Odor Intensity Research Articles

Effectiveness of a combination of laccase and green coffee extract on oral malodor: A comparative, randomized, controlled, evaluator-blind, parallel-group trial.

Oral malodor negatively impacts a person's quality of life and may affect up to 50% of the population. The aim of this randomized, placebo and no-product controlled, evaluator-blind, proof-of-concept study was to evaluate the effectiveness and safety of the single use of two experimental lozenges containing the laccase enzyme and green coffee extract (with and without flavor) in reducing intrinsic oral malodor. Following 12 to 16 h of avoidance of oral hygiene,156 generally healthy subjects presented at screening and baseline visits with a mean organoleptic odor intensity (OI) score of ≥ 2 and an OralChromaTMreading of ≥ 125 parts per billion (ppb) hydrogen sulfide (H2S) gas and were randomly assigned to receive either one of the two experimental lozenges, a placebo lozenge, or no-product. Following the supervised use of the assigned products, subjects' oral malodor was evaluated using OI assessments and OralChromaTMmeasurement for volatile sulfur compounds (VSCs) immediately following product use (approximately 5 min), and at 30 min, 1 h, 2 h, 3 h and 4 h. The two experimental lozenges, with and without flavor, showed significant reductions in OI scores compared with the placebo and no-product groups at all time points (p < 0.001). At 5 minutes post-product use, the experimental lozenges, with and without flavor, were significantly better than the no-product group in reducing the VSCs (p < 0.04). The results of individual VSC components (hydrogen sulfide, methyl mercaptan and dimethyl sulfide) were variable; both experimental lozenges notably reduced hydrogen sulfide and methyl mercaptan levels in most post-use assessments. Four minor adverse events were reported, none of which were directly linked to the product. In conclusion, the experimental lozenges, whether flavored or not, were safe and effective in reducing oral malodor over a span of 4 h, based on organoleptic OI scores.&#xD;NCT05950529.

Wing–antenna interaction reduces odour fatigue in butterfly odour-tracking flight

Flying insects exhibit remarkable capabilities in coordinating their olfactory sensory system and flapping wings during odour plume-tracking flights. While observations have indicated that their flapping wing motion can ‘sniff’ up the incoming plumes for better odour sampling range, how flapping motion impacts the odour concentration field around the antennae is unknown. Here, we reconstruct the body and wing kinematics of a forwards-flying butterfly based on high-speed images. Using an in-house computational fluid dynamics solver, we simulate the unsteady flow field and odourant transport process by solving the Navier–Stokes and odourant advection-diffusion equations. Our results show that, during flapping flight, the interaction between wing leading-edge vortices and antenna vortices strengthens the circulation of antenna vortices by over two-fold compared with cases without flapping motion, leading to a significant increase in odour intensity fluctuation along the antennae. Specifically, the interaction between the wings and antennae amplifies odour intensity fluctuations on the antennae by up to 8.4 fold. This enhancement is critical in preventing odour fatigue during odour-tracking flights. Further analysis reveals that this interaction is influenced by the inter-antennal angle. Adjusting this angle allows insects to balance between resistance to odour fatigue and the breadth of odour sampling. Narrower inter-antennal angles enhance fatigue resistance, while wider angles extend the sampling range but reduce resistance. Additionally, our findings suggest that while the flexibility of the wings and the thorax's pitching motion in butterflies do influence odour fluctuation, their impact is relatively secondary to that of the wing–antenna interaction.

Development of an Odor Evaluation Method for Citrus Unshiu Peel Using an Electronic Nose Based on the Intensity of Per Unit Length (INPULTH)

