Search Results (4,432)

Carya illinoinensis (pecan) has recently emerged as a promising oilseed crop in Eastern Europe; however, its oil has not been systematically characterized under regional growing conditions or directly compared with that of the established nut crop, Juglans regia (walnut). This study evaluated the proximate composition, fatty acid profile, and short-term oxidative stability of oils from six pooled sample groups, comprising three pecan and three walnut composite samples collected from Romania and the Republic of Moldova. Oils were extracted by hot pressing, kernel composition was determined using standard official (AOAC) methods, fatty acid composition was analyzed by gas chromatography–mass spectrometry (GC–MS), and oxidative stability was assessed by peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) during 20 days of storage. Romanian pecan oils contained 67–68% total fat and were rich in linoleic acid (55–57%), whereas walnut oils contained 59–61% fat and were dominated by oleic acid (57–58%). The PNC composite sample exhibited an oleic acid-dominant profile that differed from those of the other two pecan samples. Because cultivar identity, genotype, and environmental variables were not determined, the cause of this difference cannot be established from the present study. All samples remained below the Codex Alimentarius PV limit (3.0 meq O₂/kg). TBARS changes differed among the analyzed composite oils; however, these differences cannot be attributed solely to fatty acid composition because antioxidant constituents were not measured. Oleic and linoleic acids were strongly and inversely correlated (Pearson r = −0.9998, p < 0.001). These findings provide the first comprehensive characterization of pecan oil produced under Eastern European conditions and demonstrate compositional variation among the analyzed composite samples, although the factors responsible for this variation could not be determined. Full article

The current clinical test for ketosis in dairy cows, which is based on measuring blood β-hydroxybutyrate (BHB) concentrations, is an invasive procedure that impacts herd welfare. Alternative biomarkers, especially non-invasive ones, are urgently needed for subclinical ketosis (SCK) diagnosis. To address this, we examined the milk lipidomic profiles of healthy and SCK cows from a research dairy farm over two consecutive years. A total of 125 polar lipid species were quantified in milk samples using a targeted liquid chromatography–mass spectrometry (LC-MS) approach. Chemometric analysis identified four potential biomarkers (PC 28:0, PC 29:0, PC 30:1 and PC 31:0), which met the thresholds for p value (<0.0004) and fold change (FC > 2). Global fatty acid (FA) profiling by gas chromatography–flame ionization detection (GC-FID) after transesterification of all lipids revealed that the levels of C8:0, C10:0, C12:0, C14:0, C15:0 and C18:1t11 were significantly suppressed in the SCK group (15–52% lower compared to the control group, p < 0.01), and C15:0 and C18:1t11 were the most promising markers for SCK in dairy cows at the FA level (43–50% reduction compared to the control group, p < 0.0001). Tandem LC-MS and FA data generated by GC demonstrated that SCK also caused significant changes in regio-isomer and double bond isomer composition of a model phospholipid molecule (PC 34:1) and a model triglyceride molecule TAG 52:2; these fine-structural alterations could also be explored for discovering novel SCK biomarkers in dairy cows. The PLS-DA predictive model built from lipidomic data showed excellent accuracy (>95%) in predicting cows with SCK. All of the promising biomarkers identified and the predictive model built in this study need further validation using larger SCK cohorts from different herds. Full article

Organophosphorus pesticides (OPs) are persistent environmental contaminants requiring monitoring in aquatic ecosystems. In this study, four novel mineral–carbon composites (K-HNT, K-C-HNT, D-HNT, and D-C-HNT) were synthesized via thermal treatment at 800 °C from halloysite nanotubes, casein, dextrin, and pyrolyzed sawdust. Moreover, these materials were characterized (BET, FT-IR, Raman, SEM/EDS), revealing high specific surface areas (up to 218.3 m²/g for the D-C-HNT composite), and evaluated as solid-phase extraction (SPE) sorbents for the determination of six OPs from water. The eluates were analyzed using GC-MS/MS in MRM mode. This study examined the effect of eluent, sorbent mass, and multiple extractions on SPE efficiency. Ethyl acetate-n-hexane (1:1, v/v) was confirmed to be the most effective eluent, achieving high pesticide recoveries (>80%) at optimal sorbent masses of 50 and 75 mg. The method demonstrated satisfactory sensitivity, with limits of detection (LODs) ranging from 1.6 to 3.3 μgL⁻¹. Notably, the synthesized composites outperformed pure precursors and demonstrated extraction efficiency comparable to commercial sorbents (C-18, Florisil, active carbon). Furthermore, reusability tests confirmed that second and third extraction repetitions reduced the efficiency of the SPE process only slightly, indicating that these waste-derived composites can be reused multiple times without cartridge replacement. Full article

