CAPSULE CONTAINING BEVERAGE POWDER, IN PARTICULAR FOR PREPARING BREWED COFFEE

Abstract

A capsule, in particular for preparing a beverage from beverage powder, in particular coffee from coffee powder, by introducing water into the capsule comprising a capsule body composed of at least one polysaccharide and filled with a powder containing polysaccharide, and the capsule body is encased by at least one coating layer comprising a cross-linked polysaccharide obtained by cross-linking a polysaccharide by means of a cross-linking agent, and a method for producing such a capsule by providing a capsule body composed of at least one polysaccharide filled with a powder composed of polysaccharide, wetting at least part of and preferably the entire capsule body with a solution of a polysaccharide in a solvent or with a dispersion of a polysaccharide in a dispersant, bringing the capsule body into contact with at least one cross-linking agent, and drying the capsule body.

Claims

1.-13. (canceled)

14. A method for producing a capsule, in particular for preparing a beverage from beverage powder, in particular coffee from coffee powder, by introducing water into the capsule, which capsule comprises a capsule body composed of at least one polysaccharide and which is filled with a powder containing polysaccharide, wherein the capsule body is encased by at least one coating layer, wherein the at least one coating layer comprises a cross-linked polysaccharide, and wherein the cross-linked polysaccharide was obtained by cross-linking a polysaccharide by means of a cross-linking agent, the method comprising: i) providing a capsule body composed of at least one polysaccharide; ii) filling the capsule body with a powder composed of polysaccharide; iii) wetting at least part of and preferably the entire surface of the capsule body obtained in step ii) with a solution of a polysaccharide in a solvent or with a dispersion of a polysaccharide in a dispersant; iv) bringing the capsule body obtained in step iii) in contact with at least one cross-linking agent, and v) drying the capsule body obtained in step iv).

15. (canceled)

16. The method for producing a capsule according to claim 14, wherein the polysaccharide of the capsule body in step i) is composed of a fibrous polysaccharide.

17. The method for producing a capsule according to claim 16, wherein the fibrous polysaccharide is paper, paperboard or cardboard.

18. The method for producing a capsule according to claim 14, wherein the capsule body in step i) is shaped as a hollow cylinder, a hollow cylinder having at its one front end a collar, a hollow truncated cone, a hollow truncated cone having a collar at one of its front ends, or a cube that is hollow on the inside.

19. The method for producing a capsule according to claim 14, wherein the powder composed of polysaccharide in step ii) is a material selected from a group consisting of coffee, tea, drinking chocolate, cocoa and milk powder.

20. The method for producing a capsule according to claim 14, wherein wetting or bringing in contact of the capsule body according to step iii) and iv) takes place independent from each other.

21. The method for producing a capsule according to claim 14, wherein the solvent or dispersant is a water-based solvent or dispersant.

22. The method for producing a capsule according to claim 14, wherein in step iii), the solution of polysaccharide or dispersion of polysaccharide contains a polysaccharide selected from the group consisting of starch, cellulose, chitin, carrageen, agar and alginate.

23. The method for producing a capsule according to claim 22, wherein the polysaccharide is an alkaline metal alginate.

24. The method for producing a capsule according to claim 23, wherein in step iii) the capsule body is wetted with an aqueous 0.5 to 5 percent by weight alkaline metal alginate solution.

25. The method for producing a capsule according to claim 14, wherein in step iv), the capsule body is brought in contact with an aqueous 1 to 15 percent by weight alkaline earth metal salt solution as cross-linking agent.

26. The method for producing a capsule according to claim 25, wherein the alkaline earth metal salt is a calcium salt.

27. The method for producing a capsule according to claim 14, wherein the cross-linking agent in step iv) comprises at least one of carbonyl and/or carboxyl group.

28. The method for producing a capsule according to claim 27, wherein the polysaccharide in step iii) comprises a polyol spacer.

29. The method for producing a capsule according to claim 14, wherein steps ii) to iv) or ii) to v) are repeated 2 to 10 times.

30. The method for producing a capsule according to claim 14, wherein in step v) drying is achieved: a) by drying in an air stream of a channel, whereby the capsule body is free-floating and uniformly dried in its own rotation; and/or b) by contact drying at absorbing or warm surfaces; and/or c) through infrared driers or microwave driers.

Description

[0046] The figures thereby show the following:

[0047] FIG. 1A to 1C perspective views of a capsule body of capsules according to three embodiments of the present invention,

[0048] FIG. 2A and 2B schematic cross-sections through capsules according to two embodiment examples of the present invention,

[0049] FIG. 3A a perspective view of a capsule body encased with fibres in accordance with an embodiment example of the present invention, and

[0050] FIG. 3B a schematic cross-section through the upper half of a capsule according to one embodiment example of the present invention.

