Search Results (6,614)

Conjugated linoleic acid (CLA) comprises a group of C18 fatty acids containing conjugated double bonds and has been associated with potential anti-obesity and antitumor effects. In this study, 116 presumptive lactic acid bacteria (LAB) isolates were recovered from homemade Sichuan pickles. Primary screening identified 28 CLA-producing isolates, among which strains 7# and 31# showed the highest absorbance at 233 nm (A₂₃₃). CLA production by both strains was subsequently optimized and quantified using gas chromatography–quadrupole time-of-flight mass spectrometry (GC-Q-TOF). Under the optimized conditions, strain 31# produced 66.50 ± 3.80 μg/mL total CLA, including 52.70 ± 3.29 μg/mL c9,t11-CLA and 13.80 ± 0.51 μg/mL t10,c12-CLA. Strain 7# produced 26.79 ± 1.09 μg/mL total CLA, including 14.05 ± 0.49 μg/mL c9,t11-CLA and 12.74 ± 0.60 μg/mL t10,c12-CLA. Physiological, biochemical, and safety assessments showed that strain 31# outperformed strain 7# overall, supporting its use in further product development and mechanistic studies. Functional annotation using the COG database and pathway mapping with KEGG identified candidate genes encoding an enzyme associated with linoleic acid isomerization in both strains. Potential mechanisms underlying their different CLA-producing capacities were also examined, providing a basis for the selection and development of high-CLA-producing strains. Full article

This study characterized the pattern and timing of post-cooking quality deterioration in durum wheat held at 25, 35, and 45 °C by performing physicochemical, microbiological, and volatile compound analyses combined with a sensorially defined off-odor onset endpoint. The bulk moisture content remained high throughout holding at all temperatures. Titratable acidity increased from 1.49 to 2.15, and pH at off-odor onset decreased from 6.63 to 6.49 with increasing temperature. Off-odor was detected after 50, 45, and 34 h at 25, 35, and 45 °C, respectively. Microbial growth was fastest at 35 °C (μ_max = 0.0651 h⁻¹). Thiobarbituric acid reactive substances (TBARS) values were slightly lower at 45 °C than at 25 °C, despite the shorter holding duration, whereas lipid oxidation-derived volatile aldehydes declined more sharply over the same comparison. This pattern, together with the earliest off-odor onset occurring at 45 °C, suggests that non-lipid-derived volatiles increasingly drive off-odor perception as holding temperature increases. Gas chromatography–mass spectrometry (GC–MS)-based relative odor activity value (ROAV) analysis identified 2-methoxy-4-vinylphenol, 2,4-decadienal, 2-nonenal, 2,3-butanedione, nonanal and 2-methoxyphenol as the principal contributors to the aroma profile. These findings indicate that off-odor development during post-cooking holding results from a temperature-dependent interplay between microbial and chemical deterioration pathways and provide a basis for optimizing holding time and temperature to delay off-odor onset and limit quality losses in bulgur production. Full article

Antimicrobial resistance has intensified the search for novel antimicrobial and wound-healing agents. Ludwigia octovalvis (Jacq.) P.H. Raven is traditionally used to treat infections, inflammation, and skin disorders, although its in vitro biotechnological potential remains largely unexplored. This study reports the first successful establishment of L. octovalvis callus cultures, their characterization by gas chromatography-mass spectrometry (GC-MS), and the evaluation of their antimicrobial and wound-healing activities. Friable calluses were induced from leaf and node explants of axenic seedlings using combinations of 6-benzylaminopurine (BAP), kinetin (KIN), 2,4-dichlorophenoxyacetic acid (2,4-D), and α-naphthaleneacetic acid (NAA). Optimal callus induction was achieved in leaf explants cultured on full-strength Murashige and Skoog (MS) medium supplemented with BAP (4.44 µM) and 2,4-D (0.45 µM). After six months of subculture, the calluses showed morphological uniformity and stable biomass production. Growth kinetics followed a specific growth rate of 0.047 d⁻¹ and a doubling time of 14.54 days. GC-MS analysis identified fatty acids and phytosterols as the main components. The ethyl acetate extract significantly improved wound healing in vivo, while the methanolic extract exhibited antibacterial activity against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA). These findings demonstrate that L. octovalvis callus cultures constitute a sustainable source of bioactive compounds with promising therapeutic potential. Full article

