US20210163217A1

US20210163217A1 - Packaging for storage of perishable items

Info

Publication number: US20210163217A1
Application number: US17/267,100
Authority: US
Inventors: Louis Perez; Charles Patrick Frazier; James Rogers
Original assignee: Apeel Technology Inc
Current assignee: Apeel Technology Inc
Priority date: 2018-08-10
Filing date: 2019-08-08
Publication date: 2021-06-03
Also published as: CN112888639A; IL280746A; EP3833616A1; JP2021534041A; WO2020033750A1

Abstract

Described herein are packaging (e.g., containers) and methods for storing perishable items. The containers can include a plurality of openings that cause a reduction in the in-package relative humidity. The perishable items can be coated with a protective coating to prevent moisture loss from produce during storage. The perishable items can be coated prior to storage in the packaging or after being placed in the packaging. The container and coatings therefore allow the perishable items to be stored at lower relative humidity (e.g., lower than industry standards for shipment and storage, or lower than about 90% relative humidity), which can help delay the growth of biotic stressors such as fungi, bacteria, viruses, and/or pests.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to, and the benefit of, U.S. Provisional Patent Application No. 62/717,511, filed Aug. 10, 2018, the contents of which are hereby incorporated by reference in their entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates to containers and other packaging used to store perishable items such as harvested produce and methods of making and using thereof.

BACKGROUND

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, oxidation by oxygen that diffuses into the agricultural products from the environment, mechanical damage to the surface, and/or light-induced degradation (i.e., photodegradation). Biotic stressors such as bacteria, fungi, viruses, and/or pests can also infest and decompose the agricultural products.
Harvested produce (e.g., fruits, vegetables, berries, etc.) is often stored at high density (i.e., high total volume of produce per unit volume of storage container) for extended periods of time prior to consumption, for example during shipping. During this time, the produce can be susceptible to mass loss, molding, and/or other mechanisms for spoilage if proper storage conditions are not maintained. Equipment and methods for decreasing the rate of spoilage while maintaining high quality produce, with minimal loss in mass/moisture or infestation by fungi during storage and shipping, are therefore desirable.

SUMMARY

Described herein are packaging (e.g., containers) and methods for storing perishable items. The containers can include a plurality of openings that cause a reduction in in-package relative humidity. The perishable items can be coated with a protective coating to prevent moisture loss from produce during storage. The perishable items can be coated prior to storage in the packaging or after being placed in the packaging. The container and coatings therefore allow the perishable items to be stored at lower relative humidity (e.g., lower than industry standards for shipment and storage, or lower than about 90% relative humidity), which can help delay the growth of biotic stressors such as fungi, bacteria, viruses, and/or pests.
The protective coatings can be formed by treating the perishable items with a coating mixture that includes a coating agent dissolved or suspended in a solvent. The coating agent can include 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 added to can include water and/or an alcohol. The solvent in which the coating agent is added to can include or be formed of a sanitizing agent. For example, the solvent can include 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. In some embodiments, the mixture includes a sanitizing agent such as citric acid.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of a container that can be used for storage of perishable items.

FIG. 2 is an illustration of another container that can be used for storage of perishable items.

FIG. 3 illustrates a process for preparing perishable items (e.g., produce) for storage and subsequently storing the perishable items.

FIG. 4 illustrates a process for storing perishable items in a container in which protective coatings are formed over the items while they are in the container.

Like numbers in the drawings refer to like elements.

Definitions

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, a “coating” or “protective coating” is understood to mean one or more layers of monomers, oligomers, polymers, fatty acids, esters, triglycerides, diglycerides, monoglycerides, amides, amines, thiols, thioesters, carboxylic acids, ethers, aliphatic waxes, alcohols, salts (inorganic salts or organic salts such as fatty acid salts), acids, bases, proteins, enzymes, or combinations thereof disposed over and substantially covering a surface of a perishable item such as a piece of 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 salts or organic salts such as fatty acid salts), or combinations thereof.
The term “alkyl” refers to a straight or branched chain saturated hydrocarbon. C₁-C₆alkyl groups contain 1 to 6 carbon atoms. Examples of a C₁-C₆alkyl 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-C₆alkenyl 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-C₆alkynyl 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-C₇cycloalkyl is a cycloalkyl group containing between 3 and 7 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 ring 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 ring 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.
As used herein, a “cationic counter ion” is any organic or inorganic positively charged ion associated with a negatively charged ion. Examples of a cationic counter ion include, for example, sodium, potassium, calcium, and magnesium. As used herein, a “cationic moiety” is any organic or inorganic positively charged ion.
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”. Dodecanoic acid (e.g., lauric acid) is abbreviated to “LA”. Undecanoic acid (e.g., undecylic acid) is abbreviated to “UA”. Decanoic acid (e.g., capric acid) is abbreviated to “CA”. 1,3-dihydroxypropan-2-yl palmitate (i.e., 2-glyceryl palmitate) is abbreviated to “PA-2G”. 1,3-dihydroxypropan-2-yl octadecanoate (i.e., 2-glyceryl stearate) is abbreviated to “SA-2G”. 1,3-dihydroxypropan-2-yl tetradecanoic acid (i.e., 2-glyceryl myristate) is abbreviated to “MA-2G”. 1,3-dihydroxypropan-2-yl (9Z)-octadecenoate (i.e., 2-glyceryl oleate) is abbreviated to “OA-2G”. 2,3-dihydroxypropan-1-yl palmitate (i.e., 1-glyceryl palmitate) is abbreviated to “PA-1G”. 2,3-dihydroxypropan-1-yl octadecanoate (i.e., 1-glyceryl stearate) is abbreviated to “SA-1G”. 2,3-dihydroxypropan-1-yl tetradecanoate (i.e., 1-glyceryl myristate) is abbreviated to “MA-1G”. 2,3-dihydroxypropan-1-yl (9Z)-octadecenoate (i.e., 1-glyceryl oleate) is abbreviated to “OA-1G”. 2,3-dihydroxypropan-1-yl dodecanoate (i.e., 1-glyceryl laurate) is abbreviated to “LA-1G”. 2,3-dihydroxypropan-1-yl undecanoate (i.e., 1-glyceryl undecanoate) is abbreviated to “UA-1G”. 2,3-dihydroxypropan-1-yl decanoate (i.e., 1-glyceryl caprate) is abbreviated to “CA-1G”. Sodium salt of stearic acid is abbreviated to “SA-Na”. Sodium salt of myristic acid is abbreviated to “MA-Na”. Sodium salt of palmitic acid is abbreviated to “PA-Na”. Potassium salt of stearic acid is abbreviated to “SA-K”. Potassium salt of myristic acid is abbreviated to “MA-K”. Potassium salt of palmitic acid is abbreviated to “PA-K”. Calcium salt of stearic acid is abbreviated to “(SA)₂-Ca”. Calcium salt of myristic acid is abbreviated to “(MA)₂-Ca”. Calcium salt of palmitic acid is abbreviated to “(PA)₂-Ca”. Magnesium salt of stearic acid is abbreviated to “(SA)₂-Mg”. Magnesium salt of myristic acid is abbreviated to “(MA)₂-Mg”. Magnesium salt of palmitic acid is abbreviated to “(PA)₂-Mg”.

DETAILED DESCRIPTION

Modified Atmosphere Packaging (MAP) is commonly used for storage of perishable items such as harvested produce, for example on store shelves prior to purchase by consumers, in order to minimize degradation of the items and maintain visual, textural, and nutritional appeal of the items. Through suitable material selection and package design, MAP containers and packages can be optimized to maintain a high internal relative humidity in order to minimize the rate at which the perishable items lose mass and water over time, thereby allowing the items to be of acceptable quality when they are sold after storage and/or shipping. MAP containers and packaging can also be designed in such a way that allows the perishable items to be sufficiently cooled during storage in order to reduce the ripening rate of the items, thereby further delaying the onset of spoilage.
Table 1 below is a compilation of recommended industry standard conditions, including recommended relative humidity (RH), for long term storage of produce (e.g., fresh fruits and vegetables). As seen in Table 1, the recommended relative humidity during storage for virtually all types of common produce is at least 85%, and is typically at least 95%. 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 promote the 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 difficult to precisely control the relative humidity at such high levels throughout a storage container, and so local RH variations can further exacerbate the risks of condensation formation.

