U.S. patent application number 13/525500 was filed with the patent office on 2012-10-11 for use of c3 to c14 aliphatic aldehydes, ketones and primary and secondary c3 to c7 aliphatic alcohols to inhibit sprouting of potato tubers.
Invention is credited to Lisa O'Rear KNOWLES, Norman Richard KNOWLES.
Application Number | 20120258859 13/525500 |
Document ID | / |
Family ID | 40351069 |
Filed Date | 2012-10-11 |
United States Patent
Application |
20120258859 |
Kind Code |
A1 |
KNOWLES; Norman Richard ; et
al. |
October 11, 2012 |
USE OF C3 TO C14 ALIPHATIC ALDEHYDES, KETONES AND PRIMARY AND
SECONDARY C3 TO C7 ALIPHATIC ALCOHOLS TO INHIBIT SPROUTING OF
POTATO TUBERS
Abstract
Compositions and methods for inhibiting the sprouting of potato
tubers are provided. The compositions comprise C3 to C14 aliphatic
aldehydes and ketones, and/or C3 to C7 primary and secondary
aliphatic alcohols.
Inventors: |
KNOWLES; Norman Richard;
(Pullman, WA) ; KNOWLES; Lisa O'Rear; (Pullman,
WA) |
Family ID: |
40351069 |
Appl. No.: |
13/525500 |
Filed: |
June 18, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12186861 |
Aug 6, 2008 |
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13525500 |
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60955156 |
Aug 10, 2007 |
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Current U.S.
Class: |
504/118 |
Current CPC
Class: |
A01N 35/02 20130101;
Y10T 436/203332 20150115; A01N 31/02 20130101; A23B 7/154 20130101;
Y10T 436/200833 20150115 |
Class at
Publication: |
504/118 |
International
Class: |
A01N 35/02 20060101
A01N035/02; A01P 21/00 20060101 A01P021/00 |
Claims
1-9. (canceled)
10. A fog, spray or mist composition for use in the preparation of
a composition for inhibiting sprouting of potato tubers, said
composition comprising one or more of a) one or more C3 to C14
saturated aliphatic aldehydes; b) one or more C3 to C 14 saturated
aliphatic ketones; c) one or more C3 to C7 unsaturated aliphatic
primary alcohols; and d) one or more C3 to C7 unsaturated aliphatic
secondary alcohols, wherein a), b), c) or d) is physically in the
form of a fog, spray or mist suitable for contacting potato
tubers.
11. The fog, spray or mist composition of claim 10, wherein said
one or more C3 to C14 saturated aliphatic aldehydes has a chemical
formula ##STR00020## wherein R.sub.1 is a C2 to C13 branched or
unbranched, substituted or unsubstituted saturated alkyl.
12. The fog, spray or mist composition of claim 11, wherein said
one or more C3 to C14 saturated aliphatic aldehydes is selected
from the group consisting of nonanal, ##STR00021## and decanal,
##STR00022##
13. The fog, spray or mist composition of claim 10, wherein said
one or more C3 to C14 saturated aliphatic ketones has a chemical
formula ##STR00023## wherein R.sub.2 is C1 to C12 branched or
unbranched, substituted or unsubstituted saturated alkyl and
R.sub.3 is a C1 to C12 branched or unbranched, substituted or
unsubstituted saturated alkyl and R.sub.2 and R.sub.3 may be the
same or different.
14. The fog, spray or mist composition of claim 13, wherein said
one or more C3 to C14 saturated aliphatic ketones is selected from
the group consisting of 2-nonanone, ##STR00024## and 3-decanone,
##STR00025##
15. The fog, spray or mist composition of claim 10, wherein said
one or more C3 to C7 unsaturated aliphatic primary alcohols has a
chemical formula ##STR00026## wherein R.sub.4 is a C2 to C6
branched or unbranched, substituted or unsubstituted unsaturated
alkenyl.
16. The fog, spray or mist composition of claim 15, wherein said
one or more C3 to C7 unsaturated aliphatic primary alcohols is
selected from the group consisting of trans-2-hexen-1-ol
##STR00027## and trans-2-hepten-1-ol, ##STR00028##
17. The fog, spray or mist composition of claim 10, wherein said
one or more C3 to C7 unsaturated aliphatic secondary alcohols has a
chemical formula ##STR00029## wherein R.sub.5 is a C1 to C5
branched or unbranched, substituted or unsubstituted unsaturated
alkyl, and R.sub.6 is a C1 to C5 branched or unbranched,
substituted or unsubstituted saturated alkenyl; R.sub.5 is a C1 to
C5 branched or unbranched, substituted or unsubstituted unsaturated
alkenyl, and R.sub.6 is a C1 to C5 branched or unbranched,
substituted or unsubstituted saturated alkyl; or both R.sub.5 and
R.sub.6 are a C1 to C5 branched or unbranched, substituted or
unsubstituted unsaturated alkenyls, and wherein R.sub.5 and R.sub.6
may be the same or different.
