CA2976009C - Antimicrobial treatment solutions - Google Patents

Abstract

Various food products may be treated with an aqueous antimicrobial solution that includes a quaternary ammonium compound and an acidifying agent. Treatment may include spraying or submerging the food product in the solution. The acidifying agent may be present in the solution in an amount effective to provide the solution with a desired acidic pH value. Some solutions may include an acidifying agent that includes a generally recognized as safe (GRAS) acid. Some solutions may include additional components, such as a solubility agent.

Description

ANTIMICROBIAL TREATMENT SOLUTIONS
TECHNOLOGY
[0001] The present disclosure is directed to antimicrobial treatments of food products and, more particularly, to antimicrobial treatments and treatment solutions comprising quaternary ammonium compounds and associated methods of reducing quaternary ammonium compound residues following such treatments.
BACKGROUND

[0002] Food products are often treated with antimicrobial solutions to kill or control microbial populations that may otherwise deleteriously affect the food products. For example, food products may be covered in microbial populations that impact the safety or the quality of the food products. While such antimicrobial solutions play an essential role in food safety by reducing or eliminating microbial populations, antimicrobial solutions may also include various levels of toxicity if excessive levels are consumed. Thus, controlling microbial populations on food products with antimicrobial solutions may require achieving a delicate balance between the desired control of the microbial populations and the residual presence of the antimicrobial components used to control the microbial levels.
SUMMARY

[0003] In one aspect, an aqueous antimicrobial solution for treatment of food products comprises a quaternary ammonium compound and an acidifying agent. The acidifying agent may be present in an amount effective to provide the solution with a pH value between about 2.0 and about 1.0, between about 1.5 to about 1.2, or between about 1.5 to about 1.3. The acidifying agent may comprise a wide range of acids, including but not limited to acids that are generally recognized as safe (GRAS). In one embodiment, the acidifying agent may comprise one or more acids selected from generally GRAS acids. In one embodiment, the acidifying agent may comprise at least one of citric acid and hydrochloric acid. The quaternary ammonium compound may be present in a wide range of concentrations.
In one embodiment, the quaternary ammonium compound may be present in an amount of about 0.2% to about 0.5% by weight, about 0.3% to about 0.4% by weight, or about 0.3% to about 0.35% by weight. The quaternary ammonium compound may be an alkylpyridinium salt. In one embodiment, the alkylpyridinium salt may be cetylpyridinium chloride.

[0004] The solution may further comprise a solubility agent. In one embodiment, the solubility agent is selected from propylene glycol and glycerin. The solution may be formed from dilution of a concentrated antimicrobial solution comprising the quaternary ammonium compound and the solubility agent. The concentrated antimicrobial solution may have a pH
value less than 7Ø

[0005] In one embodiment, the quaternary ammonium compound may be present in a concentration between one of 0.2% and 0.5% by weight, 0.3% and 0.4% by weight, and 0.3%
and 0.35 A) by weight and the acidifying agent may be present in an amount effective to provide the solution with a pH value such that treatment of a food product with the solution results in an average residue of the quaternary ammonium compound below about 35 ppm.
In a further embodiment, the concentrations of the quaternary ammonium compound and acidifying agent are selected such that treatment of the food product with the solution results in an average residue of the quaternary ammonium compound below about 31.5 ppm. In yet a further embodiment, the concentration of the quaternary ammonium compound and acidifying agent are selected such that treatment of the food product with the solution results in an average residue of the quaternary ammonium compound below about 7 ppm.
The treatment may comprise spraying the solution onto the food product or submerging the food product in the solution for between about 15 seconds and about 3 seconds, between about 12 seconds and between about 4 seconds, or about 10 seconds and about 5 seconds.

[0006] In another aspect, a concentrated antimicrobial solution comprises a quaternary ammonium compound and a solubility agent, wherein the concentrated antimicrobial solution has a pH value below 7Ø In some such embodiments, the pH value of the concentrated antimicrobial solution may be below about 6.5, below about 6.0, or below about 5.5.

[0007] The quaternary ammonium compound may be present in an amount about 40%
by weight. The quaternary ammonium compound may be an alkylpyridinium salt. In one embodiment, the alkylpyridinium salt is cetylpyridinium chloride.

[0008] The solubility agent may be selected from one of an alcohol and glycerin. In one embodiment, the solubility agent is propylene glycol. The propylene glycol may be present in a wide range of values. In one embodiment, the propylene glycol may be present in an amount between about 55% and about 60% by weight of the concentrated antimicrobial solution.

[0009] In yet another aspect, a method of preparing an antimicrobial treatment solution comprises adding an acidifying agent to a solution comprising a quaternary ammonium compound. The acidifying agent may be added in an amount effective to provide the solution with a pH value between one of about 2.0 and about 1.0, about 1.5 and about 1.2, and about 1.5 and about 1.3. In one embodiment, the acidifying agent comprises one or more acids generally recognized as safe (GRAS) acids. The acidifying agent may comprise at least one of citric acid and hydrochloric acid.

[0010] The quaternary ammonium compound may be present in the solution in an amount between about 0.2% and about 0.5% by weight, between about 0.3% and about 0.4%
by weight, or between about 0.3% to about 0.35% by weight. In one embodiment, the quaternary ammonium compound may be an alkylpyridinium salt. In a further embodiment, the alkylpyridinium salt may be cetylpyridinium chloride. The concentrated quaternary ammonium compound may be provided in a concentrated antimicrobial solution comprising the quaternary ammonium compound and a solubility agent. The solubility agent may be selected from an alcohol, such as propylene glycol, and glycerin.

[0011] In one embodiment, the concentration of the quaternary ammonium compound in the solution is between one of about 0.2% and about 0.5% by weight, about 0.3% and about 0.4%
by weight, and about 0.3% and about 0.35% by weight, and the method further comprises adding the acidifying agent in an amount effective to provide the solution with a pH value such that treatment of a food product with the solution results in an average residue of the quaternary ammonium compound below about 35 ppm. The treatment may comprise spraying the solution onto the food product or submerging the food product in the solution for between about 15 seconds and about 3 seconds, between about 12 seconds and about 4 seconds, or between about 10 seconds and about 5 seconds. In a further embodiment, the concentrations of the quaternary ammonium compound and acidifying agent are selected such that treatment of a food product with the solution results in an average residue of the quaternary ammonium compound below about 31.5 ppm. In yet a further embodiment, the concentrations of the quaternary ammonium compound and the acidifying agent are selected such that treatment of a food product with the solution results in an average residue of the quaternary ammonium compound below about 7 ppm.

[0012] In still yet another aspect, a method of making a concentrated antimicrobial solution comprises formulating a concentrated antimicrobial solution comprising a quaternary ammonium compound, a solubility agent, and an acidifying agent in a solvent, wherein the acidifying agent may be added to the concentrated solution in an amount sufficient to provide a pH value of the concentrated antimicrobial solution below 7Ø In some embodiments, the pH value of the concentrated antimicrobial solution may be below about 6.5, below about 6.0, or below about 5.5.

[0013] In one embodiment, the quaternary ammonium compound may be an alkylpyridinium salt. In a further embodiment, the alkylpyridinium salt may be cetylpyridinium chloride. The cetylpyridinium chloride may be present in an amount of about 40% by weight. The solubility agent may be selected from an alcohol and glycerin. In one embodiment, the solubility agent is propylene glycol. The propylene glycol may be present in a wide range of values. In one embodiment, the propylene glycol may be present in an amount between about 55% and about 60% by weight of the concentrated antimicrobial solution. In one embodiment, the solvent is water.