Background/Objectives: The increasing prevalence of antimicrobial resistance has reduced the effectiveness of conventional antibiotics, highlighting the need for alternative or adjunct antimicrobial agents. This study aimed to investigate the antibacterial, synergistic, and antibiofilm activities of Liquidambar orientalis Mill. essential oil against clinically relevant bacterial pathogens, using 24 bacterial strains representing 12 bacterial species. Methods: The volatile constituents of L. orientalis essential oil obtained by hydrodistillation of storax balsam were characterized by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID). Antibacterial activity was evaluated using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), disk diffusion, and agar well diffusion assays against a panel of Gram-positive and Gram-negative bacterial pathogens. Synergistic interactions with erythromycin, amoxicillin, gentamicin, and enrofloxacin were assessed using fractional inhibitory concentration index (FICI) analysis. Antibiofilm activity was also evaluated against representative biofilm-forming strains. Results: A total of 90 volatile constituents were identified by GC-MS, of which styrene was the most abundant (68.6%), followed by (E)-ethyl cinnamate (6.8%), α-pinene (5.9%), and β-pinene (2.9%). The essential oil exhibited broad-spectrum antibacterial activity, with an overall inhibition rate of 60.4%. Activity was higher against Gram-positive (77.77%) than Gram-negative (73.33%) bacteria. MIC and MBC values ranged from 15.62 to 250 µg/mL and 31.25 to 250 µg/mL, respectively. FICI analysis revealed strain- and antibiotic-dependent interactions, ranging from synergistic to antagonistic effects. Variable antibiofilm activity was observed, with the strongest inhibition against Brucella melitensis and the weakest against Pseudomonas aeruginosa. No significant differences in MIC or MBC values were observed between bacterial groups (p > 0.05). Conclusions: L. orientalis essential oil demonstrated in vitro antibacterial activity against several clinically relevant pathogens, with particularly notable activity against B. melitensis. The essential oil also showed synergistic interactions with selected antibiotics and variable antibiofilm effects. These findings suggest that L. orientalis essential oil may have potential as an antibacterial agent or adjunct to antibiotic therapy; however, further in vivo and clinical studies are required to confirm its therapeutic applicability. Full article

A rare carved lacquer (tixi) plate recovered from the Southern Song Dynasty Nanhai No. 1 shipwreck was examined to reconstruct its coating stratigraphy, raw materials, and manufacturing sequence. Detached fragments collected before conservation treatment were investigated by cross-sectional optical microscopy, micro-Raman spectroscopy, thermally assisted hydrolysis–methylation pyrolysis–gas chromatography/mass spectrometry (THM-Py-GC/MS), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), and wood-anatomical microscopy. The polished cross-section contains nine lacquer layers with a combined thickness of 387.3 μm above a heterogeneous ground, yielding ten visually distinguishable strata. Alternating dark, red, and yellow layers establish the technological basis for the carved polychrome effect. Raman bands identify cinnabar (HgS) in the red layer and orpiment (As₂S₃) in the yellow layer. THM-Py-GC/MS detected homologous alkenes, alkanes, and alkylbenzenes diagnostic of Chinese lacquer derived from Toxicodendron vernicifluum. Monocarboxylic acids were present, whereas no clear dicarboxylic-acid markers of a drying oil were observed; because the object was waterlogged and degraded, this absence is treated as a lack of positive evidence rather than proof that oil was never used. The ground is enriched in Ca and P and is therefore consistent with a bone-ash-based filler, although phase-specific confirmation remains necessary. Wood anatomy identifies the substrate as Chinese fir (Cunninghamia lanceolata, Cupressaceae). Together, the results document an organic–inorganic multilayer coating system and provide material evidence for Southern Song carved-lacquer technology, while defining conservation risks associated with a waterlogged wooden core and light-sensitive pigments. The marine archaeological context and the support-to-surface, layer-resolved design distinguish this case from most previous studies of Song-dynasty lacquerware. Beyond technological reconstruction, the findings identify conservation priorities for waterlogged wood, the wood–ground–lacquer interface, and light-sensitive pigmented layers, and provide a transferable evidence framework for comparative research on archaeological lacquer. Full article

