The ultrasound (US) technology is an innovative technique that appeared in food production about ten years ago and nowadays it is a well established practice. However, in wine production, although some research has been carried out and there may be good premises, the practical application is still in an early stage.
The extraction of phenolic compounds is of fundamental importance in red grapes, particularly for those substances that affect the organoleptic properties of wine. Improvements on the extraction methods and conditions will lead to a better polymerization of tannins and anthocyanins, which gives a stronger and more stable colour.
On some white wines, the traditional technique of aging “sur lies” improves the quality in terms of stability and organoleptic properties.
The cavitation process induced by US leads to the breakage of the yeast cells walls, thus facilitates the leakage of the cell content after the fermentation.
The aim of this work is to study the effects produced by the US on crushed red grapes, seeds, lees, and young wines, in order to verify the possible speeding up of the extraction, the polymerization of the phenolic compounds, and the release of colloids from the yeast cells.
