Peach Carboxylesterase PpCXE1 Is Associated with Catabolism of Volatile Esters

Examples from various harvest regimes, storage regimes, cultivars and different packaging methods are presented to characterize volatile ester differences after cutting and how changes occur in characteristic flavors throughout the postharvest life of certain cut fruit products. In many fresh-cut cantaloupe cultivars and in honeydew, there was a relative increase in nonacetates and coinciding relative decrease in acetates during storage. A similar and consistent nonacetate:acetate ester ratio was conserved in cantaloupe from eastern and western U.S. regions, as well as different cultivars from the same field. Furthermore, similar ratios were observed in many melon cultivars over multiple years from different seasons and growing regions. Since many cultivars exhibited similar trends in 2-year repeated studies, the trend is apparently independent of year and season. Fresh-cut `Gala' apples, on the other hand, displayed a slightly different trend whereby both acetates and nonacetate esters decreased appreciably during storage. The hypothesis is put forward that recycling of esters during storage in certain fresh-cut fruits disturbs the delicate fine balance of characteristic volatiles. Consistently decreasing acetates along with increasing nonacetates could alter the overall perceived desirable flavor attributes during fresh-cut melon storage, even though volatile esters are still abundant.

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A New Role For Green Leaf Volatile Esters in Tomato Stomatal Defense Against Pseudomonas syringe pv. tomato

Frontiers in Plant Science ◽

10.3389/fpls.2018.01855 ◽

2018 ◽

Vol 9 ◽

Cited By ~ 12

Author(s):

María Pilar López-Gresa ◽

Celia Payá ◽

Miguel Ozáez ◽

Ismael Rodrigo ◽

Vicente Conejero ◽

...

Keyword(s):

Green Leaf ◽

Green Leaf Volatile ◽

Volatile Esters

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Vapor Pressures of Low-Volatile Esters of 2,4-D

Weed Science ◽

10.1017/s0043174500047986 ◽

1968 ◽

Vol 16 (4) ◽

pp. 541-544 ◽

Cited By ~ 8

Author(s):

G. W. Flint ◽

J. J. Alexander ◽

O. P. Funderburk

Keyword(s):

Dichlorophenoxyacetic Acid ◽

Gas Liquid Chromatography ◽

Vapor Pressures ◽

Butyl Ether ◽

Ether Linkage ◽

2,4 Dichlorophenoxyacetic Acid ◽

Hydrocarbon Alcohols ◽

Long Chain ◽

Volatile Esters ◽

Chain Hydrocarbon

The vapor pressures of the four most common commercial low-volatile esters and a reference high-volatile ester of 2,4-dichlorophenoxyacetic acid (2,4-D) were determined by gas-liquid chromatography. The order of increasing volatility and the vapor pressure of these esters in mm of Hg at 187 C are as follows: isooctyl—2.7; 2-ethylhexyl—3.0; butoxy ethanol—3.9; propylene glycol butyl ether—3.9; and the reference, isopropyl—16.7. Extrapolations to 25 C support this ranking at working temperatures. Commercial esters of 2,4-D derived from long-chain hydrocarbon alcohols are in the same volatility range as the commercial esters containing an ether linkage.

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Biological activity of 2,4-D esters on rubber vine (Cryptostegia grandiflora): dependence on vapour pressure and molecular weight and isomerism of the alcohol substituent

Australian Journal of Agricultural Research ◽

10.1071/ar9890685 ◽

1989 ◽

Vol 40 (3) ◽

pp. 685

Author(s):

GJ Harvey

Keyword(s):

Molecular Weight ◽

Vapour Pressure ◽

Low Molecular Weight ◽

Straight Chain ◽

Biological Efficacy ◽

Cryptostegia Grandiflora ◽

Normal Series ◽

Branched Chain ◽

The Relationship ◽

Volatile Esters

The relationship between molecular structure and biological efficacy was investigated for 16 esters of 2,4-D [(2,4-dich1orophenoxy)acetic acid] on rubber vine (Cryptostegia grandiflora). These included the normal (n) or straight-chain esters from C-1 (methyl) to C-8 (octyl), the n-decyl, n-dodecyl, isobutyl, amyl (iso-pentyl), 2-ethylhexyl (iso-octyl), and the methoxy-, ethoxy-, and butoxyethyl esters. For the normal series esters, biological efficacy was found to be a function of both the molecular weight and the vapour pressure of the esters. This relationship was linear for the higher molecular weight, low volatile esters, biological efficacy decreasing with increasing molecular weight and the accompanying decrease in vapour pressure of the esters. The low molecular weight, volatile esters were more active than the higher molecular weight, low volatile esters, and increases in the vapour pressure of these low molecular weight, volatile esters were sufficient to account for the deviation from linearity of those esters. When all esters are considered, the same relationships hold but the branched-chain (iso) and chemically substituted (alkoxy alcohol) esters are less effective than the corresponding normal esters. Possible reasons for these results are discussed.

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