Chance HOLLAND, et
al.
Cutin vs Spoilage
RELATED : KEENER: Cold Plasma Food Preservation **
SHUKLA:
Fenugreek Food Preservation
https://apeelsciences.com/
Apeel Sciences
Freshness
That Won't Go To Waste
Today, 40% of the food grown goes to waste. So we challenged
ourselves to work with nature to find a solution. The result? A
way to use plants to keep produce fresher, longer.
Apeel adds a layer of plant-derived protection to the surface of
fresh produce to slow water loss and oxidation — the factors
that cause spoilage. It sounds simple, but it took a lot of
figuring out.
https://www.usatoday.com/staff/ktyko/kelly-tyko/
USATODAY
Apeel
Sciences has developed longer-lasting avocados, and they're
coming to stores
by Kelly
Tyko
Tired of throwing away spoiled produce?
Apeel Sciences says it has gotten to the root of the problem and
developed a technology that can double or possibly triple the
shelf life of many types of produce, including avocados.
Apeel CEO James Rogers, who founded the Santa Barbara,
California-based company in 2012, said Apeel’s plant-derived
technology gives produce an extra “peel” that slows the rate of
water loss and oxidation, the primary causes of spoilage.
“We use food to preserve food,” Rogers said of the edible
coating that's applied to produce. "You can’t see it, you can’t
taste it, you can’t feel it, but by precisely controlling the
combination of plant materials that we use with these formulas,
we’re able to slow down the rate that a piece of fruit ages.”
US2019269145
Compositions
Formed from Plant Extracts and Methods of Preparation
Thereof
[ PDF ]
Embodiments described herein relate generally to plant extract
compositions and methods to isolate fatty acid esters derived
from crosslinked polyesters. Particular embodiments are directed
to methods of preparing compositions of fatty acid esters by
treating crosslinked polyesters or other crosslinked networks
with an acid and an alcohol.
BACKGROUND
[0003] Common agricultural products are susceptible to
degradation and decomposition (i.e., spoilage) when exposed to
the environment. Such agricultural products can include, for
example, eggs, fruits, vegetables, produce, seeds, nuts,
flowers, and/or whole plants (including their processed and
semi-processed forms). Non-agricultural products (e.g.,
vitamins, candy, etc.) are also vulnerable to degradation when
exposed to the ambient 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.
[0004] Conventional approaches to preventing degradation,
maintaining quality, and increasing the life of agricultural
products include refrigeration and/or special packaging.
Refrigeration requires capital-intensive equipment, demands
constant energy expenditure, can cause damage or quality loss to
the product if not carefully controlled, must be actively
managed, and its benefits are lost upon interruption of a
temperature-controlled supply chain. Special packaging can also
require expensive equipment, consume packaging material,
increase transportation costs, and require active management.
Despite the benefits that can be afforded by refrigeration and
special packaging, the handling and transportation of the
agricultural products can cause surface abrasion or bruising
that is aesthetically displeasing to the consumer and serves as
points of ingress for bacteria and fungi. Moreover, the expenses
associated with such approaches can add to the cost of the
agricultural product.
[0005] The cells that form the aerial surface of most plants
(such as higher plants) include an outer envelope or cuticle,
which provides varying degrees of protection against water loss,
oxidation, mechanical damage, photodegradation, and/or biotic
stressors, depending upon the plant species and the plant organ
(e.g., fruit, seeds, bark, flowers, leaves, stems, etc.). Cutin,
which is a biopolyester derived from cellular lipids, forms the
major structural component of the cuticle and serves to provide
protection to the plant against environmental stressors (both
abiotic and biotic). The thickness, density, as well as the
composition of the cutin (i.e., the different types of monomers
that form the cutin and their relative proportions) can vary by
plant species, by plant organ within the same or different plant
species, and by stage of plant maturity. The cutin-containing
portion of the plant can also contain additional compounds
(e.g., epicuticular waxes, phenolics, antioxidants, colored
compounds, proteins, polysaccharides, etc.). This variation in
the cutin composition as well as the thickness and density of
the cutin layer between plant species and/or plant organs and/or
a given plant at different stages of maturation can lead to
varying degrees of resistance between plant species or plant
organs to attack by environmental stressors (i.e., water loss,
oxidation, mechanical injury, and light) and/or biotic stressors
(e.g., fungi, bacteria, viruses, insects, etc.).
SUMMARY
[0006] Embodiments described herein relate generally to plant
extract compositions and methods to isolate cutin-derived
monomers, oligomers, and/or their esters, and mixtures thereof,
in particular for applications in agricultural coating
formulations. Particular embodiments are directed to methods of
preparing compositions of fatty acid esters by treating
crosslinked polyesters or other crosslinked networks with an
acid and an alcohol.
[0007] In a first aspect, a method of preparing a composition
comprising fatty acid esters includes providing a crosslinked
polyester comprising fatty acids, treating the crosslinked
polyester with an acid and an alcohol, and removing the acid and
the alcohol to isolate the resulting fatty acid esters.
[0008] In a second aspect, a method of preparing a composition
comprising esters includes providing a crosslinked network
including hydrolyzable or transesterifiable bonds, treating the
crosslinked network with an acid and an alcohol, and removing
the acid and the alcohol to isolate the resulting esters.
[0009] In a third aspect, a method of preparing a composition
comprising cutin-derived monomers, oligomers, esters, or
combinations thereof includes providing cutin obtained from
plant matter, and treating the cutin with a solvent, thereby
causing the cutin to decompose into the cutin-derived monomers,
oligomers, esters, or combinations thereof. The method further
includes removing the solvent to isolate the cutin-derived
monomers, oligomers, esters, or combinations thereof. The
resulting composition is characterized as being in the form of a
solid powder with little or no coloration.
[0010] In a fourth aspect, a method of forming a protective
coating on a substrate includes obtaining fatty acid esters,
wherein the obtaining of the fatty acid esters comprises
treating a crosslinked polyester comprising fatty acids with an
acid and an alcohol, and removing the acid and alcohol to
isolate the resulting fatty acid esters. The method further
includes causing the fatty acid esters to be applied to a
surface of the substrate to form the protective coating.
[0011] In a fifth aspect, a method of preparing a composition
comprising cutin-derived monomers, oligomers, esters, or
combinations thereof from cutin-containing plant matter includes
obtaining cutin from the cutin-containing plant matter and
adding the cutin to a solvent comprising an acid and an alcohol
to form a first mixture. The method further includes removing
the solvent to isolate the cutin-derived monomers, oligomers,
esters, or combinations thereof. The resulting cutin-derived
monomers, oligomers, esters, or combinations thereof can
comprise one or more compounds of Formula I:
Image available on "Original document"
wherein R<1>, R<2>, R<3>, R<4>,
R<5>, R<6>, R<7>, R<8>, R<9>,
R<10>, R<11>, R<12>, m, n, and o are as
described below.
[0012] Methods and formulations described herein can each
include one or more of the following steps or features, either
alone or in combination with one another. The crosslinked
polyester or crosslinked network can be naturally occurring. The
crosslinked polyester or crosslinked network can be derived from
plant matter. The crosslinked polyester or crosslinked network
can be cutin. The cutin can be derived from plant skins.
Treating the crosslinked polyester or crosslinked network with
the acid and the alcohol can include suspending or dissolving
the crosslinked polyester or crosslinked network and the acid in
the alcohol to form a solution. The acid can be a strong acid. A
concentration of the acid in the solution can be greater than
100 μmol/L. The solution can further comprise a non-reactive
secondary solvent.
[0013] The crosslinked polyester or crosslinked network can
contain endogenous water. Treating the crosslinked polyester
with the acid and the alcohol can further comprise heating the
crosslinked polyester, the acid, and the alcohol. Heating the
crosslinked polyester, the acid, and the alcohol can comprise
refluxing the polyester, the acid, and the alcohol at the
boiling point of the alcohol. The polyester, the acid, and the
alcohol can be heated in a sealed vessel above the boiling point
of the alcohol. The alcohol can comprise ethanol, methanol,
propanol, glycerol, isopropanol, or combinations thereof. The
alcohol can be a primary or secondary alcohol. Removing the acid
can comprise neutralizing the acid. Removing the alcohol can
comprise evaporating the alcohol.
[0014] The acid can be sulfuric acid, triflic acid, hydrochloric
acid, hydrobromic acid, hydroiodic acid, para-toluenesulfonic
acid, or a combination thereof. The acid can be catalytic. The
acid can be utilized in superstoichiometric amounts. A molar
ratio of the alcohol to the fatty acids can be greater than 1.
The fatty acids of the crosslinked polymer or crosslinked
network can comprise 16-hydroxy hexadecanoic acid,
9,16-dihydroxyhexadecanoic acid, 10,16-dihydroxyhexadecanoic
acid, 18-hydroxysteric acid, 18-hydroxy-(9Z)-octadec-9-enoic
acid, 9,10-epoxy-18-hydroxy octadecanoic acid,
9,10,18-trihydroxyoctadecanoic acid, or a combination thereof.
The resulting fatty acid esters can comprise ethyl
16-hydroxyhexadecanoate, ethyl 9,16-dihydroxyhexadecanoate,
ethyl 10,16-dihydroxyhexadecanoate, ethyl
18-hydroxyoctadecanoate, ethyl 18-hydroxy-(9Z)-octadec-9-enoate,
ethyl 9,10-epoxy-18-hydroxyoctadecanoate, ethyl
9,10,18-trihydroxyoctadecanoate, or a combination thereof.
