Chitin nanocrystals as natural gel modifier for yielding stronger acid-induced soy protein isolate gel

Emulsion co-stabilized with high methoxyl pectin and myofibrillar protein: Used to enhance the application in emulsified gel

This study evaluates the effects of high methoxyl pectin on the emulsion and gel properties of silver carp myofibrillar protein. An optimal concentration of pectin (3 mg/mL) enhances protein adsorption at the oil-water interface, forming a thermally induced oil-in-water emulsion gel with a denser and more robust fibrous network. The resulting gel exhibits a 3.8-fold increase in hardness and a 1.35-fold increase in water-holding capacity compared to the control. However, higher pectin concentrations (4-5 mg/mL) degrade emulsion-gel quality. By adjusting the ratio of myofibrillar protein to pectin, the emulsion's texture can transition from a fluid to a semi-solid state at room temperature, and the gel quality under heat treatment can be controlled. These findings offer a pathway to broaden the design and application of myofibrillar protein emulsions in multifunctional food products.

Physicochemical and rheological characterization of plant-based proteins, pectin, and chitin nanofibers for developing high internal phase Pickering emulsions as potential fat alternatives

This study evaluated the properties of lentil protein, pea protein, quinoa protein, and soy protein as natural nanoparticle stabilizers and their interactions with pectin and chitin nanofiber in preparing high internal phase Pickering emulsions (HIPPEs). The globular plant proteins interact with polysaccharides through hydrogen bonding and electrostatic interactions, transforming the structure into complex morphologies, including fibrous and elliptical shapes. These complex nanoparticles exhibited enhanced thermal decomposition stability, and the HIPPEs constructed by them demonstrated significantly improved apparent viscosity and elastic modulus, with a yield stress of 931.9 Pa, showing gel-like viscoelastic characteristics. The complex system not only reduced droplet size but also formed a compact network structure, which enabled the emulsion to maintain excellent stability under heat treatment, long-term storage and high-speed centrifugation. Our findings revealed the promising potential of utilizing plant-based proteins with polysaccharides to prepare HIPPEs for developing fat alternatives.

High pressure processing of glutinous Rice starch complexed with Buddleja officinalis maxim. Extract: Structural stability and digestibility improvements

This study investigated the impact of high pressure processing (HPP) on yellow glutinous rice starch (Y-GRS) formed by glutinous rice starch (GRS) complexed with Buddleja officinalis Maxim. extract (BOME). Y-GRS at 500 MPa achieved the highest complex index (0.506), indicating stronger starch-BOME interactions. Particle size analysis revealed that Y-GRS exhibited superior resistance to swelling, with D (Song et al., 2021; Leone et al., 2018 [3,4]) increasing by 18.97 μm for Y-GRS and 31.64 μm for GRS as the pressure increased from 400 to 600 MPa. Y-GRS retained higher thermal stability, with an enthalpy change of 1.55 J/g at 500 MPa, compared with 0.83 J/g for GRS. The relative crystallinity of Y-GRS was 8.81 % higher than that of GRS. Structural analyses confirmed BOME mitigated higher pressure-induced damage to starch granule, preserving double helix and crystal structure. Rheologically, Y-GRS exhibited stable peak viscosity, weaker shear thinning behavior, and greater resistance to deformation than GRS. Following HPP, Y-GRS contained lower levels of rapidly digestible starch (RDS) and higher levels of resistant starch (RS) than GRS. In conclusion, these findings highlight HPP as a promising strategy for enhancing the functional properties of Y-GRS, offering improved stability and digestibility for starch-based food applications.

Chitin nanocrystal-reinforced chitin/collagen composite hydrogels for annulus fibrosus repair after discectomy

Discectomy is a widely utilized approach for alleviating disc herniation; however, effective repair of postoperative annulus fibrosus (AF) defects remains a significant challenge. This study introduces a hydrogel patch with enhanced mechanical properties for AF repair fabricated using chitin (Ch), collagen (Col), and chitin nanocrystals (ChNCs) through a freeze-thaw cycling technique. The Ch and Col components constitute the matrix of the hydrogel patch, while uniformly dispersed ChNCs act as a nanofiller, markedly improving the mechanical performance (compression strain: 95 %; compression modulus: 0.27 MPa) of the resulting Ch/Col@ChNCs hydrogel patch. The patch demonstrates advantageous properties, including high porosity, superior water absorption, thermal stability, and biodegradability in simulated body fluid. In vitro assessments reveal excellent biocompatibility with AF cells and enhanced collagen deposition. Furthermore, in vivo studies confirm that the patch effectively repairs postoperative disc defects, exhibiting strong integration with surrounding tissues and facilitating the orderly regeneration of fibrous tissue. This innovative hydrogel patch, combining exceptional properties with a straightforward fabrication process, presents a viable strategy for advancing clinical biomaterials for postoperative AF repair.

