A SMALL-ANGLE X-RAY-SCATTERING STUDY OF THE ANNEALING AND GELATINIZATION OF STARCH

The structure of starch in its native state and during gelatinization was studied using small-angle X-ray scattering (SAXS). The scattering data were then modelled by considering the theoretical scattering from a finite number of infinite lamellar planes of crystalline and amorphous material, embedded in a medium of specified electron density. The changes in the SAXS pattern during gelatinization could be modelled simply by changing the relative electron densities of the system, thereby observing directly the absorption of water and the disruption of crystallinity. This rigorous analysis of the SAXS data from starch has provided new insights into the structure of native starch and the mechanisms of gelatinization.