Although odor is an important indicator of herbal medicine quality, an objective odor evaluation method remains undiscovered. Quantitative measurement using previous methods is complicated as Citrus Unshiu Peel (Chimpi) emits an odor when broken. To establish odor evaluation methods for herbal medicines using chimpi as an example, we developed a reproducible method for breaking samples and an objective odor evaluation method using an electronic nose (e-nose). First, an odor-emitting device (OED) was fabricated by modifying a pill cutter, which suppressed the spread of odor components into the room air while cutting the samples. The odor was emitted from chimpi with an OED and measured using an e-nose. The cut length was then measured. The sensor intensity was positively correlated with the cut length (r=0.840-0.927) in the same sample, and the intensity per unit length (INPULTH) calculated from the sensor intensity and cut length enables the comparison of the sensor intensity among different samples. In addition, average d-limonene emission level measured by GC-MS was positively correlated with average INPULTH (r=0.999), which suggests that this OED and e-nose method enables the comparison of the sensor intensity and d-limonene emissions. INPULTH also positively correlated with other seven monoterpenes such as p-cymene, β-myrcene, β-phellandrene, α-pinene, β-pinene, γ-terpinene, and α-terpinolene (r=0.701-0.865). Therefore, monoterpene content can be evaluated by measuring the odor in the same way as d-limonene. In conclusion, we developed a simple odor intensity evaluation method optimized for chimpi to establish an odor evaluation method for herbal medicines.

Olfactory Dysfunction and Limbic Hypoactivation in Temporal Lobe Epilepsy.

The epileptogenic network in temporal lobe epilepsy (TLE) contains structures of the primary and secondary olfactory cortex such as the piriform and entorhinal cortex, the amygdala, and the hippocampus. Olfactory auras and olfactory dysfunction are relevant symptoms of TLE. This study aims to characterize olfactory function in TLE using olfactory testing and olfactory functional magnetic resonance imaging (fMRI). We prospectively enrolled 20 individuals with unilateral TLE (age 45 ± 20 years [mean ± SD], 65% female, 90% right-handed) and 20 healthy individuals (age 33 ± 15 years [mean ± SD], 35% female, 90% right-handed). In the TLE group, the presumed seizure onset zone was left-sided in 75%; in 45% of the individuals with TLE limbic encephalitis was the presumed etiology; and 15% of the individuals with TLE reported olfactory auras. Olfactory function was assessed with a Screening Sniffin' Sticks Test (Burkhart, Wedel, Germany) during a pre-assessment. During a pre-testing, all individuals were asked to rate the intensity, valence, familiarity, and associated memory of five different odors (eugenol, vanillin, phenethyl alcohol, decanoic acid, valeric acid) and a control solution. During the fMRI experiment, all individuals repeatedly smelled eugenol (positively valenced odor), valeric acid (negatively valenced odor), and the control solution and were asked to rate odor intensity on a five-point Likert scale. We acquired functional EPI sequences and structural images (T1, T2, FLAIR). Compared to healthy individuals, individuals with TLE rated the presented odors as more neutral (two-sided Mann-Whitney U tests, FDR-p < 0.05) and less familiar (two-sided Mann-Whitney U tests, FDR-p < 0.05). fMRI data analysis revealed a reduced response contrast in secondary olfactory areas (e.g., hippocampus) connected to the limbic system when comparing eugenol and valeric acid in individuals with TLE when compared with healthy individuals. However, no lateralization effect was obtained when calculating a lateralization index by the number of activated voxels in the olfactory system (two-sided Mann-Whitney U test; U = 176.0; p = 0.525). TLE is characterized by olfactory dysfunction and associated with hypoactivation of secondary olfactory structures connected to the limbic system. These findings contribute to our understanding of the pathophysiology of TLE. This study was preregistered on OSF Registries (www.osf.io).

Development and characterization of “Greek Salad” edible films

“Greek salad” edible films, made from tomato puree, juices of cucumber, bell pepper and onion, oregano oil and apple pectin with and without olive oil and guar gum were successfully prepared and characterized for water vapor permeability, oxygen permeability, tensile properties, moisture sorption isotherm, heat sealing ability and color. It was found that the addition of olive oil to the basic film increased its water vapor permeability, while the incorporation of guar gum had no impact on it. The addition of olive oil and guar gum affected the tensile properties, the isotherms for moisture sorption and the color of the films. All films demonstrated good heat-sealing properties. The FTIR spectra of the films displayed several interesting characteristics, confirming the films’ composition. The sensory evaluation of the four edible films revealed that all samples scored close to or above 3 (on a scale of 0–5) in most sensory attributes, indicating general acceptability among panelists. Notably, films containing guar gum exhibited higher homogeneity and transparency, while films containing olive oil showed the highest odor, flavor, and taste intensities, but also more pronounced defects and undesirable aftertastes. The basic film appeared more balanced in most sensory attributes.It was concluded that overall the advantages of adding olive oil and guar gum to the basic film were not significant. Future experiments will concentrate on optimizing the production of the basic film and exploring the possibility of using it for packaging oily foods.

