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.