Macrowine 2021
IVES 9 IVES Conference Series 9 Effect of simulated shipping conditions on colour and SO2 evolution in soave wines

Effect of simulated shipping conditions on colour and SO2 evolution in soave wines

Abstract

AIM: The shelf life of food is defined as the period in which the product will remain safe, is certain to retain desired sensory, chemical, physical, and microbiological characteristics, and complies with any label declaration of nutritional data.1 Wine exhibits a “random” shelf life, as the chemical changes are as dependent on the initial condition of the product, including packaging, as on the storage and freight conditions of the product. However, storage and transport conditions of wine may lead to a reduction in wine quality because of unintended physical and chemical changes. These modifications are generally referred to as oxidative spoilage, and they result in browning and loss of fresh, fruity, and varietal aroma characters.2 Certain protective agents such as SO2 are also typically lost with the onset of oxidative spoilage. Recent studies have shown that the outcomes of oxidation in terms of degree of oxidative spoilage are strongly wine specific,3 so that certain wines appear to be more resistant against oxidative spoilage. In this study, chemical and electrochemical changes under the effects of shipping conditions were measured in thirteen Soave wines, to evaluate the potential of Cyclic Voltammetry in conjunction with other parameters to provide relevant information on the oxidative behaviour of individual white wines.

METHODS: The wines underwent an ageing protocol simulating a freight of 46 days, during which the wine was subjected to specific temperature cycles. In the storage of wines at the departure port, the temperature fluctuated between 16 and 25 °C, reflecting the diurnal cycle; while, during the journey of 28 days, the temperature reached 30 °C. Finally, storage at the arrival port produced an oscillation between 25 and 35 °C. Electrochemical methods, in particular the cyclic voltammetry using either glassy carbon or carbon paste electrodes, have been applied to the analysis of wine phenolics.4 Voltammograms of each wine were collected and their features were analysed in conjunction with concentration of free and total SO2, chromatic and spectrophotometric parameters.

RESULTS: The ageing protocol adopted led each wine to a different free and total SO2 consumption, also reflected in an electrochemical diversity and a general increase of chromatic parameters. Cyclic voltammograms have shown a diversity of electrochemical properties, concentration and type of oxidizable compounds present.

CONCLUSIONS

The objective of this study was to explore the electrochemical and chemical repercussions of adverse temperature conditions on Soave wines to better understand the changes due to freight and storage. Significant and seemingly correlated information derived from the electrochemical profile and SO2 consumption of each wine. This study could also constitute the beginning of research aimed at obtaining predictive parameters of the wine shelf life.

DOI:

Publication date: September 14, 2021

Issue: Macrowine 2021

Type: Article

Authors

Diletta, Invincibile

University of Verona,Davide SLAGHENAUFI, University of Verona Maurizio, UGLIANO, University of Verona

Contact the author

Keywords

wine, shelf life, freight, voltammetry

Citation

Related articles…

Organic recycled mulches in sustainable viticulture: assessment of spontaneous plants communities and weed coverage

In recent years, developing more efficient and sustainable viticulture management has been essential due to the impact of climate change in semiarid regions. For this reason, the use of recycled organic mulching (ROM) in the vineyard has become an interesting strategy to cope with water stress, isolated soil from extreme temperatures and improving soil humidity, control the presence of weeds and therefore reduce the inputs of herbicides and improve soil fertility. This work aimed to analyse the effect of three different organic mulches [straw (S), grape pruning debris (GPD) and spent mushroom compost (SMC)] and two traditional soil management techniques [herbicide (H) and interrow (IN)] on weed coverage and the spontaneous plant communities’ presence. Data sampling was collected throughout the vine vegetative cycle of 2021 in La Rioja, Spain. The different soil management techniques had a clear effect on weed coverage and his development during the vine vegetative cycle. SMC and H were the treatments with the highest and the lowest coverage percentage, respectively. IN had a delayed weed emergence at the beginning of the vine vegetative cycle, but finally it reached maximum values nearby SMC. GPD and S had similar effects on weed emergence, reaching 25-30% of the maximum coverage values. A total of 29 herbaceous species were identified during the vegetative cycle, some of them very isolated and occasional. Principal component analysis (PCAs) showed a good association between spontaneous species and treatments, furthermore, specific species-treatment associations were found. Moreover, three clear groups of herbaceous communities were identified by cluster analysis. This study provides interesting information about the effect of different alternative soil management on herbaceous plant coverage and weed species communities which could contribute to making more sustainable viticulture.

