Scattering Studies of the Internal Structure of Starch Granules

Abstract

Small Angle X-ray Scattering (SAXS) and Small Angle Neutron Scattering (SANS) are applied to the study of the internal supramolecular packing within starch granules. SAXS is able to provide information on the packing of the semicrystalline lamellae and the amorphous growth rings. Using synchrotron radiation it is possible to follow changes in structure at both elevated temperatures within the gelatinisation regime, and at sub-zero temperatures when ice crystallisation can change the packing via compression of the granule. The role of amylose in modifying the response of the granule to these temperature variations has been examined. SANS has been used to examine the distribution of water in different parts of the granule, and quantify the molecular densities in different regions of the granule.