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Michael C. Qian - One of the best experts on this subject based on the ideXlab platform.
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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 Fan, Michael C. QianAbstract: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 ...
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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 Fan, Michael C. QianAbstract: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 ...
Andrea Buettner - One of the best experts on this subject based on the ideXlab platform.
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Identification of odorous compounds in oak wood using odor extract dilution analysis and two-dimensional gas chromatography-mass spectrometry/Olfactometry.
Analytical and bioanalytical chemistry, 2018Co-Authors: Rahil Ghadiriasli, Maria Wagenstaller, Andrea BuettnerAbstract:Over the centuries, oak wood has been used in the maturation process of alcoholic beverages imparting aroma and flavor notes. Whereas several studies have dealt with the impact of oak wood on the chemical composition of, for example, wine aroma, only limited information is available on the odorant composition of unmodified and raw oak wood itself. To close this gap, a combination of human sensory and chemo-analytical techniques was applied for the elucidation of the chemical composition of oak odor, comprising extraction of the volatile fraction of oak wood by means of solvent-assisted flavor evaporation (SAFE) and subsequent mild concentration of the distillate. Odor extract dilution analysis (OEDA), which is based on gas chromatography-Olfactometry (GC-O), was then applied for the targeted characterization of the odor-active compounds. Overall, a total of 97 odorants was identified via gas chromatography-mass spectrometry/Olfactometry (GC-MS/O) and heart-cut two-dimensional gas chromatography-mass spectrometry/Olfactometry (2D-GC-MS/O). The majority of these odorants comprised a series of terpenes, mainly mono- and sesquiterpenes, aldehydes, acids, and lactones, as well as a number of odorants containing a phenolic core moiety. Several odorants are reported here for the first time as volatile organic compounds in oak wood. Identification of the molecular composition of oak wood odor helps to establish a better understanding of the distinctive smell of oak wood, and offers the basis for unveiling its potential effects on humans when being exposed to oak wood smell in daily life. Graphical abstract ᅟ.
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resolving the smell of wood identification of odour active compounds in scots pine pinus sylvestris l
Scientific Reports, 2018Co-Authors: Linda Schreiner, Patrick Bauer, Andrea BuettnerAbstract:Being one of the most common trees in forests, Pinus sylvestris L. is a frequently used raw material for wood products. Its specific odour is, however, mostly unresolved to date. Accordingly, we investigated Scots pine wood samples grown in Germany for their main odorant composition. We employed dedicated odorant analysis techniques such as gas chromatography-Olfactometry (GC-O) and aroma extract dilution analysis (AEDA) and successfully detected 44 odour-active compounds; of these, 39 substances were successfully identified by gas chromatography-mass spectrometry/Olfactometry (GC-MS/O) and two-dimensional gas chromatography-mass spectrometry/Olfactometry (2D-GC-MS/O). Among the main odorants found were (E,E)-nona-2,4-dienal, vanillin, phenylacetic acid, 3-phenylpropanoic acid, δ-octalactone and α-pinene, all of them having been detected with high flavour dilution factors during GC-O analyses. The majority of the identified odorants were fatty acid degradation products, plus some terpenoic substances and odorous substances resulting from the degradation of lignin. Although some of the detected substances have previously been reported as constituents of wood, 11 substances are reported here for the first time as odour-active compounds in wood, amongst them heptanoic acid, γ-octalactone, δ-nonalactone and (E,Z,Z)-trideca-2,4,7-trienal.
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Identification of odorants in wood of Calocedrus decurrens (Torr.) Florin by aroma extract dilution analysis and two-dimensional gas chromatography-mass spectrometry/Olfactometry.
