Search Results (150)

This study aimed to analyze the volatile organic compounds (VOCs) for different rice aroma types using sensory evaluation, headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS), and gas chromatography-ion mobility spectrometry (GC-IMS) techniques, and to explore the material basis for the flavor differences. Based on the sensory evaluation results, rice aroma was categorized into three types, distinguished by their unique aroma compounds. Type A was characterized by a prominent sweet, popcorn aroma, type B by a more prominent cereal and starchy flavor, and type C by a more complex aroma. Untargeted metabolomics analysis using HS-SPME-GC-MS identified and characterized 74 volatile compounds. A comparison of A versus B versus C revealed 8 key aroma compounds, primarily alkanes, aldehydes, ketones, alcohols, and heterocyclic compounds. (E)-2-Octenal, 6-Undecanone, 2-Acetyl-1h-pyrrole, and P-menthan-1-ol in type A gave it a better sweet aroma, Dodecane, 2,6,10-trimethyl-, 1-Octen-3-one, and 2-Methyldecane in type B gave it a better starchy and cereal flavor. 2-Acetyl-1h-pyrrole, Heptacosane, and 1-Propanol in type C contributed to a complex aroma. GC-IMS analysis showed that the fingerprints of rice with different aroma types were significantly different. The VOCs of aroma type A contained (+)-limonene, 2-methylpyrazine, 2-pentanone, ethyl butanoate, n-pentanal, styrene, 1-butanol, 3-methyl-, acetate, 1-hexanal, 1-pentanol, and 2-heptanone, which gave it a better sweet aroma. The VOCs of aroma type C contained 1-octen-3-ol, 2,6-dimethyl pyrazine, 2-acetylpyridine, and ethyl hexanoate, which gave it a better complex aroma. Full article

Background: Low-fat diet (LFD) is widely applied in type 2 diabetes mellitus (T2DM), but the limited efficacy and difficulty in maintaining it hinder its wider promotion. Partially hydrolyzed guar gum (PHGG) is well-known as a probiotic in modulating gut microbiota, which is crucial in T2DM. However, the combined effects of LFD and PHGG remain unknown. Methods: Mice with T2DM were divided into 4 groups: T2DM control (DM-high-fat diet), LFD alone (DM-LFD), or LFD combined with low or high doses of PHGG (PHGG-L/H, 2.5% and 7.5% (w/w)) for 12 weeks. Serum lipid profiles, fasting blood glucose (FBG), HOMA-IR, and intraperitoneal glucose tolerance test (IPGTT) were assessed. Furthermore, microbiota composition, fecal metabolites, and fecal short-chain fatty acids (SCFAs) were determined by 16S rRNA gene sequencing, untargeted metabolomics, and gas chromatography-mass spectrometry, respectively. Results: LFD improved dyslipidemia but not glucose metabolism disorders. However, PHGG remarkably decreased FBG and HOMA-IR, and increased glucose tolerance. PHGG upregulated the abundance of SCFA-producing bacteria, including the genera Dubosiella, Bifidobacterium, and Ruminococcus, which were negatively correlated with FBG, HOMA-IR, and AUC (IPGTT). Moreover, the metabolic pathways altered by PHGG were enriched in tryptophan, tyrosine, and galactose metabolism. Fecal propionic acid and butyric acid, positively correlated with the abundance of genera Dubosiella and Ruminococcus, were markedly decreased by 50% and 44% in the DM-LFD group, but increased 2-fold after PHGG supplementation. Conclusions: PHGG combined with LFD might be a potential strategy to ameliorate glucose metabolic disorders, likely through modulating gut microbiota and the production of propionic acid and butyric acid. Full article

