Background: Woody liquid flavourings extracted from different varieties of vine shoots and oak chips have been characterized by gas chromatography-mass spectrometry to compare the profile of compounds as potential contributors to the organoleptical properties of wine and spirits aged in oak barrels. Oak chips are frequently added to barrels to accelerate the ageing process, while vine shoots are produced in high amounts in wine-producing countries.
Results: The extracts were isolated by superheated liquid extraction (SHLE) after optimization of extraction variables. The SHLE protocol was performed using ethanol-water mixtures (pH 3) at 220 °C for 60 min. Compounds were identified using NIST databases, and the resulting profile was used as a dataset for qualitative and semi-quantitative comparison between extracts obtained from different varieties of vine shoots and oak chips.
Conclusion: Statistical analysis enabled demonstration of the similarity among extracts from vine shoots and oak wood, providing the first study on this subject. The special role of phenols and furanic derivatives has been described. This study is the first stage for characterization of vine shoots as a by-product with potential for use in the oenological field.
Keywords: oak barrels; oak chips; superheated liquid extraction; vine shoots; wine ageing; woody flavouring.
© 2013 Society of Chemical Industry.