EA040718B1 - ANTIMICROBIAL GAS RELEASE AGENTS AND SYSTEMS AND METHODS OF THEIR APPLICATION - Google Patents

Description

Cross-reference to related applications

This application claims priority under 35 U.S.C. §119(e) provisional patent application

US No. 62/421348 entitled ENTRAINED POLYMERS WITH ANTIMICROBIAL RELEASING

AGENTS, filed November 13, 2016, the contents of which are hereby incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION Technical field to which the invention relates

The present invention relates to systems and methods for reducing and preventing the growth of microbes or killing microbes in the interior of a container and/or on the product/merchandise that is stored in the package. More specifically, the present invention relates to systems and methods for reducing and preventing the growth of microbes, or killing microbes, for example, in food containers, using polymers with entrapped antimicrobial release agents.

Description of the Prior Art

There are many objects that are preferably stored, transported and/or used in a controlled and/or regulated environment. For example, in the field of moisture control, containers and/or packages having the ability to absorb excess moisture trapped within have been found desirable. Similarly, when packaging products that have a risk of contamination, such as food, it may be desirable to control the growth and reproduction of microbes.

Foodstuffs, in particular sliced or chunked foodstuffs such as meat, poultry, fruits and vegetables, are typically stored and sold in an auxiliary container such as a tray wrapped in a transparent plastic film to allow the food to be inspected. These foodstuffs typically release liquids (i.e., juices) that can be a source of growth for microbial agents. In addition, contamination of processing equipment or other food contact surfaces may remain on the food and microbes may multiply inside the packaging. Similarly, food products may be contaminated even before the packaging process. For example, the skin of a tomato may have a hole through which unwanted microorganisms enter and multiply. An interruption in food processing and/or cold chain management (e.g. interruptions in refrigeration for several hours during food transport) can encourage microbial growth on contaminated food, potentially leading to a foodborne disease outbreak. Regardless of the source or nature of microbial contamination of food, the shelf life and safety of contaminated food is affected by contamination and microbial growth.

One method used in the food industry to preserve food is to add food preservatives as a food ingredient, such as potassium sorbate, benzoate, and sodium nitrite. However, some health officials and consumers consider such preservatives to be unnatural and a health hazard. In addition, it is impractical to use such preservatives with unprocessed foods such as fresh fruits or vegetables.

Another method used in the food industry to preserve food is to use antimicrobial agents that come into direct contact with food as a component of the packaging material. However, in some applications, such direct contact may be undesirable.

For certain applications, it is desirable to provide antimicrobial agents to release an antimicrobial gas into the headspace of a product in a package or food container to control microbial growth, compared to a solid or liquid component requiring direct contact with the stored food to be effective. However, there are difficulties associated with the provision of antimicrobial gas in the headspace of the product. One such difficulty is obtaining the desired release profile of the antimicrobial gas within the headspace over the intended time period. Failure to achieve a suitable release profile for a given product may result in failure to achieve the desired shelf life for that product. Thus, there is a need for improved delivery of antimicrobial agents to control, reduce, and substantially eliminate microbial contamination in food packaging, as well as other applications such as, but not limited to, packaging of sterile disposable medical devices. The difficulty associated with this need is to maintain a balance between providing enough antimicrobial gas in the headspace of the product inside the package to effectively control and/or kill pathogens, while at the same time avoiding an overdose in the headspace of the product inside the package, which may adversely affect the quality of the product, for example lead to a deterioration in organoleptic properties.

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Brief description of the invention

Accordingly, in one aspect, the present invention provides a system for inhibiting or preventing the growth of microbes and/or for killing microbes in a closed container in which a product is located. The system contains a container containing a bottom surface, an upper opening, one or more side walls extending in the vertical direction from the bottom surface to the top opening, an internal space formed by one or more side walls, a free space above the product formed by an internal space that is not occupied goods, and a lid for closing and/or sealing the container. The system also contains at least one product made of a polymer with inclusions located in the internal space, which contains a monolithic material containing a base polymer, and an antimicrobial releasing agent configured to release the released antimicrobial gas. The system further comprises a selected material present in the internal space to initiate the release of the released antimicrobial gas.

In another aspect, the present invention provides a method for inhibiting or preventing the growth of microbes and/or killing microbes in a closed container in which a product is located. The method includes forming at least one product from a polymer with inclusions, which includes obtaining a base polymer, and combining an antimicrobial releasing agent with a base polymer to form a monolithic material, wherein the antimicrobial releasing agent is configured to release the released antimicrobial material in gaseous form upon activation by the selected material . The method also includes obtaining a container that contains a bottom surface, an upper opening, one or more side walls extending in a vertical direction from the bottom surface to the top opening, an internal space formed by one or more side walls, a free space above the product formed by an internal space, which is not occupied by the goods, and a lid for closing and/or sealing the container. The method further includes placing at least one article of polymer with inclusions in the interior of the container; placing goods in a container; closing the container; providing the selected material in the interior of the container; and releasing the released antimicrobial material into the interior at a concentration effective to reduce or prevent the growth of microbes and/or to kill microbes present in and/or on the product.

In another aspect, a package is provided for suppressing or preventing the growth of microbes and/or for killing microbes in a closed container in which the product is located. The package contains a closed container, limiting the internal space within itself. A product (optionally a food product) is provided in an interior space. The free space above the product is formed within the volume of the internal space that is not occupied by the product. The antimicrobial releasing agent is located in the interior, wherein the antimicrobial releasing agent releases chlorine dioxide gas into the headspace by reacting moisture with the antimicrobial releasing agent. The antimicrobial releasing agent is provided in an amount that releases chlorine dioxide gas to provide a headspace concentration of 10 to 35 parts per million (PPM) over a period of 16 to 36 hours, optionally 15 to 30 PPM over a period of 16 to 36 hours , optionally 15 to 30 PPM over a period of approximately 24 hours.

Optionally, in any embodiment, when the product is provided in the interior, the product is contaminated with at least one type of pathogen. The antimicrobial releasing agent provides a controlled release of gaseous chlorine dioxide to achieve, after 13 days from the date of placement of the product in the internal space and at a storage temperature of 7 ° C, at least 2 orders of magnitude reduction in colony forming units per gram (CFU / g), optionally, at least 3 orders of magnitude CFU/g reduction in at least one pathogen type; optionally, at least 4 orders of magnitude CFU/g reduction in at least one pathogen type. Optionally, at least one pathogen is Salmonella, E. coli, Listeria and/or Geotrichum.

Optionally, if the product is a food product and the antimicrobial releasing agent and/or chlorine dioxide gas is present in an amount sufficient to effect at least a 2 orders of magnitude reduction in CFU/g, (or at least a 3 orders of magnitude reduction or reduction by 4 orders of magnitude CFU/g), at least one type of pathogen, such efficiency is not achieved due to the deterioration of the organoleptic properties of the food product. For example, the food product does not lighten or otherwise discolor.

Optionally, in any embodiment, the antimicrobial releasing agent is provided in at least one inclusion polymer article located in the interior. The inclusion polymer article is a monolithic material that contains a base polymer, an antimicrobial release agent, and optionally a channeling agent. Preferably such an inclusion polymer is provided in the form

- 2 040718 films with a thickness of 0.1 to 1.0 mm, preferably 0.2 to 0.6 mm, optionally approximately 0.3 mm. Preferably, such a film is provided above the midline (preferably at least 2/3 or 3/4) of the sidewalls of the container, which helps the present inventors to achieve the desired antimicrobial gas release profile.

Optionally, in any embodiment, the antimicrobial releasing agent is a powder mixture containing an alkali metal chlorite, preferably sodium chlorite. Optionally, the powder mixture further comprises at least one catalyst, optionally sulphate clay, and at least one moisture-responsive activator, optionally calcium chloride.

