Microwave assisted acetylation of mung bean starch and the catalytic activity of potassium carbonate in free‐solvent reaction

Abstract

AbstractMung bean starch acetate has been successfully produced with transesterification reaction of the starch under microwave assistance using vinyl acetate (VAC) as esterifying agent and potassium carbonate (K2CO3) as a catalyst. Various concentration of potassium carbonate (0–0.117 mmoleq/AGU) was resulted in starch acetate with increased mood of the degree of substitution (DS = 0.003–0.27) in a short time. An increase in the degree of substitution, resulting in increase of the peak intensity of ester carbonyl group (CO) at 1742 cm−1, which was further proved by FTIR. Obvious change in the starch granules morphology, increasing in the hyrophilicity and decreasing in the temperature and enthalpy of gelatinization were noticed accordingly to the degree of the starch modification. The X‐ray pattern of native starch was A type, with similar pattern in modified derivatives.