Hydrogen and Atom Transfer Activity of Saffron Extracts by Square Wave Voltammetry

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• 作者：Rita Armellini ; Dario Compagnone ; Matteo Scampicchio and Paola Pittia
• 刊名：Electroanalysis
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：29
• 期：2
• 页码：521-528
• 全文大小：1183K
• ISSN：1521-4109

文摘

Saffron is an edible spice with highly appreciated sensory and antioxidant properties. One of the most representative redox species found in saffron extracts is crocin, whose content is used to evaluate the quality and value of the resulting spice. In this study, a voltammetry method based on the direct detection of crocin at a bare glassy carbon electrode is presented. The principle of the method is based on the monitoring of the anodic wave exhibited by crocin (0.1–1.0 mM) after its mixing with the azo radical initiator AAPH (20 mM) in ethanol:acetonitrile (1 : 1) solution. The decay rate of the anodic peak (E=+434 mV vs. Ag/Ag⁺), as a result of the consumption of crocin by AAPH, was used as index of the hydrogen transfer capacity and, thus, of its antioxidant activity. With a decay rate of k=0.02 h⁻¹, crocin exhibits only a weak antioxidant activity in comparison with tocopherols (k=0.13 h⁻¹), but still sufficient to protect against the oxidation of safranal, a further redox species found in saffron extracts and mainly responsible for its flavor. The proposed approach was finally applied to discriminate saffron extract samples from different geographical origins. The proposed approach is suitable to characterize the quality of saffron extracts and estimate its antioxidant properties.