Search Results (656)

Hybrid siloxane/silsesquioxane materials containing sterically demanding aromatic groups synthesized by hydrolysis and condensation suffer from incomplete cross-linking after thermal consolidation, limiting their thermal and mechanical performance. In this study, we systematically investigated a post-cross-linking strategy using various additives to enhance structural integrity and thermal stability. These include dimethyldimethoxysilane (DMDMS), diphenyldimethoxysilane (DPDMS) and phenyltrimethoxysilane (PTMS), as well as the organotin condensation catalyst di-n-butyltin diacetate (DBTA). Notably, we achieved thermal stability up to 453 °C and long-term transparency (up to 99%) at 200 °C with only little yellowing. Dynamic mechanical analysis demonstrated that post-cross-linking of precondensed siloxanes with PTMS, DPDMS, and DBTA enabled the formation of elastic materials exhibiting a rubbery plateau up to 200 °C. This behavior reflects enhanced structural rigidity and elasticity, which are essential for high-temperature applications. Our results show that high-temperature stability in siloxane/silsesquioxane materials is strongly influenced by factors such as the number of phenyl groups, cross-linking density, structural regularity, and degree of condensation. Most notably, the complete incorporation of a sterically demanding naphthyl-functionalized monomer during consolidation proved to be critical. Post-cross-linking significantly enhances all these parameters, which is essential for achieving robust thermal performance. Full article

As an emerging natural source of DPP-IV inhibition strategy, we report for the first time the use of Lithobates catesbeianus skin gelatin (LSG) as a novel source for DPP-IV inhibitory peptides in this study. Through enzymatic hydrolysis with multiple proteases, the papain-treated hydrolysate exhibited superior performance in hydrolysis degree, protein recovery, and DPP-IV inhibition, with 93.47% of peptides under 1 kDa. Subsequent separation and peptidomics analysis identified 13 previously unreported peptides. Molecular docking and in silico screening pinpointed four candidate peptides, i.e., LGPQR, RGFDQ, RGPVGP, and RLDDVT, which were then synthesized and functionally validated. Enzyme kinetic studies revealed that these peptides acted via competitive or mixed-type inhibition mechanisms. Notably, this study uncovered the bio-functional potential of amphibian-derived gelatin and provided a new strategy for natural DPP-IV inhibitor discovery through integrated enzymatic, computational, and biochemical approaches. This work pioneered the use of amphibian skin gelatin in antidiabetic peptide discovery and laid the foundation for its application in functional foods. Full article

The large amounts of chrome-tanned leather waste (CLTW) produced annually can be valorized by applying circular economy principles in various fields due to the valuable substances contained (mainly collagen). The main problem for the direct valorization of these wastes is the presence in their composition of dangerous substances, such as chromium. Thus, before being used as raw material in new processes, chrome-tanned leather waste must be subjected to a preliminary stage of chromium removal. In this article, we propose to identify the optimal working conditions for the extraction of chromium ions from chrome-tanned hides in the presence of oxalic acid with various concentrations, at various temperatures and contact times, so that the degree of collagen hydrolysis is minimal. In this sense, the response surface methodology (RSM) method was used to optimize the working conditions, to maximize the efficiency of chrome extraction from the leather, and to minimize the efficiency of collagen hydrolysis: An undesirable process. To optimize both the extraction yield (%) and the degree of hydrolysis (%), the key operational variables, namely oxalic acid concentration (%), contact time (%), and temperature (°C), were systematically adjusted using the Box–Behnken design within the response surface methodology (RSM). The most favorable extraction conditions were identified at an oxalic acid concentration of approximately 7%, a contact time close to 120 min, and a temperature near 49 °C. Under these optimized parameters, the hydrolysis degree remained very low, around 0.38%, indicating minimal degradation during the process. Full article

