Effect of gamma irradiation on physicochemical properties of Indian Horse Chestnut (Aesculus indica Colebr.) starch

Starch isolated from Indian Horse Chestnut (Aesculus indica Colebr.) was subject to irradiation at 0, 5, 10, 15 kGy doses. Effect of irradiation on physicochemical properties of native starch was studied. The result revealed increase in water absorption capacity from 0.94 to 1.00 g/g, carboxyl content from 0.00 to 0.06%, solubility from 0.15 to 0.53 g/g and freeze thaw stability. Syneresis, pasting properties and pH were reduced following irradiation treatment. Syneresis decreased from 3.47 to 0.64% after 120 h refrigerated storage. Peak viscosity reduced from 5156.5 to 1422.5 cP, setback viscosity from 1191.5 to 73.0 cP and final viscosity from 3232.0 to 410.5 cP. X-ray diffraction pattern showed A type of pattern in native as well as irradiated starches. Granule morphology of native and irradiated starches under scanning electron microscope revealed that granules were round, oval, irregular or elliptical with smooth surfaces. Pearson correlation studies revealed that irradiation dose was positively correlated with water absorption capacity, oil absorption capacity, and solubility index and negatively correlated with syneresis, swelling index, freeze thaw and pasting properties.