Comparison of the structure and properties of hydroxypropylated acid-hydrolysed maize starches with different amylose/amylopectin contents

Dually modified regular maize starch (RMS) and high-amylose (HAMS) were successfully prepared by first acid hydrolysis subsequently hydroxypropylation. The effects of time (0–24 h) propylene oxide (PO) content (10–30%) on the structure physicochemical properties investigated. molar substitution (MS) HAMS samples (up to 0.163) was generally higher than that RMS 0.149), suggesting reactivity amylose for Besides, PO had a greater influence MS whereas effect minor. For both starches, dual modifications did not cause apparent changes granule morphology but reduced gelatinisation temperatures enthalpy; led relative crystallinity. These results suggest hydroxypropylation occurred mainly surface granules little compact granular structure, this reaction impacted internal much more. rheological study shows introduced hydroxypropyl bulky groups weakened entanglements between chains or amylopectin with long branches. Thus, work provides insights into rational design products containing different amylose/amylopectin contents tailored properties.