Studies on Corn Starch Modified by Citric Acid

Citric acid and corn starch were used as materials to prepare Citrate Corn Starch(CCS) by semi-dry method.The effect of the mass ratio of citric acid and starch,reaction temperature,reaction time and reaction pH value on the DS of CCS was studied.The optimum conditions were:the mass ratio of starch and citric acid was 2∶ 1,reaction time was 5 h at the temperature of 120 ℃,and pH value was controlled to 3.The DS of CCS obtained was 1.44,and the product structure was characterized by IR and XRD.