18-22. (canceled)
23. The composition of claim 10, wherein said fog is a cold
fog.
24. The composition of claim 10, wherein said fog is a thermal
fog.
25. The fog, spray or mist composition of claim 10, wherein said
fog, spray or mist composition comprises one or more of a) one or
more C3 to C14 saturated aliphatic aldehydes; and b) one or more C3
to C14 saturated aliphatic ketones.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of U.S. provisional patent
application 60/955,156, filed Aug. 10, 2007, the complete contents
of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention generally relates to using C3 to C14 aliphatic
aldehydes and ketones, and C3 to C7 aliphatic primary and secondary
alcohols to inhibit sprouting when applied to potato tubers.
[0004] 2. Background of the Invention
[0005] Following harvest, potato tubers undergo a natural period of
dormancy during which sprout growth is inhibited by endogenous
hormones. As tubers emerge from dormancy and begin to sprout,
respiration increases, starch is catabolized to sugars, and weight
loss increases. The result is a decrease in quality of tubers
destined for fresh and processing markets. Hence, inhibition of
sprouting through chemical or physical means preserves quality and
prolongs the duration of storage.
[0006] The sprout inhibitors registered for use on potatoes in the
United States are CIPC (also known as chlorpropham, Sprout
Nip.RTM., etc.), maleic hydrazide (MH), DMN (also known as
dimethylnaphthalene, 1,4SIGHT.RTM., 1,4SEED.RTM., 1,4SHIP.RTM.),
DIPN (diisopropylnaphthalene, Amplify.RTM.), and clove oil
(Biox-C.RTM.; Sprout Torch.TM.). Except for MH, which is applied
pre-harvest to actively growing plants, all inhibitors are applied
post harvest when tubers are in the storage bin.
[0007] CIPC is the most effective and most widely used potato
sprout inhibitor. The chemical is most often applied as a thermal
aerosol fog into potato storages after wound-healing and prior to
sprouting. In the Pacific Northwest, this is usually in November or
December, before dormancy has ended. The chemical is fogged into
storage at the recommended rate of 1 lb chlorpropham/600 cwt. One
gallon of CIPC aerosol grade will treat 4200 cwt (210 tons) of
potatoes. CIPC can inhibit sprouting and extend the storage life of
table-stock and processing potatoes for up to 1 year with two
applications.
[0008] CIPC is an effective sprout suppressant that has been used
in the potato industry for about 40 years and the EPA considers it
as a group E chemical (non-carcinogenic). CIPC was originally
registered in the United States as a pre- and post-emergence
herbicide in 1962 and the EPA has set residue limits for potato
tubers. Notwithstanding its safety record, the trend today is to
reduce the use of synthetic pesticides in agriculture in order to
reduce residues in the world's food supply. The chemical is
continually being scrutinized by the EPA as it is among the three
pesticides found in the highest concentrations in the average
American diet (Gartrell, M. J., J. C. Craun, D. S. Podrebarac, and
E. L. Gunderson. 1986. Pesticides, selected elements, and other
chemicals in adult total diet samples October 1980-March 1982. J.
Assoc. Off. Anal. Chem. 69:146-161). CIPC constitutes over 90% of
the total synthetic residues found in U.S. potatoes (Gartrell et
al., 1986). The EPA recently issued a re-registration eligibility
decision for CIPC and dropped the tolerance level for residues on
potatoes. The economic importance of this chemical as a sprout
inhibitor to the potato industry is illustrated by the fact that
the registrants spent over $6,000,000 in this re-registration
process. While other potential sprout suppressants have been
identified (e.g. aromatic aldehydes and alcohols, methylesters of
rape oil, carvone, jasmonates, spearmint and peppermint oils), none
appear as effective as CIPC. A need thus exists to identify and
develop the most benign chemicals possible (ideally natural, phyto
chemicals) that are effective as sprout inhibitors.
[0009] 1,4SIGHT.RTM. (94.7% DMN=1,4-dimethylnaphthalene) is one
such natural chemical that is also registered for sprout control,
but it tends to be less effective than CIPC. DMN is naturally
produced in potatoes. It is more volatile than CIPC and thus
dissipates from tubers more rapidly than CIPC. Multiple
applications of DMN are required to maintain season-long sprout
inhibition. DMN is vaporized and applied as an aerosol into bulk
storages. It can be applied any time after tubers are placed in the
bin but is usually applied later in the fall or early winter when
sprouting potential begins to increase. DMN is registered for use
at a rate of 1 lb DMN/500 cwt (=20 ppm on a DMN to potato weight
basis). Because of the need for multiple applications of DMN to
achieve prolonged inhibition of sprouting, DMN is more costly to
use than CIPC.
