Antimicrobial gas releasing agents and systems and methods of use thereof

Abstract

A system and method for inhibiting or preventing microbial growth and / or killing microorganisms in a closed package or container having goods (optionally food products) contained or stored therein is disclosed. The systems and methods optionally include the use of an entrained polymer article, preferably a mulch, containing an antimicrobial release agent.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 201780069614.7.

[0002] Cross Reference to Related Applications

[0003] This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 62 / 421,348, filed November 13, 2016, entitled "ENTRAINED POLYMERS WITH ANTIMICROBIAL RELEASING AGENTS," the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0004] The present invention relates to systems and methods for reducing and preventing the growth of, or killing, microorganisms within the interior space of a container, and / or on a product / commodity stored within a package. More particularly, the present invention relates to systems and methods for reducing and preventing the growth of, or killing, microorganisms using entraned polymers with antimicrobial releasing agents, for example, in food containers. BACKGROUND

[0005] There are many items that are preferably stored, transported, and / or used in environments that must be controlled and / or regulated. For example, in the field of moisture control, it has been recognized that containers and / or packages with the ability to absorb excess moisture captured therein are desirable. Likewise, when packaging products that have a risk of contamination, such as food products, it can be desirable to control the growth and proliferation of microorganisms.

[0006] Food products, particularly sliced or cut fresh food products, such as meat, poultry, fruits, and vegetables, are typically stored and sold in support containers (e.g., trays) that are wrapped by a transparent plastic film, enabling visual inspection of the food product. These food products often produce exudates (i.e., juices), which can be a source of growth for microbial agents. In addition, contamination of processing equipment or other surfaces in contact with the food product can be left on the food product and proliferate upon packaging. Similarly, the food product can be contaminated even before the packaging process. For example, the skin of a tomato can have openings through which unwanted microorganisms enter and proliferate. Failures in food handling processes and / or cold chain management (e.g., a few hours of interruption in refrigeration during food transportation) can enable the growth of microorganisms in contaminated food products, which can lead to outbreaks of foodborne illnesses. Regardless of the source or nature of the microbial contamination in the food product, the shelf life and safety of the contaminated food product is affected by the microbial contamination and proliferation.

[0007] One way the food industry addresses food preservation is to include food-grade preservatives as an ingredient of the food, such as potassium sorbate, sodium benzoate, and nitrites. However, such preservatives are considered by some in the health community and consumers to be non-natural and present health risks. Moreover, it is not practical to use such preservatives with unprocessed foods (e.g., fresh fruits or vegetables).

[0008] Another way the food industry addresses food preservation is to use antimicrobials that directly contact the food as a component in packaging materials. However, in certain applications, such direct contact can be undesirable.

[0009] For certain applications, it is desirable to provide antimicrobials to release antimicrobial gases into the headspace of a food package or container to control the growth of microorganisms, as opposed to solid or liquid components that require direct contact with the stored food to be effective. However, there are challenges in providing antimicrobial gases in the headspace. One such challenge is to achieve a desired antimicrobial gas release profile within the headspace during a specified time period. Failure to achieve the proper release profile for a given product can result in the inability to achieve the desired shelf life of the product. Thus, there is a need to improve the delivery of antimicrobials to control, reduce, and significantly destroy microbial contamination of food packages and other applications, such as, but not limited to, the packaging of disposable medical devices for sterilization. The challenge in meeting this need is to maintain a balance between providing sufficient antimicrobial gas in the headspace of a package to effectively control and / or kill pathogens without "overdosing" the headspace of the package, which can adversely affect the quality of the product, for example, due to sensory degradation. SUMMARY

[0010] Accordingly, in one aspect, the present invention provides a system for inhibiting or preventing the growth of microorganisms and / or killing microorganisms in a closed container having a commodity therein. The system includes a container comprising a bottom surface, a top opening, one or more side walls extending in a vertical direction from the bottom surface to the top opening, an interior space formed by the one or more side walls, a headspace formed by the interior space that is not occupied by the commodity, and a cover for closing and / or sealing the container. The system further includes at least one entrained polymer article located within the interior space, the entrained polymer article comprising a bulk material comprising a base polymer and an antimicrobial release agent configured to release a released antimicrobial gas. The system further includes a selected material present in the interior space to activate the release of the released antimicrobial gas.

[0011] In another aspect, the present invention provides a method for inhibiting or preventing growth of microorganisms, and / or killing microorganisms in a closed container having a commodity therein. The method includes forming at least one entrained polymeric article, which includes obtaining a base polymer, and combining an antimicrobial releasing agent with the base polymer to form an integral material, wherein the antimicrobial releasing agent is configured to release a released antimicrobial material in a gaseous form upon being activated by a selected material. The method further includes obtaining a container, which includes a bottom surface, a top opening, one or more side walls extending in a vertical direction from the bottom surface to the top opening, an interior space formed by the one or more side walls, a headspace formed by the interior space that is not occupied by the commodity, and a cover for closing and / or sealing the container. The method further includes positioning the at least one entrained polymeric article within the interior space of the container, placing a commodity in the container, covering the container, presenting the selected material in the interior space of the container, and releasing the released antimicrobial material in the interior space at a concentration effective to reduce or prevent growth of microorganisms present in and / or on the commodity, and / or to kill microorganisms.

[0012] In another aspect, a package for inhibiting or preventing growth of microorganisms, and / or killing microorganisms in a closed container having a product therein is provided. The package includes a closed container defining an interior space therein. A product, optionally a food product, is provided within the interior space. A headspace is formed within a volume of the interior space that is not occupied by the product. An antimicrobial releasing agent is disposed within the interior space, the antimicrobial releasing agent releasing chlorine dioxide gas into the headspace through a reaction of moisture with the antimicrobial releasing agent. The antimicrobial releasing agent is provided in an amount to release the chlorine dioxide gas to provide a headspace concentration of from 10 parts per million (PPM) to 35 PPM for a period of 16 hours to 36 hours, optionally from 15 PPM to 30 PPM for a period of 16 hours to 36 hours, optionally from 15 PPM to 30 PPM for a period of about 24 hours.

[0013] Optionally, in any embodiment, the product is contaminated with at least one type of pathogen when provided within the interior space. The antimicrobial release agent provides a controlled release of chlorine dioxide gas to achieve a reduction of at least 10 as the base log 2 in colony forming units per gram (CFU / g) of the at least one type of pathogen, optionally a reduction of at least 10 as the base log 3 in CFU / g, optionally a reduction of at least 10 as the base log 4 in CFU / g of the at least one type of pathogen over a span of 13 days starting from the provision of the product within the interior space and under storage conditions of 7°C. Optionally, the at least one pathogen is Salmonella, Escherichia coli, Listeria, and / or Geotrichum.

[0014] Optionally, if the product is a food product, and the antimicrobial release agent and / or the amount of chlorine dioxide gas is present in an amount sufficient to achieve a reduction of at least 10 as the base log 2 in CFU / g of the at least one type of pathogen (or a reduction of at least 10 as the base log 3 or 10 as the base log 4 in CFU / g), such efficacy is not at the expense of causing an organoleptic degradation of the food product. For example, the food product is not bleached or otherwise colored.

[0015] Optionally, in any embodiment, the antimicrobial release agent is provided in at least one entrained polymer article located within the interior space. The entrained polymer article is a unitary material comprising a base polymer, the antimicrobial release agent, and optionally a channeling agent. Preferably, such entrained polymer is provided as a film having a thickness of 0.1 mm to 1.0 mm, preferably 0.2 mm to 0.6 mm, optionally about 0.3 mm. Preferably, such film is provided above the midline of the container sidewall (preferably at least 2 / 3 or 3 / 4), the inventors have found that this helps to achieve the desired antimicrobial gas release profile.

[0016] Optionally, in any embodiment, the antimicrobial release agent is a powdered mixture comprising an alkali metal chlorite, preferably sodium chlorite. Optionally, the powdered mixture further comprises at least one catalyst, optionally a clay sulfuric acid, and at least one humidity trigger, optionally calcium chloride.

[0017] Optionally, in any embodiment, a method for inhibiting or preventing microbial growth and / or killing microorganisms in a closed container having a food product therein is provided. The method includes providing a closed container having an interior space defined therein, and providing a food product within the interior space. A headspace is formed within the volume of the interior space that is not occupied by the product. An antimicrobial releasing agent (such as disclosed in the SUMMARY section and elsewhere in this specification) is provided in the interior space. The antimicrobial releasing agent releases an antimicrobial gas into the headspace through reaction of the antimicrobial releasing agent with moisture. The antimicrobial releasing agent is provided in an amount sufficient to release the antimicrobial gas to provide a desired headspace concentration of the antimicrobial gas over a predetermined amount of time. According to the method, if the product is contaminated with at least one type of pathogen when provided within the interior space, the antimicrobial releasing agent optionally provides a controlled release of the antimicrobial gas to achieve a reduction of at least 10 as the base log 2 in colony forming units per gram (CFU / g), optionally a reduction of at least 10 as the base log 3 in CFU / g, optionally a reduction of at least 10 as the base log 4 in CFU / g of the at least one type of pathogen after a span of 13 days at storage conditions of 7°C. Preferably, the method achieves the reduction without causing a sensory degradation of the food product, e.g., without bleaching or otherwise discoloring the food product. Preferably, the antimicrobial releasing agent is provided in an entrained polymer film, as described herein.

[0018] Optionally, in any embodiment of the package described herein, an aspect of the application can include a use of the package for storing a food product, wherein the food product exudes moisture to activate the antimicrobial releasing agent to release chlorine dioxide gas into a headspace. The use can achieve a desired headspace antimicrobial gas concentration as described herein. The use can achieve a reduction of at least 10 as the base log 2 in colony forming units per gram (CFU / g), optionally a reduction of at least 10 as the base log 3 in CFU / g, optionally a reduction of at least 10 as the base log 4 in CFU / g of the at least one type of pathogen after a span of 13 days from providing the product within the interior space and at storage conditions of 7°C. Preferably, this is achieved without causing a sensory degradation of the food product, e.g., without bleaching or otherwise discoloring the food product. BRIEF DESCRIPTION OF DRAWINGS

[0019] The application will be described with reference to the following drawings in which like numerals refer to like elements, and wherein:

[0020] Figure 1 is a perspective view of a plug formed from an entrained polymer according to an optional embodiment of the application.

[0021] Figure 2 is a cross-section taken along line 2-2 of Figure 1

[0022] Figure 3 is a cross-section similar to Figure 2

[0023] Figure 4 is a schematic of an entrained polymer according to alternative embodiments of the application, wherein the active agent is an antimicrobial gas-releasing material activated by contact with a selected material (e.g., moisture).

[0024] Figure 5 is a cross-sectional view of a sheet or film formed from an entrained polymer adhered to a barrier sheet substrate according to alternative embodiments of the application.