The Potiguar Basin, in Rio Grande do Norte (Northeastern Brazil), has an extensive coastline with a rich diversity of marine sponges that remain poorly explored for their biotechnological potential. In this study, three sponge species—Suberites aurantiacus, Mycale (Zygomycale) angulosa, and Halichondrida—were collected, and a preliminary extraction was then performed to remove the most hydrophobic fraction with n-hexane. The remaining sediment was re-extracted with chloroform and methanol (1:1), and the resulting extracts (ESUB, EMYC, and EHALI, respectively) were analyzed. Chemical characterization using Gas–Liquid Chromatography–Mass Spectrometry (GC/MS) revealed distinct profiles for each genus, with the presence of alcohols, alkaloids, phenolic compounds, and lipids, mainly sterols. ESUB presented 17 identified compounds, EMYC had 15 identified and EHALI showed 15 identified. The antioxidant potential of the extracts was evaluated in vitro using DPPH radical scavenging, copper ion chelation, and total antioxidant capacity (TAC). The EC₅₀ values (mg/mL) for DPPH were 0.05 (ESUB), 0.14 (EMYC), and 0.06 (EHALI), while for copper chelation they were 0.03, 0.034, and 0.026, respectively. Preliminary toxicological assays indicated low toxicity, with IC₅₀ values above 9.6 mg/mL in human erythrocytes and Tenebrio molitor larvae, demonstrating a favorable safety profile for potential therapeutic applications. The study presents a preliminary screening of underexplored species in an equally underexplored region and supports further studies on their bioactive potential. Full article

Background/Objectives: This study presents a gas chromatography–mass spectrometry (GC–MS) method for the derivatization-free quantification of the three major short-chain fatty acids (SCFAs)—acetate, propionate, and butyrate—in gilthead sea bream (Sparus aurata) fecal samples. SCFAs are key metabolites involved in intestinal physiology and are widely recognized as indicators of gut microbiota activity and host health across animal species. In aquaculture research, SCFA profiling can provide valuable insight into diet–microbiota interactions and gut functional status. Methods: The method was developed and optimized using gut-content samples collected from 105 gilthead sea bream at the end of two independent feeding trials, yielding 42 pooled samples (18 from FT1 and 24 from FT2). An extraction protocol based on acidified aqueous extraction with water followed by liquid–liquid extraction using methyl tert-butyl ether was developed (ExA) and subsequently optimized (ExB) to improve extraction consistency and efficiency. SCFA separation and quantification were performed by GC–MS using external calibration. Method validation included evaluation of linearity, matrix effects, and partition coefficients between water and methyl tert-butyl ether. Results: The optimized extraction method (ExB) demonstrated high analytical performance, with linearity coefficients exceeding 0.992 and matrix effects below 17.4%. Conclusions: The proposed method represents a practical and reliable approach for routine SCFA analysis in fish fecal samples. It provides a useful analytical tool for studies investigating diet–microbiota interactions, gut health, and functional responses to nutritional interventions in aquaculture species. Full article

