Defatted soybean flour dispersions of different solid concentrations (15-30%) were subjected to varying time of heating (15-75 s) in a microwave. The gels were characterized by texture measurement (penetration), dynamic testing (oscillation) and by sensory assessment. An increasing concentration of solids and/or time of heating enhanced gel strength, storage modulus (G') and complex viscosity (eta(*)) whereas loss factor decreased sharply. Marked change in G' values occur even at a low time of treatment. The few fold increase in G' values for treated soy samples over the untreated sample were observed. The microstructure of the samples revealed that an aligned gel network with fibers was formed. A mechanism of gel formation at macromolecular level has been proposed. (c) 2006 Published by Elsevier Ltd.