| Abstract: | A hydrodynamic column packed with solid beads chemically bonded with N-methyl-d -glucamine residues was used with 90% dimethylsulfoxide (DMSO)-H2O mobile phase as part of a chromatographic system to characterize jet-cooked waxy maize starch. Software calculations based on signals from refractive index and dual-angle light-scattering detectors indicated the column could fractionate molecular weights up to ≈5 × 108. Calculated molecular weight values for the highest molecular weight sample was greatest at the lowest flow rate of 0.1 mL/min. Values of molecular weights and radii of gyration determined by the in-line dual-angle light-scattering detector were significantly less than those determined with an off-line multiangle light-scattering detector that examined samples that had not traveled through the hydrodynamic column. This work has demonstrated the feasibility of using a hydrodynamic column to characterize waxy maize amylopectins. However, considerations of sample shear sensitivity and questions of in-line light scattering detection show that further efforts are required to develop and optimize a chromatographic system to characterize very high molecular weight amylopectins. |