Invasive Ant Detection: Evaluating Honeybee Learning and Discrimination Abilities for Detecting Solenopsis invicta Odor.

Invasive red imported fire ants (Solenopsis invicta) create a serious threat to public safety, agriculture, biodiversity, and the local economy, necessitating early detection and surveillance, which are currently time-consuming and dependent on the inspector's expertise. This study marks an initial investigation into the potential of honeybees (Apis mellifera) to detect and discriminate the odor of S. invicta through the olfactory conditioning of proboscis extension responses. Deceased S. invicta were used as conditioned stimuli to ensure relevance to non-infested areas. The results showed that the bees rapidly learned to respond to deceased ant odors, with response levels significantly increasing at higher odor intensities. Bees exhibited generalization across the odors of 25 minor workers, 21 median workers, 1 major worker, and 1 female alate. When conditioned with deceased ant odors, bees effectively recognized live ants, particularly when trained on a single minor worker. Discrimination abilities varied by species and were higher when S. invicta was paired with Polyrhachis dives and Nylanderia yaeyamensis, and lower with S. geminata, Pheidole rabo, and Pheidole fervens. Notably, discrimination improved significantly with the application of latent inhibition. These findings suggest that trained honeybees have the potential to detect S. invicta. Further refinement of this approach could enhance its effectiveness for detection and surveillance.

Qualitative and Quantitative Sex-Related Differences in the Perception of Single Molecules from Coffee Headspace.

One of the still-debated topics regarding the olfactory function concerns the presence or absence of sex-related differences in individuals. In this study, we checked for a relationship between the olfactory function of females and males and their ability to perceive single molecules, and researched how this can influence the intensity with which the complex odor formed by a set of single molecules is perceived. First, females and males were classified as normosmic or hyposmic based on the TDI olfactory score obtained using the Sniffin' Sticks test. Subsequently, the headspace of roasted coffee beans, as a complex olfactory stimulus, was broken down into single molecules by means of a chromatographic column; these were simultaneously conveyed to a mass spectrometer (for their subsequent classification) and to the human nose, which acts as a chemical sensor by means of an olfactometer port. The results obtained with this gas chromatography-olfactometry approach show both qualitative and quantitative differences between females and males, with females performing better than males. In addition, the odor intensity reported by females when sniffing pen #10, containing coffee aroma, is significantly higher than that reported by males. In conclusion, these data highlight that the human ability to perceive both single compounds and complex odors is strongly conditioned, not only by the olfactory function of individuals, but also by their sex.

Statistical analysis of natural and mechanical ventilation performance in improving indoor air quality, thermal comfort, and perceived air quality in a healthcare facility

Ventilation strategies in healthcare facilities are mainly directed towards mechanical systems. Due to patients’ preferences or the necessity of terminal reheat/recool, Air Handler Units are often turned off or windows are opened when mechanical systems are active. This leads to poor IAQ, nosocomial infections, and energy loss. Besides, ventilation systems are not typically intended to optimize user satisfaction. Using field measurements in 140 spaces, survey studies, and statistical analysis, this study compares ventilation strategies in providing IAQ, thermal comfort, and Perceived Air Quality as an indicator of user satisfaction. 315 samples were collected for air velocity, air temperature, relative humidity, PAQ, odor intensity, and VOC concentrations. Lowest to highest pollutant concentrations were observed respectively in mechanical ventilation with two open windows, mechanical ventilation with one open window, natural ventilation with two open windows, mechanical ventilation with closed windows, natural ventilation with one open window, and nonventilated spaces. There was no evidence of an effect of ventilation strategies on environmental parameters and user satisfaction. Users’ thermal comfort and air quality satisfaction were not guaranteed even when ventilation rate, pollutant concentrations, and environmental parameters were within the permissible range. Findings support the efficient performance of natural ventilation in providing acceptable air quality.

