Decoding the combinatorial aroma code of a commercial Cognac by application of the sensomics concept and first insights into differences from a German brandy.

Abstract

In the volatile fraction isolated from a commercial Cognac by means of extraction/SAFE distillation, 39 odor-active areas were detected, among which (E)-β-damascenone showed the highest flavor dilution (FD) factor of 2048 followed by 2- and 3-methylbutanol, (S)-2-methylbutanol, 1,1-diethoxyethane, ethyl methylpropanoate, and ethyl (S)-2-methylbutanoate, as well as 4-hydroxy-3-methoxybenzaldehyde (vanilla-like) and 2-phenylethanol. The quantitation of 37 odorants by stable isotope dilution assays and a calculation of odor activity values (OAV; ratio of concentration to odor threshold) resulted in 34 odorants with OAVs > 1. Among them (E)-β-damascenone, methylpropanal, ethyl (S)-2-methylbutanoate, ethyl methylpropanoate, and ethyl 3-methylbutanoate together with ethanol were established as key contributors to the Cognac aroma. Finally, the overall aroma of the Cognac could be mimicked by an aroma recombinate consisting of these 34 key odorants on the basis of their natural concentrations in the Cognac using an odorless matrix to simulate the influence of the nonvolatile constituents. A comparison of the FD factors of the key odorants identified in a German brandy to those in the Cognac suggested the pair (E)-β-damascenone and ethyl pentanoate as indicators to differentiate various Cognacs from German, French, and Spanish brandies. This was confirmed by calculating a ratio of the concentrations of (E)-β-damascenone to ethyl pentanoate for 12 Cognacs and 7 brandies from Germany and 2 from France and Spain, respectively.