L’utilisation du couplage CG-SM et des differents modes d'ionisation permet de resoudre 95 % du courant ionique de l'essence de Ruscus aculeatus L. Et d'identifier 120 substances sur les 200 recensees. L'etude de la... more
L’utilisation du couplage CG-SM et des differents modes d'ionisation permet de resoudre 95 % du courant ionique de l'essence de Ruscus aculeatus L. Et d'identifier 120 substances sur les 200 recensees. L'etude de la fragmentation obtenue en ionisation chimique negative a l'aide des ions hydroxyles prouve son interet dans la determination de motifs structuraux. Le comportement particulier des differentes familles chimiques est presente
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Indian cress (Tropaeolum majus L.) absolute was studied by GC-olfactometry (VIDEO-Sniff method) in order to identify odor-active aroma compounds. Because of its fruity-sulfury odor note, a compound that has never been identified in plant... more
Indian cress (Tropaeolum majus L.) absolute was studied by GC-olfactometry (VIDEO-Sniff method) in order to identify odor-active aroma compounds. Because of its fruity-sulfury odor note, a compound that has never been identified in plant extracts before stood out: O,S-diethyl thiocarbonate, present at 0.1% (percentage of the total GC/FID area) in the extract. GCxGC-TOFMS allowed for a clean mass spectrum to be obtained, and isolation by preparative GC followed by NMR studies allowed its identification. Here, we report on the first detection of O,S-diethyl thiocarbonate in Indian cress absolute by GC-olfactometry/VIDEO-Sniff and on its isolation and identification. The synthesis and odor evaluation of its homologues are presented.
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Engineering, Chemistry, Magnetic Resonance Spectroscopy, Medicine, Humans, and 13 moreSmell, Gas Chromatography, ODOR, Aroma, CHEMICAL SCIENCES, GAS LIQUID CHROMATOGRAPHY, Odors, Gas Chromatography/mass Spectrometry, Agricultural and Food Chemistry, Magnesium Hydroxide Industry Trend, Sniffing, Tropaeolum, and Drug combinations
Odor impact compounds of Tagetes minuta L. essential oil were studied by gas chromatography (GC)-olfactometry using aroma extract dilution analysis (AEDA) and vocabulary-intensity-duration of elementary odors by sniffing (VIDEO-Sniff).... more
Odor impact compounds of Tagetes minuta L. essential oil were studied by gas chromatography (GC)-olfactometry using aroma extract dilution analysis (AEDA) and vocabulary-intensity-duration of elementary odors by sniffing (VIDEO-Sniff). AEDA was conducted by direct injection and revealed the presence of 43 odorant zones. Highest flavor dilution (FD) values were obtained for ethyl 2-methylpropanoate, ethyl 3-methylbutanoate, (E)-ocimenone, two tentatively identified thiols, and two yet unknown compounds. VIDEO-Sniff was realized by dynamic headspace sampling (D-HS) combined with 8W-GC-olfactometry where eight sniffers simultaneously detect volatile compounds obtained from a single chromatographic separation and revealed the presence of 42 odorant zones. Odorant trace compounds detected by GC-O that were present in quantities inferior to the GC-qMS system's detection limit and those subject to coelutions were identified by GC x GC-time-of-flight mass spectrometry (TOFMS). A total amount of 37 odorant components could be identified by VIDEO-Sniff, and the strong influence of the fruity notes of numerous esters stood out. Highest olfactory signals were obtained for ethyl 2-methylpropanoate, ethyl 2- and 3-methylbutanoate, and oct-1-en-3-one. Both methods hence come to the conclusion that ethyl 2-methylpropanoate and ethyl 2- and 3-methylbutanoate are among the main odorants in Tagetes minuta L. essential oil. Differences, advantages, and drawbacks of both GC-O methods are discussed.
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Engineering, Chemistry, Coffee, Mass Spectrometry, Medicine, and 14 moreFood Analysis, Gas Sensors, Biological Sciences, Cooking, Volatile Organic Compounds, Foods, Process Analysis, Online Systems, CHEMICAL SCIENCES, Beverages, Time Factors, Analytical and Bioanalytical Chemistry, Protons, and Roasting
As a result of a positive response to a dithiocarbamate test, the sulphur content of caper volatiles has been investigated by GC-MS. In addition to sulphides, isothiocyanates and other flavour molecules, elemental sulphur (S 8 ) was... more
As a result of a positive response to a dithiocarbamate test, the sulphur content of caper volatiles has been investigated by GC-MS. In addition to sulphides, isothiocyanates and other flavour molecules, elemental sulphur (S 8 ) was identified for the first time in a non-processed ...
