Effect of Pulsed Electric Field on the Preparation and Properties of Cassava Starch Acetate

Abstract:

Starch acetate was prepared from cassava starch with acetic anhydride as the esterifying agent by the wet process assisted by pulsed electric field (FET) treatment. The effect of PEF) parameters on the formation of cassava starch acetate was evaluated using different strengths (0, 2, 3, 4, 5, 6, and 7 kV/cm), and treatment durations (0, 3, 6, 9, 12, and 15 ms).The effect of the concentration of acetic anhydride added (4%, 6%, 8%, 10%, and 12%) was also explored. In addition, the properties of cassava starch acetate such as paste transparency, solubility, swelling power, freeze-thaw stability, and viscosity were evaluated. Acetyl content and degree of substitution measurements showed that both were increased after PEF treatment. The degree of substitution increased from 0.084 to 0.110 under the following conditions: 6% added acetic anhydride, 4 kV/cm PEF, and 12 ms of reaction duration, indicating that PEF could facilitate esterification. Infrared spectroscopy was used for structural characterization of cassava starch acetate, which showed that the acetyl group was introduced into the cassava starch molecules and improved paste transparency, solubility, swelling power, and peak viscosity, with no effect on freeze-thaw stability.