High-resolution aerial thermography for water stress estimation in grapevines

The gustatory balance of dry wines is centered on three flavors, sourness, bitterness and sweetness. Even if certain compounds were already identified as contributing to sweetness, some taste modifications remain largely unexplained1,2. Some empirical observations combined with sensory analyzes have shown that an increase of wine sweetness occurs during post-fermentation maceration³. This step is a key stage of red winemaking during which the juice is left in contact with the marc, that contains the solid parts of the grape (seeds, skins and sometimes stems). This work aimed to identify a new taste-active compound that contributes to this gain of sweetness.

La presente relazione mira ad individuare il ruolo del paesaggio nella determinazione delle preferenze della domanda, in modo da far emergere i fattori immateriali che definiscono il valore territoriale dei vini tipici su cui far leva per le strategie di marketing. L’analisi ha riguardato vini tipici del Veneto e coinvolto soggetti non provenienti da questa Regione. Ne è emerso l’effetto amplificativo dell’immagine del paesaggio sulla qualità percepita.

Wine grapes have the ability to accumulate high amounts of hexoses (glucose and fructose), which is considered one of the main processes occurring during the ripening stage. Sugar accumulation dynamics respond to genetic, environmental and vineyard management factors, with a changing climate leading to advanced and faster sugar accumulation worldwide. Research on mitigation techniques to this phenomenon is ongoing, with the largest focus being vineyard techniques to delay sugar accumulation. Breeding represents another powerful tool to address the issue of high sugar concentration at harvest, since historical trends of selecting best sugar-accumulators may be inverted to breed varieties that accumulate diminished concentrations of hexoses while maintaining optimal acidity, color, mouthfeel and aroma compounds.

The presence of undesirable compounds in wines, such as ota, biogenic amines and pesticides residues, affects wine quality and can cause health problems for the consumer. Additionally, an excess of tannins can produce an undesirable increase in the astringency and bitterness of the wine, so tannins are also a target for reduction. The main tool that a winemaker has to reduce their content in the wine is fining. However, some of the fining agents commonly used in the winery can cause allergies or even increase the protein content in the wine, increasing the turbidity.

Powdery mildew, caused by Erysiphe necator, is a widespread disease that causes high economical losses in viticulture. The main strategy to control the disease is the recurrent application of sulphur based phytochemical compounds. However, in order to reduce their accumulation in the environment and promote the sustainability of the sector, the European Commission has applied restrictions to the number of pesticide treatments and the maximum quantity of fungicides to be applied in viticulture. Seaweeds, in particular macroalgae, are marine resources rich in sulphated polysaccharides with bio-protective potential for the plant, representing an environmentally-friendly alternative approach for sustainable wine production.