Chicken soup is widely appreciated for its nutritional value and flavor. This study investigated the effects of ultrasonic-assisted stewing (UAS) on flavor and non-volatile compounds (NVCs) using gas chromatography-mass spectrometry (GC-MS) and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis. GC-MS identified 39 volatile organic compounds (VOCs). At 120 min of stewing, the total VOCs concentration in the UAS group reached 150.08 mg/kg, approximately 5.10-fold that of the control group (29.41 mg/kg). Multivariate analysis combined with odor activity values further screened 10 differential VOCs. Aroma recombination and omission tests confirmed that 7 key VOCs, including (E)-2-octenal and (E,E)-2,4-decadienal, contributed to the meaty and fatty sensory attributes. UPLC-MS/MS analysis detected 5032 NVCs across 20 categories, among which 322 key differential NVCs, including small peptides, fatty acids, and nucleotides, showed significant differences between the UAS and control groups. Overall, UAS enhanced the flavor complexity of chicken soup by facilitating the release of flavor precursors, including small peptides, nucleotides, and lipid-derived NVCs, and promoting the formation of key VOCs. This study provides theoretical and technical support for the application of UAS in soup processing. Full article

The increasing prevalence of multidrug-resistant (MDR) Gram-negative bacteria has stimulated the search for plant-derived antimicrobials with alternative modes of action. This study investigated whether chemically distinct essential oils (EOs) differ in their antibacterial effects and their ability to modulate bacterial efflux-associated processes in clinically relevant MDR pathogens. The chemical compositions of tea tree (Melaleuca alternifolia), lemon (Citrus limon), Scots pine (Pinus sylvestris), and Eucalyptus radiata EOs, as well as their blend, were characterized by gas chromatography–mass spectrometry (GC-MS). Terpinen-4-ol, limonene, α-pinene, and eucalyptol were identified as major constituents. Antibacterial activity against Escherichia coli and Klebsiella pneumoniae strains with different resistance profiles was evaluated by broth microdilution, while effects on efflux-associated processes were assessed using an ethidium bromide accumulation assay. The EOs showed strain-dependent antibacterial effects, with E. coli being more susceptible than K. pneumoniae. E. radiata showed the lowest MIC against E. coli 130063 (0.312 mg/mL), whereas no EO inhibited the K. pneumoniae strains at concentrations below 5 mg/mL. The highest RFI values were observed for lemon oil against K. pneumoniae 33443 (1.41) and the EO blend against E. coli 128673 (1.27). These findings support further investigation of selected EOs as complementary antimicrobial agents. Full article

