EMERGENCE OF INORGANIC PHOSPHONATE RESIDUES IN GRAPEVINE PLANT PARTS, BERRIES AND WINES FROM SOURCES OTHER THAN FOLIAR SPRAYING

Phenolic, volatile and nitrogen compounds are key to wine quality. On one hand, phenolic compounds are related to wine color, mouthfeel properties, ageing potential. and are associated with beneficial health properties. On the other hand, wine aroma is influenced by hundreds of volatile compounds. Fermentative aromas represent, quantitatively, the wine aroma, and among these volatile compounds, esters, higher alcohols and acids are mainly responsible for the fermentation bouquet.

Lambrusco is a commercially successful sparkling red and rosé wine. With 13.06 million litres sold in 2021 was the second best-selling Italian wine after Chianti. According to National Catalogue of Vine Varieties there are thirteen Lambrusco Varieties with which to date are produced seven PDO wines. Among these, “Lambrusco Salamino di Santa Croce”, “Lambrusco Grasparossa di Castelvetro” and “Lambrusco di Sorbara” are the only ones that can be considered mono-varietal appellations, all located in Modena area. The PDOs contemplate the possibility of producing wines by secondary fermentation either in tank (Charmat method), or in bottle (Classico method). Sur lie is a third method commonly employed for Lambrusco, similar to the Classico method, from which differs for the absence of disgorgement.

Wine aroma is influenced by various factors, from agricultural practices in the vineyard to the enological choices made by winemakers throughout the vinification process. Spontaneous fermentations have a characteristically deeper complexity of aromas when compared to fermentations that have been inoculated with Saccharomyces (S.) cerevisiae because of the diversity of microflora naturally present on grape skins. Non-Saccharomyces yeast are being extensively studied for their ability to positively contribute to wine aroma and flavour. These yeasts are known to liberate more bound volatile compounds present in grape must than S. cerevisiae through the enzymatic action of β-glucosidases and β-lyases1.

Flow cytometry (FCM) is a powerful technique allowing the detection, characterization and quantification of microbial populations in different fields of application (medical environment, food industry, enology, etc.). Depending on the fluorescent markers and specific probes used, FCM provides information on the physiological state of the cell and allows the quantification of a microorganism of interest within a mixed population. For 15 years, the enological sector has shown growing interest in this technique, which is now used to determine the populations present (of interest or spoilage) and the physiological state of microorganisms at the different stages of winemaking.

Grape quality potential for wine production is strongly influenced by environmental parameters such as climate and agronomic factors such as rootstock. Several studies underline the effect of rootstock on vegetative growth of the scions [1] and on berry composition [2, 3] with an impact on wine quality. Rootstocks are promising agronomic tools for climate change adaptation and in most grape-growing regions the potential diversity of rootstocks is not fully used and only a few genotypes are planted. Little is known about the effect of rootstock genetic variability on the aromatic composition in wines; thus further investigations are needed.