Design principles of food gels

Acid-induced pea protein gels pretreated with media milling: Gelling properties and the formation mechanism

This study explored the effect of stirred media mill (SMM) processing on the acid-induced gelling properties of pea protein. Results showed that SMM treatment enhanced the gel strength from 75.06 g to 183.89 g and increased the water holding capacity from 46.64 % to 73.50 %. The minimum gelation concentration achieved for SMM-treated pea protein was 4 %, significantly lower than that of heat-pretreated pea protein (9 %). SMM decreased protein aggregate size from 104 μm to 180 nm. Microscopy analysis revealed that the small aggregates facilitated the formation of uniform gel networks with tight connections. Linear rheology indicated that small protein aggregates resulted in slower gelation rates with a higher G' for the formed gels. The SMM-pretreated protein gel showed strain hardening, shear thinning behaviors, and satisfactory stability to withstand large-amplitude oscillatory shear. Overall, SMM emerges as a promising technology for producing protein gel products with strong mechanical attributes and customizable rheological properties.

Carboxymethyl chitosan and dialdehyde cellulose nanocrystal based injectable self-healing emulsion gel

The study aims to demonstrate a general method for producing emulsion gels with self-healing properties. Specifically, the self-healing emulsion gels were fabricated by crosslinking carboxymethyl chitosan (CMC) stabilized emulsion with dialdehyde cellulose nanocrystal (DACNC). The reversible imine bonds between primary amino groups from CMC and aldehyde groups from DACNC endow the emulsion gel with self-healing properties. The compressive strength of the emulsion gels was greatly increased from 37.43 kPa 83.7 kPa by encapsulating emulsion droplets (φ = 0 %-40 %.) in the gel matrix. Moreover, the emulsion gels exhibited much better self-healing and injectability ability compared to hydrogel because the emulsion droplets interacted with the 3D gel matrix, which were observed by cryo-SEM and CLSM. The emulsion droplets distributed in the gel matrix improved the mobility and interfacial contact area of CMC and DACNC. Water contact measurement confirmed that the CMC/DACNC self-healing emulsion gels showed a hydrophilic surface. The CMC/DACNC emulsion gels could maintain a good structural stability as the oil loss was <1 % after centrifugation. This research provides a method to keep the structural stability of emulsion gels by inducing self-healing ability and modified cellulose nanocrystals, which could extend the shelf life and application area of emulsion gels.

Role of pectin in the delivery of β-carotene embedded in interpenetrating emulsion-filled gels made with soy protein isolate

This study investigated the effects of different matrices on gel properties, lipid digestibility, β-carotene bioaccessibility, released free amino acids and gel network degradation. Microstructure studies have proven that sugar beet pectin/soy protein isolate-based emulsion-filled gel (SBP/SPI-E) with interpenetrating networks was formed. SBP/SPI-E exhibited higher hardness (2.67 N, p < 0.05) and released lesser free amino acids (269.48-μmol/g SPI) than soy protein isolate-based emulsion-filled gel (SPI-E) in simulated intestinal fluid (SIF); however, both had similar free amino acids contents in simulated colonic fluid. SBP has the potential to delay gel network degradation in SIF, as evidenced by the sugar stain strips of SDS-PAGE and microstructure observation. Furthermore, SBP/SPI-E and SPI-E exhibited similar β-carotene bioaccessibility in SIF, suggesting that SBP from composite gel could not affect the aforementioned bioaccessibility. The study provides useful information for the design of functional gels in the application of fat-soluble nutrient delivery.

Novel strategies for modulating the gut microbiome for cancer therapy

Recent advancements in genomics, transcriptomics, and metabolomics have significantly advanced our understanding of the human gut microbiome and its impact on the efficacy and toxicity of anti-cancer therapeutics, including chemotherapy, immunotherapy, and radiotherapy. In particular, prebiotics, probiotics, and postbiotics are recognized for their unique properties in modulating the gut microbiota, maintaining the intestinal barrier, and regulating immune cells, thus emerging as new cancer treatment modalities. However, clinical translation of microbiome-based therapy is still in its early stages, facing challenges to overcome physicochemical and biological barriers of the gastrointestinal tract, enhance target-specific delivery, and improve drug bioavailability. This review aims to highlight the impact of prebiotics, probiotics, and postbiotics on the gut microbiome and their efficacy as cancer treatment modalities. Additionally, we summarize recent innovative engineering strategies designed to overcome challenges associated with oral administration of anti-cancer treatments. Moreover, we will explore the potential benefits of engineered gut microbiome-modulating approaches in ameliorating the side effects of immunotherapy and chemotherapy.

Implementation of plant extracts for cheddar-type cheese production in conjunction with FTIR and Raman spectroscopy comparison

Plant extracts have demonstrated the ability to act as coagulants for milk coagulation at an adequate concentration, wide temperatures and pH ranges. This research is focused on the use of different vegetative extracts such as Citrus aurnatium flower extract (CAFE), bromelain, fig latex, and melon extract as economical and beneficial coagulants in the development of plant-based cheddar-type cheese. The cheddar-type cheese samples were subjected to physicochemical analysis in comparison to controlled cheese samples made from acetic acid and rennet. The fat, moisture, protein, and salt contents remained the same over the storage period, but a slight decline was observed in pH. The Ferric reducing antioxidant power (FRAP) increased with the passage of the ripening period. The FTIR and Raman spectra showed exponential changes and qualitative estimates in the binding and vibrational structure of lipids and protein in plant-based cheeses. The higher FTIR and Raman spectra bands were observed in acid, rennet, bromelain, and CAFE due to their firm and strong texture of cheese while lower spectra were observed in cheese made from melon extract due to weak curdling and textural properties. These plant extracts are economical and easily available alternative sources for cheese production with higher protein and nutritional contents.

Investigation into the fabrication of plant-based simulant connective tissue utilizing algae polysaccharide-derived hydrogel

Connective tissue is an important component of meat products that provides support to animal muscles. Hydrogels are considered a promising alternative to connective tissues and simulate actual products by adjusting the gel texture and mouthfeel. This study used soybean protein isolate (SPI), corn starch (CS), konjac glucomannan (KGM), and seaweed powder (SP) as raw materials to examine the effect of different added SP and KGM concentrations on the gel texture. The G' of the gel increased five-fold when the SP and KGM concentration was increased from 1 % to 3 %. The results of mechanical property tests showed that with the addition of SP, the gel hardness increased from 316.00 g to 1827.23 g and the tensile strength increased from 0.027 MPa to 0.089 MPa. Sensory evaluation showed that the samples with 2 % SP and KGM presented the highest overall acceptability score and the most significant similarity to real connective tissue. The connective tissue simulants exhibited excellent water-holding capacity (>90 %), significantly increasing their juiciness. SEM indicated that 2 % KGM addition improved gel network structure stability. The results demonstrate the potential of seaweed polysaccharide-derived hydrogels as connective tissue mimics. This provides a new strategy for the preparation of high mechanical strength hydrogels and lays the foundation for structural diversification of plant-based meat.

