terclim by ICS banner
IVES 9 IVES Conference Series 9 HOW OXYGEN CONSUMPTION INFLUENCES RED WINES VOLTAMMETRIC PROFILE

HOW OXYGEN CONSUMPTION INFLUENCES RED WINES VOLTAMMETRIC PROFILE

Abstract

Phenolic compounds play a central role in sensory characteristics of wine, such as colour, mouthfeel, flavour and determine its shelf life. Furthermore, the major non-enzymatic wine oxidation process is due to the catalytic oxidation of phenols in quinones. Due their importance, during the years have been developed different analytical methods to monitor the concentration of phenols in wine, such as Folin-Ciocalteu method, spectrophotometric techniques and HPLC. These methods can also be used to follow some oxidation-related chemical transformations. However, these methods are complex, expensive and time consuming, thus not affordable for most small winery. Consequently, the development of several techniques that are faster, cheaper and user-friendly are currently of great interest. Among these, voltammetry has shown to be able to discriminate well wines according to their chemical composition, in particular in relationship to phenolic compounds. Aims: Our work aimed to understand the effect of oxygenation on voltammetric signals of wines. Material and Methods: DIfferent commercial red wines purchased from a local stores have been used in this study. The experimental protocol involved oxygenation of the wines in a 1 L bottle by hand shaking until the desired oxygen level was reached. Three level of oxygenation were chosen: 1.5 (TA), 5 (TB) and 7 mg/L O₂ (TC). Measures of oxygen have been carried out with a portable oximeter. The oxygenated wine was placed in 125 ml glass vials fitted with an oxygen sensor, filled without leaving any headspace and closed with sealing wax in order to not have oxygen exchanges with the outside. Electrochimical measurements were performed with a with a potentiostat using disposable screen- printed sensors in a three-electrode arrangement. Total polyphenols, anthocyanins, free and total SO₂ measurements were carried out using a multiparametric analyser and the dedicated kit. For colour de- termination were measured the absorbances at wavelengths 420, 520 and 620. The measures to determine the oxygen kinetic consumption were performed every 24 for hours. At the same time were carried out analysis with the multiparametric analyser and for colour determination. Results: Red wine voltammograms were impacted by oxygenation, with several voltametric features showing variation in profile and peak intensity according to the level of oxygen consumption. Different signal treatments strategies were applied to highlight the regions of the voltammograms mostly affected by oxidation, in particular through the use of derivative voltammetry.

 

1. Makhotkina, O., & Kilmartin, P. A. (2009). Uncovering the influence of antioxidants on polyphenol oxidation in wines using an electrochemical method: Cyclic voltammetry. Journal of Electroanalytical Chemistry, 633(1), 165-174
2. Ugliano, M., Slaghenaufi, D., Picariello, L., & Olivieri, G. (2020). Oxygen and SO₂ consumption of different enological tannins in relationship to their chemical and electrochemical characteristics. Journal of Agricultural and Food Chemistry, 68(47), 13418-13425.
3. Ferreira, C., Sáenz-Navajas, M. P., Carrascón, V., Næs, T., Fernández-Zurbano, P., & Ferreira, V. (2021). An assessment of voltammetry on disposable screen printed electrodes to predict wine chemical composition and oxygen consumption rates. Food Chemistry, 365, 130405.
4. P. A. Kilmartin, Electrochemistry applied to the analysis of wine: A mini-review, Electrochemistry Communications, 2016, 67, 39-42 

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Rosario Pascale, Leonardo Vanzo, Giacomi Cristanelli, Maurizio Uglian

Department of Biotechnology, University of Verona, 37134 Verona, Italy

Contact the author*

Keywords

Red wine, Oxygen, Phenolic compounds, Voltammetry

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

AROMA ASSESSMENT OF COMMERCIAL SFORZATO DI VALTELLINA WINES BYINSTRUMENTAL AND SENSORY METHODOLOGIES

Sforzato di Valtellina DOCG is a special dry red wine produced from partially dehydrated Nebbiolo wine-grapes growing in the Rhaetian Alps valley of Valtellina (Lombardy, Italy). Valtellina terraced vineyards are located at an altitude of 350–800 m according to ‘heroic’ viticulture on steep slopes. The harvested grape bunches are naturally dehydrated indoors, where a slow and continuous withering occurs (about 20% w/w of weight loss), until at least 1st December when the grapes reach the desired sugar content and can be processed following a normal winemaking with maceration.

ASSESSMENT OF GRAPE QUALITY THROUGH THE MONITORING OFPHENOLIC RIPENESS AND THE APPLICATION OF A NEW RAPID METHOD BASED ON RAMAN SPECTROSCOPY

The chemical composition of grape berries at harvest is one of the key aspects influencing wine quality and depends mainly on the ripeness level of grapes. Climate change affects this trait, unbalancing technological and phenolic ripeness, and this further raises the need for a fast determination of the grape maturity in order to quickly and efficiently determine the optimal time for harvesting. To this end, the characterization of variety-specific ripening curves and the development of new and rapid methods for determining grape ripeness are of key importance.

TARTARIC STABILIZATION MAY AFFECT THE COLOR AND POLYPHENOLIC COMPOSITION OF TANNAT RED WINES FROM URUGUAY

Tartrate precipitation affects the properties of wines, due to the formation of crystals that cause turbidity, even after being bottled. The forced tartaric stabilization is carried out frequently for young wines, through various physicochemical procedures. The traditional treatment for tartaric stabilization is refrigeration, but it can have a negative effect on wine’s sensory properties, and particularly on the color of red wines. The aim of this study was to evaluate the effect of different tartaric stabilization options on the color and phenolic composition of Tannat red wines from Uruguay.

OENOLOGICAL TANNINS FOR PREVENTING THE LIGHT-STRUCK TASTE IN WHITE AND ROSÉ WINES

The light exposure of wine can be detrimental as a relevant loss of aromas takes place [1] and light-induced reactions can occur. The latter involves riboflavin (RF), a photosensitive compound, that is fully reduced by acquiring two electrons. When the electron-donor is methionine, the light-struck taste (LST) can appear leading to cooked cabbage, onion and garlic odours-like [2]. The use of oenological tannins can limit the appearance of LST in both model wine [3] and white wine [4]. This research aimed to evaluate the impact of certain oenological tannins, selected in a previous study as the most effective against LST [5], in both white and rosé wines.

WHICH TERROIR-RELATED FACTORS INFLUENCE THE MOST VOLATILE COMPOUND PRODUCTION IN COGNAC BASE WINE?

Cognac is a famous spirit produced in southwest France in the region of the eponymous town from wines mainly from Vitis vinifera cv. Ugni blanc. This variety gives very acidic and poorly aromatic base wines for distillation which are produced according to a very specific procedure. Grapes are picked at low sugar concentrations ranging 13-21 °Brix and musts with high turbidity (>500 NTU) are fermented without sulphite addition [1]. Fermentative aromas, as esters and higher alcohols, are currently the main quality markers considered in Cognac spirits.