From Helical Starch Inclusion Complexes to Supramolecular Starch Assemblies

摘要

The present contribution reports on the structural features of aqueous starch dispersions as induced by starch complexation with small ligands. Complexation refers to the physical binding of suitable ligands by starch, where the ligand induces the helication of linear segments of starch. The ligands are non-covalently bound to starch, in particular to the linear starch polymer amylose, by inclusion into the helical cavity or between the helices. Potato starch dispersions were complexed with lactones and terpenes, and the structural properties of complexes were assessed by amperometric iodine titration, differential scanning calorimetry (DSC), wide-angle X-ray diffraction, rheology and microscopy. The strong tendency of starch helices to associate promoted the formation of supramolecular amylose structures. Depending on the complexation kinetics and the type of ligand, starch-ligand complexation led to the formation of a partly crystalline network gel or to spherulitic crystallization.