Optimization of the production of acetylated distarch adipates using the novel software 'MULTIPLEX'

Acetylated, cross-linked and pregelatinized cassava starches were produced in a single-screw extruder with different moisture contents (180, 220 and 2 60 g kg(-1)), reagent (adipic acetic mixed anhydride) concentrations (4, 11 and 18 g kg(-1)) and screw speeds (100, 130 and 160 r.p.m.). The acetylati on, cross-linking and pregelatinization increased cold viscosity (CV), wate r absorption index (WAI) and gel hardness, it also reduced gel cohesiveness , paste clarity and retrogradation of the modified-starches compared with c ontrol samples (CSs). A novel microcomputer program called MULTIPLEX was de veloped for the optimization of the process. The optimization process maxim ized CV, WAI, gel hardness and paste clarity, and minimized gel cohesivenes s and retrogradation of the modified-starches. The optimum conditions were moisture of 240 g kg(-1), reagent concentration of 4 g kg(-1) and screw spe ed of 100 r.p.m. Experimentally determined values for all responses found i n products processed under the optimum conditions were very close to the pr edicted values and this confirmed the validity of predicted models.