Search Results (241)

The widespread use of antibiotics in human medicine, veterinary care, and livestock production has resulted in their frequent detection in diverse environmental and food matrices, making continuous surveillance of antibiotic residues in food products essential for consumer protection. In this study, a sustainable analytical method based on dispersive liquid–liquid microextraction (DLLME) coupled with UHPLC–MS/MS was developed for the trace determination of sulfamethoxazole, sulfadimethoxine, and enrofloxacin in commercial cow milk and chicken eggs. A natural deep eutectic solvent (NADES) composed of anisaldehyde and octanoic acid (2:1, molar ratio) was employed as a biodegradable extraction solvent, and key extraction parameters were systematically optimized. Under optimized conditions, the method demonstrated excellent linearity (R² ≥ 0.9982), recoveries of 89.5–98.7%, and RSDs ≤ 6.04%. Application to 44 commercial samples from the Saudi market revealed sulfamethoxazole as the most frequently detected antibiotic, occurring in 90% of egg samples (2.17–13.76 µg kg⁻¹) and 70.8% of milk samples (0.26–26.67 µg L⁻¹). A comprehensive evaluation using ten metrics confirmed the method’s greenness, practicality, analytical performance, and innovation. Overall, the proposed NADES–DLLME–UHPLC–MS/MS approach offers a rapid, cost-effective, and environmentally friendly alternative for routine monitoring of antibiotic residues in food matrices. Full article

In the present study, ten type-V natural deep eutectic solvents (NADESs) were synthesized and comprehensively characterized, based on urea as a hydrogen-bond acceptor and three different groups of donors—glycerol, organic carboxylic acids, and carbohydrates. Their physicochemical parameters, spectral characteristics (FTIR), surface tension, and solvatochromic properties were determined using Nile Red, betaine 30, and Kamlet–Taft parameters. The densities of the systems (1.243–1.361 g/cm³) and the high values of molar refraction and polarizability indicate the formation of highly organized hydrogen-bonded networks, with the incorporated carboxyl and hydroxyl groups enhancing the structural compactness of the NADES. Surface tension varied significantly (46.9–80.3 mN/m), defining systems with low, medium, and high polarity. Solvatochromic analysis revealed high E_NR, E_T(30), and E_T^N values, positioning all NADES as highly polar media, comparable or close to water, but with distinguishable H-bond donating/accepting ability depending on the third component. The normalized Kamlet–Taft parameters show that the NADES cover a broad solvent spectrum—from highly H-bond accepting to strongly H-bond donating or dipolar systems—highlighting the potential for fine-tuning the solvent according to target applications. The obtained results highlight the applicability of these NADESs as green, tunable media for the extraction and solvation of bioactive compounds. Full article

The growing demand for biodegradable and functional packaging has driven research toward polysaccharide-based materials with improved performance. In this study, sodium alginate films were modified using natural deep eutectic solvents (NADES) and acorn polyphenolic extract to enhance their antimicrobial, mechanical, and thermal properties. The films were acquired by solvent casting and characterized through mechanical, spectroscopic, thermal, and microbiological analyses. Both NADES and the polyphenolic extract enhanced tensile strength and flexibility through additional hydrogen bonding within the alginate network, while the extract also introduced antioxidant functionality. Among all tested formulations, the A4E2 film exhibited the most balanced performance. FTIR spectra revealed hydrogen bonding between the film components, and thermogravimetric analysis showed an approximately 15 °C (F-EXT) and 20 °C (F-DES) shift in the main DTG degradation peak, indicating enhanced thermal stability. Controlled-release experiments demonstrated the gradual diffusion of phenolic compounds in aqueous, acidic, and fatty simulants, with an initial release phase within the first 6 h followed by sustained release up to 48 h, confirming the films’ suitability for various food environments. The combined modification reduced the growth of Escherichia coli and Staphylococcus aureus by 30–35%, with inhibition zone diameters reaching 27.52 ± 2.87 mm and 25.68 ± 1.52 mm, respectively, evidencing synergistic antimicrobial activity. These results highlight the potential of NADES- and extract-modified alginate films as sustainable materials for active food packaging applications. Full article

