Identification and biological properties of new resveratrol derivatives formed in red wine

The effects of different methods of soil management on the nutrient supply and the wine quality of organically grown Grüner Veltliner grapevines (wide-spaced high culture training system) were investigated in the winegrowing region Wagram of Lower Austria (municipality: Großriedenthal).

Lactic acid bacteria (LAB) are essential microorganisms in winemaking due to their role in malolactic fermentation (MLF) [1]. This process not only ensures the biological stabilization of wine through the decarboxylation of malic acid into lactic acid but also contributes to modifications in the chemical composition of the wine [2][3].

The aromatic quality of wines after a long aging period in bottle is one of key points for oenologists. The objective of this work is to determine the main representative aromatic compounds found in long aged wines from D.O.Ca. Rioja. This study was made by 32 wines from 1971 to 2010 vintages. Sotolon, acetaldehyde, phenylacetaldehyde, 1,1,6-trimethyl-1,2-dihydronaptalene (TDN), β-damascenone, Y-decalactone and Y-dodecalactone were determined as the most important oxidation markers by GC-MS analysis. Moreover, sensory analysis using triangular tests were performed from wines with and without the addition of the mentioned compounds. Four different concentrations of each odorant were added, as individual compounds and as mixtures. The additions were ranged from values close to the reference odour thresholds up to high level concentrations. The most identified aroma was sotolon, which is commonly associated to curry and coffee liqueur aromatic notes. Other oxidative compounds were easily detected by panellists, such as Y-decalactone (peach compote), Y-dodecalactone (ripe fruit). The mixtures of the odorants were most easily detected than the individual compounds. It should be noted that acetaldehyde and phenylacetaldehyde were rarely perceived and distinguished.

As Vitis vinifera varieties are susceptible to fungal diseases, numerous chemical treatments are generally required to ensure the quantity and quality of the harvest. However, in the context of sustainable viticulture, there are increasing societal request, political incitation, and winegrowers’ awareness to reduce the use of pesticides.

Solo attraverso un adeguato intervento di estirpazione e reimpianto dei vigneti è possibile preservare, adeguare e valorizzare il patrimonio viticolo e le produzioni che da esso derivano.
Il reimpianto dei vigneti è pertanto da intendersi come una normale pratica agricola, alla pari della rimonta di stalla in campo zootecnico, ma può assumere toni problematici quando, come si verifica adesso in Toscana per una serie di circostanze legate alla profonda trasfor­mazione della viticoltura avvenuta negli ultimi 30 anni, troppi impianti giungono contem­poraneamente a fine ciclo produttivo e devono essere rinnovati.