engleski

Measurement of Stevioside by Square-Wave Polarography

Steviol glycosides are electroactive compounds and can be detected by mercury electrode. The maxima of square-wave voltammograms of steviol and stevioside appear at -1.3 V vs Ag/AgCl in 1 M NaCl at approximately pH 11. The responses are quasireversible and probably caused by electro-reduction of carboxyl, or ester groups, respectively. The net peak current is linearly proportional to steviol concentration between 1 x 10-6 mol/L and 3.5 x 10-5 mol/L. This calibration plot can be used for the determination of the concentration of stevioside in extracts of stevia (Stevia rebaudiana Bertoni) leaves. The proposed method is applicable for routine analysis of stevioside in commercial products.

Stevia ; steviol ; stevioside ; square-wave voltammetry

nije evidentirano