Background and Objectives: Dairy products provide vital energy, high-quality protein, and micronutrients for over six billion people worldwide, with dairy cows contributing nearly 81% of global milk production. Sustainable strategies to enhance productivity are therefore critical. Feed additives such as essential oil blends (EOB), onion peel (OPE), and prebiotics including mannan oligosaccharides (MOS) and galacto-oligosaccharides (GOS) have been proposed to improve rumen fermentation, modulate microbial ecology, and mitigate greenhouse gas emissions. This study evaluated the combined effects of EOB, OPE, MOS, and GOS on rumen metabolism using the rumen simulation technique (RUSITEC). Materials and Methods: Rumen inoculum from three cannulated Holstein Friesian cows was incubated across 16 vessels (four treatments × four replicates) for nine days. Treatments included a control (CON; TMR only), GEO (TMR + GOS + EOB + OPE), MEO (TMR + MOS + EOB + OPE), and OLEO (TMR + a 1:1 mixture of GOS and MOS + EOB + OPE). Additives were included at 3 µL/g TMR for EOB and 30 mg/g TMR (3% w/w) for OPE, GOS, MOS, or OLG. Rumen effluents were collected for untargeted metabolomic profiling by liquid chromatography–mass spectrometry, identifying 661 metabolites. Results: Partial least squares-discriminant analysis revealed clear separation between CON and additive groups, confirming distinct metabolic shifts. GEO primarily enhanced tryptophan, tyrosine, and purine metabolism; MEO stimulated phosphonate and pyrimidine pathways and bile acid biosynthesis; OLEO promoted phosphonate, nicotinamide, and taurine metabolism. Microbial analysis showed enrichment of taxa such as Lachnospira, Succinivibrionaceae, Macellibacteroides, Lysinibacillus, and Christensenellaceae, indicating complementary effects on fermentation and microbial stability. Conclusions: These results demonstrate that dietary supplementation with GEO, MEO, or OLEO modulates rumen metabolism and microbial ecology without impairing fermentation, supporting improved nutrient utilization, antioxidant defenses, and metabolic resilience in dairy cows, with potential benefits for productivity and sustainability. Full article

The quality and flavor of chicken meat are fundamentally determined by muscle metabolite composition, which reflects the regulatory effects of genetic background on metabolic pathways and muscle development. In this study, we profiled the meat quality of breast muscle across 3 crossbreeding combinations (D×HD, HD×D, and D×LD) between the Yunong D line and Houdan chickens to elucidate the metabolic mechanisms underlying flavor variation. Eighteen representative breast muscle samples were analyzed using common physicochemical indexes, untargeted metabolomics based on Gas Chromatography-Time-of-Flight Mass Spectrometry (GC-TOF-MS) and Ultra-High-Performance Liquid Chromatography coupled with Quadrupole Exactive Mass Spectrometry (UHPLC-QE-MS). Differential metabolites were identified through Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA). Multivariate analysis revealed distinct metabolic signatures among crossbreeding combinations, with HD×D exhibiting the most favorable tenderness, color, and water-holding capacity. A total of nine differential metabolites (5 upregulated and 4 downregulated) were identified between D×HD and HD×D, and thirty-eight metabolites (18 upregulated and 27 downregulated) between D×HD and D×LD. The identified metabolites were predominantly associated with amino acid metabolism, lipid biosynthesis, nucleotide turnover, and energy metabolism. Among these, arachidonic acid, taurine, L-alanine, and citric acid exhibited marked intergroup differences. Enrichment analysis based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) indicated significant involvement of pathways such as amino acid biosynthesis, taurine and hypotaurine metabolism, and ABC transporters in flavor formation. Hierarchical clustering and Pearson correlation analyses further delineated synergistic or antagonistic interactions among key metabolites, suggesting the existence of intricate regulatory mechanisms. These findings reveal critical metabolites and metabolic pathways associated with flavor attributes, offering both a theoretical framework and potential molecular targets for enhancing poultry meat quality through breeding strategies. Full article

