Search results for "compounds"
showing 10 items of 3372 documents
Chapter 68 - Identification of Key Gin Aroma Compounds: An Integrative Approach Based on an Original Selection Procedure
2014
International audience; Potential impact aroma compounds of gin have been identified using Gas Chromatogry Olfactometry Mass-Spectrometry (GC-O-MS). In order to select some of them for a recombination study, we developed a specific procedure. Instead of only choosing the compounds on criteria such as their odor quality or their odor activity values, we also used physico-chemical parameters and information on their botanical origin. Data were organized in blocks homogeneous in terms of parameter type. Different statistical treatments were used in order to classify the compounds either by analyzing the parameters altogether or separately block by block.
The noncovalent dimerization of a G-quadruplex/hemin DNAzyme improves its biocatalytic properties.
2020
While many protein enzymes exert their functions through multimerization, which improves both selectivity and activity, this has not yet been demonstrated for other naturally occurring catalysts. Here, we report a multimerization effect applied to catalytic DNAs (or DNAzymes) and demonstrate that the enzymatic efficiency of G-quadruplexes (GQs) in interaction with the hemin cofactor is remarkably enhanced by homodimerization. The resulting non-covalent dimeric GQ–DNAzyme system provides hemin with a structurally defined active site in which both the cofactor (hemin) and the oxidant (H2O2) are activated. This new biocatalytic system efficiently performs peroxidase- and peroxygenase-type biot…
Significant biogenesis of chlorinated aromatics by fungi in natural environments
1994
Common wood- and forest litter-degrading fungi produce chlorinated anisyl metabolites. These compounds, which are structurally related to xenobiotic chloroaromatics, occur at high concentrations of approximately 75 mg of chlorinated anisyl metabolites kg of wood-1 or litter-1 in the environment. The widespread ability among common fungi to produce large amounts of chlorinated aromatic compounds in the environment makes us conclude that these kinds of compounds can no longer be considered to originate mainly from anthropogenic sources.
Analysis of fluorescent MRI contrast agent behavior in the liver and thoracic aorta of mice.
2004
To characterize the behavior of magnetofluorescent products injected in mice intravenously.The magnetic resonance imaging (MRI) products were labelled with fluorescent molecules to examine the biodistribution process in vivo and observe them at the cellular level by means of confocal microscopy. Three-dimensional (3D) sequences of images were obtained by spectral analysis of sample preparations in a multiphoton confocal microscope and analyzed by the factor analysis of medical image sequence algorithm, which provides factor curves. Factor images are the result of image-processing methods that utilize information from emission spectra. Preparations are also screened in the counting mode to p…
Implication of 24-S-hydroxycholesterol in Muller glial cell's membrane dynamics in the rat.
2016
Implication of 24-S-hydroxycholesterol in Muller glial cell's membrane dynamics in the rat.. Association-for-Research-in-Vision-and-Ophthalmology (ARVO)
Rules and Mechanisms of Perceptual Interaction of Odor Mixtures : Application to Icewine aroma
2021
Icewine was used as an experimental object, and hundreds of wine- or food-related odor mixtures were designed and investigated for the first time based on the identification and analysis of icewine’ odorants. The aim of the thesis work was to explore the key odor elements that affected the perception of odor mixtures and the general laws behind olfactory perceptual interactions. The thesis manuscript contains seven chapters:The first review of the literature gives a brief introduction to the olfactory system and odor perception. Then, odorants’ mixture perception is highlighted through examples of interactions between odorants at the perceptual level. Research progress in perceptual interac…
Screening of lactic acid bacteria for their use as aromatic starters during fermentation of vegetables
2020
Lactic acid bacteria (LAB) have good growth capacities on various food matrices and produce very diverse enzymatic activities which are notably capable of positively modifying the organoleptic properties of fermented foods. Therefore, the selection of the LAB starters possessing good metabolic abilities and interesting enzymatic activities towards the plant matrix could improve the aroma profiles of fermented foods. The main objective of this study was to enhance the aroma profiles of fermented tomatoes by using the biotechnological pathway. To achieve this, firstly, 200 LAB isolated from Cambodian and Vietnamese fermented foods were screened for their β-glucosidase activity and duplicate i…
Influence of phytosterols on the structural and dynamic properties of plant plasma membrane
2008
National audience; The complex mixture of sterols, namely phytosterols, found in the plasma membrane (PM) of plant cells is an intriguing characteristic. In the present work, we characterized the sterol composition of tobacco BY-2 cell PM, and we adapted a sterol manipulation method to this plant material. Methyl-b-cyclodextrin was found to induce a drastic reduction of the PM total free sterol content, with a low specificity for the different phytosterols, and without effect on steryl-conjugates. The consequences of phytosterols depletion were investigated by means of fluorescence spectroscopy and biochemical detergent resistant membrane (DRM) fraction purification methods. Data obtained w…
Evaluation of the environmental fate and ecotoxicological impact of the pesticide chlorpyrifos in soil for improvement of its environmental risk asse…
2016
EABIOMEUBINRA; Pesticides protect crops from various pests but can also harm nontarget organisms. To minimize risks for the environment and human health, a huge amount of studies are carried out and evaluated during the authorization process of each pesticide. However, the prediction of the environmental fate and ecotoxicological impact of a pesticide remains difficult. Several 100 formerly used pesticides are now banned because unexpected risks emerged decades after their authorization. Risk assessment documents of the organophosphate insecticide chlorpyrifos (CHL) particularly lack information about its degradation and potential transformation products in soil, and its impact on non-targe…
L'arôme du gin : identification des composés clés et rôle des matières premières
2012
Le texte intégral de cette thèse est confidentiel à durée indéfinie.; Afin d’identifier les composés responsables de l’arôme du gin, une procédure GC-O-MS se basant sur la fréquence de détection a été développée. Elle a permis de déterminer l’intensité odorante des composés volatils. Leur qualité d’odeur a pu être définie par le développement d’une roue des odeurs utilisée pour catégoriser les descripteurs obtenus. Cette approche nous a dans un premier temps permis d’identifier les composés potentiellement importants pour l’arôme du gin. L’origine de ces composés a ensuite été déterminée par l’étude de la fraction volatile de différents « botanicals » appartenant à la recette du gin. Cette …