Structural regulation of alkali-induced egg white protein gels is hindered by the difficulty in coordinately controlling gelation rate and strength. Via multi-scale characterization, this study reveals the gelation property evolution and mechanism of unfolded egg white protein modulated by ultrasound-NaCl synergy, realizing controllable optimization of gel strength. The results showed that 360 W ultrasound could effectively unfold the protein structure, increase surface hydrophobicity, and promote hydrophobic aggregation and disulfide bond cross-linking (P < 0.05); above 480 W would destroy the network due to shear effect, resulting in gel deterioration. 5-100 mM NaCl enhanced the gel density through electrostatic shielding and salt precipitation, while high concentrations of NaCl would weaken the network strength, significantly reducing the storage modulus and hardness. Preheating at 62-64 degrees C facilitated the oxidation of sulfhydryl groups and structural unfolding, with the free sulfhydryl groups reaching a peak at 62 degrees C, promoting the formation of disulfide bonds and hydrogen bonds; excessively high temperatures would cause excessive aggregation and weakened bonding. Ultimately, 360 W ultrasound combined with 100 mM NaCl and 64 degrees C preheating resulted in a gel with bright color, excellent texture, high water retention, and uniform and dense structure. This study provides a theoretical basis for precisely regulating the gel properties of egg white proteins and expanding their industrial applications.

Sarcoplasmic protein (SP), a water-soluble fraction naturally lost during post-ripening and industrial thawing. This study revealed the concentration-effect mechanism of SP in regulating the gel properties of beef mince by controlling the addition amount of SP (0%u20130.5%, m/m). Compared with the control group, the incorporation of 0.3% SP maximized gel strength and water-holding capacity (95.33%) while increasing cooking yield. Dynamic rheology confirmed a higher storage modulus, indicating an elastic-dominant network. Raman spectroscopy revealed a shift from u03B1-helix to u03B2-sheet, while scanning electron microscope observation showed a denser, more uniform microstructure with reduced pore size. The results of the chemical force analysis revealed a significant enhancement of hydrophobic interactions and disulfide bond formation, which collectively drove the elevation of u03B2-sheet relative content in the protein structure. Excess SP (u0026gt; 0.4%) formed loose aggregates that impeded myosin cross-linking and weakened the gel. Therefore, controlled SP re-addition can improve the beef minced gel property. This study provides a theoretical basis for the intensive processing and utilization of SP and the quality improvement of beef gel products.

Egg white, valued for its high protein content and superior food functional properties, is widely utilized in food processing. The amphiphilic structure and surface activity of egg white proteins enable effective adsorption at oil-water interfaces, reducing interfacial tension and forming stable interfacial films. Therefore, egg white proteins exhibit a robust interfacial regulation capacity in emulsion systems. This review systematically outlines the characteristics and formation mechanisms of multi-scale emulsion systems of egg white proteins (nano-emulsions, Pickering emulsions, and high internal phase Pickering emulsions). Additionally, a summary is presented of the research progress on the chemical/physical modification mechanisms of egg white emulsification performance, as well as their role in modifying egg white emulsification properties.

