Improvement of processable properties of plant-based high internal phase emulsions by mung bean protein isolate based on pH shift treatment.

BACKGROUND: High internal phase emulsions (HIPEs) are unique emulsion systems that transform liquid oil into solid-like fats, thus avoiding the use of saturated fat and leading to a healthier and more sustainable food system for consumers. HIPEs with oil volume fraction (ϕ) of 75-85% were fabricated with mung bean protein isolate (MPI) under different pH shift treatments at 1.0% concentration through the one-step method. In the present study, we investigated the physical properties, microstructures, processing properties, storage stability and rheological properties of HIPEs. RESULTS: The results suggested that the properties of MPI under different pH shift treatments were improved to different degrees, stabilizing HIPEs (ϕ = 75-85%) with various processability to meet food processing needs. Under alkali shift treatment conditions, the particle size of MPI was significantly reduced with better solubility. Moreover, the exposure of hydrophobic groups increased the surface hydrophobicity of MPI, awarding MPI better emulsifying properties, which could stabilize the HIPEs with higher oil phase fraction. In addition, the MPI under pH 12 shift treatment (MPI-12) had the best oil-carrying ability to form the stable HIPEs with oil volume fraction (ϕ) up to 85%, which was the highest oil phase in preparing the HIPEs using plant protein solely at a low concentration under neutral conditions. CONCLUSION: A series of stable HIPEs with different processing properties was simply and feasibly fabricated and these are of great potential in applying edible HIPEs. © 2024 Society of Chemical Industry.

Effect of tannic acid modification on the interface and emulsification properties of zein colloidal particles.

BACKGROUND: Interface modification driven by supramolecular self-assembly has been accepted as a valuable strategy for emulsion stabilization enhancement. However, there has been a dearth of comparative research on the effect of simple complexation and assembly from the perspective of the responsible mechanism. RESULTS: The present study selected zein and tannic acid (TA) as representative protein and polyphenol modules for self-assembly (coined as TA-modified zein particle and TA-zein complex particle) to explore the surface properties and interfacial behavior, as well as the stability of constructed Pickering emulsions to obtain the regulation law of different modification methods on the interfacial behavior of colloidal particles. The results demonstrated that TA-modified zein colloidal particles potentially improved the emulsifying properties. When the TA concentration was 3 mmol L-1 , the optimized TA-modified zein particle was nano-sized (109.83 nm) and had advantageous interfacial properties, including sharply reduced surface hydrophobicity, as well as a low diffusion rate at the oil/water interface. As a result, the shelf life of Pickering emulsion containing 50% oil phase was extended to 90 days. CONCLUSION: Through multi-angled research on the properties of the interfacial membrane, improvement of emulsion stability was a result of the formation of viscoelastic interfacial film that resulted from the decrease of absorption rate between particles and interface. Using refined regulation to investigate the role of different sample preparation methods from a mechanistic perspective. Overall, the present study has provided a reference for TA to regulate the surface properties and interface behavior of zein colloidal particles, enriched the understanding of colloidal interface assembly, and provided a theoretical basis for the quality control of interface-oriented food systems. © 2023 Society of Chemical Industry.

Highly Adhesive Amyloid-Polyphenol Hydrogels for Cell Scaffolding.

Rationally designing microstructures of soft hydrogels for specific biological functionalization is a challenge in tissue engineering applications. A novel and affordable soft hydrogel scaffold is constructed here by incorporating polyphenol modules with lysozyme amyloid fibrils (Lys AFs) via non-covalent self-assembly. Embedded polyphenols not only trigger hydrogel formation but also determine gel behavior by regulating the polyphenol gallol density and complex ratio. The feasibility of using a polyphenol-Lys AF hydrogel as a biocompatible cell scaffold, which is conducive to cell proliferation and spreading, is also shown. Notably, introducing polyphenols imparts the corresponding hydrogels a superior cell bioadhesive efficiency without further biofunctional decoration and thus may be successfully employed in both healthy and cancer cell lines. Confocal laser scanning microscopy also reveals that the highly expressed integrin-mediated focal adhesions form due to stimulation of the polyphenol-AF composite hydrogel, direct cell adhesion, proliferation, and spreading. Overall, this work constitutes a significant step forward in creating highly adhesive tissue culture platforms for in vitro culture of different cell types and may greatly expand prospects for future biomaterial design and development.

