Search Results (2,472)

Wine lees, a byproduct of winemaking, represent an underutilized source of β-glucans with potential functional applications in food. This study aimed to extract β-glucans using two methods—acid–alkaline treatment and autolysis assisted by ultrasound—and evaluate their effects when incorporated into low-fat stirred yogurt. The extracted β-glucans were added at a concentration of 0.3% (w/w), and rheological measurements were conducted over 20 days of storage. All yogurt samples showed shear-thinning behavior, with apparent viscosity decreasing from 10⁵ mPa·s at low shear rates (0.1 s⁻¹) to 10³ mPa·s at 100 s⁻¹. Yogurt with β-glucans from autolysis retained higher viscosity and viscoelastic moduli (G′ and G″), indicating better structural integrity. Time-dependent tests showed up to 45% decrease in shear stress over 10 min of continuous shearing in the sample with chemically extracted β-glucans, compared to only 28% for autolysis-derived ones. Oscillatory tests confirmed that all samples behaved as weak gels (G′ > G″). These findings suggest that β-glucans obtained via autolysis can improve the textural stability of yogurt, offering potential for functional dairy development and valorization of wine industry byproducts. Full article

Plant oils are increasingly explored as sustainable functional ingredients in topical emulsions due to their emollient properties and reported photoprotective potential. This study aimed to formulate physically stable W/O emulsions containing selected plant oils (olive, avocado, sesame, flaxseed, and grape seed oils) at two concentrations (15% and 30%) and to evaluate their physicochemical, rheological, occlusive, and UV-protective properties. All formulations were confirmed as W/O systems with skin-compatible pH values and demonstrated shear-thinning, non-Newtonian flow with varying degrees of thixotropy. Increasing oil content from 15% to 30% reduced shear stress, consistency index, and viscoelastic moduli, indicating a softer internal structure. Moreover, the viscosities of the emulsions were not solely determined by the viscosities of the individual oils, suggesting significant interactions with the emulsifier system. High occlusion factors were demonstrated for all emulsions, with the highest values observed for 30% olive- and grape seed oil–based formulations. Spectrophotometric SPF assessment revealed measurable UV-protective activity only for emulsions containing 30% olive, avocado, or flaxseed oil (SPF > 1). All formulations exhibited satisfactory physical stability under mechanical and thermal stress. These findings demonstrate that plant oils can modulate the structure and performance of W/O emulsions and may serve as valuable supportive ingredients in the development of photoprotective cosmetic products. Full article

This study focuses on the development and physicochemical evaluation of an alternative liquid carrier for coal dust combustion modifiers containing solid catalyst particles. A commercially used acrylic-polymer-based carrier, whose viscosity is regulated by sodium hydroxide addition, was investigated and compared with a proposed safer substitute based on an aqueous sodium carboxymethyl cellulose (Na-CMC) solution. Rheological properties were measured in the shear-rate range relevant to industrial transport and injection systems, while sedimentation behavior was assessed using image-based analysis. The results show that the Na-CMC carrier exhibits shear-thinning behavior and viscosity levels comparable to the commercial formulation, enabling stable suspension of catalyst particles without the need for alkali additives. Unlike the reference system, the alternative carrier does not generate gas during storage, eliminating potential safety hazards associated with hydrogen evolution. Although no direct combustion experiments were performed, the obtained rheological and stability characteristics indicate that the proposed Na-CMC-based carrier is suitable for short-term storage and injection of catalyst-containing modifiers in coal dust combustion systems. Direct validation of combustion performance is planned in future work. Full article

