Oxygen-permeable packaging film

Abstract

The present disclosure relates to compostable films, and more particularly to compostable films having desirable oxygen transmission properties for packaging perishable foods, such as seafood. According to one aspect, the present disclosure relates to a compostable packaging film comprising a flexible packaging material defining a plurality of pores and having a barrier coating for adjusting oxygen transmission rate. According to another aspect, the present disclosure relates to a method for preparing a packaging film, the method comprising: (a) providing a polymeric film having an interior food-contact surface and a surface facing the exterior environment opposite the interior surface; (b) modifying the polymeric film by microperforation to increase the oxygen transmission rate of the packaging film; and (c) applying a barrier coating to the exterior surface to further adjust the oxygen transmission rate of the packaging film. In one embodiment, the packaging film may be an antimicrobial film.

Description

[Technical Field]

[0001] Field FIELD OF THE DISCLOSURE

[0001] This disclosure relates to packaging films, and more particularly to packaging films having oxygen permeable properties. [Background technology]

[0002] background

[0002] Packaging films are important tools for transporting and extending the shelf life of perishable goods, including food and medicine, by avoiding environmental pollution. Compostable films for packaging are desirable if their properties are suitable for a particular application.

[0003] BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0004] [Figure 1]

[0004] A diagram of a packaging film according to one embodiment of the present disclosure is shown. [Figure 2]

[0005] Molecular structure of polybutylene adipate terephthalate (PBAT). [Figure 3]

[0006] 1 is a flowchart illustrating a method for manufacturing a packaging film according to an embodiment of the present disclosure. [Figure 4]

[0007] 1 is a schematic diagram of a method for manufacturing a packaging film according to an embodiment of the present disclosure. [Figure 5]

[0008] 1 shows a diagram of a packaging film according to one embodiment of the present disclosure. [Figure 6]

[0009] 1 shows a cross-sectional view of a packaging film according to one embodiment of the present disclosure. [Figure 7]

[0010] 1 shows a cross-sectional view of a packaging film having an antimicrobial agent bonded to the food contact film side according to one embodiment of the present disclosure. [Figure 8]

[0011] 1 is a flowchart illustrating a method for manufacturing a packaging film according to an embodiment of the present disclosure. [Figure 9]

[0012] FIG. 1 is a schematic diagram of oxygen plasma treatment of a polymer film to generate functional groups on the surface of the film. [Figure 10]

[0013] 1 shows transmittance percentage versus wave number (cm −1 ) in PBAT attenuated total reflectance (ATR) FTIR analysis of Samples S1 to S7 of Example 1. [Figure 11]

[0014] 1 shows the transmittance percentage versus wave number (cm −1 ) of PBAT ATR-FTIR for Sample S7 and Sample S7b in Example 1. [Figure 12]

[0015] Figure 1 shows the antibacterial effect of functionalized PBAT films against Escherichia coli (E. coli) treated salmon fish after 24 hours at room temperature. [Figure 13]

[0016] 1 shows photographic images of agar plates of different samples after microbiological analysis showing the visual difference between the control and plasma-treated film systems. [Figure 14]

[0017] FIG. 1 is a schematic diagram of a method for producing a PBAT film according to one embodiment of the present invention. [Figure 15]

[0018] 1 shows the OTR effect of perforated PBAT film. [Figure 16]

[0019] Figure 1 shows the OTR effect of various barrier coating thicknesses on PBAT film. [Figure 17]

[0020] 1 shows the effect of pore density in PBAT films on oxygen permeability. [Figure 18]

[0021] 1 shows the oxygen permeability effect of a barrier coating on a PBAT film. [Figure 19]

[0022] 1 shows the vacuum effect of perforating and barrier coating PBAT film. [Figure 20]

[0023] 1 shows the vacuum effect of perforating and barrier coating PBAT film. [Figure 21]

[0024] 1 shows the vacuum effect of perforating and barrier coating a PBAT film over time. DETAILED DESCRIPTION OF THE INVENTION

[0005] Detailed Description

[0025] The present disclosure relates to compostable films, and more particularly to flexible packaging materials, such as compostable films, that have desirable oxygen transmission properties for packaging perishable food products, such as seafood products.

[0006]

[0026] According to one aspect, the present disclosure relates to a compostable packaging film including a flexible packaging material having a barrier coating for controlling oxygen transmission rate and defining a plurality of pores. The compostable packaging film may include a flexible packaging material having an interior food-contact surface and a surface facing an external environment opposite the interior surface, the flexible packaging material defining a plurality of pores fluidly connecting the interior and exterior surfaces, and a barrier coating covering the exterior surface and covering the plurality of pores on the exterior surface.

[0007]

[0027] According to another aspect, the present disclosure relates to a method of preparing a packaging film, the method including: (a) providing a polymeric film having an interior food contact surface and a surface facing an exterior environment opposite the interior surface; (b) modifying the polymeric film by microperforation, such as by laser, heat, vacuum, or needle microperforation or other means, to increase the oxygen transmission rate of the packaging film; and (c) applying a barrier coating to the exterior surface to further adjust the oxygen transmission rate of the packaging film. In one embodiment, the packaging film may include an antimicrobial film.

[0008]

[0028] According to another aspect, the present disclosure relates to a method of preparing a packaging film, the method including: (a) providing a polymeric film having an interior food contact surface and a surface facing an exterior environment opposite the interior surface; (b) modifying the polymeric film by microperforation, such as laser microperforation, to increase the oxygen permeability of the packaging film; (c) applying a barrier coating to the exterior surface to further adjust the oxygen permeability of the packaging film; (d) modifying the interior surface by UV, chemical oxidation, plasma, or corona treatment; (e) chemically bonding an antimicrobial agent to the modified interior surface; (f) modifying the interior surface by UV, chemical oxidation, plasma, or corona treatment; and (g) chemically bonding an antimicrobial agent to the modified interior surface.

[0009]

[0029] Pores, which may be formed by, for example, channels or perforations, may allow fluid flow, such as gas flow, across the packaging material at a particular rate. A barrier coating on one surface of the packaging material that covers some or substantially all of the pores on one side of the surface can further regulate the rate of fluid flow as a function of the thickness or composition of the barrier coating. Thus, the overall rate of fluid flow across the film can be regulated by the pores of the packaging material, including the size and distribution of the pores, and the thickness and composition of the barrier coating on the surface of the packaging material.

[0010]

[0030] For simplicity and clarity of description, reference numbers may be repeated among the figures to indicate corresponding or similar elements. Numerous details have been described to provide an understanding of the embodiments described herein. The embodiments may be practiced without these details. In other instances, well-known methods, procedures, and components have not been described in detail to avoid obscuring the described embodiments. The description should not be considered as limiting the scope of the embodiments described herein.

[0011]

[0031] Introduction

[0032] Clostridium botulinum (C. botulinum) is a spore-forming bacterium that can release botulinum toxins during growth [2-4]. These toxins can cause botulism in humans, even when ingested in small amounts [2-4]. The U.S. Food and Drug Administration (FDA) has identified it as a major food safety risk, particularly for fresh seafood products, where C. botulinum has been shown to grow when packaged under vacuum conditions. Therefore, according to FDA guidelines, fresh seafood must be packaged and transported under aerobic conditions using packaging with a high gas transmission rate (GTR), e.g., a high oxygen transmission rate (OTR).

[0012]

[0033] Skin packaging has emerged as a desirable method for packaging perishable items such as fresh fish because it can provide a better customer experience. Skin packaging can be similar to vacuum packaging, except that the film can be heated before being vacuum-sealed to the fresh fish to make it more aesthetically appealing. Additional advantages of skin packaging over other forms of packaging include reduced packaging material waste, extended product shelf life, and reduced dripping. Therefore, to ensure that fish and seafood products can be safely skin-packaged, the packaging film must allow sufficient oxygen transmission while also retaining the vacuum.

[0013]

[0034] Compostable films for packaging are desirable if the properties of the compostable film are suitable for a particular application. In particular, packaging films with a certain level of OTR may be desirable. For example, FDA regulations for vacuum / skin packaging of fresh seafood require that packaging films have an OTR of 10,000 cc / m². 2 Requires having an OTR of at least / day.

[0014]

[0035] Therefore, films with suitable OTR and compostable films are desirable, especially with growing concerns about plastic pollution and increasing demand for sustainable packaging. Compostable films according to one or more embodiments may further include an antimicrobial agent, as described herein.

[0015]

[0036] Compostable film with desirable OTR

[0037] Embodiments of the present disclosure provide compostable films and methods for applying the films to packaging, where the films have desirable oxygen transmission properties. For example, the compostable films have a transmission rate of 7,000 cc / m 2 / day, e.g., about 10,000cc / m 2 In another example, the compostable film may have an oxygen transmission rate of about 7,000 cc / m 2 / day or less.

[0016]

[0038] In one aspect, the present disclosure provides a compostable packaging film including a flexible packaging material having an interior food contact surface and an exterior environment facing surface opposite the interior surface, the flexible packaging material may define a plurality of pores fluidly connecting the interior and exterior surfaces, and a barrier coating coating the exterior surface and covering the plurality of pores on the exterior surface.

[0017]

[0039] In one or more embodiments, the packaging film may include an antimicrobial agent chemically bonded to the interior surface, such as the antimicrobial agents described herein. The packaging film can include a hydrogel layer disposed on the interior surface, such as the hydrogel layers described herein.

[0018]

[0040] In one or more embodiments, a packaging film is provided, comprising a polymer film having an inner food contact surface and an antimicrobial agent chemically bonded to the inner surface. The polymer may be a compostable polymer. The polymer may be a polymer selected from the group consisting of polybutylene adipate terephthalate (PBAT), polylactic acid, polyhydroxyalkanoate, polybutylene succinate, cellulosic materials, polyglycolic acid, polycaprolactone, polyvinyl alcohol, carbohydrate-based materials, protein-based materials, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, and combinations thereof. The polymer may be PBAT.