Stabilization of high internal-phase Pickering emulsion using nobiletin crystals: assembly of supramolecular metal-polyphenolic coordination complexes for surface coating.

BACKGROUND: High internal-phase Pickering emulsions have attracted interest due to their unique properties and they have the potential for broad application in the food field, for example as fat replacers, for packaging, for delivery of nutrients or probiotics, and in the 3D printing of food. However, efficient and edible high internal-phase Pickering stabilizers are still a persistent challenge for food scientists. RESULTS: Nobiletin (NOB) was selected as a model substance. The particles' physicochemical properties (droplet size, rheological behavior, and transmission profile) showed that supramolecular metal-polyphenolic coordination networks could suppress the ripening and growth of crystals on the oil-water interface. When the ratio of tannic acid (TA) to Fe3+ was 3:1, the growth of NOB crystals could be inhibited effectively. Due to the reduction of energy steric hindrance in the adsorption process, the resulting NOB-TA3 -Fe3+ 1 (NT3 Fe1 ) nanoparticles had the greatest potential to extend emulsion storage time. CONCLUSION: The NOB-TA3 -Fe3+ 1 (NT3 Fe1 ) nanoparticles were able to stabilize a high internal-phase emulsion, of which the oil phase was 80%, for at least 30 days, eventually leading to high system viscosity. The findings in this work provide a novel selection of healthy emulsifiers and an effective emulsion delivery system for hydrophobic and crystalline nutrients. © 2023 Society of Chemical Industry.

Sodium caseinate enhances the effect of konjac flour on delaying gastric emptying based on a dynamic in vitro human stomach-IV (DIVHS-IV) system.

BACKGROUND: In the context of the increasing prevalence of overweight and obesity worldwide, satiety-enhancing foods may help people control their energy intake and weight. In this study, an advanced near-real human gastric simulator equipped with a dynamic in vitro human stomach-IV (DIVHS-IV) system was used to determine the gastric digestion and gastric retention ratio of konjac flour (KF)/sodium caseinate (SC) mixtures with different ratios. RESULTS: The apparent viscosity, viscoelastic properties, confocal laser scanning microscopy (CLSM) of the digested products were collected and analyzed to further study the effect of SC on the physical properties of KF during digestion. The results showed that the addition of SC could enhance the effect of KF on delaying gastric emptying in vitro. Besides, the addition of SC was shown to weaken the effect of gastric juice on the dilution of gastric contents by forming SC gel blocks in the acid environment. In particular, the synergistic gastric emptying delaying effect was the strongest in the KF/SC mixture containing 1% KF and 8% SC, and obvious massive aggregates were observed. CONCLUSION: The combination of 1% KF and 8% SC was shown to synergistically delay gastric emptying and potentially enhance the sense of fullness. © 2022 Society of Chemical Industry.

Fabrication and characterization of Pickering emulsions stabilized by desalted duck egg white nanogels and sodium alginate.