The effect of different essential oils used in stoma bags of individuals with colostomy remooval of odor, life satisfaction and effect on stoma fit: Randomized controlled study

ObjectiveThe aim of the research was conducted as a randomized controlled interventional study to determine the effect of lavender/mint essential oils placed in stoma bags on odor removal, life satisfaction and stoma compliance in individuals with colostomy. MethodThe research population is patients with permanent colostomy registered in a university hospital's stoma therapy unit. The sample consisted of 60 (20 lavender oil, 20 peppermint oil, 20 control group) patients who met the sampling criteria and voluntarily agreed to participate in the study. In the evaluation of the data the 'Numerical Evaluation Scale' (NES), the 'Satisfaction with Life Scale (SLS), and the 'Ostomy Adjustment Scale' (OAS-23) were used. ResultsThe lavender oil and peppermint oil groups had lower mean odor intensity, mean scores, higher life satisfaction, and stoma compliance scores than the control group. A statistically significant difference was found between the groups (p<0.05). In comparisons made within the groups, statistically, significant differences were found in the mean scores of odor intensity level, life satisfaction, and stoma compliance after the process (p<0.05). ConclusionIt was determined that lavender/peppermint oil placed in the stoma bag in patients with colostomy decreased the level of odor intensity, and increased life satisfaction, and stoma compliance. The trial was registered in the Clinical Trial (ClinicalTrials.gov ID: NCT05716711

Odor lateralization test is insensitive to small degrees of intranasal trigeminal activation.

Odors with prominent trigeminal compounds are more easily localized than purely olfactory ones. However, it is still unclear whether adding a small amount of a trigeminal compound to an olfactory odor significantly improves lateralization performance. We included 81 healthy adults aged 25.4 ± 4.8 years to complete odor lateralization tasks using 12 odors: two "olfactory", two "trigeminal" odors, and eight odor mixtures at two low concentrations of "trigeminal" odors (4%, 8%). This task utilized a "Squeezer" delivering odor or air to either nostril, and participants indicated which nostril received the odor. Evaluations also included olfactory function, odor intensity ratings, and individual olfactory importance. Degrees of trigeminal compounds significantly affected lateralization performance (F = 82.32, p < 0.001), with 100% irritants showing higher performance than 0%, 4%, and 8% irritants (p's < 0.001), while no significant differences were found between odors with 0%, 4%, and 8% irritants (p's > 0.05). Chi-square tests confirmed higher percentages of above-chance lateralization with 100% irritants than with 0%, 4%, and 8% irritants (χ2 = 30.89 to 47.33, p's < 0.001). Adding a small amount of a trigeminal compound to a selective olfactory odor does not significantly improve lateralization performance. Trigeminal lateralization likely follows an "accumulative" pattern rather than an "all or none" rule. With only 20 trials, the task may lack sensitivity to detect low levels of trigeminal irritation in selective olfactory odors, though it does not rule out trigeminal activation. The odor lateralization task can screen for odors with prominent trigeminal compounds by comparing group-level performance with that of purely olfactory odors. Future studies should use more ideal stimuli (e.g., PEA for olfactory, CO2 for trigeminal) to test the replicability of the results.

Diffusion behavior and environmental impact of odorants and TVOCs detected in a wastewater treatment plant for collaborative leachate treatment in Northwest China

Wastewater treatment plants (WWTPs) are major sources of volatile gaseous compounds, especially in mixed-source systems such as domestic wastewater and landfill leachate. This study aimed to investigate the emission behavior and environmental impact of gaseous substances, such as hydrogen sulfide (H2S), ammonia (NH3), carbon sulfide (CS2), and phosphine (PH3), at a WWTP in Northwest China. Odorants were detected in the air surrounding the grid room (XGS), biochemical treatment tank (SHC), secondary sedimentation tank (ECC), and sludge dewatering room (NTS). For comparison, the upwind boundary (O-SF) and downwind boundaries (O-XF) monitoring points were used, with odor concentrations ranging from 3.95 to 725.27 odor units. The concentration ranges of the odorant substances were 5.27–88.69, 5.61–71.96, 5.70–32.63, and 0.12–5.87 mg/m3 for H2S, NH3, CS2, and PH3, respectively. Meteorological factors such as temperature, relative humidity, and wind speed and direction substantially influence odorant emissions. The concentrations of various odorants and volatile organic compounds (VOCs) detected at the O-XF monitoring point were higher than those detected at the O-SF monitoring point, indicating that the wind intensified their diffusion toward the downwind plant boundary. The average odor intensities of odorant substances emitted from wastewater or sludge treatment equipment were 3.37, 5.09, 4.42, 2.00, and 3.82 for total VOCs, H2S, NH3, CS2, and PH3, respectively. Among them four, with downwind diffusion, only H2S presented olfactory and chronic toxicity risks based on Gaussian plume model calculations. The hazard index ranking across monitoring sites was XGS > NTS > SHC > ECC > O-XF > O-SF. These findings emphasize the urgent need for effective measures to control and mitigate gaseous pollutants emitted by collaborative WWTPS, thereby protecting environmental quality and public health.

