Search Results (1,657)

Microalgae and cyanobacteria are photosynthetic microorganisms capable of removing nutrients from eutrophic waters and producing biomass. Therefore, the aim of this study was to evaluate the bioremediation performance of three microalgae and one cyanobacterium native to Lake Xochimilco and to assess their potential for biofuel production (biodiesel and biogas) from biomass generated. In photobioreactors, ammonium (96.61–97.06%), nitrate (82.4–100%), and phosphate (83.95–89.71%) were effectively removed from the lake water. The specific growth rates ranged from 0.041 to 0.144 d⁻¹ and biomass productivities from 0.016 to 0.049 g L⁻¹ d⁻¹, with high biomass yield on the substrate. The estimated CO₂ fixation rates ranged from 0.024 to 0.092 g L⁻¹ d⁻¹. Chlorella sp. achieved the highest yield of fatty acid methyl esters (FAMEs) with 91.24% of the extracted lipids. Overall, saturated FAMEs were predominant in the biodiesel; however, the presence of monounsaturated FAMEs such as methyl palmitoleate and methyl oleate enhances their fluidity and oxidative stability. Synechocystis sp. and Chlorella sp. produced the most biogas using biomass after lipid extraction, at 429.5 L kg⁻¹ VS and 404.9 L kg⁻¹ VS, respectively, with over 60% biomethane. These strains represent a sustainable and promising possibility for water bioremediation and generating biofuels. Full article

To investigate the associations between genes involved in fatty acid composition and volatile flavor compounds (VOCs), Dabieshan (DBS) cattle were selected and stratified into high (H: 0.018–0.024 g) and low (L: 0.007–0.012 g) groups according to the fatty acid content in the longissimus dorsi (LD). Integrated analysis using two-dimensional gas chromatography–time-of-flight mass spectrometry (GC×GC-TOF-MS) and transcriptomics systematically revealed differences in VOCs and gene expression profiles, along with their associations with fatty acid composition. The relative contents of aldehydes, esters, and hydrocarbons were significantly higher in the group H, whereas the group L exhibited elevated levels of alcohols, acids, and heterocyclic compounds. Among 54 differentially abundant VOCs identified, (E)-2-Nonenal (ROAV = 100) was established as the key flavor contributor. Transcriptomic analysis identified 678 differentially expressed genes (DEGs), with eight candidate genes implicated in fatty acid composition pinpointed through GO and KEGG enrichment analyses. Further correlation analysis showed that the expression levels of SGPL1, KLF15 and SLC27A6 were significantly correlated with the contents of polyunsaturated fatty acids (C22:5n-3, C18:3n-3, C18:2n-6, C18:1n-9c). There was also a significant correlation between the above fatty acids and characteristic flavor compounds including 3-Hexanone, (E)-2-Nonenal, (E,E)-2,4-Octadienal and Butanal. This study suggested potential links among fatty acid composition, key genes and characteristic flavor compounds in Dabieshan cattle, providing new insights into the genetic improvement of flavor quality of local cattle breeds. Full article

Background: n-3 Docosapentaenoic acid (DPA; 22:5 n-3) is increasingly viewed as a distinct long-chain omega-3 fatty acid with biological activities that are not fully captured by eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA). However, progress remains limited by restricted access to high-purity DPA: most commercial sources contain DPA as a minor component, and published isolation strategies often yield only enriched mixtures or require multi-step workflows that are difficult to scale in standard laboratories. Objectives: We aimed to establish a robust, laboratory-accessible purification workflow to obtain DPA ethyl ester at high purity while preserving oxidative quality. Methods: Candidate lipid sources were screened to select an optimal DPA-containing feedstock. Oils were stabilized with antioxidants and pre-fractionated by cold crystallization (−20 °C) to reduce saturated lipids and oxidation by-products. Preparative separation used a stacked C18 flash system (15 μm + 45 μm in series) operated isocratically (methanol/water 92:8, v/v) at 120 mL/min. Fractions were analyzed by GC and iteratively reinjected to progressively enrich the DPA window. Solvent was recovered by distillation and reused. Results: Omegavie^® 4020EE (5.4% n-3 DPA) was identified as the best starting material. Pretreatment eliminated detectable TBARS-derived malondialdehyde. The isocratic purification-loop strategy produced tens of grams of DPA ethyl ester at >98% purity (GC–FID) defined as n-3 DPA area% of total identified fatty acid methyl esters by GC–FID, with per-cycle DPA recovery of 91–95%, overall recovery of 76% from the starting DPA content, and >90% solvent recycling. The workflow is scalable at the gram-to-tens-of-grams level for research laboratories, although solvent burden and column maintenance remain practical constraints for larger-scale implementation. Identity and purity were confirmed by GC–MS and ^1H NMR, and oxidation indices remained low (peroxide value < 0.2 meq/kg; p-anisidine < 3). Conclusions: This scalable, solvent-conscious protocol enables reliable access to high-purity DPA and should be adaptable to other low-abundance polyunsaturated fatty acids. Full article

