Oleofoams: Formulation Rules and New Characterization Methods Based on X-Rays and Neutrons to Advance Current Understanding

This chapter summarizes recent advances in oleofoam systems, the current understanding of their structure, and also proposes new characterization methods, which could give new insights into these systems. Despite their potential for food, cosmetic, and pharmaceutical products, in comparison to aqueous foam systems, oleofoam research is still in its infancy. Oleofoams could be used as food products combining a reduced fat content with a new appealing texture and sensorial properties due to the presence of gas bubbles. Oleofoams are produced by adding a high-melting fat component to a vegetable oil in the molten state, followed by cooling—to induce the formation of fat crystals—and aeration. The fat crystals stabilize both the air bubbles and the continuous phase between the bubbles. Oleofoams are multiscale hierarchical systems, for which relevant scales span from nanometers up to millimeters; as a consequence, a combination of characterization methods is required to understand the full structure and stabilization mechanisms, of which X-ray and neutron scattering and tomography offer unique opportunities.