[0025] Figure 6 is a cross-section of a package that can be formed using an entrained polymer according to alternative embodiments of the application.

[0026] Figure 7 is a perspective view of an exemplary package incorporating an entrained polymer film according to alternative aspects of the application.

[0027] Figure 8A and Figure 8B is a graph comparing growth of Geotrichum on contaminated tomatoes stored in packages using and not using an antimicrobial entrained polymer film, respectively.

[0028] Figure 9 is a graph showing measured amounts of CIO2 (chlorine dioxide) provided in the headspace of a container incorporating an entrained polymer film according to certain embodiments of the application.

[0029] Figure 10 is a graph showing measured amounts of CIO2 provided in the headspace of a container incorporating an entrained polymer film at varying heights of the sidewall according to certain embodiments of the application.

[0030] Figure 11 is a graph showing reduction in log CFU / gram of Salmonella of food stored in a container having an entrained polymer film therein according to certain embodiments compared to a container without an entrained polymer film.

[0031] Figure 12 is a graph showing reduction in log CFU / gram of E. coli of food stored in a container having an entrained polymer film therein according to certain embodiments compared to a container without an entrained polymer film.​​

[0032] Figure 13 FIG. 8 is a graph showing the log CFU / g reduction of Listeria in food stored in a container having an entrained polymer film therein according to certain embodiments compared to a container without an entrained polymer film.

[0033] Figure 14 FIG. 9 is a graph showing the measured amount of CIO2 (chlorine dioxide) provided within the headspace of a container depending on the amount of antimicrobial entrained polymer film provided in the container. DETAILED DESCRIPTION

[0034] DEFINITIONS

[0035] As used herein, the term "active" is defined as capable of acting on, interacting with, or reacting with a selected material (e.g., moisture or oxygen) according to the present invention. Examples of such action or interaction can include absorption, adsorption, or release of the selected material. Another example of "active" in relation to the primary focus of the present invention is a reagent capable of acting on, interacting with, or reacting with a selected material to cause the release of a released material.

[0036] As used herein, the term "active agent" is defined as a material that (1) is preferably immiscible with the base polymer and does not melt when mixed with the base mixture and channel-forming agent and heated, i.e., has a melting point higher than the melting point of the base polymer or channel-forming agent; and (2) acts on, interacts with, or reacts with a selected material. The term "active agent" can include, but is not limited to, a material that absorbs, adsorbs, or releases a selected material. The active agent of primary focus in this specification is an active agent that releases an antimicrobial gas, preferably a chlorine dioxide gas.

[0037] The term "antimicrobial release agent" refers to an active agent capable of releasing a released antimicrobial material, e.g., in the form of a gas. The active agent can include an active component and other components (e.g., catalysts and triggers) in a formulation (e.g., a powder mixture) configured to release an antimicrobial gas. The "released antimicrobial material" is a compound (e.g., a chlorine dioxide gas) that inhibits or prevents the growth and proliferation of microorganisms and / or kills microorganisms. The released antimicrobial material is released by the antimicrobial release agent. By way of example only, the antimicrobial release agent can be triggered (e.g., by a chemical reaction or physical change) by contact with a selected material (e.g., moisture). For example, moisture can react with the antimicrobial release agent to cause the reagent to release the released antimicrobial material.

[0038] As used herein, the term "base polymer" is a polymer that optionally has a gas permeability of a selected material that is substantially less than, less than, or substantially equal to the gas permeability of the pore-forming agent. By way of example, in embodiments where the selected material is moisture and the active agent is a moisture-activated antimicrobial gas-releasing agent, such permeability is water vapor permeability. The active agent can include active and other components in a formulation configured to release an antimicrobial gas. The primary function of the base polymer is to provide structure to the entrained polymer.

[0039] Base polymers suitable for use in the present application include thermoplastic polymers such as polyolefins, such as polypropylene and polyethylene, polyisoprene, polybutadiene, polybutene; polysiloxanes, polycarbonates, polyamides, ethylene-vinyl acetate copolymers, ethylene-methacrylate copolymers, poly(vinyl chloride), polystyrene, polyesters, polyacid anhydrides, polyacrylonitrile, polysulfones, polyacrylates, acrylics, polyurethanes and polyacetals, or copolymers or mixtures thereof.

[0040] In certain embodiments, the pore-forming agent has a water vapor permeability that is at least two times greater than the base polymer. In other embodiments, the pore-forming agent has a water vapor permeability that is at least five times greater than the base polymer. In other embodiments, the pore-forming agent has a water vapor permeability that is at least ten times greater than the base polymer. In yet other embodiments, the pore-forming agent has a water vapor permeability that is at least twenty times greater than the base polymer. In yet another embodiment, the pore-forming agent has a water vapor permeability that is at least fifty times greater than the base polymer. In yet other embodiments, the pore-forming agent has a water vapor permeability that is at least one hundred times greater than the base polymer.

[0041] As used herein, the term "pore-forming agent" or "pore-forming agents" is defined as a material that is immiscible with the base polymer and has an affinity for transporting a gas phase material at a faster rate than the base polymer. Optionally, the pore-forming agent is capable of forming channels through the entrained polymer upon mixing the pore-forming agent with the base polymer to form the entrained polymer. Optionally, such channels are capable of allowing the selected material to permeate the entrained polymer at a faster rate than in the base polymer alone.

[0042] As used herein, the term "channel" or "interconnected channels" is defined as a passageway formed by the pore-forming agent that penetrates the base polymer and can be interconnected to one another.

[0043] As used herein, the term "entrained polymer" is defined as the overall material formed from at least the base polymer with the active agent, and optionally, entrained or pervasive pore-forming agent. Thus, the entrained polymer includes a two-phase polymer (without pore-forming agent) and a three-phase polymer (with pore-forming agent).

[0044] As used herein, the term "monolithic," "monolithic structure," or "monolithic composition" is defined as a composition or material that is not comprised of two or more discrete macroscopic layers or portions. Accordingly, a "monolithic composition" does not include a multi-layer composite.

[0045] As used herein, the term "phase" is defined as a portion or component of a monolithic structure or composition that is uniformly distributed throughout to impart its overall characteristics to the structure or composition.

[0046] As used herein, the term "selected material" is defined as a material that is acted upon, acted by, or interacts with or reacts with an active agent and is capable of being transported through the channel of the entrained polymer. For example, in embodiments where the release material is an active agent, the selected material can be moisture, which reacts with or otherwise triggers the release of the release material, such as an antimicrobial gas.

[0047] As used herein, the term "three-phase" is defined as a monolithic composition or structure comprising three or more phases. An example of a three-phase composition according to the present application is an entrained polymer formed from a base polymer, an active agent, and a channel-forming agent. Optionally, a three-phase composition or structure can include additional phases, such as a colorant, but is still considered "three-phase" due to the presence of the three primary functional components.

[0048] Further, the terms "package," "pack," and "container" are used interchangeably herein to indicate an object that holds or contains a commodity, such as a food product and foodstuff. Optionally, a package can include a container in which a product is stored. Non-limiting examples of packages, packs, and containers include trays, boxes, cartons, bottle receptacles, vessels, pouches, and flexible bags. Pouches or flexible bags can be made of, for example, polypropylene or polyethylene. Packages or containers can be closed, covered, and / or sealed using various mechanisms, including, for example, covers, lids, lidding seals, adhesives, and heat seals. Packages or containers are constructed or configured from various materials, such as plastic (e.g., polypropylene or polyethylene), paper, polystyrene foam, glass, metal, and combinations thereof. In an optional embodiment, a package or container is constructed from a rigid or semi-rigid polymer, optionally polypropylene or polyethylene, and preferably has sufficient rigidity to maintain its shape under gravity.

[0049] Exemplary entrained polymers

[0050] Conventionally, desiccants, oxygen absorbers, and other active agents are used in a raw form (e.g., as loose granules contained within a sachet or canister housed within a package) to control the interior environment of the package. For many applications, it is undesirable to have such loose storage of active materials. Accordingly, the present application provides active-entrained polymers comprising active agents, where such polymers can be extruded and / or molded into a variety of desired forms, such as container liners, plugs, film sheets, pellets, and other such structures. Optionally, such active-entrained polymers can include a channeling agent, such as polyethylene glycol (PEG), that forms channels between the surface of the entrained polymer and its interior to deliver a selected material (e.g., moisture) to the entrained active agent (e.g., a desiccant to absorb moisture). As explained above, the entrained polymer can be a two-phase formulation (i.e., comprising a base polymer and an active agent, without a channeling agent) or a three-phase formulation (i.e., comprising a base polymer, an active agent, and a channeling agent). Entrained polymers are described, for example, in U.S. Patent Nos. 5,911,937; 6,080,350; 6,124,006; 6,130,263; 6,194,079; 6,214,255; 6,486,231; 7,005,459; and U.S. Patent Publication No. 2016 / 0039955, the entire contents of each of which are incorporated herein by reference.

[0051] Figures 1 to 6 Exemplary entrained polymers 20 and various packaging components formed from the entrained polymers according to certain embodiments of the present application are illustrated. The entrained polymers 20 each include a base polymer 25, optionally a channeling agent 35, and an active agent 30. As shown, the channeling agent 35 forms interconnected channels 45 through the entrained polymer 20. At least a portion of the active agent 30 is contained within these channels 45, such that the channels 45 communicate between the active agent 30 and the exterior of the entrained polymer 20 via channel openings 48 formed at the outer surface of the entrained polymer 25. The active agent 30 can be, for example, any of a wide variety of release materials, as described in further detail below. While a channeling agent, such as 35, is preferred, the present application broadly includes entrained polymers that optionally do not include a channeling agent.

[0052] Suitable pore-forming agents include polyglycols, such as polyethylene glycol (PEG), ethylene vinyl alcohol (EVOH), polyvinyl alcohol (PVOH), glycerol polyamines, polyurethanes, and polycarboxylic acids (including polyacrylic acid or polymethacrylic acid). Alternatively, for example, the pore-forming agent 35 can be a water-insoluble polymer, such as propylene oxide polymer-monobutyl ether, such as commercially available under the trade name Polyglykol B 01 / 240 produced by CLARIANT. In other embodiments, the pore-forming agent can be propylene oxide polymer monobutyl ether (commercially available under the trade name Polyglykol B 01 / 20 produced by CLARIANT), propylene oxide polymer (commercially available under the trade name Polyglykol D 01 / 240 produced by CLARIANT), ethylene vinyl acetate, nylon 6, nylon 66, or any combination of the foregoing.

[0053] The entrapping polymers with antimicrobial release agents are further described below.

