Dynamic mechanical properties and fractal analysis of texturized soybean protein/wheat gluten composite produced by high moisture extrusion

Texturized soybean protein (TSP) and wheat gluten were prepared at high moisture using a twin-screw extruder. Effects of feed moisture content, extrusion temperature and wheat gluten content on the dynamic mechanical properties, microstructures and fractal analysis of texturized soybean protein/wheat gluten composite were investigated. All extruded samples were well fitted with Burger's model in creep-recovery tests (R-2 >= 0.978). The creep-recovery rate decreased with an increasing extrusion temperature. The addition of wheat gluten increased the resistance to creep and the unrecoverable deformation of TSP samples. The extrusion parameters affected the microstructure and morphology of extruded products. The fractal dimension of TSP products decreased with an increase in moisture content and wheat gluten content. Texturized soybean protein (TSP) and wheat gluten composite could form well-structure products.