Characteristics of Hydroxypropylated and Acetylated Sago Starches

Abstract

 Sago starch was chemically modified with propylene oxide followed by acetic anhydride. Hydroxypropyl sago starch was prepared at 40°C using 0.0-7.5 ml propylene oxide in alkaline condition for 24 h. Acetyl sago starch was prepared at room temperature using 0.0-9.0 ml acetic anhydride in medium alkaline condition. The objective of this study was to determine the effects of molar substitution (MS) and degree of substitution (DS) on the properties of modified sago starch, characterized for swelling power, solubility and paste clarity (%T). The results showed that MS hydroxypropyl sago starch (HPSS) was 0.021-0.058 and DS hydroxypropyl-acetyl sago starch (HP-ASS) was 0.029-0.051 and 0.047-0.061 at acetic anhydride of 6.5 ml and 9 ml, respectively, while DS acetyl sago starch (ASS) was 0.051 and 0.057. DS HP-ASS was the lowest compared to ASS, as MS HP-ASS was 0.021 and 0.044. Swelling power, solubility and paste clarity of HPSS, ASS and HP-ASS were the highest compared to native sago starch (NSS).