The emulsification of a molten fusible metal alloy in a liquid epoxy matrix with its subsequent curing is a novel way to create a highly concentrated phase-change material. However, numerous challenges have arisen. The high interfacial tension between the molten metal and epoxy resin and the difference in their viscosities hinder the stretching and breaking of metal droplets during stirring. Further, the high density of metal droplets and lack of suitable surfactants lead to their rapid coalescence and sedimentation in the non-cross-linked resin. Finally, the high differences in the thermal expansion coefficients of the metal alloy and cross-linked epoxy polymer may cause cracking of the resulting phase-change material. This work overcomes the above problems by using nanosilica-induced physical gelation to thicken the epoxy medium containing Wood’s metal, stabilize their interfacial boundary, and immobilize the molten metal droplets through the creation of a gel-like network with a yield stress. In turn, the yield stress and the subsequent low-temperature curing with diethylenetriamine prevent delamination and cracking, while the transformation of the epoxy resin as a physical gel into a cross-linked polymer gel ensures form stability. The stabilization mechanism is shown to combine Pickering-like interfacial anchoring of hydrophilic silica at the metal/epoxy boundary with bulk gelation of the epoxy phase, enabling high metal loadings. As a result, epoxy shape-stable phase-change materials containing up to 80 wt% of Wood’s metal were produced. Wood’s metal forms fine dispersed droplets in epoxy medium with an average size of 2–5 µm, which can store thermal energy with an efficiency of up to 120.8 J/cm³. Wood’s metal plasticizes the epoxy matrix and decreases its glass transition temperature because of interactions with the epoxy resin and its hardener. However, the reinforcing effect of the metal particles compensates for this adverse effect, increasing Young’s modulus of the cured phase-change system up to 825 MPa. These form-stable, high-energy-density composites are promising for thermal energy storage in building envelopes, radiation-protective shielding, or industrial heat management systems where leakage-free operation and mechanical integrity are critical. Full article

The aim of this research was to examine the possibility of achieving optimum texture and rheological properties of cocoa spreads produced with cocoa shell, xylitol, and stevia as sugar replacers using different vegetable fats (palm and coconut oil). Samples with different proportions of cocoa shell and sweeteners used to completely replace sugar were produced under laboratory conditions, and rheology, texture, colloidal stability, and particle size were determined. The results showed that texture properties (spreadability and firmness) and yield stress directly correlated with the type of fat used in the recipe, with the best values obtained for coconut fat. Cocoa shell addition increases Casson plastic viscosity (from approximately 2 to 7 Pas) but may reduce Casson yield stress if added in a proportion up to 25% (from approximately 26 to 18 Pa for samples produced with a combination of palm and coconut oil). Overall, samples with coconut fat had better texture properties regardless of the cocoa shell and sweetener quantities, and the sample with the lowest content of cocoa shell had the best spreadability. By careful adjustment of ingredients and the right choice of substitute fat, sustainable, nutritionally improved cocoa spreads with satisfactory texture and rheology may be produced. Full article

Thermoplastic starch (TPS) nanocomposites with unprecedentedly high loadings of up to 15 wt.% of the nano-clays Laponite (LAP; a synthetic product capable of good dispersion in suitable media) or Montmorillonite (MMT; modified with dialkyldimethylammonium chloride) were prepared by means of our new, two-step TPS preparation protocol. In both the TPS/LAP and TPS/MMT composites, we achieved perfect dispersion and extensive exfoliation of the nano-clays, resulting in pronounced improvements in mechanical performance (modulus increased up to one order of magnitude) and in excellent gas-barrier properties (extremely small permeabilities for O₂, CO₂, and even H₂). MMT, owing to its larger platelet size and to the formation of partially exfoliated multi-layer structures, generated a percolating filler network that provided particularly strong reinforcement, especially at 15 wt.% loading. LAP, though more completely exfoliated, generated a somewhat smaller mechanical reinforcement, but it more strongly increased processing viscosity due to its high specific surface area, which generated highly stable physical crosslinking that persisted even at processing temperatures of T ≥ 120 °C. Efficient matrix–filler interactions were confirmed by thermogravimetric analysis, where the better-exfoliated LAP generated a higher stabilization. The combination of strong mechanical reinforcement with outstanding gas-barrier properties makes the TPS/MMT and TPS/LAP nanocomposites attractive for food-packaging applications, where their natural origin, non-toxicity, bio-degradability, and abundance of nanocomposite components are an additional bonus. Full article