[0014] In still yet another aspect, a method of treating a food product comprises applying an antimicrobial solution to a food product. The antimicrobial solution may comprise a quaternary ammonium compound and an acidifying agent. The quaternary ammonium compound may be present in an amount between one of about 0.2% and about 0.5%
by weight, about 0.3% and about 0.4% by weight, and about 0.3% and about 0.35% by weight.
The solution may have a pH value between one of about 2.0 and about 1.0, about 1.5 and about 1.2, and about 1.5 and 1.3. Applying the antimicrobial solution may comprise spraying the solution onto the food product or submerging the food product in the solution.

[0015] In one embodiment, the solution may be applied to the food product for an application time between about 15 seconds and about 3 seconds. In one embodiment, the food product comprises a poultry food product selected from one of a carcass, breast, tender, thigh, giblet, and wing.

[0016] In still yet another aspect, a method of formulating an antimicrobial treatment solution comprises selecting a solution concentration of a quaternary ammonium compound.
The quaternary ammonium compound may be cetylpyridinium chloride present in an amount of about 0.2% to about 0.5% by weight, about 0.3% to about 0.4% by weight, and about 0.3%
to about 0.35% by weight. The method may further comprise selecting a solution pH value between one of about 2.0 and about 1.0, about 1.5 and about 1.2, and about 1.5 and about 1.3.
The treatment may comprise application of the solution to the food product by one of spraying the solution onto the food product and submerging the food product in the solution for an application time between one of about 15 seconds to about 3 seconds, about 12 seconds to about 4 seconds, and about 10 seconds to about 5 seconds.

[0017] The method may further comprise selecting an acidifying agent to adjust the pH of the solution to obtain the selected solution pH value. The selected quaternary, ammonium compound may be combined with a solubility agent prior to adjusting the pH
with the selected acidifying agent to obtain the selected solution pH value. Any number of different acidifying agents may be used, but the acidifying agent may preferably be selected from one or more acids comprising generally recognized as safe (GRAS) acids. In one embodiment, the selected acidifying agent comprises at least one of citric acid and hydrochloric acid. The method may further comprise selecting a solubility agent selected from an alcohol and glycerin. In one embodiment, the method includes selecting a solubility agent comprising propylene glycol. The selected quaternary ammonium compound may be provided in a concentrated antimicrobial solution comprising the selected solubility agent.
BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 schematically illustrates an overview of the experimental protocol of Example 1;

[0019] FIG. 2 graphically illustrates residue data obtained in Example 1;

[0020] FIG. 3 schematically illustrates an overview of the experimental protocol of Example 2; and

[0021] FIG. 4 graphically illustrates residue data obtained in Example 2.

[0022] FIG. 5 schematically illustrates an overview of the experimental protocol of Example 3; and

[0023] FIG. 6 graphically illustrates microbial data obtained in Example 3.
DESCRIPTION

[0024] Various embodiments of antimicrobial treatment solutions comprising quaternary ammonium compounds are described herein. The particular quaternary ammonium compound is preferably suitable for use in preventing the growth of a broad spectrum of microorganisms on and in food products by application of the quaternary ammonium compound or treatment solution comprising the quaternary ammonium compound to such food products. In various embodiments, the food products treated may include poultry, beef, pork, lamb, venison, and other edible meat products, such as seafood, fish and shellfish, as well as fruits, vegetables, and dairy products.

[0025] Treatment Solutions

[0026] In various embodiments, an aqueous antimicrobial solution for treatment of a food product comprises a quaternary ammonium compound and an acidifying agent. The quaternary ammonium compound may be present in the solution in an amount preferably about 0.2% to about 0.5% by weight, more preferably about 0.3% to about 0.4%
by weight, and even more preferably about 0.3% to about 0.35% by weight. The quaternary ammonium compound may be present in a concentrated solution formulated for dilution to prepare the antimicrobial treatment solution. Accordingly, in some embodiments, concentrated solutions of antimicrobial compositions comprising a concentrated quaternary ammonium compound are also described herein.

[0027] The quaternary ammonium compound may be any quaternary ammonium compound known in the art for use in antimicrobial treatment of food products. For example, various suitable quaternary ammonium compounds are described in U.S. Patent Application No.
6,039,992, issued March 21, 2000, to Compadre et al. for METHOD FOR THE BROAD
SPECTRUM PREVENTION AND REMOVAL OF MICROBIAL CONTAMINATION OF
FOOD PRODUCTS BY QUATERNARY AMMONIUM COMPOUNDS. In various embodiments, the quaternary ammonium compound may be selected from the group consisting of alkylpyridinium, tetra-alkylammonium and alkylalicyclic ammonium salts. The quaternary ammonium compound is preferably an alkylpyridinium salt. In various embodiments, the alkylpyridinium salt is cetylpyridinium chloride. The quaternary ammonium compound may be selected from the group consisting of alkylpyridinium, tetra-alkylammonium and alkylalicyclic ammonium salts. The quaternary ammonium compound concentrations are described by concentrations as either parts per million (ppm) or % by weight, where 100,000 ppm is equal to 10% by weight. The examples utilize cetylpyridinium chloride and use both ppm or % to designate concentration.

[0028] Any wide range of different acidifying agents may be used, but the acidifying agent preferably comprises one or more acids generally recognized as safe (GRAS) for food uses related to human consumption as defined or recognized by the United States Food and Drug Administration or the United States Department of Agriculture, including but not limited to those identified in 21 CFR Parts 182, 184, and 186. For example, the acidifying agent may comprise one or more of acidic acid, citric acid, and hydrochloric acid. The acidifying agent is preferably present in an amount to provide the antimicrobial treatment solution with an acidic pH resulting in reduced quaternary ammonium compound residue on the food product treated with the solution compared to treatment of the food product with the antimicrobial treatment solution having a neutral pH value. The acidifying agent may be present in an amount effective to provide the solution with a pH value preferably between about 2.0 and about 1.0, more preferably between about 1.5 to about 1.2, or even more preferably between about 1.5 to about 1.3.

[0029] In one embodiment, the antimicrobial treatment solution further comprises at least one solubility agent to maintain the quaternary ammonium compound in solution.
The solubility agent may be any compatible solubility agent that solubilizes quaternary ammonium compounds in solution at concentrations of greater than preferably about 0.2% to about 0.5% by weight, more preferably about 0.3% to about 0.4% by weight, and even more preferably about 0.3% to about 0.35% by weight of the solution. However, the solubility agent may also include a solubility agent from a concentrated solution suitable to solubilized quaternary.' ammonium compound or maintain the quaternary ammonium compound in solvent at about 10% by weight is contemplated. The solvent may generally comprise water and the antimicrobial treatment solutions described herein may further generally be aqueous solutions. The solubility agent may comprise alcohols, which may include polyglycols such as polyethylene glycol. A suitable alcohol may be selected from the group consisting of a monohydric alcohol, a dihydric alcohol, a trihydric alcohol, and a combination thereof In various embodiments, any one of these types of alcohols may be used alone or in combination with one or more of the other types of alcohols to obtain the desired % by weight of the solubility agent. The choice of the alcohol may depend upon the food product treated and may be selected to be compatible with treatment steps prior to or after the quaternary ammonium compound treatment with the food product.

