IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Text mining of wine reviews to investigate quality markers of ‘Nebbiolo’ wines from Valtellina

Text mining of wine reviews to investigate quality markers of ‘Nebbiolo’ wines from Valtellina

Abstract

In Valtellina zone (north Italy), the winemaking of ‘Nebbiolo’ grapes leads to the production of two main wine types: classic red wines from fresh grapes, usually classified as Valtellina Superiore DOCG (mandatory oak aging) or Rosso di Valtellina DOC, and the Sforzato di Valtellina DOCG, which is produced using withered grapes according to traditional product specification and subjected to mandatory oak aging process. The withering process influences grape chemical composition and, in turn, the wine sensory profile, which is strongly linked to the wine quality and typicity perceived by consumers.In this study, text mining operations on reviews from renowned wine magazines and web sources (The Wine Advocate, Wine Spectator, James Suckling Wine Ratings, Wine Enthusiast) were used to explore the differences between wines produced using fresh (Valtellina Superiore-Rosso di Valtellina) and withered (Sforzato) ‘Nebbiolo’ grapes with the aim of characterising the sensory markers of these two peculiar products.Firstly, the similarities and differences of terms deriving from the reviews of Sforzato (132 reviews obtained) and the group Valtellina Superiore-Rosso di Valtellina (368 reviews obtained) were investigated through keyness analysis using the AntConc software, to identify the relevant keywords that can distinguish these wines. Then, the determination of sensory descriptors associated to the ratings of the reviews was performed using text mining strategies through IRaMuTeQ software. Sforzato and Valtellina Superiore-Rosso di Valtellina corpora, separately, were divided in low (≤86), medium-low (87-89), medium-high (90-92), and high (≥93) ratings and evaluated by clustering and correspondence analysis (CA), to find out the sensory attributes that can explain and are correlated to the quality and typicity of each category of Valtellina wines.The keyness analysis showed a very similar corpus between the two wine categories, given by the common variety and origin. Nevertheless, significantly different lemmas were found, with Sforzato described as more ‘rich’, with higher frequencies of ‘prune’ and ‘chocolate’ aromas, ‘robust’ and ‘full bodied’ on the palate, and with ‘velvet-like’ texture mouthfeel when compared to ‘Nebbiolo’ produced from fresh grapes. ‘Velvety’ descriptor was as well linked to high quality in Sforzato, because in CA it was correlated with the high-ratings group, as well as the ‘prune’ aroma descriptors. ‘Rich’ was specific for medium-high rating group, and ‘full’ and ‘chocolate’ for medium-low. Generally, in-mouth descriptors, such as mouthfeel and astringency, were able to discriminate the Sforzato wines according to the ranking group.This data analysis approach can be helpful in identifying key sensory descriptors for specific wine types and unravel markers of wine typicality. Furthermore, this knowledge will allow wine producers to modulate the winemaking strategies to obtain products noticeable by consumers.

DOI:

Publication date: June 27, 2022

Issue: IVAS 2022

Type: Poster

Authors

Paissoni Maria Alessandra1, LEE Lei1, Río Segade Susana1, Giacosa Simone1, Gerbi Vincenzo1 and Rolle Luca1

1Department of Agricultural, Forest and Food Sciences (DISAFA), University of Torino

Contact the author

Keywords

Text mining, Keyness analysis, Wine quality, Sensory descriptors, Wine reviews

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Effect of fertigation strategies to adapt PGI Côtes de Gascogne production to hot vintage

