Characteristics of partially pregelatinized sago starch from Bangka, Riau, and Papua extruded using twin-screw extruder

Sago starch from Bangka, Riau, and Papua could be increased in added value through the extrusion process without a die. This study aims to explore the physicochemical properties of sago starch classified based on its origin in Indonesia, namely Bangka, Riau, and Papua, including the same properties of its extruded product, namely partially pregelatinized sago starch (PPSS), for the selection of sago was best carried out process optimization. Native sago starches were extruded using a twin-screw extruder (TSE) with a moisture content of 41%, barrel temperature for zone 1–4 at (40 °C, 81 °C, 81 °C, and 81 °C) respectively, screw speed at 390 rpm, and without a die. Physicochemical properties such as degree of gelatinization (DG) and other properties were analyzed. DG of native sago starch from Bangka, Riau, and Papua were 14.27%, 19.00%, and 13.03%, respectively. Values of DG were significantly increased after the modification process using extrusion treatment into PPSS, which PPSS of Bangka, Riau, and Papua had DG of 48.91%, 39.82%, and 37.80%, respectively. Pasting properties, thermal properties, water absorption index (WAI), water solubility index (WSI), swelling power (SP), gel properties, viscosity, starch content, amylose, proximate composition, structural morphology, crystallinity, pH, bulk density (BD), degree of whiteness (DW), and birefringence were observed. PPSS of Sago Bangka has better characteristics in properties of DG, WSI, WAI, SP, DW, viscosity, gel strength, and adhesiveness, so it can be used as a binder in processed foods.