[0030] Concentrated Solutions

[0031] In various embodiments, the antimicrobial treatment solution may be formed from dilution of a concentrated antimicrobial solution. In various embodiments, the concentrated antimicrobial solution may be formulated to have an acidic pH value below about 6.5, about 6.0, or about 5.5 or otherwise suitable for dilution and acidification with an acidifying agent to form a antimicrobial treatment solution having a pH value preferably between 2.0 and 1.0, more preferable between 1.5 and 1.2, even more preferably between 1.5 and 1.3.
When using a composition in an industrial process, for example, it may be preferable to work with only small volumes of liquid concentrates rather than large volumes of liquid solutions. Suitable formulations of concentrated solutions of quaternary- ammonium compound, for example, may include concentrations up to 1000-fold greater than those made in water alone. In one embodiment, the concentrated antimicrobial solution comprises at least one solubility agent to provide a soluble concentrate for easy dilution to the final concentration for use in large scale industrial processing. The solubility agent functions to maintain the solubility of the quaternary ammonium compound so that it does not precipitate out of solution.

[0032] The concentrated amount of quaternary ammonium compound may be in combination with at least one solubility agent or solvent that is suitable for use in methods of preventing the growth of a broad range of microorganisms on and in food products, as well as on surfaces that come in contact with food products in the home or in an industrial environment. The concentrated antimicrobial solution may comprise a concentrated amount of the antimicrobial quaternary ammonium compound that utilizes GRAS
(generally recognized as safe) components to form a true solution, not an emulsion, of the quaternary ammonium compound. The concentrated antimicrobial solution may be formulated to have an acidic pH value below about 6.5, about 6.0, or about 5.5 or otherwise suitable for dilution and acidified by an acidifying agent to an acidic pH value preferably between 2.0 and 1.0, more preferable between 1.5 and 1.2, even more preferably between 1.5 and 1.3.
The formulations may contain solubility components which allow more concentrated compositions of quaternary ammonium compounds to be prepared. The concentrated antimicrobial solution may be a concentrated quaternary ammonium compound solution as described in U.S. Patent 6,864,269, issued March 8, 2005, to Compadre et al.
for CONCENTRATED, NON-FOAMING SOLUTION OF QUATERNARY AMMONIUM
COMPOUNDS AND METHODS OF USE. Such concentrated antimicrobial solutions may be acidified or diluted and acidified to formulate antimicrobial solutions for treatment of food products as described above. For example, in various embodiments, the dilute antimicrobial treatment solution is formed from a dilution of such concentrated antimicrobial solutions comprising the quaternary ammonium compound and the solubility agent, wherein the concentrated antimicrobial solution has been modified to have a pH value less than 7Ø The pH value of the concentrated antimicrobial solution for example may be below about 6.5, below about 6.0, or below about 5.5. Acidification of the concentrated solution may be by the same or different acidifying agents used to further acidify the dilute antimicrobial treatment solution to a pH value preferably between 2.0 and 1.0, more preferable between 1.5 and 1.2, even more preferably between 1.5 and 1.3.

[0033] One or more solubility agents may be used. Solubility agents may include alcohols such as polygylcols including polyethylene glycol for example. In one embodiment, the alcohol is selected from the group consisting of a monohydric alcohol, a dihydric alcohol, a trihydric alcohol, and a combination thereof Any one of these types of alcohols can be used alone or in combination with one or more of the other types of alcohols to obtain the desired % by weight of the solubility agent. If a monohydric alcohol is utilized, then this type of alcohol is preferably an aliphatic alcohol, and more preferably is ethyl alcohol. If a dihydric alcohol is utilized, then a glycol or a derivative thereof, is preferred. Of the glycols, propylene glycol is most preferred and is available from any number of suppliers. Propylene glycol provides advantages over other alcohols, as a solubility agent of high concentrations of quaternary ammonium compounds, such as cetylpyridinium chloride. Trihydric alcohols, such as glycerol or derivatives thereof, are also useful as a solubility agent in the present concentrated cetylpyridinium chloride solution. The choice of the alcohol may depend upon the food product that is contacted and is selected to be compatible with treatment steps prior to or after the quaternary ammonium compound contact with the food product. If a polyglycol is used as the solubility agent, for example, then polyethylene glycol may be preferred, and particularly the lower molecular weight species with an average molecular weight of less than or equal to 600, which are well known and possess properties similar to propylene glycol. If ethyl alcohol is used as the solubility agent, it may be present at a concentration up to about 49% by weight, for example. Ranges of ethyl alcohol about 0.5%

weight to about 49% by weight, from about 10% by weight to about 40% by weight, from about 15% by weight to about 30% by weight, and within the range at about 20%
may be used.

[0034] In some embodiments, any compatible solubility agent may be used, however, ethyl alcohol or glycerin may be preferred. For example, in one embodiment, the antimicrobial solution, either concentrated or a dilute treatment solution, contains ethyl alcohol, glycerin or both. In a concentrated solution for example, the solution may contain about 100,000 ppm to about 300,000 ppm quaternary ammonium compound, about 0% to about 49% ethyl alcohol and about 0 to about 20% glycerin in water. A preferred formulation may contain about 150,000 ppm to about 250,000 ppm quaternary ammonium compound, about 10% to about 40% ethyl alcohol and about 0.5 to about 10% glycerin in water. More preferably, the ethyl alcohol concentration may range from about 15% to about 30% and the glycerin concentration can range from about 0.5 to about 5%. Preferably, this formulation contains about 200,000 ppm quaternary ammonium compound, about 20% ethyl alcohol, and about 1% glycerin. This formulation may be particularly useful as a concentrate to be added to the storage tanks for use in immersion treatment of food products with quaternary ammonium compound but may also be useful in a spraying method at a final concentration of about 5,000 ppm quaternary ammonium compound. In one embodiment, the dilute antimicrobial treatment solution is formed from a dilution of the concentrated antimicrobial solution comprising the quaternary ammonium compound and the solubility agent, wherein the concentrated antimicrobial solution has a pH value less than 7Ø The pH value of the concentrated antimicrobial solution for example may be below about 6.5, below about 6.0, or below about 5.5. Acidification of the concentrated solution may be by the same or different acidifying agents used to further acidify the dilute antimicrobial treatment solution to a pH

value preferably between 2.0 and 1.0, more preferable between 1.5 and 1.2, even more preferably between 1.5 and 1.3.

[0035] The concentration of the solubility agent may vary depending on the %
weight of the quaternary ammonium compound, which is to be dissolved in solution, as well as the particular intended use of the concentrated quaternary ammonium compound solution and dilutions thereof The concentrated antimicrobial solution may comprise quaternary ammonium compound in solution at concentrations ranging from greater than about 10% or greater than about 15% by weight to about 60% by weight. Although a greater than about 60% by weight concentration of quaternary ammonium compound can be used in the concentrated quaternary ammonium compound solution, the upper limit that is useful is governed by the interaction between the % (or weight) of quaternary ammonium compound and the solubility agent(s) used to prepare the concentrated antimicrobial solution. Specific solubility agents or combinations of these agents may result in higher than 60% quaternary ammonium compound concentrated formulations. In one embodiment, the concentrated antimicrobial solution may contain at least one solubility agent, such as an alcohol at a concentration of up to about 70% by weight. In one preferred embodiment, solubility agent comprises an alcohol present at a concentration of up to about 60% by weight, and may range from about 10% by weight to about 60% by weight.

[0036] In one embodiment, the concentration of the quaternary ammonium compound in the concentrated antimicrobial solution may be about 40% by weight and at least one alcohol at a concentration of up to about 50% by weight, and preferably about 50% by weight. In this concentrated aqueous solution, the solubility agent may be a combination of alcohols, such as ethyl alcohol and propylene glycol. But glycerol also is useful as the solubility agent, alone or in combination with other alcohols or polyglycols. Glycerol is useful for this purpose at a concentration of up to and including about 20% by weight, and also is useful at concentrations ranging from about 0.5% to about 10% by weight, and within this range at about 1%. Glycerol is useful in methods where propylene glycol is not the alcohol of choice for solubilizing the quaternary ammonium compound. A further useful concentrated quaternary ammonium compound solution comprises a quaternary ammonium compound at a concentration of about 20% by weight and at least one alcohol at a concentration of about 50% by weight, such as a combination of ethyl alcohol and propylene glycol, and preferably where each alcohol is present at about 25% by weight.

