  Structuring wheat gluten proteins into gels with tunable mechanical
properties would provide more versatility for the production of plant
protein-rich food products. Gluten, a strongly elastic protein material
insoluble in water, is hardly processable. We use a novel fractionation
procedure allowing the isolation from gluten of a water/ethanol soluble protein
blend, enriched in glutenin polymers at an unprecedented high ratio (50%). We
investigate here the viscoelasticity of suspensions of the protein blend in a
water/ethanol (50/50 v/v) solvent, and show that, over a wide range of
concentrations, they undergo a spontaneous gelation driven by hydrogen bonding.
We successfully rationalize our data using percolation models and relate the
viscoelasticity of the gels to their fractal dimension measured by scattering
techniques. The gluten gels display self-healing properties and their elastic
plateaus cover several decades, from 0.01 to 10000 Pa. In particular very soft
gels as compared to standard hydrated gluten can be produced.
