AU773373B2 - Biocidal composition and method for treating raw materials, products and means of production - Google Patents

Description

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AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Q R Q4 Name of Applicant: Actual Inventor: Address for Service: P, A 4 C* SEC -o 113 L.

-7 X- 'T 0z Jan Van Os BALDWIN SHELSTON WATERS MARGARET STREET SYDNEY NSW 2000 'BIOCIDAL COMPOSITION AND METHOD FOR TREATING RAW MATERIALS, PRODUCTS AND MEANS OF PRODUCTION' Invention Title: Details of Original Application No. 25780/97 dated 17 Apr 1997 The following statement is a full description of this invention, including the best method of performing it known to me/us:- File: 31737AUP00 IP Australia Documents received on: 4 MAY 2001

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Batch No: -la- BIOCIDAL COMPOSITION AND METHOD FOR TREATING RAW MATERIALS, PRODUCTS AND MEANS OF PRODUCTION The invention relates to a composition for treating raw materials, products, water or production means, particularly in the food processing industry, which composition is prepared from hydrogen peroxide and glycerol. In addition, the invention relates to a method for preparing this composition and a method for treating raw materials, products, water and/or production means, wherein use is made of said composition.

Such a composition and such a method are described in the European patent application 0 603 329.

Described herein is a composition having hydrogen peroxide and glycerol therein, which composition can be used for treating all kinds of substances. This European patent application moreover describes devices for performing this method, which devices can otherwise also be used for the present invention.

Any discussion of the prior art throughout the specification should in no way be •oi 15 considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.

The contamination of raw materials and processed products with harmful biological material is seen increasingly as detrimental to public health and the environment. Increasingly stricter requirements are being made particularly of materials and machines applied in the food processing industry in respect of bacteriological condition. The problem is particularly urgent in for instance processes in the food eeee processing industry, wherein operations take place with conveyor belts and the like and at room temperature, because controlling and combating pathogens and other harmful constituents is difficult therein.

It is known to improve the shelf-life of foodstuffs be adding chemicals. It is thus possible according to the American patent specification 2.053.740 to add hydrogen peroxide to milk and cream, or to add substances to foodstuffs which develop hydrogen peroxide with the activity of enzymes (German patent specification 2.420.- 135). Single and multiple alcohols are also used for treating foods (EP-A-169 927, DE-A-2 119 351, GB-A-1 273 938 and GB-A-1 375 704).

In the European patent application EP-A 0 460 962 is described a method wherein vegetable foodstuffs are sprayed with an aqueous solution which can contain up to 0.025%. of an organic peracid. A treatment with aqueous thiosulphate then follows. The object of this European patent application is to perform a decontamination and.-to improve the product appearance.

DE-A-3 806 953 describes a solution for cleaning contact lenses. A disinfectant is herein present in the form of hydrogen peroxide. This disinfectant can be combined with a borate, glycerol, amino acetic acid or an 15 acetate or phosphate in order to obtain an isotonic solution.

Also generally known is the addition of sulphite to keep contamination of foodstuffs at an acceptable level.

For cleaning and decontaminating of production machines use is often made of chlorine. The use of chemicals otherwise entails the danger of too high a dosage whereby carcinogenic or allergenic effects can sometimes occur.

The use of chlorine can also result in corrosion of metal-containing machines, which in turn can itself.. form..:,.

.a source of contamination with bacteria. A further :draw-.

Sback of the chemical agents used heretofore is that.. the excess thereof is discharged together with cleaning water and can thus have an environmental impact.

A solution to such problems has been sought in.

working in a sterile area or in the use of waste-water..

purification. Such waste-water purification installationsare usually designed on the basis of the average water quality, the bacteriological impact and effluent norms.

Disruptions in production then often result in overloading of the installation, whereby it becomes necessary to resort once again to chemicals to comply with production standards. This results in an occasionally unacceptable increase in costs and environmental impact.

There therefore remains a great need for an inexpensive and simple method for treating raw materials, prod- -3ucts and productions means as well as process water from such production.

In a first aspect, the invention provides a composition for treating raw materials, products, water and for production means, which composition comprises hydrogen peroxide, glycerol and glycolic acid.

In a second aspect, the invention provides a method for preparing a composition according to the first aspect, comprising mixing a solution of glycerol and a solution of glycolic acid, and adding the obtained mixture drop by drop to a solution of hydrogen peroxide under conditions such that the solution of hydrogen peroxide retains a temperature below 7'C.

In a third aspect, the invention provides a method for treating raw materials, products, water and/or production means, comprising bringing into contact with the objects for treating the composition according to the first aspect, or obtained according to the second aspect.