[0037] In further such embodiments, the concentrated antimicrobial solution also includes an acidifying agent and is formulated to have an acidic pH, as described above. For example, the acidic pH value, such as less than about 6.5, less than about 6.0, or less than about 5.5 may be used to reduce the pH of an antimicrobial treatment solution formulated by dilution of the concentrated antimicrobial solution or the amount of a second acidifying agent needed to reach a desired acidic pH range, e.g., preferably about 2.0 and about 1.0, more preferable between about 1.5 and about 1.2, and even more preferably between about 1.5 and about 1.3, upon dilution prior to treatment of a food product. In various embodiments, the concentrated antimicrobial solution comprises an acidic pH value formulated with a low pH
version of propylene glycol. The solubility agent may be selected from an alcohol, propylene glycol, and glycerin. The quaternary ammonium compound may comprise an alkylpyridinium salt such as cetylpyridinium chloride. The acidifying agent is preferably a GRAS
acid and is more preferably a dilute solution of citric acid and hydrochloric acid. The acidifying agent may be present in the concentrated antimicrobial solution in an amount sufficient to achieve an acidic pH value below 7.0, preferably below about 6.5, and more preferably between about 6.0 and about 5.5. In one embodiment, the solubility agent is preferably propylene glycol. In one such embodiment, the concentrated antimicrobial solution comprises about 40%

quaternary ammonium compound, about 55% to about 60% propylene glycol, and up to about 5% water by weight.

[0038] In various embodiments, the quaternary ammonium compound is present at a concentration from greater than about 10% or greater than about 15% by weight to about 50% by weight, and more preferably at a concentration from greater than about 10% or about 15% by weight to about 40% by weight. The concentration of the quaternary ammonium compound in the range of greater than about 10% to about 30% by weight or between about 15% to about 25% by weight and within this range about 20% by weight is also useful in the present concentrate solution. In one embodiment, a concentrated antimicrobial solution comprises a quaternary ammonium compound with a concentration from greater than about 10% by weight and at least one solubility agent. The solubility agent or a combination of these agents, and water if necessary, to make up the remaining weight of the solution, is added to reach 100% by weight. The solubility agent is any compatible solubility agent that solubilizes quaternary ammonium compounds at concentrations of greater than about 10% by weight is contemplated, but alcohols are the preferred solubility agent. The solubility agent may be any water-miscible organic solvent that enhances the solubility of the quaternary ammonium compound in an aqueous solution so that it forms a solution at concentrations of greater than 10% by weight. A 10% by weight solution is made by weighing 10 grams of quaternary ammonium compound and dissolving it in 90 grams of liquid that comprises at least one solubility agent and water, if water is necessary to bring the weight to 90 grams of liquid. The concentrated quaternary ammonium compound solution may comprise quaternary ammonium compound in solution at concentrations of greater than about 10% by weight, and more preferably at concentrations of greater than about 15% by weight.

[0039] In one embodiment, the concentrated antimicrobial solution comprises the quaternary ammonium compound in solution at a concentration of about 40% by weight and at least one alcohol at a concentration ranging from between about 500/s by weight to about 60% by weight with water making up the remaining % weight. The preferred alcohol in this solution may be propylene glycol. More preferably, the concentrated quaternary ammonium compound solution comprises a quaternary ammonium compound at a concentration of about

40% by weight and at least one alcohol at a concentration ranging between about 55% by weight to about 60% by weight and water present at about 5% by weight. The more preferred concentrated quaternary ammonium compound solution comprises a quaternary ammonium compound at a concentration of about 40% by weight, an alcohol at a concentration of about 57% by weight and water present at about 3% by weight. In one embodiment, the dilute antimicrobial treatment solution is formed from a dilution of one of the above concentrated antimicrobial solutions comprising the quaternary ammonium compound and the solubility agent, wherein the concentrated antimicrobial solution has a pH value less than 7Ø The pH
value of the concentrated antimicrobial solution for example may be below about 6.5, below about 6.0, or below about 5.5. Acidification of the concentrated solution may be by the same or different acidifying agents used to further acidify the dilute antimicrobial treatment solution to a pH value preferably between about 2.0 and about 1.0, more preferable between about 1.5 and about 1.2, even more preferably between about 1.5 and about 1.3.
[0040] Residue Reduction Formulations

[0041] In one example, meat products such as poultry parts treated with an antimicrobial treatment solution of a quaternary ammonium compound such as cetylpyridinium chloride may result in different average levels of cetylpyridinium chloride residue for different types of parts. For instance, applying cetylpyridinium chloride of a given concentration to whole carcasses, breasts, thighs, and chicken tenders may result in lower average residues in poultry carcasses and breasts and in higher average residues in thighs and chicken tenders. As described herein addition of an acidifying agent in an amount sufficient to provide the solution with a low acidic pH value may beneficially lower average quaternary ammonium residue, such as cetylpyridinium chloride residue, on parts treated with the solution compared to treatment of the parts under the same conditions with the same solution but having a neutral pH value. Furthermore, treatment with low acidic pH solution may maintain the desired efficacy of the antimicrobial treatment solution and provide the desired microbial reductions, but with relatively reduced residue compared to the same conditions and solution but having a neutral pH value.

[0042] The herein described antimicrobial treatment solutions of a quaternary ammonium compound such as cetylpyridinium chloride having a pH value within a range of from 1.2 to 2.0, for example, may be used to significantly reduce the average residue on treated product without adversely affecting the organoleptic properties of the product. In one currently preferred embodiment, antimicrobial treatment solutions of a quaternary ammonium compound such as cetylpyridinium chloride having a low acidic pH value within a range of from about 1.5 to 1.3 may be used to provide a preferred balance of reducing residue and providing antimicrobial performance without adversely affecting the organoleptic properties of the treated product.

[0043] In one embodiment, the quaternary ammonium compound is present in a concentration selected such that treatment of a food product with the solution results in an average residue of the quaternary ammonium compound below about 35 ppm following treatment comprising spraying the solution onto the food product or submerging the food product in the solution for preferably between about 15 seconds and about 3 seconds, more preferably between about 12 seconds and about 4 seconds, and even more preferably between about 10 seconds and about 5 seconds.

[0044] In another embodiment, the concentration of the quaternary ammonium compound may be selected such that treatment of the food product with the solution results in an average residue of the quaternary ammonium compound below about 31.5 ppm following treatment comprising spraying the solution onto the food product or submerging the food product in the solution for preferably between about 15 seconds and about 3 seconds, more preferably between about 12 seconds and about 4 seconds, and even more preferably between about 10 seconds and about 5 seconds.

[0045] In yet another embodiment, the concentration of the quaternary ammonium compound is selected such that treatment of the food product with the solution results in an average residue of the quaternary ammonium compound below about 7 ppm where the treatment comprises spraying the solution onto the food product or submerging the food product in the solution for preferably between about 15 seconds and about 3 seconds, more preferably between about 12 seconds and about 4 seconds, and even more preferably between about 10 seconds and about 5 seconds.

[0046] Enhanced Contact Formulations

[0047] Various embodiments of the treatment solution may be formulated to enhance contact, such as duration, quality, quantity of contact, of the quaternary ammonium compound with treated food products. For example, a treatment solution may be formulated for enhanced access within crevasses or to penetrate materials obstructing or obscuring microbial on a surface of a food product.

