Search results for "Volatile Organic Compounds."
showing 10 items of 152 documents
Grapevine vocs emissions triggered by elicitation –assessment of two french vineyards
2022
International audience; Grapevine foliar volatile organic compounds (VOCs) releases are induced by elicitor applications.Their emissions have been followed along the growing season on two geographically separatedBurgundy and Bordeaux (Chardonnay and Cabernet franc cultivars, respectively) French vineyards. Inyear 2019, fortunately lacking of endogenous disease, VOCs were collected under non-destructivemode, in four hours with SBSE sensors entrapped into a confinement Teflon bag. Then the monitoringof VOCs enables to distinguish between weak (COS-OGA (Bastid©) and CuSO4) and strong elicitors(MeJA).Although monoterpene Ocimenes are constitutively present among the scent of the twovineyards, t…
Photocatalytic oxidation of acetonitrile in gas–solid and liquid–solid regimes
2005
Il programma NON mi ha consentito di scaricare il PDF di questo articolo. Se lo volete ditemi come inviarlo ABSTRACT Photocatalytic degradation of acetonitrile was carried out in both gas–solid and liquid–solid regimes using two commercial TiO2 catalysts (Merck and Degussa P25). For the gas–solid regime, a continuous annular photoreactor was used. The influence on photodegradation kinetics of the gas flow rate and concentrations of acetonitrile, oxygen, and water was investigated. Acetonitrile degradation products detected in the gas phase included carbon dioxide and hydrogen cyanide. The same photoactivity was exhibited in the presence and in the absence of water vapour. The liquid–solid reg…
Untargeted metabolomics of rind essential oils allowed to differentiate two closely related clementine varieties
2021
[EN] Chemical characterization of clementine varieties (Citrus clementina Hort. ex Tan.) essential oils (EO) can lead to variety identification and valorization of their potential use in food and aroma industries. The goal of this study was the chemometric discrimination between two very closely related and morphologically identical clementine varieties, Clemenules (NL) and Clemenpons (PO), based on their rind EO, to identify the differential volatile organic compounds (VOCs) and to determine their antioxidant capacity. EO rind volatile profile was determined by gas chromatography coupled to mass spectrometry in Citrus fruit at different ripening stages grown two independent years in two di…
Bresaola made from Cinisara cattle: effect of muscle type and animal category on physicochemical and sensory traits
2020
The physicochemical characteristics and sensory traits of Cinisara bresaola were investigated, to explore a new commercial opportunity for autochthonous dairy cattle farms. Semimembranosus, Semitendinosus and Biceps brachii muscles, from adult cows (AC) and grazing (GB) or housed (HB) young bulls of Cinisara breed, were processed to made bresaola. Differences due to animal category and muscle type were observed. Bresaola from AC was richer in fat and volatile organic compounds. The bresaola from Semitendinosus showed higher colorimetric parameters, fat and, when from grazing animals, Warner-Bratzler shear force than those made from other muscles. In general, all bresaola were well appreciat…
Anaerobic biodegradation of solvents from the packaging industry: study and enhancement
2017
Con el desarrollo de la política ambiental de la Unión Europea, la calidad del aire en Europa ha mejorado considerablemente. No obstante, la contaminación atmosférica continúa siendo importante lo que hace necesario el desarrollo continuo de soluciones tecnológicas de depuración del aire para mitigar los problemas de calidad ambiental. Con objeto de preservar el medio ambiente y evitar problemas de salud pública, las emisiones industriales de disolventes están estrictamente reguladas por la normativa vigente en Europa, en el marco de la Directiva Europea de Emisiones Industriales (2010/75/EU). La industria del envase y embalaje es uno de los sectores más importantes en cuanto al uso de diso…
Chemical Ecology of Insect Parasitoids: Towards a New Era
2013
Over the course of evolutionary time, insect parasitoids have developed diverse strategies for using chemical compounds to communicate with various protagonists within their environment (i.e. conspecifi cs, their hosts, and the plants on which their hosts are living). Unravelling the evolutionary meaning of such chemical communication networks not only provides new insights into the ecology of these insects but also contributes to improving the use of parasitoids for the control of insect pests in biological control programmes. A book covering our current knowledge of the chemical ecology of insect parasitoids is therefore particularly timely and will appeal to a large number of potential r…
Influence of nitrogen status in wine alcoholic fermentation
2019
Nitrogen is an essential nutrient for yeast during alcoholic fermentation. Nitrogen is involved in the biosynthesis of protein, amino acids, nucleotides, and other metabolites, including volatile compounds. However, recent studies have called several mechanisms that regulate its role in biosynthesis into question. An initial focus on S. cerevisiae has highlighted that the concept of "preferred" versus "non-preferred" nitrogen sources is extremely variable and strain-dependent. Then, the direct involvement of amino acids consumed in the formation of proteins and volatile compounds has recently been reevaluated. Indeed, studies have highlighted the key role of lipids in nitrogen regulation in…
Allylated cyclodextrins as effective affinity materials in chemical sensing of volatile aromatic hydrocarbons using an optical planar Bragg grating s…
2013
We report on the application of perallyl-substituted α-, β- and γ-cyclodextrins to an optical planar Bragg grating refractive index sensor for the effective sensitization of the sensor for airborne volatile aromatic hydrocarbons. Thereby, the emphasis of this work lies on the comparison of the different cyclodextrin types regarding their suitability as affinity material assessed by the sensors sensitivity and response behavior. The opto-chemical sensor device showed an immediate and quick response to the application of the investigated analytes benzene, toluene and m-xylene as well as a linear dependence on the concentration of those analytes. Studies on the sensors sensitivity depending on…
Quantitative Comparison of Free and Bound Volatiles of Two Commercial Tomato Cultivars (Solanum lycopersicumL.) during Ripening
2009
The changes in the profile of both free and glycosidically bound volatiles were studied in Moneymaker and Raf tomato cultivars during fruit ripening. The concentrations of 20 of 24 and of 27 of 30 compounds detected in the free volatile fraction (FVF) and glycosidically bound fraction (GBF), respectively, differed significantly between cultivars during ripening. Most free and bound volatiles increased during ripening in both cultivars. The contribution of each free volatile compound to the overall aroma was estimated by calculating its log U value, which indicated that only 11 compounds seem to exert a strong influence. Nine volatiles were detected exclusively in the GBF, among them geranio…
Distribution of volatile organic compounds in Sicilian groundwaters analysed by head space-solid phase micro extraction coupled with gas chromatograp…
2008
This work presents the results of an assessment of the existence and concentration of 13 volatile organic compounds (VOCs) in groundwaters from 14 hydrological basins in Sicily (25,710km (2)). On the basis of hydrological, hydrogeochemical and geological studies, 324 sampling points were selected. All groundwater sampled were collected twice, from October to December 2004 and from February to May 2005, and were analysed to determine the concentration and spatial distribution of the VOCs in the aquifers. The need to analyze a large number of samples in a short space of time so as to obtain quantitative analyses in trace concentration levels spurred us to create a new analytical method, both …