Optionally, in any embodiment, a method is provided for inhibiting or preventing the growth of microbes and/or killing microbes in a closed container in which a food product is located. The method includes providing a closed container that defines an internal space within itself, and a food product in the internal space. The free space above the product is formed within the volume of the internal space that is not occupied by the product. An antimicrobial releasing agent (such as disclosed in this Summary of the Invention and in any other part of this technical specification) is provided in the interior. This agent releases the antimicrobial gas into the headspace by reacting the moisture with the antimicrobial release agent. The antimicrobial releasing agent is provided in an amount sufficient to release the antimicrobial gas to provide the desired headspace concentration of the antimicrobial gas over the product over a predetermined period of time. According to this method, if the product is contaminated with at least one type of pathogen while the product is provided in the interior, the antimicrobial releasing agent does not necessarily provide a controlled release of the antimicrobial gas to effect, after 13 days at a storage temperature of 7°C, at least , a reduction of 2 orders of magnitude CFU/g, optionally at least a reduction of 3 orders of magnitude of CFU/g, optionally of at least 4 orders of magnitude of CFU/g, of at least one type of pathogen. Preferably, this method accomplishes the reduction without causing deterioration in the organoleptic properties of the food product, for example without causing clarification or otherwise causing discoloration of the food product. Preferably, the antimicrobial release agent is provided in an inclusion polymer film, for example, as described herein.

Optionally, in any packaging embodiment described herein, one aspect of the present invention may include the use of packaging to store a food product, wherein the food product releases moisture that activates the antimicrobial release agent to release chlorine dioxide gas into the headspace of the product. This application can provide the desired headspace concentrations of the antimicrobial gas as described herein. This application can carry out, after 13 days from the date of placement of the product in the internal space and at a storage temperature of 7 ° C, at least a reduction of 2 orders of colony forming units per gram (CFU / g), optionally, at least a reduction by 3 orders of magnitude CFU/g, optionally at least 4 orders of magnitude of CFU/g, of at least one type of pathogen. This is preferably done without causing deterioration in the organoleptic properties of the food product, for example without causing clarification or otherwise causing discoloration of the food product.

Brief description of graphic materials

The present invention will be described in conjunction with the following drawings, in which like reference numerals denote like elements, and in which:

in fig. 1 is a perspective view of a plug formed from an inclusion polymer according to an optional embodiment of the present invention;

in fig. 2 shows a cross section taken along the line 2-2 of FIG. 1;

in fig. 3 shows a cross section similar to that shown in FIG. 2 depicting a plug formed from another embodiment of an inclusion polymer according to an optional embodiment of the present invention;

in fig. 4 shows a schematic representation of an inclusion polymer according to an optional embodiment of the present invention, wherein the active agent is an antimicrobial gas releasing material that is activated by contact with a selected material (eg, moisture);

in fig. 5 is a cross-sectional view of a sheet or film formed from an inclusion polymer according to an optional embodiment of the present invention adhered to a barrier sheet substrate;

in fig. 6 shows a cross section of a package that can be formed using an inclusion polymer according to an optional embodiment of the present invention;

- 3 040718 in FIG. 7 is a perspective view of an exemplary package containing films of polymer with inclusions according to an optional aspect of the present invention;

in fig. 8A and 8B are graphs comparing the growth of Geotrichum on contaminated tomatoes stored in packages using and not using an antimicrobial inclusion polymer film, respectively;

in fig. 9 is a graph depicting the measured amount of C1O2 (chlorine dioxide) in the headspace of product in a container containing an inclusion polymer film, in accordance with some embodiments of the present invention;

in fig. 10 is a graph depicting the measured amount of C1O2 in the headspace of a container containing an inclusion polymer film located at various heights on the side wall, in accordance with some embodiments of the present invention;

in fig. 11 is a graph illustrating the logarithmic reduction in CFU/gram Salmonella for a food product stored in containers containing an inclusion polymer film, in some embodiments, compared to containers without an inclusion polymer film;

in fig. 12 is a graph depicting the logarithmic reduction in CFU/gram E. coli for a food product stored in containers containing an inclusion polymer film, according to some embodiments, compared to containers without an inclusion polymer film;

in fig. 13 is a graph depicting the logarithmic reduction in cfu/gram Listeria for a food product stored in containers containing an inclusion polymer film, according to some embodiments, compared to containers without an inclusion polymer film;

in fig. 14 is a graph depicting the measured amount of C1O2 present in the headspace of the product in the container versus the amount of film of antimicrobial polymer with inclusions present in the container.

Detailed Description of the Preferred Embodiments

Definitions.

As used herein, the term active is defined as being capable of acting, interacting, or reacting with a selected material (eg, moisture or oxygen) according to the present invention. Examples of such actions or interactions may include absorption, adsorption or release of the selected material. Another example of an active, corresponding to the main scope of the present invention, is an agent capable of acting, interacting or reacting with a selected material in order to initiate the release of the released material.

As used herein, the term active agent is defined as a material that (1) preferably is incapable of miscibility with the base polymer, and when mixed and heated with the base polymer and channeling agent, will not melt, i. has a melting point that is above the melting point of both the base polymer and the channeling agent, and (2) acts, interacts or reacts with the selected material. The term active agent may include, but is not limited to, materials that absorb, adsorb, or release the selected material(s). Mainstream active agents in this datasheet are those that release antimicrobial gas(s), preferably chlorine dioxide gas.

The term antimicrobial releasing agent refers to an active agent capable of releasing a releasable antimicrobial material, eg in gaseous form. This active agent may contain in the composition (for example, a powder mixture) an active ingredient and other components (such as a catalyst and an activator) configured to release an antimicrobial gas. The released antimicrobial material is a compound that inhibits or prevents the growth and reproduction of microbes and/or kills microbes, such as chlorine dioxide gas. The released antimicrobial material is released by the antimicrobial releasing agent. By way of example only, an antimicrobial releasing agent can be activated (eg, by a chemical reaction or change in physical properties) through contact with a selected material (such as moisture). For example, moisture may react with the antimicrobial releasing agent in order to initiate release of the releasable antimicrobial material by the agent.

As used herein, the term base polymer is a polymer optionally having a gas permeation rate of the selected material that is substantially lower, lower, or substantially equal to that of the channeling agent. As an example, such a penetration rate is the water vapor penetration rate in embodiments where

- 4 040718 the selected material is moisture and the active agent is a moisture-activated antimicrobial gas release agent. This active agent may contain an active ingredient and other components configured to release an antimicrobial gas. The primary function of the base polymer is to provide the polymer structure with inclusions.

Suitable base polymers for use in the present invention include thermoplastic polymers, such as polyolefins such as polypropylene and polyethylene, polyisoprene, polybutadiene, polybutene, polysiloxane, polycarbonates, polyamides, ethylene-vinyl acetate copolymers, ethylene-methacrylate copolymer, polyvinyl chloride, polystyrene, compound polyesters, polyanhydrides, polyacrylonitrile, polysulfones, polyacrylate, acrylic, polyurethane and polyacetal, or their copolymers or mixtures.

In some embodiments, the channeling agent has a water vapor penetration rate at least twice that of the base polymer. In other embodiments, the channel-forming means has a water vapor permeation rate at least five times that of the base polymer. In other embodiments, the channel-forming means has a water vapor permeation rate at least ten times that of the base polymer. In other embodiments, the channel-forming means has a water vapor permeation rate at least twenty times that of the base polymer. In yet another embodiment, the channeling means has a water vapor penetration rate at least fifty times higher than that of the base polymer. In other embodiments, the channel-forming means has a water vapor permeation rate at least one hundred times higher than that of the base polymer.

As used herein, the term channeling agent or channeling agents is defined as a material that is incapable of miscibility with a base polymer and has an affinity for transporting a gas phase material at a higher rate than the base polymer. Optionally, the channeling agent is capable of channeling through the inclusion polymer upon formation by mixing the channeling agent with the base polymer. Optionally, such channels are capable of conveying the selected material through the inclusion polymer at a higher rate than in the base polymer alone.

As used herein, the term channels or communicating channels is defined as passages formed from a channeling agent that penetrate the base polymer and can be connected to each other.

As used herein, the term inclusion polymer is defined as a monolithic material formed from at least a base polymer with the active agent, and optionally also the channeling agent, trapped or distributed throughout. Thus, the inclusion polymer contains two-phase polymers (without channeling agent) and three-phase polymers (with channeling agent).

As used herein, the term monolithic, monolithic structure, or monolithic composition is defined as a composition or material that does not consist of two or more discrete macroscopic layers or parts. Accordingly, the monolithic composition does not include a multilayer composite.

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 give the structure or composition its monolithic characteristics.

As used herein, the term selected material is defined as a material that is acted upon, affected by, or interacts with or reacts with an active agent and is capable of being transmitted through the channels of the polymer with inclusions. For example, in embodiments where the release material is an active agent, the selected material may be moisture that reacts with or otherwise activates the active agent to release the release material, such as an antimicrobial gas.

