Search Results (2,950)

Background/Objectives: During pregnancy, the body undergoes numerous physiological changes, many of which are driven by significant hormonal shifts. Pregnancy rhinitis is a condition characterized by nasal congestion that occurs during pregnancy without any other signs of respiratory infection or known allergic causes. The aim of the study was to examine the impact of pregnancy rhinitis on the sense of smell. Specifically, it focused on determining how the nasal congestion associated with pregnancy rhinitis may alter olfactory perception in pregnant people. Methods: The study group comprised fifty women, aged 18 to 41, all in their third trimester of pregnancy. The control group was made up of 25 non-pregnant women between the ages of 25 and 31. Olfactory function was assessed using Sniffin’ Sticks, and each participant completed the SNOT-22 questionnaire. Additionally, ENT examination, nasofiberoscopy, rhinomanometry were performed. Results: The comparison between the control and study groups in terms of detection, discrimination, and identification test scores revealed statistically significant differences. The study group demonstrated lower odor average test scores, indicating worse olfactory acuity and poorer identification abilities, with these effects being strong. In addition, the study group showed a lower discrimination test score compared to the study group, though this effect was weak. On the other hand, the control group showed a higher level of discrimination test score compared to the study group, though this effect was weak. However, the pregnant women did not perceive any subjective impairment in their sense of smell even though they had smell disturbances confirmed in the Sniffin Stick test. The SNOT-22 questionnaire results indicated that the study group reported subjectively worse nasal patency compared to the control group. Conclusions: This controlled study demonstrated that olfactory disturbances, confirmed by the Sniffin’ Sticks test, affected half of the pregnant participants, with reduced smell sensitivity observed in advanced pregnancy compared to non-pregnant controls. Notably, more than half of the women with objectively confirmed olfactory deficits did not report subjective complaints, highlighting the need for greater clinical awareness of sensory changes during pregnancy. Pregnancy-related swelling of the nasal mucosa leads to impaired upper airway airflow, contributing to a reduction in olfactory sensitivity. Full article

Human remains detection (HRD) dogs are vital tools in forensic science and disaster response, but their training is limited by the restricted availability of human material. Synthetic odorants such as Sigma Pseudo™ formulations provide safer, standardized alternatives, yet current products reproduce only a fraction of the volatile organic compound (VOC) profile of decomposition. In particular, sulfur-containing volatiles, which are highly odor-active and consistently present in human remains, are often missing, reducing biological fidelity. Here, we integrate analytical chemistry with canine olfactory genetics and molecular biology to explain these limitations. Dogs possess one of the largest olfactory receptor (OR) repertoires among mammals, with high allelic diversity and specialized trace amine-associated receptors (TAARs) tuned to cadaveric amines. Together with olfactory binding proteins (OBPs) and ciliary signal transduction cascades, these molecular mechanisms highlight why incomplete VOC mixtures may fail to activate the full receptor network required for reliable odor imprinting. We propose the “sulfur gap hypothesis” and suggest hybrid training strategies combining improved synthetics with ethically sourced biological samples to enhance HRD dog performance. Full article

Laying hens in the late laying period often experience reduced productivity and declining egg and meat quality, which limits breeding efficiency and resource utilization. This study aimed to evaluate the effects of multi-component Botanical Crude Extracts (BCEs) on egg and meat quality, metabolic health, and gut microbiota in aged laying hens. A total of 4320 hens were supplemented with 0.3% BCEs for 100 days, with evaluations at 60 and 100 days. BCE supplementation significantly enhanced egg flavor by promoting aromatic and fat-soluble volatiles and reducing odorous compounds (p < 0.05). BCEs improved yolk nutrition by enriching n-3 polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), and optimizing the n-6/n-3 ratio (p < 0.05). A moderate reduction in amino acids was observed, which may reduce bitterness and ammonia burden (0.05 ≤ p < 0.10, trend). In muscle, BCEs improved protein–fat distribution, increased intramuscular fat, and enhanced flavor-related metabolites, significantly improving meat quality of culled hens (p < 0.05). BCEs also reshaped gut microbiota, reducing harmful taxa and promoting short-chain fatty acid and aromatic metabolite biosynthesis (p < 0.05). Serum metabolomics revealed modulation of AMPK, calcium, and cholesterol pathways, improving antioxidant capacity and lipid regulation (p < 0.05). Correlation analyses linked beneficial bacteria and metabolites with yolk DHA levels and flavor (p < 0.05). Overall, BCEs enhanced egg and meat quality and physiological health, providing guidance for functional feed strategies in aged laying hens. Full article

