Search Results (890)

The primary processing shapes the taste characteristics of coffee beans, while the regulation pathways remain unclear. Coffee beans processed by five methods—dry processing (DP), wet processing (WP), red honey (RH), black honey (BH) and anaerobic fermentation (AF)—were evaluated using electronic tongue analysis, sensory evaluation, and untargeted metabolomics. Sensory evaluation scores for mouthfeel, balance, and overall were higher in BH and AF. Conversely, the WP and DP exhibited heightened bitterness and astringency responses on the electronic tongue sensors, particularly for the former. The multigroup metabolomic comparison identified 808 DMs, and WGCNA revealed eight sensory-related modules containing 467 hub metabolites, mainly amino acids and derivatives, organic acids, alkaloids, and phenolic acids. KEGG analysis demonstrated that pathways such as caffeine metabolism and glycerophospholipid metabolism were the main pathways responsible for the metabolic differences. Further correlation analysis revealed potential flavor components closely associated with key taste characteristics. 1,3,4,5-tetrahydroxycyclohexanecarboxylic acid and Tyr demonstrated positive associations with bitterness, while TPC, TFC, Gly, and Met exhibited negative correlations with bitterness and astringency. Glu demonstrated a positive correlation with umami. These findings elucidate the material basis by which the primary processing modulates non-volatile compounds and taste perception, offering new insights into enhancing coffee quality. Full article

Light hydrocarbons in shale oil readily volatilize during conventional coring, surface handling, storage, and laboratory preparation. The resulting evaporative loss causes systematic underestimation of Rock-Eval S₁ peak (free hydrocarbons measured by programmed pyrolysis), which can bias oil-bearing evaluation, sweet-spot delineation, and resource assessment. Here we investigate Chang 7₃ lacustrine shale oil in the Ordos Basin (China) using frozen cores recovered by pressure-retained coring from four wells. Time-series Rock-Eval pyrolysis and thermal desorption–gas chromatography (TD–GC) were used to quantify the magnitude, temporal evolution, and practical equilibrium time of light-hydrocarbon loss and to establish a practical restoration model. S₁ decreases with storage time and exhibits a clear two-stage behavior. Shale shows a rapid-loss stage during 0–90 days, followed by a practical equilibrium stage after 90 days (S₁ change less than 5%). Sandstone interbeds lose light hydrocarbons faster and more completely, reaching practical equilibrium after 60 days. TD–GC indicates that the lost fraction is dominated by n-alkane components lighter than C₁₃, with gaseous hydrocarbons showing the greatest depletion; medium and heavy fractions decrease modestly. Loss is coupled with progressive desorption from kerogen and clays, leading to enrichment of heavier components in the residual free hydrocarbons and a shift of the modal carbon number toward higher values. At the shale equilibrium time, total organic carbon (TOC) and vitrinite reflectance (R_o) jointly control the restoration factor K. We propose a two-parameter restoration model: K = (0.4024·ln (TOC) + 0.821)·(0.652·R_o + 0.4292). Applying the model to more than 50 conventionally cored wells reveals that the Qingyang–Zhengning area in the southwestern basin is the principal enrichment zone of original free hydrocarbons, followed by the Jiyuan area in the north and the Huachi area in the central basin, whereas the eastern basin is relatively depleted. The workflow provides a robust and transferable approach for correcting S₁ and improving shale-oil evaluation in lacustrine systems. Full article

