Search Results (196)

This study systematically investigated the dynamic changes in fatty acid composition and oxidative stability of hickory nut oil during accelerated oxidation, and characterized the metabolic features associated with lipid oxidation using a metabolomics approach. Accelerated oxidation was conducted using the Schaal oven method. The results showed that the peroxide value (POV) and malondialdehyde (MDA) content reached maximum levels of 121.5 meq/kg and 1.94 μg/mL, while the conjugated diene value (CDV) and carbonyl value (COV) increased to 15.12 and 19.68 meq/kg, respectively. The fatty acid profile exhibited notable changes, with unsaturated fatty acids decreasing from 92.52% to 90.65% and saturated fatty acids increasing from 6.92% to 7.88%. A total of 2026 metabolites were identified, among which fatty acyls and benzenoids were predominant. The oxidation rate remained low during the initial phase (0–10 days) but increased markedly after approximately 25 days, leading to accelerated oxidation and a pronounced decline in oil quality. Pathway enrichment analysis further revealed that α-linolenic acid metabolism was the principal pathway associated with the oxidative process of hickory nut oil. Full article

Development of new polymers that cannot be achieved by using conventional catalysts has been the central research objective, and copolymerization is an effective strategy to modify the materials’ (thermal, physical, mechanical and electronic) properties. Modified half-titanocenes, Cp’TiX₂(Y) (Cp’ = cyclopentadienyl, X = Cl, Me, etc, Y = anionic donor such as phenoxide, ketimide, amidinate, etc.), are known to be effective catalysts. This review introduces several selected efforts for efficient synthesis of ethylene copolymers containing cyclic olefins, biobased conjugated dienes, and disubstituted α-olefins, including the effect of cocatalysts. Moreover, here we introduce an analysis using XAS (X-ray absorption spectroscopy), which has been recognized as a powerful method providing direct information on the catalytically active species, such as coordination numbers and the distances of the coordinated atoms as well as oxidation state and the geometry of the metal centre in catalyst solution. Full article

Background: Oxidative degradation during deep frying negatively affects the nutritional quality and stability of edible oils. Rapid, non-destructive methods to monitor oxidation, particularly in antioxidant-enriched oils, are therefore of growing interest. Materials and Methods: This study investigates the potential of near-infrared (NIR) spectroscopy combined with chemometric modeling—specifically the Stepwise Decorrelation of Variables (SELECT) algorithm and Ordinary Least Squares (OLS) regression—to quantitatively assess oxidation dynamics in edible oils enriched with hydroxytyrosol extract from olive fruit during deep frying. Extra virgin olive oil, virgin olive oil, refined olive oil, refined sunflower oil, and high-oleic sunflower oil were evaluated under controlled thermal degradation conditions. Results: Variable selection identified key NIR spectral regions related to acidity, conjugated dienes (K₂₃₂), secondary oxidation indices (K₂₇₀ and ΔK), peroxide value (PV), anisidine value (AnV), and the total oxidation (TOTOX) index. From 700 measured wavelengths, a limited number were sufficient for robust prediction (16–30 wavelengths depending on the parameter), with critical sensitivity observed around 1792 nm and 1392 nm. The optimized NIR–SELECT–OLS models showed strong predictive performance across oil types (R² > 0.90; explained variance > 85%). Conclusions: The results demonstrate that hydroxytyrosol enrichment enhances the oxidative and nutritional stability of edible oils during deep frying. Moreover, the integration of NIR spectroscopy with chemometric modeling provides an effective, non-destructive tool for real-time monitoring of oil oxidation, supporting sustainable quality control, process optimization, and antioxidant fortification in functional edible oils. Full article

Coordination chain transfer polymerization (CCTP) has emerged as an efficient and controllable polymerization strategy that also allows for efficient in situ end-functionalization of polydienes through the highly reactive metal–carbon bonds that are generated during the CCTP process. Despite substantial progress in CCTP chemistry, reviews focusing specifically on its application to diene monomers—and particularly on its effectiveness in producing end-functionalized polydiene elastomers—remain scarce. To address this gap, this review summarizes the advances achieved over the past decade in the end-functionalization of polydienes via CCTP. We begin with a brief overview of the fundamental principles and core mechanisms of CCTP, followed by a systematic discussion of functionalization strategies for key diene monomers, including isoprene and butadiene. Finally, we highlight the existing challenges in this field and provide our perspectives on future research directions. Full article

