Abstract:

Corn starch was mechanically activated by ball milling (rolling-type) and then esterified by octenyl succinic
anhydride (OSA) in aqueous slurry systems. The process of esterification was studied with respect to the time of mechanical
activation, reaction temperature, pH, starch slurry concentration and reaction time. The optimum reaction conditions were
determined by the quadratic regression orthogonal rotation design and response surface methodology. The results indicated
that the mechanical activation considerably enhanced the esterification of corn starch and the esterification showed a low
sensitivity to pH changes. The optimum reaction conditions were determined as follows: mechanical activation time, 10 h;
the concentration of activated starch, 12.2%; reaction temperature, 33.1℃, reaction system pH, 8.45; and reaction time, 3 h.
Under these conditions, the degree of substitution of mechanical activation starch obtained was 0.020 3.

Key words: corn starch, mechanical activation, OSA, response surface methodology