MODIFIED CORN STARCH: OPTIMIZATION OF MODIFICATION CONDITIONS BY THE RESPONSE SURFACE METHODOLOGY

Abstract

This article presents the results of using the response surface methodology with a central composite design (RSM-CCD) to optimize the oxidation process of corn starch with a sodium hypochlorite agent. The model is designed as 18 experiments with six experiments at the center to build for three survey factors inclusive of active chlorine concentration, temperature, and pH. Combined with the single-factor survey, two parameters are starch content and corn starch oxidation time. Optimal conditions were found: temperature 51.85°C; active chlorine concentration 3.74% ; pH 9.06; starch content 40% and oxidation time 90 minutes. The highest degree of oxidation was achieved at 0.719% with carbonyl and carboxyl groups of 0.075% and 0.649%, respectively. The FTIR spectrum of oxidized corn starch appeared absorption peak at 1744 cm-1 correspond to the oscillation of the C=O group, indicating that the oxidation reaction has occurred.