Characterization of Odorants in Southern Mountain Mint, <i>Pycnanthemum pycnanthemoides</i>

Abstract

Southern mountain mint, <i>Pycnanthemum pycnanthemoides</i> (Leavenw.) Fernald, is a mountain mint species endemic to the southeastern United States. The odorants responsible for the plant's odor have not been previously characterized. In this study, 28 odorants were identified in a high-vacuum distillate of <i>P. pycnanthemoides</i> employing gas chromatography-olfactometry and gas chromatography-mass spectrometry. Flavor dilution (FD) factors were determined by aroma extract dilution analysis. Ten odorants with FD factors ≥16 were quantitated by stable isotope dilution assays, odor activity values (OAVs) were calculated, and the stereochemistry of chiral odorants was determined. Odorants with OAV ≥1 included β-ionone (floral, violet; OAV 310), piperitenone (mint; OAV 100), piperitone (mint; OAV 87), linalool (floral, citrus; OAV 45), myrcene (terpeny; OAV 35), (<i>R</i>)-(+)-pulegone (mint, medicinal; OAV 18), (2<i>S</i>,5<i>R</i>)-(-)-menthone (mint, fresh; OAV 6.6), and 1,8-cineole (eucalyptus; OAV 4.0). An odor simulation model based on the quantitative analysis was a close match to the sensory attributes of an aqueous infusion of dried <i>P. pycnanthemoides</i>. The study's results establish insights into the complex odor profile of <i>P. pycnanthemoides</i> and provide a foundation for future studies on the odor variability within <i>P. pycnanthemoides</i> and other species of the <i>Pycnanthemum</i> genus.