[0019]

[0041] In one aspect, the present disclosure provides a method of preparing a packaging film, the method comprising providing a polymeric film having a surface and modifying the surface by laser microperforation to increase the oxygen permeability of the packaging film.

[0020]

[0042] In one aspect, there is provided a packaging film prepared according to the methods described herein. The packaging film may be compostable or at least partially compostable.

[0021]

[0043] In one aspect, there is provided a use of the packaging film described herein in packaging a perishable item, wherein the surface of the film may be configured to contact the surface of the perishable item.

[0022]

[0044] As used herein, "oxygen transmission rate" or OTR is a measure of the rate at which oxygen permeates through a given material. OTR values ​​are expressed in cc / m2 / day, or the volume of oxygen (measured in cubic centimeters) per surface area of ​​material (measured in square meters) per day. In one example (Example 4), the PBAT film had a 700 cc / m 2 As used herein, 1000 cc / m is determined to have an OTR of 1000 cc / m. 2 / day, e.g., about 700cc / m 2 An OTR value of about 10,000 cc / m² / day can be considered a "low OTR." In another example (Example 5), a compostable film is disclosed that has an increased OTR because the surface of the film contains multiple pores. As used herein, about 10,000 cc / m² 2 An OTR value of 1 / day may be considered a "high OTR."

[0023]

[0045] polymer film

[0046] 1 shows a diagram of a packaging film according to one embodiment of the present disclosure. The packaging film according to an embodiment of the present disclosure defines a plurality of pores and has a capacity of about 10,000 cc / m 2 / day or approximately 10,000cc / m 2 The flexible packaging material includes a flexible packaging material having an oxygen transmission rate of greater than 100 / day. Figure 1 shows an embodiment of a packaging film (1) having an interior food contact surface (2), the interior surface (2) defining a plurality of pores (not shown). The plurality of pores can fluidly connect the interior surface to an exterior surface opposite the interior surface of the flexible packaging material (not shown) to allow gas flow through the plurality of pores. The plurality of pores may alternatively be referred to as, for example, a plurality of perforations or a plurality of channels.

[0024]

[0047] In one or more embodiments, the present disclosure provides a packaging film comprising: a flexible packaging material having an interior food contact surface and an exterior environment facing surface opposite the interior surface, the flexible packaging material defining a plurality of pores fluidly connecting the interior and exterior surfaces; and a barrier coating coating the exterior surface and covering the plurality of pores on the exterior surface. The packaging film may be compostable. The packaging film may comprise a polymer film. The polymer may be compostable.

[0025]

[0048] The pores may be micropores. The micropores may range in size from about 1 to about 250 μm, e.g., about 50 μm, about 65 μm, or about 80 μm. The pores may be substantially the same size or may have a variety of sizes. The flexible packaging material may define a plurality of pores having a low pore density, a medium pore density, or a high pore density. The flexible packaging material may define a plurality of pores having a substantially consistent pore density or a variety of pore densities. In one or more embodiments, the polymer film has a thickness of about 1 mil to about 5 mils, e.g., about 2 mils, 2.5 mils, or 3 mils. 1 mil corresponds to 25 microns. It will be understood that the type and thickness of the flexible packaging material, as well as the size and distribution of the pores, may be varied to achieve a target characteristic, e.g., a target OTR.

[0026]

[0049] In one or more embodiments, the packaging film of the present disclosure has a viscosity of 7,000 cc / m 2 / day, e.g., about 10,000cc / m 2 / day. It will be appreciated that the target OTR may vary depending on the application. For example, a packaging film for seafood products may have an OTR of 10,000 cc / m 2 may have a target OTR of / day.

[0027]

[0050] In one or more embodiments, the method for preparing a packaging film may include forming a polymer into a polymer film before providing the polymer film. Forming the polymer into a polymer film may include extruding a polymer resin into a polymer film by film blowing or film casting. The polymer may be a compostable polymer. The polymer may be selected from the group consisting of polybutylene adipate terephthalate (PBAT), polylactic acid, polyhydroxyalkanoate, polybutylene succinate, cellulosic materials, polyglycolic acid, polycaprolactone, polyvinyl alcohol, carbohydrate-based materials, protein-based materials, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, and combinations thereof. The polymer may be PBAT. The polymer film may have a thickness of about 1 μm to about 500 μm.

[0028]

[0051] In one or more embodiments, the method of preparing the packaging film may include applying a gel coating to the exterior surface to further adjust the oxygen transmission rate of the packaging film.

[0029]

[0052] In one or more embodiments, the method of preparing a packaging film can include adjusting the oxygen transmission rate of the packaging film by varying the thickness of the applied gel coating.

[0030]

[0053] In one or more embodiments, the gel coating may include one or more fillers to further adjust oxygen permeability.

[0031]

[0054] In one or more embodiments, the one or more fillers can be selected from the group consisting of porous micro- and nanoparticles made of organic and inorganic materials, including, but not limited to, silicon, amorphous silica, diatomaceous earth, silicon dioxide, aluminum-based particles, zeolites, calcium carbonate, kaolin, alumina trihydrate, calcium sulfate, carbon-based particles, gold, silver, copper, zinc, and their oxides. Biopolymer particles include, but are not limited to, cellulose-based particles, chitin, gelatin, chitosan, alginate, polylactic acid, and polyglycolic acid. Synthetic polymer particles include, but are not limited to, polymethyl methacrylate, polystyrene, polyacrylate, polytetrafluoroethylene, poly(vinyl acetate), poly(vinyl chloride), and the like.

[0032]

[0055] In one or more embodiments, the method of preparing a packaging film may further include applying a barrier coating to the exterior surface to further adjust the oxygen transmission rate of the packaging film.

[0033]

[0056] In one or more embodiments, the method of preparing a packaging film may further include adjusting the oxygen transmission rate of the packaging film by varying the thickness of the applied barrier coating.

[0034]

[0057] In one or more embodiments, the method for preparing a packaging film may be applied by a controlled deposition technique, which may be selected from the group consisting of Mayer rod coating, doctor blade, spray deposition, Langmuir-Blodgett film deposition, and slot die coating. The barrier coating may be chemically crosslinked to form a substantially stable hydrogel-like coating.

[0035]

[0058] The polymer film may comprise one or more polymers. The polymer film may comprise a compostable or biodegradable polymer. The polymer film may comprise, for example, PBAT, polylactic acid, polyhydroxyalkanoate, polybutylene succinate, cellulosic materials, polyglycolic acid, polycaprolactone, polyvinyl alcohol, carbohydrate-based materials, protein-based materials, or combinations thereof. The polymer film may also be a non-biodegradable polymer. The polymer film may comprise polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, or combinations thereof. The polymer film may comprise PBAT, polylactic acid, polyhydroxyalkanoate, polybutylene succinate, cellulosic materials, polyglycolic acid, polycaprolactone, polyvinyl alcohol, carbohydrate-based materials, protein-based materials, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, or combinations thereof.

[0036]

[0059] FIG. 2 shows the chemical structure of PBAT.

[0037]

[0060] Packaging films according to embodiments of the present disclosure may include other components. Packaging films may specifically exclude other components. Packaging films may be substantially free of or completely free of inorganic components. Packaging films may be free of antibiotic drugs. As used herein, the term "antibiotic drug" may be used interchangeably with "small molecule antibiotic" and encompasses small molecule antibiotics with various mechanisms of action, including targeting cell walls / membranes or interfering with bacterial enzymes. As used herein, the terms "antibacterial agent" or "antibacterial agent" include, for example, IgY, a protein that primarily targets the bacterial surface and can induce its antibacterial effect through structural changes to the bacterial surface. [8] As used herein, the term "substantially free" means about 30% by weight or less. As used herein, the term "completely free" means about 1% by weight or less.

[0038]

[0061] Packaging films according to embodiments of the present disclosure can be used in any suitable packaging product, such as a film, tray, or solid backing.

[0039]

[0062] 3 is a flowchart illustrating a method for manufacturing a packaging film according to one embodiment of the present disclosure. In one embodiment, the method includes the steps of: (a) providing a polymeric film having an interior food-contact surface and a surface facing the exterior environment opposite the interior surface; (b) modifying the polymeric film by microperforation, e.g., laser microperforation or other microperforation means, to increase the oxygen permeability of the packaging film; and (c) applying a barrier coating to the exterior surface to further adjust the oxygen permeability of the packaging film. The method may include forming a polymer into a polymeric film prior to step (a). The polymer may be a compostable polymer.

[0040]

[0063] In one or more embodiments, the method of preparing a packaging film may further include modifying the surface by UV, chemical oxidation, plasma, or corona treatment and chemically bonding an antimicrobial agent to the modified interior surface. Chemically bonding the antimicrobial agent to the modified interior surface may include chemically bonding a hydrogel layer to the modified interior surface. Modifying the interior surface by UV, chemical oxidation, plasma, or corona treatment and chemically bonding the antimicrobial agent to the modified interior surface may be performed as described herein to achieve a packaging film comprising a polymer film, the surface of which defines a plurality of pores, and an antimicrobial agent chemically bonded to the surface.

[0041]

[0064] Figure 4 is a schematic diagram of a method for producing a micro-perforated packaging film (11) from an extruded film (4) according to one embodiment of the present disclosure. The hole size in the micro-perforated extruded film 11 is exaggerated in Figure 4 to aid in illustration. Micro-perforation can be accomplished by known means, including laser, needle, or other means.

[0042] OTR adjustment

[0065] The OTR can be adjusted in one or more ways, including by selecting a desired pore size, pore density, providing a coating layer, barrier coating thickness, barrier coating composition, and / or other means.