Enhancement of gluconolactone-induced soybean protein isolate gels by low concentrations of oxidized konjac glucomannan: Gel properties and microstructure

Gluconolactone (GDL) induces soybean protein isolate (SPI) gelation by gradually releasing H+, lowering the pH to promote protein aggregation. However, excessive GDL often lead to an undesirable acidic taste in food gels. This study evaluated the effects of oxidized konjac glucomannan (OKGM) and varying H+ release levels on SPI gel properties, aiming to enhance gel quality while reducing GDL dependency. Results demonstrated that OKGM significantly improved gel texture and viscoelasticity, with low concentrations (0.5-1.5%, w/v) promoting SPI aggregation and forming a denser, more elastic gel network. Notably, OKGM accelerated the gelation process, reducing the gelation time from 12.88 ± 0.14 to 11.26 ± 0.00 min, while also increasing gel strength and stability. Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA) revealed that OKGM interacted with SPI through Schiff-base reactions, enhancing thermal stability. However, at high OKGM concentrations (2.0-2.5%, w/v), thermodynamic incompatibility led to phase separation, increasing surface hydrophobicity and free sulfhydryl content, which disrupted gel uniformity. Overall, OKGM synergized with GDL to induce gelation, enabling a reduction in acid coagulant usage while enhancing gel quality. This study provides a novel approach to designing low-calorie, fiber-rich SPI gels, offering a promising alternative to traditional soy gels in the food industry.

Effects of Konjac Glucomannan and Chitin Nanowhiskers on Structural and Physical Properties of Soy Protein Isolate Composite Hydrogels

Soybean protein isolates (SPIs) have been widely studied because of their excellent gel-forming properties. However, their unstable gel structures and poor strength limit their applications in the food industry. To address this, konjac glucomannan (KGM) and oxidized chitin nanocrystals (O-ChNCs) were introduced into SPI-based hydrogels to enhance their mechanical properties. The present study investigated the effects of incorporating KGM and O-ChNCs on the physical properties and microstructure of SPI hydrogels, as well as the possible underlying mechanisms. The rheological behavior test of the solution demonstrated that the viscoelastic properties of the sol were enhanced upon incorporating O-ChNCs and KGM. Scanning electron microscopy showed highly compact and uniformly distributed SPI hydrogels with the addition of O-ChNCs and KGM. Gel strength and textural property tests showed that the gel strength and gel hardness of SPI hydrogels with the addition of O-ChNCs and KGM were 102.57 ± 1.91 g/cm2 and 545.29 ± 6.84 g. O-ChNCs effectively filled the SPI hydrogel network, while KGM enhanced physical entanglement between SPI molecular chains and formed intermolecular hydrogen bonds. Therefore, this study provides an important basis for the introduction of SPI-based hydrogels in the biomedical and food industries.

Glucono-δ-lactone induced Auricularia auricula polysaccharide-casein composite gels for curcumin loading and delivery

Polysaccharides could be used to form the network structure of casein (CA) gel, and affect its gelling properties. Auricularia auricula polysaccharide (AAP) has good gel properties and activity, however, how the AAP affects gelling properties of CA gels remains unclear. In this study, AAP and CA were acid-induced by glucono-δ-lactone (GDL) to prepare composite gels for curcumin loading. The effects of different AAP additions on the gel structure were emphasized. Water holding capacity, rheology, texture profile analysis, sulfhydryl content, surface hydrophobicity and gel microstructure showed that the composite gels were most structurally stable upon addition of 0.4 % AAP. The composite gels exhibited a higher strength and a more regular network structure compared to the CA gels. The results of turbidity studies showed that CA and AAP formed gels through electrostatic interactions due to pH < pI. The results of FT-IR, X-ray diffraction, fluorescence spectroscopy, and UV-Vis spectroscopy indicated that curcumin interacted with the CA and was successfully encapsulated within the gel. In addition, in vitro simulated digestion experiments demonstrated that the composite gels exhibited better protection against curcumin than the single CA gel. The results suggested that composite gels can be used as a curcumin carrier, which may enhance its wider application in the food and health industries.

Sanxan-Protein Complex Particles for Stabilization of Pickering Emulsions: Improving Emulsification Properties

Sanxan (SAN) is a novel microbial polysaccharide that is both safe and edible and represents a promising new source of food resources. It exhibits gelling properties and certain emulsifying properties. To date, there have been few studies published on the enhancement of protein emulsification by sanxan. In this study, three widely used proteins were used: casein (CS), pea protein isolate (PPI), and soy protein isolate (SPI). SAN-protein composite particles were prepared by non-covalent interactions to evaluate the availability of SAN in Pickering emulsions. The effect of SAN on the ability of the complexes to stabilize the emulsion was investigated by measuring and characterizing the physicochemical properties of three SAN-protein complexes. Fourier transform infrared (FTIR) and fluorescence spectroscopy analyses showed that SAN was able to bind to three proteins to form complexes. All three complexes formed by SAN with SPI, PPI and CS had good emulsification properties, with PPI-SAN being the best. Storage results showed better stability of the composite particle-stabilized emulsion. These results indicate that the complexation of SAN with proteins improves the emulsification of proteins and increases the stability of Pickering emulsions. The findings of this study provide valuable information for the utilization of SAN in emulsions.