Coconut milk-based Filipino foods provide a favorable environment for microbial growth and are highly susceptible to spoilage. Traditionally, spoilage in such foods has been assessed through subjective sensory evaluation, a method that often lacks consistency and accuracy. The present study introduces an electronic nose system employing Support Vector Machine (SVM) algorithms to objectively and quantitatively determine spoilage in coconut milk-based Filipino foods, including Bicol Express, Ginataang Langka, Laing, Bilo-bilo, Maja Blanca, and Ginumis. The developed system integrates six MQ gas sensors connected to an Arduino Nano and a Raspberry Pi 4B to detect and process volatile organic compounds emitted from the foods. The SVM algorithm was selected for its effectiveness in high-dimensional spaces and its ability to construct a binary classifier capable of distinguishing between spoiled and fresh samples. Dimensionality reduction in sensor data was achieved using Principal Component Analysis, which further enhanced classifier performance. System evaluation results demonstrated a high classification accuracy of approximately 98.95%, indicating the robustness of the proposed approach. The utilization of this technology offers significant benefits, not only for individuals with impaired olfactory function but also for the food industry, providing a reliable tool for food quality control and safety. Moreover, the outcomes suggest broader applicability to other perishable food products, with potential contributions to improved global food safety and storage practices. Full article

Cooking-related emissions represent a major contributor to indoor air pollution in residential kitchens, producing complex mixtures of volatile organic compounds (VOCs), odor-causing gases, oil vapors, particulate matter (PM_2.5), and combustion-related pollutants (CO and NO_x). In this study, a controlled ozone-assisted oxidation approach was integrated into a recirculating (ductless) domestic kitchen hood equipped with a confined reaction chamber and experimentally evaluated under closed-loop operating conditions where treated air was returned to the indoor environment after post-treatment. A multivariate Response Surface Methodology (RSM) framework based on the Box–Behnken design was employed to quantify and optimize the coupled effects of temperature (20–30 °C), relative humidity (40–60%), ozone dosage (1–3 ppm within the confined reaction zone), and airflow rate (150–250 m³/h) on multi-pollutant removal performance. The results demonstrate that ozone assistance substantially improves the abatement of oxidation-sensitive pollutants, particularly VOCs and odor, while airflow rate strongly governs transport-dominated pollutants such as PM_2.5 and oil vapors. In contrast, CO and NO_x exhibited limited improvement, indicating that ozone-assisted oxidation alone is insufficient for comprehensive control of combustion-related gases under short-residence-time recirculating hood conditions. The main contribution of this work is the implementation of a demand-driven ozone management strategy, supported by dual ozone sensing for reaction-zone control and outlet safety verification, where ozone generation is activated only in the presence of reactive gaseous pollutants and automatically reduced or terminated once pollutant concentrations fall below predefined thresholds, minimizing unnecessary oxidant release. Residual ozone downstream of the reaction stage was continuously monitored to prevent excess ozone return to the occupied zone. Overall, the proposed closed-loop, feedback-controlled ozone-assisted recirculating range hood concept demonstrated device-level reductions in measured VOC/odor signals under controlled conditions, while also highlighting the need for complementary post-treatment components for particle- and combustion-related pollutants. However, the potential formation of secondary oxidation byproducts was not characterized in this study, and therefore the results should be interpreted with respect to device-level pollutant removal rather than comprehensive indoor air quality improvement. Full article

Modern agriculture is increasingly reliant on imported fertilizers and subject to price volatility, compounded by environmental pressures arising from the overuse of synthetic fertilizers. This study assessed the impact of Furcellaria lumbricalis algal biostimulant, produced by anaerobic fermentation, on dry matter yield and plant development indicators of garden radish (Raphanus raphanistrum subsp. sativus) in five soil substrate types. Biostimulant doses aimed at reducing mineral fertilizer application to 75% of the full rate while maintaining or improving yield were evaluated; yet no statistically significant effect on dry matter yield was observed, and the hypothesis was therefore not statistically confirmed. The experiment included five substrate types (sandy clay, sandy clay with organic matter, sand, sand with organic matter, and peat) and six fertilizer/biostimulant treatments, including 75% mineral fertilizer combined with 3%, 6%, and 12% algal biostimulant concentrations. Linear mixed models showed that substrate type (F = 19.58; p < 0.001) and fertilizer variant (F = 5.00; p < 0.001) had statistically significant effects on total dry matter yield, but their interaction was not statistically significant. All 75% and 100% mineral fertilizer variants with and without biostimulant produced statistically significantly higher yields than the unfertilized control (p = 0.0016–0.0337). The leaf development indicator (AtLeaf) index was statistically significantly higher in all biostimulant variants compared to the unfertilized control. Principal component analysis (PCA) and redundancy analysis (RDA) demonstrated that substrate type determines the primary structure of the substrate–plant system, while biostimulant effects were expressed as modulation of existing processes within the substrates. The results indicate substrate-specific responses to Baltic Sea algal Furcellaria lumbricalis digestate with statistically significant effect observed only in peat, consistent with previous findings, while no significant effects were detected in other substrates. Although the effects of the biostimulant on dry matter yield were not consistently statistically significant, the observed trends in plant development indicators and substrate–plant system responses suggest that Furcellaria lumbricalis digestate may have potential as a nutrient recycling component within a circular bioeconomy framework. Full article