BACKGROUND: The waste of salted egg white resources has always been a serious problem in the food industry. In this current study, we report on a kind of Pickering emulsion system, which was stabilized by duck egg white nanogels (DEWNs) and sodium alginate (SA), followed by which this system was crosslinked by calcium carbonate (CaCO3 ) via controlling the gluconolactone (GDL) concentrations, aiming to open up a promising route for making full use of these protein resources. RESULTS: The droplet size of the emulsion exhibited a reduction with an increase in SA concentrations, indicating that higher negative charges and steric hindrance was useful for a stable emulsion system. Meanwhile, the result of rheology measurement showed that storage modulus (G') values were higher than loss modulus (G″) values of the samples at higher GDL concentration, revealing the formation of elastic gel-like networks in the system, which was fabricated by SA and Ca2+ released by the CaCO3 particles. The gel-like network structure in the continuous phase improved both the freeze-thaw and thermal stability of the obtained Pickering emulsion system. Encouragingly, the Pickering high internal phase emulsions (HIPEs, φ = 0.75) stabilized by DEWN/SA3 -GDL3 were prepared, which could be stored at 4 °C for at least 30 days without oiling-off and creaming. CONCLUSION: These findings not only develop a green ultra-stable Pickering emulsion system but also extend the potential commercial applications of duck egg white proteins in the food, cosmetics, and pharmaceutical industries. © 2021 Society of Chemical Industry.

An innovative konjac glucomannan/κ-carrageenan mixed tensile gel.

BACKGROUND: Konjac glucomannan (KGM) showed a synergistic interaction with κ-carrageenan (CAR), which led to the formation of a promising compound hydrocolloid gel in the food field (such as jelly). Nevertheless, the mixed gels formed by adding KGM to CAR still displayed defects in gel strength and syneresis, and would hardly meet the quality requirements of some gel foods. However, deacetylated KGM and maltodextrin (MD) have always been used in gel foods and affect their viscosity and rheological properties. RESULTS: In our paper, different amounts of MD were first used to alter the textural properties, and the results showed that both tensile strength and elongation exhibited first an increasing and then a decreasing trend with the increasing MD proportion and achieved a maximum at a final maltodextrin proportion of 4 g kg-1 in the KGM/CAR/MD system. Based on the above results, we further explored the effects of deacetylation degree of KGM on the gel properties of mixed gel system. The results revealed that, compared to the native KGM, the partial deacetylated KGM was capable of significantly improving the tensile strength and elongation of KGM/CAR mixed gel. CONCLUSION: Our study found that the appropriate addition of MD (0.4%) and DKGM were able to alter the tensile properties of KGM/CAR mixed gel, with potential to meet the needs of consumers and further design innovative tensile gel products in the soft gel industry. © 2021 Society of Chemical Industry.

Phytosterols disaggregate bovine serum albumin under the glycation conditions through interacting with its glycation sites and altering its secondary structure elements.

Discovering small molecules with protein-disaggregation effects is recently needed. For the first time, we intensely studied the anti-amyloidogenic effects of 3 structurally different phytosterols (PS), namely stigmasterol, ß-sitosterol, and γ-oryzanol, on bovine serum albumin (BSA) under aggregations-promoting conditions using multispectral, microstructure, and molecular docking methods. Results found that PS dose- and structure- dependently inhibited BSA-aggregations under the glycation conditions through separating BSA-peak size, quenching Tryptophan-intensity, altering BSA-hydrophobicity, and microstructural declining the aggregates of glycated-BSA. Throughout the underlying mechanism beyond its disaggregation effects, PS reformed cross-ß-sheet structure, SDS-PAGE-bands, and XRD-peaks of glycated-BSA aggregates. Most importantly, PS were found to bind with some lysyl and arginine glycation sites of BSA, specifically Lys114, Lys116, Lys136, Lys431, Arg427, and Arg185, via Hydrogen-bonding with their -OH-groups and pi-pi interactions of their steroid core. Taken together, the current results unleash that PS could restrict BSA-aggregations under the glycation conditions and their subsequent changes, which can assist in the design of reasonable therapeutics.

The noncovalent conjugations of bovine serum albumin with three structurally different phytosterols exerted antiglycation effects: A study with AGEs-inhibition, multispectral, and docking investigations.

