Volatile Sulfur Compounds Research Articles

Initial acidity regulates microbial sulfur metabolism in the spontaneous fermentation of sesame flavor-type baijiu.

Initial acidity regulates microbial sulfur metabolism in the spontaneous fermentation of sesame flavor-type baijiu.

Mechanisms of formation and consumption of VSCs in thermal dehydration of Lentinula edodes: A transcriptomic analysis utilizing WGCNA.

Mechanisms of formation and consumption of VSCs in thermal dehydration of Lentinula edodes: A transcriptomic analysis utilizing WGCNA.

Investigating the influence of insoluble pulp particles on flavor retention and characterization of freshly squeezed and pasteurized mandarin juice.

Investigating the influence of insoluble pulp particles on flavor retention and characterization of freshly squeezed and pasteurized mandarin juice.

Malodorous Gases in Aquatic Environments: A Comprehensive Review from Microbial Origin to Detection and Removal Techniques

Malodorous gases—particularly hydrogen sulfide (H2S), ammonia (NH3), and volatile sulfur compounds (VSCs)—significantly degrade water quality, threaten public health, and disrupt ecosystems. Their production stems from microbial activity, nutrient overload, and industrial discharges, often magnified by low dissolved oxygen. This review integrates current insights into the microbial sulfur and nitrogen cycles to elucidate how these gases form, and surveys advances in detection technologies such as gas chromatography and laser-based sensors. We also assess diverse mitigation methods—including biotechnological approaches (e.g., biofilters, biopercolators), physicochemical treatments, and chemical conversion (Claus Process)—within relevant regulatory contexts in Colombia and worldwide. A case study of the Bogotá River exemplifies how unmanaged effluents and eutrophication perpetuate odor issues, underscoring the need for integrated strategies that reduce pollution at its source, restore ecological balance, and employ targeted interventions. Overall, this review highlights innovative, policy-driven solutions and collaborative efforts as pivotal for safeguarding aquatic environments and surrounding communities from the impacts of odorous emissions.

Insights into the evolution of certain sulfur-containing compounds during artificial ageing of Xinomavro PDO wines.

Insights into the evolution of certain sulfur-containing compounds during artificial ageing of Xinomavro PDO wines.

Genetic variation in the INMT gene strongly impacts the production of trimethylsulfonium in humans.

Genetic variation in the INMT gene strongly impacts the production of trimethylsulfonium in humans.

Tannin additions decrease the concentration of malodorous volatile sulfur compounds in wine-like model solutions and wine.

Tannin additions decrease the concentration of malodorous volatile sulfur compounds in wine-like model solutions and wine.

HTAS2R38 polymorphisms modulate oral microbiota and influence the prevalence and treatment outcome of halitosis

BackgroundThe genetic susceptibility of halitosis is unclear, challenging its precise management in high-risk population. Here we investigated the association of hTAS2R38 polymorphisms with the prevalence and treatment outcome of halitosis, with a particular focus on oral microbiota.MethodsA cross-sectional study including 689 participants was conducted to investigate the association between hTAS2R38 polymorphisms and halitosis. A 6-month cohort including 60 halitosis patients was established to explore the relationship between hTAS2R38 polymorphisms and treatment outcome of halitosis. Salivary microbiota was further analyzed and its correlation with hTAS2R38 polymorphisms was investigated.ResultsIn the cross-sectional study, a higher prevalence of halitosis was observed in individuals with AVI/AVI genotype as compared to non-AVI/AVI genotype (PAV/PAV + PAV/AVI) (OR = 2.380, 95% CI = 1.493–3.807). 16S rRNA sequencing revealed the enrichment of Prevotella in the saliva of AVI/AVI individuals. In the prospective study, halitosis patients with AVI/AVI genotype exhibited poor treatment outcome relative to non-AVI/AVI individuals during the 6-month follow-up after halitosis intervention (RR = 2.077, 95% CI = 1.382–3.339). Tannerella, Filifactor, and Mycoplasma were identified to be the major persistent genus in the saliva of AVI/AVI patients over the 6-month period after treatment. Furthermore, the human gingival fibroblasts with AVI/AVI genotype exhibited reduced inhibition against the growth and volatile sulfur compounds production of periodontal pathogens.ConclusionsOur work demonstrates that hTAS2R38 polymorphisms contribute to the development and treatment outcome of halitosis via modulating oral microbiota, providing new insights to the better management of halitosis.D5U2bXM-3veDLfL8au3xfZVideo

