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As a natural cationic peptide, Nisin is capable of widely inhibiting the growth of Gram-positive bacteria. However, it also has drawbacks such as its antimicrobial activity being susceptible to environmental factors. Nano-encapsulation can improve the defects of nisin in food applications. In this study, nisin-loaded egg white protein nanoparticles (AH-NEn) were prepared in fixed ultrasound-mediated under pH 3.0 and 90 °C. Compared with the controls, AH-NEn exhibited smaller particle size (112.5 ± 2.85 nm), smaller PDI (0.25 ± 0.01), larger Zeta potential (24 ± 1.18 mV), and higher encapsulation efficiency (91.82%) and loading capacity (45.91%). The turbidity and Fourier transform infrared spectroscopy (FTIR) results indicated that there are other non-covalent bonding interactions between the molecules of AH-NEn besides the electrostatic forces, which accounts for the fact that it is structurally more stable than the controls. In addition, by the results of fluorescence intensity, differential scanning calorimetry (DSC), and X-ray diffraction (XRD), it was shown that thermal induction could improve the solubility, heat resistance, and encapsulation of nisin in the samples. In terms of antimicrobial function, acid–heat induction did not recede the antimicrobial activity of nisin encapsulated in egg white protein (EWP). Compared with free nisin, the loss rate of bactericidal activity of AH-NEn was reduced by 75.0% and 14.0% following treatment with trypsin or a thermal treatment at 90 °C for 30 min, respectively.

Ionizing radiation has its unique popularity as a non-thermal decontamination technique treating with protein-rich foodstuffs to ensure the microbial and sensory quality, particularly for shell eggs. However, the changes in the functional properties of egg protein fractions such as liquid egg white (LEW) with macro/microstructural information are still controversial. Hence, this study was designed to elaborate the foaming and heat-set gelation functionality of LEW following different γ-ray irradiation dose treatments (0, 1, 3 or 5 kGy). For such, the physicochemical properties (active sulfhydryl and the hydrophobicity of protein moieties), structural characteristics (through X-ray diffraction, Fourier-transform infrared spectroscopy and differential scanning calorimetry) and interfacial activities (rheological viscosity, interfacial tension, microrheological performance) were investigated. Then, the thermal gelation of LEW in relation to the texture profile and microstructure (by means of a scanning electron microscope) was evaluated followed by the swelling potency analysis of LEW gel in enzyme-free simulated gastric juice. The results indicated that irradiation significantly increased the hydrophobicity of liquid egg white proteins (LEWPs) (p < 0.05) by exposing non-polar groups and the interfacial rearrangement from a β-sheet to linear and smaller crystal structure, leading to an enhanced foaming capacity. Microstructural analysis revealed that the higher dose irradiation (up to 5 kGy) could promote the proteins’ oxidation of LEW alongside protein aggregates formed in the amorphous region, which favored heat-set gelation. As evidenced in microrheology, ≤3 kGy irradiation provided an improved viscoelastic interface film of LEW during gelatinization. Particularly, the LEW gel treated with 1 kGy irradiation had evident swelling resistance during the times of acidification at pH 1.2. These results gave new insight into the irradiation-assisted enhancement of foaming and heat-set gelation properties of LEW.

The partial substitution of animal protein by plant protein is a new opportunity to produce sustainable food. Hence, to control the heat treatment of a composite protein ingredient, this work investigated the thermal behavior of mixtures of raw egg white (EW) and a laboratory-prepared pea protein isolate (PPI). Ten-percentage-by-weight protein suspensions prepared with different PPI/EW weight ratios (100/0, 75/25, 50/50, 25/75, 0/100) at pH 7.5 and 9.0 were analyzed by differential scanning calorimetry (DSC) and dynamic rheology in temperature sweep mode (T < 100 °C). The DSC data revealed changes in the thermal denaturation temperatures (Td) of ovotransferrin, lysozyme, and pea legumin, supposing interactions between proteins. Denaturation enthalpy (∆H) showed a high pH dependence related to pea protein unfolding in alkaline conditions and solubility loss of some proteins in admixture. Upon temperature sweeps (25–95 °C), the elastic modulus (G′) of the mixtures increased significantly with the EW content, indicating that the gel formation was governed by the EW protein. Two thermal sol–gel transitions were found in EW-containing systems. In particular, the first sol–gel transition shifted by approximately +2–3 °C at pH 9.0, probably by a steric hindering effect due to the presence of denatured and non-associated pea globulins at this pH.

In this study, oleogels were prepared by the emulsion-template method using egg-white protein microgel as a gelator and xanthan gum (XG) as thickener. The physicochemical properties of the emulsion and oleogels were investigated. The adsorption of protein on the surface of the oil droplet reached saturation when the protein microgel concentration reached 2%. The excess protein combined with XG and accumulated on the outer layer of the oleogel, which prevented the emulsion from flocculation, enhanced the oil-holding capacity of the oleogel, and had a positive effect on preventing the oxidation of oil. When the concentration of XG was less than 0.4%, the EWP microgel, combined with the XG, stabilized the emulsion. As the concentration of XG was greater than 0.4%, excessive XG in the emulsion improved the viscosity and mechanical properties of the emulsion to prevent the aggregation of oil droplets. However, the change in XG concentration had no significant effect on the oxidation of the oil.

