Preparation and physical properties of modified cassava starches

Abstract

This study was conducted to analyze the physical properties of cassava starch crosslinked with sodium trimetaphosphate (STMP) and used sodium hydroxide as a catalyst. The effect of crosslinker and catalyst (Starch/STMP/Catalyst) on thermal analysis, morphology, and structure crystal were investigated. The physical properties of native and modified cassava starch were also comparatively studied. Modified cassava starch was produced by adding different amounts of sodium trimetaphosphate (0.125, 0.25, and 0.5 % w/w) and catalyst of sodium hydroxide (0.5 and 1.0% w/w) into a reactor in water bath hotplate at 70 °C and 300 rpm for an hour. There are different diffraction patterns between the native cassava starch (NCS) and crosslink cassava starch (CLCS) samples. The sample of CLCS 1 (B); CLCS 2 (C) presented small new peaks in the regions of 32°, 38° and 41° (2θ), which may be related to changes in a three-dimensional network of the chains. It was indicated that the crosslinking process occurred successfully. The native cassava starch sample showed a smooth surface with rounded and bell shape granules. The samples CLCS presented loss of grain format, distorted and wrinkled surfaces with some rupture to the granules.