Environmental chamber analysis of objective volatile organic compounds emissions and subjective olfactory perception from main automotive interior components

This study examined the emissions of volatile organic compounds (VOCs) and their associated odors from five key automotive interior components: door panels, weatherstrips, seats, headliners, and carpets. Objective VOC emissions and subjective odor evaluations were conducted in an environmental chamber with controlled temperature, humidity, and ventilation rates. VOC analysis revealed that alkanes and aromatic compounds were the predominant emissions, together accounting for 43 %–61 % of the total number of emission types. Other notable emissions included aldehydes and ketones. The overlap in the emitted compounds was substantial, with 13 % of the compounds being universally emitted, 42 % emitted by two or more components, and 45 % unique to individual components. Subjective odor evaluations identified distinct odor fingerprints for each component, with weatherstrips having the highest odor intensity and headliners having the lowest. Perceived pleasantness (PP) ratings were generally negative, indicating the unappealing nature of the odors. Odor activity value (OAV) analysis showed a weak linear relationship with odor intensity, particularly because of the negative correlation in weatherstrips, suggesting significant masking or enhancement effects among odor molecules. Aldehydes and acids were the major contributors to OAV, whereas alkanes, which are often overlooked, were also significant because of their high emission levels.

The association between interoception and olfactory affective responses

Odors are known to affect an individual’s emotions and physiological states. Recent research has revealed that olfaction is linked to the mental representation of internal sensations, known as interoception. However, little research has examined how interoception relates to emotional responses to odors. This research aimed to fill this gap in the literature. We conducted two studies with a total of 548 Japanese women (n = 500 and n = 48 in Studies 1 and 2, respectively). Study 1 used an online survey to assess the relationship between self-reported interoceptive traits and the intensity of positive emotions in response to daily odors. Study 2 examined how self-reported interoceptive traits modulated the arousal ratings of odors presented in the laboratory and the concordance between these perceived arousal ratings and odor-evoked physiological responses. Study 1 confirmed that self-reported interoceptive traits were significant predictors of positive emotional intensity of odors. In Study 2, individuals with high interoceptive measure scores showed concordance between their perceived emotional arousal and the physiological responses associated with that emotion, whereas individuals with low scores did not. These findings suggest that how people perceive their internal sensations contributes to shaping their olfactory affective experiences, thereby broadening the scope of interoception research and aromachology. The practical implications of these findings for the development of commercial fragrances are discussed.

Quality-Driven Design of Pandan-Flavored Sponge Cake: Unraveling the Role of Thermal Processing on Typical Pandan Aroma.

Pandan (Pandanus amaryllifolius Roxb.) has been used in the production of bakery goods either as a functional ingredient or a natural flavoring that, when roasted, exerts a fragrant rice-like aroma and an attractive green color. This study elucidated the typical aroma compounds from pandan leaves and explored the influence of thermal treatments on their aroma profiles using GC-O-MS, E-nose, and GC-IMS analyses. The effects of formulation and baking conditions on the qualities of pandan-flavored sponge cake were comprehensively evaluated through a holistic approach covering several aspects including cake batter gravity, color, texture, and sensory characteristics. The baking treatment introduced more types of pleasant aromas (9 aromas vs. 17 aromas) and increased the odor intensities of the original volatile compounds, especially for the roasted and steamed rice-like odors. The increased amount of pandan flavoring reshaped the color of the cake crumb (especially for the L* and a* spaces) and significantly decreased the hardness (3.87 N to 1.01 N), gumminess (3.81 N to 0.67 N), and chewiness (13.22 mJ to 4.56 mJ) of the sponge cake. The perceived intensities of bitterness and sweetness can be adjusted by modulating the levels of 2-phenylethanol, 2-methyl-1-butanol, hexyl alcohol, and decanal, along with the total alcohols and aldehydes, due to their significant correlations revealed by correlation heatmap analyses.

