according to claim 4, wherein the first body portion (4) is formed on the side wall (8) and the first end wall (10), and the second body portion (6) is formed only on the second end wall (12).

6. Capsule (1) according to claim 4, wherein the first body portion (4) and the second body portion (6) have a lens-like shape and are connected at respective peripheral edges (9, 11) such that inner surfaces face each other.

7. The capsule (1) according to any one of claims 4 to 6, wherein the first body portion (4) is connected to the second body portion (6) by contact bonding, and wherein the capsule (1) is free of synthetic adhesive substances.

8. The capsule (1) according to claim 4, wherein at least one of the first body portion (4) and the second body portion (6) has a structure comprising at least one hole through which the liquid product can flow out of the capsule (1).

9. The capsule (1) according to claim 5, wherein at least one of the side wall (8), the first end wall (10) and the second end wall (12) has a structure comprising at least one hole through which the liquid product can flow out of the capsule (1).

10. The capsule (1) according to claim 4, wherein one of the two body parts comprises a compostable material selected from the group consisting of: paper, cellulose, polyanhydride, polyvinyl alcohol, and mixtures thereof.

11. Capsule (1) according to claim 4, wherein said dose of at least one substance for preparing a liquid product is a compressed dose of coffee.

12. A method for manufacturing a capsule (1) containing a dose of at least one food substance, the method comprising the steps of: - providing a first body portion (4) for containing said dose, - arranging the dose in the first body portion (4), - closing the capsule (1) with a second body portion (6) for closing the first body portion (4) at respective peripheral edges (9, 11), The method comprises: - providing at least one of the first body portion (4) and the second body portion (6) of a compostable material according to claim 1 or 2, - wetting at least one of the first body portion (4) and the second body portion (6) at the peripheral edge (9, 11), - bringing the first body portion (4) and the second body portion (6) into contact at respective peripheral edges (9, 11).

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