[0015] The method can be characterized as only requiring a
single step to obtain the resulting fatty acid esters from the
crosslinked polyester or crosslinked network. The fatty acid
esters formed by any of the methods described herein can be
applied to the surface of a substrate to form a protective
coating. The substrate can be an edible substrate. The substrate
can be a piece of produce. The substrate can be plant matter.
BRIEF
DESCRIPTION OF THE FIGURES
[0016] FIG. 1 is a schematic flow diagram of a first exemplary
method for preparing a composition.
[0017] FIGS. 2A and 2B are schematic representations of
reactions associated with a step of the method of FIG. 1.
[0018] FIG. 3 is a schematic flow diagram of a second exemplary
method for preparing a composition.
[0019] FIG. 4 is a schematic representation of a reaction
associated with a step of the method of FIG. 3.
[0020] FIGS. 5 and 6 illustrate results obtained from preparing
a composition according to the method of FIG. 3.
[0021] FIGS. 7A, 7B, 7C, 7D, 7E, 7F, 7G, and 7H show the
chemical structure of 10,16-dihydroxyhexadecanoic acid,
10,18-dihydroxyoctadecanoic acid, 9,16-dihydroxyhexadecanoic
acid, 9,18-dihydroxyoctadecanoic acid,
9,10,16-trihydroxyhexadecanoic acid,
9,10,18-trihydroxyoctadecanoic acid,
9,10-epoxy-16-hydroxyhexadecanoic acid, and
9,10-epoxy-18-hydroxyoctadecanoic acid, respectively.
[0022] FIGS. 8A, 8B, 8C, 8D, 8E, 8F, 8G, and 8H show the
chemical structure of ethyl 10,16-dihydroxyhexadecanoate, ethyl
10,18-dihydroxyoctadecanoate, ethyl 9,16-dihydroxyhexadecanoate,
ethyl 9,18-dihydroxyoctadecanoate, ethyl
9,10,16-trihydroxyhexadecanoate, ethyl
9,10,18-trihydroxyoctadecanoate, ethyl
9,10-epoxy-16-hydroxyhexadecanoate, and ethyl
9,10-epoxy-18-hydroxyoctadecanoic, respectively.
[0023] FIGS. 9A, 9B, 9C, 9D, 9E, 9F, 9G, and 9H show the
chemical structure of methyl 10,16-dihydroxyhexadecanoate,
methyl 10,18-dihydroxyoctadecanoate, methyl
9,16-dihydroxyhexadecanoate, methyl 9,18-dihydroxyoctadecanoate,
methyl 9,10,16-trihydroxyhexadecanoate, methyl
9,10,18-trihydroxyoctadecanoate, methyl
9,10-epoxy-16-hydroxyhexadecanoate, and methyl
9,10-epoxy-18-hydroxyoctadecanoate, respectively.
[0024] FIGS. 10A, 10B, 10C, 10D, 10E, 10F, 10G, and 10H show the
chemical structure of 2,3-dihydroxypropyl
10,16-dihydroxyhexadecanoate, 2,3-dihydroxypropyl
10,18-dihydroxyoctadecanoate, 2,3-dihydroxypropyl
9,16-dihydroxyhexadecanoate, 2,3-dihydroxypropyl
9,18-dihydroxyhexadecanoate, 2,3-dihydroxypropyl
9,10,16-trihydroxyhexadecanoate, 2,3-dihydroxypropyl
9,10,18-trihydroxyoctadecanoate, 2,3-dihydroxypropyl
9,10-epoxy-16-hydroxyhexadecanoate, and 2,3-dihydroxypropyl
9,10-epoxy-18-hydroxyoctadecanoate, respectively.
[0025] FIGS. 11A, 11B, 11C, 11D, 11E, 11F, 11G, and 11H show the
chemical structure of 1,3-dihydroxypropan-2-yl
10,16-dihydroxyhexadecanoate, 1,3-dihydroxypropan-2-yl
10,18-dihydroxyoctadecanoate, 1,3-dihydroxypropan-2-yl
9,16-dihydroxyhexadecanoate, 1,3-dihydroxypropan-2-yl
9,18-dihydroxyhexadecanoate, 1,3-dihydroxypropan-2-yl
9,10,16-trihydroxyhexadecanoate, 1,3-dihydroxypropan-2-yl
9,10,18-trihydroxyoctadecanoate, 1,3-dihydroxypropan-2-yl
9,10-epoxy-16-hydroxyhexadecanoate, and 1,3-dihydroxypropan-2-yl
9,10-epoxy-18-hydroxyoctadecanoate, respectively.
[0026] FIGS. 12 and 13 illustrate characterization of a
composition prepared according to the method of FIG. 3.
[0027] FIG. 14 depicts various cutin-derived monomers which may
be obtained from the methods described herein and/or which may
be treated according to the methods described herein for the
purpose of coating and/or preserving fruits and vegetables.
[0028] FIG. 15 depicts an epoxide ring-opening reaction. The
products of epoxide ring-opening reactions may be treated
according to the methods described herein for the purpose of
coating and/or preserving fruits and vegetables.
[0029] Like reference symbols in the various drawings indicate
like elements.
DETAILED
DESCRIPTION
[0030] The biopolyester cutin forms the main structural
component of the cuticle that composes the aerial surface of
most land plants and plays a significant role in providing
plants a protective barrier against both abiotic and biotic
stressors. The thickness, density, as well as the composition of
the cutin (i.e., the different types of monomers that form the
cutin and their relative proportions) can vary by plant species,
by plant organ within the same or different plant species, and
by stage of plant maturity. These variations can define the
amount, degree, or quality of protection (and degree of
plasticity) offered by the cutin layer to the plant or plant
organ against environmental and/or biotic stressors. Cutin is
formed from a mixture of polymerized mono- and/or polyhydroxy
fatty acids and embedded cuticular waxes. Among the hydroxy
fatty acids, polyhydroxy fatty acids (e.g., dihydroxy fatty
acids or trihydroxy fatty acids), once esterified, can in some
cases form tightly bound networks with high crosslink density
and lower permeability as compared to monohydroxy fatty acids
and can thereby provide better protection against environmental
stressors.
[0031] Embodiments described herein relate generally to plant
extract compositions and to methods of preparing plant extract
compositions that include fatty acid esters (monomers and/or
their oligomers) derived from cutin or other crosslinked
polyesters. In particular, methods described herein allow for
generation of fatty acid esters directly by treating a
crosslinked polyester (e.g., cutin) which includes a mixture of
polymerized mono- and/or polyhydroxy fatty acids with an acid
and an alcohol. Compositions which include the resulting fatty
esters can, for example, be subsequently applied to other plant
or agricultural products in order to form a protective material
(e.g., a coating) over the products, or to enhance or modify
existing coatings (either naturally occurring or deposited
coatings) which are on the outer surface of the products. The
applied coatings can, for example, serve to protect the products
from biotic stressors such as bacteria, fungi, viruses, and/or
pests. The applied coatings can also (or alternatively) serve to
increase the shelf life of produce without refrigeration, and/or
to control the rate of ripening or respiration of produce.
[0032] Conventional methods for producing fatty acid esters
typically involve performing a first step (or series of steps)
to isolate fatty acids (e.g., fatty acid monomers and/or
oligomers) and then subsequently perform a second step (or
series of steps) to convert the fatty acids to esters, for
example via Fischer esterification. Methods described herein
provide for a process for generating fatty acid esters directly
from a polyester such as cutin, without the need to first
isolate the fatty acid monomers/oligomers. Accordingly, methods
of preparing a composition comprising fatty acid esters can
include (i) providing a crosslinked polyester (e.g., cutin)
comprising fatty acids, (ii) treating the polyester with an acid
and an alcohol, and (iii) removing the acid and alcohol to
isolate the resulting fatty acid esters. In particular
embodiments described herein, the crosslinked polyester is cutin
derived from plant matter.
[0033] As used herein, “plant matter” refers to any portion of a
plant, including, for example, fruits (in the botanical sense,
including fruit peels and juice sacs), leaves, stems, barks,
seeds, flowers, peels, or roots.
[0034] A first method 100 for treating (e.g., depolymerizing)
cutin to obtain a plant extract composition is illustrated in
FIG. 1. The method 100 includes first treating plant matter to
at least partially separate a cutin-containing portion from a
non-cutin-containing portion of the plant matter (step 102).
Treating the plant matter can include, for example, thermal
treating of the plant matter. The thermal treating can include,
for example, heating the plant matter (e.g., with steam, in
water or in another solvent), freezing the plant, subjecting the
plant matter to cyclic thermal treatments, or drying. The plant
matter can include any suitable plant matter or other
agricultural product such as, for example, fruits (including
fruit peels and juice sacs), leaves, stems, barks, seeds,
flowers, peels, or roots. In some embodiments, the plant matter
can include agricultural waste products such as, for example,
tomato peels, grape skins, apple peels, pepper peels, lemon
peels, lemon leaf, lime peels, lime leaf, orange peels, orange
leaf, orange fruit, clementine leaf, clementine fruit, mandarin
leaf, mandarin fruit, pea seeds, grapefruit peels, grapefruit
leaf, grapefruit seeds, papaya peels, cherry fruits, cranberry
skins, coffee cherries, grass clippings, or any other plants or
portions of plants that can yield any embodiment of the plant
extract compositions described herein. In some embodiments, the
plant matter can be a fruit (e.g., a tomato, cranberry, or
grape) and the cutin-containing portion can be a peel of the
fruit (e.g., a tomato peel or cranberry skin or grape skin) such
that the boiling can at least partially separate the peel from
the fruit. The fruit can be washed to remove surface residue,
waxes, or other debris before operation 102. Furthermore, the
fruit can be cut into halves, quarters, or small pieces or
ground to finer pieces and then boiled until the peels or skins
are visibly separated from the fruit pulp.
