Composition Of Compounds Research Articles

Modulation of Gut Microbiota Composition and Microbial Phenolic Catabolism of Phenolic Compounds from Achillea millefolium L. and Origanum majorana L.

The impact of the nonbioaccessible fraction of two phenolic-rich extracts from Achillea millefolium L. (yarrow) and Origanum majorana L. (marjoram) on the modulation of the human gut microbiota was investigated in vitro. Microbial metabolism of the phenolic compounds was also addressed. In general, phenolic acids or O-glycosidic flavones quickly disappeared, in contrast to methoxy- or C-glycosidic flavonoids. This colonic metabolism yielded phloroglucinol, 3,4-dimethoxyphenylacetic acid, 3-(4-hydroxyphenyl)-propionic acid, and 4-hydroxybenzoic acid as the main metabolites of the microbial catabolism of rosmarinic acid or caffeoylquinic acids, among others. The 16S rRNA gene sequencing showed that the most promising modulatory effect was related to the increase in Bifidobacterium spp., Collinsella spp., Romboutsia, and Akkermansia muciniphila for both plant extracts, along with Blautia spp. and Dialister for yarrow extract. This beneficial modulation was accompanied by the increase in butyric acid production, highlighting the potential prebiotic-like effect on the gut microbiota of these two previously unstudied edible plants.

Effect of Temperature and Storage on Coffee’s Volatile Compound Profile and Sensory Characteristics

The study investigated the effects of storage temperature, type of coffee, and brewing method on coffee’s volatile compound profile and sensory quality. Three types of coffee were included in the study: Arabica, Robusta, and their 80/20 blend. Samples were stored at 5 °C and 20 °C for one month, after which the changes in the composition of volatile compounds were analysed and the sensory quality of espresso and cold brew coffee was assessed. The results showed that storing coffee at a lower temperature slows the changes in the profile of volatile compounds such as aldehydes, alcohols, pyrazines, and furans, helping preserve the desired aroma and flavour characteristics. Storage at higher temperatures resulted in greater changes in the volatile profile and sensory quality, with higher perceptions of earthy, sharp, and smoky notes and lower chocolatey and sweet notes. The brewing method also had a significant effect on the sensory quality. The espresso coffee had a higher intensity of coffee aroma, chocolate flavour, smoky aroma, and roasted notes. In contrast, cold brew coffee was perceived as sweeter, fruitier, and had more pronounced rum notes. The coffee type also significantly influenced the aroma and flavour profile. Arabica had a more harmonious and mild aromatic profile, while Robusta had a sharper aroma. The blend of Arabica and Robusta combined the characteristics of both coffees and offered a balanced aromatic profile.

From Waste to Taste: Coffee By-Products as Starter Cultures for Sustainable Fermentation and Improved Coffee Quality

Utilizing coffee by-products in the fermentation process of coffee offers a sustainable strategy by repurposing agricultural waste and enhancing product quality. This study evaluates the effect of applying a starter culture, derived from coffee residues, on the dynamics of reducing and total sugars during coffee fermentation, as well as the composition of aromatic compounds, organic acids, and the sensory profile of coffee inoculated with yeast (Saccharomyces cerevisiae) and lactic acid bacteria (Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus), in comparison to a spontaneously fermented sample. Volatile compounds were identified and quantified using dynamic headspace gas chromatography-mass spectrometry (HS/GC-MS), with predominant detection of 2-furancarboxaldehyde, 5-methyl; 2-furanmethanol; and furfural—compounds associated with caramel, nut, and sweet aromas from the roasting process. A reduction in sugars (glucose, fructose, and sucrose) occurred over the 36 h fermentation period. Lactic acid (2.79 g/L) was the predominant organic acid, followed by acetic acid (0.69 g/L). The application of the inoculum improved the sensory quality of the coffee, achieving a score of 86.6 in evaluations by Q-graders, compared to 84 for the control sample. Additionally, descriptors such as red apple, honey, and citrus were prominent, contributing to a uniform and balanced flavor profile. These findings indicate that controlled fermentation with starter cultures derived from coffee by-products enhances sustainability in coffee production. It achieves this by supporting a circular economy, reducing reliance on chemical additives, and improving product quality. This approach aligns with sustainable development goals by promoting environmental stewardship, economic viability, and social well-being within the coffee industry.