[0043]

[0066] The packaging films described herein can be used for any suitable purpose. Packaging films with a desired OTR can be used to package one or more specific perishable items or related devices. The perishable items can be food, chemicals, pharmaceuticals, plants, and animal products. The perishable items can be food products. The food products can be meat, poultry, pork, fruits, vegetables, or seafood. The food products can be fish, such as salmon, branzino, tilapia, sardine, cod, flounder, perch, walleye, catfish, tuna, yellowtail, amberjack, snapper, swordfish, grouper, trout, bluefish, mackerel, sardines, anchovies, or herring. The food products can be whole fish or fish parts, such as fish fillets.

[0044]

[0067] The packaging may be entirely composed of packaging film, or the packaging film may be only one component of the packaging. The inner surface of the film may be configured to contact the surface of the perishable item. The hydrogel layer of the film may be configured to contact the surface of the perishable item. The antimicrobial agent may remain substantially bound to the film and may not diffuse into the perishable food. The packaging may inhibit microbial growth on the perishable item. The packaging may inhibit bacterial growth on the perishable item by up to 10,000 times (i.e., 4 logs) compared to a PBAT film control without the antimicrobial surface. The packaging, or portions of the packaging, may be compostable or biodegradable.

[0045]

[0068] The packaging may also be used for medical applications such as wound care. The packaging may be used for cannabis-related packaging, such as packaging for cannabis plants or products. The packaging may also be used for other applications, such as meal kits, filtration membranes, water treatment, and textiles.

[0046]

[0069] Pore ​​size and / or density

[0070] To achieve the desired OTR of the packaging material, rolls of PBAT can be prepared by melting commercially available PBAT resin and passing it through a blown film extruder to a final thickness of about 10 μm to about 500 μm. Micropores can be created by techniques known in the art, such as laser, needle, hot pin perforation, cold pin perforation, slit perforation, tear line perforation, punch perforation, rotary punch perforation, heat perforation, vacuum perforation, embossing, and other techniques. Perforations can range from about 60 μm to about 100 μm, and pore densities can range from about 100 to about 10,000 perforations / m. 2 It may vary.

[0047]

[0071] Figure 5 shows a diagram of a packaging film according to one embodiment of the present disclosure. The film (4) can include an interior food contact surface (3) and an exterior environment facing surface (5).

[0048]

[0072] Figure 6 shows a cross-sectional view of a packaging film according to one embodiment of the present disclosure. The embodiment of Figure 6 shows a packaging film (6). The exterior of the film may be coated with a barrier coating (8). The packaging film (6) may be a compostable, micro-perforated packaging film.

[0049]

[0073] The polymer film (6) may be modified by laser micro-perforation or other micro-perforation means to create a plurality of pores (7) to increase the oxygen transmission rate of the packaging film. A barrier coating (8) may be applied to the exterior surface (5) of the polymer film (6) to further adjust the oxygen transmission rate of the packaging film. The thickness or composition of the barrier coating may be selected to adjust the OTR through the packaging film. The polymer film (6) may be further treated by corona treatment, plasma treatment, or chemical oxidation to create a more reactive exterior surface (5) prior to application of the barrier coating (8).

[0050]

[0074] Coating Layers and / or Barrier Coatings

[0075] Functional chemical groups for covalent bonding of coating layers used to further adjust the OTR of the film can be generated on the surface of the PBAT film by corona treatment in ambient air for about 1 to 30 seconds at a power range of about 0.2 kW to about 1.6 kW. The functional groups formed on the surface of the PBAT film after corona treatment can include, but are not limited to, carboxyl groups, ketones, alcohols, aldehydes, and epoxides.

[0051]

[0076] After corona treatment, a barrier coating can be prepared using an aqueous mixture of 1-10% (w / v) medium-viscosity carboxymethylcellulose (CMC) sodium salt, about 1% w / v to about 20% w / v of dried fish gelatin, and about 1% w / v to about 20% w / v of a filler such as diatomaceous earth. The CMC / gelatin coating can then be chemically crosslinked using an aqueous solution containing about 1 mg / mL to about 50 mg / mL of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and about 1 mg / mL to about 50 mg / mL of N-hydroxysuccinimide (NHS). The activated solution can be poured onto the corona-treated PBAT film and spread using techniques known in the coating art, such as a Mayer rod, gravure, doctor knife, or other means, to create a uniform coating with a thickness of about 5 μm to about 50 μm. The coated film can be thoroughly dried by ambient air or any other forced air drying technique such as an air knife or convection oven or other means.

[0052]

[0077] In one or more embodiments, the packaging film may include a barrier coating on the exterior surface to further control or regulate GTR through the packaging film. The barrier may cover all or substantially all pores on the exterior surface. The barrier coating may include at least one biopolymer. The barrier coating may cover substantially all pores. The barrier coating may include at least one biopolymer that may be crosslinked to form a substantially stable hydrogel-like coating. The barrier coating may have a specific thickness or composition to regulate the GTR of the packaging film depending on the application.

[0053]

[0078] Figure 7 shows a cross-sectional view of a packaging film according to one embodiment of the present disclosure. The embodiment of Figure 7 shows a packaging film (11). The exterior of the film may be coated with a modifiable OTR control gel (12). The packaging film (10) may be a compostable, antimicrobial, micro-perforated packaging film.

[0054]

[0079] Figure 7 shows one embodiment of a packaging film (11) having an interior food contact surface and an antimicrobial agent (9) bonded to the interior surface via a chemical bond. The interior surface of Figure 7 may be a surface having a plurality of pores (10), such as a microperforated surface. The packaging film may further include a hydrogel layer disposed on the surface, which may include the antimicrobial agent. In one embodiment, the hydrogel layer may be the antimicrobial agent. In another embodiment, the hydrogel layer may be linked to the antimicrobial agent.

[0055]

[0080] A barrier coating on the exterior surface can further adjust or regulate the oxygen transmission rate of the packaging film. A method of preparing a packaging film may include adjusting the oxygen transmission rate of the packaging film by varying the thickness of the applied barrier coating.

[0056]

[0081] The method of preparing a packaging film may include applying a barrier coating by a controlled deposition technique, which may be selected from the group consisting of Mayer rod coating, doctor blade, spray deposition, Langmuir-Blodgett film deposition, and slot die coating. The barrier coating may be chemically crosslinked to form a substantially stable hydrogel-like coating.

[0057]

[0082] In one or more embodiments, the method of preparing a packaging film can include adjusting the oxygen permeability of the packaging film by selecting a gel coating thickness to further adjust the oxygen permeability, and applying the gel coating using the selected thickness.

[0058]

[0083] vacuum maintenance

[0084] In one or more embodiments, the packaging film of the present disclosure has a viscosity of about 7,000 cc / m 2 / day or less. It will be appreciated that the target OTR may vary depending on the application.

[0059]

[0085] In one or more embodiments, the packaging film may be configured to retain a vacuum. The packaging film may be configured to retain a vacuum for use in vacuum packaging, such as skin packaging for seafood. The film may be configured to retain a vacuum for about one day or more, such as about one week or more, or about two weeks or more.

[0060]

[0086] Antibacterial properties

[0087] In one or more embodiments, the compostable film having oxygen permeability properties may be an antimicrobial film, more specifically, an antimicrobial film for packaging perishable items. According to one embodiment, the present disclosure provides a packaging film comprising a polymeric film having an interior food contact surface and an antimicrobial agent chemically bonded to the interior surface. The polymeric film having the interior food contact surface may be a compostable microperforated film. According to another embodiment, the present disclosure provides a method for preparing a packaging film, the method comprising: (a) providing a polymeric film having an interior food contact surface; (b) modifying the interior surface by microperforation and further by UV, chemical oxidation, plasma, or corona treatment; and (c) chemically bonding an antimicrobial agent to the modified interior surface. In one embodiment, the packaging film can be used to package perishable items.

[0061]

[0088] Some examples of known packaging films are as follows: Korean Patent No. 101417767B1 teaches an antibacterial film for food packaging containing chitosan and an inorganic antibacterial agent and a method for manufacturing the same; Chinese Patent No. 713367B1 teaches a method for extending the refrigerated storage period of peeled shrimp by maintaining freshness with an antibacterial active material in combination with maintaining freshness under a modified atmosphere; and U.S. Patent No. 10494493B1 teaches a biodegradable composite film with antibacterial properties consisting of nanocellulose fibers, chitosan, and S-nitroso-N-acetylpenicillamine (SNAP) for food packaging applications. Other examples can be found in WO 2018106191A1, CN 110105612A, CN 110591300A, KR 20190119501A, CN 110127769, U.S. 20060154894A1, WO 2019113520, U.S. 2012232191, and U.S. 20180340049, although this is not an exhaustive list.

[0062]

[0089] In view of the shortcomings of existing antimicrobial packaging technologies, embodiments of the present disclosure aim to produce customizable packaging films that respond to the development of antimicrobial resistance, such that various antimicrobial agents can be incorporated, either alone or in combination. This may, for example, increase the suitability of a given packaging film or film type for an increasing number of microbial targets. Furthermore, customization may enable targeting of the most commonly found microorganisms depending on the package contents.

[0063]

[0090] In one embodiment, an antimicrobial film according to the present disclosure can be produced by chemically bonding a thin hydrogel layer to the surface of a substrate, such as PBAT, to impart antimicrobial properties. The mechanism of action of the film can be to have an effective antimicrobial surface upon contact with perishable items, without the antimicrobial agent diffusing from the surface into the food.

[0064]

[0091] The thin hydrogel layer may be composed of an IgY antibody and chitosan.

[0065]

[0092] IgY against Escherichia coli (E. coli) can be produced by immunizing chickens with fully inactivated E. coli, which results in the production of IgY in the egg yolk. Chitosan may also be used because it has antibacterial properties but also anchors IgY to the PBAT surface and provides a matrix component for a hydrogel that swells upon contact with the surface of, for example, a fish fillet.

[0066]

[0093] The use of IgY antibodies may allow for the customization of antimicrobial properties to target specific microorganisms, such as bacteria. This ability to specifically target bacteria and customize the formulation depending on the most harmful microorganisms for a given perishable item can improve the shelf life of that item.

