Oxidation of starches of different amylose content was investigated to
increase carboxyl and carbonyl content and to increase water solubili
ty. Three types of cornstarches containing up to 70% amylose were oxid
ized by a reactive extrusion-drum drying process, using hydrogen perox
ide and a ferrous-cupric sulfate catalyst. Increasing the peroxide lev
el increased oxidation and solubility. Starches with higher amylose co
ntent gave reduced solubility, but higher carboxyl content than the lo
w ones. Soluble products had solution viscosities comparable to maltod
extrins of dextrose equivalent 5-10. (C) 1997 Elsevier Science B.V.