Unraveling Shengmuxiang in Jiang-flavor base baijiu using a combination of metabolomics and sensomics strategy

Shengmuxiang (SMX), an important aroma in Jiang-flavor base baijiu, significantly influences the quality of the product. This study employed untargeted metabolomics combined with sensomics to explore the key compounds responsible for SMX. Results indicated that SMX samples had higher intensities of green and woody-like odors compare to control samples. A total of 87 aroma compounds were identified by headspace solid phase microextraction combined with gas chromatography–mass spectrometry technology. Based on the variable projection importance, PCA and OPLS-DA were employed to identify 22 potential marker compounds. Quantitative results combined with hierarchical cluster and OAV analysis revealed that 9 aroma compounds (OAV > 1) had high concentrations in SMX samples. Aroma recombination and omission experiments further indicated that acetaldehyde and acetal were the key compounds responsible for the characteristic aroma of SMX in Jiang-flavor base baijiu. These findings provide valuable insights into the distinct aroma profile of SMX and offer a basis for quality control of Jiang-flavor base baijiu.

Optimization of Secondary Chlorination in Water Distribution Systems for Enhanced Disinfection and Reduced Chlorine Odor Using Deep Belief Network and NSGA-II

This research explores the strategic optimization of secondary chlorination in water distribution systems (WDSs), in order to enhance the efficiency of disinfection while mitigating odor and operational costs and promoting sustainability in water quality management. The methodology integrates EPANET simulations for water hydraulic and quality modeling with a deep belief network (DBN) within the deep learning framework for accurate chloric odor prediction. Utilizing the non-dominated sorting genetic algorithm-II (NSGA-II), this methodology systematically balances the objectives of chloride dosage and chloramine formation. It combines a chloric odor intensity assessment, a multi-component kinetic model, and dual-objective optimization to conduct a comparative analysis of case studies on secondary chlorination strategies. The optimal configuration with five secondary chlorination stations reduced chloric odor intensity to 1.20 at a cost of USD 40,020.77 per year in Network A while, with eight stations, chloric odor intensity was reduced to 0.88 at a cost of USD 71,405.38 per year in Network B. The results demonstrate a balanced trade-off between odor intensity and operational cost on one hand and sustainability on the other hand, highlighting the importance of precise chlorine management to improve both the sensory and safety qualities of drinking water while ensuring the sustainable use and management of water resources.

The Effects of Diet, Dietary Supplements, Drugs and Exercise on Physical, Diagnostic Values of Urine Characteristics.

Background/Objectives: This review summarizes the current knowledge about factors that affect the physical characteristics of urine. It highlights proper urine sample collection and displays factors like diet, hydration status, and medications that can alter urine color, odor, clarity, specific gravity and pH. Results: Urinalysis is a minimally invasive examination of a patient's health, especially concerning nephrological and endocrinological abnormalities, as well as dietary habits and stimulants used. Certain deviations in appearance, composition or frequency/pain during urination may indicate an ongoing disease process in the body. Based on laboratory results, further medical treatment is determined. The reason for a change in the color of the urine, for its clouding or intense odor may be a disease, as well as the consumption of food, medication, intensive physical exercise or inadequate hydration of the body. Well-standardized procedures for collecting, transporting, preparing and analyzing samples should become the basis for an effective diagnostic strategy in urinalysis. It is worth noting that pharmacists in pharmaceutical care are often the first people to whom a patient turns for health advice and for the interpretation of simple laboratory tests. Acquiring the ability to interpret the results of laboratory tests and the principles of proper sampling for laboratory tests is indispensable in the process of possible counseling and providing reliable answers to patients' questions. Conclusions: Although urinalysis is not recommended as a routine screening tool for the general population, it can prove to be a valuable source of patient health data in some cases as the data will be useful to physicians and pharmacists to more effectively diagnose and better care for patients.

Identification of a higher C-S lyase activity of Staphylococcus hominis in volunteers with unpleasant axillary odour.

