Physical Properties of Extrudate with Treatments of Corn Grit-Sago Flour Composition and Moisture Contents Using Twin-Screw Extruder

Abstract The abundant production of sago in Indonesia is not followed by a consumption rate. Currently, the utilization of sago flour is only limited to raw materials for making traditional food. One of the innovations in sago flour processing as a raw material for the manufacture of extruded snacks is to be mixed with corn grit. The quality of extrudate snack is influenced by extrusion process variables such as composition and moisture content. Therefore, this study aims to analyze the effects composition and moisture content of mixed corn grit and sago flour on the physical characteristics of extrudates and determine the treatment variation that produces the extrudate with the best preference. Extruded snacks made from corn grit and sago flour were processed using SYSLG-IV twin-screw extruder with capacity of 15 kg/h. This experiment conducted with two treatments, sago flour composition (0%, 10%, 20%, 30%) and moisture content (14%, 16%, 18%). The result revealed that sago flour composition had significant effect on expansion ratio (2.31-3.68), particle density (0.14-0.41 g/cm 3 ), bulk density (0.094-0.214 g/cm 3 ), extrudate moisture content (1.02-3.67 %wb), water absorption index (6.70-7.70), water solubility index (1.48-6.62%.). The moisture content of the mixture had significant effect on all measured physical characteristics including hardness (2.15-9.72 N/mm 2 ). Based on Technique for Order Preference by Similarity to Ideal Solution analysis, the treatment that produced extrudates with the best preference was 30% sago flour composition and 14% moisture content. The results are useful for optimizing the extrusion process so that food sustainability can be achieved by increasing food diversification.