The present disclosure relates to formulations and methods for treating agricultural products, such as produce, to reduce spoilage during storage and shipping.
Common agricultural products such as fresh produce can be highly susceptible to degradation and decomposition (i.e., spoilage) when exposed to the environment. The degradation of the agricultural products can occur via abiotic means as a result of evaporative moisture loss from an external surface of the agricultural products to the atmosphere and/or oxidation by oxygen that diffuses into the agricultural products from the environment and/or mechanical damage to the surface and/or light-induced degradation (i.e., photodegradation). Furthermore, biotic stressors such as, for example, bacteria, fungi, viruses, and/or pests can also infest and decompose the agricultural products.
Harvested produce (e.g., fruits, vegetables, berries, etc.) can also be stored at high density (i.e., high total mass of produce per unit volume of storage container) for extended periods of time prior to consumption. Methods for decreasing the rate of spoilage while maintaining high quality produce in a dense packing volume, with minimal loss in mass/moisture during storage and shipping, are therefore desirable.
Described herein are formulations and methods for extending storage time and reducing spoilage of harvested produce without increasing the rate of water or mass loss, thereby resulting in high quality produce with lower rates of spoilage. The present disclosure provides protective coatings, as well as methods of coating produce, to prevent moisture loss from the produce during storage and shipping. This in turn can allow the produce to be shipped and stored at lower relative humidity (e.g., lower than industry standards for shipping and storage, or lower than about 90% relative humidity), which can help inhibit or delay the growth of biotic stressors such as fungi, bacteria, viruses, and/or pests.
In one aspect, a method of reducing spoilage in harvested produce during storage includes applying a coating formulation to the produce to form a coating over a surface of the produce. The coating formulation comprises a plurality of monomers, oligomers, low molecular weight polymers, fatty acids, esters, or combinations thereof. The method further includes storing the produce at an average relative humidity level sufficiently low to suppress fungal growth in the produce during storage, wherein the coating is formulated to reduce a mass loss rate of the produce at the average relative humidity level.
In another aspect, a method of reducing spoilage in harvested produce during storage includes receiving the produce, wherein the produce is coated with a coating agent disposed over a surface of the produce, the coating agent formed from a composition comprising monomers, oligomers, low molecular weight polymers, fatty acids, esters, or combinations thereof. The method further includes storing the produce at an average relative humidity level, the average relative humidity level being sufficiently low to suppress fungal growth in the produce during storage. The coating agent is formulated to reduce a mass loss rate of the produce at relative humidity levels less than or equal to the average relative humidity level.
In another aspect, a method of storing produce includes dissolving a coating agent in a solvent to form a solution, and applying the solution to the surface of the produce. The method further includes allowing the solvent to at least partially evaporate to form a coating on the produce, and storing the produce in an enclosed container at an average relative humidity level in a range of about 50% to 90%.
In another aspect, a method of storing produce includes causing a coating agent to be applied to a surface of the produce, the coating agent formulated to form a coating over the surface of the produce, and storing the produce in an enclosed container at an average relative humidity level greater than an ambient humidity outside the container and less than 90%.
In another aspect, a method of storing produce includes dissolving a coating agent in a solvent to form a solution, and applying the solution to the surface of the produce. The method further includes allowing the solvent to at least partially evaporate to form a coating on the produce, and causing the produce to be stored at an average relative humidity level between 60% and 90%.
In another aspect, a method of storing produce includes causing a solution comprising a coating agent dissolved in a solvent to be applied to a surface of the produce, the coating agent formulated to form a coating over the surface of the produce, and causing the produce to be stored in an enclosed container at an average relative humidity level in a range of about 55% to 90%. Furthermore, the container includes a humidity controller configured to maintain a humidity level within the container at the average relative humidity level.
In another aspect, a method of storing produce comprises receiving produce that includes a coating formed thereon, the coating formed from a coating agent comprising at least one of fatty acids, esters, monomers, oligomers, and low molecular weight polymers. The method further includes storing the produce in an enclosed container at an average relative humidity level less than about 90%, wherein at least 20% of the internal volume of the container is filled with the produce.
Methods and formulations described herein can each include one or more of the following steps or features. Forming the coating can include causing the monomers, oligomers, low molecular weight polymers, or combinations thereof to cross-link, for instance on the surface of the produce. For instance, the components of the coating agent can crosslink to form the coating. The produce can be stored in a container (e.g., at the average humidity level, such as a relative humidity below about 90%) for at least about 1 day, at least about 2 days, at least about 3 days, at least about 4 days, at least about 5 days, at least about 6 days, at least about 7 days, at least about 8 days, at least about 9 days, at least about 10 days, at least about 15 days, at least about 20 days, at least about 25 days, at least about 30 days, at least about 35 days, at least about 40 days, at least about 45 days, at least about 50 days, at least about 55 days, at least about 60 days, about 1 to about 120 days, about 1 to about 110 days, about 1 to about 100 days, about 1 to about 90 days, about 1 to about 80 days, about 1 to about 70 days, about 1 to about 60 days, about 1 to about 50 days, about 1 to about 40 days, about 1 to about 30 days, about 1 to about 25 days, about 1 to about 20 days, about 1 to about 15 days, about 1 to about 10 days, about 1 to about 5 days, about 5 to about 120 days, about 5 to about 110 days, about 5 to about 100 days, about 5 to about 90 days, about 5 to about 80 days, about 5 to about 70 days, about 5 to about 60 days, about 5 to about 50 days, about 5 to about 40 days, about 5 to about 30 days, about 5 to about 25 days, about 5 to about 20 days, about 5 to about 15 days, about 5 to about 10 days, about 10 to about 120 days, about 10 to about 110 days, about 10 to about 100 days, about 10 to about 90 days, about 10 to about 80 days, about 10 to about 70 days, about 10 to about 60 days, about 10 to about 50 days, about 10 to about 40 days, about 10 to about 30 days, about 10 to about 25 days, about 10 to about 20 days, about 20 to about 120 days, about 20 to about 110 days, about 20 to about 100 days, about 20 to about 90 days, about 20 to about 80 days, about 20 to about 70 days, about 20 to about 60 days, about 20 to about 50 days, about 20 to about 40 days, or about 20 to about 30 days. A container containing the produce can be transported or shipped (e.g., while the produce is stored therein). For instance, the container, including the produce therein, can be transported from a first location to a second location, and optionally to a third location, or any number of locations. The produce can be stored at a relative humidity of less than about 90% (e.g., less than 90%) during the transporting from the first location to the second location, and so on. The produce can be stored in a container, and at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, or at least about 90% of the volume of the container can be filled with the produce. The produce can be stored in a container, and the container can include a humidity controller configured to maintain a humidity level within the container at the average relative humidity level.
The produce can be stored in a container, where the humidity level within the container is different from the ambient humidity around the container. The humidity level within the container can be greater than the ambient humidity around the container. The produce can be stored in a container, and the container can include a humidity controller configured to maintain a temperature within the container that is within a predetermined temperature range, for example within a range of −4° C. to 8° C.
The average relative humidity level in the container (e.g., for the shipment of produce after coating of the produce with a composition described herein) can be about 90% or lower. The average relative humidity level in the container (e.g., for the shipment of produce after coating of the produce with a composition described herein) can be sufficiently low to suppress fungal growth in the produce during storage. The average relative humidity level in the container can be below conventional industry standards for shipment of produce.
The coating agent can be formulated to reduce water loss from the produce (e.g., during shipment or storage). The coating agent can include at least one of monomers, oligomers, low molecular weight polymers, fatty acids, and esters. In some embodiments, the coating agent includes monoacylglycerides. The coating can further serve to prevent molding of the produce. The coating can further serve to prevent bacterial growth on the produce. The coating can be formed over a cuticular layer of the produce.
The compositions and formulations described herein can include compounds of Formula I, I-A and/or Formula I-B, as set forth below. The mass ratio of the compound of Formula I-B to the compound of Formula I-A in the compositions or formulations can be in a range of 0.1 to 1.0 or in a range of 0.2 to 0.7. The coating can be formed on the produce by dissolving the coating agent in a solvent to form a solution, applying the solution to the surface of the produce, and allowing at least a portion of the solvent to evaporate. The solvent can include at least one of ethanol and water. The average relative humidity level for the shipment of produce coated with a composition of the present disclosure can be less than about 85%, less than about 80%, less than about 75%, less than about 70%, less than about 65%, less than about 60%, less than about 55%, less than about 50%, less than about 45%, less than about 40%, less than about 35%, less than about 30%, less than about 25%, less than about 20%, less than about 15%, less than about 10%, or less than about 5%. The average relative humidity level can be in a range of about 55% to about 90%, about 60% to about 85%, about 65% to about 80%, or about 65% to about 75%.
The method can further comprise storing the produce at a temperature range of about −4° C. to about 8° C., about −2° C. to about 8° C., about −2° C. to about 6° C., or about −1° C. to about 8° C. The protective coating can have a thickness greater than about 0.1 microns. The protective coating can have a thickness less than about 1 micron. The protective coating can have an average transmittance of at least about 60% for light in the visible range. The coating can be substantially undetectable to the human eye, and/or can be substantially odorless or tasteless. The produce can be stored in a container at the average relative humidity level for at least about 20 days (e.g., at least about 25 days, at least about 30 days, about 20 to about 60 days), and the method can further include removing the produce from the container after the at least about 20 days (or at least about 25 days, at least about 30 days, about 20 to about 60 days), wherein the produce has a first mass when placed in the container and a second mass upon removal of the container, wherein the second mass is within about 30% (e.g., within about 28%, within about 26%, within about 25%, within about 24%, within about 23%, within about 22%, within about 21% or within about 20%) of the first mass.
As used herein, the term “relative humidity” (or “RH”) is defined as a ratio, expressed as a percentage, of the partial pressure of water vapor present in air to the equilibrium vapor pressure (i.e., the partial pressure of water vapor needed for saturation) at the same temperature.
As used herein, the terms “about” and “approximately” generally mean plus or minus 2% of the value stated, e.g., about 50% relative humidity would include 49% to 51% relative humidity. In regards to temperature, the terms “about” and “approximately” generally mean plus or minus 1% of the stated absolute temperature (as measured in Kelvin). For example, about 10° C. (283.15 K) would include 7.17° C. to 12.83° C. (280.32 K to 285.98 K).
As used herein, a “coating” or “protective coating” is understood to mean a layer of monomers, oligomers, low molecular weight polymers, or combinations thereof disposed over and substantially covering a surface of an agricultural product, such as a piece of produce. The monomers, oligomers, low molecular weight polymers, or combinations thereof can be, for example, of the Formula I, I-A and/or Formula I-B as set forth below.
As used herein, a “first relative humidity” or “first relative humidity level” can be understood as an industry standard relative humidity level for storage or shipment of produce. In some embodiments, a first humidity level can be higher than ambient (e.g., atmospheric) humidity. For instance, a first humidity level can be a relative humidity of about 100%, about 99%, about 98%, about 97%, about 96%, about 95%, about 94%, about 93%, about 92%, about 91%, about 90%, or about 85%. In some embodiments, it is customary (e.g., an industry standard) to ship or store produce at about 80% to 95% relative humidity. In some embodiments, the first humidity is maintained at a relatively high level in order to prevent or mitigate substantial moisture loss from the produce. However, as explained herein, a high “first humidity” can enable and promote the growth of biotic stressors such as fungi and bacteria that can lead to unwanted spoilage of the produce.
