 IVES 9 IVES Conference Series 9 Impact of closures on aroma of godello and torrontés white wines post-bottling

Impact of closures on aroma of godello and torrontés white wines post-bottling

Abstract

Aromatic composition contributes mainly to the quality aroma of white wine. A natural and gradual evolution of the aroma in the bottle occurs over storage with a very low oxygen content. During storage, volatile compounds change as a result of the occurrence of numerous reactions. These chemical and physical processes are influenced by the type and quality of the closures, storage conditions (temperature, light exposure or relative humidity), packaging, etc. [1]. Traditional winemaking mostly uses cork closure, but new natural or synthetic closures have been reported as solution to eliminate some disadvantages of natural corks and can be suppose an alternative stoppers for the wine industry [2]. Several studies have evaluated the impact of different closures on the aroma of some white wine varieties, such as Chardonnay [3], Semillon [4], Sauvignon blanc [5], Verdejo [6], etc. This study aimed to show that the evolution of wine aroma attributes of two white varieties stopped with different closures after two years of bottle storage. Unwooded Godello and Torrontés wines from 2013 vintage were sourced from the same winery. In 2014-may, industrial wines were fractioned in 750 mL transparent glass bottles and closed with three different closures: Natural cork, micro-agglomerated cork and synthetic stopper. Bottled wines were stored in darkness at low temperature (10-15 °C) during 2 years. Sampling was performed at 12, 18, 24 and 30 months after vintage. Wine samples were extracted, in triplicate, with dichloromethane and the organic phase was dried over anhydrous sodium sulphate prior to analysis by gas chromatography with flame ionization detection (GC-FID) or coupled with mass spectrometry (GC-MS) [7]. Compounds identification was based on the comparison with authentic reference standards. Fifteen days after chemical analysis, wines were evaluated by sensory descriptive analysis with 7-10 trained judges. Sensory odorant attributes (floral, fruity, grass, spicy, woody, sulfurous and caramel) were punctuated on an 0-10 scale. Mouthfeel sensations and odorant descriptors were also evaluated globally, as well the global punctuation for the wine overall quality.Wines from the two varieties showed different aromatic profiles, but their evolution during bottle-storage were similar. As expected, the chemical evolution was characterised by decreases of the acetates and ethyl esters contents, and increases of other volatile compounds such as diethyl succinate or volatile phenols [7]. Changes in sensory evaluation were also took place, altering the sensory profile of both wines, changing from fruity and floral notes (higher in November-2015, third sampling) to toasty and spicy nuances. The preference of type of closure was different according to the storage-time. For this reason, the choice of closure type is crucial to preserve the wine aroma quality and to predict their shelf life.

DOI:

Publication date: September 14, 2021

Issue: Macrowine 2021

Type: Article

Authors

Elena Falqué

Depto. Química Analítica y Alimentaria, Universidade de Vigo, Facultade de Ciencias, As Lagoas s/n, 32004 Ourense, Spain,Kelly Bello-Novo1, Iván Vázquez-Pateiro1, José Manuel Mirás-Avalos2 1 Depto. Química Analítica y Alimentaria, Universidade de Vigo, Facultade de Ciencias, As Lagoas s/n, 32004 Ourense, Spain 2 Unidad de Suelos y Riegos (Asociada a EEAD-CSIC), Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda. Montañana 930, 50059 Zaragoza, Spain.

Contact the author

Keywords

bottle storage, closure, white wine, aroma

Citation

Different soil types and relief influence the quality of Merlot grapes in a relatively small area in the Vipava Valley (Slovenia) in relation to the vine water status

Besides location and microclimatic conditions, soil plays an important role in the quality of grapes and wine. Soil properties influence…

Use of a new, miniaturized, low-cost spectral sensor to estimate and map the vineyard water status from a mobile

Optimizing the use of water and improving irrigation strategies has become increasingly important in most winegrowing countries due to the consequences of climate change, which are leading to more frequent droughts, heat waves, or alteration of precipitation patterns. Optimized irrigation scheduling can only be based on a reliable knowledge of the vineyard water status.

In this context, this work aims at the development of a novel methodology, using a contactless, miniaturized, low-cost NIR spectral tool to monitor (on-the-go) the vineyard water status variability. On-the-go spectral measurements were acquired in the vineyard using a NIR micro spectrometer, operating in the 900–1900 nm spectral range, from a ground vehicle moving at 3 km/h. Spectral measurements were collected on the northeast side of the canopy across four different dates (July 8th, 14th, 21st and August 12th) during 2021 season in a commercial vineyard (3 ha). Grapevines of Vitis vinifera L. Graciano planted on a VSP trellis were monitored at solar noon using stem water potential (Ψs) as reference indicators of plant water status. In total, 108 measurements of Ψs were taken (27 vines per date).

Calibration and prediction models were performed using Partial Least Squares (PLS) regression. The best prediction models for grapevine water status yielded a determination coefficient of cross-validation (r2cv) of 0.67 and a root mean square error of cross-validation (RMSEcv) of 0.131 MPa. This predictive model was employed to map the spatial variability of the vineyard water status and provided useful, practical information towards the implementation of appropriate irrigation strategies. The outcomes presented in this work show the great potential of this low-cost methodology to assess the vineyard stem water potential and its spatial variability in a commercial vineyard.

