BRPI0910077B1 - Disinfecting Packaging Methods Using Aseptic Packaging - Google Patents

Abstract

ANTIMICROBIAL PERACID COMPOSITIONS WITH SELECTED CATALASE ENZYMES AND METHODS OF USE IN ASEPTIC PACKAGING. The present invention relates to a specially selected catalase enzyme and its use in reducing hydrogen peroxide in applications, and particularly in aseptic packaging applications.

Description

FIELD OF THE INVENTION

[001] The present invention relates to a specially selected catalase enzyme and its use in the reduction of hydrogen peroxide in antimicrobial peracid compositions in industrial applications, and particularly in aseptic packaging applications.

CONTEXT

[002] In the food, beverage and dairy markets there is a wide variety of liquid and semi-liquid foods with packaging that does not require refrigeration. These products range from canned soups to soft drinks and highly acidified sports drinks.

[003] Up to 30 years ago, the only options available for producing low-acidity foods that do not require refrigeration were the uniform thermal sterilization of the packaging and the food. This was done through pressure cooking, processing in sealed containers, or by filling the heat-resistant packaging with a hot liquid food (the heat from the liquid food would sterilize the packaging).

[004] The introduction of aseptic packaging required thermal sterilization of the hot liquid food and, separately, chemical sterilization of the food packaging. This allowed for a reduction in the heat treatment of food and food processing that would not normally be indicated for processing foods that do not require refrigeration.

[005] A sterilizing chemical element used in aseptic packaging is peracid. Peracid exists in equilibrium with its corresponding carboxylic acids and hydrogen peroxides. The equilibrium tends toward the reactant side or toward the product side in the chemical equilibrium equation depending on the concentration of reactants or products present in the solution in question.

[006] Typically, a peracid reaches the end user as an equilibrium concentrate, and that user dilutes the concentrate to the level required for the microbial treatment of their interest. Over time, the peracid within a reservoir for the aseptic packaging process slowly degrades or re-equilibrates with the carboxylic acid and hydrogen peroxide. The result is that the container accumulates high levels of hydrogen peroxide and carboxylic acid. Manufacturers and consumers of fill materials have specifications for maximum levels of hydrogen peroxide or carboxylic acid in a reservoir. When the reservoir approaches this limit, it can be sealed, emptied, and refilled with a new solution. Other manufacturers of fill materials program the system to have a certain continuous drainage rate. This continuous drainage rate will modify the rate of accumulation of peroxide and carboxylic acid in the reservoir, so that the line can be used for longer. Both procedures increase the amount of water, energy, and chemicals required to operate an aseptic fill. It is in this context that the present invention was created.

SUMMARY

[007] Surprisingly, it was discovered that the enzyme catalase is particularly efficient at decomposing hydrogen peroxide under temperature and pH conditions found in peracid compositions, specifically in peracid compositions used in aseptic packaging.

[008] The use of this selected catalase enzyme degrades hydrogen peroxide in aseptic filling operations, leading to decreased consumption of water, chemicals, and energy, as the system needs to be drained less frequently. Therefore, this invention relates to a method of disinfecting packaging using aseptic packaging, providing an antimicrobial peracid composition comprising the selected catalase enzyme, hydrogen peroxide, carboxylic acid, and percarboxylic acid. Optionally, the antimicrobial compositions can be heated and applied to a food surface or packaging in a quantity that delivers the final food product in the packaging in a condition suitable for distribution for sale under non-refrigerated storage conditions. This invention also relates to a method of disinfecting packaging using aseptic packaging, providing an antimicrobial composition containing the selected enzyme catalase, hydrogen peroxide, a carboxylic acid selected from the group consisting of acetic acid, octanoic acid and their mixtures, and a peracid selected from the group consisting of peracetic acid, peroctanoic acid and their mixtures. Optionally, the antimicrobial composition can be heated and applied to a surface of a food package in sufficient quantity to deliver the final food product in packaging suitable for distribution and sale under non-refrigerated storage conditions.

[009] This invention also relates to a method of disinfecting packaging that utilizes aseptic packaging, forming an antimicrobial composition in a reservoir, heating the composition in the reservoir, pumping a portion of the antimicrobial composition from this reservoir into the packaging, applying the composition to the surface of a food package in sufficient quantity to deliver the final food product in the appropriate packaging for distribution and sale under non-refrigerated storage conditions while monitoring the hydrogen peroxide concentration in the reservoir and adding additional catalase enzyme to the reservoir to maintain the hydrogen peroxide concentration below a certain limit.

[010] Finally, the invention relates to a method of recycling a rinsing solution.

[011] These and other cases will be evident to people skilled in the art, and others, by considering the following detailed description of some cases. However, it should be understood that this summary, and the detailed description, illustrate only some examples of the various cases, and are not limiting factors for the claimed invention. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a schematic of a bottling operation.

DETAILED DESCRIPTION OF SOME CASES

[012] As discussed above, the invention relates generally to the use of the selected catalase enzyme in peracid compositions and specifically in peracid compositions used in aseptic packaging.

Catalase enzyme

[013] The present invention utilizes a catalase enzyme to reduce the concentration of hydrogen peroxide in antimicrobial compositions. Catalase enzymes catalyze the decomposition of hydrogen peroxide into water and oxygen. Sources of catalase enzymes include animal sources, such as bovine catalase isolated from liver; fungal catalase isolated from fungi such as Penicillium chrysogenum, Penicillium notatum, and Aspergillus niger; plant and bacterial sources such as Staphylococcus aureus; and their genetic variations and modifications. Surprisingly, fungal catalases have been found to be particularly suitable for use in peracid antimicrobial compositions, and the resulting composition is useful in applications such as aseptic packaging. The preferred catalase is desirable due to its ability to decompose hydrogen peroxide at lower concentrations of the catalase enzyme compared to the non-fungal catalase enzyme. Furthermore, the fungal catalase enzyme is more stable at the pH, temperature, and acidic environment found in peracid compositions and aseptic packaging operations.

[014] Catalase enzymes used in the present invention include catalase enzymes with a high capacity to decompose hydrogen peroxide. In some cases, the catalase enzyme is capable of degrading at least about 500 ppm of hydrogen peroxide into a peracid composition in 15 minutes.

[015] The catalase enzymes used in the present invention include catalase enzymes with a high capacity to decompose hydrogen peroxide at low concentrations of the catalase enzyme. In some cases, the concentration of catalase enzyme required to degrade 500 ppm of hydrogen peroxide into a peracid composition in 15 minutes is less than 200 ppm, less than 100 ppm, and less than 50 ppm.

[016] The catalase enzymes used in the present invention include catalase enzymes with a tolerance to temperature variations found in aseptic packaging applications. Temperatures in typical aseptic operations can range between 40 and 65 °C. A suitable enzyme should be able to maintain at least 50% of its activity when stored at 65 °C for 1 hour.

[017] The catalase enzymes used in the present invention include catalase enzymes with a tolerance to pH variations found in aseptic packaging applications. The level of acetic acid in an aseptic packaging operation can reach 20,000 ppm in the reservoir. This produces a solution with a pH range of about 2.0 and 2.5. A suitable enzyme maintains 50% of its activity when stored in a solution containing about 20,000 ppm of acetic acid for a period of one hour.

[018] Catalase can be free-floating in the antimicrobial composition, meaning that the catalase enzyme is part of the antimicrobial composition without being bound to a surface.

[019] Alternatively, catalase can be immobilized on a surface that is in fluid communication with the antimicrobial composition, so as to allow the catalase to interact with and decompose hydrogen peroxide. Immobilized catalase can be more stable than the unbound, soluble enzyme. Immobilized catalase also shows increased thermal and pH stability, which may be due to the protection the substrate provides against sudden changes in temperature and pH. An immobilized catalase has the advantage of being easily removed from the rest of the solution. An immobilized catalase may include a soluble catalase that is bound to a substrate. Examples of substrates may include polyurethane foams, polyacrylamide gels, maleic anhydride gels on polyethylene, maleic anhydride gels on polystyrene, cellulose, nitrocellulose, silastic resins, porous glasses, macroporous glass membranes, glass beads, activated clay, zeolites, alumina, silica, silicates, and other inorganic and organic substrates. The enzyme may be bound to the substrate in various ways, including covalent transport bonding, cross-linking, physical adsorption, ionic bonding, and trapping.

[020] Commercially available catalase is found in liquid and dry spray form. This catalase includes the active enzyme and additional ingredients that improve the enzyme's stability. Some examples of commercially available catalase include Genencor CA-100 and CA-400, Mitsubishi Gas and Chemical (MGC) ASC super G and ASC super 200.

[021] Preferably, the invention includes at least one fungal catalase. Preferred commercially available fungal catalases include Genencor CA-400 and MGC ASC super 200.

Hydrogen peroxide

[022] The composition includes hydrogen peroxide. Hydrogen peroxide, H2O2, offers the advantages of having a high proportion of active oxygen because of its low molecular weight (34.014 g/mol) and being compatible with various substances that can be treated by the methods of the invention, because it is a weak, clear, colorless liquid acid.