This study intends to identify and quantify the individual, perceptual, and contextual factors associated with odor-related perception and to assess the perception of odor sources according to meteorological conditions. Two face-to-face seasonal community surveys were conducted using stratified random sampling with proportional allocation, yielding representative samples of residents in a southern Brazilian city, where mild constant temperatures throughout the year and shifting prevailing wind directions expose residents to different odor sources. Chi-Square tests were applied to assess associations between odor perception and qualitative variables, while logistic regression was used to identify predictors of higher annoyance. Results showed that prevailing wind direction influenced source attribution, with steel industry and sewage-related sites most frequently cited. Proximity to the steel plant increased both source recognition and annoyance levels. Reported impacts included closing windows and reducing outdoor activities. Self-reported respiratory problems consistently predicted higher annoyance levels in both surveys. The statistical methods were effective in analyzing the likelihood of odor-related perception and its relationship with explanatory variables. These findings highlight the value of a data-driven approach—specifically, integrating wind direction, source proximity, and community-based perception—to support urban environmental management and guide odor mitigation strategies. Full article

Volatile organic compounds (VOCs) are critical indicators of the metabolic status of whole-plant maize silage (WPMS). However, the impact of inoculating various strains of fermentation agents on VOC changes has not been systematically explored. This study aimed to determine how inoculation with Lactiplantibacillus plantarum and Lentilactobacillus buchneri modulates the VOC profile and odor of WPMS after 90 days. VOCs were extracted by headspace solid-phase microextraction and analyzed by gas chromatography-mass spectrometry (HS-SPME-GC-MS). Key VOCs were screened using the variable importance in projection (VIP) and substantiated by relative odor activity values (rOAV) and odor descriptions. A total of 82 compounds were identified, including 22 esters, 19 alcohols, 3 acids, 9 aldehydes, 2 ethers, 6 hydrocarbons, 4 ketones, 10 phenols, and 8 terpenoids. L. plantarum enhanced green/fruity odors while strain L. buchneri significantly reduced undesirable phenolic and aldehydic compounds. Six key VOCs influencing the odor of WPMS were selected: 4-ethyl-2-methoxyphenol and benzaldehyde, which contribute smoky, bacon, and bitter almond aromas, and (E)-3-hexen-1-ol, benzyl alcohol, (E, E)-2,4-heptadienal and methyl salicylate, which impart green, fruity, and nutty aromas. These findings highlight the effects and contributions of various strain additives on VOCs in WPMS, providing new theoretical insights for regulating the flavor profile of WPMS. Full article

Airborne fungal exposure in confined indoor environments is a growing public health concern, however the microbial composition of air inside private vehicles remains underexplored. This study aimed to characterize culturable airborne fungi in vehicle cabins and evaluate their association with environmental and behavioral variables. Air samples (100 L) were collected from 69 vehicles using a standardized culture-based method. Simultaneously, a detailed survey was administered to vehicle owners to document usage patterns, maintenance habits, and odor perception. Results revealed a total culturable fungal load of 31,901 CFU/m³, with Cladosporium, Aspergillus, and Penicillium as the most frequently isolated genera. Statistical analysis showed that fungal abundance and community composition were significantly associated with vehicle usage factors such as air disturbance, parking environment, air filter maintenance, and perception of musty odors. Vehicles parked outdoors had significantly higher Bipolaris levels, while lack of regular filter replacement was strongly associated with elevated Alternaria abundance. The presence of musty or moldy odors correlated with a 2.5-fold increase in Aspergillus levels. Redundancy analysis confirmed that odor perception and parking behavior were the strongest predictors of fungal community structure, with specific genera displaying distinct ecological preferences across usage conditions. Usage patterns and maintenance habits significantly influence in-cabin fungal communities, with implications for respiratory health, particularly due to the presence of allergenic and opportunistic genera like Aspergillus, Alternaria, and Bipolaris. Regular air filter maintenance and attention to odor cues may help reduce fungal load and associated health risks. Full article

