Major Volatile Compounds Research Articles

Use of Non-Saccharomyces Yeast to Enhance the Acidity of Wines Produced in a Warm Climate Region: Effect on Wine Composition

One of the most notable effects of climate change, especially in warm regions, is the decrease in acidity (i.e., increase in pH) of wines and a reduction in their aromatic profile. To address this issue, must from a white grape variety with low acidity were inoculated with two non-Saccharomyces yeasts (Lachancea thermotolerans and Torulaspora delbrueckii) to enhance the acidity of the resulting wines. Basic oenological variables and major volatile compounds and polyols of the wines were analyzed, and the results were compared with those obtained through a Saccharomyces cerevisiae strain. Through multiple regression analysis, we found relations between the production of lactic acid to compounds involved in yeast metabolism and redox balance, including glycerol, acetic acid, isobutanol, isoamyl alcohols, and 2-phenylethanol. By means of principal component analysis, we obtained three components that explain more than 89% of the observed variability. The first component differentiates wines produced by L. thermotolerans; the second differentiates wines obtained by S. cerevisiae from those obtained by T. delbrueckii; and the third component is related to the temperature of fermentation. Organoleptic wines produced with S. cerevisiae were the best valuated, but taste was a highlight of the wines produced with L. thermotolerans due to possessing the best acidity.

Reducing southern California ozone concentrations in the year 2050 under a low carbon energy scenario

Recent studies predict that ozone (O3) concentrations within major California cities in the year 2050 will continue to violate the 8-h O3 standard despite the adoption of low-carbon energy. This O3 penalty largely stems from persistent NOx-rich chemistry within urban cores that causes O3 concentrations to increase when traditional combustion sources are replaced by renewable energy sources. Here we employ a Chemical Transport Model (CTM) equipped with a novel O3 source apportionment technique to better understand O3 formation and to design supplemental control measures to complement Greenhouse Gases (GHG) reduction strategies in California. Two base scenarios were analyzed: (i) a 2050 “business-as-usual” (BAU) scenario with O3 violations on 43% of simulated days, and (ii) a 2050 Greenhouse Gases reduction (GHGAi) scenario with O3 violations on 32% of simulated days. The source apportionment results of the GHGAi scenario identified offroad equipment & rail, marine vessels & aircraft, and industrial & agricultural emissions as the major NOx sources that contributed to the O3 violations, while boundary conditions & initial conditions (BCIC) and biogenic emissions were identified as the major volatile organic compounds (VOCs) sources. Despite a HCHO/NO2 ratio (FNR) suggesting that the SoCAB is in a VOC-limited chemical regime, the major VOC sources that contribute to O3 formation are not controllable. Therefore, complementary O3 control strategies are proposed that focus on NOx emissions within the GHGAi scenario. Three cumulative Supplemental Control Steps were evaluated. Control Step I reduced emissions from off-road equipment & rail, and marine vessels & aircraft (65% NOx emissions reduction relative to GHGAi). Control Step II expanded the measures in Control Step I by reducing emissions from industrial and agricultural sources (cumulative 73.6% NOx emissions reduction relative to GHGAi), while Control Step III extended the amount of control applied to all sources covered in Control Steps I and II (cumulative 85.4% NOx emissions reduction relative to GHGAi). All three Control Steps lowered O3 concentrations significantly in the SoCAB, with residual O3 violations mainly predicted in non-populated wilderness areas. The significant reductions in O3 produced by the Supplemental Control Steps decreased the predicted incidence of hay fever/rhinitis, asthma, and all-cause mortality by an order of magnitude compared to the transformation from the BAU to GHGAi scenario. The predicted public health savings associated with the Supplemental Control Steps are valued at $19.70–30.36B/yr.