The Ziziphi spinosae semen flavonoids (ZSSF) possess significant nutritional value and exhibit a wide range of health benefits, exerting positive effects on diseases related to the central nervous system. Given the excellent bioactivity and limited absorption of ZSSF, elucidating the underlying mechanism of ZSSF is imperative. In this study, in vitro fecal microbial culture fermentation was performed to investigate the metabolism of ZSSF and its effect on the gut microbiota. A total of 45 chemical constituents were identified by Ultra-performance liquid chromatography–quadrupole time-of-flight–tandem mass spectrometry (UPLC-Q-TOF-MS/MS), and possible biotransformation pathways were postulated. The degradation rates of spinosin and 6‴-feruloylspinosin were 2.53 ± 0.07 μg/mL/h and 0.79 ± 0.06 μg/mL/h, respectively, with swertisin accumulating to 55.00 ± 3.55 μg/mL at 24 h before declining. The abundance of Firmicutes increased from 8.42% at 0 h to 48.26% in the ZSSF fermentation group at 48 h, while Actinobacteria and Proteobacteria decreased from 60.02% and 30.25% to 23.46% and 20.02%, respectively. Furthermore, gas chromatography–mass spectrometry (GC-MS) was used to analyze short-chain fatty acids (SCFAs), revealing that ZSSF was associated with higher butyrate concentration at 48 h under the tested batch-fermentation conditions, with significantly higher levels observed in the ZSSF fermentation group compared to the control (1.34 ± 0.03 vs. 1.10 ± 0.05 mmol/L, p < 0.05). This study provides the first integrated analysis of ZSSF metabolism, gut microbiota modulation, and SCFAs production in a single in vitro fermentation model, offering a comprehensive understanding of the gut microbiota-mediated biotransformation of ZSSF and its metabolic consequences. Notably, these findings are derived from an in vitro batch fermentation model, and therefore, in vivo validation is required to confirm the physiological relevance of these observations. Collectively, this study provides insight into the exploration of the metabolic functions and mechanisms of ZSSF. Full article

Understanding the dynamic evolution of occurrence states of retained hydrocarbons at different thermal maturation stages is crucial for assessing shale oil mobility and enhancing oil recovery. Semi-open pyrolysis experiments were conducted on organic-rich shales from the Chang 7₃ sub-member of the Ordos Basin. Based on semi-open system hydrocarbon generation and expulsion thermal simulation experiments, combined with sequential multi-solvent extraction, gas chromatography–mass spectrometry (GC–MS), Fourier transform infrared spectroscopy (FTIR), and low-temperature N₂ adsorption, this study systematically characterized the composition, occurrence pore size, occurrence state, and quantitative evolution of retained hydrocarbons in organic-rich shales across a maturity range of vitrinite reflectance (Ro) = 0.53–1.59%. The results indicate that maturity significantly influences hydrocarbon generation and pore structure, which in turn affects the occurrence states and contents of retained hydrocarbons. As maturity increases, the contents of various occurrence states reach their peak at around Ro = 0.88%, with free oil predominating at a proportion as high as 86.57%. Beyond Ro = 0.88%, the proportion of free oil decreases rapidly, while the proportions of adsorbed oil, adsorbed–miscible oil, and miscible–adsorbed oil all increase. The content of free oil is not only related to pores in the 20–100 nm range but also to the molecular structure of kerogen. It is proposed that the Ro = 0.74–1.03% stage represents the golden window for free oil yield, with favorable exploration and development potential. These findings provide a theoretical basis for the exploration and development of organic-rich shale oil and the assessment of movable resource potential. Full article

The quality and flavor of vine tea are largely determined by its processing stages, which markedly influence its physical attributes and volatile organic compounds. Elucidating the dynamic changes in physicochemical and aromatic properties throughout processing is, therefore, essential for guiding optimized processing techniques and developing high-quality vine tea products. However, the specific effects of individual processing stages on quality attributes remain poorly understood. In this study, we combined assessments of color and physical properties with untargeted metabolomics, headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS), relative odor activity value (ROAV), and gas chromatography–olfactometry (GC-O) to identify key compounds contributing to vine tea quality. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were further applied to identify characteristic metabolites associated with aroma and flavor differentiation. A total of 280 volatile organic compounds were identified, among which 14 key VOCs (ROAV ≥ 1, aroma intensity ≥ 0.5) exhibited significant dynamic variation across processing stages. Notably, compounds such as β-ionone, β-myrcene, nonanal, and hexanal displayed higher ROAVs and strong aroma intensities (AI ≥ 1.0), indicating their substantial contribution to overall aroma. Furthermore, the metabolic transformation pathways—primarily including fatty acid degradation and carotenoid cleavage—and the content changes of key aroma-active compounds were inferred across different processing stages. Based on the differential accumulation patterns of the identified volatile markers, the possible involvement of fatty acid degradation and carotenoid cleavage pathways was inferred. Drying and fixation emerged as critical steps for vine tea aroma development, while the non-enzymatic degradation of fatty acids was potentially associated with the formation of its aroma characteristics. This study provides insights that may inform future efforts toward processing optimization and quality improvement of vine tea. Full article

