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Charles E Linn - One of the best experts on this subject based on the ideXlab platform.
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identification of host fruit volatiles from three mayhaw species crataegus series aestivales attractive to mayhaw origin rhagoletis pomonella flies in the southern united states
Journal of Chemical Ecology, 2011Co-Authors: Dong H Cha, Jeffrey L Feder, Thomas H. Q. Powell, Charles E LinnAbstract:The apple maggot fly, Rhagoletis pomonella, infests several hawthorn species in the southern USA. Here, we tested the hypothesis that these populations could serve as reservoirs for fruit odor discrimination behaviors facilitating sympatric host race formation and speciation, specifically the recent shift from downy hawthorn (Crataegus mollis) to domestic apple (Malus domestica) in the northern USA. Coupled gas chromatography and electroantennographic detection (GC-EAD), gas chromatography with mass spectrometry (GC-MS), and flight tunnel bioassays were used to identify the behaviorally active natal fruit volatile blends for three of the five major southern hawthorns: C. opaca (western mayhaw), C. aestivalis (eastern mayhaw), and C. rufula (a possible hybrid between C. opaca and C. aestivalis). A 6-component blend was developed for C. opaca (3-methylbutan-1-ol [44%], pentyl acetate [6%], butyl butanoate [6%], propyl Hexanoate [6%], butyl Hexanoate [26%], and hexyl butanoate [12%]); an 8-component blend for C. aestivalis (3-methylbutan-1-ol [2%], butyl acetate [47%], pentyl acetate [2%], butyl butanoate [12%], propyl Hexanoate [1%], butyl Hexanoate [25%], hexyl butanoate [9%], and pentyl Hexanoate [2%]); and a 9-component blend for C. rufula (3-methylbutan-1-ol [1%], butyl acetate [57%], 3-methylbutyl acetate [3%], butyl butanoate [5%], propyl Hexanoate [1%], hexyl propionate [1%], butyl Hexanoate [23%], hexyl butanoate [6%], and pentyl Hexanoate [3%]). Crataegus aestivalis and C. opaca-origin flies showed significantly higher levels of upwind directed flight to their natal blend in flight tunnel assays compared to the non-natal blend and previously developed apple, northern downy hawthorn, and flowering dogwood blends. Eastern and western mayhaw flies also were tested to the C. rufula blend, with eastern flies displaying higher levels of upwind flight compared with the western flies, likely due to the presence of butyl acetate in the C. aestivalis and C. rufula blends, an agonist compound for eastern mayhaw-origin flies, but a behavioral antagonist for western flies. The results discount the possibility that the apple fly was “pre-assembled” and originated via a recent introduction of southern mayhaw flies predisposed to accepting apple. Instead, the findings are consistent with the possibility of southern mayhaw-infesting fly host races. However, mayhaw fruits do emit several volatiles found in apple. It is, therefore, possible that the ability of the fly to evolve a preference for apple volatiles, although not the entire blend, stemmed, in part, from standing variation related to the presence of these compounds in southern mayhaw fruit.
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identification of fruit volatiles from green hawthorn crataegus viridis and blueberry hawthorn crataegus brachyacantha host plants attractive to different phenotypes of rhagoletis pomonella flies in the southern united states
Journal of Chemical Ecology, 2011Co-Authors: Dong H Cha, Jeffrey L Feder, Thomas H. Q. Powell, Charles E LinnAbstract:The apple maggot fly, Rhagoletis pomonella, infests several hawthorn species in the southern USA. In a companion paper, we showed that R. pomonella flies infesting two different mayhaw species (Crataegus opaca and C. aestivalis) can discriminate between volatile blends developed for each host fruit, and that these blends are different from previously constructed blends for northern fly populations that infest domestic apple (Malus domestica), downy hawthorn (Crataegus mollis), and flowering dogwood (Cornus florida). Here, we show by using coupled gas chromatography and electroantennographic detection (GC-EAD), gas chromatography with mass spectrometry (GC-MS), and flight tunnel bioassays, that two additional southern hawthorn fly populations infesting C. viridis (green hawthorn) and C. brachyacantha (blueberry hawthorn) also can discriminate between volatile blends for each host fruit type. A 9-component blend was developed for C. viridis (3-methylbutan-1-ol [5%], butyl butanoate [19.5%], propyl Hexanoate [1.5%], butyl Hexanoate [24%], hexyl butanoate [24%], pentyl Hexanoate [2.5%], 1-octen-3-ol [0.5%], pentyl butanoate [2.5%], and (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) [20.5%]) and an 8-component blend for C. brachyacantha (3-methylbutan-1-ol [0.6%], butyl acetate [50%], pentyl acetate [3.5%], butyl butanoate [9%], butyl Hexanoate [16.8%], hexyl butanoate [16.8%], 1-octen-3-ol [0.3%], and pentyl butanoate [3%]). Crataegus viridis and C. brachyacantha-origin flies showed significantly higher levels of upwind oriented flight to their natal blend in flight tunnel assays compared to the alternate, non-natal blend and previously developed northern host plant blends. The presence of DMNT in C. viridis and butyl acetate in C. brachyacantha appeared to be largely responsible for driving the differential response. This sharp behavioral distinction underscores the diversity of odor response phenotypes in the southern USA, points to possible host race formation in these populations, and despite the presence of several apple volatiles in both blends, argues against a functional apple race existing on southern host plants prior to the introduction of apple to North America.
