BR112019015549B1 - COATING COMPOSITIONS, SUBSTANTIALLY DRY COATING, FOOD PRODUCT, METHOD AND USE THEREOF - Google Patents

Abstract

Embodiments of a coating composition comprising cellulose nanomaterials and emulsion systems are described herein. The coating compositions provide an improved moisture barrier and wettability on fruit surfaces and can control the physiological activity and enhance the storability of food products such as fruits during storage at room temperature. Also described herein are embodiments of coatings, films, dry and substantially dry products made with the dry and substantially dry coating compositions, and methods of preparing and using the coating compositions described herein.

Description

CROSS REFERENCE TO RELATIVE REQUEST

[001] This application claims the benefit of the previous filing date of U.S. Provisional Patent Application No. 62/452,897, filed on January 31, 2017, which is incorporated herein by reference in its entirety.

FIELD

[002] Embodiments of compositions and coating films for food products and methods for manufacturing and using the same are described here.

FUNDAMENTALS

[003] The Cavendish banana (Musa acuminate) is a rich source of vitamins and bioactive compounds (e.g., dietary fiber and phenolic compounds), and one of the most consumed fruits worldwide. As a climacteric fruit, however, bananas have a relatively short shelf life, due to physiological disturbance, post-harvest diseases and senescence. Bananas are just one example of foods that typically require external modification to preserve the food's shelf life. There remains a need in the art for improved compositions and coatings that can improve the shelf life and/or pre-harvest integrity of various food items, such as perishable foods, plants and plant parts.

SUMMARY

[004] Embodiments of a coating composition comprising a cellulose nanomaterial and an emulsion system comprising a hydrophobic agent (for example, a fatty acid) and a surfactant are described here. The coating compositions may further comprise a functional agent, a plasticizer or any combination thereof. In some embodiments, the cellulose nanomaterial may comprise cellulose nanocrystals or cellulose nanofibrils.

[005] Also described here are embodiments of a dry (or substantially dry) coating comprising a cellulose nanomaterial and an emulsion system, comprising a hydrophobic agent and a surfactant and substantially free of moisture. In some embodiments, the coating composition or dried (or substantially dried) coating may be used to coat a food article, such as a plant or plant part.

[006] Also described here are embodiments of a method, comprising coating or substantially coating a plant or plant part with an embodiment of the coating composition described here.

[007] The foregoing and other objects, characteristics and advantages of the present description will become more evident from the following detailed description, which follows with reference to the attached figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[008] FIG. 1 is a schematic diagram showing the development mechanisms of different embodiments of the coating composition described herein and their effects in delaying ethylene biosynthesis in post-harvest bananas.

[009] FIG. 2A is a graph showing the effect of different coating compositions on banana chlorophyll degradation during a 10-day storage period at 25±2°C and 50±5% relative humidity, where “Ctrl” represents samples not coated; “Semp” represents samples coated with a 1.2% commercial SemperfreshÔ solution; and “CNC” represents coatings formed from a composition comprising cellulose nanocrystals (0.2% w/w on a wet basis), chitosan (2% w/w on a wet basis), and glycerol (0.4% w/w on a wet basis). w/w on a wet basis) and “CNF” represents coatings formed from a composition comprising cellulose nanofibrils (0.3% w/w on a wet basis), both with the following emulsion systems: Tween 80 only (“ CNCA” and “CNFA”); Tween 80 and oleic acid (“CNCB” and “CNFB”); and oleic acid fatty acid sucrose ester (“CNCC” and “CNFC”).

[0010] FIG. 2B is a graph showing the effect of different coating compositions on banana weight loss during a 10-day storage period at 25±2°C and 50±5% relative humidity, where “Ctrl” represents samples not coated; “Semp” represents samples coated with a commercial 1.2% SemperfreshÔ solution; and “CNC” represents coatings formed from a composition comprising cellulose nanocrystals (0.2% w/w on a wet basis), chitosan (2% w/w on a wet basis), and glycerol (0.4% w/w on a wet basis). w/w on a wet basis) and “CNF” represents coatings formed from a composition comprising cellulose nanofibrils (0.3% w/w on a wet basis), both with the following emulsion systems: Tween 80 only (“ CNCA” and “CNFA”); Tween 80 and oleic acid (“CNCB” and “CNFB”); and oleic acid fatty acid sucrose ester (“CNCC” and “CNFC”).

[0011] FIG. 2C is a graph showing the effect of different coating compositions on banana marketability during a 10-day storage period at 25±2°C and 50±5% relative humidity, where “Ctrl” represents samples not coated; “Semp” represents samples coated with a commercial 1.2% SemperfreshÔ solution; and “CNC” represents coatings formed from a composition comprising cellulose nanocrystals (0.2% w/w on a wet basis), chitosan (2% w/w on a wet basis), and glycerol (0.4% w/w on a wet basis). w/w on a wet basis) and “CNF” represents coatings formed from a composition comprising cellulose nanofibrils (0.3% w/w on a wet basis), both with the following emulsion systems: Tween 80 only (“ CNCA” and “CNFA”); Tween 80 and oleic acid (“CNCB” and “CNFB”); and oleic acid fatty acid sucrose ester (“CNCC” and “CNFC”).

[0012] FIG. 3A is a bar graph showing a comparison of ethylene production between uncoated and coated bananas, wherein the coated samples comprised a coating made with SemperfreshÔ (“Semperfresh Treatments”) or an embodiment of a ethylene nanofiber coating. cellulose (“CNFC”) made from a composition comprising 0.3% w/w (on a wet basis) CNF, 1% w/w sucrose ester of a fatty acid and 1% w/w acid oleic (on a wet basis), in which ethylene production was measured after 48 hours of banana storage in a 1.5 L bottle.

[0013] FIG. 3B is a bar graph showing a comparison of CO2 and O2 production between uncoated and coated bananas, wherein the samples coated a coating made with SemperfreshÔ (“Semperfresh Treatments”) or an embodiment of a nanofiber coating cellulose (“CNFC”) made from a composition comprising 0.3% w/w (on a wet basis) CNF, 1% w/w sucrose ester of a fatty acid and 1% w/w of oleic acid (on a wet basis), in which the production values of O2 and CO2 were evaluated after 24 hours of banana storage in a 1.5 L bottle.

[0014] FIG. 3C is a graph showing the concentration of ACC monitored during the 10 day storage period at 25±2°C and 50±5% relative humidity, in which coated and uncoated bananas were evaluated and in which coated bananas comprised a coating made with SemperfreshÔ (“Semperfresh Treatments”) or an embodiment of a cellulose nanofiber coating (“CNFC”) made from a composition comprising 0.3% w/w (on a wet basis) CNF , 1% w/w sucrose ester of a fatty acid and 1% w/w oleic acid (on a wet basis).

[0015] FIG. 3D is a graph showing the ACS activity monitored during the 10 day storage period at 25±2°C and 50±5% relative humidity, in which uncoated and coated bananas were evaluated and in which coated bananas comprised a coating made with SemperfreshÔ (“Semperfresh Treatments”) or an embodiment of a cellulose nanofiber coating (“CNFC”) made from a composition comprising 0.3% w/w (on a wet basis) CNF, 1% w/w sucrose ester and 1% w/w oleic acid (on a wet basis).

[0016] FIG. 4A includes SEM images showing the surface morphological properties of uncoated bananas at two different resolutions, 100 μm (top image) and 5 μm (bottom image).

[0017] FIG. 4B includes SEM images showing the surface morphological properties of bananas coated with a 1.2% SemperfreshÔ coating at two different resolutions, 100 μm (top image) and 5 μm (bottom image).

[0018] FIG. 4C includes SEM images showing the surface morphological properties of bananas coated with a coating formed from a CNFC coating composition comprising 0.3% w/w (on a wet basis) CNF, 1% w/w (on a wet basis) ) fatty acid sucrose ester and 1% w/w (on a wet basis) oleic acid at two different resolutions, 100 μm (top image) and 5 μm (bottom image).

[0019] FIG. 5A provides photographic images showing comparisons between the appearance of uncoated (left image), SemperfreshÔ coated (middle image) and CNFC coated (right image) bananas for 10 days of storage at 25±2°C and 50±5 % relative humidity, wherein the CNFC-coated bananas comprised a coating formed from a composition comprising 0.3% w/w (on a wet basis) CNF, 1% w/w (on a wet basis) fatty acid sucrose and 1% w/w (on wet basis) oleic acid.

[0020] FIG. 5B is a bar graph showing comparisons between the firmness of uncoated, SemperfreshÔ coated and CNFC coated bananas during 10 days of storage at 25±2°C and 50±5% relative humidity, where the SemperfreshÔ coated bananas CNFC comprised a coating formed from a composition comprising 0.3% w/w (on a wet basis) CNF, 1% w/w (on a wet basis) fatty acid sucrose ester and 1% w/w (on a wet basis) of oleic acid.

[0021] FIG. 5C is a bar graph showing comparisons between the soluble solids content of uncoated, SemperfreshÔ-coated, and CNFC-coated bananas during 10 days of storage at 25±2°C and 50±5% relative humidity, where CNFC-coated bananas comprised a coating formed from a composition comprising 0.3% w/w (on a wet basis) CNF, 1% w/w (on a wet basis) fatty acid sucrose ester and 1% w/w w/w (on wet basis) oleic acid.

[0022] FIG. 5D is a bar graph showing comparisons between the titratable acidity of uncoated, SemperfreshÔ coated and CNFC coated bananas during 10 days of storage at 25±2°C and 50±5% relative humidity, where coated bananas with CNFC comprised a coating formed from a composition comprising 0.3% w/w (on a wet basis) CNF, 1% w/w (on a wet basis) fatty acid sucrose ester and 1% w/w p (on wet basis) of oleic acid.

[0023] FIG. 6 shows photographic images comparing the appearance, weight loss and firmness of different fruits that do not comprise a coating (“Control”) and that comprise a coating (“Coated”) formed from a composition comprising 0.3% w/w ( on a wet basis) of CNF, 1% w/w (on a wet basis) of fatty acid sucrose ester and 1% w/w (on a wet basis) of oleic acid.

[0024] FIG. 7 shows photographic images comparing the external and internal appearances of mangoes after 12 days of storage, in which the mangoes were either uncoated (“Uncoated Samples”) or coated (“Coated Samples”) with a coating formed from a composition comprising 0.3% w/w (on a wet basis) CNF, 1% w/w (on a wet basis) fatty acid sucrose ester and 1% w/w (on a wet basis) oleic acid.

[0025] FIG. 8A provides photographic images of meat pastes separated by films formed using a cellulose nanomaterial composition prior to storage (leftmost image) and then being stored for 1 week at 5-7°C (where the second image from the left uses a film comprising only CNF, the third image from the left uses a film comprising CNF modified with low molecular weight chitosan and the rightmost image uses a film comprising CNF and high molecular weight CNF.

[0026] FIG. 8B is a graph of water absorption as a function of film type, in which a control film (CNF) was compared to two different chitosan-modified films (“low molecular weight CNF-CH” and “low molecular weight CNF-CH”. high molecular weight”).

DETAILED DESCRIPTION Terms overview

[0027] The following explanations of terms are provided to further describe the present description and to guide those skilled in the art in the practice of the present description. As used herein, “comprising” means “including” and the singular forms “a” or “an” or “the” or “a” include plural references unless the context clearly dictates otherwise. The term “or” refers to a single element of stated alternative elements or a combination of two or more elements, unless the context clearly indicates otherwise.

