Search Results (12,210)

The development of high-performance, sustainable biocomposites requires biodegradable matrices and optimized natural reinforcements. In this study, flax fiber-reinforced polylactic acid (PLA) hybrid biocomposites incorporating waste pistachio nut shells (WPNS), waste tea leaf fiber (WTLF), and waste quail eggshell (WQES) were developed and evaluated, with direct comparison to previously reported jute-based hybrid systems to assess the benefits of fiber substitution. The composites were fabricated via compression molding and characterized for their mechanical, thermal, acoustic, surface, and moisture-related properties. Replacing the jute with flax resulted in a consistent performance enhancement. Among the hybrids, the flax–WPNS composite exhibited the highest tensile and flexural performance, achieving tensile strength improvements of approximately 30–40% over neat PLA due to effective stress transfer and crack deflection. The flax–WTLF composite showed superior acoustic behavior, attaining a maximum sound absorption coefficient of approximately 0.65–0.70 at mid-to-high frequencies, attributed to its porous microstructure. In contrast, the flax–WQES composite demonstrated the highest thermal conductivity (0.54 W/(mK)) and apparent density (2.24 g/cm³), reflecting dense packing and the presence of CaCO₃-rich particles. Scanning electron microscopy revealed distinct microstructural mechanisms governing these property-specific responses, including differences in interfacial bonding, void distribution, and filler packing efficiency. An integrated fuzzy CRITIC–COPRAS multicriteria decision-making approach identified the flax–WPNS hybrid as the optimal overall formulation. The results clearly demonstrate that flax fibers outperform jute as a reinforcement in PLA-based hybrid biocomposites, and that targeted combinations of flax and waste-derived fillers enable multifunctional performance optimization for sustainable engineering applications. Full article

Background/Objectives: Mori fructus polysaccharides are key bioactive components with diverse activities, but structural characterization of homogeneous fractions remains limited, hindering insights into structure–activity relationships. This study addresses this gap by isolating and characterizing a homogeneous polysaccharide (MFP-III) from M. fructus. Methods: MFP-III, representing the final gel-filtration homogeneous fraction, was purified using defined procedures: DEAE-52 cellulose chromatography followed by Sephadex G-100 gel filtration. Purity and homogeneity were validated by high-performance liquid chromatography (HPLC). Structural characteristics were analyzed via HPLC, GC-MS, FTIR, and NMR spectroscopy. Meanwhile, hypoglycemic activity of MFP-III was evaluated. Results: MFP-III (94.2 ± 2.6%) has a molecular weight of approximately 6.83 kDa, primarily composed of rhamnose, arabinose, galactose, glucose, mannose, and galacturonic acid. Its backbone structure is presumed to be →2,4)-α-L-Rhap-(1 → 4)-α-D-GalpA-(1→, with branching units potentially attached to O-4. MFP-III demonstrated significant inhibitory activity against α-glucosidase (IC₅₀ = 1.56 mg/mL) and α-amylase (IC₅₀ = 2.07 mg/mL), stronger than acarbose at equivalent concentrations. Conclusions: The findings provide preliminary insights into the hypoglycemic structure–activity relationship of MFP-III, providing data support for the development of blood glucose-lowering natural inhibitors, and offering a theoretical foundation for advancing the application of polysaccharides from other sources. Full article

Oleoresin from Pinus spp. consists of turpentine and rosin, whose compositional variability demands reliable analytical methods for quality control and industrial processing. This study provides three rapid methods for qualitative and quantitative analyses of oleoresin, turpentine, and rosin by gas chromatography coupled with mass spectrometry (GC-MS) using a single DB-1 column and matrix-specific temperature programs. Oleoresin and rosin were first derivatized using diazomethane, and compounds were identified by elution order, fragmentation patterns, and reference mass spectra. Quantification employed external calibration with α-pinene and abietic acid as representative standards. In P. pinaster oleoresin, the main terpenic compounds were α-pinene (6.67 ± 1.08%), longifolene (2.45 ± 0.20%), and β-caryophyllene (1.71 ± 0.15%), while levopimaric (33.75 ± 2.70%), neoabietic (13.97 ± 1.70%), and abietic acids (12.60 ± 2.90%) predominated among resin acids. P. elliottii rosin contained mainly abietic (45.99 ± 4.82%), isopimaric (16.95 ± 2.55%), and palustric acids (9.74 ± 1.20%), and its turpentine comprised mainly α-pinene (34.16 ± 2.45%) and β-pinene (30.03 ± 1.20%). This unified GC–MS framework, supported by representative calibration standards, enables identification of >95% of compounds in pine matrices. Furthermore, once compound identification has been established through GC-MS, GC coupled with flame ionization detector (GC-FID) can be employed for routine quantitative analysis. Full article

