Search Results (6,260)

In this study, five solvent fractions from Litsea cubeba (Lour.) Pers. fruit were extracted and investigated for their antioxidant profiles. Results showed that the petroleum ether fraction (PEF) and n-butanol fraction (NBF) exhibited prominent free radical scavenging capacities in DPPH, ABTS, and hydroxyl radical assays. Gas chromatography–mass spectrometry (GC-MS) identified citral as the dominant bioactive component in both active fractions. Further mechanism analysis demonstrated that citral exerted potent antioxidant effects via dual pathways: direct free radical scavenging and transition metal ion chelation. These findings not only elucidate the material basis and molecular mechanism underlying the antioxidant activity of L. cubeba but also provide a scientific rationale for the high-value utilization of citral-rich fractions in functional foods, cosmetics, and healthcare products. Full article

Artichoke by-products (ABP) represent valuable sources of bioactive compounds with relevant health benefits. In this study, a green extraction strategy based on pressurized liquid extraction (PLE) was optimized to enhance the recovery of phenolic and flavonoid compounds from ABP using a response surface methodology. Extraction temperature and solvent composition were identified as the key factors driving extraction performance. Optimal conditions using a mixture of ethyl acetate and ethanol (90/10, v/v) at 180 °C significantly enhanced extraction yield, total phenolic and flavonoid content, and antioxidant activities, as measured by ORAC and DPPH assays. Chemical characterization via HPLC-C18-Q-TOF-MS/MS revealed a diverse profile of phenolic and flavonoid compounds, including caffeoylquinic acid derivatives and related transformation products. The neuroprotective potential of the optimized extract was further evaluated through in vitro inhibition assays targeting acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and lipoxygenase (LOX), alongside a permeability assessment using an in vitro blood–brain barrier (BBB) model. Molecular docking simulations were performed to explore the interactions of apigenin—the most representative flavonoid in the optimal extract—with the three target enzymes. Overall, these findings support the valorization of ABP as a source of bioactive compounds and highlight the potential of PLE as an efficient and sustainable extraction approach. Full article

Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa rank among the most challenging pathogens due to increasing prevalence of multidrug-resistant (MDR) strains. These pathogens pose major risks to public health and food safety, earning their inclusion on the World Health Organization (WHO) priority list of MDR bacteria. While available conventional antibiotics are becoming less effective, natural products from plant extracts offer promising alternative and synergetic effects that can restore efficacy and lower required doses. Their antimicrobial activity is attributed to phytochemicals such as phenolic compounds and terpenoids acting via membrane disruption, efflux pump inhibition, biofilm interference, and cell protein disruption. Furthermore, phytochemicals in essential oils, such as carvacrol, thymol, and cinnamaldehyde, also exhibit antimicrobial and antioxidant activities. Their broad antimicrobial effects extend shelf life and enhance food safety, making them effective natural alternatives to synthetic preservatives. Moreover, advances in extraction and characterization techniques, including green solvents, spectrometry and hyphenated chromatographic methods, have improved recovery, identification and quantification. In addition, artificial intelligence (AI) emerges as a transformative tool to accelerate discovery, optimize compound screening, and predict synergistic interactions. Notwithstanding these advances, challenges persist in standardization, bioavailability, and clinical translation. Further studies are needed to isolate active compounds, elucidate mechanisms of action, validate combined use with conventional antibiotics and overcome formulation, delivery, sensory and regulatory hurdles. This review examines current knowledge of opportunities and limitations of plant-based antimicrobials against MDR pathogens supported by advances in extraction, characterization, and AI. Full article

To address the difficulty of efficiently removing calcium impurities from the manganese sulfate stripping solution obtained during the recycling of spent lithium batteries, this work proposed a binary synergistic extraction system. Quantum chemical calculations were used to screen the optimal combination (2A + 2B). The binding energy indicated the molecules combined with calcium are relatively more stable. Experimental optimization determined the optimal conditions as follows: 50 vol% of A, 25 vol% of B, saponification rate 60%, phase ratio (O/A) 2.5:1, and pH 6.0. In continuous extraction tank experiments, the calcium concentration decreased from 681 mg/L to 5 mg/L after a seven-stage counter-current extraction, with an extraction efficiency of about 99.3%. Infrared spectroscopy confirmed that the P=O double bond was the key functional group. This study provides an efficient and feasible technological pathway for the preparation of battery-grade manganese sulfate. Full article

