Search Results (932)

Natural preservatives are gaining attention as chemical-free solutions to extend produce shelf life and prevent microbial spoilage. Therefore, sweet potato peel (SPP) was investigated as a source of antifungal bioactive compounds in this study. We evaluated essential oils and, for the first time, a bound terpene (BT) concentrate extracted from SPP against Aspergillus flavus, using both in vitro and in vivo assays. Murasaki organic Japanese sweet potato (Ipomoea batatas L.) peels, A. flavus AF13, a highly aflatoxigenic fungus, and Creole tomato (Solanum lycopersicum) fruits were used in the study. Essential oils were extracted by hydrodistillation (HD) and vacuum distillation (VD), while the BT fraction was isolated and concentrated. HD and VD yielded 19 and 10 terpenes, respectively, with linalool and α-terpineol dominating and representing more than 50% of total terpenes in both distillates. The BT concentrate demonstrated significant inhibition of A. flavus growth at concentrations starting from 12.5 µL/mL. The strongest effect was observed at 100 µL/mL, with a 26.0 ± 1.0 mm inhibition zone and 55.56 ± 4.53% growth reduction. In contrast, HD and VD distillates showed no antifungal activity in either in vitro or in vivo assays. Consistently, the BT concentrate-treated tomatoes reduced fungal growth and spoilage, with lesion diameters less than 10 mm after 7 days of storage, while the HD and VD distillate treatments had diameters over 20 mm, and the untreated control had diameters over 60 mm. These findings highlight that SPP waste could be an economical and bio-based source for developing natural antifungal ingredients. The success is anticipated to offer a potential alternative to current synthetic fungicides in preventing fungi A. flavus-induced spoilage of nightshade vegetables. Full article

This study investigated how different spectral ranges of LED light affect the synthesis of photosynthetic pigments and antioxidant systems in Thymus mastichina L., focusing on two ecotypes with distinct chemotypes: linalool and eucalyptol. The ecotypes were exposed to white, red, blue, red-blue (70:30), white-blue, or white-red light for 30 days under a 16/8 h light/dark cycle (115 μmol/m²s). Photosynthetic pigment content, lipid oxidative damage, antioxidant capacities, and both enzymatic (SOD, CAT) and non-enzymatic (tocopherols and polyphenols) antioxidant systems were assessed. For the linalool chemotype, red-blue light significantly increased carotenoid content, antioxidant capacity, and catalase activity, while elevating levels of plastochromanol-8 and phenolic compounds such as salvianolic acid B, rosmarinic acid, and 6-OH-apigenin-7-hexoside, thereby reducing oxidative stress. In contrast, for the eucalyptol chemotype, pure red light produced the most significant enhancements in carotenoid synthesis and antioxidant defenses, substantial increases in key compounds such as salvianic, neochlorogenic, rosmarinic, and lithospermic acids, and salvianolic acids E and B, and higher levels of plastochromanol-8. Additionally, both SOD and CAT activities increased, providing greater protection against lipid oxidation. These findings highlight the importance of customizing light treatments not only based on plant species but also according to chemotype to obtain optimal biochemical and physiological outcomes. Full article

Upcycling, or utilizing materials that would otherwise go to waste, enables the creation of novel products that offer sustainability advantages and generate additional value. This study evaluates the feasibility of producing alcoholic beverages using yogurt acid whey (YAW) and grape pomace (GP), byproducts of the dairy and wine industries, respectively, and compares them to commercial grape pomace beverages (piquettes) in terms of sensory attributes and chemical composition. Two YAW-GP piquettes were produced, and five commercial piquettes were obtained. Sugars and organic acids were quantified using HPLC-RID, and semi-quantitative volatile composition was determined using HS-SPME-GC-MS/MS. Descriptive analysis was conducted using a trained panel of 11 individuals. The YAW products had higher ratings for dairy, salty, acidic, and umami attributes, and lower ratings for bitterness, sweetness, red fruit, dried fruit, and overall fruity characteristics. YAW beverages were higher in titratable acidity (TA), lactose, lactic acid, citric acid, galactose, hexanoic acid, 3-methylpentanol, 1-octanol, and 1-octen-3-ol, and lower in ethanol and linalool. The commercial products were differentiated based on ethanol content, red fruit, dried fruit, fruitiness, chemical, and barnyard aromas. These results can be used to understand the breadth of chemical and organoleptic signatures of this new beverage category, which can be leveraged by stakeholders interested in entering the market. Full article