[0028] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as generally understood by one skilled in the art to which this description belongs. Although methods and materials similar or equivalent to those described herein may be used in the practice or testing of the present disclosure, suitable methods and materials are described below. The materials, methods and examples are illustrative only and are not intended to be limiting unless otherwise indicated. Other features of the description are evident from the following detailed description and the claims.

[0029] Unless otherwise indicated, all numbers expressing component amounts, molecular weights, percentages, temperatures, times and so on, as used in the specification or claims, should be understood as being modified by the term “about”. Accordingly, unless otherwise indicated, implicitly or explicitly, the numerical parameters presented are approximations that may depend on the desired properties sought and/or limits of detection under standard test conditions/methods. When directly and explicitly distinguishing embodiments of the prior art discussed, embodiment numbers are not approximate unless the word “about” is recited. Furthermore, not all alternatives mentioned here are equivalent.

[0030] The term “cellulose nanocrystal”, as used herein, refers to a cellulosic object composed of at least one elementary fibril, containing predominantly crystalline and paracrystalline regions, which do not exhibit branching or entanglement between cellulose nanocrystals or similar structures. to networks.

[0031] The term “cellulose nanofibril”, as used herein, refers to a cellulosic object composed of at least one elementary fibril, containing crystalline, paracrystalline and amorphous regions, which may exhibit longitudinal partitions, entanglement between cellulose nanofibrils or network-like structure.

[0032] The term “cross-linking”, as used herein, refers to the use of a substance (molecular or ionic) to link at least two molecules (whether the same or different) through a chemical bond, such as a covalent bond, ionic and/or electrostatic.

[0033] The term “elementary fibril” or “fibril”, as used herein, refers to a cellulosic structure, originating from a single terminal enzymatic complex, having a configuration of cellulose chains specific to each plant, animal, algae and bacterial.

[0034] The term “encapsulation”, as used herein, refers to the formation of a complete or partial barrier around a particle or object to specifically control the movement of substances into or out of the encapsulated particle or object.

[0035] The term “exogenous” refers to any material that is present in or on a living organism or cell or system or object, but which originated outside that organism/cell/system/object, as opposed to something that is endogenous. As used herein, exogenous distinguishes the synthetic films described herein from natural films or cuticles produced by plants or parts of plants.

[0036] The term “leaching”, as used herein, refers to the extraction of certain organic and inorganic materials from a plant or plant part into a liquid, such as a processing composition or other suitable aqueous or non-aqueous composition.

[0037] The term “mitigating” as used herein refers to the ability of the described composition, or to a dry (or substantially dry) coating or film made from the composition, or to a method using the composition to substantially reduce (e.g., such as 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90%) that pre- or post-harvest damage occurs. In some embodiments, pre- or post-harvest damage may be caused by biotic stress, abiotic stress, storage and/or processing (e.g., thermal processing).

[0038] The term “nanofiber”, as used herein, refers to a nano-object with two nanoscale external dimensions and a significantly larger third dimension.

[0039] The term “nutrients” as used here refers to any component that is found in a plant or part of a plant, whether naturally occurring or having been absorbed during growth. Nutrients may include, but are not limited to, primary macronutrients such as nitrogen, phosphorus, potassium; secondary macronutrients, such as calcium, sulfur and magnesium; micronutrients or trace minerals, such as boron, manganese, iron, zinc, copper, nickel and the like.

[0040] The term “plant”, as used herein, refers to an entire plant including any root structures, vascular tissues, vegetative tissues and reproductive tissues. A “plant part” includes any portion of the plant. For example, plant parts can be obtained after harvesting a plant. The parts of the plant covered by the present description include, but are not limited to, flowers, fruits, seeds, leaves, vegetables, stems, roots, branches and combinations thereof, which are smaller than the entire plant from which they are derived.

[0041] The term “prevent(going)” as used herein refers to the ability of the described composition, or to a dry (or substantially dry) coating or film made ) from the composition, or to a method using the composition to completely or substantially stop pre- or post-harvest damage from occurring. In some embodiments, pre- or post-harvest damage may be caused by biotic stress, abiotic stress, storage and/or processing (e.g., thermal processing).

[0042] The term “UV damage”, as used herein, refers to any type of damage to the objects described herein, which is caused by ultraviolet light. In some embodiments, such damage may include wilting, discoloration, shrinkage, staining, and the like.

[0043] The term “stabilizing agent” refers to a compound that can improve the properties of the material, particularly water resistance and mechanical properties of the dry (or substantially dry) coating or film made. (a) from the coating composition, and also the affinity between the cellulose nanomaterial and the inorganic salt component.

[0044] The amounts of the composition components that can be used in the coating compositions are expressed as a percentage by weight/weight based on the wet basis, unless otherwise indicated. In cases where the composition components are in the form of, or combined as, an aqueous solution, the amounts of components may be expressed as percent weight/volume (w/v%) or percent weight/weight (w/w %) as these units are essentially identical. Abbreviations CH Chitosan OA Oleic acid SEFA fatty acid sucrose ester ACC 1-aminocyclopropane-1-carboxylic acid CNC cellulose nanocrystal CNF cellulose nanofiber ACS ACC synthase CNFC Nanofiber containing chitosan CN Cellulose nanomaterial CNCC Calcium nanocarbon containing chitosan NCC Nanocarbonate calcium SEM Scanning electron microscopy

Introduction

[0045] Various post-harvest technologies, such as low temperature, edible coatings, and hypobaric and controlled atmosphere storage, have been applied to delay the ripening and deterioration of fruit quality during post-harvest storage. However, low-temperature storage can cause chilling injury and physiological damage to banana fruits, and hypobaric and controlled atmosphere storages are capital-intensive and expensive. Edible coatings have been widely applied as a cost-efficient and environmentally friendly post-harvest technology for fruits and vegetables. Such coatings can generate a modified atmosphere creating a semi-permeable barrier against oxygen, carbon dioxide, moisture and solute movement.

[0046] Although lipid and/or hydrocolloid-based coatings have been used to extend the shelf life of various fruits such as post-harvest bananas, there are several challenges such as insufficient moisture and gas barrier and poor adhesion on fruit surfaces that must be addressed in the technique. The present disclosure describes unique coating compositions, coatings and films that help food items (e.g., packaged foods, plants and plant parts) retain various properties (e.g., firmness, reduced weight loss, etc.) and thereby improve and maintain the integrity and marketability of the food item. The described compositions, coatings and films include a unique combination of cellulose nanomaterials and emulsion systems that help maintain this integrity and marketability.

Methods of carrying out Composition and Coating

[0047] Embodiments of a composition that can be used to form coatings on the outer surface of a food article, such as a packaged, perishable food product, a plant or a part of a plant, are described herein.

[0048] In some embodiments, components of the coating compositions described herein are edible and in some examples have a generally recognized as safe (GRAS) regulatory status as provided by the United States Food and Drug Administration. In other examples, components are listed on the Environmental Protection Agency's Lists 4A and 4B as being safe for the environment.

[0049] The embodiments of the coating composition described herein comprise a cellulose nanomaterial. Cellulose nanomaterial, as used herein, is a cellulosic material consisting primarily of linear chains of one hundred to more than ten thousand b-D-glucopyranose units linked by glycosidic bonds at their C1 and C4 positions, with nanoscale external dimensions, or in some forms of realization, having an internal structure or nanoscale surface structure. In some embodiments, the cellulose nanomaterials may comprise cellulose nanofibrils (which are also referred to herein as “CNF”) or cellulose nanocrystals (which are also referred to herein as “CNC”). In some independent embodiments, such nanomaterials may contain a portion of cellulose microcrystals or cellulose microfibrils. The amount of cellulose microcrystals and/or cellulose microfibrils present in such embodiments can be reduced or increased depending on the use of the extraction method to prepare the cellulose nanomaterial and/or by varying the cellulose-containing species from which these components are extracted. In some embodiments, cellulose nanomaterials consist of cellulose nanofibrils or cellulose nanocrystals. The cellulose nanomaterial typically is selected to provide a translucent coating and an improved matrix for incorporation of other materials/components described herein.

[0050] The cellulose nanomaterial of the described coating composition is typically selected to have a suitable structure and suitable chemical properties for use in the particular composition embodiments and methods of using the compositions described herein. For example, cellulose nanomaterial is typically selected to provide an absorbably clear and water-resistant coating. In some embodiments, the cellulose nanomaterial structure and properties of the compound are optimized to provide a type of cellulose nanomaterial comprising crystalline regions and amorphous regions. In some embodiments, the cellulose nanomaterial may have dimensions of 3 nm to 300 nm in width. In some embodiments, the cellulose nanomaterial may have a length ranging from 15 nm to 100,000 nm, such as 50 nm to 100,000 nm, or 100 nm to 10,000 nm, 100 nm to 5,000 nm, 100 nm to 2,500 nm, 100 nm to 2000 nm, or 100 nm to 1000 nm. In some embodiments, the cellulose nanomaterial described herein may have an aspect ratio reminiscent of elementary fibrils in plant cell walls. In some embodiments, the cellulose nanomaterial has an aspect ratio (ratio of the longest dimension to the shortest dimension) that ranges from 5 to 1000, such as 10 to 1000, or 20 to 1000, or 30 to 1000, or 50 to 1000. An exemplary cellulose nanomaterial having aspect ratios within this range is the cellulose nanocrystal material described herein. In other embodiments, the cellulose nanomaterial may have a ratio ranging from 5 to 1000, such as 5 to 500, or 5 to 250, or 5 to 200, or 5 to 150, or 5 to 100. A cellulose nanomaterial of An example having an aspect ratio within this range is the cellulose nanocrystal material described herein. In particular described embodiments, the cellulose nanomaterial may be cellulose nanofibrils which may be prepared using typical methods known to a person of ordinary skill in the art with the benefit of this disclosure, such as fibrillation with or without chemical pretreatment in refining. mechanical cellulose derived from wood fiber or non-wood vegetable fiber. The method used to prepare the cellulose nanofibrils may or may not provide a cellulose nanofibril composition containing residual hemicelluloses. In some embodiments, cellulose nanofibrils can be purchased from a commercial source and then used in the described compositions.

[0051] The coating composition embodiments described herein may additionally comprise an emulsion system, a functional additive, a plasticizer, or any combinations thereof and are typically aqueous compositions. In some embodiments, the emulsion system may comprise one or more hydrophobic agents (e.g., fatty acid), one or more surfactants, or any combinations thereof. Emulsion system embodiments, functional additives and plasticizers are described in more detail below. In particular described embodiments, the coating composition comprises, consists essentially of, or consists of a cellulose nanomaterial, a functional additive (e.g., chitosan, aloe vera, potassium sorbate, ethylenediaminetetraacetic acid (EDTA), a salt of quaternary ammonium or any combination thereof), a plasticizer (e.g., glycerol, sorbitol, polyethylene glycol 400 or any combination thereof) and an emulsion system. In a representative embodiment, the coating composition comprises, consists essentially of, or consists of nanocrystals of cellulose, chitosan, glycerol and the emulsion system. In still further embodiments, the coating composition comprises, consists essentially of, or consists of a cellulose nanomaterial and an emulsion system. In representative embodiments, the coating composition comprises, consists essentially of, or consists of cellulose nanofibrils and the emulsion system. In “consisting essentially of” embodiments, the coating composition may comprise components other than those specified in such embodiments; however, these additional non-harmful components affect the properties of the coating (as determined by comparing a food product comprising a coating made from such a composition with a food product without the coating), such as by decreasing the wettability of the coating on the food product, increasing color degradation, increasing weight loss, decreasing marketability, increasing ethylene production, increasing CO2 concentration while decreasing O2 concentration, or any combination thereof. Particular amounts of components of the coating compositions are described below; these amounts are expressed as a percentage of the total composition and, unless otherwise indicated, the percentages described below refer to w/w as determined on a wet basis.