Unless the context clearly requires otherwise, throughout the description and the claims, the words 'comprise', 'comprising', and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

According to the present invention it has now been found that the composition which is described and applied in EP-A-O 603 329 can be improved considerably by dissolving therein glycolic acid in glycerol and hydrogen peroxide. In particular, a composition is thus obtained which has a markedly more rapid activity but which still S-offers prolonged protection against post-contamination and recontamination.

Where a composition as according to EP-A-0 603 329 scores a value of 15 minutes in the European Suspension Test (EST-test; 3x5 test), the composition according to the invention scores 6-7 minutes.

•i Another significant advantage of the composition of the present invention relative to that described in EP-A-0 603 329 is that the present one has a very much better Sviricidal, fungicidal and spore-destroying activity. In addition, an organic acid is preferably used as stabilizer in EP-A-O 603 329. Of the specifically mentioned organic 30 acids acetic acid, lactic acid, benzoic acid, hexanoic acid, valeric acid, propionic acid and higher fatty acids, valeric acid is preferably applied as stabilizer. This acid is preferably present in a quantity of 1-5% by weight relative to the hydrogen peroxide.

No mention is made of any advantage in the speed of activity. Organic peracids are 3amoreover formed from said stabilizers which react considerably more aggressively than compounds from the present composition. The specifically mentioned organic acids further form toxins from micro-organisms to be destroyed.

In addition, it is pointed out that glycolic acid cannot be added without any problem. This would result in very violent reactions.

The present invention therefore also relates to a method for preparing the composition.

The method for preparing this composition comprises of mixing a solution of glycerol with a solution of glycolic acid, and adding the obtained mixture drop by drop to a solution of hydrogen peroxide under conditions such o So *ooo o/ *oo **o *oo *o° °•go o o o *o/ that the solution of hydrogen peroxide retains a temperature below 7 0 C and preferably below 4 0

C.

In this method quenching essentially takes place after each addition of a hydrogen peroxide solution to a mixture of glycolic acid and glycerol. This entails a portion of peroxide solution being added continuously during stirring, and preferably during vigorous stirring, and during cooling such that the temperatures before and after addition differ mutually by no more than 1 0 C and preferably by less than 0.5 0

C.

The invention further relates to a method for treating raw materials, products, water and/or production means wherein the composition according to the invention or the product according to the above stated method are placed in contact with the object for treating. This can for instance take place as described in EP-A-0 603 329 as already referred to several times.

The invention can greatly contribute to an improvement in the heat transfer in closed cooling and circulation systems because this composition keeps the systems free of growths of organic, inorganic and bacteriological contaminations (bio-film). In addition, it contributes to removal or elimination of already existing contaminations in these systems.

The use of the present product in water transport systems, for instance in glass horticulture, will prevent algal growth and growths of organic contaminations therein, S• 20 wherein the pathogen-free water has a positive effect on the storage life of the products (inter alia tomatoes, peppers and the like) which are transported using the water transport system.

In closed cooling water/feed water systems, for instance in glass horticulture, this product will provide a much better cleaning than the now normally used means. It also prevents calcifying of dripper systems.

It is possible with use of the composition according to the invention to switch to said product in any system where inhibitors are dosed to prevent corrosion, because said S •product prevent corrosion and leaves behind no residues which cause blockages and/or enhance growths.

•o••o The water will in addition not contain or form any toxins originating from the dosed product if the process water from a system is drained to the surface water.

The composition can also be well applied in open or closed industrial cooling water systems. In cooling air, for which the organic and bacteriological purity is a condition, such as cooling air in slaughterhouses and bakeries where contamination of the foodstuff with contaminated air will contribute to accelerated perishingof the product (food).

Another application of the product according to the invention lies in fishing vessels where for instance shrimps and cockles are boiled on board and cooling is carried out with outboard water. This product provides a rapid organic and bacteriojogical cleaning of the cooling water. No or hardly any post-contamination or- recontamination of the boiled product takes.. place. from the cooling process water. A component is moreover present in seawater which gives a catalyzing effect to the product.

20 The washing of fish and product crates in the food processing industry can thus likewise be performed very well with use of the composition according to the invent. ion. These products are protected from bacteriological contaminants for a very long time.

25 The composition according to the invention particu larly lends itself to for atomizing in stalls and spray-.

ing in production/storage areas, because it provides a more rapid activity than the composition according to EP- A-0 603 329. It is moreover very much safer for the environment than other known means. This is due mainly.to the environmental aspects peculiar to this composition.

