Influenza del sito di coltivazione nella espressione aromatica del Moscato liquoroso di Pantelleria

In this study for the first time, eight natural stilbenes (trans-resveratrol, trans-piceid, cis-piceid, trans-astringin, trans-piceatannol, (+)-trans-s-viniferin, pallidol and hopeaphenol) isolated and purified from Vitis vinifera, were simultaneously separated and analysed within 5 mn by ultra high pressure liquid chromatography coupled with photodiode array detection.

Chemical and sensory changes occurring in red wine during ageing in oak barrique are due to the slow and gradual entrance of oxygen along with a release of ellagic tannin from the wood. Though oxygen can enter the cask through the bunghole, it is not clear the role of permeation through the wood staves as well as the amount of oxygen entering by permeation. The distribution of the released ellagic tannins in the wine ageing is also unknown. The oxygen passing through the bunghole may have a different wine ageing effect compared to the oxygen permeating through the wooden staves owing to the uneven ellagic tannin concentration throughout the wine.

Odours deemed harmful by the consumer and described as “stable”, “horse sweat” or “burnt plastic” can be found in wines. The responsible molecules are volatile phenols, produced by a spoilage yeast: brettanomyces bruxellensis. This species is particularly well adapted to the wine environment and can resists many stresses such as a high alcohol level, a low ph or high levels of SO2, more or less efficiently depending on the strain considered.

Oxygen is playing a major role in wine ageing and conservation. Many chemical oxidation reactions occur but they are difficult to follow due to their slow reaction times

In addition to aroma compounds also protein composition strongly influences the quality of wines. Proteins of wine derive mainly from the plant Vitis vinifera and may be influenced by abiotic stress as well as fermentation conditions or fining. Additionally, fungal infections can affect the protein content as well by introducing fungal proteins or affecting grape protein composition. An infection of the vine with the plant pathogenic fungus Botrytis (B.) cinerea was shown to cause a degradation of proteins in the resulting wine. Moreover, it influences the foaming properties in sparkling wine.