Sonication of white grapes vs prefermentative skin maceration. Effect on aroma compounds and sensory properties in Airén and Macabeo white wines

The use of high-power ultrasound (US) has been extensively studied in red winemaking, and differences regarding the variety being treated have been reported. In white wines, US has been proposed as an alternative to prefermentative cold maceration (PM), but its performance across different varieties remains unexplored. This study evaluated the physicochemical parameters, polysaccharide profile, volatile compounds, and sensory attributes of two low-aromatic varieties (Macabeo and Airén), vinified either by direct pressing (C), or with PM (4 h) or US prior pressing. Clear varietal differences were observed. Macabeo wines produced with US treated grapes showed similar outcomes to PM vinification, although the processing time is reduced by eight hours. Both treatments enhanced terpenes and norisoprenoids concentration in musts and wines, with US treatment exerting the strongest effect, and wines from US treated grapes wines also exhibiting higher ester, acetate, and lactone concentration, which is consistent with the fruity-floral sensory notes detected in the wines In Airén, a slight browning and minor aromatic improvements were observed, although US treatment increased mouthfeel structure, and led to a greater astringency, body, and aftertaste intensity.