The composition according to the invention is thus highly suitable for "cleaning in place" in breweries, drink and dairy produce industries and milk extraction equipment and as additive in final rinsing water of packagings (bottles, pots etc.) and for cleaning water for the. equipment in the food processing industry.

A water circulation system in which the composition according to the invention is used will require less frequent changing since the composition according to the invention conditions the water for a long period. A reduction of as much as 70% of the required quantity of water can hereby be realised.

It is however advisable when using these products to mount a filter in the circulation system to separate solid contaminants which have entered the water.

The composition according to the invention can be brought without problem into contact with untreated foodstuffs.

Possible degradation products of the composition according to the invention are not substances which are foreign to the body or toxic.

For cleaning and preserving hatching eggs and eggs for consumption the composition according to the invention will also have a more rapid activity without being aggressive. The product herein has a long-lasting maintaining and protective activity on the shell of the egg. This is attributed to the activating effect deriving from the glycolic acid in the solution which thereby has a potentiating effect on organic and bacteriological contaminations.

The product is highly suitable for preserving citrus fruits, flower bulbs, potatoes and other agricultural products, which must be stored for a longer period and protected against fungoid growth and/or bacterial post contamination/recontamination during storage and transport.

The objects or materials are preferably treated by spraying the above stated S0. 20 solution under overpressure into the space in which they are situated. This method of treatment/conservation is very efficient with a very low consumption of the invented product, since it is used in the gas phase. The foodstuff hereby suffers no damage by the agent.

A quantity of the solution is preferably used in the treatment of food products such o 25 that 0.1 1 g hydrogen peroxide is applied per kg of food product.

Treatment in the above stated manner takes place in particular at a temperature 0: between 5 and 7C for about 1 minute to about 0.5 hour, depending on the treatment ooo• temperature and the concentration of the solution in the space.

0For instance and in preference the composition can be prepared form: 0 Hydrogen peroxide 50% stab: Glycerol (1,26) Clinically pure Glycolic acid 57% AgCL If the application requires.

-7- These compounds are applied in an aqueous solution. Demineralised water is preferably used as solvent system.

Glycolic acid is mixed with the glycerol before being added to hydrogen peroxide mixed with the glycerol. This is necessary to arrive at a composition with a good activity. This preferably takes place in the following manner.

The glycolic acid is added to the glycerol, this in order to prevent explosive reactions which would result with the addition of glycolic acid to a mixture of hydrogen peroxide and glycerol. The maximum percentage by weight of glycolic acid is 25 gram per kg of final composition.

In a preferred embodiment the weight ratio hydrogen peroxide: glycerol lies between 4:1 and 10:1, preferably between 2:1 and 5:1. The ratio glycerol: glycolic acid preferably lies between 5:1 and 25:1. In these embodiments the concentration of hydrogen peroxide in the solution amounts to 10-50%, preferably 25-35%. All percentages given in this description are related to the weight of the final composition unless otherwise stated.

The solution of glycerol (1,26) and the glycolic acid 57% can now be added in doses to the hydrogen peroxide via an inline-mixer, this for early quenching of a reaction so that a maximum of active substance remains in the solution, where active substances would otherwise be lost with a reaction in the mixing pan.

20 The storage area for hydrogen peroxide, the conduits and the inline-mixer and go mixing pan are cooled by means of a water cooling system.

During this combination of the components it is very important that the solution is immediately re-cooled to 4 0 C of lower. The reaction may never have a temperature increase of more than 0.5% (in the mixing tank). The whole must remain in the mixing pan for at least 20 minutes to be certain of a homogenous mixture, wherein a temperature of less than 4 0 C is maintained preferably for a minimum of 10 minutes.

SIn a preferred embodiment various operations take place in an inline-mixer.

During storage and transport and thus obtained solution remains stable for a longer period, for instance three weeks to six months.

•ooo• Storage must take place in non-transparent and approved packagings, in a cool place and separated from oxidising products and organic material such as wood, textile, paper and alkaline agents. The storage space must be sufficiently cool and ventilated.

-8- The solution will not decompose to any significant extent in brine or seawater owing to a silver chloride present therein. This may even have a catalysing effect on the solution. It is therefore not inconceivable, if required, for a dose of AgC1 to be added to the solution in order to obtain a more intensive activity of the product in some cases, and this only for non-food.

This is important because some applications for which the composition according to the invention can be used involve contact with brine/seawater of 20 degrees Brix or higher.

The concentration of glycolic acid in the composition according to the invention depends on the quantity of glycerol and hydrogen peroxide. Preferably however, no more than 25 grams of glycolic acid is applied per kilogram of composition.