[0052] Emulsion system embodiments described herein may comprise, consist essentially of, or consist of one or more hydrophobic agents, one or more surfactants, or any combinations thereof. In particular described embodiments, the emulsion comprises, consists essentially of, or consists of a surfactant and a hydrophobic agent. In embodiments in which the emulsion system consists essentially of one or more hydrophobic components, one or more surfactants, or any combinations thereof, the emulsion system does not comprise, or is free of, any components that detrimentally affect the emulsion system. (e.g., disrupting the ability of the emulsion system to form emulsion droplets and/or other types of agglomerations). For example, emulsion systems that “consist essentially” of the hydrophobic component(s), one or more surfactants, or any combinations thereof, are free from components that would result in creaming, sedimentation, flocculation, coalescence or separation of the emulsion system. In embodiments where the emulsion system comprises a fatty acid and a surfactant, the surfactant is typically selected based on its ability to form hydrophobic droplets (or other type of agglomerated structure) and promote placement of the emulsion system in the matrix. of hydrophilic cellulose nanomaterial and/or to decrease the surface tension of the coating composition to improve the stability, uniformity and spreadability of emulsion coatings.

[0053] In some embodiments, one or more hydrophobic components of the emulsion system may be an oil or a fatty acid. The oil may be an essential oil, such as, but not limited to, thyme oil, clove oil, oregano oil, lemongrass oil, marjoram oil, cinnamon oil, coriander oil or any combination thereof; vegetable oil; oil; avocado oil; coconut oil; and any combinations thereof. In particular described embodiments, the fatty acid is a medium chain fatty acid, with an aliphatic tail comprising 6 to 12 carbons (saturated or unsaturated), such as capric acid and lauric acid; a long chain fatty acid, with an aliphatic tail comprising 13 to 21 carbons (saturated or unsaturated), such as oleic acid, linoleic acid, α-linolenic acid, palmitic acid, stearic acid, arachidic acid; or any combination thereof. In some embodiments, one or more surfactants of the emulsion system may be selected from a polysorbate surfactant (e.g., polyoxyethylene (20) sorbitan monolaurate, also known as “TWEEN 20”, or polyoxyethylene (80) sorbitan monolaurate, also referred to as “Tween 80”), a sorbitan surfactant (e.g., sorbitan monolaurate, also known as “SPAN 20”; or sorbitan monooleate, also known as “SPAN 80”) , a sucrose ester of a fatty acid (e.g., a sucrose ester of a fatty acid having from one to eight carbons in the hydrocarbon chain of the fatty acid, such as a sucrose ester of propionic acid, butyric acid, valeric acid , caprylic acid or unsaturated versions thereof), or any combinations thereof. In particular described embodiments, the surfactant is Tween 80, SEFA or a combination thereof. In representative embodiments, the emulsion system comprises, consists essentially of, or consists of TWEEN 80. In still additional embodiments, the emulsion system comprises, consists essentially of, or consists of TWEEN 80 and oleic acid. In still further embodiments, the emulsion system comprises, consists essentially of, or consists of SEFA and oleic acid.

[0054] In still some additional embodiments, the coating composition may additionally comprise one or more additional components, such as a stabilizer (e.g., carboxy- or sulfate-containing polysaccharides selected from, but not limited to, alginic acid, alginate sodium, cellulose, cellulose derivatives, pectic polysaccharides, carboxymethyl dextran, xanthan gum, carboxymethyl starch, hyaluronic acid, dextran sulfate, pentosan polysulfate, carrageenans, fuciodans, or any combinations thereof), an inorganic salt (e.g., a sodium-containing salt, potassium-containing salt, calcium-containing salt, magnesium-containing salt, tin-containing salt or any combinations thereof), an acidic compound (e.g., ascorbic acid or other organic acid), or any combinations thereof. In embodiments comprising any such additional components, the stabilizer may be present in an amount ranging from 0.05% w/w (on a wet basis) to 2% w/w (on a wet basis), such as 0 .05% w/w (on a wet basis) to 0.1% w/w (on a wet basis), or 0.05% w/w (on a wet basis) to 0.75% w/w (on a wet basis), or 0.05% w/w (on a wet basis) to 0.5% w/w (on a wet basis), or 0.05% w/w (on a wet basis) to 0.25% w/w (on a wet basis). The inorganic salt may be present in an amount ranging from 0.05% w/w (on a wet basis) to 2% w/w (on a wet basis), such as 0.05% w/w (on a wet basis). wet basis) to 0.1% w/w (on wet basis), or 0.05% w/w (on wet basis) to 0.75% w/w (on wet basis), or 0. 05% w/w (on a wet basis) to 0.5% w/w (on a wet basis), or 0.05% w/w (on a wet basis) to 0.25% w/w (on a wet basis) on a wet basis). An acidic compound may be present in an amount ranging from 0.5% w/w (on a wet basis) to 3% w/w (on a wet basis), such as 0.5% w/w (on a wet basis). wet basis) at 2% w/w (on wet basis), or 0.5% w/w (on wet basis) at 1.5% w/w (on wet basis), or 0.5% w/w (on a wet basis) to 1.0% w/w (on a wet basis), or 0.05% w/w (on a wet basis) to 0.75% w/w (on a wet basis) damp). Such components do not detrimentally affect the emulsion system or the properties of the coating composition.

[0055] Coating compositions additionally comprising one or more agricultural agents selected from nutrients (e.g., fertilizers), growth stimulants, plant growth regulators, herbicides, fungicides, pesticides or combinations thereof are also contemplated. Such compositions may be made using any of the methods described herein and may be applied to crops, trees, shrubs, vines, vegetable plants, ornamental and decorative plants, such as plants cultivated for their flowers (e.g., roses, carnations, lilies , and so on) or for its decorative foliage (e.g., ivy, ferns, and so on) and the like. The amount of agricultural agent used in such coating composition may be selected to be within the limitations set forth in EPA guidelines. One of ordinary skill in the art will recognize that such quantities can be determined by reviewing the EPA guidelines relating to the selected agricultural agent and selecting a quantity within the lower and upper limits provided herein. In some such embodiments, the agricultural agent is typically provided in an amount ranging from 1 ppm to 5,000 ppm, such as 1 ppm to 4,000 ppm, 1 ppm to 3,000 ppm, 1 ppm to 2,000 ppm, or 1 ppm to 1,000 ppm. ppm. Amounts less than, or equal to, the application level suggested by the manufacturer may also be used and would be readily recognized by those of ordinary skill in the art.

[0056] In some embodiments, the amount of cellulose nanomaterial and emulsion system that is used in the coating composition is selected to provide a cellulose nanomaterial:emulsion system ratio that ranges from 1:1 to 1:20 , such as 1:2 to 1:8 or 1:1 to 1:5. In particular described embodiments, the cellulose nanomaterial is cellulose nanofibrils and this material is included in the coating composition with the emulsion system in a ratio of 1:2 to 1:20 or 1:2 to 1:8. In other particularly described embodiments, the cellulose nanomaterial is cellulose nanocrystals and this material is included in the coating composition with the emulsion system in a ratio of 1:1 to 1:20 or 1.1 to 1:5.

[0057] In some embodiments, the amount of cellulose nanomaterial used in the coating composition varies from 0.1% w/w (on a wet basis) to 1% w/w (on a wet basis), such as 0.1% w/w (on a wet basis) to 0.75% w/w (on a wet basis), or 0.1% w/w (on a wet basis) to 0.5% w/w p (on a wet basis), or 0.1% w/w (on a wet basis) to 0.4% w/w (on a wet basis), or 0.1% w/w (on a wet basis) to 0.3% w/w (on a wet basis), or 0.1% w/w (on a wet basis) to 0.2% w/w (on a wet basis). In particular representative embodiments, the amount of cellulose nanomaterial used in the coating compositions is 0.1% w/w (on a wet basis), 0.2% w/w (on a wet basis), 0.3 % w/w (on a wet basis) or 0.4% w/w (on a wet basis). In some embodiments, the amount of emulsion system used in the coating composition ranges from 0.03% w/w (on a wet basis) to 4% w/w (on a wet basis), such as 0.03 % w/w (on a wet basis) to 3.5 % w/w (on a wet basis), or 0.03% w/w (on a wet basis) to 3% w/w (on a wet basis) ), or 0.03% w/w (on a wet basis) to 2.5% w/w (on a wet basis), or 0.03% w/w (on a wet basis) to 2% w/w /wt (on a wet basis), or 0.03% w/w (on a wet basis) to 1.5% w/w (on a wet basis), or 0.03% w/w (on a wet basis) ) at 1% w/w (on a wet basis), or 0.03% w/w (on a wet basis) at 0.5% w/w (on a wet basis). In such embodiments, the emulsion system may comprise a surfactant in such amounts, or may comprise a mixture of a surfactant and a hydrophobic agent in such amounts, wherein the surfactant is present in the mixture in an amount ranging from 0. 03% w/w (on a wet basis) to 5% w/w (on a wet basis) (such as 0.03% w/w (on a wet basis) to 2% w/w (on a wet basis) ), or 0.03% w/w (on a wet basis) to 1% w/w (on a wet basis), or 0.2% w/w (on a wet basis) to 1% w/w (on a wet basis)) and the hydrophobic agent is present in the mixture in an amount ranging from 0.1% on a w/w basis) to 5% on a w/w basis (on a wet basis) (such as 0.1% on a wet basis) w/w (on a wet basis) to 4% w/w (on a wet basis), or 0.1% w/w (on a wet basis) to 3% w/w (on a wet basis), or 0 .1% w/w (on a wet basis) to 2% w/w (on a wet basis), or 0.1% w/w (on a wet basis) to 1.5% w/w (on a wet basis) wet basis), or 0.1% w/w (wet basis) to 1% w/w (wet basis)). In representative embodiments, the emulsion system comprises 0.03% w/w (on a wet basis), or 0.2% w/w (on a wet basis), or 1% w/w (on a wet basis). wet) of a surfactant and/or 1% w/w (on a wet basis) of a hydrophobic agent. In embodiments further comprising an additive and/or a functional plasticizer, the functional additive may be used in amounts ranging from 0.1% w/w (on a wet basis) to 3% w/w (on a wet basis). ), such as 0.1% w/w (on a wet basis) to 2.5% w/w (on a wet basis), or 0.1% w/w (on a wet basis) to 2% w/w (on a wet basis) w/w (on a wet basis), or 0.1% w/w (on a wet basis) to 1.5% w/w (on a wet basis) and the plasticizer may be present in amounts ranging from 0.02 % w/w (on a wet basis) to 1% w/w (on a wet basis), such as 0.02% w/w (on a wet basis) to 0.5% w/w (on a wet basis) wet) or 0.02% w/w (on a wet basis) to 0.4% w/w (on a wet basis), or 0.02% w/w (on a wet basis) to 0.3% in w/w (on wet basis). Additional representative coating compositions and amounts of components used in such compositions are also described in the Examples section and in the figures of the present specification.

