Extrusion process parameters, sensory characteristics, and structural properties of a high moisture soy protein meat analog

Soy protein isolate and wheat starch at 9:1 ratio were extruded at 60%, 65%, and 70% moisture contents and 138, 149 and 160°C cooking temperatures. The results indicated that moisture content was a more important factor than cooking temperature for both extrusion process parameters and product sensory characteristics. Extrusion at a lower moisture content resulted in a higher product temperature and higher die pressure. The resultant products were tougher, chewier, and more cohesive and had a more layered and fibrous structure. Water absorption capacity increased with both higher extrusion moisture and higher cooking temperature.