Physicochemical Properties of Modified Cassava Flour and Starch for Corrugated Board Adhesive

Abstract

Cassava flour and starch were changed in their physicochemical properties after being modified by cooking extrusion or drum drying, and by adding chemical reagents (5% w/w borax and 1% w/w sodium hydroxide) to extruded and drum dried products. After extrusion and drum drying, the products had a higher water absorption index (WAI) and water solubility index (WSI) than they have had before. Regarding to capillary viscosity, the extruded flour had the lowest viscosity (10.3 sec.). Their amylograms had the starting point viscosity and did not reach maximumviscosity. When native flour and starch were mixed with their modified products at the ratio of 1:2, with or without addition of borax and sodium hydroxide, their amylograms showed already starting point viscosity at low temperature (30 degree C) and maximum viscosity were also low. Their mixtures were also reduced the capillary viscosity. After evaluating the physicochemical properties of modified products, the suitable mixtures for using as corrugated board adhesive was the mixture of extruded flour and 5% borax.