Background/Objectives: Beeswax, a complex natural secretion primarily derived from Apis mellifera and Apis cerana, has evolved from an ancient remedy into a multifunctional excipient and bioactive material in modern pharmaceutical sciences. This review evaluates its physicochemical properties, pharmaceutical applications, and emerging biomedical potential, while addressing current quality and regulatory challenges. Methods: A narrative review was conducted by analyzing literature on the chemical composition, functional properties, conventional uses, advanced drug delivery applications, pharmacological activities, and quality control of beeswax, emphasizing structural characteristics, formulation roles, and integration into innovative delivery technologies. Results: Beeswax is a lipid-based matrix composed of over 300 constituents, including wax esters, hydrocarbons, and free fatty acids, conferring thermoplasticity, biocompatibility, and structural stability. Traditionally, it functions as a stiffening agent, viscosity modifier, and emulsion stabilizer in topical formulations, forming an occlusive barrier that enhances skin hydration. In advanced systems, it serves as a solid lipid matrix in nanostructured lipid carriers (NLCs), microspheres, and 3D-printed tablets, enabling controlled drug release and improved bioavailability of lipophilic compounds. It also exhibits antimicrobial, anti-inflammatory, and wound-healing activities, while beeswax-derived policosanols show potential cardiovascular and gastroprotective benefits. However, concerns regarding paraffin adulteration and pesticide contamination highlight the need for stringent analytical and regulatory oversight. Conclusions: With rigorous quality control and sustainable sourcing, beeswax remains a versatile, eco-friendly material bridging traditional medicine and advanced pharmaceutical innovation. Full article

The present study provides an exhaustive exploration of twelve macroalgal species from the Adriatic Sea, including seven brown algae (Ericaria amentacea, Fucus virsoides, Cutleria multifida, Cystoseira compressa, Cystoseira corniculata, Gongolaria barbata and Padina pavonica), three green algae (Codium adhaerens, Codium vermilara and Ulva lactuca), and two red algae (Scinaia furcellata and Asparagopsis taxiformis). Matrix solid-phase dispersion (MSPD) was applied as the extraction technique, using generally recognized as safe (GRAS) solvents. The bioactive profile of the extracts was assessed through the quantification of total phenolic content (TPC) and antioxidant activity. Among the three phyla, U. lactuca, F. virsoides and S. furcellata exhibited the highest TPC (0.8, 26 and 3.0 mgGAE·g⁻¹) and antioxidant activity (1.9, 38 and 7.5 mgTE·g⁻¹), respectively. Targeted HPLC-MS/MS analysis enabled the identification of nineteen phenolic compounds across all taxa. Chlorophyta showed a characteristic profile enriched in coumarins, benzaldehydes and flavanones, including the selective detection of 7-hydroxycoumarin in species with higher antioxidant potential. Additionally, compounds such as chlorogenic, rosmarinic and caffeic acids exhibited taxon-specific distributions that may explain differences in antioxidant activity. Complementary untargeted ultra-high performance liquid chromatography quadrupole time-of-flight (UHPLC-QToF) metabolomics analysis provided broader coverage, revealing eighty metabolites spanning phenolics, sugars, organic acids, lipids, amino acids and their derivatives. Notably, the proposed detection of fatty acid esters of hydroxy fatty acids (FAHFAs) represents the first report of these compounds in macroalgae, alongside a pronounced presence of sulphated phenolics. Overall, these findings provide a robust baseline on the bioactivity and chemical composition of Adriatic macroalgae, highlighting their value as a natural source of functional compounds. Full article