The antiglycation effects of three structurally different phytosterols (PS) including stigmasterol, ß-sitosterol, and γ-oryzanol on bovine serum albumin (BSA) were deeply studied in a BSA-glucose model by measuring the glycoxidation-based products, SDS-PAGE intensity, free lysine, and their fluorescence microscopy clicks. For the first time, the underlying mechanisms of the antiglycation effects of PS were wholly elucidated by measuring their interaction ability with BSA and their antiradical activity during the glycation reactions. The results showed that PS could partially inhibit the formation of advance glycation end products, block some of the lysyl residues of BSA (Lys127, 357, 434, and 524), prevent the glucose-BAS bonding, and their disaggregation effects on the glycated BSA. Throughout the underlying mechanism behind the antiglycation activity, PS were found to structurally quench the fluorescence intensity of BSA in a static mode, leading to fluctuations in its Z-average size, UV-vis spectrum, and secondary structure. Additionally, PS mitigated the formation the advanced glycation end products by scavenging the radicals produced during the glycation reactions. Overall, these results unleash that PS prevent the glycation reactions and their subsequent changes through shielding the NH2 groups via H-bonding with their OH-groups and pi-pi interaction of the steroid core, besides the antiradical activity of PS on the free radicals generating during the glycation reactions.

Food Hydrocolloids: Structure, Properties, and Applications.

Hydrocolloids are extensively used in the food industry for various functions, including gelling, thickening, stabilizing foams, emulsions, and dispersions, as well as facilitating the controlled release of flavor [...].

Constructing gellan gum/konjac glucomannan/wheat fiber composite hydrogel to simulate edible cartilage by ionic cross-link and moisture regulation.

The utilization of non-animal-derived materials to imitate cartilage is critical for the advancement of plant-based simulated meat. In this study, gellan gum (GG), konjac glucomannan (KGM), and wheat fiber (WF) were used to construct hydrogel, and the mechanical strength, water properties, and microstructure were regulated by constructing Ca2+ cross-links and moisture control. The hardness, chewiness, resilience, shear force, and shear energy of the Ca2+ cross-linked samples were significantly improved. Extrusion dehydration further changes the related mechanical properties of the hydrogel and results in a tighter microstructure. The findings suggest that the establishment of Ca2+ cross-links and water regulation are efficacious techniques for modifying the texture of the GG/KGM/WF composite hydrogel. Correlation analysis and sensory evaluation showed that the test indexes and sensory scores of the samples with Ca2+ crosslinking and 80 % moisture content were similar to chicken breast cartilage, and the samples with Ca2+ crosslinking and 70 % moisture content were similar to pig crescent bone. This study presents a framework for designing edible cartilage simulators using polysaccharide hydrogels, with implications for enhancing the resemblance of plant-based meat products to real meat and expanding the range of vegetarian offerings available.

Formulations and assessments of structure, physical properties, and sensory attributes of soy yogurts: Effect of carboxymethyl cellulose content and degree of substitution.

Soy yogurts present challenges, including absence of tender and slipperiness mouthfeel, and poor stability. This study aimed to investigate the impacts of carboxymethyl cellulose (CMC) with degrees of substitution of 0.7 (CMC0.7) and 1.2 (CMC1.2) at concentrations ranging from 0 % to 1.1 % on the stability, microstructure, rheology, tribology, and mouthfeel of soy yogurts. As the CMC concentration increased from 0 % to 0.3 %, soy yogurts displayed a coarser microstructure, decreased stability, and increased gel strength. As the concentration of CMC further increased from 0.5 % to 1.1 %, soy yogurts exhibited trends of a smoother microstructure, increased stability, and softer gel strength. Notably, soy yogurts with CMC0.7 demonstrated a superior water holding capacity (WHC) than soy yogurts with CMC1.2. Tribological measurements indicated that soy yogurts with CMC0.7 at a 0.7 % concentration had the lowest coefficient of friction (COF) value among most sliding speeds, showing a 23 % reduction compared to soy yogurts without CMC at a sliding speed of 10 mm/s. Moreover, sensory evaluation showed that soy yogurts with CMC0.7 at a 0.7 % concentration had the highest total score in mouthfeel evaluation. Therefore, the addition of CMC0.7 within the concentration range of 0.5 % to 1.1 % may produce stable and delicate yogurts.