[0048] These or other formulations of the solution may include formulations designed to increase the contact time of a quaternary ammonium compound solution on food products during processing, particularly when delivered by a spraying method. Such a formulation may potentially allow a longer contact time of the quaternary ammonium compound with the food product without additional steps which would increase the processing time. The treatment solution, by virtue of its properties, may thus be formulated to provide potential increases the antimicrobial effectiveness of the process.

[0049] In various embodiments, a concentrated treatment solution formulated for enhanced contact with a food product, such as enhanced duration of contact particularly when delivered by spraying food products, may preferably contain about 50 ppm to about 20,000 ppm quaternary ammonium compound, and at least one of a solubility agent selected from about 0 to about 10% ethyl alcohol, and about 0 to about 20% glycerin or both. More preferably this formulation may contain about 50 ppm to about 5,000 ppm, about 0 to about 10%
ethyl alcohol, and about 1.0% to about 100/0 glycerin in water. Even more preferably this formulation may contain about 500 ppm to about 5,000 ppm quaternary ammonium compound, 0 to 10% ethyl alcohol, and about 1.0 to about 5% glycerin in water and more preferably about 1.0 to about 3% glycerin. In one embodiment, the dilute antimicrobial treatment solution may be formed from a dilution of the above concentrated antimicrobial solution comprising the quaternary ammonium compound and the solubility agent, wherein the concentrated antimicrobial solution has a pH value less than 7Ø The pH
value of the concentrated solution may be provided by an acidifying agent. The pH value of the concentrated antimicrobial solution for example may be below about 6.5, below about 6.0, or below about 5.5. The acidifying agent providing the acidific pH value of the concentrated solution may comprise the same or different acidifying agents than those that may be subsequently used in dilution or acidification of the dilute antimicrobial treatment solution to a pH value preferably between 2.0 and 1.0, more preferable between 1.5 and 1.2, even more preferably between 1.5 and 1.3.

[0050] Methods of Formulating Solutions

[0051] The present disclosure also describes methods of formulating an aqueous antimicrobial treatment solution for treatment of a food product. The method may comprise formulating any of the antimicrobial solutions described above, including formulation of the antimicrobial treatment solutions from aqueous dilution of concentrated solutions of quaternary ammonium compound, which may further include addition of an acidifying agent comprising one or more acids. It is to be appreciated that as described above the solution may include the listed components at the identified percentages in an aqueous solution. The components may be added within or to various intermediate aqueous solutions to combine the components. Water may be added to obtain the remaining weight of the solution.
The quaternary ammonium compound may be a quaternary ammonium compound selected from the group consisting of alkylpyridinium, tetra-alkylammonium and alkylalicyclic ammonium salts. In one preferred embodiment, the quaternary ammonium compound is an alkylpyridinium salt comprising cetylpyridinium chloride; however, other quaternary ammonium compounds may be used. The quaternary ammonium compound may be present in or added in an amount preferably between about 0.2% and about 0.5% by weight, more preferably between about 0.3% and about 0.4% by weight, and even more preferably between about 0.3% to about 0.35% by weight of the resulting solution. The method may include adding the acidifying agent in an amount effective to provide the solution with a pH value preferably between about 2.0 and about 1Ø more preferably between about 1.5 and about 1.2, and even more preferably between about 1.5 and about 1.3. In one embodiment, the quaternary ammonium compound is combined with a solvent prior to adjusting the pH with the selected acidifying agent to the selected pH value. The acidifying agent is preferably one or more acids comprising generally recognized as safe (GRAS) acids. In one embodiment, the acidifying agent is at least one of citric acid and hydrochloric acid;
however, other acids may be used.

[0052] In one embodiment, the method of formulating the antimicrobial treatment solution comprises dilution of a concentrated antimicrobial solution of the quaternary ammonium compound and a solubility agent with an aqueous solvent and addition of the acidifying agent to obtain the desired pH value and quaternary ammonium compound concentration.
In one such example, the solubility agent is selected from an alcohol, propylene glycol, and glycerin.
In one embodiment, the quaternary ammonium compound is combined with a solvent prior to adjusting the pH with the selected acidifying agent to the selected pH value.

[0053] In one embodiment, a method of formulating a concentrated antimicrobial solution of quaternary ammonium compound comprises combining a quaternary ammonium compound and a solubility agent in a solvent, wherein the concentrated antimicrobial solution has a pH
value preferably below 7.0, more preferably below about 6.5, even more preferably below about 6.0, and most preferably below about 5.5. The quaternary ammonium compound may be a quaternary ammonium compound selected from the group consisting of alkylpyridinium, tetra-alkylammonium and alkylalicyclic ammonium salts. In one preferred embodiment, the quaternary ammonium compound is an alkylpyridinium salt comprising cetylpyridinium chloride; however, other quaternary ammonium compounds may be used. The cetylpyridinium chloride, for example, may be present or added in an amount about 40% by weight of the concentrated antimicrobial solution. In another embodiment, the cetylpyridinium chloride may be present or added in an amount about between about 10%
and about 65%, between about 20% and 50%, or between about 35% and about 45%
by weight of the concentrated antimicrobial solution. The method may further comprise adding a solubility agent. The solubility agent may be selected from an alcohol, propylene glycol, and glycerin. The solubility agent may preferably be propylene glycol.
Propylene glycol may be present in or added in an amount to between about 55% and about 60% by weight of the concentrated antimicrobial solution. The solvent may preferably be water.

[0054] Methods of Treating Food Products

[0055] A method of treating food products may comprise applying the antimicrobial treatment solution according to any of the above embodiments to a food product. The food product may comprise, for example, poultry, beef, pork, lamb, venison, and other edible meat products, which may include seafood, fish and shellfish. In one embodiment, the food product comprises a poultry food product selected from poultry carcass, breast, tender, thigh, giblet, and wing. The food product may also include fruits, vegetables, or dairy products.

[0056] Application of the antimicrobial treatment solutions to treat the food product may include covering a treatment surface of the food product with the antimicrobial treatment solution comprising the quaternary ammonium compound in solution. For example, the food product may treated by submerging, e.g., dipping, the food product in the antimicrobial treatment solution comprising the quaternary ammonium compound or the solution may be sprayed onto a surface to be treated with a saturating spray as are known in the art. One example of a dip system suitable for treatment of food products employing a treatment solution as described herein is described in U.S. Patent Application No.
14/510,439, filed October 9, 2014, titled CLOSED LOOP RECYCLING SYSTEM AND DIP TANK FOR
ANTIMICROBIAL COMPOUNDS. Additional examples of antimicrobial treatment systems, including spray application, that may employ a treatment solution as described herein are described in U.S. Patent No. 6,742,720, issued June 1, 2004, to Noland for SPRAY

APPLICATION SYSTEM; U.S. Patent Application No. 14/471,846, filed August 28, 2014, titled APPLICATION SYSTEM AND RECYCLE AND RELATED USE OF
ANTIMICROBIAL QUATERNARY AMMONIUM COMPOUND; and U.S. Patent Application No. 14/510,385, filed October 9, 2014, titled ANTIMICROBIAL
APPLICATION SYSTEM WITH RECYCLE AND CAPTURE.

[0057] The method may include positioning or transmitting a food product within or through a treatment zone. The length of the treatment zone or period of time the food product is within or transmitted through the treatment zone for application of the solution, e.g., in a dip, spray, or drench zone, may be designed so that a treated product will be present in the treatment zone for a wide range of desired times. In one embodiment, the treated product will be present in the treatment zone for a time that is preferably within a range of from about 15 seconds to about 3 seconds, more preferably in a range of from about 12 seconds to about 4 seconds, and more preferably within a range of from about 10 seconds to about 5 seconds.