In Central Europe, the fawning season of roe deer (Capreolus capreolus) directly overlaps with meadow and alfalfa harvest, typically from late May to early June. During these operations, tens or more likely hundreds of thousands of fawns are mutilated by agricultural machinery. To mitigate this unethical mortality, wildlife managers often deploy odor repellents to drive roe deer individuals from high-risk fields before mowing. Therefore, we evaluated repellent efficacy in a paired design. The abundance of roe deer was quantified by drones equipped with thermal cameras before and after repellent application and then compared with untreated control meadows. Results showed high adult abundance that did not differ significantly among treatments. The highest median was paradoxically observed on meadows “after application” (8.25 ind./10 ha), followed by “not treated” meadows (7.92 ind./10 ha), and “before application” (5.72 ind./10 ha). For fawns, differences between treated and untreated plots were likewise non-significant. Their numbers increased over time after application, consistent with the peak of parturition in the second half of May. Overall, the study confirms that the tested odor repellent, when applied according to the manufacturer’s protocol, did not reduce roe deer presence on meadows. This underscores the need to consider alternative approaches, such as the use of thermal-imaging drones combined with the subsequent translocation of detected fawns to safe locations. Full article

Collagen peptides derived from fish skin may be limited in food applications due to undesirable flavors. To investigate the effects of Maillard reaction modification on their physicochemical and flavor properties, collagen peptides from tilapia skin were prepared via enzymatic hydrolysis, followed by the Maillard reaction with four reducing sugars (xylose, ribose, glucose and glucosamine) through a combined procedure involving simultaneous enzyme inactivation and Maillard reaction at 100 °C. The resultant Maillard reaction products (MRPs) were characterized by analyzing free amino groups, peptide size distribution and color difference, while the reaction progression was monitored using UV absorption and fluorescence spectroscopy. The flavor profile of MRPs was analyzed through quantitative descriptive sensory evaluation and GC-MS coupled with principal component analysis. Among the four reducing sugars tested, glucosamine-induced Maillard reaction products exhibited the most pronounced physicochemical and sensory improvements. Specifically, glucosamine-MRPs showed the greatest reduction in free amino groups (0.69 μmol/L) and a notable decrease in high-molecular-weight peptides (3.31%), accompanied by an increase in low-molecular-weight fractions. Colorimetric analysis revealed a marked color change (ΔE = 31.78), and spectral analysis further confirmed intensified UV absorbance and fluorescence intensity in the glucosamine group, indicating advanced reaction progression. Sensory evaluation demonstrated a significant reduction in bitterness and enhancement of umami and saltiness. Moreover, GC-MS analysis revealed that the glucosamine-treated group exhibited the most favorable volatile profile, characterized by an increase in aromatic compounds and a substantial decrease in undesirable odorants. This study provides a theoretical basis for controlling the undesirable flavor of collagen peptides through low-extent Maillard reactions by different reducing sugars. Full article

