Dextran sulfate facilitates egg white protein to form transparent hydrogel at neutral pH: Structural, functional, and degradation properties

Insights into the fabrication and antibacterial effect of fibrinogen hydrolysate-carrageenan loading apigenin and quercetin composite hydrogels

Escherichia coli and Staphylococcus aureus are the most prevalent pathogenic bacteria, often resulting in the foodborne disease outbreaks through food spoilage and foodborne infections. To prevent and control food spoilage and foodborne infections induced by Escherichia coli and Staphylococcus aureus, the antibacterial hydrogels were fabricated using fibrinogen hydrolysate-carrageenan (AHs-C) and flavonoids (apigenin and quercetin), and the antibacterial effect of the composite hydrogels against Escherichia coli and Staphylococcus aureus was further investigated. The results of mechanical property exhibited that the composite hydrogels with 0.2 % of apigenin and quercetin (AHs-C-Ap/Que) showed the highest hardness and swelling property compared with the separate addition of apigenin or quercetin. Scanning electron microscopy and atomic force microscopy showed that the dense networks were formed in the hydrogels of AHs-C-Ap/Que., and the average roughness of AHs-C-Ap/Que. significantly increased to 30.70 nm compared with AHs-C. 1H NMR and FTIR spectra demonstrated that apigenin and quercetin were bound to AHs-C by hydrogen bond, hydrophobic interaction and Schiff base, where the interactions between Ap/Que. and AHs-C was stronger compared with the separate addition of apigenin or quercetin. The hydrogels of AHs-C-Ap/Que. showed the highest antibacterial capacity and antibacterial adhesion against Escherichia coli and Staphylococcus aureus. The antibacterial adhesion assay showed that 99 % removal ratios for E. coli and S. aureus were observed in AHs-C-Ap/Que. hydrogels, which showed a great potential to prevent food spoilage and foodborne infections.

Effect of microwave treatment and water-bath heating treatment on the performance of glutenin from Tiger nut seed meal: Insights into changes in structural characteristics, functional properties, and in vitro gastrointestinal digestibility

In this study, the structural characteristics, functional properties, and in vitro gastrointestinal digestibility of glutenin from Tiger nut seed meal (TNSMG) treated by microwave (140-700 W, 20-60 s) and water-bath heating (40-100 °C, 10-30 min) were investigated. Analysis of the surface hydrophobicity, intrinsic fluorescence spectroscopy and Fourier transform infrared spectroscopy indicated that both microwave and water-bath heating treatments caused structure changes of TNSMG. The results showed an increase in the exposure of sulfhydryl groups and the content of β-sheet, coupled with a decrease in the content of α-helix and β-turn. These structural changes contributed to the improved solubility, foamability, emulsification properties, and digestibility of TNSMG under proper thermal treatment conditions. TNSMG exhibited the best solubility (68.48%) and foamability (85.56%) after water-bath heating treatment for 20 min at 80 °C. Furthermore, TNSMG showed the best emulsification property (9.61 m2/g) and digestibility (78.58%) when treated by microwave treatment at 560 W for 40 s.

Cyclic Continuous Glycation Enhanced Dispersibility of Myofibrillar Protein: Reaction Efficiency and Sites Modification

Reaction efficiency in glycation lacks sufficient attention, leading to the waste of process costs. Cyclic continuous glycation (CCG) is an effective approach to accelerate covalent binding between myofibrillar protein (MP) and glucose. This study elucidated that CCG promoted the exposure of reactive glycated sites in MP with full unfolding of secondary and tertiary structures. Notably, the glycation rate was significantly increased by 65.43%. Physicochemical properties indicated that MP-glucose conjugates with high graft degree exhibited favorable solubility, dispersibility, and thermal stability. Furthermore, proteomics was applied to reveal the glycated sites and products in glycoconjugates of MP. Glycation preferentially acted on the tails of the myosin heavy chain. The glucosylation modification on the head region was enhanced by CCG contributing to the inhibition of the head-head interaction. Overall, this study systematically clarifies the mechanism of CCG, providing a theoretical basis for the application of glycation in innovative meat products.