[0058] Hereinafter, non-limiting experimental examples are described illustrating various example applications and reduced residues and methods of formulating various antimicrobial treatment solutions.

[0059] EXAMPLE 1

[0060] Comparative quaternary ammonium compound residue levels on breast tenders following treatment with quaternary ammonium compound treatment solutions having neutral and acidic pH values.

[0061] Materials and Solution Preparation

[0062] Treatment solutions identified in TABLE 1 were prepared in containers capable of holding 2500 mL of solution with extra room for dipping and agitating samples.
The containers were initially weighed and labeled A (Citrilowlm pH 1.2), B
(Propionic 1000 parts per million (ppm)), and C (Cecure ). About 2200 mL of tap water was then added to each container. Container A was pH adjusted to 1.2 with a stock CitrilowTM solution (CitrilowTM
is a blend of citric acid and hydrochloric acid (HCl) sold by Safe Foods Corporation, North Little Rock, Arkansas). Propionic acid (99%) was added to container B to achieve a concentration of 1000 ppm (2.2 mL). Containers and solution were weight adjusted to achieve a 2000 mL volume. 22 grams of Cecure 43.) solution was added to each container to target 0.4%. Cecure is an antimicrobial quaternary ammonium compound solution sold by Safe Foods Corporation, North Little Rock, Arkansas, that includes concentrated cetylpyridinium chloride, propylene glycol, and water. The concentrated Cecure solution has neutral pH and includes approximately 40% cetylpyridinium chloride by weight.
Containers with solutions were mixed, sealed, and refrigerated overnight.

[0063] Pretreatment and rinse solutions listed in TABLE 1 were prepared as follows:
containers capable of holding 2500 mL of solution with extra room for dipping and agitating samples in the solution labeled D (CitrilowTM pH 1.2), E (Propionic 1000 ppm), F (Tween 20), and (Water). About 2200 mL of tap water was added to each container.
Container D
was pH adjusted to 1.2 using CitrilowTM solution. Propionic acid (99%) was added to container E to achieve a concentration of 1000 ppm (2.2 mL to 2200 mL water).
Tween 20 (100%) was added to container F to achieve a concentration of 20%.

[0064] Treatment Protocol

[0065] FIG. 1 provides an overview of the experimental treatment protocol 10.
Breast tenders where purchased from a local grocery store (control tests (not shown) confirmed no initial cetylpyridinium chloride residue). Uniform sized tenders were selected and/or cut 12.
The selected tenders were grouped for treatment as listed in TABLE 1. Samples subjected to pretreatment 14 were placed in one of the pretreatment solutions water 14a, CitrilowTM 14b, or propionic acid 14c and were immediately removed following apretreatment duration of about 3 seconds. All samples were then treated 16 with treatment solution by placement in respective treatment containers containing Cecure (0.4%)/CitrilowTM (pH 1.2) 16a, Cecure (0.49/0)/Propionic (1000 ppm) 16b, or Cecure (0.4%) 16c with agitation for 3 seconds.
Sample numbers 91-100 were treated with Cecure CC (0.4%) 16c by spray (18 mL, 6 sec) at 3 sec per side. Samples were then removed from the treatment containers and allowed to drip.
Samples were then rinsed 18 by placement in a rinse solution Propionic (1000 ppm) 18a, CitrilowTM (pH 1.2) 18b, water 18c, or Tween 20 with agitation for 6 seconds.
Samples were then allowed to drain for 20 seconds. Sample bags (plastic) were labeled with sample numbers as shown in TABLE 1. Each sample was then individually bagged (plastic) and refrigerated overnight.

[0066] Residue Analysis

[0067] Residue analysis was performed by high pressure liquid chromatograph (HPLC) for cetylpyridinium chloride residue analysis. Et0H was added to target weight about 2 mL per gram of sample. Samples were stomached for 1 minute. Samples were then extracted for 30 minutes in the extraction fluid on a rotating platform. Extract samples were taken from the extraction fluid (approx. 10 mL aliquot) and allowed to sediment for 10 minutes to allow for gravity separation of large particles. The extract samples were then run on HPLC for cetylpyridinium chloride residue analysis. Parts per million (ppm) of cetylpyridinium chloride in each treated part were calculated using HPLC results. A 30%
extraction efficiency was added to the final ppm concentration.

[0068] TABLE I. Sample Number and Treatment Descriptions Pretreatment Treatment Rinse Conditions (All Sample Time treatments will be Time Time Numbers Conditions (seconds) cold) (seconds) Conditions (seconds) Cecure (0.4%)/CitrilowTM
1-10 None None (pH 1.2) 3 Water 6 Cecure 0 (0.4%)/Propionic 11-20 None None (1000 ppm) 3 Water 6 CitrilowTM
21-30 , (pH 1.2) , 3 Cecure 0 (0.4%) , 3 , Water 6 Propionic 31-40 (1000 ppm) 3 Cecure Ck) (0.4%) 3 Water 6 CitrilowTM
41-50 None None Cecure 0 (0.4%) 3 (pH 1.2) 6 51-60 None None Cecure CD (0.4%) 3 Tween 20 6 Propionic 61-70 None None Cecure (0.4%) 3 (1000 ppm) 6 71-80 Water 3 Cecure 0 (0.4%) 3 Water 6 81-90 None None Cecure (0.4%) 3 Water 6 Cecure 0 (0.4%) 91-100 None None Spray 3 Water 6

[0069] A summary of the data collected in this example is shown in FIG. 2 with the corresponding treatment types described and summarized in TABLE 2. Average cetylpyridinium chloride (CPC) concentration of the 10 samples (Sample Treatment 1-10 labeled along the x-axis in FIG. 2) within each treatment group is shown.
These data show that treatment of breast tenders with acidified quaternary ammonium compound solution (Cecure 0. (0.4%)), at low pH reduces quaternary ammonium compound residues as reflected in measured CPC concentration. In particular, CPC concentration of sample treatment group number 1, treated with low pH CitrilowTM (pH 1.2) and Citrilow, was significantly reduced compared to the other treatments. Sample treatment group 2 included quaternary ammonium treatment with propionic acid, which provided a solution having a greater pH
than the treatment of group 1, and provided reduced residue compared to groups such as 8 and 9 that were not treated with acidic solutions. Pretreatment with acid prior to treatment with quaternary ammonium showed reduced residue when low pH CitrilowTM (pH 1.2) (group 3) but not with the higher pH propionic acid. Rinsing with the low pH CitrilowTM
(pH 1.2) (group 5) or Tween 20 (group 6) showed reduced residue while rinsing with propionic acid (group 7) or water (group 8) did not.

[0070] TABLE 2. Summary of Residue Data with Sample Treatment Description Sample Treatment CPC
Group Pretreatment Treatment Rinse Concentration Number (3 sec) (cold, 3 sec) (6 sec) (PP11) Cecure k (0.4%) / CitrilowTM
1 None (pH 1.2) Water 5.66 Cecure k (0.4%) / Propionic 2 None (1000ppm) Water 15.75 CitrilowTM
3 (pH 1.2) Cecure k (0.4%) Water 15.01 Propionic 4 (1000ppm) Cecure k (0.4%) Water 29.74 CitrilowTM (pH
None Cecure k (0.4%) 1.2) 13.61 Tween 20 6 None Cecure 44) (0.4%) (20%) 15.28 Propionic 7 None Cecure k (0.4%) (1000ppm) 22.38 8 Water Cecure k (0.4%) Water 27.86 9 None Cecure k (0.4%) Water 36.98 Cecure k (0.4%) / Spray None (18mL, 6 sec) Water 17.56

[0071] EXAMPLE 2

[0072] Quaternary ammonium compound residue levels on breast tenders following treatment with quaternary ammonium compound treatment solutions having acidic and basic pH values.

