The use of freezing-point depression for the theoretical dextrose equivalent measurement

The determination of the theoretical dextrose equivalent was investigated, by measuring the osmolality (mel dissolved particles/kg H2O) by freezing-point depression. Relations for dextrose equivalent and increase in dry weight during a hydrolysis were derived as a function of molality and amount of dry weight at the start of the hydrolysis. With freezing-point depression it was possible to determine the theoretical dextrose equivalent of oligosaccharides (dextrose to maltoheptaose), whereas a traditional titration method (Luff-Schoorl) overestimates 20-50%. The relation for the increase of dry weight during the hydrolysis of starch with an alpha-amylase was experimentally validated. The overestimation of dextrose equivalent by Luff-Schoorl titration was also evident in the hydrolysis of amylopectin potato starch. With freezing-point depression it was possible to determine the theoretical dextrose equivalent fast and accurate.