Bacillus cereus, an important pathogen responsible for causing foodborne diseases worldwide, releases pore-forming enterotoxins, which target host epithelial cells, leading to osmotic lysis and ultimately manifesting as diarrheal syndrome. Moreover, some B. cereus strains carry antimicrobial resistance genes that confer multidrug resistance against a spectrum of antibiotics. Characterizing the survival traits of multidrug-resistant (MDR) B. cereus strains in the intestinal microenvironment is essential for developing targeted strategies to effectively manage diarrheal foodborne diseases caused by this pathogen. This study used whole-genome sequencing (WGS) to evaluate the pre- and post-digestion toxigenic potential, antimicrobial resistance profiles, and genetic diversity of MDR B. cereus strains isolated from food samples in Guangdong Province, China. The four B. cereus isolates investigated in this study exhibited a genetic diversity, as determined by multilocus sequence typing analysis of WGS data. All four isolates produced the diarrheal toxins Hbl, Nhe, and CytK to varying levels, indicative of their potential to cause outbreaks of foodborne diseases. Each of the four isolates exhibited resistance to more than three classes of antibiotics, fulfilling the criterion for multidrug resistance. At an initial concentration of 9 log colony-forming units (CFU)/mL, the intestinal concentration of these four isolates crossed the threshold required to induce widespread diarrhea in the general population. Under rice slurry protection, all tested isolates maintained intestinal concentration beyond the threshold when the initial concentration was increased to ≥8 log CFU/mL. Moreover, the upregulations of genes associated with acid tolerance, bile tolerance and stress response were observed in the surviving MDR B. cereus isolates. Digestion markedly altered the antibiotic resistance profiles of the MDR B. cereus isolates. In the absence of a food matrix, the MDR isolates lost their resistance to imipenem, meropenem, amoxicillin-clavulanic acid, and trimethoprim-sulfamethoxazole post-digestion and was influenced by the initial concentration of the strains. In the presence of food matrix rice slurry, the effects of digestion on the antibiotic resistance of MDR B. cereus isolates can be mitigated, enabling them to maintain their antibiotic resistance to the greatest extent. Most remarkably, after digestion, the isolates Bce055 and Bce166 exhibited newly emergent resistance to cefotetan and trimethoprim-sulfamethoxazole, respectively. Our findings clarify the fate of MDR B. cereus isolates in the gastrointestinal tract and inform the development of prevention and control strategies for foodborne diseases caused by this pathogen.

The mechanism of photo-oxidative phase-separation aggregation in liquid egg white protein (EWP) under light storage (0-12,000 LUX) was elucidated. The results indicated that light-induced reactive oxygen species (ROS) directly oxidised aromatic amino acid residues. This led to a significant increase in dityrosine content and a marked conformational transition. Meanwhile, the photo-triggered unfolding of EWP molecular chains enhanced the flexibility, exposing polar and hydrophobic groups. Consequently, the proteins underwent phase separation and aggregation driven by hydrophobic interactions and weak hydrogen bonds. This aggregation increased the viscosity of the high light-exposed EWP. However, due to the lack of a rigid, supportive network, the resulting aggregates exhibited decreased storage and loss modulus upon subsequent thermal gelation. Dilution disrupted these hydrophobic interactions and hydrogen bonds, causing the aggregates to dissociate into smaller fragments with smaller particle size. These findings provide critical insight for controlling the photo-oxidative deterioration of liquid egg white.

Flexible fluorescent hydrogels offer great potential for on-site heavy-metal sensing, but their practical use is often limited by a fundamental trade-off: materials that provide strong fluorescence responses typically suffer from poor stability in oxidative environments, while hydrogel matrices with good robustness or adhesion rarely support reliable fluorescence signaling. Here, we introduce a phycocyanin-polyacrylamide (PC-PAAM) hydrogel that resolves this conflict by integrating high mechanical flexibility and strong underwater adhesion with stable red fluorescence and intrinsic antioxidative protection. PC acts simultaneously as a fluorescent cross-linker and ROS-scavenging component, enabling the hydrogel to maintain signal integrity while undergoing rapid fluorescence quenching upon Hg2+ coordination. The detection limit of the sensor achieves 6.21 nM. It demonstrates conformal contact on irregular biological surfaces, enabling nondestructive detection on fish. Coupled with a deep-learning model trained on hydrogel fluorescence images, the system further enables accurate, portable, and visual quantification of Hg2+ contamination using smartphone imaging. This work provides a flexible, adhesive, and intelligent sensing platform for environmental and food-safety monitoring.