The development of fertigation could be a possible solution to adapt PGI Côtes de Gascogne (south-western France) wine production to climate change. The goal would be to limit the negative effects of water stress on yield performance expectation (around 15 tons per hectare) and to make the use of fertilizers more efficient. This study aimed to compare the effects of three strategies of water and minerals supply on grapes and wines qualities. Two fertigation practices were compared to a rainfed control which is the current standard of the local grape growing production. The fertilizers (nitrogen and potassium) were (i) fully brought by irrigation pipe during the season, (ii) partially brought by irrigation pipe and partially on the soil or (iii) fully brought on the soil at the beginning of the season for the non-irrigated control (local standard). The trial was run on cv. Colombard trained on spur pruned with vertical shoot positioning system on a sandy-silty-clay soil over the 2020 vintage which was particularly hot for the region. Moderate to strong water deficit appeared during the growing period of the berries and held on after veraison. Irrigation strategies allowed for maintaining grapevine without water deficit and being significantly different from the control water status. Grapevine with fully or partial fertigation strategies produced 25% more yield mainly due to the increase of the bunch weight. Also, the fully fertigation showed the best ratio between yield and maturity and brought 30% less of fertilizers (both nitrogen and potassium) than the two other strategies. Finally, the analysis of aromatic compounds in Colombard wines, varietal thiols family, showed the same level of concentrations for the 3 treatments, confirming that the yield performance did not impact the aromatic potential in this trial.

Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

Protected Designation of Origin “Jumilla” (PDO Jumilla) is located in the Spanish provinces of Albacete and Murcia, in the South-eastern part of the Iberian Peninsula, where most of the models predict a severe impact of climate change in next decades. PDO Jumilla covers an area of 247,054 hectares, of which more than 22,000 hectares

Legacy of land-cover changes on soil erosion and microbiology in Burgundian vineyards

Soils in vineyards are recognized as complex agrosystems whose characteristics reflect complex interactions between natural factors (lithology, climate, slope, biodiversity) and human activities. To date, most of the unknown lies in an incomplete understanding of soil ecosystems, and specifically in the microbial biodiversity even though soil microbiota is involved in many key functions, such as nutrient cycling and carbon sequestration. Soil biological properties are indicative of soil quality. Therefore, understanding how soil communities are related to soil ecosystem functioning is becoming an essential issue for soil strategy conservation. Here, we propose to assess the importance of land-cover history on the present-day microbiological and physico-chemical properties. The studied area was selected in the Burgundian vineyards (Pernand-Vergelesses, Burgundy, France) where land occupation has been reconstructed over the last 40 years. Soil samples were collected in five areas reflecting various land cover history (forest, vineyards, shifting from forest to vineyards). For each area, physico-chemical parameters (pH, C, N, P, grain size) were measured and DNA was extracted to characterize the abundance and diversity of microbial communities. The obtained results show significant differences in the five areas suggesting that present-day microbial molecular biomass and bacterial taxonomic is partly inherited from past land occupation. Over longer period of time, such study of land-uses legacies may help to better assess ecosystem recovery and the impact of management practices for a better soil quality and vineyards sustainability.

Aromatic maturity is a cornerstone of terroir expression in red wine

Harvesting grapes at adequate maturity is key to the production of high-quality red wines. Enologists and wine makers define several types of maturity, including technical maturity, phenolic maturity and aromatic maturity. Technical maturity and phenolic maturity are relatively well documented in the scientific literature, while articles on aromatic maturity are scarcer. This is surprising, because aromatic maturity is, without a doubt, the most important of the three in determining wine quality and typicity (including terroir expression). Optimal terroir expression can be obtained when the different types of maturity are reached at the same time, or within a short time frame. This is more likely to occur when the ripening takes place under mild temperatures, neither too cool, nor too hot. Aromatic expression in wine can be driven, from low to high maturity, by green, herbal, fresh fruit, ripe fruit, jammy fruit, candied fruit or cooked fruit aromas. Green and cooked fruit aromas are not desirable in red wines, while the levels of other aromatic compounds contribute to the typicity of the wine in relation to its origin. Wines produced in cool climates, or on cool soils in temperate climates, are likely to express herbal or fresh fruit aromas; while wines produced under warm climates, or on warm soils in temperate climates, may express ripe fruit, jammy fruit or candied fruit aromas. Growers can optimize terroir expression through their choice of grapevine variety. Early ripening varieties perform better in cool climates and late ripening varieties in warm climates. Additionally, maturity can be advanced or delayed by different canopy management practices or training systems.

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.