A capsule for preparation of a beverage

Abstract

 The present invention is directed to a capsule (1) for delivering a drink by injecting a pressurized fluid into the capsule comprising:
- a hollow body and an injection wall (4) which is impermeable to liquids and to gas and which is attached to the body and adapted to be punctured by an injection means (2) foreign to the capsule,
- a chamber (5) containing a bed of at least one food substance to be extracted,
- means (7, 9, 10) for retaining the internal pressure in the said chamber, said means comprising a pierceable membrane (7),

characterized in that said capsule (1) further comprises a secondary means (12) for maintaining the bed of substance at a distance d from said pierceable membrane (7), said distance d being at least 1 mm, preferably at least 2 mm, more preferably at least 3 mm.

Description

Field of the invention

[0001] The present invention concerns a capsule for the preparation of beverages in a beverage preparation machine, involving a high pressure extraction and/or dissolution.

Background of the invention

[0002] The present invention is directed to a capsule (that is preferably a completely closed capsule although one its walls might be open), for use in a beverage preparation machine. The machine comprises a receptacle for accommodating said capsule and a fluid injection system for injecting a fluid, preferably water, under pressure into said capsule. Water injected under pressure in the capsule, for the preparation of a coffee beverage according to the present invention, is preferably hot, that is to say at a temperature above 70°C. However, in some particular instances, it might also be at ambient temperature. The pressure inside the capsule chamber during extraction and/or dissolution of the capsule contents is typically about 1 to 6 bar for dissolution products, 2 to 12 bar for extraction of roast and ground coffee. Such a preparation process differs a lot from the so-called "brewing" process of beverage preparation - particularly for tea and coffee, in that brewing involves a long time of infusion of the ingredient by a fluid (e.g. hot water), whereas the beverage preparation process allows a consumer to prepare a beverage, for instance coffee within a few seconds.

[0003] The principle of extracting and/or dissolving the contents of a closed capsule under pressure is known and consists typically of confining the capsule in a receptacle of a machine, injecting a quantity of pressurized water into the capsule, generally after piercing a face of the capsule with a piercing injection element such as a fluid injection needle mounted on the machine, so as to create a pressurized environment inside the capsule either to extract the substance or dissolve it, and then release the extracted substance or the dissolved substance through the capsule. Capsules allowing the application of this principle have already been described for example in applicant's European patent n° EP 1 472 156 B1, and in EP 1 784 344 B1.

[0004] Machines allowing the application of this principle have already been described for example in patents CH 605 293 and EP 242 556. According to these documents, the machine comprises a receptacle for the capsule and a perforation and injection element made in the form of a hollow needle comprising in its distal region one or more liquid injection orifices. The needle has a dual function in that it opens the top portion of the capsule on the one hand, and that it forms the water inlet channel into the capsule on the other hand.

[0005] When the beverage to be prepared is coffee, one interesting way to prepare the said coffee is to provide the consumer with a capsule containing roast and ground coffee powder, which is to be extracted with hot water injected therein.

[0006] Capsules have been developed for such an application, which are described and claimed in applicant's European patent EP 1 784 344 B1, or in European patent application EP 2 062 831.

[0007] In short, such capsules comprise typically:

• a hollow body and an injection wall which is impermeable to liquids and to air and which is attached to the body and adapted to be punctured by e.g. an injection needle of the machine,
• a chamber containing a bed of roast and ground coffee to be extracted,
• an aluminium membrane disposed at the bottom end of the capsule, closing the said capsule, for retaining the internal pressure in the chamber, the said membrane being associated with piercing means for piercing dispensing holes in the said aluminium membrane when said internal pressure inside the chamber reaches a certain predetermined value,
• optionally, means configured to break the jet of fluid so as to reduce the speed of the jet of fluid injected into the capsule and distribute the fluid across the bed of substance at a reduced speed.

[0008] The jet-breaking means comprises an injection space between the injection wall and the chamber allowing the injection needle to inject a jet of pressurized fluid to be introduced through the injection wall. The distributing and jet-breaking means further comprises at least one punctured wall which separates the injection space from the chamber containing the bed of substance and the perforated wall is positioned, in order to keep the bed of substance in compression in the non-hydrated state of the substance.