Starch systems and their extrudates can be used as edible films, carriers, and encapsulants for bioactive substances in various industries, primarily the food, medicine, and pharmacy industries. Using appropriate modification methods, it is possible to alter their physicochemical properties to improve specific functional parameters, thereby enhancing their application potential. The aim of this study was to characterize potato starch extrudates enriched with two types of edible oils (rapeseed or sunflower) at concentrations of 3%, 6%, and 9%. Chemical modification was carried out using K₂CO₃ as a catalyst. The structure of native and modified starch extrudates was examined using optical/confocal microscopy, FTIR, and LTNA (low-temperature nitrogen adsorption). Analogous starch dispersions were studied using static and dynamic light scattering, SLS/DLS, nephelometric methods, and electrophoretic mobility measurements to determine surface charge levels and stability. Additionally, viscosity curves were determined as a function of time and temperature. It was found that starch extrudates with 6% sunflower oil content showed optimal functional properties, characterized by greater stability, higher structural order, and better oil complexation. These findings directly translate into significant potential applications, including the development of functional products in the food industry. Full article

Ionic liquids (ILs) have attracted considerable attention for light olefin separation owing to their negligible vapor pressure, excellent thermal stability, and tunable molecular structures. However, their intrinsically high viscosity severely restricts gas diffusion, leading to poor mass-transfer efficiency and limited separation performance in bulk form. Herein, we report the develop a high-performance adsorbent by immobilizing a silver-functionalized ionic liquid within ordered mesoporous MCM-41 to overcome the diffusion limitations of bulk ILs. The IL@MCM-41 composites were prepared via an impregnation–evaporation strategy, and their mesostructural integrity and textural evolution were confirmed by XRD and N₂ sorption analyses. Their C₂H₄/C₂H₆ separation performance was subsequently evaluated. The composite with a 70 wt% IL loading achieves a high C₂H₄ uptake of 25.68 mg/g and a C₂H₄/C₂H₆ selectivity of 15.59 in breakthrough experiments (298 K, 100 kPa). X-ray photoelectron spectroscopy results are consistent with the presence of reversible Ag⁺–π interactions, which governs the selective adsorption of C₂H₄. Additionally, the composite exhibits excellent thermal stability (up to 570 K) and maintains stable separation performance over 10 adsorption–desorption cycles. These IL@MCM-41 composites have significant potential for designing sorbent materials for efficient olefin/paraffin separation applications. Full article

The valorization of shrimp shell waste is crucial for promoting sustainability and a circular economy. This study aimed to extract chitin from the exoskeletal residues of deep-water rose shrimp (Parapenaeus longirostris) sourced from the Marmara Sea and synthesize low-molecular-weight chitosan (LMWC) via conventional, microwave-, and autoclave-assisted deacetylation pathways. The shell biomass was subjected to sequential demineralization (1 M HCl) and deproteinization (1 M NaOH), yielding 14.42% chitin. The extracted chitin was then converted to LMWC using the three methods, and the products were characterized using FT-IR spectroscopy, titration, viscometry, SEM, and TGA. The results demonstrated that the autoclave-assisted method achieved the highest degree of deacetylation (DD) at 95%, significantly outperforming the conventional method (81%) and the microwave-assisted method (67%). The autoclave-synthesized chitosan also exhibited the lowest viscosity (33 cP), confirming its low molecular weight. Morphological analysis showed that chitin exhibited a well-defined fibrous structure. After deacetylation, this structure transformed into a rough and porous surface morphology. Thermal analysis further demonstrated that the laboratory-synthesized chitosan exhibited higher thermal stability than the commercial chitosan sample. In conclusion, the autoclave-assisted method proved to be highly efficient for producing low-molecular-weight chitosan with a high degree of deacetylation. However, the conventional method remains the most practical option for scalable industrial production due to its simplicity and well-established infrastructure. Moreover, the laboratory-synthesized chitosan exhibited higher thermal stability, increased porosity, and a higher degree of deacetylation compared to commercially available chitosan, which may offer functional advantages in applications requiring enhanced reactivity, solubility, or thermal resistance. Overall, the findings provide valuable insights into selecting appropriate deacetylation strategies for producing low-molecular-weight chitosan with tailored properties, thereby bridging the gap between laboratory-scale synthesis and potential industrial applications. Full article