Petroleum reservoir systems of the South Mangyshlak Basin are characterized by a complex geological framework, pronounced geochemical heterogeneity, and evidence of inter-reservoir fluid interactions, which complicate the interpretation of oil origin and the assessment of geochemically inferred reservoir connectivity between productive horizons. In this study, a comprehensive geochemical characterization of crude oils from the basin was performed using high-resolution gas chromatography (HRGC), gas chromatography–mass spectrometry (GC–MS), oil fingerprinting, and Rock-Eval pyrolysis. The distributions of n-alkanes, isoprenoids, terpane, sterane, and aromatic biomarker compounds were analyzed to evaluate the genetic type of the source organic matter, thermal maturity, and hydrocarbon migration processes. The results revealed the presence of marine, lacustrine, and mixed genetic oil families, together with a general tendency toward increasing thermal maturity with reservoir depth. The most pronounced evidence of vertical hydrocarbon migration and oil mixing was identified in the Uzen oil field, where the multilayer reservoir system exhibits geochemical evidence consistent with possible inter-reservoir fluid communication and geochemically inferred reservoir connectivity. The obtained results suggest that the geochemical heterogeneity of oils in the South Mangyshlak Basin reflects the combined effects of variations in source-rock organic matter, vertical hydrocarbon migration, and oil mixing within stacked petroleum reservoir systems. Full article

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal cancers worldwide, with limited treatment options and a high prevalence of oncogenic KRAS mutations. Piper betle contains numerous bioactive phytochemicals with reported anticancer activities, although its activity against pancreatic cancer remains incompletely characterized. This study evaluated the phytochemical composition of P. betle leaf extracts and the cell viability effects of ethanolic extracts against human KRAS G12D-mutant pancreatic cancer cell lines (PANC-1, AsPC-1, Panc 02.03, Panc 04.03, Panc 08.13 and Panc 10.05). Phytochemical screening, total phenolic content (TPC), total flavonoid content (TFC) and gas chromatography–mass spectrometry (GC-MS) analyses were performed to characterize the extracts. The ethanolic extracts exhibited higher extraction yield (17.26%), TPC (395.94 ± 0.010 mg GAE/g) and TFC (121.28 ± 0.009 mg QE/g) than aqueous extracts. GC-MS analysis tentatively identified phenylpropanoid compounds, including chavicol, chavibetol, and eugenol. Based on these findings, the ethanolic extract was selected for biological evaluation. Treatment significantly reduced cell viability in a concentration-dependent manner across all pancreatic cancer cell lines, with estimated IC₅₀ values ranging from 21.54 to 54.91 µg/mL. These findings suggest that ethanolic P. betle leaf extract possesses promising biological activity and support further studies to identify its active constituents and elucidate their mechanisms of action. Full article

The occurrence of multidrug-resistant (MDR) bacteria in foods of animal origin is a public health concern that underscores the need to investigate natural antimicrobial alternatives. Although Syzygium aromaticum essential oil exhibits antibacterial activity, evidence regarding its bactericidal effects against MDR bacteria recovered from commercial eggs remains limited. This study evaluated the bactericidal activity of eugenol-rich S. aromaticum essential oil (SAEO) and explored its potential antibacterial mechanisms. SAEO was obtained by steam distillation and chemically characterized by gas chromatography–mass spectrometry (GC–MS). Its antibacterial activity was evaluated by determining the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), bacterial growth kinetics, and changes in membrane permeability. Molecular docking was performed to examine the interactions of eugenol with dihydropteroate synthase (DHPS) and β-ketoacyl-acyl carrier protein synthase III (FabH). Eugenol was the predominant constituent (73.9%), followed by dihydroeugenyl acetate (14.1%) and β-caryophyllene (6.0%). SAEO exhibited bactericidal activity against all tested strains, with MIC and MBC values ranging from 0.125 to 0.25 mg/mL and from 0.25 to 0.50 mg/mL, respectively. SAEO also produced sustained bacterial growth inhibition and concentration-associated changes in membrane permeability. Molecular docking predicted favorable interactions of eugenol with DHPS and FabH; however, these interactions require experimental validation. Overall, the findings demonstrate the in vitro bactericidal activity of eugenol-rich SAEO against MDR bacteria recovered from commercial eggs and support further investigation of its potential application in food-safety interventions. Full article