Rapid expansion of the plant-based milk market has increased the need to understand how the aroma profiles of these alternatives differ from that of dairy milk and how raw material selection and processing influence volatile formation. This study compared the volatile profiles of dairy milk, commercial plant-based milks, and laboratory-prepared cereal and pseudocereal milk prototypes to identify promising materials for plant-based milk development. Comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS) combined with chemometric analysis was used to characterize volatile compounds in bovine milk, four commercial plant milks, and five laboratory-prepared plant milks. Dairy milk was characterized by fatty acids, esters, and other lipid-derived volatiles, whereas plant-based samples were associated with hydrocarbons, pyrazines, ketones, and phenols. Within the plant-based group, volatile differences were influenced by raw material type and processing history. Commercial products showed more evident processing-related features, whereas laboratory-prepared cereal samples exhibited a simpler volatile background. Among them, barley milk displayed a distinctive toasted and cereal-like signature. Overall, the selected cereal and pseudocereal matrices showed distinct volatile characteristics, as well as relatively uniform raw material backgrounds, implying greater flexibility in aroma expression. These features make them promising candidates for dairy alternatives and may help guide future plant-based milk formulation. Full article

Sunflower oil is particularly prone to thermo-oxidative degradation due to its high content of polyunsaturated fatty acids, especially under high-temperature conditions. This study investigated the oxidative stability of sunflower oil heated at 180 °C for 4 and 8 h, focusing on the protective effect of silibinin oleate (SIL-O), a lipophilic polyphenolic derivative, compared to the synthetic antioxidant butylated hydroxytoluene (BHT). Oxidative changes were evaluated through peroxide value (PV), p-anisidine value (p-AV), and total oxidation value (TOTOX), while structural alterations were monitored using FTIR spectroscopy. Additionally, fatty acid composition was analyzed by GC-MS to assess compositional changes associated with oxidation. Thermal treatment led to increases in PV, p-AV, and TOTOX, indicating progressive oxidation, alongside a decrease in unsaturated fatty acids. FTIR analysis revealed characteristic changes, including a reduction in the unsaturation band (~3008 cm⁻¹), modifications in the ester carbonyl region (~1743 cm⁻¹), and the emergence of bands associated with cis–trans isomerization (~968–970 cm⁻¹). Strong correlations were observed between fatty acid degradation, FTIR indices, and oxidation parameters. Compared to the control, SIL-O inhibited oxidation in a dose-dependent manner. At 300 ppm, it outperformed BHT, demonstrating its potential as a natural antioxidant for enhancing the stability of sunflower oil during high-temperature processing. Full article

Aquaculture wastewater (AWW) contains elevated concentrations of nitrogen, phosphorus, and salts, in addition to many micropollutants that may cause environmental pollution if discharged untreated. This study evaluated the potential of the halophilic microalga Dunaliella salina for simultaneous phycoremediation of AWW and production of biodiesel-oriented biomass. Microalgal growth and biochemical composition were compared between AWW and synthetic f/2 medium under controlled laboratory conditions. Results showed that AWW supported efficient microalgal growth, showing a biomass yield of 1.32 g L⁻¹ with a productivity of 0.09 g L⁻¹ d⁻¹, representing 40.88% and 18.42%, respectively, over that obtained in f/2 medium. Cultivation in wastewater also enhanced the volumetric productivity of lipids, proteins, and carbohydrates by 26.20%, 12.46%, and 26.38%, respectively. Significant nutrient removal from AWW was achieved, with high reduction efficiencies for nitrate, nitrite, ammonium, phosphate, and sulfate within the range 76.80–94.10%, along with a decrease in salinity by 29.70%. The lipid fraction was dominated by fatty acid methyl esters suitable for biodiesel production, representing 94.10% of the total lipids. Biodiesel properties met the international fuel standards and were even improved when the microalga was cultivated in AWW. These findings demonstrate that AWW can serve as an effective culture medium for halophilic microalgae, enabling simultaneous wastewater treatment and sustainable biofuel feedstock production. Full article

This study explores the potential of seeds from fruit and vegetable processing waste as feedstocks for biodiesel biocomponent production. Fatty acid methyl esters (FAMEs), obtained through a transesterification reaction, were extracted using ultrasound-assisted extraction and identified by gas chromatography–mass spectrometry (GC–MS) in selected ion monitoring (SIM) mode. A total of 31 to 34 individual FAME compounds were identified across all samples. The fatty acid profiles varied both quantitatively and qualitatively depending on the raw material; however, unsaturated FAMEs predominated over saturated ones in all cases. The highest proportions were observed for γ-linolenic acid (C18:3n6), particularly in apple, melon, lemon, and pumpkin seeds. Substantial contributions of oleic acid (C18:1n9c) were found in apple, quince, cherry, and melon seeds, while linolelaidic acid (C18:2n6t) dominated in melon, pumpkin, quince, and cherry seeds. The highest total FAME contents were recorded for apple, melon, lemon, and pumpkin seeds, while the lowest values were observed in apricot and pepper seeds. Among the materials studied, grape seeds proved to be the most promising feedstock, exhibiting a favorable cetane number and a beneficial fatty acid profile characterized by high monounsaturated fatty acid (MUFA) content, low polyunsaturated fatty acid (PUFA) content, and a moderate fraction of saturated fatty acids (SFAs). Plum and peach seeds also showed significant potential, but their higher PUFA levels may compromise oxidative stability and could require antioxidant supplementation or blending with MUFA-rich feedstocks. Full article