Background: Zebrafish (Danio rerio) embryos are transparent in early stages of embryonic development; however, pigment formation at later stages hinders internal organ visualization during imaging. Chemicals such as 1-phenyl-2-thiourea (PTU) and kojic acid, used to block pigmentation, pose significant toxicity risks to human health. Therefore, effective and risk-free depigmentation agents are needed. This study investigates the efficacy of Alchemilla vulgaris (Lady’s mantle) as a safe, natural alternative for zebrafish embryo depigmentation. Methods: A. vulgaris was extracted using four solvents of varying polarities and evaluated for depigmentation efficacy and toxicity. Gas chromatography–mass spectrometry (GC–MS) was used to identify major constituents of the extract. Results: Ethyl acetate extract was more effective at removing pigments than all other extracts, and exhibited the lowest toxicity compared to PTU and kojic acid. Ethyl acetate extract of A. vulgaris remained effective even when administered 48 h post fertilization (post-pigmentation), making it suitable for long-term experiments requiring optical clarity. GC-MS revealed that this extract was rich in linoleic acid, various fatty acid esters, and phenolics, which likely contributed to its depigmentation activity. Conclusions: Based on these findings, we propose that ethyl acetate extract of A. vulgaris is a safer, natural alternative to PTU and kojic acid for depigmenting zebrafish embryos, particularly in long-term imaging experiments. The extract exhibits high efficacy at low concentrations, accompanied by a favorable toxicity profile, demonstrating potential as a depigmentation agent during early zebrafish development. However, further studies are needed to elucidate its mechanism of action. Full article

Sea fennel is a halophyte plant recognised as a valuable source of phenolics with good antioxidant and antimicrobial potential. In this study, accelerated solvent extraction (ASE) was optimised to improve the recovery of phenolic compounds from sea fennel, particularly hydroxycinnamic acids, which are known to be dominant. The effect of the applied extraction temperature (20–120 °C) and used solvent (20–80% hydroethanolic mixtures) on total phenolic content (TPC) was systematically evaluated. Individual phenolic composition, antioxidant activity, and antimicrobial properties were measured in the top four samples. TPC was determined spectrophotometrically, while individual compounds were analysed by chromatography. Antioxidant (reducing and free-radical scavenging) activity was assessed using three assays, while the minimum inhibitory concentrations and minimum bactericidal concentrations were determined using the microdilution method against five bacterial strains. Both temperature and solvent composition significantly influenced phenolic extraction efficiency. The highest TPC and concentrations of chlorogenic acid and its derivatives were obtained at 60 °C using 60–80% ethanol (664 and 673 mg of gallic acid equivalents/g of dry extract), while higher temperatures generally resulted in reduced phenolic yield. Extracts obtained under optimal ASE conditions exhibited enhanced antioxidant activity and moderate antimicrobial effects, particularly against Gram-positive bacteria, which demonstrates that accelerated solvent extraction represents an efficient approach for obtaining sea fennel extracts rich in valuable bioactives with potential use in different industries. Full article

Optimizing the recovery of bioactive compounds is critical for the accurate assessment of the quality of freeze-dried vegetables. In this context, Response Surface Methodology (RSM) was performed to optimize the ultrasound-assisted extraction (UAE) of phenolic compounds from freeze-dried broccoli (cv ‘Thassos’) and cauliflower (cv ‘Cercy’) florets. The influence of three process parameters, namely solvent-to-material ratio (20 to 60 mL/g), extraction time (10 to 40 min) and solvent mixture (methanol: water) composition (60 to 100% methanol) was evaluated. Multi-response optimization identified the optimal process conditions for both cultivars (composite desirability = 0.996) as a 60 mL/g ratio, 10 min extraction time and 76% methanol content. The application of the optimized extraction conditions to broccoli ‘Naxos’ and cauliflower ‘Guideline’ cultivars, confirmed the model applicability and revealed significant genotypic heterogeneity (p < 0.05). Pearson’s Correlation Analysis revealed a very high positive (r > 0.9) correlation between TPC and ABTS for both broccoli and cauliflower, high (r = 0.78) correlation between TPC and FRAP for broccoli and moderate (r = 0.63) for cauliflower. These findings confirm that process parameter optimization is crucial for the maximum recovery of phenolic compounds from freeze-dried broccoli and cauliflower, and UAE conditions should be carefully selected to ensure accurate cultivar evaluation. Full article

This study investigated the use of aqueous pomegranate (Punica granatum L.) leaf extracts as a source of bioactive compounds in edible coatings for strawberry postharvest preservation. Extraction conditions were evaluated by varying solid-to-solvent ratio, temperature, and time, using total phenolic content (TPC) as the response variable. Response surface analysis indicated that the best predicted extraction conditions within the studied range were 1:50 (w/v), 57.36 °C, and 25 min. Among the evaluated treatments, extract C503 (1:50 (w/v), 50 °C, and 25 min) showed the highest experimental TPC (474.62 ± 21.69 mg GAE/g DM) and was selected for further characterization. This extract also showed high antioxidant capacity (FRAP: 7085 ± 72.0 µM FeSO₄/g; ABTS: 4921 ± 149.0 µM Trolox/g) and antimicrobial activity against Listeria monocytogenes and Staphylococcus aureus. When incorporated into gelatin- and starch-based edible coatings and applied to strawberries, both coatings reduced mass loss and delayed deterioration during nine days of storage at room temperature. At the end of storage, mass loss was reduced by approximately 25% with the gelatin-based coating and 11% with the starch-based coating. These results support aqueous pomegranate leaf extract as a promising source of bioactive compounds for the development of sustainable edible coatings to improve strawberry preservation. Full article

