Quantification by UHPLC of total individual polyphenols in fruit juices

► A UHPLC-PDA-Fluo method able to analyse polyphenols of fruit juices in 28-min. ► 70 of main polyphenols of fruits can be determined in a unique and simple analysis. ► Polyphenols of fruit juices are quantified as total individual polyphenols (TIP). ► Method is useful for authentication analyses and for labelling total polyphenols. ► Good correlation of UHPLC-PDA-Fluo and Folin-Ciacalteu methods for quantification. The present work proposes a new UHPLC-PDA-fluorescence method able to identify and quantify the main polyphenols present in commercial fruit juices in a 28-min chromatogram. The proposed method improve the IFU method No. 71 used to evaluate anthocyanins profiles of fruit juices. Fruit juices of strawberry, American cranberry, bilberry, sour cherry, black grape, orange, and apple, were analysed identifying 70 of their main polyphenols (23 anthocyanins, 15 flavonols, 6 hydroxybenzoic acids, 14 hydroxycinnamic acids, 4 flavanones, 2 dihydrochalcones, 4 flavan-3-ols and 2 stilbenes). One standard polyphenol of each group was used to calculate individual polyphenol concentration presents in a juice. Total amount of polyphenols in a fruit juice was estimated as total individual polyphenols (TIP). A good correlation (r2=0.966) was observed between calculated TIP, and total polyphenols (TP) determined by the well-known colorimetric Folin-Ciocalteu method. In this work, the higher TIP value corresponded to bilberry juice (607.324mg/100mL fruit juice) and the lower to orange juice (32.638mg/100mL fruit juice). This method is useful for authentication analyses and for labelling total polyphenols contents of commercial fruit juices.