Influence of two yeast strains and different nitrogen nutrition on the aromatic compounds in Lugana wine

Aerial architecture plays a key role in plant functioning as it affects light interception and microclimate. In grapevine, this architecture is primarily shaped by winter pruning and further adjusted through practices such as leaf thinning and topping during the growth cycle.

The Tokaj Kereskedőház Ltd. is the only state owned winery in Hungary. The company is integrating grapes for wine production from 1100 hectares of vineyard, which consist of 3500 parcels with average size of 0,3 hectares, owned by about 500 families of the region. The vineyards are unevenly spread in total 27 village of Tokaj region.

Field irrigation experiments were performed on young « Nonpareil » almond trees, mature « Bartlett » pear trees and mature « Pinot Noir » grapevines, to determine the relation of a number of alternative measures of plant water status (predawn and midday stem and leaf water potential), to a number of indices of plant physiological activity (leaf conductance, vegetative growth and fruit growth and composition).

The aim of this study was to evaluate the effects of different soil types on the chemical composition of Mediterranean red wines, through untargeted and targeted 1H-NMR metabolomics. One milliliter of raw wine was analyzed by means of a Bruker Avance II 400 spectrometer operating at 400.15 MHz. The spectra were recorded by applying the NOESYGPPS1D pulse sequency, to achieve water and ethanol signals suppression. No modification of the pH was performed to avoid any chemical alteration of the matrix. The generation of input variables for untargeted analysis was done via bucketing the spectra. The resulting dataset was preprocessed prior to perform unsupervised PCA, by means of MetaboAnalyst web-based tool suite. The identification of compounds for the targeted analysis was performed by comparison to pure compounds spectra by means of SMA plug-in of MNova 14.2.3 software. The dataset containing the concentrations (%) of identified compounds was subjected to one-way analysis of variance (ANOVA) to highlight significant differences among the wines. The untargeted analysis, carried out through the PCA, revealed a clear differentiation among the wines. The fragments of the spectra contributing mostly to the separation were attributed to flavonoids, aroma compounds and amino acids. The targeted analysis leaded to the identification of 68 compounds, whose concentrations were significant different among the wines. The results were related to soils physical-chemical analysis and showed that: 1) high concentrations of flavan-3-ols and flavonols are correlated with high clay content in soils; 2) high concentrations of anthocyanins, amino acids, and aroma compounds are correlated with neutral and moderately alkaline soil pH; 3) low concentrations of flavonoids and aroma compounds are correlated with high soil organic matter content and acidic pH. The 1H-NMR metabolomic analysis proved to be an excellent tool to discriminate between wines originating from grapes grown on different soil types and revealed that soils in the Mediterranean area exert a strong impact on the chemical composition of the wines.

Aim: To identify the sensory attributes responsible for the typicity of Cabernet Sauvignon wines from three Australian Geographical Indications (GIs) and to explore consumer purchase behaviour and preference with regard to regional wines.