Used in this document, the term three-phase is defined as a monolithic composition or structure containing three or more phases. An example of a three-phase composition according to the present invention is an inclusion polymer formed from a base polymer, an active agent and a channeling agent. Optionally, a three-phase composition or structure may contain an additional phase, such as a dye, but is still considered three-phase due to the presence of three main functional components.

In addition, the terms package, container, and container may be used interchangeably herein to refer to an object that holds or contains a product, such as a food product and foodstuffs. Optionally, the package may contain a container in which the product is stored. Non-limiting examples of packaging, containers, and containers include tray, box, carton, bottle holder, receptacle, bag, and pouch. The bag or soft bag can be made from, for example, polypropylene or polyethylene. The package or container may be closed, covered, and/or sealed by a variety of mechanisms including, for example, a wrapper, lid, sealant, adhesive, and heat seal. The package or container is composed or constructed from a variety of materials such as plastic (eg polypropylene or polyethylene), paper, styrofoam, glass, metal, and combinations thereof. In one optional embodiment, the package or container is composed of a rigid or semi-rigid polymer, optionally polypropylene or polyethylene, and preferably has sufficient rigidity to retain its shape under gravity.

Illustrative polymers with inclusions.

Traditionally, desiccants, oxygen scavengers, and other active agents are used in their raw form, such as loose particles placed in sachets or boxes, to control the internal environment of the package. For many applications, the presence of active substances stored in loose form is undesirable. Thus, the present invention provides active inclusion polymers containing active agents, which polymers can be extruded and/or molded in a variety of forms, for example, as linings of containers, stoppers, film sheets, pellets, and other similar structures. Optionally, such active inclusion polymers may contain channeling agents, such as polyethylene glycol (PEG), which form channels between the surface of the inclusion polymer and its interior to transport selected material (e.g., moisture) to the trapped active agent (e.g., desiccant for absorption). moisture). As explained above, inclusion polymers can be two-phase formulations (ie, contain a base polymer and an active agent without a channeling agent) or three-phase formulations (ie, contain a base polymer, an active agent, and a channeling agent). Inclusion polymers are described, for example, in US Pat. Nos. 5,911,937; 6,080,350; 6,124,006; 6,130,263;

In FIG. 1-6 depict exemplary inclusion polymers 20 and various container assemblies formed from inclusion polymers in accordance with some embodiments of the present invention. Each of the inclusion polymers 20 comprises a base polymer 25, optionally a channeling agent 35, and an active agent 30. As shown, the channeling agent 35 forms communicating channels 45 through the inclusion polymer 20. At least a portion of the active agent 30 is contained in these channels 45 such that the channels 45 communicate between the active agent 30 and the exterior of the inclusion polymer 20 through channel openings 48 formed on the outer surfaces of the inclusion polymer 25. The active agent 30 may be, for example, any of a variety of release materials, as described in more detail below. While a channeling agent, such as 35, is preferred, the present invention broadly includes polymers with inclusions that do not necessarily contain channeling agents.

Suitable channeling agents include polyglycol such as polyethylene glycol (PEG), ethylene vinyl alcohol (EVOH), polyvinyl alcohol (PVOH), glycerol polyamine, polyurethane, and polycarboxylic acid, including polyacrylic acid or polymethacrylic acid. Alternatively, the channeling agent 35 may be, for example, a water-insoluble polymer such as propylene oxide polymer monobutyl ether, commercially available under the trade name Polyglykol B01/240, manufactured by CLARIANT. In other embodiments, the channel-forming agent may be propylene oxide polymer monobutyl ether available under the trade name Polyglykol B01/20 from CLARIANT, propylene oxide polymer available under the trade name Polyglykol D01/240 from CLARIANT, ethylene vinyl acetate, nylon 6, nylon 66, or any combination of the above.

Inclusion polymers with antimicrobial release agents are described in more detail below.

Antimicrobial release agents and optional inclusion polymer formulations containing them.

Suitable active agents according to the present invention include antimicrobial releasing agents. In FIG. 4 depicts an embodiment of the inclusion polymer 10 of the present invention wherein the active agent 30 is an antimicrobial releasing agent. The arrows indicate the trajectory of the selected material, such as moisture or other gas, outside the polymer 10 with inclusions through the channels 45 to the particles of the active agent 30 (in this case, to the antimicrobial releasing agent). Optionally, the antimicrobial releasing agent is reacted or otherwise initiated or activated by the selected material (eg, moisture) and in response releases the releasable antimicrobial material, preferably in gaseous form.

Antimicrobial agents useful in this context include volatile antimicrobial release agents, non-volatile antimicrobial release agents, and combinations thereof.

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The term volatile antimicrobial release agent includes any compound that, upon contact with a fluid (eg, water or food juice), forms a gas and/or a gas phase, such as a vapor of the released antimicrobial agent. As will be described in more detail below, the volatile antimicrobial releasing agent is generally used in a closed system such that the released antimicrobial material (gas and/or vapor) does not escape. Examples of volatile antimicrobial releasing agents include, but are not limited to, origanum, basil, cinnamaldehyde, chlorine dioxide releasing agents (e.g., a combination of sodium chlorite, catalyst and activator), carbon dioxide releasing agents, ozone releasing agents, vanillin, vanillic acid , coriander oil, clove oil, horseradish oil, peppermint oil, rosemary, sage, thyme, wasabi or its extract, bamboo extract, grapefruit seed extract, rhubarb finger extract (Rheum palmatum), Chinese coptis extract (coptis chinesis), lavender oil, lemon oil, eucalyptus oil, peppermint oil, cananga odorata, cupressus sempervirens, curcuma longa, cymbopogon citratus, eucalyptus globulus, pinus radiate, piper crassinervium, psidium guayava, rosmarinus officinalis, zingiber officinale, thyme, thymol, allyl mustard oil ( AIT), hinokitiol, carvacrol, eugenol, α-terpinol, sesame oil, or any combination the above compounds.

The term non-volatile antimicrobial agent includes any compound that, upon contact with a fluid (eg, water or food juice), produces minimal or no antimicrobial vapor. Examples of non-volatile antimicrobials include, without limitation, ascorbic acid, sorbate salt, citric acid, citric acid salt, lactic acid, lactic acid salt, benzoic acid, benzoic acid salt, bicarbonate salt, chelating compound, alum salt, nisin, ε-polylysine 10%, methyl and/or propyl parabens, or any combination of the above compounds. Salts include sodium, potassium, calcium or magnesium salts of any of the above compounds. Specific examples include calcium sorbate, calcium ascorbate, potassium bisulfite, potassium metabisulfite, potassium sorbate or sodium sorbate.

Preferred features of antimicrobial release agents used according to one aspect of the present invention include one or more of the following characteristics: (1) they evaporate at freezing temperatures; (2) they are food safe and edible in their final form; (3) they can be safely incorporated into an inclusion polymer formulation or other release mechanism; (4) they are long-term storage stable; (5) they release the releasable antimicrobial material only after the package containing the agent is hermetically sealed along with the product located in the package; (6) their composition does not affect the organoleptic properties of the stored food product, and they are designed to obtain the desired release profile within the package; and (7) they are preferably acceptable under applicable government regulations and/or regulations relating to food packaging and finished food labeling.

Antimicrobial releasing agents that release chlorine dioxide.

In one aspect of the present invention, the preferred antimicrobial release agents are volatile antimicrobials that release chlorine dioxide (C1O2) in gaseous form as the antimicrobial material released. For example, the antimicrobial releasing agent may be a compound or formulation containing an alkali metal chlorite, such as, for example, sodium chlorite or potassium chlorite, a catalyst and an activator (for example, in powder form), which are in combination initiated or activated by moisture in order to force the product to release chlorine dioxide. One exemplary antimicrobial release agent is provided under the tradename ASEPTROL 7.05 by BASF Catalysts LLC. This material and its preparation are described in US Pat. No. 6,676,850, the contents of which are incorporated by reference in their entirety. Example 6 of the above patent describes a formulation that is particularly suitable as an antimicrobial release agent according to an optional aspect of the present invention.

Optionally, a suitable antimicrobial release agent based on Example 6 of US Pat. No. 6,676,850 and configured to release chlorine dioxide gas when activated by moisture can be prepared as follows.