Plant-based bioactive compounds have been recognized as promising alternatives to conventional chemical treatments. Selenium (Se), a trace element, can be incorporated into proteins to enhance the bioactivity of plant-derived peptides. Perilla frutescens seeds are high-protein plants that have shown the ability to absorb Se and biosynthesize selenopeptides. This study examined Se biotransformation during the germination of perilla seeds to synthesize selenoprotein, investigating enzymatic hydrolysis using Alcalase and Flavourzyme as single enzymes, as well as their combinations. The results showed that Alcalase hydrolysates produced Se-peptides with the highest degree of hydrolysis and antioxidant activity. Hydrolysates were purified via ultrafiltration and size-exclusion chromatography, and Se-peptides were characterized by LC-MS/MS. Nine peptides containing Se-binding residues such as cysteine, methionine, and glutamic acid confirmed successful Se incorporation. The Se-peptides demonstrated strong antioxidant activity (ABTS: 66.30%, FRAP: 54.93%), ACE inhibition (83.87%), and cytotoxicity against A549 lung cancer cells (85.88% viability). Compared to non-Se-peptides, Se-enriched peptides showed superior bioactivity, highlighting their potential as functional ingredients in food and pharmaceutical applications. Full article

High viscosity of alginate means a relatively low substrate concentration, which limits the efficiency of hydrolysis, resulting in one of the main challenges for the large-scale production of alginate oligosaccharides (AOS). In this study, a pilot-scale degradation product (PSDP) of the recombinant enzyme 102C300C-Vgb was produced for the first time at a substrate concentration of up to 20% sodium alginate. The optimal conditions for SA digestion were: enzyme dosage of 25 U/g, enzymatic temperature of 45 °C, enzymatic pH of 7.0, and enzymatic time of 24 h. Under these conditions, the yield of enzymatic hydrolysis was consistently in the range of 69% to 70%. The average molecular weight (Mw) of PSDP was 1496.36 Da, mainly containing oligosaccharides with degrees of polymerization ranging from 2 to 4. The low-Mw PSDP was subsequently applied in the diet of sea cucumber Stichopus japonicus. The results showed that the body wall weight of S. japonicus increased significantly after 40 days of feeding with a 0.09% PSDP-supplemented diet. Furthermore, PSDP-supplemented diet significantly increased the thickness of the serosal and submucosal layers and the width folds of mucosa of the sea cucumber gut. The abundance of pathogenic bacteria was reduced effectively, and that of beneficial bacteria increased significantly after being fed with PSDP. The results demonstrated that PSDP can serve as a digestive health enhancer for sea cucumbers, promoting their healthy growth. Full article

Sesame oil extraction byproduct (SOEB) contains a high percentage of protein (49.81 g/100 g), making it a suitable plant-based source for producing protein hydrolysates with nutraceutical potential. In this study, albumins, globulins, glutelins, and prolamins fractions were extracted and characterized from SOEB. These fractions were then enzymatically hydrolyzed with alcalase, yielding high soluble protein content (>90%) and hydrolysis degrees ranging from 34.66 to 45.10%. The hydrolysates were fractionated by molecular weight (<5 kDa, 3–5 kDa, 1–3 kDa, and <1 kDa). These fractions demonstrated potential for inhibiting the DPPH radical (25.19–95.79%) and the α-glucosidase enzyme (40.14–55.63%), particularly the fractions with molecular weight <1 kDa. We identified 28 peptides, with molecular weights between 332.20 and 1096.63 Da, which showed potent antioxidant activities (IC₅₀ = 90.18 µg/mL), as well as inhibitory effects on key enzymes such as α-glucosidase (IC₅₀ = 61.48 µg/mL), dipeptidyl peptidase IV (IC₅₀ = 12.12 µg/mL), and pancreatic lipase (IC₅₀ = 6.14 mg/mL). These results demonstrate the antioxidant, antihyperglycemic, antidiabetic, and anti-obesity potential of SOEB peptides, highlighting their use in the formulation of new functional foods or nutraceuticals. Full article