Thermal and radiation effects on the cross-linking and mechanical properties of HNBR elastomers

This study investigates the enhancement of the properties of mixtures based on hydrogenated butadiene nitrile rubber (HNBR) under thermal, radiation and thermo-radiation effects by introducing into them the composition of chlorine-containing triazine and peroxide compounds (HCPX and ABTST) into the composition. It has been shown that radiation-chemical cross-linking and the formation of effective chemical cross-links in HNBR depend both on the absorbed dose of radiation and on the addition of vulcanizing agents. It has been established that the activity of hexachloroparaxylene (HCPX), dicumyl peroxide (DP) and triazine (ABTST) is not the same; the content of the gel increases markedly with increasing absorbed dose. A higher crosslinking density is observed for images subjected to thermo-radiation crosslinking. The change in the molecular structure of HNBR, observed both during heating and irradiation, has the same nature. It has been shown that the physical and mechanical properties of saturated radiation and thermal vulcanizates are practically inferior to thermo-radiation ones in strength.

Evaluation of the Mechanical and Electrical Properties of Multistage Drawn Copper-Clad Aluminum Wire After Annealing Process

This study evaluates the mechanical and electrical properties of copper-clad aluminum (CCA) wire prepared with a total cross-section reduction of 89% through a multistage cold drawing process and subjected to annealing at various temperatures. In addition to the CCA wire, individual samples of oxygen-free copper and aluminum, drawn with a cross-sectional reduction of 50%, were annealed under the same temperature conditions to enable a comparative analysis. Tensile tests for strength and elongation measurements were conducted, while electrical conductivity was assessed through resistivity tests. SEM and EDS analyses were performed to examine the diffusion thickness and the composition of intermetallic compounds generated at the Al/Cu interface of CCA wire. The tensile strength of the CCA wire decreased and its elongation increased up to 250 °C, after which were maintained. As the annealing temperature increased, intermetallic compound layers of Al2Cu, AlCu, and Al4Cu9 were formed at the Al/Cu interface of the CCA wire, and their thickness increased. Electrical conductivity reaches a maximum at 200 °C and then continuously decreases, showing a negative linear correlation with an increase in the diffusion layer thickness of intermetallic compounds. The study confirmed that cold-drawn CCA wire achieves stable mechanical properties and maximum electrical conductivity at the optimal annealing temperature.

Composition of New Compound for the Treatment of Long QT Syndrome

Composition of New Compound for the Treatment of Long QT Syndrome

Impact of yeast selection on composition of vinegar fermented from pomace of a Finnish apple cultivar

Alcoholic beverages and vinegar products were produced using the pomace of a Finnish apple cultivar, and the influence of yeast strains on the non-volatile and volatile compound contents were studied. Apple pomace mashes were fermented with Saccharomyces cerevisiae, Torulaspora delbrueckii, and sequential inoculation with Lachancea thermotolerans and S. cerevisiae to produce alcoholic beverages. Commercial non-pasteurized vinegar was used as a starter to ferment alcoholic beverages into vinegars. Ethanol, acetic acid, sugars and organic acids were determined using GC-FID. A total of 63 volatile compounds were detected in the samples using HS-SPME-GC-MS. Alcoholic beverages fermented with the sequential inoculation had the highest total content of organic acids, and pure inoculation with T. delbrueckii resulted in the highest total content of sugars. Selection of different yeast strains did not alter the content of ethanol or acetic acid, but it significantly influenced the composition of volatile compounds in alcoholic beverages and vinegars. Compared to initial apple pomace mash, significant increases in the contents of ethyl esters (up to 4810-folds), higher alcohols (up to 24-folds) and volatile acids (up to 1853-folds) were observed in fermented products depending on the yeasts used. The main volatile compounds in vinegars prepared from S. cerevisiae fermented beverage were 2-phenylethanol, octanoic acid, and decanoic acid, from T. delbrueckii beverage 2-methylpropanoic acid and 3-methylbutanoic acid, and from sequential fermentation ethyl acetate, and ethyl 2-hydroxypropanoate. In conclusion, non-Saccharomyces yeasts have potential to produce more complex aromatic profile to fermented products derived from by-products of apple juice processing.