Exploration of basil (Ocimum basilicum) essential oil profiles using E-nose and GC–MS combined with GC-O and inhalation effects on the human EEG topography and tomography (s-LORETA) and blood pressure

This study aimed to investigate the changes in human EEG activity, Brodmann area, and blood pressure during basil essential oil inhalation. Seven odor-active compounds were detected by GC–MS combined with GC–olfactometry, and three abundant volatile compounds were detected by electronic nose. Linalool was simultaneously regarded as a major volatile compound. The systolic and diastolic blood pressures and pulse levels showed a decreasing trend during BEO inhalation. The relative beta and gamma waves in most brain regions changed during BEO inhalation. The gamma waves decreased, whereas the beta waves increased during BEO inhalation. In particular, the beta waves in the left frontal and right parietal regions and Brodmann area 38 significantly increased during inhalation using sLORETA. Accordingly, these results were highly associated with reduced stress responses by decreased gamma waves, blood pressures, and pulse levels and improved language-related functions by the increased beta wave at Brodmann area 38.

Characterization and Determination of the Antibacterial Activity of Baccharis dracunculifolia Essential-Oil Nanoemulsions.

The aim of this study was to evaluate the antibacterial activity of nanoemulsions of Baccharis dracunculifolia essential oil. The volatile compounds of the essential oil were identified using gas chromatography-mass spectrometry. The properties of the nanoemulsions (droplet size, polydispersity index, pH, and electrical conductivity) were determined. The antibacterial activities of the essential oil and its nanoemulsions were evaluated using MIC, MBC, and disk diffusion. The microorganisms used were: Gram-positive bacteria (Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 14579, Streptococcus mutans ATCC 25175, and Enterococcus faecalis ATCC 29212) and Gram-negative bacteria (Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC BAA-1706, Salmonella enterica ATCC 14028, and Escherichia coli ATCC 25922). The major volatile compounds of the B. dracunculifolia essential oil were limonene (19.36%), (E)-nerolidol (12.75%), bicyclogermacrene (10.76%), and β-pinene (9.60%). The nanoemulsions had a mean droplet size between 13.14 and 56.84 nm. The nanoemulsions presented lower and statistically significant MIC values compared to the essential oil, indicating enhancement of the bacteriostatic action. The disk diffusion method showed that both the nanoemulsions and the essential oil presented inhibition zones only for Gram-positive bacteria, while there were no results against Gram-negative bacteria, indicating that B. dracunculifolia essential oil has a better antimicrobial effect on Gram-positive microorganisms.

Volatile Fingerprint and Differences in Volatile Compounds of Different Foxtail Millet (Setaria italica Beauv.) Varieties.

Aroma components in foxtail millet are one of the key factors in origin traceability and quality control, and they are associated with consumer acceptance and the corresponding processing suitability. However, the volatile differences based on the foxtail millet varieties have not been studied further. The present study was undertaken to develop the characteristic volatile fingerprint and analyze the differences in volatile compounds of 20 foxtail millet varieties by electronic nose (E-Nose), headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS), and headspace solid-phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS). A total of 43 volatile compounds were tentatively identified in foxtail millet samples, 34 and 18 by GC-IMS and GC-MS, respectively. Aldehydes, alcohols, and ketones were the major volatile compounds, and the hexanal content was the highest. The characteristic volatile fingerprint of foxtail millet was successfully constructed. A total of 39 common volatile compounds were found in all varieties. The content of hexanal, heptanal, 1-pentanol, acetophenone, 2-heptanone, and nonanal were explored to explain the aroma characteristics among the different varieties, and different varieties can be separated based on these components. The results demonstrate that the combination of E-Nose, GC-IMS, and GC-MS can be a fast and accurate method to identify the general aroma peculiarities of different foxtail millet varieties.

Quality and bioactive compound accumulation in two holy basil cultivars as affected by microwave-assisted hot air drying at an industrial scale

Holy basil (Ocimum Tenuiflorum L.) contains several bioactive compounds useful to the pharmaceutical and food industries. Microwave drying (MD) is a powerful technique for rapid drying of food or plant materials while preserving bioactive compounds during the process. However, little is known about the optimal combination of MD power with hot air drying (HAD) that can preserve the quality and yet only consume reasonable energy when drying holy basils. For that purpose, the effects of drying methods using MD combined with HAD at 45°C were examined to prevent losses in quality, antioxidant activities, and volatile flavor compounds in two holy basil cultivars (green and red cultivars). Holy basil leaves were dried at different MD powers of 200, 400, and 600 W combined with HAD and compared with a traditional tray drying (TD) at 45°C. Drying using MD at 600 W with HAD displayed significantly high levels of color retention, chlorophyll, and carotenoid content in both cultivars. The green cultivar showed a greater accumulation of total phenolic compounds (TPC), terpenoids, and DPPH free radical scavenging at 400 W with HAD. However, the red cultivar had the highest TPC, flavonoid, and terpenoid content at 600 W with HAD. The accumulation of major volatile organic compounds (VOCs) was also affected, and treatment at 600 W exhibited the highest methyl eugenol and β-caryophyllene content in both cultivars. The use of the highest power of MD (600 W) with HAD for leaf drying reduced the effective drying time and energy consumption among both cultivars. Taking into consideration the dried quality of antioxidant accumulation and energy consumed for drying, we recommend using MD at 400 or 600 W with HAD for the green cultivar and 600 W for the red.