[0058] In a representative embodiment, coating compositions comprising cellulose nanofibrils and an emulsion system comprising oleic acid and a sucrose ester of a fatty acid were particularly effective for enhancing the post-harvest storability of banana fruit. during environmental storage by controlling physiological activity and improving the adhesion of coatings on fruit surfaces. In some embodiments, the emulsion system has enhanced the hydrophobicity, stability and wettability of coatings on fruit surfaces. Such coating compositions also delayed the ethylene biosynthesis pathway and reduced fruit ethylene and CO2 production, as well as modifying the surface morphology of the fruit to provide more uniform coating coverage. Furthermore, such coating embodiments are effective in reducing the degradation of chlorophyll of banana peels and the loss of weight and firmness of the fruit, thereby enhancing marketability and storability during storage at room temperature.

[0059] Also described here are coatings formed from the embodiments of the coating composition described here. The term "coating", as used herein, refers to a layer of composition created on the exterior of a food product, such as a plant or plant part. The layer does not need to be of uniform thickness or completely homogeneous in composition. These coating compositions can be dried to form dry (or substantially dry) coatings, which are described below. Also described herein are embodiments of a film that can be made using the described embodiments of the composition. Such film embodiments can be used as flexible packaging components (e.g., biodegradable plates, films and packaging) for various perishable food products, such as meats, seafood and the like. Film embodiments are edible and thus avoid consumer concerns about food safety. In some embodiments, the film may be fibrous or crystalline and may form a durable, inert, water-resistant coating on the object to be coated. In some embodiments, the film comprises a cellulose nanomaterial and a functional agent, such as chitosan.

[0060] The coating, dry (or substantially dry) coating or film need not cover the entire object to which it is applied. In some embodiments, the coating or film may substantially coat the object. In such embodiments, the film or coating may cover 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90% of the surface area of the object. In other embodiments, the film or coating may completely coat the object - that is, it may cover 100% of the object. In some embodiments, the film or coating may have a thickness that varies by 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90% relative to the object.

[0061] Coatings and/or films made from embodiments of the described coating composition are extremely water resistant and strong. Coatings and films can provide water resistance and barrier properties while retaining the unique functionality of the non-cellulosic components of the composition. The coatings and films described herein provide protection against water loss caused by perspiration and/or freeze-thaw related drip loss, and allow for improved water resistance and barrier properties, while maintaining the unique functionality of the components. non-cellulosic composition. In still additional embodiments, the coatings and films exhibit increased adhesion between cellulose nanomaterials and hydrophobic surfaces (e.g., hydrophobic fruit surfaces).

[0062] When applied to the target surface of plants, plant parts or other food items, the described compositions form a strong external barrier after drying. The compositions may be dried to form dry (or substantially dry) coatings by allowing the water in the coating composition to evaporate. In some embodiments, the coatings are dried using heat to facilitate faster drying of the coating composition, thereby preventing or reducing long-term exposure to oxygen and light. Temperatures ranging from 30°C to 35°C can be used to dry the compositions after they have been applied to an object. In some embodiments, a hot air drying technique may be used to (at least partially) dry the coating composition after it is applied to the object. Such hot air drying techniques may use temperatures ranging from 60°C to 90°C for a period of time ranging from 2 minutes to 10 minutes. Coatings produced using embodiments of the described coating compositions can reduce the loss of color appearance and physical integrity associated with the leaching of anthocyanins and other biological pigments (e.g., betalains), nutrients and water-soluble compounds. In plants and food items, preventing water loss before and after harvest is important for the products' marketability. The described compositions and coatings formed from such compositions can be used to prevent such water loss in susceptible plants, and other food products.

[0063] In particular described embodiments, a plant or plant part comprising a coating made from the compositions described herein exhibits properties that would not be exhibited by an equivalent plant or plant part (i.e., a plant or part of identical unmodified plant) does not comprise such coating. For example, in some embodiments, the plant or plant part comprising a coating formed from the described composition exhibits reduced weight loss (such as reduction of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90%) after thawing compared to an equivalent plant or part of a plant that is not coated with the coating. In some embodiments, the plant or plant part comprising a coating made from the composition described herein exhibits reduced morphological defects (such as reduction of 10%, 20%, 30%, 40%, 50%, 60%, 70 %, 80%, 90% or 100%) compared to an equivalent plant or part of a plant that is not coated with the coating. In still other embodiments, the plant or plant part comprising a coating made from the described composition exhibits less loss of firmness (such as 10%, 20%, 30%, 40%, 50%, 60%, 70% , 80% or 90% less loss of firmness) compared to an equivalent plant or part of a plant that is not coated with the coating.

Ways to carry out the Method

[0064] Embodiments of method for making and using the coating composition embodiments described herein are described herein.

[0065] Embodiments of the method of preparing the described composition may comprise dispersing in water (which may be deionized, purified and the like) a suitable amount of each component of the composition described herein. In some embodiments, the components of the composition may be added to the water simultaneously. In other embodiments, each component may be added sequentially to the same aqueous solution. In still other embodiments, separate aqueous solutions of each component may be prepared and then mixed together. Certain components may not need to be dispersed in water before mixing and therefore may be added to one or more solutions containing other components. As used herein, “mixing” may be accomplished by any means known in the art. For example, mixing, stirring or mechanical co-spraying components can be used to “mix” the components described herein. In particular described embodiments, the emulsion system is first prepared separately from the cellulose nanomaterial and then combined with the cellulose nanomaterial (which may be formulated with additional components described above, such as an additive and/or a functional plasticizer). In particular described embodiments, the emulsion system is made by suspending a surfactant in water at room temperature or higher temperatures (e.g., 70°C). In embodiments of emulsion systems additionally comprising a hydrophobic agent (e.g., a fatty acid), the hydrophobic agent may be added to the surfactant solution, followed by homogenization. In embodiments where the coating composition comprises an additive and/or a functional plasticizer, the functional additive may be pretreated (e.g., dissolved in an acidic solution) and then combined with the plasticizer and/or the nanomaterial of cellulose.

[0066] Once each component is dispersed in water (together or separately), the solution is then homogenized using a homogenizer at low or high shear. The level of shear used can be modified according to the type of coating composition used. The solution is typically homogenized for a period of time suitable to completely dissolve, disperse and/or emulsify the components in water at room temperature. The final composition may then be formulated for administration by soaking, spray coating, dipping, coating or any other technique suitable for applying the composition to an object as described herein. Representative methods for making additional coating compositions are described in the Examples section of the present specification.

[0067] In some embodiments, the composition is not intended for immediate use, for example, when the composition is packaged for future sale. Such compositions are shelf stable, such that less than 20%, 30%, 40% or 50% of the composition will separate after 5, 10, 20, 30 or 60 days of storage. Even longer storage periods are also contemplated. One of ordinary skill in the art will appreciate that methods of preparing shelf-stable compositions may involve choosing appropriate stabilizers to be added to the composition.

[0068] The compositions described here can be used to prevent pre- and post-harvest damage to plants, or parts thereof, thus prolonging storage time and increasing the marketability of fresh products. The compositions can also be used in food articles to promote the storage and appearance of food articles, particularly perishable articles. The coatings and/or films formed from the coating compositions described herein can be easily removed before sale, simply picked up by consumers, and can even be safely ingested.

[0069] In some embodiments, the coating and processing compositions described herein can be used to reduce and prevent color and nutrients that are leached from fruits and/or vegetables. The described compositions are also useful as food coatings and in preparing frozen foods to prevent drip loss and to maintain integrity during thawing. Food articles experience significant water losses during the freezing and thawing process due to syneresis (i.e., loss of water after thawing) and evaporation; Films formed from compositions described herein can reduce this water loss. For example, the described compositions can be used to reduce water loss/gain in bakery products (e.g., cookies, cakes and breads) and/or meat during storage (cold or ambient). Some embodiments can be used to reduce water loss/gain and/or stickiness of candy and other confectionery products during storage (cold or ambient). In still other embodiments, the described compositions may be used to reduce gas exchange (e.g., O2 and CO2) or exposure to harmful gases (e.g., ethylene gas) from various foods or other organic materials with air in the environment during storage and while on the shelf.

[0070] The compositions described herein can also be used in an agricultural context to protect parts of plants (e.g., seeds of agricultural crops), plants and/or seedlings against biotic and/or abiotic stresses before and after harvest. In some embodiments, the compositions described herein may be used alone or may be combined with one or more agricultural agents to inhibit biotic stresses, such as insect, nematode and/or microbial infestation, and also to resist abiotic stresses. such as environmental stresses. One skilled in the art will appreciate that there are several methods that can be used to determine the decrease in infestation attributable to the application of the compositions described herein. For example, for microbial levels cultures can be taken and the number of colony forming units (CFUs) can be determined and compared with plant parts (e.g. seeds of agricultural crops), plants and/or seedlings that have not been treated with the composition. Similarly, the number of insects or insect larvae can be counted and parts of plants (e.g., seeds of agricultural crops), plants and/or seedlings that have been treated with the compositions described herein can be compared with parts of similar plants (e.g. example, seeds of agricultural crops), plants and/or seedlings in the same geography that were not treated. Generally, treated plants will exhibit 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90% less microbial, nematode and/or insect infestation compared to plant parts of control (e.g. agricultural crop seeds), plants and/or seedlings.

[0071] In some examples, coating compositions are used to prevent or reduce weight loss, molding and/or loss of firmness. By way of example only, embodiments of the described composition can be used to prevent molding and/or morphological changes in parts of plants (e.g., fruits), such as tropical fruits. Exemplary plant parts that can be coated with the coating compositions described herein include, but are not limited to, avocados, cantaloupe, papayas, mangos, melons and the like.

[0072] The compositions also provide safe, visibly transparent coatings that do not impart any significant odor or flavor to food and that also prevent discoloration or other damage to fruit caused by UV exposure. Films can also prevent moisture loss caused by heat and/or sunlight.

[0073] Modifying the physical properties of biodegradable products such as plates, films and packaging, for example, to provide greater resistance to degradation, improved barrier properties and/or improved strength is yet another application for films made from compositions described here. It is also contemplated that the films, dry (or substantially dry) coatings, and coating compositions provided herein may be used as a protective surface treatment or coating for durable materials, such as to reduce or prevent damage during transit and handling. . The majority of flexible packaging materials in the food industry are petroleum-derived polymers. Its lack of sustainability and concerns about toxic waste result in diminished appeal to consumers. Alternative natural materials (e.g. cellulose and chitosan) do not have water resistance. The films described herein can be used to provide coatings that address these limitations.

[0074] In particular described embodiments, the coating compositions can be applied to an object using any suitable method to partially or fully coat the object and form a coating after drying. For example, the object may be immersed in the coating composition. In other embodiments, the coating composition may be dripped or brushed onto the object. In still other embodiments, the object may be coated (partially or fully) by spray coating the coating composition onto the object. The object can also be covered (partially or fully) using a mechanical applicator or a brush to apply the coating composition to the object. In embodiments relating to compositions that are used to coat plants and/or parts of plants, such as fruits and/or vegetables, the composition may be added to the object before being harvested or after harvesting. Suitable sprayers and coatings would be recognized by those skilled in the art. In some embodiments, the coating method may be chosen based on the viscosity of the coating composition. For example, if the coating composition is viscous and the object to be coated is a post-harvest product (e.g., fruit or vegetable), then dip or drip methods are typically used. Pre-harvest application typically involves applying the coating to the plant or plant part using a spray method.