This study comprehensively analyzed the effects of gamma irradiation (GI) on the flavor profile of aged light-flavor tartary buckwheat Baijiu (LTB) using E-nose, E-tongue, and high-sensitivity headspace–gas chromatography–ion mobility spectrometry (HS-GC-IMS). A total of 30 volatile organic compounds (VOCs) were identified, with concentrations showing significant dose-dependent correlations with GI treatment. Aging alone reduced harsh and pungent VOCs (e.g., 1-propanol, 2-methyl butanoic acid ethyl ester), while GI followed by aging further decreased undesirable compounds (e.g., butanal-D, pyrrolidine) and enhanced beneficial flavor components, such as 1,1-diethoxy ethane-D and butanoic acid propyl ester. Notably, this treatment partially restored 1-propanol, triethylamine, and 2-butanone-M, though their levels remained significantly lower than in newly brewed LTB, achieving a more balanced purity and flavor complexity. The significantly elevated levels of tetrahydrofuran-M/D, 1,1-diethoxy ethane-D, and cyclohexane in GI-treated aged LTB, along with their dose-dependent accumulation patterns, suggest their potential as reliable markers. Multivariate analysis confirmed that all three techniques (E-nose, E-tongue, and HS-GC-IMS) effectively differentiated LTB samples, with strong correlations between E-nose and HS-GC-IMS data, as well as between E-tongue and HS-GC-IMS results. This work provides flavor fingerprints and potential markers for gamma-irradiated LTB identification, while proposing an innovative technical approach for rapid flavor assessment of light-flavor Baijiu. Full article

The integration of rooted plant flour into traditional noodle matrices, such as rice noodles and qingke noodles, represents a novel approach to enhancing the nutritional and sensory profiles of staple foods. This study investigates the volatile flavor components and functional compounds derived from rooted plant flours, including Gongmi “tribute rice”, qingke “highland barley” flour, kudzu vine flour, Gastrodia elata blume flour, dried ginger flour, and fishwort root flour, when incorporated into rice and qingke noodles. The novelty of this research lies in its comprehensive analysis of how these flours influence not only the nutritional and textural properties but also the volatile organic compounds (VOCs) that define sensory acceptance and health benefits. Using advanced gas chromatography mass spectrometry (GC-MS), we identified key VOCs, such as esters, aldehydes, and terpenes, which contribute to unique flavor profiles like umami, sweetness, and earthy notes in fortified noodles. Additionally, the study highlights the best functional compounds for health, including polyphenols, resistant starch, and polysaccharides, which demonstrate significant antioxidants, anti-inflammatory, and cholesterol-lowering properties. For instance, highland barley enriched flour exhibited high levels of phenolic compounds and carotenoids, which correlated with improved antioxidant activity and a reduced glycemic index. Similarly, Gongmi flour contributed elevated levels of γ-aminobutyric acid (GABA) and rutin, enhancing the rice noodles’ potential to manage metabolic diseases and support cardiovascular health. Molecular docking analyses predicted strong interactions between key volatile compounds (e.g., 3-dihydro-1, 3-trimethyl-33-phenyl-1H-indene) and metabolic targets like ACE and SGLT1, suggesting mechanisms for their cardioprotective and anti-diabetic effects. This research provides a groundbreaking framework for developing next generation functional foods by leveraging rooted plant flours to bridge the gap between sensory appeal and health efficacy, offering strategic insights for personalized nutrition and sustainable food production. Full article

