GB2255347A

GB2255347A - Clarification of aqueous systems using a collagen paste

Info

Publication number: GB2255347A
Application number: GB9201491A
Authority: GB
Inventors: Walter John Evett
Original assignee: ALPHA BETA Ltd
Current assignee: ALPHA BETA Ltd
Priority date: 1991-01-23
Filing date: 1992-01-23
Publication date: 1992-11-04
Anticipated expiration: 2012-01-23
Also published as: AU653382B2; GB9101458D0; GB2255347B; GB9201491D0; AU1045292A

Abstract

The invention relates to a process for the utilisation of a hydrated collagen in paste form, suitably as a fining agent in the clarification of an aqueous system, wherein such paste is added directly to the system without any acid needing to be added to the paste to solubilise same. A preferred method for producing such collagen paste comprises subjecting raw collagen to the following treatment steps:- (a) a washing treatment for a period sufficient to remove bacterial contamination; (b) a water wash treatment; (c) a softening treatment; (d) a second water wash treatment; (e) addition of a preservative; (f) a comminuting treatment; and (g) a paste making treatment. la

Description

PROCESS AND PRODUCT FOR THE CLARIFICATION OF AQUEOUS SYSTEMS The present invention relates to a process for the use of collagen for the clarification of aqueous systems. More particularly, the present invention is concerned with a process for utilising collagen for the clarification of fermented liquor, for example, beer, wine and cider, as well for the clarification of aqueous systems containing unwanted, finely divided organic matter in suspension.

Solubilised collagen has been utilised for many years in the clarification of fermented liquor such as beer, wine and cider. During the fermentation process for production of such liquor, residual organic matter is produced, and such must be removed if the liquor is to be clear and bright.

The process of clarification is tnow" as "fining" and agents for achieving such clarirication are known as "finings".

Collagen has a complex molecular structure which is believed to comprise a triple helix, each member of the helix comprising repeating amino acids such as alanine, glycine, proline, hydroxyproline etc.

Collagen is present in the connective. tissue of all creatures but is absent in plants.

Heretofore, the traditional process for utilising collagen for the clarification of fermented liquors has been to solubilise the collagen, which collagen is derived from the skins or swim bladders of certain tropical and sub-tropical fish, or from mammalian sources, for example, the skins of cattle, in a dilute acid at a pH of less than 5.0, generally in the range of from 1.5 to 4.0. lshen the collagen is derived from a fish source, same is known as isinglass.

Heretofore, finings have been supplied in various forms, for example: (a) a fine powder; (b) a fluffy floc; (c) a liquid; and (d) a paste.

All the forms contain collagen and generally a preservative, usually sulphur dioxide derived from a bisulphite. In addition, the forms (a) and (b) generally contain an acid or mixture of acids. In the case of forms (a) and (b) a powdered or crystalline organic acid is generally present, for example citric, tartaric or malic. Form (c) generally contains phosphoric acid either alone or in admixture with one or more organic acids. Form (d) as supplied does not contain an acid but such acid is added at the point of use after dispersing the paste in water.

Acid has always been used to solubilise the collagen and the process is known as "cutting", which is a hydrolytic process.

We have now discovered a process for the utilisation of collagen in paste form, particularly isinglass paste, which paste can be added directly to a fermented liquor with an excellent fining action, without any acid having to be added. This is a substantial advance over the art in that it is now possible to dispense with the previously utilised acid to solubilise the collagen (isinglass). Such result was completely unpredictable and unexpected and is a complete departure from previous processes for clarifying fermented liquor.

The invention contemplates the use of collagen in a non-acid solubilised form, which has not been thermally degraded and does not require the addition of acid to solubilise the collagen.

It is believed that the preferred method for preparing the collagen paste utilised in the present invention enables the resultant collagen (isinglass) to be utilised as a fining agent, without the need to add acid thereto.

The fining agent most generally utilised in the clarification of fermented liquors is isinglass, which is a proteinaceous material derived from the dried swim bladders of certain tropical and subtropical fish. Heretofore, such swim bladders have been subjected to a variety of mechanical pretreatments, involving rolling and subsequent shredding and/or grinding to produce a dry product. Such product when soaked in a dilute acid to solubilise same, converts to liquid finings. However, it is believed that such previous dry mechanical treatment tends to generate heat which, in turn, leads to varying degrees of degradation of the protein material, thereby resulting in finings of inferior quality and performance.

In accordance with the present invention there is provided a process for the clarification of an aqueous system, preferably for the clarification of a fermented liquorJherein a hydrated collagen in paste form, preferably isinglass paste, is added directly to the aqueous system or fermented liquor without any acid being added thereto.

The paste so produced can then be used as a fining agent in accordance with the present invention without the need for an acid to be added thereto to solubilise same. The paste is suitably dispersed in water and added to the fermented liquor. In a preferred embodiment, a dispersion of the isinglass in water is added to beer. This dispersion reacts with yeast cells and proteins in the beer which tends to drop down to the bottom of a container and the liquor is clarified.

The paste utilised in the method of the present invention can be diluted as desired, generally, dilution rates of the order of 25 times with water will produce the desired concentration.

The paste product utilised in the method of the present invention is not as sensitive to heat as the so-called "cut" isinglass and is not susceptible to the degradation which occurs with solubilised collagen.

It is known to mix cut isinglass liquid finings with a silica sol hydrogel which improves the fining performance. However, the solution must be kept agitated otherwise the hydrogel will form a sludge on the bottom of the mixing tank. Thus, when stored, the mixture must be agitated. On the other hand, it is possible to add silicaceous materials to the isinglass paste utilised in the present invention since the silica hydrogel does not separate out as the material has sufficient viscosity. Thus, the treated paste is ready to be used, suffers from no degradation and no continual mixing thereof is necessary when diluted.

ready to be used, suffers from no degradation and no continual mixing thereof is necessary when diluted.