[0067]

[0094] Unlike broad-spectrum antibacterial agents, IgY can be produced to target resistant bacteria that can build up resistance to widely used antibacterial agents. The experiments herein were performed using IgY produced against Escherichia coli (E. coli). However, IgY against other microorganisms, such as three of the main spoilage bacteria in fresh salmon, may also be possible.

[0068]

[0095] The antibacterial agent can be immunoglobulin Y (IgY). The IgY can be against bacteria, viruses, or fungi. The IgY can be against viruses, such as Sars-CoV-2. The IgY can be against bacteria, such as spoilage or contaminating bacteria. The IgY can be against bacteria selected from the group consisting of Escherichia coli, Shewanella putrefaciens, Pseudomonas fluorescens, Photobacterium phosphoreum, Listeria monocytogenes, Lactic Acid Bacteria, and Clostridium botulinum. The IgY can be against Escherichia coli (E. coli). The IgY can be IgY against viruses, for example, SARS-related coronaviruses such as SARS-CoV and SARS-CoV-2, influenza A and B, such as types A H1N1, H3N2, or types B Victoria and Yamagata. IgY can be isolated from chicken egg yolk. IgY against Escherichia coli (E. coli) can be isolated from chicken egg yolk produced in chickens immunized with completely inactivated E. coli bacteria. IgY can also be produced by any other suitable method, such as methods well known in the art (see, for example, references [1 and 5-7]).

[0069]

[0096] The terms chemically bonded, covalently bonded, and crosslinked may be used interchangeably. Chemically bonded may include any means of linking the antimicrobial agent to the interior surface, such as by covalent bond formation. For example, the antimicrobial agent may be covalently bonded to the hydrogel by an amide bond. The hydrogel may be chemically bonded to the film surface. The hydrogel itself may be an antimicrobial agent. The hydrogel may be a weak antimicrobial agent. The hydrogel may not be an antimicrobial agent or may be bonded to an antimicrobial agent.

[0070]

[0097] The hydrogel layer may comprise one or more polymers. The hydrogel layer may be natural, naturally derived, or synthetic. The hydrogel layer may be selected from dextran, cellulose and its derivatives (e.g., carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, hydroxypropylmethylcellulose, cellulose acetate phthalate), hyaluronic acid, chitosan, gelatin, starch, pectin, alginate, polyacrylamide, polyacrylic acid, polymethylmethacrylate, polylactic acid, polyvinylpyrrolidone, poly(2-hydroxyethylmethacrylate), and combinations thereof.

[0071]

[0098] 8 is a flowchart illustrating a method for manufacturing a packaging film according to one embodiment of the present disclosure. In one embodiment, the method includes the steps of: (a) providing a polymer film having an interior food contact surface; (b) modifying the interior surface with UV, chemical oxidation plasma, or corona treatment; and (c) chemically bonding an antimicrobial agent to the modified interior surface. The method may include forming the polymer into a polymer film prior to step (a).

[0072]

[0099] The method may include extruding the polymer resin into a polymer film by film blowing or film casting. It will be understood that any other suitable means of forming a polymer film may be used without departing from the scope of the present disclosure. The polymer film may be formed from PBAT, polylactic acid, polyhydroxyalkanoate, polybutylene succinate, cellulosic materials, polyglycolic acid, polycaprolactone, polyvinyl alcohol, carbohydrate-based materials, protein-based materials, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, or a combination thereof. The polymer film may be formed from PBAT.

[0073]

[0100] The polymer film may have a thickness of about 10 μm to about 500 μm. The polymer film may have a thickness of about 80 μm. The polymer film may have a thickness of about 10 μm, about 20 μm, about 30 μm, about 40 μm, about 50 μm, about 60 μm, about 70 μm, about 75 μm, about 80 μm, about 85 μm, about 90 μm, about 100 μm, about 200 μm, about 300 μm, about 400 μm, or about 500 μm. The polymer film may have a thickness of about 20 to about 100 μm, about 30 to about 100 μm, about 40 to about 100 μm, about 50 to about 100 μm, about 60 to about 100 μm, about 70 to about 100 μm, about 80 to about 100 μm, about 90 to about 100 μm, about 100 to about 200 μm, about 200 to about 300 μm, about 300 to about 400 μm, about 400 to about 500 μm, about 250 to about 500 μm, about 100 to about 500 μm, about 70 to about 90 μm, about 80 to about 90 μm, about 70 to about 80 μm, about 75 to about 85 μm, or about 79 to about 81 μm.

[0074]

[0101] The step of modifying the inner surface of the polymer film by UV, plasma, or corona treatment ("step (b)" or "modification step") can be carried out by any suitable procedure or method. Treatment with UV light of an appropriate wavelength can be used to modify the inner surface. For example, the modification step can be carried out in the presence of UV light of about 100 to about 400 nm, or about 254 nm, at a power of 1 to 500,000 milliwatts, or about 15 mW, with an exposure time of about 1 to 216,000 seconds, or about 60 seconds. For example, arc discharge, corona discharge, dielectric barrier discharge, etc. can be used. Atmospheric pressure plasma can also be used. The modification step can be carried out in a plasma chamber in the presence of oxygen. The modification step can be carried out in a plasma chamber at about 5 to about 1000 watts. The modification step can be carried out at about 200 watts. The reforming step may be carried out at about 5, about 10, about 20, about 50, about 100, about 150, about 200, about 250, about 300, about 350, about 400, about 450, about 500, about 600, about 700, about 800, about 900, or about 1000 watts. The reforming step may be carried out at about 150 to about 250 watts, about 150 to about 200 watts, about 200 to about 250 watts, about 100 to about 300 watts, about 100 to about 400 watts, about 100 to about 500 watts, about 100 to about 1000 watts, about 500 to about 1000 watts, about 750 to about 1000 watts, or about 50 to about 500 watts. The modification step may be carried out at any suitable pressure, such as from about 250 mTorr to about 760 mTorr. The modification step may be carried out at atmospheric pressure. The modification step may be carried out for any suitable time to achieve surface modification of the polymer film. The modification step may be carried out for a few milliseconds to a few minutes. The modification step may be carried out for about 100 milliseconds to about 10 minutes. The modification step may be carried out for about 3 minutes. The modification step may be carried out for about 1 minute, about 2 minutes, about 4 minutes, or about 5 minutes. The modification step may be carried out for less than 1 minute. The modification step may be carried out for more than 5 minutes.

[0075]

[0102] The modification step can include treating the interior surface with a solution after UV, chemical oxidation plasma, or corona treatment. The solution can be any suitable solution for facilitating surface modification of the polymer film. The solution can include a carboxylic acid. As used herein, the term "carboxylic acid" can refer to a carboxylic acid or any molecule containing a reactive carboxyl chemical group. For example, the carboxylic acid can be formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, fumaric acid, malic acid, acrylic acid, citric acid, gluconic acid, itaconic acid, adipic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, keto acids, aspartic acid, glutamic acid, sodium acetate, potassium acetate, ammonium acetate, or vinyl acetate, or a combination thereof. The carboxylic acid can be acetic acid, citric acid, or acrylic acid. The solution can be about 25% to about 99% acetic acid in water. The solution can be about 25%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, about 95%, or about 99% acetic acid in water or any suitable solvent. The solution can be glacial acetic acid or about 100% acetic acid. The modification step can include rinsing the interior surface with water after treating the interior surface with the solution. The modification step can include rinsing the interior surface with any suitable solvent after treating the interior surface with the solution.

[0076]

[0103] The step of chemically linking the antimicrobial agent to the modified interior surface ("step (c)" or "linking step") can be carried out by any suitable procedure or method. Chemical linking can include covalent bonding, cross-linking, or any means of linking the antimicrobial agent to the interior surface. The antimicrobial agent may be covalently attached to the interior surface by an amide bond. The linking step can include cross-linking the antimicrobial agent to the modified surface in the presence of a cross-linking reagent. The cross-linking reagent can be 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). The linking step can include treating the modified interior surface with the antimicrobial agent, EDC, and NHS in an aqueous solution. The linking step can include treating the modified interior surface with chitosan, IgY, EDC, and NHS in an aqueous solution. The linking step may include treating the modified interior surface with chitosan, IgY, EDC, and NHS to form a film having a chitosan hydrogel layer disposed on the interior surface, and forming amide bonds between (i) the chitosan and the film, (ii) the chitosan and the IgY, and / or (iii) the IgY and the film. The linking step may be performed under any suitable conditions for crosslinking the antimicrobial agent and the modified interior surface. The linking step may be performed at about 20 to about 60°C, e.g., about 40°C. The linking step may be performed at about room temperature to about 65°C. The linking step may be performed for about 100 milliseconds to about 1 hour. The linking step may be performed for about 15 minutes, about 30 minutes, about 45 minutes, or about 1 hour. The linking step may be performed for more than about 1 hour. The linking step may be performed for less than about 15 minutes. The linking step may be performed for less than 1 minute, e.g., less than 1 second.

[0077]

[0104] The method of manufacturing the packaging film may include washing the film to remove unreacted cross-linking reagent and / or unbound antimicrobial agent. Washing may be performed with water or any other suitable solvent.

[0078]

[0105] The packaging films described herein can be customized to target specific bacteria. The packaging films can have the ability to target bacteria that have developed resistance to other antimicrobial agents. The customizability of the films allows them to be used to package a variety of products. [Example]

[0079]

[0106] Example

[0107] Example 1

[0108] Preparation of PBAT films

[0109] PBAT is a polymer with the chemical structure shown in Figure 2. Plasma O2 treatment of polymer films can be performed as shown in Figure 9. Figure 9 is a schematic diagram of oxygen plasma treatment of a polymer film to generate functional groups on the film's surface. The functional groups formed on the surface of PBAT films after oxygen plasma treatment include carboxyl groups, alcohols, and epoxides. The carboxyl groups can then be crosslinked to amines using an EDC / NHS crosslinker. For example, ethanolamine can be used as a model amine to test the crosslinking reaction. FTIR can then be used to detect the amide bonds formed.