Synthetic and natural polymer hydrogels: A review of 3D spheroids and drug delivery

This review centers on the synthesis and characterization of both natural and synthetic hydrogels, highlighting their diverse applications across various fields. We will delve into the evolution of hydrogels, focusing on the importance of polysaccharide-based and synthetic variants, which have been particularly chosen for 3D spheroid development in cancer research and drug delivery. A detailed background on the research and specific methodologies, including the in-situ free radical polymerization used for synthesizing these hydrogels, will be extensively discussed. Additionally, the review will explore various applications of these hydrogels, such as their self-healing properties, swelling ratios, pH responsiveness, and cell viability. A comprehensive literature review will support this investigation. Ultimately, this review aims to clearly outline the objectives and significance of hydrogel synthesis and their applications.

Millet Bran Dietary Fibers Modified by Heating and Enzymolysis Combined with Carboxymethylation, Acetylation, or Crosslinking: Influences on Properties of Heat-Induced Egg White Protein Gel

Applications of millet bran dietary fiber (MBDF) in the food industry are limited by its poor hydration properties. Herein, MBDF was modified by heating, xylanase and cellulase treatment separately combined with carboxymethylation, acetylation, and phosphate crosslinking, and the effects of the modified MBDFs on heat-induced egg white protein gel (H-EWG) were studied. The results showed that three composite modifications, especially heating and dual enzymolysis combined with carboxymethylation, increased the surface area, soluble fiber content, and hydration properties of MBDF (p < 0.05). MBDF and the modified MBDFs all made the microstructure of H-EWG denser and decreased its α-helix content. Three composite modifications, especially heating and dual enzymolysis combined with carboxymethylation, enhanced the improving effect of MBDF on the WRA (from 24.89 to 35.53 g/g), pH, hardness (from 139.93 to 323.20 g), chewiness, and gumminess of H-EWPG, and enhanced the gastric stability at 3-5 g/100 g. MBDFs modified with heating and dual enzymolysis combined with acetylation or crosslinking were more effective in increasing the antioxidant activity of the gastrointestinal hydrolysates of H-EWG than MBDF (p < 0.05). Overall, heating, xylanase and cellulase treatment separately combined with carboxymethylation, acetylation and crosslinking can enhance the hydration properties and the improving effect of millet bran fibers on H-EWG properties.

Mechanistic insights into the interaction of Lycium barbarum polysaccharide with whey protein isolate: Functional and structural characterization

Protein-polysaccharide interactions are crucial for food system structure and stability. This study investigates the interaction of Lycium barbarum polysaccharide (LBP) at 0-2.00 % concentrations with whey protein isolate (WPI), focusing on functionality and structural changes. LBP covalently grafted onto WPI, as confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), forming WPI-LBP complexes with a maximum degree of grafting (DG) of 44.58 % at 2.00 % LBP. This grafting reduced WPI's surface hydrophobicity (H0) and improved solubility, emulsifying properties, and digestibility under certain conditions, with optimal antioxidant activity at 1.00 % LBP. Multispectral analysis and microscopy showed LBP grafting alters WPI's secondary, tertiary, crystalline, and micro/nanostructures. The comprehensive analysis indicates that the interaction between LBP and WPI involves covalent bonding, hydrogen bonding, hydrophobic interactions, and electrostatic forces, as supported by zeta potential and chemical forces results. These findings suggest LBP-protein complexes as promising food materials for enhancing functionality and stability in the food industry.

An unfolding/aggregation kinetic instructed rational design towards improving graft degree of glycation for myofibrillar protein

Glycation is an effective strategy for the application of myofibrillar protein (MP) in beverage formulas by improving water solubility. In conventional glycation, the efficiency was limited as MP-saccharides conjugates mostly produced at low temperature due to thermosensitivity. This study was aimed to explore unfolding/aggregation kinetics of MP, including aggregate behavior, structural characteristics, and micromorphology, which guided the selection of temperature for glycation. It was shown that 40 °C/47.5 °C were critical temperature for MP unfolding/aggregation, respectively. Accordingly, an innovative technology of glycation (cyclic continuous glycation, CCG) was established by combining such temperatures. The results confirmed that cyclic continuous heating (CCH) inhibited excessive exposure of sulfhydryl and hydrophobic groups impeding protein aggregation. Importantly, it was revealed that rational designed CCG promoted covalent binding of MP to glucose by regulating unfolding-aggregation balance, exhibiting higher glycation degree. Overall, CCG-modified MP is expected to motivate the application of meat proteins in food formulations.

