Search Results (150)

Background: During food processing and storage, traditional protein-based delivery systems encounter significant challenges in maintaining the structural and functional integrity of bioactive compounds, primarily due to their temporal instability. Methods: In this study, a nanocomposite hydrogel was prepared through the co-assembly of a self-assembling peptide, 9-Fluorenylmethoxycarbonyl-phenylalanine-arginine-glycine-aspartic acid-phenylalanine (Fmoc-FRGDF), and hyaluronic acid (HA). The stability of this hydrogel as a quercetin (Que) delivery carrier was systematically investigated. Furthermore, the impact of Que co-assembly on the microstructural evolution and physicochemical properties of the hydrogel was characterized. Concurrently, the encapsulation efficiency (EE%) and controlled release kinetics of Que were quantitatively evaluated. Results: The findings indicated that HA significantly reduced the storage modulus (G′) from 256.5 Pa for Fmoc-FRGDF to 21.1 Pa with the addition of 0.1 mg/mL HA. Despite this reduction, HA effectively slowed degradation rates; specifically, residue rates of 5.5% were observed for Fmoc-FRGDF alone compared to 14.1% with 0.5 mg/mL HA present. Notably, Que enhanced G′ within the ternary complex, increasing it from 256.5 Pa in Fmoc-FRGDF to an impressive 7527.0 Pa in the Que/HA/Fmoc-FRGDF hydrogel containing 0.1 mg/mL HA. The interactions among Que, HA, and Fmoc-FRGDF involved hydrogen bonding, electrostatic forces, and hydrophobic interactions; furthermore, the co-assembly process strengthened the β-sheet structure while significantly promoting supramolecular ordering. Interestingly, the release profile of Que adhered to the Korsmeyer–Peppas pharmacokinetic equations. Conclusions: Overall, this study examines the impact of polyphenol on the rheological properties, microstructural features, secondary structure conformation, and supramolecular ordering within peptide–polysaccharide–polyphenol ternary complexes, and the Fmoc-FRGDF/HA hydrogel system demonstrates a superior performance as a delivery vehicle for maintaining quercetin’s bioactivity, thereby establishing a multifunctional platform for bioactive agent encapsulation and controlled release. Full article

Minced lamb remains one of the most produced meat products in the meat industry, across both the food service and retail sectors. Tea polyphenols (TPs), renowned for their diverse biological activities, are increasingly being employed as natural food additives in research and development. Tea polyphenols at concentrations of 0.00% (CG), 0.01% (TP1), 0.10% (TP2), and 0.30% (TP3) were added to lamb which had undergone a series of freeze–thaw cycles. The presence of tea polyphenols led to a significant decrease in the number of disulfide bonds, resulting in a slower oxidation rate. In addition, the surface hydrophobicity and juice loss of the minced lamb supplemented with tea polyphenols were 91.23 ± 0.22 and 20.00 ± 0.46, respectively, representing a reduction of 1.5% and 7.59% compared to the group without the addition of tea polyphenols. However, the addition of high-dose tea polyphenols also led to a reduction in emulsification stability, alterations in protein conformation, and changes in water migration. Furthermore, the incorporation of a minimal quantity of tea polyphenols (0.01%) resulted in enhanced emulsification stability, water retention, textural properties, and microstructures in minced lamb. This suggests that tea polyphenols have the potential to improve the quality of minced lamb following freezing and thawing processes. Full article