[0010] Other natural volatile sprout inhibitors have been
identified. Carvone (derived from caraway seed) is commercially
available for use on potatoes in the Netherlands (Hartmans, K. J.,
P. Diepenhorst, W. Bakker and L. G. M. Gorris. 1995. The use of
carvone in agriculture--sprout suppression of potatoes and
antifungal activity against potato-tuber and other plant-diseases.
Industrial Crops and Products 4:3-13). The following US patents
describe the use of various compounds for the inhibition of potato
sprout formation: U.S. Pat. No. 5,436,226 to Lulai, et al. (Jul.
25, 1995) describes the use of jasmonates; U.S. Pat. No. 5,580,596
to Winkelmann et al. (Dec. 3, 1996) describes the use of rape oil
and certain long-chain alcohols, either alone or in combination;
U.S. Pat. No. 5,139,562 to Vaughn et al., (Aug. 16, 1992) describes
the use of volatile monoterpenes (e.g. from eucalyptus, peppermint,
spearmint, etc.); and U.S. Pat. No. 5,129,951 to Vaughn et al.,
(Jul. 14, 1992) describes the use of aromatic aldehydes and
alcohols. In addition, Vokou et al. (1993) have demonstrated that
the essential oils from a multitude of herbs (e.g. sage and
rosemary) possess sprout inhibiting activity in potatoes.
[0011] There remains an ongoing need to provide alternative sprout
inhibitors that are safe and effective, particularly sprout
inhibitors that are natural compounds, and that do not pose a
threat to the environment or to the health of humans and other
species.
SUMMARY OF THE INVENTION
[0012] A novel method for inhibiting (e.g. preventing,
forestalling, slowing, reversing, or otherwise hindering) the
development of sprouts in potato tubers is provided. The method
includes the step of exposing potato tubers to one or more C3 to
C14 aliphatic aldehydes or ketones, and/or to C3 to C7 aliphatic
primary or secondary alcohols to inhibit sprouting of the tubers.
Examples of such compounds include 2-nonanone, nonanal, 2-heptanol,
and trans-2-hepten-1-ol and analogous aliphatic compounds of 3 to
14-carbons in the case of aldehydes and ketones, or 3 to 7 carbons
in the case of primary or secondary alcohols.
[0013] The compounds may be applied directly to potato tubers.
Alternatively, the compounds may be derived from the breakdown of
C3 to C14 .alpha.,.beta.-unsaturated aldehydes and ketones such as
those described in U.S. Pat. No. 6,855,699 to Knowles et al. (Feb.
15, 2005). 6,855,699 describes the use of C3 to C14
.alpha.,.beta.-unsaturated aldehydes and ketones, many of which are
naturally produced in fruits and vegetables, to inhibit the
sprouting of potato tubers. However, it has been discovered that
the breakdown products of these C3 to C14
.alpha.,.beta.-unsaturated aldehydes and ketones, including the
compounds described herein, are also useful for this purpose.
[0014] In addition, the invention provides methods for detecting
the appearance of the metabolites of C3 to C14
.alpha.,.beta.-unsaturated aldehydes and ketones in or on potato
tubers to which they have been applied. Such methods involve
measuring an amount or level of C3 to C14 aliphatic aldehydes or
ketones, and/or C3 to C14 aliphatic primary or secondary alcohols,
in order to track or monitor the breakdown or catabolism of the C3
to C14 .alpha.,.beta.-unsaturated aldehydes and ketones.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1. Levels of 3-nonen-2-one, 2-nonanone, and 2-nonanol
in tubers initially treated with 0.75 mmol/kg 3-nonen-2-one and
stored at 9.degree. C. Content of residues in the outer 20 mm of
tuber.
[0016] FIG. 2. Levels of trans-2-nonenal, nonanal,
trans-2-nonen-1-ol and 1-nonanol in tubers initially treated with
0.75 mmol/kg trans-2-nonenal and stored at 9.degree. C. Content of
residues in the outer 20 mm of tuber.
[0017] FIG. 3. Effects of 3-nonen-2-one (3N2) in various
combinations with 2-nonanone on sprouting of Russet Burbank tubers.
The compounds were applied as described in Example 1. Tubers were
treated for 24 h, removed from treatment chambers, and placed at
22.degree. C. to sprout for 3 weeks. Sprout fresh weight is
expressed as a percentage of control (non-treated), which were 100%
sprouted.
[0018] FIG. 4. Effect of trans-2-hexen-1-ol, 2-heptanol, decanal
and 3-decanone on sprouting in Premier Russet tubers during long
term storage at 9.degree. C. Compounds were initially applied 98
days after harvest to tubers which had emerged from dormancy and
displayed small (<3 mm) sprouts.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE
INVENTION
[0019] The present invention is based on the discovery that C3 to
C14 aliphatic aldehydes and ketones, and/or C3 to C7 aliphatic
primary and secondary alcohols, function to inhibit the development
of potato sprouts. These compounds have been identified as
metabolites of the previously known potato tuber sprout inhibitors
C3 to C14 .alpha.,.beta.-unsaturated aldehydes and ketones, and
have certain advantages in terms of production, use and
performance. Many of the compounds offer the advantage of being
naturally occurring and thus relatively safe and nontoxic to use.