[023] Another advantage of hydrogen peroxide is that it decomposes into water and oxygen. It is advantageous to have these decomposition products because they are generally compatible with the substances being treated. For example, the decomposition products are generally compatible with metallic substances (e.g., considerably non-corrosive) and compatible with food products (e.g., they do not substantially alter the color, taste, or nutritional value of a food). And the decomposition products are generally harmless to accidental contact with humans and do not harm the environment.

[024] The composition of the invention typically includes hydrogen peroxide in an amount effective to maintain the balance between a carboxylic acid, hydrogen peroxide, and a peracid. The amount of hydrogen peroxide should not exceed an amount that could negatively affect the antimicrobial activity of a composition of the invention. Furthermore, a composition of the invention preferably contains hydrogen peroxide at a concentration as close to zero as possible. That is, the concentration of hydrogen peroxide is minimized, especially by the use of selected catalase enzymes.

[025] One advantage of minimizing the hydrogen peroxide concentration is that the antimicrobial activity of a composition of the invention is enhanced, compared to conventional compositions. It also increases runtime when peracid compositions are used in aseptic packaging operations, because the composition needs to be drained and refreshed less frequently.

[026] Hydrogen peroxide may typically be present in a solution for use in amounts up to 2,500 ppm, preferably between about 3 ppm and 1,850 ppm, and more preferably between about 6 ppm and 1,250 ppm.

Carboxylic acid

[027] One composition of the invention also includes a carboxylic acid. A carboxylic acid includes any compound of the formula R - (COOH)n, wherein R can be hydrogen, alkyl, alkenyl, an alicyclic, aryl, heteroaryl or heterocyclic group, and n is 1, 2 or 3. R is preferably a hydrogen, alkyl or alkenyl group.

[028] The term "alkyl" includes a simple or branched saturated chain of aliphatic hydrocarbons of 1 to 12 carbon atoms, such as, for example, methyl, ethyl, propyl, isopropyl (1-methylethyl), butyl, tert-butyl (1,1-dimethylethyl), and so on.

[029] The term alkenyl includes a chain of unsaturated aliphatic hydrocarbons of 2 to 12 carbon atoms, such as, for example, ethenyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-methyl-1-propenyl, and so on.

[030] The above alkyl or alkenyl group can be replaced at the end by a heteroatom, for example, of nitrogen, sulfur or an oxygen atom, forming aminoalkyl, oxyalkyl or thioalkyl, for example, aminomethyl, thiomethyl, oxypropyl, and so on. Similarly, the above alkyl or alkenyl group can be interrupted in the chain by a heteroatom, forming an alkylamine, alkylthioalkyl or alkoxyalkyl, for example, methylaminoethyl, ethyl thiopropyl, methoxymethyl, and so on.

[031] The term "alicyclic" includes any cyclic hydrocarbyl containing from 3 to 8 carbon atoms. Suitable examples of alicyclic groups include cyclopropanyl, cyclobutanyl, cyclopentanyl, etc.

[032] The term "heterocyclic" includes any cyclic hydrocarbyl containing 3 to 8 carbon atoms that is interrupted by a heteroatom, such as, for example, nitrogen, sulfur, or an oxygen atom. Appropriate examples of heterocyclic groups include groups derived from tetrahydrofurans, furans, thiophenes, pyrrolidines, piperidines, pyridines, pyrroles, picolin, komaline, etc.

[033] Alkyl, alkenyl, alicyclic groups and heterocyclic groups may or may not be substituted by aryl, heteroaryl, C1-4 alkyl, C1-4 alkenyl, C1-4 alkoxy, amine, carboxy, halo, nitro, cyano, -SO3H, phosphone or hydroxy. When alkyl, alkenyl, an alicyclic group or a heterocyclic group is substituted, the substitution is preferably C1-4 alkyl, halo, nitro, amido, hydroxy, carboxy, sulfo, or phosphone. In one case, R includes a hydroxy-substituted alkyl.

[034] The term "aryl" includes aromatic hydrocarbyls, including fused aromatic rings, such as phenyl and naphthyl.

[035] The term "heteroaryl" includes aromatic heterocyclic derivatives with at least one heteroatom, such as nitrogen, oxygen, phosphorus or sulfur, and includes, for example, furyl, pyrrolyl, thienyl, oxazolyl, pyridyl, imidazolyl, thiazolyl, isoxazolyl, pyrazolyl, isothiazolyl, etc.

[036] The term "heteroaryl" also includes fused rings in which at least one ring is aromatic, such as, for example, indolyl, purynyl, benzofuryl, etc.

[037] Aryl and heteroaryl groups may or may not be substituted in the ring by aryl, heteroaryl, alkyl, alkenyl, alkoxy, amine, carboxy, halo, nitrocyano, -SO3H, phosphone, or hydroxy. When aryl, aralkyl, or heteroaryl is substituted, the preferred substitution is C1-4 alkyl, halo, nitro, amido, hydroxy, carboxy, sulfo, or phosphone. In one case, R includes an aryl substituted by C1-4 alkyl.

[038] Examples of suitable carboxylic acids include a variety of monocarboxylic acids, dicarboxylic acids, and tricarboxylic acids.

[039] Monocarboxylic acids include, for example, formic acid, acetic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, glycolic acid, lactic acid, salicylic acid, acetylsalicylic acid, mandelic acid, etc.

[040] Dicarboxylic acids include, for example, adipic acid, fumaric acid, glutaric acid, maleic acid, succinic acid, malic acid, tartaric acid, etc.

[041] Tricarboxylic acids include, for example, citric acid, trimellitic acid, isocitric acid, agaric acid, etc.

[042] A carboxylic acid suitable for use in a composition of the invention may be selected based on its solubility, cost, approval as a food additive, odor, purity, etc.

[043] A particularly useful carboxylic acid for a composition of the invention includes a carboxylic acid that is soluble in water, such as formic acid, acetic acid, propionic acid, butanoic acid, lactic acid, glycolic acid, citric acid, mandelic acid, glutaric acid, maleic acid, malic acid, adipic acid, succinic acid, tartaric acid, etc. These carboxylic acids may also be useful because water-soluble carboxylic acids can be food additives, such as formic acid, acetic acid, lactic acid, citric acid, tartaric acid, etc.

[044] Preferably, a composition of the invention includes acetic acid, octanoic acid, propionic acid, lactic acid, heptanoic acid, octanoic acid, or nonanoic acid.

[045] The composition of the invention may include a carboxylic acid in an amount that can be effectively removed from inside or outside a package in an aseptic filling during the rinsing step of the aseptic packaging process. A carboxylic acid may typically be present in a solution for use, in an amount less than 40,000 ppm, preferably less than 30,000 ppm and, more preferably, less than 20,000 ppm.

Peracid

[046] One composition of the invention also includes a peracid. A peracid is also known in the field as a percarboxylic acid, a peroxyacid, and a peroxycarboxylic acid.

[047] A peracid includes any compound of the formula R - (COOOH)n wherein R can be hydrogen, alkyl, alkenyl, an alicyclic, aryl, heteroaryl or heterocyclic group, and n is 1, 2 or 3. R is preferably a hydrogen, alkyl or alkenyl group.

[048] The terms "alkyl", "alkenyl", "alicyclic group", "aryl", "heteroaryl" and "heterocyclic group" have been defined above.

[049] The peracids used in this invention include any peroxycarboxylic acid that can be prepared from the acid-catalyzed equilibrium reaction between a carboxylic acid and a hydrogen peroxide described above. Preferably, a composition of the invention includes peracetic acid, peroxyoctanoic acid, or peroxypropionic acid, peroxylactic acid, peroxyheptanoic acid, per-roxoctanoic acid, or peroxinonanoic acid.

[050] A peroxycarboxylic acid can also be prepared by auto-oxidation of aldehydes or by the reaction of hydrogen peroxide with hydrochloric acid, hydric acid, carboxylic acid anhydride, or sodium alcoholate.

[051] In some cases, a peroxycarboxylic acid includes at least one water-soluble peroxycarboxylic acid, wherein R includes an alkyl group with 1 to 4 carbon atoms. For example, in one case, a peroxycarboxylic acid includes a peroxyacetic acid. In another case, a peroxycarboxylic acid has an R group that is an alkyl group with 1 to 4 carbon atoms substituted with a hydroxyl group.

[052] Methods of preparing peracetic acid are known to qualified persons, including those disclosed in U.S. Patent No. 2,833,813, which is incorporated herein by reference.

[053] One advantage of using a peroxycarboxylic acid wherein R includes an alkyl group with 1 to 4 carbon atoms is that these acids traditionally have a lower pKa than acids where R is an alkyl group with more than 4 carbon atoms. This lower pKa may favor a faster rate of equilibrium of the peroxycarboxylic acid, and may be effective in providing a composition of the invention with, for example, an acidic pH, which may be advantageous for improving lime scale and/or soil removal.

[054] In other cases, a peroxycarboxylic acid includes at least one water-soluble peroxycarboxylic acid whose R includes an alkyl group of 5 to 12 carbon atoms, and at least one water-soluble peroxycarboxylic acid whose R includes an alkyl group of 1 to 4 carbon atoms. For example, in one case, a peroxycarboxylic acid includes peracetic acid and at least one other peroxycarboxylic acid such as those mentioned above. Preferably, a composition of the invention includes peracetic acid and peroxyoctanoic acid.