Multistep Approach Points to Compounds Responsible for the Biological Activity and Safety of Hydrolates from Nine Lamiaceae Medicinal Plants on Human Skin Fibroblasts.

As byproducts of essential oil distillation, hydrolates are used in natural cosmetics/biomedicine due to their beneficial skin effects. However, data on their safety with relevant biological targets, such as human skin cells, are scarce. Therefore, we have tested nine hydrolates from the Lamiaceae family with skin fibroblasts that are responsible for extracellular collagenous matrix builds. Thyme, oregano, and winter savoury hydrolates showed several times higher total phenolics, which correlated strongly with their radical scavenging and antioxidative capacity; there was no correlation between their viability profiles and the reducing sugar levels. No proteins/peptides were detected. All hydrolates appeared safe for prolonged skin exposure except for 10-fold diluted lavender, which showed cytotoxicity (~20%), as well as rosemary and lavandin (~10%) using viability, DNA synthesis, and cell count testing. Clary sage, oregano, lemon balm, and thyme hydrolates (10-fold diluted) increased fibroblast viability and/or proliferation by 10-30% compared with the control, while their viability remained unaffected by Mentha and winter savoury. In line with the STITCH database, increased viability could be attributed to thymol presence in oregano and thyme hydrolates in lemon balm, which is most likely attributable to neral and geranial. The proliferative effect of clary sage could be supported by alpha-terpineol, not linalool. The major volatile organic compounds (VOCs) associated with cytotoxic effects on fibroblasts were borneol, 1,8-cineole, and terpinene-4-ol. Further research with pure compounds is warranted to confirm the roles of VOCs in the observed effects that are relevant to cosmetic and wound healing aspects.

Sensory profile and the contribution of key aroma compounds in Jiang-flavor rounded-base Baijiu produced in the Chishui river basin

The flavor characteristics of Jiang-flavor rounded-base Baijiu (JRBB) in four producing areas of the Chishui River Basin were systematically investigated. A total of 246 major volatile flavor compounds were detected through a gas chromatography-flame ionization detection (GC-FID) and liquid-liquid microextraction, headspace solid-phase microextraction combined gas chromatography-mass spectrometry (LLME/HS-SPME-GC-MS). Partial least squares discriminant analysis (PLS-DA) revealed that different rounds of JRBB had a significant classification effect. Based on odor activity value (OAV) and variable important in projection, the 20 most key aroma compounds in samples were identified. Among them, furfural (OAV: 524.07), hexanal (OAV: 506.33) and ethyl acetate (OAV: 264.45) contributed remarkably to flavor. Moreover, flavor reconstruction analysis showed jiang aroma in reconstructed samples had the highest similarity to the original ones. The 17 flavor compounds were positively correlated with aroma profiles (jiang, ethanol, liang, honey, fruity, floral, roasted, and baked aroma). The liang, jiang, and baked aromas were respectively prominent in the first and second round of JRBB, the third to fifth round of JRBB, as well as the sixth and seventh round of JRBB. This study provides comprehensive understanding regarding sensory profile of JRBB, which provides theoretical support for Baijiu blending techniques and improves the development of Baijiu industry.