[0009] It was found that in such coffee capsules, pressure inside the capsule chamber increases during extraction/dissolution by the injection fluid by the fact that the self-opening system present at the bottom of the capsule - which is an excellent system to guarantee the product freshness throughout storage - builds a pressure inside the capsule when fluid is injected therein. This is due to the mechanical resistance of the aluminum membrane, which is pierced by the piercing means only after some pressure inside the capsule pushes said membrane onto the piercing means. The pressure necessary to open the membrane can be varied by selecting a material having a lower resistance (thinner aluminum for instance). However the membrane thickness cannot be decreased below a certain level, so as not to comprise its gas, and light properties.

[0010] It was found that this effect of pressure build-up inside the capsule before it self-opens, is increased by the fact that the smallest coffee particles (so-called "fines") present in the mass of roast and ground coffee powder, move downwards during circulation of the extraction fluid inside the capsule chamber, and clog the dispensing holes of the aluminum membrane that is present at the bottom part of the membrane. In that case, liquid circulation is slowed-down, and fluid pressure inside the capsule builds-up even more, as the pump of the machine continues to inject fluid inside the capsule chamber.

[0011] The purpose of the present invention is to obviate the aforementioned problems, and provide a capsule allowing preparation of a brew-like (i.e. low-pressure coffee, that is to say between 1 and 3 bar) beverage without - or at least with very little - foam, in a capsule comprising a self-opening freshness system as described above.

Summary of the invention

[0012] The purpose mentioned above is met with the present invention, with a capsule for delivering a drink by injecting a pressurized fluid into the capsule comprising:

• a hollow body and an injection wall which is impermeable to liquids and to gas and which is attached to the body and adapted to be punctured by an injection means foreign to the capsule,
• a chamber containing a bed of at least one food substance to be extracted,
• means for retaining the internal pressure in the said chamber, said means comprising a pierceable membrane,

characterized in that said capsule further comprises a secondary means for maintaining the bed of substance at a distance d from said pierceable membrane, said distance d being at least 1 mm, preferably at least 2 mm, more preferably at least 3 mm.

[0013] The invention provides a solution to prepare a product having filter-coffee taste and look, while preparing the cup using a high-pressure machine. According to the invention, the new capsule of the present invention allows to decrease the pressure inside the capsule chamber, with minimum mixing/shearing of coffee. Hence, in this invention coffee is separated from the Aluminum membrane. The coffee thus produced has very little foam (also called "crema"), or no foam at all.

[0014] In one preferred embodiment of the present invention, the capsule which further comprises means configured to break the jet of fluid so as to reduce the speed of the jet of fluid injected into the capsule and distribute the fluid across the bed of substance at a reduced speed wherein it comprises an injection space between the injection wall and the chamber allowing the injection means to inject at least one jet of pressurized fluid to be introduced through the injection wall, wherein the distributing and jet-breaking means comprise at least one punctured wall which separates the injection space from the chamber containing the bed of substance and the perforated wall is positioned in order to keep the bed of substance in compression in the non-hydrated state of the substance. By non-hydrated it is meant state of the coffee powder prior to the extraction fluid wetting the mass of coffee.

[0015] Advantageously, the wall can comprise welding edges which are welded against the internal surface of the hollow body in such a way as to position the said wall back from the injection wall.

[0016] Preferably, the wall is a deformable flexible film.

[0017] Also preferably, the openings of the perforated wall are distributed substantially uniformly across the wall so as to distribute the stream of fluid substantially uniformly across the bed of substance

[0018] Advantageously, the pressure retaining means can comprise:

• the pierceable membrane,
• raised elements which open the said membrane in order to create punctures and allow the liquid extract to pass through the punctures; the punctures in the membrane being obtained under the effect of the rise in pressure in the chamber of the capsule.

[0019] In this case, the raised elements are preferably distributed over a plate which comprises ducts leading to openings, passages or slots through which the drink can flow

[0020] In any case, the secondary means can advantageously comprise a perforated wall chosen from a plastic or fiber wall with holes, a film with holes, a grating, a layer of woven or nonwoven material, a porous layer or a combination thereof.

[0021] In one possible embodiment, the space between the secondary means and the pierceable membrane comprises a layer or mass of discrete elements for instance a layer of granulate inert material to limit the deformation of the secondary means during the beverage preparation. Such a layer or mass of discrete elements, allows to keep the secondary means at a distance from the pierceable membrane, whatever the conditions of pressure inside the capsule, and even though fluid circulates within said capsule; at the same time, the said layer or mass allows to completely let the extraction/dissolution fluid circulate, due the spaces between the discrete elements.

[0022] In a particularly preferred embodiment of the present invention, the capsule chamber containing the bed of substance to be extracted and/or dissolved, is divided by at least one dividing wall into at least two corresponding compartments, each containing one type of substance to be extracted and/or dissolved in an at least partially sequential manner.