TABLE 1

Properties and Recommended Conditions for Long-Term Storage of Fresh
Fruits and Vegetables

				Highest	Ethyl-	Ethyl-	Approx-	Observations
	Scientific	Storage	Relative	freezing	ene*	ene**	imate	and beneficial
Common name	name	temperature	humidity	temperature

Acerola;	Malpighia	0	32	85-90	−1.4	29.4			6-8
Barbados	glabra								weeks
African horned	Cucumis	13-15	55-59	90			L	M	3-6
melon;	metuliferus								months
Amaranth;	Amaranthus	0-2	32-36	95-100			VL	M	10-14
Anise; Fennel	Foeniculum	0-2	32-36	90-95	−1.1	30.0			2-3
Apple	Malus pumila									2-3% O2 + 1-2%
not chilling		−1.1-0	30-32	90-95	−1.5	29.3	VH	H	3-6
chilling	Yellow	4	40	90-95	−1.5	29.3	VH	H	1-2
sensitive	Newtown								months
Apricot	Prunus	−0.5-0	31-32	90-95	−1.1	30.0	M	M	1-3	2-3% O2 + 2-3%
Artichoke
Globe artichoke	Cynara	0	32	95-100	−1.2	29.9	VL	L	2-3	2-3% O2 + 3-5%
Chinese	Stachys affinia	0	32	90-95			VL	VL	1-2
Jerusalem	Helianthus	−0.5-0	31-32	90-95	−2.5	27.5	VL	L	4
Arugula	Eruca vesicaria	0	32	95-100			VL	H	7-10
	var. sativa								days
Asian pear,	Pyrus serotina;	1	34	90-95	−1.6	29.1	H	H	4-6
Nashi	P. pyrifolia								months
Asparagus,	Asparagus	2.5	36	95-100	−0.6	31.0	VL	M	2-3	5-12% CO2 in
green, white	officinalis								weeks	air
Atemoya	Annona	13	55	85-90			H	H	2-4	3-5% O2 + 5-
	squamosa x A.								weeks	10% CO2
Avocado	Persea
cv Fuerte, Hass		3-7	37-45	85-90	−1.6	29.1	H	H	2-4	2-5% O2 + 3-
cv. Fuchs,		13	55	85-90	−0.9	30.4	H	H	2 weeks
cv. Lula, Booth		4	40	90-95	−0.9	30.4	H	H	4-8
Babaco, Mt.	Carica	7	45	85-90					1-3
Banana	Musa	13-15	55-59	90-95	−0.8	30.6	M	H	1-4	2-5% O2 + 2-5%
	paradisiaca var.								weeks	CO2
Barbados cherry	see Acerola
Beans
Snap; Wax;	Phaseolus	4-7	40-45	95	−0.7	30.7	L	M	7-10	2-3% O2 + 4-7%
Fava, Broad	Vicia faba	0	32	90-95					1-2
Lima beans	Phaseolus	5-6	41-43	95	−0.6	31.0	L	M	5-7 days
Winged bean	Psophocarpus	10	50	90					4 weeks
	tefragonolobus
Long bean;	Vigna	4-7	40-45	90-95			L	M	7-10
Beet, bunched	Beta vulgaris	0	32	98-100	−0.4	31.3	VL	L	10-14
beet, topped		0	32	98-100	−0.9	30.3	VL	L	4
Berries
Blackberries	Rubus spp.	−0.5-0	31-32	90-95	−0.8	30.6	L	L	3-6 days	5-10% O2 + 15-
Blueberries	Vaccinium	−0.5-0	31-32	90-95	−1.3	29.7	L	L	10-18	2-5% O2 + 12-
Cranberry	Vaccinium	2-5	35-41	90-95	−0.9	30.4	L	L	8-16	1-2% O2 + 0-5%
Dewberry	Rubus spp.	−0.5-0	31-32	90-95	−1.3	29.7	L	L	2-3 days
Elderberry	Rubus spp.	−0.5-0	31-32	90-95	−1.1	30.0	L	L	5-14
Loganberry	Rubus spp.	−0.5-0	31-32	90-95	−1.7	28.9	L	L	2-3 days
Raspberries	Rubus idaeus	−0.5-0	31-32	90-95	−0.9	30.4	L	L	3-6 days	5-10% O2 + 15-
Strawberry	Fragaria spp.	0	32	90-95	−0.8	30.6	L	L	7-10	5-10% O2 + 15-
Bittermelon;	Momordica	10-12	50-54	85-90			L	M	2-3	2-3% O2 + 5%
Bitter gourd	charantia								weeks	CO2
Black salsify;	Scorzonera	0-1	32-34	95-98			VL	L	6
Bok choy	Brassica	0	32	95-100			VL	H	3 weeks
Breadfruit	Artocarpus	13-15	55-59	85-90					2−4
Broccoli	B. oleracea var.	0	32	95-100	−0.6	31.0	VL	H	10-14	1-2% O2 + 5-
Brussels sprouts	Brassica	0	32	95-100	−0.8	30.5	VL	H	3-5	1-2% O2 + 5-7%
	oleracea								weeks	CO2
Cabbage
Chinese;	Brassica	0	32	95-100	−0.9	30.4	VL	M-H	2-3	1-2% O2 + 0-5%
Napa	campesfris var.								months	CO2
Common, early	B. oleracea	0	32	98-100	−0.9	30.4	VL	H	3-6
late crop		0	32	95-100	−0.9	30.4	VL	H	5-6	3-5% O2 + 3-7%
Cactus pads or	Opuntia spp.	5-10	41-50	90-95			VL	M	2-3
stems,									weeks
Cactus fruit;	Opuntia spp.	5	41	85-90	−1.8	28.7	VL	M	2-6	2% O2 +
Prickly pear									weeks	2-5% CO2
Caimito	see Sapotes
Calamondin	see Citrus
Canistel	see Sapotes
Carambola,	Averrhoa	9-10	48-50	85-90	−1.2	29.8			3-4
Carrots, topped	Daucus carota	0	32	98-100	−1.4	29.5	VL	H	3-6	no CA benefit;
									months	ethylene causes
bunched;		0	32	98-100	−1.4	29.5	VL	H	10-14	ethylene causes
Cashew apple	Anacardium	0-2	32-36	85-90					5 weeks
Cassava,	Manihot	0-5	32-41	85-90			VL	L	1-2	no CA benefit
Yucca,	esculenta								months
Cauliflower	Brassica	0	32	95-98	−0.8	30.6	VL	H	3-4	2-5% O2 + 2-5%
	oleracea var.								weeks	CO2
Celeriac	Apium	0	32	98-100	−0.9	30.4	VL	L	6-8	2-4% O2 + 2-
	graveolens								months	3% CO2
Celery	Apium	0	32	98-100	−0.5	31.1	VL	M	1-2	1-4% O2 + 3-
	graveolens var.								months	5% CO2
Chard	Beta vulgaris	0	32	95-100			VL	H	10-14
Chayote	Sechium edule	7	45	85-90					4-6
Cherimoya;	Annona	13	55	90-95	−2.2	28.0	H	H	2-4	3-5% O2 +
Custard apple	cherimola								weeks	5-10% CO2
Chenies, sour	Prunus cerasus	0	32	90-95	−1.7	29.0	VL	L	3-7 days	3-10% O2 + 10-
Cherries, sweet	Prunus avium	−1 to 0	30-32	90-95	−2.1	28.2	VL	L	2-3	10-20% O2 + 20-
Chicory	see Endive
Chiles	see Pepper
Chinese	Brassica	0	32	95-100			VL	H	10-14
Chinese date	See Jujube
Chives	Allium	0	32	95-100			VL	H	2-3	5-10% O2 + 5-
Cilantro, Chinese	See Herbs
Citrus
Calamondin	Citrus reticulta	9-10	48-50	90	−2.0	28.3			2 weeks
orange	x Fortunella
Grapefruit	Citrus paradisi									3-10% O2 + 5-
