Two rums differing in their overall aroma profile and price level (rum A, high price; rum B, low price) were analyzed by means of the Sensomics approach. Application of aroma extract dilution analysis (AEDA) on a distillate of volatiles prepared from rum A revealed 40 aroma-active compounds in the flavor dilution (FD) factor range from 8 to 2048. The identification experiments indicated cis-whiskey lactone, vanillin, decanoic acid, and 2- and 3-methylbutanol with the highest FD factors. The AEDA of a distillate prepared from rum B showed only 26 aroma-active compounds in the same FD factor range. Among them, in particular, ethyl butanoate, 1,1-diethoxyethane, ethyl (S)-2-methylbutanoate, and decanoic acid appeared with the highest FD factors. Thirty-seven compounds having at least an FD factor ≥32 in one of the two rums were quantitated using stable isotope dilution assays or enzyme kits (2 compounds). The calculation of odor activity values (OAVs; ratio of concentration to respective odor threshold) indicated ethanol, vanillin, ethyl (S)-2-methylbutanoate, and (E)-β-damascenone with the highest OAVs in rum A, whereas ethanol, 2,3-butanedione, 3-methylbutanal, and ethyl butanoate revealed the highest OAVs in rum B. Most compounds were present in similar concentrations in both rums, but significant differences were determined for vanillin, cis-whiskey lactone, and 4-allyl-2-methoxyphenol (all higher in rum A) and 3-methylbutanal, 2,3-butanedione, and ethyl butanoate (all higher in rum B). Finally, the aromas of both rums were successfully simulated by a recombinate using reference odorants in the same concentrations as they naturally occurred in the spirits.
Keywords: aroma extract dilution analysis; aroma recombination; odor activity value; rum; stable isotope dilution assay.