Functional Redundancy in Bat Microbial Assemblage in the Presence of the White Nose Pathogen.

Understanding how host-associated microbial assemblages respond to pathogen invasion has implications for host health. Until recently, most investigations have focused on understanding the taxonomic composition of these assemblages. However, recent studies have suggested that microbial assemblage taxonomic composition is decoupled from its function, with assemblages being taxonomically varied but functionally constrained. The objective of this investigation was to understand how the Tri-colored bat, Perimyotis subflavus cutaneous microbial assemblage responds to fungal pathogen invasion within a functional context. We hypothesized that at a broad scale (e.g., KEGG pathways), there will be no difference in the functional assemblages between the white nose pathogen, Pseudogymnoascus destructans, positive and negative bats; and this pattern will be driven by the functional redundancy of bacterial taxa. At finer scales (e.g., gene models), we postulate differences in function attributed to interactions between bacteria and P. destructans, resulting in the production of antifungal metabolites. To test this, we used a combination of shotgun metagenomic and amplicon sequencing to characterize the bat cutaneous microbial assemblage in the presence/absence of P. destructans. Results showed that while there was a shift in taxonomic assemblage composition between P. destructans positive and negative bats, there was little overall difference in microbial function. Functional redundancy across bacterial taxa was clear at a broad-scale; however, both redundancy and variation in bacterial capability related to defense against pathogens was evident at finer scales. While functionality of the microbial assemblage was largely conserved in relation to P. destructans, the roles of particular functional pathways in resistance to fungal pathogens require further attention.

Modulation of Brain-Derived Neurotrophic Factor (BDNF) Signaling Pathway by Culinary Sage (Salvia officinalis L.).

Culinary sage (Salvia officinalis L.) is a common spice plant in the mint family (Lamiaceae) well known for its distinctive culinary and traditional medicinal uses. Sage tea has been used traditionally as a brain-enhancing tonic and extracts from sage have been reported to have both cognitive and memory enhancing effects. Brain-derived neurotrophic factor (BDNF) is an endogenous signaling molecule involved in cognition and memory function. In this study, activity-guided fractionation employing preparative reverse-phase high performance liquid chromatography (RP-HPLC) of culinary sage extracts led to the discovery of benzyl 6-O-ß-D-apiofuranosyl-ß-D-glucoside (B6AG) as a natural product that upregulates transcription of neurotrophic factors in C6 glioma cells. Purified B6AG showed a moderate dose response, with upregulation of BDNF and with EC50 at 6.46 µM. To better understand the natural variation in culinary sage, B6AG was quantitated in the leaves of several commercial varieties by liquid chromatography-mass spectrometry (LC-MS). The level of B6AG in dried culinary sage was found to range from 334 ± 14 to 698 ± 65 µg/g. This study provided a foundation for future investigations, including quantitative inquiries on the distribution of B6AG within the different plant organs, explorations in optimizing post-harvest practices, and aid in the development of sage varieties with elevated levels of B6AG.

Chemistry and biological activity of steroidal glycosides from the Lilium genus.

Plants from the Lilium genus are a rich source of chemical diversity and have been the focus of natural products chemistry research for over twenty years. This manuscript provides a background on the chemistry and nomenclature of steroidal glycosides, as well as a chronological account of the progress between the years of 1989 up to 2014, with respect to their isolation and characterization from the genus. This review highlights the traditional use of lilies, as both food and medicine, and brings attention to the fact that the genus contains 110 accepted species of which the chemistry and biological activity of the steroidal glycosides from the majority have not been investigated to date. Thus, making the genus a relatively untapped resource that contains a potential treasure trove of chemical diversity waiting to be discovered.

Saltiness Enhancement through the Synergism of Pyroglutamyl Peptides and Organic Acids.

Excess sodium intake poses health risks, prompting the exploration of taste modulators to reduce the salt content in low-sodium foods yet maintain salty perception. Previous research found a subthreshold synergistic effect among pyroglutamyl dipeptides on saltiness enhancement. This study investigated the subthreshold synergistic effect of pyroglutamyl peptides and organic acids on saltiness perception. Pyroglutamyl dipeptides (pgluE, pgluV), pyroglutamyl tripeptides (pgluVL and pgluVC), and organic acids (malic acid and succinic acid) were explored in a model system and subsequently in commercial brown onion sauce. The detection thresholds of peptides (pgluE, pgluV, pgluVL, and pgluVC) were determined to be 646, 77, 273, and 221 µmol/L, respectively, and the subthreshold synergistic effect of the pyroglutamyl tripeptides and organic acids was determined using the isobologram method. One of the eight combinations of pyroglutamyl tripeptides with pyroglutamyl dipeptide (pgluV) showed a subthreshold synergistic effect, whereas four combinations of tripeptides with malic acid and one combination with succinic acid exhibited a subthreshold synergistic effect. In commercial brown onion sauce, 25 and 30% salt reductions were achieved using the combinations of the tripeptides with malic acid and succinic acid, respectively. This research lays the foundation for future investigations into the potential combinations of pyroglutamyl peptides and organic acids for saltiness enhancement in low-sodium foods.