Falciparum malaria is a life-threatening vector-borne disease prevalent in tropical and subtropical regions. The complexity of severe malaria demands a thorough investigation of host–parasite interactions. Twenty male Sprague Dawley rats were divided into two groups: uninfected controls and Plasmodium berghei-infected rats, infected via intraperitoneal injection of parasitized red blood cells. Serum samples were analysed using high-resolution untargeted Gas Chromatography–Time-of-Flight Mass Spectrometry. Metabolomic analyses revealed altered metabolites and enriched metabolic pathways. Distinct metabolite profiles were observed between infected and control groups. Infected rats showed elevated urea levels and reduced concentrations of 1,5-anhydroglucitol, D-(+)-Talose, and arachidonic acid. Pathway analysis revealed significant enrichment of the glucose-alanine cycle, alpha-linolenic acid metabolism, and linoleic acid metabolism in infected rats. Minimal enrichment was observed in arachidonic acid metabolism and lactose biosynthesis. The upregulation of the glucose-alanine cycle suggests increased gluconeogenesis in response to parasite-induced glucose depletion and energy demand. Elevated urea indicates enhanced amino acid catabolism. These findings highlight the potential of metabolomics as a diagnostic tool for malaria detection and prognosis. Full article

This pilot study explored the feasibility and acceptability of utilizing silicone wristbands to assess exposure to endocrine-disrupting chemicals (EDCs) among 25 Black and Hispanic breast cancer survivors recruited in Washington, DC, and Hackensack, NJ. Over half of participants (58%) were diagnosed with Stage I breast cancer and the mean age was 58 ± 9 years. Most of the 24 survey respondents (95.83%) reported that the wristband did not interfere with daily activities and few (4) removed the wristband during the 7-day data collection period, demonstrating feasibility of use. Acceptability of passive sampling via silicone wristband was high with 73.91% of survivors reporting being “very satisfied” and 21.74% reporting being “satisfied” with their experience. The wristbands were analyzed via gas chromatography mass spectrometry for approximately 1500 semi-volatile organic compounds. This untargeted approach detected sixty distinct chemicals with an average of 21.8 per wristband. Personal care product, flame retardant, commercial product, and pesticide chemical classifications were detected in every wristband and frequently detected chemicals included biologically active compounds with potential genotoxic or endocrine-disrupting effects. This study demonstrates the feasibility of use and technical feasibility, as well as the acceptability, of utilizing silicone wristbands to assess exposure to semi-volatile organic compounds, including EDCs, among Black and Hispanic breast cancer survivors and lays the foundation towards engaging diverse cancer survivors in environmental health research. Full article

Endometrial carcinoma (EC) is the most common malignancy of the female reproductive tract, with increasing incidence driven by aging populations and obesity. While molecular classification has improved diagnostic precision, the identification of clinically relevant metabolic biomarkers remains incomplete, and targeted therapies are not yet standardized. In this study, we investigated metabolic alterations in four EC cell lines (AN3-CA, EFE-184, HEC-1B and MFE-296) compared to non-malignant controls under normoxic and stress conditions (hypoxia and lactic acidosis) to identify metabolomic differences with potential clinical relevance. Untargeted gas chromatography–mass spectrometry (GC/MS) and targeted liquid chromatography–mass spectrometry (LC/MS) profiling revealed two distinct metabolic subtypes of EC. Cells of metabolic subtype 1 (AN3-CA and EFE-184) exhibited high biosynthetic and energy demands, enhanced cholesterol and hexosyl-ceramides synthesis and increased RNA stability, consistent with classical cancer-associated metabolic reprogramming. Cells of metabolic subtype 2 (HEC-1B and MFE-296) displayed a phospholipid-dominant metabolic profile and greater hypoxia tolerance, suggesting enhanced tumor aggressiveness and metastatic potential. Key metabolic findings were validated via real-time quantitative PCR. This study identifies and characterizes distinct metabolic subtypes of EC within the investigated cancer cell lines, thereby contributing to a better understanding of tumor heterogeneity. The results provide a basis for potential diagnostic differentiation based on specific metabolic profiles and may support the identification of novel therapeutic targets. Further validation in three-dimensional culture models and ultimately patient-derived samples is required to assess clinical relevance and integration with current molecular classifications. Full article