The growing concern over plastic pollution and the widespread presence of micro- and nanoplastics has renewed interest in polyhydroxybutyrate (PHB) as a biodegradable alternative; however, its industrial deployment remains constrained by costly recovery operations with a high environmental burden. This study examines how PHB biosynthesis and intracellular organization, physicochemical properties, and the characteristics of the producing microorganism influence the performance of conventional recovery routes, including extraction with organic solvents, alkaline/oxidative chemical digestion, and enzymatic–physical schemes coupled with mechanical disruption. Based on this foundation, quantitative data are analyzed for PHB content in bacteria, mixed microbial cultures, cyanobacteria, and microalgae, along with extraction yields, polymer purity, and solvent recyclability in processes employing chlorine-free solvents, green solvents, and hydrophobic natural deep eutectic solvents (NaDESs) formulated with terpenes and organic acids. The analysis integrates mechanistic perspectives on NaDES–cell and NaDES–PHB interactions with solvent design criteria, biorefinery configurations, and preliminary evidence from technoeconomic and life cycle assessments. The findings identify NaDES as an up-and-coming platform capable of reconciling biopolymer quality with the principles of green chemistry while delineating critical gaps in recovery efficiency, viscosity management, solvent recycling, and pilot-scale validation. Full article

Active biopolymer-based packaging incorporating phytochemicals offers promising sustainable alternatives for reducing postharvest losses and extending food shelf life. This study aimed to advance natural food packaging by (i) developing and characterizing natural deep eutectic solvents (NADES) using choline chloride combined with citric acid (CC-CA), glucose (CC-G), and urea (CC-U); (ii) obtaining bioactive extracts from Uxi bark and Jambolan leaves using these NADES; (iii) formulating babassu mesocarp-based coatings enriched with CC-CA extracts; and (iv) evaluating their application on cherry tomatoes. CC-U exhibited the lowest density (1.152 ± 0.037 g cm⁻³), while CC-G demonstrated the highest viscosity (18.375 ± 0.430 mPa s), and CC-CA presented the lowest polarity parameter (E_NR) value (44.6 ± 0.1 kcal mol⁻¹). Extracts obtained with CC-CA (YU-CA and JL-CA) showed high extraction efficiency, strong antioxidant activity (DPPH inhibition > 95%), and antimicrobial activity, particularly against Pseudomonas aeruginosa. Although the coatings exhibited lower bioactivity than the extracts, they effectively reduced weight loss, maintained firmness, and preserved the microbiological quality of tomatoes for up to 9 days. Sensory analysis of bruschetta prepared with coated tomatoes indicated high acceptance (>80%). Babassu mesocarp-based coatings enriched with Amazonian plant extracts emerge as an innovative active packaging strategy aligned with the 2030 Agenda. Full article

Paeonia lactiflora Pall. is a perennial herbaceous plant widely renowned for its floral ornamental appeal, distinctive pleasant scent, and utilization in folk remedies. Roots and barks are traditionally used in Chinese medicine for various properties, including anti-inflammatory, antioxidant, antibacterial, anticancer, cardiovascular, and neuroprotective effects. Considering the growing interest and demand in the pharmaceutical and cosmetic fields for sustainable and bioactive botanical derivatives, this study aimed to apply NADES (natural deep eutectic solvents) extraction on fresh flowers of Paeonia lactiflora Pall. The purpose was to obtain a natural, multifunctional, and ready-to-use cosmetic ingredient with concurrent antioxidant activity, antimicrobial functionalities, and olfactive properties. The eutectic systems selected in this study were composed of betaine as the hydrogen bond acceptor and glycerol and/or sorbitol as the hydrogen bond donors. These eutectic systems under microwave activation led to a rapid extraction, from peony fresh flowers, of considerable phenolic amounts (from 33.0 to 34.4 mg of gallic acid equivalents per gram of fresh flowers), which confer to the whole NADES-based extract an excellent radical scavenging activity (around 87.5%, compared to Trolox) and a pleasant fragrance, due to the extraction of some characteristic volatile compounds, as confirmed by GC-MS analysis. Antimicrobial assays against different Gram-positive and Gram-negative strains demonstrated good inhibitory activity of the sample against multidrug-resistant Staphylococcus species (MIC ranging from 0.9 to 14.5 mg/mL) and against Enterococcus species (from 28.8 to 57.8 mg/mL). Furthermore, results on different Staphylococcus aureus strains disclosed additional interesting anti-biofilm properties. Preliminary long-term studies (up to 9 months) on these combined properties highlighted the stabilizing effect of NADESs on the active metabolites, confirming their potential as natural and functional ingredients that could be directly incorporated into pharmaceutical and cosmetic formulations, offering enhanced efficacy and improved stability. Full article