[0073] Materials and Solution Preparation

[0074] Containers capable of holding 2500 mL of solution with extra room for dipping and agitating samples in treatment solution were weighed and labeled A (CitrilowTM
pH 1.2), B
(HC1 pH 1.2), and C (NaOH pH 9.0) as identified in TABLE 3. Treatment solutions identified in TABLE 3 were prepared in the containers by addition of about 2200 mL of tap water. The solutions were pH adjusted to the identified pH with the identified pH agent as listed in TABLE 3. CitrilowIm was taken from a stock Citrilowrm solution (citric acid /HC1).
Containers and solution were weight adjusted to achieve a 2000 mL volume. 22 grams of Cecure 0 solution was added to each container to target 0.4%. Containers with solutions were mixed, sealed, and refrigerated overnight. Rinse solutions identified in TABLE 3 were prepared from tap water, Tiveen 20 (100%) diluted with tap water to 20%, and a stock 1.5 pH
CitnlowTM solution, all held at room temperature.

[0075] Treatment Protocol

[0076] FIG. 3 provides an overview of the experimental treatment protocol 30.
Treatment 32 of non-Cecure treated in a treatment solution Cecure Cg.) (0.4%)/CitrilowTM (pH 1.19) 32a, Cecure (0.4%);HC1 (pH 1.21) 32b, or Cecure 0 (0.4%)/Na0H(pH 11.1) 32c, as identified in TABLE 3 (samples 1-90), for 3 seconds with agitation. The samples were then removed from the treatment container and allowed to drip for less than 10 seconds. The samples were next rinsed with rinse solution 34 by placement in a rinse solution water 34a, Tween 20 34b, or CitrilowTM (pH 1.5) 34c, as identified in TABLE 3, for 6 seconds with agitation. The samples were then allowed to drain for 20 seconds. The rinsed samples were bagged individually and refrigerated overnight.

[0077] Residue Analysis

[0078] Residue analysis was performed by high pressure liquid chromatograph (HPLC) for cetylpyridinium chloride residue analysis. Et0H was added to target weight about 2 mL per gram of sample. Samples where stomached for 1 minute. Samples were then extracted for 30 minutes in the extraction fluid on a rotating platform. Extract samples were taken from the extraction fluid (approx. 10 mL aliquot) and allowed to sediment for 10 minutes to allow for gravity separation of large particles. The extract samples were then run on HPLC for cetylpyridinium chloride residue analysis. Parts per million (ppm) of cetylpyridinium chloride in each treated part were calculated using HPLC results. A 30%
extraction efficiency was added to the final ppm concentration.

[0079] TABLE 3. Sample Number and Treatment Descriptions Treatment Rinse Conditions Conditions Sample Time Time (All treatments will be (Room Numbers (seconds) (seconds) cold) Temperature) 1-10 3 Water 6 Cecure CgD
11-20 3 Tween 20% 6 (0.4%)/CitrilowTM
21-30 (pH 1.19) 3 CitrilowTM (pH

1.5) 31-40 3 Water 6 41-50 Cecure 6g) (0.4%)/HC1 3 Tween 20% 6 51 60 (pH 1.21) CitrilowTM (pH 6 - 1.5) 61-70 3 Water 6 71-80 Cecure 3 Tween 20% 6 (0.4%)/Na0H(pH 11.1) CitrilowTM (pH

1.5) 91-91 None None None None

[0080] A summary of the residue data collected in this example is shown in FIG. 4. Bars represent average cetylpyridinium chloride (CPC) residue of the 10 samples (identified along the x-axis) in each treatment subgroup of the 3 treatment groups. These data show that treatment with acidified quaternary ammonium compound solution at low pH
reduces quaternary ammonium compound residues. Quaternary ammonium compound treatment with quaternary ammonium compound solution at alkaline pH, pH 11.1-samples 61-90, does not appear to reduce quaternary ammonium compound residues to levels corresponding to the solution at acidic pH values, pH 1.19-samples 1-30 and pH 1.21-samples 31-60.
The identity of the acidifying agents does not appear to have a significant effect on the reduction of quaternary ammonium compound residue.

[0081] EXAMPLE 3

[0082] Treatment efficacy following antimicrobial treatment of thighs with acidic pH
quaternary ammonium compound solution using commercial application equipment.

[0083] Materials and Solution Preparation

[0084] Treatment solutions and conditions tested are identified in TABLE 4.
Thigh samples were treated using a commercial part dip system. The system was initially filled with ice and water. For acidified treatments, CitrilowTM was then added to obtain a pH of 1.2. The pH
was verified using a pH meter. Cecure (g) was added to the concentration listed in TABLE 4 (verified by titration using Cecure lk titration kit, sold by Safe Foods Corporation, North Little Rock, Arkansas).

[0085] Treatment Protocol

[0086] Treatment solutions and conditions tested are identified in TABLE 4.
FIG. 5 provides an overview of the experimental treatment protocol 50 used in this example. Whole post-chill untreated poultry carcasses were obtained from a local processing plant 51 and transported to lab on ice. Thighs (n=200) were cut from the carcasses 52.
Treatments with CitrilowTM (pH of 1.2)/ Cecure (0.4%) agitation on 54a, CitrilowTM (pH of 1.2)/ Cecure (0.4%) agitation off 54b, Cecure Eg) neutral solution (0.4%), or agitation on 54c were performed by placing 50 parts onto the dip system belt and treating the parts for 3 seconds in the identified treatment solution with flow system pumps were turned on. The commercial belt system was operated at the application parameters. The parts were caught in a wire rack cart, placed into a large water rinse bucket, and rinsed for 6 seconds with agitation 56. The application system was drained and refilled for each treatment solution. The parts were then removed from the rinse water and placed on the wire rack and allowed to drain for 5 minutes 58. The parts used for the control samples were not treated 54d. All parts were then individually bagged in labeled sterile sample bags and refrigerated overnight 60, 62.

[0087] APC Plate Count Assays

[0088] Microbial samples were removed from refrigeration. Butterfield phosphate diluent (BPD) was added at 100 mL per 454 grams of sample. Samples were then rinsed for 1 minute. Dilutions 1-3 were made. Dilutions 0-3 on Aerobic Plate Count (APC) petrifilmTM.
bag will be zero dilution.

[0089] TABLE 4. Sample Numbers and Treatment Descriptions Application Sample Number Solution pH Cecure Concentration Parameter 1-25 Flow Agitation On 1.2 0.40%
Flow Agitation 26-50 1.2 0.40%
OFF
76-100 Flow Agitation On Neutral 0.40%
101-125 N/A None None 126-147 Flow Agitation On Neutral 0.60%

[0090] A summary of the APC microbial data obtained in this example is shown in FIG. 6.
Bars represent average counts (colony forming unites per mL) of the 25 samples tested in each treatment group with the exception of the control, which represents average counts from the 23 samples tested in the control treatment group. These data show that increased concentration of quaternary ammonium compound (cf. samples 76-100 and samples 126-147) does not increase efficacy of the treatments and acidity of the treatment solution does not impair efficacy of the treatments.