[0023] In the latter embodiment, the compartments preferably comprise an upper compartment containing a powdered soluble coffee to be dissolved to produce a liquid coffee solution, and a lower compartment containing a mass of roast and ground coffee to be extracted under pressure by said liquid coffee solution.

[0024] Also, at least one of the compartments advantageously encloses a bed of substance to be extracted and/or dissolved, such that said substance is in a compressed state at least at the time pressurized fluid circulates through said substance.

Brief description of the drawings

[0025] 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:

Figure 1 is a schematic profile cut view of a capsule according to the invention;

Figure 2 is a schematic profile cut view of an alternative embodiment of a capsule according to the invention.

Detailed description of the invention

[0026] In the following detailed description, the embodiment considers that the capsule according to the invention comprises coffee, in roast and ground and/or soluble powder form. However, the capsule as described herebelow could be filled with any other food ingredient that would be suitable for being extracted and/or dissolved by a fluid under pressure, in a beverage preparation machine described in preamble. Such ingredients can be in gel, concentrate, powder or particulate soluble form and include but are not limited to: tea, dehydrated soup, milk powder, infant formula powder, fruit juice concentrate, dairy creamers, sweetening ingredients, natural or artificial, cocoa-based ingredients, spices, meat, fish, vegetable ingredients, and mixtures thereof.

[0027] Illustrated in figure 1, is a capsule 1 for delivering a drink by injecting a pressurized fluid into said capsule. The injection is done by placing the capsule into a machine (not illustrated in the drawing), which machine comprises a needle 2 through which a extraction fluid is pumped under pressure (illustrated by a dashed arrow), and injected in the capsule.

[0028] The capsule 1 comprises a hollow body 3 and a top injection wall 4 which is a flexible membrane welded onto the capsule body 3, the said membrane 4 being impermeable to liquids and to gas. The top membrane wall 4 is adapted to be punctured by the needle 2.

[0029] The capsule 1 further comprises a chamber 5 containing a bed of at least one food substance 6 to be extracted.

[0030] The chamber 5 of the capsule is closed at its bottom side by means for retaining the internal pressure in the said chamber. This pressure retaining means comprises:

• a pierceable aluminum membrane 7 that is sealed onto an edge 8 in the lower part of the capsule, and
• raised elements 9 to create punctures through the membrane 7 and allow the liquid extract produced inside the capsule to pass through the said punctures; the raised elements are pyramid-shaped pins 9 which are distributed over a plate 10. The plate 10 comprises ducts (not illustrated in the drawing) leading to a dispensing opening 11 of the capsule through which the prepared liquid drink can flow.

[0031] Punctures in the membrane 7 are obtained under the effect of the rise in pressure in the chamber of the capsule, which presses said membrane 7 against the pins 9 of the plate 10, such that the pins perforate the membrane. The membrane is made in aluminum and has a thickness comprised between 5 and 50 µm, preferably between 10 and 45 µm, and most preferably a thickness comprised between 25 and 40 µm. The thicker the membrane, the higher the pressure inside the capsule to allow a perforation of the membrane, and hence, the higher dissolution/extraction pressure inside the capsule chamber. Particularly, it was found that the thinner the bottom aluminum membrane, the lower the pressure. Specific piercing plate should be able to create holes on Aluminum easily without the need for building a high pressure inside the capsule.

[0032] In the example described with reference to figure 1, the thickness of the aluminum membrane 7 is chosen such that the extraction pressure inside the capsule chamber 5 before the said membrane is open by the pins 9 is between 0.1 and 3 bars (relative pressure), preferably between 1 and 3 bar (relative pressure).

[0033] According to the invention, the capsule 1 comprises secondary means 12 for maintaining the bed of substance 6 at a distance d from said pressure-retaining means 8, 9, 10. In the example, said distance d is 3 mm.

[0034] As illustrated in figure 1, the secondary means 12 comprise a perforated wall which is a membrane with holes having a diameter not greater than 500 µm. Particularly, it was found that it is important that roast and ground (R&G) coffee fines cannot reach the Aluminum membrane because this would increase the internal pressure inside the capsule by clogging at least partially the dispensing holes pierced through said aluminum membrane, as previously explained: the R&G average size is 150 to 1000 µm, with an average particle size of 500 µm. More precisely, the membrane 12 is manufactured from filter paper, of the type used for producing tea bags. It could alternatively be manufactured from a non-woven material.

