Measurement of Stevioside by Square‐Wave Polarography |
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| Authors: | Šebojka Komorsky‐Lovrić Ivana Novak Bruno Novak |
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| Affiliation: | 1. Ru?er Bo?kovi? Institute, Bijeni?ka 54, HR‐10000 Zagreb, Croatia;2. Faculty of Food Technology, J.?J. Strossmayer University, F. Kuha?a 18, HR‐31000 Osijek, Croatia;3. Faculty of Agriculture, University of Zagreb, Sveto?imunska 25, HR‐10000 Zagreb, Croatia |
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| Abstract: | Steviol glycosides are electroactive compounds and can be detected by mercury electrode. The maxima of square‐wave polarograms 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 electroreduction of carboxyl, or ester groups, respectively. The net peak current is linearly proportional to steviol concentration between 1×10?6 mol/L and 3.5×10?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. |
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| Keywords: | Stevia Steviol Stevioside Square‐wave polarography |
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