HPLC-analysis of polyphenolic compounds in Spanish white wines and determination of their antioxidant activity by radical scavenging assay

A high-performance liquid chromatographic method coupled with UV and fluorescence detectors for the determination of polyphenols in white wines samples is reported. The proposed method was validated regarding linearity, repeatabilities within day and between days, recoveries and polyphenol stabilities. Eleven phenolic compounds including, flavanols and flavanols dimmers (procyanidins), hydroxycinnamates, flavonols and stilbene derivatives were identified and quantified. Samples were injected into the chromatograph directly without previous treatment. The in-house method validation provided good results with respect to repeatabilities (within day (RSD <= 4%) and between days (RSD <= 5%)) and recoveries (>= 97.3%). In the second part of the work the antioxidant activity of the wine samples was determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. The correlation between specific polyphenols and the antioxidant activity in samples was also investigated. (C) 2009 Elsevier Ltd. All rights reserved.