These compounds may be used alone or in combination with each
other, or in combination with other known tuber sprout inhibitors,
pesticides and growth regulators. Aliphatic C3 to C14 aldehydes
that may be used in the practice of the invention generally have
the chemical formula
##STR00001##
[0020] where R.sub.1 is a C2 to C13 branched or unbranched,
substituted or unsubstituted saturated alkyl or a C2 to C13
branched or unbranched, substituted or unsubstituted unsaturated
alkenyl. In some embodiments of the invention, the aldehyde is
nonanal,
##STR00002##
or decanal,
##STR00003##
[0021] Aliphatic C3 to C14 ketones that may be used in the practice
of the invention generally have the chemical formula
##STR00004##
where R.sub.2 is a C1 to C12 branched or unbranched, substituted or
unsubstituted saturated alkyl or a C1 to C12 branched or
unbranched, substituted or unsubstituted unsaturated alkenyl, and
R.sub.3 is a C1 to C12 branched or unbranched, substituted or
unsubstituted saturated alkyl or a C1 to C12 branched or
unbranched, substituted or unsubstituted unsaturated alkenyl.
R.sub.2 and R.sub.3 may be the same or different. In some
embodiments of the invention, the ketone is 2-nonanone,
##STR00005##
or 3-decanone,
##STR00006##
[0022] Aliphatic C3 to C7 primary alcohols that may be used in the
practice of the invention generally have the chemical formula
##STR00007##
where R.sub.4 is a C2 to C6 branched or unbranched, substituted or
unsubstituted saturated alkyl or a C2 to C6 branched or unbranched,
substituted or unsubstituted unsaturated alkenyl. In various
embodiments of the invention, the unsaturated C3 to C7 primary
alcohol is
[0023] 1-hexanol,
##STR00008##
[0024] 1-heptanol,
##STR00009##
[0025] trans-2-hexen-1-ol,
##STR00010## [0026] or
[0027] trans-2-hepten-1-ol,
##STR00011##
[0028] The aliphatic C3 to C7 secondary alcohols that may be used
in the practice of the present invention generally have the
chemical formula
##STR00012##
where R.sub.5 is a C1 to C5 branched or unbranched, substituted or
unsubstituted saturated alkyl or a C1 to C5 branched or unbranched,
substituted or unsubstituted unsaturated alkenyl. R6 is a C1 to C5
branched or unbranched, substituted or unsubstituted saturated
alkyl or a C1 to C5 branched or unbranched, substituted or
unsubstituted unsaturated alkenyl. R.sub.5 and R.sub.6 may be the
same or different. In one embodiment of the invention, the
saturated C3 to C7 secondary alcohol is 2-heptanol,
##STR00013##
[0029] Examples of additional compounds that may be used in the
practice of the invention include but are not limited to the
following:
[0030] Aliphatic C3 to C14 aldehydes that may be used in the
practice of the present invention include but are not limited to:
propanal, butanal, pentanal, hexanal, heptanal, octanal, 4-nonenal,
6-nonenal, decanal, undecanal, dodecanal, tridecanal, and
tetradecanal.
[0031] Aliphatic C3 to C14 ketones that may be used in the practice
of the present invention include but are not limited to: propanone,
2-butanone, 2-pentanone, 2-hexanone, 2-heptanone, 2-octanone,
3-octanone, 3-nonanone, 2-decanone, 3-decanone, 2-undecanone,
2-dodecanone, 2-tridecanone, and 2-tetradecanone.
[0032] Aliphatic C3 to C7 primary alcohols that may be used in the
practice of the present invention include but are not limited to:
1-propanol, 1-butanol, 2-buten-1-ol, 1-pentanol, 2-penten-1-ol,
1-hexanol, 2-hexen-1-ol, and 1-heptanol.
[0033] Aliphatic C3 to C7 secondary alcohols that may be used in
the practice of the present invention include but are not limited
to: 2-propanol, 2-butanol, 2-pentanol, and 2-hexanol.
[0034] By "substituted" we mean the replacement of hydrogen with a
monovalent or divalent radical. Suitable substitution groups
include but are not limited to, for example, hydroxyl, nitro,
amino, imino, cyano, halo, thio, thioamido, amidino, imidino, oxo,
oxamidino, methoxamidino, guanidino, sulfonamido, carboxyl, formyl,
lower alkyl, halo-lower alkyl, lower alkoxy, halo-lower alkoxy,
lower alkoxyalkyl, alkylcarbonyl, cycloalkyl, heterocycloalkyl,
alkylthio, aminoalkyl, cyanoalkyl, and the like.