Enterovirus A71 (EV-A71), a major etiological agent of hand-foot-mouth disease, can cause severe neurological complications. However, the mechanisms underlying EV-A71-induced cell damage and potential therapeutic strategies remain inadequately understood. Here, we investigated EV-A71 replication dynamics and associated cytopathic effects in nine distinct cell lines, including epithelial, neuronal, immune, and other cell types. Cell viability, membrane integrity, and energy metabolism were assessed using Cell Counting Kit-8 (CCK-8), lactate dehydrogenase (LDH), and adenosine triphosphate (ATP) assays. The antiviral activity of rosmarinic acid (RA), a natural polyphenol, was evaluated by plaque reduction, qPCR, and Western blot. EV-A71 exhibited cell-type-specific replication and cytotoxicity patterns. RA significantly preserved cell viability, reduced LDH release, maintained ATP levels, and suppressed IL-6 expression. Mechanistically, RA inhibited viral replication by downregulating VP1 expression and viral RNA levels. Molecular docking indicated strong binding of RA to the hydrophobic pocket of VP1, potentially disrupting virus-host interactions. Collectively, these findings highlight RA’s combined antiviral and cytoprotective potential, supporting its candidacy as a therapeutic agent against EV-A71 infection. Full article

Morin is a natural flavonoid with potent antioxidant activity, yet its clinical and nutraceutical applications remain limited due to poor aqueous solubility and low bioavailability. This study explores the interaction of morin with bovine serum albumin (BSA) and the development of BSA-based nanoparticles as a delivery platform. Fluorescence spectroscopy confirmed the formation of a stable 1:1 morin–BSA complex, governed by hydrophobic interactions, with a binding constant (Ka) of 1.87 × 10⁵ L·mol⁻¹. Binding conferred enhanced photostability, as BSA attenuated morin degradation under oxidative stress conditions. BSA nanoparticles prepared by desolvation encapsulated morin with high monodispersity and encapsulation efficiencies up to 26%. Co-encapsulation with ellagic acid or tocopherol succinate improved loading capacity but reduced morin release, suggesting intermolecular stabilization. Release studies in simulated intestinal fluid showed controlled diffusion, while compatibility assays in milk-based food matrices confirmed colloidal stability in whole and reduced-fat milk. These findings support BSA–morin nanoparticles as a promising system for the oral delivery and functional food incorporation of polyphenolic antioxidants. Full article

A covalent complex of okra seed protein (OSP) and rutin was prepared using the alkali-induced method and characterized. Its application in nanoemulsions was also evaluated. Multi-spectral analysis confirmed the formation of the covalent complex, with OSP as the main body. With an increasing rutin dosage during the preparation process, the amount of rutin in the complex progressively ascended, and the α-helix structure and surface hydrophobicity of the complex gradually declined. The complex exhibited remarkable ABTS radical scavenging capacity and reducing power, which were proportional to the total phenolic content. The OSP/rutin complex could be utilized for the fabrication of O/W nanoemulsions, which remained stable in terms of droplet size and appearance after 28 days of storage at both 4 °C and 25 °C. Furthermore, lipid oxidation in the nanoemulsion stabilized by the OSP/rutin covalent complex could be effectively inhibited, and the emulsion could enhance the UV irradiation resistance of lutein loaded in the oil phase. Our results can provide a reference for the development of protein–polyphenol covalent complexes. Full article

The mechanistic effects of Zanthoxylum bungeanum on the textural properties of Tibetan pig sausages remain inadequately elucidated. We conducted a dose–response analysis using Z. bungeanum aqueous extraction (ZBAE) containing 36.97 mg GAE/g polyphenols, applied at concentrations from 0.125% to 1.20% in the meat paste. Optimal textural enhancement was achieved at 0.25% ZBAE, as proved by significantly improving water holding capacity (1.77% increase), hardness (139.87% increase), and gel strength (46.04% increase) relative to the control group (p < 0.05). Specifically, this concentration: (i) promoted protein molecular rearrangement of by enhancing hydrophobic interactions (33.33% increase) and hydrogen bonding (287.99% increase); (ii) induced conformational transitions from α-helix (42.62% decrease) to β-sheet formations (21.11% increase); and (iii) generated a homogeneous three-dimensional protein network characterized by a fractal dimension of 2.769 ± 0.006 and a porosity of 38.350 ± 0.333%. The addition of natural polyphenols from Z. bungeanum may optimize the textural quality of processed meat products. Full article