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identification of host fruit volatiles from hawthorn crataegus spp attractive to hawthorn origin rhagoletis pomonella flies
Journal of Chemical Ecology, 2003Co-Authors: Satoshi Nojima, Charles E Linn, Aijun Zhang, Bruce D Morris, Wendell L RoelofsAbstract:Solid-phase microextraction (SPME) and gas chromatography coupled with electroantennographic detection (GC-EAD) were used to identify volatile compounds from hawthorn fruit (Crataegus spp.) acting as behavioral attractants for hawthorn-infesting Rhagoletis pomonella flies. Consistent EAD activity was obtained for six chemicals: ethyl acetate (94.3%), 3-methylbutan- 1-ol (4.0%), isoamyl acetate (1.5%), 4,8-dimethyl-1,3(E),7-nonatriene (0.07%), butyl Hexanoate (0.01%), and dihydro-β-ionone (0.10%). In a flight-tunnel bioassay, there was a dose-related increase in the percentage of flies flying upwind to the six-component mixture. Hawthorn-origin flies also made equivalent levels of upwind flight with the synthetic blend and an adsorbent extract of volatiles collected from whole fruit, each containing the same amount of the 3-methylbutan-1-ol compound. Significantly lower levels of upwind flight occurred to a previously identified volatile blend of ester compounds that attracts R. pomonella flies infesting domestic apples, compared with the hawthorn volatile mix. Selected subtraction assays showed further that the four-component mixture of 3-methylbutan-1-ol, 4,8-dimethyl-1,3(E),7-nonatriene, butyl Hexanoate, and dihydro-β-ionone also elicited levels of upwind flight equivalent to the six-component mix. Removal of 3-methylbutan-1-ol from the four-component blend resulted in complete loss of upwind flight behavior. Removal of dihydro- β-ionone, 4,8-dimethyl-1,3(E),7-nonatriene, or butyl Hexanoate from the four-component mixture resulted in significant decreases in the mean number of upwind flights compared to the four- or six-component mixtures.
Wenlai Fan - One of the best experts on this subject based on the ideXlab platform.
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Characterization of aroma compounds of chinese "Wuliangye" and "Jiannanchun" liquors by aroma extract dilution analysis.
Journal of agricultural and food chemistry, 2006Co-Authors: Wenlai FanAbstract:Aroma compounds in Chinese “Wuliangye” liquor were identified by gas chromatography−olfactometry (GC−O) after fractionation. A total of 132 odorants were detected by GC−O in Wuliangye liquor on DB-wax and DB-5 columns. Of these, 126 aromas were identified by GC−mass spectrometry (MS). Aroma extract dilution analysis (AEDA) was further employed to identify the most important aroma compounds in “Wuliangye” and “Jiannanchun” liquors. The results showed that esters could be the most important class, especially ethyl esters. Various alcohols, aldehydes, acetals, alkylpyrazines, furan derivatives, lactones, and sulfur-containing and phenolic compounds were also found to be important. On the basis of flavor dilution (FD) values, the most important aroma compounds in Wuliangye and Jiannanchun liquors could be ethyl butanoate, ethyl pentanoate, ethyl Hexanoate, ethyl octanoate, butyl Hexanoate, ethyl 3-methylbutanoate, hexanoic acid, and 1,1-diethoxy-3-methylbutane (FD ≥ 1024). These compounds contributed to fruit...
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headspace solid phase microextraction and gas chromatography olfactometry dilution analysis of young and aged chinese yanghe daqu liquors
Journal of Agricultural and Food Chemistry, 2005Co-Authors: Wenlai FanAbstract:The aroma compounds of young and aged Chinese “Yanghe Daqu” liquor samples were extracted by solid phase microextraction (SPME) and analyzed by gas chromatography (GC)−olfactometry dilution analysis. The original liquor samples were diluted with deionized water to give a final alcohol content of 14% (v/v). The samples were stepwise diluted (1:1) with 14% (by volume) ethanol−water solution and then extracted by headspace SPME. The samples were preequilibrated at 50 °C for 15 min and extracted with stirring at the same temperature for 30 min prior to injection into GC. The aroma compounds were identified by both GC-MS and GC−olfactometry using DB-Wax and DB-5 columns. The results suggested that esters were the major contributors to Yanghe Daqu liquor aroma. Ethyl Hexanoate, ethyl butanoate, and ethyl pentanoate had very high flavor dilution values in both young and aged liquors (FD > 8192). Methyl Hexanoate, ethyl heptanoate, ethyl benzoate, and butyl Hexanoate could also be very important because of their ...