[0035] The application of sprout inhibiting compounds to potato
tubers is generally known to those of skill in the art. The
treatment of potato tubers is described, for example, in U.S. Pat.
No. 6,855,669 (Knowles et al.), the complete contents of which are
hereby incorporated by reference. Application is typically to bulk
potatoes in storage bins, although this need not be the case as the
compounds may be applied to potatoes stored or sorted in any
manner, so long as sufficient contact is made between the compounds
and the potato tubers to inhibit sprouting. Application of the
compounds to the potatoes may be carried out by any of several
methods. Generally, the compound(s) will be volatilized, e.g. by
cold fogging, or at high temperature to create a thermal fog, or by
atomization, and introduced into storage bins e.g. via the
ventilation system. This introduction may be a discrete event that
is carried out once or multiple times throughout the storage
period. Alternatively, a slow-release mechanism or formulation may
be employed in which the compound gradually enters the storage area
over a longer period of time, for example by evaporation from a
source impregnated with the compound(s). Further, the compounds may
also be advantageously applied by spraying or misting a liquid form
of the compound onto the potatoes, or by dipping or otherwise
coating the potatoes with the compound, either prior to, during, or
after the potatoes are stored (e.g. between storage and boxing or
bagging for commercial purposes). Such compounds can also be used
to coat or impregnate consumer containers (such as cardboard boxes,
burlap bags, plastic bags etc) which typically hold potatoes coming
out of storage sheds or bins for the express purpose of making
available the precursor or metabolite compounds to delay sprouting
in transit and at final destinations (e.g. homes, grocery stores,
restaurants and other food establishments). For such applications,
the compounds may also be mixed with various other agents known to
facilitate the delivery of gases. liquids, or gels as appropriate
(e.g. emulsifiers, slow release agents or matrices and the
like).
[0036] The timing of exposure of the potatoes to the compounds of
the invention can be prior to or after emergence from dormancy.
[0037] The application of the compounds may be carried out only
once as described above (i.e. early in the storage of the
potatoes). Alternatively, depending on the factors such as the
cultivar, the time of harvest of the potatoes, the length of
storage of the potatoes, the fate of the potatoes, etc. multiple
applications of the compounds may be made. For example, if the
potatoes are to be used as seed potatoes, only one application may
be necessary as the eventual sprouting of the potatoes will be
desirable. However, if the potatoes are to be stored long term
(e.g. over the entire winter for distribution in the spring or the
following summer) multiple applications may be made. In this case,
the first application will generally be made early in the storage
process (e.g. at between 4 and 32 weeks following harvest), and
subsequent applications may also be made at roughly 4 to 12 week
intervals as needed, until the potatoes are retrieved for use.
[0038] The amount of compound (or compounds) that is applied is
sufficient to terminate, slow, prevent, and/or inhibit sprout
growth on the potato tubers. The development of sprouts may thus be
prevented altogether, or the onset of sprouting may be delayed, or
existing sprouts may be killed, or the development of sprouts may
be slowed compared to untreated tubers, etc. In any case, the
process of sprouting is, in general, inhibited by treating the
potato tubers with the compounds as described herein, or with their
precursor compounds (e.g. see U.S. Pat. No. 6,855,669, for examples
of precursor .alpha.,.beta.-unsaturated aldehydes and ketones which
can be used to make the ketones and aldehydes and alcohols of this
invention), in comparison to potato tubers that are not exposed to
or contacted by the compounds in a similar manner. In general, such
inhibition will result in a decrease in the number, length, or
fresh weight of sprouts developing on the tubers, and/or a decrease
in the rate of growth (as determined by length, number, and/or
weight) of sprouts that develop on the treated tubers, in
comparison to potato tubers that are not exposed to or contacted by
the compounds. The decrease will be in the range of at least about
10 to 100%, preferably in the range of about 50 to 100%, and most
preferably in the range of about 75 to 100%. Thus, the treated
tubers will display a decrease in sprout development of about 10,
20, 30, 40, 50, 60, 70, 80 90, or 100%, compared to untreated
tubers.
[0039] The amount of a compound (or mixture of compounds) that is
used to inhibit sprouting according to the invention may vary from
situation to situation. However, the amount will generally be in
the range of from about 0.1 mmol/kg tuber fresh weight to about 3.0
mmol/kg tuber fresh wt.
[0040] According to the present invention, the compounds of the
invention may be applied directly, or they may arise indirectly as
metabolites from the application of precursor compounds such as,
but not limited to, those described herein and in U.S. Pat. No.
6,855,669. The compounds of the invention may also be derived from
the application of a formulation of an inactive chemically related
species which is released as an active form upon application to
tubers. Examples of this chemistry are an acetal or hemiacetal of
the active aldehyde or the ketal or hemiketal of the active ketone.
The compounds may be applied in combination with other agents used
to treat potatoes, examples of which include but are not limited to
other substances that also inhibit sprouting. In this case, the use
of the compounds of the present invention may allow the use of less
of another substance whose use is less desirable (e.g. a substance
that is not naturally occurring, is more expensive, toxic, etc).