Microwave technology is being used increasingly in polymer processing, where significant time and energy savings have been demonstrated across many systems. In this work, we first provide an overview of microwave-assisted processes involving agro-based materials, with emphasis on microwave-assisted modification reactions and extractions. A more detailed review then highlights several examples from the authors’ laboratories. For example, microwave heating has been shown to greatly accelerate the synthesis of cellulosic derivatives from cellulose and the formation of a polyurethane from a carbohydrate and a diisocyanate, while still producing polymers comparable in structure to those obtained by conventional heating. Likewise, microwave treatment can speed up pericyclic reactions involving triglycerides and cardanol, leading to products with enhanced viscosity. In extraction applications, such as recovering phenolic compounds from common beans, microwave methods can sometimes yield higher extraction efficiencies. Beyond time and energy savings, the reduced processing duration also decreases workers’ exposure to chemicals and solvents, thereby improving safety and lowering chemical hazards. Thus, microwave treatment can be considered a “green”, energy-efficient tool for many polymer reactions and processes. Full article

The valorization of agri-food by-products aligns with circular economy principles and offers sustainable sources of bioactive compounds. This study investigated the peels of the purple-fleshed Solanum tuberosum L. cv. Vitelotte Noire (VN), cultivated in Sardinia, as a potential resource for nutraceutical antioxidants. Extracts were obtained using solvents of different polarities (water, 80% and 96% ethanol) and characterized. Phytochemical screening revealed high concentrations of total phenolics, flavonoids, and anthocyanins, with the 96% ethanolic extract showing superior anthocyanin content. Antioxidant capacity, assessed via ORAC-PYR, TEAC-ABTS, and DPPH assays, was highest in the alcoholic extracts. Furthermore, all extracts showed protective effects in an in vitro model of AAPH-induced oxidative DNA damage, as indicated by the preservation of plasmid supercoiling. Untargeted LC-QTOF-MS analysis detailed a rich metabolomic profile, including organic acids, amino acids, and vitamins. The findings confirm VN peel as a potent, sustainable source of antioxidants, supporting its valorization for developing high-added-value nutraceutical and functional food ingredients, while reducing waste disposal costs and environmental impact. Full article

The aim of the study was to modify polylactide with zinc oxide nanoparticles (ZnO), raspberry leaf extract (E), and a combined ZnO/extract system (EZnO) in order to prepare novel packaging materials via a solvent-free method, namely cast extrusion. Physicochemical properties: Morphology (GPC, SEM, FTIR), mechanical (tensile tests, puncture), barrier (WVTR, OTR, UV-Vis) and water contact angle for PLA-based films with two thickness ranges were investigated. Additionally, antimicrobial (antibacterial, antifungal and antiviral) tests were performed. GPC results revealed that the presence of the extract counteracted biopolyester degradation during hot melt processing. The best mechanical properties (TS ca. 50 MPa, EB ca. 18%) were obtained for PLA modified with raspberry leaf extract (PLA/E). EZnO addition led to the highest increase in oxygen (with 25%) and water vapor (up to ca. 28%) barrier properties. The material with EZnO addition was also found to be the only one to demonstrate antibacterial effectiveness, although the activity was insignificant. However, the incorporation of EZnO into the biopolymer matrix enhanced its antiviral properties, resulting in the complete inactivation of Φ6 bacteriophage particles used as a surrogate of SARS-CoV-2 virus. Full article

Conventional and emerging extraction methods for recovering phenolic compounds (PCs) from Pinus radiata bark were investigated for their potential use in bio-composites and bio-based biomaterial applications. To optimize the recovery process, a Response Surface Methodology (RSM) based on a Box–Behnken design was used to evaluate the effects of extraction time (20–100 min), temperature (20–80 °C), and water or ethanol-water solvent concentrations with β-cyclodextrin (βCD) or NaOH (0.5–1.5% w/v CD/db). Polyphenolic profiles of the extracts were characterized using Fourier transform infrared spectroscopy (FTIR), LC-LTQ-Orbitrap-MS, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to evaluate the thermal stability and degradation behavior of the powdered extracts. Antioxidant capacity (DPPH, FRAP, ABTS) and antibacterial activity against Escherichia coli and Staphylococcus aureus were assessed by spectrophotometric assays and the agar diffusion method, respectively. Highest extraction yields were obtained using alkaline extraction (14.32%) and ultrasound-assisted extraction (UAE) (13.86%), followed by ethanol extraction (12.74%). Minimum inhibitory concentration (MIC) for P-βCD was 0.04 mg/mL, and the minimum bactericidal concentration (MBC) was 0.32 mg/mL against S. aureus. These results suggest a strong inhibitory capacity at low concentrations and the potential incorporation of these extracts into bio-based antimicrobial biomaterials. Full article