Anatomical and chemical characterization of leaves from Oreopanax spp. (Araliaceae), the Mexican xoco tamale food complex

Background: Based on the concept of “plant species complex,”, defined as a group sharing local names and morphological, aromatic, and curative properties, we analyzed the leaves of three species of the genus Oreopanax that are used as wrappers for tamales called “xocos” or “chocos” in Veracruz, Mexico, searching for common traits.
 Question: Do leaves of the genus Oreopanax form an ethnobotanical food complex sharing chemical and anatomical characteristics?
 Studied species / data description: Leaves from three species of the genus Oreopanax: O. capitatus, O. echinops, and O. flaccidus.
 Study site and dates: Leaves of O. capitatus and O. echinops were recollected on January 25 and 26, 2021, in the Clavijero Botanic Garden of the Instituto de Ecología, A. C. in Xalapa, Veracruz; leaves of O. flaccidus were recollected in Atapalchico, Tlacolulan, Veracruz.
 Methods: Chemical analyses consisted of oil extraction of the studied species' leaves, which were then injected into a gas chromatographer coupled to a mass spectrometer (GC-MS). Anatomical analyses included: fixation, paraffin sectioning, and staining of leaf sections of the three species. Observations were performed with a compound microscope using a bright field or UV light.
 Results: For the first time, we are reporting major volatile compounds common in the three analyzed species (several aliphatic and aromatic alcohols, and terpenoids). The three species present resin canals in the mesophyll and the cortex of the midrib of the leaf.
 Conclusions: The studied Oreopanax species form an ethnobotanical food complex since they share similar uses, smells, and tastes.

Metabolism-linked methylotaxis sensors responsible for plant colonization in Methylobacterium aquaticum strain 22A.

Motile bacteria take a competitive advantage in colonization of plant surfaces to establish beneficial associations that eventually support plant health. Plant exudates serve not only as primary growth substrates for bacteria but also as bacterial chemotaxis attractants. A number of plant-derived compounds and corresponding chemotaxis sensors have been documented, however, the sensors for methanol, one of the major volatile compounds released by plants, have not been identified. Methylobacterium species are ubiquitous plant surface-symbiotic, methylotrophic bacteria. A plant-growth promoting bacterium, M. aquaticum strain 22A exhibits chemotaxis toward methanol (methylotaxis). Its genome encodes 52 methyl-accepting chemotaxis proteins (MCPs), among which we identified three MCPs (methylotaxis proteins, MtpA, MtpB, and MtpC) responsible for methylotaxis. The triple gene mutant of the MCPs exhibited no methylotaxis, slower gathering to plant tissues, and less efficient colonization on plants than the wild type, suggesting that the methylotaxis mediates initiation of plant-Methylobacterium symbiosis and engages in proliferation on plants. To examine how these MCPs are operating methylotaxis, we generated multiple gene knockouts of the MCPs, and Ca2+-dependent MxaFI and lanthanide (Ln3+)-dependent XoxF methanol dehydrogenases (MDHs), whose expression is regulated by the presence of Ln3+. MtpA was found to be a cytosolic sensor that conducts formaldehyde taxis (formtaxis), as well as methylotaxis when MDHs generate formaldehyde. MtpB contained a dCache domain and exhibited differential cellular localization in response to La3+. MtpB expression was induced by La3+, and its activity required XoxF1. MtpC exhibited typical cell pole localization, required MxaFI activity, and was regulated under MxbDM that is also required for MxaF expression. Strain 22A methylotaxis is realized by three independent MCPs, two of which monitor methanol oxidation by Ln3+-regulated MDHs, and one of which monitors the common methanol oxidation product, formaldehyde. We propose that methanol metabolism-linked chemotaxis is the key factor for the efficient colonization of Methylobacterium on plants.

Volatile profiling as a potential biochemical marker for validation of gamma irradiation derived putative mutants in polyembryonic genotypes of mango (Mangifera indica L.).

