Starch esters obtained by microwave radiation - structure and functionality

The structure and functionality of starch esters obtained in rotating roasters and in microwave ovens were examined. Native potato starch was prepared for esterification according to the procedure applied in industrial processes. It was found that microwave heating is a convenient way to obtain a wide range of products of inorganic starch ester type usually produced in rotating roasters. Microwaves do not affect the kind of chemical groups substituted into the starch and the molecular mass distribution of inorganic starch esters as compared to traditional products. There are no changes in the chemical structure, microstructure and crystal structure between inorganic starch esters obtained in microwave and in conventional technology. In order to obtain a satisfactory degree of substitution by microwave radiation a significantly shorter time is required than in conventional technology. (C) 2000 Elsevier Science B.V. All rights reserved.