In Chinese cuisine, seasoning oil enhances the aroma and appearance of dishes. This study examined how processing affects flavor release in multi-ingredient oils. Volatile organic compounds (VOCs), relative odor activity value (ROAV), and variable importance projection (VIP) were used to assess flavor changes. Optimal frying was 160 °C for 15 min with 11% green Sichuan peppercorn, 3% ghost pepper, 6% green onion, 0.1% bay leaf, 0.2% deseeded tsaoko, 0.5% star anise, 0.3% fennel seeds, 1.5% dried Erjingtiao chili, 5% ginger, and 2.5% red Sichuan peppercorn. Gas chromatography–ion mobility spectrometry (GC-IMS) and gas chromatography–mass spectrometry (GC-MS) analyzed heating at 150 °C, 160 °C, and 170 °C. Temperature strongly influenced VOC formation; 160 °C produced the most diverse VOCs, including aldehydes, ketones, terpenes, esters, and alcohols. Multivariate analysis identified 73 key compounds (VIP > 1) between 150 and 160 °C, but only 39 between 160 and 170 °C, indicating that high heat reduces complexity. Compounds such as 2-methylpyrazine and (E)-2-heptenal contributed caramel, nutty, buttery notes, with 2-methoxy-3-(1-methylethyl)-pyrazine as the core aroma. Frying at 160 °C balanced sweet, floral, and roasted aromas, offering guidance for precise seasoning oil flavor control. Full article

The anaerobic digestion process generally generates volatile fatty acids (VFAs) depending upon the metabolic pathway. VFAs are short chain fatty acids containing from one up to eight interlinked carbon atoms. Separation, identification, and quantification of VFAs can enhance metabolic process especially biogas production during anaerobic digestion. Therefore, the continuous monitoring of VFAs is mandatory and is typically performed by liquid chromatography combined with mass spectrometry (LC–MS) and gas chromatography equipped with flame ionization detector (GC–FID) that require sample derivatization and larger sample size of 10–30 mL. Therefore, the current study develops a simple and readily applicable protocol to determine and quantify VFAs (C1–C7) in liquid digestate samples by gas chromatography combined with mass spectrometry (GC–MS) with a reduced sample size of only 0.5 mL. The protocol utilized mix VFAs standard solution for calibration and solvent extraction technique to extract and dissolve VFAs from digestate samples to a volatile solvent dimethyl carbonate (DMC). The results indicate the effective and well separated peaks of all analyte acids from C1 to C7 with regression coefficients r² ≥ 0.98 (C1–C4) and ≥ 0.93 (C5–C7) during calibration. The digestate samples analyzed showed abundance of acetic acid from 4.6 to 11 mM concentration in all four samples followed by propanoic acid (C3) to hexanoic acid (C6) in a range from 0.3 to 4.5 mM concentration. The method is suitable for quantifying all VFAs from C1 to C7 analyte acids as well as the isomers of C4 to C6 analyte acids. Moreover, the method is applicable to a variety of liquid samples from water treatment to energy valorization. Full article

In traditional Chinese medicine (TCM), Gardeniae Fructus is classified as a “cold” herb, a property that is increasingly explained by modern research showing that it can alleviate related disorders through modulation of the central nervous and endocrine systems, energy metabolism, and gut microbiota. This study aimed to elucidate the material foundation and biological mechanisms underlying its cold property. Chemical components of Gardeniae Fructus were separated via multi-stage extraction and characterized by GC-MS and LC-MS, yielding four distinct fractions: aliphatic, iridoid, crocin, and polysaccharide. In a rat model of heat syndrome induced by levothyroxine sodium, administration of the total extract or individual fractions over 15 days modulated central nervous, endocrine, and energy metabolism indicators, with the iridoid, crocin, and polysaccharide fractions demonstrating significant cold properties. Gut microbiota analysis revealed that the total extract, polysaccharide, and iridoid fractions notably reshaped microbial structure, reducing Firmicutes and Lactobacillus abundance. These findings indicate that the iridoid, crocin, and polysaccharide fractions may be key material bases for the cold property of Gardeniae Fructus, with the iridoid fraction exhibiting the strongest effect. Full article

