Gels最新文献

Food gels were obtained using fish protein isolate recovered from Atlantic cod (Gadus morhua) by-products using the isoelectric solubilisation/precipitation method. The use of low temperatures (not exceeding 10 °C) at the alkaline solubilisation stage resulted in the production of a fish protein isolate with high-molecular mass (FPI-1), while the use of high temperatures (24 °C) resulted in the production of a fish protein isolate with low-molecular mass (FPI-2). The isolates demonstrated excellent gelling and nutritional properties based on their amino acid profiles. The denaturation temperatures of FPI-1 and FPI-2 determined by DSC were 163.0 and 158.5 °C. The secondary structure of FPI-1 demonstrated a high α-helix content and a low random coil content compared to FPI-2. The high-molecular isolate formed stronger gels than the low-molecular isolate, which is explained by the formation of a dense gel network with small pores of about 250 nm. The recovered cod protein isolates can be successfully used as food ingredients or food additives in the production of gel-like/enriched products.

Protein-enriched fruit gels, such as spoonable sauces and cuttable gels, can meet consumers' desire for high protein/fiber value-added health foods. High pressure processing (HPP) is a nonthermal pasteurizing method that has shown additional usage as a novel structuring method for gels by affecting protein-protein interactions. This work studied HPP (575 MPa, 3 min, 5 °C) compared to heat (85-90 °C, 3-10 min) pasteurization as a method to produce novel fruit gels from whole Concord grapes enriched with 4, 6, and 8% (w/w) chickpea and pea protein. Physicochemical and rheological analyses were conducted, as well as sensory evaluation of a model gel. Heat-treated gels produced spoonable high viscosity gels compared to free standing gels produced through HPP. Chickpea protein-enriched samples exhibited a greater change with an increase in heat processing due to non-protein constituents compared to pea protein. Sensory analysis showed a desire for added nutritional value, though flavor was ultimately the deciding factor in preference, with heat-treated gels achieving higher liking scores compared to a HPP counterpart.

Polysaccharide intervention is an effective strategy to regulate properties of emulsions. In this study, xanthan gum (XG), konjac glucomannan (KGM), guar gum (GG), and inulin (IN) were selected to regulate physical and gastrointestinal digestive properties of sodium caseinate (CAS) oil-in-water (O/W) emulsions. The results indicate that IN could not improve CAS emulsion properties, while XG, KGM, and GG significantly reduced droplet size and improved emulsions' stability. With the increase of the polysaccharide concentration, the G' and G″ of the emulsions increased and the emulsions showed an obvious "solid-like" state, which effectively slowed down the "strain-thinning" phenomenon. The microstructure demonstrated that the polysaccharide chains are effectively connected with the surface membrane of droplets, which effectively improves interfacial membrane strength and inhibits droplet aggregation. In vitro digestion simulations proved that polysaccharides effectively modulate emulsion lipid release, providing an excellent lipid environment for curcumin absorption in the gastrointestinal tract. The order of the four polysaccharides in improving CAS emulsions was XG > KGM > GG > IN. This study dissects the differential regulation of physical and gastrointestinal digestive properties of emulsion by polysaccharides, providing theoretical support for functional emulsions for diverse requirements.

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The global increase in the older population presents a nutritional challenge; therefore, the development of food products for this group must take into account the physiological changes associated with aging. This work aimed to evaluate the effects of droplet size, conventional emulsion (CE) and nanoemulsion (NE), and different hydrocolloids, soy protein (SPI), whey protein (WPI), agar (AG), and κ-carrageenan (CAR), on the physical properties, lipid digestibility, and bioaccessibility of emulsion-based gels enriched with vitamin D. The main findings indicated that all gels exhibited non-Newtonian behavior and suitable viscosity and texture for the swallowing needs of older people. The highest release of free fatty acids (~30%) was observed in the NE + WPI sample, independent of droplet size. Instead, SPI gels showed the highest vitamin D bioaccessibility, likely due to their less-structured gel network. Thus, gels containing WPI + AG provide a favorable balance between an easy-to-swallow texture and efficient nutrient release, making them suitable for producing food based on emulsion-filled gels with good physical and nutritional properties. Hence, these results highlight the potential of tailored hydrocolloid combinations to develop nutrient-fortified and texture-appropriate gels that address the nutritional needs of the older population.

Conductive hydrogels are ideal for flexible strain sensors, yet their practical use is often limited by water evaporation, signal hysteresis, and structural instability, which impair linearity, durability, and long-term reliability. To overcome these challenges, we developed a robust multiple-network hydrogel composed of poly(vinyl alcohol) (PVA), polyacrylic acid (PAA), in situ polymerized polyaniline (PANi), and the ionic liquid [EMIM][TFSI]. The resulting composite exhibits an exceptional linear piezoresistive response across its entire working range-from rest to fracture strain of 290%-together with high conductivity (0.68 S/cm), fast response/recovery (0.34 s/0.35 s), and a maximum gauge factor of 2.78. Mechanically robust (tensile strength ≈ 3.7 MPa, modulus ≈ 1.3 MPa), the hydrogel also demonstrates outstanding cyclic durability, withstanding over 12,000 stretching-relaxation cycles, and markedly improved dehydration resistance, retaining about 60% of its mass after 3 days at room temperature. This work provides a holistic material solution for developing high-performance, reliable strain sensors suitable for wearable electronics and soft robotics.