As used herein, a “coating agent” refers to a chemical formulation that can be used to coat the surface of a substrate (e.g., after removal of a solvent in which the coating agent is dispersed) to form a coating (e.g., a protective coating) on the surface of produce. The coating agent can comprise one or more coating components. For example, the coating components can be compounds of Formula I, I-A and/or Formula I-B, or monomers or oligomers of compounds of Formula I, I-A and/or Formula I-B. Coating components can also comprise fatty acids, fatty acid esters, fatty acid amides, amines, thiols, carboxylic acids, ethers, aliphatic waxes, alcohols, salts (inorganic and organic), or combinations thereof.
The coating agent can comprise a plurality of monomers, oligomers, fatty acids, esters, amides, amines, thiols, carboxylic acids, ethers, aliphatic waxes, alcohols, salts, or combinations thereof. The coating agent can be a non-sanitizing coating agent. The solvent in which the coating agent is dissolved can comprise water and/or an alcohol. The solvent in which the coating agent is dissolved can comprise or be formed of a sanitizing agent. For example, the solvent can comprise ethanol, methanol, acetone, isopropanol, or ethyl acetate. Sanitizing the produce or edible product can result in a reduction in a rate of fungal growth on the produce or edible product, or in an increase in the shelf life of the produce or edible product prior to fungal growth.
The term “alkyl” refers to a straight or branched chain saturated hydrocarbon. C1-C6 alkyl groups contain 1 to 6 carbon atoms. Examples of a C1-C6 alkyl group include, but are not limited to, methyl, ethyl, propyl, butyl, pentyl, isopropyl, isobutyl, sec-butyl and tert-butyl, isopentyl and neopentyl.
The term “alkenyl” means an aliphatic hydrocarbon group containing a carbon-carbon double bond and which may be straight or branched having about 2 to about 6 carbon atoms in the chain. Preferred alkenyl groups have 2 to about 4 carbon atoms in the chain. Branched means that one or more lower alkyl groups such as methyl, ethyl, or propyl are attached to a linear alkenyl chain. Exemplary alkenyl groups include ethenyl, propenyl, n-butenyl, and i-butenyl. A C2-C6 alkenyl group is an alkenyl group containing between 2 and 6 carbon atoms. As defined herein, the term “alkenyl” can include both “E” and “Z” or both “cis” and “trans” double bonds.
The term “alkynyl” means an aliphatic hydrocarbon group containing a carbon-carbon triple bond and which may be straight or branched having about 2 to about 6 carbon atoms in the chain. Preferred alkynyl groups have 2 to about 4 carbon atoms in the chain. Branched means that one or more lower alkyl groups such as methyl, ethyl, or propyl are attached to a linear alkynyl chain. Exemplary alkynyl groups include ethynyl, propynyl, n-butynyl, 2-butynyl, 3-methylbutynyl, and n-pentynyl. A C2-C6 alkynyl group is an alkynyl group containing between 2 and 6 carbon atoms.
The term “cycloalkyl” means monocyclic or polycyclic saturated carbon rings containing 3-18 carbon atoms. Examples of cycloalkyl groups include, without limitations, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptanyl, cyclooctanyl, norboranyl, norborenyl, bicyclo[2.2.2]octanyl, or bicyclo[2.2.2]octenyl. A C3-C8 cycloalkyl is a cycloalkyl group containing between 3 and 8 carbon atoms. A cycloalkyl group can be fused (e.g., decalin) or bridged (e.g., norbornane).
The term “aryl” refers to cyclic, aromatic hydrocarbon groups that have 1 to 2 aromatic rings, including monocyclic or bicyclic groups such as phenyl, biphenyl or naphthyl. Where containing two aromatic rings (bicyclic, etc.), the aromatic rings of the aryl group may be joined at a single point (e.g., biphenyl), or fused (e.g., naphthyl). The aryl group may be optionally substituted by one or more substituents, e.g., 1 to 5 substituents, at any point of attachment.
The term “heteroaryl” means a monovalent monocyclic or bicyclic aromatic radical of 5 to 12 ring atoms or a polycyclic aromatic radical, containing one or more ring heteroatoms selected from N, O, or S, the remaining ring atoms being C. Heteroaryl as herein defined also means a bicyclic heteroaromatic group wherein the heteroatom(s) is selected from N, O, or S. The aromatic radical is optionally substituted independently with one or more substituents described herein.
As used herein, the term “halo” or “halogen” means fluoro, chloro, bromo, or iodo.
The following abbreviations are used throughout. Hexadecanoic acid (i.e., palmitic acid) is abbreviated to PA. Octadecanoic acid (i.e., stearic acid) is abbreviated to SA. Tetradecanoic acid (i.e., myristic acid) is abbreviated to MA. (9Z)-Octadecenoic acid (i.e., oleic acid) is abbreviated to OA. 1,3-dihydroxypropan-2-yl palmitate (i.e., 2-glycero palmitate) is abbreviated to PA-2G. 1,3-dihydroxypropan-2-yl octadecanoate (i.e., 2-glycero stearate) is abbreviated to SA-2G. 1,3-dihydroxypropan-2-yl tetradecanoic acid (i.e., 2-glycero myristate) is abbreviated to MA-2G. 1,3-dihydroxypropan-2-yl (9Z)-Octadecenoate (i.e., 2-glycero oleate) is abbreviated to OA-2G. 2,3-dihydroxypropan-2-yl palmitate (i.e., 1-glycero palmitate) is abbreviated to PA-1G. 2,3-dihydroxypropan-2-yl octadecanoate (i.e., 1-glycero stearate) is abbreviated to SA-1G. 2,3-dihydroxypropan-2-yl tetradecanoate (i.e., 1-glycero myristate) is abbreviated to MA-1G. 2,3-dihydroxypropan-2-yl (9Z)-Octadecenoate (i.e., 1-glycero oleate) is abbreviated to OA-1G. Ethyl hexadecanoate (i.e., ethyl palmitate) is abbreviated to EtPA.
Produce and other agricultural products (e.g., fruits, vegetables, roots, tubers, flowers) that are stored after harvesting, for example as a result of excess production or during shipping, are typically densely packed into storage bins, containers, or modified atmospheric packaging (MAP), and maintained at high average relative humidity (RH) levels (e.g., greater than 90% average relative humidity). The high relative humidity levels reduce the rate at which the agricultural products lose mass and water over time, thereby allowing the agricultural products to be of acceptably high quality when they are sold after storage and/or shipping, and preventing sellers and shippers from having to over pack the containers in order to provide a desired produce mass at the point of sale. However, such high humidity conditions can facilitate the growth of pathogens such as mold, fungi, and bacteria. The effects can be exacerbated particularly at high packing densities, thereby resulting in a high rate of spoilage.
Table 3 below is a compilation of recommended conditions, including recommended relative humidity, for long term storage of fresh fruits and vegetables. The recommended storage conditions for most types of produce represents a compromise between preventing mass loss from the produce during storage and minimizing the risk of growth of postharvest pathogens. Specifically, most produce items would benefit from nearly saturated environments (e.g., an in-package relative humidity of at least 95%) in order to minimize mass loss during storage. However, such high RH levels can create environments that run serious risk of growth of fungi and other postharvest pathogens (e.g., mold, bacteria), especially should condensation form on the surface of the produce or in any packaging within which the produce is stored, or should the produce experience damage at its surfaces due to high packing densities or handling of the produce. Furthermore, it can be quite difficult to precisely control the relative humidity at such high levels throughout a storage or shipping container, and so local RH variations can further exacerbate the risks of condensation formation. As such, improved methods for decreasing the rate of spoilage while maintaining high quality produce, with minimal loss in mass/moisture during storage and shipping, are desirable.
Described herein are methods of reducing spoilage in harvested produce and other agricultural products without increasing the rate of water or mass loss, thereby resulting in high quality produce with both reduced mass loss and lower rates of spoilage. Prior to packing the produce into a storage/shipping container, a protective coating is formed over the surface of the produce, which serves as a barrier to moisture transfer, as further described below. The protective coating serves to reduce the mass loss rate of the produce, even if the produce is kept at a lower average relative humidity level (e.g., less than about 90%, about 85%, about 80%, about 75%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35% about 30%, about 25%, about 20%, about 15%, about 10%, or about 5% relative humidity, or in a range of about 40% to about 90%, about 45% to about 90%, about 50% to about 90%, about 55% to about 90%, about 60% to about 90%, about 65% to about 90%, about 70% to about 90%, about 75% to about 90%, about 80% to about 90%, about 40% to about 85%, about 45% to about 85%, about 50% to about 85%, about 55% to about 85%, about 60% to about 85%, about 65% to about 85%, about 70% to about 85%, about 75% to about 85%, about 80% to about 85%, about 40% to about 80%, about 45% to about 80%, about 50% to about 80%, about 55% to about 80%, about 60% to about 80%, about 65% to about 80%, about 70% to about 80%, about 40% to about 75%, about 45% to about 75%, about 50% to about 75%, about 55% to about 75%, about 60% to about 75%, or about 65% to about 75% relative humidity). The produce is subsequently maintained at the lower average RH level (e.g., less than about 90%, about 85%, about 80%, about 75%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35% about 30%, about 25%, about 20%, about 15%, about 10%, or about 5% relative humidity, or in a range of about 40% to about 90%, about 45% to about 90%, about 50% to about 90%, about 55% to about 90%, about 60% to about 90%, about 65% to about 90%, about 70% to about 90%, about 75% to about 90%, about 80% to about 90%, about 40% to about 85%, about 45% to about 85%, about 50% to about 85%, about 55% to about 85%, about 60% to about 85%, about 65% to about 85%, about 70% to about 85%, about 75% to about 85%, about 80% to about 85%, about 40% to about 80%, about 45% to about 80%, about 50% to about 80%, about 55% to about 80%, about 60% to about 80%, about 65% to about 80%, about 70% to about 80%, about 40% to about 75%, about 45% to about 75%, about 50% to about 75%, about 55% to about 75%, about 60% to about 75%, or about 65% to about 75% relative humidity) during storage/shipping. The reduced relative humidity level during storage and/or shipping can result in a lower rate of spoilage (e.g., spoilage caused by biotic stressors), while the protective coating prevents higher rates of water and mass loss at the lower relative humidity levels, and in some cases can reduce water and mass loss as compared to uncoated produce that is stored at a higher average relative humidity. As such, the quality of the stored produce can be maintained while at the same time mass/water loss is minimized and spoilage rates are reduced.
The process steps 102, 104, 106, and 108 of process 100 (
The monomers, oligomers, polymers, fatty acids, esters, triglycerides, diglycerides, monoglycerides, amides, amines, thiols, thioesters, carboxylic acids, ethers, aliphatic waxes, alcohols, salts (inorganic and organic), acids, bases, proteins, enzymes, or combinations thereof of which the coating agent is comprised can be extracted or derived from plant matter, and in particular from cutin obtained from plant matter. Plant matter typically includes some portions that contain cutin and/or have a high density of cutin (e.g., fruit peels, leaves, shoots, etc.), as well as other portions that do not contain cutin or have a low density of cutin (e.g., fruit flesh, seeds, etc.). The cutin-containing portions can be formed from the monomer and/or oligomer and/or polymer units that are subsequently utilized in the formulations described herein for forming the coatings over the surface of the agricultural products. The cutin-containing portions can also include other constituents such as non-hydroxylated fatty acids and esters, proteins, polysaccharides, phenols, lignans, aromatic acids, terpenoids, flavonoids, carotenoids, alkaloids, alcohols, alkanes, and aldehydes, which may be included in the formulations or may be omitted.
