THE USE OF FREEZING-POINT DEPRESSION FOR THE THEORETICAL DEXTROSE EQUIVALENT MEASUREMENT

The determination of the theoretical dextrose equivalent was investiga ted, by measuring the osmolality (mel dissolved particles/kg H2O) by f reezing-point depression. Relations for dextrose equivalent and increa se in dry weight during a hydrolysis were derived as a function of mol ality and amount of dry weight at the start of the hydrolysis. With fr eezing-point depression it was possible to determine the theoretical d extrose equivalent of oligosaccharides (dextrose to maltoheptaose), wh ereas a traditional titration method (Luff-Schoorl) overestimates 20-5 0%. The relation for the increase of dry weight during the hydrolysis of starch with an alpha-amylase was experimentally validated. The over estimation of dextrose equivalent by Luff-Schoorl titration was also e vident in the hydrolysis of amylopectin potato starch. With freezing-p oint depression it was possible to determine the theoretical dextrose equivalent fast and accurate.