Such combinations may also allow the use of lower doses of the
compounds of the present invention.
[0041] The preparation of the compounds for use in the practice of
the present invention is known to those of skill in the art. Many
of the compounds are commercially available. Others may be
synthesized by well-known methods. Still others may be isolated
from natural sources, e.g. from potatoes or other plants in which
they are naturally produced, or in which their precursors are
produced. Alternatively, the compounds may be produced in plants or
other organisms that have been genetically engineered to
overproduce the compounds. One advantage of the method of the
present invention is that some of the compounds that are used in
the method may be relatively inexpensive to procure, or can be
expected to arise from the metabolism of relatively inexpensive
.alpha.,.beta.-unsaturated carbonyls that have been applied to
potato tubers, and thus may offer an advantage when compared to
more costly alternatives.
[0042] The invention includes methods for determining whether
potato tubers have been previously exposed to C3 to C14
.alpha.,.beta.-unsaturated aldehydes or ketones. The detection of
prior exposure is important in identifying tubers treated with
unregistered or illegally applied .alpha.,.beta. unsaturated
carbonyls that yield metabolites (for example C8 C14 alcohols).
Such methods generally involve monitoring the conversion of C3 to
C14 .alpha.,.beta.-unsaturated aldehydes and C4 to C14
.alpha.,.beta.-unsaturated ketones by detecting metabolites
produced by the breakdown of these substances. The precursor
compounds for which metabolites are of interest include those
disclosed in U.S. Pat. No. 6,855,699. Such breakdown products occur
regardless of the method of application of the precursor (e.g. cold
fogging, thermal fogging, direct spray, slow release matrices,
etc.). The precursors are applied in an amount sufficient to
achieve or generate an inhibitory amount of metabolites.
[0043] Representative precursor C3 to C14 unsaturated aliphatic
aldehyde parent molecules may be represented by the formula:
##STR00014##
and the C4 to C14 unsaturated aliphatic ketone parent molecules may
be represented by the formula
##STR00015##
where R.sub.7 is H.sub.2 or a branched or unbranched, substituted
or unsubstituted C1 to C11 lower alkyl, or branched or unbranched,
substituted or unsubstituted C1 to C11 lower alkenyl. R.sub.8 is
H.sub.2 or branched or unbranched, substituted or unsubstituted C1
to C10 lower alkyl, or branched or unbranched, substituted or
unsubstituted C1 to C10 lower alkenyl. R.sub.9 is branched or
unbranched, substituted or unsubstituted C1 to C11 lower alkyl, or
branched or unbranched, substituted or unsubstituted C1 to C11
lower alkenyl. Preferred aliphatic aldehydes for which breakdown
products are traced include trans-2-pentenal; trans-2-hexenal;
trans-2-heptenal; trans-2-octenal; trans-2-nonenal;
trans-2-decenal; trans-2-undecenal; trans-2-dodecenal; trans,
trans-2,4,-nonadienal; and trans-2, cis-6-nonadienal. Preferred
aliphatic ketones for which breakdown products are traced include
trans-3-hepten-2-one, trans-3-octen-2-one, trans-3-nonen-2-one, and
trans-3-decen-2-one.
[0044] The breakdown products that are detected by the methods of
the invention include, for example, aliphatic aldehydes having the
chemical formula
##STR00016##
[0045] where R.sub.1 is a C2 to C13 branched or unbranched,
substituted or unsubstituted saturated alkyl or a C2 to C13
branched or unbranched, substituted or unsubstituted unsaturated
alkenyl.
[0046] Ketones that may be detected in the practice of the
invention generally have the chemical formula
##STR00017##
where R.sub.2 is a C1 to C12 branched or unbranched, substituted or
unsubstituted saturated alkyl or a C1 to C12 branched or
unbranched, substituted or unsubstituted unsaturated alkenyl.
R.sub.3 is a C1 to C12 branched or unbranched, substituted or
unsubstituted saturated alkyl, or a C1 to C12 branched or
unbranched, substituted or unsubstituted unsaturated alkenyl.
R.sub.2 and R.sub.3 may be the same or different.
[0047] Aliphatic C3 to C14 primary alcohols that may be detected in
the practice of the invention generally have the chemical
formula
##STR00018##
where R.sub.4 is a C2 to C13 branched or unbranched, substituted or
unsubstituted saturated alkyl or a C2 to C13 branched or
unbranched, substituted or unsubstituted unsaturated alkenyl.
[0048] Aliphatic C3 to C14 secondary alcohols that may be detected
in the practice of the present invention generally have the
chemical formula
##STR00019##
where R.sub.5 is a C1 to C12 branched or unbranched, substituted or
unsubstituted saturated alkyl or a C1 to C12 branched or
unbranched, substituted or unsubstituted unsaturated alkenyl; and
R6 is a C1 to C12 branched or unbranched, substituted or
unsubstituted saturated alkyl or a C1 to C12 branched or
unbranched, substituted or unsubstituted unsaturated alkenyl.