In a preferred composition 125 grams of glycerol is applied per kilogram of composition and 5 to 25 grams of glycolic acid will be present per kilogram of composition. This may depend on the application and the standard activity on a contamination.

Quality indication: 100, 125, 150, 175 grams of glycerol, of which 125 grams of glycerol per kilogram of product is the most usual. The specific gravity of the components is not applicable herein. However, in the case of glycerol the 5 grams of glycolic acid is reckoned per kilogram glycerol.

Detailed ratios of the components can be as follows.

g Glycerol with glycolic acid dissolved therein is in the following ratios: e*e* Concentration 100 125 150 175 glycerol 1 H 2 0 2 e.

(g/kg) SGlycolic acid ego* 1:20 1:25 1:30 1:35 10 g 1:10 1:15:5 1:15 1:17.5 gee.oi g 1:6.6 1:8.5 1:10 1:11.6 g 1:5 1:6.25 1:7.5 1:8.1 1:4 1:5 1:6 1:7 -9- The ratio of hydrogen peroxide to these mixtures is (hydrogen peroxide 10%, and 50% solution in water) 9:1, 7:1, 6.7:1, 5.7:1.

Subject to the application, the above-mentioned ratios can be dissolved in water, preferably demineralised water.

Meaning of the letters: A Hydrogen peroxide B Water C Glycerol D Glycolic acid solution for the purpose of spraying A:B as 5:95 A:B as 5:95 A:B as 5:95 A:B as 5:95 A:C as 9:1 A:C as 8:1 A:C as 6.7:1 A:C as 5.7:1 C:D as 20:1 C:D as 25:1 C:D as 30:1 C:D as 35:1 The table shows more combinations of different combinations of different concentrations as stated above.

5 grams of glycolic acid are reckoned hereinbelow as rule of thumb but in the first line other quantities are also mentioned which can be used depending on the application.

5 5*55

S

1: A:B as 1:9 A:B as 1:9 A:B as 1:9 A:B as 1:9 2: A:B as 1:5 A:B as 1:5 A:B as 1:5 A:B as 1:5 A:C as 9:1 A:C as 8:1 A:C as 6.7:1 A:C as 5.7:1 A:C as 9:1 A:C as 8:1 A:C as 6.7:1 A:C as 5.7:1 C:D as 20:1 and 25, 30 and 35:1 C:D as 25:1 and C:D as 30:1 and C:D as 35:1 and C:D as 20:1 and 25, 30 and 35:1 C:D as 25:1 and C:D as 30:1 and C:D as 35:1 and 3: A:B as 1:4 A:C as 9:1 C:D as 20:1 and 25, 30 and 35:1 A:B as 1:4 A:C as 8:1 C:D as 25:1 and A:B as 1:4 A:C as 6.7:1 C:D as 30:1 and A:B as 1:4 A:C as 5.7:1 C:D as 35:1 and 4: A:B as 1:2 A:C as 9:1 C:D as 20:1 and 25, 30 and 35:1 A:B as 1:2 A:C as 8:1 C:D as 25:1 and A:B as 1:2 A:C as 6.7:1 C:D as 30:1 and A:B as 1:2 A:C as 5.7:1 C:D as 35:1 and Addition of glycolic acid dissolved in the glycerol and hydrogen peroxide is surprisingly found to have an effect such that it gives the composition a more rapid activity while retaining a prolonged protection against post-contamination and recontamination of objects for treatment or air or water flows.

More effective use is made here by the composition of the Pauling and depole effect, which is very important in warmer environments, such as glass horticulture, and in southern continents.

The surprising thing about the present invention is that, when hydrogen peroxide is 10 mixed with glycerol and glycolic acid dissolved therein, this in a solution of preferably demineralised water and this solution is then sprayed on or round the unprocessed or processed food product or devices (air conditioning), an effective preservation occurs, wherein essentially all bacteria, yeasts, fungi, pathogens and the like are destroyed.

The effect in eliminating fungi on plants and in room areas where fungoid growth is the rule rather than the exception can herein be described as considerable, particularly when compared to the composition according to EP-A-0 603 329.

The preservative (decontaminating agent) according to the invention is i characterized in that it consists of a solution of hydrogen peroxide and glycerol with glycol dissolved therein preferably in demineralised water. The weight ratio of hydrogen peroxide and the glycerol solution preferably lies between 1:1 and 10:1, more preferably between 2:1 and 7:1. The solution preferably contains 10-25-35% by weight and in particular 50% by weight of hydrogen peroxide (stabilized).