Distention of the urinary bladder wall during filling stretches the urothelium and induces the release of chemical mediators, including adenosine 5′-triphosphate (ATP) and prostaglandins (PGs), that transmit signals between cells within the bladder wall. The urothelium also releases soluble nucleotidases (s-NTDs) that control the availability of ATP and its metabolites at receptor sites in umbrella cells and cells deeper in the bladder wall, as well as in the urine. This study investigated whether PGs regulate the intravesical breakdown of ATP by s-NTDs. Using a murine decentralized mucosa-only bladder model and an HPLC technology with fluorescence detection, we evaluated the decrease in ATP and increase in ADP, AMP, and adenosine (ADO) in intraluminal solutions (ILS) collected at the end of physiological bladder filling. PGD₂, PGE₂, and PGI₂, but not PGF_2α, inhibited the conversion of AMP (produced from ATP) to ADO, likely due to a suppressed intravesical release of s-AMPases. The effects of exogenous PGD₂, PGE₂, and PGI₂ were mediated by DP1/DP2, EP2, and IP prostanoid receptors, respectively. Activation of either DP1 or DP2 receptors by endogenous PGD₂ also led to AMP increase and ADO decrease in ILS-containing ATP substrate. Finally, PGs produced by either COX-1 or COX-2 inhibited the hydrolysis of AMP to ADO. Together, these observations suggest that (1) endogenous PGs (chiefly PGD₂, and to lesser degree PGE₂ and PGI₂) allow release of s-NTDs like s-ATPases and s-ADPases but impede the formation of ADO from intravesical ATP by inhibiting the release of s-NTDs/s-AMPases; (2) it is possible that high concentrations of PGD₂, PGE₂ and PGI₂, as anticipated in inflammation or bladder pain syndrome, delay the ADO production and prolong the action of excitatory purine mediators; and (3) either COX-1 and COX-2 are constitutively expressed in the mouse bladder mucosa or COX-2 is induced by distention of the urothelium during bladder filling. Full article

This study investigated the feasibility of using both the solid and the liquid fractions of waste from the anaerobic digestion process—the digestate—as a possible liquid growth medium for fungal production of chitosan. An enriched liquid phase (ELP), combining both fractions, and derived from mild acid hydrolysis treatment at 120 °C with 6% H₂SO₄ (w/v) for 70 min, was screened for its ability to support biomass and chitosan production by 17 fungal strains. The best results were obtained with Absidia blakesleeana NRRL 2696 and Rhizopus oryzae NRRL 1510 cultures, which yielded chitosan volumetric productions of 444 and 324 mg L⁻¹, respectively. The chitosan preparations of the former and the latter strain, characterized by infrared spectroscopy, elemental analysis, viscosimetry and thermogravimetric analysis, showed deacetylation degrees of 79% and 84.2%, respectively, and average viscosimetric molecular weights of around 20 and 5.4 kDa, respectively. Moreover, both fungal chitosan samples exerted significant antibacterial activity towards Gram-negative (i.e., Pseudomonas syringae and Escherichia coli) and Gram-positive (i.e., Bacillus subtilis) species. Full article

Alzheimer’s disease is the most widespread neurodegenerative disease in the world. Galantamine hydrobromide (GH) is one of the drugs used to treat mild to moderate dementia of the Alzheimer type. Due to the fact that the specificity of the disease requires maximally facilitated intake, orodispersible films present such an opportunity. In the present study orodispersible films based on poly(2-ethyl-2-oxazoline) as well as partially hydrolyzed poly(2-ethyl-2-oxazoline) were prepared and studied as delivery systems for GH. Two samples of partially hydrolyzed PEtOx were synthesized—one of relatively low degree of hydrolysis and another one of relatively high degree of hydrolysis, and studied by Nuclear Magnetic Resonance (NMR). Cytotoxicity assay was performed that validated the low hydrolyzed derivative as biocompatible polymer that maintained desirable physicochemical characteristics without compromising the safety, thereby it was selected for further research. The films were prepared by the solution casting method and characterized by different methods. FTIR was used to determine the potential interactions between the galantamine molecule and the film components. Based on the Thermogravimetric Analysis (TGA) conducted, it was concluded that all films were sufficiently thermally stable, as the component decomposition stage (after initial solvent removal) began above 180 °C. The polymer films were further characterized with the determination of Shore hardness and the results showed that the films containing glycerol as a plasticizer exhibited higher hardness compared to those with PEG as a plasticizer. The disintegration time of the films was determined visually using Petri dishes and it was found that the films disintegrated within the range of 0.52 to 1.58 min, fully meeting the pharmacopoeial requirements. GH release profiles in PBS at 37 °C were obtained, and it was found that by the second minute, 80–90% of the drug were released from the different films, and the release followed an anomalous diffusion mechanism (Case II). Full article