Effects of different temperatures on the physicochemical characteristics, microstructure and protein structure of preserved egg yolk

To clarify the mechanism of lower temperatures promoted the solidification of preserved egg yolk, the effects of temperature (4 °C, 10 °C and 25 °C) on the physicochemical properties, microstructure and protein structure of preserved egg yolk were studied. Results showed that the exterior egg yolk (EEY) exhibited higher pH, hardness and free sulfhydryl content at low-temperature pickling. The microstructure showed that the EEY gradually formed a denser gel network structure at lower temperatures. Electrophoresis results and Fourier transform infrared spectroscopy (FTIR) indicated that there were different degrees of protein degradation and cross-linking of proteins in the IEY (the interior egg yolk) and EEY and the decrease of β-sheets in the secondary structure was accompanied by an increase of β-turns during the formation of egg yolk gels. These results indicated that egg yolk solidification was faster and denser gel structure at 4 °C and 10 °C.

Chicken Egg White Gels: Fabrication, Modification, and Applications in Foods and Oral Nutraceutical Delivery

Chicken egg white (EW) proteins possess various useful techno-functionalities, including foaming, gelling or coagulating, and emulsifying. The gelling property is one of the most important functionalities of EW proteins, affecting their versatile applications in the food and pharmaceutical industries. However, it is challenging to develop high-quality gelled foods and innovative nutraceutical supplements using native EW and its proteins. This review describes the gelling properties of EW proteins. It discusses the development and action mechanism of the physical, chemical, and biological methods and exogenous substances used in the modification of EW gels. Two main applications of EW gels, i.e., gelling agents in foods and gel-type carriers for nutraceutical delivery, are systematically summarized and discussed. In addition, the research and technological gaps between modified EW gels and their applications are highlighted. By reviewing the new modification strategies and application trends of EW gels, this paper provides insights into the development of EW gel-derived products with new and functional features.

Formation of pH-responsive hydrogel beads and their gel properties: Soybean protein nanofibers and sodium alginate

Hydrogel beads prepared from protein nanofibers are popular because of their safety, sleek appearance, and protection of biologically active substances. However, extreme external environmental variations, such as pH and temperature, can limit their practical application. To meet the application requirements of hydrogel beads in different environments, non-covalent mixtures of CaCl2 cross-linked soybean protein nanofibers (SNF) and sodium alginate (SA) were used to prepare hydrogel beads. In the present study, the hardness (782.48 g) and elasticity of hydrogel beads formed at SNF/SA = 7:3 and CaCl2 concentration of 0.1 mol/L were the maximum. Furthermore, the water content and pH swelling also reached a peak (98.68 %, 43.85 g/g) due to the best morphology and regular internal network structure. Meanwhile, the pH-responsive hydrogel beads with added anthocyanins were able to respond to the ambient pH under different temperatures and pH conditions and maintained color stability during 96 h of storage (ΔE < 5). In this experiment, a pH-responsive hydrogel bead based on soybean protein nanofiber (SNF) and sodium alginate (SA) was prepared by simple ionic crosslinking. It provides a theoretical and experimental basis for the future application of plant protein nanofibers as pH-responsive hydrogel materials.

Gallic acid-functionalized soy protein-based multiple cross-linked hydrogel: Mechanism analysis, physicochemical properties, and digestive characteristics

Herein, carbodiimide hydrochloride/N-hydroxysuccinimide was used to mediate the grafting of gallic acid (GA) (0.005, 0.0015, and 0.025 wt%) with soybean protein isolate (SPI) in the preparation of SPI-GA conjugates and hydrogels. The modified materials were primarily joined via the CN bonds and exhibited excellent antioxidant properties. In addition, spectral analysis revealed that the grafting of GA increased the flexibility of the SPI structure. The SPI-GA hydrogel is fabricated through covalent/non-covalent cross-linking mechanisms, including Schiff base, Michael addition, and hydrogen bonding. Furthermore, the microstructure, rheological properties, thermal stability, and textural properties of the hydrogel were affected by the amount of GA grafted. The SPI-GA hydrogel exhibited the best performance when the amount of GA graft was 0.015 wt%. Furthermore, the tightly cross-linked structure of SPI-GA prevented premature degradation of the protein by pepsin. In conclusion, these capabilities provide numerous possibilities for the development of multifunctional and active substance delivery carriers.

