Phosphate positioning and availability in the starch granule matrix as studied by EPR

Abstract

CU2(divided by) was introduced as an EPR probe into the starch granules isolated from different starch crop genotypes including transgenically modified potatoes generated for extreme amylose and starch phosphate monoester concentrations. Several discrete copper adducts bound to the starch matrix with different strength was revealed. It was found that phosphate has a significant influence on the type of these species, their number, location in the structure, and strength of binding. Well dispersed Cull complexes with axial symmetry are formed in the sernicrystalline part of the starch linked through O-P- bonds in the phosphorylated starches. In the amorphous part of the starch, freely rotating hexaaqua complexes of Cull and complexes coupled antiferromagnetically are formed. The amount of the former increases with content of phosphate indicating enhanced binding of water in the granules. The results complement previous experimental data and molecular models for the starch granule with respect to the location and effects of phosphate and crystalline matter

Published in

Biomacromolecules
2006, Volume: 7, number: 3, pages: 965-974 Publisher: AMER CHEMICAL SOC

SLU Authors

• Andersson, Roger

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Food Science


Publication identifier

DOI: https://doi.org/10.1021/bm050919g

Permanent link to this page (URI)

https://res.slu.se/id/publ/10716