Search results for "Odor"
showing 10 items of 569 documents
Use of Catalyst in a 3D-QSAR Study of the Interactions between Flavor Compounds and β-Lactoglobulin
2003
This paper reports a 3D-QSAR study using Catalyst software to explain the nature of interactions between flavor compounds and beta-lactoglobulin. A set of 35 compounds, for which dissociation constants were previously determined by affinity chromatography, was chosen. The set was divided into three subsets. An automated hypothesis generation, using HypoGen software, produced a model that made a valuable estimation of affinity and provided an explanation for the lack of correlation previously observed between the hydrophobicity of terpenes and the affinity for the protein. On the basis of these results, it appears that aroma binding to beta-lactoglobulin is caused by both hydrophobic interac…
Caractérisation des enzymes du métabolisme des xénobiotiques olfactives chez le rat : régulation et rôle dans la détection périphérique des molécules…
2010
Diplôme : Dr. d'Université; Les enzymes du métabolisme des xénobiotiques (EMX) jouent un rôle central dans la biotransformation et l’élimination de composés étrangers à l’organisme. Organisées en réseau de biotransformation, ces enzymes catalysent des réactions variées (oxydations, conjugaisons …) afin de rendre ces composés plus hydrophiles. Les EMX sont fortement exprimées dans l’épithélium olfactif de mammifères et des études in vitro ont montré qu’elles possèdent des activités élevées. Outre un rôle dans le métabolisme de molécules toxiques, ces enzymes pourraient être impliquées dans la modulation périphérique de l'olfaction. Les EMX pourraient contribuer à maintenir la sensibilité du…
Sirreālisma izmantojums un vēstījuma analīze A.Hodorovska filmā “Realitātes deja”
2018
Darbā apskatīts un izpētīts sirreālisma izmantojums un nozīme kā arī vēstījuma analīze Alehandro Hodorovska filmā “Realitātes deja”. Teorijas daļā apskatīta kino semiotika un svarīgākie kinematogrāfiskie izteiksmes līdzekļi, kuri atainoti filmas veidošanas procesā, kā arī to, kā tie ietekmē skatītāja uztveri. Metodoloģijas daļā apskatīta izvēlētā pētniecības metode – semiotiskā un naratīva analīze. Pētījuma ietvaros veikta galveno varoņu un tēlu analīze, kā arī sirreālisma izmantojuma skaidrojums. Pētījuma rezultāti liecina, ka Hodorovskis ar sirreālisma palīdzību nojauc robežas starp sapni un realitāti. Filma kalpo kā dialogs starp skatītāju un režisoru, kas abpusēji kalpo kā dziedinošs pr…
Heliodorus Parthenopaeus: The "Aithiopika" in Baroque Naples
1998
L'articolo è frutto di un lavoro comune; i paragrafi 1, 3 e 6 sono stati redatti da Massimo Fusillo, i paragrafi 2, 4 e 5 da Clotilde Bertoni. Il lavoro analizza il "Teagene", poema epico di Giambattista Basile ispirato alle "Etiopiche" di Eliodoro, e prende in esame altre opere seicentesche legate al romanzo ellenistico. The article results from a common work: paragraphs 1, 3 and 6 have been written by Massimo Fusillo, paragraphs 2, 4 and 5 by Clotilde Bertoni. It analyzes "Teagene" an epic poem by Giambattista Basile, based on Heliodorus' Aethiopica, and it also examines some other works of the same period connected with th Hellenistic novel.
Interspecific hybridisation among diverse Saccharomyces species: A combined biotechnological solution for low-temperature and nitrogen-limited wine f…
2019
Lack of the prezygotic barrier in the Saccharomyces genus facilitates the construction of artificial interspecific hybrids among different Saccharomyces species. Hybrids that maintain the interesting features of parental strains have been applied in industry for many beneficial purposes. Two of the most important problems faced by wine makers is nitrogen deficiency in grape must and low-temperature fermentation. In our study, hybrids were constructed by using selected low nitrogen-demanding cryotolerant S. eubayanus, S. uvarum strains and S. cerevisiae. The fermentation capacity of the hybrid strains was tested under four conditions by combining two temperatures, 12 °C and 28 °C, and two ni…
Wine active compounds. Proceedings of the WAC2008 international conference
2008
International audience
Release of isoamyl acetate from starch pastes of various structures : thermodynamic and kinetic parameters
2004
The release of isoamyl acetate from starch-based matrices was studied on the basis of a cumulative dynamic headspace analysis. Two corn starches were compared, which are known to yield pastes and gels differing in their structures and properties. These properties were assessed by viscometry and viscoelastic measurements. Aroma release was discussed as a function of the structure and texture parameters of the matrix. The release curves obtained from water and from the various starch-based matrices at 25 degrees C showed similar patterns but differed in their initial slopes and in the final plateau values. The lowest initial slopes were obtained for the normal starch dispersions that formed g…
Assessment wine aroma persistence by using an in vivo PTR-ToF-MS approach and its relationship with salivary parameters
2019
To better understand wine aroma persistence, the nasal cavity of nine volunteers was monitored by Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS) after they rinsed their mouths with three rosé wines (one control and the same wine supplemented with two tannin extracts) during four minutes. Wines were aromatised with a mixture of five target aroma compounds. Results showed that wine aroma persistence was highly compound-dependent: while esters disappeared very fast, other compounds such as linalool remained in the oral cavity for longer times after wine expectoration. A low effect of tannins (at 50 mg/L) on nasal cavity parameters was observed, with the exception for th…
Understanding the release and metabolism of aroma compounds using micro-volume saliva samples by ex vivo approaches
2018
International audience; This study investigated the behaviour of key aroma compounds in the presence of human saliva (200 mu L) from different individuals (n = 3) submitted or not to centrifugation (whole vs clarified saliva). HS-GC results showed that human saliva strongly decreased the release of carbonyl compounds (aldehydes and ketones). This effect was dependent on i) the structure of the aroma compounds and ii) the saliva composition. Whole saliva exerted a higher effect than clarified saliva on aroma compounds. Moreover, this effect was individual-dependent and related to the total protein content and the total antioxidant capacity of saliva. HS-SPME and LLE-GC/MS analyses revealed t…
Molecular mechanisms of aroma persistence: From noncovalent interactions between aroma compounds and the oral mucosa to metabolization of aroma compo…
2021
International audience; The present study aims to reveal the molecular mechanisms underlying aroma persistence, as it plays a major role in food appreciation and quality. A multidisciplinary approach including ex vivo experiments using a novel model of oral mucosa and saliva as well as in vivo dynamic instrumental and sensory experiments was applied. Ex vivo results showed a reduction in aroma release between 7 and 86% in the presence of the thin layer of salivary proteins covering the oral mucosa (mucosal pellicle). This reduction was explained by hydrophobic interactions involving the mucosal pellicle and by the ability of oral cells and saliva to metabolize specific aroma compounds. The …