In this study, eggs were treated with Paraffin and NaHCO3 to alter CO2 mass transfer rates by modulating eggshell structure to elucidate the cascade effects of CO2 mass transfer regulation on egg quality in terms of ovomucin response. Results indicate that NaHCO3 treatment increased eggshell porosity and reduced its effective thickness, accelerating CO2 mass transfer and egg respiration. As a consequence, the pH of the egg white rose rapidly from 8.4 to 9.36, leading to a significant decrease in the Haugh unit, protein index, and buffering capacity of the egg white (P < 0.05). Paraffin treatment inhibited CO2 mass transfer by sealing the micropores of the eggshell, maintaining the internal carbonate buffer equilibrium and high viscoelasticity of the egg white and significantly delaying the deterioration of egg storage quality. As the CO2 mass transfer intensified and the storage time increased, ovomucin underwent denaturation. α2-OVM and β-OVM were degraded during storage, with hydrophobic groups exposed and hydrogen bonds broken, causing them to gradually disintegrate from a macromolecular cross-linked network into fragmented proteins with increased solubility. Sequential cleavage of C-O-H, SO, and CO bonds in the glycan chains led to the reduced glycosylation of ovomucin and gradual detachment of sulfated glycan structures, causing the protein to become increasingly disordered and ultimately resulting in egg white thinning. This study provided a theoretical basis for elucidating the mechanisms underlying changes in egg storage quality and offers scientific insights for the future regulation of egg white quality.

Deep eutectic solvents (DES) have emerged as green and designable solvents for extracting natural active substances. Recent studies have systematically investigated the key factors governing extraction efficiency, including DES structure, process parameters, and solvent properties. These investigations have established DES as a viable alternative to conventional organic solvents in natural substances extraction. This review examines the application of DES in extracting some major classes of bioactive compounds,e.g., phenolic compounds, polysaccharides, proteins and alkaloids. The analysis focuses on: characterization of DES and factors affecting extraction, synergistic extraction techniques and industrial potential beyond extraction. The high efficiency of DES in extracting active components are also explored. DES-extracted compounds (e.g., anthocyanins and proteins) exhibit enhanced stability due to H-bonding. Polyol/acidic DES systems offer a reliable method of safeguarding thermosensitive components. Combined with green methodologies, DES extraction enhances efficiency and reduces energy consumption. Additionally, DES have been demonstrated to enhance mechanical and barrier properties of films, the DES-based microextraction technique detects food contaminants and it is extensively employed in the domain of biorefining. Nevertheless, DES are still many challenges to be addressed, including the lack of clarity surrounding microscopic interaction mechanisms, difficulties in solvent recovery, and so on. Future research should focus on mechanistic exploration, system optimization, and expanding green applications.

This study investigated a low-frequency ultrasound-driven, resveratrol-induced hydrocolloid composed of ovalbumin and lysozyme amyloid-like fibrils for the efficient stabilization of aqueous cyanidin-3-O-glucoside. Results demonstrated that resveratrol, under ultrasonic treatment, acted as a molecular bridge, disrupting the long-range order of linear β-sheets and promoting fibril cross-linking via intramolecular hydrogen bonds. This process significantly reduced the average particle size of the fibrils, transforming the system into a three-dimensional hydrocolloid network with improved viscoelasticity. The resulting hydrocolloid with adjusted surface hydrophobicity and surface hydrophobicity effectively stabilized emulsion- hydrocolloids loaded with cyanidin-3-O-glucoside, yielding uniform droplets with enhanced stability against aggregation and oxidation during storage. The confidence interval of the Cole-Cole curve of the emulsion hydrocolloid narrated and linearized with the increase in resveratrol ratio, and the formed single relaxation network microstructure significantly enhanced the environmental stimulation stability of the emulsion hydrocolloid. In vitro digestion studies revealed that prepared emulsion-hydrocolloids significantly enhanced the bioaccessibility of cyanidin-3-O-glucoside. Furthermore, in a Caco-2 cell monolayer model, the digestively derived micelles from the emulsion-hydrocolloid notably improved the absorption rate of cyanidin-3-O-glucoside over 120 min and exhibited strong cytoprotective effects under H2O2-induced oxidative stress by effectively reducing intracellular ROS levels, increasing SOD activity, and decreasing MDA content. All treatments maintained high cell viability (>95%), indicating excellent biocompatibility. These findings suggest that the ultrasound-assisted resveratrol-induced fibril hydrocolloid is a highly promising vehicle for improving the stability, bioavailability, and bioactivity of hydrophilic polyphenols.