[0035] The effect of the filter membrane 12 is to remove foam in the final product that flows out of the capsule. It was found that foam is removed by the conjunction of two effects: first, the filtering effect of the membrane 12 breaks air bubbles within the liquid, this effect being reinforced by the fact that a free space is created in the distance between the aluminum bottom membrane 7, and the filter membrane 12. The filter membrane could be made of woven polymer.

[0036] The second effect, is the fact that the filter membrane 12 prevents smallest coffee particles ("fines") to flow with the liquid coffee that is produced inside the capsule chamber, and clog the aluminum membrane 7 at the time the latter is pierced by the pyramid pins 9. It was found that in known capsules, the fines are moved towards with the liquid circulation in the roast and ground coffee mass, and clog the holes of the aluminum membrane, once the latter is opened. The result is an increase of pressure inside the capsule, due to the fact that liquid is prevented from correctly flowing out of the capsule. Such a pressure increase produces coffee foam ("crema"). This crema is characteristic of espresso-like coffee, but is undesirable when a brew-like coffee production is sought. With the present invention, it was made possible to produce a brew-like coffee cup (i.e. long cup, made with low pressure and no foam) from a closed capsule.

[0037] The capsule 1 illustrated in figures 1 and 2 further comprises a liquid-permeable wall 13 configured to break the jet of fluid injected by the needle into the capsule, so as to reduce its speed, and distribute the said fluid across the bed of substance 6 in a even manner. The jet-breaking wall 13 is positioned in the capsule so as to create an injection space 14 between the injection wall 4 and the chamber 5 that contains the ingredient or ingredients 6 to be extracted and/or dissolved.

[0038] In this case the needle injects the pressurized fluid through the injection wall into the headspace 14, and the distributing and jet-breaking wall 13 separates the said injection space 14 from the chamber 5 containing the bed of substance 6.

[0039] Importantly, the bed of substance 6 is held in a compressed state in the non-hydrated state of said substance, between the jet-breaking wall 13 on top, and the filter membrane 12 at the bottom. The wall 13 and membrane 12 are made of materials which are permeable only to liquids and gas, but not to solids (even very fine particles).

[0040] The jet-breaking liquid permeable wall 13 comprises welding edges which are welded against the internal surface of the hollow body 3 of the capsule.

[0041] The liquid permeable openings of the perforated wall 13 are distributed substantially uniformly across the wall so as to distribute the stream of fluid substantially uniformly across the bed of substance 6.

[0042] Figure 1 shows the proposed new capsule design for filter coffee. Coffee is placed between two plastic membranes which comprise many small holes through which a liquid can flow, but which are sufficiently small to prevent passage of solid particles, even small fine particles, like small roast and ground coffee or soluble coffee particles.

[0043] According to an essential requirement of the invention, coffee contained within the capsule chamber is not in direct contact with the Aluminum bottom membrane, would it be soluble, or roast and ground coffee, or a mixture thereof. The piece above the coffee is to distribute the water evenly. However, it is not necessary to have this piece if coffee particle size is large enough and if coffee is loose.

[0044] In figure 2 is shown a capsule 1 which is very close in its construction to the capsule already described above with reference to figure 1. However, in this particular embodiment, the capsule comprises a dividing wall 15, which separates the chamber containing ingredients to be extracted/dissolved in one upper compartment 16 and one lower compartment 17, both being superimposed. The dividing wall is manufactured such that no solid, even fine particles can pass through one compartment to another, but the wall 15 is liquid permeable.

[0045] In this case, when an extraction fluid is injected through the needle 2 within the headspace 14, it then passes through the jet-breaking liquid-permeable wall 13, into the upper compartment 16. In this compartment 16, the fluid interacts with powdered soluble coffee, and dissolves the latter to produce a liquid coffee solution, which then circulates through the perforated liquid-permeable dividing wall 15, towards the lower compartment 17. The lower compartment 17 contains a mass of roast and ground coffee, which is extracted by the liquid coffee solution prepared in the upper compartment. Solids of the roast and ground coffee are extracted by the liquid coffee at a pressure of about 1 to 3 bars (relative pressure). Such a pressure allows a good extraction of the coffee solids from the roast and ground coffee powder particles, and sensory tests have shown that the final product thus obtained is particularly rich in terms of flavour profile and taste body. With a multi-compartment capsule as shown in figure 2, it is possible to produce a long cup of coffee (at least 25 cl., preferably between 33 cl. and 50 cl., using a capsule which contains less than 20 gram of coffee ingredient, and especially less than 15 gram of roast and ground coffee. Such a construction is therefore particularly interesting as the capsule size remains small, while allowing a consumer to produce a long cup of coffee having a very pleasant taste and body profile. The result product in cup is a so-called "brew-like" coffee that is to say without foam.