Lactoferrin-Chitosan Composite Hydrogels Induced by Microbial Transglutaminase: Potential Delivery Systems for Thermosensitive Bioactive Substances

In this work, lactoferrin (LF)-chitosan (CS) composite hydrogels with good loading capacity of thermosensitive bioactive substances were successfully obtained by microbial transglutaminase (MTG)-induced cross-linking. We evaluated the rheological, textural, and microstructural characteristics of the composite hydrogels under different conditions. The results demonstrated that the concentrations of LF and CS as well as the amount of MTG could regulate the textural properties, rheological properties, and water holding capability. The results of FTIR and fluorescence spectroscopy indicated that the main interactions within the composite gel were hydrogen and isopeptide bonds. Additionally, in vitro digestion simulation results verified that riboflavin kept stable in stomach due to the protection of LF-CS composite hydrogels and was released in small intestine. These results suggested that thermosensitive bioactive substance could be encapsulated and delivered by the LF-CS composite hydrogel, which could be applied in lots of potential applications in functional food as a new material.

Carboxymethyl cellulose and carboxymethyl chitosan-based composite nanogel as a stable delivery vehicle for oyster peptides: Characterization, absorption and transport mechanism

An oyster peptide (OPs)-loaded composite nanogel based on carboxymethyl cellulose and carboxymethyl chitosan (CMC@CMCS@OPs) was prepared, and the characterization, absorption and transport mechanism were further investigated. CMC@CMCS@OPs, a dense spherical microstructure with a diameter of ∼64 nm, which enhanced the thermal and digestive stabilities of individual OPs and improved its retention rate of hypoglycemic activity in vitro. The swelling response and in-vitro release profiles showed that CMC@CMCS@OPs could help OPs achieve targeted and controlled release in the intestine. In addition, CMC@CMCS@OPs had no cytotoxicity on Caco-2 cells, and its apparent permeability coefficients increased 4.70-7.45 times compared with OPs, with the absorption rate increased by 129.38 %. Moreover, the transcytosis of CMC@CMCS@OPs nanogel occurred primarily through the macropinocytosis pathway, endocytosis pathway and intestinal efflux transporter-mediated efflux. Altogether, these results suggested that CMC@CMCS@OPs nanogel could be as an effective OPs delivery device for enhancing its stability and absorption.

Protein and protein-polysaccharide composites-based 3D printing: The properties, roles and opportunities in future functional foods

The food industry is undergoing a significant transformation with the advancement of 3D technology. Researchers in the field are increasingly interested in using protein and protein-polysaccharide composite materials for 3D printing applications. However, maintaining nutritional and sensory properties while guaranteeing printability of these materials is challenging. This review examines the commonly used protein and composite materials in food 3D printing and their roles in printing inks. This review also outlines the essential properties required for 3D printing, including extrudability, appropriate viscoelasticity, thixotropic properties, and gelation properties. Furthermore, it explores the wide range of potential applications for 3D printing technology in novel functional foods such as space food, dysphagia food, kid's food, meat analogue, and other specialized food products.

Single-site iron-anchored amyloid hydrogels as catalytic platforms for alcohol detoxification

Constructing effective antidotes to reduce global health impacts induced by alcohol prevalence is a challenging topic. Despite the positive effects observed with intravenous applications of natural enzyme complexes, their insufficient activities and complicated usage often result in the accumulation of toxic acetaldehyde, which raises important clinical concerns, highlighting the pressing need for stable oral strategies. Here we present an effective solution for alcohol detoxification by employing a biomimetic-nanozyme amyloid hydrogel as an orally administered catalytic platform. We exploit amyloid fibrils derived from β-lactoglobulin, a readily accessible milk protein that is rich in coordinable nitrogen atoms, as a nanocarrier to stabilize atomically dispersed iron (ferrous-dominated). By emulating the coordination structure of the horseradish peroxidase enzyme, the single-site iron nanozyme demonstrates the capability to selectively catalyse alcohol oxidation into acetic acid, as opposed to the more toxic acetaldehyde. Administering the gelatinous nanozyme to mice suffering from alcohol intoxication significantly reduced their blood-alcohol levels (decreased by 55.8% 300 min post-alcohol intake) without causing additional acetaldehyde build-up. Our hydrogel further demonstrates a protective effect on the liver, while simultaneously mitigating intestinal damage and dysbiosis associated with chronic alcohol consumption, introducing a promising strategy in effective alcohol detoxification.

Salting-out effect-mediated size-control of protein nanoparticles towards controllable microstructures for sustained release of eugenol

Size and monodispersity of solid particles are essential to their structuring behaviors at biphasic interfaces. However, delicate control over biomolecular nanoparticle sizes is challenging. In this study, we prepared monodisperse rice protein (RP) nanoparticles by neutralizing RP solutions (pH 12.0) using combined treatments of cationic exchange resins (CERs) and HCl. CERs absorbed Na+ by releasing H+ without producing salt during neutralization. By compromising the usages of CERs and HCl when preparing RPs, the generation of NaCl can be delicately tailored, leading to controllable nanoparticle sizes from 20 nm to 30 nm. By mixing these nanoparticles with eugenol in an aqueous solution, the nanoparticles accommodated eugenol in their cores due to inward diffusion. Furthermore, such eugenol-contained nanoparticles with different sizes demonstrated tunable releases of eugenol due to size-dependent capillary forces, which can be harnessed for suppression of microbial growth on fruit with prolonged effective eugenol concentration.

Regulation of glycose and lipid metabolism and application based on the colloidal nutrition science properties of konjac glucomannan: A comprehensive review

The physicochemical properties of dietary fiber in the gastrointestinal tract, such as hydration properties, adsorption properties, rheological properties, have an important influence on the physiological process of host digestion and absorption, leading to the differences in satiety and glucose and lipid metabolisms. Based on the diversified physicochemical properties of konjac glucomannan (KGM), it is meaningful to review the relationship of structural characteristics, physicochemical properties and glycose and lipid metabolism. Firstly, this paper bypassed the category of intestinal microbes, and explained the potential of dietary fiber in regulating glucose and lipid metabolism during nutrient digestion and absorption from the perspective of colloidal nutrition. Secondly, the modification methods of KGM to regulate its physicochemical properties were discussed and the relationship between KGM's molecular structure types and glycose and lipid metabolism were summarized. Finally, based on the characteristics of KGM, the application of KGM in the main material and ingredients of fat reduction food was reviewed. We hope this work could provide theoretical basis for the study of dietary fiber colloid nutrition science.