CA, AZ, dry		14-15	58-59	85-90	−1.1	30.0	VL	M	6-8
FL, humid		10-15	50-59	85-90	−1.1	30.0	VL	M	6-8
Kumquat	Fortunella	4	40	90-95			VL	M	2-4
Lemon	Citrus limon	10-13	50-55	85-90	−1.4	29.4			1-6	5-10% O2 + 0-
Lime, Mexican,	Citrus	9-10	48-50	85-90	−1.6	29.1			6-8	5-10% O2 + 0-
Tahiti or Persian	aurantifolia;								weeks	10% CO2
Orange	Citrus sinensis									5-10% O2 + 0-
CA, AZ, dry		3-9	38-48	85-90	−0.8	30.6	VL	M	3-8
FL; humid		0-2	32-36	85-90	−0.8	30.6	VL	M	8-12
Blood orange		4-7	40-44	90-95	−0.8	30.6			3-8
Seville; Sour	Citrus	10	50	85-90	−0.8	30.6	L	M	12
Pummelo	Citrus grandis	7-9	45-48	85-90	−1.6	29.1			12
Tangelo,	C. reticulata x	7-10	45-50	85-95	−0.9	30.3			2-4
Tangerine,	Citrus	4-7	40-45	90-95	−1.1	30.1	VL	M	2-4
Coconut	Cocos nucifera	0-2	32-36	80-85	−0.9	30.4			1-2
Collards	B. oleracea var.	0	32	95-100	−0.5	31.1	VL	H	10-14
	Acephala								days
Corn, sweet and	Zea mays	0	32	95-98	−0.6	30.9	VL	L	5-8 days	2-4% O2 + 5-
baby										10% CO2; to 4
Cowpeas	See Peas
Cucumber,	Cucumis sativus	10-12	50-54	85-90	−0.5	31.1	L	H	10-14	3-5% O2 + 0-5%
slicing									days	CO2
pickling		4	40	95-100			L	H	7 days	3-5% O2 + 3-5%
Currants	Ribes sativum;	−0.5-0	31-32	90-95	−1.0	30.2	L	L	1-4	CA can extend
	R. nigrum; R.								weeks	storage life to 3-
Custard apple	see Cherimoya
Daikon; Oriental	Raphanus	0-1	32-34	95-100			VL	L	4
Dasheen	see Taro
Date	Phoenix	−18-0	0-32	75	−15.7	3.7	VL	L	6-12
Dill	see Herbs
Durian	Durio	4-6	39-42	85-90					6-8	3-5% O2 + 5-
Eggplant	Solanum	10-12	50-54	90-95	−0.8	30.6	L	M	1-2	3-5% O2 + 0%
Endive, Escarole	Cichorium	0	32	95-100	−0.1	31.7	VL	M	2-4
Belgian endive;	Cichorium	2-3	36-38	95-98			VL	M	2-4	light causes
Witloof chicory	intybus								weeks	greening;
Epazote	See Herbs
Fava bean	See Beans
Feijoa, Pineapple	Feijoa	5-10	41-50	90			M	L	2-3
Fennel, see anise
Fig	Ficus carica	−0.5-0	31-32	85-90	−2.4	27.6	M	L	7-10	5-10% O2 + 15-
Garlic bulb	Allium sativum	−1-0	30-32	65-70	−2.0	28.4	VL	L	6-7	0.5% O2 + 5-
Ginger	Zingiber	13	55	65			VL	L	6	no CA benefit
Gooseberry	Ribes	−0.5-0	31-32	90-95	−1.1	30.0	L	L	3-4
Granadilla	see Passionfruit
Grape	Vitis vinifera	−0.5-0	31-32	90-95	−2.7 a	27.1	VL	L	1-6	2-5% O2 + 1-
	a = fruit;				−2.0 b	a			months	3% CO2; to 4
	b = stem
American grape	Vitis labrusca	−1 to -	30-31	90-95	−1.4	29.4	VL	L	2-8
Grapefruit	see Citrus
Guava	Psidium	5-10	41-50	90			L	M	2-3
Herbs, fresh	See specific									5-10% O2 + 5-
Basil	Ocimum	10	50	90			VL	H	7 days	2% O2 + 0
Chives	Allium	0	32	95-100	−0.9	30.4	L	M
Cilantro,	Coriandrum	0-1	32-34	95-100			VL	H	2 weeks	3% O2 + 7-
Chinese	sativum									10% CO2; air +
Dill	Anethum	0	32	95-100	−0.7	30.7	VL	H	1-2	5-10% O2 + 5-
Epazote	Chenopodium	0-5	32-41	90-95			VL	M	1-2
	ambrosioides								weeks
Mint	Mentha spp.	0	32	95-100			VL	H	2-3	5-10% O2 + 5-
Oregano	Origanum	0-5	32-41	90-95			VL	M	1-2
Parsley	Pefroselinum	0	32	95-100	−1.1	30.0	VL	H	1-2	5-10% O2 + 5-
Perilla, Shiso	Perilla	10	50	95			VL	M	7 days
Sage	Salvia	0	32	90-95					2-3
Thyme	Thymus	0	32	90-95					2-3
Horseradish	Armoracia	−1 to 0	30-32	98-100	−1.8	28.7	VL	L	10-12
Husk tomato	see Tomatillo
Jaboticaba	Myrciaria	13-15	55-59	90-95					2-3 days
	cauliflora =
Jackfruit	Artocarpus	13	55	85-90			M	M	2-4
Jerusalem	see Artichoke
Jicama,	Pachyrrhizus	13-18	55-65	85-90			VL	L	1-2
Jujube; Chinese	Ziziphus jujuba	2.5-10	36-50	85-90	−1.6	29.2	L	M	1 month
Kaki	see Persimmon
Kale	Brassica	0	32	95-100	−0.5	31.1	VL	H	10-14
	oleracea var.								days
Kiwano	see African
Kiwifruit;	Actinidia	0	32	90-95	−0.9	30.4	L	H	3-5	1-2% O2 + 3-5%
Chinese	chinensis								months	CO2
Kohlrabi	Brassica	0	32	98-100	−1.0	30.2	VL	L	2-3	no CA benefit
	oleracea var.								months
Kumquat	See Citrus
Langsat;	Aglaia sp.;	11-14	52-58	85-90					2 weeks
Leafy Greens
Cool season	various genera	0	32	95-100	−0.6	31.0	VL	H	10-14
Warm season	various genera	7-10	45-50	95-100	−0.6	31.0	VL	H	5-7 days
Leek	Allium porrum	0	32	95-100	−0.7	30.7	VL	M	2	1-2% O2 + 2-5%
Lemon	see Citrus
Lettuce	Lactuca sativa	0	32	98-100	−0.2	31.7	VL	H	2-3	2-5% O2 + 0%
Lima bean	see Beans
Lime	see Citrus
LoBok	see Daikon
Longan	Dimocarpus	4-7	39-45	90-95	−2.4	27.7			2-4
	longan								weeks
Long bean	See Beans
Loquat	Eriobotrya	0	32	90-95	−1.9	28.6			3 weeks
Luffa; Chinese	Luffa spp.	10-12	50-54	90-95			L	M	1-2
Lychee, Litchi	Litchi chinensis	1-2	34-36	90-95			M	M	3-5	3-5% O2 + 3-5%
Malanga, Tania,	Xanthosoma	7	45	70-80			VL	L	3
New cocoyam	sagittifolium								months
Mamey	see Sapote
Mandarin	see Citrus
Mango	Mangifera	13	55	85-90	−1.4	29.5	M	M	2-3	3-5% O2 + 5-
Mangosteen	Garcinia	13	55	85-90			M	H	2-4
Melons
Cantaloupes	Cucurbita melo	2-5	36-41	95	−1.2	29.9	H	M	2-3	3-5% O2 + 10-
and other	var.								weeks	15% CO2
Casaba	Cucurbita melo	7-10	45-50	85-90	−1.0	30.3	L	L	3-4	3-5% O2 + 5-
Crenshaw	Cucurbita melo	7-10	45-50	85-90	−1.1	30.1	M	H	2-3	3-5% O2 + 5-