This study investigates the synthesis and photochemical behavior of a series of (E)-1-aryl-1,3-butadienes with different aromatic substituents. Despite their simple structure and straightforward preparation, detailed studies of their photochemical properties, especially UV light-induced (E) to (Z) isomerization, are scarce. Our results demonstrate that these compounds can efficiently undergo photo-triggered geometric changes, highlighting their potential as functional units in photochemical applications. The findings underline the significance of extended conjugation in managing excited-state processes, providing new insights into the dynamics of photoinduced transformations in conjugated diene systems. Additional computational analyses show how geometric modifications influence conformational energies in the synthesized compounds. Overall, these results improve understanding of structure–reactivity relationships and lay the foundation for designing photoresponsive materials based on (E) and (Z)-1-aryl-1,3-butadiene frameworks, with promising applications in photochemistry and materials science. Full article

This study examined the effects of ochratoxin A (OTA) exposure and graded dietary selenium (Se) supplementation on fatty acid (FA) composition and oxidative stress markers in the liver of broiler chickens. OTA is known to generate oxidative stress, promote lipid peroxidation, and affect the antioxidant system. Se, an essential trace element with antioxidant properties, may help counteract OTA-induced toxicity. In this short-term (5-day) in vivo feeding experiment, 21-day-old broiler chickens were divided into six groups, each with six birds: Control (diet free from Se), 0.3 mg/kg Se, 0.5 mg/kg Se, 2 mg/kg OTA, 2 mg/kg OTA + 0.3 mg/kg Se, 2 mg/kg OTA + 0.5 mg/kg Se. Our findings show that supplementing 0.3 mg/kg (p < 0.01) or 0.5 mg/kg Se (p < 0.001) in OTA-exposed birds significantly reduced the early oxidative stress markers (conjugated dienes and trienes) and significantly increased (0.3 mg/kg p < 0.01; 0.5 mg/kg p < 0.001) glutathione levels, indicating enhanced glutathione-dependent antioxidant protection. The treatments also significantly altered the ratio of monounsaturated and n6/n3 polyunsaturated FAs. OTA with 0.3 mg/kg Se supplementation significantly (p ˂ 0.05) reduced total unsaturation and FA average chain length. At a dose of 0.3 mg/kg, the interaction of Se and OTA altered the PUFA composition, while 0.5 mg/kg Se supplementation enhanced antioxidant defense and reduced lipid peroxidation. These results highlight the dual but separate role of Se, where inadequate doses may enhance OTA toxicity, while optimal supplementation may have a protective effect on hepatic lipid homeostasis. These findings can be used in the future progress of the mitigation strategy against OTA exposure in poultry nutrition. Full article

Sesame seed oil is a bioactive-rich lipid source, notable for lignans, tocopherols, and unsaturated fatty acids that underpin its antioxidant and cardioprotective properties. This study optimized two innovative, non-thermal extraction techniques—pulsed electric field (PEF) and ultrasound bath-assisted extraction (UBAE)—to maximize yield and preserve oil quality for functional food applications. A blocked definitive screening design combined with response surface methodology modeled the effects of energy power (X₁, 60–100%), liquid-to-solid ratio (X₂, 10–20 mL/g), and extraction time (X₃, 10–30 min) on fat content, DPPH antiradical activity, and oxidative stability indices (Conjugated Dienes, CDs/Conjugated Trienes, CTs). UBAE achieved the highest fat yield—59.0% at low energy (60%), high X₂ (20 mL/g), and short X₃ (10 min)—while PEF maximized DPPH to 36.0 μmol TEAC/kg oil at high energy (100%), moderate X₂ (17 mL/g), and short X₃ (10 min). CDs were minimized to 19.78 mmol/kg (UBAE, 60%, 10 mL/g, 10 min) and CTs to 3.34 mmol/kg (UBAE, 60%, 12 mL/g, 10 min). Partial least squares analysis identified X₂ and X₃ as the most influential variables (VIP > 0.8), with energy–time interplay (X₁ × X₃) being critical for antioxidant capacity. Compared to cold-pressing and Soxhlet extraction, PEF and cold-pressing retained higher antioxidant activity (~19 μmol TEAC/kg) and oxidative stability (TBARS ≤ 0.30 mmol MDAE/kg), while Soxhlet—though yielding 55.65% fat—showed the poorest quality profile (Totox value > 560). Both non-thermal techniques can deliver bioactive-rich sesame oil with lower oxidative degradation, supporting their application in functional foods aimed at improving dietary antioxidant intake and mitigating lipid oxidation burden. PEF at high energy/short time and UBAE at low energy/short time present complementary, scalable options for producing high-value edible oils aligned with human health priorities. As a limitation, we did not directly quantify lignans or tocopherols in this study, and future work will address their measurement and bioaccessibility. Full article