Botanical insecticides have gained interest due to a rising demand for environmentally friendly pest control methods for stored-product protection. The insecticidal effectiveness of the essential oil (EO) obtained from the oleo-gum-resin of myrrh (Commiphora myrrha (Nees) Engl.), against Prostephanus truncatus (Horn) and Sitophilus zeamais Motschulsky, and the metabolic shifts of the two species, were investigated in this work. A thorough gas chromatography-mass spectrometry (GC-MS) investigation showed that the composition of this EO was dominated by furanosesquiterpenes, specifically, furanoeudesma-1,3-diene and curzerene. Commiphora myrrha EO treatments, especially at 1000 ppm, resulted in high adult mortality for P. truncatus (up to 85.6%), while S. zeamais showed only moderate mortality (up to 25.6%). To investigate the different species-specific effectiveness of the EO, untargeted GC-MS metabolomic profiling was conducted to elucidate the impact of the EO on the metabolism of the insects, with subsequent data analysis employing multivariate, univariate, and network methods. Each species reacts differently to the treatments (myrrh EO versus the synthetic insecticide pirimiphos-methyl (PM)), according to the analysis results. In particular, myrrh EO caused distinct shifts in metabolic pathways that varied between P. truncatus and S. zeamais. Overall, C. myrrha EO exhibits potential as a botanical insecticide, especially against P. truncatus, and it causes metabolic disturbances specific to the species. The results demonstrate the significance of metabolomic technologies in assessing bioinsecticide mechanisms and lend credence to their possible incorporation in integrated pest management methodologies or their contribution to the creation of diagnostic indicators of insecticidal exposure. Full article

With the increasing consumption of mulberry fruits in commercial markets, flavor profiles have emerged as critical determinants of consumer preference and market acceptance. This investigation utilized four Morus laevigata (Morus L.) accessions exhibiting pronounced variations in fruit pigmentation and flavor characteristics as experimental materials. Comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC-TOF MS) was employed to identify key volatile aromatic compounds, while integrated untargeted metabolomics and transcriptomics approaches were applied to elucidate the underlying mechanisms of flavor biosynthesis. Analysis revealed that aldehydes, ketones, lactones, and heterocyclic compounds constitute the primary volatile organic compounds responsible for M. laevigata flavor complexity. The biosynthesis of these volatile aromatic compounds exhibits a direct correlation with lipid metabolite oxidation pathways. Concurrently, oxidative processes are modulated by M. laevigata flavonoid metabolites with antioxidant properties, which subsequently regulate both the compositional profile and quantitative distribution of volatile aromatic compounds. These findings offer novel insights into the metabolite–volatile compound interactions within mulberry systems, establishing a foundational framework for advancing fruit flavor research and cultivar development programs. Full article

Gas chromatography–mass spectrometry (GC-MS) plays a crucial role in analyzing complex water samples due to its high sensitivity, selectivity, and robustness. Recent developments have transformed GC-MS into a powerful chemosensor platform, capable of generating detailed chemical fingerprints for targeted or untargeted environmental analysis. This review highlights the integration of GC-MS with atomistic modeling approaches, including quantum chemical calculations and molecular simulations, to enhance the interpretation of mass spectra and support the identification of emerging contaminants and transformation products. These computational tools offer mechanistic insight into fragmentation pathways, molecular reactivity, and pollutant behavior in aqueous environments. Emphasis is placed on recent trends that couple GC-MS with machine learning, advanced sample preparation, and simulation-based spectrum prediction, forming a synergistic analytical framework for advanced water contaminant profiling. The review concludes by addressing current challenges and outlining future perspectives in combining experimental and theoretical tools for intelligent environmental monitoring. Full article