Effect of banana cultivars and ripening stages on bioactive compounds and antioxidant capacity of fresh clear low-viscosity banana juice

Food-based antioxidants reduce oxidative stress caused by metabolic processes, scavenge free radicals, promote cardiovascular health, and preventing oxidative-stress related diseases, among other health advantages. The current study aims to investigate the low-viscosity banana juices’ bioactive compounds and antioxidant capacity dependence on cultivars and ripening stages. Five banana cultivars were studied: Mbilabile, Pisang Awak (PSA), Yangambi km5 (YKM5), Ndeshi, and Mlonga. An improved mechanical extraction method involving malaxation of peeled banana pulp until low-viscosity banana juice separates from the pulp was used to extract banana juice. Considered ripening stages were stage 3; more green than yellow, 4; more yellow than green, 5; yellow with a trace of green, 6; all yellow, and 7; all yellow with brown spots. It was revealed that banana juice is rich in polyphenolic compounds 145.02–320 mg GAE/L and ascorbic acid, 0.45–1.40 g/L. In addition, the composition of total phenolic compounds (TPC) and ascorbic acid varied with banana cultivars and ripening stages. Furthermore, banana juice could reduce 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radicals by 67–93%. The antioxidant capacity of banana juice varied with cultivars and ripening stages (p < 0.05). Correlation analysis suggested ascorbic acid influenced banana juice free radical scavenging capacity.

Composition, Anti-Diabetic, and Antioxidant Potential of Raphanus sativus Leaves.

Limiting and/or slowing down the starch digestion process and consequently the release of glucose can be an important strategy for the prevention of type 2 diabetes (T2D). The aim of the current in vitro study was to assess the anti-diabetic and antioxidant potential of red radish leaves of the Carmen, Jutrzenka, Saxa, and Warta cultivars. In the context of anti-diabetic activity, the effect of leaves on potato starch digestion and free glucose binding, as well as inhibitory effects of leaf extracts against α-amylase and α-glucosidase and non-enzymatic glycation (AGEs) were determined. The basic chemical composition, quantitative composition of phenolic compounds, and antioxidant activity of leaves were also estimated. This study showed that all radish leaves inhibited the breakdown of potato starch and showed their ability to bind glucose. This activity was correlated with the content of hydroxycinnamic acids, protein and dietary fiber while flavones was probably responsible for glucose binding. Leaf extracts inhibited α-glucosidase activity and formation of AGEs but were practically inactive towards α-amylase. Inhibition of α-glucosidase activity was related to the content of proanthocyanidins and inhibition of AGEs formation to flavonols. These results point to radish leaves, especially the Warta and Jutrzenka cultivars, as a potential natural remedy for treating T2D.

Metabolite profile analysis of methanol extract of belulang grass (Eleusine indica (L.) GAERTN) leaves by gas chromatography-mass spectrophotometry (GC-MS) method

Leaf of belulang grass (Eleusine indica (L.) Gaertn) is one of the wild plants that is used as herbal medicine by the community because of its many health benefits for the treatment of certain diseases such as diabetes, high blood pressure, and cholesterol. A materil is said to have potential as a medicine because the composition of the chemical compounds contained in a plant is not always the same and requires further testing. Differences in chemical compound content can be influenced by environmental factors and plant metabolism. The aim of this research is to analyze the metabolite profile and abundance of metabolite compounds using the GC-MS instrument analysis approach. Sampling was conducted in Sidomulyo Village, Air Kumbang District, Banyuasin Regency, South Sumatra. Samples of belulang grass leaves obtained were dried, pulverized, and extracted with methanol solvent. The methanol extract was analyzed using GC-MS. The results showed that the highest 20 compound peaks were obtained based on the relative area percent of the 69 compounds obtained with an abundance of compounds amounting to 80.86%. At the highest peak, the compounds n-hexadecanoic acid, I-(+)-ascorbic acid 2, 6- dihexadecanoate, and pentadecanoic acid were found with a percent area of 31.25%.

Firsthand data acquisition for hypertension, its amelioration by extract of Bougainvillea spectabilis and formulation of nanoparticles

Hypertension is a widespread cardiovascular condition characterized by persistently elevated blood pressure, leading to serious health complications such as heart disease, stroke, and renal failure. This study investigates the antihypertensive properties of Bougainvillea spectabilis extract, focusing on its potential mechanisms of action and therapeutic efficacy. Using a controlled experimental design, hypertensive rats were treated with varying doses of Bougainvillea spectabilis extract. Blood pressure measurements were taken before and after treatment using a non-invasive tail-cuff method. Phytochemical analysis of the extract revealed a rich composition of bioactive compounds, including flavonoids, alkaloids, and tannins, known for their cardioprotective and vasodilatory effects. Results demonstrated a significant reduction in both systolic and diastolic blood pressure in treated subjects compared to the control group. Additionally, improvements in endothelial function were observed, indicated by increased nitric oxide levels and decreased oxidative stress markers. Histological analysis of vascular tissues showed enhanced integrity and reduced inflammation. These findings suggest that Bougainvillea spectabilis extract exerts a dual action: promoting vasodilation and improving endothelial health. The results support the potential of Bougainvillea spectabilis as a natural antihypertensive agent, highlighting the need for further research to elucidate its mechanisms and evaluate its clinical applicability in managing hypertension.

