γ-Irradiation of oat grain - Effect on physico-chemical, structural, thermal, and antioxidant properties of extracted starch.

Three different varieties of oat grains, Sabzaar, SKO-20, SKO-90 maintained at the moisture level of 12% were γ-irradiated at four different dosage levels - 5, 10, 15, and 20kGy. Starch was extracted and its physicochemical, structural, thermal, and antioxidant properties were studied. Amongst the physico-chemical properties, syneresis, solubility index, swelling index and light transmittance values showed a varied significance from their native counterparts. Irradiation also had an effect on RVA profiles which exhibited a decrease in peak, trough, final and set back viscosities whereas the pasting temperatures showed a significant (P≤0.05) decline. The exposure of hydroxyl groups in starch chain due to irradiation was confirmed via ATR FT-IR. γ-Irradiation resulted in the formation of ridges on the surface of starch as revealed from SEM. Irradiation resulted in a significant improvement in antioxidant activity of the extracted starches.