Analytical and bioanalytical chemistry, 2017Co-Authors: Linda Schreiner, Helene M. Loos, Andrea BuettnerAbstract:General emissions of volatile organic compounds from wood are well investigated, but only limited information is available on the odor-active substances contained therein. To close this gap, we aimed at specifically elucidating the odorous constituents of wood from incense cedar [Calocedrus decurrens (Torr.) Florin]; this material is commonly used for the production of a range of products such as pencils and interior accessories. Targeted odorant analysis requires specialized techniques combining modern odorant analytical tools with human-sensory evaluation. Following this concept, the odor profile of the wood sample was first evaluated by human-sensory analyses. Then, the most potent wood odorants were characterized by means of gas chromatography–Olfactometry and ranked according to their odor potency via aroma extract dilution analysis. With use of this approach, more than 60 odorous substances were detected, and the 22 most potent odorants were successfully identified by gas chromatography–mass spectrometry/Olfactometry and two-dimensional gas chromatography–mass spectrometry/Olfactometry. Among the main odorants found were a series of terpenes, several degradation products of fatty acids, and a number of odorants with a phenolic core moiety. Five odorants are reported here for the first time as wood odorants, such as γ-octalactone and 3-phenylpropanoic acid; thymoquinone was demonstrated for the first time to have a pencil-like odor quality.
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identification of odorants in frankincense boswellia sacra flueck by aroma extract dilution analysis and two dimensional gas chromatography mass spectrometry Olfactometry
Phytochemistry, 2015Co-Authors: Johannes Niebler, Andrea BuettnerAbstract:Frankincense has been known, traded and used throughout the ages for its exceptional aroma properties, and is still commonly used in both secular and religious settings to convey a pleasant odor. Surprisingly, the odoriferous principle(s) underlying its unique odor profile have never been published. In this study, resin samples of Boswellia sacra Flueck. from both Somalia and Oman were investigated by aroma extract dilution analysis. In a comprehensive, odor-activity guided approach both chemo-analytical and human-sensory parameters were used to identify odor active constituents of the volatile fraction of B. sacra. Among the key odorants found were α-pinene, β-myrcene, linalool, p-cresol and two unidentified sesquiterpenoids. Overall, a total of 23 odorants were detected and analyzed by gas chromatography–Olfactometry and heart-cut two-dimensional gas chromatography–mass spectrometry/Olfactometry. The majority of the identified odorant compounds were oxygenated monoterpenes, along with some relevant mono- and sesquiterpenes and only one diterpenoid substance. Several of these compounds were reported here for the first time as odorous constituents in B. sacra. Identifying bioactive compounds might support a better understanding with regard to the potential benefits of frankincense, for example in aromatherapy or ecclesial settings.
Elisabeth Guichard - One of the best experts on this subject based on the ideXlab platform.
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GC-Olfactometry and odour recombination
2015Co-Authors: Elisabeth GuichardAbstract:GC-Olfactometry and odour recombination. 16. international symposium on olfaction and electronic nose
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changes in headspace volatile concentrations of coffee brews caused by the roasting process and the brewing procedure
Journal of Agricultural and Food Chemistry, 2006Co-Authors: Isabel Lopezgalilea, Nicole Fournier, Elisabeth GuichardAbstract:Headspace-solid-phase microextraction technique (HS-SPME) coupled with gas chromatography−mass spectrometry (GC-MS) and gas chromatography−Olfactometry (GC-O) were used to characterize the aroma compounds of coffee brews from commercial conventional and torrefacto roasted coffee prepared by filter coffeemaker and espresso machine. A total of 47 volatile compounds were identified and quantified. Principal component analysis (PCA) was applied to differentiate coffee brew samples by volatile compounds. Conventional and torrefacto roasted coffee brews were separated successfully by principal component 1 (68.5% of variance), and filter and espresso ones were separated by principal component 2 (19.5% of variance). By GC Olfactometry, a total of 34 aroma compounds have been perceived at least in half of the coffee extracts and among them 28 were identified, among which octanal was identified for the first time as a contributor to coffee brew aroma. Keywords: Coffee; HS-SPME; GC-MS; GC-O; torrefacto, espresso cof...
