Enhanced automatic flow-injection determination of the total polyphenol index in wines using Folin-Ciocalteu reagent

A new automated flow-injection method for the determination of the total polyphenol index in wines based on the Folin-Ciocalteau reaction in 0.5 mol 1−1 NaOH is proposed. The method allows different types of wine to be analysed automatically at a rate of 60 h−1 by using gallic or tannic acid as standard. By applying the proposed method to real samples of white, rosé and red wines, their total polyphenol indices were determined with a higher...