Volatile metabolomics and metagenomics reveal the effects of lactic acid bacteria on alfalfa silage quality, microbial communities, and volatile organic compounds

Lactic acid bacteria metabolism affects the composition of volatile organic compounds (VOCs) in alfalfa silage, which results in differences of odor and quality. The aim of this study was to reveal the effects of commercial Lactobacillus plantarum (CL), screened Lactobacillus plantarum (LP), and screened Pediococcus pentosaceus (PP) on quality, microbial community, and VOCs of alfalfa silage based on volatile metabolomics and metagenomics. The results showed that the LP and PP groups had higher sensory and quality grades, and the dominant bacteria were Lactiplantibacillus plantarum and Pediococcus pentosaceus. The main VOCs in alfalfa silage were terpenoids (25.29%), esters (17.08%), and heterocyclic compounds (14.43%), and esters such as methyl benzoate, ethyl benzoate, and ethyl salicylate were significantly increased in the LP and PP groups (P < 0.05). Correlation analysis showed that terpenoids, esters, and alcohols with aromatic odors were positively correlated with Lactiplantibacillus plantarum and Pediococcus pentosaceus. Microbial functions in carbohydrate and amino acid metabolism, biosynthesis of secondary metabolites, and degradation of aromatic compounds were significantly enriched. In conclusion, the addition of lactic acid bacteria can increase the aromatic substances in silage and further improve silage odor and quality.

Electrochemical Oxidation of Biomass-Derived Wastewaters for Simultaneous H2 Production

As the world continues to search for new ways to support the growth of a sustainable energy future, biomass conversion emerges as a potential method to produce carbon-neutral biofuels and biochemicals. For example, hydrothermal liquefaction (HTL) can be used to convert biomass- and waste-derived feedstocks into bio-crudes, which then undergo catalytic upgrading with exogenous molecular hydrogen (H2) for biofuel production (gasoline, diesel, jet oil.). HTL also generates an aqueous phase (HTL-AP) that contains up to 5 wt.% of organic compounds that cannot be treated with traditional wastewater treatment technologies (e.g., anaerobic digestion). Instead, we propose to use the HTL-AP to in situ generate the H2 needed for biofuel production via the electrochemical oxidation (ECO) of HTL-AP.1 2 In this work, we evaluate how the HTL-AP composition of both organic and inorganic compounds as well as the applied potential affect the ECO activity, energy consumption, and electrode stability. Initially, our electrochemical experiments were performed in batch cells to understand the performance of anode and cathode for ECO and H2 generation in terms of onset potential, exchange current densities, and Tafel slopes. This was followed by a demonstration of ECO long-term stability in a continuous-flow electrolyzer. Our studies show that the presence of organic compounds decreases the current density at high potential region but increases at low potential region for some HTL-AP. The anode stability increased from 24 h to &gt;3,000 h by optimizing the applied potential and the source of HTL-AP. However, the cathode performance and stability remained unaffected by the HTL-AP and potential. The resulting energy requirement for COD removal (kWh/kgCOD) of the optimized system is lower than that of the traditional wastewater treatment process. Furthermore, the energy requirement for H2 production (kWh/kgH2) is found to be almost half compared to the commercial electrolyzer. References (1) Andrews, E.; Lopez-Ruiz, J. A.; Egbert, J. D.; Koh, K.; Sanyal, U.; Song, M.; Li, D.; Karkamkar, A. J.; Derewinski, M. A.; Holladay, J. Performance of base and noble metals for electrocatalytic hydrogenation of bio-oil-derived oxygenated compounds. ACS sustainable chemistry &amp; engineering 2020, 8 (11), 4407-4418. (2) Qiu, Y.; Lopez-Ruiz, J. A.; Zhu, G.; Engelhard, M. H.; Gutiérrez, O. Y.; Holladay, J. D. Electrocatalytic decarboxylation of carboxylic acids over RuO2 and Pt nanoparticles. Applied Catalysis B: Environmental 2022, 305, 121060. Figure 1

The Applications of Plant Polyphenols: Implications for the Development and Biotechnological Utilization of Ilex Species.

