 IVES 9 IVES Conference Series 9 From vineyard to bottle. Rationalizing grape compositional drivers of the expression of valpolicella aroma ‘terroir’

From vineyard to bottle. Rationalizing grape compositional drivers of the expression of valpolicella aroma ‘terroir’

Abstract

AIM: Valpolicella is a renowned Italian wine-producing region (Paronetto, 1981). Wines produced in its different sub-regions are anecdotally believed to be aromatically different, although there is no systematic study addressing the chemical bases of such diversity. Aroma is the product of a biochemical and technological series of steps (Kotseridis, et al., 1999), as well as one of the most important features in the expression of the geographic identity and sensory uniqueness of a wine. The aim of this study was to investigate the volatile chemical composition of wines obtained from grapes harvested in selected vineyards during three consecutive vintages, assess the existence of recurring patterns that could represent unique aroma chemical signatures and to identify key grape compositional features underling such aroma signature.

METHODS: Corvina and Corvinone grapes were harvested from five different vineyards located in two sub-regions within Valpolicella during three consecutive vintages. Winemaking was performed under standardized conditions. Free volatile compounds and glycosidic precursors were analysed with GC-MS analysis co. Sensory characteristics of the wines have been investigated through sorting tasks performed with semi-trained panel.

RESULTS: Application of multivariate data analysis techniques allowed to identify volatile chemical patterns representing the unique aroma chemical signature of the geographical origin of each wine regardless of vintages. The main drivers associated with these chemical signatures were terpenes (linalool, α-terpineol), norisoprenoids (vitispirane, TDN, TPB), and, unexpectedly some fermentation derived esters. Wines’ terpenes content was related with grapes terpenes pool. In particular variations in wine linalool content were strongly associated with the grape content of different linalool forms. Finally, in the case of esters, a strong correlation between grape content of yeast assimilable nitrogen (YAN) and wine ester content was observed, further broadening the boundaries of vineyard factors able to influence wine aroma. Patterns of odor similarities were observed during sensory evaluation, indicating a recurring association between geographical origin and occurrence of aroma compounds such as linear and cyclic terpenes, esters or norisoprenoids.

CONCLUSIONS:

This study provides evidence for the existence of volatile chemical signatures that are representative of geographical origin. Identification of grapes compositional characteristics related to the main drivers of wines chemical signature provides clues to support producers in identifying and managing appropriate vineyard and/or winemaking practices, in the quest of producing wines expressing their sense of place and ‘terroir’

DOI:

Publication date: September 10, 2021

Issue: Macrowine 2021

Type: Article

Authors

Giovanni Luzzini

University of Verona,Davide SLAGHENAUFI, University of Verona Maurizio, UGLIANO, University of Verona Jessica, SAMANIEGO-SOLIS, University of Verona Riccardo TEDESCHI, Azienda Agricola F.lli Tedeschi

Contact the author

Keywords

chemical signature of geographical identity, red wine aroma, valpolicella, terroir, crus

Citation

Contribution of seeds to red wine phenolic composition

Tannin composition is an important attribute in red wine quality, and it is therefore critical to understand the factors influencing tannin extraction during alcoholic fermentation. Tannins contribute to the mouthfeel of wines, but they also form pigmented polymers...

Using nanopore skim-sequencing to characterise regional epigenetic variability in New Zealand Sauvignon Blanc

Recent advancements in genomic sequencing technologies have enabled more detailed and direct studies of DNA methylation, which can help characterise epigenetic variations in plants. The Grapevine Improvement team at the Bragato Research Institute is studying the use of Oxford Nanopore sequencing to identify epigenetic changes associated with environmental differences among clonally-propagated grapevines.

This study involved sequencing DNA from the same Sauvignon Blanc clone, sourced from diverse New Zealand viticultural regions, using the PromethION platform.

Phototropic and geotropic shoot orientation: effect on physiological, vegetative and reproductive parameters

[English version below]

On a étudié l’effet de l’orientation des rameaux sur les paramètres physiologiques, végétatifs et reproductif durant deux saisons de croissance (2002/2003 et 2003/2004) dans la région de Stellenbosch dans une vignoble du cépage Merlot sur 99R conduite en espalier et taillé à cordon coursonné. Les vignes étaient espacées 2.7 x 1.5 m.

The modification of cultural practices in grapevine cv. Syrah, does it modify the characteristics of the musts?

The work shows the results of a year of experimentation (2020) in a Syrah variety vineyard in La Roda (Castilla-La Mancha, Spain). The trial approach was on a randomized block design with two factors: Irrigation (I) and Pruning (P).
Irrigation schedules were adjusted to apply amounts close to 1,500 m3/ha. With this provision, 2 different irrigation treatments were proposed: I1) Start of irrigation from pea-sized grape to post-harvest (providing at least 20 % of the total amount of irrigation water to be provided post-harvest); I2) Start of irrigation from pea-sized grape to harvest (usual irrigation practice in the study area). Pruning was proposed with two treatments, one at the end of January (P1), which is pruning on a conventional date; and P2) pruning carried out at the beginning of budding. In total, 4 repetitions were designed with 4 elementary plots, each one of them representing one of the proposed treatments (I1P1; I1P2; I2P1; I2P2). In total, 16 plots were worked on and each elementary plot consisted of 30 strains, distributed in 3 lines.
The productive response was evaluated with the yield results of the harvest harvested at 23 ºBrix. The qualitative response was measured in the musts through the indices of technological (acidity, pH and potassium) and phenolic maturity and aromatic compounds in free and glycosylated fractions. The treatments tested had, in general, an effect on the different variables analyzed.

Can different green manure fertilizations affect the vine balance and grape quality? First evidence of multi-year study

In the context of sustainable viticulture that implements organic practices to maintain soil fertility, green manuring plays a crucial role due to its ability to stock carbon and nitrogen in soil while supporting biodiversity.