1,3-Butadiene and its analogues constitute an important raw material in the petrochemical industry. What is more, due to their specific structure, these compounds are attractive components in the synthesis of heterocyclic compounds. Modification of the 1,3-butadiene structure allows obtaining compounds characterized by different reactivity and possessing various biological properties. In order to thoroughly investigate this phenomenon, an analysis of 20 compounds, including 1,3-butadiene and its analogues, was carried out. For this purpose, a study based on MEDT, ADME, and PASS was performed. In this research, changes in electronic properties and basic physicochemical parameters under the presence of various substituents at various positions in the structure of 1,3-butadiene were studied. At the end, the influence of modifications on biological activities for the tested compounds was evaluated. Based on the presented results, it was found that substituent modifications cause significant changes in both electronic structures and in physicochemical properties of all the compounds. This fact is probably caused by the small size of the considered compounds. On the other hand, the main preferences for the most important active sites in the tested molecules remain the same due to the presence of a strongly conjugated system of double bonds. Full article

This study explores a novel feeding strategy in the nutrition of dairy goats, utilizing milk thistle cake supplements to mitigate milk oxidation determined by the presence of oxidized linseed oil in diets. An experimental trial involving 30 dairy goats was conducted with three groups: a control group fed a diet with 7% fresh linseed oil (CON), an experimental group fed a diet where the fresh linseed oil from the CON group was replaced with oxidized linseed oil (LOO), and an experimental group fed a diet with 7% oxidized linseed oil and 10% milk thistle cake (LOM). The milk thistle cake had a rich antioxidant composition (vitamin E, xanthophylls, and polyphenols) with potential beneficial effects on milk degradation parameters. The results showed that the LOM diet led to a decrease in milk casein content (p = 0.041) while positively influencing the concentration of iron (13.24 vs. 14.93 mg/kg). In terms of fatty acids, the results suggested that milk thistle cake can counteract the negative effects of the oxidized oil (increasing SFAs, decreasing PUFAs and MUFAs) by modulating the content and reducing its negative effects. Moreover, the LOM group positively influenced the milk antioxidant potential by increasing the levels of antioxidant compounds (vitamin E, p < 0.001; total polyphenols, p < 0.01; antioxidant capacity, p < 0.0001). Moreover, an improvement in the milk primary and secondary degradation parameters was observed, i.e., a significant decrease in the levels of conjugated dienes (p = 0.023) and p-anisidine (p < 0.0001). The study demonstrated the benefits of using milk thistle cake in goat nutrition as it helps reduce the oxidative effects induced by oxidized linseed oil on the nutritional quality of milk and its degradation. Full article