The invention also relates to a method for treating raw materials, products, water and/or production means, inclusive of space, wherein the composition according to the -11 invention or the products prepared according to the present method are brought into contact with the objects for treating. This can take place by bringing the objects into contact with the solution in any known manner. Treatment with the composition according to the invention can take place in diverse ways, for instance by spraying, irrigating, immersing, rinsing and the like. The composition is preferably sprayed.

Spraying can thus take place in accordance with the principle of an air humidifier and can be applied for the storage of foodstuffs, for instance in cooler or freezer areas for the storage of foodstuffs such as potatoes, or without special cooling provisions. When the composition according to the invention is atomised in the space around materials for treating, this preferably takes place such that the concentration of hydrogen peroxide in the air amounts to 0.001 to 0.01% by volume and a temperature of 5 to 25C the treatment time will usually lie between 1 and 5 minutes. When treatment takes place with the mixture as a solution with a concentration of 0.2-0.3% by weight of hydrogen peroxide and a temperature of 50 to 60 0 C, the treatment time will usually lie between 3 and 20 minutes.

The mixture of hydrogen peroxide, glycerol and glycolic acid according to the invention is a clear and virtually odourless liquid which reacts in mildly acidic manner.

The mixture has a broad micro-organism-destroying activity and eliminates inter alia •bacteria, fungi, algae and viruses. The composition counteracts slime formation and produces no foaming. Treatment of foodstuffs with the mixture produces no discolorations or changes in smell and taste. The mixture can be used throughout the food processing industry, in the production, treatment and storage of foodstuffs. The •Too device described in EP-A-0 603 329 can be used in both large and small production units. This device comprises transport means for the material or product for treating and 25 at least one treatment room through which the material or product can be guided. The treatment room is provided with means for atomising and/or spraying of a liquid agent, V, as well as means for dosing, pumping and removing the agent.

see.

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Claims (15)

1. Composition for treating raw materials, products, water and/or production means, which composition comprises hydrogen peroxide, glycerol and glycolic acid.

2. Composition as claimed in claim 1, wherein the weight ratio hydrogen peroxide:glycerol lies between 4:1 and 10:1.

3. Composition as claimed in claim 2, wherein the weight ratio hydrogen peroxide:gylcerol lies between 2:1 and 5:1.

4. Composition as claimed in any one of claims 1 to 3, wherein the ratio glycerol:glycolic acid lies between 5:1 and 25:1.

5. Composition as claimed in any of claims 1 to 4, wherein the solution contains hydrogen peroxide.

6. Composition as claimed in claim 5, wherein the solution contains 25-35% hydrogen peroxide.

7. Method for preparing the composition as claimed in any one of claims 1 to 6, comprising mixing a solution of glycerol and a solution of glycolic acid, and adding the obtained mixture drop by drop to a solution of hydrogen peroxide under conditions such that the solution of hydrogen peroxide retains a temperature below 7'C.

8. Method as claimed in claim 7, wherein the solution of hydrogen peroxide retains a temperature below 4'C. V.. g 20 9. Method as claimed in claim 7 or claim 8, wherein the conditions are adjusted such that the temperatures before and after addition of a portion of hydrogen peroxide solution differ mutually by no more than 1C. Method as claimed in claim 9, wherein the temperatures before and after addition of a portion of hydrogen peroxide solution differ mutually by less than

11. Method as claimed in any one of claims 7 to 10, wherein mixing of the solutions take place in an inline-mixer.

12. Method as claimed in any one of claims 7 to 1 1, wherein the whole is further mixed for so long that the final composition is homogenous.

13. Method as claimed in claim 12, wherein the first stage of the further mixing takes place at a temperature below 7'C.

14. Method as claimed in claim 13, wherein the first stage of the further mixing takes place at a temperature below 4'C. -14- Method for treating raw materials, products, water and/or production means, comprising bringing into contact with the objects for treating the composition as claimed in any one of the claims 1 to 6 or obtained according to the method as claimed in any one of claims 7 to 14.

16. A composition for treating raw materials, substantially as herein described with reference to any one of the preferred embodiments but excluding comparatives.

17. A method for preparing a composition for treating raw materials, substantially as herein described with reference to any one of the preferred embodiments but excluding comparatives.

18. A method for treating raw materials, substantially as herein described with reference to any one of the preferred embodiments but excluding comparatives. DATED this 6th Day of May 2002 SCHAEFERS BEHEER B.V. F: Attorney: PAUL G. HARRISON So. 15 Fellow Institute of Patent Attorneys of Australia of BALDWIN SHELSTON WATERS 0° •9