Determination of "Polydextrose"

A simple determination method was devised for “Polydextrose ” (PD), a synthetic glucose polymer, by using high performance liquid chromatography (HPLC). PD showed a main peak on HPLC at 5.57 minutes of elution time together with several minor peaks. The area under the main peak was proportional to the amount of PD applied, thus allowing its determination from the calibration curve. The presence of monosaccha-rides and oligosaccharides up to polymerization degree 5 did not affect the determination. With samples containing higher oligosaccharides, such as starch syrup, HPLC was carried out after digestion to glucose by glucoamylase (Sigma, amyloglucosidase). Experiments on model samples containing 1g PD and 2g starch syrup showed a recovery of 98.9 ±3.6%. Starch-containing samples were liquefied by a thermostable α-tamylase (Novo, Termamyl 120L), followed by glucoamylase treat-ment prior to HPLC. Recovery tests made on model samples containing 1g PD and 0.5g starch indicated a recovery of 103.3 ±4.3%.