The overall objective of this investigation has been to evaluate the performance of soy proteins during extrusion and to provide the basis for a technology in twin-screw extrusion texturization that will facilitate greater utilization of soy proteins. Specifically, our research efforts will be focused on: (1) investigation of the behavior of each major globulin soy protein fraction (7S and 11S) in the texturization process; (2) studies on the effect of inclusion of various anionic polysaccharides and pH-modified soy protein isolates on the extrusion performance of soy flour and (3) studies on the interactions of soy proteins with other food additives, such as salts, sugars and lipids. Through this study, we expect to achieve a better understanding with respect to the mechanisms involved in soy protein texture formation during extrusion. Information attained will also facilitate the development of a better process for the production of texturized soy protein products.