[0091] Other Matters

[0092] All numerical quantities stated herein are approximate unless stated otherwise, meaning that the term "about" or "approximately" may be inferred when not expressly stated.
The numerical quantities disclosed herein may be nominal numerical quantities and are to be understood as not being strictly limited to the exact numerical values recited. Instead, unless stated otherwise, each numerical value is intended to mean both the recited value and a functionally, for example pharmaceutically, equivalent range surrounding that value. All numerical ranges stated herein include all sub-ranges subsumed therein. For example, a range of approximately or about 1 to 10 is intended to include all sub-ranges between and including the recited minimum value of 1 and the recited maximum value of 10.
Any maximum numerical limitation recited herein is intended to include all lower numerical limitations. Any minimum numerical limitation recited herein is intended to include all higher numerical limitations. Additionally, in some illustrative embodiments, quantities or ranges may be given. It is to be understood that any such quantity or range is provided as an illustrative example or instance of an embodiment and is not intended to limit that or other embodiments.

[0093] This disclosure describes various elements, features, aspects, and advantages of various embodiments antimicrobial solutions, concentrated solutions, methods of making and formulating such solutions, and methods of treating food products with such solutions. It is to be understood that certain descriptions of the various embodiments have been simplified to illustrate only those elements, features and aspects that are relevant to a more clear understanding of the disclosed embodiments, while eliminating, for purposes of brevity or clarity, other elements, features and aspects. Any references to "various embodiments,"
"certain embodiments,- "some embodiments,- "one embodiment,- or "an embodiment"
generally means that a particular element, feature and/or aspect described in the embodiment is included in at least one embodiment. The phrases "in various embodiments,"
"in certain embodiments,- "in some embodiments,- "in one embodiment,- or "in an embodiment-may not refer to the same embodiment." Furthermore, the phrases "in one such embodiment", "in a further embodiment", or "in certain such embodiments," while generally referring to and elaborating upon a preceding embodiment, is not intended to suggest that the elements, features, and aspects of the embodiment introduced by the phrase are limited to the preceding embodiment; rather, the phrase is provided to assist the reader in understanding the various elements, features, and aspects disclosed herein and it is to be understood that those having ordinary skill in the art will recognize that such elements, features, and aspects presented in the introduced embodiment may be applied in combination with other various combinations and sub-combinations of the elements, features, and aspects presented in the disclosed embodiments. The present disclosure is not intended to be limited by the percent composition of the examples unless claimed otherwise. Percent compositions are to be understood as being by weight unless specified otherwise.

[0094] "Consisting of' refers to the inclusion of exactly one element of a number or list of elements. The grammatical articles "one", "a", "an", and "the", as used in this specification, are intended to include "at least one" or "one or more", unless otherwise indicated. Thus, the articles are used in this specification to refer to one or more than one (i.e., to "at least one") of the grammatical objects of the article. By way of example, "a component" means one or more components, and thus, possibly, more than one component is contemplated and may be employed or used in an implementation of the described embodiments. Further, the use of a singular noun includes the plural, and the use of a plural noun includes the singular, unless the context of the usage requires otherwise.

Claims (30)

What is claimed is:

1. An aqueous antimicrobial solution for treatment of food products, the solution comprising:
a quaternary ammonium compound; and an acidifying agent in an amount effective to provide the solution with a pH
value between about 1.5 and about 1Ø

2. The solution of claim 1, wherein the acidifying agent is present in an amount effective to provide the solution with a pH value between about 1.5 to about 1.2.

3. The solution of claim 1, wherein the acidifying agent is present in an amount effective to provide the solution with a pH value between about 1.5 to about 1.3.

4. The solution of claim 1, wherein the acidifying agent comprises of one or more acids selected from generally recognized as safe (GRAS) acids.

5. The solution of claim 1, wherein the acidifying agent comprises at least one of citric acid and hydrochloric acid.

6. The solution of claim 1, wherein the quaternary ammonium compound is present in an amount about 0.2% to about 0.5% by weight.

7. The solution of claim 1, wherein the quaternary ammonium compound is present in an amount about 0.3% to about 0.4% by weight.

8. The solution of claim 1, wherein the quaternary ammonium compound is present in an amount about 0.3% to about 0.35% by weight.

9. The solution of claim 19 wherein the quaternary ammonium compound is an alkylpyridinium salt.

10. The solution of claim 1, wherein the quaternary ammonium compound is cetylpyridinium chloride.

11. The solution of claim 1, wherein the solution further comprises a solubility agent.

12. The solution of claim 11, wherein the solubility agent is selected from propylene glycol and glycerin.

13. The solution of claim 1, wherein the quaternary ammonium compound is present in a concentration between one of 0.2% and 0.5% by weight, 0.3% and 0.4% by weight, or 0.3%
and 0.35% by weight and the acidifying agent is present in an amount effective to provide the solution with a pH value such that treatment of a food product with the solution results in an average residue of the quaternary ammonium compound below 35 ppm, and wherein the treatment comprises spraying the solution onto the food product or submerging the food product in the solution for between about 15 seconds and about 3 seconds.

14. The solution of claim 13, wherein the treatment comprises spraying the solution onto the food product or submerging the food product in the solution for between about 12 seconds and about 4 seconds.

15. A method of preparing an antimicrobial treatment solution, the method comprising:
adding an acidifying agent to a solution comprising a quaternary ammonium compound in an amount effective to provide the solution with a pH value between about 1.5 and about 1Ø

16. The method of claim 15, further comprising adding the acidifying agent in an amount effective to provide the solution with a pH value between about 1.5 and about 1.3.

17. The method of claim 15, wherein the acidifying agent comprises of one or more acids comprising generally recognized as safe (GRAS) acids.

18. The method of claim 15, wherein the acidifying agent comprises at least one of citric acid and hydrochloric acid.

19. The method of claim 15, wherein the quaternary ammonium compound is present in the solution in an amount between about 0.2% and about 0.5% by weight.

20. The method of claim 15, wherein the quaternary ammonium compound is present in the solution in an amount between about 0.3% to about 0.35% by weight.

21. The method of claim 15, wherein the quatemary ammonium compound is an alkylpyridinium salt.

22. The method of claim 15, wherein the concentrated quatemary ammonium compound is provided in a concentrated antimicrobial solution comprising the quatemary ammonium compound and a solubility agent.

23. The method of claim 15, wherein the solubility agent is selected from propylene glycol and glycerin.

24. The method of claim 15, wherein the concentration of the quatemary ammonium compound in the solution is between one of 0.2% and 0.5% by weight, 0.3% and 0.4% by weight, and 0.3% and 0.35% by weight, and wherein the method further comprises adding the acidifying agent in an amount effective to provide the solution with a pH
value such that treatment of a food product with the solution results in an average residue of the quatemary ammonium compound below 35 ppm, and wherein the treatment comprises spraying the solution onto the food product or submerging the food product in the solution for between about 15 seconds and about 3 seconds.

25. The method of claim 24, wherein the treatment comprises spraying the solution onto the food product or submerging the food product in the solution for between about 12 seconds and about 4 seconds.

26. A method of treating a food product, the method comprising:
applying an antimicrobial treatment solution to a food product, wherein the antimicrobial treatment solution comprises a quatemary ammonium compound and an acidifying agent, wherein the quatemary ammonium compound is present in an amount between one of about 0.2% and about 0.5% by weight, about 0.3% and about 0.4%
by weight, and about 0.3% and about 0.35% by weight, and wherein the a solution has a pH
value between about 1.5 and about 1.0; and wherein applying the antimicrobial treatment solution comprises spraying the solution onto the food product or submerging the food product in the solution.

27. The method of claim 26, wherein the solution is applied to the food product for an application time between about 15 seconds and about 3 seconds.

28. The method of claim 26, wherein the solution is applied to the food product for an application time between about 12 seconds and about 4 seconds.

29. The method of claim 26, wherein the solution is applied to the food product for an application time between about 10 seconds and about 5 seconds.

30. The method of claim 26, wherein the food product comprises a poultry food product selected from carcass, breast, tender, thigh, giblet, and wing.