Supramolecular structure of high hydrostatic pressure treated quinoa and maize starches

Abstract The supramolecular structures of high hydrostatic pressure (HHP) treated quinoa and maize starches were analyzed using wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS) techniques. Quinoa starch lost its lamellar structure at a lower pressure (500 MPa) compared to maize starch (600 MPa). WAXS studies showed that HHP could enhance the formation of amylose-lipid inclusion complexes in maize starch but not in quinoa starch. The lamellar thickness of quinoa starch was significantly shorter than that of maize starch in their native state. Up to 500 MPa, the lamellar thickness of maize starch remained constant, while that of quinoa starch increased significantly. HHP treatment could cause an increase in length of the transition layer and this effect was less obvious in quinoa starch (0.1 nm) than in maize starch (0.3 nm) at 500 MPa. Two fractal regions were found in both quinoa and maize starches. HHP could reduce the compactness and roughness of the starch granules, while increasing the correlation length of these two starches. The difference in the structural changes after HHP treatment measured by SAXS between quinoa and maize starches was discussed in relation to their molecular structure.