Impact of prefermentative maceration on the phenolic and volatile compounds in Monastrell red wines

The effects of two prefermentation treatments (cold soak at 6–8 °C and cold soak at 0–2 °C with dry ice) and two different maceration times (4 and 8 days) in must and wine composition have been studied. Grapes from Vitis vinifera var. Monastrell were harvested at two maturation levels. Total phenolic, colour density, anthocyanins and fractioned anthocyanins, ionized anthocyanins, polymeric pigments colour, condensed tannins and aromatic compounds were estimated. The effects of temperature in the grape juice composition were determined with constant monitoring during the prefermentation step. Significant differences were found among the measured parameters in the grape juice and wine. Prefermentative maceration produces wines with higher phenolics compounds, anthocyanins, especially malvidin-3-glucoside, ionized and polymeric anthocyanins and aromatic compounds values compared to control wines. This increase is more significant when the prefermentation treatments are done with the use of dry ice and the must is produced from less mature grapes. The maceration time showed not to be significant during the process.