The monomers, oligomers, polymers, or combinations thereof can be obtained by first separating (or at least partially separating) portions of the plant that include molecules desirable for the coating agents from those that do not include the desired molecules. For example, when utilizing cutin as the feedstock for the coating agent composition, the cutin-containing portions of the plant matter are separated (or at least partially separated) from non-cutin-containing portions, and cutin is obtained from the cutin-containing portions (e.g., when the cutin-containing portion is a fruit peel, the cutin is separated from the peel). The obtained portion of the plant (e.g., cutin) is then depolymerized (or at least partially depolymerized) in order to obtain a mixture including a plurality of fatty acid or esterified cutin monomers, oligomers, polymers (e.g., low molecular weight polymers), or combinations thereof. The cutin derived monomers, oligomers, polymers, or combinations thereof can be directly dissolved in the solvent to form the solution used in the formation of the coatings, or alternatively can first be activated or chemically modified (e.g., functionalized). Chemical modification or activation can, for example, include glycerating the monomers, oligomers, polymers, or combinations thereof to form a mixture of 1-monoacylglycerides and/or 2-monoacylglycerides, and the mixture of 1-monoacylglycerides and/or 2-monoacylglycerides is dissolved in the solvent to form a solution, thereby resulting in the formulation formed in step 102 of
In some implementations, the coating agent comprises fatty acids, esters, triglycerides, diglycerides, monoglycerides, amides, amines, thiols, thioesters, carboxylic acids, ethers, aliphatic waxes, alcohols, salts (inorganic and organic), acids, bases, proteins, enzymes, or combinations thereof. In some implementations, the coating agent can be substantially similar to or the same as those described in U.S. patent application Ser. No. 15/330,403 (published as US 2017/0073532) entitled “Precursor Compounds for Molecular Coatings,” filed on Sep. 15, 2016, the disclosure of which is incorporated herein by reference in its entirely. For example, the coating agent can include compounds of Formula I:
wherein:
R is selected from —H, —C1-C6 alkyl, —C2-C6 alkenyl, —C2-C6 alkynyl, —C3-C7 cycloalkyl, aryl, or heteroaryl, wherein each alkyl, alkenyl, alkynyl, cycloalkyl, aryl or heteroaryl is optionally substituted with one or more C1-C6 alkyl or hydroxy;
R1, R2, R5, R6, R9, R10, R11, R12 and R13 are each independently, at each occurrence, —H, —OR14, —NR14R15, —SR14, halogen, —C1-C6 alkyl, —C2-C6 alkenyl, —C2-C6 alkynyl, —C3-C7 cycloalkyl, aryl, or heteroaryl, wherein each alkyl, alkenyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with one or more —OR14, —NR14R15, —SR14, or halogen;
R3, R4, R7 and R8 are each independently, at each occurrence, —H, —OR14, —NR14R15, —SR14, halogen, —C1-C6 alkyl, —C2-C6 alkenyl, —C2-C6 alkynyl, —C3-C7 cycloalkyl, aryl, or heteroaryl, wherein each alkyl, alkenyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with —OR14, —NR14R15, —SR14, or halogen; or
R3 and R4 can combine with the carbon atoms to which they are attached to form a C3-C6 cycloalkyl, a C4-C6 cycloalkenyl, or a 3- to 6-membered ring heterocycle; and/or
R7 and R8 can combine with the carbon atoms to which they are attached to form a C3-C6 cycloalkyl, a C4-C6 cycloalkenyl, or a 3 to 6-membered ring heterocycle;
R14 and R15 are each independently, at each occurrence, —H, —C1-C6 alkyl, —C2-C6 alkenyl, or —C2-C6 alkynyl;
the symbol represents an optionally single or cis or trans double bond;
n is 0, 1, 2, 3, 4, 5, 6, 7, or 8;
m is 0, 1, 2, or 3;
q is 0, 1, 2, 3, 4, or 5; and
r is 0, 1, 2, 3, 4, 5, 6, 7, or 8.
In some embodiments, R is —H, —CH3, or —CH2CH3.
In some implementations, the coating agent comprises monoacylglyceride (e.g., 1-monoacylglyceride or 2-monoacylglyceride) esters and/or monomers and/or oligomers and/or low molecular weight polymers formed thereof. The difference between a 1-monoacylglyceride and a 2-monoacylglyceride is the point of connection of the glycerol ester. Accordingly, in some embodiments, the coating agent comprises compounds of the Formula I-A (e.g., 2-monoacylglycerides):
wherein:
each Ra is independently —H or —C1-C6 alkyl;
each Rb is independently selected from —H, —C1-C6 alkyl, or —OH;
R1, R2, R5, R6, R9, R10, R11, R12 and R13 are each independently, at each occurrence, —H, —OR14, —NR14R15, —SR14, halogen, —C1-C6 alkyl, —C2-C6 alkenyl, —C2-C6 alkynyl, —C3-C7 cycloalkyl, aryl, or heteroaryl, wherein each alkyl, alkenyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with one or more —OR14, —NR14R15, —SR14, or halogen;
R3, R4, R7, and R8 are each independently, at each occurrence, —H, —OR14, —NR14R15, —SR14, halogen, —C1-C6 alkyl, —C2-C6 alkenyl, —C2-C6 alkynyl, —C3-C7 cycloalkyl, aryl, or heteroaryl wherein each alkyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with one or more —OR14, —NR14R15, —SR14, or halogen; or
R3 and R4 can combine with the carbon atoms to which they are attached to form a C3-C6 cycloalkyl, a C4-C6 cycloalkenyl, or 3- to 6-membered ring heterocycle; and/or
R7 and R8 can combine with the carbon atoms to which they are attached to form a C3-C6 cycloalkyl, a C4-C6 cycloalkenyl, or 3- to 6-membered ring heterocycle;
R14 and R15 are each independently, at each occurrence, —H, —C1-C6 alkyl, —C2-C6 alkenyl, or —C2-C6 alkynyl;
the symbol represents a single bond or a cis or trans double bond;
n is 0, 1, 2, 3, 4, 5, 6, 7 or 8;
m is 0, 1, 2 or 3;
q is 0, 1, 2, 3, 4 or 5; and
r is 0, 1, 2, 3, 4, 5, 6, 7 or 8.
In some implementations, the coating agent comprises compounds of the Formula I-B (e.g., 1-monoacylglycerides):
wherein:
each Ra is independently —H or —C1-C6 alkyl;
each Rb is independently selected from —H, —C1-C6 alkyl, or —OH;
R1, R2, R5, R6, R9, R10, R11, R12 and R13 are each independently, at each occurrence, —H, —OR14, —NR14R15, —SR14, halogen, —C1-C6 alkyl, —C2-C6 alkenyl, —C2-C6 alkynyl, —C3-C7 cycloalkyl, aryl, or heteroaryl, wherein each alkyl, alkenyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with one or more —OR14, —NR14R15, —SR14, or halogen;
R3, R4, R7, and R8 are each independently, at each occurrence, —H, —OR14, —NR14R15, —SR14, halogen, —C1-C6 alkyl, —C2-C6 alkenyl, —C2-C6 alkynyl, —C3-C7 cycloalkyl, aryl, or heteroaryl wherein each alkyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with one or more —OR14, —NR14R15, —SR14, or halogen; or
R3 and R4 can combine with the carbon atoms to which they are attached to form a C3-C6 cycloalkyl, a C4-C6 cycloalkenyl, or 3- to 6-membered ring heterocycle; and/or
R7 and R8 can combine with the carbon atoms to which they are attached to form a C3-C6 cycloalkyl, a C4-C6 cycloalkenyl, or 3- to 6-membered ring heterocycle;
R14 and R15 are each independently, at each occurrence, —H, —C1-C6 alkyl, —C2-C6 alkenyl, or —C2-C6 alkynyl;
the symbol represents a single bond or a cis or trans double bond;
n is 0, 1, 2, 3, 4, 5, 6, 7 or 8;
m is 0, 1, 2 or 3;
q is 0, 1, 2, 3, 4 or 5; and
r is 0, 1, 2, 3, 4, 5, 6, 7 or 8.
In some embodiments, the coating agent includes one or more of the following fatty acid compounds:
In some embodiments, the coating agent includes one or more of the following methyl ester compounds:
In some embodiments, the coating agent includes one or more of the following ethyl ester compounds:
In some embodiments, the coating agent includes one or more of the following 2-glycerol ester compounds:
In some embodiments, the coating agent includes one or more of the following 1-glycerol ester compounds:
In some embodiments, the coating agent is formed of a combination of at least 2 different compounds. For example, the coating agent can comprise a compound of Formula I-A and an additive. The additive can, for example, include a saturated or unsaturated compound of Formula I-B, a saturated or unsaturated fatty acid, an ethyl ester, or a second compound of Formula I-A which is different from the (first) compound of Formula I-A (e.g., has a different length carbon chain). The compound of Formula I-A can make up at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, or at least about 90% of the mass of the coating agent. A combined mass of the compound of Formula I-A and the additive can be at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, or at least about 90% of the total mass of the coating agent. A molar ratio of the additive to the compound of Formula I-A in the coating agent can be in a range of 0.1 to 5, for example in a range of about 0.1 to about 4, about 0.1 to about 3, about 0.1 to about 2, about 0.1 to about 1, about 0.1 to about 0.9, about 0.1 to about 0.8, about 0.1 to about 0.7, about 0.1 to about 0.6, about 0.1 to about 0.5, about 0.15 to about 5, about 0.15 to about 4, about 0.15 to about 3, about 0.15 to about 2, about 0.15 to about 1, about 0.15 to about 0.9, about 0.15 to about 0.8, about 0.15 to about 0.7, about 0.15 to about 0.6, about 0.15 to about 0.5, about 0.2 to about 5, about 0.2 to about 4, about 0.2 to about 3, about 0.2 to about 2, about 0.2 to about 1, about 0.2 to about 0.9, about 0.2 to about 0.8, about 0.2 to about 0.7, about 0.2 to about 0.6, about 0.2 to about 0.5, about 0.3 to about 5, about 0.3 to about 4, about 0.3 to about 3, about 0.3 to about 2, about 0.3 to about 1, about 0.3 to about 0.9, about 0.3 to about 0.8, about 0.3 to about 0.7, about 0.3 to about 0.6, about 0.3 to about 0.5, about 1 to about 5, about 1 to about 4, about 1 to about 3, or about 1 to about 2. The coating agent can, for example, be formed from one of the combinations of a compound of Formula I-A and an additive listed in Table 1 below.
In some embodiments, the coating agent is formed from one of the combinations of compounds listed in Table 2 below.
As seen in Table 2 above, the coating agent can include a first component and a second component, where the first component is a compound of Formula I-B and the second component is either a fatty acid or a second compound of Formula I-B which is different than the (first) compound of Formula I-B. The compound of Formula I-B can make up at least about 5%, at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, or at least about 90% of the mass of the coating agent. A combined mass of the first component and the second component can be at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90% or at least about 95% of the total mass of the coating agent.