Photovoltaic (PV) systems are important for sustainable energy infrastructure, but their rapid deployment introduces complex fire dynamics that current regulations fail to address adequately. While existing standards focus on the electrical safety of individual components, they often neglect the risks arising from the interaction between the PV array and the building envelope. This review synthesizes current research on ignition mechanisms, thermal behavior, and the aerodynamic propagation of smoke to evaluate these overlooked hazards. A primary finding is that the interstitial space between the panel and the roof functions as a “heat trap,” significantly altering airflow patterns and accelerating flame spread even across fire-rated materials. The analysis further highlights that standard testing protocols do not sufficiently account for the urban dispersion of toxic combustion byproducts, such as hydrogen fluoride and volatile organic compounds. By evaluating recent advancements in Computational Fluid Dynamics (CFD) and helium-based surrogate testing, this paper demonstrates that accurate prediction of pollutant transport requires coupled modeling of wind effects and thermal buoyancy. The study concludes that ensuring urban fire resilience demands an evolution from component certification to integrated system assessments that include installation geometry, ventilation strategies, and environmental impact. Full article

This study aimed to provide a comprehensive characterization of floral volatile organic compounds (VOCs), perform systematic comparative analysis among multiple fragrant camellias, and establish a classification framework based on aroma components for cultivars derived from Camellia Sect. Theopsis. Volatile compounds were analyzed from 21 fragrant camellias using headspace solid-phase microextraction coupled with gas chromatography–time-of-flight mass spectrometry (HS-SPME-GC-TOFMS), followed by cluster and correlation analyses. A total of 51 volatile compounds were identified, including 20 alcohols, 15 aldehydes, and five esters, among which 27 were designated as major aroma components. Alcohols were the dominant class, and phenylethyl alcohol was detected in all cultivars, with a relative abundance ranging from 1.30% to 45.86%. Certain compounds, such as eugenol and 2-pentylfuran, exhibited cultivar-specific enrichment. Cluster analysis revealed a high degree of similarity in volatile profiles, with the strongest correlation observed between Camellia ‘Himenoka’ and Camellia ‘Minato-no-haru’ (r = 0.97). This similarity may be associated with a shared parental background, particularly the frequent use of Camellia lutchuensis in breeding. These findings provide a systematic understanding of floral VOC composition and offer a chemical basis for the utilization of Camellia Sect. Theopsis germplasm in fragrance-oriented breeding. Full article

The intestinal mucosal barrier is a layered structure comprising fundamental components that play important roles in regulating paracellular permeability. Disruption of intestinal barrier homeostasis predisposes to infections, mucosal damage, and metabolic and allergic diseases. To provide protection against potential damage to the intestinal mucosa, agents such as prebiotics and probiotics are recommended due to their ability to secrete components and metabolites (e.g., bacteriocins, organic acids, enzymes) that can exert beneficial biological effects. The aim of this study is to comprehensively investigate the effects of a postbiotic derived from Pediococcus acidilactici on healthy rat intestinal tissue. A total of 78 Wistar Albino rats were used in this study. Following compositional analysis of the postbiotic, the animals were administered the postbiotic orally via gavage for different durations (7, 14, 21, 28 days) and at different doses (250 mg/Kg, 500 mg/Kg, 1000 mg/Kg). Characterization of the produced postbiotic revealed a diverse spectrum of biologically active compounds, including organic acids, phenolics, and volatile compounds. Histopathological examination of intestinal sections (duodenum, jejunum, ileum, cecum, colon, and rectum) showed no pathological lesions in any of the experimental groups. Conversely, immunohistochemical analysis revealed that the postbiotic increased the expression of CLDN3, OCLN, ZO1, AQP4, and AQP8, proteins involved in intestinal permeability and fluid transport, in a dose-dependent manner. These results highlight the potential of Pediococcus acidilactici as a supportive agent in a range of intestinal pathologies, including major intestinal diseases such as Crohn’s disease, ulcerative colitis, and inflammatory bowel disease (IBD). Full article