[0075] Innumerable objects can be contacted with embodiments of the composition described herein, thus providing improved products. In some embodiments, the object is a food product, such as a plant or part of a plant. Exemplary objects include fruits, particularly fruits having hydrophobic surfaces, and vegetables, particularly vegetables having hydrophobic surfaces.

[0076] Generally, objects comprising a coating produced by the composition include components as described here, but after drying the relative concentration of the components is changed due, for example, to the loss of water from the composition. Therefore, a dry (or substantially dry) coating formed from the coating compositions will generally contain less water and higher concentrations/ratios of the compositional (non-evaporative) components. A substantially dry coating may further comprise a low level of moisture, such as greater than 0% to 10% moisture, or greater than 0% to 7% moisture, or greater than 0% to 5% moisture, or greater than 0% to 4% humidity, or greater than 0% to 3% humidity. Table 1 provides representative ranges for the amounts of components present in a substantially dry coating, and are expressed as % w/w on a dry basis. In a representative example, a substantially dry coating may comprise cellulose nanofibrils or cellulose nanocrystals which may be present in an amount ranging from 4.5% w/w on a dry basis to 9.8% w/w on a dry basis. dry, such as 5.0% w/w on a dry basis to 8.0% w/w on a dry basis. In some embodiments, the dry basis of each component of a substantially dry coating can be calculated with a formula: (percentage of solids in the dry coating) damp). In some other embodiments, the dry basis for each component of a dry coating can be calculated as: Wdry = component portion/sum total of all components. By way of example only, in a representative embodiment where the concentration of cellulose nanofibrils ranges from 4.5% w/w on a dry basis to 9.3% w/w on a dry basis, this range was obtained using this calculation (which represents 5% moisture to be retained in the substantially dry coating): 95 X 1.0/21 and 95 X 0.1/1.02, respectively. In some embodiments, the objects may comprise a dry or substantially dry coating having a thickness ranging from more than 0 μm to 50 μm, such as 1 μm to 40 μm, or 1 μm to 30 μm. * Dry basis was calculated based on 5% dry coating moisture content

Overview of Various Embodiments

[0077] Embodiments of a coating composition are described herein, comprising: a cellulose nanomaterial in an amount ranging from 0.1% w/w on a wet basis to 1% w/w on a wet basis; and an emulsion system, comprising a fatty acid and a surfactant, wherein the fatty acid is present in an amount ranging between 0.1% w/w on a wet basis and 5% w/w on a wet basis and the Surfactant is present in an amount ranging from 0.1% w/w on a wet basis to 2% w/w on a wet basis.

[0078] In some embodiments, the cellulose nanomaterial comprises cellulose nanofibrils. In some embodiments, cellulose nanofibrils are present in an amount ranging from 0.1% w/w on a wet basis to 0.5% w/w on a wet basis.

[0079] In some embodiments, the cellulose nanomaterial comprises cellulose nanocrystals. In some embodiments, cellulose nanocrystals are present in an amount ranging from 0.1% w/w on a wet basis to 1% w/w on a wet basis.

[0080] In any or all of the above embodiments, the fatty acid is oleic acid, capric acid, lauric acid, linoleic acid, α-linolenic acid, palmitic acid, stearic acid, arachidic acid and any combinations thereof.

[0081] In any or all of the above embodiments, the surfactant is a sucrose ester of a fatty acid or a polysorbate surfactant.

[0082] In any or all of the above embodiments, additionally comprising a functional agent, a plasticizer, or a combination thereof. In some embodiments, the functional agent is chitosan.

[0083] In any or all of the above embodiments, the plasticizer is glycerol.

[0084] In any or all of the above embodiments, the coating composition comprises a functional agent and a plasticizer, wherein the functional agent is present in an amount ranging from 0.1% w/w on a wet basis to 2% w/w on a wet basis and the plasticizer is present in an amount varying between 0.02% w/w on a wet basis and 1% w/w on a wet basis.

[0085] In some embodiments, the coating composition comprises a cellulose nanomaterial in an amount ranging from 0.1% w/w on a wet basis to 1% w/w on a wet basis; and an emulsion system, comprising an oleic acid and a sucrose ester of a fatty acid, wherein the oleic acid is present in an amount ranging from 0.1% w/w on a wet basis to 5% w/w. p on a wet basis and the sucrose ester of a fatty acid is present in an amount ranging from 0.1% w/w on a wet basis to 2% w/w on a wet basis.

[0086] In some embodiments, the cellulose nanomaterial comprises cellulose nanofibrils.

[0087] In some embodiments, the coating composition comprises a cellulose nanomaterial in an amount ranging from 0.1% w/w on a wet basis to 1% w/w on a wet basis; and an emulsion system, comprising a polysorbate surfactant present in an amount ranging between 0.1% w/w on a wet basis and 2% w/w on a wet basis; and a functional agent, a plasticizer or a combination thereof.

[0088] In some embodiments, the cellulose nanomaterial comprises cellulose nanocrystals.

[0089] In any or all of the above embodiments, the functional agent is chitosan and the plasticizer is glycerol.

[0090] Also described here are embodiments of a substantially dry coating, comprising a cellulose nanomaterial and an emulsion system, comprising a fatty acid and a surfactant.

[0091] In some embodiments, the cellulose nanomaterial is present in an amount ranging from 4.5% w/w on a dry basis to 9.8% w/w on a dry basis.

[0092] In any or all of the above embodiments, the fatty acid is present in an amount ranging from 9.5% w/w on a dry basis to 23% w/w on a dry basis.

[0093] In any or all of the above embodiments, the surfactant is present in an amount ranging from 9.5% w/w on a dry basis to 9.8% w/w on a dry basis.

[0094] In any or all of the above embodiments, the cellulose nanomaterial comprises cellulose nanofibrils.

[0095] In any or all of the above embodiments, the cellulose nanomaterial comprises cellulose nanocrystals. In some embodiments, the composition additionally comprises chitosan in an amount ranging from 9.5% w/w on a dry basis to 9.8% w/w on a dry basis.

[0096] In any or all of the above embodiments, the composition additionally comprises glycerol in an amount ranging from 2% w/w on a dry basis to 4.7% w/w on a dry basis.

[0097] Also described here are embodiments of a plant part comprising a coating formed from the coating composition in accordance with any or all of the above embodiments of the coating composition.

[0098] Also described here are embodiments of a plant part comprising a substantially dry coating in accordance with any or all of the above dry coating embodiments.

[0099] In any or all of the above embodiments, the plant part is a tropical fruit.

[00100] In any or all of the above embodiments, the plant part is a banana, a papaya, an avocado, a melon or a mango.

[00101] Also described herein are embodiments of a method comprising coating or substantially coating a plant or a plant part with a coating composition comprising a cellulose nanomaterial in an amount ranging from 0.1 wt% /wt on a wet basis at 1% w/w on a wet basis; and an emulsion system, comprising a fatty acid and a surfactant, wherein the fatty acid is present in an amount ranging between 0.1% w/w on a wet basis and 5% w/w on a wet basis and the Surfactant is present in an amount ranging from 0.1% w/w on a wet basis to 2% w/w on a wet basis.

Examples

[00102] The following materials and methods may be useful in the preparation and use of various embodiments of the present description.

Materials

[00103] CNF and CNC, derived from softwood Kraft pulp with solids content of 2.95% and 11.8%, respectively, were produced from the Process Development Center at the University of Maine (ME, USA) . Chitosan (97% degree of deacetylation, MW 149 kDa) was purchased from Premix (Iceland), Tween 80 from Amresco (OH, USA), SEFA from TCI American (OR, USA), OA and glycerol from Alfa Aesar ( MA, USA) and acetic acid from JT Baker (NJ, USA). 1-Aminocyclopropane-1-carboxylic acid (ACC) and N-(2-hydroxyethyl)piperazine-N'-3-propanesulfonic acid (EPPS) were purchased from Chem Impex Internation, Inc. (IL, USA), HgCl2 from MP biomedicals (CA, USA), pyridoxal phosphate from TCI American (OR, USA), dithiothreitol (DTT) from Sigma (MO, USA) and trichloroacetic acid (TCA) and NaOCl from JT Baker (NJ, USA).

[00104] Organic Cavendish bananas (Piura, Peru) at ripening stage 2 (green with a trace of yellow) without visual defects were purchased from a local supermarket (OR, USA) on the day of their arrival at the store, and coated in same day of purchase.

Example 1

[00105] In this example, two types of nonionic surfactants, including Tween 80 and sucrose fatty acid ester (SEFA) that have different hydrophilic heads (carbohydrates for Tween 80 and ethoxylate for SEFA), were evaluated as surfactants in coating compositions representative.

[00106] In this example, the cellulose nanomaterial includes cellulose nanofibers (CNF), which have high flexibility and absorption capacity, and cellulose nanocrystals (CNC), which are highly rigid, rod-like structures having a negative surface charge , which can be combined with a functional additive, such as chitosan, to provide a matrix. The ability of coating compositions comprising these components to improve the storability of post-harvest bananas by improving the adhesion of coatings to fruit surfaces, enhancing the moisture barrier of coatings, controlling physiological activity and/or modifying morphology surface of the fruit was evaluated.

[00107] Fruit adhesion, coating hydrophobicity and external fruit quality parameters (e.g. chlorophyll degradation, weight loss and marketability of fruit) were evaluated, as well as the effect of coatings on surface characteristics (e.g., critical surface tension of fruit peels and cell morphology) and physiological activity (e.g., ethylene biosynthesis pathway and ethylene and CO2 production) of fruits. Additionally, the coatings were evaluated for their ability to enhance the storage capacity of the fruit, monitoring the internal quality of the fruit (e.g., starch degradation, firmness, soluble solids content and titratable acidity) during storage at room temperature, of the fruit.

[00108] The coating compositions were prepared on a wet basis (w/w) and the concentration range of each component was determined based on our preliminary studies (data not shown). Each coating matrix, including 0.3% CNF and 0.2% chitosan reinforced with 2% CNC, was formulated with surfactants (Tween 80 or SEFA) and/or OA and derived into six different types of emulsion coatings. as reported in FIG. 1 (with reference to Fig. 1, the types of surfactants to form oleic acid (OA) emulsion included Tween 80 and sucrose fatty acid ester (SEFA); q represents the contact angle of the reference liquid on the banana surface ; gL is the reference liquid surface tension on the banana peel; and gc is the critical surface tension of the banana peel). Emulsion systems with different types of surfactant agents were first prepared as follows: 1% Tween 80 was suspended in water at room temperature, and SEFA was dispersed at 70°C to enhance water solubility. Then, 1% OA (1% w/w) was added to the surfactant solution and homogenized for 1 minute. A coating composition with only Tween 80 (10% w/w on a dry basis) was also prepared as a positive control. For CNF-based emulsion coating compositions, 0.3% CNF was mixed with surfactants and/or OA (CNFA: 0.03% Tween 80 alone, CNFB: Tween 80 with 1% OA, and CNFC 1%: 1% SEFA with 1% OA) and homogenized for 1 minute (Polytron PT10-35, Luzernerstrasse, Switzerland). For CNC-reinforced chitosan emulsion coating compositions, 2% (w/w) chitosan was dissolved in 1% (w/v) acetic acid solution and homogenized with 0.2% CNC and 0.2% glycerol. 4% for 1 minute. The prepared coating compositions were mixed with surfactants and/or OA (CNCA: 0.2% Tween 80 only, CNFB: 1% Tween 80 with 1% OA and CNFC: 1% SEFA with 1% OA). , homogenized for 3 minutes, and then degassed using a self-constructed water flow vacuum system.