Volatile Sulphur Compounds in Wine Distillates by Stir Bar Sorptive Extraction-Gas Chromatography-Mass Spectrometry

A Stir Bar Sorptive Extraction-Gas Chromatography-Mass Spectrometry (SBSE-GC-MS) method has been optimized and validated for the determination of eight volatile sulphur compounds in wine distillates: diethyl sulphide (DES), dimethyl disulphide (DMDS), diethyl disulphide (DEDS), 2-thiophenecarboxaldehyde (TC), dibutyl sulphide (DBS), dipropyl disulphide (DPDS), dipropyl sulphide (DPS), and dimethyl trisulphide (DMTS). After optimization by 24 factorial design, the SBSE-GC-MS extraction conditions were as follows: a polydimethylsiloxane twister (10 mm × 0.5 mm), 35 °C as the extraction temperature, 10 mL as the sample volume, 7% (v/v) as the alcoholic grade, 47 min as the extraction time, 10% (w/v) of NaCl, and 1% (w/v) of EDTA (ethylenediaminetetraacetic acid). Under optimal conditions, adequate analytical figures of merit were obtained for eight of the ten compounds initially considered, with low quantification and detection limits and relative standard deviations for inter-twister and inter-day repeatability values ranging from 7.5 to 21.8% and from 7.2 to 27.5%, respectively. The methodology was applied to 34 wine distillates (continuous column distillation and distillation in pot still) elaborated for the production of Brandy de Jerez: 15 aged distillates aged for different periods of time in American oak wood and 19 non-aged distillates. The most significant volatile sulphur compounds were DBS, DMDS, and DPS. The Cluster Analysis (CA) on the volatile sulphur compounds grouped the samples according to the use of sulphur dioxide. In general, lower amounts of volatile sulphur compounds were found in the aged samples, although the high standard deviations obtained highlight that their contents depend on multiple factors related to the elaboration process.

Проблемы устранения запахового загрязнения окружающей среды побочными продуктами птицеводства (обзор)

The operation of modern poultry farms is accompanied by the formation of a significant amount of by-products, chicken manure (CM) is among them. The accumulation of manure near poultry farms causes odor pollution of residential areas. Odor-forming substances (OFS) are formed during the metabolism of undigested feed residues a variety of microorganisms that enter the manure from the intestines of chickens and the external environment. Short-chain fatty acids, volatile sulfur compounds (H2S, thioalcohols, thioethers, etc.) and nitrogen (NH3, biogenic amines, etc.) make the main contribution to odor formation. Such bacteria as Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, as well as fungi Mucor, Aspergillus, Penicillium, Fusarium dominate in fresh CM. The microbiota composition changes significantly during storage or composting. In particular, the number of Firmicutes decreases and the number of Actinobacteria increases. The microbial community transformation is accompanied by a change in odor. Fresh CM have the most intense odor. Active research is underway to develop methods to deodorize CM. Methods involving the use of microbiological preparations, acidity regulators, and natural sorbents are of greater practical interest. Materials used as deodorants inhibit OFS-producing putrefactive microbiota or eliminate odor by destroying, immobilizing, and masking of OFS. Chemical and physical-chemical methods of deodorization are more convenient for industrial processing of CM into commercial forms of fertilizers. The combined effect of lime (a chemical reagent) and glauconite (a sorbent) followed by drying the mixture leads to a significant reduction of CM odor. The disadvantages of this method include significant losses of nitrogen (in the form of NH3) during the decomposition of ammonium salts in an alkaline medium. To prevent the NH3 emission into the atmosphere, it is possible to use the technology of absorption of this gas by an acid solution (for example, sulfuric acid). The ammonium sulfate formed in this way can be used as a nitrogen fertilizer.

The Breathomics Profile of Volatile Sulfur Compounds in the Bipolar Spectrum, Does It Represent a Potential Tool for Early Diagnosis?

