Comparative study of the volatile substances and ellagitannins released to wine by barrels of Quercus pyrenaica, Quercus petraea and Quercus alba

Abstract

Aim: The aim of the study was to study the volatile substances and ellagitannins released to wine by barrels of Quercus pyrenaica (Spanish Oak) in comparison with barrels of Quercus petraea (French Oak) and Quercus alba (American Oak) as well as to determine their sensory impact. 

Materials and methods: For that purpose, a red wine of Cabernet Sauvignon from 2016 vintage was aged for 12 months in new barrels of these three oak species. A similar wine from the following vintage (2017) was aged in the same barrels for knowing how the use of the barrels affects their capacity to release volatile substances and its organoleptic impact. The volatile compounds released from the oak wood were analyzed by GC/MS according with the procedure described by Ibarz et al. (2006). The ellagitannins were analyzed by HPLC-DADESI-MS/MS according with the method reported by Navarro et al. (2017). Dscriptive sensory analysis was performed by a trained panel. This panel was made up of 16 students (10 males and 6 females) aged between 21 and 25, who had been training together for 3 years while studying sensory analysis as part of the enology degree.

Results and discussion: As expected, the wine aged in new Q. alba barrels presented the highest concentration in β-methyl-γ-octalactones and the lowest concentration of ellagitannins whereas the wine aged in new Q. petraea barrels presented much higher concentration of ellagitannins and much lower concentration of β-methyl-γ-octalactones. In contrast, the wine aged in new Q. pyrenaica barrels presented a concentration of ellagitannins even higher than the wine aged in new Q. petraea barrels and an intermediate concentration of β-methyl-γ-octalactones. No significant differences were found in vanillin and other volatile substances. Finally, ellagitannins and all volatile substances concentration decreased drastically the wines aged in all the one year used barrels. In general, the results of sensory analysis showed that wines aged in Q. pyrenaica barrels were somewhat less appreciated than those aged in barrels of Q, petraea but better than those aged in barrels of Q. alba.

Conclusions: The main conclusion is that Q. pyrenaica has a great interest as a source of wood for cooperage.

References

Ibarz M., Ferreira V., Hernández-Orte P., Loscos N. and Cacho J., 2006. Optimization and evaluation of a procedure for the gas chromatographic-mass spectrometric analysis of the aromas generated by fast acid hydrolysis of flavors precursors extracted from grapes. Journal of Chromatography A, 1116, 217–229. doi:10.1016/j.chroma.2006.03.020
Navarro M., Kontoudakis N., Canals J.M., García- Romero E., Gómez-Alonso S., Zamora F., and Hermosín-Gutíerrez I., 2017. Improved method for the extraction and chromatographic analysis on fused-core columns of occurring ellagitannins in oak-aged wine. Food Chemistry, 226, 23–31. doi:10.1016/j. foodchem.2017.01.043