Twin-screw Extrusion of Rice Flour, Carrot Flour and Soy Protein Isolate (SPI) Blends: A Response Surface Analysis

Abstract

The present study focused on the use of the blends of Carrot, Rice and Soy Protein isolate flours to produce ready-toeat snack products using extrusion cooking. Response surface methodology (RSM) was used to optimize the process. Response (dependent) variables were Expansion ratio (ER), Bulk density (BD), Rehydration ratio (RR), Water Solubility Index (WSI), and Breaking stress (BS). Independent variables were blended with Carrot (5-15%), SPI (15-25%), and Rice (60-80%). All other processing variables (barrel temperature, screw speed, feed moisture, and die diameter) was kept constant (170 °C, 90r.p.m, 26%, and 30 mm respectively). The result indicated that optimum ER, BD, RR, BS, and WSI were found to be 1.49, 824.249 kg.m-3, 65.76%, 27.56 N and 3.41%, respectively, at a blend of Carrot (5 %), SPI (15%) and Rice (80%).