Background/Objectives: Emerging laboratory technologies, such as breathomics, may enhance the early diagnosis of psychiatric disorders, including Bipolar Disorder (BD). This study investigates the detection of volatile sulfur compounds (VSCs) in exhaled breath as potential biomarkers for BD, comparing VSC levels between individuals with BD, healthy controls, and individuals with non-pathological hyperactivity. Methods: A matched case-control study was conducted involving 24 patients with BD and 95 healthy controls recruited at the University Hospital of Cagliari. Controls were selected using a matched-pair design based on age (±5 years) and sex through a block-matching technique to ensure comparability with cases. Participants underwent psychiatric interviews, completed the Mood Disorder Questionnaire (MDQ), and had their exhaled breaths analyzed for VSCs using a gas chromatograph (OralChroma™). Controls were selected and randomized for age and sex. Results: Patients with BD exhibited significantly higher levels of methyl mercaptan (CH3SH) compared to healthy controls (18.62 ± 5.04 vs. 9.45 ± 18.64 ppb, p = 0.022). Among individuals without BD, those with positive MDQ scores showed lower levels of CH3SH than those with negative scores (9.17 ± 5.42 vs. 15.05 ± 18.03); however, this difference did not reach statistical significance (p = 0.254), highlighting how the deep connection between some clinical and laboratory aspects needs to be investigated more thoroughly. Conclusions: The results suggest a correlation between oral dysbiosis and metabolic alterations in patients with BD, with CH3SH levels being higher in cases compared to controls. Further studies are needed to validate the use of VSCs as potential biomarkers for BD and to investigate their role in individuals with non-pathological hyperactivity.

Effects of Trehalose on Halitosis: A Randomized Cross-Over Clinical Trial.

Background/Objectives: Halitosis is a condition characterized by an unpleasant malodor. Intra-oral halitosis is caused by volatile sulfur compounds (VSCs) and can be associated with oral dryness. Trehalose is one of the materials used to relieve oral dryness. The aim of the present study was to investigate the effect of trehalose on halitosis. Methods: This prospective, double-blinded, placebo-controlled, cross-over study enrolled volunteers from Okayama University Hospital. The participants were randomly divided into two groups, with one group receiving trehalose (a 10% trehalose solution) and the other receiving a placebo (distilled water) in a 1:1 allocation. The primary study outcome was the subjective organoleptic test. The secondary outcomes were the concentrations of the VSCs, which were measured using a portable gas chromatography device, and the oral moisture status, which was measured using an oral moisture meter. The planned sample size was 10 participants based on the previous study. Results: The final intention-to-treat analysis was performed using the data from 9 participants. After applying 10% trehalose as an oral spray, the organoleptic score decreased in a time-dependent manner. However, no significant differences were seen between the trehalose and placebo groups. In terms of secondary outcomes, the oral moisture levels increased immediately after the trehalose spray application, and significant differences in the amount of change from the baseline were seen between the trehalose and placebo groups (p = 0.047). No significant differences were seen in any of the other variables (p > 0.05). Conclusions: We could not identify any positive effects on halitosis from a one-time 10% trehalose application as an oral spray in this prospective, double-blinded, placebo-controlled, cross-over study. However, the trehalose application immediately improved the oral moisture levels and was useful for treating oral dryness.

Red Betel Leaf (Piper crocatum) Mouthwash for Effective Plaque Control and Halitosis Prevention: A Pre-Experimental Study

Halitosis, or bad breath, is a prevalent oral health issue primarily caused by volatile sulfur compounds (VSCs) produced by the microbial breakdown of food particles in the oral cavity. The accumulation of dental plaque, a biofilm composed of bacteria and their byproducts, provides a conducive environment for VSC production. Red betel leaf (Piper crocatum) has been traditionally used for its medicinal properties, including its potential benefits for oral health. This study aimed to investigate the effectiveness of red betel leaf mouthwash in controlling plaque and preventing halitosis. A pre-experimental study design with a one-group pretest-posttest approach was employed. Participants were recruited from a high school student council, with a sample size of 20 students. The intervention involved the use of red betel leaf mouthwash over a period of one week. The plaque index was assessed using the Loe and Silness index before and after the intervention. Data were analyzed using the paired T-test to determine the significance of changes in the plaque index. The mean plaque index before using the red betel leaf mouthwash was 2.15 ± 0.676, which decreased significantly to 0.94 ± 0.562 after one week of intervention (p = 0.000; p < 0.05). This indicates a substantial reduction in plaque accumulation following the use of red betel leaf mouthwash. Red betel leaf mouthwash demonstrated significant efficacy in reducing plaque index, suggesting its potential as an effective natural alternative for plaque control and halitosis prevention. Further research with larger sample sizes and control groups is recommended to confirm these findings and explore the long-term effects of red betel leaf mouthwash on oral health.

