Monitoring Oxidative Status in Winemaking by Untargeted Linear Sweep Voltammetry

Abstract

An electrochemical portable device based on linear sweep voltammetry was evaluated for studying the redox behavior of polyphenolic compounds in industrial scale winemaking to infer the effects of selected early processing steps on the vinification trials of Pinot gris, Chardonnay, Vermentino and Sangiovese grapes. For each sample, the redox behavior showed a distinctive voltammetric signal pattern related to the processing step during winemaking, therefore being useful as a potential fingerprint for wine identification and to provide insights about the phenolic content. For instance, there was a high correlation (R2 = 0.72) between the total phenolic compounds (PhenOx) and the easily oxidizable compounds (EasyOx), the latter representing approx. 30% on average of the total phenolics. Furthermore, the maceration of red grapes was concluded after 29 days based on information driven by the phenolics pattern. As expected, during alcoholic fermentation, white wines showed a lower content of phenolic compounds than those found in red wines, with an average ratio PhenOx/EasyOx of about 4.7, 5.0 and 3.6 for Chardonnay, Pinot gris and Vermentino, respectively. The portable tool with miniaturized disposable electrodes showed interesting analytical features that can be exploited for on-site and real-time quality control for monitoring change in phenolic composition during wine processing and storage, and for tailoring winemaking practices to enhance the color stability of products.

White wine phenolics: current methods of analysis

“…Another study performed monitored white wine's antioxidant pattern during early winemaking steps 118 . This study was performed using linear sweep voltammetry with disposable single‐use electrodes at an industrial scale.…”

“…117 Another study performed monitored white wine's antioxidant pattern during early winemaking steps. 118 This study was performed using linear sweep voltammetry with disposable singleuse electrodes at an industrial scale. The methodology was successful and insights into the impact of different winemaking techniques on the oxidisation of phenolic compounds was established.…”

“…The methodology was successful and insights into the impact of different winemaking techniques on the oxidisation of phenolic compounds was established. 118…”

Observation of Spontaneous Maturation Process of Young Wine by Application of the Voltammetric Quadruple Disk Iridium Sensor Combined with Chemometrics

“…6 Wine is a complex mixture of a great number of compounds arising from grape, fermentation and aging processes. Regarding technological aspects, analytical methods for monitoring quality of wines have been developed using spectrophotometric, [7][8][9] colorimetric, 7 enzymatic, 10 chromatographic, 11 electrochemical, [12][13][14] and electrophoretic techniques. 2,15 To simplify analysis methods and to improve the quality and safety of the final product, development and construction of sensors for wine compositional analysis is a task to which much attention is paid nowadays.…”

“…Usefulness of an electrochemical portable device based on linear sweep voltammetry was also evaluated for studying the redox behavior of polyphenolic compounds in industrial scale winemaking, to infer the effects of selected early processing steps on the vinification trials of various grapes. 12 For each sample, the redox behavior showed a distinctive voltammetric signal pattern related to the processing step during winemaking, therefore being useful as a potential fingerprint for wine identification and to provide information about the phenolic compounds content in wine.…”