[0035] The method 100 can optionally include mechanically
processing the plant matter to at least partially separate the
cutin-containing portion from the non-cutin-containing portion
of the plant matter (step 104). The mechanical process can be
performed before and/or after thermal treatment of the plant
matter (i.e., 102) (e.g., boiling of the plant matter in water)
to facilitate separation of the cutin-containing portion from
the non-cutin-containing portion of the plant matter. Suitable
mechanical processes can include, for example, centrifugation,
(ultra)sonication, pressing, ball milling, grinding, etc. In
some embodiments, mechanical separation can include separating a
fruit peel from the fruit pulp. In some embodiments, mechanical
removal of the pulp might not be performed and the fruit skins
(e.g., waste fruit skins left over after processing of the
fruit) may be macerated, blended, cut, shredded, food processed,
or otherwise subjected to some other mechanical treatment
operation to physically break down the fruit skins into smaller
or finer pieces. In some embodiments, a plurality of
intermediate mechanical processes can be used to obtain the
plant extract composition. For example, a mechanical step can be
used to separate the cutin from the non-cutin-containing
portion, as described herein, or be used to augment any other
operation included in the method 100. Such mechanical processes
can include any of the mechanical processes described herein
such as, for example, centrifugation, sonication,
(ultra)sonication, milling, grinding, filtration, etc.
[0036] The cutin-containing portion is then optionally heated
(e.g., boiled) in a mixture of ammonium oxalate and oxalic acid
to separate the cutin from the non-cutin-containing portion
(step 106). Optionally this process can also be achieved (or
assisted) using enzymes capable of breaking down polysaccharides
or pectin. For example, the cutin can include the cuticular
layer of the plant matter. The heating in the ammonium oxalate
and oxalic acid mixture disrupts the pectinaceous glue that
attaches the cuticle to the underlying cells of the plant matter
and helps release the cuticle. Furthermore, this step disrupts
the pectinaceous glue that is found within primary cell walls
and between plant cells (e.g., in the middle lamella that binds
neighboring cells), aiding in the isolation of a
cutin-containing portion. In this manner, the ammonium oxalate
and oxalic acid solution can facilitate at least partial
chemical detachment of remaining debris from the
cutin-containing portion of the plant (e.g., removal of any
remaining pulp from the fruit peel). The heating can be
performed at any suitable temperature (e.g., 35 degrees Celsius,
50 degrees Celsius, 55 degrees Celsius, 60 degrees Celsius, 65
degrees Celsius, 70 degrees Celsius, 75 degrees Celsius, 80
degrees Celsius, 85 degrees Celsius, 90 degrees Celsius, 95
degrees Celsius, or 100 degrees Celsius, inclusive of all ranges
and values therebetween) and for any suitable time (this process
can be accelerated if carried out under elevated pressure). For
example, in some embodiments, the cutin-containing portion can
be heated in the mixture of ammonium oxalate and oxalic acid at
a temperature of about 75 degrees Celsius for about 24 hours. In
some embodiments, the portion of the plant, for example, the
fruit peel, after treatment with the ammonium oxalate and oxalic
acid solution, can be isolated by filtration and dried (e.g.,
air-dried under ambient conditions, oven-dried or freeze-dried)
to remove any residual water.
[0037] In some embodiments, the cutin can optionally be treated
with an enzyme (step 108). For example, the cutin can be treated
with an enzyme such as a carbohydrate-hydrolyzing enzyme to
digest or otherwise remove carbohydrates (e.g., cellulose or
pectin) attached to or embedded within the cutin. Such enzymes
can include, for example, naturally derived or synthetic
cellulases, pectinases, and hemicellulases. The enzymatic
degradation can be used before, after, or otherwise in place of
step 106 to obtain the cutin from the non-cutin-containing
portion. In some embodiments, the reverse process may be
employed, wherein the cutin is treated with an enzyme that can
at least partially depolymerize the cutin to yield any
combination of cutin-derived oligomers and cutin-derived
monomers and to leave behind the non-cutin-containing
components, which could be filtered out or otherwise separated.
Such enzymes can include, for example, cutinases, esterases, or
lipases.
[0038] Optionally, the cutin is refluxed or subjected to soxhlet
extraction in at least one suitable solvent (e.g., chloroform
and/or methanol) to remove soluble waxes or polar impurities
from the cutin (step 110). For example, the cutin can be
refluxed or subjected to soxhlet extraction only in chloroform,
refluxed or soxhlet extracted in chloroform followed by
refluxing or soxhlet extraction in methanol, refluxed or
subjected to soxhlet extraction only in methanol, or refluxed or
subjected to soxhlet extraction in a mixture of chloroform and
methanol, or any other suitable solvent(s) (or combinations
thereof) in which the wax and/or polar components are soluble.
In some embodiments, the cutin can be refluxed in a dilute
solution of a strong base (e.g., potassium hydroxide in water or
in alcoholic solvent), or a solution of a moderately strong or
weak base (e.g., potassium carbonate in water or in alcoholic
solvent) to remove soluble pigmented impurities. Alternatively,
removal of residual waxes and remaining soluble components can
be achieved using supercritical CO2 or supercritical H2O. The
refluxing can be performed at any suitable temperature and for
any suitable length of time. For example, in some embodiments,
the cutin can be refluxed in chloroform at about 60-65 degrees
Celsius for about 24-36 hours to remove any wax and/or non-polar
compounds embedded in the cutin. This can be followed by
refluxing in methanol at 65-70 degrees Celsius for about 4-12
hours, for example, to remove any polar organic components
(e.g., flavonoids and flavonoid glycosides) present in the
cutin. The completion of the operation can be determined by the
clarity of solvents. For example, the process can be monitored
with instrumentation (e.g., NMR, GC-MS, React-IR, FTIR,
spectrophotometry, etc.) configured to analyze the clarity of
the solvents and can continue until a predetermined clarity is
achieved. Each of the chloroform and/or methanol extraction
processes can be performed in any apparatus capable of refluxing
(i.e., recirculating and/or recycling) the solvents such as, for
example, a reaction flask equipped with a condenser, a Soxhlet
apparatus, a Kumagawa extractor, an ultrasound assisted
extractor, a robot automated extractor, or any other suitable
extraction apparatus. Such an apparatus can, for example, reduce
the amount of solvent used in the extraction process. Any other
solvent or combinations thereof (i.e., a binary or ternary
mixture) can be used to wash out undesired impurities. Suitable
solvents can include, for example, diethyl ether,
dichloromethane, hexane, petroleum ether, ethyl acetate,
acetone, isopropanol, ethanol, acetonitrile, supercritical
carbon dioxide, supercritical water, water, and mixtures
thereof. In some embodiments, multiple extraction steps in one
or more solvents can also be performed. In some embodiments,
intermediate enzymatic treatment steps can also be performed
between the solvent extraction processes, for example, to
liberate undesired compounds from the cutin. The solution
obtained after operation 110 can include a relatively pure
sample of the cutin included in the portion of the plant along
with any residually attached or embedded polysaccharides (e.g.,
cellulose), plant metabolites (e.g., flavonoids), and/or
proteins.
[0039] The cutin is then heated in a base solution (e.g., metal
alkoxide or metal hydroxide dissolved in a solvent such as
ethanol or methanol or water or combinations thereof) to at
least partially depolymerize the cutin and obtain a plant
extract including a plurality of cutin-derived monomers,
oligomers, or combinations thereof (step 112). The pH of the
solution can, for example, be in a range of about 10 to 14, for
example in a range of 12 to 14. The metal alkoxide can include,
for example, sodium methoxide, sodium ethoxide, sodium
iso-propoxide, sodium n-propoxide, sodium iso-butoxide, sodium
n-butoxide, potassium methoxide, potassium ethoxide, potassium
iso-propoxide, potassium n-propoxide, potassium iso-butoxide, or
potassium n-butoxide. The metal hydroxide can include, for
example, Group I or Group II metal hydroxides, such as lithium,
sodium, potassium, calcium, rubidium, or cesium hydroxide. Also
included are precursors or compounds that will generate alkoxide
or hydroxide in a suitable reaction medium (such as neat metals
(e.g., sodium metal) or oxides in methanol, or ammonia in
water). Refluxing of the cutin in the presence of the metal
alkoxide or metal hydroxide can be performed at any suitable
temperature and for any suitable length of time such as, for
example, at about 65 degrees Celsius for about 24 hours. In some
embodiments, the temperature and/or the refluxing time can be
such that the cutin is only partially depolymerized to yield a
predetermined combination of oligomers and monomers. In some
embodiments, the temperature and/or the refluxing time can be
adjusted such that the cutin is mostly depolymerized by the
metal alkoxide or metal hydroxide into a plurality of
cutin-derived monomers and/or oligomers. In some embodiments,
the refluxing in the metal alkoxide or metal hydroxide can be
performed in a mixture of the metal alkoxide or metal hydroxide
and a solvent, for example, methanol, ethanol, hexane, toluene,
etc. In some embodiments, the solvent can include methanol. The
concentration of metal alkoxide, solvent, and/or the pH of the
solution can, for example, facilitate the preservation of the
depolymerized cutin components in monomeric form, which can
prevent oligomerization or repolymerization of the liberated
cutin monomers included in the plant extract. Although an acid
catalyst for the reaction (utilizing methods further described
below) could be used in place of the base catalyst, base
catalysts are commonly used for transesterification of oils, as
in many cases the reaction rate can be higher than that for an
acid catalyst.