The roots of Cannabis sativa L., historically overlooked, are gaining attention as a potential source of bioactive compounds with antioxidant, antimicrobial, and anti-inflammatory properties. While previous studies have focused on extractions using ethanol, water, or supercritical CO₂, the feasibility of edible oil-based extraction remains largely unexplored. This study evaluated the extraction of root compounds using hemp seed oil, MCT coconut oil, and grape seed oil at six temperatures (50–90 °C). Extracts were analyzed by GC–MS for compound identification and quantification, and antioxidant activity was assessed using the DPPH assay, ABTS test and β-carotene bleaching method, with results statistically evaluated by ANOVA. Friedelin was successfully extracted with all oils, with grape seed oil yielding the highest concentration (0.810 mg/g dry roots), achieving recoveries higher than those previously reported for ethanol-based extractions. All extracts demonstrated positive antioxidant activity, with grape seed oil, both alone and combined with extracts, showing higher values across the three methods. ANOVA revealed a significant effect of solvent type on both Friedelin concentration and antioxidant capacity. These results demonstrate that edible oils are effective solvents for extracting bioactive compounds from C. sativa roots, supporting their potential application in cosmetic or medicinal formulations. Full article

This study provides a comprehensive evaluation of the phytochemical composition, antioxidant capacity, antibacterial activity, and mineral content of Trigonella foenum-graecum, Linum usitatissimum, and Panicum miliaceum extracts obtained using aqueous, ethanolic, and methanolic solvents. An integrated analytical strategy combining LC–MS/MS-based metabolite profiling, mineral analysis, and multivariate statistical tools (PCA) was applied to investigate the relationships between chemical composition and biological activities. The ethanolic extract of P. miliaceum showed the highest total phenolic content (TPC: 157.438 ± 0.521 µg GAE/mg extract), whereas L. usitatissimum exhibited the strongest antioxidant activity (IC₅₀ ≈ 65 µg/mL). Trigonella foenum-graecum displayed the most significant antibacterial activity, with a minimum inhibitory concentration (MIC) of 62.5 mg/mL against Staphylococcus aureus. LC–MS/MS analysis allowed the identification and structural characterization of more than twenty bioactive compounds through multiple reaction monitoring (MRM), including flavonoids, phenolic acids, and anthocyanins. Principal Component Analysis indicated that sample discrimination was mainly driven by solvent polarity rather than plant species, underlining the critical influence of extraction conditions on phytochemical profiles and associated bioactivities. These findings highlight the relevance of combining analytical and statistical approaches to better understand the interplay between plant origin, extraction conditions, and biological properties, and support the potential of these species as promising sources of nutraceutical and pharmaceutical compounds. Full article

The global seafood industry faces persistent challenges related to product quality, safety, and authenticity, driven by complex supply chains, increasing demand, and the perishable nature of aquatic products. Traditional analytical methods often fall short in providing rapid, comprehensive, and non-destructive insights into the intricate biochemical changes occurring in seafood. ¹H Nuclear Magnetic Resonance (¹H NMR) spectroscopy has emerged as a powerful and versatile tool for metabolomics, offering a holistic view of the low-molecular-mass compounds (metabolites) present in biological samples. The present study applied ¹H NMR for chemical fingerprint identification in mullets (Mugil liza) from Brazil. Dorsal muscle samples were taken from the fish during summer, autumn, and winter. The procedure involved freeze-drying the muscle tissue, thereafter extracting polar metabolites using designated solvents (methanol, water, and chloroform), and analyzing them using a 600 MHz spectrometer. As a result, 23 metabolites related to degradation biomarkers, essential metabolites, energy expenditure, and muscle structure were identified. The statistical analysis demonstrated a distinct separation between the geographical origins (RJ vs. SC), mostly influenced by variations in the concentrations of lactate, histidine, threonine, phenylalanine, and ornithine. Factors like fish size and seasonal variations did not markedly affect the overall metabolic profile, underscoring the reliability of these chemicals as stable origin indicators. The Principal Component Analysis identified two distinct groups of metabolites, establishing a profile for each geographical origin. The developed protocol can be applied to the processes of geographical identification. Thus, the ¹H NMR tool was efficient in determining metabolites that can be considered biomarkers in analyses for seafood traceability. Full article