The antimicrobial releasing agent contains a composition containing sodium chlorite (as an active ingredient), a basic catalyst and an activator. The catalyst and activator are prepared separately, then combined with each other and finally combined with sodium chlorite.

The base catalyst is optionally prepared by first preparing a 25-30% by weight sodium silicate solution (2.0 to 3.3 weight ratio of SiO2:Na2O). This solution is mixed with an aqueous slurry containing 28-44 wt. % Georgia kaolin clay (approximately 80% less than one micrometer in particle diameter), where the sodium silicate solution makes up 2 wt. % of the slurry. The suspension is then dried at 100° C. to form agglomerates or microspheres of approximately 70 microns. 300 g of these microspheres are saturated with 280 g of a 2.16 N sulfuric acid solution. This 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 vessel, where the hermetic seal is wrapped with tape. This mixture forms the main catalyst.

Then, 84.6 g of base catalyst is mixed with 10.1 g of activator, dry calcium chloride. This mixture of base catalyst and activator is ground with a pestle and mortar at room temperature. This mixture is dried for 2 hours at 200°C. The mixture of base catalyst and activator is then cooled to room temperature in a sealed glass vessel with tape wrapped around a sealed seal.

Finally, the mixture of base catalyst and activator is combined with 5.3 g of sodium chlorite (which is the active component of the active agent). The complete mixture is then ground with a mortar and pestle at room temperature, thus forming an optional embodiment of the antimicrobial releasing agent. The antimicrobial release agent is then placed in a sealed glass jar with tape wrapped around a sealed seal in order to store it substantially free of moisture which would cause it to prematurely activate (to release chlorine dioxide gas).

Optionally, the antimicrobial release agent is a component of an inclusion polymer, preferably a three-phase polymer, containing an active agent (eg 40-70% by weight), a base polymer and a channeling agent. Optionally, such inclusion polymer is in the form of a film located inside a sealed package containing fresh food products, such as meat or agricultural products.

It is generally believed that the higher the concentration of antimicrobial releasing agent in the mixture of polymer with inclusions, the higher the ability of absorption, adsorption or release of the finished composition. However, too high an active agent concentration can lead to excessive brittleness of the polymer with inclusions. It can also result in the molten mixture of active agent, base polymer and (if used) channeling agent being less amenable to heat forming, extrusion or injection molding. In one embodiment, the loading level or concentration of the antimicrobial releasing agent can range from 10% to 80%, preferably 40% to 70%, more preferably 40% to 60%, and even more preferably 45% to 55% by weight of the total weight of the polymer. with inclusions. Optionally, the channeling agent may be provided in the range of 2 to 10% by weight, preferably about 5% by weight. Optionally, the base polymer may be in the range of 10 to 50% by weight of the total composition, preferably 20 to 35% by weight. Optionally, a dye is added, for example, about 2% by weight of the entire composition.

In one embodiment, the inclusion polymer may be a three-phase formulation containing 50% by weight of antimicrobial release agent ASEPTROL 7.05 in the form of a powder mixture, 38% by weight of ethyl vinyl acetate (EVA) as the main polymer and 12% by weight of polyethylene glycol (PEG) in as a channeling agent.

In FIG. 1 shows a plug 55 composed of an inclusion polymer 20, in accordance with some embodiments of the present invention. Stopper 55 may be placed inside the container. As previously mentioned, the inclusion polymer 20 comprises a base polymer 25, a channeling agent 35, and an active agent 30.

In FIG. 2 is a cross-sectional view of the plug 55 shown in FIG. 1. In addition, in FIG. 2 shows that the inclusion polymer 20 has cured such that the channeling agent 35 forms communicating channels 45 to create passages through the cured plug 55. At least a portion of the active agent 30 is contained in these channels 45 such that the channels 45 communicate between the active agent 30 and the outer part of the polymer 20 with inclusions through the openings 48 of the channels formed on the outer surfaces of the polymer 25 with inclusions.

In FIG. 3 depicts one embodiment of a plug 55 similar in design and composition to the plug 55 shown in FIG. 2 where the communicating channels 45 have a smaller diameter than those shown in FIG. 2. This may be the result of using a dimeric agent (i.e., a plasticizer) together with the channeling agent 35. The dimeric agent may improve compatibility between the base polymer 25 and the channeling agent 35. This improved compatibility is facilitated by the lower viscosity of the mixture, which can provide more thorough mixing. a base polymer 25 and a channeling agent 35, which under normal conditions may resist being combined into a homogeneous solution. After curing of the inclusion polymer 20 to which the dimeric agent is added, the communicating channels 45 formed therein have greater dispersion and less porosity, thereby forming a higher density of communicating channels in the plug 55.

Interconnecting channels 45, such as those described herein, facilitate the transfer of a desired material, such as moisture, gas, or odor, through the base polymer 25, which typically acts as a barrier to these materials. For this reason, the base polymer 25 itself acts as a barrier material within which the active agent 30 can be trapped. The communicating channels 45 formed from the channeling agent 35 provide passageways for the movement of the desired material through the inclusion polymer 10. It is believed that without these communicating channels 45, relatively small amounts of the desired material would be transferred through the base polymer 25 to or from the active agent 30. Additionally, when the desired material is transferred from the active agent 30, it may be released from the active agent 30, for example, in embodiments in which the active agent 30 is a releasing material, such as an antimicrobial gas releasing material.

In FIG. 5 depicts an active sheet or film 75 formed from an inclusion polymer 20 used in combination with a barrier sheet 80 to form a composite, in accordance with one aspect of the present invention. The characteristics of the active sheet 75 are similar to those described with respect to the plug 55 shown in FIG. 1 and 2. The barrier sheet 80 may be a substrate such as a foil and/or a polymer (such as a container wall) with low moisture or oxygen permeability. The barrier sheet 80 is compatible with the active sheet 75 and thus is thermally bondable to the active sheet 75 when the active sheet 75 cures after application. In FIG. 6 depicts an embodiment in which two sheets 75, 80 are combined to form a packaging wrap having active characteristics on the inner surface formed by the inclusion polymer 20/active sheet 75 and vapor barrier characteristics on the outer surface formed by the barrier sheet 80.

In one embodiment, sheets 75, 80 of FIG. 5 are connected to each other so as to form an active package 85 as shown in FIG. 6. As shown, two laminates or composites are provided, each consisting of an active sheet 75 bonded to a barrier sheet 80. The sheets of the laminate are stacked with each active sheet 75 facing the other so that they are placed on the inside. package, and are connected in the area 90 of the seal formed around the perimeter of the sealed area of the inside of the package.

Optionally, in any of the above embodiments, the inclusion antimicrobial polymer is in the form of a film located within a sealed food package. Optionally, the film may be adhered, for example by means of an adhesive, to the inner surface of the package. Alternatively, the film may be heat-shrink-bonded (without adhesive) to the inside surface of the package. The process of attaching a film to a substrate by heat shrinkage is known in the art and is described in detail in US Pat. No. 8,142,603, which is incorporated herein by reference in its entirety. Film size and thickness may vary. In some embodiments, the film has a thickness of approximately 0.3 mm. Optionally, the film thickness may be in the range of 0.1 to 1.0 mm, more preferably 0.3 to 0.6 mm.

In FIG. 7 shows a package 100 for storing fresh food, such as agricultural produce or meat, in accordance with some embodiments of the present invention. Packaging 100 is shown in the form of a plastic tray 102. However, other shapes and materials are also contemplated within the scope of the present invention. The tray 102 includes a base 104 and side walls 106 extending vertically from the base 104 and leading to the opening 108 of the tray. The base 104 and the side walls 106 together form the interior 110, for example, to hold and store fresh agricultural products. The package 100 also contains a flexible plastic cover film 112 which is placed over the opening 108 and seals it. It is contemplated and implied that a wide variety of coatings or lids may be used to close and seal opening 108. Optionally, the coating or lid is transparent so that the interior is visible. When a product (eg, sliced tomatoes) is stored in the interior 110, the empty space around and above the product is referred to herein as headspace (not shown).