Referring now to steps 104 and 106 of process 100 (
Properties of the coating, such as thickness, cross-link density of monomers/oligomers/polymers, and permeability, can be varied to be suitable for a particular agricultural product by adjusting the specific composition of the coating agent, the specific composition of the solvent, the concentration of the coating agent in the solvent, and conditions of the coating deposition process (e.g., the amount of time the solution is applied to the surface of the produce or agricultural product before the solvent is removed, the temperature during the deposition process, the standoff distance between the spray head and the sample, and the spray angle). For example, too short an application time can result in too thin a protective coating being formed, whereas too long an application time can result in the produce or agricultural product being damaged by the solvent. Accordingly, the solution can be applied to the surface of the produce or agricultural product for between about 1 and about 3,600 seconds, for example between 1 and 3000 seconds, between 1 and 2000 seconds, between 1 and 1000 seconds, between 1 and 800 seconds, between 1 and 600 seconds, between 1 and 500 seconds, between 1 and 400 seconds, between 1 and 300 seconds, between 1 and 250 seconds, between 1 and 200 seconds, between 1 and 150 seconds, between 1 and 125 seconds, between 1 and 100 seconds, between 1 and 80 seconds, between 1 and 60 seconds, between 1 and 50 seconds, between 1 and 40 seconds, between 1 and 30 seconds, between 1 and 20 seconds, between 1 and 10 seconds, between about 5 and about 3000 seconds, between about 5 and about 2000 seconds, between about 5 and about 1000 seconds, between about 5 and about 800 seconds, between about 5 and about 600 seconds, between about 5 and about 500 seconds, between about 5 and about 400 seconds, between about 5 and about 300 seconds, between about 5 and about 250 seconds, between about 5 and about 200 seconds, between about 5 and about 150 seconds, between about 5 and about 125 seconds, between about 5 and about 100 seconds, between about 5 and about 80 seconds, between about 5 and about 60 seconds, between about 5 and about 50 seconds, between about 5 and about 40 seconds, between about 5 and about 30 seconds, between about 5 and about 20 seconds, between about 5 and about 10 seconds, between about 10 and about 3000 seconds, between about 10 and about 2000 seconds, between about 10 and about 1000 seconds, between about 10 and about 800 seconds, between about 10 and about 600 seconds, between about 10 and about 500 seconds, between about 10 and about 400 seconds, between about 10 and about 300 seconds, between about 10 and about 250 seconds, between about 10 and about 200 seconds, between about 10 and about 150 seconds, between about 10 and about 125 seconds, between about 10 and about 100 seconds, between about 10 and about 80 seconds, between about 10 and about 60 seconds, between about 10 and about 50 seconds, between about 10 and about 40 seconds, between about 10 and about 30 seconds, between about 10 and about 20 seconds, between about 20 and about 100 seconds, between about 100 and about 3,000 seconds, or between about 500 and about 2,000 seconds.
Furthermore, the concentration of the coating agent in the solvent can, for example, be in a range of 0.1 to 200 mg/mL or about 0.1 to about 200 mg/mL, such as in a range of about 0.1 to about 100 mg/mL, about 0.1 to about 75 mg/mL, about 0.1 to about 50 mg/mL, about 0.1 to about 30 mg/mL, about 0.1 to about 20 mg/mL, about 0.5 to about 200 mg/mL, about 0.5 to about 100 mg/mL, about 0.5 to about 75 mg/mL, about 0.5 to about 50 mg/mL, about 0.5 to about 30 mg/mL, about 0.5 to about 20 mg/mL, 1 to 200 mg/mL, 1 to 100 mg/mL, 1 to 75 mg/mL, 1 to 50 mg/mL, 1 to 30 mg/mL, about 1 to about 20 mg/mL, about 5 to about 200 mg/mL, about 5 to about 100 mg/mL, about 5 to about 75 mg/mL, about 5 to about 50 mg/mL, about 5 to about 30 mg/mL, or about 5 to about 20 mg/mL.
The protective coatings formed from coating agents described herein can be edible coatings. The protective coatings can be substantially undetectable to the human eye, and can be odorless and/or tasteless. The protective coatings can have an average thickness in the range of about about 0.1 microns to about 300 microns, for example in the range of about about 0.5 microns to about 100 microns, about 1 micron to about 50 microns, about 0.1 microns to about 1 micron, about 0.1 microns to about 2 microns, about 0.1 microns to about 5 microns, or about 0.1 microns to about 10 microns. In some implementations, the protective coatings are entirely organic (e.g., organic in the agricultural sense rather than the chemistry sense). In some embodiments, the produce is a thin-skinned fruit or vegetable. For instance, the produce can be a berry or grape. In some embodiments, the produce can include a cut fruit surface (e.g., a cut apple surface).
The protective coatings formed from coating agents described herein can serve a number of purposes. For example, the protective coatings can extend the shelf life of the produce or other agricultural products, even in the absence of refrigeration. Furthermore, produce and other agricultural products tend to lose mass (due to water loss) at a higher rate when maintained at lower relative humidity levels (e.g., lower than 90% relative humidity) as compared to higher relative humidity levels, as the driving force for water evaporation is increased at the lower relative humidity levels. As such, the protective coatings can be formulated to reduce the mass loss rate of the produce or agricultural product even at the lower relative humidity levels. For example, the protective coating can be formulated to reduce a mass loss rate of the produce at relative humidity levels less than or equal to a first relative humidity level (e.g., less than 90% relative humidity, less than 80% relative humidity, or less than 70% relative humidity). In some implementations, the first relative humidity level is sufficiently low to suppress fungal growth in the produce during storage. In some implementations, the protective coating causes the mass loss rate of the coated produce to be lower at relative humidity levels lower than the first relative humidity level than the mass loss rate of similar uncoated produce at relative humidity levels higher than or equal to the first relative humidity level.
Referring now to step 108 of process 100 (in
In cases where the produce is stored and/or shipped in a container but is not coated as previously described, the produce is stored at a high enough in-package relative humidity level (e.g., at least 90% average relative humidity) to maintain a sufficiently low rate of mass loss for the time during which the produce is stored and/or shipped. For example, in some cases it may be required that the produce maintain at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, or at least 95% of its original mass during storage. Accordingly, the produce is maintained at a sufficiently high average humidity during the duration of storage to ensure that the desired percent mass is maintained during storage. However, a problem arises in that the high relative humidity levels result in excessively high rates of molding, fungal growth, and spoilage.
Table 3 is a table showing recommended industry standard conditions, including recommended relative humidity, for long-term storage and/or shipment of fresh produce (e.g., fruits and vegetables). As shown in Table 3, humidity levels greater than about 90%, which are levels recommended for storage of a large number of types of produce, have been found to lead to particularly high rates of fungal growth and spoilage in a wide variety of produce.
Malpighia glabra
Cucumis metuliferus
Amaranthus spp.
Foeniculum vulgare
Malus pumila
Prunus armeniaca
Cynara acolymus
Stachys affinia
Helianthus tuberosus
Eruca vesicaria var.
sativa
Pyrus serotina; P. pyrifolia
Asparagus officinalis
Annona squamosa × A. cherimola
Persea americana
Carica candamarcensis
Musa paradisiaca var.
sapientum
see Acerola
Phaseolus vulgaris
Vicia faba
Phaseolus lunatus
Psophocarpus
tetragonolobus
Vigna sesquipedalis
Beta vulgaris
Rubus spp.
Vaccinium corymbosum
Vaccinium macrocarpon
Rubus spp.
Rubus spp.
Rubus spp.
Rubus idaeus
Fragaria spp.
Momordica charantia
Scorzonera hispanica
Brassica chinensis
Artocarpus altilis
B. oleracea var. Italica
Brassica oleracea var.
Gemnifera
Brassica campestris var.
Pekinensis
B. oleracea var. Capitata
Opuntia spp.
Opuntia spp.
Averrhoa carambola
Daucus carota
Anacardium occidentale
Manihot esculenta
Brassica oleracea var.
Botrytis
Apium graveolens var.
Rapaceum
Apium graveolens var.
Dulce
Beta vulgaris var. Cicla
Sechium edule
Annona cherimola
Prunus cerasus
Prunus avium
Brassica alboglabra
Allium schoenoprasum
Citrus
Citrus reticulta ×
Fortunella spp.
Citrus paradisi
Fortunella japonica
Citrus limon
Citrus aurantifolia; C. latifolia
Citrus sinensis
Citrus aurantium
Citrus grandis
C. reticulata × paradisi
Citrus reticulata
Cocos nucifera
B. oleracea
var.
Acephala
Zea mays
Cucumis sativus
Ribes sativum;
R. nigrum; R. rubrum
Raphanus sativus
Phoenix dactylifera
Durio zibethinus
Solanum melongena
Cichorium endivia
Cichorium intybus
Feijoa sellowiana
Ficus carica
Allium sativum
Zingiber officinale
Ribes grossularia
Vitis vinifera a = fruit;
Vitis labrusca
Psidium guajava
Ocimum basilicum
Allium schoenoprasum
Coriandrum sativum
Anethum graveolens
Chenopodium
ambrosioides
Mentha spp.
Origanum vulgare
Petroselinum crispum
Perilla frutescens
Salvia officinalis
Thymus vulgaris
Armoracia rusticana
Myrciaria cauliflora =
Eugenia cauliflora
Artocarpus heterophyllus
Pachyrrhizus erosus
Ziziphus jujuba
Brassica oleracea var.
acephala
Actinidia chinensis
Brassica oleracea var.
Gongylodes
Aglaia sp.; Lansium sp.
Allium porrum
Lactuca sativa
Dimocarpus longan =
Euphoria longan
Eriobotrya japonica
Luffa spp.
Litchi chinensis
Xanthosoma sagittifolium
Mangifera indica
Garcinia mangostana
Cucurbita melo var.
reticulatus
Cucurbita melo
Cucurbita melo
Cucurbita melo
Cucurbita melo
Agaricus, other genera
Brassica juncea
Prunus persica
Abelmoschus esculentus
Olea europea
Allium cepa
Carica papaya
Pastinaca sativa
Passiflora spp.
Prunus persica
Pyrus communis
See Asian Pear
Pisum sativum
Vigna sinensis = V. unguiculata
Solanum muricatum
Capsicum annuum
Capsicum annuum and C. frutescens
Diospyros kaki
Ananas comosus
Musa paradisiaca var.
paradisiaca
Prunus domestica
Punica granatum
Solanum tuberosum
Cucurbita maxima
Cydonia oblonga
Cichorium intybus
Raphanus sativus
Nephelium lappaceum
Rheum rhaponticum
Brassica napus var.
Napobrassica
Trapopogon porrifolius
Chrysophyllum cainito
Pouteria campechiana
Diospyros ebenaster
Casimiroa edulis
Calocarpum mammosum
Achras sapota
Allium cepa var
ascalonicum
Annona muricata
spinacia oleracea
spondias spp.
Medicago sativa
Phaseolus sp.
Raphanus sp.
Cucurbita pepo
Cucurbita moschata; C. maxima
Ipomea batatas
Annona squamosa;
Annona spp.
Cyphomandra betacea
Tamarindus indica
Colocasia esculenta
Physalis ixocarpa
Lycopersicon esculentum
Brassica campestris var.
Rapifera
Eleocharis dulcis
Lepidium sativum;
Nasturtium officinales
Citrullus vulgaris
Dioscorea spp.
When the produce is coated as described above prior to storage, the relative humidity level can be substantially reduced while still allowing for the desired percent mass of the produce to be maintained during storage. For example, in some cases the coated produce can be stored and/or shipped at average relative humidity levels less than about 90%, less than about 85%, less than about 80%, less than about 75%, less than about 70%, less than about 65%, or less than about 60%. As such, fungal growth in and spoilage of the produce is reduced while mass loss during storage is maintained at acceptable levels.
With reference to Table 3, leafy greens, herbs, or vegetables that have a very high surface area to volume ratio, such as artichoke, arugula, asparagus, bok choy, broccoli, Brussels sprouts, cabbage, cauliflower, celery, chives, corn, daikon, cilantro, mint, parsley, kale, leek, lettuce, green onions, bell peppers, spinach, sprouts (e.g., alfalfa sprouts, bean sprouts, radish sprouts), and carrots tend to lose percent mass at a higher rate than most other produce, and are therefore usually stored and shipped at very high relative humidity, typically at least 95%, making them very susceptible to molding and spoilage during storage. Forming a protective coating over the surfaces of these agricultural products, as described above, can allow them to be stored and/or shipped at lower relative humidity levels, for example less than 95% RH, less than 90% RH, or less than 85% RH, thereby reducing the rate of spoilage while still maintaining a sufficiently low mass loss rate.