The Preparation and Characterization of Quinoa Protein Gels and Application in Eggless Bread

The properties of xanthan gum protein gels composed of quinoa protein (XG-QPG) and ultrasound-treated quinoa protein (XG-UQPG) were compared for the preparation of high-quality quinoa protein gels. The gel qualities at different pH values were compared. The gels were used to produce eggless bread. Microscopically, the secondary structure of the proteins in XG-QPG (pH 7.0) was mainly α-helix, followed by random coiling. In contrast, the content of β-sheet in XG-UQPG was higher, relative to the viscoelastic properties of the gel. Moreover, the free sulfhydryl groups and disulfide bonds of XG-QPG (pH 7.0) were 48.30 and 38.17 µmol/g, while XG-UQPG (pH 7.0) was 31.95 and 61.58 µmol/g, respectively. A high disulfide bond content was related to the formation of gel networks. From a macroscopic perspective, XG-QPG (pH 7.0) exhibited different pore sizes, XG-UQPG (pH 7.0) displayed a loose structure with uniform pores, and XG-UQPG (pH 4.5) exhibited a dense structure with small pores. These findings suggest that ultrasound can promote the formation of a gel by XG-UQPG (pH 7.0) that has a loose structure and high water-holding capacity and that XG-UQPG (pH 4.5) forms a gel with a dense structure and pronounced hardness. Furthermore, the addition of the disulfide bond-rich XG-UQPG (pH 7.0) to bread promoted the formation of gel networks, resulting in elastic, soft bread. In contrast, XG-UQPG (pH 4.5) resulted in firm bread. These findings broaden the applications of quinoa in food and provide a good egg substitute for quinoa protein gels.

Fat analogue emulsions stabilized by peanut protein microgel particles: microscale and nanoscale structure and stabilization process analysis

BACKGROUND

Biopolymer-based microgels are being regarded increasingly as promising building blocks in food applications. This study aimed to clarify the evolution process of the network for fat analogue emulsions stabilized by peanut protein isolate (PPI) microgel particles. It also investigated the interfacial structure and characteristics of emulsions (50% oil phase, w/w) stabilized by microgels under different pH conditions.

RESULTS

There was an increasing interfacial adsorption capacity for PPI microgels over time (from 85.26% to the maximum of 89.78% at 24 h of storage) due to the aggregation of microgels around droplets and the development of cross-linking microgel chains between adjacent interfaces. The increased β-sheet content (from 35.51% to 41.12%) of adsorbed microgels indicated unfolding and the enhanced aggregation of microgels, which led to stronger droplet interaction. The network evolution observed with different microscopes clarified the transition to a self-supporting emulsion. The uneven adsorption of large microgel aggregates at the oil-water interface promoted larger and deformed droplets, so more fat-like medium internal phase emulsion stabilized by PPI microgel could be obtained by adjusting the microgel pH to 4.5. The interfacial membranes observed by scanning electron microscopy were thicker and coarser at pH 3.0 and 4.5 than those at pH 7.0 and 9.0. The adsorption of PPI microgel aggregates enhanced the structural strength and improved emulsion stability.

CONCLUSION

This work could form a basis for further studies relating physical properties to the design of plant protein-based fat analogues. © 2024 Society of Chemical Industry.

Fibrous whey protein mediated homogeneous and soft-textured emulsion gels for elderly: Enhancement of bioaccessibility for curcumin

Homogeneous and soft-textured food gels are critical for designing precise and personalized nutrient food for elderly. Effects of whey protein morphology (fibrous and granular) with/without NaCl addition on oil-water state and texture properties of protein emulsion gels were investigated, to explore the feasibility of developing homogeneous and soft-textured food for elderly. Lower gelation temperature and higher stability of its emulsion droplets, resulted in fibrous whey protein emulsion gels (FWPG) had even distribution of embedded oil droplets, compared to native whey protein emulsion gels. FWPG had the lowest hardness and chewiness, and exhibited better tolerance to the harden effects of NaCl on emulsion gels. FWPG can deliver curcumin more effectively during simulated gastrointestinal digestion, as evidenced by higher retention ratio and enhancement of bioaccessibility (increased by ∼ 20 %). This study provided new strategy to fabricate a homogenous emulsion gel using fibrous whey protein and to design multi-nutrient food gels for elderly.

Modulating the texture of heat-set gels of phosphorylated walnut protein isolates through Glucono-δ-lactone acidification

The gelation of walnut protein isolates has not been extensively studied, mainly due to their inherent poor dispersity. This study investigated the gelation of alkaline-extracted walnut protein isolates (AWPI) and phosphorylated walnut protein isolates (PWPI) induced by heat treatment with glucono-δ-lactone (GDL) acidification, focusing on the impact of GDL concentrations on microstructure, rheology, and texture of the resulting gels. The PWPI gel exhibited lower hardness but a smoother structure than the AWPI gel. Notably, acidification with GDL (0.6-1.2%) significantly increased the stiffness of PWPI gels, increasing storage modulus and yield stress 10-50 times, while weakening AWPI gels. Varying concentrations of GDL effectively modulated the microstructure of the PWPI gels, leading to the altered texture (from a soft-solid state to a well-self-supporting stiff-solid gel) and water holding capacity (from approximately 46% to 85%). Additionally, hydrophobic interactions and disulfide bonds were identified as the primary forces involved in the gels.

The formation mechanism and textural properties of a complex gel based on soybean glycinin-chitosan complex coacervates: Effects of pH, heat treatment temperature and centrifugation

The soybean glycinin (11S)-chitosan (CS) complex gels with various textural properties were successfully constructed. The process involved the initial formation of 11S-CS coacervates through electrostatic interactions, followed by a heating treatment to obtain the final complex gels. The impacts of pH, heating temperature, and centrifugation on 11S-CS complex gel properties were investigated. The results indicated that the pore arrangement of the gel formed at pH 7.3 was more tightly and uniformly packed than those formed at pH 6.8 and 7.8. Centrifugation facilitated denser and more ordered gel structures at the three pH values, while increasing the heating temperature exhibited the opposite trend at pH 6.8 and 7.8. These structural differences were also reflected in the rheological and textural properties of the gel. The 11S-CS complex gels exhibited an elasticity-based gel property. The textural properties of gels formed at pH 6.8 were stronger compared to those formed at pH 7.3 and 7.8. However, when the 11S-CS coacervates were heated without centrifugation, the resulting gels were weak. This study emphasizes the potential of using protein/polysaccharide associative interactions during gel formation to alter the microstructure of the gel, meeting various production requirements.

