Comparative study of the antioxidant capacity and polyphenol content of Douro wines by chemical and electrochemical methods

• Published in: Food chemistry Vol. 141; no. 1; pp. 566 - 573
• Main Authors: Rebelo, M.J., Rego, R., Ferreira, M., Oliveira, M.C.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.11.2013; Elsevier
• Subjects: Alcoholism and acute alcohol poisoning; Antioxidant capacity; Antioxidants - analysis; Biological and medical sciences; Chemistry Techniques, Analytical - methods; Cyclic voltammetry; Differential pulse voltammetry; Douro wines; Electrochemical methods; Electrochemical Techniques - methods; Medical sciences; Polyphenols; Polyphenols - analysis; Toxicology; Vitaceae; Wine - analysis; Douro wines; Cyclic voltammetry; Polyphenols; Antioxidant capacity; Electrochemical methods; Differential pulse voltammetry; Wine; Chemical compound; Voltammetry; Antioxidant; Micronutrient; Alcoholic beverage; Polyphenol; Cyclic; Content; Plant origin; Phenols; Proanthocyanidin; Comparative study
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2013.02.120

•Cyclic voltammetry underestimates the antioxidant capacity.•ABTS and differential pulse voltammetric results are comparable.•Antioxidant capacity of Douro wines: red>ruby>tawny>white wines>muscatel. A comparative study of the antioxidant capacity and polyphenols content of Douro wines by chemical (ABTS and Folin–Ciocalteau) and electrochemical methods (cyclic voltammetry and differential pulse voltammetry) was performed. A non-linear correlation between cyclic voltammetric results and ABTS or Folin–Ciocalteau data was obtained if all types of wines (white, muscatel, ruby, tawny and red wines) are grouped together in the same correlation plot. In contrast, a very good linear correlation was observed between the electrochemical antioxidant capacity determined by differential pulse voltammetry and the radical scavenging activity of ABTS. It was also found that the antioxidant capacity of wines evaluated by the electrochemical methods (expressed as gallic acid equivalents) depend on background electrolyte of the gallic acid standards, type of electrochemical signal (current or charge) and electrochemical technique.