[0054] Antimicrobial release agents and optional entrapping polymer formulations comprising the same

[0055] Suitable active agents according to the present application include antimicrobial release agents. Figure 4 Embodiments of the entrapping polymer 10 according to the present application are shown in which the active agent 30 is an antimicrobial release agent. The arrows indicate the path of a selected material (e.g., moisture or another gas) from outside the entrapping polymer 10 through the channels 45 to the particles of the active agent 30 (in this case, an antimicrobial release agent). Optionally, the antimicrobial release agent reacts with the selected material (e.g., by moisture) or is otherwise triggered or activated, and in response releases a released antimicrobial material, preferably in the form of a gas.

[0056] Antimicrobial agents useful herein include volatile antimicrobial release agents, non-volatile antimicrobial release agents, and combinations thereof.

[0057] The term "volatile antimicrobial release agent" includes any compound that produces a gas and / or gas phase (such as a vapor of the released antimicrobial agent) when in contact with a fluid (e.g., water or juice from a food product). As will be discussed in greater detail below, volatile antimicrobial release agents are typically used in a closed system such that the released antimicrobial material (gas and / or vapor) does not escape. Examples of volatile antimicrobial release agents include, but are not limited to, oregano, basil, cinnamaldehyde, chlorine dioxide release agents (e.g., a combination of sodium chlorite, a catalyst, and an activator), carbon dioxide release agents, ozone release agents, vanillin, vanillic acid, cilantro oil, clove oil, horseradish oil, peppermint oil, rosemary, sage, thyme, mustard or extracts thereof, bamboo extract, grapefruit seed extract, rhubarb extract, goldenseal extract, lavender oil, lemon oil, eucalyptus oil, peppermint oil, ylang-ylang, cypress, turmeric, lemon grass, blue gum, radiata pine, piper crassinervium, guava, rosemary, ginger, thyme, thymol, allyl isothiocyanate (AIT), hinokitiol, carvacrol, eugenol, a-terpineol, sesame oil, or any combination of the foregoing compounds.

[0058] The term "non-volatile antimicrobial agent" includes any compound that produces little to no vapor of the antimicrobial agent when in contact with a fluid (e.g., water or juice from a food product). Examples of non-volatile antimicrobial agents include, but are not limited to, ascorbic acid, sorbate salts, sorbic acid, citric acid, citrate salts, lactic acid, lactate salts, benzoic acid, benzoate salts, bicarbonate salts, chelating compounds, alum salts, nisin, epsilon-polylysine 10%, methyl and / or propyl paraben, or any combination of the foregoing compounds. Salts include sodium, potassium, calcium, or magnesium salts of any of the compounds listed above. Specific examples include calcium sorbate, calcium ascorbate, potassium metabisulfite, potassium metabisulfite, potassium sorbate, or sodium sorbate.

[0059] Preferred features of antimicrobial release agents used in accordance with an aspect of the present application include any one or more of the following properties: (1) volatile at refrigerated temperatures; (2) food safe and consumable in finished product form; (3) can be safely incorporated into an entraining polymer formulation or other release mechanism; (4) shelf stable under long term storage conditions; (5) releases the released antimicrobial material only if the package in which the antimicrobial release agent is disposed is sealed with the product disposed in the package; (6) does not affect the sensory qualities of the stored food product when formulated and configured to achieve the desired release profile within the package; and (7) is preferably acceptable in accordance with applicable government regulations and / or guidelines for labeling of food packaging and finished food products.

[0060] Antimicrobial release agents that release chlorine dioxide

[0061] In one aspect of the application, the preferred antimicrobial release agent is a volatile antimicrobial agent that releases chlorine dioxide (C102) as the released antimicrobial material in gaseous form. For example, the antimicrobial release agent can be a compound or formulation that includes a basic chlorite salt (e.g., sodium chlorite or potassium chlorite), a catalyst, and a trigger (e.g., in powder form), which in combination is triggered or activated by moisture to cause the release of chlorine dioxide from the agent. One exemplary antimicrobial release agent is provided by BASF Catalysts LLC under the brand name ASEPTROL 7.05. This material and its preparation are described in U.S. Patent No. 6,676,850, the entire contents of which are incorporated herein by reference. According to an alternative aspect of the application, Example 6 of the above-identified patent describes a formulation that is particularly suitable as an antimicrobial release agent.

[0062] Alternatively, a suitable antimicrobial release agent (based on Example 6 of U.S. Patent No. 6,676,850, and configured to release chlorine dioxide gas upon activation by moisture) can be prepared as follows.

[0063] The antimicrobial release agent includes a formulation that contains sodium chlorite as the active component, an alkali catalyst, and a trigger. The catalyst and trigger formulations are prepared separately, then combined together and finally combined with the sodium chlorite.

[0064] Alternatively, the alkali catalyst is prepared by first preparing a 25-30 wt.% solution of sodium silicate (Si02:Na20 ratio of 2.0 to 3.3 by weight). This solution is mixed into an aqueous slurry of 28-44 wt% Georgia Kaolin (about 80% of the particle size diameter is less than one micron), with the sodium silicate solution being 2 wt.% of the slurry. The slurry is oven dried at 100°C to produce agglomerates or microspheres of about 70 μm in size. 280 g of a 2.16 N solution of sulfuric acid is used to impregnate 300 g of these microspheres. The mixture is then dried at 100°C. Next, the dried mixture is subjected to a calcination process at 350°C for 3 hours, followed by an additional calcination process at 300°C in a sealed glass jar with a seal wrapped with tape. The mixture forms the alkali catalyst.

[0065] Next, 84.6 g of the alkali catalyst is mixed with 10.1 g of the dry calcium chloride trigger. The alkali catalyst and trigger mixture is ground with a mortar and pestle at room temperature. The mixture is dried at 200°C for 2 hours. The alkali catalyst and trigger mixture is then cooled to room temperature in a glass jar sealed with tape wrapped around the seal.

[0066] Finally, the base catalyst is mixed with the trigger mixture and 5.3 g of sodium chlorite, which is the active component of the active agent. The entire mixture is then ground with a mortar and pestle at room temperature, thereby forming an optional embodiment of the antimicrobial release agent. The antimicrobial release agent is then deposited in a glass jar sealed with tape wrapped around the seal to protect it and render it substantially free of moisture, which would otherwise prematurely activate (release chlorine dioxide gas).

[0067] Optionally, the antimicrobial release agent is a polymer-entrained component, preferably a three-phase polymer component comprising an active agent (e.g., 40-70% by weight), a base polymer, and a pore former. Optionally, such polymer-entrained is in the form of a film disposed within a sealed package containing fresh food (e.g., meat or produce).

[0068] It is generally believed that the higher the concentration of antimicrobial release agent in the polymer-entrained mixture, the greater the absorption, adsorption, or release capacity of the final composition. However, too high of an active agent concentration can render the polymer-entrained too brittle. This can also make the molten mixture of active agent, base polymer, and (if used) pore former more difficult to thermoform, extrude, or injection mold. In one embodiment, the antimicrobial release agent loading level or concentration can range from 10% to 80% by weight, preferably 40% to 70% by weight, more preferably 40% to 60% by weight, and even more preferably 45% to 55% by weight, relative to the total weight of the polymer-entrained. Optionally, the pore former can be provided in the range of 2% to 10% by weight, preferably about 5% by weight. Optionally, the base polymer can comprise 10% to 50% by weight, preferably 20% to 35% by weight, of the total composition. Optionally, a colorant is added, e.g., about 2% by weight of the total composition.

[0069] In one embodiment, the polymer-entrained can be a three-phase formulation comprising 50% by weight of ASEPTROL 7.05 antimicrobial release agent in the form of a powder mixture, 38% by weight of ethyl vinyl acetate (EVA) as a base polymer, and 12% by weight of polyethylene glycol (PEG) as a pore former.

[0070] Figure 1 A plug 55 constructed from a polymer-entrained 20 according to certain embodiments of the present application is shown. The plug 55 can be placed inside a container. As described above, the polymer-entrained 20 includes a base polymer 25, a pore former 35, and an active agent 30.

[0071] Figure 2 A cross-sectional view of the plug 55 is shown. In addition, Figure 1 A cross-sectional view of the plug 55 is shown. In addition, Figure 2The entrained polymer 20 has been solidified, such that the pore forming agent 35 forms interconnected channels 45 to establish a pathway throughout the solidified plug 55. At least a portion of the active agent 30 is contained within these channels 45, such that the channels 45 communicate between the active agent 30 and the exterior of the entrained polymer 20 via channel openings 48 formed at the outer surface of the entrained polymer 25.

[0072] Figure 3 The illustrated embodiment of the plug 55 has a similar construction and composition to the plug 55 of Figure 2 , wherein the interconnected channels 45 are finer than those shown in Figure 2 . This can be achieved through the use of a dimerizing agent (i.e., plasticizer) and the pore forming agent 35. The dimerizing agent can enhance the compatibility between the base polymer 25 and the pore forming agent 35. The lower blend viscosity contributes to this enhanced compatibility, which can facilitate more thorough blending of the base polymer 25 and the pore forming agent 35, both of which can resist being combined into a homogeneous solution under normal conditions. After the solidification of the entrained polymer 20 with the addition of the dimerizing agent, the interconnected channels 45 formed therethrough have greater dispersity and smaller porosity, thereby establishing a greater density of interconnected channels throughout the plug 55.

[0073] The interconnected channels 45, such as those disclosed herein, facilitate the transport of a desired material (e.g., moisture, gas, or odor) through the base polymer 25, which is typically used as a barrier to the penetration of these materials. To this end, the base polymer 25 itself serves as a barrier substance that can entrain the active agent 30. The interconnected channels 45 formed by the pore forming agent 35 provide a pathway for the desired material to move through the entrained polymer 10. Without these interconnected channels 45, it is believed that a relatively small amount of the desired material can permeate through the base polymer 25 to or from the active agent 30. Additionally, for example, in embodiments where the active agent 30 is a releasing material, such as an antimicrobial gas releasing material, where the desired material is transported from the active agent 30, it can be released from the active agent 30.

[0074] Figure 5 An active sheet or film 75 formed from the entrained polymer 20 for use in combination with a barrier sheet 80 to form a composite according to aspects of the present invention is illustrated. The properties of the active sheet 75 are similar to those described with respect to the plug 55 shown in Figure 1 and Figure 2 . The barrier sheet 80 can be a substrate having low moisture or oxygen permeability, such as a foil and / or a polymer (e.g., a container wall). The barrier sheet 80 is compatible with the active sheet 75, and is thus configured to thermally bond to the active sheet 75 when the active sheet 75 is solidified after dispensing. Figure 6The following embodiment is shown: wherein two sheets 75, 80 are combined to form a package wrap having active properties at the inner surface formed by the entrained polymer 20 / active sheet 75, and vapor resistant properties at the outer surface formed by the barrier sheet 80.

