terclim by ICS banner
IVES 9 IVES Conference Series 9 VOLTAMETRIC PROFILING OF RED WINE COMPOSITION DURING MACERATION: A STUDY ON FOUR GRAPE VARIETIES

VOLTAMETRIC PROFILING OF RED WINE COMPOSITION DURING MACERATION: A STUDY ON FOUR GRAPE VARIETIES

Abstract

During red wine vinification, maceration allows the must, and consequently the wine, to be enriched with several compounds that contribute to the creation of the typical organoleptic characteristics of red wines. Among these, extraction of polyphenols (PPs) during maceration is a major process of enological interest.

The purpose of this study was the evaluate the suitability of a rapid analytical approach based in linear sweep voltammetry to monitor PPs extraction during vinification. Four red grape varieties were investigated, and fermentations were carried out with three different yeasts in triplicate. The density was evaluated daily and every 48h samples were taken to monitor changes in voltametric profiles and in the anthocyanins, polyphenols and precipitable tannins content.

The voltametric profiles of the wines were monitored using disposable screen-printed carbon electrodes with the working and counter electrode in carbon paste and an Ag/AgCl reference electrode. A drop of sample was loaded onto the sensor, and linear sweep voltammograms were acquired between 0-1200mV at a scan rate of 100mV/s. Analyzing the voltammograms, it was possible to observe differences between varieties and, within each variety, the temporal evolution of maceration.

In the second-derivative voltammograms, a positive peak was observed at low potentials, it increases initially showing a maximum after 7 days of fermentation. This peak is associated with the more easily oxidized compounds in wine. Another region of the voltammogram that shows a trend associated with the progress of fermentation is that around 440mV; in this region the negative peak reaches a maximum after 24 h after the start of maceration and then slowly decreases. This region has been associated with the concentration of monomeric anthocyanins and flavanols. The negative peak around 780mV results initially influenced by the presence of free SO₂, when SO₂ is bound the peak decreases in intensity and then increases again during maceration. By constructing PLS-R models for the concentration of anthocyanins, polyphenols and precipitable tannins the best pre-processing method resulted the second derivative and good regression models were obtained (R2 from 0.75 to 0.95).

In conclusion, this study provides a first proof of concept of the suitability of a simple analytical approach based on linear sweep voltammetry to monitor the evolution of phenolic composition during red wine maceration.

 

1. P. A. Kilmartin, Electrochemistry applied to the analysis of wine: A mini-review, Electrochemistry Communications, 2016, 67, 39-42
2. M. Ugliano, Rapid fingerprinting of white wine oxidizable fraction and classification of white wines using disposable screen printed sensors and derivative voltammetry, Food Chemistry, 2016, 212, 837-843
3. C. Ferreira, M.P. Sáenz-Navajas, V. Carrascón, T. Næs, P. Fernández-Zurbano, V. Ferreira, An assessment of voltammetry on disposable screen printed electrodes to predict wine chemical composition and oxygen consumption rates, Food Chemistry, 2021, 365, 130405

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Leonardo Vanzo¹, Nicola Dalla Valle¹, Giacomo Cristanelli¹, Davide Slaghenaufi¹, Maurizio Ugliano¹

1. Department of Biotechnology, University of Verona

Contact the author*

Keywords

Maceration, Voltammetry, Polyphenols, Red wine

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

Influence of agrophotovoltaic on vine and must in a cool climate

The current energy crisis means that interest in agrophotovoltaics has increased significantly. The reason behind this is that the system aims to combine agricultural production with energy production. During the three-year period from 2020 to 2022, the effects of photovoltaic panels on the vine, the yield and the quality of the must were studied in Walenstadt in northern Switzerland, an area with a cool, humid climate. 65 Pinot noir vines were planted in the 160m2 study area. Because of the large edge effects, only 3 repetitions with 4 vines each could be created. A significantly lower leaf infestation by Plasmopara viticola was observed among the panels in each of the three years.

Read More

IMPACT OF GRAPE-ASSOCIATED MOLDS IN FRESH MUSHROOM AROMA PRODUCTION

Mycobiota encountered from vine to wine is a complex and diversified ecosystem that may impact grape quality at harvest and the sensorial properties of wines, thus leading to off-flavors [1-3]. Among known off-flavors in wine, fresh mushroom aroma (FMA) has been linked to some mold species, naturally pre-sent on grapes, producing specific volatile organic compounds (VOC) [4-5]. The most well-known are 1-octen-3-ol and 1-octen-3-one, although many other VOC are likely involved. To better understand the FMA defect, biotic and abiotic factors impacting growth kinetics and VOC production of selected fungal species in must media and on grapes were studied.

Read More

EFFECTS OF INDUCED SUNBURN DAMAGES ON WHITE WINE PROPERTIES

Climate change is a great challenge for the environment and affects the wine industry as well. Sunburn damage of sensitive grapes increase with severe heat periods. Besides significant loss of yield sunburn, modifies sensory properties of the wines and may cause climate-related off-flavours. To initiate sunburn in a controlled way, in 2021 sunburn was directly induced in the vineyard with the GrapeBurner device, exposing grapes of the varieties Riesling and Pinot Blanc with UV and IR radiation. This device was first assembled by Kai Müller of the university in Geisenheim and consists of a carriage with 6 UV/IR lamps. A 15 min irradiation was applied in early September at 60°Oe. Due to the colder season in 2021 the grapes were not harmed by previous sunburn damage.

Read More

IMPACT OF CLIMATIC ZONES ON THE AROMATIC PROFILE OF CORVINA WINES IN THE VALPOLICELLA REGION

In Italy, in the past two decades, the rate of temperature increases (0.0369 °C per year) was slightly higher compared to the world average (0.0313 °C per year). It has also been indicated that the number and intensity of heat waves have increased considerably in the last decades. (IEA, 2022). Viticultural zones can be classified with climatic indexes. Huglin’s index (HI) considers the temperature in a definite area and has been considered as reliable to evaluate the thermal suitability for winegrape production (Zhang et al., 2023).

Read More

SENSORY IMPROVEMENT OF DEALCOHOLISED WINES

Interest and willing-ness to buy alcohol-free wines by customers is increasing for several years [1]. Due to the rising relevance of dealcoholised wines it is the objective of this study to contribute to a better understanding of the flavor variation among dealcoholised wines and to explore enological measures, how to improve final quality.
First a range of commercial, alcoholfree white wines were analysed by the holistic sensory method projective mapping, including a question for hedonic acceptance. Based on the combination of a non-target-HS-SPME-GC/MS analysis with sensory analysis we obtained a clustering of the wines into three groups.

Read More