[055] One advantage of combining a water-soluble carboxylic acid or peroxycarboxylic acid with a carboxylic acid or peroxycarboxylic acid having limited water solubility is that the water-soluble carboxylic acid or peroxycarboxylic acid can provide a hydrotropic effect on less water-soluble carboxylic and peroxycarboxylic acids, which can facilitate uniform dispersion and/or consequent physical stability within the composition.

[056] Another advantage of this combination of peroxycarboxylic acids is that it can provide a composition of the invention with desirable antimicrobial activity in the presence of high organic loads in the soil.

[057] The composition of the invention may include a peroxycarboxylic acid, or mixtures thereof, in an amount effective for sterilizing bacterial and fungal spores of great significance to public health and spoilage on the inner and outer surfaces of a food package in an aseptic filling, as well as within the seal of the filling itself. Typically, a peroxycarboxylic acid may be present in this composition in an amount between about 500 ppm and 6,000 ppm, preferably between approximately 1,000 ppm and 5,000 ppm, and more preferably between about 1,500 ppm and 4,000 ppm.

Additional optional materials

[058] The composition may optionally include additional ingredients to enhance the composition, including stabilizing agents, hydrotropes, surfactants, antifoaming agents, corrosion inhibitors, rheology modifiers, colorants and fragrances.

Stabilizing agents

[059] As an option, the composition may include stabilizing agents to stabilize the peracid and hydrogen peroxide and prevent premature oxidation of this component within the composition.

[060] Chelating or sequestering agents generally useful as stabilizing agents in current compositions include phosphonic acid and phosphonates, phosphates, aminocarboxylates and their derivatives, pyrophosphates, ethylenediamine, ethylenetriamine and their derivatives, hydroxy acids and mono-, di- and tricarboxylates and their corresponding acids. Other chelating agents include nitroloacetates and their derivatives and mixtures. Examples of aminocarboxylates include amino acetates and their salts. Suitable aminoacetates include: N-hydroxyethylaminodiacetic acid, hydroxyethylenediaminetetraacetic acid; nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), N-hydroxyethylethylenediaminetriacetic acid (HEDTA); Tetrasodium ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and N-alanine, N-diacetic acid, N-hydroxyethyliminodiacetic acid, their alkali metal salts and mixtures. Suitable aminophosphates include trismethylene nitrile phosphates and other aminophosphates with alkyl or alkali groups with less than 8 carbon atoms. Iminodisuccinic acids (IDS) of polycarboxylates, sodium polyacrylates, citric acid, gluconic acid, oxalic acid, their salts and exemplary mixtures. Additional polycarboxylates include citric or citrate-type chelating agents, polymeric polycarboxylate, and polyacrylic or acrylic acid-type chelating agents. Additional chelating agents include polyaspartic acid or cocondensates of aspartic acid with other amino acids, C4-C25-mono- or dicarboxylic acids, and C4-C25-mono- or diamines. Exemplary polymeric polycarboxylates include polyacrylic acid, maleic/olefin copolymer, acrylic/maleic copolymer, polymethacrylic acid, methacrylic acid/acrylic copolymers, hydrolyzed polyacrylamide, hydrolyzed polymethacrylamide, hydrolyzed polyamide/methacrylamide copolymers, hydrolyzed polyacrylonitrile, hydrolyzed polymethacrylonitrile, hydrolyzed acrylonitrile/methacrylonitrile copolymers, and the like.

[061] The chelating agent may be present in an amount of about 0.01 to 5% of the weight, ranging from about 0.05 to 3% of the weight, and from about 0.1 to 1.5% of the weight.

Hydrotropes

[062] As an option, the composition may include a hydrotropic coupler or solubilizer. These materials can be used to ensure that the composition remains phase-stable and in a highly active single phase in aqueous form. Such hydrotropic solubilizers or couplers can be used in concentrations that maintain phase stability but do not result in an undesirable compositional interaction.

[063] Representative classes of hydrotropic or coupling solubilizing agents include an anionic surfactant, such as alkyl sulfate, an alkyl or alkane sulfonate, a linear alkylbenzene or naphthalene sulfonate, a secondary alkane sulfonate, an alkyl ether sulfate or sulfonate, an alkyl phosphate or phosphanate, a dialkyl sulfosuccinic acid ester, sugar esters (e.g., sorbitan esters), and a C8-10 alkyl glycoside.

[064] Coupling agents may also include n-octane sulfonate, aromatic sulfonates such as alkyl aryl sulfonates (e.g., sodium xylene sulfonate or naphthalene sulfonate) and alkylated diphenyl disulfonic acid oxide, such as those sold under the brand name DOWFAX™, preferably the acidic forms of hydrotropes.

[065] The concentration of useful hydrotrope in the present invention generally ranges from 0.1 to 20% by weight, preferably about 2 to 18% by weight, and more preferably about 3 to 15% by weight.

Surfactants

[066] The composition may optionally include a surfactant or a mixture of surfactants. The surfactant may include commercially available anionic, nonionic, cationic, zwitterionic surfactants, and mixtures thereof. In one case, the surfactant includes either a nonionic or anionic surfactant. For a discussion of surfactants, see Kirk-Othmer, Encyclopedia of Chemical Technology, third edition, volume 8, pages 900–912.

[067] Nonionic surfactants may include those that have a polyalkylene oxide polymer as part of the surfactant molecule. These surfactants may be protected or unprotected. Nonionic surfactants include, for example: chloro-, benzyl-, methyl-, ethyl-, propyl-butyl- and others such as polyethylene glycol ethers of protected alkyl fatty alcohols; non-ionic free polyalkylene oxide, such as alkyl polyglycosides; sucrose and sorbitan esters and their ethoxylates; alkoxylated ethylenediamine; alkoxylated alcohol, such as ethoxylated and propoxylated alcohol, propoxylated alcohol, propoxylated alcohol ethoxylate propoxylate, butoxylated alcohol ethoxylate, fatty alcohol ethoxylate (e.g., tridecyl alkoxylated alcohol, ethylene oxide adduct), and the like; Nonylphenol ethoxylate, polyoxyethylene glycol esters, and the like; carboxylic acid esters, such as glycerol esters, polyoxyethylene esters, glycol esters, and ethoxylated fatty acids, and the like; carboxylic amides, such as diethanolamine condensates, monoalkanolamine condensates, polyoxyethylene fatty acid amides, and the like; block polyalkylene oxide copolymers, including a block ethylene/propylene oxide copolymer, such as those commercially available under the brand name PLURONIC (BASF-Wyandotte), and the like; ethoxylated amines and ether amines commercially available from Tomah Corporation and other similar nonionic compounds. Silicone surfactants, such as ABIL B8852 (Goldschmidt), may also be used.

[068] Nonionic surfactants may include linear and secondary alcohol ethoxylates (fatty alcohol ethoxylates, for example, tridecyl alcohol alkoxylate, ethylene oxide adduct), alkylphenol ethoxylates, ethoxy/propoxy block surfactants, and the like. Examples of preferred linear and secondary alcohol ethoxylates (fatty alcohol ethoxylates, e.g., tridecyl alcohol alkoxylate, ethylene oxide adduct) include 5 moles of ethoxylate of the alcohol with 12 to 14 linear and primary carbons (C12-14H25-29)--O--(CH2CH2O)5H (one of which is sold under the brand name LAE 24-5), 7 moles of ethoxylate of the alcohol with 12 to 14 linear and primary carbons (C12-14H25-29)--O--(CH2CH2O)7H (one of which is sold under the brand name LAE 24-7), 12 moles of ethoxylate of the alcohol with 12 to 14 linear and primary carbons (C12-14H25-29)--O-- (CH2CH2O)12 H (one of which is sold under the brand name LAE 24-12), and similar products.

[069] Anionic surfactants may include, for example, carboxylates such as alkylcarboxylates (carboxylic acid salts) and polyalkoxycarboxylates, alcohol ethoxylate carboxylates, nonylphenol ethoxylate carboxylates and the like; sulfonates such as alkylsulfonates, alkylbenzenesulfonates (for example, linear dodecylbenzene sulfonic acid, or its salts), alkylarylsulfonate, sulfonated fatty acid esters and the like; sulfates such as sulfated alcohols, sulfated alcohol ethoxylate, sulfated alkylphenols, alkylsulfates, sulfosuccinates, alkyl ether sulfates and the like; and phosphate esters such as alkyl phosphate esters, ethoxylated alcohol phosphate esters and others. Preferred anionic compounds include sodium alkylaryl sulfonates, alkylbenzene sulfonates (e.g., linear dodecylbenzene sulfonic acid or its salts), and the like.

[070] Surface-active substances are classified as cationic if the charge on the hydrophilic part of the molecule is positive. Surfactants in which the hydrophilic part has no charge unless the pH is lowered near or below neutrality, but which are cationic (e.g., alkyl amines), are also included in this group.

[071] Cationic surfactants may include compounds containing at least one long carbon chain hydrophobic group and at least one positively charged nitrogen. The long carbon chain group may be directly linked to the nitrogen atom by a simple substitution, or indirectly by a bridging functional group or groups called interrupted alkylamines and amide amines. These functional groups may make the molecule more hydrophilic and/or more dispersible in water, more readily soluble in water through co-surfactant mixtures, and/or soluble in water. To increase water solubility, additional primary, secondary, or tertiary amine groups may be introduced, or the amine nitrogen may be quaternized by low molecular weight alkyl groups. Furthermore, the nitrogen may be part of a branched or linear half-chain, with varying degrees of unsaturation, or of a saturated or unsaturated heterocyclic ring. Furthermore, cationic surfactants can contain complex bonds with more than one cationic nitrogen atom.