Honeydew, and	Cucurbita melo	5-10	41-50	85-90	−1.1	30.1	M	H	3-4	3-5% O2 +
Orange-									weeks	5-10% CO2
Persian	Cucurbita melo	7-10	45-50	85-90	−0.8	30.6	M	H	2-3	3-5% O2 + 5-
Mint	see Herbs
Mombin	see Spondias
Mushrooms	Agaricus, other	0	32	90	−0.9	30.4	VL	M	7-14	3-21% O2 + 5-
Mustard greens	Brassica juncea	0	32	90-95			VL	H	7-14
Nashi	see Asian pear
Nectarine	Prunus persica	−0.5-0	31-32	90-95	−0.9	30.3	M	M	2-4	1-2% O2 + 3-5%
									weeks	CO2; internal
Okra	Abelmoschus	7-10	45-50	90-95	−1.8	28.7	L	M	7-10	air + 4-10% CO2
Olives, fresh	Olea europea	5-10	41-50	85-90	−1.4	29.4	L	M	4-6	2-3% O2 + 0-1%
Onions	A llium cepa
Mature bulbs,		0	32	65-70	−0.8	30.6	VL	L	1-8	1-3% O2 + 5-
Green onions		0	32	95-100	−0.9	30.4	L	H	3 weeks	2-4% O2 + 10-
Orange	see Citrus
Papaya	Carica papaya	7-13	45-55	85-90	−0.9	30.4	M	M	1-3	2-5% O2 + 5-8%
Parsley	see Herbs
Parsnips	Pastinaca	0	32	95-100	−0.9	30.4	VL	H	4-6	ethylene causes
Passionfruit	Passiflora spp.	10	50	85-90			VH	M	3-4
Peach	Prunus persica	−0.5-0	31-32	90-95	−0.9	30.3	M	M	2-4	1-2% O2 + 3-
									weeks	5% CO2;
										internal
Pear, European	Pyrus	−1.5 to	29-31	90-95	−1.7	29.0	H	H	2-7	Cultivar
	communis	−0.5							months	variations; 1-
Pear, Asian	See Asian Pear
Peas in pods;	Pisum sativum	0	32	90-98	−0.6	30.9	VL	M	1-2	2-3% O2 + 2-3%
Snow, Snap &									weeks	CO2
Southern peas;	Vigna sinensis =	4-5	40-41	95					6-8 days
Cowpeas	V.
Pepino; Melon	Solanum	5-10	41-50	95			L	M	4 weeks
Peppers
Bell Pepper,	Capsicum	7-10	45-50	95-98	−0.7	30.7	L	L	2-3	2-5% O2 + 2-5%
Hot peppers,	Capsicum	5-10	41-50	85-95	−0.7	30.7	L	M	2-3	3-5% O2 + 5-
Chiles	annuum and C.								weeks	10% CO2
Persimmon; Kaki	Diospyros kaki									3-5% O2 + 5-8%
Fuyu		0	32	90-95	−2.2	28.0	L	H	1-3
Hachiya		0	32	90-95	−2.2	28.0	L	H	2-3
Pineapple	Ananas	7-13	45-55	85-90	−1.1	30.0	L	L	2-4	2-5% O2 + 5-
Plantain	Musa	13-15	55-59	90-95	−0.8	30.6	L	H	1-5
	paradisiaca var.								weeks
Plums and	Prunus	−0.5	- 31-32	90-95	−0.8	30.5	M	M	2-5	1-2% O2 + 0-
Pomegranate	Punica	5-7.2	41-45	90-95	−3.0	26.6	VL	L	2-3	3-5% O2 + 5-
Potato, early	Solanum	10-15	50-59	90-95	−0.8	30.5	VL	M	10-14	no CA benefit
late crop		4-8	40-46	95-98	−0.8	30.5	VL	M	5-10	no CA benefit
Pumpkin	Cucurbita	12-15	54-59	50-70	−0.8	30.5	L	M	2-3
Quince	Cydonia	−0.5-0	31-32	90	−2.0	28.4	L	H	2-3
Radicchio	Cichorium	0-1	32-34	95-100					4-8
Radish	Raphanus	0	32	95-100	−0.7	30.7	VL	L	1-2	1-2% O2 + 2-
Rambutan	Nephelium	12	54	90-95			H	H	1-3	3-5% O2 + 7-
Rhubarb	Rheum	0	32	95-100	−0.9	30.3	VL	L	2-4
Rutabaga	Brassica napus	0	32	98-100	−1.1	30.1	VL	L	4-6
	var.								months
Sage	see Herbs
Salsify;	Trapopogon	0	32	95-98	−1.1	30.1	VL	L	2-4
Sapotes
Caimito, Star	Chrysophyllum	3	38	90	−1.2	29.9			3 weeks
Canistel,	Pouteria	13-15	55-59	85-90	−1.8	28.7			3 weeks
Black sapote	Diospyros	13-15	55-59	85-90	−2.3	27.8			2-3
White sapote	Casimiroa	20	68	85-90	−2.0	28.4			2-3
Mamey sapote	Calocarpum	13-15	55-59	90-95			H	H	2-3
Sapodilla,	Achras sapota	15-20	59-68	85-90			H	H	2 weeks
Scorzonera	see Black
Shallots	A llium cepa var	0-2.5	32-36	65-70	−0.7	30.7	L	L
	ascalonicum
Snap bean	see Beans
Soursop	Annona	13	55	85-90					1-2	3-5% O2 + 5-
Spinach	Spinacia	0	32	95-100	−0.3	31.5	VL	H	10-14	5-10% O2 + 5-
Spondias,	Spondias spp.	13	55	85-90					1-2
Mombin, Wi									weeks
Sprouts from	various genera	0	32	95-100					5-9 days
Alfalfa sprouts	Medicago	0	32	95-100					7 days
Bean sprouts	Phaseolus sp.	0	32	95-100					7-9 days
Radish sprouts	Raphanus sp.	0	32	95-100					5-7 days
Squash
Summer (soft	Cucurbita pepo	7-10	45-50	95	−0.5	31.1	L	M	1-2	3-5% O2 + 5-
rind);									weeks	10% CO2
Winter (hard	Cucurbita	12-15	54-59	50-70	−0.8	30.5	L	M	2-3	large differences
rind);	moschata; C.								months	among varieties
Star-apple	see Sapotes
Starfruit	see Carambola
Strawberry	see Berries
Sweetpotato,	Ipomea batatas	13-15	55-59	85-95	−1.3	29.7	VL	L	4-7
Sweetsop; Sugar	Annona	7	45	85-90			H	H	4 weeks	3-5% O2 +
apple; Custard	squamosa;									5-10% CO2
Tamarillo, Tree	Cyphomandra	3-4	37-40	85-95			L	M	10
tomato	betacea								weeks
Tamarind	Tamarindus	2-7	36-45	90-95	−3.7	25.3	VL	VL	3-4
Taro, Cocoyam,	Colocasia	7-10	45-50	85-90	−0.9	30.3			4	No CA benefit
Eddoe,	esculenta								months
Thyme	see Herbs
Tomatillo; Husk	Physalis	7-13	45-55	85-90			VL	M	3 weeks
tomato	ixocarpa
Tomato, mature-	Lycopersicon	10-13	50-55	90-95	−0.5	31.0	VL	H	2-5	3-5% O2 + 2-
Tomato, firm-ripe		8-10	46-50	85-90	−0.5	31.1	H	L	1-3	3-5% O2 + 3-
Turnip root	Brassica	0	32	95	−1.0	30.1	VL	L	4-5
	campestris var.								months
Water chestnut	Eleocharis	1-2	32-36	85-90					2-4
Watercress;	Lepidium	0	32	95-100	−0.3	31.5	VL	H	2-3
Garden cress	sativum;								weeks
Watermelon	Cifrullus	10-15	50-59	90	−0.4	31.3	VL	H	2-3	no CA benefit
Winged bean	See Beans
Witloof chicory	See Endive
Yam	Dioscorea spp.	15	59	70-80	−1.1	30.0	VL	L	2-7
Yard-long bean	See Beans
Yucca	see Cassava