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We report on the in vivo breath-by-breath analysis of volatiles released in the mouth during eating of ripe and unripe banana. The air exhaled through the nose, nosespace (NS), is directly introduced into a proton transfer reaction mass... more
We report on the in vivo breath-by-breath analysis of volatiles released in the mouth during eating of ripe and unripe banana. The air exhaled through the nose, nosespace (NS), is directly introduced into a proton transfer reaction mass spectrometer and the time-intensity profiles of a series of volatiles are monitored on-line. These include isopentyl and isobutyl acetate, two characteristic odour compounds of ripe banana, and 2E-hexenal and hexanal, compounds typical of unripe banana. Comparing the NS with the headspace (HS) profile, two differences are outlined. First, NS concentrations of some compounds are increased, compared to the HS, while others are decreased. This indicates that the in-mouth situation has characteristics of its own—mastication, mixing/dilution with saliva, temperature and pH—which modify the aroma relative to an HS aroma. Second, we discuss the temporal evolution of the NS. While 2E-hexenal and hexanal steadily increase in the NS during mastication of unrip...
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ABSTRACT Many flavour regulations around the world contain a list of so-called ‘restricted substances’ (RS), i.e. substances that occur naturally in source materials for flavourings and food ingredients with flavouring properties, but... more
ABSTRACT Many flavour regulations around the world contain a list of so-called ‘restricted substances’ (RS), i.e. substances that occur naturally in source materials for flavourings and food ingredients with flavouring properties, but whose presence in certain foods is restricted and/or for which maximum levels are set, for example, the European regulation 1334/2008. Only a few publications refer to the determination of RS in compound flavourings or their raw materials, and the latter only concern the analysis of one or two individual RS in single essential oils. The Working Group on Methods of Analysis of the International Organization of the Flavor Industry (IOFI) has developed a method for the rapid routine determination of β-asarone, coumarin, menthofuran, methylchavicol, methyleugenol, pulegone, safrole and α- and β-thujones in flavourings and their raw materials by gas chromatography-mass spectrometry (GC-MS), using selected-ion monitoring and internal standards. The method has been evaluated by nine flavour-industry laboratories using a complex surrogate flavouring containing all of the above analytes, at concentrations that would be likely to produce levels in finished foods of around typical maximum limits for these RS. Results were obtained from a total of 15 columns and sets of analytical conditions, using 11 GC/MS instruments, with in each case a determination of the analyte in two versions of the flavouring. With reproducibility relative standard deviations (RSDR) of less than about 20%, and recoveries of 80–120%, the method performance can be considered as satisfactory for rapid routine checks on the levels of restricted substances in compound flavourings. The method is intended for flavour-industry laboratories in order for them to fulfil their obligation to inform food-industry clients of the amounts of these substances in commercial flavourings, but is not intended for their analysis in finished foods. Copyright © 2014 John Wiley & Sons, Ltd.
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This study aimed to discriminate 22 samples of commercial Iris rhizomes (orris root) by species and origin (Iris germanica (Morocco), I. albicans (Morocco), I. pallida (Morocco), I. pallida (China), I. pallida (Italy)) by applying a... more
This study aimed to discriminate 22 samples of commercial Iris rhizomes (orris root) by species and origin (Iris germanica (Morocco), I. albicans (Morocco), I. pallida (Morocco), I. pallida (China), I. pallida (Italy)) by applying a strategy derived from those adopted in metabolomics. The specimens' fingerprints from conventional analysis methods (LC-UV and/or LC-MS) were unable to provide clear discrimination. A strategy combining UHPLC/TOF-HRMS, in positive and negative modes, with multivariate statistical methods was therefore applied. Exact mass/retention time (EMRT) pairs obtained by UHPLC-TOF/HRMS were successfully submitted to statistical processing by principal component analysis (PCA), partial least square discriminant analysis (PLS-DA), and then orthogonal partial least square-discriminant analysis (OPLS-DA), to extract the discriminating EMRT pairs through their trend views. 146 EMRT pairs were selected on the basis of their trend views, because they significantly var...
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Vetiver essential oils (VEO) are important raw ingredients used in perfume industry, entering the formula of numerous modern fragrances. Vetiver oils are considered to be among the most complex essential oils, resulting most of the time... more
Vetiver essential oils (VEO) are important raw ingredients used in perfume industry, entering the formula of numerous modern fragrances. Vetiver oils are considered to be among the most complex essential oils, resulting most of the time in highly coeluted chromatograms whatever the analytical technique. In this context, conventional gas chromatography has failed to provide a routine tool for the accurate qualitative and quantitative analysis of their constituents. Applying comprehensive two-dimensional gas chromatography techniques (GC×GC-FID/MS) afforded the mean to separate efficiently vetiver oil constituents in order to identify them in a more reliable way. Moreover, this is the first time that a complete true quantitation of each constituent is carried out on such complex oils by means of internal calibration. Finally, we have studied the influence of the injection mode on the determined chemical composition, and showed that several alcohols underwent dehydration under defined chromatographic conditions (splitless mode) usually recommended for quantitation purposes.