[072] The cationic surfactant may include a quaternary ammonium surfactant, such as a tallow quaternary ammonium surfactant, composed of ethoxylated tallow amine quaternary ammonium. For example, an ethoxylated tallow amine quaternary ammonium compound may include a quaternary nitrogen bonded to a methyl group, a tallow moiety, and two ethoxylated moieties. The ethoxylated moieties may include 6 to 10 ethoxylated groups. In a given case, the present composition may include about 1 to 10% by weight, or about 5% by weight of this cationic surfactant.

[073] Surfactant compounds classified as amine, amphoteric, and zwitterian oxides are typically cationic in solutions with near-neutral to acidic pH and may overlap with surfactant classifications. Polyoxyethylated cationic surfactants generally behave as nonionic surfactants in alkaline solution and as cationic surfactants in acidic solution.

[074] Most commercially available cationic surfactants can be subdivided into four main classes and additional subgroups, for example, as described in "Surfactant Encyclopedia", Cosmetics & Toiletries, vol. 104 (2) 86-96 (1989). The first class includes alkylamines and their salts. The second class includes alkyl imidazolines. The third class includes ethoxylated amines. The fourth class includes quaternaries, such as alkylbenzyldimethylammonium salts, alkylbenzene salts, heterocyclic ammonium salts, dialkylammonium salts, and the like. Cationic surfactants are known to have a variety of properties that may be beneficial in the present compositions. These desirable properties may include detergent action, antimicrobial activity, and the like.

Antifoaming agents

[075] The composition may optionally include antifoaming agents. Generally, antifoaming agents may include silica and silicones, aliphatic acids or esters, alcohols, sulfates or sulfonates; amines or amides, halogenated compounds such as fluorochlorohydrocarbons, vegetable oils, waxes, mineral oils and their sulfated derivatives; phosphates and phosphate esters such as alkyl and alkaline diphosphates and tributyl phosphates among others, and mixtures thereof.

[076] Edible antifoaming agents are preferred. For this purpose, one of the most effective antifoaming agents includes silicones. Silicones, such as dimethylsilicone, polysiloxane glycol, polysiloxanemethylphenol, tetraalkyl or trialkyl silanes, hydrophobic silica antifoaming agents and their mixtures can be used in antifoaming applications. Commonly available commercial antifoaming agents include silicones such as Ardefoam®, from Armour Industrial Chemical Company, which is a silicone bonded to an organic emulsion; Foam Kill® or Kresseo®, made available by Krusable Chemical Company, which are silicone and non-silicone antifoaming agents, as well as silicone esters; and Anti-Foam A® and DC-200, from Dow Corning Corporation, which are food-grade silicones, among others. These antifoaming agents may be present in a concentration range of about 0.01 to 5% by weight, preferably about 0.01 to 2% by weight, and even more preferably about 0.01 to 1% by weight.

Corrosion inhibitors

[077] As an option, the composition may include a corrosion inhibitor. Useful corrosion inhibitors include polycarboxylic acids such as short-chain dicarboxylic acids, triacids, as well as phosphate esters and their combinations. Useful phosphate esters include alkyl phosphate esters, monoalkyl aryl phosphate esters, dialkyl aryl phosphate esters, trialkyl aryl phosphate esters, and mixtures thereof, such as Emphos PS 236, commercially available from Witco Chemical Company. Other useful corrosion inhibitors include triazoles such as benzotriazole, tolyltriazole, and mercaptobenzothiazole, and in combinations with phosphonates, such as 1-hydroxyethylidene-1,1-diphosphonic acid, and surfactants such as oleic acid diethanolamide and cocoamphohydroxypropyl sodium sulfonate, etc. Useful corrosion inhibitors include polycarboxylic acids, such as dicarboxylic acids. Preferred acids include adipic, glutaric, and succinic acids, and mixtures thereof. A favorite is a mixture of adipic, glutaric, and succinic acids, which is a raw material sold by BASF under the name SOKALAN® DCS. Rheology modifiers

[078] A composition may optionally include one or more rheology modifiers.

[079] Useful water-soluble or water-dispersible rheology modifiers can be classified as organic or inorganic. Organic thickeners can be further divided into natural and synthetic polymers. Synthetic polymers can be further subdivided into naturally based synthetics and petroleum-based synthetics.

[080] Inorganic thickeners are generally compounds, such as colloidal aluminum magnesium silicate (VEEGUM®), colloidal clays (Bentonites), or silicas (CAB-O-SILS®) that have been precipitated or vaporized to create particles with large surface area to size ratios. Suitable natural hydrogel thickeners are primarily exudates derived from plants. For example, alcantira, karaya, and acacia gums, extractives such as carrageenan, locust bean gum, guar gum, and pectin, or even pure culture fermentation products such as xanthan gum. Chemically, all these materials are complex anionic polysaccharide salts. Synthetic thickeners based on natural sources with applications are cellulose derivatives in which the free hydroxyl groups in linear anhydrous glucose polymers have been etherified or esterified to generate a family of substances that dissolve in water and provide viscous solutions. This group of materials includes alkyl and hydroxyalkylcellulose, specifically methylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, hydroxybutylmethylcellulose, hydroxyethylcellulose, ethylhydroxyethylcellulose, hydroxypropylcellulose, and carboxymethylcellulose. Water-soluble synthetic petroleum-based polymers are prepared by direct polymerization of suitable monomers, of which polyvinylpyrrolidone, polyvinylmethyl ether, polyacrylic acid and polymethacrylic acid, polyacrylamide, polyethylene oxide, and polyethyleneimine are representative.

Dyes and fragrances

[081] Optionally, the composition may include various colorants, odors, including perfumes, and other aesthetic enhancement agents. Preferred colorants include FD&C dyes, D&C dyes, and the like.

Use in aseptic packaging

[082] Aseptic packaging fills can be divided into two basic categories: Single-use fills and reuse or recirculation fills.

[083] The single-use system provides a weak concentrated solution of peracid. It sprays a small amount of this solution inside the container to sterilize it. The solution can be heated at the injection point or pre-heated before injection into the vial. In either case, the operating conditions (temperature, contact time and peracid concentration) are chosen so that the vial is commercially presented as sterile. After contact with the inside of the vial, this solution is removed and exported to a drain or other parts of the machine for antimicrobial and environmental treatments or treatment of the exterior of the vials.

[084] After the bottle is treated, it will be washed with microbiologically pure water, filled with a liquid food, and sealed. All these steps occur within a positive pressure zone inside the so-called sterile filling zone.

[085] In a reuse filler, the filler contains a reservoir of the diluted peracid solution. This reservoir is made at the desired temperature (40 to 65 °C). The filler comes from this reservoir and uses the solution to sterilize the inside and outside of the bottles. The solution is drained from the bottles, collected, and exported back to the same reservoir from which it originated.

[086] After the vial is treated, it will be washed with microbiologically pure water, filled with a liquid food, and sealed. All these steps occur within a positive pressure zone inside the so-called sterile filling zone.

[087] The solution used to wash food packaging can be reused. During packaging washing, some of the peroxycarboxylic composition ends up in the cleaning solution when the cleaning solution is drained out of the packaging. As with the peroxycarboxylic acid reservoir, the hydrogen peroxide concentration in the cleaning solution can increase over time and eventually reach levels where the cleaning solution cannot be reused and must be diluted with fresh water or completely discarded, and a new solution used. Antimicrobial compositions containing selected catalase enzymes also advantageously allow the cleaning solution to be reused for longer because the hydrogen peroxide levels in the solution do not rise to a level where the solution must be diluted or discarded, saving time, money, chemicals, and water. The hydrogen peroxide concentration in the cleaning solution preferably remains below 45 or 35 ppm in a recycled cleaning solution.

[088] The cleaning solution includes water. The cleaning solution may also include an antimicrobial additive to make the water microbiologically pure (i.e., free of microorganisms). It may also include other additives to promote effective washing as cleaning aids. Finally, the cleaning solution may include a portion of the antimicrobial composition with the enzyme catalase. In one case, the cleaning solution includes approximately 0.15 to 1.5% by weight of the antimicrobial composition used to sterilize the bottles.

[089] When wash water is recycled or reused, it can be processed. Processing may include filtering out any remaining cleaning solution, for example, with a screen or column. Processing may include filtering out some chemicals or additives present in the solution after draining from the food packaging, for example, through a column or membrane. Processing may also include adding more additives to the cleaning solution (e.g., more antimicrobial agents) to make the solution more effective when used again.

[090] Recycling the cleaning solution can be part of a packaging disinfection method in which, after applying the selected catalase-based antimicrobial composition to a food package, the package is allowed to drain. Then, this package is washed with a cleaning solution, this solution is drained, collected, and processed to subsequently form a recycled cleaning solution that can be reused or recycled to wash food packages or used as an environmental cleaner, disinfectant, or rinse.