*Ethylene production rate:
VL = very low (<0.1 μL/kg-hr at 20° C.)
L = low (0.1 = 1.0 μL/kg-hr)
M = moderate (1.0-10.0 μL/kg-hr)
H = high (10-100 μL/kg-hr)
VH = very high (μL/kg-hr)
**Ethylene sensitivity (detrimental effects include yellowing, softening, increased decay, abscission or loss of leaves, browning)
L = low sensitivity
M = moderately sensitive
H = highly sensitive
indicates data missing or illegible when filed

FIG. 1 is an illustration of a container 100 for storage of perishable items such as harvested produce at relative humidity levels in accordance with Table 1 above. The container 100 includes an enclosure 102 made up of a material structure 110 and a lid 130. In some implementations, the material structure 110 is a rigid or semi-rigid structure. The material structure 110 includes a first opening 112 which is sufficiently large to allow any of the perishable items which the container is configured to store (not shown) to be able to pass through, such that the perishable items can be inserted into the container through the first opening. When the perishable items are in the container, the container is closed by affixing (e.g., sealing or fastening) the lid 130 over the first opening 112. Although FIG. 1 shows the lid 130 as being detachable from the rest of the container, in some embodiments the lid is attached to the rest of the container and can swing or bend from the open to the closed position. In some embodiments, the lid 130 is formed of a flexible material such as a plastic or foil that can be sealed (e.g., with an adhesive or with heat) over the first opening 112. In some embodiments, the lid is resealable. In some embodiments, the lid is formed of the same material as the material structure 110. In some embodiments, the lid is omitted, and the material structure 110 is formed of a flexible material such that the material structure can be folded, deformed or shaped once the perishable items are in the container in such a way that the enclosure surrounds the enclosed perishable items. In some embodiments, the material that forms the material structure 130 includes plastic, polycarbonate (PC), or polyethylene (PET). In some embodiments, the material of the material structure is impermeable to water, oxygen, and/or carbon dioxide. The bottom or footprint of container 100 can be manufactured in a variety of shapes including, but not limited to, circles, ovals, squares, and rectangles.
As used herein, a “rigid or semi-rigid” structure is a structure that is sufficiently rigid such that its shape is not substantially modified or deformed while the structure is filled with perishable items and no other external forces are applied to the side of the structure. A mesh sack would therefore not be a rigid or semi-rigid structure, since its shape will change as it is filled with perishable items, whereas a container made of hard plastic may be rigid or semi-rigid if the plastic is sufficiently thick such that the shape of the container does not substantially change when the container is filled with perishable items.
The enclosure 102 also includes a plurality of second openings 114, where each of the second openings 114 is sufficiently small to prevent any of the perishable items that are stored in the container from being able to pass through. Accordingly, while the perishable items are stored in the container 100 with the lid 130 covering the first opening 112, the perishable items are not able to fall out of the container 100. Although FIG. 1 shows the second openings 114 formed entirely in the side of the material structure 110, second openings can also be formed in the bottom of the material structure or in the lid 130.
As previously described, during storage of perishable items such as harvested produce in the container 100, it may be beneficial to cool the items in order to reduce their ripening rate, thereby further delaying the onset of spoilage. Cooling of the items can be achieved via convective cooling through the plurality of second openings 114. That is, cold air or gas can be blown or otherwise taken in through the second openings 114 in order to cool the stored perishable items. In cases where the items are cooled by placing the container 100 in cold storage (e.g., in a refrigeration unit), the relative humidity within the container during cooling typically approaches that of the cold storage environment (e.g., the environment within the refrigeration unit), which can be at least 90% relative humidity.
The cooling efficiency of the stored items in container 100 is maximized by maximizing the ratio of the collective area of all of the second openings 114 to the total area of the enclosure 102 (i.e., the total area of the surface enclosing the stored items) in order to improve convective air flow through the region in which the perishable items are stored. However, after the container and the stored perishable items are removed from cold storage and placed in ambient, if the ratio of area of the openings 114 to total enclosure area is large, the relative humidity in the region containing the perishable items will decrease, as water vapor (including vapor escaping from the stored perishable items) is more easily able to escape from inside the container. This in turn causes the stored items to lose mass at a higher rate and degrade more quickly. Accordingly, in the container 100 of FIG. 1, the ratio of the collective area of all of the second openings 114 to the total area of the enclosure 102 can be made small, for example less than 0.2, less than 0.18, less than 0.16, less than 0.14, less than 0.12, less than 0.1, less than 0.08, less than 0.05, less than 0.03, less than 0.02, less than 0.01, less than 0.008, less than 0.005, less than 0.003, less than 0.002, less than 0.001, less than 0.0008, or less than 0.0005.
FIG. 2 is an illustration of another container 200 suitable for storage of perishable items such as harvested produce. Container 200 is the same as container 100 in FIG. 1, except that the collective area of the openings 214 is larger than the collective area of the openings 114 in container 100 (e.g., the total number of openings per unit area of the enclosure is larger and/or individual openings have larger areas). Accordingly, the ratio of the collective area of all of the second openings 214 to the total area of the enclosure 202 in FIG. 2 is larger than the corresponding ratio for the container 100 of FIG. 1. For example, for the container 200, the ratio of the collective area of all of the second openings 214 to the total area of the enclosure 202 can be greater than 0.002, greater than 0.004, greater than 0.006, greater than 0.008, greater than 0.01, greater than 0.012, greater than 0.014, greater than 0.016, greater than 0.018, greater than 0.02, greater than 0.025, greater than 0.03, greater than 0.035, greater than 0.04, greater than 0.045, greater than 0.05, greater than 0.06, greater than 0.07, greater than 0.08, greater than 0.09, greater than 0.1, greater than 0.11, greater than 0.12, greater than 0.13, greater than 0.14, greater than 0.15, greater than 0.16, greater than 0.17, greater than 0.18, greater than 0.19, greater than 0.2, greater than 0.21, greater than 0.22, greater than 0.23, greater than 0.24, or greater than 0.25. Furthermore, the ratio of the collective area of all of the second openings 214 to the total area of the enclosure 202 can be less than 0.95, less than 0.94, less than 0.93, less than 0.92, less than 0.91, less than 0.9, less than 0.88, less than 0.86, less than 0.84, less than 0.82, less than 0.8, less than 0.78, less than 0.76, less than 0.74, less than 0.72, less than 0.7, less than 0.68, less than 0.66, less than 0.64, less than 0.62, less than 0.6, less than 0.55, or less than 0.5. In some embodiments, the openings 214 are substantially rectangular, circular, or oval. That is, their shape is identical or similar to that of a rectangle, circle, or oval, respectively.
If container 200 is used to store conventional perishable items such as produce that are susceptible to degradation by water/mass loss, the in-package relative humidity during storage may be lower than that recommended in Table 1, and thus the perishable items will lose mass at a higher rate and therefore degrade more quickly. For example, depending on the specific ratio of collective area of openings to total package area, the in-package relative humidity during storage may be less than 95%, less than 90%, less than 85%, less than 80%, less than 75%, less than 70%, less than 65%, less than 60%, less than 55%, less than 50%, less than 45%, less than 40%, less than 35%, less than 30%, less than 25%, less than 20%, less than 15%, less than 10%, or less than 5%, 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.
While such low in-package relative humidity can have deleterious effects on many conventional perishable items, if the perishable items are coated prior to storage with a protective coating that acts as a barrier to water loss and therefore reduces the mass and/or water loss rate of the perishable items, the coated perishable items can still maintain their mass during storage and may last as long as conventional (uncoated) perishable items that are held at higher relative humidity. In fact, in many cases, the average storage lifetime of coated perishable items stored in container 200 (at lower relative humidity) is greater than that of similar perishable items (either coated or uncoated) stored at the same temperature in container 100, since the higher humidity conditions can facilitate the growth of pathogens such as mold, fungi, and bacteria, which also cause spoilage of the perishable items, particularly at high packing densities.
In some embodiments, produce or other perishable items stored in containers 100 or 200 may not be highly susceptible to degradation via water/mass loss. However, it may be desirable to minimize the respiration rate (i.e., the rate at which CO₂is produced per unit mass of the items) of the perishable items in order to reduce the ripening rate of the items in order to prolong their lifetime before spoilage. In these cases, if the perishable items are uncoated, having a smaller area of openings in the container (as in container 100) results in a lower respiration rate, since more CO₂remains trapped within the container during storage. However, for the same reasons stated earlier, the relative humidity within the container is also higher when the area of the openings is smaller, which can increase the rate of molding.
If the perishable items are coated with a protective coating that reduces the respiration rate of the items (e.g., a coating with a low permeability to CO₂), then the lifetime of the items may be maximized by storage in a container with a higher area of openings (as in container 200). This is because the respiration rate of the items remains low even though the ambient concentration of CO₂in the container is lower, since the protective coating keeps the respiration rate of the items low by reducing CO₂transfer from the items to ambient. Additionally, the higher area of holes decreases the relative humidity within the container, which can decrease the rate of molding. In cases where the perishable items are not highly susceptible to degradation via water/mass loss, the low relative humidity may not substantially impact the rate of spoilage due to water/mass loss, even if the protective coating does not serve as a barrier to water/mass loss.
In view of the above, rates of spoilage of perishable items can be reduced by (a) forming a coating on the items that reduces the rate of mass loss of the items, and storing the items in a container such as container 200 that has a large area of openings; (b) forming a coating on the items that reduces the respiration rate of the items, and storing the items in a container such as container 200 that has a large area of openings; or (c) forming a coating on the items that reduces both the respiration rate and the mass loss rate of the items, and storing the items in a container such as container 200 that has a large area of openings. Furthermore, if coated perishable items stored in container 200 are cooled by placing the container 200 with the items in cold storage, the relative humidity in the cold storage environment can be set to be lower than conventional levels, for example less than less than 90%, less than 85%, less than 80%, less than 75%, less than 70%, less than 65%, less than 60%, less than 55%, less than 50%, less than 45%, less than 40%, less than 35%, less than 30%, less than 25%, less than 20%, less than 15%, less than 10%, or less than 5%. Protective coatings that are suitable for applying to perishable items that are stored in container 200, and methods of applying the coatings, are described in more detail below.
