Physicochemical properties of native and γ-irradiated wild arrowhead (Sagittaria sagittifolia L.) tuber starch

Starch isolated from wild arrowhead tuber was treated by γ-irradiation at 0, 5, 10 and 15kGy doses. Arrowhead tubers yielded 40.33% starch and its chemical composition revealed moisture, protein, ash and fat were 8.34±0.09%, 0.26±0.04%, 0.58±0.02% and 0%, respectively. Physicochemical, morphological and pasting properties of native and irradiated tuber starches were investigated. The results showed that peak, trough, final, and setback viscosities were significantly (p≤0.05) reduced, whereas the breakdown viscosity increased following irradiation. Physicochemical properties differed significantly and showed strong dose dependent relationship. Solubility, water absorption capacity and transmittance increased, whereas swelling power, bulk density and syneresis decreased upon increase in irradiation of starch. Correlation studies showed that irradiation dose was positively correlated with water absorption capacity and solubility index while it correlated negatively with pasting properties, swelling index, syneresis, and freeze thaw stability.