Peter Schreier - One of the best experts on this subject based on the ideXlab platform.
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on line gas chromatography combustion pyrolysis isotope ratio mass spectrometry hrgc c p irms of pineapple ananas comosus l merr volatiles
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Christina Preston, Elke Richling, Sandra Elss, Markus Appel, Frank Heckel, And Ariane Hartlieb, Peter SchreierAbstract:By use of extracts prepared by liquid−liquid separation of the volatiles from self-prepared juices of pineapple fruits (Ananas comosus) (n = 14) as well as commercial pineapple recovery aromas/water phases (n = 3), on-line capillary gas chromatography-isotope ratio mass spectrometry was employed in the combustion (C) and the pyrolysis (P) modes (HRGC-C/P-IRMS) to determine the δ13CVPDB and δ2HVSMOW values of selected pineapple flavor constituents. In addition to methyl 2-methylbutanoate 1, ethyl 2-methylbutanoate 2, methyl Hexanoate 3, ethyl Hexanoate 4, and 2,5-dimethyl-4-methoxy-3[2H]-furanone 5, each originating from the fruit, the δ13CVPDB and δ2HVSMOW data of commercial synthetic 1−5 and “natural” (biotechnologically derived) 1−4 were determined. With δ13CVPDB data of pineapple volatiles 1−4 varying from −12.8 to −24.4‰, the range expected for CAM metabolism was observed. Compound 5 showed higher depletion from −20.9 to −28.6‰. A similar situation was given for the δ2HVSMOW values of 3−5 from pineapp...
Luigi Mondello - One of the best experts on this subject based on the ideXlab platform.
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headspace solid phase microextraction coupled to gas chromatography combustion isotope ratio mass spectrometer and to enantioselective gas chromatography for strawberry flavoured food quality control
Journal of Chromatography A, 2011Co-Authors: Luisa Schipilliti, Paola Dugo, Ivana Bonaccorsi, Luigi MondelloAbstract:Authenticity assessment of flavoured strawberry foods was performed using headspace-solid phase microextraction (HS-SPME) coupled to gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). An authenticity range was achieved, investigating on the carbon isotope ratio of numerous selected aroma active volatile components (methyl butanoate, ethyl butanoate, hex-(2E)-enal, methyl Hexanoate, buthyl butanoate, ethyl Hexanoate, hexyl acetate, linalool, hexyl butanoate, octyl isovalerate, γ-decalactone and octyl Hexanoate) of organic Italian fresh strawberries. To the author's knowledge, this is the first time that all these components were investigated simultaneously by GC-C-IRMS on the same sample. The results were compared, when applicable, with those obtained by analyzing the HS-SPME extracts of commercial flavoured food matrices. In addition, one Kenyan pineapple and one fresh Italian peach were analyzed to determine the δ(13)C(VPDB) of the volatile components common to strawberry. The δ(13)C(VPDB) values are allowed to differentiate between different biogenetic pathways (C(3) and CAM plants) and more interestingly between plants of the same CO(2) fixation group (C(3) plants). Additional analyses were performed on all the samples by means of Enantioselective Gas Chromatography (Es-GC), measuring the enantiomeric distribution of linalool and γ-decalactone. It was found that GC-C-IRMS and Es-GC measurements were in agreement to detect the presence of non-natural strawberry aromas in the food matrices studied.
Christina Preston - One of the best experts on this subject based on the ideXlab platform.
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on line gas chromatography combustion pyrolysis isotope ratio mass spectrometry hrgc c p irms of pineapple ananas comosus l merr volatiles
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Christina Preston, Elke Richling, Sandra Elss, Markus Appel, Frank Heckel, And Ariane Hartlieb, Peter SchreierAbstract:By use of extracts prepared by liquid−liquid separation of the volatiles from self-prepared juices of pineapple fruits (Ananas comosus) (n = 14) as well as commercial pineapple recovery aromas/water phases (n = 3), on-line capillary gas chromatography-isotope ratio mass spectrometry was employed in the combustion (C) and the pyrolysis (P) modes (HRGC-C/P-IRMS) to determine the δ13CVPDB and δ2HVSMOW values of selected pineapple flavor constituents. In addition to methyl 2-methylbutanoate 1, ethyl 2-methylbutanoate 2, methyl Hexanoate 3, ethyl Hexanoate 4, and 2,5-dimethyl-4-methoxy-3[2H]-furanone 5, each originating from the fruit, the δ13CVPDB and δ2HVSMOW data of commercial synthetic 1−5 and “natural” (biotechnologically derived) 1−4 were determined. With δ13CVPDB data of pineapple volatiles 1−4 varying from −12.8 to −24.4‰, the range expected for CAM metabolism was observed. Compound 5 showed higher depletion from −20.9 to −28.6‰. A similar situation was given for the δ2HVSMOW values of 3−5 from pineapp...