Proteins and polyphenols are important components in barley malt. During the roasting process of barley malt, proteins and polyphenols interact and influence each other, ultimately altering the nutritional profile and functional properties of barley malt. In this research, polyphenol-free proteins and protein–polyphenol complexes were extracted from barley malt subjected to varying degrees of roasting. The antioxidant activity of protein–polyphenol complexes was assessed by ABTS, FRAP, and ORAC assays. The structural characteristics of the proteins were examined through UV, FL, CD, FTIR, and SEM. We found that roasting enhances the solubility of globulin, prolamin, and glutenin and facilitates the binding of these proteins with polyphenols. Conversely, the impact of roasting on albumin exhibits a trend opposite to that observed in the other three proteins. The antioxidant activity of protein–polyphenol complexes was significantly higher than that of polyphenol-free proteins. Additionally, the microenvironment of the amino acid residues of the four proteins exhibited increased polarity following the roasting process, and the structural conformation of albumin, globulin, and glutelin transitioned from an ordered to a disordered state. Our results indicate that roasting enhances the antioxidant activity of protein–polyphenol complexes by altering the secondary and tertiary structures of these proteins, thereby exposing more hydrophobic side-chain groups inside the proteins and offering more binding sites for polyphenols. Full article

ADAMTS-5 (aggrecanase-2) is a major metalloprotease involved in regulating the cartilage extracellular matrix. Due to its role in removing aggrecan in the progression of osteoarthritis (OA), ADAMTS-5 is often regarded as a potential therapeutic target for OA. Punicalagin (PCG), a polyphenolic ellagitannin found in pomegranate (Punica grunatum L.), and ellagic acid (EA), a hydrolytic metabolite of PCG, have been widely investigated as potential disease-modifying osteoarthritis drugs (DMOADs) due to their potent antioxidant and anti-inflammatory properties, but their interaction with ADAMTS-5 has yet to be determined. In this study, molecular docking simulations were used to predict enzyme–inhibitor binding interactions. The results suggest that both compounds may be able to bind within the active site via the formation of H bonds and interactions between the ligand’s aromatic rings and hydrophobic residue in the enzyme with inhibition constants of 183.3 µM and 1.13 µM for PCG and EA, respectively. Biochemical activity against recombinant human ADAMTS-5 was assessed using a dimethylmethylene blue-based assay to determine residual sulfated glycosaminoglycan (sGAG) in porcine articular cartilage. Although its loss could not be attributed to ADAMTS-5, sGAG was effectively persevered by PCG and EA. The potential conversion of PCG to EA by enzyme-catalyzed hydrolysis activity was then investigated using liquid chromatography–mass spectroscopy to determine the potential for the use of PCG and EA as a prodrug–proactive metabolite pair in the development of drug delivery systems to arthritic synovial joints. Full article

A new water-soluble not-colored antioxidant (Z)-N′-(4-(3,4-dihydroxyphenyl)-3-ethylthiazol-2(3H)-ylidene)-4-hydroxybenzohydrazide hydrochloride (DHTH) was obtained and characterized. The interaction between DHTH and β-CD was studied by experimental thermodynamic methods such as isothermal titration calorimetry (ITC) and ¹H NMR spectroscopy and confirmed by in silico calculations. Thermodynamic data indicated that the inclusion process is driven by enthalpy, predominantly as a result of the guest–host hydrophobic interactions. ¹H NMR measurements were applied to study the interaction with β-CD by changing the studied compound concentration in the solution. UV-vis titration and in vitro antiradical assay were performed, to study the antioxidant activity of DHTH, free and included in β-CD. A molecular docking study added supplementary insight to the experimental analyses regarding the binding conformation of the new polyphenolic compound to β-CD. Full article