Characterization of Odorants in a Commercial Culinary Sage (Salvia officinalis L.) and Several Cultivars.

Culinary sage, Salvia officinalis L., is a popular spice plant commonly used throughout the world. In this study, 35 odorants were identified in dried sage via solvent-assisted flavor evaporation (SAFE) and aroma extract dilution analysis (AEDA), including 9 that were identified in sage for the first time. Fifteen odorants were quantitated by stable isotope dilution analysis (SIDA), and their odor activity values (OAVs) were determined. Odorants with high OAVs included (2E,6Z)-nona-2,6-dienal, 1,8-cineole, and ß-myrcene. A formulated aroma simulation model closely matched the aroma profile of an aqueous infusion of dried sage. Enantiomeric proportions of selected odorants were determined by chiral gas chromatography. Furthermore, 6 different sage cultivars were grown in the greenhouse, dried under the same conditions, and analyzed. Sensory analysis determined that all cultivars were dominated by an herbaceous sensory attribute and had varying intensities of eucalyptus, mint, clove, pine, green, earthy, floral, and citrus notes. Cultivars with varying intensities of herbaceous, eucalyptus, pine, and green sensory notes correlated with the OAVs of α-thujone/ß-thujone, 1,8-cineole, α-pinene, and (2E,6Z)-nona-2,6-dienal, respectively. This study identified the odorants driving the sensory profiles of different sage cultivars and serves as a foundation for future studies on the aroma chemistry of culinary sage.

Mycelium: A Nutrient-Dense Food To Help Address World Hunger, Promote Health, and Support a Regenerative Food System.

There is a need for transformational innovation within the existing food system to achieve United Nations Sustainable Development Goal 2 of ending hunger within a sustainable agricultural system by 2030. Mycelium, the vegetative growth form of filamentous fungi, may represent a convergence of several features crucial for the development of food products that are nutritious, desirable, scalable, affordable, and environmentally sustainable. Mycelium has gained interest as technology advances demonstrate its ability to provide scalable biomass for food production delivering good flavor and quality protein, fiber, and essential micronutrients urgently needed to improve public health. We review the potential of mycelium as an environmentally sustainable food to address malnutrition and undernutrition, driven by food insecurity and caloric dense diets with less than optimal macro- and micronutrient density.

Contribution of Key Odorants from Skins, Seeds, and Stems to the Aroma of Chardonnay Marc: A Valuable Coproduct of the Wine Industry.

Chardonnay marc, a co-product of the wine making industry, has recently garnered attention due to its health-promoting properties and is growing in popularity as a potential healthy and flavorful food ingredient. While previous studies have characterized the odorants in marc skins and identified the key odorants in marc seeds, the key odorants in the skins and stems and the contribution of each component to the whole marc aroma remains unknown. In this study, 27 odorants were identified in marc stems using solvent-assisted flavor evaporation and aroma extract dilution analysis. Four odorants were quantitated employing stable isotope dilution assays, and odor activity values (OAVs) were calculated. An odor simulation model prepared using odorants with OAVs > 1 sensorially matched the aroma of the marc stems. Omission studies showed that 3-methylnonane-2,4-dione, ethyl octanoate, oct-1-en-3-one, (2E,4E)-deca-2,4-dienal, (2E,4E)-nona-2,4-dienal, ß-ionone, linalool, hexanal, HDMF, and 3-(methylsulfonyl)propanal were the key odorants in marc skins, while hexanal and 3-methylnonane-2,4-dione were the key odorants in marc stems. Mass balance studies suggested that the skins were the main contributor to the hay, floral, and fruity attributes of the whole marc, the seeds contributed mostly to the fatty attribute, and the stems had a minor contribution.

Characterization of Key Odorants in Chardonnay Seeds.