Fabrication, characterization and emulsifying properties of myofibrillar protein-chitosan complexes in acidic conditions

Polysaccharides are employed to modify proteins, forming complexes that enhance the functional properties of proteins, such as emulsification and stability. In this study, myofibrillar protein (MP)-chitosan (CS) complexes were formed between CS and MP under acidic conditions (pH 3.0-6.0). Results showed that CS can improve the solubility and emulsifying properties of MP, and the MP-CS complexes at pH 3.0 and 6.0 had better emulsifying properties. Concurrently, the particle size results indicated that better the emulsifying properties of the complex, the smaller the particle size. Consequently, the characteristics of the MP-CS complexes (at pH 3.0 and 6.0) were investigated. Our analysis using Fourier transform infrared spectroscopy revealed that the amide I band of MP was blue-shifted with the addition of CS, signifying a decrease in hydrogen bonding within MP. The endogenous fluorescence spectra showcased that the hydrophobicity surrounding the tryptophan residues in the protein changed, leading to enhanced polarity. Thermogravimetric analysis and differential scanning calorimetry further confirmed that the addition of CS improved the thermal stability of MP. These findings provide valuable insights into the interactions between MP and CS. Furthermore, the MP-CS complex can be leveraged to create a Pickering emulsion system for the efficient delivery of bioactive substances.

Impact of κ-Carrageenan on the Cold-Set Pea Protein Isolate Emulsion-Filled Gels: Mechanical Property, Microstructure, and In Vitro Digestive Behavior

More understanding of the relationship among the microstructure, mechanical property, and digestive behavior is essential for the application of emulsion gels in the food industry. In this study, heat-denatured pea protein isolate particles and κ-carrageenan were used to fabricate cold-set emulsion gels induced by CaCl2, and the effect of κ-carrageenan concentration on the gel formation mechanism, microstructure, texture, and digestive properties was investigated. Microstructure analysis obtained by confocal microscopy and scanning electron microscopy revealed that pea protein/κ-carrageenan coupled gel networks formed at the polysaccharide concentration ranged from 0.25% to 0.75%, while the higher κ-carrageenan concentration resulted in the formation of continuous and homogenous κ-carrageenan gel networks comprised of protein enriched microdomains. The hydrophobic interactions and hydrogen bonds played an important role in maintaining the gel structure. The water holding capacity and gel hardness of pea protein emulsion gels increased by 37% and 75 fold, respectively, through increasing κ-carrageenan concentration up to 1.5%. Moreover, in vitro digestion experiments based on the INFOGEST guidelines suggested that the presence of 0.25% κ-carrageenan could promote the digestion of lipids, but the increased κ-carrageenan concentration could delay the lipid and protein hydrolysis under gastrointestinal conditions. These results may provide theoretical guidance for the development of innovative pea protein isolate-based emulsion gel formulations with diverse textures and digestive properties.

Waste to value: Enhancing xanthan gum hydrogel with wine lees extract for optimal performance

The current study investigated the potential of utilizing wine lees extract (WLE) from red wine to enhance the sustainability and cost-effectiveness of xanthan gum (XG). A novel hydrogel system was successfully generated by cross-linking WLE and XG. Response surface methodology (RSM) was used to thoroughly analyze the characteristics of this novel hydrogel to understand its behavior and possible applications. Consistency index (K), flow behavior index (n), water holding capacity (%), and oil binding capacity (%) of the cross-linked hydrogels were optimized, and the best formulation was determined to be 0.81 % XG + 0.67 % WLE and crosslink temperature of 47 °C. The addition of WLE (0-1 % w/v) to different concentrations of XG (0-1 % w/v) was found to have a notable impact on the rheological properties, but changes in cross-link temperature (45-65 °C) did not have a significant effect. The activation energy was increased by incorporating WLE at XG concentration above 0.5 %, indicating a more robust and stable structure. FTIR and SEM analyses confirmed the chemical bonding structure of the optimum hydrogel. Incorporating WLE could significantly improve the functional properties of XG hydrogels, allowing the development of healthier product formulations.

Chocolates, compounds and spreads: A review on the use of oleogels, hydrogels and hybrid gels to reduce saturated fat content

This study is a bibliometric analysis and literature review on the use of oleogels (OGs), hydrogels (HGs) and hybrid gels (HYGs) in chocolate, compounds and spreads with the aim of reducing the saturated fat in these products. The articles were selected by analyzing titles, keywords and abstracts in the Web of Science (WoS), Scopus and Google Scholar databases. Supplementary documents were obtained from government sources, including patent registrations. The theoretical and practical aspects were critically analyzed, highlighting the main points of agreement and disagreement between the authors. The results revealed a lack of regulations and official guidelines that widely allow the use of OGs, HGs and HYGs in chocolate confectionery products. The type and characteristics of raw materials affect the properties of products. Replacing cocoa butter (CB) with OGs, HGs or HYGs also affects texture, melting point and behavior, and nutritional aspects. These substitutions can result in products with better sensory acceptance and health benefits, such as reducing saturated fat and promoting cardiovascular health. However, it is important to find the ideal combination and proportions of components to obtain the desired properties in the final products.

Protein Nanotubes as Advanced Material Platforms and Delivery Systems

Protein nanotubes (PNTs) as state-of-the-art nanocarriers are promising for various potential applications both in the food and pharmaceutical industries. Derived from edible starting sources like α-lactalbumin, lysozyme, and ovalbumin, PNTs bear properties of biocompatibility and biodegradability. Their large specific surface area and hydrophobic core facilitate chemical modification and loading of bioactive substances, respectively. Moreover, their enhanced permeability and penetration ability across biological barriers such as intestinal mucus, extracellular matrix, and thrombus clot, make it promising platforms for health-related applications. Most importantly, their simple preparation processes enable large-scale production, supporting applications in the biomedical and nanotechnological fields. Understanding the self-assembly principles is crucial for controlling their morphology, size, and shape, and thus provides the ground to a multitude of applications. Here, the current state-of-the-art of PNTs including their building materials, physicochemical properties, and self-assembly mechanisms are comprehensively reviewed. The advantages and limitations, as well as challenges and prospects for their successful applications in biomaterial and pharmaceutical sectors are then discussed and highlighted. Potential cytotoxicity of PNTs and the need of regulations as critical factors for enabling in vivo applications are also highlighted. In the end, a brief summary and future prospects for PNTs as advanced platforms and delivery systems are included.

Combustion Enhancement of Gel Propellant Containing High Concentration Aluminum Particles Based on Carbon Synergistic Effect

The addition of aluminum particles to gel propellants can improve combustion performance. However, the agglomeration of aluminum during the combustion process can result in a series of negative effects. In this paper, the aluminum agglomeration inhibition method of gel propellant based on carbon synergistic effect is proposed. Carbon particles exhibit excellent combustion properties, and the gaseous product CO2 generated during combustion can mitigate the agglomeration of aluminum. The research demonstrates that incorporating carbon particles into aluminum-containing gel effectively reduces the incomplete combustion of aluminum particles and increases the volumetric calorific value of the gel. When the mass fraction of carbon is 5 wt%, the volume calorific value of the gel reaches the highest. Meanwhile, the rheological experiments show that the addition of carbon particles can improve the shear-thinning properties of the gel, which is beneficial to the atomization and combustion processes of the gel.