Still referring to Table 3, berries, including blackberries, blueberries, cranberries, dewberries, elderberries, loganberries, raspberries, and strawberries, are typically all stored at a relative humidity of at least 90%. Forming a protective coating over the surfaces of these agricultural products, as described above, can allow them to be stored and/or shipped at lower relative humidity levels, for example less than 90% RH, less than 85% RH, or less than 80% RH, thereby reducing the rate of spoilage while still maintaining a sufficiently low mass loss rate.
Still referring to Table 3, other thin skinned fruits and vegetables, including apricots, pears, cherries, kumquats, cucumbers, grapes, mushrooms, nectarines, peaches, pears, plums, prunes, potatoes, tomatoes, are also typically stored at a relative humidity of at least 90%. Many thicker skinned fruits, including apples, melons, bananas, beans (e.g., snap beans, green beans, lima beans, long beans), blood oranges, tangerines, eggplant, guavas, kiwifruit, lychee, persimmons, pomegranates, watermelon, are also typically stored at a relative humidity of at least 90%. Forming a protective coating over the surfaces of these agricultural products, as described above, can allow them to be stored and/or shipped at lower relative humidity levels, for example less than 90% RH, less than 85% RH, or less than 80% RH, thereby reducing the rate of spoilage while still maintaining a sufficiently low mass loss rate.
Referring still to Table 3, other fruits and vegetables, for example cherries, avocados, papayas, starfruit, oranges (other than blood oranges), pummelos, tangelos, lemons, limes, grapefruit, figs, jicama, mangoes, many melons (casaba, crenshaw, honeydew, and Persian melons), papaya, passionfruit, yams, cassava, are typically stored at a relative humidity of at least 85%. Forming a protective coating over the surfaces of these agricultural products, as described above, can allow them to be stored and/or shipped at lower relative humidity levels, for example less than about 85% RH, less than about 80% RH, or less than about 75% RH, thereby reducing the rate of spoilage while still maintaining a sufficiently low mass loss rate.
For the chart in
Without wishing to be bound by theory, the results shown in
Through extensive experimentation, it has been found that coatings formed from compounds described above, and in particular from combinations of 2-monoacylglycerides and one or more of the other compounds described above (e.g., 1-monoacylglycerides, fatty acids, esters, triglycerides, diglycerides, monoglycerides, amides, amines, thiols, thioesters, carboxylic acids, ethers, aliphatic waxes, alcohols, salts (e.g., inorganic and organic salts), acids, bases, proteins, enzymes, or combinations thereof), are effective at reducing mass/water loss and increasing the shelf of the agricultural products, even at reduced relative humidity levels. In some cases, the coatings were further found to be effective at preventing or reducing molding and spoilage in produce as compared to similar produce maintained at the same temperature and relative humidity but without a coating.
As shown in
In order to form the coatings, the blueberries were placed in bags, and the solution containing the composition was poured into the bag. The bag was then sealed and lightly agitated until the entire surface of each blueberry was wet. The blueberries were then removed from the bag and allowed to dry on drying racks. The blueberries were then kept at the temperature and relative humidity levels specified above for the entire duration of time they were tested. The desired relative humidity was achieved by sealing groups of 50 blueberries in 7 L containers with exposed saturated salt solutions: sodium chloride for 75% relative humidity, potassium chloride for 85%, and pure water for 100%.
As seen in
As seen in
In order to form the coatings, the finger limes were placed in bags, and the solution containing the composition was poured into the bag. The bag was then sealed and lightly agitated until the entire surface of each finger lime was wet. The finger limes were then removed from the bag and allowed to dry on drying racks. The finger limes were kept under ambient room conditions at a temperature in the range of about 23° C.-27° C. and humidity in the range of about 40%-55% while they dried and for the entire duration of the time they were tested.
As shown in
Each bar in the graph represents a group of 30 avocados. All coatings were formed by dipping the avocados in a solution comprising the associated mixture dissolved in substantially pure ethanol at a concentration of 5 mg/mL, placing the avocados on drying racks, and allowing the avocados to dry under ambient room conditions at a temperature in the range of about 23° C.-27° C. and humidity in the range of about 40%-55%. The avocados were held at these same temperature and humidity conditions for the entire duration of the time they were tested.
As seen, for both the MA-1G/PA-2G and SA-1G/PA-2G combinations, the greatest shelf life factor was achieved for a 1-monoacylglyceride to PA-2G molar ratio of about 0.33. For the case of the PA-1G/PA-2G combinations, the greatest shelf life factor was achieved for the avocados coated with the PA-1G/PA-2G ratio of 75:25.
Each bar in the graph represents a group of 30 avocados. All coatings were formed by dipping the avocados in a solution comprising the associated mixture dissolved in substantially pure ethanol at a concentration of 5 mg/mL, placing the avocados on drying racks, and allowing the avocados to dry under ambient room conditions at a temperature in the range of about 23° C.-27° C. and humidity in the range of about 40%-55%. The avocados were held at these same temperature and humidity conditions for the entire duration of the time they were tested. As seen, for all three of these combinations, the greatest shelf life factor was achieved for a fatty acid to PA-2G molar ratio of about 0.33.
Bars 2101-2103 correspond to mixtures of PA-2G (compound of Formula I-A) with ethyl palmitate as an additive. Bars 2111-2113 correspond to mixtures of PA-2G (compound of Formula I-A) with oleic acid (unsaturated fatty acid) as an additive. Bars 2101 and 2111 correspond to a 25:75 mixture of additive to PA-2G (molar ratio of additive to PA-2G of about 0.33). The mass ratios are both about 0.86. Bars 2102 and 2112 correspond to a 50:50 mixture of additive to PA-2G (molar ratio of additive to PA-2G of about 1). The mass ratios both are about 0.43. Bars 2103 and 2113 correspond to a 75:25 mixture of additive to PA-2G (molar ratio of additive to PA-2G of about 3). The mass ratios are both about 2.58. As seen for the combinations of PA-2G and EtPA as well as for the combinations of PA-2G and OA, the greatest shelf life factor was achieved with additive to PA-2G molar ratio of about 0.33.
Bars 2121-2123, 2131-2133, and 2141-2143 correspond to coatings formed of a compound of Formula I-B (e.g., a 1-monoacylglyceride) and an additive (e.g., a fatty acid). Bars 2121-2123 correspond to mixtures of SA-1G (compound of Formula I-B) with myristic acid as an additive. Bars 2131-2133 correspond to mixtures of SA-1G (compound of Formula I-B) with palmitic acid as an additive. Bars 2141-2143 correspond to mixtures of SA-1G (compound of Formula I-B) with stearic acid as an additive. Bars 2121, 2131, and 2141 correspond to a 25:75 mixture of fatty acid to SA-1G (molar ratio of fatty acid to SA-1G of about 0.33). The mass ratios are about 0.21, 0.23, and 0.26, respectively. Bars 2122, 2132, and 2142 correspond to a 50:50 mixture of fatty acid to SA-1G (molar ratio of fatty acid to SA-1G of about 1). The mass ratios are about 0.32, 0.35, and 0.40, respectively. Bars 2123, 2133, and 2143 correspond to a 75:25 mixture of fatty acid to SA-1G (molar ratio of fatty acid to SA-1G of about 3). The mass ratios are about 1.89, 2.13, and 2.37, respectively. As seen for all three of these combinations, the greatest shelf life factor was achieved for a fatty acid to SA-1G molar ratio of about 0.33.
As shown, the shelf life factor tended to increase as the carbon chain length of the 1-monoacylglyceride was increased. For example, all mixtures having a 1-monoacylglyceride with a carbon chain length greater than 13 exhibited a shelf life factor great than 1.2, all mixtures having a 1-monoacylglyceride with a carbon chain length greater than 15 exhibited a shelf life factor great than 1.35, and all mixtures having a 1-monoacylglyceride with a carbon chain length greater than 17 exhibited a shelf life factor great than 1.6.
The study illustrated in
Bar 2402 corresponds to avocados coated with a mixture including SA-1G (first additive, compound of Formula I-B) and PA-2G (compound of Formula I-A) mixed at a mass ratio of 30:70. This coating resulted in a shelf life factor of about 1.6. Bar 2404 corresponds to avocados coated with a mixture including SA-1G, PA-2G, and PA mixed at a respective mass ratio of 30:50:20. That is, as compared to the compounds corresponding to bar 2402, the coating formulation of bar 2404 could be formed by removing a portion of the PA-2G in the formulation corresponding to bar 1602 and replacing it with PA, such that the formulation of bar 2404 was 50% compounds of Formula I-A (by mass) and 50% additives (by mass). As shown, the shelf life factor is only reduced slightly (as compared to bar 2402) to about 1.55. Bar 2406 corresponds to avocados coated with a mixture including SA-1G, PA-2G, and PA mixed at a respective mass ratio of 30:30:40 (i.e., removing additional PA-2G and replacing it with PA). In this case, the formulation was only 30% compounds of Formula I-A (by mass) and 70% additives (by mass). As shown, although the shelf life factor is reduced (as compared to bars 2402 and 2404) to about 1.43, this coating formulation was still highly effective at reducing the rate of mass loss in avocados.
It will be understood by one of skill in the art that the relative humidity of the air around fresh produce in a shipping container is dependent upon transpiration (and respiration) through the surface of the produce, the rate of fresh air ventilation, the relative humidity of the fresh air, and the temperature of the refrigerant coil relative to the dew point of the air in the cargo space.
The relative humidity of the air around fresh fruit and vegetables can be dependent upon the following factors: (i) when humid air is cooled down at the start of the transport, the relative humidity can increase; (ii) transpiration and respiration through the surface of the produce can provide additional humidity to the air; (iii) fresh-air ventilation with humid air can raise the relative humidity level further; (iv) the cooling process itself can remove humidity from the container air through condensation at the evaporator fins. Accordingly, although in some cases it can be operationally difficult to maintain a precise relative humidity when shipping or storing produce, a natural balance around approximately a range of RH values (e.g., about 85% to 95%) and having an average relative humidity level (e.g., about 90%) can be readily formed. Further, the temperature at which fresh produce is transported can be between about −3° C. to about 16° C. (e.g., about 0° C. to about 10° C.). The present disclosure enables the transportation of produce at lower average relative humidity than under current conventional practice (e.g., less than about 90% or less than about 85% relative humidity).
In view of the above, for produce which is coated with a coating described herein and then subsequently stored and/or shipped, parameters of the storage/shipping container such as reflow of air or other gasses and vapors through the storage container, level of cooling/refrigeration, and amount of ventilation can all be controlled to result in a lower average relative humidity within the container than would be maintained for identical produce that had not been coated prior to storage while still resulting in an acceptably low rate of mass loss during storage. For example, coated produce such as blueberries can be stored in a container at about 60% to about 90% average RH, about 60% to about 85% average RH, or about 65% to about 85% average RH for at least about 20 days and only lose less than about 30%, less than about 25%, or less than about 20% of their mass. The produce can then be removed from the container, for example to be consumed or to be packaged for sale.
In some embodiments, produce can be grown and harvested in one location and then transported to another location for sale and/or consumption. Often the produce is stored for days or weeks after harvest and/or before sale or consumption in addition to the shipping time.
