Varietal volatile patterns of Italian white wines

Among the macromolecules of enological interest in white wines, much attention has been paid to polysaccharides.

The current levels of greenhouse gas emissions are expecting to provoke a change on the environmental conditions which, among others, will include a rise of global mean surface temperature and an increment of atmospheric CO2 levels (IPCC, 2014), known as climate change. The response of grapevine (Vitis vinifera L.), one of the most important crops in Europe, from both a cultural and economic point of view, is not completely understood yet and the studies considering the interaction between factors are scarce. Besides, the potential variety of responses among somatic variants needs to be studied in order to be exploited in the avoidance of undesired traits linked to climate change (Carbonell‐Bejerano et al., 2015).

In Washington State, the majority of winegrape (Vitis vinifera) vineyards are planted to their own roots. This practice is possible due to the lack of established phylloxera populations, and is preferred due to the ease of retraining after damaging winter cold events. However, own-rooted V. vinifera is generally susceptible to most plant parasitic nematodes that attack grape. In Washington State, management of nematodes is dominated by preplant soil fumigation. One practice that may mitigate economic loss due to nematodes is the adoption of nematode-“resistant” rootstocks.

Copper in white wine can be associated with Cu(II) organic acids (Cu fraction I), Cu(I) thiol species (Cu fraction II), and Cu sulfides (Cu fraction III). The first two fractions are associated with the repression of reductive aromas in white wine, but these fractions gradually decrease in concentration during the normal bottle aging of wine. Although exposure of white wine to fluorescent light is known to induce the accumulation of volatile sulfur compounds, causing light-struck aroma, the influence on the loss of protective Cu fractions is uncertain. Riboflavin is known to be a critical initiator of photochemical reac-tions in wine, but the rate of its decay under short-term light exposure in different coloured bottles and for wine of different oxygen concentrations is not well understood.

Bioprotection, leveraging beneficial microorganisms, has emerged as a sustainable approach to modern winemaking, minimizing reliance on chemical preservatives like as sulfur dioxide (SO₂).