γ Irradiation of Cowpea and Potato Starch: Effect on Physicochemical Functional and Rheological Properties

Changes in the physicochemical, thermo-rheological and antioxidant properties of the cowpea and potato starch subjected to gamma irradiation were studied. It was found that apparent amylose content, swelling index, enthalpy of gelatinization, transition temperature and total crystallinity of the starches significantly (p ≤ 0.05) decreased with an increase in irradiation dose. Similarly, significant (p ≤ 0.05) decline in the pasting properties (peak, trough, setback, final viscosity, and pasting temperature) for both the starches was observed with increasing the ionizing dose. On the contrary, the increased solubility index was incurred upon subjecting the starch to gamma irradiation. The irradiated starch granules remained intact showing no surface fissures. Antioxidant capacity, FRAP values, and DPPH% inhibition, increased as the irradiation dose increases.