Translucency mechanism of heat-induced pigeon egg white gel

In this study, the properties of pigeon egg white (PEW) and chicken egg white (CEW) thermal gels were compared, with the aim of revealing the mechanisms involved in the high transparency of PEW thermal gels. Results demonstrated that PEW gels exhibited higher transparency than CEW gels. Scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis revealed that PEW gels formed a fine chain gel network structure with an average diameter of thermal aggregates (89.84 ± 7.13 nm). The molecular properties of PEW proteins, such as higher content of β-sheet structures (32.73 %), reactive groups (free sulfhydryl groups, hydrophobic groups), and absolute zeta potential (-3.563 mV), were found to contribute to the formation of smaller thermal aggregates during thermal denaturation. The microrheology measurements showed that these features allowed PEW proteins to interact less with each other and form smaller thermal aggregates during thermal denaturation, which facilitated the formation of fine chain gel networks and thus improved the transparency of the gels. The present study initially reveals the molecular basis of the high transparency of PEW thermal gels and provides a theoretical reference for the development of new highly transparent protein materials.

Purification and separation of glucomannan from porang tuber flour (Amorphophallus muelleri) using microwave assisted extraction as an innovative gelatine substituent

Gelatine is frequently used as a food ingredient. However, Indonesia imports almost all of its gelatine, totaling 3990152 tons annually. Gelatine could be replaced with glucomannan compound which was found in porang tubers. However, it also contains calcium oxalate, which is harmful for the human body. In this study, calcium oxalate was first eliminated by the purification process using 10 % NaCl (w/w). Moreover, the microwave-assisted extraction method was used to extract the glucomannan compound by applying 300 W of microwave power with different extraction times (5, 10, 15, and 20 min) and different ethanol concentrations (60, 70, 80, and 96 %). Statistical analysis was used to optimize and identify significant parameters influencing the glucomannan concentration. The best conditions for glucomannan extraction were an extraction time of 10 min and an ethanol concentration of 80 % (v/v), resulting in a glucomannan yield of ≥96 %. Machine learning was successfully applied for data modelling using a Long Short-Term Memory block with an average R-square of 0.9772 (97.72 % accuracy) and an average MSE of 4.7719. Furthermore, physical and chemical characteristics of the extracted porang flour were accorded with SNI gelatine standards 06-3735 in 1995, which consisted of glucomannan (96.359 ± 1.164 %), calcium oxalate (0.009 ± 0.001 %), water (2.290 ± 0.986 %), ash (0.018 ± 0.002 %), fat (0.0235 ± 0.120 %), heavy metals (not identified), and pH (6.455 ± 0.191). Finally, the extracted glucomannan can be used as a potential regional substitute for gelatine production.

Rheological and physicochemical properties of heat-induced ovalbumin gels in presence of sodium carboxymethyl cellulose

In this study, the effect of sodium carboxymethylcellulose (CMC-Na) on the rheological and physicochemical properties of heat-induced ovalbumin (OVA) gels was evaluated. The OVA/CMC-Na composite gels were prepared by heat-induced (85 °C, pH 7.0) a mixture of CMC-Na (0, 0.2, 0.4, 0.8 and 1%) and OVA. The results revealed that the addition of CMC-Na dramatically reduced the springiness and hardness of the composite gels, while slightly enhancing the intermolecular hydrogen bonding interactions, which facilitated the improvement of the softness of the gels. It can be observed by SEM that the added CMC-Na was stacked on the surface of the OVA, resulting in visible "linear bumps". All gel samples exhibited shear-thinning behavior. The apparent viscosity of the composite gels increased with the addition of CMC-Na, and the OVA gel with 1% CMC-Na showed the highest apparent viscosity and the lowest storage modulus (G'). Additionally, low field nuclear magnetic resonance (LF-NMR) measurements indicated that the increasing CMC-Na boosted the water mobility of the composite gel. This study offers a novel approach to the development of ovalbumin-based soft gel foods, especially for certain populations with swallowing difficulties.