Background: Crude oil refinery waste sludge (COWS) ranks among the most compositionally complex and ecotoxicologically hazardous industrial residues. Although bulk total petroleum hydrocarbon (TPH) and summed polycyclic aromatic hydrocarbon (PAH) removal are routinely reported, the metabolite-level biochemical fate of individual petrogenic compounds, spanning ring dihydroxylation, catechol cleavage, and entry into central carbon metabolism, remains largely unmapped under co-composting with diverse animal manures. Objectives: This study aimed to construct a metabolite-resolved, microbially anchored biochemical fate map of crude oil sludge during co-composting. Methods: Aerobic microcosms combining crude oil sludge, garden soil, and a wood-chip bulking agent were amended separately with poultry, horse, cow, or swine/pig manure alongside an unamended control and then incubated at 22 °C for 300 days. Analyses integrated untargeted gas chromatography-mass spectrometry (GC-MS) metabolomics, targeted PAH quantification (EPA Methods 3541/8270), 16S rRNA gene amplicon sequencing (Illumina MiSeq, V1–V3, paired-end 300 bp), physicochemical monitoring, and culture-dependent isolation, with National Institute of Standards and Technology (NIST) Mass Spectral library annotation. Results: GC-MS resolved 1169 metabolite features across 17 samples, comprising 538 annotated compounds within 11 chemical classes and 631 unknowns, of which 151 recurred in at least 10 samples. Petrogenic markers (n-alkanes C₁₄–C₃₆, hopanoids, steranes, and alkylated dibenzothiophenes) and ring-cleavage intermediates (2-hydroxyfluorene, 1,4-naphthoquinone, phenanthrene-methanol, benzenediols, butanedioic acid, fatty alcohols C₁₆–C₂₀) elucidated a four-stage degradation cascade consistent with Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways map01220 and map00624. PAH mean-removal ranked swine/pig (88.0%) > horse (87.0%) > poultry (80.5%) > cow (79.1%) > control (68.2%). Sequencing recovered 2969 operational taxonomic units (OTUs) enriched in Pseudomonas, Achromobacter, Stutzerimonas, Dietzia, Gordonia, and Mycobacterium, with Pseudomonas dominating high-removal systems; respiration peaked at 18.7 mg CO₂-C g⁻¹ in poultry treatments. Conclusions: This work establishes a metabolite-resolved map linking hydrocarbonoclastic taxa to separate degradation steps. The co-occurrence of oxygenated PAH intermediates with decreasing parent PAH concentrations serves as an indicator of transformation processes and may assist in identifying potential residual-risk signals, thereby supporting remediation evaluation and process optimization. Full article

Although neonicotinoids (NEOs) insecticides have been extensively detected in environmental matrices, their electron ionization (EI) fragmentation patterns have never been systematically elucidated. Because of the poor thermal stability of NEOs, gas chromatography–mass spectrometry (GC-MS) is rarely used in analysis of NEOs. This work investigated eight representative NEOs by GC-MS using multiple isotopically labeled standards, including ²H and ¹³C labeled standards to clarify fragmentation routes and establish robust structural assignment criteria. We found two main factors affecting EI fragmentation patterns. (1) The pharmacophore controlled the backbone cleavage pathway. Specifically, nitroguanidines underwent transketolation with loss of N₂O, while cyanoamidines fragment via α-cleavage. (2) The heterocycle moiety determined the diagnostic fragment ion. A heterocyclic group with chloropyridine gave the diagnostic fragment ion of m/z 126, and a chlorothiazole moiety gave the diagnostic fragment ion of m/z 132. The lack of m/z 126 and m/z 132 ions in the case of dinotefuran (DNT), which contained neither of these two moieties, indirectly suggested the rules. This set of rules effectively bridged the gap in EI mass spectral interpretation, providing a basis for ion transition selection and fragment assignment during GC-MS method development. Moreover, it could provide supportive mass-spectrometric clues for potential application in the structural elucidation of related compounds. Full article

Background/Objectives: The increasing global prevalence of chronic diseases has intensified the search for potential natural therapeutic agents. Fagonia arabica is a medicinal plant widely used in traditional medicine; however, comparative information on the phytochemical composition and biological activities of its leaves and seeds remains limited. To the best of our knowledge, this study represents the first comparative investigation of the phytochemical profiles and bioactivities of methanolic leaf (FALE) and seed (FASE) extracts of F. arabica collected from Riyadh, Saudi Arabia. Methods: Methanolic extracts were analyzed by gas chromatography–mass spectrometry (GC–MS), and their total phenolic content (TPC), total flavonoid content (TFC), antioxidant, antimicrobial, anticancer, and antidiabetic activities were evaluated using standard in vitro assays. Results: GC–MS analysis identified 60 and 68 compounds in FALE and FASE, respectively, with (9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid, hexadecanoic acid, dimethyl-2,3,4,7,8,9,11,12,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-3-ol, and (1R,3aR,5aR,5bR,7aR,9S,11aR,11bR,13aR,13bR)-3a,5a,5b,8,8,11a-Hexamethyl-1-(prop-1-en-2-yl)-1,2,3,4,5,6,7,7a,9,10,11,11b,12,13,13a,13b-hexadecahydrocyclopenta[a]chrysen-9-ol as major constituents. FASE exhibited higher TPC and TFC values (104.13 mg GAE/g and 62.16 mg QE/g, respectively) than FALE. Both extracts demonstrated antioxidant activity, with FASE showing greater potency against DPPH and ABTS radicals (IC₅₀ = 63.3 and 42.4 μg/mL, respectively). FASE also displayed broad-spectrum antimicrobial activity, particularly against Staphylococcus aureus (MIC = 7.81 μg/mL). Furthermore, FASE exhibited stronger concentration-dependent cytotoxicity against MCF-7 and HepG2 cells, with IC₅₀ values of 106.8 and 89.5 μg/mL, respectively, compared with 112.5 and 103.1 μg/mL for FALE. Apoptosis induction in MCF-7 and HepG2 cells was associated with upregulation of caspase-3, caspase-8, caspase-9, and Bax, alongside downregulation of Bcl-2 and Bcl-xL. In addition, FASE exhibited potent α-amylase and α-glucosidase inhibitory activities (IC₅₀ = 61.62 and 67.38 μg/mL, respectively), comparable to acarbose. Conclusions: These findings highlight F. arabica seed extract as a promising source of multifunctional bioactive compounds with potential pharmaceutical application. Full article