Starch particles (SPs) were extracted from underutilized wild yam (Dioscorea remotiflora) tubers using two methods: (1) acid hydrolysis (AH) alone and (2) acid hydrolysis assisted by ultrasound (AH-US). The SPs were chemically modified through esterification (using acetic anhydride [AA] and lauroyl chloride [LC]) and crosslinking (with citric acid [CA] and sodium hexametaphosphate [SHMP]). They were subsequently characterized by their yield, amylose content, and structural and physical properties. The yield of particles was 17.5–19.7%, and the residual amylose content was 2.8–3.2%. Particle sizes ranged from 0.46 to 0.55 µm, which exhibited mono-modal and bi-modal distributions for AH and AH-US treatments, respectively. Following chemical modification, yield notably increased, especially with substitution by LC (33.6–36.5%) and CA (32.6–38.7%). Modified SPs exhibited bi-modal particle distributions with micro- and nanoparticles and variable peak intensities depending on the chemical compound used. Unmodified SPs displayed irregular morphologies, showing disruptions (AH) or aggregation (AH-US). Chemical substitutions altered morphologies, leading to amorphous surfaces (CA: AH), clustering (LC), or fragmentation into smaller particles (SHMP) under AH-US treatment. FT-IR analysis indicated a decrease in hydroxyl groups’ peak area (A(-OH)), confirming the substitution of these groups in the starch structure. Crosslinking with CA resulted in the highest degree of substitution (AH: 0.43; AH-US: 0.44) and melting enthalpy (ΔH_f: 343.0 J/g for AH-US), revealing stronger interactions between SPs from both methods. These findings demonstrate that the extraction treatment of D. remotiflora SPs and the type of chemical modifier significantly influence the properties of SPs, underscoring their potential applications as natural biocarriers. Full article

Red deer fat makes up approximately 7–10% of the animal’s weight and is not currently used. Regarding sustainability in the food industry, it is desirable to look for opportunities for its processing and use, not only in the food industry. The aim of this study is the enzymatic modification of red deer fat, leading to modification of its physicochemical properties, and the study of changes in phase transitions of modified fat, its structure, color, and texture. Hydrolysis was performed using sn-1,3-specific lipase at different water concentrations (10–30%) and reaction times (2–6 h). The results showed that there was a significant decrease in melting and crystallization temperatures with an increasing degree of hydrolysis, which was confirmed by differential scanning calorimetry. FTIR spectra revealed a decrease in the intensity of the ester bonds, indicating cleavage of triacylglycerols. Texture analysis of the modified fats confirmed a decrease in hardness of up to 50% and an increase in spreadability. The color parameter values remained within an acceptable range. The results show that enzymatic modification is an effective tool for targeted modification of red deer fat properties, and this expands the possibilities of its application in cosmetic matrices and food applications as functional lipids. Full article

This study identified the optimal enzymatic treatment for improving the foaming characteristics of oat globulin, and alkaline protease was found to be the most effective enzyme. The impact of alkaline protease on the foaming properties and structural changes in oat globulin was explored. The results show that the foaming capacity of oat globulin hydrolysates is negatively correlated with surface hydrophobicity and positively correlated with the degree of hydrolysis. The results of circular dichroism (CD) and size-exclusion chromatography (SEC) indicate that hydrolysis generated smaller, disordered peptides. Under equilibrium conditions at a 2% concentration, a reduction of 1.62 mN/m in surface tension and an increase of 3.82 μm in foam film thickness were observed. These peptides reduce surface tension between air and water, forming larger, thicker, and more stable foams. Compared to untreated oat globulin, the foaming capacity of hydrolyzed ones increased by 87.17%. Under comparable conditions, these findings demonstrate that limited hydrolyzed oat globulin exhibits potential as an effective plant-based foaming agent up to a degree of hydrolysis of 15.06%. Full article