[0080]

[0110] A series of PBAT samples (Samples 1-7) were prepared using PBAT films previously fabricated by extruding PBAT resin into 80 μm thick sheets. This can be done, for example, by film blowing or film casting. Samples (S1-S7) were prepared as follows:

[0081]

[0111] Sample 1 (S1): PBAT film

[0112] S1 was prepared as follows: the PBAT film was washed with water. No other treatments of modification were applied.

[0082]

[0113] Sample 2 (S2): PBAT + acetic acid (AA)

[0114] S2 was prepared as follows: PBAT films were placed in glacial acetic acid for 5 min and washed three times with water.

[0083]

[0115] Sample 3 (S3): PBAT + EDC + NHS + ETH amine

[0116] S3 was prepared as follows: a PBAT film was immersed in a solution of EDC, NHS, and ethanolamine for 1 hour, and then washed with water three times.

[0084]

[0117] Sample 4 (S4). High-power plasma O2 at 180 s with PBAT, EDC, NHS, and ETH amine (PH-EDC).

[0118] S4 was prepared as follows: The PBAT film was placed in a plasma chamber at 400 watts and 250 mTorr for 3 minutes. It was then immersed in a solution of EDC, NHS, and ethanolamine for 1 hour. The film was then washed three times with water.

[0085]

[0119] Sample 5 (S5). Plasma O2 at medium power (PBAT + EDC + NHS + ETH amine (PM-EDC)) for 180 seconds.

[0120] S5 was prepared according to the method of S4, using medium power (200W) instead of high power (400W).

[0086]

[0121] Sample 6 (S6). Plasma O2 at high power for 180 seconds, followed by immersion in PBAT+EDC+NHS+ETH amine (PH-AA-EDC).

[0122] S6 was prepared as follows: A PBAT film was placed in a plasma chamber at 400 watts and 250 mTorr for 3 minutes. It was then immersed in a glacial acetic acid solution for 5 minutes. The film was then washed three times with water and then placed in a solution of EDC, NHS, and ethanolamine for 1 hour. The film was then washed three times with water.

[0087]

[0123] Sample 7 (S7). Plasma O2 at medium power for 180 seconds, followed by AA, followed by PBAT+EDC+NHS+ETH amine (PM-AA-EDC).

[0124] S7 was prepared according to the method of S6 using medium power (200W) instead of high power (400W).

[0088]

[0125] Samples S1–S7 were placed in a vacuum oven for 4 h before analysis. The samples were measured using a Bruker Alpha II instrument equipped with a diamond crystal. The spectra were taken from 4000 to 200 cm. -1 The resolution was 4cm -1 Thirty-two scans were performed for each sample. The background was automatically removed by the software. The peaks expected for secondary amides were the intense peaks (1700–1650 cm). -1 ), medium peak (1580-1500 cm -1 ), and a moderate peak (3400-3100 cm -1 )

[0089]

[0126] Figure 10 shows the ATR-FTIR analysis of samples S1 to S7. For example, Figure 10 shows the wavenumber (cm) in the PBAT attenuated total reflectance (ATR) FTIR analysis of samples S1 to S7. -1 ) is shown as a transmittance percentage. According to FIG. 10, S7 is, for example, a transmittance percentage of 1560 cm -1 , 1645cm -1 , and 3295 cm -1 The presence of a peak at 1000 nm indicates the most amide bond formation on the surface.

[0090]

[0127] Figure 11 shows the ATR-FTIR analysis of the treated (interior food contact surface) side of sample S7 (S7) and the surface facing the external environment of the film of sample 7 (S7b). Figure 11 shows that amide bonds were formed only on the surface exposed to plasma.

[0091]

[0128] Example 2

[0129] Preparation of antibacterial PBAT films

[0130] PBAT resin was extruded into 80 μm thick sheets to produce PBAT films, which can be done, for example, by film blowing or film casting.

[0092]

[0131] The sheet was then cut into film samples of the desired size for experimental or commercial purposes, for example, the sheet may be cut into 1 cm x 1 cm squares.

[0093]

[0132] A notch may be cut or other identifying means may be applied to indicate the active side of the film.

[0094]

[0133] An activation solution is then prepared as follows.

[0095]

[0134] First, prepare 100 mL of a 2.5 mg / mL chitosan solution in 0.06 M HCl (stock solution). For experimental purposes, the pH of the desired volume of chitosan solution can be adjusted by the dropwise addition of 1 M sodium hydroxide.

[0096]

[0135] Second, prepare 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) solution from a stock solution of 20 mg / mL EDC in distilled water.

[0097]

[0136] Third, prepare N-hydroxysuccinimide (NHS) solution from a stock solution of 20 mg / ml NHS in distilled water.

[0098]

[0137] Fourth, prepare an IgY antibody solution from a 21.5 mg / mL IgY stock solution in phosphate buffer solution. The IgY antibody used in this protocol was prepared by Exalpha Biologics specifically for Escherichia coli (E. coli).

[0099]

[0138] An antibacterial PBAT film is then prepared as follows.

[0100]

[0139] The PBAT sample film is placed in a plasma chamber and treated with oxygen at 200 W and 250 mTorr for 3 minutes. The top surface exposed to the plasma is considered the treated surface (i.e., the active or antibacterial surface), while the bottom surface is not.

[0101]

[0140] Immediately after plasma treatment, the film samples are immersed in 99% acetic acid for 5 minutes.

[0102]

[0141] The film samples are then washed 3-4 times with distilled water.

[0103]

[0142] To functionalize the films and provide an antibacterial surface, two film samples were placed in 2 mL low-binding Eppendorf tubes. 1.6 mL of 2.5 mg / mL chitosan solution and 18 μL of 0.2 mg / mL IgY solution were added to the Eppendorf tubes. Then, 0.2 mL each of freshly prepared EDC and NHS solutions were added to the Eppendorf tubes to achieve a final concentration of 2 mg / mL. The film samples were then left to undergo the crosslinking reaction for 1 hour.

[0104]

[0143] The film sample is then washed thoroughly 3-4 times for 10 min each with water to ensure complete removal of unreacted EDC, NHS, and any chitosan and IgY not bound to the film sample.

[0105]

[0144] The film samples are then allowed to dry at room temperature for 15 minutes and stored in a Petri dish until needed.

[0106]

[0145] Before use, wash the film samples with water for 10 min three to four times.

[0107]

[0146] Example 3

[0147] Efficacy of compostable active films on E. coli-treated salmon after 24 hours at room temperature (RT)

[0148] Chitosan / IgY was grafted onto PBAT films, and the developed films were then tested in situ on salmon fish inoculated with Escherichia coli (E. coli).

[0108]

[0149] method

[0150] Three types of samples were prepared:

[0151] 1. PBAT film (control): PBAT film was prepared according to the method of Example 1, S1.

[0152] 2. Plasma-treated PBAT film (PBAT + plasma): PBAT films were prepared by placing the PBAT film in a plasma chamber and treating it with oxygen at 200 W and 250 mTorr for 3 min.

[0153] 3. PBAT film grafted with chitosan and IgY (PBAT+ system): PBAT film was crosslinked with chitosan and IgY according to the method of Example 2.

[0109]

[0154] To test the specific antibacterial effect of the film against E. coli, other bacteria in the fish were first removed by sterilization with a 2.5% chlorine solution (calcium hypochlorite 70% Ca(ClO)2). The fish samples were then washed three times with water and inoculated with E. coli.

[0110]

[0155] 10 μL of 10 5 ~10 6 A 0.3 g salmon sample was inoculated with CFU / ml of pre-cultured E. coli. The fish sample was placed on one of three PBAT film samples (two pieces—one on top and one on the bottom of the fish sample, 1.5 cm). 2 ) in a covered Petri dish.

[0111]

[0156] result:

[0157] FIG. 12 shows the antibacterial effect of functionalized PBAT film against Escherichia coli (E. coli) treated with salmon fish after 24 hours at room temperature.

[0112]

[0158] FIG. 13 shows photographic images of agar plates of different samples after microbiological analysis showing the visual differences between the control and plasma-treated film systems.

[0113]

[0159] Escherichia coli (E. coli) growth in the control sample reached 6.95 log colony forming units per milliliter (CFU / mL) after a 24-hour incubation period at room temperature (RT).

[0114]

[0160] For samples incubated with plasma-treated PBAT films, bacterial growth was 6.65 log CFU / mL.

[0115]

[0161] In samples treated with functionalized (i.e., active) films, growth was 3.28 log CFU / mL, representing a reduction of approximately 3.3 log CFU / mL after 24 hours of incubation compared to the control samples.

[0116]

[0162] The results of this experiment demonstrate significant antibacterial efficacy of the activated PBAT film against Escherichia coli (E. coli). Similarly, this platform technology can include IgY produced against specific spoilage organisms (SSOs) involved in the spoilage of various fresh produce to extend shelf life [9-11]. The ability to customize the activated film also allows for targeting resistant bacteria, allowing for broad-spectrum protection (i.e., immunizing chickens with an antigen common to all Gram-negative bacteria) or highly specific targeting (i.e., antigens specific to one bacterial species).

[0117]

[0163] Example 4

[0164] PBAT films (uncoated), such as those in Examples 1 or 2, have a viscosity of 700 cc / m when tested at a thickness of 3 mils (75 microns) using ASTM D3985. 2 It was determined to have an oxygen transmission rate (OTR) of 1 / day.

[0118]

[0165] Example 5

[0166] Effect of microperforation on OTR

[0167] As mentioned above, in certain applications, 10,000cc / m 2 It may be desirable to increase the oxygen transmission rate (OTR) of a compostable film to produce a compostable film with an OTR of 100 / day. Such compostable films can be formulated to comply with FDA regulations for vacuum / skin packaging of fresh seafood.