[00109] When applying coatings to the surface of the fruit, three different coating application methods (dipping, spraying and dripping) were evaluated, and there was no significant difference in the storage capacity of the fruits. A brushing method was used to further improve the spreadability of coatings over the surface of the fruit. Each coating composition was manually brushed onto bananas using a paint brush (width: 25 mm) to obtain a uniform coating. The fruits were dried under forced air flow for 1 hour. Uncoated and coated fruits were stored for 10 days at ambient conditions under fluorescent light without packaging (20±2°C and 50±5% RH). Fruit coated with SemperfreshÔ (Semp, 1.2% w/w, Pace International, LLC, Wa, USA) was used as a positive control. SemperfreshÔ is a commercial coating product containing fatty acid sucrose ester, mono- and di-glycerides and carboxymethyl cellulose and has been used for coating various fruits and vegetables, including bananas.

Example 2

[00110] The performance of the coating is strongly influenced by the wettability of the coating formulation associated with the surface characteristics of the fruit. Previously, limited efforts have been made to understand the correlation of coating wettability with fruit surfaces. In this example, the contact angle (CA) of the coating formulation and spreading coefficient (Ws) of the coating compositions on the banana surface were evaluated, as well as the surface tension (ST) of the coating compositions to meet the ST of the surfaces. of banana to ensure sufficient adhesion of coatings on banana surfaces.

[00111] CA was determined using a video contact angle system (FTA 32, First Ten Angstroms, Inc., USA) equipped with a face contact angle meter. 10 μL of coating composition was dropped from 10 mm height onto a horizontal surface of the banana surface. CA was recorded after 30 seconds for all samples excluding the influence of dispersion time on spreadability. The ST of the coating compositions was determined using a model FTÂ T10 (First Ten Angstroms, Portsmouth, VA) equipped with a Du Nuoy ring (CSC Scientific Co, Fairfax, VA). All data were collected within 5 minutes to reach ST steady state. The spreading ability of the coating compositions was calculated and expressed as the spreading coefficient (Ws = Wa - Wc) derived from the adhesion coefficient (Wa = gSV + gLV - gSL, impacting spreading) and cohesion coefficient (Wc = 2gLV , impacting shrinkage), where gSV, gSL and gLV represented solid-vapor, solid-liquid and liquid-vapor interfacial tensions of a coating composition.

[00112] To ensure sufficient and uniform adhesion of the coating compositions to the surface of the coated fruit, the ST of the developed coating compositions must be lower than or close to the critical ST (gC) of that fruit surface. The critical ST of the banana surface was obtained by extrapolation from the Zisman graph, which was constructed using water, formamide and 1-methyl naphthalene as reference liquids. In some embodiments, the critical ST of fruit surfaces depends on the texture and composition of that fruit.

Example 3

[00113] In this example, the contact angle (CA) of the coating composition and derived film WVP were determined to measure hydrophobicity. The CA of the coating compositions on the silicon wafer surface was determined using the same method mentioned above. The coatings were derived from developed coating compositions. Briefly, 60 mL of coating compositions were uniformly cast in a 150 mm diameter polystyrene petri dish (Falcon, PA, USA), and dried at room temperature for 2 days. The derived coatings were then conditioned at 25°C and 50% RH in a self-assembled chamber prior to measurement (Versa, PA, USA) (Jung et al., 2016). WVP of the coatings were measured using a cup method based on ASTM E96-87 (ASTM 2000; Park & Zhao, 2004). Each film sample (75 x 75 mm) was sealed with vacuum grease between the lid and the Plexiglas test cup (57 x 15 mm) filled with 11 mL of distilled (DI) water, and the sealing ring was closed securely using elastic bands. The test cup assemblies were stored in the self-assembled chamber at 25OC and 50% RH and weighed every hour for 6 hours. Data were reported as the mean value and standard deviation of three replications.

Example 4

[00114] In this example, chlorophyll content of banana peels, weight loss (%), and marketability (%) of uncoated (control) and coated fruit samples were evaluated and used as the scientific basis for selecting the coating compositions to improve the storability of fruit. Eighteen bananas were randomly distributed into three groups (6 fruits/group), with each group as one replicate and three replicates per treatment. The chlorophyll content of banana peels was measured using a DA meter (Sinteleia, Bolonga, Italy), and the percentage of chlorophyll degradation was reported as change in chlorophyll content at different sampling times (1-10 days) of the content. initial chlorophyll. Fruit weight loss (%) was calculated as weight change at different sampling times from the initial weight and multiplied by 100. Fruit marketability (%) was determined based on visual observation of brown spots on fruit peels. banana, in which the fruit was considered unmarketable when 20% of the fruit peels were covered with brown spots. Marketability (%) was then calculated as the number of marketable fruits at different sampling times (1-10 days) divided by the total number of fruits per treatment (18 ea) and multiplied by 100.

[00115] Coating composition embodiments comprising cellulose nanofibrils, such as coating embodiments comprising CNF, oleic acid, and SEFA (e.g., a “CNFC” coating as described in certain figures) have exhibited good performance with based on the parameters measured above. Such coatings were further validated by coating a new set of fruits. Starch degradation, firmness, titratable acidity (TA) and total soluble solids (TSS) of uncoated and coated fruits (CNFC and Semp) were evaluated and photos of fruits were taken at various sampling times (0, 3, 7 and 10 days). during the same storage conditions tested above. The starch content of the pulp was determined using the iodine dyeing method to estimate the conversion of starch to sugar as a result of fruit ripening. The iodine solution was freshly prepared using 2.5 g/L iodine and 10 g/L potassium iodide. The banana cross-section was immersed in the iodine solution for 5 seconds at each sampling time and visually observed for six cross-section sections randomly selected from six fruits for each treatment. Fruit firmness was determined as the maximum penetration force (N) using a texture analyzer (TA-XT2 Texture Analyzer, Texture Technologies Corp., NY, USA), in which the individual banana was penetrated by a cylinder probe stainless steel P/6 with a depth of 7 mm at a speed of 10 mm/s. Three measurements at different locations for each individual fruit were performed as one replication per treatment. Mean values and standard deviations were reported with six replications. For SST and TA, 40 g of banana pulp was mixed with 160 ml of DI water using a mixer (Proctor Silex, NACCO Industry Inc., VA, USA). The mixture was filtered using a qualitative filter paper with the pore size of 2.5 μm (Whatman, GE Healthcare Bio-Sciences, PA, USA). The SST of the filtrate was measured using a refractometer (RA250-HE, KEM, Tokyo, Japan). The filtrate was then titrated with 0.1 N NaOH to pH 8.3 using a pH meter (Orion 410A, Fisher Scientific, MA, USA) and digital titrator (Brinkmann, TX, USA). TA was reported as the equivalent percentage of malic acid as the predominant acid in ripe banana. One measurement was performed for each fruit as one replicate per treatment, and mean values and standard deviations were reported with six replicates.

Example 5

[00116] In this example, the physiological activity of the fruit and the surface characteristics of uncoated and coated fruits were investigated to understand the mechanisms of effective coating.

[00117] Respiration (O2 and CO2) and ethylene production of bananas were measured using a gas chromatograph (CG-2014, greenhouse gas analyzer, Shimadzu, Japan) with a flame ionization detector (FID, ethylene and CO2) and thermal conductivity detector (TCD, O2). Five bananas were randomly selected, weighed, placed inside a 1.5 L airtight glass jar with a lid containing a 10 mm rubber septum for headspace gas sampling, and stored at room temperature (20±2°C ). O2 and CO2 productions were monitored after 24 hours, while ethylene production was measured after 48 hours due to the low amount of ethylene production. For each vial, 1 mL of headspace gas was collected using an airtight syringe (Series A, Valco Instrument Co., USA) and then injected into the GC with three types of packed columns: 80/100 HAYESEP D, 8/100 HAYESEP N and 60/80 molecular sieve column (Supelco, Bellefonte, PA, USA). Helium was applied as a carrier gas at a pressure of 350 kPa and a flow rate of 21.19 mL min-1. The temperature of the injector, column and FID detector was set at 150, 90 and 250°C, respectively. Standard gases O2, CO2, and ethylene were purchased from Air Liquide (ScottÔ, PA, USA), and GC solution software (Shimadzu, Japan) was used to calculate the amount of O2, CO2, and ethylene.

[00118] As illustrated in FIG. 1, the coatings could impact the ethylene biosynthesis pathway of fruits, generating modified atmosphere conditions. ACC was measured as the precursor of ethylene and the activity of ACS as an enzyme that catalyzes the synthesis of ACC from S-adenosyl methionine (SAM).

[00119] For the measurement of ACC and ACS, fresh banana samples were collected at different sampling times (0, 3, 7 and 10 days), and stored at -80oC before analysis. For ACC extraction, 2 g of freshly thawed banana in 10 mL of 9% TCA were homogenized for 60 seconds and incubated at 4°C for 24 hours. The extract was centrifuged at 10,000 x g for 30 minutes, and the supernatant was adjusted to pH 7-8 with 1N NaOH. two of the sample reaction mixtures were prepared with 500 μL of supernatant, 100 μL of 10 mM HgCl2 (100 μL), and 300 μL of DI water in capped 10 mL vials. One of them was contaminated using internal standard ACC (50 μL of 0.05 mM ACC). Both were incubated for 3 minutes at 4°C after adding 100 μL of saturated NaOH and 5.25% NaOCl for hydrolysis of ACC in ethylene. Then, 5 mL of gas sample was taken for ethylene measurements and quantified using GC. ACC concentration was expressed as pmol/g of fresh sample.

[00120] To measure ACS, 5 g of freshly thawed banana pulp was homogenized in 10 ml of buffer with 100 mM N-(2-hydroxyethyl)piperazine-N'-3-propanesulfonic acid (EPPS), pyridoxal phosphate 0.5 μM, and 4 mM dithiothreitol (DTT) for 60 s, and adjusted to pH 8.5 with KOH. The extract was centrifuged at 10,000 x g for 30 minutes, and the supernatant was dialyzed overnight at 4°C in dialysis buffer solution (pH 8.5) containing 2 mM EPPS, 0.2 μM pyridoxal phosphate, and 0.1 mM DTT. . Similarly, two reaction mixtures containing 400 μL of enzyme solution, 50 μL of 600 mM EPPS (pH 8.5), and 90 μL of DI water were prepared in capped 10 mL vials. One of them was contaminated using the ACC internal standard (50 μL of 0.05 mM ACC). After adding 60 μL of 0.5 mM SAM, both reaction mixtures were incubated for 3 hours at 30°C and then mixed with 100 μL of 10 mM HgCl2 and 200 μL of DI water. The reaction mixture was finally hydrolyzed by adding 100 μL of saturated NaOH and 5.25% NaOCl. 5 mL of headspace gas was then collected after incubation at 4°C for 3 minutes, and ethylene production was measured using GC. ACS activity was expressed as pmol of ethylene/g of fresh sample.

