Effect of ohmic heating nixtamalization on the structural and physicochemical characteristics of instant maize flours and their relation to starch modifications

The study investigated the changes in the physicochemical properties of maize starch on nixtamalized flours produced with ohmic heating under different voltage and thermal conditions. Changes were studied using their viscosity profile, differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results indicated flour viscosity was affected by increasing time/temperature, but also by greater electrical fields, due to gelatinization and electroporation, shown as damage of the starch granule in SEM. DSC and XRD indicated gelatinization and loss of crystalline structures, but also formation of new amylose-lipid interactions stabilizing the starch system and causing lower peak viscosity.