The effects of dual modification on functional, microstructural, and thermal properties of tapioca starch

The aim of this study was to investigate the effects of dual modification on the functional, microstructural, and thermal properties of tapioca starch. Tapioca starch was first hydrolyzed by 0.14 M HCl for 0, 6, 12, 18, and 24 hr and then hydroxypropylated by adding 0%, 10%, 20%, and 30% (v/w) propylene oxide. The degree of hydroxypropylation, solubility, water absorption, rheological, thermal, and microstructure characterization of dually modified tapioca starch was determined. Hydroxypropylation did not cause any considerable changes in the starch granular size and shape of tapioca starch. Acid hydrolysis disrupts the starch granules, and the starches with smaller sizes were produced. The degree of molar substitution (DS) of dual modified starches ranged from 0.118 to 0.270. The dual modified starches significantly had higher solubility than native starch (p