Chinese steamed bread (CSB) is an important fermented wheat product, but controlled strategies for modulating its volatile profile remain limited. This study evaluated defined composite sourdoughs comprising Wickerhamomyces anomalus CRFSZY16 or Kluyveromyces marxianus FYY7 in combination with Lactiplantibacillus plantarum SDgsM3 for CSB production using the direct fermentation method (DFM) and the refrigerated sponge-dough method (RSDM). Technological stress tolerance, preliminary safety-related phenotypes, acidification capacity, volatile organic compounds (VOCs), multivariate profiles, and specific volume were assessed. SDgsM3 showed dough-relevant stress tolerance and rapid acidification, while both yeasts tolerated moderate fermentation stresses. Headspace solid-phase microextraction coupled with gas chromatography-triple quadrupole mass spectrometry (HS-SPME-GC-TQ-MS) revealed stage-dependent remodeling of volatile profiles from mature sourdough to fully proofed main dough and final CSB. RSDM selectively modified representative alcohols, aldehydes, furans, ketones, and esters rather than uniformly increasing all VOCs. In the final CSB, the K. marxianus-based RSDM system showed relatively higher levels of 3-methyl-1-butanol, whereas the W. anomalus-based RSDM system showed relatively higher levels of hexanal, nonanal, 1-hexanol, and 2-pentylfuran. Composite sourdough treatments also yielded specific volumes of 2.56–2.66 mL/g versus 2.44 mL/g for the commercial yeast control. These findings demonstrate strain- and process-dependent modulation of CSB volatile profiles and support flavor-oriented composite sourdough design. Full article

Off-odor development during retort sterilization limits the sensory quality of canned Antarctic krill, but measurements in whole krill cannot distinguish intrinsic fatty acid oxidation from matrix-dependent odor expression. To separate these effects, six major fatty acids (C14:0, C16:0, C16:1, C18:1, eicosapentaenoic acid [EPA], and docosahexaenoic acid [DHA]) were examined in a three-tier thermal oxidation model comprising fatty acid-only, lipid-depleted krill matrix, and complete krill meat systems heated at 115 °C for 36 min. Volatile profiles were characterized by gas chromatography–ion mobility spectrometry (GC–IMS) and headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME–GC–MS), together with peroxide value (POV), thiobarbituric acid-reactive substances (TBARS), odor activity values (OAVs), sensory evaluation, and exploratory cross-tier correlation analysis. In the fatty acid-only model, EPA and DHA showed the highest POVs (5.26 ± 0.53 and 4.96 ± 0.57 meq/kg), whereas C16:1 and C18:1 produced broader volatile profiles. After matrix incorporation, these patterns changed: C18:1 supplementation was associated with a pronounced aldehydic profile, whereas DHA- and EPA-supplemented complete krill meat showed the highest TBARS values (3.37 ± 0.40 and 3.12 ± 0.37 mg MDA/kg) and high fishy odor scores (6.21 and 5.95). Total OAV was not significantly associated with fishy or oxidized odor, whereas (Z)-4-heptenal, (Z)-1,5-octadien-3-ol, 1-penten-3-ol, and trimethylamine showed closer sensory associations. Thus, intrinsic oxidation potential did not directly predict off-odor intensity; sensory deterioration was more closely related to the matrix-dependent expression of selected potentially odor-active compounds than to fatty acid unsaturation or total OAV. Full article