Engineering Strategies to Modulate the Gut Microbiome and Immune System

The gut microbiota, predominantly residing in the colon, is a complex ecosystem with a pivotal role in the host immune system. Dysbiosis of the gut microbiota has been associated with various diseases, and there is an urgent need to develop new therapeutics that target the microbiome and restore immune functions. This Brief Review discusses emerging therapeutic strategies that focus on oral delivery systems for modulating the gut microbiome. These strategies include genetic engineering of probiotics, probiotic-biomaterial hybrids, dietary fibers, and oral delivery systems for microbial metabolites, antimicrobial peptides, RNA, and antibiotics. Engineered oral formulations have demonstrated promising outcomes in reshaping the gut microbiome and influencing immune responses in preclinical studies. By leveraging these approaches, the interplay between the gut microbiota and the immune system can be harnessed for the development of novel therapeutics against cancer, autoimmune disorders, and allergies.

A comprehensive review on the utilization of biopolymer hydrogels to encapsulate and protect probiotics in foods

Probiotics must survive in foods and passage through the human mouth, stomach, and small intestine to reach the colon in a viable state and exhibit their beneficial health effects. Probiotic viability can be improved by encapsulating them inside hydrogel-based delivery systems. These systems typically comprise a 3D network of cross-linked polymers that retain large amounts of water within their pores. This study discussed the stability of probiotics and morphology of hydrogel beads after encapsulation, encapsulation efficiency, utilization of natural polymers, and encapsulation mechanisms. Examples of the application of these hydrogel-based delivery systems are then given. These studies show that encapsulation of probiotics in hydrogels can improve their viability, provide favorable conditions in the food matrix, and control their release for efficient colonization in the large intestine. Finally, we highlight areas where future research is required, such as the large-scale production of encapsulated probiotics and the in vivo testing of their efficacy using animal and human studies.

Structured Emulgels by Interfacial Assembly of Terpenes and Nanochitin

Interfacial assemblies formed by colloidal complexation are effective in multiphase stabilization, as shown in structured liquids and Pickering emulgels. Herein, we demonstrate a type of biobased colloidal system that spontaneously stabilizes an organic phase in a continuous hydrogel phase. Specifically, a triterpene extracted from bark (betulin, BE) is added to an organic phase containing a coniferous resin (rosin acid, a diterpene). BE is shown to take part in strong noncovalent interactions with the nanochitin dispersed in the aqueous (hydrogel) phase, leading to a complex of high interfacial activity. The viscoelastic response of the system is rationalized by the presence of a superstable structured dual network. When used as a templating material, the emulgel develops into structured liquids and cryogels. The herein introduced all-biobased type of nanoparticle surfactant system forms a gel ("emulsion-filled" with "aggregated droplets") that features the functional benefits of both betulin and nanochitin.

Larval Rearing and Nutrition of the Polyphagous Tephritid Pest Anastrepha ludens on Artificial Diets with Calcium Alginate, Agar, or Carrageenan as Gelling Agents at Various Concentrations and across Extreme Larval Density Conditions

Research on larval rearing and nutrition of tephritid flies on artificial diets is key for the sterile insect technique. Here, we examined the effects of the type of gel (calcium alginate, agar, or carrageenan), at varying percentages in artificial diets for the polyphagous pest Anastrepha ludens, on the physicochemical and nutritional traits of the diets, and the effects of the type of gel, the gel content and the larval density (larvae/g of diet) used in production, quality parameters for mass-reared tephritids, diet removal (an indirect estimation of diet consumption), and nutritional traits of flies. Regardless of the gel content, calcium alginate diets were firmer and more resistant to penetration than the agar and carrageenan diets. The larval recovery, pupation, pupal weight, and flight ability of A. ludens were lower in calcium alginate diets than in agar and carrageenan diets. Diet removal was higher in calcium alginate diets; however, low levels of ammonium and high levels of uric acid in excretions from larvae on these diets suggest an alteration in protein metabolism. The firmness and penetration resistance characteristics of calcium alginate diets may have limited movement and feeding of larvae, but this could be overcome by the collective feeding of large groups of larvae. Our findings provide insights into the mechanism governing gel-diet rearing systems for A. ludens.

Enzymes Immobilized into Starch- and Gelatin-Based Hydrogels: Properties and Application in Inhibition Assay

The present work is a review of the research on using hydrogels based on natural biodegradable polymers, starch, and gelatin for enzyme immobilization. This review addresses the main properties of starch and gelatin that make them promising materials in biotechnology for producing enzyme preparations stable during use and storage and insensitive to chemical and physical impacts. The authors summarize their achievements in developing the preparations of enzymes immobilized in starch and gelatin gels and assess their activity, stability, and sensitivity for use as biorecognition elements of enzyme inhibition-based biosensors.

Interface-mediated protein aggregation

The aggregation of proteins at interfaces has significant roles and can also lead to dysfunction of different physiological processes. The interfacial effects on the assembly and aggregation of biopolymers are not only crucial for a comprehensive understanding of protein biological functions, but also hold great potential for advancing the state-of-the-art applications of biopolymer materials. Recently, there has been remarkable progress in a collaborative context, as we strive to gain control over complex interfacial assembly structures of biopolymers. These biopolymer structures range from the nanoscale to mesoscale and even macroscale, and are attained through the rational design of interactions between biological building blocks and surfaces/interfaces. This review spotlights the recent advancements in interface-mediated assembly and properties of biopolymer materials. Initially, we introduce the solid-liquid interface (SIL)-mediated biopolymer assembly that includes the inorganic crystalline template effect and protein self-adoptive deposition through phase transition. Next, we display the advancement of biopolymer assembly instigated by the air-water interface (AWI) that acts as an energy conversion station. Lastly, we discuss succinctly the assembly of biopolymers at the liquid-liquid interface (LLI) along with their applications. It is our hope that this overview will stimulate the integration and progression of the science of interfacial assembled biopolymer materials and surfaces/interfaces.

Drying Technique Providing Maximum Benefits on Hydrogelling Ability of Avocado Seed Protein: Spray Drying

The current study focused on creating natural hydrogels consisting of mixtures of avocado seed proteins dried with different techniques and locust bean gum. Proteins were extracted from avocado seed by alkali and isoelectric precipitation methods. Avocado seed proteins were dried by five different drying methods, namely ambient drying, oven drying, vacuum drying, freeze drying, and spray drying. FT-IR spectra were used to analyze the chemical structure of proteins dried using various techniques. Additionally, hydrogel models were constructed in the presence of avocado seed proteins and locust bean gum to clarify the effect of drying techniques on their hydrogelling ability. The impact of drying techniques on the functional behavior of hydrogels was notable. The maximum water holding capacity values were detected in the hydrogel system containing spray-dried proteins (93.79%), followed by freeze-dried (86.83%), vacuum-dried (76.17%), oven-dried (72.29%), and ambient-dried (64.8%) counterparts. The swelling ratio was 34.10, 33.51, 23.05, 18.93, and 14.39% for gels in the presence of freeze-dried, spray-dried, vacuum-dried, oven-dried, and ambient-dried proteins, respectively. Additionally, the desirable values for the amount of protein leaking from the systems prepared using spray-dried (7.99%) and freeze-dried (12.14%) proteins were obtained compared to others (ambient-dried: 24.03%; oven-dried: 17.69%; vacuum-dried: 19.10%). Superior results in terms of textural properties were achieved in hydrogel models containing spray-dried and freeze-dried proteins. In general, hydrogel models exhibited elastic behavior rather than viscous properties; however, the magnitudes of elasticity varied. Furthermore, the success of gels containing hydrogel models containing spray-dried protein and locust bean gum in the bioactive compound delivery system was obvious compared with protein ones alone.