Plants belonging to the Ilex species are distinguished by their rich composition of diverse phenolic compounds and various bioactive substances, which demonstrate dual functionalities in therapeutic applications and health promotion. In recent years, these plants have garnered significant interest among researchers. While the application scope of plant polyphenols (PPs) is extensive, the exploration and utilization of holly polyphenols (HPs) remain comparatively underexplored. This article reviews the research advancements regarding the predominant phenolic compounds present in commonly studied Ilex species over the past five years and summarizes the application studies of PPs across various domains, including pharmacological applications, food technology, health supplements, and cosmetic formulations. The objective of this review is to provide insights into the systematic research and development of HPs, offering references and recommendations to enhance their value.

Protocol Refinement for the Development of Coconut Inflorescence Powder

Aims: Coconut inflorescence holds significant potential as a nutraceutical due to its rich composition of bioactive compounds, including vitamins, minerals, and antioxidants. Its use in promoting health and preventing diseases has made it a valuable ingredient in both traditional medicine and modern functional foods. The aim of the study is the protocol refinement for the development of coconut inflorescence powder with acceptable moisture content and superior sensory quality. Study Design: Completely randomized design (CRD). Place and Duration of Study: Department of Plantation, Spices, Medicinal and Aromatic Crops, College of Agriculture, Vellayani, Kerala Agricultural University, between May 2024 and October 2024. Methodology: In the present study, coconut inflorescence was harvested at 5-6 months before inflorescence opening, size reduced (1 cm3 pieces), and precooked by adopting different methods, viz., steaming, boiling, dry roasting, and microwave cooking (non-precooked inflorescence was used as the control). The precooked inflorescence pieces were dried by different drying methods viz., hot-air oven drying at 600C (Control), cabinet drier at 600C, 700C, 800C and solar drying for developing coconut inflorescence powder (CIP). CIP was analyzed for moisture content and sensory quality. Results: CIP prepared by steaming the coconut inflorescence pieces for 30 minutes and drying in cabinet dryer at 600C (C1D1) recorded the least moisture content, 1.83±0.07 per cent. However, CIP prepared by boiling (95-1000C) the inflorescence pieces by submerging for 30 minutes and drying in cabinet dryer at 600C (C2D1) showed the highest mean rank value for all the sensory attributes viz., colour (735.50), consistency (730.63), flavour (730.68), mouthfeel (734.75) and taste (735.23) on a nine-point hedonic scale with a moisture content, 4.20±0.04 per cent. The lowest mean rank value for colour was recorded by C1D1 and C2D0 (211.06). The lowest values for consistency, mouthfeel, flavour and taste were observed for the treatments C4D1 (289.81), C4D1 (290.61), C4D0 (226.05) and C0D0 (216.50), respectively. Hence, C2D1 was identified as the best precooking and drying method for the preparation of coconut inflorescence powder.

In Vitro Antimicrobial Activity of Volatile Compounds from the Lichen Pseudevernia furfuracea (L.) Zopf. Against Multidrug-Resistant Bacteria and Fish Pathogens.

Lichens are symbiotic organisms with unique secondary metabolism. Various metabolites from lichens have shown antimicrobial activity. Nevertheless, very few studies have investigated the antimicrobial potential of the volatile compounds they produce. This study investigates the chemical composition and antimicrobial properties of volatile compounds from Pseudevernia furfuracea collected in two regions of Morocco. Hydrodistillation was used to obtain volatile compounds from samples collected in the High Atlas and Middle Atlas. Gas chromatography-mass spectrometry (GC-MS) analysis identified phenolic cyclic compounds as the primary constituents, with atraric acid and chloroatranol being the most abundant. Additionally, eight compounds were detected in lichens for the first time. The antimicrobial activity of these compounds was assessed using disc diffusion and broth microdilution methods. Both samples demonstrated significant antimicrobial effects against multidrug-resistant human bacteria, reference microorganisms, fish pathogens, and Candida albicans, with minimum inhibitory concentrations (MICs) ranging from 1000 µg/mL to 31.25 µg/mL. This study provides the first report on the volatile compounds from Pseudevernia furfuracea and their antimicrobial effects, particularly against fish pathogens, suggesting their potential as novel antimicrobial agents for human and veterinary use. Further research is warranted to explore these findings in more detail.

Schinus terebinthifolia Raddi-Untargeted Metabolomics Approach to Investigate the Chemical Variation in Volatile and Non-Volatile Compounds.

