Nanostructured Silica/Wheat Gluten Hybrid Materials Prepared by Catalytic Sol-Gel Chemistry

The main physicochemical properties of nanostructured silica/wheat gluten hybrid composites are presented. The extraction experiments suggest that the protein phase is intimately encased within the silica matrix, with silicaprotein interactions driven by hydrogen bonding, as indicated by IR spectra. Spectroscopic results also show that silica induces a higher degree of constraint of the wheat gluten matrix, despite less aggregation. Moisture diffusion properties of the hybrid materials are investigated by a combined desorption/sorption approach. While the reduction of the moisture diffusivity in the presence of silica can be described by the geometrical impedance of a sintered porous solid, a time-dependent relaxation/restructuring of the composite apparently occurs during the sorption-desorption cycle.