While protein-stabilized emulsions have demonstrated potential for various applications in food, their poor lipid oxidation remains a major challenge. The relationship between the architecture of polyphenolic compounds and their capacity to suppress lipid oxidation has not received extensive scrutiny. In this research, pea protein isolate (PPI)–polyphenol complexes were synthesized to examine their capability of maintaining emulsion stability and suppressing lipid oxidation. The collective evidence from fluorescence spectroscopy and molecular dynamics simulations pointed towards non-covalent and self-initiated interactions between the polyphenols and PPI. The presence of additional hydroxyl groups on the polyphenols could significantly boost the extent of these interactions. Specific clusters in PPI and polyphenols which might have formed hydrogen bonds and hydrophobic interactions. Polyphenols also reduced the interfacial tension and increased the surface hydrophobicity of the complex, thus driving more proteins to adsorb at the oil–water interface. The PPI-rosmarinic acid (RA)-stabilized emulsion had a smaller droplet size and higher electrostatic repulsion, enabling it to resist droplet aggregation. This emulsion stood out as having the most robust stability amongst all PPI-polyphenol emulsions and proved highly efficient in preventing lipid oxidation. This study bolsters the viability of employing polyphenol and pea protein-stabilized emulsions in developing new food products. Full article

Hydroxytyrosol is a natural phenolic compound found in olives. Phenylacetaldehyde reductase (PAR) is a key enzyme in the final step of the hydroxytyrosol biosynthesis pathway in olives. However, genome-wide studies on the PAR gene family in olives have not been reported. In this study, 21 genes were identified through a genome-wide analysis. Phylogenetic analysis classified these genes into three subgroups: PAR, CCR (Cinnamoyl-CoA reductase), and DFR (Dihydroflavonol 4-reductase). Expression pattern analysis suggested that genes within these subfamilies may play crucial roles in the biosynthesis of polyphenols, lignin, and anthocyanins, respectively. Three-dimensional structural modeling and molecular docking of the OePAR1 revealed that hydrogen bonds, hydrophobic interactions, and π–π stacking interactions collectively influence the affinity between PAR and its substrates. Residues at the active site form hydrogen bonds, with variations contributing to substrate specificity. The substrate with the strongest affinity for OePAR1 was identified as 3,4-dihydroxyphenylacetaldehyde (3, 4-DHPAA), with a binding energy of −4.98 kcal/mol, in agreement with previous enzymatic activity validation. Subcellular localization studies revealed that OePAR1 is localized to the chloroplast. This study provides essential insights into the biological functions of OePARs in olives and lays the groundwork for enhancing olive oil quality through genetic engineering. Full article

Amyloid fibril hydrogels prepared via protein acid heating currently exhibit inadequate gel properties and biological activity. These limitations can be addressed by modifying the amyloid fibrils with polyphenols. In this study, two types of polyphenols—tannic acid (TA) and gallic acid (GA)—were selected to prepare hydrogels with soy protein fibrils (SPIFs) at varying proportions to investigate structure, gel properties, and biological activity. TEM results revealed that polyphenols are deposited on the surface of SPIFs by hydrogen bonding and hydrophobic interaction to form hybrid supramolecules. The greater the mass ratio of polyphenols to SPIF, the more pronounced the structural changes. When the mass ratios of TA, GA, and SPIF were 1:20 and 1:2, respectively, the β-sheet content reached the maximum. The gel strength increased by 6 times and 5 times, respectively, with the modulus reaching 334.91 Pa and 317.79 Pa, respectively. The hydrogels exhibited optimal apparent viscosity and structural recovery properties. Bacteriostatic and cytotoxicity tests demonstrated that the hydrogels exhibited excellent antibacterial properties while maintaining safety. In summary, TA demonstrates significant advantages in remodeling SPIF at low concentrations, thereby enhancing the gel characteristics and antibacterial properties of the hydrogel. Full article

