0000000000652676
AUTHOR
Céline Moreau
showing 9 related works from this author
Diffusion des arômes par RMN-DOSY
2009
National audience
The effect of salt content on the structure of iota-carrageenan systems: Na-23 DQF NMR and rheological studies
2009
International audience; 23Na NMR spectroscopy has been used to study the effects of Na+ ion concentrations on the structure of 1% (w/w) iota-carrageenan systems, a natural gelling polysaccharide used as a thickener in the food industry. Rheological and 23Na T1 relaxation time measurements revealed that gel formation correlates with decreases in ion mobility over the range of 0-3% (w/w) sodium content. 23Na single-quantum (SQ) and double-quantum-filtered (DQF) NMR experiments performed on these systems provided evidence for a bound sodium ion fraction in a specifically ordered environment. These results have allowed us to propose a model for the carrageenan gelation mechanism in the presence…
Investigation of sodium ions in cheeses by 23Na NMR spectroscopy
2008
International audience; The reduction in the salt content of foods without affecting their production methods and sensorial properties is a current challenge for the food industry. In foods, sodium ions can adopt various motional states through interactions with macromolecules such as hydrocolloids or exchange between two phases in heterogeneous systems. A correlation between sodium ion mobility and the saltiness perception has been suggested, the role of sodium ions with restricted motion or "bound" sodium being of particular consideration. There is therefore a need to investigate the mobility states of the different pools of sodium ions and to quantify these fractions to develop a better …
Interactions between aroma compounds and beta-lactoglobulin in the heat-induced molten globule state
2010
; he present study aims to elucidate the binding of small hydrophobic ligands onto the molten globule state of β-lactoglobulin (BLG). The conversion of the native BLG into a molten globule state was induced by heat treatment at acidic pH. The molten globule state was evidenced by far and near-UV circular dichroism spectra. β-Ionone and guaiacol exhibited a higher binding ability to BLG in the heat-induced molten globule state compared to unheated BLG, as assessed by protein surface hydrophobicity measurements, using 6-propionyl-2-(dimethylamino)naphthalene (PRODAN) fluorescent probe. The binding sites of the two aroma compounds were determined by 2D nuclear magnetic resonance (NMR) spectro…
Hydrophobic interactions between aroma compounds and beta-Lactoglobulin using a specific fluorescent probe and NMR
2008
International audience; Many aroma compounds are known to bind with proteins, and elucidating these bindind interactions is a key in a better knowledgment of flavour perception mechanisms (1). beta-Lactoglobulin (bLg), the major whey protein of milk, has been used as a model food protein in numerous studies. Previous work have shown different binding sites on bLg for aroma compounds as a function of their chemical class, and emphasized the importance of hydrophobic interactions (2). (...)
Hydrophobic interactions between aroma compounds and beta-Lactoglobulin using NMR and a fluorescent probe
2010
International audience; beta-lactoglobulin (bLg) is known to interact with aroma compounds affecting their release, and hence, their perception. bLg, composed of two hydrophobic binding sites, was used as a simple model food protein to investigate binding mechanisms as a function of ligand nature. Indeed, binding of small ligands to bLg sites is often selective, although some ligands bind to both sites. Interactions between bLg and one ketone, beta-ionone, and one phenol, guaiacol were investigated by combining two techniques: 2D Nuclear Magnetic Resonance for binding site location, and fluorescence using the 6-propionyl-2-(N, N-dimethylamino)naphthalene (PRODAN) probe for surface hydrophob…
Chapter 6 Contribution of NMR Spectroscopy to Flavour Release and Perception
2008
Abstract The control of flavouring of a food product as well as the flavour perception during consumption is a great challenge for improving food quality. However, the various ingredient composition and the different textural properties of foods can significantly affect the release of aroma compounds or sapid molecules. It is thus of major importance to determine physicochemical factors that govern diffusion and binding phenomena of these small solutes in food products. In this way, NMR spectroscopy is an efficient tool to characterize these mechanisms at a molecular scale. Diffusion rates of small solutes in aqueous, viscous and gel solutions can be extracted from relaxation or diffusion N…
Identification and quantification of phosphorus in cheeses - methodological investigations by solid-state 31P NMR spectroscopy
2008
International audience; NMR has been shown to be an interesting tool for investigating dairy foods, in particular cheese products, for which the method is non-destructive and well suited for investigating their compounds showing different structure and mobility during ripening. Solid-state magic angle spinning 31P NMR spectroscopy was used to characterize the structure and composition of semi-hard cheeses. Assignment including overlapping resonances from mobile/immobile phosphorylated serine residues and inorganic calcium phosphates, has been realised using different NMR techniques (spin echo, cross polarisation and single pulse excitation) and by comparison with spectra of literature. Stud…
Distribution and mobility of phosphates and sodium ions in cheese by solid-state 31 P and double-quantum filtered 23 Na NMR spectroscopy
2010
The feasibility of solid-state magic angle spinning (MAS) (31)P nuclear magnetic resonance (NMR) spectroscopy and (23)Na NMR spectroscopy to investigate both phosphates and Na(+) ions distribution in semi-hard cheeses in a non-destructive way was studied. Two semi-hard cheeses of known composition were made with two different salt contents. (31)P Single-pulse excitation and cross-polarization MAS experiments allowed, for the first time, the identification and quantification of soluble and insoluble phosphates in the cheeses. The presence of a relatively 'mobile' fraction of colloidal phosphates was evidenced. The detection by (23)Na single-quantum NMR experiments of all the sodium ions in t…