[0119]

[0168] One approach to increasing OTR is laser microporation. For use with vacuum-packaged and skin-packaged fish fillets, the pore size and density are optimized to retain the vacuum for two weeks or more. In one or more embodiments, the packaging film may further comprise an antimicrobial formulation, such as those described herein. The effect of such coatings, along with optimization of pore size and density, can be used to control OTR.

[0120]

[0169] Baseline chemical and physical characterization can be performed on films of various thicknesses (e.g., 2 mil and 2.5 mil), and on films with or without a coating on the surface of the film, such as an antimicrobial and / or hydrogel layer. Optical microscopy, SEM, and TEM can be used to determine the thickness of the antimicrobial coating on the surface. ATR-FTR can be used to characterize the proper bonding of the coating to the surface of the film.

[0121]

[0170] The effect of laser micro-drilling hole sizes (50 μm, 65 μm, and 80 μm) can be tested on various films (e.g., on films with thicknesses of 2 and 2.5 mils). Additionally, low, medium, and high pore densities (pores / cm) can be tested to obtain the desired OTR. 2 ) various pore sizes can be studied. Pore density values ​​can be informed by CFD simulations.

[0122]

[0171] The microperforated film can be coated with an antimicrobial agent and / or hydrogel layer, such as those exemplified in Examples 1 and 2. The thickness of the antimicrobial coating, its distribution on the surface, and its ability to coat the micropores can be examined using SEM / TEM. ATR-FTR can be used to characterize the proper bonding of the coating to the surface of the film.

[0123]

[0172] In one or more embodiments, the microperforated, coated compostable film has a viscosity of 10,000 cc / m 2 It can have an OTR of 1 / day and can be configured to hold a vacuum for up to 2 weeks.

[0124]

[0173] Example 6

[0174] Adjustment of OTR of PBAT film with micro-perforations

[0175] To verify that microperforated PBAT could have a successfully applied barrier coating, rolls of PBAT were made by melting commercially available PBAT resin and passing it through a blown film extruder to a final thickness of approximately 50 µm. Laser perforations with an average size of approximately 60 µm to approximately 100 µm were then made into the blown PBAT film, producing three degrees of microperforation density: low (approximately 100 perforations / m); 2 ), medium (approximately 1000 holes / m 2 ), and high (2500 holes / m 2 ).

[0125]

[0176] Functional chemical groups for covalent bonding on the hydrogel were generated on the surface of PBAT by corona treatment at 1.6 kW for approximately 1 second in ambient air. The functional groups formed on the surface of the PBAT film after corona treatment can include, but are not limited to, carboxyl groups, ketones, alcohols, aldehydes, and epoxides.

[0126]

[0177] After corona treatment, a barrier coating was prepared using an aqueous mixture of 1% (w / v) carboxymethylcellulose (CMC) sodium salt, medium viscosity, and 20% w / v dried fish gelatin. A crosslinking solution containing 50 mg / mL 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and 50 mg / mL N-hydroxysuccinimide (NHS) was then prepared. The film was then removed from the corona treater table and placed on a flat surface. The EDC / NHS solution was mixed into the CMC / gelatin solution and mixed. The activation solution was then poured onto the corona-treated PBAT film and spread using a Mayer rod to create a uniform coating with a thickness of approximately 12.7 μm. Finally, the coated film was then completely dried. For this barrier coating, no initial filler was used to isolate the effect of the OTR pore density.

[0127]

[0178] A schematic of this procedure is shown in Figure 14.

[0128]

[0179] For control purposes, additional modified PBAT films were prepared: S8, S9, and S10.

[0129]

[0180] Sample 8 (S8) contained a PBAT film without microperforations and further modification.

[0130]

[0181] Sample 9 (S9) contained a medium density microperforated PBAT film without a coating.

[0131]

[0182] Sample 10 (S10) comprised a medium density microperforated PBAT film and an oxygen barrier coating of approximately 12.7 μm wet thickness applied (as described above) in the absence of filler.

[0132]

[0183] Samples S8-S10 were tested for their OTR using either ASTM F2714-08 or ASTM D-3985. As shown in Figure 15, the control film S8 has low oxygen permeability. Introducing microperforations into the film (S9) resulted in higher oxygen permeability. The coated film with microperforations (S10) resulted in a lower OTR than either S8 or S9.

[0133]

[0184] Example 7

[0185] Adjusting the OTR of PBAT films by coating thickness

[0186] In another example, additional modified PBAT films were prepared for control purposes: S11, S12, and S13.

[0134]

[0187] Sample 11 (S11) contained a PBAT film without microperforations and further modification.

[0135]

[0188] Sample 12 (S12) contained a PBAT film with high density microperforations and an increased coating thickness of 25.4 μm using a Mayer rod without filler present.

[0136]

[0189] Sample 13 (S13) contained a PBAT film with a high density of microperforations.

[0137]

[0190] Samples S11-S13 were tested for their OTR using ASTM D-3985. As shown in Figure 16, the control film S11 shows the oxygen permeability of a control PBAT film. Samples S12 and S13 demonstrate how varying the coating thickness can fine-tune the oxygen permeability, limiting the oxygen that can pass through the pores.

[0138]

[0191] Example 8

[0192] Tuning the OTR of PBAT films by pore density

[0193] In another example, additional modified PBAT films were prepared for control purposes: S14, S15, and S16.

[0139]

[0194] Sample 14 (S14) contained a PBAT film without microperforations and further modification.

[0140]

[0195] Sample 15 (S15) contained a PBAT film with a low density of microperforations and no further modification.

[0141]

[0196] Sample 16 (S16) contained a PBAT film with a medium density of microperforations without further modification.

[0142]

[0197] The oxygen permeability of these samples was tested by placing a 7-cm diameter film disk as a membrane between two chambers. S14 had one pore, while S15 had 11 pores within the 7-cm disk. The first chamber was an oxygen-rich environment, supplied with 93% oxygen (most of the remainder was nitrogen) at a rate of 1 L / min. The second chamber was attached to a gaseous oxygen electrochemical sensor, initially filled with ambient air. As more oxygen permeated the membrane, the electrochemical sensor detected and recorded this change. The higher the film's OTR, the faster the electrochemical sensor responded to a high-concentration oxygen flow being turned on.

[0143]

[0198] Pore ​​density can play a role in regulating the OTR through a film, as shown in Figure 17. The areas of the film where pores are present govern the rate at which oxygen can permeate the film compared to areas without pores.

[0144]

[0199] Example 9

[0200] Adjustment of OTR of PBAT film by coating composition

[0201] In another example, additional modified PBAT films were prepared for control purposes: S17, S18, S19, and S20.

[0145]

[0202] Sample 17 (S17) contained a PBAT film without microperforations and further modification.

[0146]

[0203] Sample 18 (S18) was prepared similarly to S10 in Example 6, but contained PBAT films in which 6% (w / v) DE particles were added to the initial CMC / gelatin solution and vigorously shaken. Additionally, no NHS was added, and 0.4 mL of 100 mg / mL EDC was used.

[0147]

[0204] Sample 19 (S19) contained a PBAT film prepared as S18, except that 7% (w / v) DE particles were added to the initial CMC / gelatin solution and shaken vigorously.

[0148]

[0205] Sample 20 (S20) contained a reference OTR as a film with a known OTR of 9212 cc / m2 / day as determined by ASTM D3985.

[0149]

[0206] Samples S17, S18, S19 and S20 were prepared and then placed one by one in the same oxygen permeability measurement chamber as described in Example 8. The results of this experiment are shown in FIG.

[0150]

[0207] Example 10

[0208] Maintaining a vacuum in PBAT film with a barrier coating

[0209] In another example, additional modified PBAT films were prepared for control purposes: S21, S22, and S23.

[0151]

[0210] Sample 21 (S21) contained a PBAT baseline film (no perforations or modifications to the base film).

[0152]

[0211] Sample 22 (S22) contained a perforated PBAT film, with the perforation locations shown as small black circles in Figure 19.

[0153]

[0212] Sample 23 (S23) comprised a PBAT film that was perforated and then coated with the same process as film S18 in Example 9. It is therefore a high OTR transmission film (greater than 10,000 OTR).

[0154]

[0213] A 15 cm x 25 cm sheet of PBAT was cut and folded in half lengthwise. Starting at either edge of the film, the edge was folded inward approximately 3 cm and heat-sealed for approximately 4 seconds (twice, one adjacent to the other to ensure a proper seal). This process was repeated on the other side of the film, forming a pouch. A small "puck" was 3D printed with a hole in the center and placed inside the pouch. The puck was used as a semi-quantitative measure of the vacuum within the package by measuring the distance between the two concave package sides. With proper vacuum, the package was concave inside the pack hole, but without vacuum, the package was not concave into the pack hole.

[0155]

[0214] Figure 19 shows an image of the films immediately after forming the vacuum seal. S22 did not hold the vacuum and remained slack. However, S21 and S23 both maintained their vacuum. The gap was also measured at regular intervals, and this data is shown in Figure 20. The gap measurements continued for 44 hours, and both samples (S21 and S23) held the vacuum strongly, as shown qualitatively in Figure 21 and again quantitatively in Figure 20.

[0156]

[0215] In the preceding description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the embodiments. However, it will be apparent to one skilled in the art that these specific details are not required.

[0157]

[0216] The structures, features, accessories, and alternatives of the specific embodiments described herein and shown in the drawings are intended to apply generally to all teachings of the present disclosure, including all of the embodiments described herein and shown, to the extent they are compatible. In other words, the structures, features, accessories, and alternatives of a specific embodiment are not intended to be limited to only that specific embodiment, unless otherwise indicated.