Liquid egg white protein (EWP) readily undergoes undesirable photooxidation triggered by endogenous photosensitizers such as riboflavin during routine shipping and ambient storage, which deteriorates the functional quality of liquid egg products. This study employed β-cyclodextrin (β-CD) to encapsulate β-carotene (β-C), which was subsequently incorporated into liquid egg white to suppress photosensitizer activity and quench ROS within EWP. Results showed that β-CD encapsulates the polyene chain and β-ionone ring of β-C within its hydrophobic cavity, driven primarily by hydrophobic interactions. The 2:1 β-CD/β-C composite showed superior thermal stability and a high thermal decomposition temperature of 425 °C. This complex may gradually release β-C to quench singlet oxygen (1O2) and scavenge triplet riboflavin (3RF), thereby preventing ROS from attacking EWP side chains, inhibiting protein cross-linking, and lowering viscosity. The 4:1 β-CD/β-C-EW preserves bulk EWP structure but causes partial amino acid oxidation and fast β-C breakdown from surplus free β-CD, even with high starting β-C levels. In comparison, optimal host-guest matching in the 2:1 formulation securely entraps β-C within cyclodextrin cavities, preserving greater β-C retention and the minimum riboflavin fluorescence throughout storage. In contrast, the physical mixture group of β-CD and β-C due to the inclusion lag, and the pure β-C group due to easy oxidation inactivation, show decreasing protective effects with storage time. The 2:1 β-CD/β-C complex effectively suppresses photooxidative damage in EWP, providing a basis for controlling photooxidation of egg white during processing and storage.

In this paper, the differences in thermal aggregation behavior of egg white protein (EWP) mediated by reactive oxygen species (ROS) at different heat temperatures were investigated. Results showed that an increase in EWP turbidity and the change in particle size during the heating process depended on the interactions after protein peptide chain unfolding. With the increase in heating temperature, the EWP aggregates changed from indeterminate fiber-like structure to regular network structure. The thermal stability results showed an increase in the thermal stability of EWP after oxidation. The formation of thermally induced aggregates was accompanied by a significant increase in the hydrophobicity of the protein surface from 249.93 to 2748.10. Raman spectroscopy indicated that oxidized EWP exposed hydrophobic groups to inhibit aggregation during heating, and EWP demonstrated significant anti-aggregation properties when heated at 72 °C. This study provides certain theoretical support for improving the thermal processing level of egg products.

This study investigates the effects of oxidative levels on egg storage quality and the physicochemical properties of egg white protein (EWP) by regulating the concentration of reactive oxygen species (ROS) in egg white. The results demonstrated that elevated ROS concentrations accelerated egg quality deterioration, causing a significant decrease in egg protein index from 1.25 to 0.6 and a significant increase in CO2 emission rate. This consequently led to a substantial rise in egg white pH from 8.99 to 9.21. Sustained accumulation of ROS induces a significant decrease in antioxidant enzyme activity and causes egg white oxidation, resulting in a significant increase of carbonyl content from 0.11 mmol/mg to 0.42 mmol/mg. The aromatic amino acids on the surface of EWP are attacked by ROS, which disturbed the hydrogen bond interaction and reduced protein α-helix ratio. Rheological scanning results showed that the depolymerization of the egg white network and conformational deterioration synergistically accelerate the process of egg white thinning, which is related to ROS concentration.

The regulation of protein recombination is inherently associated to its functional properties. This study explored the recombination behavior and structural characteristics of egg white protein (EWP), utilizing ultrasound and salt ion-driven modifications of preheated EWP. The research elucidated the mechanism through which the hydration properties of EWP regulate foaming at the gas-liquid interface. Results demonstrated a significant positive correlation between the turbidity and particle size of EWP. An increased level of aggregation of EWP corresponded to larger particle sizes and heightened turbidity. Optimal stability of EWP was observed at 66 degrees C, under low NaCl concentrations (0-50 mM) and an ultrasonic power of 360 W. Moreover, the mechanical forces generated by high ultrasonic power altered the structure of the protein's rigid regions, making its internal structure more readily extended and exposed. Meanwhile, high salt ion concentration competed with the EWP surface hydration layer, weakening EWP surface hydration layer, forming a "hydrated Na+-water" double-shell structure that enhanced hydration force, exposed amino acid residues, and increased molecular flexibility and surface hydrophobicity. High-temperature preheating made the EWP structure flexible, creating a tough foam film, which, along with the other factors, improved foam stability. Rheological results indicated that ultrasonic enhancement decreased gel stiffness and covalent bond strength, while salt concentration (below 300 mM) had the opposite effect. Electrophoretic results revealed that ultrasonic cavitation and salt ions modified the EWP surface hydration layer. High-temperature treatment (66 degrees C) further promoted ovalbumin degeneration and disintegration, reducing protein band gray scale.