The chemical composition of Iris songarica rhizome extracts was systematically investigated using GC-MS and UHPLC-MS. Their biological activity was further evaluated in vivo. The chloroform rhizome extract contained 33 identified compounds distributed across five main classes. Flavonoids predominated (50.7% of total ionic current), with tectochrysine (42.15%) as the major component, followed by 3,7-dihydroxy-2-(3,4-dimethoxyphenyl)-4H-chromene-4-one (5.18%) and a naringenin derivative (3.99%). Fatty acid esters comprised 30.6%, dominated by linoleic acid ethyl ester (11.05%), ethyl oleate, and hexadecanoic acid ethyl ester. Phenolic and aromatic compounds accounted for 14.24%, including (E)-4-(3-hydroxyprop-1-en-1-yl)-2-methoxyphenol and flamenol. Quantitative HPLC revealed hesperetin (69.72 µg/mL) and fisetin (12.32 µg/mL) as predominant in the 50% aqueous ethanol extract, and cinarin (6.28 µg/mL) in the ethyl acetate root extract. HPLC-MS identified 25 polyphenols, mainly isoflavonoids and flavones, with key markers songaricol, irilin B, tectorigenin, irisflavone A, and irizon B, some reported for the first time in Kazakhstan irises. Biological evaluation demonstrated potent activity: the 50% aqueous ethanol extract inhibited xylene-induced ear oedema in mice by 72.7% at 300 mg/kg, comparable to diclofenac (90.9%), without observable toxicity. These findings confirm I. songarica as a valuable source of bioactive polyphenols with anti-inflammatory potential. Full article

Cellulose paper, a natural polymeric dielectric, determines the lifetime of oil–paper insulation systems in transformers, yet its molecular degradation behavior in ester-based insulating media remains insufficiently clarified. This study investigates the electro–thermal aging of cellulose polymer immersed in soybean-based natural ester (SBNE) and palm fatty acid ester (PFAE), with emphasis on depolymerization and its relationship with partial discharge (PD) activity. Accelerated aging experiments were conducted under combined electrical and thermal stress, and the evolution of the degree of polymerization (DP) was measured to quantify polymer chain scission. Phase-resolved PD (PRPD) patterns were recorded during aging, and multi-dimensional statistical features were extracted and reduced using principal component analysis to characterize degradation-sensitive electrical responses. The results show a progressive decrease in DP with aging time in both ester media, accompanied by distinct PD evolution characteristics, indicating different influences of the two esters on cellulose polymer stability. An ensemble learning model integrating multiple classifiers was further employed to identify aging stages based on PD features, achieving reliable discrimination performance. These findings establish a correlation between cellulose depolymerization and dielectric discharge behavior, providing a polymer-centered interpretation of aging mechanisms in ester-based oil–paper insulation systems. Full article

The high viscosity of biodiesel fuel, caused by the presence of saturated fatty acid esters, limits its application, particularly at low temperatures. Supercritical fluid extraction (SFE) using carbon dioxide represents a promising method for selective fractionation, enabling the removal of high-viscosity saturated components and the enrichment of the fuel with less viscous unsaturated esters. However, the rational design of such processes requires a deep understanding of the interrelationship between flow hydrodynamics, thermodynamic conditions, and mass transfer in a supercritical medium. In this work, a comprehensive computational fluid dynamics (CFD) modeling study of the fractionation process was performed for a model ethyl oleate/ethyl palmitate mixture (25.28:74.72 wt.%) in supercritical CO₂ at pressures of 11 and 14 MPa and a temperature of 40 °C. A three-dimensional model of a laboratory-scale extractor was developed using the Ansys Fluent software version 2020 R1 environment. Since the target esters are absent from the standard material database, a custom property library and compiled User-Defined Function (UDF) routines were developed. These describe the temperature dependence of density, viscosity, heat capacity, and thermal conductivity for both the individual components and their mixture using established mixing rules. The calculations employed an Eulerian multiphase model, the realizable k–ε turbulence model, and species transport equations. The modeling revealed pronounced selectivity: under the chosen thermodynamic conditions, ethyl palmitate is extracted preferentially over ethyl oleate, with this difference becoming more pronounced as pressure increases. The developed and verified CFD model deepens the fundamental understanding of hydrodynamics and mass transfer during supercritical fractionation and serves as a basis for optimizing process parameters to produce biodiesel with reduced viscosity. The regime at P = 14 MPa and t = 40 °C provides the most favorable thermodynamic and hydrodynamic conditions for the selective removal of saturated esters. Full article