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Engineering, Chemistry, Magnetic Resonance Spectroscopy, Medicine, Humans, and 13 moreSmell, Gas Chromatography, ODOR, Aroma, CHEMICAL SCIENCES, GAS LIQUID CHROMATOGRAPHY, Odors, Gas Chromatography/mass Spectrometry, Agricultural and Food Chemistry, Magnesium Hydroxide Industry Trend, Sniffing, Tropaeolum, and Drug combinations
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Odor impact compounds of Tagetes minuta L. essential oil were studied by gas chromatography (GC)-olfactometry using aroma extract dilution analysis (AEDA) and vocabulary-intensity-duration of elementary odors by sniffing (VIDEO-Sniff).... more
Odor impact compounds of Tagetes minuta L. essential oil were studied by gas chromatography (GC)-olfactometry using aroma extract dilution analysis (AEDA) and vocabulary-intensity-duration of elementary odors by sniffing (VIDEO-Sniff). AEDA was conducted by direct injection and revealed the presence of 43 odorant zones. Highest flavor dilution (FD) values were obtained for ethyl 2-methylpropanoate, ethyl 3-methylbutanoate, (E)-ocimenone, two tentatively identified thiols, and two yet unknown compounds. VIDEO-Sniff was realized by dynamic headspace sampling (D-HS) combined with 8W-GC-olfactometry where eight sniffers simultaneously detect volatile compounds obtained from a single chromatographic separation and revealed the presence of 42 odorant zones. Odorant trace compounds detected by GC-O that were present in quantities inferior to the GC-qMS system's detection limit and those subject to coelutions were identified by GC x GC-time-of-flight mass spectrometry (TOFMS). A total amount of 37 odorant components could be identified by VIDEO-Sniff, and the strong influence of the fruity notes of numerous esters stood out. Highest olfactory signals were obtained for ethyl 2-methylpropanoate, ethyl 2- and 3-methylbutanoate, and oct-1-en-3-one. Both methods hence come to the conclusion that ethyl 2-methylpropanoate and ethyl 2- and 3-methylbutanoate are among the main odorants in Tagetes minuta L. essential oil. Differences, advantages, and drawbacks of both GC-O methods are discussed.
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Engineering, Chemistry, Chromatography, Medicine, Humans, and 15 moreVolatile Organic Compounds, Smell, Gas Chromatography, ODOR, Agricultural, CHEMICAL SCIENCES, Plant extracts, Odors, Comprehensive Two Dimensional Gas Chromatography, Olfactometry, Gas Chromatography/mass Spectrometry, Agricultural and Food Chemistry, Sniffing, Volatile Compounds, and Tropaeolum
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Pyrrolizidine alkaloids are naturally occurring toxins produced by certain weeds that can, if accidentally co-harvested, contaminate plant-based food, feed, and herbal medicinal products. Focusing on herbal medicinal products, the... more
Pyrrolizidine alkaloids are naturally occurring toxins produced by certain weeds that can, if accidentally co-harvested, contaminate plant-based food, feed, and herbal medicinal products. Focusing on herbal medicinal products, the presence of pyrrolizidine alkaloids is restricted by regulatory prescribed thresholds to assure patient safety. Among the multitude of different herbal active substances utilized in herbal medicinal products, the class of pharmaceutically effective essential oils is considered to exhibit a negligible contribution to pyrrolizidine alkaloid contamination. Within the present investigation, this hypothesis should be scientifically scrutinized. For this purpose, an experimental set-up was chosen that reproduces the typical manufacturing step of hydrodistillation. Essential oils of eucalyptus and lemon were selected exemplarily and spiked with 3 representative pyrrolizidine alkaloids (retrorsine, retrorsine-N-oxide, and lycopsamine), whereupon hydrodistillation ...
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A targeted search for heliotropin (or piperonal) in the flower fragrance of heliotrope and in cured vanilla beans of Tahitian origin is reported. Heliotropin is not detected in the fragrance emitted by heliotrope, using dynamic headspace... more
A targeted search for heliotropin (or piperonal) in the flower fragrance of heliotrope and in cured vanilla beans of Tahitian origin is reported. Heliotropin is not detected in the fragrance emitted by heliotrope, using dynamic headspace SBSE sampling, followed by thermal desorption and analysis by conventional GC-MS. Main constituents are anisaldehyde and benzaldehyde, which confirms previous findings. Less than one part per million of heliotropin is accurately detected in authentic Tahitian vanilla bean, in using both GC-MS and LC-MS/MS. This confirms previous observations, which had shown that 4-methoxyaromatic compounds are the characteristic elements in the flavor of Tahitian vanilla, with p-anisaldehyde as the the main aroma donator. We suggest that heliotropin was named after the discovery of piperonal by degradation of piperine, the odor of which was reminiscent of the heliotrope flower. Later, its identification in vanilla extracts was the result of either a wrong interpret...