It will be understood by one of skill in the art that in some embodiments, a produce grower (e.g., a farmer) will not be responsible for shipment and sale of produce he or she grows. In other words, there can be multiple parties involved in the supply chain necessary to deliver produce from the point of production (e.g., the fields or orchards in which it is produced) to an appropriate point for sale (e.g., a grocery store). Such parties include, but are not limited to: farmers, shippers, distributors, retailers (e.g., grocery stores), and consumers as well as wholesalers, which may receive produce from shippers and subsequently deliver the produce to retailers (e.g., grocery stores).
For instance, a farmer may contract with a shipper to transport a harvest of produce from the point of production (e.g., fields or orchards where the produce is grown). The shipper can contract with a retailer (e.g., a grocer or grocery store chain) to deliver the produce to the retailer, who in turn sells the produce to a consumer. In some instances, a shipper may deliver a harvest of produce from a farmer to a wholesaler who in turn delivers produce to the retailer (e.g., a grocery chain). In such instances, a second shipper can be necessary to transport the produce from the wholesaler to the retailer. Accordingly, one of skill in the art will understand that there are potentially multiple parties (e.g., growers, shippers, wholesalers, distributors, retailers, and the like) who can be charged with delivering produce from the point of harvest to an end-consumer.
In some embodiments of the above-scenario, each of the parties involved in bringing produce from the point of production to the consumer (e.g., farmer, shipper, distributor, retailer) can be independent parties. Alternatively, in some embodiments, one single organization can be responsible for one or all parts of the supply chain necessary to deliver produce from the point of production to a consumer. In other words, one organization can control the growing, harvesting, shipment and distribution of the produce. In some embodiments, one organization can be responsible for some but not all of the supply chain necessary to deliver produce from the point of production to a consumer. For instance, a distributor can be responsible for the shipment and sale of produce to a consumer, but not the growing or harvesting of the produce.
Accordingly, the present disclosure contemplates multiple scenarios under which produce can be transported from the point of production to a consumer. Additionally, the present disclosure contemplates multiple scenarios under which produce can be coated, or caused to be coated, with a coating of the present disclosure and transported to a consumer.
For instance, a grower can apply a coating of the present disclosure to the produce he or she grows. In some embodiments, a grower can apply a coating of the present disclosure prior to harvesting the produce or after harvesting the produce (e.g., after harvesting the produce but prior to shipment). In some embodiments, the grower can then store the produce before selling the produce directly to a consumer. In such embodiments, the grower can store the coated produce at a relative humidity level below current industry standards (e.g., less than 90% relative humidity) between coating the produce and selling it to the consumer.
Alternatively, in some embodiments the grower can coat the produce he or she produces with a coating of the present disclosure and sell the produce to a distributor, a retailer (e.g., a grocery store), or a wholesaler. In some embodiments, the grower may contract with a shipper to deliver the produce to the distributor, retailer, or wholesaler. In some embodiments, the distributor, retailer, or wholesaler may contract with a shipper to deliver the produce to the distributor, retailer, or wholesaler from the grower. In any of the above-embodiments, the grower, the wholesaler, distributor, retailer, or another party may direct the shipper to transport the coated produce at a relative humidity below current industry standards (e.g., below about 90% relative humidity). Alternatively, the shipper may elect independently to transport the coated produce at a relative humidity below current industry standards (e.g., below about 90% relative humidity). The wholesaler or distributor can then collect the produce from the shipper at a desired destination.
In some embodiments, a wholesaler, distributor, or retailer can provide a grower with a coating formulation of the present disclosure and direct the grower to coat the produce before shipment (e.g., immediately before or after harvest). The wholesaler, distributor, or retailer can request that a grower coat the produce as a condition of purchasing the produce from the grower. In such embodiments, any of the grower, wholesaler, distributor, or retailer can direct a shipper to transport the produce at a relative humidity below current industry standards (e.g., below about 90%). Alternatively, the shipper may independently transport the produce at a relative humidity below current industry standards (e.g., below about 90%).
For instance, a shipper or wholesaler or distributor or retailer can apply a coating of the present disclosure to the produce obtained from a grower or other party along the supply chain. In some embodiments, a grower can sell produce to a wholesaler or distributor or retailer. The wholesaler or distributor or retailer can apply a coating of the present disclosure to produce prior to shipment of the produce. The produce can then be shipped at a relative humidity below current industry standards (e.g., below about 90% relative humidity). Alternatively, the wholesaler or distributor or retailer can direct a shipper to apply the coatings before shipment and then ship the produce at a relative humidity below current industry standards (e.g., below about 90% relative humidity).
For instance, a wholesaler or distributor or retailer can apply a coating of the present disclosure to the produce obtained from a grower or shipper. Alternatively, a wholesaler or distributor or retailer can direct a grower or a shipper to coat the produce prior to shipment or storage.
In view of the above analysis, the present disclosure contemplates that any party involved with the distribution of produce (e.g., a grower, shipper, wholesaler, distributor, or retailer) can not only coat the produce with a coating of the present disclosure, but can also cause the produce to be coated with a coating of the present disclosure. That is, a party involved with the distribution of the produce can direct (e.g., can request) another party to coat the produce prior to shipment or storage. Thus, for example, even if a distributor or retailer does not coat produce by the methods and compositions described herein, the distributor or retailer may still cause the produce to be coated and shipped at a low relative humidity (e.g., less than about 90% relative humidity) by requesting such practice from, for instance, a grower or shipper.
Accordingly, as used herein, the act of coating a piece of produce also includes directing another party to coat the produce, or causing the produce to be coated with a coating of the present disclosure. The act of shipping a piece of produce as used herein is also understood to mean directing another party to ship the produce, or causing the produce to be shipped. The act of storing a piece of produce as used herein is also understood to mean directing another party to store the produce or causing the produce to be stored.
The current disclosure contemplates a number of different shipment and storage methods. For instance, produce can be shipped over land (e.g., by truck, or rail); over sea (e.g., by boat such as a barge or container ship); or through the air (e.g., in a cargo plane). The produce can be shipped in a shipping container. The shipping container can be, for instance, an intermodal container. An intermodal container is understood as a standardized shipping container that can be used across different modes of transportation, such as those listed above. An intermodal container may have standardized dimensions to enable modular stacking with other intermodal containers. Some exemplary dimensions for intermodal containers are about twenty feet or about forty feet in length; about 8 feet 6 inches or about 9 feet 6 inches in height and width. In some embodiments, the produce can be shipped in “dry freight” or “general purpose” containers.
In some embodiments, a shipping container containing produce can be equipped with a temperature controller and/or a humidity controller for controlling the temperature and/or humidity within the container (e.g., an air conditioning unit or refrigeration system) in order to maintain freshness of the produce therein. In some conventional applications, it is customary to keep the relative humidity at about 90%. The refrigeration system or air conditioning system can also be charged with maintaining a consistent temperature inside the shipping container. For instance, the refrigeration system or air conditioning system can be charged with maintaining a specific temperature (e.g., about 5° C.) and a specific relative humidity (e.g., about 90%).
While such relative humidity levels can help to prevent the effects of moisture loss from reducing the value of the produce, they can also enable spoilage of the same produce by facilitating the growth of germs such as fungus or mold. Accordingly, the present disclosure provides methods to keep produce fresh, even when the conditions of the temperature and/or humidity controller are adjusted such that the produce is stored or shipped at relatively low humidity (e.g., relative humidity below industry standards or below about 90%) by coating the produce with a coating that prevents moisture loss. This allows the produce to remain fresh while also helping to prevent the growth of products that could spoil the produce during storage or shipment (e.g., fungus, mold, and the like).
In some embodiments, storage container 2610 or any other containers described herein in which produce can be stored or shipped can be enclosed containers. As used herein, an “enclosed container” is a container for which the stored contents are sufficiently surrounded by a material impenetrable to flow of gas and/or moisture such that a desired relative humidity and/or temperature range can be maintained within. In some embodiments, an enclosed container can include holes or other openings which allow for a certain degree of transfer of gas or vapor between the inside of the container and the surrounding environment. In some embodiments, the holes or other openings can be sufficiently small to limit the amount of gas or vapor transfer between the inside of the container and the surrounding environment.
Additionally, the current disclosure contemplates a number of different storage methods. In some embodiments, produce is stored in containers between the point of harvest and the point of sale. For instance, the produce can be stored in baskets, “clamshells”, or other vessels. Moreover, the produce can be stored in large storage or shipping containers. In some embodiments, the produce is stored in baskets or “clamshells” and loaded into shipping containers for storage or transportation (e.g., baskets or “clamshells” of produce can be loaded into a shipping container on pallets).
One of skill in the art can understand that the effect of storing or shipping produce can be redundant in terms of the effect on fresh produce. That is, in some embodiments, the amount of spoilage experienced by a harvest of produce can be viewed as a function of time, regardless of whether the produce is being stored or shipped. Accordingly, in some embodiments, the effect of shipping produce can have substantially the same effect as storing the produce for the same amount of time. That is, in some embodiments, it does not matter whether produce is being stored or shipped, but rather the amount of spoilage is dependent upon the amount of time that the produce is being stored and/or shipped. Therefore, as understood herein, the term “storage” or “storing” can include “shipping” or “transporting” the produce, and vice versa.
The disclosure is further illustrated by the following examples and synthesis examples, which are not to be construed as limiting this disclosure in scope or spirit to the specific procedures herein described. It is to be understood that the examples are provided to illustrate certain embodiments and that no limitation to the scope of the disclosure is intended thereby. It is to be further understood that resort may be had to various other embodiments, modifications, and equivalents thereof which may suggest themselves to those skilled in the art without departing from the spirit of the present disclosure and/or scope of the appended claims.
For each of the Examples below, palmitic acid was purchased from Sigma Aldrich, 2,3-dihydroxypropan-2-yl hexadecanoate (PA-1G) was purchased from Tokyo Chemical Industry Co, 1,3-dihydroxypropan-2-yl hexadecanoate (PA-2G) was prepared following the method of Example 1, stearic acid (octadecanoic acid) was purchased from Sigma Aldrich, 2,3-dihydroxypropan-2-yl octadecanoate (SA-1G) was purchased from Alfa Aesar, 1,3-dihydroxypropan-2-yl octadecanoate (SA-2G) was prepared following the method of Example 2, tetradecanoic acid was purchased from Sigma Aldrich, 2,3-dihydroxypropan-2-yl tetradecanoate (MA-1G) was purchased from Tokyo Chemical Industry Co, oleic acid was purchased from Sigma Aldrich, and ethyl palmitate (EtPA) was purchased from Sigma Aldrich. All solvents and other chemical reagents were obtained from commercial sources (e.g., Sigma-Aldrich (St. Louis, Mo.)) and were used without further purification unless noted otherwise.
70.62 g (275.34 mmol) of palmitic acid, 5.24 g (27.54 mmol) of p-TsOH, 75 g (275.34 mmol) of 1,3-bis(benzyloxy)propan-2-ol, and 622 mL of toluene were charged into a round bottom flask equipped with a Teflon coated magnetic stir bar. A Dean-Stark Head and condenser were attached to the flask and a positive flow of N2 was initiated. The flask was heated to reflux in a heating mantle while the reaction mixture was stirred vigorously until the amount of water collected (˜5 mL) in the Dean-Stark Head indicated full ester conversion (˜8 hr). The flask was allowed to cool down to room temperature and the reaction mixture was poured into a separatory funnel containing 75 mL of a saturated aqueous solution of Na2CO3 and 75 mL of brine. The toluene fraction was collected and the aqueous layer was extracted with 125 mL of Et2O. The organic layers were combined and washed with 100 mL of brine, dried over MgSO4, filtered and concentrated in vacuo. The crude colorless oil was dried under high vacuum providing (135.6 g, 265.49 mmol, crude yield=96.4%) of 1,3-bis(benzyloxy)propan-2-yl hexadecanoate.