Floral–fruity aroma Pu-erh tea (FFAPET) is highly valued by consumers for its distinctive and appealing fragrance. This study conducted a comprehensive investigation into the volatile components of FFAPET using advanced analytical techniques, including GC-O-MS, GC-MS/MS, aroma recombination, and omission tests. Compared with traditional stale aroma Pu-erh tea, FFAPET exhibited higher levels of alcohols and alkenes. Through GC-O-MS combined with OAV analysis, 10 key active-aroma compounds were identified in representative FFAPET samples. These compounds included (E, E)-2,4-heptadienal, phenylethyl alcohol, geraniol, (E, Z)-2,6-nonadienal, (Z)-4-heptenal, 2-phenethyl acetate, 2,2,6-trimethylcyclohexanone, D-limonene, β-ionone, and linalool, all of which made significant contributions to the development of the characteristic floral–fruity aroma profile. Tests involving aroma recombination and omission further confirmed that seven of these odorants played essential roles in defining the overall aroma of FFAPET. These findings offer valuable theoretical insights for the enhancement and regulation of Pu-erh tea flavor, particularly for the optimization of the floral–fruity aroma characteristics. Full article

Gongora is a neotropical epiphytic orchid found from Mexico to South America, with 11 species recorded in Brazil. Little is known about the aromas produced by the flowers of these orchid species. This study aimed to identify the volatile constituents of the flowers of Gongora histrionica (1), G. jauariensis (1), G. longiracemosa (2), G. minax (1), and G. pleiochroma (2), all of which are found in the Amazon. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the volatile constituents of Gongora. Additionally, multivariate statistical analysis was employed to evaluate the variability of volatile constituents in their floral aromas. The principal constituents (>25%) of Gongora specimens were (Z)-α-bisabolene, terpinen-4-ol, cis-β-elemenone, (E,E)-geranyl linalool, β-bisabolene, (E,E)-α-farnesene, and 1,8-cineole. Based on the identified compounds, the multivariate statistical analysis revealed seven distinct groups for the Gongora volatile concentrates, indicating a significant variability between the studied species. These results contribute to a better understanding of the genus Gongora chemotaxonomy analysis. Full article

Ageing in oak barrels affects the tertiary aroma of red wine, yet further research on the impact of different conditions used for medium toasting of barrels could still be conducted to optimise wine production and meet consumer preferences. In this study, using the GC/MS method, the aroma profiles of two consecutive vintages of Cabernet Sauvignon wine and samples aged for 12 months in different vessels were determined. Besides the stainless steel tanks, Excellence barrels with medium, medium plus, and medium long toasting, and Premium barrels with medium toasting were used. A total of 48 aroma compounds were identified, and their odour activity value (OAV ≥ 1) was calculated. According to it, 10 key compounds were selected: β-damascenone, ethyl octanoate, ethyl vanillate, ethyl cinnamate, lauric acid, linalool, hotrienol, ethyl hexanoate, diethyl succinate, and 2-phenylethanol. The results showed that wooden barrels have a greater impact on wine aroma during ageing, compared to stainless steel tanks. The initial wine aroma and key compounds with fruity, floral, and fatty notes were most preserved in the stainless steel tank. The study highlights that controlled selection of barrel type (grain density) and toasting method can significantly modulate the aromatic complexity of Cabernet Sauvignon wines. Toasted barrels resulted in an increase in smoky and woody notes (volatile phenols and lactones), and a decrease in fruity and floral notes (β-damascenone, 2-phenylethanol, hotrienol, linalool, etc.). These findings could provide practical guidelines for winemakers for optimising ageing strategies and contributing new insights into the impact of wine vessels on aroma development and sensory perception. Full article

