Search results for "chromatographie"
showing 10 items of 19 documents
(Z)-dodec-3-en-1-ol, a novel termite trail pheromone identified after solid phase microextraction form Macrotermes annandalei
2001
International audience
Perception of non-processed semi-hard cheese aroma
2012
Perception of the aroma of food products depends on several factors, involving both the. chemical composition of food and human neurophysiology. The perception of food flavour,. including cheese often relies on the perception of several aroma compounds in mixture in. balanced proportions. The existence of perceptual interactions among aroma compounds in. mixtures and also the release of aroma compounds from the food product are the main factors. that influence the global perceived aroma of food. Hence, the objective of this PhD study was. to investigate the mixture of aroma compounds representing the aroma of semi-hard cheese by. taking into account perceptual interactions among odorants an…
Pleurotus ostreatus volatile aroma compounds identified from fruit-body and from mycelium grown in submerged and solid-state cultures
2003
Comparative analyses of volatile aroma compounds of the Pleurotus ostreatus JMO.95 fruit-body and its corresponding mycelium grown in liquid, on agar surface, or on solid support cultures have been carried out by dynamic headspace concentration using GC/MS and GC/sniffing. The aroma of the fruit-body was due essentially to the presence of octan-3-one and, in a lesser extent, to the presence of octan-3-ol. Other compounds, such as oct-l-en-3-ol, oct-l-en, 2-methylbutanol and a-pinene were also present in low concentrations. The comparison of the aromatic spectra of the fruit-body with the aromatic spectra of mycelia obtained under different culture conditions indicated that the main aromatic…
Portable microwave assisted extraction: An original concept for green analytical chemistry.
2013
International audience; This paper describes a portable microwave assisted extraction apparatus (PMAE) for extraction of bioac-tive compounds especially essential oils and aromas directly in a crop or in a forest. The developed procedure, based on the concept of green analytical chemistry, is appropriate to obtain direct in-field information about the level of essential oils in natural samples and to illustrate green chemical lesson and research. The efficiency of this experiment was validated for the extraction of essential oil of rosemary directly in a crop and allows obtaining a quantitative information on the content of essential oil, which was similar to that obtained by conventional m…
Evaluation of the toxicity of mussels from 2 sites of the Moroccan Atlantic Coast (Jorf Lasfar and Oualidia) used as bioindicators of contamination :…
2012
Toxic substances generated by various human activities are spilled on different area of the Moroccan coast. Shellfishes can concentrate pollutants and have some adverse effects on human health through the food chain. Despite the strengthening of food safety rules, the involvement of chemical pollution of food on metabolic disorders is not known. To predict the impact of pollutants on the aquatic ecosystem and human health, the development of appropriate biomonitoring tools is required.We quantified heavy metals (Cd, Cr and Pb) in mussels (Mytilus galloprovincialis) from two sites of Moroccan Atlantic coast (industrial site Jorf Lasfar (JL) and touristic site Oualidia (OL)) due to the proxim…
Gas chromatography-mass spectrometry study of polycyclic aromatic hydrocarbons in grass and milk from urban and rural farms
2000
Polycyclic aromatic hydrocarbon (PAH) levels were studied in grass and milk sampled at two farms, one located in a non-contaminated, rural area, and another located in a urban area close to PAH sources such as highways, busy roads, fuel-powered trains and a steel plant. PAH concentration were measured by gas chromatography coupled to mass spectrometry (GC-MS) using internal deuterated standards. In grasses, unexpectedly, although the sum of PAH concentrations was only slightly higher at the urban farm (83.1 ± 16.1 ng g−1) than the rural farm (51.8 ± 10.6 ng g−1), this difference was not observed for all PAH members. This absence of a striking difference of PAH levels between urban and rura…
Evaluation of seven immunochromatographic assays for the rapid detection of human rotaviruses in fecal specimens
2007
International audience; Seven commercially available immunochromatographic assays were tested for the rapid detection of group A rotaviruses in fecal samples compared to a enzyme immunoassay (Argene). Detection of rotaviruses in 80 ELISA positive frozen stool samples showed rates superior to 90% for three reagents (Rota Strip (Cypress Diagnostics), 98.8%; Rotascreen (Microgen), 95.0%; VIKIA Rota/Adeno (bioMérieux), 92.5%); from 82.5% to 88.8% for three others (Diarlex with centrifugation (Orion Diagnostica), 88.8%; Combo Rota/Adeno (All Diag), 87.5%; Rota/Adeno Combi Stick (bmd), 82.5%) and only 70.0% for Diarlex with filtration vial (Orion Diagnostica). The evaluation of the specificity, p…
Identification of volatile compounds of fruit juice by head space (HSSE) and immersion stir bar sorptive extraction (SBSE) and thermal desorption-cry…
2015
Identification of volatile compounds of fruit juice by head space (HSSE) and immersion stir bar sorptive extraction (SBSE) and thermal desorption-cryogenic focusing-gas chromatography mass spectrometry. 16. International Symposium on Olfaction and Electronic Noses (ISOEN 2015)
Qualité aromatique de la framboise (Rubus idaeus L.) II. Interprétation de l'indice d'arôme
1982
International audience; La mesure de l'indice d'Arôme, basée sur l'intensité de la coloration bleue qui se développe dans les distillats de framboises aromatiques traités par la vanilline en solution sulfurique concentrée, est interprétée en identifiant les principaux composés participant à cette réaction colorée. Six composés : géraniol, linalol, nérol, α-terpinéol, α- et β-ionones, ont été séparés, révélés et inolés par chromatographie sur couche mince de gel de silice (CCM) et identifiés par couplage chromatographie en phase gazeuse (CPG) et spectrométrie de masse (SM). Ces composés représentent près de 80% de la valeur de l'Indice d'Arôme d'un distillat d'une variété aromatique : Mallin…
Bilan et perspectives des deux écoles techniques sur l'analyse des gaz
2013
Résumé. L'analyse des gaz est utilisée notamment pour des recherches concernant l'atmosphère, le sol, les plantes, les animaux, l'humain et les composés volatils dans les aliments. L'analyse des gaz présente une pluralité de domaines d'application, d'espèces gazeuses à analyser, de gammes de concentrations ainsi que de techniques de mesure. C'est à l'occasion des Journées de la Mesure et de la Métrologie de 2006 que le besoin d'une école thématique portant sur la mesure et la métrologie appliquées à l'analyse des gaz a été exprimé. Deux écoles ont été organisées pour répondre aux besoins, la deuxième (2011) ayant bénéficié des enseignements tirés de la première (2009) suite à l'évaluation a…