Putative mutants were generated through gamma irradiation in the polyembryonic mango genotype Nekkare. The putative mutant progenies along with control seedlings and mother plants were evaluated by comparing the compositions and relative proportions of their major volatile compounds. Volatile profiling was done using headspace-solid phase micro-extraction (HS SPME) method coupled with gas chromatography-mass spectrometry (GC-MS MS). Furthermore, characterisation of putative mutants and control seedlings was carried out using simple sequence repeat (SSR) markers to ascertain the genetic diversity present in the samples under study. Monoterpenes were the most abundant volatile compound in all the studied samples (ranging from 34.76% to 91.41%) out of which I-Phellandrene and cis-Ocimene formed the major fraction in mother plants (20.45%-21.86% and 16.17%-21.27%, respectively) and control seedlings (23.32%-24.95% and 18.95%-20.81%, respectively), while beta-Phellandrene was dominant in the selected putative mutant samples (2.34%-29.53%). Among sesquiterpenes, trans-Caryophyllene was detected only in the putative mutant samples (0.10%-30.18%). Grouping together of mother plants and control seedlings was seen in the cluster analysis, while the putative mutants grouped apart from them suggesting genetic diversity. Genetic distance between the mother plants and control seedlings ranged from 0.97 to 2.73, while between putative mutants, control seedlings, and mother plants, it ranged from 6.54 to 9.82. SSR-based characterisation of putative mutant seedlings showed that mutation caused variability in the treated population. This was evident from the high allelic richness ranging from 4 to 12 with a mean of 7 and a higher mean Shannon's Information Index (1.50) of the putative mutant population. The study demonstrates that volatile profiling and molecular characterisation using SSR markers could be used as a tool to detect variation in a mutated population. In addition, volatile profiling can be used to validate putative mutants in polyembryonic mango genotypes where the seedlings of nucellar origin are similar to mother plants.

Effect of Temperature Storage on Chemical Properties of Lokio Leaves (Allium chinense G Don)

Lokio (Allium chinense G Don) is widely used as seasoning in cooking because it contains amino acids that contribute to taste. Lokio is easily damaged during physical and chemical storage, affecting its quality. The study aims to determine the chemical changes of lokio leaves during storage. This study used a randomized design group with 3 temperature treatments, namely room temperature (30 ⁰C), air conditioning (20 ⁰C), and refrigerator (10 ⁰C). Weight loss was tested using a digital scale, color was tested using a chromameter, water content was tested using thermogravimetry, fat using Soxhlet, protein using Kjeldal, and ash using a muffle furnace. Reducing sugars were tested using the DNS method, amino acids using HPLC, and volatile compounds using GC MS Headspace. The data was analyzed using ANOVA then continued with Duncan test if the treatment has a significant difference (p < 0.05). In the room temperature treatment, the best treatment was obtained for 2 days of storage, AC storage for 4 days, and refrigerator temperature for 14 days of storage. Of all the best treatments for each storage temperature, the best treatment was obtained in the storage treatment using AC temperature (20 ⁰C) for 4 days. The treatment found that Lokio has a water content of 92.247%, fat of 2.47%, protein of 19.05%, ash of 14.20%, carbohydrates of 64.28%, and reducing sugar of 11.24 mg/ml. The major volatile compound content of the total storage is trimethyl sulfide and glutamic acid is the most amino acid in lokio leaves.

Effects of degree of milling on nutritional quality, functional characteristics and volatile compounds of brown rice tea.

This study investigated the effects of rice preparation using different degrees of milling (DOM) from 0% to 13% on the nutritional composition, functional properties, major volatile compounds and safety of brown rice tea (BRT). We found that 2% DOM reduced 52.33% of acrylamide and 31.88% of fluorescent AGEs. When DOM was increased from 0% to 13%, the total phenolic content (TPC) of brown rice tea decreased by 48.12%, and the total flavonoid content (TFC) and condensed tannin content (CTC) also decreased significantly, with the smallest decrease at 2% DOM. In addition, the inhibitory activities of α-amylase, α-glucosidase and pancreatic lipase as well as the antioxidant activity also decreased gradually. Analysis by electronic nose and gas chromatography-mass spectrometry (GC-MS) showed that alkanes, furans, aldehydes, pyrazines and alcohols were the major volatiles in BRT, with 2% DOM having the greatest retention of aroma compounds. An orthogonal partial least squares discriminant analysis (OPLS-DA) and VIP score (VIP > 1 and p < 0.05) analysis were used to screen 25 flavor substances that contributed to the differences in BRT aroma of different DOMs. These results suggest that 2% milled BRT can improve safety and palatability while maximizing the retention of flavor compounds and nutrients. The findings of this study contribute to an enhanced understanding of the dynamics of changes and preservation of aroma compounds and nutrients present during the processing of BRT.