[0075] In one embodiment, Figure 5 The sheets 75, 80 are joined together to form an active package 85, as shown in Figure 6 The two laminates or composites are provided, each formed from an active sheet 75 joined with a barrier sheet 80. These sheet laminates are stacked with each active sheet 75 facing the other so as to be disposed inside the package, and joined at a seal area 90 formed around the perimeter of the sealed area inside the package.

[0076] Optionally, in any of the foregoing embodiments, the antimicrobial entrained polymer is in the form of a film, disposed within a sealed food package. Optionally, the film can be adhered to the inner surface of the package, for example using an adhesive. Alternatively, the film can be heat staked (without adhesive) to the inner surface of the package. The process of heat staking a film to a substrate is known in the art, and is described in detail in U.S. Patent No. 8,142,603, the entirety of which is incorporated herein by reference. The size and thickness of the film can vary. In certain embodiments, the film has a thickness of about 0.3 mm. Optionally, the film can vary in the range from 0.1 mm to 1.0 mm, more preferably from 0.3 mm to 0.6 mm.

[0077] Figure 7 A package 100 for storing fresh food, such as produce or meat, in accordance with certain embodiments of the present application is shown. The package 100 is shown in the form of a plastic tray 102. Nonetheless, other forms and materials are contemplated as being within the scope of the present application. The tray 102 includes a base 104 and sidewalls 106 extending vertically from the base 104 to an open 108 of the tray. The base 104 and sidewalls 106 together define an interior 110, such as for containing and storing fresh produce. The package 100 further includes a flexible plastic lidding film 112, which is disposed over and seals the opening 108. It is contemplated and understood that a variety of covers or lids can be used to close and seal the opening 108. Optionally, the cover or lid is transparent, such that the interior can be seen. When product (e.g., sliced tomatoes) is stored within the interior 110, the empty space above and around the product is referred to herein as "headspace" (not shown).

[0078] The package 100 further includes a portion of antimicrobial entrained polymer film 114 disposed on the side walls 106. In the illustrated embodiment, such film 114 has four portions, one on each side wall 106. The film 114 is preferably disposed at or near the top of the side walls 106, proximate the opening 108. At least a portion, but preferably most or all, of each film portion 114 protrudes above a midline 116 of the side wall 106, which is centered between the base 104 and the opening 108. It has been found that placement of the film at or toward the top of the package 100 has an impact on the efficacy of the film portion 114, as such placement facilitates the desired distribution of the released antimicrobial material in the headspace of the package 100. It has been found that placement of the entrained polymer too low above the base 104, or below the food in the package, does not provide the desired distribution of the released antimicrobial material in the headspace. If the placement mass transfer of the antimicrobial is not optimal, some of the food / commodity will not be properly protected from the growth of microorganisms. Additionally, the food can undesirably react with and / or absorb the released antimicrobial material. As explained further below, it has been found that placement of the film above the midline of the side wall, preferably at least 67% or 75% or about 80% of the height of the side wall, facilitates achieving the desired antimicrobial gas release profile and headspace concentration.

[0079] Optionally, the entrained polymer film 114 is heat staked to the package (e.g., to the side wall, as described and illustrated). Advantageously, heat staking can allow the film to be permanently adhered to the side wall without the use of adhesives. In some cases, adhesives can be problematic as they can release undesirable volatiles in the food-containing headspace. Aspects of a heat staking process that can be used in accordance with alternative embodiments of the present application are disclosed in U.S. Patent No. 8,142,603, referenced above. In this case, heat staking refers to heating a seal layer substrate on the side wall while applying sufficient pressure on the film and seal layer substrate to adhere the film to the container wall. Figure 7

[0080] In certain embodiments, instead of or in addition to the film portion 114 on the side wall 106, the antimicrobial entrained polymer film 114 can be attached to the surface of the lidding film 112 (or lid) inside the container. Alternatively, the antimicrobial entrained polymer film 114 can be incorporated into the composition of the lidding film 112 (or lid).

[0081] In addition to placement of the film 114, another important factor is the release profile of the released antimicrobial material. As noted above, to ensure proper shelf life, the agent should not be released immediately, but rather, the release should be extended, sustained and predetermined to achieve the desired shelf life. ​

[0082] In general, the polymer with the antimicrobial release agent entrained therein is self-activating, meaning that the release of the released antimicrobial gas does not begin until the antimicrobial release agent is exposed to a selected material (e.g., moisture). Typically, prior to placing the food product inside the container, there is no moisture in the interior (e.g., headspace) of the container. Upon placement, the food product generates moisture that interacts with the antimicrobial release agent entrained in the polymer to generate the antimicrobial release agent in the headspace. In one embodiment, the container is sealed in a manner that is moisture-tight to capture the moisture generated by the moisture exuding from the food product within the container.

[0083] In certain embodiments, the controlled release and / or desired release profile can be achieved by applying a coating to the active agent, for example, using a spray coater, where the coating is configured to release the released antimicrobial agent over a desired time frame. Different coatings can be applied to the antimicrobial release agent to achieve different release effects. For example, if a 14-day shelf life is desired, the amount of the selected material (moisture) that triggers the antimicrobial release agent can be determined based on the intended relative humidity of the package. Based on this determination, the agent can be coated with a prolonged release coating of different thickness and / or characteristics to achieve the desired release profile. For example, some active agents will be coated so that it does not begin to release the released antimicrobial material until after a week, while other active agents begin to release almost immediately. Spray coating techniques are known in the art. For example, pharmaceutical beads and the like are spray coated to control the release rate of the active ingredient, for example, to produce a prolonged or sustained release of the drug. Alternatively, such techniques can be adapted to apply a coating to the active agent to achieve the desired controlled release rate of the antimicrobial gas.

[0084] Alternatively, the controlled release and / or desired release profile can be achieved by optionally providing a layer of material on both sides of the film that is configured to control the moisture uptake into the entraining polymer (which in turn triggers the release of the released antimicrobial material). For example, the film can include a polymeric liner, for example, made of low density polyethylene (LDPE) disposed on either or both sides thereof. The thickness of the film and liner can vary. In certain embodiments, the film is approximately 0.3 mm thick and the LDPE liner on both sides is approximately 0.02 mm to 0.04 mm thick. The LDPE liner can be co-extruded with the film or laminated thereto.

[0085] Alternatively, controlled release and / or desired release profiles can be achieved by varying the formulation of the trigger of the antimicrobial release agent. For example, the trigger liquefies upon contact with moisture, and then reacts with the active component (e.g., sodium chlorite) to cause release of the antimicrobial gas. The trigger can be formulated to liquefy at different rates upon contact with moisture. The faster the trigger liquefies, the faster the antimicrobial gas is released, and vice versa. In this way, modification of the trigger is yet another way to provide a desired rate of antimicrobial gas release.

[0086] Any combination of the foregoing mechanisms can be utilized to achieve a desired release rate and release profile of the antimicrobial gas within the headspace of the container.

[0087] Different release rates depending on the nature of the stored food

[0088] The inventors have discovered that the desired release profile of chlorine dioxide gas in the headspace of the container can vary depending on the nature of the stored product. For example, the inventors have discovered that foods with high water content appear to require a high burst of antimicrobial gas followed by a decline in headspace concentration during storage, while foods with more moderate water content appear to respond well to a relatively stable headspace concentration over the storage period.

[0089] Non-limiting examples of foods that exude significant amounts of moisture and are better protected by having a release profile with a rapid burst of chlorine dioxide gas followed by a decline include sliced, diced or chopped foods selected from the group consisting of tomatoes, washed peppers, washed onions, watermelon, honey dew, cantaloupe, strawberries, peaches, pineapples, oranges, seafood, meats and poultry. For such foods, an amount of antimicrobial release agent is provided to release chlorine dioxide gas to provide a headspace concentration of from 10 parts per million (PPM) to 35 PPM for a period of 16 hours to 36 hours, optionally from 15 PPM to 30 PPM for a period of 16 hours to 36 hours, optionally from 15 PPM to 30 PPM for a period of about 24 hours. Head space concentration measurements can be obtained, for example, by using a PORTASENS II gas detector from Analytical Technology, Inc. to obtain readings taken by chlorine dioxide sensors placed within the packaging. These sensors can be one or more of the following: 00-1004 chlorine dioxide, 0-1 / 5 PPM (2 PPM Std.), 00-1005 chlorine dioxide, 0-5 / 200 (20 PPM Std.), and 00-1359 chlorine dioxide, 0-200 / 1000 PPM (1000 PPM Std.), and are compatible with the PORTASENS II gas detector.

[0090] This type of "rapid burst" (headspace concentration of from 10 parts per million (PPM) to 35 PPM for a period of 16 hours to 36 hours) appears to be necessary so that the chlorine dioxide gas dissolved in the water can be maintained ahead of the dissolution curve to provide sufficient antimicrobial effect during the peak headspace concentration to improve the shelf life of the contaminated food over a period of approximately two weeks. Although the release is characterized as a "rapid burst," it can still be considered a controlled release in that the headspace concentration is still regulated to fall within a desired concentration over a given period of time, even if relatively "rapid." For example, the inventors have found that the above headspace concentrations work well to significantly reduce the microbial count of contaminated sliced tomatoes over a period of about thirteen days without bleaching the tomatoes. This is demonstrated by the examples provided below.

[0091] Non-limiting examples of foods that exude moderate or low amounts of moisture are whole or minimally processed products selected from the group consisting of broccoli, brussel sprouts, cabbage, cucumbers, bananas, herbs, whole peppers, carrots, root vegetables, and potatoes. For such foods, an amount of antimicrobial release agent releases chlorine dioxide gas to preferably provide a headspace concentration of from 8 PPM to 15 PPM for a period of 13 days. Regardless of whether this precise headspace concentration is met, it is preferred that, as described herein, for such low or moderate moisture exuding foods, the antimicrobial release agent is provided in an entrained polymer film.

[0092] The release profile and headspace concentration described above assumes the presence of a moisture exuding food in the package.

[0093] In either case (high moisture exuding or moderate / low moisture exuding foods) where the product is contaminated with at least one type of pathogen, chlorine dioxide gas is provided at a headspace concentration over a determined period of time to achieve at least a 10 as the base log 2 reduction, optionally at least a 10 as the base log 3 reduction, optionally at least a 10 as the base log 4 reduction in CFU / g of the at least one type of pathogen after a 13 day span from the time the product is provided in the interior space and under storage conditions of 7°C without causing sensory degradation of the food. Such sensory degradation can include bleaching or other discoloration of the food.

[0094] Optionally, according to any embodiment, 700-950 mg of antimicrobial release agent is effective when used in a 1 L container with 1.25 lbs of tomatoes stored therein. It is contemplated that the mass of antimicrobial release agent can be scaled according to variations in container volume and the amount / type of contents.

