Evaluation and optimization of disc grating machine for sago starch production (Metroxylon spp.).

Abstract

The production of Sago starch involving multiple processes and the grating process was the most important since the recovery of sago starch was directly affected. In order to produce a finer size of grated sago and high starch recovery, a new design of sago disc grating machine has been developed. A evaluation was performed to determine the optimum operation on the basis of the feeding rate and grating speed input on the sago disc grating machine, and the starch recovery as the output. The grated sago was dried and sieved at different sizes to analysis the size. A model equation was developed to predict the starch recovery. As the result, the optimum feeding rate was 0.1 m/min with 1500 rpm of grating speed produce 23.57% of sago starch recovery. Studies show that the feeding rate and grating speed affects the size of the grated sago produced (P<0.01) and directly affects starch recovery.