Polymer-Based Hydrogels Applied in Drug Delivery: An Overview

Polymer-based hydrogels are hydrophilic polymer networks with crosslinks widely applied for drug delivery applications because of their ability to hold large amounts of water and biological fluids and control drug release based on their unique physicochemical properties and biocompatibility. Current trends in the development of hydrogel drug delivery systems involve the release of drugs in response to specific triggers such as pH, temperature, or enzymes for targeted drug delivery and to reduce the potential for systemic toxicity. In addition, developing injectable hydrogel formulations that are easily used and sustain drug release during this extended time is a growing interest. Another emerging trend in hydrogel drug delivery is the synthesis of nano hydrogels and other functional substances for improving targeted drug loading and release efficacy. Following these development trends, advanced hydrogels possessing mechanically improved properties, controlled release rates, and biocompatibility is developing as a focus of the field. More complex drug delivery systems such as multi-drug delivery and combination therapies will be developed based on these advancements. In addition, polymer-based hydrogels are gaining increasing attention in personalized medicine because of their ability to be tailored to a specific patient, for example, drug release rates, drug combinations, target-specific drug delivery, improvement of disease treatment effectiveness, and healthcare cost reduction. Overall, hydrogel application is advancing rapidly, towards more efficient and effective drug delivery systems in the future.

Insights into the in vitro digestibility of pork myofibrillar protein with different ionic polysaccharides from the perspective of gel characteristics

In this work, the simulated gastrointestinal digestion of myofibrillar protein gels (MPGs) with anionic xanthan (XMP) and sodium alginate (SMP)/cationic chitosan (CSMP)/neutral curdlan (CMP) and konjac (KMP) was investigated to develop muscle-gelled foods with good qualities before and after eating. The results indicated that the neutral CMP and KMP groups had higher gel strength and protein digestibility than the CSMP group. Xanthan and sodium alginate facilitated myosin degradation in gastrointestinal digestion because of the weak wraps between protein and anionic polysaccharides, gaining plentiful peptides (1790 and 1692 respectively) with molecular weights below 2000 Da. Chitosan and neutral curdlan could improve the strength of MP gel but inhibited proteolysis and resulted in low contents of released amino acids via the strong cross-linked network blocking trypsin contact. This work provides a theoretical basis for developing low-fat meat products with good qualities and digestion behaviors by simply controlling the ionic types of polysaccharides.

Preparation of high complex concentration emulsion stabilized by soy protein/dextran sulfate composite particles

BACKGROUND

Soy protein isolate (SPI) could be used as an emulsifier to stabilize emulsions, while SPI is unstable under low acidic conditions. The stable composite particles of SPI and dextran sulfate (DS) could be formed by the electrostatic interaction at the pH was 3.5. And the SPI/DS composite particles were used to prepare the high complex concentration emulsion. The stabilization properties of high complex concentration emulsion were investigated.

RESULTS

Compared to uncompounded SPI, the particle size of SPI/DS composite particles was smaller at 1.52 μm, and the absolute value of the potential increased to 19.9 mV when the mass ratio of SPI to DS was 1:1 and the pH was 3.5. With the DS ratio increased, the solubility of the composite particles increased to 14.44 times of the untreated protein at pH 3.5, while the surface hydrophobicity decreased. Electrostatic interactions and hydrogen bonds were the main forces between SPI and DS, and DS was electrostatically adsorbed on the surface of SPI. The emulsion stability significantly enhanced with the increase of complex concentration (38.88 times higher than at 1% concentration), the emulsion average droplet size was the lowest (9.64 μm), and the absolute value of potential was the highest (46.67 mV) when the mass ratio of SPI to DS was 1:1 and the complex concentration of 8%. The stability of the emulsion against freezing was improved.

CONCLUSION

The SPI/DS complex has high solubility and stability under low acidic conditions, and the SPI/DS complex' emulsion has a well stability. This article is protected by copyright. All rights reserved.