This study characterizes the volatile organic compound (VOC) profiles of young monovarietal red wines from five cultivars widely grown in Alentejo, Portugal—Aragonez, Castelão, Merlot, Syrah, and Trincadeira, across two consecutive vintages (2021 and 2022), in a total of 20 samples. Understanding how grape variety and harvest year shape VOC composition is essential for defining varietal typicity, supporting authenticity assessments, and guiding quality-driven enological practices. VOCs were extracted using headspace solid-phase microextraction (HS-SPME) and analyzed by gas chromatography coupled to time-of-flight mass spectrometry (GC–TOFMS), providing a semi-quantification of 142 volatile compounds across nine chemical families. Statistical analyses, including ANOVA and Principal Component Analysis (PCA), unveiled significant effects of variety, vintage, and their interactions on VOC composition, enabling clear discrimination of the wines. Notably, terpenes and C₁₃-norisoprenoids exhibited strong varietal differentiation patterns: Castelão and Trincadeira showed higher relative proportions of monoterpenes like linalool, β-citronellol, and geraniol, whereas Aragonez presented increased sesquiterpene levels including β-bisabolene and α-muurolene, and Syrah and Merlot displayed more diverse terpenoid patterns. Despite their lower abundance, C₁₃-norisoprenoids, particularly trans-β-ionone, consistently differentiated wines across vintages. A 100% ribbon chart of the main terpenoids and C₁₃-norisoprenoids highlighted genotype-driven and vintage-independent patterns, underscoring their potential as robust markers of Portuguese red wines. This study presents a high-resolution HS-SPME–GC–TOFMS chemometric workflow for the profiling and classification of young Alentejo red wines, highlighting consistent varietal patterns in terpene and C₁₃-norisoprenoid distributions under the studied conditions. Full article

Condiment sauces such as soy sauce, fish sauce, oyster sauce, and Worcestershire sauce play a vital role in culinary practices and cultural identity, particularly in the Philippines. These sauces are distinguished by their unique volatile organic compound profiles, which define their aroma and flavor. With the growing demand for these condiment products, there is an increasing need for accurate and efficient methods to classify them, ensuring product authenticity and strengthening quality control. However, conventional approaches such as sensory evaluation and laboratory-based chemical analysis are often expensive, time-consuming, and subjective. To address this limitation, we used an electronic nose (e-nose) system integrated with a Support Vector Machine (SVM) classifier for the classification of dark condiment sauces. The system consists of an array of MQ-series gas sensors connected to an Arduino Mega 2560 for analog-to-digital conversion, with Raspberry Pi 5 serving as the primary processing unit. Sensor data undergo preprocessing steps, including standardization and dimensionality reduction through principal component analysis, before being classified using SVM. A total of 120 samples, consisting of 40 readings per condiment type, were used for training and testing, while 60 additional samples—15 per class—were reserved for validation. The e-nose system achieved a 95% classification performance, as evaluated using a confusion matrix and overall accuracy metrics. These results demonstrate the potential of the e-nose combined with SVM as a reliable tool for condiment classification. The system offers practical applications in quality control and product authentication. Future work may extend its capabilities toward spoilage detection, the integration of different gas sensors, and the classification of a wider variety of condiment sauces. Full article

