Influence of Physical State and Molecular Mobility of Freeze‐Dried Maltodextrin Matrices on the Oxidation Rate of Encapsulated Lipids

A glassy model of freeze‐dried maltodextrin was developed for the encapsulation of flaxseed oil. Kinetics of lipid oxidation have shown that the matrices efficiently protected lipids from oxidation for a moisture content corresponding to the monolayer value. An NMR method based on the 2nd moment, M2, was used to study the molecular mobility and physical state of the freeze‐dried maltodextrin and water mixtures. Physical state transitions were observed at temperatures very close to the glass transition temperature (Tg) determined from the equation of Vuataz (1999), suggesting a relationship between glass transition and proton relaxation behavior. No apparent relation between molecular mobility and oxidation rate were observed whatever the DE of maltodextrins.