[091] The aseptic packaging process involves bringing the container into contact with a composition according to the present invention. Such contact can be made using a spray device, tank, or immersion container to cause the interior of the container to come into contact with the composition for a period of time sufficient to clean or reduce the microbial population in the container. The container is then emptied. After emptying, the container can be rinsed with potable or sterilized water (which may contain rinsing additives) and then emptied again. After rinsing, the container can be filled with the food. Then, the container is sealed, capped, or closed and then packaged for shipment for final sale.

[092] Examples of containers that can be filled include polyethylene terephthalate (PET), high-density polyethylene (HDPE), polypropylene (PP), low-density polyethylene, polycarbonate (PC), polyvinyl alcohol (PVA), aluminum, single or multilayer films or bags, cardboard, steel, glass, multilayer bottles, other polymeric packaging materials, combinations of these materials in films, bags, bottles or other food packaging materials.

[093] During the operation, the enzyme can be added all at once (bulk) or sequentially. The enzyme can float freely or be immobilized in the substrate. The enzyme can be added to the peracid in the reservoir. The enzyme is also preferably added at the time required, and not before the product is shipped.

[094] Figure 1 shows a schematic for a spray bottle/bottling operation using a composition according to the present invention. The operation can be cold and aseptic. Figure 1 shows a factory 100 that can bring beverage bottles into contact with a peroxycarboxylic acid composition for disinfection. In Figure 1, the bottles 110 are passed through a sterilization tunnel 102. Then, the disinfected bottles 110a pass through a washing tunnel 103 and emerge as sanitized bottles 110b.

[095] In the process, the composition is added to a holding tank 101. Commonly, the materials are kept at a temperature of about 22 °C in tank 101. The peroxycarboxylic acid use composition is passed through a heater 108 to reach a temperature of about 40 to 65 °C. The heated peroxycarboxylic acid use composition is sprayed inside the sterilization tunnel 102 and on all surfaces of the bottle 110. The composition can be pumped from the holding tank or reservoir to the bottle, at a rate of about 0.01 to 5.0 liters per second.

[096] After contact with the peroxycarboxylic acid composition and after removing any excess composition from the bottles, the sanitized bottles 110 are passed to a fresh water tunnel for rinsing 103. Fresh water 108 is supplied by a spray washing tunnel 103. The fresh water may contain cleaning additives. Excess spray is drained from the tunnel 103 to a drain 106, or it may be collected and reused as described above. Inside the tunnel 103, the sanitized bottles 110a are continuously rinsed with fresh water. Complete removal of the peroxycarboxylic acid composition from the bottles 110a is important to maintain the high quality of the beverage. The sanitized and rinsed bottles 110b are removed from the washing tunnel.

[097] The daily tank 101, the sterilization tunnel 102 and the washing tunnel 103 are respectively vented to a wet scrubber or vented 111a, 111b or 111c to remove vapors or smoke from system components. The disinfectant material that has been sprayed and drained from the bottles 110a accumulates at the bottom of the spray tunnel 102 and is then optionally recycled through the recycling line and heater 107 to the daily tank 101, out of the system to the drain, for use or exported to another part of the installation.

[098] Contact between the bottles and the peroxycarboxylic acid antimicrobial composition may occur at temperatures above 0 °C, above 25 °C, or above 40 °C. Temperatures between 40 °C and 90 °C may be used. In certain cases, contact is implemented at a temperature between 40 °C and 60 °C for a minimum of 5 or 10 seconds.

[099] In the cold aseptic filling of 28.4 g (16 oz) polyethylene terephthalate (PET bottle), or other polymers and beverage containers, a process using a peroxycarboxylic acid composition has been adopted. The peroxycarboxylic acid composition can be diluted to a use concentration of about 0.1 to 10% by weight and maintained at an effective elevated temperature of about 25 °C to 70 °C, for example, about 40 °C to 60 °C. Spraying or filling the bottle with the material ensures contact between the bottle and the disinfectant material for at least 5, for example, about 10 seconds up to 2 minutes. After filling, the bottle can be drained of all contents for at least 2 seconds and optionally followed by a 5-second rinse with about 200 ml of sterilized water at 38 °C (100 °F). If the bottle is filled with rinsing water, it is then drained for at least 2 seconds and immediately filled with the beverage. The rinsing water may include an additive containing the selected catalase enzyme, which is particularly useful in aseptic packaging. It is understood that this additive can be used in any situation where peracid compositions are used, as catalase can be introduced into the peracid composition without storing the peracid and catalase together. Such uses include peracid compositions in healthcare (e.g., for disinfection and cleaning of instruments such as endoscopes), in food and beverages, machinery washing, laundry, and household chores.

[0100] For a better understanding of the invention, the following examples are provided to illustrate some cases. These examples and experiments should be understood as illustrative, and not as limiting. All parts are presented by weight, except where indicated.

EXAMPLES

[0101] The following table provides a brief explanation of certain chemical components used in the following examples: Trade names and corresponding descriptions of some chemical elements used in the examples

Example 1

[0102] Example 1 compared the ability of various catalase enzymes at a concentration of 100 ppm to decompose hydrogen peroxide. For this example, an aliquot of a concentrated catalase solution was added to 1000 ml of a solution containing 20,000 ppm of acetic acid and 500 to 800 ppm of hydrogen peroxide at 60°C. Catalase was added at a rate that produced an enzyme concentration of 100 ppm in 1000 ml of the solution. The hydrogen peroxide concentration was measured at time zero and at 5, 10, and 15 minutes. The hydrogen peroxide concentration was measured by titrating a 10 mL aliquot of solution, including 1 to 2 mL of KI 10.0 solution, 1 to 2 mL of concentrated sulfuric acid, 4 to 5 drops of an oxygen catalyst (saturated ammonium molybdate solution), and a few drops of a starch solution. The titrant was 0.1 N sodium thiosulfate. The solution was titrated to a colorless endpoint, and the peroxide concentration was calculated using the following formula: H2O2 in ppm = (Na2S2O3 in ml)(Normality of titration) (H2O2 in weight equivalent)(sample size)(2) H2O2 in ppm = (Na2S2O3 in ml)(0.1)(34)(10 g)(2) The hydrogen peroxide concentration is shown in Table 1. Table 1 - Hydrogen peroxide concentration (ppm) during Time (minutes) in the presence of 100 ppm catalase

[0103] Table 1 shows that fungal catalase, mainly ASC Super G, ASC Super 200 and CA-400, managed to reduce the hydrogen peroxide concentration to zero after 10 minutes. Bovine catalase only reduced the hydrogen peroxide concentration to 28.9 ppm.

Example 2

[0104] Example 2 compared the ability of various catalase enzymes at a concentration of 20 ppm to decompose hydrogen peroxide. For this example, 20 ppm of catalase enzyme was diluted in 20,000 ppm of acetic acid and 500 to 800 ppm of hydrogen peroxide at 60°C. The hydrogen peroxide concentration was evaluated at time zero and at 5, 10, and 15 minutes in the same way as described in Example 1. The hydrogen peroxide concentration is shown in Table 2. Table 2 - Hydrogen peroxide concentration (ppm) during Time (minutes) in the presence of 0.20 ppm of catalase

[0105] Table 2 shows that fungal catalase, mainly ASC Super G, ASC Super 200 and CA-400, were able to measurably reduce the hydrogen peroxide concentration. Bovine catalase was not able to measurably reduce the hydrogen peroxide concentration.

Example 3

[0106] Example 3 determined the temperature stability of catalase CA-400. For this example, a 5,000 ppm sample of CA-400 was placed in a small glass vial and placed in a water bath at 60°C. Samples of CA-400 were removed from the water bath and placed in an ice water bath after a specified exposure time. After the ice water bath, the sample was tested against hydrogen peroxide at room temperature in a UV-VIS spectrophotometer at 240 nm for 2 minutes. The enzyme sample in distilled water was also tested. Using a pipette, 3 ml of a concentrated hydrogen peroxide solution were prepared for the spectrophotometer in a 1 cm x 1 cm quartz cuvette. 250 microliters of the catalase solution were added to the hydrogen peroxide solution. The spectrophotometer took measurements at 15-second intervals. The raw absorbance numbers are presented in Table 3. The adjusted absorbance numbers (raw catalase in hydrogen peroxide - distilled water as control) are shown in Table 4. The spectrophotometer measurements were converted to a hydrogen peroxide concentration. The hydrogen peroxide concentration was calculated using the following formula: H2O2 in ppm = (Abs of H2O2 with enzyme solution - Abs of enzyme solution in water)(0.0012)(1,000,000) The hydrogen peroxide concentration (ppm) over time is shown in Table 5. Table 3 - Spectrophotometer measurements for CA-400 in hydrogen peroxide Table 4 - Spectrophotometer measurements adjusted for CA-400 Table 5 - Hydrogen peroxide concentration (in ppm) with CA-400 over time

[0107] Example 3 shows that CA-400 is stable at 60 °C over time, because even after being in a water bath for 4 hours, it is still able to decrease the hydrogen peroxide concentration to zero in 75 seconds.