Chardonnay marc, a co-product of the winemaking industry, is a combination of skins, seeds, and stems remaining after the juice is pressed from the grapes. This co-product amounts to over half a million tons per year. Recently, Chardonnay marc has been emerging as a healthy and flavorful food ingredient. The aroma contribution of the seeds to the overall aroma of Chardonnay marc remains unknown. In the present study, 43 odorants were identified in Chardonnay seeds employing aroma extract dilution analysis (AEDA) performed on a distillate prepared by solvent extraction and solvent-assisted flavor evaporation (SAFE) distillation. Of those, 6 odorants with a flavor dilution (FD) factor ≥64 were quantitated using stable isotope dilution assays (SIDAs). The odorants included (2E,4E)-deca-2,4-dienal (fatty, OAV 8028), 3-methylnonane-2,4-dione (hay, OAV 4772), (2E,4E)-nona-2,4-dienal (fatty, OAV 1750), hexanal (green, OAV 1481), linalool (floral, citrus, OAV 28), and 2-phenylethanol (floral, rose, OAV 2). An aroma simulation model was prepared based on the quantitative data, and its aroma was a close match to the Chardonnay seed powder. Omission studies applied to the aroma simulation model showed that hexanal and 3-methylnonane-2,4-dione were the key odorants driving the aroma profile. This research established a foundation for future studies aimed at optimizing the flavor of Chardonnay marc powder.

Characterization of Odorants in Southern Mountain Mint, Pycnanthemum pycnanthemoides.

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 ß-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.

Characterization of Odorants in White Leaf Mountain Mint, Pycnanthemum albescens.

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), ß-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.

Characterization of Odorants in Loomis' Mountain Mint, Pycnanthemum loomisii.

Loomis' mountain mint, Pycnanthemum loomisii Nuttall, is a species of mint native to the American Southeast. In the present study, 38 odorants were identified employing aroma extract dilution analysis (AEDA) performed on a distillate prepared by solvent extraction and solvent-assisted flavor evaporation (SAFE) distillation of dried P. loomisii. Seven odorants with flavor dilution (FD) factors ≥16 were quantitated using stable isotope dilution assays (SIDA), and their odor activity values (OAV) were calculated. In addition, the stereochemical composition of chiral odorants was also determined by chiral chromatography. Odor simulation experiments demonstrated that when 1,8-cineole (eucalyptus; OAV 6400), linalool (floral, citrus; OAV 120), ß-ionone (floral, violet; OAV 86), borneol (earthy; OAV 56), and eugenol (clove; OAV 2.5) were combined in their natural concentrations, the model successfully mimicked the plant's aroma. The results of this investigation provide a foundation for additional investigations into the natural variation in aroma chemistry of different selections of P. loomisii and other members of the Pycnanthemum genus.

Characterization of Key Odorants in Cumberland Rosemary, Conradina verticillata.

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.

Analysis of Derivatized Wall Teichoic Acids Confirms that a Mutation in Phage-Resistant Listeria monocytogenes Impacts Rhamnose Decoration.

Listeria monocytogenes is a Gram-positive foodborne pathogen that causes listeriosis, an illness that may result in serious health consequences or death. Wall teichoic acids (WTAs) are external cell wall glycopolymers that play many biological roles. Here, the WTA composition was determined for several phage-resistant mutant strains of L. monocytogenes. The strains included wild-type (WT) L. monocytogenes 10403S, and three phage-resistant mutant strains derived from 10403S, consisting of two well-characterized strains and one with unknown impact on cell physiology. Several WTA monomers were prepared from WT 10403S, as analytical standards. The WTA monomer fraction was then isolated from the mutant strains and the corresponding per-trimethylsilylated derivatives were analyzed by gas chromatography-flame ionization detection. WTA monomer, GlcNAc-Rha-Rbo, was detected in 10403S, and not detected in the phage-resistant strains known to lack rhamnose and N-acetylglucosamine; although the expected monomers GlcNAc-Rbo and Rha-Rbo were detected, respectively. GlcNAc-Rha-Rbo was also detected in strain UTK P1-0001, which is known to impact phage adsorption through an undetermined mechanism, albeit at a lower intensity than the WT 10403S, which is consistent with partial loss of function through truncation in RmlC protein. WTA monomers were also detected in an unpurified cell pellet, demonstrating that the method employed in this study can be used to rapidly screen L. monocytogenes without laborious WTA purification. This study lays the groundwork for future studies on WTA compositional analysis to support genomic data, and serves as a foundation for the development of new rapid methods for WTA compositional analysis.

Chardonnay Marc as a New Model for Upcycled Co-products in the Food Industry: Concentration of Diverse Natural Products Chemistry for Consumer Health and Sensory Benefits.

