ANTIMICROBIAL BIODEGRADABLE COMPOSITIONS FOR FOOD PRODUCTS - Patent application

Abstract

The present disclosure provides a food contact article. According to one embodiment, the food contact article includes at least one food contact surface. The at least one food contact surface is composed of at least 50% by weight of at least one biodegradable polymer, such as a polyhydroxyalkanoate, and about 0.1% to about 1.0% by weight of at least one antimicrobial agent.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of the earlier filing date of U.S. Provisional Patent Application No. 63 / 068,401, filed August 21, 2020. [Technical field]

[0002] The present disclosure relates to biodegradable polymer compositions. More particularly, the present disclosure relates to polymer compositions for food contact applications that are biodegradable and also have antimicrobial properties. [Background technology]

[0003] Foodborne diseases are most commonly transmitted via the oral route. Therefore, reducing the number of ingested bacteria is of paramount importance to reduce gastrointestinal bacterial infections. In this regard, food containers may act as carrier materials in spreading bacteria and other pathogens from food handlers or as incubators in promoting bacterial growth on hot foods.

[0004] Therefore, to improve food safety, it would be desirable to provide food containers that are capable of killing, or at least inhibiting the growth of, bacteria or other pathogens that may be introduced into the container during use. Moreover, it would be particularly desirable to provide such food containers that are formed from biodegradable and / or compostable materials. Summary of the Invention

[0005] In a first aspect, the present disclosure provides a food contact article. According to one embodiment, the food contact article includes at least one food contact surface. The at least one food contact surface is comprised of at least 50% by weight of at least one biodegradable polymer and about 0.1% to about 1.0% by weight of at least one antimicrobial agent.

[0006] In some embodiments, the food contact article is preferably a food container, a cup, a dish, or a food packaging film.

[0007] According to a particular embodiment, the food contact article is preferably comprised of a biodegradable substrate having a coating formed thereon. The coating constitutes a food contact surface and is preferably comprised of at least 50% by weight of at least one biodegradable polymer and about 0.1% to about 1.0% by weight of at least one antimicrobial agent. More preferably, the biodegradable substrate is comprised of paperboard.

[0008] In certain embodiments, the food contact surface is preferably composed of at least 75% by weight of at least one biodegradable polymer, and more preferably from about 80% to about 99.9% by weight of at least one biodegradable polymer.

[0009] Optionally, the antimicrobial agent is preferably selected from the group consisting of antibacterial agents, antifungal agents, antiparasitic agents, antialgal agents, antiprion agents, and combinations thereof.

[0010] In certain preferred embodiments, the antimicrobial agent comprises about 0.1 to about 1.0% lysozyme by weight of the food contact article. Additionally, in certain embodiments, the food contact article also comprises a second antimicrobial agent selected from the group consisting of antibacterial agents, antifungal agents, antiparasitic agents, antialgal agents, antiprion agents, and combinations thereof.

[0011] According to certain embodiments, the antimicrobial agent is preferably applied as a spray onto at least one food contact surface. In other embodiments, the antimicrobial agent may be applied as a coating. In yet other embodiments, the antimicrobial agent may be applied by dipping the food contact article into a mixture of the antimicrobial agent and allowing the food contact surface to absorb the antimicrobial agent.

[0012] In certain aspects, the at least one biodegradable polymer is preferably selected from the group consisting of polyhydroxyalkanoates, poly(butylene succinate), poly(butylene succinate-co-adipate), poly(butylene adipate-co-terephthalate), poly(caprolactone), poly(lactic acid), cellulose esters, thermoplastic starch, and mixtures thereof. More preferably, the at least one biodegradable polymer comprises a polyhydroxyalkanoate.

[0013] According to a particular embodiment, the polyhydroxyalkanoate is preferably comprised of a copolymer comprised of about 75 to about 99.9 mole percent of monomer residues of 3-hydroxybutyrate and about 0.1 to about 25 mole percent of monomer residues of a second hydroxyalkanoate having 5 to 12 carbon atoms.

