Influence of temperature on the apparent molar masses and sizes of pregelatinized wx corn in aqueous media determined using asymmetrical flow field‐flow fractionation

Pre-gelatinized wx corn starch dispersions in aqueous media were heated at various temperatures ranging from 100 to 200°C (in 20°C increment) employing a dedicated microwave reactor. The influence of varying temperature upon the apparent molar masses and sizes of pre-gelatinized wx corn heated in aqueous media (water and 1 M KSCN) were determined using asymmetrical flow field-flow fractionation coupled with a multi-angle light scattering and a RI detector (AF4/MALS/RI). The microwave reactor allowed the accurate monitoring and regulation of temperature, microwave energy, and pressure during the dispersion/dissolution process. The ultra-high apparent molar masses, apparent radii of gyration and hydrodynamic sizes determined for wx corn starch heated for 60 s in water indicate the presence of large aggregates. However, the lower apparent molar masses and radii of gyration values obtained for wx corn starch heated in 1 M KSCN suggest that KSCN reduced the aggregation of starch macromolecules. Significant structural changes were observed for wx corn starch heated in the presence of KSCN at 200°C.