Storage of a Touriga Nacional red wine in contact with Juglans regia L. and Quercus petraea L. wood chip species: comparative influence on phenolic and sensory characteristics

Several previous research works have demonstrated the value of different wood species in oenology. However, the use of walnut wood from Juglans regia L. species was not totally previously considered, for wine aging. Thus, this work focuses on the comparative evolution over a period of 30 storage days of phenolic composition and sensory characteristics of a Touriga Nacional red wine stored in contact with toasted chips from walnut ( Juglans regia L.) and oak ( Quercus petraea L.) wood chip species. In addition, in this study a previous global phenolic analysis was also carried out for both wood chip species by the use of model wine solutions. The results obtained in our research demonstrated an absence of a clear differentiation between the two wood chip species studied. However, taking into account the impact of these two wood chip species on wine phenolic composition, the results also showed that the wine stored in contact with Quercus petraea L. chips exhibited in general the highest values for the majority of the global phenolic parameters analyzed. Wine stored in contact with Juglans regia L. chips showed significantly higher values for oligomeric fraction of proanthocyanidins. However, from a sensory point of view, a tendency for lower scores for the majority of sensory descriptors considered in this study was obtained for this wine compared to the same wine but stored in contact with Quercus petraea L. chips, as well as the control wine. The outcomes of this work improved the knowledge of the impact of a no conventional wood species ( Juglans regia L.) in oenology.