Application of small-angle neutron scattering to the study of the structure of starch granules

The use of contrast variation to provide detailed information on local composition from small-angle neutron scattering (SANS) is a well established technique for synthetic polymers. However, it has been much less exploited in the field of biopolymers. In this present paper the approach is described in its application to understanding the distribution of water within waxy maize starch granules. On the basis of small-angle X-ray scattering, starch granules have been modelled as containing three regions, namely semicrystalline stacks containing alternating crystalline and amorphous Iamellae, which are embedded in a matrix of amorphous material. By using the results obtained from SANS studies of starch dispersed in water with different D2O contents it has been possible to quantify for the first time, the water contents in each of these three regions. Copyright (C) 1996 Elsevier Science Ltd.