R.sub.5 and R.sub.6 may be the same or different.
[0049] In a preferred embodiment, the metabolites of C3 to C14
.alpha.,.beta.-unsaturated aldehydes include but are not limited to
the primary alcohols, the aldehydes, and the
.alpha.,.beta.-unsaturated primary alcohols having the same carbon
number as the parent compound. For example, to trans-2-nonenal is
expected to be metabolized to nonanal, 1-nonanol and
trans-2-nonen-1-ol.
[0050] In other preferred embodiments, the metabolites of C4 to C14
.alpha.,.beta.-unsaturated ketones include but are not limited to
the saturated ketone or secondary alcohol having the same carbon
number as the parent compound, and having the hydroxyl bound to the
(former) carbonyl carbon of the parent compound. For example,
trans-3-nonen-2-one is expected to be metabolized to 2-nonanone and
2-nonanol.
[0051] Preferred methods of detecting these metabolites include but
are not limited to solvent extraction or solid phase
microextraction of tuber tissue and analysis of the extract by, for
example, high performance liquid chromatography-mass spectrometry
or gas chromatography-mass spectrometry. Levels of breakdown
products in potato tuber tissue will be dependent upon cultivar,
length of exposure to the parent compound(s), storage time and
storage temperature, etc. Generally, detection of the presence of
one or more of the breakdown products at a level in the range of
from about 14 ng/g fresh weight to about 1000 ng/g fresh weight,
and preferably at least about twice the level present in
non-treated potatoes, is sufficient to establish that potato tubers
have previously been exposed to C3 to C14
.alpha.,.beta.-unsaturated aldehydes and ketones. Those of skill in
the art will recognize that control potatoes are typically potatoes
that have not been exposed to C3 to C14 .alpha.,.beta.-unsaturated
aldehydes and ketones from exogenous sources, but which may
naturally contain background levels of the metabolites of interest,
which do occur naturally in potato tubers. The following
non-limiting examples serve to further illustrate the practice of
the invention.
EXAMPLES
Example 1
Determination of the Metabolites of 3-nonen-2-one (3N2) and
trans-2-nonenal (T2N)
[0052] The objective of this study was to determine the metabolites
of 3-nonen-2-one (3N2) and trans-2-nonenal (T2N), which are two
examples of .alpha.,.beta.-unsaturated aldehydes and ketones that
inhibit sprouting in potatoes as described in U.S. Pat. No.
6,855,669. Potato tubers were treated with 3N2 or T2N (0.75 mmol/kg
tuber) for 24 h in a closed chamber. The chemicals were volatilized
from filter paper inside the chamber. The tubers were removed from
the treatment chamber and placed at 9.degree. C. for up to 28
days.
[0053] Samples were taken for analysis of residues and metabolite
identification over the 28-day storage period. FIG. 1 shows that
the tubers metabolized the 3N2 to 2-nonanone and 2-nonanol.
2-Nonanol was the most persistent, maintaining a 1.2 ppm residue in
the outermost 20 mm of tubers through 28 days following treatment
with 3N2 (FIG. 1). When tubers were treated similarly with T2N, the
metabolites were trans-2-nonen-1-ol, nonanal and 1-nonanol (FIG.
2). The trends in residue levels were similar to that of 3N2 and
the most persistent metabolite was trans-2-nonen-1-ol.
Example 2
Use of nonanal, 1-nonanol, and trans-2-nonen-1-ol as Inhibitors of
Sprouting of Potato Tubers
[0054] The objective of this study was to determine the extent to
which nonanal, 1-nonanol, and trans-2-nonene-1-ol (metabolites of
T2N) inhibit sprouting of potato tubers relative to T2N. Tubers
were treated separately with 0.25, 0.5 and 0.75 mmol/kg of T2N,
nonanal, 1-nonanol, and trans-2-nonene-1-ol for 24 h as described
in Example 1. The treated tubers were placed at 19.degree. C. and
sprout fresh weights were measured 21 days after treatment. The
percentage inhibition of sprouting relative to untreated control
tubers is shown in Table 1. T2N inhibited sprouting (100%) at all
concentrations. Nonanal and 1-nonanol inhibited sprouting by 13 to
51%, depending on the compound and the concentration that was
used.