Package 100 further comprises sections of film 114 of an antimicrobial polymer with inclusions located on side walls 106. In the embodiment shown, there are four sections of such film 114, one section of film 114 for each side wall 106. Film 114 is preferably located at the top of the side wall 106 or near it, proximate opening 108. At least some, although preferably most or all, of each section of film 114 protrudes above centerline 116 of sidewall 106, with centerline 116 located centrally between base 104 and opening 108. Placing the film at or near the top of the package 100 has been found to affect the effectiveness of the film sections 114, as this placement promotes the desired distribution of the released antimicrobial material into the headspace above the product in the package 100. Placing the inclusion polymer too low above based 104 or under the food in the package does not provide the desired distribution of the released antimicrobial material in the headspace above the product. If placement does not provide optimal mass transfer of the antimicrobial, some food/commodity will not be adequately protected.

- 9 040718 against microbial growth. Additionally, the food may react undesirably with and/or absorb the released antimicrobial material. As described in more detail below, placement of the film above the sidewall centerline, preferably at least 67% or 75% or approximately 80% of the sidewall, has been found to achieve the desired antimicrobial gas release profile and headspace concentration.

Optionally, the inclusion polymer film 114 is heat-shrink-bonded to the package (eg, on the side wall, as described and shown in FIG. 7). Advantageously, the heat shrink may allow the film to be irreversibly adhered to the side wall without the use of adhesive. Adhesives can be problematic in some circumstances because they can release unwanted volatile compounds into the headspace of the food. Aspects of the heat shrink process that can be used in accordance with optional embodiments of the present invention are disclosed in US Pat. No. 8,142,603 as indicated above. In this case, heat shrinking refers to heating the seal layer substrate on the side wall while applying sufficient pressure to the film and the seal layer substrate to adhere the film to the container wall.

In some embodiments, the antimicrobial polymer film 114 with inclusions may be attached to the surface of the liner 112 (or lid) that is inside the container, instead of or in addition to the sections of film 114 on the side wall(s) 106. Alternatively, the antimicrobial polymer film 114 with inclusions may be incorporated into the release film 112 (or lid).

In addition to the placement of the film 114, another important factor is the release profile of the released antimicrobial material. As mentioned earlier, to ensure sufficient shelf life, the release of the agent should not be immediate; instead, release must be extended, maintained, and predetermined to achieve the desired shelf life.

In general, the entrapped antimicrobial release agent polymer is self-activating, i. release of the released antimicrobial gas is not initiated until the antimicrobial release agent is exposed to the selected material, such as moisture. Typically, moisture is not present in the interior, for example in the headspace of the product, in the container before the food product is placed inside the container. Upon placement, the food product releases moisture which interacts with the antimicrobial release agent trapped in the polymer to create the antimicrobial release agent in the headspace of the product. In one embodiment, the container is sealed in a moisture-tight manner to retain moisture generated by moisture-releasing foods within the container.

In some embodiments, a controlled release and/or a desired release profile can be achieved by coating the active agent, for example using a spray gun, the coating being capable of releasing the releasable antimicrobial agent in the desired time range. Antimicrobial release agents may have different coatings applied to them to achieve different release effects. For example, if a 14 day shelf life is needed, based on the predetermined relative humidity of the package, the amount of selected material (moisture) present to activate the antimicrobial release agent can be determined. Based on this determination, sustained release coatings having different thicknesses and/or properties can be applied to the agent to achieve the desired release profile. For example, some active agent will be coated in such a way that it does not begin to release the released antimicrobial material until one week has elapsed, while another active agent will begin to release almost immediately. Spray coating technology is known in the art. For example, pharmaceutical beads and the like have a spray coating to control the rate of release of the active ingredient, for example, to create drugs with a slow or sustained release. Optionally, such technology can be adapted to coat the active agent to achieve the desired controlled release rate of the antimicrobial gas.

Alternatively, a controlled release and/or a desired release profile can be achieved by providing, optionally on both sides of the film, a layer of material configured to control the entry of moisture into the inclusion polymer (which in turn triggers the release of the releasable antimicrobial material). For example, the film may comprise a polymeric protective layer, made of, for example, low density polyethylene (LDPE), applied to either or both sides of the film. The thickness of the film and protective layer(s) may vary. In some embodiments, the film thickness is approximately 0.3 mm and the thickness of each of the LDPE protective layers on either side is approximately 0.02 to 0.04 mm. Protective layers of LDPE can be co-extruded with or laminated to the film.

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Alternatively, a controlled release and/or a desired release profile can be achieved by modifying the formulation of the antimicrobial release agent activator. For example, the activator liquefies on contact with moisture and then reacts with the active ingredient (eg, sodium chlorite) to initiate the release of an antimicrobial gas. The composition of the activator can be chosen such that it liquefies on contact with moisture at different rates. The faster the activator turns into a liquid, the faster the antimicrobial gas is released, and vice versa. Thus, modification of the activator is another way to achieve the desired rate of release of the antimicrobial gas.

Any combination of the above mechanisms can be used to achieve the desired release rates and release profiles of the antimicrobial gas in the headspace of the product in the container.

Varying release rates depending on the properties of the stored food product.

The inventors of the present invention have found that the desired release profile of chlorine dioxide gas in the headspace above the product in the container can vary depending on the properties of the stored product. For example, the present inventors have found that food products with a high water content require a rapid release of a large amount of antimicrobial gas, followed by a decrease in the headspace concentration over the product during shelf life, while food products with a lower water content respond well to a relatively constant concentration in the headspace of the product during the shelf life.

Non-limiting examples of food products that release large amounts of moisture and that are better protected by a release profile with rapid release of chlorine dioxide gas followed by a fall include sliced, diced or otherwise cut food products selected from the group consisting of: tomatoes, washed peppers, washed onions, watermelon, nutmeg, cantaloupe, strawberries, peaches, pineapple, oranges, seafood, meat and poultry. For such food products, an amount of antimicrobial releasing agent is provided that releases gaseous chlorine dioxide to provide a headspace concentration of 10 ppm (PPM) to 35 PPM over a period of 16 to 36 hours, optionally from 15 to 30 PPM per period. 16 to 36 hours, optionally 15 to 30 PPM over a period of approximately 24 hours. Headspace concentration measurements can be performed, for example, using the PORTASENS II Gas Detector from Analytical Technology, Inc. based on readings obtained from chlorine dioxide sensors placed inside the package. Sensors can be one or more of the following models: Chlorine Dioxide Sensor 00-1004, 0-1/5 PPM (2 PPM Rate), Chlorine Dioxide Sensor 00-1005, 0-5/200 (20 PPM Rate), and Dioxide Sensor Chlorine 00-1359, 0-200/1000 PPM (Norm 1000), also from Analytical Technology, Inc., which are compatible with the PORTASENS II Gas Detector.

This type of rapid release (10 ppm headspace (PPM) to 35 PPM over a period of 16 to 36 hours) is necessary so that chlorine dioxide gas, which dissolves in water, can stay ahead of the dissolution curve to provide sufficient antimicrobial effect during peak headspace concentrations to extend the shelf life of contaminated food beyond approximately a two week period. Although the release is characterized as a fast release, it will still be considered a controlled release because the headspace concentration is still controlled to stay within the desired concentration for a given period, even if the release is relatively fast. The present inventors have found, for example, that the aforementioned headspace concentration works well to significantly reduce the number of microbes on contaminated sliced tomatoes for thirteen days without discoloration of the tomatoes. This is supported by the examples provided below.

Non-limiting examples of foods that release moderate or low moisture are whole or minimally processed agricultural products selected from the group consisting of: broccoli, Brussels sprouts, cabbage, cucumbers, bananas, herbs, peppercorns, carrots, root vegetables, and potatoes . For such food products, some of the antimicrobial releasing agent releases chlorine dioxide gas to preferably provide a headspace concentration of 8 to 15 PPM over a period of 13 days. Whether or not this particular headspace concentration is provided, it is preferred that antimicrobial release agents be provided in inclusion polymer films as described herein for such low to moderate moisture release foods.

The above release profiles and headspace concentrations assume the presence of a moisture releasing food product in the package.

- 11 040718

In any case (high moisture or medium/low moisture foods) where the product is contaminated with at least one type of pathogen, chlorine dioxide gas has a certain concentration in the head space above the product for a certain period of time to be carried out, after 13 days after placing the product in the interior and at a storage temperature of 7°C, at least 2 orders of magnitude reduction in colony forming units per gram (CFU/g), optionally, at least 3 orders of magnitude CFU/g, optionally , at least 4 orders of magnitude CFU/g of at least one type of pathogen, without causing a deterioration in the organoleptic properties of the food product. Such deterioration in organoleptic properties may include clarification or other discoloration of the food product.