Schinus terebinthifolia Raddi is used in Brazilian folk medicine due to the wound healing and antiseptic properties of its bark, and its fruit are used as a condiment. However, the aerial parts of this plant have been studied and present some bioactive compounds as well. The aim of this study was to investigate the variation in volatile and non-volatile composition of S. terebinthifolia leaves using untargeted metabolomics. The leaves of four trees were collected over one year; ethanolic extracts were analyzed by UHPLC-MS and fresh leaves were analyzed by GC-MS using HS-SPME. The data were processed using online software. The results suggest seasonality interfered little with the chemical composition of leaves. On the other hand, the sex of the plant clearly determined the chemical composition of both volatile and non-volatile compounds. Chemical variability between plants with male and female flowers is fundamental information for the standardized use of its leaves. Compounds with important biological activities were putatively identified, confirming the potential use of S. terebinthifolia leaves as a source of bioactive compounds, reducing waste and increasing economic gains for local farmers throughout the year.

The Complexation in Co(NO3)2 ⋅ 6H2O/2,2′‐bipyridine/Y(NO3)3 ⋅ 6H2O/MeOH System: Still More to Uncover

AbstractThe formation of novel uncommon heterodinuclear complex was detected in Co(NO3)2 ⋅ 6H2O/2,2′‐bipyridine/Y(NO3)3 ⋅ 6H2O/MeOH system. The peculiarities of composition and structure of this new compound were found to alter its vibrational and thermal properties compared to those of reported major product formed in the same system.

Unexpectedly strong heat stress induction of monoterpene, methylbutenol, and other volatile emissions for conifers in the cypress family (Cupressaceae)

We investigated the biogenic volatile organic compound (BVOC) emission rates and composition of Cupressaceae species and how the emissions change in response to moderate warming and more severe heat stress. A total of 8 species from 7 distinct Cupressaceae genera were targeted in this study and exposed to laboratory-simulated heatwaves. Each plant was enclosed in a temperature-controlled glass chamber and allowed to equilibrate at 30 °C for 24 h. The temperature was then increased stepwise from 33 °C to 43 °C in 2 °C increments, with each step lasting 2 h, and was finally kept at 45 °C for 12 h. The BVOC emissions were measured periodically using an automated air sampler coupled to a gas chromatograph.Most of the sampled Cupressaceae species (6 out of 8) were low BVOC emitters (<0.3 μgC g−1 h−1) at 30 °C. However, the BVOC emissions of all 8 species increased strongly with temperature, and in most species (5 out of 8), the emissions continued to increase with longer exposure times to heat stress. The largest increase was observed in Thuja occidentalis and Chamaecyparis thyoides, which reached maximum emissions of 350 and 190 μgC g−1 h−1, respectively. Of the different BVOCs, monoterpenes responded most strongly to heat stress, with Q10 temperature coefficients typically ranging between 7.6 and 22, which were significantly greater than the model-predicted value of 2.7. Other BVOCs including sesquiterpenes, C9 aromatics (only detected in Calocedrus decurrens), methylbutenols, and other C5 oxygenates were also induced by heat stress, but generally at a lower magnitude than monoterpenes.Our results indicate that Cupressaceae are a large but typically dormant source of reactive volatile hydrocarbons (mostly monoterpenes) whose emissions can be activated by heat stress. This phenomenon could have important implications for ozone and aerosol formation, air quality, and human health, particularly in urban areas that are prone to heatwaves.

Chemical and Sensory Profile of Grape Distillates Aged in Quercus alba Casks Previously Used for Sherry Wine or Brandy.

This work investigates the influence of oak-cask ageing on the chemical composition and sensory profile of a variety of grape distillates. Wine spirit, wine distillate, neutral alcohol, and grape marc distillate were investigated. It is known that the characteristics of the ageing casks may have a considerable impact on the ageing process, so casks that had previously contained some type of sherry wine, sherry cask®, and casks that had previously contained brandy were studied. The results showed that ageing in either type of cask resulted in significant changes regarding volatile compound composition and a noticeable increase in phenolic and furfural compound content. Furthermore, sherry casks® contributed with sherry wine characteristic compounds that enriched the aromatic profile of the distillates, such as a greater increase in ethyl esters of organic acids. A less noticeable evolution was exhibited by the distillates with higher levels of congeners (wine spirit and grape marc distillate) when compared to wine distillate or neutral alcohol, where changes due to ageing were more evident. The sensory analysis confirmed that ageing significantly modified the organoleptic characteristics of all the distillates, with an increasing perception of certain notes such as oak, vanilla, spicy, and vinous when aged in sherry cask®.