Example 6

[00121] In this example, the effect of coatings on the surface morphology of bananas was evaluated by a scanning electron microscope (SEM) (FEI Quanta 600, Cressington Scientific Instruments Ltd., United Kingdom). Uncoated, Semp-coated, and CNFC-coated banana peels were cut into 5 mm pieces and placed in a modified Karnovsky fixative for 2 hours. Samples were rinsed in 0.1 M sodium cacodylate buffer and dehydrated in a graded series of acetone (10%, 30, 50, 70, 90, 95, 100-100%), 10-15 minutes each. The samples were dried in an EMS 850 critical point dryer, mounted in the SEM on the top side of a piece of skin, and coated with gold and palladium. Digital images were acquired at an accelerating voltage of 5 kV.

[00122] A completely randomized two-factorial design considering two treatment factors (types of coating matrix: chitosan reinforced with CNF and CNC; types of emulsions: Tween 80 only, Tween 80 with OA and SEFA with OA) was applied to analyze the performance of coating compositions and derived coatings. GLM PROC was used to identify significant differences and interactions between each factor using the SAS program (SAS v 9.2, The SAS Institute, USA), and the post-hoc least significant difference (LSD) was used for multiple comparisons. All measurements were performed in triplicate and results were considered significantly different at P<0.05.

[00123] A completely randomized design with a single treatment factor (type of coating compositions: uncoated, Semp-coated and CNFC-coated) was then applied to further study the fruit's internal quality, physiological activity and characteristics. from the surface of bananas. All measurements were taken in duplicates or triplicates. One-way ANOVA was performed to determine significant differences between treatments, and a post-hoc LSD was performed using statistical software (SAS v 9.2, The SAS Institute, USA). The results were considered significantly different at P<0.05. Table 2: Results analysis of variance (ANOVA) and LSD post-hoc multiple comparison tests to investigate the main effects of matrix and emulsion and their interactions (matrix x emulsion) on the scattering coefficient, contact angle (CA) on silicone and banana peel, tension of coating formulations and water vapor permeability (WVP) of derived films * CNC It was made from 2% chitosan with 0.2% cellulose nanocrystals (CNC) and 0.4% glycerol. **CNF was made from 0.3% cellulose nanofiber (CNF). + Post-hoc LSD multiple comparison test was performed only for the factor showing the significant effect (P<0.05) based on the ANOVA results. ++ OA indicates oleic acid. +++ SEFA indicates fatty acid sucrose ester.

Example 7

[00124] The effectiveness of fruit coatings to reduce water loss and control post-harvest respiration is based on the sufficient wettability and adhesion of coating compositions on fruit surfaces and the hydrophobicity of the coatings formed. In this example, the wettability and hydrophobicity of coating compositions were evaluated by measuring the wettability (contact angle and mirroring coefficient) of the coating compositions on the fruit surface and the correlation of the surface tension (ST) of the coating compositions with the ST criticality of the fruit surface, hydrophobicity (contact angle) of the coating compositions on the hydrophobic silica wafer, and WVP of the derived coatings.

[00125] The type of emulsions incorporated into coating compositions had a significant impact (P<0.05) on CA on banana surfaces, showing lower CA in the coating composition containing OA/Tween 80 (36.8°) or OA/ SEFA (31.2°) than with Tween 80 alone (44.8°) (Table 2). The spreading coefficient (Ws) of the coating compositions was significantly (P<0.05) affected by the interactive effect between the type of coating matrix and emulsion, with the highest Ws in the emulsified coating compositions (CNCB, CNCC, CNFB and CNFC) than in those without emulsion (CNCA and CNFA). For ST, the two treatment factors (coating matrix and emulsion) had a significant (P<0.05) interactive effect on the ST of the coating compositions, showing the lowest ST in the CNCC and CNFC coating compositions (26.0 mM/m and 25.4 mM/m, respectively) among all treatments (Table 2). These results supported that the emulsified coating compositions improved the wettability of the coatings on the hydrophobic banana surfaces that make up the cutin and wax in the cell wall. Furthermore, the ST of the developed coating compositions was lower than the critical ST of fruit surfaces, derived from the Zisman graph, was 35.2 mN/m (FIG. 1), indicating that banana surfaces have low surface energy (<100 mN/m). Many fruit surfaces have low surface tension due to the presence of a natural wax layer. Although this layer of natural wax protects the fruit, it can lead to the need for high wettability of the aqueous coatings to be uniformly adhered to the fruit surfaces. To enhance the wettability of coatings on the fruit surface, the ST of coating compositions should be closer to and/or lower than the critical ST of the fruit surface. The above results supported that all coating compositions developed from this example, except CNFA, had ST less than the critical ST of the banana surface, thus ensuring sufficient adhesion of the coatings to the banana surfaces.

[00126] Regarding hydrophobicity, the coating composition with OA/SEFA showed a significantly lower CA (P<0.05) on hydrophobic silicon wafer than with OA/Tween 80 (Table 2), which could be attributed to more hydrophobic SEFA compared to Tween 80, thus reducing the oil-water interfacial tension and improving the hydrophobicity of the coatings. However, the type of coating matrix and incorporated emulsion had a significant effect (P<0.05) on WVP of derived coatings, in which WVP of the CNFC film (0.03 g mL/m2 d Pa) had the highest value. low among all coating compositions, indicating a superior moisture barrier (Table 2). Without being limited to a single theory, it is currently believed that the OA/SEFA emulsion system can be well dispersed in continuous CNF phase with light surface charges and flexible structure compared to the CNC-reinforced chitosan coating, thus avoiding the diffusion of moisture throughout the hydrophobic CNF emulsion matrix. The CNC-reinforced chitosan matrix may be less compatible with the OA/SEFA emulsion system, as shown by the reduced surface charges due to the electrostatic interaction between the positively charged chitosan and negative CNC surface charges and high crystallinity of the continuous phase. Therefore, the emulsion system composed of OA and SEFA in CNF-based coating matrix could derive hydrophobic coatings with improved moisture barrier function.

Example 8

[00127] The effect of coating compositions on chlorophyll degradation, weight loss and marketability of bananas during 10 days of ambient storage is reported in FIGS 2A-2C. The CNFC coating resulted in the lowest and slowest degradation of chlorophyll from banana peels among all coating compositions (FIG. 2A). The CNFC coating also caused the least weight loss (~17%) of fruit at the end of 10 days of storage compared to uncoated treatments (~24%) and other treatments (~19-23%) (FIG. 2B ). Furthermore, CNFC retained the highest marketability of the fruit compared to other coating compositions during the storage period (FIG. 2C). About 50% of uncoated (control) fruits lost marketability after 5 days of storage, while about 90% of CNFC-coated fruits were still marketable after 8 days of storage. Without being limited to a single theory, it is currently believed that the effectiveness of CNFC coating can be attributed to the well-dispersed OA/SEFA emulsion system in the CNF coating matrix that closely interacted with fruit surfaces to provide a Uniform coating coverage and good moisture barrier, thus preventing moisture loss, reducing chlorophyll degradation, and improving the marketability of fruits during storage.

Example 9

[00128] In this example, uncoated fruits, semp-coated fruits, and CNFC-coated fruits were further studied for their effect on the physiological activity (FIG. 3A-3D) and surface characteristics (FIG. 4A-4C) of bananas during storage at room temperature. The CNFC coating significantly reduced the ethylene production of the fruit (0.82 ppm/g), compared to uncoated fruit (4.41 ppm/g) and Semp-coated fruit (2.38 ppm/g) (FIG. 3A). The CNFC-coated fruit also contained lower CO2 and higher O2 compared to the uncoated one, while it had similar CO2 and O2 to the Semp-coated fruit (FIG. 3B). Fruit respiration (O2 and CO2) and ethylene production are the main physiological indices that track the change of ripening and senescence during the storage period. These data confirmed that the CNFC coating suppressed the respiration and ethylene production of bananas through the formation of modified internal atmosphere inside the fruit, thereby delaying fruit ripening and senescence.

[00129] Post-harvest climacteric fruit produces ethylene through autocatalytic ethylene biosynthesis, in which ACC as the ethylene precursor and ACS as the catalytic enzyme synthesize ACC from SAM (figure 1). As shown in FIG. 3C, CNFC coating resulted in a significantly higher concentration of ACC in fruits compared to uncoated and Semp-coated. This result indicated that the CNFC coating modified the internal atmosphere of the fruit, which limited the hydrolysis of ACC to ethylene, thus generating lower ethylene production with ACC accumulated in the fruit. This result was consistent with the lower ethylene production in CNFC-coated fruits compared to uncoated and Semp-coated ones (Figure 3B). Meanwhile, ACS activity was peaked at 0 days of storage, then gradually reduced during the first 4-5 days of storage, but increased again for CNFC- and Semp-coated fruits during the rest of storage (FIG. 3D). . The higher initial activity of ACS could be associated with the onset of yellowing of the skin of subsequently obtained fruit samples. It was possible that the banana obtained from the local market had already reached the beginning of yellowing of the skin before the local store. The increased ACS activity in Semp- and CNFC-coated fruits after 7 days of storage may be associated with delayed ripening at the late ripening stage of fruits. The CNFC coating resulted in lower ACS activity in fruits than semp coatings, showing a slower ripening process. Thus, the CNFC coating can control the physiological activity of bananas, as shown by lower ethylene and CO2 production and lower ACS activity, delaying fruit ripening.

[00130] The influence of coatings on fruit surface characteristics through SEM analysis is illustrated in FIGS. 4A-5C. The CNFC coating (FIG. 4C) uniformly covered the pericarp surface with no cleavage between epidermal cells, while some cracks and/or cleavage between cells appeared for the uncoated (FIG. 4A) and Semp-coated (FIG. 4B) fruit. ). This insufficient coverage can potentially accelerate moisture loss, respiration and fungal invasion. Furthermore, the size and shape of the epidermal cells of CNFC-coated fruits were changed as marked in FIGS. 4C, which may result from interactions between the CNF fibrous matrix and the epidermal cells of banana peels. Thus, the fruit surface morphology further ensured that the fibrous and hydrophobic CNFC coating could be well associated with the banana surfaces to provide effective coating performance.

Example 10

[00131] In this example, a validation study was carried out for uncoated fruits, coated with Semp, and fruits coated with CNFC. The visual appearance of the fruit was monitored at 3, 7 and 10 days of storage at room temperature (Figure 5A). During the yellowish-green life of the banana (0-3 days of storage), coatings with Semp (middle image of FIG. 5A) and CNFC (right image of FIG. 5A) slowed chlorophyll degradation. During the yellowish-brown life (7-10 days of storage), the CNFC coating further reduced the incidence of browning spots on fruit surfaces compared to uncoated and Semp-coated. In the yellow phase, the banana fruit continues to ripen, the presence of polyphenol oxidase (PPO) further promotes the changes of phenol to quinine and increases in macromolecules by polymerization, thus leading to the accumulation of brown pigment. The CNFC coating reduced enzymatic browning in the yellow stage of the fruit, delaying banana ripening and senescence.

[00132] The starch test showed the high starch content in bananas coated with CNFC, as reflected by the darker blue/black color on the surfaces of cross-cut fruits from the iodine reaction compared to uncoated and Semp-coated fruits (FIG 5A). A similar trend was observed from the TSS at 3 and 7 days of storage, showing that the coating with CNFC resulted in lower TSS of the fruit compared to the uncoated and the Semp coated (Figure 5A). These results proved that the CNFC coating delayed banana ripening, preventing the hydrolysis of starch and its conversion into soluble sugars. However, the TSS of CNFC-coated bananas had no significant difference compared to uncoated bananas at 10 days of storage, indicating that the proper ripening process continued in the bananas during storage. This result was also supported by increased ACS activity after 7 days of storage, indicating that adequate ripening continued in CNFC-coated bananas.