In this paper, using a single-step method, resveratrol (RES)-loaded egg white protein (EWP) nanospheric particles were successfully prepared. The micelle behavior, micromorphology, molecular structure changes, and emulsifying properties of the nanoparticle were analyzed, and the molecular interaction between EWP and RES and the environmental response stability of the nanoparticle was characterized. The results show that I-373/I-385 dropped from 1.1 to about 0.8, indicating that high concentration of ethanol induced EWP to form a more hydrophobic and less polar structure. RES promoted the uniformity of the nanoparticle and formed a tightly-packed spherical three-dimensional structure by characterizing microstructure. Raman and infrared spectroscopy revealed enhanced hydrogen bonding between EWP and RES, increased g-g-g and t-g-t disulfide bonds, and the formation of three-dimensional helical structures due to the opening of flexible structural intervals. Molecular docking analysis identified hydrogen bonds and hydrophobic interactions as the main forces facilitating the binding between RES and EWP. Particle size analysis showed that D-3,D-2 decreased from 30.51 to 17.88 mu m, indicating better emulsion stability. The preservation of RES at 0.4 mg/mL was 94.49% in 50 mM NaCl and 83.68% in 500 mM NaCl, with no significant stability change (p > 0.05) over 48 h, revealing a concentration dependence of salt ions and storage stability of RES in the nanoparticle. This study establishes a foundation for exploring the incorporation of high-value hydrophobic compounds into EWP.

This study explored the mechanism by which lysozyme (LYZ) actively quenched reactive oxygen species (ROS) to inhibit egg white protein (EWP) oxidation. By depleting/replenishing LYZ in EWP systems, we evaluated EWP stability, oxidation degree, microstructure, and conformational changes during storage. Results showed that compared to the control group with significantly reduced LYZ activity, 0.1-0.5 % LYZ replenishment maintained stable LYZ activity and significantly decreased ROS production by 15.71 % and 95.36 %, respectively. LYZ protected EWP via side-chain reducing amino acids to disrupt ROS chain reactions, promoting storage stability, evidenced by uniform average particle size and negligible changes in zeta-potential and apparent viscosity. LYZ mitigated ROS-induced damage to α-helix and β-sheet structures, hindering surface amino acid rearrangement and hydrogen bond network disruption. Notably, 0.5 % LYZ increased α-helix content from 29.24 % to 32.17 %. Thus, LYZ protected EWP from oxidation through "self-sacrificial" ROS scavenging, providing a scientific basis for EWP storage stability regulation.

This review summarized the processes and mechanisms of deterioration in different components of eggs during storage. The mechanisms linked to reduced glycosylation, structural decay, and ovomucin degradation during egg-white thinning were elucidated, along with the weakening of lysozyme-ovomucin interactions. The degradation and S-conformation transformation of ovalbumin were studied, and the potential application of solubility-viscosity theory in egg-white thinning was discussed. Furthermore, the metabolic pathways of glycerophospholipids and glycerolipids during lipid hydrolysis in egg yolk were scrutinized, and the mechanism of fatty acid auto-oxidation was concluded. The review also delineated the mechanism of cuticle thinning and the impact of preservation strategies on cuticle quality. The reproductive and adaptive strategies of dominant bacteria during egg spoilage were addressed, summarizing the microbial perspective. Lastly, methods for assessing egg freshness were reviewed, encompassing both traditional destructive testing methods and advanced photoelectric nondestructive testing techniques.