Example 4

[0108] Example 4 determined the temperature stability of catalase CA-400 in the presence of 20,000 ppm acetic acid. The enzyme was stored in acetic acid for 0 to 1, 2, or 4 hours in a glass vial. For this example, a 5,000 ppm sample of CA-400 was placed with a 20,000 ppm acetic acid solution in a small glass vial and placed in a water bath at 60°C. Samples of CA-400 were removed from the water bath and placed in an ice water bath after a certain exposure time. After the ice water bath, the sample was tested against hydrogen peroxide at room temperature in a UV-VIS spectrophotometer at 240 nm for 2 minutes. The enzyme sample in distilled water was also tested. Using a pipette, 3 ml of a concentrated hydrogen peroxide solution was prepared for the spectrophotometer in a 1 cm x 1 cm quartz cuvette. 250 microliters of catalase solution were added to the hydrogen peroxide solution. The spectrophotometer took measurements at 15-second intervals. The raw numbers are presented in Table 6. The adjusted numbers (raw catalase to hydrogen peroxide numbers - distilled water as a control) are shown in Table 7. The spectrophotometer measurements were converted to a hydrogen peroxide concentration. These values were calculated in the same way as indicated in Example 3. The hydrogen peroxide concentration (in ppm) over time is shown in Table 8. Table 6 - Spectrophotometer measurements for CA-400 in hydrogen peroxide Table 7 - Spectrophotometer measurements adjusted for CA-400 Table 8 - Hydrogen peroxide concentration (in ppm) with CA-400 over time

[0109] Example 4 shows that CA-400 is stable at 60 °C over time, because even after being in a water bath for four hours and exposed to 20,000 ppm of acetic acid it is still able to decrease the hydrogen peroxide concentration over time.

Example 5

[0110] Example 5 determined the temperature stability of catalase CA-100. For this example, a 5,000 ppm sample of CA-100 was placed in a small glass vial and placed in a water bath at 60°C. Samples of CA-100 were removed from the water bath and placed in an ice water bath after a specified exposure time. After the ice water bath, the sample was tested against hydrogen peroxide at room temperature in a UV-VIS spectrophotometer at 240 nm for 2 minutes. The enzyme sample in distilled water was also tested. Using a pipette, 3 ml of a concentrated hydrogen peroxide solution were prepared for the spectrophotometer in a 1 cm x 1 cm quartz cuvette. 250 microliters of the catalase solution were added to the hydrogen peroxide solution. The spectrophotometer took measurements at 15-second intervals. The raw numbers are presented in Table 9. The adjusted numbers (raw catalase in hydrogen peroxide numbers - distilled water as control) are shown in Table 10. The spectrophotometer measurements were converted to a hydrogen peroxide concentration. These values were calculated in the same way as indicated in Example 3. The hydrogen peroxide concentration (in ppm) over time is shown in Table 11. Table 9 - Spectrophotometer measurements for CA-100 in hydrogen peroxide Table 10 - Spectrophotometer measurements adjusted for CA-100 Table 11 - Hydrogen peroxide concentration (in ppm) with CA-100 over time

[0111] Example 5 shows that CA-100 is stable at 60 °C over time, because even after being in a water bath for 4 hours, it is still able to decrease the concentration of hydrogen peroxide.

Example 6

[0112] Example 6 determined the temperature stability of catalase CA-100 in the presence of 20,000 ppm acetic acid. For this example, a 5,000 ppm sample of CA-100 was placed with a 20,000 ppm acetic acid solution in a small glass vial and placed in a water bath at 60°C. Samples of CA-100 were removed from the water bath and placed in an ice water bath after a certain exposure time. After the ice water bath, the sample was tested against hydrogen peroxide at room temperature in a UV-VIS spectrophotometer at 240 nm for 2 minutes. The enzyme sample in distilled water was also tested. Using a pipette, 3 ml of a concentrated hydrogen peroxide solution were prepared for the spectrophotometer in a 1 cm x 1 cm quartz cuvette. 250 microliters of catalase solution were added to the hydrogen peroxide solution. The spectrophotometer took measurements at 15-second intervals. The raw numbers are presented in Table 12. The adjusted numbers (raw catalase to hydrogen peroxide numbers - distilled water as a control) are shown in Table 13. The spectrophotometer measurements were converted to a hydrogen peroxide concentration as in Example 3. The hydrogen peroxide concentration (in ppm) over time is presented in Table 14. Table 12 - Spectrophotometer measurements for CA-100 in hydrogen peroxide Table 13 - Spectrophotometer measurements adjusted for CA-100 Table 14 - Hydrogen peroxide concentration (in ppm) with CA-100 over time

[0113] Example 6 shows that CA-100 is stable at 60 °C in the presence of 20,000 ppm of acetic acid, because even after being in a water bath for 4 hours, it is still able to decrease the concentration of hydrogen peroxide.

Example 7

[0114] Example 7 determined the temperature stability of ASC Super G catalase. For this example, a 5,000 ppm sample of ASC Super G was placed in a small glass vial and placed in a water bath at 60°C. Samples of ASC Super G were removed from the water bath and placed in an ice water bath after a specified exposure time. After the ice water bath, the sample was tested against hydrogen peroxide at room temperature in a UV-VIS spectrophotometer at 240 nm for 2 minutes. The enzyme sample in distilled water was also tested. Using a pipette, 3 ml of a concentrated hydrogen peroxide solution were prepared for the spectrophotometer in a 1 cm x 1 cm quartz cuvette. 250 microliters of the catalase solution were added to the hydrogen peroxide solution. The spectrophotometer took measurements at 15-second intervals. The raw numbers are presented in Table 15. The adjusted numbers (raw catalase in hydrogen peroxide numbers - distilled water as control) are shown in Table 16. The spectrophotometer measurements were converted to a hydrogen peroxide concentration as in example 3. The hydrogen peroxide concentration (in ppm) over time is presented in Table 17. Table 15 - Spectrophotometer measurements for ASC Super G in hydrogen peroxide Table 16 - Spectrophotometer measurements adjusted for ASC Super G Table 17 - Hydrogen peroxide concentration (in ppm) with ASCSuper G over time

[0115] Example 7 shows that ASC Super G is stable at 60 °C over time, because even after being in a water bath for 4 hours, it is still able to decrease the hydrogen peroxide concentration.

Example 8

[0116] Example 8 determined the temperature stability of catalase ASC Super G in the presence of 20,000 ppm acetic acid. For this example, a 5,000 ppm sample of ASC Super G along with 20,000 ppm acetic acid was placed in a small glass vial and placed in a water bath at 60°C. Samples of ASC Super G were removed from the water bath and placed in an ice water bath after a specified exposure time. After the ice water bath, the sample was tested against hydrogen peroxide at room temperature in a UV-VIS spectrophotometer at 240 nm for 2 minutes. The enzyme sample in distilled water was also tested. Using a pipette, 3 ml of a concentrated hydrogen peroxide solution were prepared for the spectrophotometer in a 1 cm x 1 cm quartz cuvette. 250 microliters of catalase solution were added to the hydrogen peroxide solution. The spectrophotometer took measurements at 15-second intervals. The raw numbers are presented in Table 18. The adjusted numbers (raw catalase to hydrogen peroxide numbers - distilled water as a control) are shown in Table 19. The spectrophotometer measurements were converted to a hydrogen peroxide concentration. The hydrogen peroxide concentration (ppm) over time is shown in Table 20. Table 18 - Spectrophotometer measurements for ASC Super G in hydrogen peroxide Table 19 - Spectrophotometer measurements adjusted for ASC Super G Table 20 - Hydrogen peroxide concentration (in ppm) with ASCSuper G over time

[0117] Example 8 shows that ASC Super G is stable at 60 °C in the presence of 20,000 ppm of acetic acid, because even after being in a water bath for 4 hours, it is still able to decrease the hydrogen peroxide concentration.

Example 9

[0118] Example 9 determined the effect of sequential addition of catalase CA-100 versus bulk addition of catalase CA-100. For this example, a 10% by weight enzyme concentrate was prepared. A peracid concentrate was also prepared. It included 13.5% peracetic acid, 10.88% hydrogen peroxide, and 23.15% acetic acid. The peracid concentrate was diluted to form a solution with approximately 3,000 ppm of peracetic acid. Additional glacial acetic acid was added to the diluted solution to bring the acetic acid concentration to 20,000 ppm.

[0119] To test the effect of sequential addition, 1 ml of concentrated enzyme solution (100 ppm enzyme) was added to 1000 ml of diluted peracid solution. The enzyme and peracid solution were placed in a water bath at 50 °C and stirred with a magnetic stirrer. The solution was titrated to peracetic acid and hydrogen peroxide using an iodometric titration with 0.1 N sodium thiosulfate. After 30 minutes, another 1 ml of concentrated enzyme solution (100 ppm enzyme for a total of 200 ppm enzyme) was added to the diluted peracid solution and a new titration was performed.

[0120] To test the effect of one-time addition, 2 ml of concentrated enzyme solution (enzyme at 200 ppm) were added to 1000 ml of diluted peracid solution. The enzyme and peracid solution were placed in a water bath at 50 °C and stirred with a magnetic stirrer. The solution was titrated to peracetic acid and hydrogen peroxide using an iodometric titration with 0.1 N sodium thiosulfate. Table 21 - Sequential addition of 2 ml of enzyme Table 22 - One-time addition of 2 ml of enzyme

[0121] Example 9 shows that the one-time addition of CA-100 is better at decreasing the hydrogen peroxide concentration than the sequential addition, because the one-time addition decreased the hydrogen peroxide concentration to 136 ppm compared to 552.5 ppm from the sequential addition.