[0095] Use of the invention in non-food consumer goods

[0096] In another aspect, the invention relates to the use of an entrained polymer comprising an antimicrobial agent outside of food preservation applications. For example, the solution disclosed herein can be applicable to the sterilization of disposable medical devices, i.e., reducing the biological load of such devices at the time of packaging. The main difference between the preservation of fresh food and medical devices is the shelf life. The preservation of fresh food implies a shelf life measured in days or weeks, while maintaining the sterility of packaged medical devices requires a shelf life measured in months or years. Accordingly, the release profile over time of one application versus the other will necessarily vary.

[0097] The application will be shown in greater detail with reference to the following examples, but it should be understood that the application should not be considered as being limited thereto.

[0098] Example

[0099] Example 1 - Control of CIO2 gas release

[0100] A storage temperature of 7°C was chosen to replicate a storage temperature slightly above the ideal storage temperature (or to stimulate an unintentional temperature spike during storage, for example, when a refrigeration unit fails for a few hours). Three packages were utilized in this experiment similar to those shown in Figure 7 All three of the antimicrobial entrained polymer film portions contained were placed substantially as shown in Figure 7 The film was a three-phase entrained polymer film that included an antimicrobial release agent in the form of a powdered mixture containing sodium chlorite (to generate chlorine dioxide gas), bentonite clay (as a catalyst), and calcium chloride (as a humidity trigger). The powdered mixture was commercially available from BASF under the trade name ASEPTROL and as described above.

[0101] The formulation of the film itself was a three-phase formulation containing 50% by weight of the antimicrobial release agent in the form of a powdered mixture described above, 38% by weight of ethyl vinyl acetate (EVA) as a base polymer, and 12% by weight of polyethylene glycol (PEG) as a cell forming agent. The film formulation is described herein as X2597, and is considered to be one exemplary non-limiting embodiment of an entrained polymer according to aspects of the disclosed concept. As described above, the antimicrobial release agent is triggered by moisture to release chlorine dioxide (CIO2) gas as the released antimicrobial material. The films between the three packages had the same formulation and dimensions. However, two of the films had outer layers that controlled moisture uptake, and the other did not. The film in Package A was sandwiched between about 0.02 mm thick co-extruded LDPE layers. The film in Package B was sandwiched between about 0.04 mm thick co-extruded LDPE layers. The film in Package C (control) had no such polymer layers on either side of the film.

[0102] The CIO2 levels in the packages were measured for 13 days with a detection sensor calibrated for a desired concentration known to have antimicrobial effects on most organisms. The results were as follows (values expressed in ppm CIO2 concentration).

[0103] This example demonstrates that Package B has the most stable and consistent release profile, due to the thicker polymer liner that sandwiches the antimicrobial film, allowing for controlled moisture uptake in the film. For some applications, such as when a food, such as broccoli, exudes a relatively large amount of moisture, the release profile of Package B can be desirable.

[0104] Example 2 - Geotrichum growth test

[0105] A common cause of poor quality of tomatoes is Geotrichum candidum, a yeast-like mold that grows as white fuzz. In this example, sliced tomatoes were intentionally contaminated with G. Cauliflower was packaged and tested. A storage temperature of 7°C was chosen to replicate a storage temperature that is slightly above the ideal storage temperature (or to stimulate an unintentional temperature spike during storage, such as when a refrigeration unit fails for a few hours).

[0106] The contaminated sliced tomatoes were stored using a package as shown in Figure 7 wherein the CIO2-releasing antimicrobial film was placed facing the top of the package. A second package (identical to the first package except without the antimicrobial film) was used to store the contaminated sliced tomatoes. The results are provided on the graphs shown in Figure 8A and Figure 8B The results conclusively show that the antimicrobial film significantly inhibited the growth of Geotrichum on the sliced tomatoes compared to the package without the film. In the package without the antimicrobial film, the proliferation of Geotrichum on the sliced tomatoes was easily visible to the naked eye. In contrast, the sliced tomatoes in the package with the sandwiched polymer-releasing CIO2antimicrobial film appeared fresh and showed no visible signs of Geotrichum growth. This was further evident considering the suboptimal 7°C storage conditions for the 14-day trial.

[0107] It should be understood that the example with tomatoes is merely exemplary and that other products and fresh foods (e.g., meat) can be used in accordance with the present application. It should be further understood that while chlorine dioxide is a preferred released antimicrobial material, other released antimicrobial materials are within the scope of the present application and can be preferred for other applications.

[0108] Example 3 - Antimicrobial film position test

[0109] An entrained polymer film (X2597 film as described above) was placed in the headspace of the tray at various height locations on the sidewall to test the effectiveness of various antimicrobial film positions / orientations, as well as various sampling locations. The abbreviation "MCT" as used herein refers to Maxwell Chase Technologies, LLC of Atlanta, Georgia. The abbreviation "FPT" refers to the FRESH-R-PAX® tray of Maxwell Chase Technologies, LLC.

[0110] The following materials were used in this example:

[0111] The MCT FPT125D (1 / 4 steam size, deep white polypropylene) tray was modified as follows. Three holes approximately 8.5 mm wide and 2 cm apart were made in the MCT FPT125D tray with an Xacto knife. The edges of the holes were cleaned, the CPC valve was screwed into the hole, O-rings were placed on both sides, and compression fittings were tightened onto the 2 rings. The 2 valves were placed with QDVs on the outside of the lid and container to allow for sampling with the auto- shut off valves located externally.

[0112] Flex® GP70 3 / 16" inner diameter, " outer diameter OD black PVC tubing (MCM #5231K35) was used for the inlet and outlet of the C16 portable gas analyzer, as well as the other end of the CPC #3438400 quick disconnect valve with compression stub to sample the headspace in the tray.

[0113] CSP film samples were cut from the same film and had the same width. Each sample was then weighed to 1.000 g and attached to the sidewall of the tray with plastic sheeting to hold it in place. There were two samples in each tray, so each tray had 2 g of CSP film. Each sample was attached to a different sidewall of the tray.

[0114] The tomatoes were sliced with a hand-cranked slicer with the petal side facing down. The ends were discarded. Approximately 7 tomato slices were placed on the bottom surface of each tray.

[0115] The hand sealer was heated to 375°F and each tray with tomatoes in it was placed on the corresponding sealing plate. The lidding / sealing film was placed on the tray, the sealing handle was pressed and held for approximately 1-2 seconds to cover / seal the tomatoes in the tray.

[0116] For each tray, the CIO2 release rate was measured at 1 hour intervals over 11 hours. Figure 9The CIO2 release (ppm) corresponding to various positions of the CSP film in the tray is shown, i.e., at heights of 0%, 50%, 64%, 79%, and 100% from the bottom surface based on the total height of the sidewall. These respective heights are measured from the midline of the film. Figure 10 The effect of CSP film height on headspace concentration is shown.

[0117] The results indicate that changing the height of the CSP film in the tray has an effect on the presence of CIO2 in the headspace. From the bottom of the tray (0%) to the midpoint (50% - approximately 2 inches up the sidewall in this particular non-limiting example), there is only a small, e.g., insignificant, change in headspace concentration. However, from the midpoint of the tray to the top, increasing the height results in a significant increase in concentration. From the position of 64% of the total height to the top of the tray (100%), the concentration doubles. The data indicates that in order to maximize the headspace concentration of CIO2 for optimal effect and / or to minimize the amount of film required, the placement of the film should preferably be within the top 20% of the tray, i.e., positioned at a vertical height of 80% to 100% of the total height of the sidewall measured from the bottom surface, and should be placed at at least 64% of the total height of the sidewall of the tray.

[0118] Example 4 - Using a rapid burst release profile to kill pathogens

[0119] The effectiveness of a CSP CIO2 film applied on the upper portion of the tray in reducing levels of Listeria monocytogenes, E. coli, and Salmonella was evaluated as compared to control trays without a CSP CIO2 film.

[0120] A CSP CIO2 emitting film was used, referred to as Formulation X 2597 (as described above), having a thickness of 0.3 mm. This formulation was designed to have a rapid CIO2 release profile and did not use an overlying polyethylene layer to reduce the rate of moisture uptake into the film. As described above, the X-2597 film is a three-phase formulation comprising 50% by weight of an antimicrobial releasing agent, 38% by weight of ethyl vinyl acetate (EVA) as a base polymer, and 12% by weight of polyethylene glycol (PEG) as a pore former. Trays with either 4 grams or 3 grams of film per tray were used. The tomatoes in the trays were each inoculated with three pathogens, i.e., Listeria monocytogenes, E. coli, and Salmonella.

[0121] The following materials were used in this example:

[0122] Prepare Salmonella, Listeria monocytogenes, and E. coli O157:H7 5-strain cocktail, mix and hold overnight. The goal is to achieve a 5-log inoculum of each pathogen on the tomatoes. The inoculated tomatoes have 10 9 CFU pathogens / ml of inoculum. Plate the inoculum for verification and to obtain initial levels.

[0123] Use warm water to prepare a solution of 200 ppm free chlorine solution. Dip the slicer in the solution for 2 minutes, then rinse with tap water.

[0124] Use warm water (approximately the same temperature as the tomatoes) to prepare a 200 ppm free chlorine solution. First, place the tomatoes in tap water, then in the chlorine solution for 2 minutes, and rinse with tap water. Slice the tomatoes using a hand-cranked slicer with the corolla facing down. Discard the ends so that each tray contains 42 slices (6 tomatoes each sliced into 7 slices / tomato).

[0125] Inoculate eighteen (18) tomato slices in each tray with Salmonella, Listeria monocytogenes, and E. coli (6 of each) inoculum to achieve a triple analysis in each tray. Identify the selected 18 tomato slices by marking each slice with a Sharpie adjacent to the area to be inoculated. Vortex the inoculum and quickly pipette 10 μl of the inoculum with a sterile pipette tip onto the top two marked slices. Repeat twice more per pathogen per tray.

[0126] Heat the hand sealer to 375°F. Place each tray on the sealing plate and pull the lidding film across the tray. Press the sealing handle down and hold in place for approximately 1-2 seconds. After sealing, inspect each tray to confirm that the lidding film is fully attached to the tray.

[0127] Analyze the test trays on days 0, 5, 8, and 12. For each tray, there are a total of three samples for each pathogen, three pathogens per tray, take three APC (aerobic plate count) samples from each tray. Each sample consists of two slices removed using sterile forceps. Place the two slices into a sterile stomacher bag (approximately 40-50 g in weight) and add three times the amount of sterile peptone water. Agitate the tomatoes at 260 rpm for 1 minute. Then prepare the necessary dilutions (~3) from the homogenate and replicate the platings on the appropriate PCA, MOX, SMAC, or XLD plates.

[0128] Data was calculated as colony forming units (CFU) per gram. CFU values were converted to log values for data analysis. Data was averaged for each tray and each sample type. The term "CSP3" refers to trays using 3 g X2597 film, while the term "CSP4" refers to trays using 4 g X2597 film.