Background/Objectives: Anaerobic gut fungi (Neocallimastigomycota) are biotechnologically relevant, lignocellulose-degrading microbes with under-explored biosynthetic potential for secondary metabolites. Untargeted metabolomic profiling with gas chromatography–mass spectrometry (GC-MS) was applied to two gut fungal strains, Anaeromyces robustus and Caecomyces churrovis, to establish a foundational metabolomic dataset to identify metabolites and provide insights into gut fungal metabolic capabilities. Methods: Gut fungi were cultured anaerobically in rumen-fluid-based media with a soluble substrate (cellobiose), and metabolites were extracted using the Metabolite, Protein, and Lipid Extraction (MPLEx) method, enabling metabolomic and proteomic analysis from the same cell samples. Samples were derivatized and analyzed via GC-MS, followed by compound identification by spectral matching to reference databases, molecular networking, and statistical analyses. Results: Distinct metabolites were identified between A. robustus and C. churrovis, including 2,3-dihydroxyisovaleric acid produced by A. robustus and maltotriitol, maltotriose, and melibiose produced by C. churrovis. C. churrovis may polymerize maltotriose to form an extracellular polysaccharide, like pullulan. GC-MS profiling potentially captured sufficiently volatile products of proteomically detected, putative non-ribosomal peptide synthetases and polyketide synthases of A. robustus and C. churrovis. The triterpene squalene and triterpenoid tetrahymanol were putatively identified in A. robustus and C. churrovis. Their conserved, predicted biosynthetic genes—squalene synthase and squalene tetrahymanol cyclase—were identified in A. robustus, C. churrovis, and other anaerobic gut fungal genera. Conclusions: This study provides a foundational, untargeted metabolomic dataset to unmask gut fungal metabolic pathways and biosynthetic potential and to prioritize future efforts for compound isolation and identification. Full article

Strawberries are highly perishable despite their popularity, as their limited shelf life compromises both freshness and market value. The study investigated the effects of 1-methylcyclopropene (1-MCP), modified atmosphere packaging (MAP), and their combined treatments on the quality and flavor of strawberries during cold storage and simulated shelf life. 1-MCP was applied by enclosing strawberry fruits in a hermetically sealed container and exposing them to 250 nL/L 1-MCP at 20 °C for 18 h. Three initial MAP gas compositions were tested: MAP1 (5% O₂, 15% CO₂, 80% N₂), MAP2 (10% O₂, 10% CO₂, 80% N₂), and MAP3 (15% O₂, 5% CO₂, 80% N₂), with MAP1 identified as optimal based on strawberry postharvest quality metrics. The results showed that all treatments could inhibit the deterioration of strawberry quality, and the 1-MCP + MAP treatment had the best fresh-keeping effect. Untargeted Gas Chromatography-Mass Spectrometry (GC-MS) analysis identified 85 volatile compounds, and sensory correlation analysis revealed that 1-MCP + MAP-treated strawberries maintained the highest consumer acceptability, with odor characteristics closely resembling those of pre-storage controls. Further studies demonstrated that the combined treatment uniquely suppressed the generation of fatty acid oxidation-derived volatiles while stabilizing critical aroma-active esters, thereby decelerating flavor degradation. Collectively, these findings highlight the potential of 1-MCP + MAP as a postharvest strategy to delay the postharvest senescence of strawberries and maintain their storage quality. GC-MS provided a scientific method for the flavor quality evaluation of this preservation technology. Full article