[0046] In all cases, and particularly in the examples described in detail above, it is preferable to use large particle size coffee with this design to prevent small particles (so-called "fines") clogging the holes of the filter membrane 12. As it is difficult to avoid all coffee fines after grinding, a non-woven type plastic filter or a filter with small holes can be added to the design or can replace the plastic piece with holes as shown in Figure 1. In one of the capsules tested by the applicant, the pore size of the filter material was 100 microns.

[0047] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be covered by the appended claims.

Claims

1. Capsule (1) for delivering a drink by injecting a pressurized fluid into the capsule comprising:

- a hollow body and an injection wall (4) which is impermeable to liquids and to gas and which is attached to the body and adapted to be punctured by an injection means (2) foreign to the capsule,

- a chamber (5) containing a bed of at least one food substance to be extracted,

- means (7, 9, 10) for retaining the internal pressure in the said chamber, said means comprising a pierceable membrane (7),

characterized in that said capsule (1) further comprises a secondary means (12) for maintaining the bed of substance at a distance d from said pierceable membrane (7), said distance d being at least 1 mm, preferably at least 2 mm, more preferably at least 3 mm.

2. Capsule (1) according to claim 1, which further comprises means (13) configured to break the jet of fluid so as to reduce the speed of the jet of fluid injected into the capsule and distribute the fluid across the bed of substance at a reduced speed wherein it comprises an injection space (14) between the injection wall (4) and the chamber (5) of the capsule that contains the bed of substance (6), allowing the injection means (2) to inject at least one jet of pressurized fluid to be introduced through the injection wall (4), wherein the distributing and jet-breaking means comprise at least one punctured wall (13) which separates the injection headspace (14) from the chamber (5) containing the bed of substance (6), and the perforated wall (13) is positioned in order to keep the bed of substance (6) in compression in the non-hydrated state of the substance.

3. Capsule (1) according to claim 2, wherein the wall (13) comprises welding edges which are welded against the internal surface of the hollow body of the capsule in such a way as to position the said wall back from the injection wall (4).

4. Capsule (1) according to any of the preceding claims 2 or 3, wherein the wall (13) is a deformable flexible film.

5. Capsule (1) according to any of the preceding claims 2 to 4, wherein the openings of the perforated wall (13) are distributed substantially uniformly across the wall so as to distribute the stream of fluid substantially uniformly across the bed of substance

6. Capsule (1) according to any of the preceding claims 1 to 5, wherein the pressure retaining means comprise :

- the pierceable membrane (7),

- raised elements (9) which open the said membrane (7) in order to create punctures and allow the liquid extract to pass through the punctures; the punctures in the membrane (7) being obtained under the effect of the rise in pressure in the chamber (5) of the capsule (1).

7. Capsule (1) according to claim 6, wherein the raised elements (9) are distributed over a plate (10) which comprises ducts leading to openings (11), passages or slots through which the drink can flow.

8. Capsule (1) according to any of the preceding claims, wherein the secondary means comprise a perforated wall (12) chosen from a plastic wall with holes, a film with holes, a grating, a layer of woven or nonwoven material, a porous layer or a combination thereof.

9. Capsule (1) according to any of the preceding claims, wherein the space between the secondary means (12) and the pierceable membrane (7) comprises a layer or mass of discrete elements, such as a layer of granulate inert material to limit the deformation of the secondary means during the beverage preparation.

10. Capsule (1) according to any of the preceding claims, wherein the chamber (5) containing the bed of substance (6) to be extracted and/or dissolved, is divided by at least one dividing wall (15) into at least two corresponding compartments (16, 17), each containing one type of substance to be extracted and/or dissolved in an at least partially sequential manner.

11. Capsule (1) according to claim 10, wherein the compartments comprise an upper compartment (16) containing a powdered soluble coffee to be dissolved to produce a liquid coffee solution, and a lower compartment (17) containing a mass of roast and ground coffee to be extracted under pressure by said liquid coffee solution.

12. Capsule (1) according to any of the claims 10 or 11, wherein at least one of the compartments (16, 17) encloses a bed of substance to be extracted and/or dissolved, such that said substance is in a compressed state at least at the time pressurized fluid circulates through said substance.

Drawing