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Changes in headspace volatile concentrations of coffee brews caused by the roasting process and the brewing procedure
Journal of Agricultural and Food Chemistry, 2006Co-Authors: Isabel López-galilea, Concepción Cid, Nicole Fournier, Elisabeth GuichardAbstract:Headspace-solid-phase microextraction technique (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) and gas chromatography-Olfactometry (GC-O) were used to characterize the aroma compounds of coffee brews from commercial conventional and torrefacto roasted coffee prepared by filter coffeemaker and espresso machine. A total of 47 volatile compounds were identified and quantified. Principal component analysis (PCA) was applied to differentiate coffee brew samples by volatile compounds. Conventional and torrefacto roasted coffee brews were separated successfully by principal component 1 (68.5% of variance), and filter and espresso ones were separated by principal component 2 (19.5% of variance). By GC Olfactometry, a total of 34 aroma compounds have been perceived at least in half of the coffee extracts and among them 28 were identified, among which octanal was identified for the first time as a contributor to coffee brew aroma.
Jean-pierre Dufour - One of the best experts on this subject based on the ideXlab platform.
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The combination of gas chromatography-Olfactometry and multidimensional gas chromatography for the characterisation of essential oils.
Journal of chromatography. A, 2006Co-Authors: Graham Eyres, Philip J. Marriott, Jean-pierre DufourAbstract:A research area of great interest to the flavour industry is the analysis of odour active compounds in essential oils. In this paper, a methodology is presented for the identification of character-impact odorants in essential oil samples using (a) gas chromatography-Olfactometry (GC-O); (b) comprehensive two-dimensional gas chromatography (GC x GC) combined to time-of-flight mass spectrometry (TOFMS) and (c) heart-cut multidimensional gas chromatography-Olfactometry (MDGC-O). The specific advantages and limitations of each technique are discussed. The advantage of combining these techniques in a strategy to identify character-impact odorants is demonstrated using examples from coriander leaf (Coriandrum sativum) and hop (Humulus lupulus) essential oils. In particular, resolution of co-eluting regions of compounds and evaluation of their individual odour activity is discussed. In coriander leaf, only E-2-dodecenal was found to contribute to a co-eluting odour region, E-2-dodecen-1-ol and 1-dodecanol being present below detection threshold. Using MDGC on a hop essential oil sample, eight significant peaks were resolved from an 18 s heart-cut where a potent odorant was perceived during GC-O.
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Gas chromatography-Olfactometry
Journal of Separation Science, 2006Co-Authors: Claire M. Delahunty, Graham Eyres, Jean-pierre DufourAbstract:GC-Olfactometry (GC-O) refers to the use of human assessors as a sensitive and selective detector for odour-active compounds. The aim of this technique is to determine the odour activity of volatile compounds in a sample extract, and assign a relative importance to each compound. Methods can be classified into three types: detection frequency, dilution to threshold and direct intensity. Dilution to threshold methods measure the potency of odour-active compounds by using a series of extract dilutions, whereas detection frequency and direct-intensity methods measure odour-active compound intensity, or relative importance, in a single concentrated extract. Factors that should be considered to improve the value of GC-O analysis are the extraction method, GC instrument conditions, including the design and operation of the odour port, methods of recording GC-O data and controlling the potential for human assessor bias using experimental design and a trained panel. Considerable emphasis is placed on the requirement for multidimensional GC analysis, and on best practice when using human assessors.
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Gas chromatography‐Olfactometry
Journal of separation science, 2006Co-Authors: Claire M. Delahunty, Graham Eyres, Jean-pierre DufourAbstract:GC-Olfactometry (GC-O) refers to the use of human assessors as a sensitive and selective detector for odour-active compounds. The aim of this technique is to determine the odour activity of volatile compounds in a sample extract, and assign a relative importance to each compound. Methods can be classified into three types: detection frequency, dilution to threshold and direct intensity. Dilution to threshold methods measure the potency of odour-active compounds by using a series of extract dilutions, whereas detection frequency and direct-intensity methods measure odour-active compound intensity, or relative importance, in a single concentrated extract. Factors that should be considered to improve the value of GC-O analysis are the extraction method, GC instrument conditions, including the design and operation of the odour port, methods of recording GC-O data and controlling the potential for human assessor bias using experimental design and a trained panel. Considerable emphasis is placed on the requirement for multidimensional GC analysis, and on best practice when using human assessors.
Wenlai Fan - One of the best experts on this subject based on the ideXlab platform.
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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 Fan, Michael C. QianAbstract: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 ...
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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 Fan, Michael C. QianAbstract: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 ...
