IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Effect of terroir and winemaking protocol on the chemical and sensory profiles of Pinot Blanc wine

Effect of terroir and winemaking protocol on the chemical and sensory profiles of Pinot Blanc wine

Abstract

Wine research in the past years has mainly been focused on laboratory scale due to the possibility of controlling winemaking variables. Conversely, studies on wine quality in relation to the winemaking variables at the winery scale may be able to better account for the actual challenges encountered during wine production. Winemaking problems are recently arising from progressive changes in environmental conditions in relation to the terroir. It is important to realize that each wine region may have specific winemaking protocols and that winemakers often base their decisions on subjective, emotional, and empirical opinions. Due to all the above-mentioned issues, taking the correct decision in winemaking to achieve the desired goals may become even more challenging. Hence, comprehensive analytical and sensory tools could provide substantial support for winemakers to base their decisions on data obtained from validated methodologies throughout the winemaking process. This report presents an example of a collaboration study on a winery-scale production of Pinot Blanc which has become an important production in South Tyrol (Italy) over the last decades, with its cultivation covering 10.3% of the total vineyards (www.altoadigewines.com). The main objective of the present project is to build a fingerprint database for wine identity (chemical and sensory data of Pinot Blanc in that area) to understand how terroir and winemaking practices are influencing the analytical and sensory/hedonic qualities of this wine, and to provide guidelines to winemakers accordingly to aid their decisions. 

The experimental plan for this study included factors such as (I) vineyard location, (II) pre-fermentation freezing of the grapes, and (III) simultaneous alcoholic and malolactic fermentations The samples were analyzed by HPLC-DAD for the determination of the phenolic compounds and by HS-SPME-GCxGC-ToF/MS for determining the volatile profiles. The sensory analysis was performed using Quantitative Descriptive Analysis (QDA ®) (Poggesi et al., 2021). The application of whole grape freezing in pre-processing turned out to be the main differentiating factor of the wines. The results also showed a strong dependence of the measured parameters on the vineyard which could be classified according to significantly different relative abundances of phenolic and volatile compounds. No difference was observed in the phenolic profile as a function of co-inoculation with malolactic bacteria. On the other hand, specific volatile compounds could differentiate samples undergoing simultaneous alcoholic and malolactic fermentation. The chemical results were then integrated with sensory data to create multivariate models, to show how the factors played out on the final quality of the wine obtained. Prospectively, fingerprint databases can be built on these models for authenticity purposes and to assist the winemaker during production.

References

• Alto Adige Wine – Exquisite Wines from Northern Italy (altoadigewines.com)
• Poggesi, S., Dupas de Matos, A., Longo, E., Chiotti, D., Pedri, U., Eisenstecken, D., & Boselli, E. (2021). Chemosensory Profile of South Tyrolean Pinot Blanc Wines: A Multivariate Regression Approach. Molecules, 26(20), 6245. https://doi.org/10.3390/molecules26206245
• Philipp, C., Eder, P., Sari, S., Hussain, N., Patzl-Fischerleitner, E., & Eder, R. (2020). Aromatypicity of Austrian Pinot Blanc Wines. Molecules, 25(23), 5705. https://doi.org/10.3390/molecules25235705
• Philipp, C., Eder, P., Brandes, W., Patzl-Fischerleitner, E., & Eder, R. (2018). The pear aroma in the Austrian Pinot blanc wine variety: evaluation by means of sensorial-analytical-typograms with regard to vintage, wine styles, and origin of wines. Journal of Food Quality, 2018. https://doi.org/10.1155/2018/5123280

DOI:

Publication date: June 27, 2022

Issue: IVAS 2022

Type: Poster

Authors

Darnal Aakriti1, Poggessi Simone1, Merkyte Vakare1, Longo Edoardo1, Montali Marco2 and Boselli Emanuele1

1Faculty of Science and Technology, Free University of Bozen-Bolzano
2Faculty of Computer Science, Free University of Bozen-Bolzano

Contact the author

Keywords

Pinot Blanc, wine identity, QDA, volatile profiles

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Heatwaves and grapevine yield in the Douro region, crop model simulations

Heatwaves or extreme heat events can be particularly harmful to agriculture. Grapevines grown in the Douro winemaking region are particularly exposed to this threat, due to the specificities of the already warm and dry climatic conditions. Furthermore, climate change simulations point to an increase in the frequency of occurrence of these extreme heat events, therefore posing a major challenge to winegrowers in the Mediterranean type climates. The current study focuses on the application of the STICS crop model to assess the potential impacts of heatwaves in grapevine yields over the Douro valley winemaking region. For this purpose, STICS was applied to grapevines using high-resolution weather, soil and terrain datasets over the Douro. To assess the impact of heatwaves, the weather dataset (1989-2005) was artificially modified, generating periods with anomalously high temperatures (+5 ºC), at certain onset dates and with specific durations (from 5 to 9 days). The model was run with this modified weather dataset and results were compared to the original unmodified runs. The results show that heatwaves can have a very strong impact on grapevine yields, strongly depending on the onset dates and duration of the heatwaves. The highest negative impacts may result in a decrease in the yield by up to -35% in some regions. Despite some uncertainties inherent to the current modelling assessment, the present study highlights the negative impacts of heatwaves on viticultural yields in the Douro region, which is critical information for stakeholders within the winemaking sector for planning suitable adaptation measures.
Read More

