Analysis of several phenolic compounds with potential antioxidant properties in grape extracts and wines by high-performance liquid chromatography-photodiode array detection without sample preparation.

A RP-HPLC method that allows the separation of several types of phenolic compounds present in grapes and wines by direct injection of samples, using a binary gradient with solvents free of salts and photodiode array detection is described. Results show that more than 15 different phenolic molecules with antioxidant properties (flavan-3-ols, anthocyanins, cinnamic acid derivatives, flavonol derivatives and trans-resveratrol) may be separated in a single run by direct injection of red wine. The method is also valuable for the analysis of these compounds in white wine and in skins, seeds and pulp extracts of red and white grapes.