Characterization of Key Odorants in Meehan’s Mint, <i>Meehania cordata</i>

Abstract

Thirty-five odorants from Meehan's mint, <i>Meehania cordata</i>, were identified using solvent-assisted flavor evaporation (SAFE) and aroma extract dilution analysis (AEDA). Twelve compounds with flavor dilution factors ≥16 were quantitated using stable isotope dilution assays (SIDA). Odor activity values (OAVs) and sensory experiments revealed (-)-(<i>E</i>)-pinocarvyl acetate as a key impact odorant contributing to the plant's unique woody and minty odor. Odor simulation experiments revealed a mixture of 10 compounds, including (2<i>E</i>,6<i>Z</i>)-nona-2,6-dienal (OAV 48000), β-ionone (OAV 33000), (<i>E</i>)-pinocarvyl acetate (OAV 8600), 1-octen-3-one (OAV 2800), and linalool (OAV 990), successfully mimicked the plant odor when combined in their natural concentrations. Three stereoisomers of pinocarvyl acetate were identified including (-)-(<i>E</i>)-, (+)-(<i>E</i>)-, and (-)-(<i>Z</i>)-isomers. The (<i>E</i>) to (<i>Z</i>)-ratio was determined as 95.5% (<i>E</i>) and 0.5% (<i>Z</i>). The enantiomeric ratio of (-)-(<i>E</i>)- to (+)-(<i>E</i>)- was determined as 96% (-)-(<i>E</i>)- and 4% (+)-(<i>E</i>)-pinocarvyl acetate. This study established the basis for future investigations aimed at determining the odorant variability of individual genotypes from natural populations of <i>M. cordata</i> and other members of the <i>Meehenia</i> genus.