Ankylosing spondylitis (AS) displays wide inter-patient variability that is not accounted for by HLA-B27 alone, suggesting that additional immune and metabolic modifiers contribute to disease severity. Using a genetically matched design, we profiled peripheral blood mononuclear cells from two brother pairs discordant for AS severity and one healthy brother pair. Strand-specific RNA-seq was analyzed with a family-blocked DESeq2 model, while untargeted metabolites were quantified using gas chromatography–mass spectrometry (GC-MS) and liquid chromatography–mass spectrometry (LC-MS). Differential features were defined as follows: differentially expressed genes (DEGs) (|log₂FC| ≥ 1 and FDR < 0.05) and metabolites (VIP > 1, FC ≥ 1.2, and BH-adjusted p < 0.05). Pathway enrichment was performed with KEGG and Gene Ontology (GO). A total of 325 genes were differentially expressed. Type I interferon and neutrophil granule transcripts (e.g., IFI44L, ISG15, S100A8/A9) were markedly up-regulated, whereas mitochondrial β-oxidation genes (ACADM, CPT1A, ACOT12) were repressed. Metabolomics revealed 110 discriminant features, including 25 MS/MS-annotated metabolites. Primary bile acid intermediates were depleted, whereas oxidized fatty acid derivatives such as 12-Z-octadecadienal and palmitic amide accumulated. Spearman correlation identified two antagonistic modules (i) interferon/neutrophil genes linked to pro-oxidative lipids and (ii) lipid catabolism genes linked to bile acid species that persisted when severe and mild siblings were compared directly. Enrichment mapping associated these modules with viral defense, neutrophil degranulation, fatty acid β-oxidation, and bile acid biosynthesis pathways. This sibling-paired peripheral blood mononuclear cell (PBMC) dual-omics study delineates an interferon-driven lipid–bile acid axis that tracks AS severity, supporting composite PBMC-based biomarkers for future prospective validation and highlighting mitochondrial lipid clearance and bile acid homeostasis as potential therapeutic targets. Full article

C. humilis is a small shrub belonging to the Rosaceae family, and grafting is one of the main ways for propagation. However, the influence of different rootstocks on volatile aroma is still unclear. In this study, an untargeted metabolomics approach based on gas chromatography–mass spectrometry (GC-MS) was utilized to analyze the volatile differential metabolites between the rootstock–scion combinations and self-rooted seedlings. Furthermore, metabolic pathway enrichment analysis was performed using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. In total, 191,162 and 150 volatile differential metabolites were identified in different rootstock–scion combinations. The rootstock–scion combinations of ZG/MYT and ZG/BT could improve the volatile aroma in the fruit of C. humilis and made significant contributions to the rose and fruity flavors. KEGG pathway analysis indicated that the differential metabolites were mainly enriched in the butanoate metabolism and glycolysis/gluconeogenesis pathways, showing an increasing trend. Prunus tomentosa and Amygdalus communis can serve as preferred rootstocks for enhancing the aroma quality of C. humilis fruits. These results provide new insight into rootstock-based propagation and breeding and also offer some guidance for graft-based fruit production. Full article

The impact of seasonality on the aroma quality of tea has been documented in various tea types, but not specifically in oolong tea. This study is the first to explore the complex relationships between seasonality, volatile compounds, and aroma quality in oolong tea. Using Headspace Solid-Phase Microextraction Gas Chromatography–Mass Spectrometry (HS-SPME-GC-MS)-based untargeted metabolomics, we analyzed 266 samples of Tieguanyin oolong tea. The data identified linalool, linalool oxides (trans-linalool oxide (furanoid) and trans-linalool oxide (pyranoid)), and their metabolites (diendiol I; hotrienol) as key seasonal discriminants. Four out of the top ten key differential compounds for distinguishing aroma scores were metabolites from fatty acid degradation, namely trans-3-hexenyl butyrate, trans-2-hexenyl hexanoate, hexyl hexanoate, and hexyl 2-methyl butyrate. Approximately one-fifth of the seasonal discriminant volatile compounds were significant in influencing aroma quality. Overall, the impact of seasonality on the aroma quality of finished Tieguanyin oolong tea is marginal. These findings enhance our understanding of the interplay between seasonal variations, volatile composition, and aroma quality in oolong tea. Full article