[0040] In efforts to obtain fatty acid ester products (or
oligomers thereof) from the depolymerization step 112 of method
100, the refluxing of the cutin in the presence of the metal
alkoxide was carried out by the inventors of the present
disclosure in anhydrous reagents and anhydrous solvents (e.g.,
ethanol) in a closed, nitrogenous atmosphere. Specifically,
cutin obtained from tomato pomace was refluxed in a solution
comprising sodium ethoxide (prepared by dissolving sodium in
ethanol) according to the process described in Example 2 below
in order to favor ester formation over saponification and acid
formation. The expected reaction is schematically represented in
FIG. 2A for the case of an anhydrous solution comprising sodium
ethoxide dissolved in ethanol. Referring to FIG. 2A, cutin 202
is represented by a crosslinked network of polyhydroxy fatty
acids, where R and R′ represent adjacent fatty acid units.
Depolymerization of the cutin 202 by the sodium ethoxide present
in the EtOH in the absence of water is expected to form isolated
ethyl esters 204, as shown in FIG. 2A.
[0041] FIG. 2B is a schematic representation of the
depolymerization reaction for the case where water is present in
the solution. In this case, the reaction produces both ethyl
esters 204 and carboxylic acid 206. As further shown in FIG. 2B,
the base in the solution causes the carboxylic acid 206 to be
converted to carboxylate 208. If enough water is present in the
solution, substantially all of the depolymerized product is
driven to the carboxylic acid 206 and then converted to the
carboxylate 208 by the base in the solution, such that no
measurable concentration of ethyl esters 204 is present in the
resulting composition.
[0042] Without wishing to be bound by theory, the inventors of
the current disclosure observed that despite extensive drying
and/or other efforts to ensure that no water was present in the
reaction during cutin depolymerization according to Example 2,
the apparently dry cutin appeared to contain sufficient
endogenous water to result in all of the depolymerized product
being shunted to the carboxylate 208. Consequently, no
substantial concentration of esters 204 could be detected in the
resulting extract composition.
[0043] A second method 300 for depolymerizing cutin to obtain a
plant extract composition is illustrated in FIG. 3. Steps 302,
304, 306, 308, and 310, in which cutin is obtained from plant
matter, are the same as steps 102, 104, 106, 108, and 110,
respectively, of method 100 in FIG. 1. However, in step 312 of
method 300, the cutin is refluxed in an acid and an alcohol
(rather than a base and an alcohol as in step 112 of method 100)
in order to obtain a plant extract composition including
cutin-derived monomers and/or oligomers.
[0044] The specific reaction associated with the second method
300, and specifically with step 312, is schematically
represented in FIG. 4 for the case of a solution comprising an
acid dissolved in ethanol. The reaction in FIG. 4 assumes the
presence of water in the solution (e.g., endogenous water
contained within the cutin). Similar to FIG. 2, in FIG. 4 cutin
202 is represented by a crosslinked network of polyhydroxy fatty
acids, where R and R′ represent adjacent fatty acid units.
Depolymerization of the cutin 202 in the acidified solution in
the presence of water is expected to form ethyl esters 204 and
carboxylic acid 206 in a state of equilibrium with one another,
thus producing a plant extract composition including fatty acid
esters (e.g., ethyl esters 204). In step 312 of method 300, due
to the absence of a base catalyst, the carboxylic acid 206 is
not converted to a carboxylate, as in method 100 and
corresponding FIG. 2B. Consequently, the reaction is expected to
produce a composition comprising a mix of ethyl esters 204 and
carboxylic acid 206, where the product distribution
approximately reflects the ratio of esterification partner to
water.
[0045] In efforts to obtain a composition including fatty acid
esters (or oligomers thereof) by way of method 300 (and in
particular by utilizing step 312 of method 300), the inventors
of the subject matter in the current application refluxed cutin
obtained from tomato pomace in a solution comprising sulfuric
acid dissolved in ethanol according to the process described in
Example 3 below. Results are illustrated in FIGS. 5 and 6. As
shown in Example 3 and FIGS. 5 and 6, the process resulted in
the production and isolation of ethyl
10,16-dihydroxyhexdecanoate (herein “EtDHPA”).
[0046] It was found through extensive experimentation that a
larger amount of acid than predicted from catalytic calculations
was needed to ensure high yields of products. For instance,
under refluxing conditions, an increase in both crude isolate
and purified isolate was seen when increasing the equivalence of
sulfuric acid used from 0.1 to 0.25 to 0.5 to 1 to 2
equivalents, from negligible material to 8.1% isolated yield,
over the course of 48 hours. Furthermore, the reaction could
additionally be accelerated by sealing the system to generate
pressure, such that the reaction could be conducted above the
atmospheric boiling point of the solvent (see Example 4). A
further increase in crude isolate and purified isolate yields
was seen when the temperature was increased from reflux (78° C.)
to 100° C. to 120° C., with one equivalent of acid, up to 14%
isolated yield. However, without wishing to be bound by theory,
there appears to be an upper limit, after which the isolated
yield appears to decrease, as seen in FIGS. 5 and 6 (120° C., 2
eq. H2SO4, 48 hrs).
[0047] While EtDHPA 204 (in FIG. 4) can be produced by method
300 of FIG. 3 with ethanol utilized as the alcohol and with a
cutin source (or other crosslinked polymer) that includes
10,16-dihydroxyhexadecanoic acid (or esters thereof) as a
building block of the crosslinked network, other types of ethyl
esters can be produced by method 300 using cutin from plant
sources (or other crosslinked polymers/networks) that are formed
of different molecular building blocks. For example, cutin from
tomatoes tends to have a high proportion of C16 fatty acids
(e.g., fatty acids having a carbon chain length of 16) such as
that of FIGS. 7A, 7C, 7E, and 7G, where FIG. 7A shows the
chemical composition of 10,16-dihydroxyhexadecanoic acid (700 in
FIG. 7A), FIG. 7C shows the chemical composition of
9,16-dihydroxyhexadecanoic acid (704 in FIG. 7C), FIG. 7E shows
the chemical composition of 9,10,16-trihydroxyhexadecanoic acid
(708 in FIG. 7E), and FIG. 7G shows the chemical composition of
9,10-epoxy-16-hydroxyhexadecanoic acid (712 in FIG. 7G).
Accordingly, ethyl esters that can be produced by method 300
using cutin from tomatoes can include ethyl
10,16-dihydroxyhexadecanoate (800 in FIG. 8A), ethyl
9,16-dihydroxyhexadecanoate (804 in FIG. 8C), ethyl
9,10,16-trihydroxyhexadecanoate (808 in FIG. 8E), and/or ethyl
9,10-epoxy-16-hydroxyhexadecanoate (812 in FIG. 8G).
[0048] On the other hand, cutin from cranberries tends to have a
high proportion of Cis fatty acids (e.g., fatty acids having a
carbon chain length of 18) such as that of FIGS. 7B, 7D, 7F, and
7H, where FIG. 7B shows the chemical composition of
10,18-dihydroxyoctadecanoic acid (702 in FIG. 7B), FIG. 7D shows
the chemical composition of 9,18-dihydroxyoctadecanoic acid (706
in FIG. 7D), FIG. 7F shows the chemical composition of
9,10,18-trihydroxyoctadecanoic acid (710 in FIG. 7F), and FIG.
7H shows the chemical composition of
9,10-epoxy-18-hydroxyoctadecanoic acid (714 in FIG. 7H).
Accordingly, ethyl esters that can be produced by method 300
using cutin from cranberries can include ethyl
10,18-dihydroxyoctadecanoate (802 in FIG. 8B), ethyl
9,18-dihydroxyhexadecanoate (806 in FIG. 8D), ethyl
9,10,18-trihydroxyoctadecanoate (810 in FIG. 8F), and/or ethyl
9,10-epoxy-18-hydroxyoctadecanoate (814 in FIG. 8H).
[0049] Furthermore, alcohols other than (or in addition to)
ethanol can be used in the method 300 of FIG. 3, which can
result in other types of esters being produced. For example,
using methanol as the alcohol can result in the production of
methyl esters such as methyl 10,16-dihydroxyhexadecanoate (900
in FIG. 9A), methyl 10,18-dihydroxyoctadecanoate (902 in FIG.
9B), methyl 9,16-dihydroxyhexadecanoate (904 in FIG. 9C), methyl
9,18-dihydroxyhexadecanoate (906 in FIG. 9D), methyl
9,10,16-trihydroxyhexadecanoate (908 in FIG. 9E), methyl
9,10,18-trihydroxyoctadecanoate (910 in FIG. 9F), methyl
9,10-epoxy-16-hydroxyhexadecanoate (912 in FIG. 9G), and/or
methyl 9,10-epoxy-18-hydroxyoctadecanoate (914 in FIG. 9H). Or,
using glycerol as the alcohol can result in the production of
glyceryl esters (e.g., 1-glyceryl or 2-glyceryl esters). For
example, 1-glyceryl esters that can be produced include
2,3-dihydroxypropyl 10,16-dihydroxyhexadecanoate (1000 in FIG.