This study focuses on the optimization of modern extraction techniques for selected by-product materials, including apple, lemon, and tangerine peels, and onion skins, using artificial neural network (ANN) models. The extraction methods included ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) with water as the extractant, as well as maceration (MAC) with natural deep eutectic solvents (NADES). Key parameters, such as total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities, including reducing power (EC₅₀) and free radical scavenging capacity (IC₅₀), were evaluated to compare the efficiency of each method. Among the techniques, UAE outperformed both MAE and MAC in extracting bioactive compounds, especially from onion skins and tangerine peels, as reflected in the highest TPC, TFC, and antioxidant activity. UAE of onion skins showed the best performance, yielding the highest TPC (5.735 ± 0.558 mg CAE/g) and TFC (1.973 ± 0.112 mg RE/g), along with the strongest antioxidant activity (EC₅₀ = 0.549 ± 0.076 mg/mL; IC₅₀ = 0.108 ± 0.049 mg/mL). Tangerine peel extracts obtained by UAE also exhibited high phenolic content (TPC up to 5.399 ± 0.325 mg CAE/g) and strong radical scavenging activity (IC₅₀ 0.118 ± 0.099 mg/mL). ANN models using multilayer perceptron architectures with high coefficients of determination (r² > 0.96) were developed to predict and optimize the extraction results. Sensitivity and error analyses confirmed the robustness of the models and emphasized the influence of the extraction technique and by-product type on the antioxidant parameters. Principal component and cluster analyses showed clear grouping patterns by extraction method, with UAE and MAE showing similar performance profiles. Overall, these results underline the potential of UAE- and ANN-based modeling for the optimal utilization of agricultural by-products. Full article

This study aimed to enhance the extraction efficiency and elucidate the mechanism of ultrasound-assisted extraction (UAE) of taxanes from Taxus chinensis by natural deep eutectic solvents (NADES). The processes of kinetics and thermodynamics were systematically investigated. These extractions adhered to a pseudo-second-order kinetic model (R² > 0.972), with intraparticle diffusion identified as the dominant mechanism. Key parameters such as temperature, ultrasonic power, and solid/liquid ratio significantly improved the effective diffusion coefficient (D_e) and mass transfer coefficient (K_T), reaching values of 6.21 × 10⁻⁹ m²/s and 4.14 × 10⁻³ m/s, respectively. A high Biot number (B_i > 59.21) confirmed that internal diffusion is the rate-determining step. Thermodynamic analysis indicated that the process is endothermic (ΔH > 0), irreversible (ΔS > 0), and spontaneous (ΔG < 0). These results elucidate the underlying mechanisms of UAE and establish a foundational framework for its industrial-scale implementation. Full article

Thunbergia laurifolia Lindl. is a plant known for its promising biological activity, including antioxidant and anti-inflammatory activities, and a rich source of rosmarinic acid (RA). The extraction of T. laurifolia for cosmetic and skincare products using conventional solvents has encountered difficulties, including safety concerns, skin irritation, undesirable odors, and inefficient extraction. In this work, 14 types of natural deep eutectic solvents (NaDESs) with varying compositions and ratios were investigated to compare their efficiency in extracting RA from T. laurifolia by HPLC analysis. The NaDES with the highest extraction efficiency was further utilized in ultrasonic-assisted extraction (UAE), and the extraction parameters were optimized using response surface methodology. The optimized RA content and DPPH scavenging activity were predicted by response surfaces methodology to be 7.52 mg/g DW and 37.6 mg TE/g DW, respectively. The optimal extraction condition was achieved using a propylene glycol-lactic acid NaDES (at an 8:1 molar ratio) with 37% (w/w) H₂O, a 30 mL/g liquid-to-solid ratio, an 80 °C extraction temperature, and a 32 min extraction time. The optimized extract was proved to suppress ROS in H₂O₂-induced keratinocytes. The extract demonstrated robust stability against basic, oxidative, and photolytic stresses, and maintained long-term chemical stability up to 90 days. This study introduces a new green solvent for the effective extraction of T. laurifolia, thereby improving the safety and quality of the extracts for skincare and cosmetic products. Full article