Editorial on Special Issue "Recent Developments in Food Gels"

Food gels have been a crucial component in the food industry for many years [...].

Food gels: principles, interaction mechanisms and its microstructure

Food hydrogels are important materials having great scientific interest due to biocompatibility, safety and environment-friendly characteristics. In the food industry, hydrogels are widely used due to their three-dimensional crosslinked networks. Furthermore, they have attracted great attention due to their wide range of applications in the food industry, such as fat replacers, encapsulating agents, target delivery vehicles, and many more. In addition to basic and recent knowledge on food hydrogels, this review exclusively focuses on sensorial perceptions, nutritional significance, body interactions, network structures, mechanical properties, and potential hydrogel applications in food and food-based matrices. Additionally, this review highlights the structural design of hydrogels, which provide the forward-looking idea for future applications of food hydrogels (e.g., 3D or 4D printing).

Food amyloid fibrils are safe nutrition ingredients based on in-vitro and in-vivo assessment

Food protein amyloid fibrils have superior technological, nutritional, sensorial, and physical properties compared to native monomers, but there is as yet insufficient understanding of their digestive fate and safety for wide consumption. By combining SDS-PAGE, ELISA, fluorescence, AFM, MALDI-MS, CD, microfluidics, and SAXS techniques for the characterization of β-lactoglobulin and lysozyme amyloid fibrils subjected to in-vitro gastrointestinal digestion, here we show that either no noticeable conformational differences exist between amyloid aggregates and their monomer counterparts after the gastrointestinal digestion process (as in β-lactoglobulin), or that amyloid fibrils are digested significantly better than monomers (as in lysozyme). Moreover, in-vitro exposure of human cell lines and in-vivo studies with C. elegans and mouse models, indicate that the digested fibrils present no observable cytotoxicity, physiological abnormalities in health-span, nor accumulation of fibril-induced plaques in brain nor other organs. These extensive in-vitro and in-vivo studies together suggest that the digested food amyloids are at least equally as safe as those obtained from the digestion of corresponding native monomers, pointing to food amyloid fibrils as potential ingredients for human nutrition.

Double network hydrogels: Design, fabrication, and application in biomedicines and foods

Research on the design, fabrication, and application of double network (DN) hydrogels, assembled from pairs of polymers, has grown recently due to their unique structural, physicochemical, and functional properties. DN hydrogels can be designed to exhibit a broader range of functional attributes than single network (SN) ones, which extends their applications in various fields. There has been strong interest in the development of biopolymer DN hydrogels because of their environmental, sustainability, and safety benefits. However, there is limited knowledge on the formation and application of these novel materials. This article reviews the principles underlying the design and fabrication of hydrogels using different crosslinking approaches, including covalent and/or non-covalent bonding, and the formation mechanisms, network structures, and functional attributes of different DN hydrogels. The impact of polymer composition, structural organization, and bonding on the mechanical and functional properties of DN hydrogels is reviewed. Potential applications of these hydrogels are highlighted, including in tissue engineering, biomedicines, and foods. The functional attributes of DN hydrogels can be tailored to each of these applications by careful selection of the biopolymers and crosslinking mechanisms used to assemble them. Finally, areas where further research are needed to overcome the current limitations of DN hydrogels are highlighted.

Mechanism behind the deterioration in gel properties of collagen gel induced by high-temperature treatments: A molecular perspective

This study aims to elucidate the mechanism behind the deterioration in the gel properties of collagen gel resulting from high-temperature treatment. The results show that the high level of triple-helix junction zones and related lateral stacking contribute to the dense and orderly collagen gel network with high gel strength and storage modulus. The analysis of the molecular properties of heated collagen shows that high-temperature treatment leads to serious denaturation and degradation of collagen, resulting in the formation of gel precursor solutions composed of low-molecular-weight peptides. The short chains in the precursor solution are not easy to nucleation and can limit the growth of triple-helix cores. To conclude, the decrease in triple-helix renaturation and crystallization abilities of peptide components is the reason for the deterioration in the gel properties of collagen gel induced by high temperature. The findings presented in this study add the understanding of texture deterioration in high-temperature processed collagen-based meat products and related products, and provide a theoretical basis for establishing methods to overcome the production dilemma faced by these products.

Perspectives on recent advancements in energy harvesting, sensing and bio-medical applications of piezoelectric gels

The development of next-generation bioelectronics, as well as the powering of consumer and medical devices, require power sources that are soft, flexible, extensible, and even biocompatible. Traditional energy storage devices (typically, batteries and supercapacitors) are rigid, unrecyclable, offer short-lifetime, contain hazardous chemicals and possess poor biocompatibility, hindering their utilization in wearable electronics. Therefore, there is a genuine unmet need for a new generation of innovative energy-harvesting materials that are soft, flexible, bio-compatible, and bio-degradable. Piezoelectric gels or PiezoGels are a smart crystalline form of gels with polar ordered structures that belongs to the broader family of piezoelectric material, which generate electricity in response to mechanical stress or deformation. Given that PiezoGels are structurally similar to hydrogels, they offer several advantages including intrinsic chirality, crystallinity, degree of ordered structures, mechanical flexibility, biocompatibility, and biodegradability, emphasizing their potential applications ranging from power generation to bio-medical applications. Herein, we describe recent examples of new functional PiezoGel materials employed for energy harvesting, sensing, and wound dressing applications. First, this review focuses on the principles of piezoelectric generators (PEGs) and the advantages of using hydrogels as PiezoGels in energy and biomedical applications. Next, we provide a detailed discussion on the preparation, functionalization, and fabrication of PiezoGel-PEGs (P-PEGs) for the applications of energy harvesting, sensing and wound healing/dressing. Finally, this review concludes with a discussion of the current challenges and future directions of P-PEGs.

