Assessment of the impact of the addition of antimicrobial plant extracts to wine: Volatile and phenolic composition

[Background]: Antimicrobial plant phenolic-rich extracts have been proposed as alternative to sulfites in the control of the malolactic fermentation (MLF) during winemaking. This addition may affect wine organoleptic properties. In this paper, we have investigated the changes in wine volatile and phenolic composition, after MLF, of a red wine treated with antimicrobial extracts from eucalyptus leaves and almond skins. [Results]: Although addition of both extracts led to statistically significant changes (P < 0.05) in the concentration of several esters, alcohols, C13 nor-isoprenoids and volatile phenols, only few of these volatile compounds showed values of odour activity>1 aroma unit; that is to say, whose concentrations were higher than their corresponding odour thresholds. With regard to phenolic compounds, the addition of both extracts did not significantly modify the content of anthocyanins, which predicts minor changes in wine colour. However, the content of non-anthocyanin phenolics was significantly higher in the wines treated with antimicrobial extracts, especially for flavonols, being the dose-over-taste factor for these wines significantly higher. Finally, principal component analysis showed that wines were mainly differentiated on the basis of whether MLF was conducted or not, and its method of performance (inoculated/spontaneous). [Conclusion]: Addition of antimicrobial extracts leads to some compositional changes in the wine, whose relevance needs to be addressed in future experiments, including wine sensorial analysis. © 2013 Society of Chemical Industry.

This work has been funded by the Spanish Ministry for Science and Innovation (AGL2006-04514, AGL2009-13361-C02-00, PRIPIBAR-2011-1358, and CSD2007-00063 Consolider Ingenio 2010 FUN-C-FOOD Projects) and the Comunidad de Madrid (ALIBIRD P2009/AGR-1469 Project). A.G.R. and J.J.R.B. are the recipients of fellowships from the DANONE Institute and the JAE-Doc Program (CSIC), respectively.

Peer Reviewed