[0158]

[0217] Additionally, the steps and order of steps of the methods described herein are not meant to be limiting, and methods including different steps, a different number of steps, and / or steps in a different order are contemplated.

[0159]

[0218] The above-described embodiments are intended to be examples only. Those of skill in the art may effect changes, modifications, and variations to the particular embodiments without departing from the scope, which is defined solely by the claims appended hereto. Further numbered embodiments are outlined below.

[0160]

[0219] Embodiment Embodiment 1. A compostable packaging film, the packaging film comprising: a flexible packaging material having an interior food contact surface and a surface facing an exterior environment opposite the interior surface, the flexible packaging material defining a plurality of pores fluidly connecting the interior surface and the exterior surface; and a barrier coating covering the exterior surface and covering the plurality of pores on the exterior surface.

[0161] Embodiment 2. The film of embodiment 1, wherein the pores are micropores.

[0162] Embodiment 3. The film of embodiment 2, wherein the micropores are about 1 to about 250 μm in size, for example, about 50 μm, about 65 μm, or about 80 μm.

[0163] Embodiment 4. The film of any one of embodiments 1-3, wherein the pores are substantially the same size.

[0164] Embodiment 5. The film according to any one of embodiments 1 to 3, wherein the pores have different sizes.

[0165] Embodiment 6. The film of any one of embodiments 1-5, wherein the flexible packaging material defines a plurality of pores having a low pore density, a medium pore density, or a high pore density.

[0166] Embodiment 7. The film of any one of embodiments 1-6, wherein the flexible packaging material defines a plurality of pores at a substantially consistent pore density.

[0167] Embodiment 8. The film of any one of embodiments 1-6, wherein the flexible packaging material defines a plurality of pores having varying pore densities.

[0168] Embodiment 9. The film of any one of embodiments 1-8, wherein the flexible packaging material has a thickness of about 1 mil to about 5 mils, e.g., about 2 mils, 2.5 mils, or 3 mils.

[0169] Embodiment 10. The flexible packaging material has a viscosity of about 7,000 cc / m 2 / day, e.g., about 10,000cc / m 210. The film of any one of embodiments 1 to 9, having an oxygen permeability of 1000 sq ft / day or more.

[0170] Embodiment 11. The flexible packaging material has a viscosity of about 7,000 cc / m 2 10. The film of any one of embodiments 1 to 9, having an oxygen transmission rate of 1000 ppm or less per minute.

[0171] Embodiment 12. The film of any one of embodiments 1-11, wherein the flexible packaging material is configured to hold a vacuum.

[0172] Embodiment 13. The film of any one of embodiments 1 to 12, wherein the flexible packaging material is configured to retain a vacuum for about 1 day or more, such as about 1 week or more or about 2 weeks or more.

[0173] Embodiment 14. The film of any one of embodiments 1-13, further comprising an antimicrobial agent chemically bonded to the interior surface.

[0174] Embodiment 15. The film of any one of embodiments 1 to 14, further comprising a hydrogel layer disposed on the interior surface.

[0175] Embodiment 16. The film of any one of embodiments 1 to 15, wherein the flexible packaging material comprises a polymer selected from the group consisting of polybutylene adipate terephthalate (PBAT), polylactic acid, polyhydroxyalkanoate, polybutylene succinate, a cellulosic material, polyglycolic acid, polycaprolactone, polyvinyl alcohol, a carbohydrate-based material, a protein-based material, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, and combinations thereof.

[0176] Embodiment 17. The film of embodiment 16, wherein the polymer is PBAT.

[0177] Embodiment 18. The film of embodiment 1, wherein the barrier coating comprises at least one biopolymer.

[0178] Embodiment 19. A film according to any one of embodiments 1 to 18, wherein the barrier coating covers substantially all of the pores.

[0179] Embodiment 20. A film according to any one of embodiments 1 to 19, wherein the barrier coating is crosslinked to form a substantially stable hydrogel-like coating on the exterior surface.

[0180] Embodiment 21. A method for preparing a packaging film, comprising: (a) providing a polymeric film having an interior food contact surface and a surface facing the exterior environment opposite the interior surface; (b) modifying the polymer film by microperforation to increase the oxygen permeability of the packaging film; and (c) Applying a barrier coating to the outer surface to further adjust the oxygen transmission rate of the packaging film. A method comprising:

[0181] Embodiment 22. (d) modifying the interior surface by UV, chemical oxidation, plasma or corona treatment; and (e) Chemically bonding an antimicrobial agent to the modified interior surface. further comprising 22. The method of embodiment 21, wherein steps (d) and (e) are performed after step (b).

[0182] Embodiment 23. (f) modifying the internal surface by UV, chemical oxidation, plasma or corona treatment; and (g) Chemically bonding an antimicrobial agent to the modified interior surface. further comprising 22. The method of embodiment 21, wherein steps are performed in the order (a), (f), (g), (b), and (c).

[0183] Embodiment 24. The method of embodiment 22, wherein (d) further comprises chemically bonding a hydrogel layer to the modified interior surface.

[0184] Embodiment 25. The method of any one of embodiments 21-24, further comprising forming the polymer into a polymer film prior to step (a).

[0185] Embodiment 26. The method of embodiment 25, wherein forming the polymer into a polymer film comprises extruding the polymer resin into a polymer film by film blowing or film casting.

[0186] Embodiment 27. The method of any one of embodiments 21-26, wherein the polymer is selected from the group consisting of polybutylene adipate terephthalate (PBAT), polylactic acid, polyhydroxyalkanoate, polybutylene succinate, cellulosic materials, polyglycolic acid, polycaprolactone, polyvinyl alcohol, carbohydrate-based materials, protein-based materials, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, and combinations thereof.

[0187] Embodiment 28 The method of embodiment 27, wherein the polymer is PBAT.

[0188] Embodiment 29. The method of any one of embodiments 21 to 28, wherein the polymer film has a thickness of about 1 μm to about 500 μm.

[0189] Embodiment 30. The method of any one of embodiments 21 to 29, wherein the polymer is a compostable polymer.

[0190] Embodiment 31. The method of any one of embodiments 21-30, further comprising applying a gel coating to the exterior surface to further adjust the oxygen transmission rate of the packaging film.

[0191] Embodiment 32. Selecting the thickness of the gel coating based on the target oxygen permeability; and Controlling the oxygen transmission rate of packaging films by applying gel coatings using selected thicknesses 32. The method of embodiment 31, further comprising:

[0192] Embodiment 33. Adjusting the oxygen permeability of the packaging film by changing the thickness of the applied gel coating 33. The method of embodiment 31 or 32, further comprising:

[0193] Embodiment 34. The method of any one of embodiments 31 to 33, wherein the gel coating comprises one or more fillers to further adjust the oxygen permeability of the packaging film.

[0194] Embodiment 35. The method of embodiment 34, wherein the one or more fillers are selected from the group consisting of porous micro- and nanoparticles made of organic and inorganic materials, including but not limited to silicon, amorphous silica, diatomaceous earth, silicon dioxide, aluminum-based, zeolites, calcium carbonate, kaolin, alumina trihydrate, calcium sulfate, carbon-based particles, gold, silver, copper, zinc, and oxides thereof, and the like; the biopolymer particles include but are not limited to cellulose-based, chitin, gelatin, chitosan, alginate, polylactic acid, and polyglycolic acid; and the synthetic polymer particles include but are not limited to polymethyl methacrylate, polystyrene, polyacrylate, polytetrafluoroethylene, poly(vinyl acetate), poly(vinyl chloride), and the like.

[0195] Embodiment 36. Selecting a barrier coating thickness based on a target oxygen permeability; and Controlling the oxygen transmission rate of packaging films by applying a barrier coating using a selected thickness 36. The method of any one of embodiments 21 to 35, further comprising:

[0196] Embodiment 37. Adjusting the oxygen permeability of the packaging film by varying the thickness of the applied barrier coating 37. The method of any one of embodiments 21 to 36, further comprising:

[0197] Embodiment 38. The method of any one of embodiments 21 to 37, wherein the barrier coating is applied by a controlled deposition technique.

[0198] Embodiment 39. The method of embodiment 38, wherein the controlled deposition technique is selected from the group consisting of Mayer rod coating, doctor blade, spray deposition, Langmuir-Blodgett film deposition, and slot die coating.

[0199] Embodiment 40. The method of any one of embodiments 21 to 39, wherein the barrier coating is chemically crosslinked to form a substantially stable hydrogel-like coating.

[0200] Embodiment 41. A packaging film prepared according to the method of any one of embodiments 21 to 40.

[0201] Embodiment 42. The packaging film of embodiment 41, wherein the packaging film is compostable.

[0202] Embodiment 43. Use of a film according to any one of embodiments 1 to 20, 41 or 42 in packaging perishable items.

[0203] Embodiment 44. The use of embodiment 43, wherein the food contact surface of the film is configured to contact the surface of a perishable item.