Physicochemical properties and in vitro digestion behavior of emulsion gels stabilized by rice bran protein aggregates: Effects of heating time and induction methods

To investigate the effects of heating time and induction methods on the physicochemical properties and in vitro digestion behavior of emulsion gels, rice bran protein aggregates (RBPAs) were formed by acid-heat induction (90 °C, pH 2.0) and the emulsion gels were further prepared by adding GDL or/and laccase for single/double cross-linked induction. Heating time affected the aggregation and oil/water interfacial adsorption behavior of RBPAs. Suitable heating (1-6 h) was conducive to faster and more adsorption of aggregates at the oil/water interface. While excessive heating (7-10 h) resulted in protein precipitation, which inhibited the adsorption at the oil/water interface. The heating time at 2, 4, 5 and 6 h was thus chosen to prepare the subsequent emulsion gels. Compared with the single cross-linked emulsion gels, the double-cross-linked emulsion gels showed higher water holding capacity (WHC). After simulated gastrointestinal digestion, the single/double cross-linked emulsion gels all exhibited slow-release effect on free fatty acid (FFA). Moreover, the WHC and final FFA release rate of emulsion gels were closely related to the surface hydrophobicity, molecular flexibility, sulfhydryl, disulfide bond and interface behavior of RBPAs. Generally, these findings proved the potential of emulsion gels in designing fat alternatives, which could provide a novel technique for the fabrication of low-fat food.

Nordic Crops as Alternatives to Soy-An Overview of Nutritional, Sensory, and Functional Properties

Soy (Glycine max) is used in a wide range of products and plays a major role in replacing animal-based products. Since the cultivation of soy is limited by cold climates, this review assessed the nutritional, sensory, and functional properties of three alternative cold-tolerant crops (faba bean (Vicia faba), yellow pea (Pisum sativum), and oat (Avena sativa)). Lower protein quality compared with soy and the presence of anti-nutrients are nutritional problems with all three crops, but different methods to adjust for these problems are available. Off-flavors in all pulses, including soy, and in cereals impair the sensory properties of the resulting food products, and few mitigation methods are successful. The functional properties of faba bean, pea, and oat are comparable to those of soy, which makes them usable for 3D printing, gelation, emulsification, and extrusion. Enzymatic treatment, fermentation, and fibrillation can be applied to improve the nutritional value, sensory attributes, and functional properties of all the three crops assessed, making them suitable for replacing soy in a broad range of products, although more research is needed on all attributes.

Tailoring Food Biopolymers into Biogels for Regenerative Wound Healing and Versatile Skin Bioelectronics

An increasing utilization of wound-related therapeutic materials and skin bioelectronics urges the development of multifunctional biogels for personal therapy and health management. Nevertheless, conventional dressings and skin bioelectronics with single function, mechanical mismatches, and impracticality severely limit their widespread applications in clinical. Herein, we explore a gelling mechanism, fabrication method, and functionalization for broadly applicable food biopolymers-based biogels that unite the challenging needs of elastic yet injectable wound dressing and skin bioelectronics in a single system. We combine our biogels with functional nanomaterials, such as cuttlefish ink nanoparticles and silver nanowires, to endow the biogels with reactive oxygen species scavenging capacity and electrical conductivity, and finally realized the improvement in diabetic wound microenvironment and the monitoring of electrophysiological signals on skin. This line of research work sheds light on preparing food biopolymers-based biogels with multifunctional integration of wound treatment and smart medical treatment.

Legume protein/polysaccharide food hydrogels: Preparation methods, improvement strategies and applications

For the development of innovative foods and nutritional fortification, research into food gel is essential. As two types of rich natural gel material, both legume proteins and polysaccharides have high nutritional value and excellent application potential, attracting wide attention worldwide. Research has focused on combining legume proteins with polysaccharides to form hybrid hydrogels as their combinations show improved texture and water retention compared to single legume protein or single polysaccharide gels, and these properties can be tailored for specific applications. This article reviews hydrogels of common legume proteins and discusses heat induction, pH induction, salt ion induction, and enzyme-induced assembly of legume protein/polysaccharide mixtures. The applications of these hydrogels in fat replacement, satiety enhancement, and delivery of bioactive ingredients are discussed. Challenges for future work are also highlighted.

CO2-responsive gels

CO₂-responsive materials undergo a change in chemical or physical properties in response to the introduction or removal of CO₂. The use of CO₂ as a stimulus is advantageous as it is abundant, benign, inexpensive, and it does not accumulate in a system. Many CO₂-responsive materials have already been explored including polymers, latexes, surfactants, and catalysts. As a sub-set of CO₂-responsive polymers, the study of CO₂-responsive gels (insoluble, cross-linked polymers) is a unique discipline due to the unique set of changes in the gels brought about by CO₂ such as swelling or a transformed morphology. In the past 15 years, CO₂-responsive gels and self-assembled gels have been investigated for a variety of emerging potential applications, reported in 90 peer-reviewed publications. The two most widely exploited properties include the control of flow (fluids) via CO₂-triggered aggregation and their capacity for reversible CO₂ absorption-desorption, leading to applications in Enhanced Oil Recovery (EOR) and CO₂ sequestration, respectively. In this paper, we review the preparation, properties, and applications of these CO₂-responsive gels, broadly classified by particle size as nanogels, microgels, aerogels, and macrogels. We have included a section on CO₂-induced self-assembled gels (including poly(ionic liquid) gels).

Multi-dimensional analysis of heat-induced soybean protein hydrolysate gels subjected to ultrasound-assisted pH pretreatment

This study aimed to evaluate the gelation characteristics of soybean protein hydrolysate (SPH) extracted by enzyme-assisted aqueous extraction. Specifically, the changes in gelation behaviors for heat-induced (95 °C, 20 min) SPH dispersions treated with pH (pH 3, 5, 9; pH 7 as control) and ultrasound (U; 240 W, 30 min) were investigated. The results showed that typical gel behavior with high elastic nature in the viscoelasticity and network structures were observed during the heating process, where the disulfide bond played a dominant role in the gel network formation of all the samples. Notably, the heat-induced aggregation in the SPH gels was mainly formed by the association of the basic B polypeptide in 11S and β subunit in 7S. The most superior SPH gel was formed at pH 7 when assisted by ultrasonication during the heating process. This as-synthesized gel showed a uniform filamentous structure and exhibited the more excellent textural, rheological and thermal properties than those of the samples formed under acidic and alkaline conditions. These results are of great value in revealing the gelation mechanism of SPH.

Construction of transglutaminase covalently cross-linked hydrogel and high internal phase emulsion gel from pea protein modified by high-intensity ultrasound

BACKGROUND

The poor gelling and emulsification properties of pea protein (PeaP) limit its application in gel-based products. In this study, a strong hydrogel and a high internal phase emulsion (HPLE) gel of PeaP were constructed by covalent cross-linking of transglutaminase (TGase) assisted by high-intensity ultrasound.

