viernes, 26 de mayo de 2017

An Approach to Study the Interactions between Ellagitannins and Oxygen during Oak Wood Aging

Estudio sobre las interacciones entre los elagitaninos y el oxígeno durante el envejecimiento con madera de roble

Grupo Investigacion Polifenoles USAL & UVaMOX

During the aging of red wine in oak wood barrels, or in alternative aging systems, interactions between the compounds released from wood, the compounds of the wine and oxygen can take place. The main objective of the present work was to study oxygen ellagitannin interactions by monitoring their levels in three model systems all containing the same amounts of French oak chips and only differing in the oxygen content: total absence, only the oxygen released from the chips and air-saturated (model systems F, OW and OS, respectively). This study has highlighted the influence of oxygen in the ellagitannins evolution and the relevance of the oxygen trapped into the oak chips, reporting for the first time the kinetics of oxygen release to the model wine. Furthermore, the indirect contribution of oxygen to the ellagitannin disappearance by boosting auto-oxidative reactions has also been pointed out. Vescalgin seems to be the ellagitannin most affected by the initial oxygen levels.

This new paper has been published in the Journal of Agricultural and Food Chemistry, and  can be read here. One interesting and practical result is that it has been estimated that only 20-35% of the ellagitannin disappearance is directly related to the oxygen present in the model systems.