Acetylation of Amaranthus viridis starch: Modeling and process parameters optimization

The optimum reaction conditions for the derivation of acetylated (esterified) starch using response surface methodology ( RSM ) and artificial neural network ( ANN ) were studied. All the independent variables (starch solids, acetic anhydride concentration, and reaction time) were of significant ( p  < .05) importance in achieving esterified starch of Amaranthus viridis . Optimum conditions of 152.46 g of starch, 11 ml of acetic anhydride and time of 2.92 min with corresponding acetyl content and degree of substitution ( DS ) of 1.74% and 0.06, respectively, were established for ANN . The RSM gave optimum conditions of 149.57 g (starch), 10.38 ml (acetic anhydride) and 3 min (time) with corresponding acetyl content and DS of 1.61% and 0.06, respectively. The order of priority of the process variables was established as acetic anhydride (42.59%), starch solids (33.90%), and reaction time (23.51%). The results provided useful information on development of economic and efficient acetylation process for modification of A .  viridis starch.