[0129] Day 0: 1 MCT tray, inoculated w / 3 Salmonella, 3 E. coli, 3 Listeria, and 3 APC trials / tray = 12 trials; 1 CSP4 tray, inoculated w / 3 Salmonella, 3 E. coli, 3 Listeria, and 3 APC trials / tray = 12 trials; 1 CSP3 tray, inoculated 3 Salmonella, 3 E. coli, 3 Listeria, and 3 APC trials / tray = 12 trials; 1 UN tray (negative control) uninoculated x 4 trials (sal, E. coli, Lm, APC) / tray = 4 trials. Cumulatively, this totals 40 trials.

[0130] Day 5: 3 MCT trays, inoculated w / 3 Salmonella, 3 E. coli, 3 Listeria, and 3 APC trials / tray = 36 trials; 3 CSP4 trays, inoculated w / 3 Salmonella, 3 E. coli, 3 Listeria, and 3 APC trials / tray = 36 trials; 3 CSP3 trays, inoculated w / 3 Salmonella, 3 E. coli, 3 Listeria, and 3 APC trials / tray = 36 trials; 1 UN tray (negative control) uninoculated x 4 trials (sal, E. coli, Lm, APC) / tray = 4 trials. Cumulatively, this totals 112 trials.

[0131] Day 8: 3 MCT trays, inoculated w / 3 Salmonella, 3 E. coli, 3 Listeria, and 3 APC trials / tray = 36 trials; 3 CSP4 trays, inoculated w / 3 Salmonella, 3 E. coli, 3 Listeria, and 3 APC trials / tray = 36 trials; 3 CSP3 trays, inoculated w / 3 Salmonella, 3 E. coli, 3 Listeria, and 3 APC trials / tray = 36 trials; 1 UN tray (negative control) uninoculated x 4 trials (sal, E. coli, Lm, APC) / tray = 4 trials. Cumulatively, this totals 112 trials.

[0132] Day 12: 3 MCT trays, inoculated w / 3 Salmonella, 3 E. coli, 3 Listeria, and 3 APC trials / tray = 36 trials; 3 CSP4 trays, inoculated w / 3 Salmonella, 3 E. coli, 3 Listeria, and 3 APC trials / tray = 36 trials; 3 CSP3 trays, inoculated w / 3 Salmonella, 3 E. coli, 3 Listeria, and 3 APC trials / tray = 36 trials; 1 UN tray (negative control) uninoculated x 4 trials (sal, E. coli, Lm, APC) / tray = 4 trials. Cumulatively, this totals 112 trials.

[0133] Overall, the experiment cumulatively included a total of 376 trials (94 Salmonella, 94 E. coli, 94 Listeria, 94 APC). Figures 11 to 13 Results are shown in Table 2.

[0134] Figure 11 Salmonella reduction is shown after day 0 and for the CSP3 trays, the decline continues until day 12, and the CSP4 trays continue. Each of these samples shows at least a 1.8 log reduction in Salmonella count at day 5, 2.5 logs at day 8, and 3 logs at day 12, respectively. This exemplifies a 99.9% reduction in Salmonella after 12 days in the CSP trays.

[0135] Figure 12 E. coli results are shown similar to the Salmonella results. E. coli reduction after day 0 achieves at least a 2 log reduction at day 5, 4 logs at day 8, and 3 logs at day 12. Against Salmonella, similar, Figure 11 Similarly, Figure 12 An increase for the CSP3 trays at day 12 is shown. It was determined that E. coli was reduced by 99.9% after 12 days. Figure 13 The CSP film also reduced Listeria by 1 log over the 12 day shelf life. This was consistent when samples were taken daily and exemplifies a 90% continued reduction in Listeria monocytogenes over 12 days.

[0136] These results exemplify the effectiveness of the CSP trays with sliced tomatoes (optional aspect according to the invention) in reducing the amount of Salmonella, E. coli, and Listeria inoculated on the tomato slices and stored at 8°C over a 12 day storage period. This is not a normal storage condition, but it mimics potential misuse in the cold chain, which is cited in food safety storage practices as a major cause of spoilage and pathogen growth. Use of these trays helps reduce the likelihood of pathogen growth to harmful levels in sliced tomatoes.

[0137] Example 5 - Rapid burst antimicrobial gas release profile

[0138] As described in Example 4 above, trays using either 3 g or 4 g of X2597 film demonstrated significant activity in inhibiting pathogenic growth and proliferation during the test period. As discussed elsewhere in this specification, these film formulations are configured to provide a rapid burst release profile. Figure 14 Release profiles are provided for the 3 g and 4 g versions used in Example 4. Figure 14 Release profiles are also provided for trays using only 2 g of film.

[0139] As Figure 14 shown, the tray using 4 g of film (CSP4) peaked at approximately hour 18 with approximately 30 ppm of CIO2 while remaining above 10 ppm between about hours 6 and 33. The tray using 3 g of film (CSP3) peaked at approximately hour 15 with approximately 23 ppm of CIO2 while remaining above 10 ppm between about hours 6 and 33. As described in Example 4 above, these embodiments provide sufficient headspace concentration to achieve the desired microbial kill and do so without bleaching the tomatoes.

[0140] Figure 14 Release profiles are also shown for trays using 2 g of film. As shown by this profile, the peak in this embodiment occurs between hours 12 and 18 with approximately 16 ppm of CIO2. However, the profile shows that the CIO2 concentration remains above 10 ppm between about hours 8 and 26. In some cases, this concentration and release profile can provide sufficient antimicrobial effect, but in this case, the concentration is not preferred (although still within the scope of optional aspects of the disclosed concept).

[0141] The present invention provides the following embodiments:

[0142] 1. A package for inhibiting or preventing the growth of microorganisms, and / or killing microorganisms, in a closed container having a product therein, the package comprising:

[0143] a. a closed container having an interior space defined therein;

[0144] b. a product provided within the interior space;

[0145] c. a headspace formed within the volume of the interior space that is not occupied by the product; and

[0146] d. an antimicrobial releasing agent disposed within the interior space, the antimicrobial releasing agent releasing chlorine dioxide gas into the headspace by reaction of moisture with the antimicrobial releasing agent, wherein the antimicrobial releasing agent is provided in an amount to release the chlorine dioxide gas to provide a headspace concentration of from 10 parts per million (PPM) to 35 PPM for a period of 16 hours to 36 hours, optionally from 15 PPM to 30 PPM for a period of 16 hours to 36 hours, optionally from 15 PPM to 30 PPM for a period of about 24 hours.

[0147] 2. The package of embodiment 1, wherein, upon providing the product within the interior space, the product is contaminated with at least one type of pathogen, the antimicrobial releasing agent providing a controlled release of chlorine dioxide gas to achieve a reduction of at least 10 as the base log 2 in colony forming units per gram (CFU / g), optionally at least 10 as the base log 3 in CFU / g, of the at least one type of pathogen after a span of 13 days starting from providing the product within the interior space and under storage conditions of 7°C.

[0148] 3. The package of embodiment 2, wherein the at least one pathogen is selected from the group consisting of Salmonella, E. coli, Listeria, and Geotrichum.

[0149] 4. The package of any preceding embodiment, wherein the product is a food product.

[0150] 5. The package of embodiment 2 or 3, wherein the product is a food product, and the amount of antimicrobial releasing agent and / or chlorine dioxide gas is present in an amount sufficient to achieve a reduction of at least 10 as the base log 2 in CFU / g, optionally at least 10 as the base log 3 in CFU / g, of the at least one type of pathogen without causing a sensory degradation of the food product, e.g., without bleaching or otherwise discoloring the food product.

[0151] 6. The package of any preceding embodiment, wherein the product exudes moisture that reacts with the antimicrobial releasing agent to release the chlorine dioxide gas.

[0152] 7. The package of any preceding embodiment, wherein the antimicrobial releasing agent is provided in at least one entrained polymer article located within the interior space, the entrained polymer article comprising a bulk material comprising a base polymer, the antimicrobial releasing agent, and optionally a channeling agent.

[0153] 8. The package of embodiment 7, wherein the at least one entrained polymer is provided as a film having a thickness of 0.1 mm to 1.0 mm, preferably 0.2 mm to 0.6 mm, optionally about 0.3 mm.

[0154] 9. The package of any preceding embodiment, wherein the container comprises a base and one or more sidewalls extending vertically from the base to a top opening, and a cover that closes and / or seals the top opening to form the closed container.

[0155] 10. The package of embodiment 9, wherein the antimicrobial release agent is provided in at least one entrained polymer article located within the interior space, the entrained polymer article comprising a bulk material comprising a base polymer, the antimicrobial release agent, and optionally a channeling agent, wherein the at least one entrained polymer is provided as a film having a thickness of 0.1 mm to 1.0 mm, preferably 0.2 mm to 0.6 mm, optionally about 0.3 mm, the film being disposed, optionally permanently affixed, to at least one sidewall having a sidewall midline equidistant from the base and the opening, the film having a film midline equidistant from a top edge and a bottom edge of the film, wherein the film midline is at least as high as the sidewall midline.

[0156] 11. The package of any preceding embodiment, wherein the antimicrobial release agent is a powdered mixture comprising an alkali metal chlorite, preferably sodium chlorite.

[0157] 12. The package of embodiment 11, wherein the powdered mixture further comprises at least one catalyst, optionally a clay in sulfuric acid, and at least one humidity trigger, optionally calcium chloride.

[0158] 13. The package of any preceding embodiment, wherein the interior space has a volume of from 0.5 L to 10.0 L, preferably from 1.0 L to 5.0 L, optionally about 2.1 L, optionally about 4.4 L.

[0159] 14. The package of any preceding embodiment, wherein the product is sliced, diced, or cut and is a food product selected from the group consisting of tomatoes, washed peppers, washed onions, watermelons, honeydew melons, cantaloupes, strawberries, peaches, pineapples, oranges, seafood, meats, and poultry.

[0160] 15. A method for inhibiting or preventing microbial growth, and / or killing microorganisms in a closed container having a food product therein, the method comprising:

[0161] a. providing an enclosed container having an interior space defined therein;

[0162] b. providing a food product within the interior space;

[0163] c. providing a headspace formed within the volume of the interior space that is not occupied by the product; and

[0164] d. providing an antimicrobial releasing agent within the interior space that releases an antimicrobial gas into the headspace by reaction of moisture with the antimicrobial releasing agent, wherein the antimicrobial releasing agent is provided in an amount sufficient to release the antimicrobial gas to provide a desired headspace concentration of the antimicrobial gas over a predetermined amount of time;

[0165] wherein, if the product is contaminated with at least one type of pathogen upon providing the product within the interior space, the controlled release of antimicrobial gas by the antimicrobial releasing agent achieves a reduction of at least 10 as the base log 2 in CFU / g, optionally a reduction of at least 10 as the base log 3 in CFU / g of the at least one type of pathogen after a span of 13 days at storage conditions of 7°C.

