CAPSULE CONTAINING MATERIAL SUCH AS BEVERAGE POWDER, IN PARTICULAR FOR PREPARING BREWED COFFEE

Abstract

A capsule containing a beverage powder is particularly useful for preparing a beverage, such as preparing coffee from ground coffee by introducing water into the capsule. In one example, the capsule includes a capsule body composed of at least one polysaccharide and the capsule body is filled with a powder containing polysaccharide. The capsule body is encased all around by at least one coating layer that contains at least one polyvinyl alcohol and/or a polyvinyl alcohol copolymer.

Claims

1. A capsule comprising a capsule body composed of at least one polysaccharide and filled with a polysaccharide-containing material, the capsule body being entirely encased by at least one first coating layer, the at least one first coating layer comprising at least one polyvinyl alcohol and/or a polyvinyl alcohol copolymer.

2. The capsule according to claim 1, wherein the polysaccharide-containing material with which the capsule body is filled is selected from the group consisting of coffee, tea, drinking chocolate, cocoa and milk powder.

3. The capsule according to claim 1, wherein the at least one first coating layer has a thickness of from 0.5 to 10 μm.

4. The capsule according to claim 1, wherein the at least one first coating layer comprises at least one polyvinyl alcohol and/or polyvinyl alcohol copolymer having a weight average molecular weight, measured by gel permeation chromatography using a polystyrene standard, of from 9000 to 120000 g/mol.

5. The capsule according to claim 1, wherein the at least one first coating layer has, at a layer thickness of 1 to 2 μm, a gas permeability of less than 3 cm.sup.3/m.sup.2/day/1.01325 MPa.

6. The capsule according to claim 1, wherein the at least one first coating layer comprises 1 to 5, layer(s), each comprising at least one polyvinyl alcohol and/or a polyvinyl alcohol copolymer.

7. The capsule according to claim 1, wherein the outermost of the at least one first coating layer is coated with at least one second coating layer, wherein the at least one second coating layer comprises a polysaccharide.

8. The capsule of claim 7, wherein said at least one second coating layer comprises a crosslinked polysaccharide selected from the group consisting of starch, cellulose, chitin, carrageenan, agar and alginates.

9. The capsule according to claim 8, wherein the polysaccharide of the at least one second coating layer is an alginate.

10. The capsule according to claim 8, wherein the at least one second coating layer comprises fibres.

11. The capsule according to claim 1, wherein the capsule body is composed of one or more layers of uncrosslinked polysaccharide.

12. The capsule according to claim 1, wherein the capsule body is composed of one or more layers of crosslinked polysaccharide.

13. The capsule according to claim 1, wherein the polysaccharide-containing material with which the capsule body is filled is present as a pellet.

14. A method of making a capsule according to claim 1, comprising the steps of: i) providing a capsule body composed of at least one polysaccharide and filled with a polysaccharide-containing material, ii) wetting the entire surface of the capsule body provided in step i) with a solution of a polyvinyl alcohol and/or a polyvinyl alcohol copolymer in a solvent or with a dispersion of a polyvinyl alcohol and/or a polyvinyl alcohol copolymer in a dispersant, (iii) drying the capsule body obtained in step (ii); and iv) optionally repeating steps ii) to iii) for 1 to 10 times.

15. (canceled)

16. The capsule according to claim 9, wherein the alginate is an alkaline earth metal alginate.

17. The capsule according to claim 10, wherein the fibres are cellulose fibres.

18. The capsule according to claim 11, wherein the uncrosslinked polysaccharide is cellulose.

19. The capsule according to claim 11, wherein the uncrosslinked polysaccharide is paper, cardboard or paperboard.

20. The capsule according to claim 12, wherein crosslinked polysaccharide is an alginate.

21. The capsule according to claim 13, wherein the pellet was obtained by pressing at a pressure of 0.01 to 1000 MPa.

Description

EXAMPLE 1

[0057] 6.5 g of ground roasted coffee was pressed into a spherical pellet using a press. The resulting spherical pellet was immersed in a 1.5 wt % aqueous sodium alginate solution and removed from the sodium alginate solution after 1 to 2 seconds. After the pellet was removed from the sodium alginate solution, it was sprayed with a 5 wt % CaCl.sub.2 solution. The pellet was then air dried for 15 minutes at room temperature.

[0058] A capsule consisting of a pellet with a coating layer of calcium alginate was obtained.

[0059] The obtained capsule was immersed in 5 wt % aqueous polyvinyl alcohol solution (Kuraray Exceval AQ-4104) and removed from the polyvinyl alcohol solution after 1 to 2 seconds. After removal of the capsule, it was dried for 5 minutes at room temperature in the air stream.

[0060] A spherical capsule was obtained that was fully encased, had no cracks or holes, and had a film thickness for polyvinyl alcohol in the range of less than 5 μm.

[0061] It was shown that this thin layer of polyvinyl alcohol is already sufficient to achieve a very high oxygen tightness.

EXAMPLE 2

[0062] A coffee capsule was prepared as in Example 1. Thereafter, this capsule was immersed in a 1.5 wt % aqueous sodium alginate solution and removed from the sodium alginate solution after 1 to 2 seconds. After the capsule was removed from the sodium alginate solution, it was sprayed with a 5 wt % CaCl.sub.2 solution. The capsule was then air dried for 15 minutes at room temperature.

[0063] A capsule was obtained which had gained strength from the outer calcium alginate layer and which prevented the polyvinyl alcohol from the interlayer from going into solution during the brewing process.

EXAMPLE 3

[0064] A cup-shaped capsule body with an upper rim was formed from papier mâchéand dried. This capsule base body was filled with 6.5 g of ground roasted coffee. The filled capsule body was then sealed with a paper cap, which was glued to the capsule body rim with a methyl cellulose. The capsule thus sealed was immersed in a 1.5 wt % aqueous sodium alginate solution and removed from the sodium alginate solution after 1 to 2 seconds. After the capsule was removed from the sodium alginate solution, it was sprayed with a 5 wt % CaCl.sub.2 solution. The capsule was then air dried for 15 minutes at room temperature.

[0065] A capsule was obtained consisting of a base body formed of paper, filled with coffee grounds, with a coating layer of calcium alginate.

[0066] The obtained capsule was immersed in 5 wt % aqueous polyvinyl alcohol solution (Kuraray Exceval AQ-4104) and removed from the polyvinyl alcohol solution after 1 to 2 seconds. After removal of the capsule, it was dried for 5 minutes at room temperature in the air stream.

[0067] A cup-shaped capsule was obtained, which was fully sheathed, had no cracks or holes and had a layer thickness for polyvinyl alcohol in the range of less than 5 μm.

[0068] It turned out that this thin layer of polyvinyl alcohol is already sufficient to achieve a very high oxygen tightness.