Preparation and characterization of modified starches obtained in acetic anhydride/tartaric acid medium

Abstract

In the current contribution chemically modified starches are prepared by reaction of corn starch in hot acetic anhydride, containing tartaric acid. Characterization of the starch products shows evidence that the incorporation of acetyl groups increases with reaction time. Moreover, the modified starches show properties typical of cross-linked starches, such as reduced solubility in common starch solvents, increased resistance to amylolytic enzymes action, and significantly altered gelatinization behavior. Characterization results also give clear evidence of the evolution of derivatization within the granules volume, illustrating how cross-linking and acetyl group incorporation proceeds. The modified starches obtained may be of interest for different food and non-food uses in which singular characteristics resulting from the acetyl groups introduction and starch cross-linking by a non-toxic, naturally occurring organic acid such as tartaric acid may be of use to effectively meet products properties demands.