The role of electroanalytical techniques in analysis of polyphenols in wine

Voltammetric and spectrometric determination of antioxidant capacity of selected wines

“…On the other hand, the processing features of some specific types of wines showed to exert major influence on the phenolic content and as consequence on the final antioxidant power. This is similar to the results found in a study by [20,23,24]. 50 values when compared to their white and rose analogues may be also related to the inherent dilution effect of bubbles.…”

“…In turn, it was also observed that red wines present higher antioxidant activity than juices (Tables 1 and 3), demonstrating that the overall process of fabrication of such wines may really promote higher phenolic extraction from the skin of grapes, as it was already demonstrated in previous studies [23][24][25].…”

“…In this study it was observed that peaks 1a (Figure 1) are related to orto-diphenolic compounds, i.e. quercetin, rutin, caffeic acid, as well as gallic acid, while the peaks 2a and 3a (Figure 1), may be associated to the presence of resorcinol and mono-phenol-pattern, such as the major compounds ferullic acid, resveratrol, malvidin, coumaric acid [21,24].…”

“…Hence, natural phenolic and non-phenolic compounds and also some wine additives present native electroactivity, which could lead to the observed voltammetric profile. For instance, it was observed that sulfur dioxide may cause some distortions on cyclic voltammograms obtained for wine or phenolic compounds in model wine solutions [6,23,24]. However, such distortions might be corrected and minimized in differential pulse voltammetry.…”

“…However, such distortions might be corrected and minimized in differential pulse voltammetry. Though sugar and ethanol, when present at higher concentrations leads to an ohmic drop, they do not show any great effect on the redox behavior of phenolic compounds and wines at the assay conditions [6,24,27]. However, it is possible to standardize the electrolyte and sample´s dilution in order to reproduce some results and to avoid comparative errors.…”