Taste and odor (T&O) compounds in freshwater are frequently produced by certain cyanobacteria; however, their occurrence remains difficult to predict. This study examined the temporal and spatial variations in the mibC gene, which encodes a critical enzyme in the biosynthesis of 2-methylisoborneol (2-MIB), by analyzing environmental DNA (eDNA) and RNA (eRNA) in the North Han River, Republic of Korea, from July 2019 to October 2021. Surface water was sampled at twelve sites and analyzed for mibC DNA copy number, RNA expression, cyanobacterial cell density, and 2-MIB concentration using quantitative PCR (qPCR), microscopy, and gas chromatography–mass spectrometry (GC–MS). The mibC gene was present throughout the year, exhibiting peaks from late summer to early winter; higher concentrations typically initiated upstream and subsequently moved downstream. RNA expression was elevated from summer to autumn, rapidly declined following heavy rainfall, and reliably preceded increases in 2-MIB concentrations by 2–4 weeks. RNA levels were strongly correlated with 2-MIB concentrations (r = 0.879, p < 0.001) but showed only a moderate association with Pseudanabaena cell density, whereas DNA demonstrated weaker correlations. More than 95% of total 2-MIB was dissolved, limiting the ability to directly estimate concentrations from eRNA data alone. The results indicate that eRNA monitoring is an effective early warning tool for T&O events. In addition, combining eDNA and eRNA analyses enables a more accurate evaluation of T&O-producing cyanobacteria, presenting practical benefits for proactive management of drinking water. Full article

Consumers increasingly demand dairy products with improved nutritional quality, particularly regarding their fatty acid (FA) composition, due to recognized implications for human health. This study aimed to evaluate the modification in the composition, FA profile, and sensory profile of cheeses elaborated with ewe milk, through the diet inclusion of crushed sunflower (Helianthus annuus) seeds and sunflower seed silage in corn silage-based diets. The study was conducted with six East-Friesian ewes in a double 3 × 3 Latin square design, including three 21-day periods. Three diets were based on ad libitum corn silage as follows: control (CTRL, without supplementation), sunflower seeds (SFS, supplemented with 86 g/kg crushed sunflower seeds), and sunflower seed silage (SFSS, supplemented with 137 g/kg sunflower seed silage). The composition and FA profile of milk and cheese, and the sensory properties of cheese, together with the sensory profile, were evaluated. Dietary feeding with SFS and SFSS did not affect milk production and milk fat percentage but increased protein percentage. SFS and/or SFSS increased C18:0, C18:1 trans-9, and C18:1 cis-9 compared to CTRL in milk and cheese. Cheeses from SFS ewes showed improved taste and total acceptability, while odor, color, and texture of cheese remained unaffected. Therefore, SFS and SFSS appeared as a viable strategy to increase the contribution of FA with beneficial effects for health in milk and cheeses. Full article

Flooding from hurricanes creates damp indoor environments that support mold growth and microbial contamination, posing long-term health risks for occupants. This pilot study evaluated TMVOCs, microbial activity, and environmental conditions in 13 Hurricane Ian-affected residences across multiple flood-affected neighborhoods. Air samples were collected using sorbent tubes and analyzed by gas chromatography–mass spectrometry, while microbial activity on surfaces was assessed via ATP bioluminescence. Visible mold and dampness were documented with the CDC/NIOSH Dampness and Mold Assessment Tool, and environmental measurements included temperature, relative humidity, and surface as well as hidden moisture. Median (IQR) TMVOC concentrations were 12 (8) µg/m³, with 61% of homes exceeding the 10 µg/m³ benchmark set by previous researchers despite minimal visible contamination. Spearman’s correlation revealed significant negative relationships between odor and surface microbial activity (ρ = −0.569, p < 0.05), indicating that organic debris may play a more crucial role in microbial activity within the tested homes, and that odors might originate from hidden microbes instead of surface microbial growth. Our study emphasizes the necessity of utilizing both chemical (TMVOC) and biological (ATP) indicators to evaluate poor air quality caused by molds in flood-affected homes, serving as a supplement to routine visible mold assessments. Full article

Oxide semiconductor gas sensors are widely used due to their low cost, rapid response, small footprint, and ease of integration. However, in complex gas mixtures their selectivity is often limited by inherent cross-sensitivity. To address this, we developed a reconfigurable sensor-array system that supports up to 12 chemiresistive sensors with four- or six-electrode configurations, independent thermal control, and programmable gas paths. As a representative case study, we designed a customized array for fish-spoilage biomarkers, intentionally leveraging the cross-sensitivity and broad-spectrum responses of metal-oxide sensors. Following principal component analysis (PCA) preprocessing, we evaluated convolutional neural network (CNN), random forest (RF), and particle swarm optimization–tuned support vector machine (PSO-SVM) classifiers. The RF model achieved 94% classification accuracy. Subsequent channel optimization (correlation analysis and feature-importance assessment) reduced the array from 12 to 8 sensors and improved accuracy to 96%, while simplifying the system. These results demonstrate that deliberately leveraging cross-sensitivity within a carefully selected array yields an information-rich odor fingerprint, providing a practical platform for complex gas-mixture identification and food-freshness assessment. Full article

