Pycnanthemum incanum, a species of wild mountain mint endemic to North America, has a pungent mint-like odor that has not been fully characterized. Due in part to its high terpene content, P. incanum has broad potential for health-promoting, cosmetic, culinary, and food flavoring applications. Therefore, odorants of P. incanum were identified by coupling solvent assisted flavor evaporation (SAFE) and aroma extract dilution analysis (AEDA), which afforded 24 odorants including 14 odorants with flavor dilution (FD) factors ≥4. Selected odorants, including those with FD factors ≥16, were quantitated by stable isotope dilution assays (SIDAs), and odor activity values (OAVs) were determined. The odorants with the highest OAVs included β-ionone (floral, violet; OAV 300), myrcene (terpeny, OAV 120), linalool (floral, citrus; OAV 79), and pulegone (mint, medicinal; OAV 58). An odor-simulation model based on the quantitation closely matched the sensory attributes of the original P. incanum plant material. In addition, enantiomeric proportions of chiral odorants in P. incanum were determined by chiral chromatography.

Chardonnay marc, consisting of grape skins, seeds, and stems, is a coproduct of grape juice production for Chardonnay wine making. The discovery that marc contains a rich source of health-promoting molecules has led to its growing popularity as a flavorful healthy food ingredient. However, the odorants responsible for its pleasant fruity aroma remain unknown. In this study, 35 odorants were identified in Chardonnay marc skins using solvent-assisted flavor evaporation (SAFE) and aroma extract dilution analysis (AEDA). Thirteen odorants were quantitated employing stable isotope dilution assays (SIDAs), and odor activity values (OAVs) were calculated. Odorants with OAVs >1 included 3-methylnonane-2,4-dione (hay, OAV 5800), β-ionone (floral, violets, OAV 2900), (2E,4E)-nona-2,4-dienal (fatty, OAV 1200), β-damascenone (cooked apple, OAV 370), hexanal (green, OAV 260), oct-1-en-3-one (mushroom, OAV 200), linalool (floral, citrus, OAV 61), (2E,4E)-deca-2,4-dienal (fatty, OAV 60), 2phenylethanol (floral, rose, OAV 16), 3-(methylsulfanyl)propanal (potato, OAV 3.7), HDMF (caramel, OAV 2.0), and ethyl octanoate (fruity, OAV 1.1). An odor simulation model prepared using odorants with OAVs >1 sensorially matched the aroma of the Chardonnay marc skins. This investigation establishes a foundation for future studies aimed at determining the contribution of individual Chardonnay marc components (skins, seeds, and stems) to the aroma profile of Chardonnay marc powder and aiding producers in delivering optimal and consistent aroma profiles by region.

Southern mountain mint, Pycnanthemum pycnanthemoides (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 P. pycnanthemoides 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), (R)-(+)-pulegone (mint, medicinal; OAV 18), (2S,5R)-(−)-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 P. pycnanthemoides. The study’s results establish insights into the complex odor profile of P. pycnanthemoides and provide a foundation for future studies on the odor variability within P. pycnanthemoides and other species of the Pycnanthemum genus.

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White leaf mountain mint, Pycnanthemum albescens Torrey & A. Gray, also known as white mountain mint or white leaved mountain mint, is a species endemic in the American Southeast. In the present study, 24 odorants were identified using solvent-assisted flavor evaporation, aroma extract dilution analysis, and gas chromatography–mass spectrometry. Nine odorants with flavor dilution factors ≥16 were quantitated by stable isotope dilution assays, and odor activity values (OAVs) were calculated. In addition, the enantiomeric proportions of several chiral odorants were determined by chiral chromatography. Odorants with OAV ≥1 included 1,8-cineole (eucalyptus; OAV 9200), myrcene (terpeny; OAV 1400), linalool (floral, citrus; OAV 370), β-ionone (floral, violet; OAV 64), borneol (earthy; OAV 55), bornyl acetate (earthy, fruity; OAV 19), and eugenol (clove; OAV 3.1). Odor simulation experiments revealed that a mixture of the odorants with OAV ≥1 successfully mimicked the odor of an aqueous extract of the plant when combined in their natural concentrations. This study lays the groundwork for future studies aimed at determining the natural aroma variation within different populations of P. albescens and aids in the future development of selections and hybrids with targeted aroma profiles of commercial interest.

Conradina verticillata Jennison, commonly known as Cumberland Rosemary, is an endangered plant from the mint family Lamiaceae. This species is a flowering, perennial shrub found only in a few counties in Kentucky and Tennessee. Although the odorants responsible for Cumberland Rosemary's unique aroma have not been previously characterized, in this study, a total of 32 odorants were identified using gas chromatography−olfactometry (GC−O) and gas chromatography−mass spectrometry (GC− MS). Odorant flavor dilution (FD) factors were determined through the application of aroma extract dilution analysis (AEDA). Seven odorants with FD factors ≥64 were quantitated by stable isotope dilution assays (SIDA), and their odor activity values (OAV) were calculated. Odorants with OAV ≥1 included 1-octen-3-one (earthy-mushroom, OAV 2,900,000), 1,8-cineole (eucalyptus, OAV 510,000), borneol (earthy, OAV 10,000), bornyl acetate (earthy-fruity, OAV 3,700), eugenol (spicy, OAV 2,200), menthone (mint, OAV 130), and camphor (herbaceous, OAV 72). Sensory analysis revealed that an odor simulation model based on the quantitative data was a close match to the aroma of the plant. Omission studies determined that 1-octen-3-one, 1,8-cineole, and eugenol were the key odorants critical to Cumberland Rosemary's distinct aroma profile. The stereochemistry of selected odorants was also determined by chiral chromatography. This study established a foundation for future experiments on the aroma chemistry of C. verticillata and the other six members of the Conradina genus.

Thirty-five odorants from Meehan's mint, Meehania cordata, 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 (−)-(E)-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 (2E,6Z)-nona-2,6-dienal (OAV 48000), β-ionone (OAV 33000), (E)-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 (−)-(E)-, (+)-(E)-, and (−)-(Z)-isomers. The (E) to (Z)-ratio was determined as 95.5% (E) and 0.5% (Z). The enantiomeric ratio of (−)-(E)-to (+)-(E)-was determined as 96% (−)-(E)-and 4% (+)-(E)-pinocarvyl acetate. This study established the basis for future investigations aimed at determining the odorant variability of individual genotypes from natural populations of M. cordata and other members of the Meehenia genus.

Propolis is a fragrant material produced by bees and is commonly used as an ingredient in food, beverage, and consumer goods industries. Application of a comparative aroma extract dilution analysis (cAEDA) to volatiles isolated from propolis over three consecutive years afforded 48 odorants with flavor dilution (FD) factors ≥ 4, including 21 compounds not previously reported in propolis. Despite differences in FD factors of some compounds, the overall temporal variation in the odorants was low. Compounds with FD ≥ 64 were quantitated by stable isotope dilution assays (SIDAs), and odor activity values (OAVs) were calculated. A total of 22 compounds showed OAVs ≥ 1, including (E)-isoeugenol (clove; OAV 3700), linalool (floral; OAV 380), butanoic acid (sweaty, rancid; OAV 370), and 3-phenylpropanoic acid (floral; OAV 270). An odor reconstitution model prepared from deodorized beeswax and the 22 odorants in their natural concentrations closely matched the olfactory profile of authentic propolis. The results of this study will help to establish a basis for future research on the variability of propolis sourced from different geographical locations, produced by different bee species, and collected from different botanical sources, all of which are largely unknown.