Background: Wampee (Clausena lansium (Lour.) Skeels) is an understudied Rutaceae crop native to southern China, whose fruit features a complex aroma profile with simultaneous sour, sweet, bitter and astringent notes. Although bioactive compounds including flavonoids, alkaloids and volatile oils in wampee fruit have been partially characterized, the tissue-specific metabolic and transcriptional basis underlying its distinctive aroma formation remains largely unclear. Methods: We performed an integrated volatile metabolomic and transcriptomic analysis on the pericarp (peel) and flesh of wampee fruit across three cultivars (Shanyellowpi, Heijingang, Bingtangxin). Volatile metabolites were profiled via headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS), and transcriptome profiles were generated by RNA-Seq. Multi-omics integration was conducted using Procrustes analysis, gene–metabolite correlation network construction and weighted gene co-expression network analysis (WGCNA). Results: A total of 288 volatile metabolites were identified, representing the most comprehensive volatile inventory for C. lansium reported to date. Principal component analysis and partial least squares discriminant analysis revealed distinct volatile profiles between pericarp and flesh; terpenoids were the dominant chemical class, accounting for 71.56–91.48% of total volatiles in pericarp and 61.88–67.22% in flesh. Notably, organoheterocyclic compounds were significantly enriched in Shanyellowpi flesh (40.45%), forming a cultivar-specific metabolic signature absent in the other two cultivars. Transcriptomic analysis showed that phenylpropanoid biosynthesis was the most significantly enriched pathway among differentially expressed genes, followed by monoterpene biosynthesis and sesquiterpenoid biosynthesis. Procrustes analysis demonstrated a strong global concordance between the two omics layers (M² = 0.535, p < 0.001). Gene–metabolite correlation networks identified terpene synthase (TPS) genes (HP075360, HP217350) and oxidoreductase genes (SOD1, GST, 10HGO) as candidate co-regulators of terpenoid biosynthesis. WGCNA further prioritized TPS genes, cytochrome P450 genes and MYB transcription factor genes as key regulators driving volatile metabolic divergence between tissues. Conclusion: This study provides a comprehensive volatile and transcriptomic atlas of wampee fruit, and identifies tissue-specific and cultivar-specific metabolic signatures as well as their candidate regulatory genes. These findings advance our understanding of quality differentiation in Rutaceae fruits and lay a foundation for molecular breeding and flavor improvement of wampee. Full article

