Determination of red wines total antioxidant capacity by electrometric and spectrophotometric methods

Abstract

Phenolic compounds from various food matrices can be investigated with different analytical techniques such as spectrophotometric, cromatographic or electrochemic methods. Cupric Reducing Antioxidant Capacity method (CUPRAC) is a convenient assay for determining total antioxidant capacity in food substrates. In this work, electrochemical and spectrophotometrical approaches were used to estimate the total antioxidant capacity by means of an alternative of the CUPRAC assay, as the concentrations of the participating species ([Cu(Nc)2]2+ and [Cu(Nc)2]1+) can be evaluated by electrochemical and spectrophotometrical methods. The electrometric–CUPRAC methods have been applied to measure total antioxidant capacity of different local wines and validated against the spectrophotometric CUPRAC assay. The electrochemical methods proved to be easy, fast and with low detection limits. A good correlation for the total antioxidant capacity determined by CUPRAC spectrofotometric and electrometric method versus total phenol content (determined by Folin-Ciocalteu Method) was recorded, wich highlights that wines antioxidant activity results mainly from their phenolics content.