Evaluation of total polyphenol content of wines by means of voltammetric techniques: Cyclic voltammetry vs differential pulse voltammetry

• Published in: Food chemistry 2019-03, Vol.276, p.719-725
• Main Authors: Vilas-Boas, Ângela, Valderrama, Patrícia, Fontes, Natacha, Geraldo, Dulce, Bento, Fátima
• Format: Article
• Language: English
• Subjects: Chemometrics; Electrochemical Techniques - methods; Food Analysis - methods; Oxidation-Reduction; Polyphenols; Polyphenols - analysis; Polyphenols - chemistry; Sulfur Dioxide - analysis; Sulphur dioxide; Voltammetric techniques; Wine - analysis; Wine characterization
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2018.10.078

•Oxidizable species present in wines influence most physical-chemistry parameters.•CV is less efficient than DPV to differentiate wines with dissimilar composition.•DPV voltammograms are correlated with polyphenols in narrower potential ranges.•Sulphur dioxide interference is less important for results from DPV than from CV. Taking advantage of the low oxidation potential of polyphenolic compounds, voltammetric techniques, such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV) are used rather indiscriminately. In this work, we report Total Polyphenols results (TPP) obtained by these two techniques from a set of nine samples of red and Tawny Port wine. The CV and DPV voltammograms display significant correlations with the physical-chemical parameters used to characterize red and Tawny Port wines, particularly with polyphenols. Although data obtained from CV and DPV for a single polyphenol are directly proportional, important deviations are found between voltammetric results from wines. Results from CV tend to be larger than those from DPV. This difference, that can reach 50% of the TPP value, was related to the presence of total sulphur dioxide. In view of the present study, the polyphenol quantification in wines should be performed by DPV to minimize the interference of SO2.