Optionally, in any embodiment, 700-950 mg of the antimicrobial releasing agent is effective in a 1 liter container holding 1.25 pounds of tomatoes. It is contemplated that proportional adjustment of the weight of the antimicrobial release agent can be made according to changes in container volume and amount/type of content.

Applications of the present invention for non-food products.

In another aspect, the present invention is directed to the use of antimicrobial-containing inclusion polymers for use outside of food preservation applications. For example, the solutions disclosed herein may be adapted for use in the sterilization of disposable medical devices, i.e. to reduce the bioburden of such devices during packaging. The main difference between keeping fresh food and medical devices is shelf life. Keeping food fresh requires 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 for one application will necessarily change compared to another application.

The present invention will be described in more detail with reference to the following examples, however, it should be understood that the present invention should not be construed as limited to these examples.

Examples

Example 1 Controlled release of gaseous C1O2.

The storage temperature of 7°C was chosen to reproduce a storage temperature that is slightly elevated from the ideal storage temperature (or to encourage an unintended temperature spike during storage, such as a refrigeration equipment failure for several hours). Three packages like the one shown in FIG. 7 were used in this experiment. All three contained inclusion antimicrobial polymer film sections arranged substantially as shown in FIG. 7. The film was a three-phase inclusion polymer film containing an antimicrobial releasing agent in the form of a powder mixture containing sodium chlorite (which produces chlorine dioxide gas), sulphate clay (as a catalyst) and calcium chloride (as a moisture-responsive activator). ). This powder mixture is commercially available from BASF under the name ASEPTROL and is described above.

The formulation for the film itself was a three-phase formulation containing 50% by weight of the aforementioned antimicrobial releasing agent in the form of a powder mixture, 38% by weight of ethyl vinyl acetate (EVA) as the base polymer, and 12% by weight of polyethylene glycol (PEG) as the channeling agent. This film composition is described herein as X2597 and is considered to be one illustrative non-limiting embodiment of an inclusion polymer according to one aspect of the described concept. As described above, the antimicrobial releasing agent is activated by moisture to release gaseous chlorine dioxide (C1O2) as the released antimicrobial material. The film present in the three packages had the same composition and dimensions. However, two of the films contained moisture control outer layers and one did not. The film in package A was sandwiched between co-extruded layers of LDPE approximately 0.02 mm thick. The film in package B was sandwiched between co-extruded layers of LDPE approximately 0.04 mm thick. The film in package C (control) did not contain such polymer layers on either side of the film.

The levels of C1O2 in the packs were measured over a period of 13 days with detection sensors calibrated to the desired concentration known to have antimicrobial effects on most organisms. The results are presented below (values of C1O2 concentration expressed in ppm are presented).

- 12 040718

Day Package A Pack B Packaging C 1 24 17 34 2 27 22 43 3 28 21 29 4 27 21 27 5 28 20 26 6 29 20 25 7 26 21 18 8 21 21 12 9 17 19 9 10 13 17 4 eleven eleven 16 4 12 8 13 4 13 6 eleven 4

This example demonstrates that package B had the most uniform and most uniform release profile attributed to the thicker polymeric protective layer located on both sides of the antimicrobial film, which controlled the entry of moisture into the film. The release profile in package B may be desirable for certain applications, for example where the food product releases a relatively low amount of moisture, such as broccoli.

Example 2 Geotrichum Growth Test.

A common cause of deterioration in tomato quality is Geotrichum candidum, a yeast-like mold that grows as white fluff. In this example, sliced tomatoes intentionally infected with candidum were packaged and tested. The storage temperature of 7°C was chosen to reproduce a storage temperature that is slightly elevated from the ideal storage temperature (or to encourage an unintended temperature spike during storage, such as a refrigeration equipment failure for several hours).

A package similar to that shown in Fig. 7, with a C1O2 releasing antimicrobial film placed at the top of the package, was used to store contaminated sliced tomatoes. A second package, otherwise identical to the first except for the lack of an antimicrobial film, was used to store contaminated sliced tomatoes. The results are shown in the graphs shown in FIG. 8A and 8B. The results strongly suggest that the antimicrobial film significantly inhibited the growth of Geotrichum on sliced tomatoes when compared to non-film packaging. In packaging without antimicrobial film, Geotrichum reproduction on sliced tomatoes was clearly visible to the naked eye. In contrast, sliced tomatoes packaged with C1O2-releasing antimicrobial polymer film with inclusions looked fresh, with no visible signs of Geotrichum growth. This is even more noticeable given the sub-optimal temperature of 7°C during the daytime test.

It should be understood that the use of tomatoes as examples is illustrative only and that other agricultural products and fresh food products (eg, meat) may be used in accordance with the present invention. It should also be understood that while chlorine dioxide is one preferred releasable antimicrobial material, other releasable antimicrobial materials are also within the scope of the invention and may be preferred for other uses.

Example 3 Antimicrobial Film Location Test.

An inclusion polymer film (X2597 film described above) was placed in the headspace above the product in the tray at various heights on the sidewalls to test the effectiveness of various antimicrobial film locations/locations as well as various sample locations. The abbreviation MCT as used herein refers to Maxwell Chase Technologies, LLC of Atlanta, Georgia. The abbreviation FPT refers to FRESH-RPAX® trays from Maxwell Chase Technologies, LLC.

- 13 040718

In this example, the following materials were used:

strips of film X2597 weighing 1 g lot #02116A030A (CSP Technologies - Auburn, Alabama).

tomatoes (5x5 red tomatoes purchased from the grocery store on the day of the experiment).

MCT tray FPT 125D (Maxwell Chase Technologies - Atlanta, Georgia) having a bottom surface and an opposite opening, with four side walls extending vertically from the bottom surface. The side walls were 10 inches long and 3 5/8” high (measured from the bottom surface).

plastic holder (made from cut MCT FPT125D trays).

Polypropylene (PP) oriented liner film approx. 90 cm ³ /100 in ² /day OTR, 0.8 g/100 in ² /day WVTR (MST - Atlanta, Georgia).

MCT-MTS Manual Tray Sealer at 375°F (MCT Atlanta, GA).

SABER manual tomato slicer, 7/32" slices (Prince Castle, Carol Stream, IL).

Portable gas analyzer ATI C16 (Analytical Technology Inc., Collegeville, Pennsylvania).

C1O2 sensor #00-1425 1/5 (ATI Collegeville, PA).

C1O2 sensor #00-1004 1/5.

C1O2 sensor #00-1005 5/200.

C1O2 sensor #00-1359 200/2000.

Tempure Scientific top mounted laboratory refrigerator (Model #LP-75-HG-TP) equipped with a Dixell XR40CX computer control set to 7C with an 8°C top cooling setting and a 6°C bottom setting.

set of quick-release valves CPC #3438400 with compression fittings per glass jar with a screw cap (McMaster-Carr (MCM) #5012K122).

Black Flex® GP 70 PVC Tubing 3/16" ID x %" OD (MCM #5231K35).

O-ring 011 Buna-N, oil resistant, round profile (MCM #9408K41).

KnifeHas1o.

MCT trays FPT125D (1/4 size, rich white polypropylene) have been modified as follows. MCT FPT125D trays were drilled with a Xacto cutter into three holes approximately 8.5 mm wide at 2 cm intervals. Both of these valves were placed with quick-release valves on the outside of the lid and container in order to place auto-closing valves on the outside for sampling purposes.

3/16" ID x ^1/4 " OD Flex® GP 70 Black PVC Tubing (MCM#5231K35 ₎ was used with both the inlet and outlet of the C16 Portable Gas Analyzer and the other end of the CPC 3438400 Quick Connect Valves with compression fittings for connecting to trays to obtain samples from the free space above the product in the trays.

The CSP film samples were cut from the same strip of film and had the same width. Then, 1000 g of each sample was weighed and attached to the side wall of the tray with a plastic piece to hold it in place. There were two samples per tray, resulting in 2 g of CSP film per tray. Each of the samples was connected to a separate side wall of the tray.

The tomatoes were sliced using a manual slicing knife with the calyx facing down. The ends were thrown away. Approximately 7 tomato slices were placed on the bottom surface of each tray.

