PHYSICAL PROPERTIES IMPROVEMENT OF GADUNG (Dioscorea hispidaDennst.) STARCH OXIDIZED BY HYDROGEN PEROXIDE

Oxidation is chemical modification which alters and improves the properties of starch.This study investigated the effect of oxidation using hydrogen peroxide on Gadung starch towards its physical characteristics.The different concentrations of oxidant (0; 2; 4; 6 and 8%) were studied.The effect of oxidation were evaluated based on swelling power, solubility, freeze thaw stability, viscosity, and whiteness of the oxidized starch.A significant difference was observed on the value of swelling power, solubility, freezethaw stability, viscosity and whiteness of Gadung starch.H2O2 at 4% concentration showed the best swelling power with 263% increase than that of native starch.The highest solubility was shown by 8% H2O2 concentration which was 55.66 g/100g.The syneresis of 8% H2O2 was also the lowest, 11.67% which showed the highest freeze thaw stability.The viscosity has decreased to 94.3% compared to native starch at 8% H2O2.The whiteness of oxidized starch is increased along with increasing concentration of hydrogen peroxide that given.