Effects of Extrusion Variables and Die Configuration on Physicochemical Characteristics of Texturized Soy Protein Isolate

摘要

This study determined the effect of moisture content (45, 50, 55%), barrel temperature (140, 150°C), and two die configurations on the physical properties of extruded soy protein isolate (SPI). Water absorption capacity (WAC), texture, integrity index, and nitrogen solubility index (NSI) of extruded SPI were all analyzed. The texture of extruded SPI was affected by the die configuration. The physical properties of extruded SPI were significantly influenced by the barrel temperature, moisture content, and die configuration. The increase in barrel temperature led to increased WAC. The higher water injection rate led to a decreased integrity index and texture (elasticity, cohesiveness, chewiness, cutting strength). The extruded SPI using the 8 cm dieconfiguration had a higher integrity index than that using the 5 cm die configuration. The integrity index and NSI were negatively correlated. Thus, the die configuration can be useful to control quality of the extruded SPI.