The manual sealer was heated to 375°F and each tomato tray was placed on the appropriate sealing plate. The cover/sealing film was placed over the tray, the sealing handle was pressed down and held for about 1-2 s to close/seal the tomatoes inside the tray.

For each of the trays, the C1O2 release rate was measured at one hour intervals for 11 hours. FIG. 9 shows the release of C1O2 (ppm) corresponding to different positions of the CSP film in the tray, i.e. at a height of 0, 50, 64, 79 and 100% of the bottom surface relative to the total height of the side wall. These respective heights are measured from the center line of the film. In FIG. 10 shows the effect of CSP film height on headspace concentration.

The results show that changing the height of the CSP film in the tray had an effect on the presence of C1O2 in the headspace. From the bottom of the tray (0%) to midpoint (50% - about 2 inches up the side wall in this particular non-limiting example) there was only a slight, eg negligible, change in headspace concentration. However, from the midpoint to the top of the flume, the increase in height resulted in a significant increase in concentration. The concentration doubled from the position at 64% of the total height to the top of the tray (100%). The data shows that to maximize headspace C1O2 concentration for optimum efficiency and/or to minimize the amount of film required, the film should preferably be placed in the top 20% of the tray, i.e. placed at a vertical height of 80 to 100% of the total sidewall height, measured from the bottom surface, and must be placed at least 64% of the total tray sidewall height.

Example 4 Use of rapid release profiles to kill pathogens.

The effectiveness of reducing the level of Listeria monocytogenes, E. coli and Salmonella was evaluated for CSP C1O2 film applied to the top of the tray, compared with control trays, where there was no CSP C1O2 film.

C1O2 releasing CSP films were used with a formulation called X2597 (described above), 0.3 mm thick. This formulation was designed to have a C1O2 fast release profile and did not use a polyethylene topsheet to reduce moisture ingress into the film. As described above, X-2597 film is a three phase formulation containing 50 wt % antimicrobial release agent, 38 wt % ethyl vinyl acetate (EVA) as base polymer, and 12 wt % polyethylene glycol (PEG) as channeling agent. Trays were used with either 4 grams or 3 grams of film per tray. Each tomato in the tray was seeded with three pathogens, i.e. Listeria monocytogenes, E. Coli and Salmonella.

In this example, the following materials were used:

250 tomatoes - category 5x5 (with a margin in case of defects) (5 boxes, 50 pcs/box)

Manual tomato slicing knife (Prince Castle)

Manual sealing device set at 375°F (Maxwell Chase Tech).

Polypropylene cover film, approx. 90 OTR (Maxwell Chase Tech) Listeria monocytogenes inoculums (food isolates) Salmonella inoculums (food isolates) E. coli O157:H7 inoculums (food isolates)

Sterile water for dilution and tubing

Sterile forceps

Beaker with alcohol and a burner for sterilizing forceps

Sterile surgical knives FPT 125D trays (1/4 size white polypropylene trays) with 1 g of 002 film in each upper corner of FPT 125D trays (1/4 size white polypropylene trays) with 0.75 g C1O2 film in each upper corner of FPT 125D trays (White 1/4 size polypropylene trays) labeled MCT uninoculated trays labeled UN

Refrigerator set temperature 7 °C

564 MOX petri dishes (60 on day 0. 168 on days 5, 8, 12), labeled List.

564 XLD petri dishes (60 on day 0. x 168 on days 5, 8, 12) labeled Sal.

564 petri dishes PCA (60 on day 0. 168 on days 5, 8, 12) labeled APC

564 MAC petri dishes (60 on day 0. 168 on days 5, 8, 12) labeled E. coli

Nutrient broth for relevant pathogens

Additional Petri dishes to check the streak culture of inoculums with strains of Salmonella, Listeria monocytogenes, and E. Coli O157:H7 were prepared, mixed and left overnight. The goal was to achieve seeding of tomatoes by 5 orders of magnitude with each pathogen. The seeded tomatoes had an inoculum of 10 ⁹ cfu pathogens/ml. Inoculations were placed in Petri dishes to check and determine starting levels.

- 15 040718

A solution of 200 ppm free chlorine solution was prepared with lukewarm water. The slicing knife was immersed in the solution for 2 minutes and then rinsed with tap water.

A 200-ppm free chlorine solution was prepared with warm water (approximately the same temperature as for tomatoes). First, the tomatoes were placed in tap water, then in a chlorine solution for 2 minutes and washed with tap water. The tomatoes were sliced using a manual slicing knife with the calyx facing down. The tips were discarded so that 42 slices (6 tomatoes x 7 slices/tomato) were packed in each tray.

Eighteen (18) tomato slices were topically seeded with Salmonella, Listeria monocytogenes, and E. coli inoculums (6 each) to achieve three parallel assays in each tray. The 18 selected tomato slices were identified by marking each slice with a marker next to the area to be planted. The inoculum was vortexed and 10 µl of inoculum was quickly aspirated with the tip of a sterile pipette and dispensed into two top-marked slices. This was repeated two more times per tray per pathogen.

The hand sealer was heated to 375°F. Each tray was placed on a sealing plate and a release liner was pulled over the tray. The sealing knob was pressed and held in place for approximately 1-2 s. After sealing, each tray was checked to make sure that the release liner was completely attached to the tray.

Test trays were analyzed on days 0, 5, 8, and 12. For each tray, a total of three samples per pathogen, three pathogens per tray, and three APC samples were taken from each tray. . Each sample consisted of two slices, which were taken with sterile forceps. Two slices were measured by weight into a sterile Stomacher homogenizer (weight was approximately 40-50 g) and three times as much sterile Peptone water was added. The tomatoes were homogenized at 260 rpm for 1 minute. The required dilutions (~3) were then prepared from the homogenate and redistributed onto appropriate PCA, MOX, SMAC or XLD petri dishes.

Data were calculated in colony forming units (CFU) per gram. CFU values were converted to logarithmic values for data analysis. The data were averaged for one tray and for one type of sample. The following is a summary of the tests that were carried out on the respective days. The term CSP3 refers to trays using 3g of X2597 film and the term CSP4 refers to trays using 4g of X2597 film.

Day 0: 1 MCT tray inoculated with 3 Salmonella, 3 E. coli, 3 Listeria and 3 APC trials/tray=12 trials; 1 tray CSP4 inoculated with 3 Salmonella, 3 E. coli, 3 Listeria and 3 APC trials/tray=12 trials; 1 tray CSP3 inoculated with 3 Salmonella, 3 E. coli, 3 Listeria and 3 APC trials/tray=12 trials; 1 tray UN, uninoculated (negative control) x4 trials (sal, E. coli, Lm, APC)/tray=4 trials. A total of 40 such tests were carried out.

Day 5: 3 MCT trays inoculated with 3 Salmonella, 3 E. coli, 3 Listeria and 3 APC trials/tray=36 trials; 3 trays of CSP4 inoculated with 3 Salmonella, 3 E. coli, 3 Listeria and 3 APC trials/tray=36 trials; 3 trays of CSP3 inoculated with 3 Salmonella, 3 E. coli, 3 Listeria and 3 APC trials/tray=36 trials; 1 tray UN, uninoculated (negative control) x4 trials (sal, E.coH, Lm, APC)/tray=4 trials. A total of 112 such tests were carried out.

Day 8: 3 MCT trays inoculated with 3 Salmonella, 3 E. coli, 3 Listeria and 3 APC trials/tray=36 trials; 3 trays of CSP4 inoculated with 3 Salmonella, 3 E. coli, 3 Listeria and 3 APC trials/tray=36 trials; 3 trays of CSP3 inoculated with 3 Salmonella, 3 E. coli, 3 Listeria and 3 APC trials/tray=36 trials; 1 tray UN, uninoculated (negative control) x4 trials (sal, E. coli, Lm, APC)/tray=4 trials. A total of 112 such tests were carried out.

Day 12: 3 MCT trays inoculated with 3 Salmonella, 3 E. coli, 3 Listeria and 3 APC trials/tray=36 trials; 3 trays of CSP4 inoculated with 3 Salmonella, 3 E. coli, 3 Listeria and 3 APC trials/tray=36 trials; 3 trays of CSP3 inoculated with 3 Salmonella, 3 E. coli, 3 Listeria and 3 APC trials/tray=36 trials; 1 tray UN, uninoculated (negative control) x 4 trials (sal, E. coli, Lm, APC)/tray = 4 trials. A total of 112 such tests were carried out.