Optimisation Using Response Surface Methodology of Quality, Nutritional and Antioxidant Attributes of ‘Wichita’ Pecan Nuts Roasted by Microwaves

Pecan (Carya illinoinensis) nuts are rich in functional compounds (unsaturated fatty acids, phytosterols, polyphenols, and tocopherols) associated with various health benefits. Commercially, pecan nuts are roasted to enhance their physical, chemical, and sensory properties. In the present study, response surface methodology (RSM) was used to optimise the quality and nutritional and antioxidant attributes of ‘Wichita’ pecan nuts roasted by using a microwave process with a range of microwave power (96.45–803.55 W) and roasting time (1.37–5.62 min). The microwave-roasted pecan nuts were analysed for hardness, total colour difference (TCD), and radical scavenging activity and modelled using the central composite design. The results showed that microwave power and roasting time significantly (p &lt; 0.05) influenced the quality attributes of the pecan. The quadratic model adequately described the changes in TCD and hardness, respectively, while the 2FI model adequately described the changes in DPPH radical scavenging activity. To obtain the desired pecan nuts quality attributes (TCD = 1863.391; hardness = 28.755 N and DPPH radical scavenging activity = 33.877 mmol Trolox/g), the determined conditions were 700 W and 2.24 min, with a desirability of 0.557. The primary unsaturated fatty acids, including cis-oleic, cis-linoleic, α-linolenic, and stearic acids, were not affected (p &lt; 0.05) by microwave roasting the pecan nuts at determined conditions. Volatile compounds, such as alcohols, aldehydes, ketones, lactones, hydrocarbons, and carboxylic acids, were identified in both raw and microwave-roasted pecan nuts, with limonene, which possesses various health properties, being the major volatile compound. It can be concluded that microwave roasting may be optimised using response surface methodology to produce quality pecan nuts that can be used as snacks or as an ingredient in other snack products.

The Promoting Effect of Metal Vacancy on CoAl Hydrotalcite-Derived Oxides for the Catalytic Oxidation of Formaldehyde

Formaldehyde (HCHO) is a major harmful volatile organic compound (VOC) that is particularly detrimental to human health indoors. Therefore, effectively eliminating formaldehyde is of paramount importance to ensure indoor air quality. In this study, CoAl hydrotalcite (LDH) was prepared using the co-precipitation method and transformed into composite metal oxides (LDO) through calcination. Additionally, a metal Al vacancy was constructed on the surface of the composite metal oxides (EX-LDO and EX-LDO/NF) using an alkaline etching technique. SEM demonstrated the successful loading of CoAl-LDO onto nickel foam surfaces (LDO/NF), and an extended etching time resulted in a greater number of porous structures in the samples. XRD confirmed the successful synthesis of the precursor materials, CoAl hydrotalcite (CoAl-LDH) and CoAl layered double oxides (CoAl-LDO). EDS analysis confirmed a reduction in aluminum content after alkaline etching. XPS analysis verified the presence of abundant Co2+ and surface oxygen as crucial factors contributing to the catalyst’s excellent catalytic activity. The experimental results indicated that catalysts containing metal cation vacancies exhibited superior catalytic performance in formaldehyde oxidation compared to conventional hydrotalcite-derived composite oxides. H2-TPR confirmed a significant enhancement in the participation of lattice oxygen in the catalytic oxidation reaction; it was found that the proportion of surface lattice oxygen consumption by the E5-LDO catalyst (30.2%) is higher than that of the LDO catalyst (23.4%), and the proportion of surface lattice oxygen consumption by the E1-LDO/NF catalyst (27.5%) is higher than that of the LDO/NF catalyst (14.6%), suggesting that cation vacancies can activate the surface lattice oxygen of the material, thereby facilitating improved catalytic activity. This study not only reveals the critical role of surface lattice oxygen in catalytic oxidation activity, but also aids in the further development of novel catalysts for efficient room-temperature oxidation of HCHO. Moreover, it provides possibilities for developing high-performance catalysts through surface modification.

