Optimization of Extrusion Rice Bran Stabilization Process

ABSTRACT Effects of processing variables, production rate, number of die openings and initial moisture content on the discharge temperature and power input during rice bran extrusion with an autogenous single‐screw extruder were analyzed. At extrusion temperatures above 128°C, all lipase activity in the bran was lost regardless of moisture content of the bran fed. Net specific energy input (NSE) varied with changes in die opening and moisture contents and total power efficiency was increased with increasing production rate without change in NSE value. Percolation rate through the extruded bran bed was increased to nine times over that of raw bran; the extraction time to reach 1% residual oil in extruded bran was reduced to 10 min from 100 min for the raw bran.