Example 10

[0122] Example 10 determined the effect of sequential addition of catalase CA-400 versus one-time addition of catalase CA-400. For this example, a 2% by weight enzyme concentrate was prepared. A peracid concentrate was also prepared. It included 13.5% peracetic acid, 10.88% hydrogen peroxide, and 23.15% acetic acid. The peracid concentrate was diluted to form a solution with 3,000 ppm peracetic acid. Additional glacial acetic acid was added to the diluted solution to bring the acetic acid concentration to 20,000 ppm.

[0123] To test the effect of sequential addition, 2 ml of concentrated enzyme solution (enzyme at 40 ppm) were added to 1000 ml of diluted peracid solution. The enzyme and peracid solution were placed in a water bath at 50 °C and stirred with a magnetic stirrer. The solution was titrated to peracetic acid and hydrogen peroxide using an iodometric titration with 0.1 N sodium thiosulfate. After 30 minutes, another 2 ml of concentrated enzyme solution (40 ppm enzyme for a total of 80 ppm enzyme) was added to the diluted peracid solution and a new titration was performed.

[0124] To test the effect of one-time addition, 4 ml of concentrated enzyme solution (80 ppm enzyme) were added to 1000 ml of diluted peracid solution. The enzyme and peracid solution were placed in a water bath at 50 °C and stirred with a magnetic stirrer. The solution was titrated to peracetic acid and hydrogen peroxide using an iodometric titration with 0.1 N sodium thiosulfate. Table 23 - Sequential addition of 2 ml of enzyme Ta bela 24 - Addition of 4 ml of enzyme at once

[0125] Example 10 shows that the sequential addition of CA-400 is better at decreasing the hydrogen peroxide concentration than adding it all at once, because the sequential addition decreased the hydrogen peroxide concentration to 102 ppm compared to 544 ppm for the one-time addition.

Example 11

[0126] Example 11 determined the effect of sequential addition of catalase ASC Super G versus a single addition of catalase ASC Super G. For this example, a 10% by weight enzyme concentrate was prepared. A peracid concentrate was also prepared. It included 13.5% peracetic acid, 10.88% hydrogen peroxide, and 23.15% acetic acid. The peracid concentrate was diluted to form a solution with 3,000 ppm peracetic acid. Additional glacial acetic acid was added to the diluted solution to bring the acetic acid concentration to 20,000 ppm.

[0127] To test the effect of sequential addition, 1 ml of concentrated enzyme solution (100 ppm enzyme) was added to 1000 ml of diluted peracid solution. The enzyme and peracid solution were placed in a water bath at 50 °C and stirred with a magnetic stirrer. The solution was titrated to peracetic acid and hydrogen peroxide using an iodometric titration with 0.1 N sodium thiosulfate. After 30 minutes, another 1 ml of concentrated enzyme solution (100 ppm enzyme for a total of 200 ppm enzyme) was added to the diluted peracid solution and a new titration was performed.

[0128] To test the effect of the one-time addition, 2 ml of the concentrated enzyme solution (enzyme at 200 ppm) were added to 1000 ml of the diluted peracid solution. The enzyme and peracid solution were placed in a water bath at 50 °C and stirred with a magnetic stirrer. The solution was titrated to peracetic acid and hydrogen peroxide using an iodometric titration with 0.1 N sodium thiosulfate. Table 25 - Sequential addition of 2 ml of enzyme Table 26 - One-time addition of 2 ml of enzyme

[0129] Example 11 shows that the sequential addition of ASC Super G is better at decreasing the hydrogen peroxide concentration than adding it all at once, because the sequential addition decreased the hydrogen peroxide concentration to 170 ppm compared to 187 ppm for the one-time addition.

Example 12

[0130] Example 12 determined the effect of sequential addition of catalase ASC Super 200 versus a single addition of catalase ASC Super 200. For this example, a 2% by weight enzyme concentrate was prepared. A peracid concentrate was also prepared. It included 13.5% peracetic acid, 10.88% hydrogen peroxide, and 23.15% acetic acid. The peracid concentrate was diluted to form a solution with 3,000 ppm peracetic acid. Additional glacial acetic acid was added to the diluted solution to bring the acetic acid concentration to 20,000 ppm.

[0131] To test the effect of sequential addition, 2 ml of concentrated enzyme solution (enzyme at 40 ppm) were added to 1000 ml of diluted peracid solution. The enzyme and peracid solution were placed in a water bath at 50 °C and stirred with a magnetic stirrer. The solution was titrated to peracetic acid and hydrogen peroxide using an iodometric titration with 0.1 N sodium thiosulfate. After 30 minutes, another 2 ml of concentrated enzyme solution (40 ppm enzyme for a total of 80 ppm enzyme) was added to the diluted peracid solution and a new titration was performed.

[0132] To test the effect of one-time addition, 4 ml of concentrated enzyme solution (80 ppm enzyme) were added to 1000 ml of diluted peracid solution. The enzyme and peracid solution were placed in a water bath at 50 °C and stirred with a magnetic stirrer. The solution was titrated to peracetic acid and hydrogen peroxide using an iodometric titration with 0.1 N sodium thiosulfate. Table 27 - Sequential addition of 2 ml of enzyme Table 28 - One-time addition of 2 ml of enzyme

[0133] Example 12 shows that sequential addition of ASC Super 200 is better at decreasing the hydrogen peroxide concentration than adding it all at once, because sequential addition decreased the hydrogen peroxide concentration to 0 ppm compared to 187 ppm for the one-time addition, even with the addition of H2O2 before the second addition of the enzyme.

Example 13

[0134] Example 13 provides a contrast between how a conventional peracid chemical element in equilibrium acts as an antimicrobial agent relative to the same chemical element with the addition of catalase ASC super 200 described in the examples above.

[0135] The test solutions described below were made up to a concentration of 2,000 ppm of active peracid from the 13.5% concentrated peracid described in Example 9.

[0136] A 500 ml aliquot of this solution was treated with 0.25 g of ASC super 200. The remaining solution was not treated.

[0137] Both solutions were heated to 50 °C. Three different spore cultures were tested against each solution to show the effectiveness of each solution over various contact time periods. Table 29 - Test solutions Table 30 - Efficacy against Bacillus cereus BC896CB Table 31 - Efficacy against Bacillus thuringiensis ATCC 10792 Table 32 - Efficacy against Bacillus thuringiensis ATCC 33679

[0138] The results clearly show the positive impact of the combined composition of catalase and peracid compared to the native POAA solution.

Example 14

[0139] A second important feature of this technology is its ability to meet the effectiveness requirements for aseptic packaging applications at reduced temperatures.

[0140] The test requirements in this case relate to a vehicle test. The vehicle test requires drying a spore inoculum in a small cylindrical vehicle. These vehicles are then placed in an antimicrobial test solution for a specified period of time. They are then removed from the solution, neutralized, and placed in series in a set of tubes containing growth nutrients. Growth or lack of growth in these tubes is a measure of the detergent's effectiveness.

[0141] This example tested a 3,000 ppm POAA solution treated with approximately 100 ppm ASC Super 200, as well as the same solution without the addition of this enzyme. The assay conditions were: 19 seconds of exposure to the chemical element with the element detained at 50 or 60 °C. Table 33 - Efficacy against Clostridium sporogenes ATCC 3584

[0142] For the test to pass, the result must be 60/60. These results show the advantage of including catalase for this application.

Example 15

[0143] Example 15 shows the accumulation of hydrogen peroxide over time with or without catalase. For this example, solutions of 3,000 and 6,000 ppm of peracetic acid were made from a commercially available concentrated peracid containing approximately 10% POAA and 10% hydrogen peroxide. These solutions were separated. Half was treated with the catalase enzyme ASC super G, and the other half was left untreated. Both solutions were placed in a water bath at 60°C and monitored for changes in peroxide concentration over time.

[0144] Table 34 shows the results of this experiment. Examples 34a and 34b represent an untreated peracid solution. Examples 34c and 34d represent the same peracid solutions treated with a catalase enzyme after measurement time 0 until the peroxide level equals 0. Table 34.

[0145] Examples 34a and 34b show the natural accumulation of peroxide that follows the dilution of a concentrated peracid. Examples 34c and 34d show the same effect with a peracid solution that had all the peroxide eliminated through the catalytic reaction. These results demonstrate that the preferential range of peroxides and peracids can be maintained only when combined with the addition of the enzyme catalase.

Definitions

[0146] For the terms defined below, these definitions shall apply unless a different definition is provided in the claims or elsewhere in this specification.

[0147] All numerical values in this document are assumed to be modified by the term "approximately," whether explicitly indicated or not. The term "approximately" generally refers to a series of numbers that someone knowledgeable in the field would consider equivalent to the quoted value (i.e., with the same function or result). In many cases, the term "approximately" may include numbers rounded to the nearest significant value.

[0148] Percentage by weight, percentage by weight, % by weight, % of weight, and similar terms, are synonyms that refer to the concentration of a substance as the weight of the substance is divided by the weight of the composition and multiplied by 100.

