 IVES 9 IVES Conference Series 9 Macrowine 9 Macrowine 2021 9 Grapevine diversity and viticultural practices for sustainable grape growing 9 Volatile and phenolic composition of Agiorgitiko wines from eight different areas of PDO Nemea zone

Volatile and phenolic composition of Agiorgitiko wines from eight different areas of PDO Nemea zone

Abstract

AIM: Agiorgitiko (Vitis vinifera L. cv.) is the most cultivated red grapewine variety in Greece1 located mainly in Nemea region, the largest PDO zone in Greece2. Although Agiorgitiko is considered as one of the most interesting red grape varieties, not only in Greece3, but also at international level4,5, however, there is a lack of knowledge concerning the phenolic and aromatic profile of the Agiorgitiko varietal wines. For this study eight vineyards, from the most representative areas of the PDO Nemea zone, were selected in order to study the phenolic and aromatic potential of the variety and the heterogeneity of the wine composition among the different areas.

METHODS: Within the eight vineyards, vines were selected according to the same selection protocol. From the selected vineyards, 60 kg of grapes were harvested at the optimum technological maturity level using a defined picking protocol. Microvinifications were conducted, in triplicate, applying the same winemaking protocol. The produced wines were analyzed for their main oenological parameters and for their phenolic and volatile composition. Moreover, the wines were evaluated sensorially by a trained panel.

RESULTS: Phenolic and anthocyanidin content of wines ranged from medium to high levels in comparison to other international or Greek red varietal wines. Also, the volatile compounds concentrations presented differences among the wines (p<0.05) from different areas as also found when applying sensory evaluation of the samples. Statistical analysis of the sensory evaluation results illustrated an aromatic profile of Agiorgitiko wines composed by red fruit aroma descriptors and this was characterized for most of the wines analyzed.

CONCLUSIONS:

The present study provides a detailed approach on the characterization of the phenolic and aromatic content of Agiorgitiko wines, which is a great tool for improving the quality of the PDO Nemea wines. Also, in this study the variability of Nemea’s region pedoclimatic conditions that were depicted on wine and grape characteristics from different areas, implies the need of further research on the impact of “terroir” in Agiorgitiko wines produced from different areas.

DOI:

Publication date: September 1, 2021

Issue: Macrowine 2021

Type: Article

Authors

Maria Ioanna Xenia , Elli GOULIOTI, Nikolaos KONTOUDAKIS, Greece Yorgos KOTSERIDIS

AUA Department of FS&HN, Laboratory of Enology and Alcoholic Drinks, Athens, Greece,

Contact the author

Keywords

Red wine phenolics, aromatic content, agiorgitiko, nemea

Citation

Vineyard innovative tools based on the integration of earth observation services and in-field sensors (VitiGEOSS project)

Climate change is having an unprecedented impact on the wine industry, which is one of the major agricultural sectors around the world. Global warming, combined with the variation in rainfall patterns and the increase in frequency of extreme weather events, is significantly influencing vine physiology and exposing, more frequently, plants to severe biotic and abiotic stresses. This represents a challenge for viticulturists who need to take complex decisions to adjust vineyard management and achieve oenological goals.

Extreme vintages affect grape varieties differently: a case study from a cool climate wine region

Eger wine region is located on the northern border of grapevine cultivation zone. In the cool climate, terroir selection is one of the foundations of quality wine making. However, climate change will have a significant impact on these high value-added vineyards. This study presents a case study from 2021 and 2022 with the investigation of three grape varieties (Kadarka, Syrah, Furmint). The experiment was conducted in a steep-sloped vineyard (Nagy-Eged hill) with a southern exposure.

An analytical framework to site-specifically study climate influence on grapevine involving the functional and Bayesian exploration of farm data time series synchronized using an eGDD thermal index

Climate influence on grapevine physiology is prevalent and this influence is only expected to increase with climate change. Although governed by a general determinism, climate influence on grapevine physiology may present variations according to the terroir. In addition, these site-specific differences are likely to be enhanced when climate influence is studied using farm data. Indeed, farm data integrate additional sources of variation such as a varying representativity of the conditions actually experienced in the field. Nevertheless, there is a real challenge in valuing farm data to enable grape growers to understand their own terroir and consequently adapt their practices to the local conditions. In such a context, this article proposes a framework to site-specifically study climate influence on grapevine physiology using farm data. It focuses on improving the analysis of time series of weather data. The analytical framework includes the synchronization of time series using site-specific thermal indices computed with an original method called Extended Growing Degree Days (eGDD). Synchronized time series are then analyzed using a Bayesian functional Linear regression with Sparse Steps functions (BLiSS) in order to detect site-specific periods of strong climate influence on yield development. The article focuses on temperature and rain influence on grape yield development as a case study. It uses data from three commercial vineyards respectively situated in the Bordeaux region (France), California (USA) and Israel. For all vineyards, common periods of climate influence on yield development were found. They corresponded to already known periods, for example around veraison of the year before harvest. However, the periods differed in their precise timing (e.g. before, around or after veraison), duration and correlation direction with yield. Other periods were found for only one or two vineyards and/or were not referred to in literature, for example during the winter before harvest.

Pests and biodiversity management on a climate change scenario: A practical case

The weather anomalies comparing the 1971-2000 time frame and the last years has showned a dramatic scenario when, in some months, average temperature in above 3ºC and the reduction in precipitation in more than 30%.

Comportement hydrique des sols viticoles et leur influence sur le terroir

L’étude des relations Terroir – Vigne – Raisin est complexe. La recherche et le développement des facteurs qualitatifs qui influencent le caractère des vins sont multiples. Divers travaux mettent en évidence la relation entre l’alimentation en eau de la plante, son développement végétatif et les caractéristiques de ses raisins.