Excessive and unpleasant odours that emanate from the skin can induce bromhidrosis and substantially impair a person's quality of life. Enzymatic pathways generating unpleasant odours are well detailed, and among them, the C-S lyase is one of the enzymes involved in the conversion of non-volatile precursors into thiol-type malodorous volatile molecules such as 3M3SH. This study aimed to investigate the variation of axillary odour intensity correlated with Staphylococcus (S.) hominis C-S lyase activity within a group of volunteers after a physical activity. First, a group of 24 volunteers from the same ethnicity with standardized hygienic and alimentary practices participated in a supervised indoor cycling activity. Following this session, worn T-shirts were recovered to enable the olfactory evaluation of axillary odours by qualified experts. To go further, the microbiota from the axillary zone of each volunteer was sampled and the bacterial relative abundance was investigated by using 16S rRNA metasequencing. Then, S. hominis isolates were obtained by culturomics from these microbiota samples and the C-S lyase activity was measured by spectrofluorometry in protein crude extracts. The evaluation of the odour intensity revealed that within the panel, two groups were significantly distinct. A non-odorous group and a malodorous one with volunteers having unpleasant odours. The 16S rRNA metasequencing reveals differences in bacterial communities between the two groups with a significant increase in the relative abundance of S. hominis in the malodorous group compared with the non-odorous one. The C-S lyase activities measured on S. hominis sampled on volunteers from the two groups demonstrate that for an equivalent quantity of protein, this enzymatic activity is significantly higher for the samples originating from the malodorous group. Hence, this study demonstrates that beyond the increase of S. hominis relative abundance, the C-S lyase enzymatic activity of this bacteria is also higher in volunteers with unpleasant axillary odours.

Studying how dry extract can affect the aroma release and perception in different red wine styles.

Four red wine matrices representing different red wine styles with the same VOCs (volatile organic compounds), were obtained by enriching a bleed wine with increasing amounts of deodorized dry extract obtained from the pressed wine of the same vinification. The release of VOCs was determined by solid phase micro-extraction-gas chromatography-mass spectrometry (SPME-GC-MS), in conditions mimicking those applied during sensory assessments. Results show that even though the perception of the overall odor intensity was not significantly influenced by the matrix, this latter modulated the odor profiles: at rising wine dry extract, fruity, floral odors decreased, while dehydrated fruit, woody-toasty, vegetal-earthy notes increased. These changes cannot be fully explained by the observed significant influence of the matrix on the release of VOCs or by their correlations with the considered matrix components (ethanol, residual sugars, phenolics, pH), but findings suggest that perceptual interactions are involved. This study could be useful in pressing and blending management for wine aroma quality also considering wine compositional trends under the current climate change context. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Characterization of fuel-induced water contamination: chemical composition, odor threshold, and ecotoxicological implications

Fuel spills pose significant environmental risks, particularly to drinking water sources and aquatic ecosystems. The composition of fuels has changed over the decades to reduce fossil greenhouse gas emissions. In Sweden, although the number of spill incidents has declined, with around 600 cases reported annually, there remains limited knowledge on the environmental and health impacts of modern fuels. This study aimed to address this gap through comprehensive chemical analysis and ecotoxicological assessments of 31 fuel samples, including petrol, diesel, fuel oil, and marine gas oil. Using gas chromatography-mass spectrometry (GC-MS), we determined 53 substances, including aromatic and aliphatic hydrocarbons, ethers, esters, and 17 polycyclic aromatic hydrocarbons (PAHs). A key focus was on forming a stable water-accommodated fraction (WAF) to isolate non-dissolved fuel elements from water, which is crucial for assessing subsurface aquatic life and drinking water production impacts. Results indicated significant differences in fuel odor profiles, with ethers enhancing odor intensity. Petrol components showed higher water solubility than diesel, partly due to ethanol. Ecotoxicological tests revealed varying toxicity across fuels, with petrol showing the highest toxicity to aquatic organisms, although activated sludge exhibited resilience. Fuels containing water-soluble ethers posed the highest risks to drinking water, while modern diesel was of lower concern due to its low solubility and toxicity. In freshwater ecosystems, petrol and hydrophobic toxins in fuel oil had severe effects during spills. Overall, this study offers critical insights into the environmental impact of common fuels, supporting improved risk assessment and management strategies for spill mitigation and water resource protection.