Ultra high pressure (UHP)-assisted hydroxypropylation of corn starch

Reactivity and property of corn starches hydroxypropylated under ultra high pressure were investigated as a function of either pressure levels or pressure holding times Corn starch was derivatized with propylene oxide (PO) either at 01-400 MPa for 15 min or at 400 MPa for 5-25 min and assessed with respect to molar substitution (MS) X-ray diffraction pattern solubility swelling power gelatinization and pasting behavior While an increase in pressure level enhanced MS values of UHP-assisted PO starch derivatives starch reactivity was less influenced by pressure holding time UHP-assisted PO reaction reduced reaction time to the greatest extents compared to long reaction time in conventional PO reaction UHP-assisted PO starch derivatives revealed similar solubilities/swelling powers and gelatinization properties regardless of pressure levels Higher gelatinization temperature was observed for UHP-assisted PO starch derivatives and their respective controls relative to native starch implying that UHP-assisted reaction might involve starch annealing (C) 2010 Elsevier Ltd All rights reserved