The flavor and scent of Chinese Baijiu are closely linked to the quantity of fatty acid ethyl esters, and their generation is closely associated with Baijiu brewing yeast, most notably ethyl acetate (EA) and ethyl hexanoate (EH). At present, however, the specific mechanism of EA and EH produced by Wickerhamomyces anomalus under ethanol stress during the brewing of Baijiu remains unclear. Our study findings revealed that ethanol stress inhibited the generation of precursor substances (pyruvate and acetyl-CoA) in the fatty acid ethyl ester biosynthesis pathway of W. anomalus NCU003. The high level of EA produced in the fatty acid ethyl ester biosynthesis pathway was associated with the enhanced expressions of ATF1 and EAT1 and the increased activity of C2 esterase under 3% and 6% ethanol stress. The lower EA content was related to the high expression of IAH1 and low activity of C2 esterase under 9% ethanol stress. We also found that the expression of ACC, FAS1, FAS2, EHT1, and EEB1 was up-regulated, which may promote the synthesis of EH under ethanol stress, whereas the activity of C6 esterase may have no effect on the synthesis of EH. Our study results indicated that the above genes and C2 esterase can be modulated in W. anomalus NCU003 under ethanol stress, thus promoting the synthesis of fatty acid ethyl esters during the brewing of Baijiu. Full article

Lipid recovery efficiency from microalgal biomass is a critical factor in the commercial viability of biodiesel. Scenedesmus sp. presents a robust cell wall that necessitates the evaluation of specialised disruption techniques to enhance intracellular lipid release and subsequent fuel quality. This study investigated the efficacy of five cell disruption methods—microwaves, ultrasonication, lyophilisation, autoclaving, and electroporation—integrated with three distinct extraction procedures: cold extraction, Soxhlet extraction system, and microwave-assisted extraction. The qualitative and quantitative impacts of these treatments were assessed by analysing the fatty acid methyl ester (FAME) profiles via gas chromatography (GC) following transesterification. The highest total lipid yield (88.97%) was achieved through a combination of microwave disruption and Soxhlet extraction. However, the maximal proportion of methyl esters was obtained when ultrasonication was paired with microwave-assisted extraction (97.64%). Surface analysis using scanning electron microscopy (SEM) of samples subjected to different disruption procedures could support the conclusions. Similarly, when the microalgal biomass was lyophilised beforehand, microwave extraction increased the oleic acid content. These results indicate that the choice of disruption and extraction protocols significantly influences both lipid recovery rate and the proportion of fatty acids in the chemical composition of microalgae. Tailoring these processes is essential for optimising the fatty acid profile for high-quality biodiesel production. Full article

Donor human milk (DHM) provided by human milk banks is considered the optimal feeding alternative to mother’s own milk for premature or medically compromised infants. Before distribution, DHM is subjected to Holder pasteurization (HoP) by milk banks to eliminate potential pathogens. In this study, FT-IR, GC and GC-MS were applied to characterize changes in the volatile organic compounds (VOCs) and lipid components of human milk (HM) samples that were treated by HoP. FT-IR analysis revealed changes in specific band regions, indicating modifications to triglycerides and fatty acid (FA) organization and possible disruption of the milk fat globule membrane. There was also an increase in ester groups, suggesting that HoP increases lipid oxidation. GC analysis showed a reduction in long-chain FAs, including certain omega-3 and omega-6 polyunsaturated FAs (PUFAs). GC-MS analysis showed that HoP-treated samples contained higher levels of alkanes, aldehydes, aromatics and ketones than raw HM. Conversely, other compounds, including furans, and alkynes, were found exclusively in pasteurized HM. These results show that HoP affects the lipid and VOC components of HM, highlighting the need for research into alternative pathogen elimination strategies in human milk bank practices. Full article