Almond skin (AS) from industrial almond peeling is considered an agri-food waste with adequate composition to obtain composite films for food packaging due to its richness in polysaccharides, proteins, and phenolic compounds. Composite films based on amorphous polylactic acid (PLA) or partially acetylated polyvinilalcohol (PVA) were obtained by melt blending and compression moulding, incorporating different ratios of defatted AS powder (0, 5, 10, and 15 wt.%). The filler was better integrated in the polar PVA matrix, where more interactions were detected with the filler compounds, affecting glass transition and crystallization of the polymer. The AS particles provided the films with the characteristic colour of the powder and strong UV light-blocking effect, while improving the oxygen barrier capacity of both polymeric matrices (24% in PLA with 15% AS and 42% in PVA with 10% AS). The water vapour permeability increased in PLA (by 192% at 15% AS), but decreased in PVA films, especially with low AS content (by 19% with 5% particles). The filler also provided the PLA and PVA films with antioxidant properties due to its phenolic richness, improving the oxygen barrier capacity of the materials and delaying the unsaturated oil oxidation. This was reflected in the lower peroxide and conjugated dienes and trienes values of the sunflower oil packaged in single-dose bags of the different materials. The high oxygen barrier capacity of the PVA bags mainly controlled the preservation of the oil, which made the effect of the antioxidant AS powder less noticeable. Full article

Lipid peroxidation driven by polyunsaturated fatty acid (PUFA) oxidation compromises feed quality and animal health. Single antioxidants (e.g., ethoxyquin (EQ), butylated hydroxytoluene (BHT)) face limitations including dose-dependent toxicity, bioaccumulation risks, and inadequate protection against multistage oxidation. Composite systems leveraging complementary mechanisms offer a promising alternative. This study evaluated synergistic efficacy of rationally formulated composite antioxidants (combining synthetic radical scavengers and metal chelators) versus single-component systems in enhancing lipid oxidative stability in high-fat animal feed. The basal diet containing oxidized oil served as the control group (CON). Seven groups were supplemented with the basal diet as follows: Treatment A, 36 g/ton Butylated Hydroxytoluene (BHT); Treatment B, 60 g/ton Ethoxyquin (EQ); Treatment C, 132 g/ton EQ; Treatment D, 10 g/ton EQ + 12 g/ton BHT; Treatment E, 10 g/ton EQ + 12 g/ton BHT + 6 g/ton Citric acid (CA); Treatment F, 20 g/ton EQ + 6 g/ton BHT + 6 g/ton CA; and treatment G, 2 g/ton EQ + 25 g/ton BHT + 6 g/ton CA. Oxidative stability was assessed over a 10-week period under natural storage (T0-T10) and acute thermal stress (120 °C drying for 2 h followed by ambient storage; HT0 to HT10). Oxidative stability was assessed via: antioxidant capacity (DPPH (2,2-Diphenyl-1-picrylhydrazyl)/ABTS (2,2′-Azinobis (3-ethylbenzothiazoline-6-sulfonic acid) scavenging, total antioxidant capacity), physical indices: Color (L*, a*, b*), and chemical oxidation markers: conjugated dienes (CD), peroxide value (PV), p-anisidine value (p-AV), malondialdehyde (MDA), acid value (AV), total oxidation (TOTOX). Superior synergistic performance of the ternary blend (Treatment E) was demonstrated versus singles (A/B/C). Retention of radical scavenging capacity was significantly enhanced, with greater stability observed under accelerated storage. Primary oxidation (PV) and secondary oxidation (MDA, p-AV) were most effectively suppressed by Treatment E. Superior color stability (minimal L* change) was maintained under thermal stress. The lowest TOTOX values were achieved across all conditions by Treatment E. Stage-specific vulnerabilities were shown by single antioxidants (BHT volatilization; pro-oxidative effects of EQ at high doses). Comprehensive, temperature-resilient protection was delivered collectively by the synergistic EQ+BHT+CA system (Treatment E) via combined radical quenching and metal chelation. The inherent limitations of individual antioxidants were effectively overcome by the optimized composite, enabling reduced total dosage while substantially extending the lipid oxidative stability period. Full article