[0014] In certain other embodiments, the polyhydroxyalkanoate is preferably comprised of a terpolymer composed of about 75 to about 99.9 mole % monomer residues of 3-hydroxybutyrate, about 0.1 to about 25 mole % monomer residues of 3-hydroxyhexanoate, and about 0.1 to about 25 mole % monomer residues of a third hydroxyalkanoate having 5 to 12 carbon atoms.

[0015] In some cases, the polyhydroxyalkanoate preferably has an initial weight average molecular weight of about 50,000 to about 4,000,000 daltons, more preferably about 100,000 to about 3,000,000 daltons, and most preferably about 100,000 to about 2,000,000 daltons. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] In one aspect, the present disclosure provides a food contact article. The food contact article comprises at least one food contact surface. In many cases, the article may comprise multiple food contact surfaces. In certain embodiments, for example, the food contact article may take the form of a food container, a cup, a dish, or a food packaging film.

[0017] In some cases, the food contact article is comprised of a biodegradable substrate having a coating formed thereon. In such cases, the coating serves as the food contact surface. Preferably, the biodegradable substrate is comprised of paperboard. However, alternatively, the biodegradable substrate may be comprised of a film, sheet, cardboard, or paper.

[0018] According to the present disclosure, the food contact article is preferably biodegradable and / or compostable. More particularly, the food contact article is both biodegradable and compostable.

[0019] As used herein, the term "biodegradable" refers to plastic or polymeric materials that will undergo biodegradation by living organisms (microorganisms) in anaerobic and aerobic environments (as determined by ASTM D5511), soil environments (as determined by ASTM 5988), freshwater environments (as determined by ASTM D5271 (EN 29408)), or marine environments (as determined by ASTM D6691). The biodegradability of biodegradable plastics can also be determined using ASTM D6868 and European EN 13432.

[0020] As used herein, the term "compostable" refers to plastic or polymeric materials, which may be for either industrial or household use, constructed in accordance with ASTM D6400.

[0021] Generally, the food contact surface is comprised of a polyhydroxyalkanoate and at least one antimicrobial agent.

[0022] Typically, the at least one food contact surface is comprised of at least 50% by weight of the at least one biodegradable polymer. Preferably, the at least one food contact surface is comprised of at least 75% by weight of the at least one biodegradable polymer. More preferably, the at least one food contact surface is comprised of at least 80% by weight of the polyhydroxyalkanoate, and even more preferably from about 85 to about 99.9% by weight of the at least one biodegradable polymer.

[0023] In certain aspects, the at least one biodegradable polymer is preferably selected from the group consisting of polyhydroxyalkanoates, poly(butylene succinate), poly(butylene succinate-co-adipate), poly(butylene adipate-co-terephthalate), poly(caprolactone), poly(lactic acid), cellulose esters, thermoplastic starch, and mixtures thereof.

[0024] More preferably, the at least one biodegradable polymer comprises a polyhydroxyalkanoate, and optionally also further biodegradable polymers. In some cases, the polyhydroxyalkanoate of the food contact surface may be composed of a homopolymer, such as polyhydroxybutyrate. However, more typically, the polyhydroxyalkanoate of the food contact surface is a copolymer or even a terpolymer formed from different hydroxyalkanoate monomers.

[0025] For example, in some embodiments, the polyhydroxyalkanoate is comprised of a copolymer comprised of about 75 to about 99.9 mole percent monomer residues of 3-hydroxybutyrate and about 0.1 to about 25 mole percent monomer residues of a second hydroxyalkanoate having 5 to 12 carbon atoms, more preferably the second hydroxyalkanoate is 3-hydroxyhexanoate.

[0026] In another embodiment, the polyhydroxyalkanoate is preferably comprised of a terpolymer composed of about 75 to about 99.9 mole percent monomer residues of 3-hydroxybutyrate, about 0.1 to about 25 mole percent monomer residues of 3-hydroxyhexanoate, and about 0.1 to about 25 mole percent monomer residues of a third 3-hydroxyalkanoate having 5 to 12 carbon atoms.