This study examines the influence of virgin polyethylene (vPE), recycled polyethylene (rPE), and Aerosil (A) on the performance of bitumen binders modified with partially devulcanized rubber (DVR). The experimental program included morphology analysis, determination of devulcanization degree, dynamic viscosity measurements, shear stress–shear rate analysis, load–displacement (F–Δl) testing, storage-stability evaluation, ring and ball softening point (R&B), penetration (P), and elastic recovery (ER) testing. The results show that DVR-rPE-modified bitumen binders exhibit 20–35% higher viscosity and up to 25% greater elongation at the break compared to DVR-vPE-modified bitumen systems, indicating more effective interaction with the bitumen matrix. The incorporation of Aerosil increased viscosity ca. 1.5–2 times for DVR-rPE and DVR-vPE-modified systems, respectively. Meanwhile, top and bottom differences in R&B decreased by a factor of 1.6–5 for DVR-rPE and DVR-vPE-containing composites, respectively, demonstrating significant enhancement in structural stability during storage. Mechanical testing further revealed that DVR-rPE + A binders absorbed 10–20% more deformation energy and consistently maintained ER values above 70–80%, corresponding to a higher elastic recovery grade at 25 °C. Overall, the DVR-rPE + A system provided the most balanced improvements in rheological, mechanical, and thermal properties, confirming its potential for use in high-performance, thermally stable, and environmentally sustainable bituminous materials for pavement applications. Full article

This study evaluated the effects of three milling methods, which are dry, semi-dry, and wet milling, on the physicochemical, thermal, and rheological properties of three types of broken rice (indica, japonica, and glutinous rice). The aim was to evaluate how these milling methods affect key flour characteristics, including starch damage, particle size distribution, swelling power, solubility, and gelatinization behavior. Dry milling resulted in the highest degree of starch damage, leading to increased solubility and swelling power, but also a reduction in gelatinization temperature and paste viscosity. Semi-dry milling exhibited moderate starch damage, enhanced thermal stability, and superior functional properties in comparison to dry milling. Wet milling, while minimizing starch damage, produced finer particles but resulted in lower swelling power and solubility. The results also indicated that Japonica rice exhibited the least starch damage, followed by Indica and Glutinous rice. These findings provide important insights into optimizing milling techniques for high-quality rice flour production, particularly for gluten-free food products. Overall, milling method substantially modulates structure and function relations in rice flour, and semi-dry and wet milling preserve starch integrity better than dry milling. These results provide practical guidance for selecting milling strategies to tailor flour functionality for specific rice-based products. Full article

This study aimed to prepare water-based nanofluids using Al₂O₃ nanoparticles with different types of surfactants, and to investigate the colloidal and thermophysical properties of the obtained nanofluids. In this context, water-based Al₂O₃ nanofluids have been prepared using six surfactants with anionic, cationic, and nonionic characteristics SDS, CTAC, PVP, Tween 80, PVA, and Triton X-100. The electrostatic colloidal stability of the prepared samples has been determined by zeta potential and particle size measurements. To understand the interactions at the molecular level and the stabilities in terms of interaction Gibbs free energy, nanoparticle–surfactant interactions have been modeled using the DFT (Density Functional Theory) method. The overall colloidal stability rankings of nanofluids have been performed using both zeta potential measurements and DFT analysis. Furthermore, the thermophysical properties of nanofluids, which are crucial for industrial applications, have been measured. The results showed that the type of surfactant has a significant effect on the colloidal and thermophysical properties of nanofluids. It has been concluded that Al₂O₃-SDS and Al₂O₃-CTAC nanofluids can be used in cooling systems due to their high zeta potential and thermal conductivity, and low viscosity and size. Full article

