Red fruit juice quality and authenticity control by HPLC

The present work used International Federation of Fruit-Juice Producers (IFU) Method No. 71 with minor modifications for the analysis of anthocyanins, betacyanins, synthetic red pigments, hydroxycinnamic acids, hydroxybenzoic acids and catechins present in red fruit and vegetable juices and red-purple soft-drinks. The proposed HPLC method has been implemented with simultaneous UV–Visible and fluorescence detection and offers unambiguous composition results for 9 red fruit and vegetable juices: strawberry, red raspberry, blueberry, European cranberry, blackcurrant, sour cherry, red grape, purple carrot and purple prickly pear. Twenty-eight anthocyanins, 4 betacyanins, 1 natural and 6 synthetic pigments, 11 hydroxycinnamic acids, 6 hydroxybenzoic acids and 2 catechins were determined in a 30-min chromatogram. This method is useful for quality and authentication analyses of red fruit and vegetable juices, and red-purple soft-drinks. The use of a unique analysis method for polyphenol analysis is encouraged as a helpful tool to build up an unambiguous polyphenol composition database of foods.