[0204] Embodiment 45. A method for preparing a packaging film, comprising: (a) providing a polymeric film having an interior food contact surface and a surface facing the exterior environment opposite the interior surface; (b) modifying a polymer film by microperforation to increase the oxygen permeability of the packaging film; (c) applying a barrier coating to the exterior surface to further adjust the oxygen transmission rate of the packaging film; (d) modifying the internal surface by UV, chemical oxidation, plasma or corona treatment; (e) chemically bonding an antimicrobial agent to the modified interior surface; (f) modifying the internal surface by UV, chemical oxidation, plasma or corona treatment; and (g) Chemically bonding an antimicrobial agent to the modified interior surface. A method comprising:

[0205] References 1. Abbas, A.T., et al., IgY antibodies for the immunoprophylaxis and therapy of respiratory infections. Hum Vaccin Immunother, 2019. 15(1): p.264 - 275. 2. Camerini, S., Marcocci, L., Picarazzi, L., Iorio, E., Ruspantini, I., Pietrangeli, P., Crescenzi, M., & Franciosa, G. (2019). Type E Botulinum Neurotoxin - Producing Clostridium butyricum Strains Are Aerotolerant during Vegetative Growth. MSystems, 4(2). https: / / doi.org / 10.1128 / msystems.00299 - 18 3. Centers for Disease Control and Prevention. (2021, June 1). About Botulism. Retrieved September 20, 2022, from http: / / www.cdc.gov / botulism / general.html 4. Gilbert, S., Lake, R., Hudson, A., & Cressey, P. (2006). Risk Profile: Clostridium Botulinum in ready - to - eat smoked seafood in sealed packaging. A Crown of Research Institute. www.esr.cri.nz 5.Hu, B., et al., The preparation and antibacterial effect of egg yolk immunoglobulin (IgY) against the outer membrane proteins of Vibrio parahaemolyticus.J Sci Food Agric, 2019.99(5): p.2565-2571. 6.Kollberg, H., Avian antibodies (IgY) to fight antibiotic resistance.Clinical Microbiology: Open Access, 2015.4(2). 7.Sui, J., L.Cao, and H.Lin, Antibacterial activity of egg yolk antibody (IgY) against Listeria monocytogenes and preliminary evaluation of its potential for food preservation.J Sci Food Agric, 2011.91(11): p.1946-50. 8.Lee, E.N., et al., In vitro studies of chicken egg yolk antibody (IgY) against Salmonella enteritidis and Salmonella typhimurium.Poult Sci, 2002.81(5): p.632-41. 9.Boziaris, I.S.and F.F.Parlapani, Specific spoilage organisms (SSOs) in fish, in The microbiological quality of food.2017, Elsevier.p.61-98. 10.Nychas, G.J., et al., Meat spoilage during distribution.Meat Sci, 2008.78(1-2): p.77-89. 11.Wang, G.Y., et al., Evaluation of the spoilage potential of bacteria isolated from chilled chicken in vitro and in situ.Food Microbiol, 2017.63: p.139-146.

Claims

1. 1. A compostable packaging film comprising: a flexible packaging material having an interior food contact surface and an exterior environment facing surface opposite the interior surface, the flexible packaging material defining a plurality of pores fluidly connecting the interior surface and the exterior surface; a barrier coating covering the exterior surface and the plurality of pores on the exterior surface; Including, packaging film.

2. The film of claim 1 , wherein the pores are micropores.

3. The film of claim 2, wherein the pores are about 1 to about 250 μm in size, for example, about 50 μm, about 65 μm, or about 80 μm.

4. The film of any one of claims 1 to 3, wherein the plurality of pores are substantially the same size.

5. The film of any one of claims 1 to 3, wherein the pores are of different sizes.

6. The film of any one of claims 1 to 5, wherein the flexible packaging material defines the plurality of pores having a low pore density, a medium pore density, or a high pore density.

7. The film of any one of claims 1 to 6, wherein the flexible packaging material defines the plurality of pores at a substantially consistent pore density.

8. The film of any one of claims 1 to 6, wherein the flexible packaging material defines the plurality of pores having a varying pore density.

9. The film of any one of claims 1 to 8, wherein the flexible packaging material has a thickness of about 1 mil to about 5 mils, for example, about 2 mils, 2.5 mils, or 3 mils.

10. The flexible packaging material has a flow rate of about 7,000 cc / m ２ / day, e.g., about 10,000 cc / m ２ The film according to any one of claims 1 to 9, having an oxygen transmission rate of 1000 kJ / day or more.

11. The flexible packaging material has a flow rate of about 7,000 cc / m ２ The film according to any one of claims 1 to 9, having an oxygen transmission rate of 1000 kJ / day or less.

12. The film of any one of claims 1 to 11, wherein the flexible packaging material is configured to hold a vacuum.

13. The film of any one of claims 1 to 12, wherein the flexible packaging material is configured to retain a vacuum for about 1 day or more, such as about 1 week or more or about 2 weeks or more.

14. The film of any one of claims 1 to 13, further comprising an antimicrobial agent chemically bonded to the interior surface.

15. The film of any one of claims 1 to 14, further comprising a hydrogel layer disposed on the inner surface.

16. 16. The film of any one of claims 1 to 15, wherein the flexible packaging material comprises a polymer selected from the group consisting of polybutylene adipate terephthalate (PBAT), polylactic acid, polyhydroxyalkanoate, polybutylene succinate, cellulosic materials, polyglycolic acid, polycaprolactone, polyvinyl alcohol, carbohydrate-based materials, protein-based materials, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, and combinations thereof.

17. 17. The film of claim 16, wherein the polymer is PBAT.

18. The film of claim 1 , wherein the barrier coating comprises at least one biopolymer.

19. The film of any one of claims 1 to 18, wherein the barrier coating covers substantially all of the pores.

20. 20. The film of any one of claims 1 to 19, wherein the barrier coating is crosslinked to form a substantially stable hydrogel-like coating on the exterior surface.

21. 1. A method for preparing a packaging film, comprising: (a) providing a polymeric film having an interior food contact surface and a surface facing an exterior environment opposite said interior surface; (b) modifying the polymer film by microperforation to increase the oxygen permeability of the packaging film; (c) applying a barrier coating to the exterior surface to further adjust the oxygen transmission rate of the packaging film; A method comprising:

22. (d) modifying the interior surface by UV, chemical oxidation, plasma or corona treatment; (e) chemically bonding an antimicrobial agent to the modified interior surface; further comprising 22. The method of claim 21, wherein steps (d) and (e) are performed after step (b).

23. (f) modifying the interior surface by UV, chemical oxidation, plasma or corona treatment; (g) chemically bonding an antimicrobial agent to the modified interior surface; further comprising 22. The method of claim 21, wherein the steps are performed in the following order: (a), (f), (g), (b), (c).

24. 23. The method of claim 22, wherein (d) further comprises chemically bonding a hydrogel layer to the modified interior surface.

25. The method of any one of claims 21 to 24, further comprising forming a polymer on the polymer film before step (a).

26. 26. The method of claim 25, wherein forming the polymer into the polymer film comprises extruding a polymer resin into the polymer film by film blowing or film casting.

27. 27. The method of any one of claims 21 to 26, wherein the polymer is selected from the group consisting of polybutylene adipate terephthalate (PBAT), polylactic acid, polyhydroxyalkanoate, polybutylene succinate, cellulosic materials, polyglycolic acid, polycaprolactone, polyvinyl alcohol, carbohydrate-based materials, protein-based materials, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, and combinations thereof.

28. 28. The method of claim 27, wherein the polymer is PBAT.

29. The method of any one of claims 21 to 28, wherein the polymer film has a thickness of from about 1 μm to about 500 μm.

30. The method of any one of claims 21 to 29, wherein the polymer is a compostable polymer.

31. The method of any one of claims 21 to 30, further comprising applying a gel coating to the exterior surface to further adjust the oxygen transmission rate of the packaging film.

32. selecting a thickness of the gel coating based on a target oxygen permeability; adjusting the oxygen permeability of the packaging film by applying the gel coating using the selected thickness; 32. The method of claim 31 , further comprising:

33. 33. The method of claim 31 or 32, further comprising adjusting the oxygen transmission rate of the packaging film by varying the thickness of the applied gel coating.

34. The method of any one of claims 31 to 33, wherein the gel coating comprises one or more fillers to further adjust the oxygen permeability of the packaging film.

35. 35. The method of claim 34, wherein the one or more fillers are selected from the group consisting of porous micro- and nanoparticles made of organic and inorganic materials, including but not limited to, silicon, amorphous silica, diatomaceous earth, silicon dioxide, aluminum-based, zeolites, calcium carbonate, kaolin, alumina trihydrate, calcium sulfate, carbon-based particles, gold, silver, copper, zinc, and oxides thereof; biopolymer particles, including but not limited to, cellulose-based, chitin, gelatin, chitosan, alginate, polylactic acid, and polyglycolic acid; and synthetic polymer particles, including but not limited to, polymethyl methacrylate, polystyrene, polyacrylate, polytetrafluoroethylene, poly(vinyl acetate), and poly(vinyl chloride).

36. selecting a thickness of the barrier coating based on a target oxygen permeability; adjusting the oxygen transmission rate of the packaging film by applying the barrier coating using the selected thickness; The method of any one of claims 21 to 35, further comprising:

37. 37. The method of any one of claims 21 to 36, further comprising adjusting the oxygen transmission rate of the packaging film by varying the thickness of the applied barrier coating.

38. A method according to any one of claims 21 to 37, wherein the barrier coating is applied by a controlled deposition technique.

39. 39. The method of claim 38, wherein the controlled deposition technique is selected from the group consisting of Mayer rod coating, doctor blade, spray deposition, Langmuir-Blodgett film deposition, and slot die coating.

40. 40. The method of any one of claims 21 to 39, wherein the barrier coating is chemically crosslinked to form a substantially stable hydrogel-like coating.

41. A packaging film prepared according to the method of any one of claims 21 to 40.

42. 42. The packaging film of claim 41, wherein the packaging film is compostable.

43. 43. Use of a film according to any one of claims 1 to 20, 41 or 42 in packaging of perishable goods.

44. 44. The use of claim 43, wherein the food contact surface of the film is configured to contact the surface of the perishable item.

45. 1. A method for preparing a packaging film, comprising: (a) providing a polymeric film having an interior food contact surface and a surface facing an exterior environment opposite said interior surface; (b) modifying the polymer film by microperforation to increase the oxygen permeability of the packaging film; (c) applying a barrier coating to the exterior surface to further adjust the oxygen permeability of the packaging film; (d) modifying the interior surface by UV, chemical oxidation, plasma or corona treatment; (e) chemically bonding an antimicrobial agent to the modified interior surface; (f) modifying the interior surface by UV, chemical oxidation, plasma or corona treatment; (g) chemically bonding an antimicrobial agent to the modified interior surface; A method comprising:

Images