10A), 2,3-dihydroxypropyl 10,18-dihydroxyoctadecanoate (1002 in
FIG. 10B), 2,3-dihydroxypropyl 9,16-dihydroxyhexadecanoate (1004
in FIG. 10C), 2,3-dihydroxypropyl 9,18-dihydroxyhexadecanoate
(1006 in FIG. 10D), 2,3-dihydroxypropyl
9,10,16-trihydroxyhexadecanoate (1008 in FIG. 10E),
2,3-dihydroxypropyl 9,10,18-trihydroxyoctadecanoate (1010 in
FIG. 10F), 2,3-dihydroxypropyl
9,10-epoxy-16-hydroxyhexadecanoate (1012 in FIG. 10G), and/or
2,3-dihydroxypropyl 9,10-epoxy-18-hydroxyoctadecanoate (1014 in
FIG. 10H). 2-glyceryl esters that can be produced include
1,3-dihydroxypropan-2-yl 10,16-dihydroxyhexadecanoate (1100 in
FIG. 11A), 1,3-dihydroxypropan-2-yl 10,18-dihydroxyoctadecanoate
(1102 in FIG. 11B), 1,3-dihydroxypropan-2-yl
9,16-dihydroxyhexadecanoate (1104 in FIG. 11C),
1,3-dihydroxypropan-2-yl 9,18-dihydroxyhexadecanoate (1106 in
FIG. 11D), 1,3-dihydroxypropan-2-yl
9,10,16-trihydroxyhexadecanoate (1108 in FIG. 11E),
1,3-dihydroxypropan-2-yl 9,10,18-trihydroxyoctadecanoate (1110
in FIG. 11F), 1,3-dihydroxypropan-2-yl
9,10-epoxy-16-hydroxyhexadecanoate (1112 in FIG. 11G), and/or
1,3-dihydroxypropan-2-yl 9,10-epoxy-18-hydroxyoctadecanoate
(1114 in FIG. 11H).
[0050] In general, the method 300 in FIG. 3 can produce one or
more compounds of Formula I:
Image available on "Original document"
wherein:
[0051] R<1>, R<2>, R<3>, R<4>,
R<5>, R<6>, R<7>, R<8>, R<9>, and
R<10 >are each independently —H, —OR<13>,
—NR<13>R<14>, —SR<13>, halogen, —C1-C6 alkyl,
—C1-C6 alkenyl, —C1-C6 alkynyl, —C3-C7 cycloalkyl, aryl, or 5-
to 10-membered ring heteroaryl, wherein each alkyl, alkenyl,
alkynyl, cycloalkyl, aryl, or heteroaryl is optionally
substituted with —OR<13>, —NR<13>R<14>,
—SR<13>, or halogen;
[0052] R<13 >and R<14 >are each independently —H,
—C1-C6 alkyl, —C1-C6 alkenyl, or —C1-C6 alkynyl;
[0053] R<11 >is —H, -glyceryl, —C1-C6 alkyl, —C1-C6
alkenyl, —C1-C6 alkynyl, —C3-C7 cycloalkyl, aryl, or 5- to
10-membered ring heteroaryl, wherein each alkyl, alkenyl,
alkynyl, cycloalkyl, aryl, or heteroaryl is optionally
substituted with —OR<13>, —NR<13>R<14>,
—SR<13>, or halogen;
[0054] R<12 >is —OH, —H, —C1-C6 alkyl, —C1-C6 alkenyl,
—C1-C6 alkynyl, —C3-C7 cycloalkyl, aryl, or 5- to 10-membered
ring heteroaryl, wherein each alkyl, alkenyl, alkynyl,
cycloalkyl, aryl, or heteroaryl is optionally substituted with
—OR<13>, —NR<13>R<14>, —SR<13>, halogen,
—COOH, or —COOR<1>; and
[0055] m, n, and o are each independently an integer in the
range of 0 to 30, and 0≤m+n+o≤30.
[0056] In some implementations, R<1>, R<2>,
R<3>, R<4>, R<5>, R<6>, R<8>,
R<9>, R<10>, and R<12 >in Formula I are each
H. Additionally, the method 300 in FIG. 3 can produce one or
more compounds of Formula II:
Image available on "Original document"
[0057] wherein:
[0058] R<1>, R<2>, R<5>, R<6>,
R<9>, R<10>, R<11>, R<12 >and R<13
>are each independently, at each occurrence, —H,
—OR<14>, —NR<14>R<15>, —SR<14>, 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 —OR<14>, —NR<14>R<15>,
—SR<14>, or halogen;
[0059] R<3>, R<4>, R<7>, and R<8 >are
each independently, at each occurrence, —H, —OR<14>,
—NR<14>R<15>, —SR<14>, 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
—OR<14>, —NR<14>R<15>, —SR<14>, or
halogen; or
[0060] R<3 >and R<4 >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
[0061] R<7 >and R<8 >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;
[0062] R<14 >and R<15 >are each independently, at
each occurrence, —H, —C1-C6 alkyl, —C2-C6 alkenyl, or —C2-C6
alkynyl;
[0063] the symbol
[0068] R is selected from —H, —C1-C6 alkyl, —C2-C6 alkenyl,
—C2-C6 alkynyl, —C3-C7 cycloalkyl, aryl, 1-glyceryl, 2-glyceryl,
or heteroaryl.
[0069] In some implementations, R is selected from —H, —CH3, or
—CH2CH3. The method 300 described herein can be used to produce
one or more of the following methyl ester compounds:
[0070] The method 300 described herein can also be used to
produce one or more of the following ethyl ester compounds:
[0071] The method 300 described herein can also be used to
produce one or more of the following 2-glyceryl ester compounds:
[0072] The method 300 described herein can also be used to
produce one or more of the following 1-glyceryl ester compounds:
[0073] In some embodiments, the acid included in the solution
used to depolymerize the crosslinked polyester is a strong acid.
As used herein, a “strong acid” is one for which substantially
all of the acid ionizes (dissociates) in a solution (provided
there is sufficient solvent). A strong acid has a pKa<−1.74.
[0074] In some embodiments, the polyester, the acid, and the
alcohol are heated in a sealed vessel above the atmospheric
boiling point of the alcohol. This sealed vessel can allow
higher temperatures to be reached, which can allow for shorter
reaction times and/or less acid needed to obtain the product.
[0075] The fatty acid esters obtained by way of method 300 can
be used in a variety of applications. For example, they can be
applied directly to a plant or other agricultural product to
form a protective coating, as further described below. Or, the
esters may serve as starting material for further chemical
transformations, for example for the production of free fatty
acids. Although free fatty acids can be extracted from
crosslinked polymers such as cutin using other methods (e.g.,
using method 100 of FIG. 1), forming free fatty acids via
transesterification of esters obtained by way of method 300 can
result in more highly purified product. For example, when
methods 100 and 300 are each used to depolymerize cutin, the
resulting crude extract in both cases is an oil. However,
purification of the extract obtained by method 300 results in
product which is a solid powder with little or substantially no
coloration, and when dissolved in a solvent produces a solution
with a low viscosity. On the other hand, purification of the
extract obtained by method 100 results in product which remains
oily with substantial coloration, and when dissolved in a
solvent produces a solution with a substantially higher
viscosity.
[0076] In some embodiments, the plant extract composition can be
applied directly to a portion of a plant, e.g., to form a
protective coating on the plant. In some embodiments, the plant
extract composition can be heated to modify the physical and/or
chemical properties of the composition prior to and/or during
and/or after the application process. In some embodiments, the
plant extract composition can be dissolved and/or suspended in a
solvent, in aqueous solutions, or in a carrier liquid to form
the coating. The solvent can include any polar, non-polar,
protic, or aprotic solvents, including any combinations thereof.
Examples of solvents that can be used to dissolve the plant
extract compositions described herein include water, methanol,
ethanol, isopropanol, butanol, acetone, ethyl acetate,
chloroform, acetonitrile, tetrahydrofuran, diethyl ether, methyl
tert-butyl ether, any other suitable solvent or a combination
thereof. Aqueous solutions, suspensions, or emulsions of such
plant extract compositions can be suitable for coating on
agricultural products, for example, forming a coating on the
agricultural product. For example, the aqueous solutions,
suspensions, or emulsions can be applied to the surface of the
agricultural product, after which the solvent can be removed
(e.g., by evaporation or convective drying), leaving a
protective coating formed from the plant extract composition on
the surface of the agricultural product.
[0077] In some embodiments, the coatings can be configured to
change the surface energy of the agricultural product. Various
properties of coatings described herein can be adjusted by
tuning the crosslink density of the coating, its thickness, or
its composition. This can, for example, be used to control the
ripening of postharvest fruit or produce. For example, coatings
formed of plant extract compositions that primarily include
bifunctional or polyfunctional cutin monomer units can, for
example, have higher crosslink densities than those that include
monofunctional cutin monomer units. Thus, plant extract
composition coatings formed from bifunctional or polyfunctional
cutin monomer units can in some cases result in slower rates of
ripening as compared to coatings formed from monofunctional
monomer units.
[0078] In some embodiments, an acid or a base can be added to
the coating formulation to achieve a desired pH suitable for
coating the agricultural product with the plant extract
composition coating. In some embodiments, additives such as, for
example, surfactants, emulsifiers, thickening agents, nonionic
polymers, waxes, or salts can be included in the coating
formulation. In some embodiments, weak acids, ions, or
non-reactive molecules can be included in the coating
formulation to control or adjust the properties of the resulting
films or coatings. In some embodiments, pH stabilizers or
modifiers can also be included in the coating formulation. In
some embodiments, the coating formulation can include additional
materials that are also transported to the surface with the
coating, or are deposited separately and are subsequently
encapsulated by the coating (e.g., the coating is formed at
least partially around the additional material), or are
deposited separately and are subsequently supported by the
coating (e.g., the additional material is anchored to the
external surface of the coating). Examples of such additional
materials can include cells, biological signaling molecules,
vitamins, minerals, pigments, aromas, enzymes, catalysts,
antifungals, antimicrobials, and/or time-released drugs. The
additional materials can be non-reactive with surface of the
agricultural product and/or coating, or alternatively can be
reactive with the surface and/or coating.