Spontaneously fermented camel milk from Xinjiang is valued for its nutrition but faces quality inconsistency due to complex microbial ecosystems. This study investigated how regional microbial communities correlate with volatile flavor profiles. Nine samples from three distinct areas—Dabancheng, Hami, and Keping—were analyzed using bacterial 16S rRNA gene and fungal ITS region amplicon sequencing combined with comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC×GC-TOF MS). Bacterial communities were dominated by Firmicutes and Proteobacteria, while Ascomycota and Basidiomycota prevailed among fungi. Dominant genera varied by region: Lactobacillus and Dekkera in Dabancheng; Lactobacillus and Dipodascus in Hami; Lactococcus and Cutaneotrichosporon in Keping. Flavor profiles also diverged, with Dabancheng being rich in esters, alcohols, and ketones; Hami featuring hydrocarbons and alcohols; and Keping containing elevated hydrocarbons, alcohols, and esters. Key statistical associations were identified: Lactobacillus, Rahnella, and Acetobacter were positively associated with propene and 3-decyn-2-ol (VIP > 1.0, |r| > 0.8), while Pseudomonas, Lactococcus, and Klebsiella showed negative correlations with vinyl n-caproate. These findings reveal statistical associations between geographic origin, specific microbial taxa, and flavor attributes, providing a scientific foundation that may inform future efforts toward developing targeted starter cultures pending microbial isolation and functional validation. Full article

Objectives: The present study evaluated the association between plasma concentrations of selected endocrine-disrupting chemicals (EDCs)—bisphenol A (BPA), methylparaben (MeP), propylparaben (PrP), 4-nonylphenol (4-NP), 4-octylphenol (4-OP), bis(2-ethylhexyl) phthalate (DEHP), and imazalil (IMZ)—and prior coronavirus disease 2019 (COVID-19) status. Methods: Plasma EDC levels were quantified via gas chromatography–mass spectrometry in 262 voluntary blood donors (121 convalescents and 141 controls) at the Regional Centre for Transfusion Medicine in Bialystok, Poland. Results: The cohort exhibited widespread environmental exposure to all selected EDCs (BPA: 1.14 ng/mL, MeP: 1.20 ng/mL, PrP: 1.38 ng/mL, 4-NP: 1.90 ng/mL, 4-OP: 0.57 ng/mL, DEHP: 49.68 ng/mL, IMZ: 20.06 ng/mL). Convalescents had significantly higher concentrations of MeP, PrP, 4-OP, and 4-NP. Logistic regression revealed that MeP, PrP, and 4-NP were significantly associated with prior COVID-19 status, increasing infection odds by 80%, 70%, and 63%, respectively. While 4-OP was strongly associated with prior COVID-19 status (odds ratio > 300 per unit change and 1.79 per 0.1 unit change), the wide confidence interval for the unit change estimate requires cautious interpretation. Conclusions: These findings suggest a strong link between selected paraben and alkylphenol exposure and prior COVID-19 status in blood donors. Additionally, the high IMZ levels highlight the need for urgent evaluation of its safety and environmental prevalence. Full article

Fruit wines fermented from citrus fruits are highly popular worldwide. The flavor profiles of fruit wines (ELFW, SLFW, PLFW) fermented from three different varieties of lemons (Eureka lemon, ELFW; Sweet lemon, SLFW; and Perfume lemon, PLFW) were investigated by odor activity values combined with multivariate statistical analysis. Volatile compounds in fruit wines were qualitatively and quantitatively analyzed using solid-phase microextraction (SPME) coupled with gas chromatography–mass spectrometry (GC–MS) and multidimensional GC–MS (MDGC–MS). A total of 85 volatile compounds were identified across the samples, with ELFW containing the highest number (67), followed by SLFW (65) and PLFW (58). Alcohols (51.25–73.50%) dominated the volatiles, followed by hydrocarbons and esters. α-Terpineol, 4-terpineol, and d-limonene dominated ELFW, SLFW, and PLFW respectively. Forty-six characteristic flavor compounds were screened, and fenchol showed the highest OAVs. Using OPLS-DA combined with variable importance in projection (VIP), 17 key flavor markers were identified to distinguish flavor difference among three lemon cultivar-based fermented fruit wines. Full article

