Effect of Acetylation on the Physicochemical Properties of Starch Extract from Caladium bicolor

Abstract

The study reports on the effect of acetylation on the physicochemical parameters of Caladium bicolor starch. The starch was extracted and acetylated using various acetic acid volumes and reaction periods (30, 60, and 90 minutes). Both unmodified and acetylated starches were characterized with Fourier transform infrared spectrometry (FTIR) and some models. The findings estimated a low amylose content of 16.95%, and amylopectin at 83.05% in unmodified starch. The swelling power was 72.45 (unmodified), and 64.9–68.5 (modified); paste clarity was 2.013 (unmodified), and 1.73–1.91 (modified); gelatinization temperature was 75oC (unmodified), and 76–78oC (modified); water binding capacity was 68.6% (unmodified), and 68–92.7% (modified); oil binding capacity was 53.8% (unmodified), and 53.2–92.63% (modified); % acetyl group and degree of substitution were 0.73-3.63 and 0.03-0.13. The FTIR reveals the vibration frequencies of 3283.62 cm-1, 1018 cm-1 and 1240 cm-1 affirm the presence of OH, C-O, and CH3 in the unmodified. Whereas, the prominent peak at 1647.28 cm-1 assigned to the carbonyl C=O and its increase in intensity and height affirmed the increase in the acetylation of starch molecules. Starch obtained from Caladium bicolor and the acetylated products could be used as glue, thickeners, gelling agents and adhesives for paper products and textile industry.