Flavonoids electrochemical detection in fruit extracts and total antioxidant capacity evaluation

• Published in: Talanta (Oxford) 2016-07, Vol.154, p.284-291
• Main Authors: Gomes, Sara M.C., Ghica, Mariana-Emilia, Rodrigues, Isaide Araujo, de Souza Gil, Eric, Oliveira-Brett, Ana Maria
• Format: Article
• Language: English
• Subjects: Antioxidants; Boron doped diamond electrode; Chromatography, High Pressure Liquid; Detectors; Diamonds; EC50 and EI assays; Electrochemical analysis; Electrochemical Techniques; Electrodes; Flavonoids; Free radicals; Fruit; Fruits; Glassy carbon electrode; Phenolic compounds; Phenols; Plant Extracts; RP-HPLC-EC
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2016.03.083

Phenolic compounds detection in fruit extracts from: açai, bacuri, buriti, blackberry, black mulberry, blueberry, juçara, physalis, raspberry, and tamarillo, have been performed by reverse-phase high performance liquid chromatography with electrochemical detection (RP-HPLC-EC), using two detectors in series: a wall-jet detector flow cell with a glassy carbon electrode, and a thin-layer flow cell detector with a boron doped diamond electrode. This methodology, in gradient elution mode, was successfully used to detect seventeen phenolic compounds in the fruit extracts. The total antioxidant capacity of the fruit extracts by the electrochemical quantitative index (EI) and the method of capture of diphenilpicrilhydrazil (DPPH●) free radical “efficient concentration” (EC50), was evaluated. A very good correlation between EI and EC50 assays has been obtained, the fruit with the highest total antioxidant capacity being blackberry, while physalis exhibited the lowest antioxidant power. [Display omitted] •Flavonoids identification in 10 red fruit extracts.•RP-HPLC-EC using two detectors in series.•Detectors: wall-jet glassy carbon and thin-layer boron doped diamond electrode.•The EI determination of fruit extracts total antioxidant capacity.•The EC50 assays determination of fruit extracts total antioxidant capacity.