Whey protein concentrate (WPC-80) was reconstituted to 10% (m/v) and pumped through a pulsed electric field (PEF) system using three treatment conditions. The PEF-treated whey solution was assessed for viscosity, whereas dried whey was resolubilized and tested for protein structure integrity by circular dichroism (CD), fluorescence, and differential scanning calorimetry (DSC), and functionality was assessed by measuring solubility, foamability, emulsification, and particle size. PEF treatment resulted in a reduction in apparent viscosity (from 2.74 cP down to 2.57 cP) and particle size (from 325.9 nm down to 297.6 nm), and increased solubility (from 90.41% up to 92.34%) and emulsification stability (from 1727 min up to 4821 min), while emulsification stability decreased initially (from 1.645 m²/g to 1.283 m²/g) then increased at the high treatment level (1.915 m²/g). The foamability and molecular weight profile did not change with PEF treatment. Exposure to PEF resulted in no statistically significant changes to protein structure based on data obtained from CD, fluorescence, or DSC. This study represents the first instance of a WPC-80 being treated with a commercially available, scalable, continuous flow PEF system at a higher concentration (10% m/v), resulting in favorable changes to the physical and functional properties of the whey solution and dried powder. Full article

Tissue engineering is a multidisciplinary field that aims to address tissue and organ failure by integrating scientific, engineering, and medial expertise. Gelatin is valued in this field for its biocompatibility; however, it faces thermal and mechanical weaknesses that limit its biomedical utility. This work proposes a strategy for improving gelatin properties by fabricating semi-interpenetrating polymer networks via in situ Diels–Alder crosslinking within gelatin colloidal solutions. Ten systems with variable polymer concentrations (2–4%) and crosslinking degrees (2–5%) were prepared and characterized. Rheological analysis revealed that elastic modulus, zero-shear viscosity, and complex viscosity were substantially enhanced, being especially dependent on the crosslinking degree, while critical strain values mostly depended on gelatin concentration. The incorporation of a synthetic Diels–Alder-crosslinked network also improved the thermal stability of gelatin hydrogels, particularly at physiological temperatures. Additionally, these systems exhibit favorable buoyancy, swelling and biodegradation profiles. Collectively, the resultant hydrogels are cytocompatible, solid-like, and mechanically robust, allowing for further tunability of their properties for specific biomedical uses, such as injectable matrices, load-bearing scaffolds for tissue repair, and 3D bioinks. Full article

Protein-based materials such as human serum albumin (HSA) have demonstrated significant potential for the development of novel wound management materials. For the first time, the formation of HSA-based hydrogels was proposed using a combination of thermal- and ethanol-induced approaches. The combination of phosphate-buffered saline (PBS) and limited (up to 20% v/v) ethanol content offers a promising strategy for fabricating human serum albumin-based hydrogels with tunable properties. The hydrogel formation was studied using in situ dynamic light scattering (DLS) for qualitative and semi-quantitative analysis of the patterns of protein hydrogel formation through thermally induced gelation. The rheological properties of human serum albumin-based hydrogels were investigated. Hydrogels synthesized via thermally induced gelation using a denaturing agent exhibit a dynamic viscosity ranging from 100 to 10,000 mPa·s. The biocompatibility, biodegradability, and structural stability of human serum albumin-based hydrogels were comprehensively evaluated in physiologically relevant media. These human serum albumin-based hydrogels represent a promising platform for developing topical therapeutic agents for wound management and tissue engineering applications. This study investigated the kinetics of tetracycline release from human serum albumin-based hydrogels in PBS and fetal bovine serum (FBS). All tested formulations of HSA-based hydrogels loaded with tetracycline (1 mg/mL) demonstrated antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus, and Corynebacterium striatum strains. Full article