One of the main factors constraining the growth of the tea business is the low use rate of summer tea. To enhance the utilization rate and improve the quality of summer tea, this study innovatively integrated shaking, freezing, and rolling into the traditional processing methods of white tea. Processing parameters were optimized through single-factor experiments combined with an L₉(3⁴) orthogonal experimental design. The quality of summer teas was systematically evaluated using sensory analysis, gas chromatography–mass spectrometry, and high-performance liquid chromatography. This study found that the optimal processing for summer tea was as follows: fresh leaves, room-temperature cold-air withering for 6.5 h, shaking at 10 rpm for 10 min, −20 °C freezing for 5 h, 25% strength rolling for 9 min, and drying at 75 °C for 2 h. The relative content of esterified catechins in summer tea produced by the optimal processing method was reduced by 14.62% compared with the control group. There were alterations in the content of amino acid components, with fresh and sweet amino acids increasing by 4.96% and 2.95%, respectively, and bitter amino acids reducing by 2.15%. Furthermore, γ-aminobutyric acid and L-theanine contents increased by 0.51% and 5.77%, respectively. Five characteristic volatile compounds were identified, namely, methyl salicylate, phenethyl formate, linalool, dimethyl sulfide, and isobutyraldehyde. The volatile profile was dominated by floral and fruity notes, except for dimethyl sulfide, which exhibited a distinct cooked corn-like aroma characteristic. This process was shown to improve the quality of summer tea. The results of this study provide a metabolite-level grounds for improving the quality of summer tea. Full article

This study established a novel detection method for volatile organic compounds in forest therapy tree species based on direct thermal desorption technology. The optimized parameters included 20 mg sample loading, 110 °C desorption temperature, 30 min desorption time, and 1:30 split ratio. The optimal loading was 5–65 mg to balance the separation resolution and detection sensitivity. Desorption temperature significantly affected component detection: terpenoids accounted for the highest proportion (82.0%) at 90 °C; alkanes surged to 53.3% at 150 °C; acids (19.0%) and esters (19.4%) became dominant; and ascorbyl dipalmitate (17.3%) exceeded linalool (14.6%) at 180 °C. Chemotype analysis revealed that camphor-type leaves were dominated by camphor (72.8%) while linalool-type leaves by linalool (54.3%). Compared with steam distillation, DTD increased the camphor/linalool extraction efficiency while eliminating solvent contamination. Relative to dynamic headspace sampling, DTD mitigated the environmental interference and reduced the pretreatment time. The study confirmed that 110 °C is the optimal temperature for maximized characterization of terpenoids (63.3%), providing technical support for selecting high-terpenoid-emitting trees in forest therapy and evaluating the therapeutic efficacy. It also reveals the linkages between leaf volatiles and stand-level air composition and promotes the development of dynamic forest VOC databases. Full article