Traditional hydrogel preparation methods typically require multiple steps and certain external stimuli. In this study, rapid and stable gelation of polyvinyl alcohol (PVA)-tannic acid (TA)-based hydrogels was achieved through the regulation of hydrogen bonds. The cross-linking between PVA and TA is triggered by the evaporation of ethanol. Rheological testing and analysis of the liquid-solid transformation process of the hydrogel were performed. The gelation onset time (GOT) could be tuned from 10 s to over 100 s by adjusting the ethanol content and temperature. The addition of polyhydroxyl components (e.g., glycerol) significantly enhances the hydrogel’s water retention capacity (by 858%) and tensile strain rate (by 723%), while concurrently increasing the gelation time. Further studies have shown that the addition of alkaline substances (such as sodium hydroxide) promotes the entanglement of PVA molecular chains, increasing the tensile strength by 23% and the fracture strain by 41.8%. The experimental results indicate that the optimized PVA-TA hydrogels exhibit a high tensile strength (>2 MPa) and excellent tensile properties (~600%). Moreover, the addition of an excess of weakly alkaline substances (such as sodium acetate) reduces the degree of hydrolysis of PVA, enabling the system to form a hydrogel with extrudable characteristics before the ethanol has completely evaporated. This property allows for patterned printing and thus demonstrates the potential of the hydrogel in 3D printing. Overall, this study provides new insights for the application of PVA-TA based hydrogels in the fields of rapid prototyping and strength optimization. Full article

Amaranth is a nutritional and naturally gluten-free pseudocereal with several food applications. The germination and pepsin/pancreatin hydrolysis in amaranth releases antioxidant and anti-inflammatory compounds but the hydrolysis times (270 or 360 min) are too long to scale up in the development of amaranth functional ingredients. The aim of this study was to estimate the influence of the germination and pepsin/pancreatin hydrolysis reduction time on the techno-functional properties and nutraceutical potential of amaranth flours and hydrolysates. The germination process increased 12.5% soluble protein (SP), 23.7% total phenolics (TPC), 259% water solubility, and 26% oil absorption in germinated amaranth flours (GAFs) compared to ungerminated amaranth flours (UAFs). The ungerminated (UAFH) and germinated (GAFH) amaranth hydrolysates showed values of degree of hydrolysis up to 50% with 150 min of sequential (pepsin + pancreatin) hydrolysis. The enzymatic hydrolysis released 1.5-fold SP and 14-fold TPC in both amaranth flours. The water solubility was higher in both hydrolysates than in their unhydrolyzed flour counterparts. The reduction in hydrolysis time did not significantly affect the nutraceutical potential of GAFH, enhancing its potential for further investigations. Finally, combining germination and enzymatic hydrolysis in amaranth enhances nutraceutical and techno-functional properties, increasing the seed. Consequently, GAF or GAFH could be used to elaborate on functional or gluten-free food products. Full article

Electrohydrodynamic atomization (EHDA) has significant advantages for microencapsulating compounds in various structures using biopolymers, where more research using pure starch is required. Concerning this, jicama starch and its hydrolysates have not yet been tested, despite their unique characteristics, which come from an alternative low-value-added crop source. Rapid acid hydrolysis of jicama starch with H₂SO₄ resulted in dextrins with a degree of hydrolysis (DE) from 0.4 to 19% within 1–12 h, and syrup solids at 24 h (DE = 42%). This process modifies the water retention capacity of jicama starch, gel viscosity, surface tension, and electrical conductivity. Hydrolyzed starch particles obtained by electrospraying (10 kV, L = 10 cm, Q = 2 mL/h) showed Feret diameters and roundness significantly influenced (p ≤ 0.05) by the degree of hydrolysis rather than the concentration of solids. It was found that hydrolyzed jicama starch with a DE < 6.3% can be used as the sole wall material to form particles by electrospraying, as they facilitate the formation of stable and rounded like-microspheres particles; this was not feasible above this threshold. The results suggest that the jicama starch’s ability to be used as a wall material in the electrospray synthesis of particles or microspheres appears to be determined by the degree of hydrolysis. Full article