FIG. 3 illustrates a process 300 for preparing perishable items (e.g., produce) for storage and subsequently storing the perishable items such that the mass/water loss rate and/or the respiration rate is minimized, and at the same time the spoilage rate via biotic stressors such as mold, fungi, or bacteria is reduced. First, a solid mixture of a coating agent (e.g., a composition of monomer and/or oligomer, and/or polymer units) is dissolved or suspended in a solvent (e.g., ethanol, methanol, acetone, isopropanol, ethyl acetate, water, or combinations thereof) to form a solution or suspension (step 302). In some embodiments, a sanitizing agent such as citric acid is include in the solution/suspension. The concentration of the coating agent in the solvent can, for example, be in a range of about 0.1 to 200 mg/mL. Next, the solution/suspension, which includes the coating agent, is applied over the surface of the produce or other perishable item to be coated (step 304), for example by spray coating the produce/items or by dipping the produce/items in the solution/suspension. In the case of spray coating, the solution/suspension can, for example, be placed in a spray bottle that generates a fine mist spray. The spray bottle head can then be held an appropriate distance, e.g., approximately three to twelve inches, from the produce/items, and the produce/items then sprayed. In the case of dip coating, the produce/items can, for example, be placed in a bag, the solution/suspension containing the coating agent poured into the bag, and the bag then sealed and its contents lightly tumbled or agitated until the surfaces of the produce/items are entirely wet. After applying the solution/suspension to the produce/items, the produce/items are allowed to dry until the solvent has at least partially evaporated, thereby allowing a protective coating composed of the constituents of the coating agent (e.g., monomer and/or oligomer and/or polymer units) to form over the surface of the produce/items (step 306). Finally, the coated produce/items are stored in the container of FIG. 2 at a reduced relative humidity and/or ambient CO₂concentration than would otherwise be required to allow for a sufficiently low rate of water/mass loss and/or rate of respiration if the produce/items had not been coated (step 308). Optionally, during storage, the perishable items can be cooled. In some embodiments, cooling is achieved via convection through the openings 214 in the container 200 if FIG. 2.
The process steps 302, 304, 306, 308, and 310 of process 300 (FIG. 3) and their associated processing agents and resultant coatings are now described in further detail. The coating agent that is added to the solvent (step 302) can include a plurality of monomers, oligomers, polymers, fatty acids, esters, triglycerides, diglycerides, monoglycerides, amides, amines, thiols, thioesters, carboxylic acids, ethers, aliphatic waxes, alcohols, salts (inorganic salts or organic salts such as fatty acid salts), acids, bases, proteins, enzymes, or combinations thereof. As such, the resulting protective coating may be formed from components that are not naturally occurring on the perishable items, either individually or in the ratios in which they are combined in the coatings.
The specific composition of monomers, oligomers, polymers, fatty acids, esters, triglycerides, diglycerides, monoglycerides, amides, amines, thiols, thioesters, carboxylic acids, ethers, aliphatic waxes, alcohols, salts (inorganic salts or organic salts such as fatty acid salts), acids, bases, proteins, enzymes, or combinations thereof can be formulated such that the resulting coating formed over the perishable items (during step 306) mimics or enhances the cuticular layer of the product. The biopolyester cutin forms the main structural component of the cuticle that composes the aerial surface of most land plants. The cuticular layer is formed from a mixture of polymerized mono- and/or polyhydroxy fatty acids and esters, as well as embedded cuticular waxes. The hydroxy fatty acids and esters of the cuticle layer form tightly bound networks with high crosslink density. This crosslinked network in combination with the embedded cuticular waxes acts as a barrier to moisture loss and oxidation, as well as providing protection against other environmental stressors.
The monomers, oligomers, polymers, fatty acids, esters, triglycerides, diglycerides, monoglycerides, amides, amines, thiols, thioesters, carboxylic acids, ethers, aliphatic waxes, alcohols, salts (inorganic salts or organic salts such as fatty acid salts), acids, bases, proteins, enzymes, or combinations thereof 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 (or molecules that can be readily modified for use in 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 or suspended in the solvent to form the solution/suspension 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 esterifying (e.g., 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/suspended in the solvent to form a solution/suspension, thereby resulting in the formulation formed in step 302 of FIG. 3 for preparation of the protective coating.
In some implementations, the coating agent includes fatty acids, esters, triglycerides, diglycerides, monoglycerides (i.e., monoacylglycerides), amides, amines, thiols, thioesters, carboxylic acids, ethers, aliphatic waxes, alcohols, salts (inorganic salts or organic salts such as fatty acid salts), 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. In some implementations, the coating agent can include one or more compounds of Formula I:
wherein:
R is selected from —H, -glyceryl, —C₁-C₆alkyl, —C₂-C₆alkenyl, —C₂-C₆alkynyl, —C₃-C₇cycloalkyl, aryl, or heteroaryl, wherein each alkyl, alkenyl, alkynyl, cycloalkyl, aryl or heteroaryl is optionally substituted with one or more groups selected from halogen (e.g., Cl, BR, or I), hydroxyl, nitro, —CN, —NH₂, —SH, —SR¹⁵, —OR¹⁴, —NR¹⁴R¹⁵, C₁-C₆alkyl, C₂-C₆alkenyl, or C₂-C₆alkynyl;
R¹, R², R⁵, R⁶, R⁹, R¹⁰, R¹¹, R¹²and R¹³are each independently, at each occurrence, —H, —(C═O)R¹⁴, —(C═O)H, —(C═O)OH, —(C═O)OR¹⁴, —(C═O)—O—(C═O)R¹⁴, —O(C═O)R¹⁴, —OR¹⁴, —NR¹⁴R¹⁵, —SR¹⁴, halogen, —C₁-C₆alkyl, —C₂-C₆alkenyl, —C₂-C₆alkynyl, —C₃-C₇cycloalkyl, 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, R⁷and R⁸are each independently, at each occurrence, —H, —OR¹⁴, —NR¹⁴R¹⁵, —SR¹⁴, halogen, —C₁-C₆alkyl, —C₂-C₆alkenyl, —C₂-C₆alkynyl, —C₃-C₇cycloalkyl, aryl, or heteroaryl, wherein each alkyl, alkenyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with —OR¹⁴, —NR¹⁴R¹⁵, —SR¹⁴, or halogen; or
R³and R⁴can combine with the carbon atoms to which they are attached to form a C₃-C₆cycloalkyl, a C₄-C₆cycloalkenyl, or a 3- to 6-membered ring heterocycle; and/or
R⁷and R⁸can combine with the carbon atoms to which they are attached to form a C₃-C₆cycloalkyl, a C₄-C₆cycloalkenyl, or a 3 to 6-membered ring heterocycle;
R¹⁴and R¹⁵are each independently, at each occurrence, —H, —C₁-C₆alkyl, —C₂-C₆alkenyl, or —C₂-C₆alkynyl;
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, R is —H, —CH₃, or —CH₂CH₃.
In some implementations, the coating agent includes 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 includes compounds of the Formula I-A (e.g., 2-monoacylglycerides):
wherein:
each R^ais independently —H or —C₁-C₆alkyl;
each R^bis independently selected from —H, —C₁-C₆alkyl, or —OH;
R¹, R², R⁵, R⁶, R⁹, R¹⁰, R¹¹, R¹²and R¹³are each independently, at each occurrence, —H, —OR¹⁴, —NR¹⁴R¹⁵, —SR¹⁴, halogen, —C₁-C₆alkyl, —C₂-C₆alkenyl, —C₂-C₆alkynyl, —C₃-C₇cycloalkyl, 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 R⁸are each independently, at each occurrence, —H, —OR¹⁴, —NR¹⁴R¹⁵, —SR¹⁴, halogen, —C₁-C₆alkyl, —C₂-C₆alkenyl, —C₂-C₆alkynyl, —C₃-C₇cycloalkyl, aryl, or heteroaryl wherein each alkyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with one or more —OR¹⁴, —NR¹⁴R¹⁵, —SR¹⁴, or halogen; or
R³and R⁴can combine with the carbon atoms to which they are attached to form a C₃-C₆cycloalkyl, a C₄-C₆cycloalkenyl, or 3- to 6-membered ring heterocycle; and/or
R⁷and R⁸can combine with the carbon atoms to which they are attached to form a C₃-C₆cycloalkyl, a C₄-C₆cycloalkenyl, or 3- to 6-membered ring heterocycle;
R¹⁴and R¹⁵are each independently, at each occurrence, —H, —C₁-C₆alkyl, —C₂-C₆alkenyl, or —C₂-C₆alkynyl;
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 includes compounds of the Formula I-B (e.g., 1-monoacylglycerides):
wherein:
each R^ais independently —H or —C₁-C₆alkyl;
each R^bis independently selected from —H, —C₁-C₆alkyl, or —OH;
R¹, R², R⁵, R⁶, R⁹, R¹⁰, R¹¹, R¹²and R¹³are each independently, at each occurrence, —H, —OR¹⁴, —NR¹⁴R¹⁵, —SR¹⁴, halogen, —C₁-C₆alkyl, —C₂-C₆alkenyl, —C₂-C₆alkynyl, —C₃-C₇cycloalkyl, 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 R⁸are each independently, at each occurrence, —H, —OR¹⁴, —NR¹⁴R¹⁵, —SR¹⁴, halogen, —C₁-C₆alkyl, —C₂-C₆alkenyl, —C₂-C₆alkynyl, —C₃-C₇cycloalkyl, aryl, or heteroaryl wherein each alkyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with one or more —OR¹⁴, —NR¹⁴R¹⁵, —SR¹⁴, or halogen; or
R³and R⁴can combine with the carbon atoms to which they are attached to form a C₃-C₆cycloalkyl, a C₄-C₆cycloalkenyl, or 3- to 6-membered ring heterocycle; and/or
R⁷and R⁸can combine with the carbon atoms to which they are attached to form a C₃-C₆cycloalkyl, a C₄-C₆cycloalkenyl, or 3- to 6-membered ring heterocycle;
R¹⁴and R¹⁵are each independently, at each occurrence, —H, —C₁-C₆alkyl, —C₂-C₆alkenyl, or —C₂-C₆alkynyl;
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.
Any of the coating agents described herein can additionally or alternatively include fatty acid salts such as sodium salts (e.g., SA-Na, PA-Na, or MA-Na), potassium salts (e.g., SA-K, PA-K, MA-K), calcium salts (e.g., (SA)₂-Ca, (PA)₂-Ca, or (MA)₂-Ca) or magnesium salts (e.g., (SA)₂-Mg, (PA)₂-Mg, or (MA)₂-Mg), where. Accordingly, the coating agents herein can include one or more compounds of Formula II or Formula III, wherein Formula II and Formula III are:
wherein for each formula:
X is a cationic moiety;
X^p+ is a cationic counter ion having a charge state p, and p is 1, 2, or 3;
R¹, R², R⁵, R⁶, R⁹, R¹⁰, R¹¹, R¹²and R¹³are each independently, at each occurrence, —H, —(C═O)R¹⁴, —(C═O)H, —(C═O)OH, —(C═O)OR¹⁴, —(C═O)—O—(C═O)R¹⁴, —O(C═O)R¹⁴, —OR¹⁴, —NR¹⁴R¹⁵, —SR¹⁴, halogen, —C₁-C₆alkyl, —C₂-C₆alkenyl, —C₂-C₆alkynyl, —C₃-C₇cycloalkyl, 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 R⁸are each independently, at each occurrence, —H, —OR¹⁴, —NR¹⁴R¹⁵, —SR¹⁴, halogen, —C₁-C₆alkyl, —C₂-C₆alkenyl, —C₂-C₆alkynyl, —C₃-C₇cycloalkyl, aryl, or heteroaryl wherein each alkyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with one or more —OR¹⁴, —NR¹⁴R¹⁵, —SR¹⁴, or halogen; or
R³and R⁴can combine with the carbon atoms to which they are attached to form a C₃-C₆cycloalkyl, a C₄-C₆cycloalkenyl, or 3- to 6-membered ring heterocycle; and/or
R⁷and R⁸can combine with the carbon atoms to which they are attached to form a C₃-C₆cycloalkyl, a C₄-C₆cycloalkenyl, or 3- to 6-membered ring heterocycle;
R¹⁴and R¹⁵are each independently, at each occurrence, —H, aryl, heteroaryl, —C₁-C₆alkyl, —C₂-C₆alkenyl, or —C₂-C₆alkynyl;
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-glyceryl ester compounds:
In some embodiments, the coating agent includes one or more of the following 1-glyceryl ester compounds:
The coating agents herein can include one or more of the following fatty acid salts (e.g., compounds of Formula II or Formula III), where X is a cationic counter ion and n represents the charge state (i.e., the number of proton-equivalent charges) of the cationic counter ion:
In some embodiments, n is 1, 2, or 3. In some embodiments, X is sodium, potassium, calcium, or magnesium.
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 2 below.