Thermal oxidation of edible oils during high-temperature cooking produces complex fumes containing harmful volatile compounds. However, the role of water, a common co-reactant in practical cooking, remains insufficiently understood. In this study, oleic acid was used as a model compound to investigate thermal oxidation. Online monitoring using synchrotron radiation photoionization mass spectrometry (SR-PIMS) revealed that water significantly increased the emission of volatile acetaldehyde and acrolein, with maximum increases of 164% and 123% at 10% water addition. Complementary offline GC-MS analysis showed enhanced formation of (E)-2-decenal, (E,E)-2,4-decadienal, and (E)-2-undecenal, suggesting these unsaturated aldehydes may be key intermediates. Mechanistically, oleic acid underwent free radical-mediated peroxidation to form (E)-2-decenal, (E)-2-undecenal, and (E,E)-2,4-decadienal. These intermediates subsequently decomposed into acetaldehyde and acrolein via hydration, retro-aldol condensation, and hydroperoxide scission, with water accelerating both processes. Overall, these findings highlight water’s critical role in promoting the generation of harmful volatile aldehydes in oil fumes. Full article

Flowering street trees provide ecological services and health benefits to humans. In this study, three commonly used flowering street trees, Paulownia tomentosa (Thunb.) Steud., Melia azedarach L., and Magnolia grandiflora L., were selected for analysis of floral volatiles during different flowering stages along roadsides in Shanghai, China. Headspace sampling solid-phase microextraction (HS–SPME) coupled with gas chromatography–mass spectrometry (GC–MS) was used to identify volatiles from different floral samples. Simultaneously, selected-ion flow-tube mass spectrometry (SIFT–MS) was employed to detect biogenic volatile organic compounds (BVOCs) in roadside air samples. The results indicated that (1) P. tomentosa volatiles consisted predominantly of alcohols and phenolic ethers, M. azedarach volatiles consisted primarily of alcohols and aldehydes, and M. grandiflora volatiles consisted mainly of terpenes. (2) Air samples from P. tomentosa and M. azedarach were dominated by alcohols, whereas air samples from M. grandiflora were dominated by terpenes and aldehydes. The ozone formation potential (OFP) of some VOCs fluctuated throughout the flowering period. (3) Antibacterial and antioxidant volatiles released from the flowers of all species, such as eugenol, have demonstrated health-promoting effects in essential oils. The results of this study provide a foundation for optimizing the selection and planting of flowering street trees in urban roadside areas that will enhance ecological services and public health benefits. Full article

Increasing constraints related to water consumption and operational complexity have intensified interest in dry coal beneficiation as an alternative to conventional wet cleaning, particularly for low-calorific coals used in thermal power plants. In this study, the performance of a gravity-based dry beneficiation process using an air table was experimentally investigated for run-of-mine coals from the Soma Coal Basin, utilized in the Soma A Thermal Power Plant. The coal was crushed to −10 mm and classified into three size fractions, 5–10 mm, 3–5 mm, and 1–3 mm, before beneficiation. A pilot-scale air table with a capacity of 10 t/h was employed, and operating parameters including table inclination, airflow rate, and vibration frequency were optimized for each size fraction. Clean coal yields of 86.8–88.7% were achieved, while the ash content was reduced from 32 to 35% in the feed to 27.8%–29.7% in the clean coal (dry basis), remaining within the acceptable ash limits of the boiler design. The reject fractions exhibited high ash contents of approximately 71%–72%, indicating effective de-stoning and removal of high-density gangue minerals. Low and consistent E_p values (0.05–0.06) together with nearly constant cut-point densities (D₅₀ ≈ 1.82%–1.83 g/cm³) demonstrated sharp and stable density-based separation. The dust fraction remained limited (1.4%–2.1%), confirming mechanically stable operation. The removal of approximately 10% of the feed as high-density reject was found to reduce coal milling energy demand and lower the energy consumption of ash handling and disposal systems. Overall, the results show that air table-based dry beneficiation enables water-free and energy-efficient pre-concentration of low-calorific coals, offering strong potential for application in water-scarce regions. Full article