Cannabis sativa L. is an aromatic medicinal plant with various biologically active classes of compounds such as cannabinoids, polyphenols, and terpenes. Unlike the widely investigated inflorescence and leaf, the stembark of C. sativa has been overlooked regarding its medicinal potential. This study, therefore, was aimed at determining the chemical composition and antioxidant activity of the essential oils (EOs) obtained from the fresh and dried stembark of two C. sativa cultivars, Lifter and Cherrywine, grown in Komga, South Africa, with a view to ascertaining the more promising cultivar. The chemical profiles of the hydro-distilled EOs were analyzed by gas chromatography-mass spectrometry (GC-MS), while an in vitro antioxidant activity assessment of the EOs was performed using DPPH and H₂O₂ spectrophotometric methods. The identified constituents from the EOs were molecularly docked against NOX2, a protein implicated in oxidative stress. The afforded EOs were colorless with a mild skunk-like odor. A total of thirty-two constituents were identified in both fresh and dry oils from the Lifter cultivar while the Cherrywine cultivar contained a total of forty-two constituents. The EOs of both cultivars contained twenty compounds, notably Cannabidiol (0.25–85.03%), Caryophyllene oxide (1.27–19.58%), Caryophyllene (0.64–16.61%), Humulene (0.37–8.15%), Octacosane (3.37–6.55%), Humulene-1,2-epoxide (0.45–5.78%), Nerolidol (0.32–4.99%), Palmitic acid (1.45–4.45%), Tetracosane (1.75–2.91%), Dronabinol (0.86–2.86%), Cannabinol (0.54–1.64%), 7-epi-γ-eudesmol (0.53–1.00%), Guaiol (0.37–0.66%), Linoleic acid (0.22–0.60%), γ-Selinene (0.15–0.48%), β-Eudesmol (0.34–0.50%), and Linalool (0.24–0.30%). The dried Lifter stembark oil (DLSO) gave the best antioxidant activity among the four investigated cannabis oils, exhibiting the lowest IC₅₀ values of 21.68 ± 1.71 and 26.20 ± 1.34 µg/mL against DPPH and H₂O₂ radicals, respectively. The notable antioxidant activity of the DLSO may be attributed to the higher number (30) of constituents compared to the fresh Lifter stembark oil (LSO) with 11 constituents. Additionally, the DLSO showed a unique chemical profile comprising monoterpenes, oxygenated and hydrocarbon sesquiterpenes. Further in silico studies on the putative constituents in the Lifter cultivar revealed Cannabinol, Cannabidiol, and Linalool as the promising constituents based on their higher binding energy scores of −9.7, −8.5, and −6.5 kcal/mol, respectively, compared to L-Ascorbic acid (−5.7 kcal/mol). It can be inferred from this study that the EOs from the stembark of C. sativa contain promising compounds, such as Cannabinol, Cannabidiol, and Linalool, which might be responsible for the displayed antioxidant activity of the oils. Thus, the study findings underscore the biological importance of C. sativa stembark in the management of oxidative stress-related conditions. Full article

The plants from the Ocimum genus, belonging to the Labiatae family, serve as important bioresources of essential oils (EOs) rich in biologically active secondary metabolites, widely used in medicine, food, and cosmetics. This study explored the volatile composition, enantiomeric distribution, and in vitro biological activities of EOs from three Ocimum species native to Nepal: O. tenuiflorum L., O. basilicum L., and O. americanum L. EOs were extracted via hydro-distillation and analyzed using gas chromatography–mass spectrometry (GC-MS) for chemical profiling and chiral GC-MS for enantiomeric composition. Hierarchical cluster analysis was performed for major chemotypes. Antioxidant activity was assessed using DPPH and ABTS assays. Antimicrobial efficacy was evaluated using the microbroth dilution method, and cytotoxicity was tested on NIH-3T3 (normal) and MCF-7 (breast cancer) cell lines via the Cell Counting Kit-8 assay. EO yield was highest in O. tenuiflorum (1.67 ± 0.13%) during autumn and lowest in O. americanum (0.35 ± 0.02%) during winter among all Ocimum spp. The major compounds identified in O. tenuiflorum were eugenol (32.15–34.95%), trans-β-elemene (29.08–32.85%), and β–caryophyllene (19.85–21.64%). In O. americanum, the major constituents included camphor (51.33–65.88%), linalool (9.72–9.91%), germacrene D (7.75–1.83%), and β–caryophyllene (6.35–3.97%). For O. basicilum, EO was mainly composed of methyl chavicol (62.16–64.42%) and linalool (26.92–27.05%). The oxygenated monoterpenes were a dominant class of terpenes in the EOs except for O. tenuiflorum (sesquiterpene hydrocarbon). A hierarchical cluster analysis based on the compositions of EOs revealed at least three different chemotypes in Ocimum species. Chiral GC-MS analysis revealed β-caryophyllene and germacrene D as enantiomerically pure, with linalool consistently dominant in its levorotatory form. O. tenuiflorum exhibited the strongest antimicrobial activity, particularly against Candida albicans, and showed notable anticancer activity against MCF-7 cells (IC₅₀ = 23.43 µg/mL), with lower toxicity to normal cells. It also demonstrated the highest antioxidant activity (DPPH IC₅₀ = 69.23 ± 0.10 µg/mL; ABTS IC₅₀ = 9.05 ± 0.24 µg/mL). The EOs from Ocimum species possess significant antioxidant, antimicrobial, and cytotoxic properties, especially O. tenuiflorum. These findings support their potential application as natural agents in medicine, food, and cosmetics, warranting further validation. Full article