Fabrication of grape seed proanthocyanidin-loaded W/O/W emulsion gels stabilized by polyglycerol polyricinoleate and whey protein isolate with konjac glucomannan: Structure, stability, and in vitro digestion

In this work, the effects of konjac glucomannan (KGM) concentrations on microstructure, gel properties, stability and digestibility of water-in-oil-in-water emulsion gels stabilized by polyglycerol polyricinoleate and whey protein isolate were investigated. Visual appearance indicated that a non-layered double emulsion gel was formed when KGM increased to 0.75%. Emulsion gels with 1.5% KGM showed the highest encapsulation, freeze-thaw and photochemical stability due to the formation of the smallest droplets, which were supported by microscopic observations. Moreover, the addition of KGM improved water holding capacity, rheological and texture properties of emulsion gels. Particularly, at 1.5% or 1.75% KGM, color and potential of hydrogen showed the most stable level after 14 days of storage. During in vitro digestion, KGM delayed the hydrolysis of protein and oil droplets, and then improved the bioavailability of grape seed proanthocyanidin. These results promoted the application of KGM in emulsion gels and the encapsulation of nutraceuticals.

Locust bean gum provides excellent mechanical and release attributes to soy protein-based natural hydrogels

The current study concentrated on designing soy protein (SP)-based natural hydrogels in the presence of locust bean gum (LBG). For this, the gums were recovered from the kernel of the relevant plant and incorporated into SP gel models. Three more hydrogels were fabricated using commercial carbohydrates (gum Arabic (GA), maltodextrin (MD), and pectin (PC)) to decipher exactly the ability of LBG in these models. The chemical and morphological structures of the samples were elaborated by FTIR and SEM analyses. The coexistence of protein and carbohydrates led to an enhancement in functional (water holding capacity (WHC), swelling ratio, protein leachability, volumetric gel index (VGI)) and mechanical (textural and rheological behavior) features of natural gels compared to SP alone (control) but the quality of hydrogels was impressed by the carbohydrate type. Hydrogels designed with LBG came to the fore in terms of these attributes. Additionally, these gel models created awareness for phenolic delivery.

Designation and characterization of cold-set egg white protein/dextran sulfate hydrogel for curcumin entrapment

This study aimed to design a cold-set hydrogel of egg white protein (EWP) with good mechanical properties for encapsulating curcumin. Dextran sulfate (DS) and transglutaminase (TGase) were used to control the aggregation and gelation behavior of EWP at preheating step and gelation step, respectively. The optimum soluble protein aggregate size was obtained in the EWP/DS mixture at a mass ratio of 10 under 85 °C preheated (HED₁₀). The presence of TGase further enhanced the cross-linking degree between protein aggregates during the gelation step. The highest gel hardness was found in HED₁₀ hydrogel with TGase, which is almost 10 times the pure EWP gel. Besides, the HED hydrogels effectively slowed down the release rate of curcumin in gastrointestinal digestion. This work provides a theoretical basis for the development of cold-set EWP hydrogel with good mechanical strength by sulfated polysaccharide addition and TGase cross-linking as encapsulation delivery systems.

Effect of high intensity ultrasonic treatment on structural, rheological, and gelling properties of potato protein isolate and its co-gelation properties with egg white protein

The study aimed to investigate the effect of high intensity ultrasonic (HIU) treatment at different times (0, 10, 20, and 30 min) on the structure and gel properties of water-soluble potato protein isolate (WPPI) and to further investigate the improvement of gel properties of ultrasonicated WPPI (UWPPI) by the addition of egg white protein (EWP). HIU reduced the particle size of WPPI, whose structure became loose and disordered, which improved gelling properties of UWPPI. Fourier transform infrared results indicated that α-helix content decreased, whereas the proportion of irregular curl increased with the increase in ultrasonication time (0-20 min), indicating that the initially ordered structure of UWPPI became disordered. After HIU treatment, the free sulfhydryl groups of UWPPI and surface hydrophobicity decreased and fluorescence intensity increased. These results demonstrated that the HIU loosened the structure of UWPPI, exposing more chromogenic groups while embedding more hydrophilic groups. After thermal induction, UWPPI gel hardness increased and exhibited excellent water holding capacity. After the addition of EWP, rheological properties stabilized, and the hardness of UWPPI-EWP gels increased significantly, forming internally structured protein gels with a tightly ordered structure and increased brightness. Thus, HIU changed the structure and gelling properties of WPPI, and the addition of EWP further enhanced the performance of hybrid protein gels. PRACTICAL APPLICATION: High intensity ultrasonic changed the structure of water-soluble potato protein isolate (WPPI) and improved the properties of WPPI gels. The addition of egg white protein significantly improved the quality of mixed protein gels which showed great potential industrial value.

