Effects of ultrasound treatment on the phenolic fraction of a red wine aged on lees

Sonication is an emerging non-thermal technology useful to disrupt cell wall and increase polysaccharides release when applied to red wines aged on lees. At the same time, ultrasound treatment may cause changes in the composition of the wine, both in the phenolic and aromatic compounds. In this work, we evaluated the influence of ultrasounds treatment (frequency: 50 KHz; ultrasonic power: 200 W; acoustic energy density: 0.02 W cm−3) on polyphenols content and colour parameters of a red wine (Vitis vinifera L. cv. Tempranillo) by comparing different ultrasound treatments, lees dosages and yeast species. In general, total anthocyanin content and total polyphenol index decreased in wines treated with ultrasounds and high lees dosage, and hue increased as a result of oxidation associated with the sonication process. Regarding the effect of the yeast species, anthocyanins loss was smaller in Saccharomyces cerevisiae and Schizosaccharomyces pombe.