Natural deep eutectic solvents (NADES) have been extensively used for the extraction of a wide spectrum of plant materials. However, limited data about the in vivo toxicity of NADES extracts restrict their future practical application. In this study, we are aiming to assess the safety of a Sorbitol–lactic acid (3:1 mol./mol.; 30% water) NADES extract of Glycyrrhiza roots (GR) in mice. LC-MS/MS analysis revealed the presence of 17 metabolites, including phenolic acids, flavonoids, their glycosides, chalcones, terpene saponins, and coumarins. Interestingly, most of the identified compounds were found in higher amounts in NADES extract compared to water and EtOH extracts. No skin edema, inflammation, or erythema was observed in mice after topical application of NADES extract of GR and NADES at the doses of 50, 100, and 150 µL/mice in comparison with the control group. The calculated primary irritation index was about 0.45 both for NADES and NADES extract of GR only in high doses and falls into mild irritant categories. The individual Draize scores indicate that erythema was evident in the first three days and that all signs had disappeared by day five. No acute toxic signs or mortality of animals was observed in mice following oral administration of single doses of 4, 6, and 20 g/kg of NADES or NADES extract of GR. The NADES and extract seem to be safe at doses of up to 20 g/kg, and the LD50 was considered to be >20 g/kg. Our results open prospects for the use of NADES extract of GR for the development of transdermal and peroral formulations in the cosmetic, food, and pharmaceutical industries. Full article

This study develops biodegradable chitosan (CS) films plasticized with natural deep eutectic solvents (NaDES) composed of choline chloride and glycolic acid (1:3 molar ratio). The same NaDES served as an effective extraction medium for bioactive compounds from hawthorn (Crataegus monogyna), which were incorporated into the chitosan matrix to enhance functionality. CS films with 44–70 wt% NaDES were evaluated, and the 50 wt% formulation exhibited the optimal mechanical and barrier performance. Upon extract incorporation, this film showed marked decreases in Young’s modulus (131→30 MPa) and tensile strength (24→12 MPa), relative to the extract-free counterparts, indicating enhanced flexibility. Stress–strain analyses confirmed a progressive reduction in stiffness with increasing NaDES content, evidencing its plasticizing effect. FTIR analysis revealed extensive hydrogen-bonding between CS and NaDES, alongside successful integration of polyphenolics extracted from hawthorn. Morphological analysis showed smooth, dense, homogeneous surfaces. Films exhibited strong UV absorption, with extract-loaded samples extending into the UVA and visible ranges, enhancing light-barrier properties. The presence of polyphenolic compounds enhanced the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity to nearly twice that of the neat CS films. These combined mechanical, optical, and antioxidant properties highlight the potential of these NaDES-based chitosan films for sustainable active packaging. Full article

Medicinal and aromatic plants continue to attract attention as rich sources of natural bioactive compounds with potential health benefits. Among them, Greek mountain tea (Sideritis scardica) is widely recognized for its high content of phytochemicals, which have been associated with various biological activities. In this study, Natural Deep Eutectic Solvents (NADESs) were investigated as a sustainable and efficient alternative to conventional solvents for the extraction of such compounds, aiming to the development of a more efficient extraction process. Six task-specific designed NADESs were prepared and evaluated for their extraction efficiency, based on the Total Phenolic Content (TPC) and Total Flavonoid Content (TFC) of the extract. The most promising NADES, comprising betaine and 1,3-propandeiol, was selected for process optimization using a Box–Behnken design and key extraction parameters were systematically examined to maximize TPC and TFC. The extract obtained under the proposed conditions (S/L = 20 mg/g, 240 min, 40% water as cosolvent) exhibited a TPC and TFC value of 49.2 mg_GAE/g and 45.9 mg_CAE/g, respectively, approximately two times higher than the values of a hydroethanolic extract, obtained under the same conditions (TPC = 26.6 mg_GAE/g, TF = 19.9 mg_CAE/g). The optimum extract was further analyzed using HPLC-DAD to determine its phytochemical profile and was compared with the conventional hydroethanolic extract, revealing the role of the selected media on the extracted compounds. Full article

