Characterization of Physicochemical and Baking Expansion Properties of Oxidized Sago Starch Using Hydrogen Peroxide and Sodium Hypochlorite Catalyzed By UV Irradiation

Abstract

This study investigate the effect of oxidation using hydrogen peroxide and sodium hypochlorite on physicochemical and baking expansion properties of oxidized sago starch.  Type of oxidant and irradiation time (10,15 and 20 min) were studied. The extent of oxidation was determined based on starch color, carboxyl, carbonyl, and amylose contents, swelling power and solubility, and baking expansion properties of oxidized starch. The results showed that L* value increased with oxidation reaction using peroxide and hypochlorite as oxidant and longer time of UV irradiation. Carbonyl content of peroxide- and hypochlorite-oxidized starch decreased by increasing of UV irradiation time. Carboxyl content was increased by increasing irradiation time at 15 min and then decrease at 20 min irradiation time. Increasing irradiation time, increasing amylose content of oxidized sago starch. Swelling power and solubility of oxidized sago starch increase from 10 min to 15 min irradiation time and then decrease at 20 min irradiation time. Swelling power and solubility of peroxide-oxidized sago starch was higher than hypochlorite-oxidized starch. Oxidation reaction decrease the pasting temperature and increase peak viscosity, hot paste viscosity and cool paste viscosity of sago starch. The peak viscosity and hot paste viscosity of peroxide-oxidized sago starch are higher than hypochlorite-oxidized starch. Oxidation of starch using peroxide and hypochlorite catalyzed UV irradiation increased specific volume of starch. Baking expansion of hypochlorite-oxidized starch is lower than peroxide-oxidized starch. Oxidation starch using peroxide with UV irradiation for 15 min gave the highest specific volume of sago starch at 8.65 mL/g with degree of baking expansion 65,6%.

Keywords: Sago starch, oxidation, hydrogen peroxide, sodium hypochlorite, UV irradiation