[0051] The capsule bodies shown in FIG. 1A to 1C have the shape of a hollow truncated cone open at both front sides with a collar at the lower front side (FIG. 1A), a hollow cylinder with a collar at its lower front side closed on all sides (FIG. 1b) or a cube closed on all sides with a hollow inside (FIG. 1C).

[0052] The capsule shown in a cross-section in FIG. 2A consists of a capsule body 2 filled with a coffee powder 1 comprising the hollow truncated cone shape with collar open at both front sides shown in FIG. 1A, the outside of which is fully encased with a coating layer 3 consisting of calcium alginate. Due to the two open front sides of the capsule body in the shape of a hollow truncated cone, the coffee powder 1 is encased with the capsule body 2 only at the shell surfaces of the hollow truncated cone, however, at the two front sides of the hollow truncated cone it is directly encased with the coating layer 3.

[0053] In FIG. 2B a cross-section of a capsule is illustrated which comprises the capsule body shown in FIG. 1B. As this capsule body is closed on all sides, the coffee powder 1 in this embodiment is encased by the capsule body 2 on all sides, which, in turn, is encased by the coating layer 3 on all sides. However, the two front sides 2B, 2C of the capsule body 2 are closed by a polysaccharide that can be perforated more easily than the shell surface 2A of the capsule body 2. Consequently, due to its strong shell surface, the capsule body has a high mechanical stability, however, it can easily be perforated at its front sides in a coffee machine so as to introduce water into the capsules.

[0054] FIG. 3A shows a capsule body in the shape shown in FIG. 1C that is coated in several layers of cotton fibre.

[0055] FIG. 3B finally shows the cross-section of an upper half of a capsule that was produced by provision a coating layer 3 on the capsule body shown in FIG. 3A. The coffee powder 1 is thereby encased by the capsule body 2 shown in FIG. 1 C, whereby the capsule body 2, in turn, is encased by the coating layer 3A in which the cotton fibres 3B are embedded.

[0056] The present invention is exemplified hereunder based on three examples illustrating, but not restricting the invention.

EXAMPLE 1

[0057] 6.5 g of ground roasted coffee 1 were filled into a capsule body 2 made of paperboard that is shaped in accordance with the embodiment shown in FIG. 1A. The thus obtained body was coated first from one side with a 1 percent by weightage aqueous sodium alginate solution. After the one-sided coating of the body with the sodium alginate solution, this was sprayed with a 5 percent by weightage CaCl.sub.2 solution. As immediately a gel layer starts to form that is not touch sensitive, the shaped body could be rotated and coated in the same way on the other side as well. Subsequently, the body was dried for two minutes in an air stream at room temperature Immediately thereafter, another coating process has taken place, only that this time the overall shaped body was fully coated.

[0058] In this way, the coffee capsule illustrated in FIG. 2A was obtained after another drying process that took approximately 20 minutes. The capsule body 2 filled with coffee 1 was thus permanently encased with the coating 3.

[0059] At the upper side and the bottom side of the capsule the coffee powder was only encased by the coating substance in the form of a membrane. This membrane could thus be easily perforated, whereas the capsule body 2 formed a correspondingly stable protection for the brewing operation and the ejection from the coffee machine.

EXAMPLE 2

[0060] It was processed as described in example 1, with the exception that a capsule body 2 made of paperboard shaped in accordance with FIG. 2A was applied in order to obtain the coffee capsule a cross-section of which is shown in FIG. 2B.

[0061] The front sides 2B, 2C of the capsule body 2 were thereby closed by a polysaccharide that could be perforated more easily than the shell surface 2A of the capsule body 2. Because of its strong shell surface, the capsule body thus has a high mechanic stability, however, it could be easily perforated in a coffee machine at its front sides.

EXAMPLE 3

[0062] A capsule body 2 as shown in FIG. 1C was produced by folding a suitable paperboard. Thereafter, the capsule body 2 was wrapped with long fibres made of cleaned cotton in the form of a cube after being filled with coffee powder 1, as is apparent from the schematic illustration in FIG. 3A. In a next step the capsule body 2 was coated with a 2 percent by weight aqueous sodium alginate solution. Following the coating of the shaped body with the sodium alginate solution was sprayed with a 5 percent by weightage CaCl.sub.2 solution.

[0063] After the approximately 20 minutes of drying, a capsule was obtained with a structure as shown in FIG. 3B. The coffee powder 1 was encased by the paperboard 2. In the coating layer of cross-linked polysaccharide 3A the long fibres of cotton 3B were embedded.

[0064] With that, a very stable structure of the capsule was achieved.