The effect of salt content on the structure of iota‐carrageenan systems: 23Na DQF NMR and rheological studies |
| |
| Authors: | Mallory Gobet Mohamed Mouaddab Nathalie Cayot Jean‐Marie Bonny Elisabeth Guichard Jean‐Luc Le Quéré Céline Moreau Loïc Foucat |
| |
| Affiliation: | 1. INRA, UMR1129 FLAVIC, F‐21000 Dijon, France;2. ENESAD, UMR1129 FLAVIC, F‐21000 Dijon, France;3. Université de Bourgogne, UMR 1129 FLAVIC, F‐21000 Dijon, France;4. INRA, UR370 QuaPA, F‐63122 Saint Genès Champanelle, France |
| |
| Abstract: | 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 of Na+ ions. Copyright © 2009 John Wiley & Sons, Ltd. |
| |
| Keywords: | NMR 23Na double‐quantum filter rheology iota‐carrageenan sodium binding state |
|
|