Industrial odour is a common pollution concern raised with local regulatory authorities, with communities citing impacts to their mental health and wellbeing. We performed a systematic review to determine if industrial odours are associated with psychosocial wellbeing in nearby communities. PubMed, Medline, PsycINFO, and Web of Science were searched for peer-reviewed articles published between 2003 and 2023, assessing associations between industrial odour and psychosocial wellbeing (mental health or quality of life). Critical appraisal of the studies was conducted using JBI’s assessment tools. We undertook a narrative synthesis of results. After screening, 13 articles met the inclusion criteria: 11 cross-sectional and 2 longitudinal studies. Sample sizes ranged from 23 to 25,236 participants. Odour exposure was assessed through self-reported measures (intensity, annoyance) and objective measures (proximity to source, odorous chemical concentration). Psychosocial health outcomes included stress, psychological distress, quality of life, depression and anxiety. Of the 13 studies, 11 identified an association between odour exposure and poorer psychosocial wellbeing, with the strongest evidence relating to quality of life. However, the critical appraisal identified quality issues with most studies. The findings suggest that industrial odours may be associated with poorer psychosocial wellbeing for nearby residents, particularly in terms of quality of life. Future research using consistent objective and subjective measures of odour exposure, and prospective data collection, would strengthen the quality of the evidence. Full article

Electronic nose (e-nose) systems have emerged as transformative tools for odor and gas analysis, leveraging advances in nanomaterials, sensor arrays, and machine learning (ML) to mimic biological olfaction. This review synthesizes recent developments in e-nose technology, focusing on innovations in sensor design (e.g., graphene-based nanomaterials, MEMS, and optical sensors), drift compensation techniques, and AI-driven data processing. We highlight key applications across healthcare (e.g., non-invasive disease diagnostics via breath analysis), food quality monitoring (e.g., spoilage detection and authenticity verification), and environmental management (e.g., pollution tracking and wastewater treatment). Despite progress, challenges such as sensor selectivity, long-term stability, and standardization persist. The paper underscores the potential of e-noses to replace conventional analytical methods, offering portability, real-time operation, and cost-effectiveness. Future directions include scalable fabrication, robust ML models, and IoT integration to expand their practical adoption. Full article

In this study, inter-brand variations in volatile flavor compound profiles of four lager beers were systematically investigated by integrating sensory evaluation with GC-MS, GC×GC-TOF-MS, and GC-O-MS. A total of 594 volatile compounds were identified, of which 71 with odor activity values (OAV) ≥ 1 were found to contribute directly to aroma expression. Additionally, 59 compounds with taste activity values (TAV) ≥ 1 were identified and may also contribute to taste perception. Furthermore, 53 aroma-active compounds were confirmed through GC-O-MS, providing additional evidence for their sensory contribution. Partial least squares discriminant analysis (PLS-DA), correlation analysis, and flavor addition experiments revealed brand-specific differential flavor compounds. Ultimately, twenty key differential flavor compounds, encompassing esters, alcohols, aromatic compounds, acids, lactones, and others, were confirmed to contribute to fruity, floral, burnt, and sweet notes. Phenethyl alcohol, with concentrations varying from 1377.1 mg/L in QD to 3297.5 mg/L in HR, showed a more than 2.4-fold difference across brands and was strongly associated with fruity (r = 0.553) and floral (r = 0.564) aroma. These compounds acted in combination to shape distinct aroma profiles. This study provides a molecular-level basis for understanding lager beer flavor and offers practical guidance for targeted flavor modulation in brewing. Full article