Climate change impacts on the Sado River (southwest Portugal) flow rates (FRs) were assessed for the first time under the 2041–2060 Shared Socioeconomic Pathways: 1–2.6 W/m² (SSP1-2.6), 3–7.0 W/m² (SSP3-7.0), and 5–8.5 W/m² (SSP5-8.5), using bias-adjusted and downscaled General Circulation Model (GCM) ensemble projections from the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP3b-Sado). ISIMIP3b-Sado was used to estimate future precipitation and temperature changes, and as input for Hydrological Simulation Program—FORTRAN (HSPF) simulations. The HSPF projected decreases in the Sado FRs, mainly under SSP3-7.0 and SSP5-8.5, due to temperature increases and autumn/spring precipitation decreases. The FR decreases may lead to 29%/33% reductions in yearly accumulated riverine water volume under SSP3-7.0/SSP5-8.5 and a 31% summertime riverine water deficit increase under SSP3-7.0. Surface-water demand fulfilment in the Sado Basin could suffer a 22-day delay, and the wintertime precipitation range is projected to increase. Hence, in the near-future, summertime surface-water needs and reservoir recharge in the Sado Basin could become more dependent on wintertime precipitation. With Sado being an agricultural region, our results should prompt agriculture stakeholders and decision makers to improve wintertime surface water storage and management to sustain summertime crop irrigation needs. Full article

The objective of this study was to evaluate the individual and synergistic antimicrobial efficacy of Juniperus excelsa berry essential oil (JEO) and the cell-free supernatant (CFS) from Streptococcus thermophilus against Escherichia coli (ATCC 43888), Staphylococcus aureus (ATCC 25923), and multidrug-resistant Salmonella enterica serovar Infantis S2 isolated from chicken meat. In vitro antimicrobial effects were assessed using the agar well diffusion and microdilution methods (MIC and MBC assays). The in vivo antimicrobial effect of these natural bioactive substances in controlling microbial growth in chicken meat stored at 4 °C for 48 h was also evaluated. Bioactive components of JEO were determined via GC–MS, identifying alpha-pinene (84.56%) as the primary compound. In vitro assays revealed that JEO showed high antimicrobial activity against Gram-positive S. aureus with a zone diameter of 35.50 mm (p < 0.05). JEOCFS treatment, which is the combination of CFS and JEO, demonstrated a significant synergistic interaction against S. aureus, resulting in an MIC value of 25 mg/mL. CFS alone exerted a measurable inhibitory effect on S. aureus, with an MIC of 50 mg/mL, indicating its potential antimicrobial capability. Further evaluation of the in vivo antimicrobial efficacy using chicken meat stored at 4 °C revealed that the JEOCFS treatment significantly inhibited microbial growth (p < 0.05). After 48 h of storage under refrigerated conditions, the number of psychrophilic bacteria in the control group reached 8.40 log cfu/g, while it remained significantly lower at 6.44, 5.37, and 6.74 log cfu/g in the JEO, JEOCFS, and CFS treatments, respectively. These results indicate that the synergistic application of JEO and CFS effectively suppresses foodborne pathogens, particularly S. aureus, and extends the microbiological shelf life of refrigerated chicken meat. Full article

Sichuan Pepper is a high-value spice, but traditional drying often degrades its unique flavor and quality. This study investigates the applicability of contact ultrasound-assisted hot air drying (US-HAD) to address these issues. The effects of drying temperature (45, 50, 55 °C), ultrasonic power (48, 60, 72 W), and frequency (25, 28, 40 kHz) on drying kinetics, effective moisture diffusivity (D_eff), and physicochemical quality were systematically evaluated. Results showed that US-HAD significantly reduced drying time by 20.00–33.33% compared to hot air drying (HAD). The Page model (R² > 0.99) best described the drying kinetics. Ultrasound enhancement increased D_eff (6.55 × 10⁻⁶ to 9.63 × 10⁻⁶ m²/s) by inducing micro-channel formation and stomatal opening, as evidenced by Scanning electron microscopy (SEM). Critically, US-HAD at 50 °C, 60 W, and 28 kHz minimized color degradation ( = 18.73), maximized the retention of total phenols and flavonoids, and increased antioxidant activity by 18.62%. GC-MS analysis confirmed better retention of volatile flavor compounds. However, the slight decrease in D_eff at higher temperatures (55 °C) suggests potential surface hardening risks. This study confirms US-HAD as a promising technology for high-quality spice processing, though further research is still needed on the cost-effectiveness of industrial-scale expansion. Full article