HRMS (ESI-TOF) (m/z): calcd. for C33H50O4Na, [M+Na]+, 533.3607; found, 533.3588;
1H NMR (600 MHz, CDCl3): δ 7.41-7.28 (m, 10H), 5.28 (p, J=5.0 Hz, 1H), 4.59 (d, J=12.1 Hz, 2H), 4.54 (d, J=12.1 Hz, 2H), 3.68 (d, J=5.2 Hz, 4H), 2.37 (t, J=7.5 Hz, 2H), 1.66 (p, J=7.4 Hz, 2H), 1.41-1.15 (m, 24H), 0.92 (t, J=7.0 Hz, 3H) ppm.
13C NMR (151 MHz, CDCl3): δ 173.37, 138.09, 128.43, 127.72, 127.66, 73.31, 71.30, 68.81, 34.53, 32.03, 29.80, 29.79, 29.76, 29.72, 29.57, 29.47, 29.40, 29.20, 25.10, 22.79, 14.23 ppm.
7.66 g (15.00 mmol) of 1,3-bis(benzyloxy)propan-2-yl hexadecanoate, 79.8 mg (0.75 mmol) of 10 wt % Pd/C and 100 mL of EtOAc were charged to a 3 neck round bottom flask equipped with a Teflon coated magnetic stir bar. A cold finger, with a bubbler filled with oil attached to it, and a bubbling stone connected to a 1:4 mixture of H2/N2 gas tank were affixed to the flask. H2/N2 was bubbled at 1.2 LPM into the flask until the disappearance of both starting material and mono-deprotected substrate as determined by TLC (˜60 min). Once complete, the reaction mixture was filtered through a plug of Celite, which was then washed with 100 mL of EtOAc. The filtrate was placed in a refrigerator at 4° C. for 24 hrs. The precipitate from the filtrate (white and transparent needles) was filtered and dried under high vacuum yielding (2.124 g, 6.427 mmol, yield=42.8%) of 1,3-dihydroxypropan-2-yl hexadecanoate.
HRMS (FD-TOF) (m/z): calcd. for C19H38O4, 330.2770; found, 330.2757;
1H NMR (600 MHz, CDCl3): δ 4.93 (p, J=4.7 Hz, 1H), 3.84 (t, J=5.0 Hz, 4H), 2.37 (t, J=7.6 Hz, 2H), 2.03 (t, J=6.0 Hz, 2H), 1.64 (p, J=7.6 Hz, 2H), 1.38-1.17 (m, 26H), 0.88 (t, J=7.0 Hz, 3H) ppm.
13C NMR (151 MHz, CDCl3): δ 174.22, 75.21, 62.73, 34.51, 32.08, 29.84, 29.83, 29.81, 29.80, 29.75, 29.61, 29.51, 29.41, 29.26, 25.13, 22.85, 14.27 ppm.
28.45 g (100 mmol) of stearic acid acid, 0.95 g (5 mmol) of p-TsOH, 27.23 g (275.34 mmol) of 1,3-bis(benzyloxy)propan-2-ol, and 200 mL of toluene were charged into a round bottom flask equipped with a Teflon coated magnetic stir bar. A Dean-Stark Head and condenser were attached to the flask and a positive flow of N2 was initiated. The flask was heated to reflux in an oil bath while the reaction mixture was stirred vigorously until the amount of water collected (˜1.8 mL) in the Dean-Stark Head indicated full ester conversion (˜16 hr). The flask was allowed to cool down to room temperature and the solution was diluted with 100 mL of hexanes. The reaction mixture was poured into a separatory funnel containing 50 mL of a saturated aqueous solution of Na2CO3. The organic fraction was collected and the aqueous layer was extracted twice more with 50 mL portions of hexanes. The organic layers were combined and washed with 100 mL of brine, dried over MgSO4, filtered and concentrated in vacuo. The crude colorless oil was further purified by selective liquid-liquid extraction using hexanes and acetonitrile and the product was again concentrated in vacuo, yielding (43.96 g, 81.60 mmol, yield=81.6%) of 1,3-bis(benzyloxy)propan-2-yl stearate.
1H NMR (600 MHz, CDCl3): δ 7.36-7.27 (m, 10H), 5.23 (p, J=5.0 Hz, 1H), 4.55 (d, J=12.0 Hz, 2H), 4.51 (d, J=12.1 Hz, 2H), 3.65 (d, J=5.0 Hz, 4H), 2.33 (t, J=7.5 Hz, 2H), 1.62 (p, J=7.4 Hz, 2H), 1.35-1.22 (m, 25H), 0.88 (t, J=6.9 Hz, 3H) ppm.
6.73 g (12.50 mmol) of 1,3-bis(benzyloxy)propan-2-yl stearate, 439 mg (0.625 mmol) of 20 wt % Pd(OH)2/C and 125 mL of EtOAc were charged to a 3 neck round bottom flask equipped with a Teflon coated magnetic stir bar. A cold finger, with a bubbler filled with oil attached to it, and a bubbling stone connected to a 1:4 mixture of H2/N2 gas tank were affixed to the flask. H2/N2 was bubbled at 1.2 LPM into the flask until the disappearance of both starting material and mono-deprotected substrate as determined by TLC (˜120 min). Once complete, the reaction mixture was filtered through a plug of Celite, which was then washed with 150 mL of EtOAc. The filtrate was placed in a refrigerator at 4° C. for 48 hrs. The precipitate from the filtrate (white and transparent needles) was filtered and dried under high vacuum yielding (2.12 g, 5.91 mmol, yield=47.3%) of 1,3-dihydroxypropan-2-yl stearate.
LRMS (ESI+) (m/z): calcd. for C21H43O4 [M+H]+, 359.32; found 359.47.
1H NMR (600 MHz, CDCl3): δ 4.92 (p, J=4.7 Hz, 1H), 3.88-3.78 (m, 4H), 2.40-2.34 (m, 2H), 2.09 (t, J=6.2 Hz, 2H), 1.64 (p, J=7.3 Hz, 2H), 1.25 (s, 25H), 0.88 (t, J=7.0 Hz, 3H) ppm.
13C NMR (151 MHz, CDCl3): δ 174.32, 75.20, 62.63, 34.57, 32.14, 29.91, 29.89, 29.87, 29.82, 29.68, 29.57, 29.47, 29.33, 25.17, 22.90, 14.32 ppm.
Lemons were harvested simultaneously and divided into two groups, each of the groups being qualitatively identical (i.e., lemons in both groups were of approximately the same average size and quality). The first group was untreated, while the second group was coated according to the following procedure. First, a composition was formed by combining PA-1G and PA-2G at a 25:75 molar ratio. The composition was dissolved in ethanol at a concentration of 10 mg/mL to form a solution. The lemons to be coated were placed in a bag, and the solution containing the composition was poured into the bag. The bag was then sealed and lightly agitated until the entire surface of each lemon was wet. The lemons were then removed from the bag and allowed to dry on drying racks under ambient room conditions at a temperature in the range of about 23-27° C. and relative humidity in the range of about 40-55% (ambient temperature and relative humidity). Both the coated and uncoated lemons were held at these same temperature and relative humidity conditions for the entire duration of the time they were tested.
Five solutions using C16 glyceryl esters were prepared to examine the effect of the coating agent composition on the rate of mass loss in strawberries stored at low average relative humidity. Five solutions used to coat the strawberries were each composed of one of the following coating agents dissolved in pure ethanol at a concentration of 10 mg/mL. The coating agent of the first solution was pure PA-1G. The coating agent of the second solution was 75% PA-1G and 25% PA-2G by mass. The coating agent of the third solution was 50% PA-1G and 50% PA-2G by mass. The coating agent of the fourth solution was 25% PA-1G and 75% PA-2G by mass. The coating agent of the fifth solution was pure PA-2G.
Strawberries were harvested simultaneously and divided into six groups of 15 strawberries each, each of the groups being qualitatively identical (i.e., all groups had strawberries of approximately the same average size and quality). In order to form coatings over five of the groups of strawberries from the five solutions described above (the sixth group was left untreated), the strawberries were spray coated according to the following procedure. First, the strawberries were placed on drying racks. The five solutions were each placed in a spray bottle which generated a fine mist spray. For each bottle, the spray head was held approximately six inches from the strawberries, and the strawberries were sprayed and then allowed to dry on the drying racks. The strawberries were kept under ambient room conditions at a temperature in the range of 23° C.-27° C. and humidity in the range of 40%-55% while they dried and for the entire duration of the time they were tested.
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Two solutions including a coating agent formed of a mixture of PA-1G (25%) and PA-2G (75%) dissolved in pure ethanol (sanitizing agent) were prepared. For the first solution, the coating agent was dissolved in the ethanol at a concentration of 10 mg/mL, and for the second solution, the coating agent was dissolved in the ethanol at a concentration of 20 mg/mL.
Blueberries were harvested simultaneously and divided into three groups of 60 blueberries each, each of the groups being qualitatively identical (i.e., all groups had blueberries of approximately the same average size and quality). The first group was a control group of untreated blueberries, the second group was treated with the 10 mg/mL solution, and the third group was treated with the 20 mg/mL solution.
To treat the blueberries, each blueberry was picked up with a set of tweezers and individually dipped in the solution for approximately 1 second, after which the blueberry was placed on a drying rack and allowed to dry. The blueberries were kept under ambient room conditions at a temperature in the range of 23° C.-27° C. and humidity in the range of 40%-55% while they dried and for the entire duration of the time they were tested. Mass loss was measured by carefully weighing the blueberries each day, where the reported percent mass loss was equal to the ratio of mass reduction to initial mass.
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Five solutions using C16 glyceryl esters were prepared to examine the effect of the coating agent composition on the rate of mass loss in finger limes stored at low average relative humidity. Five solutions used to coat the finger limes were each composed of one of the following coating agents dissolved in pure ethanol at a concentration of 10 mg/mL. The coating agent of the first solution was pure PA-1G. The coating agent of the second solution was 75% PA-1G and 25% PA-2G by mass. The coating agent of the third solution was 50% PA-1G and 50% PA-2G by mass. The coating agent of the fourth solution was 25% PA-1G and 75% PA-2G by mass. The coating agent of the fifth solution was pure PA-2G.
Finger limes were harvested simultaneously and divided into six groups of 24 finger limes each, each of the groups being qualitatively identical (i.e., all groups had finger limes of approximately the same average size and quality). In order to form coatings over five of the groups of finger limes from the five solutions described above (the sixth group was left untreated), the groups of 24 finger limes were each placed in a bag, and the solution containing the associated composition was poured into each bag. The bag was then sealed and lightly agitated until the entire surface of each finger lime was wet. The finger limes were then removed from the bags and allowed to dry on drying racks. The finger limes were kept under ambient room conditions at a temperature in the range of about 23° C.-27° C. and humidity in the range of about 40%-55% while they dried and for the entire duration of the time they were tested.
As shown in
Nine solutions using combinations 1-glyceryl and 2-glyceryl esters were prepared to examine the effect of the coating agent composition on the rate of mass loss on avocados treated with a solution comprising the coating agent dissolved in a solvent to form a coating over the avocados. Each solution was composed of the coating agents described below dissolved in pure ethanol at a concentration of 5 mg/mL.
