A Thick-film Sensor as a Novel Device for Determination of Polyphenols and Their Antioxidant Capacity in White Wine

Abstract

A thick-film electrochemical sensor with an iridium-carbon working electrode was used for determining polyphenols and their antioxidant capacity in white wine. Caffeic acid was used as a model species because it has the ability to produce the highest oxidation current. The correlation coefficient of 0.9975 was obtained between sensor response and caffeic acid content. The total phenolic content (TPC) and scavenging activity on 1,1-diphenyl-2-pycrylhydrazyl (DPPH·) radical were also found to be strongly correlated with the concentration of caffeic acid, with a correlation coefficient of 0.9823 and 0.9958, respectively. The sensor prototype was proven to be a simple, efficient and cost effective device to evaluate the antioxidant capacity of substances.

Electrochemical Methods for Total Antioxidant Capacity and its Main Contributors Determination: A review

“…1 A illustrates cyclic voltammograms of caffeic acid, wine, and caffeic acidadded wine and Fig. 1 B presents the voltammograms obtained at different dilutions of the white wine sample, as obtained by the authors [65].…”

“…Several studies have been dedicated to the electrochemical behavior and quantitation of key phenolics contributing to the total antioxidant capacity of wines [45,[65][66][67][68][69].…”

“…Moreover, since it was identified as the major polyphenol in white wine, caffeic acid was presumed to be the major contributor to the white wine samples' antioxidant capacity. Furthermore, the use of iridium-containing carbon as the electrode material allowed lowering of the oxidation potential, hence minimizing noise, with measurements viable even in undiluted wine samples [65].…”

“…The observed results confirm the higher amount of phenolics characterizing red wines. Glassy carbon significantly reduced interferences A B Figure 1: Cyclic voltammograms obtained at caffeic acid and white wine analysis; caffeic acid generated the most pronounced peak when added to the wine sample (A) and the analytical signal for the wine sample was recorded at different dilutions (B) [65]. given by ethanol (oxidizable at inert metal surfaces, like Pt and Au).…”

A Novel Low-Cost Sensor Prototype for Monitoring Temperature during Wine Fermentation in Tanks

“…Previous researchers have developed mechanisms to determine the rheological properties of fluids [2] and to evaluate the antioxidant capacity of substances [3]. Microbial biosensors have been used for sensing phenolic compounds in commercial wines [4], or different methods have been applied to the measurement of sulfite in wines [5].…”