Construction of a soybean protein isolate/polysaccharide-based whole muscle meat analog: Physical properties and freeze-thawing stability study.

A growing interest has arisen in recreating real meat by mimicking its texture characteristics and muscle fiber structure. Our previous work successfully created meat analog fiber based on soybean protein isolate (SPI) and sodium alginate (SA) with the wet-spinning method. In this work, we analyzed the microstructure, texture profile, and water retainability of the assembled plant-based whole muscle meat analog (PMA) made of SPI/SA-based meat analog fiber and systematically studied the effect of different combinations and contents of transglutaminase (TG), salt, and soybean oil on the rheological behavior of the formulated adhesive. The estimated optimal condition that has the most similar texture characteristic with real chicken breast meat is: for every 1:1 mass ratio of simulated plant meat fibers to the adhesive, add 0.1 % TG enzyme addition in the adhesive and 100 mM NaCl addition. The physical behavior of PMA during cryopreservation was investigated through freeze-thaw cycles and freezing times. The addition of a small amount of oil and salt can efficiently prevent the PMA through freezing conditions which is comparable with the addition of D-Trehalose (TD). Overall, this study not only created a plant-based whole muscle meat analog product that is similar in texture to real chicken breast meat but also provided a new direction for constructing fiber-rich structure protein-based muscle meat analogs and their further commercialization.

Construction and Properties of Oil-Loaded Soybean Protein Isolate/Polysaccharide-Based Meat Analog Fibers.

Rationally designing the fibrous structure of artificial meat is a challenge in enriching the organoleptic quality of meat analogs. High-quality meat analog fibers have been obtained by wet-spinning technique in our previous study, whereas introducing oil droplets will further achieve their fine design from the insight of microstructure. Herein, in this current work, oil was introduced to the soybean protein isolate/polysaccharide-based meat analog fibers by regulating the oil droplets' size and content, which, importantly, controlled the spinning solution characterization as well as structure-related properties of the meat analog fiber. Results showed that the oil dispersed in the matrix as small droplets with regular shapes, which grew in size as the oil content increased. Considering the effect of oil droplets' size and content on the spinnability of the spinning solution, the mechanical stirring treatment was chosen as the suitable treatment method. Importantly, increasing the oil content has the potential to enhance the juiciness of meat analog fibers through improvements in water-holding capacity and alterations in water mobility. Overall, the successful preparation of oil-loaded plant-based fiber not only mimicked animal muscle fiber more realistically but also provided a general platform for adding fat-soluble nutrients and flavor substances.

Mechanism of Reduced Glutathione Induced Lysozyme Defolding and Molecular Self-Assembly.

The distinctive assembly behaviors of lysozyme (Lys) feature prominently in food, materials, biomedicine, and other fields and have intrigued many scholars. Although our previous work suggested that reduced glutathione (GSH) could induce lysozyme to form interfacial films at the air/water interface, the underlying mechanism is still obscure. In the present study, the effects of GSH on the disulfide bond and protein conformation of lysozyme were investigated by fluorescence spectroscopy, circular dichroism spectroscopy, and infrared spectroscopy. The findings demonstrated that GSH was able to break the disulfide bond in lysozyme molecules through the sulfhydryl/disulfide bond exchange reaction, thereby unraveling the lysozyme. The ß-sheet structure of lysozyme expanded significantly, while the contents of α-helix and ß-turn decreased. Furthermore, the interfacial tension and morphology analysis supported that the unfolded lysozyme tended to arrange macroscopic interfacial films at the air/water interface. It was found that pH and GSH concentrations had an impact on the aforementioned processes, with higher pH or GSH levels having a positive effect. This paper on the exploration of the mechanism of GSH-induced lysozyme interface assembly and the development of lysozyme-based green coatings has better instructive significance.

