Institut Charles Sadron Event

In order to gel the oils, we can use organogelators: these small compounds self-assemble into fibrillar networks, thus providing the oils with mechanical properties close to solid. These compounds are used in the food applications to replace animal fats, negative for health, with healthier vegetable oils; in cosmetics they are used for oil-based formulations. This thesis focuses on the development of new oleogelators, endogenous and naturally assimilable compounds. We studied the thermodynamic and rheological properties of their gels in edible oils and established the c-T phase diagrams of these systems. The structure of the aggregates was studied by microscopy and X-ray scattering. The results show the existence of gel-gel transitions, due to polymorphism of the aggregates. This polymorphism explains how the properties vary and can be controlled with thermal history. To establish the phase diagrams more quickly and accurately than by DSC and rheology, we optimized the use of NMR at variable temperature in a deuterated oil. The combination of these approaches improves the optimization of the gel properties for the targeted applications. Keywords : organogelators, oleogels, edible oils, phase diagrams, VT-NMR, SAXS, rheology.