Phenolic composition of Tempranillo Blanco grapes changes after foliar application of urea

Our research aimed to determine the effect and efficiency of foliar application of urea on the phenolic composition of Tempranillo Blanco grapes. The field experiment was carried out in 2019 and 2020 seasons and the plot was located in D.O.Ca Rioja (North of Spain). The vineyard was Vitis vinifera L. Tempranillo Blanco and grafted on Richter-110 rootstock. The treatments were control (C), whose plants were sprayed with water and three doses of urea: plants were sprayed with urea 3 kg N/ha (U3), 6 kg N/ha (U6) and 9 kg N/ha (U9). The applications were performed in two phenological stages, pre-veraison (Pre) and veraison (Ver). Also, each of the treatments was repeated one week later. Control and treatments were performed in triplicate and arranged in a randomised block design. Grapes were harvested at optimum ripening stage. High-performance liquid chromatography was used to analyse the phenolic composition of the grapes. Finally, the results obtained from the analytical determinations – flavonols, flavanols and non-flavonoid (hydroxybenzoic acids, hydroxycinnamic acids and stilbenes) – were studied statistically by analysis of variance. The results showed that, in 2019, U6-Pre and U9-Pre treatments increased the hydroxybenzoic acid content in grapes, and also all foliar treatments applied at Pre enhanced the stilbene concentration. Moreover, U3-Ver was the only treatment that rose flavonol and stilbene contents in the Tempranillo Blanco grapes. In 2020, all treatments applied at Pre enhanced the flavonol concentration in grapes. Furthermore, U3-Pre and U9-Pre treatments increased stilbene content in grapes. Nevertheless, the hydroxybenzoic acid content was improved by U6-Ver and U9-Ver and besides, hydroxycinnamic acid concentration in grapes was increased by all treatments applied at Ver. In conclusion, the lower and highest dose of urea (U3 and U9), applied at pre-veraison, were the best treatments to improve the Tempranillo Blanco grape phenolic composition.

A better understanding of the climate effect on anthocyanin accumulation in grapes using a machine learning approach

The current climate changes are directly threatening the balance of the vineyard at harvest time. The maturation period of the grapes is shifted to the middle of the summer, at a time when radiation and air temperature are at their maximum. In this context, the implementation of corrective practices becomes problematic. Unfortunately, our knowledge of the climate effect on the quality of different grape varieties remains very incomplete to guide these choices. During the Innovine project, original experiments were carried out on Syrah to study the combined effects of normal or high air temperature and varying degrees of exposure of the berries to the sun. Berries subjected to these different conditions were sampled and analyzed throughout the maturation period. Several quality characteristics were determined, including anthocyanin content. The objective of the experiments was to investigate which climatic determinants were most important for anthocyanin accumulation in the berries. Temperature and irradiance data, observed over time with a very thin discretization step, are called functional data in statistics. We developed the procedure SpiceFP (Sparse and Structured Procedure to Identify Combined Effects of Functional Predictors) to explain the variations of a scalar response variable (a grape berry quality variable for example) by two or three functional predictors (as temperature and irradiance) in a context of joint influence of these predictors. Particular attention was paid to the interpretability of the results. Analysis of the data using SpiceFP identified a negative impact of morning combinations of low irradiance (lower than about 100 μmol m−2 s−1 or 45 μmol m−2 s−1 depending on the advanced-delayed state of the berries) and high temperature (higher than 25oC). A slight difference associated with overnight temperature occurred between these effects identified in the morning.

The rootstock, the neglected player in the scion transpiration even during the night

Water is the main limiting factor for yield in viticulture. Improving drought adaptation in viticulture will be an increasingly important issue under climate change. Genetic variability of water deficit responses in grapevine partly results from the rootstocks, making them an attractive and relevant mean to achieve adaptation without changing the scion genotype. The objective of this work was to characterize the rootstock effect on the diurnal regulation of scion transpiration. A large panel of 55 commercial genotypes were grafted onto Cabernet Sauvignon. Three biological repetitions per genotype were analyzed. Potted plants were phenotyped on a greenhouse balance platform capable of assessing real-time water use and maintaining a targeted water deficit intensity. After a 10 days well-watered baseline period, an increasing water deficit was applied for 10 days, followed by a stable water deficit stress for 7 days. Pruning weight, root and aerial dry weight and transpiration were recorded and the experiment was repeated during two years. Transpiration efficiency (ratio between aerial biomass and transpiration) was calculated and δ13C was measured in leaves for the baseline and stable water deficit periods. A large genetic variability was observed within the panel. The rootstock had a significant impact on nocturnal transpiration which was also strongly and positively correlated with maximum daytime transpiration. The correlations with growth and water use efficiency related traits will be discussed. Transpiration data were also related with VPD and soil water content demonstrating the influence of environmental conditions on transpiration. These results highlighted the role of the rootstock in modulating water deficit responses and give insights for rootstock breeding programs aimed at identifying drought tolerant rootstocks. It was also helpful to better define the mechanisms on which the drought tolerance in grapevine rootstocks is based on.