Abstract
This study optimized the extrusion process parameters for producing high-moisture meat analogs (HMMA) incorporating isolated rice protein (IRP). A Box-Behnken response surface design was applied to evaluate the effects of moisture content (50, 55, and 60%), barrel temperature (160, 170, and 180 °C), and screw speed (100, 150, and 200 rpm) on physicochemical and textural properties. Moisture content was identified as the most influential factor. Increasing moisture reduced fiber structure, integrity index, and nitrogen solubility index, whereas higher barrel temperature improved textural characteristics such as springiness, cohesiveness, and chewiness. Water holding capacity increased with rising moisture content and temperature. Screw speed showed no consistent pattern in textural effects. Optimal extrusion conditions were predicted by the model as approximately 56% moisture content, 172 °C barrel temperature, and 138 rpm screw speed, producing HMMA with desirable water retention and chewiness. These results provide practical insights for improving the processing of IRP-based high-moisture meat analogs.