[0079] In some embodiments, the coating can include an additive
configured, for example, to modify the viscosity, vapor
pressure, surface tension, or solubility of the coating. In some
embodiments, the additive can be configured to increase the
chemical stability of the coating. For example, the additive can
be an antioxidant configured to inhibit oxidation of the
coating. In some embodiments the additive can be added to reduce
or increase the melting temperature or the glass-transition
temperature of the coating. In some embodiments, the additive
can be configured to reduce the diffusivity of water vapor,
oxygen, CO2, or ethylene through the coating or enable the
coating to absorb more ultra violet (UV) light, for example to
protect the agricultural product (e.g., any of the products
described herein). In some embodiments, the additive can be
configured to provide an intentional odor, for example a
fragrance (e.g., smell of flowers, fruits, plants, freshness,
scents, etc.). In some embodiments, the additive can be
configured to provide color and can include, for example, a dye
or a US Food and Drug Administration (FDA) approved color
additive. In some embodiments, the additives can include
sweeteners, color additives, flavors, spices, flavor enhancers,
fat replacers, and components of formulations used to replace
fats, nutrients, emulsifiers, bulking agents, cleansing agents,
stabilizers, emulsion stabilizers, thickeners, flavor or
fragrance, an ingredient of a flavor or fragrance, binders,
texturizers, humectants, pH control agents, acidulants,
leavening agents, anti-caking agents, antifungal agents,
antimicrobial agents, antioxidants, and/or UV filters. In some
embodiments, the coating can include a photoinitiator, which can
initiate crosslinking of the coating on exposure to an
appropriate light source, for example, UV light.
[0080] In some embodiments, any of the plant extract composition
coatings described herein can be flavorless or have high flavor
thresholds, e.g. above 500 ppm, and can be odorless or have a
high odor threshold. In some embodiments, the materials included
in any of the coatings described herein can be substantially
transparent. For example, the plant extract composition, the
solvent, and/or any other additives included in the coating can
be selected so that they have substantially the same or similar
indices of refraction. By matching their indices of refraction,
they may be optically matched to reduce light scattering and
improve light transmission. For example, by utilizing materials
that have similar indices of refraction and have a clear,
transparent property, a coating having substantially transparent
characteristics can be formed.
[0081] Any of the coatings described herein can be disposed on
the external surface of an agricultural product using any
suitable means. For example, in some embodiments, the
agricultural product can be dip-coated in a bath of the coating
formulation (e.g., an aqueous or mixed aqueous-organic or
organic solution of the plant extract composition). The
deposited coating can form a thin layer on the surface of an
agricultural product, which can protect the agricultural product
from biotic stressors, water loss, and/or oxidation. In some
embodiments, the deposited coating can have a thickness of less
than about 1500 nm, such that the coating is transparent to the
naked eye. For example, the deposited coating can have a
thickness of about 10 nm, about 20 nm, about 30 nm, about 40 nm,
about 50 nm, about 100 nm, about 150 nm, about 200 nm, about 250
nm, about 300 nm, about 350 nm, about 400 nm, about 450 nm,
about 500 nm, about 550 nm, about 600 nm, about 650 nm, about
700 nm, about 750 nm, about 800 nm, about 850 nm, about 900 nm,
about 950 nm, 1,000 nm, about 1,100 nm, about 1,200 nm, about
1,300 nm, about 1,400 nm, or about 1,500 nm, inclusive of all
ranges therebetween. In some embodiments, the deposited coating
can be uniformly deposited over the agricultural product and
free of defects and/or pinholes. In some embodiments, the
dip-coating process can include sequential coating of the
agricultural product in baths of coating precursors that can
undergo self-assembly or covalent bonding on the agricultural
product to form the coating. In some embodiments, the coating
can be deposited on agricultural products by passing the
agricultural products under a stream of the coating formulation
(e.g., a waterfall of the liquid coating). For example, the
agricultural products can be disposed on a conveyor that passes
through the stream of the coating formulation. In some
embodiments, the coating can be misted, vapor- or dry
vapor-deposited on the surface of the agricultural product. In
some embodiments, the coating can be configured to be fixed on
the surface of the agricultural product by UV crosslinking or by
exposure to a reactive gas, for example, oxygen.
[0082] In some embodiments, the plant extract composition
coating can be spray-coated on the agricultural products.
Commercially available sprayers can be used for spraying the
coating or precursors of the coating onto the agricultural
product. In some embodiments, the coating formulation can be
electrically charged in the sprayer before spray-coating on to
the agricultural product, such that the deposited coating
electrostatically and/or covalently bonds to the exterior
surface of the agricultural product.
[0083] The coatings formed from plant extract compositions
described herein can be configured to prevent water loss or
other moisture loss from the coated portion of the plant, delay
ripening, and/or prevent oxygen diffusion into the coated
portion of the plant, for example, to reduce oxidation of the
coated portion of the plant. The coating can also protect the
coated portion of the plant against biotic stressors, such as,
for example, bacteria, fungi, viruses, and/or pests that can
infest and decompose the coated portion of the plant. Since
bacteria, fungi and pests all identify food sources via
recognition of specific molecules on the surface of the
agricultural product, coating the agricultural products with the
coating containing the plant extract compositions can deposit
molecularly contrasting molecules on the surface of the portion
of the plant, which can render the agricultural products
unrecognizable. Furthermore, the coating can also alter the
physical and/or chemical environment of the surface of the
agricultural product making the surface unfavorable for
bacteria, fungi or pests to grow. The coating can also be
formulated to protect the surface of the portion of the plant
from abrasion, bruising, or otherwise mechanical damage, and/or
protect the portion of the plant from photodegradation. The
portion of the plant can include, for example, a leaf, a stem, a
shoot, a flower, a fruit, a root, etc. In some embodiments, the
coating can be used to coat fruits and, for example, delay
ripening of the fruit.
[0084] Any of the coatings described herein can be disposed on
the external surface of an agricultural product using any
suitable means. For example, in some embodiments, the
agricultural product can be dip coated in a bath of the coating
composition (e.g., an aqueous solution of hydrogen-bonding
organic molecules). The coating can form a thin layer on the
surface of agricultural product, which can protect the
agricultural product from biotic stressors, water loss, and/or
oxidation. In some embodiments, the deposited coating can have a
thickness of less than about 2 microns, for example less than 1
micron, less than 900 nm, less than 800 nm, less than 700 nm,
less than 600 nm, less than 500 nm, less than 400 nm, less than
300 nm, less than 200 nm, or less than 100 nm, such that the
coating is transparent to the naked eye. For example, the
deposited coating can have a thickness of about 50 nm, 60 nm, 70
nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150
nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 600
nm, 700 nm, 800 nm, 900 nm, or about 1,000 nm inclusive of all
ranges therebetween. The deposited coating can have a high
degree of crystallinity to decrease permeability, such that the
coating is conformally deposited over the agricultural product
and is free of defects and/or pinholes. In some embodiments, the
dip coating process can include sequential coating of the
agricultural product in baths of precursors that can undergo
self-assembly or covalent bonding on the agricultural product to
form the coating. In some embodiments, the coatings can be
deposited on agricultural products by passing the agricultural
products under a stream of the coating (e.g., a waterfall of the
liquid coating). For example, the agricultural products can be
disposed on a conveyor that passes through the stream of the
coating. In some embodiments, the coating can be vapor deposited
on the surface of the agricultural product. In some embodiments,
the coating can be formulated to be fixed on the surface of the
agricultural product by UV cross-linking or by exposure to a
reactive gas, for example, oxygen. In some embodiments, the
coating can be applied in the field before harvest as an
alternative to pesticides.
[0085] In some embodiments, the fatty acid esters and/or
oligomers thereof are dissolved in a suitable solvent (e.g.,
water, ethanol, or a combination thereof) prior to coating the
agricultural product. In some embodiments the process of
disposing the composition on the agricultural product comprises
dip-coating the agricultural product in a solution comprising
the plurality of cutin-derived monomers, oligomers, or
combinations thereof. In some embodiments the process of
disposing the composition on the agricultural product comprises
spray-coating the produce with a solution comprising the
plurality of fatty acid esters and/or oligomers thereof.
[0086] In some embodiments, any of the coatings can be spray
coated on the agricultural products. Commercially available
sprayers can be used for spraying the coating or precursors of
the coating onto the agricultural product. In some embodiments,
the coatings can be electrically charged in the sprayer before
spray coating on the agricultural product, such that the coating
covalently bonds to the exterior surface of the agricultural
product.
[0087] In some embodiments, the coating can be deposited on the
agricultural product such that the coating is unbound to the
surface of the agricultural product. In some embodiments, one or
more components of the coating, for example, the
hydrogen-bonding organic molecule, can be covalently (or
hydrogen) bonded to at least a portion of the surface of the
agricultural product. This can result in improved coating
properties such as, for example, higher durability, tighter
control of coating permeability and thickness. In some
embodiments, multiple layers of the coating can be deposited on
the surface of agricultural product to achieve a durable
coating.
