Effect of varying flow regimes upon elution behaviour, apparent molecular characteristics and hydrodynamic properties of amylopectin isolated from normal corn starch using asymmetrical flow field-flow fractionation

A detailed study of the elution behaviour, apparent molecular characteristics and hydrodynamic properties of amylopectin-type fraction (isolated from normal corn starch) in aqueous media employing asymmetrical flow field-flow fractionation (AF4) was undertaken by systematically varying the channel flow (Fch), cross flow (Fcr) and Fcr/Fch ratios. Distributions of apparent molar masses and radii of gyration, mass recoveries and hydrodynamic radii decreased as a function of increasing Fcr at a fixed Fch, due to the increase in the retention of amylopectin-type fraction in the AF4 channel. Increased retention of the amylopectin-type fraction in the AF4 channel was also observed at low Fch and high Fcr/Fch ratios. Large amylopectin-type molecules/particles (possibly aggregates) eluted at high Fch, low Fcr and low Fcr/Fch ratios.