Microplastics (MPs) and nanoplastics (NPs) accumulate in human hepatic and gastrointestinal (GI) tissues. However, differences in sampling strategies, tissue preparation, analytical techniques, and quality assurance procedures have resulted in substantial methodological heterogeneity, limiting the comparability and reproducibility of published findings. Therefore, this review aims to critically evaluate current analytical methodologies for the detection and characterization of MPs and NPs in hepatic and GI tissues, highlight methodological strengths, limitations, and emerging technologies, and identify priorities for methodological standardization. Studies demonstrate that no single analytical technique can simultaneously provide comprehensive information on particle size, morphology, polymer composition, spatial localization, and concentration. While Raman spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, pyrolysis gas chromatography–mass spectrometry (Py-GC/MS), and emerging multimodal imaging techniques each offer distinct advantages, reflecting their different underlying detection principles, methodological variability remains a major barrier to cross-study comparison. Human tissue studies are further constrained by limited sample availability, contamination risks, and inconsistent quality assurance procedures. Future progress will depend on harmonized, organ-specific analytical workflows integrating optimized tissue digestion, rigorous contamination control, complementary spectroscopic approaches, and standardized reporting metrics. Establishing unified methodological guidelines is essential to improve reproducibility, facilitate quantitative evidence synthesis, and advance both environmental exposure assessment and clinical research on MPs and NPs in hepatic and gastrointestinal tissues. Full article

The increasing prevalence of dermatophytosis and biofilm-associated infections highlights the need for new therapeutic approaches. This study evaluated the potential of Lavandula luisieri essential oil against clinically relevant dermatophytes. The essential oil obtained by hydrodistillation was chemically characterized by gas chromatography–mass spectrometry (GC–MS). Antifungal activity was assessed through determination of minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC), while antibiofilm activity against Epidermophyton floccosum was evaluated by measuring biofilm biomass, extracellular matrix (ECM) deposition, and cell viability. An ex vivo model of Trichophyton rubrum-induced skin infection was used to assess efficacy under tissue-relevant conditions. The essential oil was mainly composed of oxygenated monoterpenes, with trans-α-necrodyl acetate (19.1%), lavandulyl acetate (13.6%), camphor (8.8%), 1,8-cineole (6.1%), and trans-α-necrodol (5.3%)as major constituents. The oil exhibited antifungal activity against all tested dermatophytes (MIC: 12.5–100 μg/mL), induced hyphal morphological alterations, significantly inhibited E. floccosum biofilm formation, particularly ECM deposition, and reduced fungal dissemination in the ex vivo skin model. These findings support the antidermatophytic and antibiofilm potential of L. stoechas subsp. luisieri essential oil, although further studies are required. Full article

This study investigates the antioxidant efficacy and selectivity of a quercetagetin-rich extract (QG, 89% purity) from Tagetes erecta in soybean oil under accelerated storage conditions (65 °C, 56 days). Using gas chromatography–mass spectrometry (GC-MS) fatty acid profiling, Headspace Solid-Phase Microextraction Gas Chromatography–Mass Spectrometry (HS-SPME-GC-MS) volatile analysis, and Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) chemometrics, QG at 200 ppm was compared against a solvent control and propyl gallate (PG). QG preserved polyunsaturated fatty acids 5.2-fold more effectively than the control (p < 0.01), though it was less effective than PG in terms of overall Polyunsaturated Fatty Acid (PUFA) preservation. OPLS-DA-VIP analysis identified hexanal, hexanoic acid, and (E)-2-nonenal as preferentially suppressed volatiles (inhibition rates: 74.2%, 100%, and 81.2%, respectively), exceeding the average total volatile reduction (65.7%). A quantitative Selectivity Index (SI) combined with kinetic analysis supported preferential—rather than non-selective—inhibition of specific oxidation endpoints. Structure–activity relationship analysis suggested that the selectivity of the QG-rich extract may be associated with the catechol B-ring and unique 6-hydroxyl substitution of quercetagetin, its major component. The extract’s purity corresponds to a registered feed additive (Ministry of Agriculture and Rural Affairs (MOA) No. 618, 2022), ensuring industrial applicability. These findings establish the quercetagetin-rich extract as a promising selective natural antioxidant for PUFA-rich oils. Full article