[0166] 16. The method of embodiment 15, wherein the controlled release of antimicrobial gas achieves the reduction without causing a sensory degradation of the food product, e.g., without bleaching or otherwise discoloring the food product.

[0167] 17. The method of embodiment 15 or 16, wherein the antimicrobial gas is chlorine dioxide.

[0168] 18. The method of embodiment 17, wherein the antimicrobial releasing agent is a powdered mixture comprising a basic chlorite salt, preferably sodium chlorite or potassium chlorite.

[0169] 19. The method of embodiment 18, wherein the powdered mixture further comprises at least one catalyst, optionally a sulfuric acid clay, and at least one humidity trigger, optionally calcium chloride.

[0170] 20. The method of any one of embodiments 17 to 19, wherein the antimicrobial releasing agent releases chlorine dioxide gas into the headspace by reaction of moisture with the antimicrobial releasing agent, wherein the antimicrobial releasing agent is provided in an amount sufficient to release the chlorine dioxide gas to provide a headspace concentration of from 10 parts per million (PPM) to 35 PPM for a period of time of from 16 hours to 36 hours, optionally from 15 PPM to 30 PPM for a period of time of from 16 hours to 36 hours, optionally from 15 PPM to 30 PPM for a period of time of about 24 hours.

[0171] 21. The method of embodiment 20, wherein the food product is sliced, diced, or chopped and is a food product selected from the group consisting of tomatoes, washed peppers, washed onions, watermelon, honey dew, cantaloupe, strawberries, peaches, pineapples, oranges, seafood, meat, and poultry.

[0172] 22. The method of any one of embodiments 17 to 20, wherein the antimicrobial releasing agent releases chlorine dioxide gas into the headspace by reaction of moisture with the antimicrobial releasing agent, wherein the antimicrobial releasing agent is provided in an amount sufficient to release the chlorine dioxide gas to provide a headspace concentration of from 8 PPM to 15 PPM for a period of time of 13 days.

[0173] 23. The method of embodiment 22, wherein the food product is a whole or minimally processed product selected from the group consisting of broccoli, Brussels sprouts, cabbage, cucumbers, bananas, herbs, whole peppers, carrots, root vegetables, and potatoes.

[0174] 24. The method of any one of embodiments 15 to 23, wherein the at least one pathogen is selected from the group consisting of Salmonella, Escherichia coli, Listeria, and Geotrichum.

[0175] 25. The method of any one of embodiments 15 to 24, wherein the antimicrobial releasing agent is provided in at least one entrained polymer article positioned within the interior space, the entrained polymer article comprising a unitary material comprising a base polymer, the antimicrobial releasing agent, and optionally a channeling agent.

[0176] 26. The method of embodiment 25, wherein the at least one entrained polymer is provided as a film having a thickness of from 0.1 mm to 1.0 mm, preferably from 0.2 mm to 0.6 mm, optionally about 0.3 mm.

[0177] 27. A package for inhibiting or preventing the growth of microorganisms, and / or killing microorganisms, in a closed container having a product therein, the package comprising:

[0178] a container comprising:

[0179] a base;

[0180] a top opening;

[0181] one or more side walls extending from the base to the top opening in a vertical direction;

[0182] an interior space formed by the one or more side walls;

[0183] a headspace formed by the interior space that is not occupied by the product; and a cover for closing and / or sealing the container;

[0184] at least one entrained polymeric article comprising a bulk material located within the interior space, the bulk material comprising:

[0185] a base polymer; and

[0186] an antimicrobial release agent capable of releasing a released antimicrobial gas; and

[0187] a selected material present in the interior space for activating the release of the released antimicrobial gas.

[0188] 28. The package of embodiment 27, wherein the bulk material comprises a pore former.

[0189] 29. The package of embodiment 25 or 28, wherein the antimicrobial release agent releases chlorine dioxide gas, and wherein the selected material is moisture.

[0190] 30. The package of any one of embodiments 27 to 29, wherein the at least one entrained polymeric article is a film having a thickness optionally from 0.1 mm to 1.0 mm, preferably from 0.2 mm to 0.6 mm, optionally about 0.3 mm, the film being disposed, optionally permanently affixed to, at least one side wall having a side wall midline equidistant from the base and the opening, the film having a film midline equidistant from the top and bottom edges of the film, wherein the film midline is at least as high as the side wall midline.

[0191] 31. Use of the package of any of embodiments 1 or 27-30 for storing a food product, wherein the food product exudes moisture to activate the antimicrobial release agent to release chlorine dioxide gas into the headspace.

[0192] 32. The use of embodiment 31, wherein the antimicrobial release agent is provided in an amount sufficient to release the chlorine dioxide gas to provide a headspace concentration of from 10 parts per million (PPM) to 35 PPM for a period of 16 hours to 36 hours, optionally from 15 PPM to 30 PPM for a period of 16 hours to 36 hours, optionally from 15 PPM to 30 PPM for a period of about 24 hours.

[0193] 33. The use of embodiment 31 or 32, wherein the product is contaminated with at least one type of pathogen when the food product is provided within the interior space, the antimicrobial release agent providing a controlled release of chlorine dioxide gas to achieve a reduction of at least 10 base log 2 in colony forming units per gram (CFU / g), optionally a reduction of at least 10 base log 3 in CFU / g, of the at least one type of pathogen after a span of 13 days from providing the product within the interior space and under storage conditions of 7°C.

[0194] 34. The use of embodiment 33, wherein the controlled release of chlorine dioxide gas achieves the reduction without causing a sensory degradation of the food product, e.g., without bleaching or otherwise discoloring the food product.

[0195] 35. The use of embodiment 33 or 34, wherein the at least one pathogen is selected from the group consisting of Salmonella, E. coli, Listeria, and Geotrichum.

[0196] While the application has been described in detail with reference to particular examples thereof, it should be understood that various changes can be made and equivalents can be substituted for elements thereof without departing from the spirit and scope of the application.

Claims

1. A packaging material for inhibiting or preventing the growth of microorganisms and / or killing microorganisms in a closed container in which a product is placed, said packaging material comprising: a. A closed container defining its internal space, the closed container comprising: Base, One or more sidewalls extending vertically from the base to the top opening, and A cover that closes and / or seals the top opening to form the closed container; b. Products provided within the said internal space; c. A top space formed within the volume of the internal space that is not occupied by the product; and d. A three-phase entrained polymer integral article located within the internal space, the three-phase entrained polymer integral article comprising: The base polymers selected from the group consisting of: polypropylene, polyethylene, polyisoprene, polybutadiene, polybutene, polysiloxane, polycarbonate, polyamide, ethylene-vinyl acetate copolymer, ethylene-methacrylate copolymer, poly(vinyl chloride), polystyrene, polyester, polyanhydride, polyacrylonitrile, polysulfone, polyacrylate, polyurethane, polyacetal, or copolymers or mixtures thereof. An antimicrobial release agent, comprising an alkali metal chlorite, is disposed within the interior space. The antimicrobial release agent releases chlorine dioxide gas into the overhead space through a reaction between moisture and the antimicrobial release agent. A pore-forming agent for forming channels in the three-phase entrained polymer monolithic article, wherein the pore-forming agent is selected from the group consisting of: polyethylene glycol (PEG), ethylene-vinyl alcohol (EVOH), polyvinyl alcohol (PVOH), glycerol polyamine, polyurethane, polycarboxylic acid, propylene oxide polymer-monobutyl ether, propylene oxide polymer, ethylene vinyl acetate, nylon 6, nylon 66, or mixtures thereof. The at least one triphase encased polymer monolithic article is placed on at least one of the one or more sidewalls within the interior space, above the centerline of the at least one sidewall located at the center between the substrate and the top opening, and / or the at least one triphase encased polymer monolithic article is placed on the cover.

2. The packaging as claimed in claim 1, wherein the antimicrobial release agent is provided in an amount to release the chlorine dioxide gas to provide a headspace concentration of 10 parts per million (PPM) to 35 PPM for a period of 16 to 36 hours.

3. The packaging of claim 1, wherein when the product is provided in the internal space, the product is contaminated with at least one type of pathogen, and the antimicrobial release agent provides controlled release of chlorine dioxide gas to achieve a reduction of at least log2, base 10, of the colony-forming units (CFU / g) of the at least one type of pathogen after a 13-day span starting from when the product is provided in the internal space and stored at 7°C.

4. The packaging as claimed in claim 2, wherein the at least one pathogen is selected from the group consisting of: Salmonella, Escherichia coli, Listeria, and Geotrichum.

5. The packaging as claimed in any of the preceding claims, wherein the product is food.

6. The packaging as claimed in claim 3 or claim 4, wherein the product is food, and the amount of the antimicrobial release agent and / or chlorine dioxide gas is sufficient to achieve a reduction of at least 10 log 2 in CFU / g of the at least one type of pathogen without causing sensory degradation of the food.

7. The packaging as claimed in any of the preceding claims, wherein the product exudes moisture to react with the antimicrobial release agent, thereby releasing the chlorine dioxide gas.

8. The packaging as claimed in claim 7, wherein the at least one triphase encapsulated polymer integral article is provided as a film with a thickness of 0.1 mm to 1.0 mm.

9. The packaging of claim 8, wherein the film is disposed on or permanently attached to at least one sidewall, the at least one sidewall having a sidewall centerline equidistant from the base and the opening, the film having a film centerline equidistant from the top edge and the bottom edge of the film, wherein the film centerline is at least as high as the sidewall centerline.

10. The packaging as claimed in any of the preceding claims, wherein the antimicrobial release agent is a powdered mixture comprising an alkali metal chlorite, at least one catalyst and at least one humidity trigger.

11. The packaging as claimed in claim 10, wherein the alkali metal chlorite is sodium chlorite or potassium chlorite, the catalyst is sulfuric acid clay, and the humidity trigger is calcium chloride.

12. The packaging as claimed in any of the preceding claims, wherein the internal space has a volume of 0.5 L to 10.0 L.

13. The packaging as claimed in any of the preceding claims, wherein the three-phase entrained polymer monolithic article is coated with a polymer liner configured to control moisture absorbed into the three-phase entrained polymer monolithic article.

14. The packaging as claimed in claim 1, wherein the base polymer is polypropylene, polyethylene, polyisoprene, polybutadiene, polybutene, ethylene-vinyl acetate copolymer, ethylene-methacrylate copolymer, poly(vinyl chloride), polystyrene, or copolymers or mixtures thereof.

15. The packaging as claimed in claim 1, wherein the pore-forming agent is polyethylene glycol (PEG), ethylene-vinyl alcohol (EVOH), polyvinyl alcohol (PVOH), or a mixture thereof.