Egg white protein-based delivery system for bioactive substances: a review

Some bioactive substances in food have problems such as poor solubility, unstable chemical properties and low bioavailability, which limits their application in functional food. Recently, many egg white protein-based delivery carriers have been developed to improve the chemical stability, biological activity and bioavailability of bioactive substances. This article reviewed the structure and properties of several major egg white proteins commonly used to construct bioactive substance delivery systems. Several common carrier types based on egg white proteins, including hydrogels, emulsions, micro/nanoparticles, aerogels and electrospinning were then introduced. The biological functions of common bioactive substances, the limitations, and the role of egg white protein-based delivery systems were also discussed. At present, whole egg white protein, ovalbumin and lysozyme are most widely used in delivery systems, while ovotransferrin, ovomucoid and ovomucin are less developed and applied. Egg white protein-based nanoparticles are currently the most commonly used delivery carriers. Egg white protein-based hydrogels, emulsions, and microparticles are also widely used. Future research on the application of various egg white proteins in developed new delivery systems will provide more choices for the delivery of various bioactive substances.

Synthesis, characterization, and methylene blue adsorption of multiple-responsive hydrogels loaded with Huangshui polysaccharides, polyvinyl alcohol, and sodium carboxyl methyl cellulose

Huangshui (HS), a typical by-product of traditional Chinese Baijiu, has attracted more and more attention since its rich resources of polysaccharides. However, there's little information on hydrogels preparation by Huangshui polysaccharides (HSPs). A series of novel HSP-loaded hydrogels were synthesized using crude HSP (cHSP), polyvinyl alcohol (PVA), sodium carboxyl methyl cellulose (CMC), and in situ incorporation of Fe₃O₄ for methylene blue (MB) adsorption for the first time. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and texture tests indicated the paramagnetic hydrogels with porous structure were formed via physical crosslinking, and cHSP had no effect on hydrogel texture. Notably, cHSP enhanced the swelling capacity and MB adsorption ability of the hydrogels, and the corresponding maximum value was 38.67 g/g and 71.07 mg/g, respectively, when the additive amount of cHSP to the hydrogels was 2 % at 25°С. In addition, the swelling kinetics of hydrogels followed the Schott's second-order kinetics model, while MB adsorption fitted well with the Freundlich isotherm and pseudo-second-order model. Furthermore, intraparticle and film diffusion-controlled MB adsorption process. Significantly, cHSP amount could counteract the negative influence of high temperature on MB adsorption, and the prepared hydrogels could be reusable, demonstrating cHSP effectively promoted the properties of hydrogels and had potential application in MB removal. The adsorption mechanism of MB onto the hydrogels involved ion-exchange, hydrogen bonding, electrostatic interaction, and chemical reaction according to the above results together with the analysis by X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray (EDX) characterizations, thermodynamic, etc.

Effects of Different Ionic Polysaccharides in Cooked Lean Pork Batters on Intestinal Health in Mice

The effects of cooked lean pork batters with three ionic types of polysaccharides (anionic xanthan-gum/sodium-alginate, neutral curdlan-gum/konjac-gum and cationic chitosan) on the intestinal health of mice were investigated in this study. The results showed that the zeta potential in the sodium-alginate group (−31.35 mV) was higher (p < 0.05) than that in the chitosan group (−26.00 mV), thus promoting the protein hydrolysis in the anionic group because of electrostatic repulsion. The content of total free amino acids in the small intestine in the xanthan-gum and sodium-alginate groups (2754.68 μg and 2733.72 μg, respectively) were higher (p < 0.05) than that in the chitosan group (1949.78 μg), which could decrease the amount of undigested protein entering the colon. The two anionic groups could also increase the abundance of Lactobacillus and the balance of Faecalibaculum and Alistipes in the colon. The content of proinflammatory factor IL−6 of colon tissues in the sodium-alginate group (1.02 ng/mL) was lower (p < 0.05) than that in chitosan, curdlan-gum and konjac-gum groups (1.29, 1.31 and 1.31 ng/mL, respectively). The result of haematoxylin-eosin staining of the colon also revealed that sodium alginate was beneficial for colonic health. The two neutral groups increased the content of faecal short-chain fatty acids in mice. These results demonstrated that anionic polysaccharides have potential for developing functional low-fat meat products.