Synthesis of Oxidized Corn Starch by Composite Oxidation under Ultrasonic Irradiation

Corn starch was used as material under acid condition to prepare oxidized corn starch by composite oxidation under ultrasonic irradiation with hydrogen peroxide and potassium sulfate as composite oxidant and Fe2+ as catalyst.With starch milk concentration,composite oxidant mass fraction,reaction system pH value,numerical control ultrasonic cleaning power,catalyst mass fraction,reaction temperature,reaction time as the objects,with content of carboxyl indicating oxidation agree of starch as the index,the optimum synthetic conditions of oxidized corn starch were determined by the single factor experiment and the orthogonal experiment as follows:the starch milk concentration was 30%,the composite oxidant mass fraction was 10%,the system pH value was 3.00,the numerical control ultrasonic cleaning power was 90 W,the catalyst mass fraction was 0.3%,the reaction temperature was 55 ℃,the reaction time was 40 min.Under above conditions,oxidized corn starch could be obtained with oxidation degree of 0.203%.