[0027] Typically, the polyhydroxyalkanoates used in food contact surfaces have an initial weight average molecular weight of about 50,000 to about 4,000,000 Daltons. More preferably, the polyhydroxyalkanoates used in food contact surfaces have an initial weight average molecular weight of about 100,000 to about 3,000,000 Daltons, and most preferably about 100,000 to about 2,000,000 Daltons.

[0028] As discussed above, the food contact surface comprises at least one antimicrobial agent. For example, the food contact surface may comprise at least one antimicrobial agent selected from the group consisting of antibacterial agents, antifungal agents, antiparasitic agents, antialgae agents, antiprion agents, and combinations thereof.

[0029] Examples of suitable antimicrobial agents that may be included on food contact surfaces are zinc pyrithione, silver-based compounds, Includes quaternary ammonium compounds, ethylenediaminetetraacetic acid (EDTA), and lysozyme.

[0030] Examples of suitable antifungal agents that may be included on food contact surfaces include isothiolinone and thiabendazole, Lactobacilli suspension with or without chitosan, salicylic acid solution, and natamycin.

[0031] Examples of suitable antiparasitic agents that may be included on food contact surfaces include atovaquone, pyrethroids, silver nanoparticles, permethrin, S-bioallethrin, piperonyl butoxide permethrin, pyriproxyfen, benzyl benzoate, lufenoxuron, and abamectin.

[0032] Examples of suitable anti-algae agents that may be included in food contact surfaces include several biochemical products produced by Streptomycetes sp., or copper dehydrogenated phosphate (Cu-DHP). Examples of suitable anti-prion agents that may be included in food contact surfaces include pentosan polysulfate, suramin, amphotericin B, congo red, dendritic polyamines, bisacridines, polyphenols, phenothiazines, antihistamines, statins, and quinacrine.

[0033] Preferably, the food contact surfaces include at least an antimicrobial agent. A particularly preferred antimicrobial agent comprises lysozyme in an amount of about 0.1% to about 1.0% by weight of the food contact article.

[0034] Lysozyme is an enzyme produced by animals that exhibits antibacterial activity, in particular, it catalyzes hydrolysis reactions that degrade the cell walls of Gram-positive bacteria, ultimately resulting in the lysis of the bacteria.

[0035] Given lysozyme's ability to catalyze hydrolytic degradation reactions, it was previously expected that the use of lysozyme would be incompatible with biodegradable polymers such as polyhydroxyalkanoates. However, the present inventors have surprisingly observed that the inclusion of lysozyme in polyhydroxyalkanoates does not result in significant degradation of the polyhydroxyalkanoates.

[0036] In some embodiments, a food contact surface may include two or more antimicrobial agents used in combination, for example, a food contact surface may include lysozyme, as discussed above, along with a second antimicrobial agent selected from the group consisting of antibacterial agents, antifungal agents, antiparasitic agents, antialgae agents, antiprion agents, and combinations thereof.

[0037] According to certain embodiments, the antimicrobial agent is preferably applied as a spray onto at least one food contact surface. In other embodiments, the antimicrobial agent may be applied by aqueous coating, rotogravure, aralox, or formula molding. In further embodiments, the antimicrobial agent may be applied by immersing the food contact article in a bath of the antimicrobial agent so that the agent is absorbed onto the food contact surface. In yet other embodiments, the antimicrobial agent may be mixed with the polyhydroxyalkanoate prior to forming the food contact surface.

[0038] In some embodiments, the food contact surface may include other ingredients in addition to the biodegradable polymer and antimicrobial agent, for example, the food contact surface may also include nucleating agents, plasticizers, fillers, and / or impact modifiers.

[0039] Suitable nucleating agents for use in food contact surfaces include, for example, erythritol, pentaerythritol, In some embodiments, the additive may be selected from the group consisting of ethylhexyl ether, dipentaerythritol, artificial sweeteners, stearates, sorbitol, mannitol, inositol, polyester waxes, nanoclays, behenamide, erucamide, stearamide, oleamide, polyhydroxybutyrate, and mixtures thereof.