Effect of sanxan as novel natural gel modifier on the physicochemical and structural properties of microbial transglutaminase-induced mung bean protein isolate gels

Mung bean protein isolate (MBPI) has attracted much attention as an emerging plant protein. However, its application was limited by the poor gelling characteristics. Thus, the effect of sanxan (SAN) on the gelling behavior of MBPI under microbial transglutaminase (MTG)-induced condition were explored in this study. The results demonstrated that SAN remarkably enhanced the storage modulus, water-holding capacity and mechanical strength. Furthermore, SAN changed the microstructure of MBPI gels to become more dense and ordered. The results of zeta potential indicated the electrostatic interactions existed between SAN and MBPI. The incorporation of SAN altered the secondary structure and molecular conformation of MBPI, and hydrophobic interactions and hydrogen bonding were necessary to maintain the network structure. Additionally, in vitro digestion simulation results exhibited that SAN remarkably improved the capability of MBPI gels to deliver bioactive substances. These findings provided a practical strategy to use natural SAN to improve legume protein gels.

Fabrication of enhanced aerogel template oleogels with enzyme-hydrolyzed soy protein isolate and covalent cross-linking

In recent years, the utilization of aerogel templates in oleogels to replace animal fats has garnered considerable attention due to health concerns. This study employed a "fiber-particle core-shell nanostructure model" to combine sodium carboxymethylcellulose (CMCNa) and soy protein isolate (SPI) or SPI hydrolysate (SPIH), and freeze-dried to form aerogel template, which was then dipped into oil to induce oleogels. The results showed that adding SPIH significantly improved the physicochemical properties of oleogels. The results of ζ-potential, FTIR, and rheology demonstrated a stronger binding of SPIH to CMC-Na compared to SPI. The CMC-Na-SPIH aerogels exhibited a coarser surface and denser network structure in contrast to CMC-Na-SPI aerogels, with an oil holding capacity (OHC) of up to 84.6 % and oil absorption capacity (OAC) of 47.4 g/g. The mechanical strength of oleogels was further enhanced through chemical crosslinking. Both CMC-Na-SPI and CMC-Na-SPIH oleogels displayed excellent elasticity and reversible compressibility, with CMC-Na-SPIH oleogels demonstrating superior mechanical strength. Additionally, CMC-Na-SPIH oleogels exhibited enhanced slow release of antimicrobial substances and antioxidant properties. Increasing the content of SPI/SPIH significantly improved the mechanical strength, antioxidant capacity, and OHC of the oleogels. This research presents a straightforward and promising approach to enhance the performance of aerogel template oleogels.

Effects of water-soluble and water-insoluble α-glucans produced in situ by Leuconostoc citreum SH12 on physicochemical properties of fermented soymilk and their structural analysis

This study investigated the effect of in situ produced water-soluble α-glucan (LcWSG) and water-insoluble α-glucan (LcWIG) from Leuconostoc citreum SH12 on the physicochemical properties of fermented soymilk. α-Glucans produced by Leuc. citreum SH12 improved water-holding capacity, viscosity, viscoelasticity and texture of fermented soymilk. Gtf1365 and Gtf836 of the five putative glucansucrases were responsible for synthesizing LcWSG and LcWIG during soymilk fermentation, respectively. Co-fermentation of soymilk with Gtf1365 and Gtf836 and non-exopolysaccharide-producing Lactiplantibacillus plantarum D1031 indicated that LcWSG effectively hindered the whey separation of fermented soymilk by increasing viscosity, while LcWIG improved hardness, springiness and accelerated protein coagulation. Fermented soymilk gel formation was mainly based on hydrogen bonding and hydrophobic interactions, which were promoted by both LcWSG and LcWIG. LcWIG has a greater effect on α-helix to β-sheet translation in fermented soymilk, causing more rapid protein aggregation and thicker cross-linked gel network. Structure-based exploration of LcWSG and LcWIG from Leuc. citreum SH12 revealed their distinct roles in the physicochemical properties of fermented soymilk due to their different ratio of α-1,6 and α-1,3 glucosidic linkages and various side chain length. This study may guide the application of the water-soluble and water-insoluble α-glucans in fermented plant protein foods for their quality improvement.

Synergistic effects of microbial transglutaminase and apple pectin on the gelation properties of pea protein isolate and its application to probiotic encapsulation

The low gelation capacity of pea protein isolate (PPI) limits their use in food industry. Therefore, microbial transglutaminase (MTG) and apple pectin (AP) were combined to modify PPI to enhance its gelling characteristics, and the mechanism of MTG-induced PPI-AP composite gel generation was investigated. PPI (10 wt%) could not form a gel at 40 °C, while MTG-treated PPI (10 wt%) formed a self-supporting gel at 40 °C. Subsequently, the addition of AP further promoted the crosslinking of PPI and significantly improved the water holding capacity, rheology, and strength of PPI gels, which was attributed to both hydrogen and isopeptide bonds in the composite gel. Additionally, the PPI-AP composite gel showed excellent protection ability, and the survival rate of probiotics could reach over 90%, which could be used as an effective delivery system. This study verified that MTG and AP were efficient in enhancing the functional quality of PPI gels.