 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

Enological potential of red grapes: cultivars and geographic origin of vineyards

The study of technologic and phenolic maturation is very efficient to determinate quality potential of red grapes cultivars and clones under different maturity levels or geographic origins

Screening of hydroxytyrosol and tyrosine related metabolites in commercial wines by an UHPLC/MS validated method.

Hydroxytyrosol (HT) is a bioactive phenolic compound with antioxidant activity. Yeast synthetise tyrosol from tyrosine by the Ehrlich pathway which is subsequently hydroxylated to HT. The aim of the present work is to develop and validate an UHPLC–HRMS method to assess the metabolites involved in this pathway as well as to screen Spanish commercial wines for HT bioactive compound.

Effect of different pH values on the interaction between yeast mannoproteins and grape seed flavanols

The consequences of the global climate change in the vitiviniculture are revealed as a gap between phenolic and technological grape maturities, higher grape sugar concentration that leads to high wine alcohols levels, lower acidities and high pH values, among others. The unbalanced phenolic maturity caused in this scenario leads to harsh astringency and to instable colour of wines. Previous studies have reported that the addition of yeast mannoproteins (MPs) to wines may have positive effects on these two organoleptic properties due to their capability to interact with wine polyphenols [1]; however, studies about the effect of the pH on these interactions have not been carried out so far.

Nitrogen forms and Iron deficiency: how do Grapevine rootstocks responses change?

Grapevine rootstocks provide protection against environmental biotic and abiotic stresses. Nitrogen (N) and iron (Fe) are growth-limiting factors in many crop plants due to their effects on the chlorophyll and photosynthetic characteristics. Iron nutrition of plants can be significantly affected by different nitrogen forms through altering the uptake ratio of cations and anions, and changing rhizosphere pH. The aim of this study was to investigate the response mechanisms of grapevine rootstocks due to the interaction between different nitrogen forms and iron uptake.

Learning from remote sensing data: a case study in the Trentino region

Recent developments in satellite technology have yielded a substantial volume of data, providing a foundation for various machine learning approaches. These applications, utilizing extensive datasets, offer valuable insights into Earth’s conditions. Examples include climate change analysis, risk and damage assessment, water quality evaluation, and crop monitoring. Our study focuses on exploiting satellite thermal and multispectral imaging, and vegetation indexes, such as NDVI, in conjunction with ground truth information about soil type, land usage (forest, urban, crop cultivation), and irrigation water sources in the Trentino region in North-East of Italy.