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…

δ13C : A still underused indicator in precision viticulture  

The first demonstration of the interest of carbon isotope composition of sugars in grapevine, as an integrated indicator of vineyard water status, dates back to 2000 (Gaudillère et al., 1999; Van Leeuwen et al., 2001). Thanks to the isotopic discrimination of Carbon that takes place during plant photosynthesis, under hydric stress conditions, it is possible to accurately estimate the photosynthetic activity. Ever since, δ13C has been widely applied with success to zonation, terroir studies and vine physiology research, but is still not widely used by viticulturists. This is quite astonishing by considering the impact of global warming on viticulture and the need to improve water management, that would justify a widespread use of δ13C.
The lack of private laboratories proposing the analysis, the cost of the technology, as well as the long analytical delays, have been detrimental to its development. Some laboratories tried to overcome the analytical difficulties of isotopic analysis by using fourier transformed infrared spectroscopy, as a fast and cheap alternative to the official OIV method (IRMS). These claimed FTIR models have never been published or peer reviewed and cannot be considered robust. In this work, thanks to the recent acquisition of IRMS technology, new modern and robust applications of δ13C for viticulture are proposed. This includes the use of the analysis to make parcel separations at harvesting, the possibility to increase the precision of hydric stress cartography and the potential cost reduction when compared with Scholander pressure bomb analysis.

Grapevine varietal diversity as mitigation tool for climate change: Agronomic and oenologic potential of 14 foreign varieties grown in Languedoc region (France)

Climate change effects in Languedoc include an expected rise in temperatures, increased evapotranspiration as well as more severe and frequent climatic hazards, such as frost, drought periods and heat waves. For winegrowers theses phenomena impact both yield and quality, resulting in more frequent unbalanced wines. Research on identified mitigation tools for vineyard management is necessary to improve resilience of grapevine agrosystems. Varietal assortment is one of them. This study focuses on agronomic and oenologic potential of 14 foreign varieties grown in Languedoc French region. Fourteen grapevine varieties were monitored during 2021 from June until harvest on eight different sites, some of which occurring on more than one site adding up to 21 different modalities: 7 white varieties Alvarinho B, Assyrtiko B (2), Malvasia Istriana B, Parellada B, Verdejo B, Verdelho B, Xarello B, and 7 black varieties Saperavi N (2), Touriga nacional N, Baga N, Aleatico N, Montepulciano N (2), Primitivo N (3), Calabrese N (3). Varietals were compared through the following parameters: phenology was assessed by using the information collected in the Database Network of French Vine Conservatories (INRAE-SupAgro-IFV, 2005-2015). The number of inflorescences for shoots from secondary buds and bourillons and suckers were observed to assess post-bud break frost tolerance potential. Grapevine water status was studied through stem water potential measurement, observation of foliage symptoms of drought, and 𝛿13C on must. Frequencies and intensities of downy mildew, powdery mildew, and black rot attacks were estimated before harvest on leaves and clusters and botrytis at harvest to assess disease susceptibilities. Berry composition was monitored from end of veraison until harvest. Yield and mean bunch weight were also calculated. Varieties were then ranked on a 1-4 scale for each parameter and compared through PCA. Forty two stations of the Mediterranean basin were compared by PCA with the Multicriteria Climatic Classification indicators in order to confront the collected information during 2021 campaign to the hypothesis that plants coming from dry and hot regions are genetically adapted to such climatic conditions.

Effects of graft quality on growth and grapevine-water relations

Climate change is challenging viticulture worldwide compromising its sustainability due to warmer temperatures and the increased frequency of extreme events. Grafting Vitis vinifera L.