16. The use of the packaging material as claimed in any of the preceding claims for inhibiting or preventing the growth of microorganisms and / or killing microorganisms in packaging in which food is provided.

17. A method for inhibiting or preventing the growth of microorganisms and / or killing microorganisms in closed packaging, the method comprising providing food in the packaging of claim 1.

18. A method for inhibiting or preventing the growth of microorganisms and / or killing microorganisms in a closed container in which food is placed, the method comprising: a. Providing an enclosed container defining an internal space, the enclosed container comprising: Base, One or more sidewalls extending vertically from the base to the top opening, and A cover that closes and / or seals the top opening to form the closed container; b. To provide food within the interior space; c. Providing a top space within the volume of the internal space that is not occupied by the food; and d. An antimicrobial release agent comprising an alkali metal chlorite is provided within the interior space, the antimicrobial release agent releasing antimicrobial gas into the headspace by reacting with water, wherein the antimicrobial release agent is provided in an amount sufficient to release the antimicrobial gas to provide a desired headspace concentration of the antimicrobial gas over a predetermined time period; The antimicrobial release agent is provided in at least one triphase entrained polymer monolithic article located within the internal space, the at least one triphase entrained polymer monolithic article comprising: The base polymers selected from the group consisting of: polypropylene, polyethylene, polyisoprene, polybutadiene, polybutene, polysiloxane, polycarbonate, polyamide, ethylene-vinyl acetate copolymer, ethylene-methacrylate copolymer, poly(vinyl chloride), polystyrene, polyester, polyanhydride, polyacrylonitrile, polysulfone, polyacrylate, polyurethane, polyacetal, or copolymers or mixtures thereof. The antimicrobial release agent; and A pore-forming agent for forming channels in the three-phase entrained polymer monolithic article, wherein the pore-forming agent is selected from the group consisting of: polyethylene glycol (PEG), ethylene-vinyl alcohol (EVOH), polyvinyl alcohol (PVOH), glycerol polyamine, polyurethane, polycarboxylic acid, propylene oxide polymer-monobutyl ether, propylene oxide polymer, ethylene vinyl acetate, nylon 6, nylon 66, or combinations thereof. The at least one triphase encased polymer monolithic article is placed on at least one of the one or more sidewalls within the interior space, above the centerline of the at least one sidewall located at the center between the substrate and the top opening, and / or the at least one triphase encased polymer monolithic article is placed on the cover, and If the food is contaminated with at least one type of pathogen when it is provided in the interior space, the antimicrobial release agent provides a controlled release of chlorine dioxide gas to achieve a reduction of at least log2 to base 10 in the colony-forming units (CFU / g) of the at least one type of pathogen after a 13-day span starting from when the food is provided in the interior space and stored at 7°C.

19. The method of claim 18, wherein the controlled release of the antimicrobial gas achieves the reduction without causing sensory degradation of the food.

20. The method of claim 18, wherein the antimicrobial gas is chlorine dioxide.

21. The method of claim 20, wherein the antimicrobial release agent is a powdered mixture comprising alkaline chlorite, a catalyst, and a humidity trigger.

22. The method of claim 21, wherein the alkali metal chlorite is sodium chlorite or potassium chlorite, the catalyst is sulfuric acid clay, and the humidity trigger is calcium chloride.

23. The method of claim 18, wherein the antimicrobial release agent releases chlorine dioxide gas into the headspace through a reaction of water with the antimicrobial release agent, wherein the antimicrobial release agent is provided in an amount sufficient to release chlorine dioxide gas to provide a headspace concentration of from 10 parts per million (PPM) to 35 PPM for a period of 16 to 36 hours.

24. The method of claim 18, wherein the food is sliced, diced, or cut and is selected from the group consisting of: tomatoes, washed peppers, washed onions, watermelon, honeydew melon, cantaloupe, strawberries, peaches, pineapples, oranges, seafood, meat, and poultry, or wherein the food is a wholly or minimally processed product selected from the group consisting of: broccoli, Brussels sprouts, cabbage, cucumber, banana, herbs, whole peppers, carrots, root vegetables, and potatoes.

25. The method of claim 18, wherein the antimicrobial release agent releases chlorine dioxide gas into the headspace through a reaction of water with the antimicrobial release agent, wherein the antimicrobial release agent is provided in an amount sufficient to release the chlorine dioxide gas to provide a headspace concentration of 8 PPM to 15 PPM for a period of 13 days.

26. The method of claim 18, wherein the at least one pathogen is selected from the group consisting of Salmonella, Escherichia coli, Listeria, and Geotrichum.

27. The method of claim 18, wherein the base polymer is polypropylene, polyethylene, polyisoprene, polybutadiene, polybutene, ethylene-vinyl acetate copolymer, ethylene-methacrylate copolymer, poly(vinyl chloride), polystyrene, or copolymers or mixtures thereof.

28. The method of claim 18, wherein the pore-forming agent is polyethylene glycol (PEG), ethylene-vinyl alcohol (EVOH), polyvinyl alcohol (PVOH), or a mixture thereof.

29. The method of claim 18, wherein the at least one three-phase entrained polymer monolithic article is provided as a film with a thickness of 0.1 mm to 1.0 mm.

30. The method of claim 18, wherein the food exudes moisture to activate the antimicrobial release agent, thereby releasing chlorine dioxide gas into the headspace.

31. The method of claim 18, wherein when the food is provided in the interior space, the food is contaminated with at least one type of pathogen, and the antimicrobial release agent provides controlled release of chlorine dioxide gas to achieve a reduction of at least log2, base 10, of the colony-forming units (CFU / g) of the at least one type of pathogen after a 13-day span starting from when the food is provided in the interior space and stored at 7°C.

32. The packaging of claim 1, wherein the at least one triphase encapsulated polymer integral article is placed on at least one of the one or more sidewalls at a height of at least 67% of the total height of the at least one sidewall as measured from the substrate.

33. The packaging of claim 1, wherein the at least one triphase encapsulated polymer integral article is placed on at least one of the one or more sidewalls at a height of at least 75% of the total height of the at least one sidewall as measured from the substrate.

34. The packaging of claim 1, wherein the at least one triphase encapsulated polymer integral article is placed on at least one of the one or more sidewalls at a height of at least about 80% of the total height of the at least one sidewall as measured from the substrate.

35. The method of claim 18, wherein the at least one triphase encapsulated polymer integral article is placed on at least one of the one or more sidewalls at a height of at least 67% of the total height of the at least one sidewall as measured from the substrate.

36. The method of claim 18, wherein the at least one triphase encapsulated polymer integral article is placed on at least one of the one or more sidewalls at a height of at least 75% of the total height of the at least one sidewall as measured from the substrate.

37. The method of claim 1, wherein the at least one triphase encapsulated polymer integral article is placed on at least one of the one or more sidewalls at a height of at least about 80% of the total height of the at least one sidewall as measured from the substrate.

38. A packaging material for inhibiting or preventing the growth of microorganisms and / or killing microorganisms in a closed container in which a product is placed, said packaging material comprising: a. A closed container that defines the internal space; b. Products provided within the said internal space; c. The top space formed within the volume of the internal space that is not occupied by the product; as well as d. A three-phase entrained polymer integral article located within the internal space, the three-phase entrained polymer integral article comprising: The base polymers selected from the group consisting of: polypropylene, polyethylene, polyisoprene, polybutadiene, polybutene, polysiloxane, polycarbonate, polyamide, ethylene-vinyl acetate copolymer, ethylene-methacrylate copolymer, poly(vinyl chloride), polystyrene, polyester, polyanhydride, polyacrylonitrile, polysulfone, polyacrylate, polyurethane, polyacetal, or copolymers or mixtures thereof. An antimicrobial release agent, comprising an alkali metal chlorite, is disposed within the interior space. The antimicrobial release agent releases chlorine dioxide gas into the overhead space through a reaction between moisture and the antimicrobial release agent. A pore-forming agent for forming channels in the three-phase entrained polymer monolithic article, wherein the pore-forming agent is selected from the group consisting of: polyethylene glycol (PEG), ethylene-vinyl alcohol (EVOH), polyvinyl alcohol (PVOH), glycerol polyamine, polyurethane, polycarboxylic acid, propylene oxide polymer-monobutyl ether, propylene oxide polymer, ethylene vinyl acetate, nylon 6, nylon 66, or mixtures thereof. The at least one triphase encapsulated polymer monolithic article is not placed below the product in the closed container.

39. A method for inhibiting or preventing the growth of microorganisms and / or killing microorganisms in a closed container in which food is placed, the method comprising: a. Provide a closed container that defines the internal space; b. To provide food within the interior space; c. Providing a top space within the volume of the internal space that is not occupied by the food; and d. An antimicrobial release agent comprising an alkali metal chlorite is provided within the interior space, the antimicrobial release agent releasing antimicrobial gas into the headspace by reacting with water, wherein the antimicrobial release agent is provided in an amount sufficient to release the antimicrobial gas to provide a desired headspace concentration of the antimicrobial gas over a predetermined time period; The antimicrobial release agent is provided in at least one three-phase entrained polymer monolithic article located within the internal space, the three-phase entrained polymer monolithic article comprising: The base polymers selected from the group consisting of: polypropylene, polyethylene, polyisoprene, polybutadiene, polybutene, polysiloxane, polycarbonate, polyamide, ethylene-vinyl acetate copolymer, ethylene-methacrylate copolymer, poly(vinyl chloride), polystyrene, polyester, polyanhydride, polyacrylonitrile, polysulfone, polyacrylate, polyurethane, polyacetal, or copolymers or mixtures thereof. The antimicrobial release agent; and A pore-forming agent for forming channels in the three-phase entrained polymer monolithic article, wherein the pore-forming agent is selected from the group consisting of: polyethylene glycol (PEG), ethylene-vinyl alcohol (EVOH), polyvinyl alcohol (PVOH), glycerol polyamine, polyurethane, polycarboxylic acid, propylene oxide polymer-monobutyl ether, propylene oxide polymer, ethylene vinyl acetate, nylon 6, nylon 66, or combinations thereof. The at least one triphase encased polymer monolithic article is placed on at least one of the one or more sidewalls within the interior space, above the centerline of the at least one sidewall located at the center between the substrate and the top opening, and / or the at least one triphase encased polymer monolithic article is placed on the cover. The at least one triphase encapsulated polymer integral article is not placed below the product in the closed container, and If the food is contaminated with at least one type of pathogen when it is provided in the interior space, the antimicrobial release agent provides a controlled release of chlorine dioxide gas to achieve a reduction of at least log2 to base 10 in the colony-forming units (CFU / g) of the at least one type of pathogen after a 13-day span starting from when the food is provided in the interior space and stored at 7°C.

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