Zanthoxylum armatum DC. (Z. armatum) is a versatile plant species valued for its aroma oil and nutritional components. However, the variability of chemical composition in Z. armatum fruits in the field remains largely unknown, and it is still unclear how harvest parameters affect the aroma and nutritional quality of the fruits. To address this gap, Z. armatum fruits from varying harvest times, tree ages, and fruiting positions were analyzed for physicochemical properties, nutrients, minerals, aroma profiles, and antioxidant activity. A quality assessment method was developed based on key Z. armatum fruit parameters. Results showed significant differences in the size, weight, total phenol, flavonoid and sanshool content of Z. armatum fruit from different harvest parameters. Z. armatum fruits contained abundant minerals, showing diverse harvest-condition variations. In vitro antioxidant assays showed higher ABTS/DPPH scavenging activity and reducing capacity (23–54 mg/g). HS-SPME-GC-MS identified 64 aroma compounds, encompassing terpenes, alcohols, etc. Linalool was the predominant constituent (46.65%). PLS-DA and Volcano plot analyses highlighted significant differences in VOCs among harvest times and tree ages, while fruit positions showed minimal impact. The Mantel test identified aroma-active compounds associated with antioxidant activity. These findings facilitate a science-based harvesting strategy to standardize Z. armatum fruit quality and marketability. Full article

Hydrolates are aromatic aqueous solutions saturated with volatile water-soluble compounds of essential oil. Despite their potential, hydrolates remain less explored than essential oils. In this work, the hydrolate of Pelargonium odoratissimum (L.) L’Hér. has been analyzed by multiple analytical techniques in order to describe its chemical composition. Headspace (HS-) and Direct Immersion-Solid Phase Microextraction-Gas Chromatography/Mass spectrometry (DI-SPME-GC/MS) and Proton Transfer Reaction Time-of-Flight Mass Spectrometry (PTR-ToF-MS) were employed to reveal the VOC emission from the hydrolate. Further, a direct injection of the pure hydrolate and of the hydrolate after extraction with hexane was performed by Large-Volume Injection Gas Chromatography/Mass Spectrometry (LVI-GC/MS) and GC/MS. The results obtained by HS- and DI-SPME-GC/MS highlighted a nearly overlapping chemical profile with linalool, isomenthone, and α-terpineol as the main volatiles. On the other hand, analysis of the hydrolate by GC/MS after solvent extraction revealed a lower overall number of compounds but allowed the detection of thujone and cis-linalool oxide. In comparison, LVI-GC/MS was the technique that allowed the identification of a higher number of volatiles with citronellol, linalool, and α-terpineol as the principal compounds. Finally, PTR-ToF-MS was a fundamental approach to quantify and evaluate total terpene emissions from this complex matrix starting from low-molecular-weight compounds such as acetylene, methanol, acetaldehyde, acetone, and ethanol, which were the most abundant. Among the detected compounds, dimethyl sulfide and small amounts of dimethyl-furan and 2-butylfuran were also identified. Overall, the findings showed that the hydrolate was rich in monoterpene compounds while sesquiterpene compounds were missing. A very low intensity relating to sesquiterpenes was recorded only by PTR-ToF-MS technique. Full article