Oxidative Stress by H2O2 as a Potential Inductor in the Switch from Commensal to Pathogen in Oncogenic Bacterium Fusobacterium nucleatum.

Fusobacterium nucleatum is a pathobiont that plays a dual role as both a commensal and a pathogen. The oral cavity typically harbors this anaerobic, Gram-negative bacterium. At the same time, it is closely linked to colorectal cancer due to its potential involvement in tumor progression and resistance to chemotherapy. The mechanism by which it transforms from a commensal to a pathogen remains unknown. For this reason, we investigated the role of oxidative status as an initiatory factor in changing the bacterium's pathogenicity profile. A clinical strain of F. nucleatum subsp. animalis biofilm was exposed to different oxidative stress levels through varying subinhibitory amounts of H2O2. Subsequently, we investigated the bacterium's behavior in vitro by infecting the HT-29 cell line. We evaluated bacterial colonization, volatile sulfur compounds production, and the infected cell's oxidative status by analyzing HMOX1, pri-miRNA 155, and 146a gene expression. The bacterial colonization rate, dimethyl sulfide production, and pri-miRNA 155 levels all increased when stressed bacteria were used, suggesting a predominant pathogenic function of these strains. The response of F. nucleatum to different oxidative conditions could potentially explain the increase in its pathogenic traits and the existence of environmental factors that may trigger the bacterium's pathogenicity and virulence.

Olfactometric and Chemical Characterisation of Gaseous Emission from Crude Oils

This study focuses on the olfactometric and chemical characterisation of gaseous and vapour emissions from different crude oils. To investigate this topic, laboratory experiments were set up to obtain comparable gaseous samples: they were estimated in terms of odour concentration (Cod), via dynamic olfactometry, and chemical-specific characterisation. It was found that, even if considered similar in regard to physical properties and chemical composition, the gaseous emissions of different crude oils are significantly different in terms of odorous potential. The observed discrepancy appears to be associated with the presence of volatile organic sulphur compounds (VOSCs), and the highest values of Cod were found in samples containing mercaptans and sulphides. In addition, from the conducted comparison, it appeared that crude odorous potential, in terms of Cod, is not strictly linked to the quantity of the volatile organic compounds (VOCs), H2S concentration, or a priori knowledge of the percentage of elemental sulphur in the crude; on the contrary, the presence of volatile organic sulphur compounds in the gaseous emissions is the most influential parameter for the odour potential of this matrix.

Understanding the complex aroma profile of durian fruit: A concise review.

Durian fruit (Durio sp.) is a tropical fruit native to Southeast Asian countries known for its strong and unique characteristic smell. This review provides comprehensive information on durian fruit aroma, which is characterized by various volatile compounds, with esters and sulfur compounds playing a key role. Additionally, the contribution of ketones, alcohols and aldehydes to its unique aroma cannot be overlooked. The important precursors for the generation of these volatiles are branched-chain amino acids and polyunsaturated fatty acids. Moreover, the abundance and composition of aroma volatiles in durian fruit can be affected by various influencing factors, including genetic background, postharvest handling, and processing. This review also provides the common methods used to extract and analyze durian aroma components, with solid-phase microextraction gas chromatography-mass spectrometry emerging as a suitable and precise method to extract and analyze the complex aroma chemistry of the durian fruit.

Impact of Cu Fractions on the Light-Induced Spoilage Aromas of Chardonnay Wine at Variable Riboflavin Concentrations.