Fermented walnut (FW) meal exhibits antifungal activity against Penicillium victoriae (the fungus responsible for prickly pear spoilage), which is mainly attributed to the synergistic effect of antimicrobial peptides and salicylic acid (SA). This study aimed to investigate the synergistic mechanism between YVVPW (YW-5, the peptide with the highest antifungal activity) and SA against the cell membrane of P. victoriae. Treatment enhanced prickly pear’s rot rate, polyphenol concentration, and superoxide dismutase (SOD) activity by 38.11%, 8.11%, and 48.53%, respectively, while reducing the microbial count by 19.17%. Structural analyses revealed β-sheets as YW-5′s predominant structure (41.18%), which increased to 49.0% during SA interaction. Molecular docking demonstrated YW-5′s stronger binding to β-(1,3)-glucan synthase and membrane protein amino acids via hydrogen bonds, hydrophobic forces, and π-π conjugate interactions. Spectroscopic analyses demonstrated SA’s major role in YW-5 synergy at the interface and polar head region of phospholipids, enhancing lipid chain disorder and the leakage of cell components. Malondialdehyde and SOD levels increased nearly two-fold and six-fold when treated with YW-5/SA, and YW-5 showed a more pronounced effect. Scanning electron and transmission electron microscopy confirmed that SA caused greater damage to spore morphology and cell ultrastructure. These findings support this formulation’s functions as an efficient antifungal substance in fruit storage. Full article

Pollen is a cornerstone of life for plants. Its durability, adaptability, and complex design are the key factors to successful plant reproduction, genetic diversity, and the maintenance of ecosystems. A detailed study of its chemical composition is important to understand the mechanism of pollen–pollinator interactions, pollination processes, and allergic reactions. In this study, a multimodal approach involving Fourier transform infrared spectrometry (FTIR), direct mass spectrometry with an atmospheric solids analysis probe (ASAP), matrix-assisted laser desorption/ionization (MALDI) and ultra-high-performance liquid chromatography–mass spectrometry (UHPLC-MS) was applied for metabolite profiling. ATR-FTIR provided an initial overview of the present metabolite classes. Phenylpropanoid, lipidic, and carbohydrate structures were revealed. The hydrophobic outer layer of pollen was characterized in detail by ASAP-MS profiling, and esters, phytosterols, and terpenoids were observed. Diacyl- and triacylglycerols and carbohydrate structures were identified in MALDI-MS spectra. The MALDI-MS imaging of lipids proved to be helpful during the microscopic characterization of pollen species in their mixture. Polyphenol profiling and the quantification of important secondary metabolites were performed by UHPLC-MS in context with pollen coloration and their antioxidant and antimicrobial properties. The obtained results revealed significant chemical differences among Magnoliophyta and Pinophyta pollen. Additionally, some variations within Magnoliophyta species were observed. The obtained metabolomics data were utilized for pollen differentiation at the taxonomic scale and provided valuable information in relation to pollen interactions during reproduction and its related applications. Full article

Conventional hair-straightening methods that use chemical treatments to break disulfide bonds cause severe damage to the hair shaft, leading to weakened hair that is prone to reverting to its curly form in high humidity. Therefore, a unique haircare coating technology is required to protect hair integrity and provide a long-lasting straightening effect. Herein, we designed a hair-straightening technology by integrating a nature-inspired polyphenol–inorganic sulfate (PIS) redox agent into formulated shampoo, which achieves a desirable straightening effect through sulfate-induced disulfide breakage while preserving hair integrity through a polyphenol-reinforced structure. The interaction between polyphenols and residual thiols from the straightening process maintained a long-lasting straight hair structure and hair strength. Ellman’s assay showed a lower free thiol content from reductant-induced damaged keratin in PIS shampoo-treated hair than in sulfate-treated hair as the polyphenol–thiol bond was formed through the Michael addition reaction, thereby restoring the natural structure of the hair and enhancing its mechanical properties. Owing to the polyphenol coating, PIS shampoo-treated hair exhibited an antistatic effect and high hydrophobicity, indicating healthy hair. Furthermore, the polyphenol coating effectively scavenged radical oxygen species (ROS) in the hair, thereby improving damage protection. Thus, PIS shampoo offers an alternative approach for effective hair straightening. Full article