Evolution of polyphenolic compounds of Grenache wine obtained from grapes treated by Pulsed Electric Fields during aging in oak barrel

MARCOS MAZA; JAVIER RASO; IGNACIO ALVAREZ

Congreso; Macrowine 2018; 2018

Phenolic compounds play a very important role in the quality of red wine. These compounds are affected by oenological practices. The most important factor affecting the content of these compounds in wine is the winemaking process technology and their transformation during the wine aging process. The effect of pulsed electric field (PEF) on the improvement of the extraction of polyphenols during maceration-fermentation step of red winemaking has been extensively investigated. However, the evolution of the wines obtained from grapes treated by PEF during aging in oak barrel has been scarcely investigated. The objective of this research was to compare the evolution of polyphenols during oak barrel aging of Grenache wine obtained from untreated and PEF treated grapes. PEF treatments were conducted at a flow of 2.5T/h. Six tons of grapes were treated at 4 KV/cm. Maceration time for both control and PEF wine were 3 and 6 days.Evolution of anthocyanin content (AC), total polyphenols (TPI) and color intensity (CI) was similar for the control and PEF wines. While the TPI and CI were kept constant after 6 months of aging, the AC decreased.After 6 months of aging in oak barrel the AC, TPI and CI of the PEF wine obtained with 3 maceration days were similar to those for the control wine obtained with 6 maceration days. Therefore, the benefits observed at the end of the fermentation in terms of improving polyphenolic extraction caused by the application of a PEF treatment were maintained during aging in oak barrels.