Research continues to provide compelling insights into potential health benefits associated with diets rich in plant-based natural products (PBNPs). Coupled with evidence from dietary intervention trials, dietary recommendations increasingly include higher intakes of PBNPs. In addition to health benefits, PBNPs can drive flavor and sensory perceptions in foods and beverages. Chardonnay marc (pomace) is a byproduct of winemaking obtained after fruit pressing that has not undergone fermentation. Recent research has revealed that PBNP diversity within Chardonnay marc has potential relevance to human health and desirable sensory attributes in food and beverage products. This review explores the potential of Chardonnay marc as a valuable new PBNP ingredient in the food system by combining health, sensory, and environmental sustainability benefits that serves as a model for development of future ingredients within a sustainable circular bioeconomy. This includes a discussion on the potential role of computational methods, including artificial intelligence (AI), in accelerating research and development required to discover and commercialize this new source of PBNPs.

Taste-Active Dipeptides from Hydrolyzed Mushroom Protein Enhance Saltiness.

An activity-guided fractionation approach applied to thermally treated, enzymatically hydrolyzed mushroom, Agaricus bisporus L., protein led to the identification of several saltiness- and kokumi-enhancing peptides. The identification was accomplished by employing a combination of solid-phase extraction (SPE), gel-permeation chromatography (GPC), and semipreparative reverse-phase high-performance liquid chromatography (RP-HPLC), coupled with sensory analysis. As a result, this study led to the identification of a collection of common mushroom derived tastants, including 5'-mononucleotides and free amino acids, along with several taste-modulating pyroglutamyl dipeptides, including pyroglutamylcysteine (pGlu-Cys), pyroglutamylvaline (pGlu-Val), pyroglutamylaspartic acid (pGlu-Asp), pyroglutamylglutamic acid (pGlu-Glu), and pyroglutamylproline (pGlu-Pro). The taste-modulating thresholds for the pyroglutamyl dipeptides were calculated in a model mushroom broth containing natural concentrations of guanosine 5'-monophosphate and 14 amino acids, all with dose-over-threshold (DoT) factors ≥1. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed to quantitate the pyroglutamyl dipeptides, and their concentrations ranged from 2 to 58 µmol/L; however, they were determined to be present in the hydrolysate below their individual taste-modulating thresholds. Despite being present below their individual thresholds, when the dipeptides were collectively added to a model mushroom broth at their natural concentrations (143 µmol/L combined), both salty (p = 0.0061) and kokumi (p = 0.0025) taste attributes were significantly enhanced, demonstrating a synergistic subthreshold taste-modulating effect. This study lays the groundwork for future investigations on the saltiness-enhancing potential of mixtures of subthreshold levels of pyroglutamyl dipeptides found in mushrooms and other sources.

Characterization of Odorants in a 10-Year-Old Riesling Wine.

Riesling wines are mostly enjoyed as young wines, usually consumed within the first few years after bottling. Throughout several years of aging, Riesling wines begin to develop more robust flavor profiles, often displaying less fruity and floral notes and more pronounced maple, honey, and caramel notes. A body of scientific literature has been conducted on the aroma chemistry of young Riesling wines; however, comparatively less scientific reports have been published on the aroma chemistry of aged Riesling wines, and a comprehensive aroma analysis of a 10-year-old Riesling wine has not been previously completed. In this study, a total of 36 odorants were identified in a 10-year-old aged Riesling wine using solvent-assisted flavor evaporation and aroma extract dilution analysis. A total of 26 odorants were quantitated by employing stable isotope dilution assays. Odorants with high odor activity values (OAV) included wine lactone (coconut, OAV 460), ethyl octanoate (fruity, OAV 240), ethyl hexanoate (fruity, OAV 97), ß-damascenone (cooked apple, OAV 60), 5-ethyl-3-hydroxy-4-methyl-(5H)-furan-2-one (maple, OAV 33), (S)-ethyl 2-methylbutanoate (fruity, OAV 22), 3-(methylsulfanyl) propanal (cooked potato, OAV 20), ethyl 2-methylpropanoate (fruity, OAV 9.5), ethyl butanoate (fruity, 7.1 OAV), and 1,1,6-trimethyl-1,2-dihydronapthalene (petrol, OAV 6.4). An odor simulation model prepared from all the odorants with an OAV greater than 1 closely matched the sensory profile of the authentic wine. The results of this study provide insight about odorants present in a 10-year-old bottle aged Riesling wine, and this knowledge may be useful for future studies aimed at probing the influence of aging on the aroma chemistry of Riesling wines and other white wines.

Characterization of Odorants in Chardonnay Marc Skins.

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), ß-ionone (floral, violets, OAV 2900), (2E,4E)-nona-2,4-dienal (fatty, OAV 1200), ß-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), 2-phenylethanol (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.