TABLE 2

Exemplary Coating Agent Compositions

Com-
pound of
Formula
I-A	Additive	Note

SA-2G	SA-1G	Additive is a saturated compound of Formula I-B
		(1-monoacylglyceride) with the same length
		carbon chain as the compound of Formula I-A
PA-2G	PA-1G	Additive is a saturated compound of Formula I-B
		(1-monoacylglyceride) with the same length
		carbon chain as the compound of Formula I-A
PA-2G	MA-1G	Additive is a saturated compound of Formula I-B
		(1-monoacylglyceride) with a shorter length
		carbon chain than the compound of Formula I-A
PA-2G	OA-1G	Additive is an unsaturated compound of Formula
		I-B (1-monoacylglyceride) with a longer length
		carbon chain than the compound of Formula I-A
PA-2G	SA-1G	Additive is a saturated compound of Formula I-B
		(1-monoacylglyceride) with a longer length carbon
		chain than the compound of Formula I-A
PA-2G	PA	Additive is a saturated fatty acid with the same
		length carbon chain as the compound of Formula
		I-A
PA-2G	OA	Additive is an unsaturated fatty acid with a longer
		length carbon chain than the compound of
		Formula I-A
PA-2G	SA	Additive is a saturated fatty acid with a longer
		length carbon chain than the compound of
		Formula I-A
PA-2G	MA	Additive is a saturated fatty acid with a shorter
		length carbon chain than the compound of
		Formula I-A
PA-2G	OA-2G	Additive is an unsaturated compound of Formula
		I-A (2-monoacylglyceride) with a longer carbon
		chain than PA-2G (Formula I-A)
PA-2G	EtPA	Additive is an ethyl ester.

In some embodiments, the coating agent is formed from one of the combinations of compounds listed in Table 3 below.

TABLE 3

Exemplary Coating Agent Compositions

		(Optional)
Component 1	Component 2	Component 3

SA-1G	MA (Fatty acid,
(Formula I-B)	shorter length carbon
	chain than compound
	of Formula I-B)
SA-1G	PA (Fatty acid, shorter
(Formula I-B)	length carbon
	chain than compound
	of Formula I-B)
SA-1G	SA (Fatty acid,
(Formula I-B)	same length carbon
	chain as compound
	of Formula I-B)
PA-1G	MA (Fatty acid,
(Formula I-B)	shorter length carbon
	chain than compound
	of Formula I-B)
PA-1G	PA (Fatty acid,
(Formula I-B)	same length carbon
	chain as compound
	of Formula I-B)
PA-1G	SA (Fatty acid,
(Formula I-B)	longer length carbon
	chain than compound
	of Formula I-B)
MA-1G	MA (Fatty acid,
(Formula I-B)	same length carbon
	chain as compound
	of Formula I-B)
MA-1G	PA (Fatty acid,
(Formula I-B)	longer length carbon
	chain than compound
	of Formula I-B)
MA-1G	SA (Fatty acid, longer
(Formula I-B)	length carbon
	chain than compound
	of Formula I-B)
SA-1G (First	PA-1G (Second
compound	compound of Formula
of Formula I-B)	I-B, shorter carbon
	chain than First
	compound of
	Formula I-B)
SA-1G (First	MA-1G (Second
compound	compound of
of Formula I-B)	Formula I-B, shorter
	carbon chain
	than First compound
	of Formula I-B)
MA-1G (First	PA-1G (Second
compound	compound of Formula
of Formula I-B)	I-B, longer carbon
	chain than First
	compound of Formula I-B)
SA-1G	PA (Fatty acid, shorter	OA (Fatty acid, same
(Formula I-B)	length carbon	length carbon chain as
	chain than compound	compound of
	of Formula I-B)	Formula I-B)