Polybutadiene (PB) and polyisoprene (PI) rubbers are indispensable synthetic elastomeric materials widely used in tires, footwear, hose, belts, sealants, electricity, construction, and other applications. Nowadays, PB and PI elastomers are produced from butadiene (BD) and isoprene (IP) monomers via transition-metal-mediated coordination polymerization. Transition metal catalytic systems consist of a precise characteristic structural unit at the molecular level: well known as “single-site catalysts” (SSCs). These have experienced a revolutionary advance in the recently developed conjugated dienes synthetic rubber method. Among the SSCs, a class of rare-earth, metal-centered half-sandwich molecule has been identified as a high-performance catalytic system for conjugated dienes polymerization. These novel half-sandwich rare-earth (HSRE) catalytic systems exhibit several irreplaceable advantages compared with the conventional Ziegler–Natta-type catalytic systems. These HSRE catalytic systems can create novel conjugated diene rubbers (CDRs) with high catalytic reactivity, high stereoselectivity, an adjustable polymer chain microstructure, and high molecular weights and are considered to be the next generation of ecofriendly and economic catalytic systems for industrial applications. This paper delivers a concise review of some important synthetic methods for representative HSRE complexes with characteristic structures and of the utilization of some HSRE catalytic systems for the preparation of high-performance CDRs, especially highly stereoregular PI and PB materials. Full article

Phenylbutanoids, commonly found in various medicinal plants, have attracted significant attention due to their remarkable biological activities, including antioxidant, anti-inflammatory, and neuroprotective effects, as well as for their versatility as starting materials in organic synthesis. Among phenylbutanoids, phenyl-1,3-butadienes represent a unique class of conjugated dienes, characterized by a phenyl (C₆H₅) group attached to a 1,3-butadiene (-CH=CH-CH=CH₂) backbone. In this study, we synthesized the hydroxylated biphenyl 5,5′-di((E)-buta-1,3-dien-1-yl)-2,2′,3,3′-tetramethoxy-1,1′-biphenyl 1, closely related to its corresponding monomer 2, which is known for its broad range of pharmacological activities. The synthesis was carried out using microwave-assisted technologies. The structure of the synthesized compound was confirmed through elemental analysis, ¹³C-NMR, ¹H-NMR, and ESI-MS spectrometry. Furthermore, we computed this novel compound’s conformational energy profile (CEP), evaluating how its energy varies with changes in the dihedral bond angle. Full article

This study presents a theoretical investigation of the electronic properties of mono- and pentasubstituted cyclopentadiene analogs and variously substituted conjugated nitroalkenes bearing electron-donating and electron-withdrawing groups. Conceptual Density Functional Theory (CDFT) and Electron Localization Function (ELF) analyses were employed to characterize the global and local reactivity indices of the reactants. The obtained data provided insights into the nucleophilic and electrophilic nature of the investigated systems, allowing for the prediction of their reactivity patterns in Diels–Alder reactions. A reactivity model for conjugated alkenes toward cyclopentadienes was developed based on correlation analysis using Hammett substituent constants. This approach enabled the prediction of reaction polarity in (4+2) cycloaddition processes, providing insight into how the electronic effects of substituents influence the reaction course. These findings contribute to a deeper understanding of structure–reactivity relationships in Diels–Alder processes. Full article

In the present study, methanolic extracts from rapeseed meal, an oil industry by-product, were treated with alkaline hydrolysis, acid hydrolysis, and lyophilization to enhance their antioxidant features. Antioxidant activity (AA) of the prepared rapeseed meal extracts was determined using three modified spectrophotometric methods: 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) methods. The effect of acid-hydrolyzed and lyophilized rapeseed meal extract (HLRME) at 200 ppm on the antioxidant properties of refined rapeseed oil heating at 180 °C for 24 h and French fries fried in it was estimated. Moreover, the total phenolic content (TPC) in rapeseed meal extracts, enriched rapeseed oils before and after the thermo-degradation processes, and fried French fries was analyzed. The addition of HLRME affected the oxidation stability of refined rapeseed oil heated for 8 h daily for 3 days at 180 °C by preventing an increase in the peroxide values (PV), anisidine values (p-AnV), TOTOX and INTOX indexes, conjugated dienes (K₂₃₂), and total polar material (TPM). However, thermal degradation generated similar amounts of conjugated trienes (K₂₆₈) in non-supplemented and supplemented rapeseed oils. Fortified rapeseed oils after each heating cycle and French fries fried in them revealed higher antioxidant properties than those prepared in refined rapeseed oils without HLRME. Results from the present study suggest that HLRME, as a potential source of natural antioxidants from oil industry by-products, can prevent the degradation of refined rapeseed oil and help improve the quality of French fries. Full article