1,298 research outputs found

    Quantitative analysis of headspace volatile compounds using comprehensive two-dimensional gas chromatography and their contribution to the aroma of Chardonnay wine.

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    The quantitative determination of volatile compounds of Chardonnay wines using HS-SPME-GC × GC/TOFMS along with the determination of odor activity value (OAV) and relative odor contribution (ROC) of volatiles are reported for the first time. The use of GC × GC/TOFMS for the analysis of Chardonnay wine of Serra Gaucha resulted in the tentative identification of 243 compounds, showing the superior performance of this analytical technique for this specific varietal wine, considering that the number of compounds usually separated by 1D-GC for this type of wine is lower. Furthermore, 42 compounds co-eluted in the first dimension and 34 of them were separated in the second dimension, while the others were resolved by spectral deconvolution (8), which indicates that the conventional 1D-GC/MS may result in misleading results. The calculation of OAV and ROC allowed the determination of the volatile compounds that presented the greater contribution to wine aroma. Ethyl octanoate, ethyl hexanoate, ethyl butanoate, and beta-damascenone showed the highest OAV and ROC values, although other 43 compounds showed also potential to contribute to wine aroma. Figures of merit of the developed method were: accuracies from 92.4 to 102.6%, repeatability from 1.2% to 13.4%, LOD from 0.001 ?g L?1 (ethyl isovalerate and hexanoic acid) to 2.554 ?g L?1 (ethyl 3-hydroxybutanoate), LOQ from 0.003 ?g L?1 (ethyl isovalerate and hexanoic acid) to 7.582 ?g L?1 (ethyl 3-hydroxybutanoate)

    Determination of the possible contribution to aroma using odor activity values of volatile compounds of wines analyzed by comprehensive two dimensional gas chromatography.

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    The aim of this study was to use the HS-SPME-GC × GC/TOFMS to quantify volatile compounds of wines produced with Chardonnay grapes in Serra Gaúcha region, Brazil and determine their possible contribution to aroma through the determination of OAV for each tentatively identified compound

    Entropy production by resonance decays

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    We investigate entropy production for an expanding system of particles and resonances with isospin symmetry -- in our case pions and ρ\rho mesons -- within the framework of relativistic kinetic theory. A cascade code to simulate the kinetic equations is developed and results for entropy production and particle spectra are presented.Comment: 17 pages, 10 ps-figures included, only change: preprint number adde

    Simultaneous determination of toxic compounds produced during fermentation of wine.

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    The objective of this study was to investigate the need to use of GC×GC to quantify toxic compounds (acetaldehyde, formaldehyde, ethyl carbamate and acrolein) produced during the fermentation of Syrah wine

    Evaluation of toxic compounds produced during the elaboration of Syrah wines.

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    The objective of this study was to verify the occurrence of four toxic compounds (acetaldehyde, formaldehyde, ethyl carbamate and acrolein) in Syrah wines through the use of comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry detection

    Influence of stage of ripeness and time of maceration of Syrah grapes on levels of toxic compounds in wines.

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    The aim of this study was to evaluate the influence of ripeness stage and time of maceration of Syrah grapes on the levels of six toxic compounds (formaldehyde, acetaldehyde, ethyl carbamate, furan, furfural and acrolein) formed during the vinification

    Characterization of risk exposure to carbonyl and furan compounds through wine consumption.

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    The objective of this study was to: (i) quantify acetaldehyde, formaldehyde, ethyl carbamate, furan, furfural and acrolein in wine using headspace-solid phase microextraction (HS-SPME) and comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometric detection (GC×GC/TOFMS) and (ii) characterize the risk of exposure to these toxic compounds through wine consumption

    Quantitative analysis of headspace volatile compounds using comprehensive two-dimensional gas chromatography and their contribution to the aroma of Chardonnay wine.

    Get PDF
    The quantitative determination of volatile compounds of Chardonnay wines using HS-SPME-GC × GC/TOFMS along with the determination of odor activity value (OAV) and relative odor contribution (ROC) of volatiles are reported for the first time. The use of GC × GC/TOFMS for the analysis of Chardonnay wine of Serra Gaucha resulted in the tentative identification of 243 compounds, showing the superior performance of this analytical technique for this specific varietal wine, considering that the number of compounds usually separated by 1D-GC for this type of wine is lower. Furthermore, 42 compounds co-eluted in the first dimension and 34 of them were separated in the second dimension, while the others were resolved by spectral deconvolution (8), which indicates that the conventional 1D-GC/MS may result in misleading results. The calculation of OAV and ROC allowed the determination of the volatile compounds that presented the greater contribution to wine aroma. Ethyl octanoate, ethyl hexanoate, ethyl butanoate, and beta-damascenone showed the highest OAV and ROC values, although other 43 compounds showed also potential to contribute to wine aroma. Figures of merit of the developed method were: accuracies from 92.4 to 102.6%, repeatability from 1.2% to 13.4%, LOD from 0.001 ?g L?1 (ethyl isovalerate and hexanoic acid) to 2.554 ?g L?1 (ethyl 3-hydroxybutanoate), LOQ from 0.003 ?g L?1 (ethyl isovalerate and hexanoic acid) to 7.582 ?g L?1 (ethyl 3-hydroxybutanoate).DOI 10.1016/j.foodres.2014.02.00
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