As seen in Table 3 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 a fatty acid, a fatty acid salt, 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 304 and 306 of process 300 (FIG. 3), after adding the coating agent to the solvent to form a solution or suspension, the solution/suspension is applied over the surface of a piece of produce or other agricultural product in order to form a protective coating over the surface, the protective coating being formed from constituents of the coating agent. As previously described, the solution/suspension can, for example, be applied to the surface by dipping the produce or agricultural product in the solution/suspension, or by spraying the solution/suspension over the surface. The solvent is then removed from the surface of the produce or agricultural product, for example by allowing the solvent to evaporate or at least partially evaporate. In some embodiments, the act of at least partially removing of the solvent from the surface of the produce can comprise removing at least 90% of the solvent from the surface of the produce. As the solvent is removed (e.g., evaporated), the coating agent re-solidifies on the surface of the produce or agricultural product to form the protective coating over the surface. In some cases, the monomers, oligomers, polymers (e.g., low molecular weight polymers), or combinations thereof of the coating agent cross-link as the coating is formed while the solvent is removed from the surface. The resulting protective coating can then serve as a barrier to water loss from the agricultural product, as a barrier to oxidation of the agricultural product, and/or can reduce the respiration rate of the agricultural product, and can thereby protect the produce or agricultural product from biotic and/or abiotic stressors.
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/suspension 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. The protective coatings can have a thickness of less than 5 microns, less than 4 microns, less than 3 microns, less than 2 microns, less than 1 micron, less than 0.5 microns, or less than 0.3 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 perishable items is one of the types of produce listed in Table 1. 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 (e.g., lower than 90% relative humidity) as compared to higher relative humidity, as the driving force for water evaporation is increased at the lower relative humidity. 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. For example, the protective coatings can reduce the mass loss rate of the produce or other agricultural products (as compared to similar uncoated products) by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 100%, at least 125%, at least 150%, or at least 200%. Alternatively or in addition, the protective coatings can be formulated to reduce the respiration rate (i.e., the rate at which CO₂is produced per unit mass of the items) of the produce or agricultural products. For example, the protective coatings can reduce the respiration rate of the produce or other agricultural products (as compared to similar uncoated products) by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 100%, at least 125%, at least 150%, or at least 200%.
Referring now to step 308 of process 300 (in FIG. 3), after forming the coating over the produce or other perishable items, the coated produce/items are stored in the container 200 of FIG. 2, often for extended periods of time. The perishable items can occupy at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, or at least 70% of the internal volume of the container 200. As used herein, the percent of the internal volume of a container that one or more items occupy refers to the cumulative volume of all the items in the container divided by the total internal volume of the container (expressed as a percentage). As such, for a container that stores the maximum amount of items that can fit in the container's internal volume, the items will typically occupy substantially less than 100% of the internal volume of the container due to the space between each of the items.
Optionally, during storage, the perishable items are also cooled, for example via convection through the plurality of openings 214 in the container 200 (step 310). In some embodiments, while the perishable items are being cooled or after the perishable items have been cooled, the relative humidity in the container is less than 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, or 40%. In some embodiments, the container is configured such that during a time that the perishable items are stored in the container 200 continuously for at least 12 hours, the relative humidity in the container remains at less than 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, or 40%.
While the perishable items that are stored in container 200 can be coated prior to placing them in the container 200, in some embodiments the coatings are formed after the perishable items are placed in the container 200. For example, FIG. 4 illustrates a process 400 for storing perishable items in container 200 in which coatings are formed over the items while they are in the container 200. First, uncoated perishable items are received or placed in the container 200 of FIG. 2 (step 402). Next, a protective coating is formed on each of the perishable items by disposing a coating solution/suspension (e.g., a coating agent in a solvent) on the items, for example by spraying the items with a spray or mist of the solution/suspension, and allowing a coating formed from the coating agent to be formed over the perishable items (step 404). In some embodiments, the coating solution/suspension is injected (e.g., as a mist or spray) through one or more of the openings 214 or through opening 212 in the container 200. The items are then stored in the container 200, often for extended periods of time (step 406). Optionally, during storage, the perishable items are also cooled, for example via convection through the plurality of openings 214 in the container 200 (step 408). In some embodiments, for the entire duration of time that the perishable items are being cooled, the relative humidity in the container remains at less than 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, or 40%. In some embodiments, the container is configured such that during a time that the perishable items are stored in the container 200 continuously for at least 12 hours, the relative humidity in the container remains at less than 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, or 40%.
Various implementations of the containers and methods of storage 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.

Claims

1.-48. (canceled)

49. A container configured for storage of perishable items, comprising:

an enclosure comprising a rigid or semi-rigid structure and a lid, the rigid or semi-rigid structure comprising a first opening therein, and the enclosure comprising a plurality of second openings, wherein the rigid or semi-rigid structure and the first opening collectively have a first area, and the plurality of second openings collectively have a second area; wherein

the first opening is sufficiently large to allow any of the perishable items which the container is configured to store to be able to pass through;

the lid covers the first opening when the container is in a closed state;

the enclosure and the plurality of second openings completely surround a region in which the perishable items are stored;

each of the second openings is sufficiently small to prevent any of the perishable items which the container is configured to store from being able to pass through; and

a ratio of the second area to the first area is greater than 0.002.

50. The container of claim 49, wherein the perishable items which the container is configured to store comprise harvested produce.

51. The container of claim 49, wherein the openings are substantially rectangular, circular, or oval.

52. A container having a plurality of perishable items stored therein, the container comprising:

an enclosure having a first area, the enclosure comprising a material structure having a plurality of openings therein, wherein the plurality of openings collectively have a second area; wherein

each of the perishable items is covered with a protective coating that reduces a mass loss rate or a respiration rate of the perishable item;

the enclosure completely surrounds a first region in which the perishable items are stored;

each of the openings is sufficiently small to prevent any of the perishable items from being able to pass through; and

a ratio of the second area to the first area is greater than 0.002 and less than 0.9.

53. The container of claim 52, wherein the perishable items comprise one or more types of harvested produce.

54. The container of claim 53, wherein the harvested produce is cut or sliced.

55. The container of claim 54, wherein the protective coating is not naturally occurring on any of the perishable items.

56. The container of claim 55, wherein the protective coating is substantially odorless or tasteless.

57. The container of claim 52, wherein the protective coating is formed from a coating agent comprising at least one of fatty acids, esters, and salts.

58. The container of claim 57, wherein the coating agent comprises monoacylglycerides.

59. The container of claim 58, wherein the protective coating has a thickness less than about 5 microns.

60. The container of claim 52, wherein the perishable items comprise produce, and the protective coating is formed over a cuticular layer of the produce.

61. The container of claim 52, wherein the perishable items occupy at least 25% of the volume of the first region.

62. The container of claim 52, wherein the container is configured such that during a time that the perishable items are in the first region continuously for at least 12 hours, a relative humidity in the first region is less than 80%.

63. A method of storing a plurality of perishable items, comprising:

providing the perishable items in a container, wherein the container comprises an enclosure having a first area, the enclosure comprising a rigid or semi-rigid structure and having a plurality of openings therein, wherein the plurality of openings collectively have a second area; and

storing the perishable items in the container; wherein

the enclosure and the plurality of openings completely surround a first region in which the perishable items are stored;

a ratio of the second area to the first area is greater than 0.002.

64. The method of claim 63, wherein the perishable items comprise one or more types of harvested produce.

65. The method of claim 64, wherein the harvested produce is cut or sliced.

66. The method of claim 65, wherein while the perishable items are being cooled, a relative humidity in the first region is less than 80%.

67. The method of claim 65, wherein the protective coating is not naturally occurring on any of the perishable items.

68. The method of claim 63, wherein the perishable items occupy at least 25% of the volume of the first region.