Whilst the present invention has been specifically directed to the utilisation of isinglass paste, it is also to be understood that the process can also be applied to the utilisation of collagen paste wherein the collagen is obtained from animal hides.

It will thus be seen that the paste utilised in accordance with the present invention has superior qualities to that produced heretofore.

Also in accordance with the present invention there is provided a process for the clarification of an aqueous system comprising the addition of a hydrated collagen in paste form to said aqueous system, without the addition of acid.

In accordance with such preferred process, the raw material, suitably in the form of dried swim bladders of tropical and sub-tropical fish, is subjected to a wet treatment whereby the product is never allowed to dry following an initial soaking treatment and wet comminution. By utilising such wet treatment there is no heat generated in the process and therefore no degradation of the proteinaceous material takes place.

In addition to carrying out the wet treatment, we have also discovered that such treatment can be modified to produce finings of excellent quality and performance.

A suitable method for preparing a paste for utilisation in the process of the present invention comprises an initial washing treatment suitably with a dilute bleach solution, preferably containing 50 to 200 parts per million, further preferably 100 parts per million, of available chlorine. This treatment is suitably carried out for a time period of not more than 30 minutes and removes bacterial contamination.

Thereafter, a water wash treatment is applied to remove any remaining bleach and other extraneous foreign bodies.

The material is then subjected to a softening treatment, suitably in the presence of an oxidising agent, such as hydrogen peroxide, and suitably in the presence of a pH adjusting material such as ammonium hydroxide or sodium bicarbonate, suitably at a pH of 810. The treatment is preferably conducted over a period of up to 3 days until the material is sufficiently soft. It has also been found advantageous to agitate the solution during the softening treatment.

Once the material is of the desired softness, it is subjected to a further water wash to free same from any peroxide/ammonium salt remaining. Thereafter, a preservative is added to the material, suitably a metabisulphite, such as sodium metabisulphite, to produce sulphur dioxide to act as the preservative. At this stage, the material is still in the form of whole pieces.

Such material is then passed to a comminuting or mincing machine wherein the product is reduced to the form of small wet granules. Thereafter, such granules are passed to a paste making tank including blenders to produce a coarse paste. Such coarse paste is then passed through one or more colloidal mills having reducing size apertures, so as to produce small particle sized material in paste form.

It is to be understood that various modifications can be effected to the process steps described and the parameters disclosed which will produce a collagen (isinglass) paste utilisable in accordance with the present invention.

Claims

1. A process for the clarification of an aqueous system comprising the addition of a hydrated collagen in paste form to said aqueous system, without the addition of acid.

2. A process as claimed in claim 1, in which hydrated isinglass in paste form is utilised.

3. A process as claimed in claim 1 or 2, in which the aqueous system is a fermented liquor.

4. A process as claimed in claim 1, 2 or 3, in which the paste is dispersed in water.

5. A process as claimed in claim 4, in which the paste is dispersed in water by being diluted in a dilution rate of the order of 25 times with water.

6. A process as claimed in any one of claims 1 to 5, in which the collagen paste is mixed with silicaceous materials.

7. A process as claimed in any one of claims 1 to 6, substantially as hereinbefore described.

8. An aqueous system whenever clarified by a process as claimed in any one of claims 1 to 7.

9. A process for the preparation of a collagen paste, suitable for use as a fining agent in the clarification of an aqueous system without the addition of acid, comprising subjecting raw collagen to the following treatment steps: (a) a washing treatment for a period sufficient to remove bacterial contamination (b) a water wash treatment; (c) a softening treatment; (d) a second water wash treatment; (e) addition of a preservative; (f) a comminuting treatment; and (g) a paste making treatment.

10. A process as claimed in claim 9, in which the raw collagen is raw isinglass.

11. A process as claimed in claim 9 or 10, in which step (a) comprises treatment with a dilute bleach solution.

12. A process as claimed in claim 11, in which the dilute bleach solution contains 50 to 200 parts per million of available clorine.

13. A process as claimed in claim 11 to 12, in which the washing treatment is carried out for a time period of not more than thirty minutes.

14. A process as claimed in any of claims 9 to 13, in which the step (c) is carried out in the presence of an oxidising agent.

15. A process as claimed in claim 14, in which the oxidising agent is hydrogen peroxide.

16. A process as claimed in claim 14 or 15, in which the softening treatment is carried out at a pH of 8 - 10.

17. A process as claimed in claim 14, 15 or 16, in which the softening treatment is carried out over a period of up to three days.

18. A process as claimed in any one of claims 14 to 17, wherein the solution is agitated during the softening treatment.

19. A process as claimed in any one of claims 9 to 18, in which in step (e) metabisulphite is added as a preservative.

20. A process as claimed in claim 14, in which the metabisulphite is sodium metabisulphite.

21. A process as claimed in any one of claims 9 to 20, in which in step (f) the product is reduced to the form of small wet granules by passing through a comminuting or mincing machine.

22. A process as claimed in claim 21, in which the granules from step (f) are passed to a paste making tank including blenders to produce a coarse paste.

23. A process as claimed in claim 22, in which said coarse paste is passed through one or more colloidal mills having reducing size apertures so as to produce small particle size material in paste form.

24. A process for the preparation of a collagen paste, as claimed in any one of claims 9 to 23, substantially as hereinbefore described.

25. Collagen paste whenever prepared by a process as claimed in any one of claims 9 to 24.