TABLE-US-00001 TABLE 1 Effects of 9-carbon aliphatic aldehydes and
primary alcohols on sprouting of potato tubers. mmol/kg tubers 0.25
0.5 0.75 Inhibitor % Inhibition trans-2-nonenal 100 100 100 nonanal
13.2 32.1 17.0 1-nonanol 28.3 24.5 50.9 trans-2-nonen-1-ol 8.9 62.8
31.6
Example 3
Use of 2-nonanone and 2-nonanol as Inhibitors of Sprouting of
Potato Tubers
[0055] The objective of this study was to determine the extent to
which 2-nonanone and 2-nonanol (metabolites of 3N2) inhibit
sprouting of potato tubers relative to 3N2. Tubers were treated
separately as described in Example 1 with 0, 0.25, 0.5, and 0.75
mmol/kg of 3N2, 2-nonanone, and 2-nonanol. The treated tubers were
placed at 18.degree. C. and sprout fresh weights were measured 21
days after treatment. All three compounds inhibited sprouting at
0.5 and 0.75 mmol/kg, relative to non-treated controls (Table 2).
At 0.50 and 0.75 mmol/kg, 3N2 and 2-nonanone substantially
inhibited sprout growth.
TABLE-US-00002 TABLE 2 Effects of 9-carbon aliphatic ketones and
secondary alcohols on sprouting of potato tubers. mmol/kg tubers
0.25 0.5 0.75 Inhibitor % Inhibition 3-nonen-2-one 99.6 99.9 99.9
2-nonanone 77.22 97.9 98.8 2-nonanol 65.1 79.8 72.9
Example 4
Use of Mixtures of 3N2 and 2-nonanone as Inhibitors of Sprouting of
Potato Tubers
[0056] The objective of this study was to determine the efficacy of
mixtures of 3N2 and its metabolite, 2-nonanone, on sprout
inhibition. Tubers were treated as described in Example 1 with 0 to
0.75 mmol/kg of 3N2 combined factorially with 0 to 0.75 mmol/kg of
2-nonanone. The treated tubers were placed at 22.degree. C. and
sprout fresh weights were measured 21 days after treatment. Sprout
growth from tubers treated with 0.5 and 0.75 mmol/kg 2-nonanone
averaged 58% of non-treated tubers, compared with 9% for 0.75% 3N2
applied alone (FIG. 3). The 0.25 mmol/kg 3N2+0.5 mmol/kg 2-nonanone
treatment inhibited sprouting to the same extent as the 0.75
mmol/kg 3N2 treatment.
Example 5
Use of C3 to C7 Alcohols as Inhibitors of Sprouting of Potato
Tubers
[0057] The objective of this study was to determine the extent to
which 1-heptanol, 1-hexanol, 2-heptanol, trans-2-hepten-1-ol,
trans-2-hexen-1-ol and 1-pentanol (C5 to C7 alcohols) inhibit
sprouting of potato tubers. Tubers were treated separately with
0.25, 0.5, 0.75 or 1 mmol/kg of each alcohol for 24 h as described
in Example 1. The treated tubers were placed at 18.degree. C. and
sprout fresh weights were measured 21 days after treatment. All
compounds inhibited sprouting (Table 3). C7 alcohols inhibited
sprouting by about 50 to about 100%, depending on the precise
treatment.
TABLE-US-00003 TABLE 3 Effects of 5-7-carbon aliphatic primary and
secondary alcohols on sprouting of potato tubers. mmol/kg tubers
0.25 0.50 0.75 Inhibitor % Inhibition 1-pentanol 7.5 32.5 45.8
1-hexanol 36.6 61.3 71.9 1-heptanol 51.8 94.0 95.7
trans-2-hexen-1-ol 96 100.0 100.0 trans-2-hepten-1-ol 91.7 98.7
99.4 2-heptanol 49.4 89.0 97.7
Example 6
Use of an Aliphatic Aldehyde, an Aliphatic Ketone and Two Aliphatic
Alcohols for Long Term Sprout Inhibition in Potato Tubers
[0058] The objective of this study was to determine the extent to
which trans-2-hexen-1-ol, 2-heptanol, decanal, and 3-decanone
inhibit sprouting during extended storage under typical commercial
storage conditions. Premier Russet tubers were treated separately
with 0.75 mmol/kg of each compound in 190 L plastic barrels at room
temperature. Chemicals were volatilized from filter paper within
the barrels which were sealed for 24 hours during application.
Tubers were then stored at 9.degree. C. and sampled monthly to
determine the amount of sprouting on a per tuber basis. All
treatments were re-applied between the second and third month of
storage. The sprout fresh weight per tuber of each of the
treatments over time relative to untreated tubers is shown in FIG.
4. Trans-2-hexen-1-ol was eliminated from the study after 83 days
due to excessive damage to the periderm, but sprouts were
effectively controlled up to this point. 2-heptanol and decanal
suppressed sprouting for 114 days (about 4 months of control).
3-decanone suppressed sprouting for 83 days.
[0059] While the invention has been described in terms of its
preferred embodiments, those skilled in the art will recognize that
the invention can be practiced with modification within the spirit
and scope of the appended claims. Accordingly, the present
invention should not be limited to the embodiments as described
above, but should further include all modifications and equivalents
thereof within the spirit and scope of the description provided
herein.
* * * * *