Despite the known ability of copper(II) to suppress sulfidic aromas, particularly the Cu fractions associated with organic acids and Cu(I) thiol species, the action of these copper fractions on the accumulation of light-induced sulfidic aromas in bottle-aged white wine is unknown. Chardonnay wine, containing different concentrations of riboflavin and copper(II), was exposed to fluorescent light for 6.5 months. The Cu fractions were measured by colorimetry, volatile sulfur compounds by gas chromatography-sulfur chemiluminescence detector (GC-SCD), and volatile aldehydes by gas chromatography-mass spectrometry (GC-MS). The protective Cu fractions inhibited light-induced sulfidic odor accumulation; however, light exposure accelerated the loss of these Cu fractions, and this loss was further accelerated with elevated riboflavin concentration. Upon depletion of the protective Cu fractions, the presence of copper sulfides led to an elevated hydrogen sulfide concentration with further light exposure. The results demonstrated that Cu(II) offers transient protection against the deleterious effects of short-term light exposure but can promote reductive characters with long-term light exposure.

Extraoral halitosis in functional dyspepsia and its association with small intestinal bacterial overgrowth

Small intestinal bacterial overgrowth (SIBO) and extraoral halitosis are often observed in functional dyspepsia (FD). We aimed to identify their associations for the first time. In this study, extraoral halitosis was diagnosed and assessed through the organoleptic score (OLS). Total symptom score (TSS) of FD, SIBO, gastricHelicobacter pylori(H. pylori) infection, and three exhaled volatile sulfur compounds (VSCs) (hydrogen sulfide, methyl mercaptan, and dimethyl sulfide (DMS)), were evaluated. Finally, 63 non-halitosis patients and 45 halitosis patients with extraoral halitosis were identified. Compared to non-halitosis patients, halitosis patients exhibited significantly higher TSS (86 [56, 123] vs 43 [34, 57],P< 0.001) and SIBO positivity rate (66.67% vs 11.11%,P< 0.001), but similarH. pyloripositivity rate. The adjusted odds ratios of TSS and SIBO were 1.06 and 5.02, respectively. The area under curve of the combination of TSS and SIBO for predicting extraoral halitosis was 0.89. Positive correlations were observed between TSS and OLS (r= 0.64), and between TSS and exhaled DMS level (r= 0.86), respectively. The other two VSCs were undetectable or of little value. We conclude that: (1) Extraoral halitosis is closely associated with FD and SIBO; (2) DMS is its primary contributing VSC; (3) FD patients with SIBO as opposed to gastricH. pyloriinfection are more prone to extraoral halitosis; (4) Clinicians should be aware of SIBO in the management of extraoral halitosis in FD.

Clinical and measurement variables affecting halitosis intensity following cysteine challenge test

The cysteine challenge test is a reliable and efficient method for halitosis diagnosis and assessing treatment effectiveness by measuring the capacity to produce hydrogen sulfide. However, several aspects related to the test including evaluation timing and total duration following cysteine loading has not been investigated in-depth and a standardized protocol is yet to be established. This observational study compared concentrations of volatile sulfur compounds (VSCs) following cysteine challenge at various time points based on different measurement tools to investigate clinical factors influencing the results. Cysteine challenge (rinsing for 30 s with 5 mL of 6 mM L-cysteine solution) was applied in 100 healthy subjects. VSC concentration of oral cavity gas was analyzed with standard and portable gas chromatography (GC) at 5 time points (before, immediately, 10, 20, and 30 min after cysteine challenge). The Community Periodontal Index of Treatment Needs (CPITN), Winkel’s Tongue Coating Index, and salivary flow rate were assessed. VSC levels significantly increased immediately after cysteine challenge (p < 0.001 for hydrogen sulfide, p < 0.001 with standard GC and p < 0.05 with portable GC for methyl mercaptan). Levels significantly decreased at 10 min after cysteine challenge except for methyl mercaptan measured with standard GC (p < 0.001). Subjects still showing VSCs 20 min after cysteine challenge was less than 15% of those initially positive. The amount of tongue coating showed significant association with methyl mercaptan levels immediately after (β = 0.202, p = 0.049) and 10 min following (β = 0.207, p = 0.045) cysteine challenge and CPITN showed acceptable discriminative power for persistent detection of methyl mercaptan (cut-off = 1.5, AUC = 0.668). Cysteine challenge may enhance the possibility of detecting VSCs during halitosis diagnosis. Standardized test protocols should address measurement timing, tools used, and tongue coating levels as clinical factors influencing VSC detection.

Odour prevention strategies in wastewater treatment and composting plants: A review.

Odour prevention strategies in wastewater treatment and composting plants: A review.