[0088] Any of the coatings described herein can be used to
protect any agricultural product. In some embodiments, the
coating can be coated on an edible agricultural product, for
example, fruits, vegetables, edible seeds and nuts, herbs,
spices, produce, meat, eggs, dairy products, seafood, grains, or
any other consumable item. In such embodiments, the coating can
include components that are non-toxic and safe for consumption
by humans and/or animals. For example, the coating can include
components that are U.S. Food and Drug Administration (FDA)
approved direct or indirect food additives, FDA approved food
contact substances, satisfy FDA regulatory requirements to be
used as a food additive or food contact substance, and/or is an
FDA Generally Recognized as Safe (GRAS) material. Examples of
such materials can be found within the FDA Code of Federal
Regulations Title 21, located at
“http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm”,
the entire contents of which are hereby incorporated by
reference herein. In some embodiments, the components of the
coating can include a dietary supplement or ingredient of a
dietary supplement. The components of the coating can also
include an FDA approved food additive or color additive. In some
embodiments, the coating can include components that are
naturally derived, as described herein. In some embodiments, the
coating can be flavorless or have a high flavor threshold of
below 500 ppm, are odorless or have a high odor threshold,
and/or are substantially transparent. In some embodiments, the
coating can be configured to be washed off an edible
agricultural product, for example, with water.
[0089] In some embodiments, the coatings described herein can be
formed on an inedible agricultural product. Such inedible
agricultural products can include, for example, inedible
flowers, seeds, shoots, stems, leaves, whole plants, and the
like. In such embodiments, the coating can include components
that are non-toxic, but the threshold level for non-toxicity can
be higher than that prescribed for edible products. In such
embodiments, the coating can include an FDA approved food
contact substance, an FDA approved food additive, or an FDA
approved drug ingredient, for example, any ingredient included
in the FDA's database of approved drugs, which can be found at
“http://www.accessdata.fda.gov/scripts/cder/drugsatfda/index.cfm”,
the entire contents of which are hereby incorporated herein by
reference. In some embodiments, the coating can include
materials that satisfy FDA requirements to be used in drugs or
are listed within the FDA's National Drug Discovery Code
Directory,
“http://www.accessdata.fda.gov/scripts/cder/ndc/default.cfm”,
the entire contents of which are hereby incorporated herein by
reference. In some embodiments, the materials can include
inactive drug ingredients of an approved drug product as listed
within the FDA's database,
“http://www.accessdata.fda.gov/scripts/cder/ndc/default.cfm”,
the entire contents of which are hereby incorporated herein by
reference.
[0090] Embodiments of the coatings described herein provide
several advantages, including, for example: (1) the coatings can
protect the agricultural products from biotic stressors, i.e.
bacteria, viruses, fungi, or pests; (2) the coatings can prevent
evaporation of water and/or diffusion of oxygen; (3) coating can
help extend the shelf life of agricultural products, for
example, postharvest produce, without refrigeration; (4) the
coatings can introduce mechanical stability to the surface of
the agricultural products eliminating the need for expensive
packaging designed to prevent the types of bruising which
accelerate spoilage; (5) use of agricultural waste materials to
obtain the coatings can help eliminate the breeding environments
of bacteria, fungi, and pests; (6) the coatings can be used in
place of pesticides to protect plants, thereby minimizing the
harmful impact of pesticides to human health and the
environment; (7) the coatings can be naturally derived and
hence, safe for human consumption. Since the components of the
coatings described herein can in some embodiments be obtained
from agricultural waste, such coatings can be made at a
relatively low cost. Therefore, the coatings can be particularly
suited for small scale farmers, for example, by reducing the
cost required to protect crops from pesticides and reducing
postharvest losses of agricultural products due to decomposition
by biotic and/or environmental stressors.
[0091] In some embodiments, the treating of the crosslinked
polymer and/or forming of the plant extract composition is
carried out by a first party, while the application of the plant
extract composition to an agricultural product to form a
protective coating over the agricultural product is carried out
by a second party different from the first party. For example, a
manufacturer of the plant extract compositions (i.e., a first
party) can form the compositions by one or more of the methods
described herein. The manufacturer can then sell or otherwise
provide the resulting plant extract composition to a second
party, for example a farmer, shipper, distributor, or retailer
of produce, and the second party can apply the composition to
one or more agricultural products to form a protective coating
over the products. Alternatively, the manufacturer can sell or
otherwise provide the resulting plant extract composition to an
intermediary party, for example a wholesaler, who then sells or
otherwise provides the plant extract composition to a second
party such as a farmer, shipper, distributor, or retailer of
produce, and the second party can apply the composition to one
or more agricultural products to form a protective coating over
the products.
[0092] In some cases where multiple parties are involved, the
first party may optionally provide instructions or
recommendations about the extract composition, either written or
oral, indicating one or more of the following: (i) that the
composition is intended to be applied to a product for the
purpose of coating or protecting the product, to extend the life
of the product, to reduce spoilage of the product, or to modify
or improve the aesthetic appearance of the product; (ii)
conditions and/or methods that are suitable for applying the
compositions to the surfaces of products; and/or (iii) potential
benefits (e.g., extended shelf life, reduced rate of mass loss,
reduced rate of molding and/or spoilage, etc.) that can result
from the application of the composition to a product. While the
instructions or recommendations may be supplied by the first
party directly with the plant extract composition (e.g., on
packaging in which the composition is sold or distributed), the
instructions or recommendations may alternatively be supplied
separately, for example on a website owned or controlled by the
first party, or in advertising or marketing material provided by
or on behalf of the first party.
[0093] In view of the above, it is recognized that in some
cases, a party that manufactures a plant extract composition
according to one or more methods described herein (i.e., a first
party) may not directly form a coating over a product from the
extract composition, but can instead direct (e.g., can instruct
or request) a second party to form a coating over a product from
the extract composition. That is, even if the first party does
not coat a product by the methods and compositions described
herein, the first party may still cause the plant extract
composition to be applied to the product to form a protective
coating over the product by providing instructions or
recommendations as described above. Accordingly, as used herein,
the act of applying a plant extract composition to a product
(e.g., a plant or agricultural product) also includes directing
or instructing another party to apply the plant extract
composition to the product, or causing the plant extract
composition to be applied to the product.
[0094] The following examples describe plant extract
compositions and methods for obtaining the same. These examples
are only for illustrative purposes and are not meant to limit
the scope of the present disclosure.
Examples
[0095] In each of the examples below, all reagents and solvents
were purchased and used without further purification unless
specified. All reactions were carried out under an atmosphere of
nitrogen with commercial grade solvents unless otherwise stated.
Reactions were monitored by thin layer chromatography (TLC)
carried out on 0.25 mm E. Merck silica gel plates (60 Å, F-254)
using UV light as the visualizing agent and an acidic mixture of
anisaldehyde, ceric ammonium molybdate, or basic aqueous
potassium permanganate (KMnO4), and heat as developing agents.
NMR spectra were recorded on a Bruker Avance 500 MHz and/or
Varian VNMRs 600 MHz instruments and calibrated using residual
un-deuterated solvent as an internal reference (eg. CHCl3@ 7.26
ppm <1>H NMR, 77.16 ppm <13>C NMR). The following
abbreviations (or combinations thereof) were used to explain the
multiplicities: s=singlet, d=doublet, t=triplet, q=quartet,
m=multiplet, br=broad. Mass spectra (MS) were recorded on a
Waters Xevo UPLC equipped with a Cis column and a ESI TQD MS.
Absolute ethanol was dried to low residual water according to
the procedures in Purification of Laboratory Chemicals (7thed.)
Example 1:
Method for Preparing Tomato Pomace Prior to Depolymerization
[0096] Tomato pomace obtained from a commercial tomato
processing facility was milled in a cutting mill, and sifted to
give different particle size distributions (eg. >500 μm,
250-500 μm, 125-250 μm, etc.). The fraction corresponding to
250-500 μm was sequentially extracted with CHCl3 overnight in a
Soxhlet extractor and with methanol overnight in a Soxhlet
extractor to remove the surface waxes and other soluble
components, followed by drying under vacuum (<1 torr). The
washed pomace was then lyophilized overnight (<0.02 torr) to
remove water, and then stored in a desiccator before use.
Example 2:
Method for Preparing a Composition from Tomato Skin/Peel
Treated in a Base and an Alcohol
[0097] A general procedure for base catalyzed depolymerization
is as follows. To depolymerize the dried and washed pomace, an
ethanolic solution including a stoichiometric excess (relative
to tomato pomace) of sodium ethoxide was prepared in an oven
dried three neck round bottom by adding 2 eq. sodium metal (rel.
to tomato pomace, assuming that the mass is entirely composed of
cutin polymer) to 250 mL anhydrous ethanol under a nitrogen
atmosphere. The mixture was stirred under nitrogen until the
sodium had completely dissolved, after which 10.0 g of the
tomato pomace (250-500 m in size) was added against a
counter-flow of nitrogen. The mixture was refluxed under
nitrogen for 48 hours, followed by cooling the reaction to room
temperature and quenching it with 3 mL glacial acetic acid to a
pH of about 7. The resulting solution was filtered using Grade 1
Whatman filter paper to remove any leftover solids and the
filtrate was collected. Any excess solvent was removed from the
filtered solution by rotary evaporation. The crude isolate was
dried under high vacuum (<0.1 torr), and was analyzed by UPLC
and NMR. The crude isolate was found to contain
(9)10,16-dihydroxypalmitic acid, with no evidence of ethyl ester
formation.