[0149] Citing numerical ranges using the first and last numbers includes all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0150] It is necessary to observe that, as used in these specifications and the attached claims, the singular forms “a”, “an” and “the” include their respective plural forms, unless the content clearly indicates otherwise. Thus, for example, reference to a composition containing “a compound” includes a mixture with two or more compounds. As used in this specification and the attached claims, the term “or” is generally employed in its sense including “and/or”, unless the content clearly indicates otherwise.

[0151] The use of the term "antimicrobial" in this application does not mean that the resulting products are approved for use as an antimicrobial agent.

[0152] The preceding summary, detailed description, and examples provide a solid basis for understanding the invention, and in some cases, a concrete example of the invention. Since the invention may encompass various applications, the above information should not be understood as a limitation. The invention is based on the following assertions.

Claims (29)

1. Method of disinfecting packaging by aseptic packaging CHARACTERIZED in that it comprises: (a) providing an antimicrobial composition at the time of use, comprising (i) 20 ppm-250 ppm of a catalase enzyme selected from the group consisting of bovine-derived catalase and/or fungal-derived catalase; (ii) 0.00001%-0.5% by weight of hydrogen peroxide; (iii) 0.1%-20.0% by weight of a C1-C10 carboxylic acid having the structure R-(COOH)n, wherein R may be hydrogen, alkyl, alkenyl, alicyclic, aryl, heteroaryl, or heterocyclic, and n is 1, 2, or 3; (iv) 0.1%–2.0% by weight of a C1–C10 percarboxylic acid having the structure R–(COOOH)n, wherein R may be hydrogen, alkyl, alkenyl, alicyclic, aryl, heteroaryl, or heterocyclic, and n is 1, 2, or 3; (b) heating the antimicrobial composition at 40 °C to 65 °C; and (c) applying the antimicrobial composition to a food packaging surface to reduce any microorganisms by 2 logs. 2. Method according to claim 1, characterized in that the enzyme catalase is capable of degrading 500 ppm of hydrogen peroxide in 15 minutes. 3. Method according to claim 1, CHARACTERIZED in that the catalase retains 50% of its initial catalytic activity for a period of one hour at 40 °C and 65 °C and a pH of 2.0-2.5. 4. Method according to claim 1, characterized in that catalase is added in a one-time addition of 20 ppm–250 ppm of catalase enzyme. 5. Method according to claim 1, CHARACTERIZED in that catalase is added in serial applications. 6. Method according to claim 1, characterized in that the catalase floats freely in the antimicrobial composition. 7. Method according to claim 1, CHARACTERIZED in that the catalase is immobilized on a water-insoluble substrate selected from the group of a polyurethane foam, a polyacrylamide gel, maleic anhydride gel on polyethylene, maleic anhydride gel on polystyrene, cellulose, nitrocellulose, silastic resin, porous glass, macroporous glass membrane, glass bead, activated clay, zeolite, alumina, silica, and silicate that is in contact with the remaining antimicrobial composition. 8. Method according to claim 1, CHARACTERIZED in that the carboxylic acid is selected from the group consisting of acetic acid and/or octanoic acid, and the peracid is selected from the group consisting of peracetic acid and/or peroctanoic acid. 9. Method of disinfecting packaging by aseptic packaging CHARACTERIZED in that it comprises: (a) providing an antimicrobial composition comprising (i) 20 ppm-250 ppm of a catalase enzyme of fungal origin; (ii) 0.00001%-0.3% by weight of hydrogen peroxide; (iii) 0.1%-2.0% by weight of acetic acid and/or octanoic acid; and (iv) 0.15%-0.4% by weight of peracetic acid and/or peroctanoic acid; (c) heating the antimicrobial composition to 40 °C to 65 °C; and (d) applying the antimicrobial composition to a surface of a food packaging to reduce any microorganisms by 2 logs. 10. Method according to claim 9, CHARACTERIZED in that the enzyme catalase is capable of degrading 500 ppm of hydrogen peroxide in 15 minutes. 11. Method according to claim 9, CHARACTERIZED in that the catalase retains 50% of its initial catalytic activity for a period of 1 hour at 40 °C and 65 °C and a pH of 2.0-2.5. 12. Method according to claim 9, CHARACTERIZED in that catalase is added in a one-time addition of 20 ppm–250 ppm of catalase enzyme. 13. Method according to claim 9, CHARACTERIZED in that catalase is added in serial applications. 14. Method according to claim 9, CHARACTERIZED in that the catalase floats freely in the antimicrobial composition. 15. Method according to claim 9, CHARACTERIZED in that the catalase is immobilized on a water-insoluble substrate selected from the group of a polyurethane foam, a polyacrylamide gel, maleic anhydride gel on polyethylene, maleic anhydride gel on polystyrene, cellulose, nitrocellulose, silastic resin, porous glass, macroporous glass membrane, glass bead, activated clay, zeolite, alumina, silica, and silicate that is in contact with the remaining antimicrobial composition. 16. Method of disinfecting packaging by aseptic packaging CHARACTERIZED in that it comprises: (a) forming an antimicrobial composition in a reservoir, the antimicrobial composition comprising (i) 20 ppm-250 ppm of a catalase enzyme of fungal origin; (ii) 0.00001%-0.3% by weight of hydrogen peroxide; (iii) 0.1%-2.0% by weight of acetic acid and/or octanoic acid; (iv) 0.15%-0.4% by weight of peracetic acid and/or peroctanoic acid; (b) heat the composition in the reservoir at 20°C to 65°C; (c) pump 0.01-5.0 liters per second of the antimicrobial composition from the reservoir to the packaging; (d) apply the composition to a surface of a food packaging to reduce any microorganisms by 2 logs; (e) monitor the hydrogen peroxide concentration in the reservoir; and (f) add additional catalase to the reservoir to maintain a hydrogen peroxide concentration of 0.00001-0.1% by weight. 17. Method according to claim 16, CHARACTERIZED in that catalase is added to the reservoir in response to a reading from a sensor. 18. Method according to claim 16, CHARACTERIZED in that catalase is added to the reservoir in a time-based addition. 19. Method according to claim 16, CHARACTERIZED in that catalase is added to the reservoir in serial applications. 20. Method according to claim 16, CHARACTERIZED in that catalase is added to the reservoir in a one-time addition of 20 ppm–250 ppm of catalase enzyme. 21. Method according to claim 16, CHARACTERIZED in that the food packaging is selected from the group consisting of polyethylene terephthalate, high-density polyethylene, polypropylene, low-density polyethylene, polycarbonate, polyvinyl alcohol, aluminum, single-layer films, multi-layer films, cardboard, steel, glass and/or multi-layer bottles. 22. Method of disinfecting packaging by aseptic packaging CHARACTERIZED in that it comprises: (a) providing an antimicrobial composition at the time of use, comprising (i) 20 ppm-250 ppm of a catalase enzyme selected from the group consisting of bovine catalase and/or fungal catalase; (ii) 0.00001%-0.5% by weight of hydrogen peroxide; (iii) 0.1%-20.0% by weight of a C1-C10 carboxylic acid having the structure R-(COOH)n, wherein R may be hydrogen, alkyl, alkenyl, alicyclic, aryl, heteroaryl, or heterocyclic, and n is 1, 2, or 3; (iv) 0.1%–2.0% by weight of a C1–C10 percarboxylic acid having the structure R–(COOOH)n, wherein R may be hydrogen, alkyl, alkenyl, alicyclic, aryl, heteroaryl, or heterocyclic, and n is 1, 2, or 3; (b) heating the antimicrobial composition at 40 °C to 65 °C; (c) applying the antimicrobial composition to a surface of a food packaging to reduce any microorganisms by 2 logs; (d) allowing the antimicrobial composition to drain from the food packaging; (e) rinsing the food packaging with a rinsing solution; (f) allowing the rinsing solution to drain from the food packaging; (g) collecting the drained rinsing solution; (h) processing the collected rinsing solution to form a recycled rinsing solution; and (i) using the recycled rinsing solution. 23. Method according to claim 22, CHARACTERIZED in that the enzyme catalase is capable of degrading 500 ppm of hydrogen peroxide in 15 minutes. 24. Method according to claim 22, CHARACTERIZED in that the catalase retains 50% of its initial catalytic activity for a period of 1 hour at 40 °C and 65 °C and a pH of 2.0-2.5. 25. Method according to claim 22, CHARACTERIZED in that catalase is added in a one-time addition of 20 ppm–250 ppm of catalase enzyme. 26. Method according to claim 22, CHARACTERIZED in that catalase is added in serial applications. 27. Method according to claim 22, CHARACTERIZED in that the catalase floats freely in the antimicrobial composition. 28. Method according to claim 22, CHARACTERIZED in that the catalase is immobilized on a water-insoluble substrate selected from the group of a polyurethane foam, a polyacrylamide gel, maleic anhydride gel on polyethylene, maleic anhydride gel on polystyrene, cellulose, nitrocellulose, silastic resin, porous glass, macroporous glass membrane, glass bead, activated clay, zeolite, alumina, silica, and silicate that is in contact with the remaining antimicrobial composition. 29. Method according to claim 22, CHARACTERIZED in that the carboxylic acid is selected from the group consisting of acetic acid and/or octanoic acid, and the peracid is selected from the group consisting of peracetic acid and/or peroctanoic acid.