Background: Gumming disease caused by Fusarium tricinctum severely threatens Zanthoxylum bungeanum production. This study investigated the antifungal potential of volatile organic compounds (VOCs) produced by an endophytic fungus, Schizophyllum commune, isolated from Z. bungeanum. Methods: A dual-culture assay evaluated VOCs inhibition against F. tricinctum. Compounds were identified using headspace solid-phase microextraction gas chromatography-mass spectrometry, and the antifungal mechanism of this component was explored. Results: VOCs from S. commune significantly inhibited mycelial growth and sporulation of the pathogen. Among 53 identified compounds, 1-octen-3-ol (mushroom alcohol) was the most abundant (35.98% relative content) and exhibited strong antifungal activity with an EC₅₀ of 0.15 µL/mL against F. tricinctum. Mechanistically, 1-octen-3-ol disrupted cell membrane integrity by increasing alkaline phosphatase and β-1,3-glucanase activities, leading to enhanced permeability and content leakage. It also induced oxidative stress by promoting reactive oxygen species accumulation via elevated NADPH oxidase and superoxide dismutase activities, while suppressing antioxidant enzymes. Conclusions: 1-octen-3-ol inhibits F. tricinctum through membrane disruption and oxidative stress, offering a promising eco-friendly strategy for controlling gumming disease. Full article

Storage temperature (ST) and grain moisture content (GMC) critically influence cereal quality during storage. However, their interactive effects, the associations among oxidative indicators, quality components and major volatile organic compounds (VOCs) variations in millet during storage are not fully understood. In this study, foxtail millet was stored for 360 days at three STs (−18 °C, 4 °C and 25 °C) and three GMC levels (11.50%, 12.80% and 14.30%). Changes in oxidative indicators (malondialdehyde [MDA], electrical conductivity [EC] and catalase activity [CAT]) and quality components (crude protein [CP], yellow pigment [YP] and soluble sugar [SS]) were monitored. Viscosity characteristics and VOCs were analysed after storage. Under this study, ST was the primary factor driving the changes in oxidative indicators and quality components during the storage stage. The viscosity characteristics of stored millet are primarily influenced by ST, while the changes in major VOCs are mainly affected by ST, GMC, and their interaction effects. Significant negative correlations were observed between EC or MDA and dodecanenitrile and (E/Z)-4-heptenal, whereas the YP, CP, and SS were significantly positively correlated with both compounds. After day 360, the samples stored at −18 °C with 11.5% GMC exhibited 34.05% lower MDA content and 29.55% lower EC than those stored at 25 °C with 14.3% GMC. The treatment better preserved CAT, SS, YP, viscosity characteristics and major VOCs, including (E/Z)-4-heptenal. These findings provide a scientific basis for optimising storage conditions to maintain the nutritional and sensory quality of foxtail millet. Full article

Conventional paints pose major environmental and health concerns due to their reliance on heavy-metal pigments and volatile organic compound (VOC)-emitting binders, emphasizing the need for sustainable alternatives. Previous formulations of biologic paints that combined bacteria-derived dsRED pigment protein and casein-based binders, while devoid of toxic components, suffered from prolonged drying times (~16 min), limiting their practical applicability. The present study addresses this key limitation by incorporating cellulose nanocrystals (CNC) and chitosan as biologic additives to enhance drying kinetics. Paint formulations containing 2%, 5%, and 10% of each additive were tested under controlled environmental conditions (20 °C, 60% relative humidity) following the GB/T 1728–2020 standard. Both CNC and chitosan significantly reduced drying time in a concentration-dependent manner (p < 0.001). The 10% CNC and 10% chitosan formulations achieved 61% and 44% reductions in drying time, respectively, relative to the unmodified biologic paint (12.96 ± 1.07 min at baseline). Regression analyses indicated that each 1% increase in CNC or chitosan concentration reduced drying time by 0.77 min and 0.58 min, respectively. The optimized paints exhibited acceptable drying times (5–7 min). These findings demonstrate an advancement in the development of biologically derived coatings, providing a feasible pathway toward safe and sustainable alternatives to conventional synthetic paints. Full article