Andiroba oil (Carapa guianensis): Descriptive analysis and applicability

Andiroba oil (Carapa guianensis) is widely used in the Amazon region and elsewhere. Commercial products containing andiroba oil are available for various purposes. In this study, oil obtained using a traditional process was studied. The oil exhibited acceptable quality parameters. The major cations were Ca, K, and Na. Oleic acid was the major fatty acid in the lipid fraction. Hexanal was the major volatile compound. Owing to its composition, we hypothesized that andiroba oil could have insect repellent or antibacterial effects. Its repellent ability against weevils (Acanthoscelides obtectus) was high, although no antimicrobial activity against Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, or Salmonella was observed.

Policy-Related Gains in Urban Air Quality May Be Offset by Increased Emissions in a Warming Climate.

Air quality policies have made substantial gains by reducing pollutant emissions from the transportation sector. In March 2020, New York City's activities were severely curtailed in response to the COVID-19 pandemic, resulting in 60-90% reductions in human activity. We continuously measured major volatile organic compounds (VOCs) during January-April 2020 and 2021 in Manhattan. Concentrations of many VOCs decreased significantly during the shutdown with variations in daily patterns reflective of human activity perturbations, resulting in a temporary ∼28% reduction in chemical reactivity. However, the limited effect of these dramatic measures was outweighed by larger increases in VOC-related reactivity during the anomalously warm spring 2021. This emphasizes the diminishing returns from transportation-focused policies alone and the risk of increased temperature-dependent emissions undermining policy-related gains in a warming climate.

Antidepressant Effects of Essential Oils: A Review of the Past Decade (2012-2022) and Molecular Docking Study of Their Major Chemical Components.

Depression is a mental disorder that affects more than 300 million people worldwide. The medications available for treatment take a long time to exhibit therapeutic results and present several side effects. Furthermore, there is a decrease in the quality of life of people suffering from this affliction. Essential oils are traditionally used to relieve the symptoms of depression due to the properties of the constituents of these oils to cross the blood-brain barrier acting on depression-related biological receptors associated with reduced toxicity and side effects. In addition, compared to traditional drugs, they have several administration forms. This review provides a comprehensive assessment of studies on plants whose essential oil has exhibit antidepressant activity in the past decade and the mechanism of action of the major components and models tested. An additional in silico study was conducted with the frequent compounds in the composition of these essential oils, providing a molecular approach to the mechanism of action that has been reported in the past decade. This review is valuable for the development of potential antidepressant medications in addition to providing a molecular approach to the antidepressant mechanism of action of the major volatile compounds that have been reported in the past decade.

Impact of Commercial Inactive Yeast Derivatives on Antiradical Properties, Volatile and Sensorial Profiles of Grašac Wines

This study shows the impact of three different commercial inactive yeast derivatives (IYDs) (Opti Less™, Noblesse™, Optimum White™, Lallemand, Canada and Oenolees MP™ Lafort, USA) during the 6-month aging period on the volatile profile, sensory attributes and antiradical activity, including polyphenols and the total free sulfhydryl (-SH groups) content, of Grašac wines made in sequential fermentation with native Hanseniaspora uvarum S-2 and Saccharomyces cerevisiae QA23. The addition of IYDs helped in maintaining the constant values of antiradical activity during aging by increasing polyphenolic values and mitigating the decrease in -SH groups. HS-SPME-GC-MS analysis showed that esters were the major volatile compounds, with ethyl-acetate and 2-phenyl-ethyl-acetate being the most abundant among all the samples, followed by ethyl-dodecaonate, ethyl-decanoate and 3-methyl-butyl-octanoate, all of them contributing to fruity and floral aromas in wine. As the concentration of IYDs increased, a corresponding rise in the levels of certain volatiles, such as 2-methyl-1-propanol, phenyl-ethyl-alcohol and ethyl-octanoate, was observed. Sensory analysis showed that the addition of IYDs generally improved the taste and odor profile of the wine by reducing astringency and increasing fullness and complexity, regardless of the IYD type. The results demonstrated that different IYDs may have varying effects on wine, with each product having its specific purposes, providing the tools for winemakers to carefully regulate and obtain the desired sensory profile of the wine.

Spectral Light Treatment Influenced Morpho-Physiological Properties and Carvacrol Accumulation in Indian Borage.

The online version contains supplementary material available at 10.1007/s00344-023-11028-6.