In the present study, alginate–silver nanoparticle (Alg-AgNP) nanocomposite hydrogels possessing antibacterial activity were synthesized via an innovative route. A task-specific designed Natural Deep Eutectic Solvent (NADES), composed of glucose, lactic acid, and water, was utilized as a green extraction solvent of bioactive compounds from olive leaves (OLs). The NADES–olive leaf extract (NADES-OLE) was used as obtained for the preparation of the Alg-AgNP nanocomposite hydrogel as a multiple-role component. The NADES-OLE acts (a) as a crosslinking agent for the preparation of the alginate hydrogels, (b) as a reducing agent for the in situ synthesis of AgNPs during hydrogel formation, and (c) as a bioactivity enhancement agent due to the presence of compounds obtained from the olive leaves. The Alg-AgNP hydrogel preparation process was optimized through a Box–Behnken experimental design. The resulting nanocomposite hydrogels were characterized for their swelling capacity and water retention in phosphate buffer (pH 5.5), achieving 538% swelling capacity within 180 min and 90% water retention after 250 min. The AgNPs formed within the hydrogels were found to have an average size of 103.2 ± 5.6 nm, with a concentration of 1.2 10⁸ ± 2.2 ∗ 10⁷ particles/mL. Antibacterial testing of the nanocomposite hydrogels against foodborne pathogens, including Gram-negative (Escherichia coli, Salmonella Typhimurium, Yersinia enterocolitica) and Gram-positive bacteria (Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus), revealed significant antibacterial activity, particularly against E. coli (64.9%), Y. enterocolitica (60.6%), S. aureus (79.1%), and B. cereus (55.3%), at a concentration of 1 mg/mL. Full article

The medicinal plant Malva neglecta Wallr. is known for its high concentration of beneficial bioactive compounds. This study investigated extracts prepared from the plant’s flowers, leaves, and roots. Different green solvents were used: 70% ethanol, and for the first time in relation to this plant species, natural deep eutectic solvents (NADES)—one based on choline chloride and citric acid (NADES1) and another using choline chloride and glycerol (NADES2). Key bioactive compounds were identified and quantified using spectrophotometric assays and HPLC-PDA-MS profiling to determine their role in the plant’s antioxidant activity. The analysis revealed that M. neglecta contains a wide range of flavonoid glycosides and phenolic acids, with the flowers and leaves exhibiting the highest diversity and concentrations of these compounds with a predominance of quercetin and kaempferol glycosides. Among the solvents tested, the ethanolic extracts showed the highest total contents of phenols, flavonoids, and condensed tannins. The flower extracts—regardless of the solvent used—exhibited the strongest antioxidant activity, as demonstrated by the DPPH, FRAP, and ABTS assays. Alkaloids were detected in all organs tested only in low quantities. The antibacterial (against Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) and antifungal activity (against Penicillium chrysogenum, Fusarium oxysporum, Aspergillus parasiticus, A. carbonarius, A. niger, A. flavus, and A. ochraceus) of the extracts was evaluated and compared. As a whole, the NADES1 extracts exhibited higher antibacterial potential than the ethanolic extracts. Such a clear trend regarding the antifungal activity was not observed. The highest antifungal activity was exhibited by NADES1 root extracts. NADES2 extracts showed a complete lack of antimicrobial effects. Full article

In the Yucatán Peninsula, Citrus aurantium L. has a strong cultural and culinary relevance where local industries already process its juice and essential oils, producing large amounts of by-products. In this context, green chemistry strategies have accelerated the valorization of agro-industrial residues, where Natural Deep Eutectic Solvents (NADESs) stand out due to their low cost, ease of preparation, and high extraction efficiency. This study focuses on evaluating different NADES combinations for the extraction of bioactive compounds from C. aurantium by-products, obtained after essential oil (cold pressing) and juice (mechanical pressing) extraction. A 3 × 2 × 2 factorial design was implemented to evaluate the effect of hydrogen bond donor (HBD: fructose, glucose and glycerol), molar ratio (MR: 1:1 and 1:2 mol/mol choline chloride (ChCl:HBD)) and added water (AW: 50 and 70%) on the polyphenolic profile, total phenolic content, total flavonoid content, ascorbic acid content and antioxidant capacity. HBD was the most critical factor in the extraction of bioactive compounds; the extract obtained with glycerol and 70% AW exhibited the highest hesperidin content (2186.08 mg/100 g dry mass), while the same HBD with 50% AW exhibited the highest quercetin + luteolin extraction (721.32 mg/100 g dry mass), both at the same MR (1:1 mol/mol). Glycerol also achieved the highest recovery of total flavonoids (1829.7 ± 17.85 mg quercetin equivalent/100 g dry mass) with an MR of 1:2 mol/mol and 70% AW. Finally, all other maximum values were obtained with fructose-based NADESs: the highest total phenolic content (3603. 7 ± 52.9 mg gallic acid equivalent/100 g dry mass) was achieved at an MR of 1:1 mol/mol and 50% AW, while for both vitamin C (1964.8 ± 33.7 mg ascorbic acid equivalent/100 g dry mass) and antioxidant capacity (84.31% inhibition), the maximum was reached at an MR of 1:2 mol/mol and 50% AW. Full article