Molecular characterization of corn starches by HPSEC-MALS-RI: A comparison with AF4-MALS-RI system

The functional properties of starch are determined to a large extent by the molecular structure. The starch solubilization is dependent on the procedure and solvent. Structural parameters, like weight average molar mass and radius of gyration, can be calculated by the analysis of solubilized polymers using HPSEC-MAL-RI and AF4-MALS-RI systems. The difference between both systems is the separation procedure of starch components (amylose and amylopectin). This work explored HPSEC-MALS-RI method as a strategy for molecular structure characterization of corn starches. To this end, starches with different amylose/amylopectin ratios (normal and waxy corn starches, and Hylon® V) were considered. The results showed that estimated structural parameters, such as molar mass, gyration radius and apparent particle density, were in the range of values reported in the recent literature and differences were found with the results obtained with AF4-MALS-RI system. In general, HPSEC-MALS-RI is a viable strategy for the accurate characterization of starch molecular structure.