Shagamite, KFe₁₁O₁₇ (IMA 2020-091) was discovered in the ferrite zone of gehlenite hornfels from the Hatrurim Complex exposed near Mt. Ye’elim, Hatrurim Basin, Israel. The mineral occurs in outer zones of gehlenite rock blocks that were heterogeneously altered by high-temperature (>1200 °C) ferritization. Ferritization was induced by K-bearing fluids or melts, generated as a by-product of late combustion processes. Shagamite crystallized from a thin melt that formed on the rock surface during cooling to approximately 800–900 °C. It is mainly associated with minerals of the magnetoplumbite group like barioferrite, Sr-analog of barioferrite, and gorerite but also with magnetite, maghemite, harmunite, devilliersite and K(Sr,Ca)Fe₂₃O₃₆ hexaferrite. Shagamite is a modular compound with a β-alumina-type structure (P6₃/mmc, a = 5.9327 (5), c = 23.782 (3) Å, γ = 120°, V = 724.91 (13) ų, Z = 2), and it is isostructural with diaoyudaoite, NaAl₁₁O₁₇, and kahlenbergite, KAl₁₁O₁₇. Its structure is also closely related, though non-isotypic, to those of the magnetoplumbite-group minerals. Shagamite is dark brown with a semi-metallic luster and forms platy crystals flattened on (001). Its mean empirical formula is: (K_1.00Ca_0.15Mn²⁺_0.05Na_0.04Rb_0.01)_Σ1.25(Fe_10.36Mn²⁺_0.15Al_0.14Mg_0.12Zn_0.10Ni_0.07Cu_0.03Cr³⁺_0.02Ti⁴⁺_0.01)_Σ11.00O₁₇. The Vickers microhardness VHN₂₅ = 507 kg/mm² corresponds to a Mohs hardness of ~5. The calculated density, based on the empirical formula and unit-cell parameters, is 4.12 g·cm⁻³. The main bands in the Raman spectrum of shagamite occur at 685 and 715 cm⁻¹ and are assigned to ν₁(FeO₄)⁵⁻ tetrahedral vibrations. Full article

Flavor-relevant trace volatiles and microbial communities were examined in six sauce-aroma high-temperature Daqu samples. Headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS) quantified 210 trace volatile compounds across 14 chemical classes. Orthogonal partial least squares discriminant analysis (OPLS-DA) with variable importance in projection (VIP) screening was integrated with sensory scoring, correlation analysis, and molecular docking to an olfactory receptor model. Volatile profiles showed clear stratification in total abundance. Pyrazines dominated the high-total group. Tetramethylpyrazine served as a major driver. Sensory evaluation indicated that aroma explained overall quality best. (E)-2-pentenal and dimethyl trisulfide showed significant positive associations with aroma and overall scores. In the olfactory receptor, the polar residue module that provides directional constraints for Daqu odor activation was formed by Ser75, Ser92, Ser152, Ser258, Thr74, Thr76, Thr98, Thr200, Gln99, and Glu94. The hydrogen-bond or charge network was further reinforced by Arg150, Arg262, Asn194, His180, His261, Asp182, and Gln181. The core discriminant set comprised acetic acid, hexanoic acid, (E)-2-pentenal, nonanal, decanal, dimethyl trisulfide, trans-3-methyl-2-n-propylthiophane, 2-hexanone oxime, ethyl linoleate, propylene glycol, 2-ethenyl-6-methylpyrazine, 4-methylquinazoline, 5-methyl-2-phenyl-2-hexenal, and 1,2,3,4-tetramethoxybenzene. Sequencing revealed higher bacterial diversity than fungal. Bacillus and Kroppenstedtia were dominant bacterial genera. Aspergillus, Paecilomyces, Monascus, and Penicillium were major fungal genera. Correlation patterns suggested that Bacillus and Monascus were positively linked to acetic acid and 1,2,3,4-tetramethoxybenzene. Together, these results connected chemical fingerprints, sensory performance, receptor-level plausibility, and microbial ecology. Concrete targets are provided for quality control of high-temperature Daqu. Full article

This study involved developing a novel lemon flower-scented white tea (LT) through multiple aroma-imparting cycles, and taking an integrated approach to investigating its flavour formation mechanism. Sensory evaluation and electronic tongue analysis revealed that the LT exhibited more balanced taste characteristics, with significantly reduced bitterness and astringency, attributed to the decreased caffeine content and conversion of esterified catechins. Electronic nose and HS-SPME/GC-MS results confirmed that the LT had acquired a distinctive aroma characterised by floral and citrus notes, primarily originating from lemon flower volatiles such as methyl anthranilate and limonene. Multivariate statistical analysis identified 32 key differential compounds (variable importance in projection value > 1), with methyl anthranilate, β-ionone, and geraniol (relative odour activity value > 80) jointly forming the shared flavour base among teas. These findings demonstrate that lemon flower infusion can effectively enhance the sensory quality of white tea and provide theoretical support for the development of diverse floral teas. Full article