Macrowine 2021
IVES 9 IVES Conference Series 9 The impact of acetaldehyde on phenolic evolution of a free-SO2 red wine

The impact of acetaldehyde on phenolic evolution of a free-SO2 red wine

Abstract

AIMS: Some wine producers, in good years, can produce free-SO2 red wines and decide to add the minimum amount of sulphur dioxide only at bottling. To manage this addition, it is important to know the oxidative history of the wine. Acetaldehyde, the main wine oxidation product, is a powerful electrophile that reacts with numerous wine compounds giving desired products as the stable red polymeric pigments and the less astringent tannins but, also negative off-flavours. Although all these reactions are well known, the border between those increasing wine longevity and those decrementing wine quality is difficult to determine. This study has the aim to investigate the kinetics of consumption of acetaldehyde in red wines to give information useful for the further management of sulphur dioxide.

METHODS: Free-SO2 red wines were spiked with increasing levels of acetaldehyde (from 0 to 190 mg/L) and analysed over time. Chromatic properties and main phenolic classes were analysed by conventional spectrophotometric methods. Small phenolics, polymeric pigments (PP) and polymeric tannins (PT) were detected by HPLC, MS and NMR analysis.  Reactivity of tannins towards BSA and saliva was also determined (1-2-3).

RESULTS: Already two hours after the addition of acetaldehyde the 50% was consumed in reactions with phenolic compounds and the consumption increased over time. Also when a great excess of aldehyde was added (190 mg/L) and after one year of aging a loss of 75% of the initial value was detected. The first compounds that were consumed in reactions with acetaldehyde were anthocyanins and flavanols and a contemporary increase of polymeric pigments and tannins occurred. BSA and saliva reactive tannins increased over time when high concentration of acetaldehyde were added.

CONCLUSIONS

For a correct management of sulphur dioxide when bottling a free-SO2 red wine the content of acetaldehyde and phenolic strong reactants (anthocyanins and flavanols) should be determined to limit or favour further acetaldehyde reactions

DOI:

Publication date: September 14, 2021

Issue: Macrowine 2021

Type: Article

Authors

Francesca Coppola

Department of Agricultural Sciences, Division of Vine and Wine Sciences, University of Naples Federico II, Avellino, (Italy),Luigi Picariello, Martino Forino,  Luigi Moio, Angelita Gambuti Department of Agricultural Sciences, Division of Vine and Wine Sciences, University of Naples Federico II, Avellino, (Italy)

Contact the author

Keywords

wine longevity, polyphenols

Citation

Related articles…

Influence of withering on valpolicella docgs grapes volatile composition

The blend of grapes used in the production of the four Valpolicella PDOs red wines, namely Valpolicella, Valpolicella Classico Superiore, Recioto della Valpolicella and Amarone della Valpolicella is quite unique, and includes two main varieties Corvina and Corvinone, and other minor varieties. To a very large extent all these grapes are only grown in the province of Verona. One of the main characteristics of Valpolicella is the use of grapes that are submitted to post-harvest withering. The aim of this study was therefore to evaluate the evolution of the free and glycosidically-bound volatile compounds in Corvina and Corvinone grapes under real production conditions.

Investigating the Ancient Egyptian wines: The wine jars database

In Ancient Egypt, wine was a luxury product consumed mainly by the upper classes and the royal family and offered to gods in daily religious rituals in the temples.
Since the Predynastic (4000-3100 BC) period, wine jars were placed in tombs as funerary offerings. From the Old Kingdom (2680-2160 BC) to the Greco-Roman (332 BC-395 AD) period, viticulture and winemaking scenes were depicted on the private tombs’ walls. During the New Kingdom (1539-1075 BC), wine jars were inscribed to indicate: vintage year, product, quality, provenance, property and winemaker’s name and title.

Impact of nitrogen addition timing on the synthesis of fermentative aromas in alcoholic fermentation

Among the different compounds present in the must, nitrogen is an essential nutrient for the management of the fermentation kinetics but it also plays an important role in the synthesis of fermentative aromas.

Monitoring of grapevine stem potentials with an embedded microtensiometer

Vine water status is a crucial determinant of vine growth, productivity, fruit composition and terroir or wine style; therefore, regulating water stress is of great importance. Since vine water status depends on both soil moisture and aerial environment and is very temporally dynamic, direct measurement of vine water potential is highly preferable. Current methods only provide limited data. To regulate vine water status it is critical to monitor vine water status to be able to: (1) measure vine water status to predict the effect of water stress on the overall vineyard performance and fruit quality and optimize harvest management and wine-making (2) properly regulate the water status to impose for a desired fruit quality or style (3) determine if water management has reached the desired stress level.

EFFECT OF MICRO-OXYGENATION IN COLOR OF WINES MADE WITH TOASTED VINE-SHOOTS

The use of toasted vine-shoots (SEGs) as an enological tool is a new practice that seeks to improve wines, differentiating them and encouraging sustainable wine production. The micro-oxygenation (MOX) technique is normally combined with alternative oak products with the aim to simulate the oxygen transmission rate that takes place during the traditional barrel aging. Such new use for SEGs implies a reduction in color due to the absorption by the wood of the responsible compounds, therefore, given the known effect that MOX has shown to have on the modification of wine color, its use together with the SEGs could result in an interesting implementation with the aim to obtain final wines with more stable color over time.