Orange spiny whitefly (Aleurocanthus spiniferus Quaintance) is a major pest with economic significance to tea plants, as both nymphs and adults suck plant sap and contribute to the development of tea sooty mold. The occurrence of this pest varies considerably among different tea cultivars, even within the same plantation. This study aims to characterize the bioactive constituents of tea volatiles mediating A. spiniferus host selection, and leverage these semiochemicals to develop effective field trapping systems. Through field investigations and Y-tube olfactometer tests, we identified two highly preferred tea cultivars (‘Huangjinya’ and ‘Fuding white tea’) and two cultivars (‘Baiye No. 1’ and ‘Longjing 43’) that were not preferred. Behavioral assays and gas chromatography-mass spectrometry (GC-MS) analysis revealed four attractive compounds [hexanol, (E)-2-hexenal, linalool, and (E,E)-α-farnesene] and two repellent compounds [nonanal and (Z)-3-hexenol] in the volatile emissions of the four cultivars. A hexane solution (10 µL) of nonanol, (Z)-3-hexenol, linalool, and (E,E)-α-farnesene at a concentration of 100 µg/µL was able to elicit an obvious electrophysiological (EAG) response. In field trials, the synergistic bait trap equipped with two types of attractants, 500 µL of hexane solution of the mixture of linalool and (E,E)-α-farnesene (3:1, v/v), and the mixture of linalool and (Z)-3-hexenol (3:1, v/v) at the concentration of 100 μg/μL, showed significantly higher attractant efficacy and selectivity. Overall, this study indicates that tea volatiles play a crucial role in the host selection of A. spiniferus, and the synthetic mixtures of tea volatiles have the potential to be developed as commercial plant-based attractants for adult A. spiniferus. This study contributes to the development of sustainable, environmentally friendly management strategies for a pest that is challenging to prevent and control. Full article

The present study investigated the chemical composition of the main components of five commonly occurring Thymus species in Bulgaria: T. sibthorpii Benth., T. pulegioides L., T. glabrescens Willd. (syn. T. odoratissimus Mill.), T. callieri Borbas ex Velen. (syn. T. roegneri K. Koch), and T. zygioides Griseb. The phytochemical profiling of the Thymus species was performed using GC-MS for the analysis of essential oils and HPLC for the identification and quantification of phenolic compounds in the ethanolic extracts. Linalool was the dominant essential oil constituent in T. sibthorpii (48.17%), T. pulegioides (50.96%), and T. callieri (38.08%) while thymol prevailed in T. glabrescens (35.35%). A novel chemotype was observed in T. zygioides. The HPLC analysis confirmed rosmarinic acid as the major phenolic acid across all species. Rutin was the predominant flavonoid in four species whereas T. sibthorpii exhibited a remarkably high concentration of (+)-catechin. Overall, the high chemical diversity within the Thymus genus was confirmed. Due to the variability of compounds among plant species, the findings of the present study suggest that, along with essential oils, phenolic components may also contribute to the chemotaxonomic classification of the Thymus genus and influence the pharmacological activity of the species, which requires further study. Full article

In this study, we investigated the impact of two native strains of Starmerella bacillaris, used both in pure culture and in a co-inoculation with Saccharomyces cerevisiae, on the volatile profile of a chemically defined fermented model must. The focus of this study was the production of monoterpenes and sesquiterpenes and their potential sensory contributions. Geraniol and linalool were detected in all fermentations with Starmerella bacillaris, in ranges of 26.7–43.9 µg/L and 34.3–41.3 µg/L, respectively, independent of the inoculation strategy used. Both strains produced concentrations above their respective odour thresholds of 20 µg/L and 25.5 µg/L. Odour activity value (OAV) analysis confirmed that fermentations with Starmerella bacillaris, particularly under co-inoculation conditions, generated the highest OAVs for these monoterpenes. Citronellol was only detected in mixed fermentations, while nerolidol and farnesol isomers were produced in variable amounts, depending on the strain and inoculation strategy, at concentrations below the odour threshold. These findings demonstrate the ability of Starmerella bacillaris to facilitate de novo biosynthesis of linalool, geraniol, and sesquiterpenes during alcoholic fermentation—in the case of linalool and geraniol, at concentrations exceeding their respective odour thresholds—highlighting the biotechnological potential of these native strains to enhance aroma in wines, particularly those made from neutral grape varieties. Full article