 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

Characterization of spatial and temporal soil water status in vineyard by DC resistivity measurements

We performed a DC resistivity monitoring experiment during eight months in 2003. Low, medium and high resolution measurements have been carried out at various locations of a vineyard. General apparent resistivity mapping evidences the spatial variations of the summer drying of the subsurface.

Dialing in grapevine water stress indicators to better reflect holistic stress responses

Current remote sensing strategies rely heavily on reflectance data and energy balance modelling using thermal imagery to estimate crop water use and stress. These approaches show great promise for driving precision management decisions, but still require work to better understand how detected changes relate to meaningful physiological changes. Under water stress, grapevines exhibit a range of responses involving both biological and physical changes within leaves and canopies.

EFFECTS OF INDUCED SUNBURN DAMAGES ON WHITE WINE PROPERTIES

Climate change is a great challenge for the environment and affects the wine industry as well. Sunburn damage of sensitive grapes increase with severe heat periods. Besides significant loss of yield sunburn, modifies sensory properties of the wines and may cause climate-related off-flavours. To initiate sunburn in a controlled way, in 2021 sunburn was directly induced in the vineyard with the GrapeBurner device, exposing grapes of the varieties Riesling and Pinot Blanc with UV and IR radiation. This device was first assembled by Kai Müller of the university in Geisenheim and consists of a carriage with 6 UV/IR lamps. A 15 min irradiation was applied in early September at 60°Oe. Due to the colder season in 2021 the grapes were not harmed by previous sunburn damage.

Diffuse light due to wildfire smoke enhances gas exchange of shaded leaves

The risk of wildfires is increasing as the frequency and severity of drought and heat waves continue to rise. Wildfires are associated with the combustion of plant materials and emit smoke. In the atmosphere, smoke may spread readily across large areas. Smoke is composed of solid and liquid phase particulates and gases and has been identified as a causal agent of “smoke taint” in wine. On a smoky day, the intensity of direct light decreases because these particulates scatter sunlight. Even though this effect is frequently assumed to decrease plant photosynthesis, this assumption ignores the potential changes in diffuse light and may be based on scant evidence.

Influence of pre-fermentative steps on varietal thiol precursors

The content of 3-sulfanyl-1-hexanol and its acetate ester in wine is affected by a number of factors, including the concentration of its precursors S-3-(hexan-1-ol)-L-glutathione (G-3SH),