[Objective]This study aimed to develop a modification method to stabilize emulsions using molten-globule state egg white protein(MGEWP).[Methods]MGEWP was prepared through partial denaturation of egg white protein via pH induction.The synergistic effects of D-xylose and tannic acid on the emulsifying properties of MGEWP were analyzed.[Results]Increasing tannic acid concentration significantly elevated the turbidity and browning degree of D-xylose glycosylated MGEWP(X-MGEWP)(P<0.05).Tannic acid facilitated the unfolding of X-MGEWP,exposing free sulfhydryl and active groups,which enhanced molecular flexibility,apparent viscosity,storage modulus and loss modulus(P<0.05).However,under extreme pH value treatment,the active groups of MGEWP were passivated,inhibiting the Maillard reaction with D-xylose.As a result,there was no significant difference in emulsification properties between glycosylated X-MGEWP and untreated MGEWP(P>0.05).The addition of tannic acid enhanced the emulsifying activity of X-MGEWP obviously(P<0.05),and it was dose-dependent with tannic acid concentration.[Conclusion]The synergistic modification of MGEWP with D-xylose/tannic acid represents a promising method for enhancing the emulsifying properties of MGEWP,offering potential applications in emulsion stabilization.

To improve the freeze-thaw stability of the emulsion, a Pickering emulsion stabilized by grafted protein was prepared and characterized through blending with hyaluronic acid (HA) and trehalose (TH). The results indicated that HA crosslinked with proteins to form a surface coating on the droplets. TH prevented aggregation by imparting spatial repulsion, when combined with HA, resulted in a significant reduction in emulsion particle size from 35.95 mu m to 22.99 mu m. The emulsion showed well stability against droplet flocculation after freeze-thaw cycles. Microstructural observation revealed that the cross-linking of HA and TH inhibited the ice crystal damage. In-vitro digestive characterization indicated that HA and TH prevented digestive enzymes from destroying the droplet structure, realising efficient delivery of curcumin. Among them, the bioaccessibility and stability of curcumin were improved by 8.19 % and 15.25 %. Moreover, 1HNMR analysis demonstrated that the stabilization of HA and TH at the oil-water interface improved the antioxidant properties of the emulsion.

Extracting and applying waste feather keratin are important environmental challenges. This study utilized microwave-assisted L-cysteine treatment on chicken feathers, pH adjustments varied reducing capacity of L- cysteine, while modulated microwave power explored synergistic extraction effects on properties of keratin. The highest yield of regenerated keratin was achieved at an L-cysteine concentration of 15 g/L, pH 12, and a microwave power of 400 W. Micromorphological and particle size results revealed that the keratin particle size increased with pH dependency, the highest proportion of particle size values in keratin increasing from 164 nm in L1 (extracted at pH 11) to 220 nm in L5 (extracted at pH 13). Increasing the intensity of both treatments led to a transition of the secondary structure of regenerated keratin from alpha-helix to beta-sheet, but the increasing reducibility of the system resulted in a decrease in the content of tryptophan residues in keratin, whereas the increase in microwave power led to the masking of some fluorescent chromophores within the keratin. The regenerated keratin demonstrated low crystallinity, and it may have undergone refolding and aggregation under microwave-assisted highly reducing extraction conditions. The foaming properties indicated that the highly reducing extraction system significantly decreased foam stability from 95.4% for L1 to 19.8% for L5 (p < 0.05) and improved foaming ability to keratin. Considering the widespread applications of keratin, this study provides a comprehensive characterization of regenerated keratin under different extraction conditions, aiming to offer experimental materials and extraction conditions tailored to specific requirements in the field of biomaterials.

This study aimed to investigate the mechanism of NaCl perturbed preheat-treated egg white proteins' (EWPs) physicochemical and structural properties to modulate the foaming property (FP). The results revealed that NaCl regulated the salinolysis (5 mM) - salt precipitation (50 mM) - gradual or complete coverage with hydrated Na+ of the hydration layer (100-300 mM) - enhanced Cl- hydration repulsion (500 mM) of EWP, showing a gradual decrease in aggregates particle size, and reversibility of structural freedom, including moleculer flexibility and surface hydrophobicity. Whereas preheating temperature affected the secondary structure rearrangement and tertiary conformation exposure, and excessive temperature reduced foaming capacity while enhanced foam stability, with a tight correlation between NaCl-mediated EWPs' FP and the extent of Na+ covering the hydration layer. The findings provide a theoretical basis for processing factors to modulate the protein hydration layer to influence the functional properties.