[00133] Both Semp-coated and CNFC-coated bananas retained greater firmness than the uncoated sample at 3 and 7 days of storage (FIG. 5B). Firmness is an important parameter to determine the ripening stage and quality of the banana. While ripening, pectinesterase and polygalacturonase hydrolyzed the pectin and starch, leading to destruction and deterioration of the cell wall structure, in turn softening the fruit. Based on the results reported and discussed above, coating CNFC with a uniform surface on the fruit surface through interactions between CNF and banana peel epidermal cells was able to delay the physiological activity and ripening of the coated fruits while maintaining firmness. of the fruit during storage.

[00134] The CNFC coating resulted in the lowest soluble solids content of the fruit compared to the uncoated and Semp coated at 3 and 7 d of storage (FIG. 5C). The soluble solids content is a good indicator of fruit ripeness, since starch is hydrolyzed into soluble sugars during ripening. Soluble solids content data proved that the CNFC coating additionally delayed fruit ripening compared to the Semp coating. However, the soluble solids content of bananas coated with CNFC showed no significant difference compared to uncoated bananas after 10 days of storage, indicating that the adequate ripening process continued in the bananas during storage. This result was also supported by increased ACS activity after 7 days of storage, indicating that adequate ripening continued in CNFC-coated bananas.

[00135] The TA of CNFC-coated fruits was significantly (P<0.05) higher than uncoated and Semp-coated fruits over the 10 days of storage (FIG. 5D). It was assumed that the CNFC coating reduced the consumption of organic acids as a primary substrate for the respiration process during storage, due to the controlled physiological activity of the fruit. The validation study confirmed that the CNFC coating was effective in delaying ripening, delaying quality deterioration and extending the storability of post-harvest bananas during environmental storage.

Example 11

[00136] In this example, the effect of emulsion CNF coatings on the appearance and selected quality parameters of various fruits in room temperature storage was examined. The results are shown in FIG. 6, in which the means followed by different superscript letters between control and coated fruit are significantly different (P<0.05) and WL = weight loss.

Example 12

[00137] In this example, the sleeves were coated using a coating composition comprising cellulose nanofibrils and an emulsion system comprising oleic acid and a fatty acid sucrose ester. The mangoes were stored for 12 days at ambient conditions. It was observed that the coating application prolonged the green state and improved the storage capacity of the fruit (see FIG. 7).

Example 13

[00138] Uncoated and coated fruits were measured for weight loss, firmness, total soluble solids (TSS) and titratable acidity (TA) in 12 days of storage. Only a significant difference (P<0.05) was observed for TA, showing higher in fruit with a coating embodiment described here than in the uncoated one. Higher TA could indicate that fruit ripening was delayed. The results are provided below in Table 3.

Example 14

[00139] In this example, films made from CNF incorporated in CH were evaluated for use as films for meat separation. Consistently, CNF films incorporated in CH (including 20% w/w on a dry basis of CH at 68 kDa and 287 kDa) had significantly lower liquid absorption (lower WA values) than CNF films without CH, indicating the enhanced water resistance of CNF films incorporated in CH. These results (see FIGS. 8A and 8B) demonstrated that CH-incorporated CNF films are durable against high humidity conditions, so they can potentially be applied to highly moist surface foods as separation sheets to prevent moisture transfer between layered products. All films, different from the control (which comprises only CNF), were prepared incorporating 0.5% CNF (w/w of water on a wet basis) and 10% glycerol (w/w of chitosan on a dry basis) .

[00140] Taking into account the many possible embodiments to which the principles of the present description can be applied, it should be recognized that the illustrated embodiments are only preferred examples and should not be considered as limiting the scope of the present description. Instead, the scope is defined by the following claims. We therefore claim as our invention everything that comes within the scope and spirit of these claims.

Claims (22)

1. Coating composition characterized by the fact that it comprises: a cellulose nanomaterial in an amount ranging between 0.1% w/w on a wet basis and 1% w/w on a wet basis, wherein the cellulose nanomaterial comprises cellulose nanofibrils, cellulose nanocrystals or a combination thereof; and an emulsion system, comprising (i) a fatty acid selected from a medium chain and/or long chain fatty acid, and (ii) a surfactant selected from a sucrose ester of a fatty acid, a polysorbate, a sorbitan, or any combination thereof; wherein the fatty acid is present in an amount ranging from 0.1% w/w on a wet basis to 5% w/w on a wet basis and the surfactant is present in an amount ranging from 0.1% w/w on a wet basis w/w on wet basis 2% w/w on wet basis. 2. Coating composition according to claim 1, characterized by the fact that the emulsion system consists of one or more emulsion droplets dispersed in the cellulose nanomaterial, and in which the surfactant forms an external hydrophilic region of one or more drops of emulsion and the fatty acid forms an internal hydrophobic region of one or more drops of emulsion. 3. Coating composition according to claim 1 or 2, characterized by the fact that cellulose nanofibrils are present in an amount ranging between 0.1% w/w on a wet basis and 0.5% w/w /p on wet basis; and/or cellulose nanocrystals are present in an amount ranging from 0.1% w/w on a wet basis to 1% w/w on a wet basis. 4. Coating composition according to any one of claims 1 to 3, characterized in that the fatty acid is oleic acid, capric acid, lauric acid, linoleic acid, α-linolenic acid, palmitic acid, stearic acid, acid arachidic and any combinations thereof. 5. Coating composition according to any one of claims 1 to 4, characterized in that the surfactant is a sucrose ester of a fatty acid. 6. Coating composition according to any one of claims 1 to 5, characterized in that it additionally comprises a functional agent, a plasticizer or a combination thereof; optionally wherein the functional agent is chitosan; and/or wherein the plasticizer is glycerol. 7. Coating composition according to any one of claims 1 to 6, characterized in that the composition comprises a functional agent and a plasticizer, wherein the functional agent is present in an amount ranging from 0.1% in w/w on a wet basis to 2% w/w on a wet basis and the plasticizer is present in an amount ranging between 0.02% w/w on a wet basis and 1% w/w on a wet basis. 8. Coating composition according to any one of claims 1 to 7, characterized in that a portion of the cellulose nanomaterial further comprises cellulose microfibrils, cellulose microcrystals or a combination thereof. 9. Coating composition characterized by the fact that it comprises: a cellulose nanomaterial in an amount ranging between 0.1% w/w on a wet basis and 1% w/w on a wet basis, wherein the cellulose nanomaterial comprises cellulose nanofibrils, cellulose nanocrystals or a combination thereof, and wherein a portion of the cellulose nanomaterial further comprises cellulose microfibrils, cellulose microcrystals or a combination thereof; and an emulsion system, comprising oleic acid and a sucrose ester of a fatty acid, wherein the oleic acid is present in an amount ranging from 0.1% w/w on a wet basis to 5% w/w on a wet basis and the sucrose ester of a fatty acid is present in an amount ranging between 0.1% w/w on a wet basis and 2% w/w on a wet basis. 10. Coating composition according to claim 9, characterized by the fact that the emulsion system consists of one or more emulsion droplets dispersed in the cellulose nanomaterial, and in which the fatty acid sucrose ester forms an outer hydrophilic region of one or more emulsion drops and oleic acid forms an inner hydrophobic region of one or more emulsion drops. 11. Coating composition according to claim 9 or 10, characterized in that the cellulose nanomaterial comprises cellulose nanofibrils. 12. Coating composition characterized by the fact that it comprises: a cellulose nanomaterial in an amount ranging between 0.1% w/w on a wet basis and 1% w/w on a wet basis, wherein the cellulose nanomaterial comprises cellulose nanofibrils, cellulose nanocrystals or a combination thereof; and an emulsion system, comprising a medium chain and/or long chain fatty acid present in an amount ranging from 0.1% w/w on a wet basis to 3% w/w on a wet basis; and a functional agent. 13. Coating composition according to claim 12, characterized in that the cellulose nanomaterial comprises cellulose nanocrystals; and/or wherein the functional agent is chitosan. 14. Coating composition according to claim 12 or 13, characterized in that a portion of the cellulose nanomaterial further comprises cellulose microfibrils, cellulose microcrystals or a combination thereof. 15. Substantially dry coating characterized by the fact that it comprises: a cellulose nanomaterial comprising cellulose nanofibrils, cellulose nanocrystals or a combination thereof; and one or more emulsion droplets dispersed in the cellulose nanomaterial, wherein the one or more emulsion droplets comprise(s) (i) a fatty acid selected from a medium chain and/or heavy chain fatty acid, and ( ii) a surfactant selected from a sucrose ester of a fatty acid, a polysorbate, a sorbitan or any combination thereof, and wherein the surfactant forms an outer hydrophilic layer of one or more emulsion droplets and the fatty acid forms an internal hydrophobic region of one or more emulsion drops. 16. The substantially dry coating of claim 15, wherein the cellulose nanomaterial is present in an amount ranging from 4.5% w/w on a dry basis to 9.8% w/w on a dry basis; and/or wherein the fatty acid is present in an amount ranging between 9.5% w/w on a dry basis and 23% w/w on a dry basis; and/or wherein the surfactant is present in an amount ranging from 9.5% w/w on a dry basis to 9.8% w/w on a dry basis. 17. The substantially dry coating of claim 15, wherein a portion of the cellulose nanomaterial further comprises cellulose microfibrils, cellulose microcrystals, or a combination thereof. 18. Substantially dry coating according to claim 17, characterized in that it additionally comprises chitosan in an amount ranging between 9.5% w/w on a dry basis and 9.8% w/w on a dry basis ; and/or wherein it further comprises glycerol in an amount ranging from 2% w/w on a dry basis to 4.7% w/w on a dry basis. 19. Food product characterized by the fact that it comprises the coating composition as defined in any one of claims 1 to 14; and/or the substantially dried coating as defined in any one of claims 15 to 18. 20. Method characterized by the fact that it comprises coating or substantially coating a plant or a part of the plant with a coating composition comprising a cellulose nanomaterial in an amount ranging from 0.1% w/w on a wet basis to 1% on a wet basis w/w, wherein the cellulose nanomaterial comprises cellulose nanofibrils, cellulose nanocrystals or a combination thereof; and one or more emulsion droplets dispersed in the cellulose nanomaterial, wherein the one or more emulsion droplets comprise(s) (i) a fatty acid selected from a medium-chain and/or long-chain fatty acid, and (ii) a surfactant selected from a sucrose ester of a fatty acid, a polysorbate, a sorbitan, or a combination thereof, wherein the fatty acid is present in an amount ranging from 0.1% w/w in wet basis and 5% w/w wet basis and the surfactant is present in an amount ranging from 0.1% w/w wet basis to 2% w/w wet basis, and wherein the surfactant forms an outer hydrophilic layer of one or more emulsion drops and the fatty acid forms an inner hydrophobic region of one or more emulsion drops. 21. Use of a coating composition as defined in any one of claims 1 to 14 and/or a substantially dry coating as defined in any one of claims 15 to 18 for forming coatings on the external surface of a food item , such as a packaged perishable food product, or a plant part. 22. Method according to claim 20, characterized by the fact that a portion of the cellulose nanomaterial further comprises cellulose microfibrils, cellulose microcrystals or a combination thereof.