Preparation and properties of the succinic ester of porous starch

Porous starch (PS) was prepared by replacing ice crystals in frozen starch gel with ethanol using a solvent exchange technique. It was then modified by succinic anhydride (SA) in a solvent/catalyst-free medium, and the obtained SA-modified PSs (SAPSs) were characterized. The degrees of substitution (DSs) of SA could be controlled by changing the SA/starch molar ratios. A high linear relationship (>0.99) between the DS and molar ratio was found. The effect of different DSs (0–1.90) on the pore size, apparent density, moisture adsorption, oil adsorption capacity and methylene blue (MB) adsorption of SAPSs was investigated. Apparent density, oil adsorption capacity and methylene blue (MB) adsorption of SAPSs increased gradually with the increasing DSs. SAPSs exhibited higher moisture content at equilibrium than PS. In addition, the adsorption of MB by SAPSs could be described well by a pseudo second-order model.