Search results for "proton transfer reaction"

Gaining deeper insight into aroma perception: An integrative study of the oral processing of breads with different structures

2017

WOS:000394071900015; International audience; The objective of this study was to investigate for the first time the influence of bread structure, volatile compounds, and oral processing on aroma perception. 3 types of French baguette were created using the same raw ingredients but different bread-making processes; they consequently varied in their crumb and crust structures. We characterized the initial volatile profiles of two bread structural subtypes-namely bread crumb and bread crumb with crust-using proton transfer reaction-mass spectrometry (PTR-MS) headspace analysis. Three types of bread were characterized by thirty-nine ion fragments from m/z 45 to 139. We then conducted a study in …

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 …

Proton-Transfer-Reaction Mass-Spectrometry (PTR-MS) for the study of the aromatic potential of bakery starter strains

2016

PTR-SRI-ToF-MS analysis of aroma compounds: influence of drift tube E/N ratio on sensitivity and fragmentattion

2013

Livre ISBN-13 : 978-3-902811-91-2; International audience; The aim of this work was to compare detection and fragmentation patterns of aroma compounds obtained with three different precursor ions and several E/N source parameter values with the proton transfer reaction (PTR-MS) methodology. The reactant ions H3O+, NO+ and O2+. were generated in a Switchable Reagent Ions (SRI) source of a PTR-ToF-MS (Ionicon 8000, Innsbruck, Austria). Precursor ions plasmas were characterized at different E/N ratio in the drift tube. For proton transfer reaction, the hydronium primary ion was the most abundant ion (> 80%) for all E/N ratios above 120 Td, but the sensitivity decreased quickly with the highest…

In vivo aroma release by APCI-MS and PTR-MS: impact of water content of exhaled air and evidence for competition between aroma compounds

2013

Livre ISBN-13 : 978-3-902811-91-2; International audience; Atmospheric pressure chemical ionization mass spectrometry (APCI-MS) or proton transfer reaction mass spectrometry (PTR-MS) has been in use frequently for in vivo aroma release studies. In APCI-MS, protonated water clusters formed from moisture in the expired air are used as reagent ions. Yet the influence of a change in relative water content in the ionization gas on the data collected have been rarely studied and conflicting results were obtained. In this context our first objective was to study the impact of water content of the expired air on the level of aroma release measured by APCI-MS and to compare with the results obtained…