Studies on the optimisation of preparation of succinate derivatives from corn and amaranth starches

Conditions for the preparation of half esters of corn and small sized (1–2 μm) waxy amaranth starch using succinic anhydride were compared in a non-aqueous medium. The synthesis was followed in terms of % succinyl content and the degree of substitution (DS). The parameters optimised included succinic anhydride concentration, reaction time and starch/pyridine ratio required in the process. Succinate derivatives from both the starches gave DS as a function of the succinic anhydride concentration and reaction time. A starch/pyridine ratio of 1:2 was found to be necessary for the reaction to be carried out smoothly.