Determination of polyphenol content and colour index in wines through PEDOT-modified electrodes

Abstract

Poly(3,4-ethylenedioxythiophene)-modified electrodes have been used for the estimation of the polyphenolic content and of the colour index of different samples of wines. Synthetic wine solutions, prepared with different amount of oenocyanins, have been analysed spectrophotometrically and electrochemically in order to find a correlation between the total polyphenolic content or colour index and the current peak. The regression curves obtained have been used as external calibration lines for the analysis of several commercial wines, ranging from white to dark red wines. In this way, a rapid estimation of the total polyphenolic content and of the colour index may be accomplished from a single voltammetric measurement. Furthermore, principal component analysis has also been used to evaluate the effect of total polyphenolic content and colour index on the whole voltammetric signals within a selected potential range, both for the synthetic solutions and for the commercial products. Graphical abstract Electrochemical sensors for the rapid determination of colour index and polyphenol content in wines.

PAOT-Liquid® Technology: An Easy Electrochemical Method for Evaluating Antioxidant Capacity of Wines

“…A shown in Figure 3, we evidenced that the PAOT-Liquid ® activity and TPC of wines were highly correlated (r = 0.9540; p < 0.0001). Other authors using electrochemical detection with laccase biosensor [18], poly(3,4-ethylenedioxythiophene)-modified electrodes [20] or carbon nanotube-modified electrodes [21] reported similar findings. The high correlation between TPC and PAOT-Liquid ® activity provided such strong evidence that the majority of the antioxidant activity was attributed to the polyphenolic compounds in such beverages.…”

Progress in Electrochemical (Bio)Sensors for Monitoring Wine Production

“…In another report, electrode modification with the conducting polymer poly-3,4-ethylenedioxythiophene (PEDOT) led to enhanced sensitivity, antifouling capacity and selectivity, i.e., the electrochemical oxidation signals from ascorbic acid, phenolic compounds and sulphite can be resolved at PEDOT-covered electrodes [15,87]. For the analysis of wine samples with the NDC/GCE sensor, different volumes of wine were added incrementally in the electrochemical cell ( Figure 5B) and the anodic peak current intensity was interpolated on the calibration curve for caffeic acid.…”

“…In another report, electrode modification with the conducting polymer poly-3,4-ethylenedioxythiophene (PEDOT) led to enhanced sensitivity, antifouling capacity and selectivity, i.e., the electrochemical oxidation signals from ascorbic acid, phenolic compounds and sulphite can be resolved at PEDOT-covered electrodes [15,87].…”

“…In particular, applications of cyclic voltammetry include measuring the content of total polyphenols and total antioxidant capacity of wines [5][6][7], free sulphur dioxide [8,9] or the allergenic protein lysozyme [10]. In addition to CV, DPV [11,12], SWV [13], and LSV [14] have been shown to be very useful for obtaining qualitative and quantitative information regarding the poliphenolic composition [11,13] and the content of sulphites [14] or ascorbic acid [12] in wines.Voltammetric responses were correlated with organoleptic attributes such as color [15] or astringency [16] and can, moreover, be used to study wine oxidation [8,17] and ageing [18]. More information can be found in several reviews on the determination of wine phenolics [19]; electrochemical methods for determining the antioxidant capacity in food [20], or on electronic tongues (e-tongues) for food and wines [21,22].…”

“…Voltammetric responses were correlated with organoleptic attributes such as color [15] or astringency [16] and can, moreover, be used to study wine oxidation [8,17] and ageing [18]. More information can be found in several reviews on the determination of wine phenolics [19]; electrochemical methods for determining the antioxidant capacity in food [20], or on electronic tongues (e-tongues) for food and wines [21,22].…”