Pickering emulsions stabilized by homogenized ball-milled eggshell particles in combination with sodium alginate.

Eggshells, by-products of egg processing, were ball-milled and homogenized into particles (eggshell particles, ESPs) and then were used as the stabilizer with a two-step oil addition method to produce Pickering emulsions. Meanwhile, sodium alginate (SA) was used to modify the emulsifying ability of ESPs. The results indicated that SA addition helped to improve the dispersion performance and increase the negative charge of ESPs. Pickering emulsions stabilized by ESPs/SA showed much smaller particle size than those stabilized by ESPs. The maximum oil fraction in the ESPs/SA-stabilized emulsions reached up to 0.8, while that was only 0.75 in ESPs-stabilized emulsions. The presence of SA significantly enhanced the freeze-thaw, thermal, dilution, and centrifuge stability of ESPs-stabilized Pickering emulsions. The findings demonstrate the potential of eggshell particles as a kind of natural Pickering stabilizer, which will increase the high value-added utilization of poultry egg industry by-products.

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.

Physicochemical properties, phenolic content and in vitro digestion profile of Chinese black rice (Oryza sativa L.).

Yangxian black rice, as one of the ancient Chinese black rice varieties, is widely planted in the Yangxian area of China. This study investigated the physicochemical properties, phenolic content and in vitro digestion profile of Chinese black rice under gradient milling treatment. The chemical composition, color, pasting and thermal properties of black rice with different milling degrees were comprehensively compared. In vitro digestion analysis indicated that cooked rice flour had higher rapidly digestible starch (RDS) and lower resistant starch (RS) contents compared with the uncooked one. Besides, all cooked black rice samples exhibited high predicted glycemic index (pGI) value and whole black rice showed a lower pGI than refined rice. The microstructure and the abundance of phenolic compounds in the solid matrix during different treatments or digestion stages were observed by CLSM. Furthermore, a total of 102 phenolic constituents were absolutely quantified by targeted metabolomics techniques. Methanol extraction and moderate cooking treatment contributed to the release of phenolic compounds from the solid matrix of whole black rice. Besides, compared to the gastric digestion stage, the transition in the intestinal environment caused a decrease in the majority of the analyzed polyphenols. Identifying the phenolic constituents was favorable for a better elucidation of the chemical basis of the function and nutritional value of Chinese black rice.

Effect of Ultrasound and Salt on Structural and Physical Properties of Sodium Alginate/Soy Protein Isolates Composite Fiber.

Recently, there has been a growing interest in advancing plant-based or cultured meat substitutes as environmentally and ethically superior alternatives to traditional animal-derived meat. In pursuit of simulating the authentic meat structure, a composite fiber composed primarily of soy protein isolates (SPIs) was fashioned, employing a fiber-based plant-based analog meat construct. To refine the spinning process and enhance fiber quality, we employed ultrasound treatment, a physical modification technique, to scrutinize its influence on SPI protein structure. This inquiry extended to the examination of the interplay between sodium alginate (SA) and SPI, as well as the impact of salt ions on the SA and ultrasound soy protein isolates (USPI) interaction. A comprehensive exploration encompassing ultrasound treatments and salt concentrations within the composite solution, along with their repercussions on composite fiber characterization, with a rise in negative zeta potential value, states the ultrasound treatment fosters protein aggregation. Moreover, the introduction of salt augments protein aggregation as salt content escalates, ultimately resulting in a reduced structural viscosity index and improved spinnability. The presence of Ca2+ ions during the coagulation process leads to interactions with SA. The involvement of ultrasound prompts the exposure of hydrophilic amino acid segments in the protein to water, leading to the development of a more porous structure. Solely under the influence of ultrasound, the fiber exhibits 5% higher water-holding capacity and superior mechanical properties while maintaining comparable thermal stability.