微波辅助复合氧化法合成氧化玉米淀粉

以玉米淀粉为原料、以过氧化氢和过硫酸钾为复合氧化剂、以Fe2＋为催化剂,在酸性条件下采用微波辅助复合氧化法合成氧化玉米淀粉。以反应温度、微波催化合成/萃取仪功率、催化剂质量分数（占干淀粉总量,下同）、复合氧化剂质量分数（占干淀粉总量,下同）、淀粉乳浓度、体系pH值、反应时间等因素为变量,以氧化度为衡量指标,采用单因素实验和正交实验确定微波辅助复合氧化法合成氧化玉米淀粉的最佳工艺条件为：反应温度55℃、微波催化合成/萃取仪功率400 W、催化剂质量分数0.3%、复合氧化剂质量分数8%、淀粉乳浓度45%、体系pH值4.00、反应时间21min,在此条件下,可以制得氧化度为0.140%的氧化玉米淀粉。

Synthesis of Oxidized Corn Starch by Composite Oxidation with Microwave

Using corn starch as raw material, hydrogen peroxide and potassium sulfate as composite oxidant, Fe2＋ as catalyst, the oxidized corn starch was prepared by composite oxidation with microwave under acid condi- tions. With reaction temperature, microwave catalytic synthesis/extraction apparatus power, catalyst mass fraction, composite oxidant mass fraction, starch milk concentration, system pH value and reaction time as variable, with oxidation degree as index, the optimum synthetic conditions of oxidized corn starch were determined by single factor experiment and orthogonal experiment as follows, the reaction temperature was 55 ℃, the microwave catalytic synthesis/extraction apparatus power was 400 W,the catalyst mass fraction was 0.3 %,the com- posite oxidant mass fraction was 8%, the starch milk concentration was 45%the system pH value was 4.00, the reaction time was 21 min. Under above conditions,oxidized corn starch could be obtained with oxidation degree（--COOH） of 0.140%.