Example 3:
Method for Preparing a Composition from Tomato Skin/Peel
Treated in an Acid and an Alcohol
[0098] To 250 mL of absolute ethanol was added sulfuric acid
(7.36 g, 4.00 mL, 75.0 mmol) and tomato pomace (10.0 g, 500
m-250 m in size) with stirring. The reaction was then heated to
reflux for 48 hours. Once complete, the reaction was cooled and
the solution neutralized to pH 7 with ̃70 mL sat. NaHCO3(aq).
The neutralized mixture was then filtered through a Buchner
funnel and Grade 1 Whatman (70 mm) filter paper. The filtrate
was dried by sequential rotary evaporation and high vacuum
(<0.1 torr). When the crude material was dry, it was taken up
in ethyl acetate (140 mL) and three forward extractions were
conducted with H2O (2×160 mL) and brine (160 mL). The organic
layer was separated, and the combined aqueous phases were
extracted with an additional 200 mL ethyl acetate, and the
organic phases combined, and dried with MgSO4. The solvent was
removed with rotary evaporation and high vacuum, yielding 3.35 g
(avg.) of crude isolate.
[0099] The crude isolate from the ethanolysis was dissolved in
methanol, and three times the mass of the crude isolate in
Celite 545 was added. The methanol was removed by rotary
evaporator and dried Celite admixture transferred to a cellulose
extraction thimble. Glass wool was placed on top of the material
to ensure it stayed in the thimble. The material was extracted
in a Soxhlet extractor for 20 hours under nitrogen with 600 mL
of heptane. After 20 hours, the Soxhlet apparatus and contents
were cooled. The Soxhlet apparatus was then dismantled, and the
round bottom was placed in a fumehood overnight, which allowed a
first crop of ethyl 10,16-dihydroxyhexdecanoate (EtDHPA) to
precipitate out of the heptane. The round bottom was then placed
in a 2° C. fridge overnight, giving a second crop of EtDHPA. The
second crop was then filtered and transferred to a scintillation
vial. Both crops were dried by sequential treatment with a
rotary evaporator and high vacuum (<0.1 torr), resulting in a
yellowish (first crop)/white (second crop) powder. Both crops
were analyzed by NMR and UPLC/ESI MS, matching the expected
spectra for EtDHPA; yield (combined crops): 0.76 g. <1>H
NMR (600 MHz, Chloroform-d) δ 4.11 (q, J=7.1 Hz, 2H), 3.63 (t,
J=6.8 Hz, 2H), 3.57 (s, 1H), 2.27 (t, J=7.6 Hz, 2H), 1.66-1.51
(m, 6H), 1.49-1.25 (m, 21H), 1.24 (t, J=7.1 Hz, 3H). See FIG. 12
(UPLC) and FIG. 13 (NMR).
Example 4:
Method for Preparing a Composition from Tomato Skin/Peel
Treated in an Acid and an Alcohol at High Temperatures
[0100] To a thick-walled sealed tube containing 250 mL of
absolute ethanol was added sulfuric acid (7.36 g, 4.00 mL, 75.0
mmol), followed by tomato pomace (10.0 g, 500 m-250 m in size).
The reaction was then heated to temperatures greater than the
atmospheric boiling point of ethanol, such as 100° C. or 120° C.
for 24 or 48 hours. Once complete, the reaction was cooled and
the solution neutralized to pH 7 with ̃70 mL sat. NaHCO3(aq.).
The neutralized mixture was then filtered through a Buchner
funnel and Grade 1 Whatman (70 mm) filter paper. The filtrate
was dried by sequential rotary evaporation and high vacuum
(<0.1 torr). When the crude material was dry, it was taken up
in ethyl acetate (140 mL), and three forward extractions were
conducted with H2O (2×160 mL) and brine (160 mL). The organic
layer was separated, and the combined aqueous phases were
extracted with an additional 200 mL ethyl acetate, and the
organic phases combined, and dried with MgSO4. The solvent was
removed with rotary evaporation and high vacuum, yielding the
crude isolate. The amounts of crude recovered at each of the
different temperature and time conditions are plotted in FIG. 5.
[0101] The crude isolate obtained from the ethanolysis was
dissolved in methanol, and three times the mass of the crude
isolate in Celite 545 was added. The methanol was removed by
rotary evaporator and the dried Celite admixture transferred to
a cellulose extraction thimble. Glass wool was placed on top of
the material to ensure it stayed in the thimble. The material
was extracted for 20 hours under nitrogen in a Soxhlet extractor
with 500 mL of heptane and then cooled. The Soxhlet apparatus
was then dismantled and the round bottom was placed in the
fumehood overnight, which allowed a first crop of EtDHPA to
precipitate out of the heptane. The round bottom was then placed
in a 4° C. fridge overnight, providing a second crop of EtDHPA.
This precipitate was then filtered and transferred to a
scintillation vial. Both crops were dried by sequential
treatment with a rotary evaporator and high vacuum (<0.1
torr) to give a white/yellowish powder. Both crops were analyzed
by NMR and UPLC/ESI MS, matching the expected spectra for
EtDHPA. The amounts recovered of the EtDHPA isolate are shown in
FIGS. 5 and 6.
[0102] While various embodiments of the system, methods and
devices have been described above, 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 modification are in accordance with the variations of the
invention. Additionally, certain of the steps may be performed
concurrently in a parallel process when possible, as well as
performed sequentially as described above. The embodiments 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.
US2019269144
Methods
of Controlling the Rate of Ripening in Harvested Produce
[ PDF ]
The present disclosure provides methods for controlling the rate
of ripening for agricultural produce. The present disclosure
further provides coating compositions that can be applied to
produce to control (e.g., lessen) the rate of ripening of the
produce.
US2018368427
Method
of reducing spoilage in harvested produce during storage and
shipping
[ PDF ]
Described herein are formulations and methods of reducing
spoilage in harvested produce by reducing the rate of water or
mass loss, thereby resulting in high quality produce with lower
rates of spoilage. The present disclosure provides coatings and
methods of coating produce to prevent moisture loss from produce
during storage and shipment of the produce. This in turn allows
the produce to be shipped and 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.
WO2019036686
PREVENTION OF POSTHARVEST PHYSIOLOGICAL DETERIORATION USING
SULFUR-DONATING COMPOUNDS
[ PDF ]
The present disclosure is directed to the prevention of spoilage
of agricultural products (e.g., tuberous roots such as cassava
roots). The disclosure teaches the use of a sulfur-donating
compound (e.g., a thiosulfate salt such as sodium thiosulfate)
to enable the agricultural product to scavenge
endogenously-produced HCN, prevent the buildup of reactive
oxygen species, prevent the buildup of insoluble byproducts,
and/or prevent the loss of starch from the agricultural product.
US10407377
Plant
Extract Compositions for Forming Protective Coatings
[ PDF ]
Described herein are methods of preparing cutin-derived
monomers, oligomers, or combinations thereof from
cutin-containing plant matter. The methods can include heating
the cutin-derived plant matter in a solvent at elevated
temperature and pressure. In some preferred embodiments, the
methods can be carried out without the use of additional acidic
or basic species.
US10092014
METHOD
FOR PREPARING AND PRESERVING SANITIZED PRODUCTS
[ PDF ]
Described herein are methods of sanitizing and preserving
produce and other agricultural products, for example for
consumption as Ready-to-Eat. The methods can comprise treating
the products with a sanitizing agent and forming a protective
coating over the products.
US10266708
Precursor Compounds for Molecular Coatings
[ PDF ]
The protective coatings formed from the compositions can be used
to prevent food spoilage due to, for instance, moisture loss,
oxidation, or infection by a foreign pathogen.
US2017318827
Plant
extract compositions and methods of preparation thereof
Embodiments described herein relate generally to plant extract
compositions and methods to isolate cutin-derived monomers,
oligomers, and mixtures thereof for application in agricultural
coating formulations, and in particular, to methods of preparing
plant extract compositions that include functionalized and
non-functionalized fatty acids and fatty esters (as well as
their oligomers and mixturesthereof), which are substantially
free from accompanying plant-derived compounds (e.g., proteins,
polysaccharides, phenols, lignans, aromatic acids, terpenoids,
flavonoids, carotenoids, alkaloids, alcohols, alkanes, and
aldehydes) and can be used in agricultural coating formulations.
US2015030780
AGRICULTURAL
SKIN GRAFTING
A method of forming a material structure from structural
units contained within a liquid solution in a spray head is
described. The liquid solution includes a solvent and a solute,
the solute comprising a plurality of the structural units, the
structural units including monomer units, oligomer units, or
combinations thereof. The method comprises forming droplets of
the liquid solution including the structural units, and spraying
the droplets on a substrate, thereby substantially increasing
the reactivity of the structural units within the droplets
relative to the structural units within the liquid solution in
the spray head. The increase in reactivity can result from the
droplets containing an excess of a particular ion, the ion
excess resulting from a voltage applied to conductive walls of
the device which dispenses the droplets. The material structure
is then formed on the substrate from the more highly reactive
structural units within the droplets.
WO2019028043
APPARATUS AND METHOD FOR TREATMENT AND INSPECTION OF PRODUCE
Described herein are conveyor systems and application units
which can be used to transport and simultaneously treat, or to
facilitate treatment and inspection of produce, agricultural
products, or other items. The conveyor systems and application
units can be configured to allow products to be simultaneously
rotated as they are moved along a packing line, which can
facilitate the uniform application of spray coatings and/or
allow the products to be uniformly blow dried while they are
moved. Exemplary conveyor systems and application units can
include a bed formed of a plurality of rollers and a rotation
inducing device that causes the rollers to rotate while they are
laterally transported, thereby causing the products lying on top
of the bed to rotate during transport.