RESULTS

Ultrasound promoted the catalytic efficiency of TGase, with the gel-point temperature dropping from 44 °C to 28 °C after 10 min of ultrasound. As the ultrasound time increased from 1 min to 10 min, the microstructure of the hydrogel also changed from an irregular macropore structure to a relatively homogeneous honeycomb structure. This was accompanied by an improvement in gel strength, water holding capacity, and ultimate stress. Ultrasound enhanced the binding of water to PeaP, but had little effect on the water-locking ability of the network structure. Ultrasonication improved the self-supporting ability of the HPIE gels. The oil droplets within the HPIE gels were closely aligned to form a hexagonal structure. The PeaP layer was further cross-linked by TGase, strengthening the network structure. High internal phase emulsion gel displayed a higher gel strength, viscosity, and good self-healing ability under 1 min ultrasound. Meanwhile, HPIE gel at 1 min of ultrasound could be printed with the highest clarity.

CONCLUSION

This work provided some insights into improving the functional properties of PeaP, which is helpful for the design and development of PeaP-based gel products. © 2022 Society of Chemical Industry.

Tuning the electrostatic interaction between rice protein and carboxymethyl cellulose toward hydrophilic composites with enhanced functional properties

Protein-polysaccharide interactions have attracted much attention due to inherent potential in generating new structures and functionalities. In the present study, by simply mixing rice proteins (RPs) with carboxymethyl cellulose (CMC) at pH 12.0 prior neutralization, novel protein-polysaccharide complexes (RCs) were structured with water dispersibility and functionalities highly dependent on the degree of substitution (DS) and molecular weight (Mw) of CMC. Specifically, the water-dispersibility of RPs was increased from 1.7 % to 93.5 % at a RPs/CMC mass ratio of 10:1 with CMC of DS1.2 (Mw = 250 kDa). Fluorescence and circular dichroism spectra showed suppressed folding tendency of RPs by CMC during neutralizing the basicity, indicating controllable protein conformations. Furthermore, the structures of RCs became more unfolded for CMC with a larger DS or a smaller Mw. This enabled RCs with highly controllable functionalities in terms of emulsifying and foaming properties, which may have promising applications in developing food matrix with customized structures and textures.

Role of the in-situ-produced dextran by lactic acid bacteria in the texture modification of pea flour pastes

The application of pea flour (PF) was restricted by the resulting non-satisfying texture of food with a high addition level of PF. Four lactic acid bacteria (LAB) strains with the ability to synthesize dextran (DX) were used to ferment PF in order to modify the texture of PF pastes, screen out promising DX producers, and evaluate the role of the in-situ-produced DX in texture modification. The microbial growth, acidity, and DX contents of PF pastes were first analyzed. Then, the rheological and textural properties of PF pastes after fermentation were assessed. After this, the in-situ-produced DXs in PF pastes were further hydrolyzed, and the corresponding changes were studied. Finally, the protein and starch in PF pastes were hydrolyzed separately to evaluate the role of macromolecular interactions between DX and protein/starch in the texture modification of PF pastes. The four LAB strains were all dominant in PF pastes, and the in-situ-produced DXs by these four strains played a critical role in the texture modification of PF pastes. Among the four DX-positive strains, Ln. pseudomesenteroides DSM 20193 and W. cibaria DSM 15878 were promising DX producers in PF-based media due to their high capacity in synthesizing DX and texture modification. The in-situ-produced DX promoted the formation of a porous network structure that was important for water-holding and texture-retaining. The DX-protein interaction contributed more to the texture modification of PF pastes than did the DX-starch interaction. This study clearly showed the role of the in-situ-produced DX and the DX-protein/starch interactions in the texture modification of PF pastes, which could further guide the utilization of in-situ-produced DXs in legume-based food and promote the exploitation of plant proteins.

Konjac glucomannan/xanthan gum/sodium alginate composite hydrogel simulates fascial tissue by pre-stretching and moisture regulation

Improving the mechanical strength and creating an anisotropic structure of edible macromolecular hydrogels is crucial to accurately simulate the texture of connective tissues. In this study, konjac glucomannan (KGM), xanthan gum (XG), and sodium alginate (SA) were used to construct hydrogels, and the effects of different pre-stretching degrees and moisture control on the composite gels were investigated. The results of the mechanical property tests and microstructure tests indicate that pre-stretching and moisture control can significantly enhance the strength of the gels and induce anisotropic structures. In addition, the feasibility of the composite gel structure in simulating brisket fascia was investigated, and it was concluded that 1.5 × -DR samples were most suitable for simulating connective tissue. This study provides compelling evidence for the potential of macromolecular hydrogels in simulating connective tissue and provides theoretical guidance for regulating gel texture.

The Rising Aerogel Fibers: Status, Challenges, and Opportunities

Aerogel fibers garner tremendous scientific interest due to their unique properties such as ultrahigh porosity, large specific surface area, and ultralow thermal conductivity, enabling diverse potential applications in textile, environment, energy conversion and storage, and high-tech areas. Here, the fabrication methodologies to construct the aerogel fibers starting from nanoscale building blocks are overviewed, and the spinning thermodynamics and spinning kinetics associated with each technology are revealed. The huge pool of material choices that can be assembled into aerogel fibers is discussed. Furthermore, the fascinating properties of aerogel fibers, including mechanical, thermal, sorptive, optical, and fire-retardant properties are elaborated on. Next, the nano-confining functionalization strategy for aerogel fibers is particularly highlighted, touching upon the driving force for liquid encapsulation, solid-liquid interface adhesion, and interfacial stability. In addition, emerging applications in thermal management, smart wearable fabrics, water harvest, shielding, heat transfer devices, artificial muscles, and information storage, are discussed. Last, the existing challenges in the development of aerogel fibers are pointed out and light is shed on the opportunities in this burgeoning field.

Fibrillization kinetics and rheological properties of panda bean (Vigna umbellata (Thunb.) Ohwi et Ohashi) protein isolate at pH 2.0

Recently, research interests are growing regarding the formation and mechanisms of amyloid fibrils from plant proteins. This study investigated the fibrillization kinetics and rheological behaviors of panda bean protein isolate (PBPI) at pH 2.0 and 90 °C for various heating times (0-24 h). Results showed that PBPI formed two distinct classes of fibrils after heating for 10 h, including flexible fibril with a contour length of ∼751 nm, and rigid fibril with periodicity of ∼40 nm. The secondary structural changes during fibril formation were monitored by circular dichroism spectroscopy and indicated that β-sheet content increased first (0-12 h) and then decreased (>12 h), which coincided with similar changes in thioflavin T fluorescence. The gel electrophoresis revealed that the polypeptides of PBPI were progressively hydrolyzed upon heating, and the resulting short fragments were involved in fibril formation rather than PBPI monomer. PBPI-derived fibrils showed extremely high viscosity and storage modulus. A plausible molecular mechanism for PBPI fibrillation process was hypothesized, including protein unfolding, hydrolysis, assembly into matured fibrils, and dissociation of the fibrils. The findings provide useful information to manipulate the formation of legume proteins-based fibrils and will benefit future research to explore their potential applications.