WAC 2022 banner
IVES 9 IVES Conference Series 9 WAC 9 WAC 2022 9 3 - WAC - Posters 9 Oenotannins addition in wine: can be the modulation of redox potential predictable?

Oenotannins addition in wine: can be the modulation of redox potential predictable?

Abstract

The purpose of this research was to study the interaction between oenotannins and wine matrix in order to design a targeted oenotannins addition for modulating the redox status of wine. It is in fact known that oenotannins can regulate the redox potential of musts and wines since they are electroactive substances (1).

To this aim, the present study was divided in two steps:

(i)        twenty different commercial tannin preparations (including condensed and hydrolysable tannins) were characterized in order to prepare three oenotannins mixtures suitable for diverse modulations of the redox potential in wine (increase, decrease and stabilize). In particolar, tannins were dissolved in a model wine solution (12% alcohol, pH 3.5 with tartaric acid) and analyzed to determine the total polyphenol content, anti-radical activity, polyphenolic composition by HPLC-MS, and reactivity with proteins. The effect of tannins on the redox potential modulation was monitored for 48 hours after addition to the model wine solution, in standard condition (20 °C, no oxygen) as suggested by Vivas et al. (2);

(ii)        the three oenotannins mixtures obtained were added to eight different red and white wines with the aim of modulating their redox potential. Wines were chemically analyzed and the redox potential monitored for three months.

The results here obtained highlighted that commercial oenotannins, when added to the model wine solution, showed a different impact in the redox potential: condensed tannins from grape seed, quebracho and tea showed the ability to raise the redox potential; hydrolysable tannins from gallnuts and tara showed an important increase in redox potential, as well as for some oenotannins derived from oak. In this last case, the ability to modulate the redox potential (increase or decrease) was linked to the wood origin, toasting and drying prior the tannins extraction.

The three oenotannins mixtures added to the red and white wines affected their chemical composition  as well as their redox potential.

A PLS1 model was successfully built using the wine chemical parameters and the redox potential monitored for three months, in order to predict the redox status of wines through the oenotannins addition.

Reference: 1) Vivas, N. (2003) In: Prodotti di trattamento ed ausiliari di elaborazione dei mosti e dei vini. Ed. Eno-one srl.; 2) Vivas, N., Glories, Y., Bertrand, A. and Zamora, F. (1996) Bulletin OIV 69, 617-633.

DOI:

Publication date: June 27, 2022

Issue: WAC 2022

Type: Article

Authors

Valentina, Canuti, Francesco, Maioli, Lorenzo, Cecchi, Monica, Picchi

Presenting author

Valentina, Canuti – Department of Agricultural, Food and Forestry Systems Management (DAGRI), University of Florence, Piazzale Delle Cascine 16, 50144, Florence, Italy

Department of Agricultural, Food and Forestry Systems Management (DAGRI), University of Florence, Piazzale Delle Cascine 16, 50144, Florence, Italy | Department of NEUROFARBA, University of Florence, Via Ugo Schiff 6, 50019 Sesto F.no, Florence, Italy | Department of Agricultural, Food and Forestry Systems Management (DAGRI), University of Florence, Piazzale Delle Cascine 16, 50144, Florence, Italy, Luigi, Sanarica. Enolife SrL, Montemesola (TA), ,

Contact the author

Keywords

oenotannins, redox potential, PLS model

Tags

IVES Conference Series | WAC 2022

Citation

Related articles…

Mechanisms involved in the heating of the environment by the aerodynamic action of a wind machine to protect a vineyard against spring frost

