Characterization of the key aroma compounds in bartlett pear brandies by means of the sensomics concept

The aroma compounds in two commercial Bartlett pear brandies clearly differing in their overall aroma profiles were detected in the volatile fractions by the aroma extract dilution analysis. In brandy A eliciting the more intense pear-like, fruity aroma, ethyl (S)-2-methylbutanoate, (E)-β-damascenone, 1,1-diethoxyethane, 2- and 3-methylbutanol, (S)-2- and 3-methylbutanoic acid, and 2-phenylethanol were found with the highest Flavor Dilution (FD) factors. In brandy B judged to have a weaker overall aroma, also (E)-β-damascenone, ethyl (S)-2-methylbutanoate, and 2-phenylethanol revealed high FD factors, while many odorants showed lower FD factors. Fourty-four odor-active compounds were quantitated by stable isotope dilution assays, and the odor activity values (OAVs; ratio of concentrations to odor thresholds) confirmed (E)-β-damascenone and ethyl (S)-2-methylbutanoate as important aroma compounds in brandy A, while the OAVs of most odorants were much lower in brandy B. By aroma recombination studies, the aromas of both brandies could be matched using reference odorants in the same concentrations as they occurred in the spirits. In 15 commercial Bartlett pear brandies ethyl (E,Z)-2,4-decadienoate and (E,E)-2,4-decadienoate eliciting a pear-like aroma showed a reasonable correlation of their concentrations with the overall aroma quality.