The first solution contained 2,3-dihydroxypropan-2-yl tetradecanoate and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 1:3. The second solution contained 2,3-dihydroxypropan-2-yl tetradecanoate and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 1:1. The third solution contained 2,3-dihydroxypropan-2-yl tetradecanoate and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 3:1. The fourth solution contained 2,3-dihydroxypropan-2-ylhexadecanoate and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 3:1. The fifth solution contained 2,3-dihydroxypropan-2-yl hexadecanoate and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 1:1. The sixth solution contained 2,3-dihydroxypropan-2-yl hexadecanoate and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 1:3. The seventh solution contained 2,3-dihydroxypropan-2-yl octadecanoate and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 1:3. The eighth solution contained 2,3-dihydroxypropan-2-yl octadecanoate and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 1:1. The ninth solution contained 2,3-dihydroxypropan-2-yl octadecanoate and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 3:1.
Avocados were harvested simultaneously and divided into nine groups of 30 avocados, each of the groups being qualitatively identical (i.e., all groups had avocados of approximately the same average size and quality). In order to form the coatings, the avocados were each individually dipped in one of the solutions, with each group of 30 avocados being treated with the same solution. The avocados were then placed on drying racks and allowed to dry under ambient room conditions at a temperature in the range of about 23° C.-27° C. and relative humidity in the range of about 40%-55%. The avocados were all held at these same temperature and humidity conditions for the entire duration of time they were tested.
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Nine solutions using combinations of fatty acids and glyceryl esters were prepared to examine the effect of the coating agent composition on the rate of mass loss on avocados treated with a solution comprising the coating agent dissolved in a solvent to form a coating over the avocados. Each solution was composed of the coating agents described below dissolved in pure ethanol at a concentration of 5 mg/mL.
The first solution contained tetradecanoic acid and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 1:3. The second solution contained tetradecanoic acid and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 1:1. The third solution contained tetradecanoic acid and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 3:1. The fourth solution contained hexadecanoic acid and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 1:3. The fifth solution contained hexadecanoic acid and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 1:1. The sixth solution contained hexadecanoic acid and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 3:1. The seventh solution contained octadecanoic acid and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 1:3. The eighth solution contained octadecanoic acid and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 1:1. The ninth solution contained octadecanoic acid and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 3:1.
Avocados were harvested simultaneously and divided into nine groups of 30 avocados, each of the groups being qualitatively identical (i.e., all groups had avocados of approximately the same average size and quality). In order to form the coatings, the avocados were each individually dipped in one of the solutions, with each group of 30 avocados being treated with the same solution. The avocados were then placed on drying racks and allowed to dry under ambient room conditions at a temperature in the range of about 23° C.-27° C. and relative humidity in the range of about 40%-55%. The avocados were all held at these same temperature and humidity conditions for the entire duration of time they were tested.
As shown in
Fifteen solutions using combinations ethyl esters and glyceryl esters or fatty acids and glyceryl esters were prepared to examine the effect of the coating agent composition on the rate of mass loss on avocados treated with a solution comprising the coating agent dissolved in a solvent to form a coating over the avocados. Each solution was composed of the coating agents described below dissolved in pure ethanol at a concentration of 5 mg/mL.
The first solution contained ethyl palmitate and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 1:3. The second solution contained ethyl palmitate and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 1:1. The third solution contained ethyl palmitate and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 3:1. The fourth solution contained oleic acid and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 1:3. The fifth solution contained oleic acid and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 1:1. The sixth solution contained oleic acid and 1,3-dihydroxypropan-2-yl hexadecanoate combined at a molar ratio of 3:1. The seventh solution contained tetradecanoic acid and 2,3-dihydroxypropan-2-yl octadecanoate combined at a molar ratio of 1:3. The eighth solution contained tetradecanoic acid and 2,3-dihydroxypropan-2-yl octadecanoate combined at a molar ratio of 1:1. The ninth solution contained tetradecanoic acid and 2,3-dihydroxypropan-2-yl octadecanoate combined at a molar ratio of 3:1. The tenth solution contained hexadecanoic acid and 2,3-dihydroxypropan-2-yl octadecanoate combined at a molar ratio of 1:3. The eleventh solution contained hexadecanoic acid and 2,3-dihydroxypropan-2-yl octadecanoate combined at a molar ratio of 1:1. The twelfth solution contained hexadecanoic acid and 2,3-dihydroxypropan-2-yl octadecanoate combined at a molar ratio of 3:1. The thirteenth solution contained octadecanoic acid and 2,3-dihydroxypropan-2-yl octadecanoate combined at a molar ratio of 1:3. The fourteenth solution contained octadecanoic acid and 2,3-dihydroxypropan-2-yl octadecanoate combined at a molar ratio of 1:1. The fifteenth solution contained octadecanoic acid and 2,3-dihydroxypropan-2-yl octadecanoate combined at a molar ratio of 3:1.
Avocados were harvested simultaneously and divided into nine groups of 30 avocados, each of the groups being qualitatively identical (i.e., all groups had avocados of approximately the same average size and quality). In order to form the coatings, the avocados were each individually dipped in one of the solutions, with each group of 30 avocados being treated with the same solution. The avocados were then placed on drying racks and allowed to dry under ambient room conditions at a temperature in the range of about 23° C.-27° C. and relative humidity in the range of about 40%-55%. The avocados were all held at these same temperature and humidity conditions for the entire duration of time they were tested.
As shown in
Nine solutions using combinations of 1-glycerol esters and fatty acids were prepared to examine the effect of the coating agent compositions on the rate of mass loss on avocados treated with a solution comprising the coating agent dissolved in a solvent to form a coating over the avocados. All coatings were formed by dipping the avocados in a solution comprising the associated mixture dissolved in substantially pure ethanol at a concentration of 5 mg/mL, placing the avocados on drying racks, and allowing the avocados to dry under ambient room conditions at a temperature in the range of about 23° C.-27° C. and humidity in the range of about 40%-55%. The avocados were held at these same temperature and humidity conditions for the entire duration of the time they were tested.
The results are shown in
As shown, the shelf life factor tended to increase as the carbon chain length of the 1-monoacylglyceride was increased. Treatment with the first solution (2201) resulted in a shelf life factor of 1.25. Treatment with the second solution (2202) resulted in a shelf life factor of 1.35. Treatment with the third solution (2203) resulted in a shelf life factor of 1.32. Treatment with the fourth solution (2211) resulted in a shelf life factor of 1.51. Treatment with the fifth solution (2212) resulted in a shelf life factor of 1.51. Treatment with the sixth solution (2213) resulted in a shelf life factor of 1.37. Treatment with the seventh solution (2221) resulted in a shelf life factor of 1.69. Treatment with the eight solution (2222) resulted in a shelf life factor of 1.68. Treatment with the ninth solution (2223) resulted in a shelf life factor of 1.70.
Three solutions using combinations of two different 1-glycerol esters were prepared to examine the effect of the coating agent compositions on the rate of mass loss on avocados treated with a solution comprising the coating agent dissolved in a solvent to form a coating over the avocados. All coatings were formed by dipping the avocados in a solution comprising the associated mixture dissolved in substantially pure ethanol at a concentration of 5 mg/mL, placing the avocados on drying racks, and allowing the avocados to dry under ambient room conditions at a temperature in the range of about 23° C.-27° C. and humidity in the range of about 40%-55%. The avocados were held at these same temperature and humidity conditions for the entire duration of the time they were tested.
The results are shown in
As shown, the PA-1G/MA-1G mixture (2306) resulted in a shelf life factor greater of 1.44, the SA-1G/PA-1G mixture (2302) resulted in a shelf life factor of 1.51, and the SA-1G/MA-1G mixture (2304) resulted in a shelf life factor of 1.6.
Three solutions comprising a combination of SA1G, PA2G, and optionally PA were prepared to examine the effect of three-component compositions on the rate of mass loss on avocados treated with a solution comprising the coating agent dissolved in a solvent to form a coating over the avocados.
All coatings were formed by dipping the avocados in a solution comprising the associated mixture dissolved in substantially pure ethanol at a concentration of 5 mg/mL, placing the avocados on drying racks, and allowing the avocados to dry under ambient room conditions at a temperature in the range of about 23° C.-27° C. and humidity in the range of about 40%-55%. The avocados were held at these same temperature and humidity conditions for the entire duration of the time they were tested. The results are shown in
Bar 2402 corresponds to avocados coated with a mixture including SA-1G (first additive, compound of Formula I-B), PA-2G (compound of Formula I-A), and PA (compound of Formula I) mixed at a mass ratio of 30:70:0. This coating resulted in a shelf life factor of 1.6. Bar 2404 corresponds to avocados coated with a mixture including SA-1G, PA-2G, and PA mixed at a respective mass ratio of 30:50:20. That is, as compared to the compounds corresponding to bar 2402, the coating formulation of bar 2404 could be formed by removing a portion of the PA-2G in the formulation corresponding to bar 1602 and replacing it with PA, such that the formulation of bar 2404 was 50% compounds of Formula I-A (by mass) and 50% additives (by mass). As shown, the shelf life factor is 1.55. Bar 2406 corresponds to avocados coated with a mixture including SA-1G, PA-2G, and PA mixed at a respective mass ratio of 30:30:40 (i.e., removing additional PA-2G and replacing it with PA). In this case, the formulation was only 30% compounds of Formula I-A (by mass) and 70% additives (by mass). As shown, the shelf life factor is 1.43.
Three solutions comprising a combination of SA1G, optionally OA, and PA were prepared to examine the effect of three-component compositions on the rate of mass loss on avocados treated with a solution comprising the coating agent dissolved in a solvent to form a coating over the avocados.
All coatings were formed by dipping the avocados in a solution comprising the associated mixture dissolved in substantially pure ethanol at a concentration of 5 mg/mL, placing the avocados on drying racks, and allowing the avocados to dry under ambient room conditions at a temperature in the range of about 23° C.-27° C. and humidity in the range of about 40%-55%. The avocados were held at these same temperature and humidity conditions for the entire duration of the time they were tested. The results are shown in
Bar 2502 corresponds to avocados coated with a mixture including SA-1G (compound of Formula I-B), OA and PA (first fatty acid) mixed at a mass ratio of 50:0:50. The shelf life factor for these avocados was 1.47. Bar 2504 corresponds to avocados coated with a mixture including SA-1G, OA, and PA mixed at a respective mass ratio of 45:10:45. That is, as compared to the compounds corresponding to bar 2502, the coating formulation of bar 2504 could be formed by removing equal portions (by mass) of the SA-1G and PA in the formulation of bar 2502 and replacing them with OA. The shelf life factor for these avocados was 1.41. Bar 2506 corresponds to avocados coated with a mixture including SA-1G, OA, and PA mixed at a respective mass ratio of 40:20:40. That is, as compared to the compounds corresponding to bar 2504, the coating formulation of bar 2506 could be formed by further removing equal portions (by mass) of the SA-1G and PA in the formulation of bar 2504 and replacing them with OA. The shelf life factor for these avocados was 1.33.
Various implementations of the compositions and methods have been described above. However, it should be understood that they have been presented by way of example only, and not limitation. Where methods and steps described above indicate certain events occurring in certain order, those of ordinary skill in the art having the benefit of this disclosure would recognize that the ordering of certain steps may be modified and such modifications are in accordance with the variations of the disclosure. The implementations have been particularly shown and described, but it will be understood that various changes in form and details may be made. Accordingly, other implementations are within the scope of the following claims.
This application is a bypass continuation of PCT/US2017/024799, filed Mar. 29, 2017, which claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 62/316,741, filed Apr. 1, 2016.
Number | Date | Country | |
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62316741 | Apr 2016 | US |
Number | Date | Country | |
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Parent | PCT/US2017/024799 | Mar 2017 | US |
Child | 16121513 | US |