Facile Preparation of Starch Triacetates

Abstract

Abstract Commercial high‐amylose corn, ordinary corn and potato starches were fully acetylated by reacting the starches at 123°C for 5 h in fourfold quantities of acetic anhydride to which 11% (w/w starch) of sodium hydroxide catalyst had been added as 50% aqueous solution. Intrinsic viscosities of the starches regenerated from their esters were slightly lower than the values for the corresponding unreacted starches and indicated that only minor degradation hat occurred during acetylation. Amylose obtained by the butanol fractionation of corn starch was also readily acetylated by this procedure. However, commercial potato amylose required removal of the small amount of magnesium sulfate present to achieve both full acetylation (44.8% acetyl) and minimum depolymerization of the starch.