We present an exploration of an overlooked process in gel cleaning that promotes efficient cleaning of discoloration and stains from artworks on paper: adsorption. Agarose, in both solid and gelled forms, is an efficient adsorbent of crystal violet, which is used here as a marker to assess the capability of a system to immobilize solutes. Incorporating additional adsorbents, either 1% by mass microcellulose or silica gel, into the gel before casting greatly improves the efficiency of removing and retaining dye from water. This addition induces a slight (2×) increase in the elastic modulus but results in no impactful change in the handling properties for conservation practice. We show that the addition of silica gel increases the efficacy of removing water-soluble degradation products from a sheet of historic book paper. A case study of a water-damaged eighteenth-century print, with element maps collected using mapping µX-ray fluorescence analysis before and after gel cleaning, demonstrates that microcellulose-containing gels can be used to remove water-soluble salts from the print. This work provides a new methodology for tailoring gels to target specific conservation treatment outcomes. Specifically, efficient adsorption of solubilized material increases the efficacy of the gel cleaning and minimizes redeposition.

Lithium-sulfur (Li-S) batteries are renowned for their high theoretical energy density and low cost, yet their practical implementation is hampered by the polysulfide shuttle effect and sluggish redox kinetics. Herein, a sol-gel strategy is proposed to engineer a multifunctional MXene/Fe₃O₄ composite as an efficient mediator for the cathode interlayer. The synthesized composite features Fe₃O₄ nanospheres uniformly anchored on the highly conductive Ti₃C₂T_x MXene lamellae, forming a unique 0D/2D conductive network. This structure not only provides abundant polar sites for strong chemical adsorption of polysulfides but also significantly enhances charge transfer, thereby accelerating the conversion kinetics. As a result, the Li-S battery based on the MXene/Fe₃O₄ interlayer delivers a high initial discharge capacity of 1367.1 mAh g^-1 at 0.2 C and maintains a stable capacity of 1103.4 mAh g^-1 after 100 cycles, demonstrating an exceptionally low capacity decay rate of only 0.19% per cycle. Even at a high rate of 1 C, a remarkable capacity of 1066.1 mAh g^-1 is retained. Electrochemical analyses confirm the dual role of the composite in effectively suppressing the shuttle effect and catalyzing the polysulfide conversion. This sol-gel engineering approach offers valuable insight into the design of high-performance mediators for advanced Li-S batteries.

The rapid advancement of flexible electronics has propelled the development of lightweight, wearable piezoresistive sensors that integrate high sensitivity, excellent mechanical properties, and multifunctionality, making them a research hotspot. This work presents a flexible and lightweight multifunctional polyvinyl alcohol (PVA) composite hydrogel film, which is constructed based on a synergistic conductive network of cuttlefish ink-derived carbon nanospheres (CNPs) and polypyrrole (PPy). Within this composite, the CNPs and PPy form an interpenetrating conductive network throughout the PVA matrix, where PPy effectively suppresses the agglomeration of CNPs, thereby significantly enhancing the electron transport efficiency. This unique structure endows the material with improved flame retardancy and hydrophobicity while maintaining its lightweight characteristic. Consequently, the sensor demonstrates fast response (64 ms) and recovery times (66 ms) and a high sensitivity factor of 4.34 kPa^-1 within a pressure range of 11.2-16.8 kPa. Excellent stability is retained after nearly 6000 loading-unloading cycles, primarily attributed to the efficient response of the contact points and conductive pathways within the synergistic network under stress. Furthermore, this flexible sensor can not only reliably monitor human physiological activities (such as finger joint bending and facial expression changes) but also generate distinct current responses to subtle mouse-clicking actions, enabling tactile handwriting input. This study provides a novel strategy for constructing high-performance sensing materials by utilizing natural biomass-derived carbon materials and conductive polymers, highlighting the significant application potential of such lightweight, multifunctional hydrogel films in next-generation flexible electronic devices.

Advanced cell-based therapies, including immunotherapy, regenerative medicine, and other biotechnological applications, require large quantities of viable mammalian cells for research and clinical use. Conventional enzymatic harvesting methods, such as trypsini-zation, can compromise cell integrity and reduce viability. This study investigates an al-ternative temperature-responsive approach using alginate beads incorporated with poly(N-isopropylacrylamide) (PNIPAAm), a polymer exhibiting a lower critical solution temperature (LCST) of approximately 32 °C. This system enables temperature-controlled cell detachment while preserving cellular structure and extracellular matrix components, thereby potentially improving post-harvest viability compared to trypsin treatment. Ho-mogeneous alginate hydrogel beads were synthesized using a standard infusion pump and ionically crosslinked with calcium cations. The beads were characterized by scanning electron microscopy (SEM) for morphology and by Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and micro-computed tomography (µ-CT) for compositional and thermal analysis. Mouse fibroblast cells (L929 cell line) were cultured on the beads, and their proliferation and viability were assessed using CCK-8 and Live/Dead assays, demonstrating significant cell growth over seven days. The results suggest that PNIPAAm-modified alginate beads provide a promising, enzyme-free platform for efficient mammalian cell harvesting and delivery, with potential applications across advanced cell manufacturing and therapeutic technologies.