In total, this experiment included a total of 376 trials (94 Salmonella, 94 E. Coli, 94 Listeria, 94 APC). The results are shown in FIG. 11-13.

In FIG. 11 shows the decrease in Salmonella after day 0, and this decrease was maintained until day 12 for CSP3 trays and continued for CSP4 trays. Each of these samples showed a reduction in Salmonella of at least 1.8 orders of magnitude on day 5, 2.5 orders of magnitude on day 8, and 3 orders of magnitude on day 12, respectively. This demonstrated a 99.9% reduction in Salmonella after 12 days in CSP trays.

In FIG. 12 shows results for E. coli which are similar to those for Salmonella. The decrease in E. coli after day 0 resulted in a decrease of at least 2 orders of magnitude on day 5, 4 orders of magnitude on day 8, and 3 orders of magnitude on day 12. Similar to FIG. 11 for Salmonella, in FIG. 12 shows the increase for the CSP3 tray on day 12. A 99.9% decrease in E. coli was determined after the 12 day period.

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Claims (16)

In FIG. 13 shows that the CSP film also reduced Listeria by 1 order over the 12 day shelf life. This is consistent with each of the daily samples obtained, and demonstrated a stable reduction of Listeria monocytogenes by 90% within 12 days. These results demonstrate the effectiveness of CSP trays (according to optional aspects of the present invention) with sliced tomatoes over a 12 day shelf life to reduce Salmonella, E. coli and Listeria inoculation on tomato slices stored at 8°C. This is not a normal storage condition, but it does model a potential cold chain disruption that is considered a major cause of spoilage and pathogen growth in food safety practice. The use of these trays can help reduce the growth potential of pathogens to dangerous levels in sliced tomatoes. Example 5 Rapid Release Plots of Antimicrobial Gas. As described in Example 4 above, trays using 3 g or 4 g of X2597 film showed a significant contribution to inhibiting the growth and reproduction of pathogens during the test period. The film formulations were designed to provide a fast release profile as described elsewhere in this specification. In FIG. 14 shows the release schedules for the 3 g and 4 g versions used in Example 4. FIG. 14 also shows a release plot for trays using only 2g of film. As shown in FIG. 14, trays using 4 g of film (CSP4) had a maximum C1O2 concentration of approximately 30 ppm at approximately 6 pm and also maintained a concentration above 10 ppm from approximately 6 to 33 hr. Trays using 3 g of film ( CSP3) had a maximum C1O2 concentration of approximately 23 ppm at approximately 3 pm and also maintained a concentration above 10 ppm between approximately 6 and 33 hours. As noted in Example 4 above, these embodiments provided sufficient headspace concentration over the product to achieve the desired microbial kill and did so without bleaching the tomatoes. In FIG. 14 also shows a release plot for trays using 2g of film. As shown in the graph, this embodiment had a maximum C1O2 concentration of about 16 ppm over the 12 to 18 hour interval. However, this graph shows that the C1O ₂ concentration was maintained above 10 ppm only in the interval from about 8 to 26 hours In some circumstances, this concentration and release schedule may provide a sufficient antimicrobial effect, but in this case, this concentration was not preferred (although still within the scope of the optional aspects of the described ideas). Although the present invention has been described in detail and with reference to its specific examples, it will be obvious to a person skilled in the art that various changes and modifications can be made to it without departing from its essence and scope. CLAIM 1. Packaging for suppressing or preventing the growth of microbes and/or for killing microbes in a closed container in which the product is located, and the package contains: a) a closed container delimiting the internal space within itself; b) product provided in the interior; c) the free space above the product, formed within the volume of the internal space which is not occupied by the product; and an antimicrobial releasing agent comprising an alkali metal chlorite disposed in the interior, wherein the antimicrobial releasing agent releases chlorine dioxide gas into the headspace of the product by reaction of the alkali metal chlorite with moisture, wherein the antimicrobial releasing agent is provided in at least one copolymer article. inclusions located in the internal space, and the product of the polymer with inclusions contains a monolithic material that contains a base polymer, an antimicrobial releasing agent and a channeling agent, where the monolithic material is characterized by channels passing through the polymer with inclusions formed by the channeling agent. 2. The package of claim 1 wherein the antimicrobial releasing agent is provided in an amount that releases chlorine dioxide gas to provide a headspace concentration of 10 to 35 parts per million (PPM) over a period of 16 to 36 hours. 3. Packaging according to claim 1 or 2, characterized in that when the product is provided in the internal space, the product is contaminated with at least one type of pathogen, the antimicrobial releasing agent provides a controlled release of chlorine dioxide gas to be carried out, after 13 days from the date of placement of the product in the interior and at a storage temperature of 7°C, at least 2 orders of magnitude reduction in colony forming units per - 17 040718 one gram (CFU/g), optionally, at least 3 orders of magnitude reduction in CFU/g of at least one type of pathogen. 4. Packaging according to claim 2, characterized in that at least one pathogen is selected from the group consisting of: Salmonella, E. coli, Listeria and Geotrichum. 5. Packaging according to any one of the preceding claims, characterized in that the product is a food product. 6. A package according to claim 2, 3 or 4, characterized in that the product is a food product and the antimicrobial releasing agent and/or chlorine dioxide gas is present in an amount sufficient to effect at least a 2 orders of magnitude reduction in CFU/ g, optionally at least 3 orders of magnitude CFU/g reduction of at least one type of pathogen without causing deterioration in the organoleptic properties of the food product. 7. A package according to any one of the preceding claims, characterized in that the polymer product with inclusions is provided in the form of a film with a thickness of 0.1 to 1.0 mm. 8. A package according to any one of the preceding claims, characterized in that the container comprises a base, and one or more side walls extending vertically from the base to the top opening, and a lid that closes and/or seals the top opening to form a closed container. 9. The package according to claim 8, characterized in that the polymer product with inclusions is a film located on at least one side wall, which has a side wall center line equidistant from the base and the opening, and the film has a film center line, equidistant from the top edge and the bottom edge of the film, and the center line of the film is located at least at the same height as the center line of the side wall. 10. The package according to claim 9, characterized in that the film is located at a vertical height which is from 80 to 100% of the total height of the side wall, measured from the lower surface of the base. 11. A package according to any one of the preceding claims, characterized in that the antimicrobial release agent is a powder mixture containing a catalyst and a moisture-responsive activator. 12. A package according to claim 11, wherein the alkali metal chlorite is sodium chlorite or potassium chlorite, the catalyst is sulphate clay, and the moisture-reactive activator is calcium chloride. 13. A package according to any one of the preceding claims, characterized in that the article of polymer with inclusions is coated with a polymeric protective layer designed to control the entry of moisture into the polymer. 14. A package according to any one of the preceding claims, characterized in that the main polymer is polypropylene, polyethylene, polyisoprene, polybutadiene, polybutene, ethylene-vinyl acetate copolymer, ethylene-methacrylate copolymer, polyvinyl chloride, polystyrene, or copolymers or mixtures thereof. 15. A package according to any one of the preceding claims, characterized in that the channeling agent is polyethylene glycol (PEG), ethylene vinyl alcohol (EVOH), polyvinyl alcohol (PVOH), or mixtures thereof. 16. A method for suppressing or preventing the growth of microbes and/or killing microbes in a closed package in which a food product is located, the method comprising: a) providing a closed container that delimits the internal space within itself; b) provision of the food product in the interior space; c) provision of free space above the product, formed within the volume of internal space that is not occupied by the product, and d) providing an antimicrobial release agent in the interior comprising alkali metal chlorite that releases chlorine dioxide gas into the headspace by reacting the alkali metal chlorite with moisture, the antimicrobial release agent being provided in an amount sufficient to release chlorine dioxide gas to provide a desired headspace concentration of chlorine dioxide gas over a predetermined period of time; wherein the antimicrobial release agent is provided in at least one inclusion polymer article disposed in the internal space, wherein the inclusion polymer article comprises a monolithic material that contains a base polymer, an antimicrobial release agent, and a channel-forming agent, wherein the monolithic material is characterized by channels extending through the polymer with inclusions formed by the channeling agent, and if the product is contaminated with at least one type of pathogen while the product is exposed to the interior, the antimicrobial releasing agent provides a controlled release of antimicrobial gas for exercise, after 13 days at a temperature