Phylogeny of the Bacillus altitudinis Complex and Characterization of a Newly Isolated Strain with Antilisterial Activity.

ABSTRACT: Bacillus strain UTK D1-0055 was isolated from a laboratory environment and appeared to have antilisterial activity. The genome was sequenced, the strain was identified as Bacillus altitudinis, and a high-quality complete annotated genome was produced. The taxonomy was evaluated for this and related Bacillus species (B. aerophilus, B. pumilus, B. safensis, B. stratosphericus, and B. xiamenensis) because the taxonomy is unclear and contains errors in public databases such as NCBI. The included strains grouped into seven clusters based on average nucleotide identity. Strains designated as B. aerophilus, B. altitudinis, and B. stratosphericus grouped together in the cluster containing the B. altitudinis type strain, suggesting that these three species should be considered a single species, B. altitudinis. The antimicrobial activity of UTK D1-0055 was evaluated against a panel of 15 Listeria strains (nine Listeria monocytogenes serotypes, Listeria innocua, and Listeria marthii), other foodborne pathogens (six Salmonella enterica serotypes and Escherichia coli), and three representative fungi (Saccharomyces cerevisiae, Botrytis cinerea, and Hyperdermium pulvinatum). Antibacterial activity was observed against all Listeria strains, but no antibacterial effects were found against the other tested bacterial and fungal strains. Biosynthetic gene clusters were identified in silico that may be related to the observed antibacterial activity, and these clusters included genes that putatively encode bacteriocins and nonribosomally synthesized peptides. The B. altitudinis strain identified in this investigation had a broad range of antilisterial activity, suggesting that it and other related strains may be useful for biocontrol in the food industry.

Changes in Tennessee Whiskey Odorants by the Lincoln County Process.

Authentic freshly distilled Tennessee whiskey is filtered through maple charcoal in a processing step known as the Lincoln County Process (LCP). Changes in odorants resulting from the LCP were characterized by a comparative aroma extract dilution analysis (cAEDA), quantitated by stable isotope dilution assays (SIDA), and odor activity values (OAVs) were calculated. Sensory evaluation showed a decrease in malty, rancid, fatty, and roasty aroma attributes of the distillate after LCP treatment. Forty-nine odorants were identified, nine of which have not been previously reported in the whiskey distillate literature. Thirty-one odorants were quantitated, all showing a decrease in concentration as a result of LCP treatment. Odorants, including (2E,4E)-nona-2,4-dienal (fatty), 3-methylbutanoic acid (rancid), 2'-aminoacetophenone (foxy), and 2-acetyl-1-pyrroline (roasty), dropped below detection thresholds (OAV < 1) following LCP treatment. Concentrations of lipid-derived aldehydes, organic acids, and other odorants decreased between 13 and >99%. The present investigation lays the groundwork for future studies aimed at flavor optimization for Tennessee whiskey production.

Fermentation Dynamics and Benzylic Derivative Production in Ischnoderma resinosum Isolates.

Fermentation dynamics and benzylic derivative production were evaluated in the fermentation broth of six different Ischnoderma resinosum (P. Karst) isolates over a period of 30 days to understand their potential applications in bioreactor optimization for natural flavor compound production. d-Glucose and d-fructose levels decreased from 20.4 ± 0.4 to 7.1 ± 1.4 g/L and 1.0 ± 0.1 to <0.1 g/L, respectively, in all fermentations. Isolate I2 produced the highest concentration of ethanol (546. 4 ± 0.4 mg/L). l-Lactic acid production varied between 4.3 ± 0.6 and 3.7 ± 0.2 mg/L, whereas acetic acid concentrations decreased from 81.0 ± 3.3 to <40.0 mg/L. pH decreased from 4.9 ± 0.0 to 3.6 ± 0.4 at the end of 30 days in all fermentations. Isolate I3 was the highest producer of benzaldehyde (BA) (12.0 ± 0.2 mg/kg) and 4-methoxybenzaldehyde (4-MBA) (239.6 ± 3.9 mg/kg), while isolate I4 was the highest producer of 3,4-dimethoxybenzaldehyde (3,4-DMBA) (27.8 ± 0.2 mg/18 kg). Identification of isolate I3 as a high BA and 4-MBA producer and isolate I4 as a high 3,4-DMBA producer suggested differential benzylic derivative production among I. resinosum isolates. This study lays the foundation for future investigations evaluating additional I. resinosum isolates for benzylic derivative production as well as studies aimed at bioreactor optimization with potential commercial application.