The application of high power ultrasounds for improving the phenolic extraction and color from grape-derived products
High power ultrasound is a powerful, non-thermal technique that can be used to increase the extraction of phenolic compounds from grapes. The mechanical activity of the ultrasound breaks the cell wall by the cavitation shear forces and facilitates the transfer of phenolic compounds from the cell into the must. It is of especial interest in the processing of red grapes due to the economic resources that companies must invest for the extraction of the phenolic compounds responsible for must and wine color and mouthfeel. In this work, high power ultrasounds were used during the processing of red grapes. Crushed grapes were treated with ultrasound, and three different lengths of skin maceration period (2, 3 or 7 days) were applied and the results were compared with a control, where grapes were not subjected to any treatment and were skin macerated for 7 days. Grapes with two different maturation levels were tested. The chromatic characteristics and the phenolic compound composition of the corresponding wines were studied. The wines obtained from ultrasound treated grapes presented differences from control wine, especially regarding color, total phenol content and tannin content, the wines obtained with two to three days of maceration time presenting similar chromatic characteristics to those of control musts and wines with 7 days of maceration time.
Gómez-Plaza, E., Osete-Alcaraz, A., Jurado, R., Iniesta, J.A. and Bautista-Ortín, A.B. (2020). The application of high power ultrasounds for improving the phenolic extraction and color from grape-derived products. Acta Hortic. 1274, 1-8
grape, wine, ultrasound, color, phenolic compounds