[0040] Suitable plasticizers for use in food contact surfaces may be selected from the group consisting of, for example, sebacates, citrates, fatty esters of adipic acid, succinic acid, and glucaric acid, lactates, alkyl diesters, citrates, alkyl methyl esters, dibenzoates, propylene carbonate, caprolactone diols having a number average molecular weight of 200 to 10,000 g / mol, poly(ethylene) glycols having a number average molecular weight of 400 to 10,000 g / mol, esters of vegetable oils, long chain alkyl acids, adipates, glycerol, isosorbide derivatives or mixtures thereof, HALLGREEN IM-8830 esters, HALLGREEN R-8010 esters, polyhydroxyalkanoate copolymers containing at least 18 mole % of monomeric residues of hydroxyalkanoates other than hydroxybutyrate, and mixtures thereof.

[0041] Suitable fillers for use in food contact surfaces may be selected from the group consisting of, for example, calcium carbonate, talc, nanoclay, nanocellulose, hemp fiber, kaolin, carbon black, wollastonite, glass fiber, carbon fiber, graphite fiber, mica, silica, dolomite, barium sulfate, magnetite, halloysite, zinc oxide, titanium dioxide, montmorillonite, feldspar, asbestos, boron, steel, carbon nanotubes, cellulose fibers, flax, cotton, starch, polysaccharides, aluminum hydroxide, magnesium hydroxide, chitin, and mixtures thereof.

[0042] Suitable impact modifiers for use in food contact surfaces may be selected, for example, from the group consisting of organic peroxyacids, inorganic peroxyacids, isosorbide derivatives, or mixtures thereof.

[0043] The foregoing description of preferred embodiments for the present invention has been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments have been chosen and described in an attempt to provide the best explanation of the principles of the invention and its practical application, thereby enabling those skilled in the art to use the invention in various embodiments and with various modifications suited to the particular uses intended. All such modifications and variations are within the scope of the invention, as determined by the appended claims, when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.

Claims

1. 1. A food contact article having at least one food contact surface, the at least one food contact surface comprising at least 50% by weight of a polyhydroxyalkanoate and 0.1% to 1.0% by weight of lysozyme, the lysozyme being absorbed onto the food contact surface for contacting the food.

2. 10. The food contact article of claim 1, wherein the food contact article comprises a food container, a cup, a dish, or a food packaging film.

3. 10. The food contact article of claim 1, wherein the food contact article comprises a biodegradable substrate, the food contact surface comprises a coating formed on the substrate, the coating comprising at least 50% by weight of at least one biodegradable polymer and 0.1% to 1.0% by weight of at least one antimicrobial agent.

4. 4. The food contact article of claim 3, wherein the biodegradable substrate comprises paperboard.

5. 10. The food contact article of claim 1, wherein the food contact surface comprises 80-99.9% by weight of at least one biodegradable polymer.

6. 10. The food contact article of claim 1, further comprising a second antimicrobial agent selected from the group consisting of antibacterial agents, antifungal agents, antiparasitic agents, antialgal agents, antiprion agents, and combinations thereof.

7. 2. The food contact article of claim 1, wherein the polyhydroxyalkanoate comprises a copolymer comprised of 75 to 99.9 mole percent of monomeric residues of 3-hydroxybutyrate and 0.1 to 25 mole percent of monomeric residues of a second hydroxyalkanoate having 5 to 12 carbon atoms.

8. 2. The food contact article of claim 1, wherein the polyhydroxyalkanoate comprises a terpolymer composed of 75 to 99.9 mole percent monomeric residues of 3-hydroxybutyrate, 0.1 to 25 mole percent monomeric residues of 3-hydroxyhexanoate, and 0.1 to 25 mole percent monomeric residues of a tertiary hydroxyalkanoate having 5 to 12 carbon atoms.

9. 2. The food contact article of claim 1, wherein the polyhydroxyalkanoate has a weight average molecular weight of 100,000 to 3,000,000 Daltons.