One of the main consequences of global warming is the rise of the mean temperature. Thus, the heat summation by the plants begins sooner in the early spring, and by cumulating growing degree-days, phenological development tends to happen earlier. However, spring frost is still a recurrent phenomenon causing serious damages to buds and therefore, threatening the harvests of the winegrowers. The wind machine is a solution to protect fruit crops against spring frost that is increasingly used. It is composed of a 10-m mast with a blowing fan at its peak. By tapping into the strength of the nocturnal thermal inversion, it sweeps the crop by propelling warm air above to the ground. Thus, stratification is momentarily suppressed. Furthermore, the continuous action of the machine, alone or in synergy, or the addition of a heater allow the bud to be bathed in a warmer environment. Also, the punctual action of the tower’s warm gust reaches the bud directly at each rotation period. All these actions allow the bud to continuously warm up, but with different intensities and over a different period. Although there is evidence of the effectiveness of the wind machines, the thermal transfers involved in those mechanisms raise questions about their true nature. Field measurements based on ultrasonic anemometers and fast responding thermocouples complemented by laboratory measurements on a reduced scale model allow to characterize both the airflow produced by the wind machine and the local temperature in its vicinity. Those experiments were realized in the vineyard of Quincy, in the framework of the SICTAG project. In the future paper, we will detail the aeraulic characterization of the wind machine and the thermal effects resulting from it and we will focus on how the wind machine warms up the local atmosphere and enables to reduce the freezing risk.

A comprehensive ecological study of grapevine sensitivity to temperature; how terroir will shift under climate change

Fossil fuel combustion continues to drive increases in atmospheric carbon dioxide, consequently elevating the global annual mean temperature and specifically increasing the growing season temperatures in many of the world’s most important wine growing regions (IPCC 2014; Jones et al 2005). Grapes are sensitive to changes in growing season temperatures, and past models have shown a direct link between warming temperatures and earlier harvest dates (Cook and Wolkovich 2016). Globally, there have been shifts of 1-2 weeks for wine growing regions (Wolkovich et al 2017 and references within). The phenological shifts resulting from growing season temperature increases are documented internationally, and models predicting phenology using temperature are becoming more precise (Parker et al 2011).

New ways of grape pomaces valorization: production of functional beverages or nutraceuticals

The wine industry generates each year 20 million tons of by-products. Among them grape pomaces represent a big part that can be considered as a source of potentially bioactive molecules such as polyphenols. Kombucha fermentation is an ancestral process which allow to increase the biological properties of tea by the action of a microbial consortium formed by yeasts and bacteria called scoby.

Biodiversity in the vineyard agroecosystem: exploring systemic approaches

Biodiversity conservation and restoration are essential for guarantee the provision of ecosystem services associated to vineyard agroecosystem such as climate regulation trough carbon sequestration and control of pests and diseases. Most of published research dealing with the complexity of the vineyard agroecosystems emphasizes the necessity of innovative approaches, including the integration of information at different temporal and spatial scales and development of systemic analysis based on modelling. A biodiversity survey was conducted in the Franciacorta wine-growing area (Lombardy, Italy), one of the most important Italian wine-growing regions for sparkling wine production, considering a portion of the territory of 112 ha. The area was divided into several Environmental Units (EUs), defined as a whole vineyard or portion of vineyard homogenous in terms of four agronomic characteristics: planting year, planting density, cultivar, and training system. In each EU a set of compartments was identified and characterised by specific variables. The compartments are meteorology, morphology (altitude, slope, aspect, row orientation, and solar irradiance), ecological infrastructures and management. The landscape surrounding EU was also characterised in terms of land-use in a buffer zone of 500 m. For each component a specific methodology was identified and applied. Different statistical approaches were used to evaluate the method to integrate the information related to different compartments within the EU and related to the buffer zone. These approaches were also preliminarily evaluated for their ability to describe the contribution of biodiversity and landscape components to ecosystem services. This methodological exploration provides useful indication for the development of a fully systemic approach to structural and functional biodiversity in vineyard agroecosystems, contributing to promote a multifunctional perspective for the all wine-growing sector.

Influence of berry maturity, maceration time and wine maturation on the polyphenols and sensory characteristics of pinot noir and Cabernet-Sauvignon

AIM: Combined investigation of the influence of berry maturity, maceration time and wine maturation on the changes in polyphenols and sensory characteristics of Pinot noir and Cabernet-Sauvignon.