Phenolic Composition and Total Antioxidant Capacity by Electrochemical, Spectrophotometric and HPLC‐EC Evaluation in Portuguese Red and White Wines

Abstract

AbstractPhenolic composition and in vitro total antioxidant capacity have been evaluated, in red and white Portuguese wines, by electrochemical methods, spectrophotometric methods, and reverse‐phase high performance liquid chromatography with electrochemical detection (HPLC‐EC). The different phenolic compounds present in seventeen red and white wines, with different grape varieties, and from different geographical locations, were successfully identified and detected. The wines in vitro total antioxidant capacity, using the method of capture of diphenilpicrilhydrazil (DPPH.) free radical “efficient concentration” (EC50), and the electrochemical quantitative index (EI), was determined. The wine with the highest total antioxidant capacity exhibited the lowest antioxidant power, and the EI and EC50 assays had a very good correlation.