Grapevine sugar concentration model in the Douro Superior, Portugal

Increasingly warm and dry climate conditions are challenging the viticulture and winemaking sector. Digital technologies and crop modelling bear the promise to provide practical answers to those challenges. As viticultural activities strongly depend on harvest date, its early prediction is particularly important, since the success of winemaking practices largely depends upon this key event, which should be based on an accurate and advanced plan of the annual cycle. Herein, we demonstrate the creation of modelling tools to assess grape ripeness, through sugar concentration monitoring. The study area, the Portuguese Côa valley wine region, represents an important terroir in the “Douro Superior” subregion. Two varieties (cv. Touriga Nacional and Touriga Franca) grown in five locations across the Côa Region were considered. Sugar accumulation in grapes, with concentrations between 170 and 230 g l-1, was used from 2014 to 2020 as an indicator of technological maturity conditioned by meteorological factors. The climatic time series were retrieved from the EU Copernicus Service, while sugar data were collected by a non-profit organization, ADVID, and by Sogrape, a leading wine company. The software for calibrating and validating this model framework was the Phenology Modeling Platform (PMP), version 5.5, using Sigmoid and growing degree-day (GDD) models for predictions. The performance was assessed through two metrics: Roots Mean Square Error (RMSE) and efficiency coefficient (EFF), while validation was undertaken using leave-one-out cross-validation. Our findings demonstrate that sugar content is mainly dependent on temperature and air humidity. The models achieved a performance of 0.65

Read More

The combined effects of climate, soils, and deficit irrigation on yield and quality of Touriga Nacional under high atmospheric demand in the Douro Region

Global warming is one of the biggest environmental, social and economic threats in several viticultural regions. In the Douro Valley, changes are expected in the coming years, namely an increase in temperature and a decrease in precipitation. These changes are likely to have consequences for the production and quality of wine.
The aim of this study was to explore the effects of different soil characteristics combined with several deficit irrigation strategies, managed throughout ETc references and predawn leaf water potentials thresholds, on physiology, yield, and qualitative attributes on the Touriga Nacional variety under years of mild to severe water and heat stress.
The studies were conducted over seven years (2015 to 2021) in two plots of a commercial vineyard located at Quinta do Ataíde (Symington Family Estates) planted in 2011 and 2014 at 170 meters elevation, growing under three water regimes: non-irrigated (NI) and two deficit irrigation strategies (30% and 60% ETc) assessed weekly by Ψpd. The site has an annual rainfall below 500 mm, with high atmospheric demand. Climate data was collected from a weather station, located on site. Berry ripening was followed weekly for fruit analysis. At harvest, yield, vigour and pruning weight per vine were determined from 90 vines by treatment. Each season at veraison the NDVI Index was accessed by a drone. The soils physic-chemistry in the experimental blocs were analysed and grouped by SWHC. Delta C-13 analyses were also performed per treatment in two years.Irrigation had a positive effect on yield per vine, mostly due to an increase in berry and cluster weight, and fertility index through the years. A significant increase in sugar content, colour and phenols was observed with deficit irrigation in some years, but vine vigour related to soil characteristics had by far the greatest impact on quality.

Read More

Adaptation to soil and climate through the choice of plant material

Choosing the rootstock, the scion variety and the training system best suited to the local soil and climate are the key elements for an economically sustainable production of wine. The choice of the rootstock/scion variety best adapted to the characteristics of the soil is essential but, by changing climatic conditions, ongoing climate change disrupts the fine-tuned local equilibrium. Higher temperatures induce shifts in developmental stages, with on the one hand increasing fears of spring frost damages and, on the other hand, ripening during the warmest periods in summer. Expected higher water demand and longer and more frequent drought events are also major concerns. The genetic control of the phenotypes, by genomic information but also by the epigenetic control of gene expression, offers a lot of opportunities for adapting the plant material to the future. For complex traits, genomic selection is also a promising method for predicting phenotypes. However, ecophysiological modelling is necessary to better anticipate the phenotypes in unexplored climatic conditions Genetic approaches applied on parameters of ecophysiological models rather than raw observed data are more than ever the basis for finding, or building, the ideal varieties of the future.

Read More

Green berries on Gewürztraminer (Vitis vinifera L.) in South Tyrol (Italy)

The grape variety Gewürztraminer is known to be affected by two physiological disorders namely berry shrivel and bunch stem necrosis. During the season 2014 we noticed a new symptomatology type of ripening disorder on the variety. The new symptom showed not all berries fallowing the normal maturation stages, but single berries remaining at a soft but green stage till harvest. The broad distribution of these so called “green berries” symptoms in different production sites of our region, caused huge damage due to the difficulty of eliminating single berries per bunch before harvesting. Therefore, the Research Centre Laimburg began to investigate the reasons and origins of this new symptom. This work shows the results of first attempts to find causes for the symptom as well as the resulting approach to mitigate symptoms. Applications of magnesium leaf fertilizer showed first promising results against this putative disorder. To study the causal effect of the green berries 30 symptomatic vineyards in 2014 have been selected for a monitoring during the season 2016. To evaluate the foliar nutrient treatment two vineyards have been selected for application of magnesium sulfate and magnesium chloride. Leaf and berry nutrient analysis, as well as the main quality parameters during ripening have been performed. As soon as “green berries” symptoms appeared, incidence and severity have been evaluated. Most of the symptomatic vineyards of the 2016 monitoring showed light to clear magnesium deficit symptoms on their foliage. Only during the seasons 2020 and 2021 “green berries” symptoms could be found in the leaf fertilizer treatment vineyards. Both seasons showed a significant effect of the magnesium treatments to reduce the incidence and severity of the symptom. It seems that the appearance of the “green berries” symptom on Gewürztraminer is correlated to a disturbed uptake of magnesium of the vines.

Read More