Synthesis of bread fruit (Artocarpus communis)-based hydroxypropyl starch through etherification using propylene oxide

Abstract

Hydroxypropyl starch was synthesized from bread fruit (Artocarpus altilis) starch that modified with the variation of propylene oxide, i.e. 8, 10 and 12%; and reaction time, i.e. 30, 60 and 90 min, in alkaline condition. The optimum condition to prepare hydroxypropyl starch was found at 12% of propylene oxide concentration and 90 min of reaction. As an ether starch modification, the obtained hydroxypropyl starch was confirmed by the presence of FT-IR band at 1149-1157 cm-1 that assigned as the C-O-C vibration. The1H-NMR confirmed the ether starch modification was successfully synthesized with the disappearance of the peak at 4.5-5.5 ppm, and the appeared of a new doublet peak at 3-4 ppm that confirmed the presence of hydroxypropyl group. The highest substitution degree of hydroxypropyl was 1.8 that found a variation of 12% propylene oxide and 90 min of reaction. The obtained hydroxypropyl starch showed swelling power of 12.05, the solubility of 9.42%, and water content of 4.16%.