The study investigated the effects of different microwave vacuum freeze-drying powers (100–500 W) on the emulsifying properties and structural characteristics of egg white protein, which is of great significance in enhancing the added value of EWP and promoting its application. Emulsification analysis revealed that the emulsification performance was significantly influenced by microwave power and reached its maximum at 300 W. Fourier-transform infrared spectroscopy (FT-IR) and sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) analyses showed that microwave vacuum freeze-drying treatment altered the secondary structure of EWP without changing its peptide structure. Fluorescence measurements indicated that the maximum fluorescence emission intensity decreased, and the maximum emission wavelength shifted towards blue as the power increased. Particle size, zeta potential, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) analyses showed that the average particle size of EWP reached the minimum value of 1203.66 nm, the absolute value of zeta potential reached the maximum value of 41.35 mV, and the thermal stability was strongest, with a more uniform and loose structure observed at 300 W. Texture profile analysis (TPA) showed that appropriate power treatment significantly enhanced the chewiness and viscoelasticity of egg white protein. Therefore, appropriate power treatment could effectively improve the emulsifying properties and stability.

Abnormal skin pigmentation commonly occurs during the wound healing process due to the overproduction of melanin. Chicken egg white (CEW) has long been used to improve skin health. Previous published works had found CEW proteins house bioactive peptides that inhibit tyrosinase, the key enzyme of melanogenesis. The current study aimed to evaluate the anti-pigmentation potential and mechanism of the CEW-derived peptide (GYSLGNWVCAAK) and hydrolysates (CEWHmono and CEWHdi), using a cell-based model. All of these peptide and hydrolysates inhibited intracellular tyrosinase activity and melanin level up to 45.39 ± 1.31 and 70.01 ± 1.00%, respectively. GYSLGNWVCAAK and CEWHdi reduced intracellular cAMP levels by 13.38 ± 3.65 and 14.55 ± 2.82%, respectively; however, CEWHmono did not affect cAMP level. Moreover, the hydrolysates downregulated the mRNA expression of melanogenesis-related genes, such as Mitf, Tyr, Trp-1 and Trp-2, but GYSLGNWVCAAK only suppressed Tyr gene expression. Downregulation of the genes may lower the catalytic activities and/or affect the structural stability of TYR, TRP-1 and TRP-2; thus, impeding melanogenesis to cause an anti-pigmentation effect in the cell. Outcomes from the current study could serve as the starting point to understand the underlying complex, multifaceted melanogenesis regulatory mechanism at the cellular level.

Egg white protein is a non-toxic and biodegradable biopolymer that forms a gel easily via simple thermal denaturation treatment. A novel aerogel on the basis of egg white protein crosslinked with graphene oxide was prepared via a facile freeze-drying method. The structure and physicochemical characteristics of the aerogels were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and Brunauer–Emmett–Teller (BET) analysis. The adsorption properties of the aerogels were investigated by studying the influencing factors such as the solution pH, dose, temperature and contact time. The adsorption capacity of methylene blue onto the aerogels was tested, whose maximum adsorption capacity, calculated by the Langmuir isotherm equation, reached 91.7 mg/g. Adsorption kinetics studies showed that the adsorption followed the pseudo-second-order kinetic model. Thermodynamic data implied that methylene blue adsorbed by the aerogels was an exothermic and spontaneous process.

This study evaluated the effects of three polysaccharides, xanthan gum (XG), kappa-carrageenan (CA), and guar gum (GG), on the foaming and emulsifying properties of egg white liquid (EWL) and explored the intermolecular interactions and aggregation states in the initial polysaccharide–EWL complex. The results showed that the addition of XG and GG significantly improved the foaming stability of EWL on the one hand, from 66% to 78% and 69%, respectively (p < 0.05). On the other hand, the addition of XG and GG significantly improved the foam uniformity and density, and the average foam area decreased from 0.127 to 0.052 and 0.022 mm2, respectively (p < 0.05). The addition of XG and CA significantly improved the emulsification activity index (from 13.32 to 14.58 and 14.36 m2/mg, respectively, p < 0.05) and the emulsion stability index (from 50.89 to 53.62 and 52.18 min, respectively, p < 0.05), as well as the interfacial protein adsorption at the oil–water interface; it also reduced the creaming index. However, GG negatively affected these indicators. Furthermore, the electrostatic and hydrophobic interactions among molecules in EWL due to XG and the electrostatic, hydrogen bonding, and hydrophobic interactions among molecules in EWL due to CA ultimately led to the irregular aggregation of egg white proteins. Hydrophobic interactions and disulfide bonds between molecules in EWL–containing GG formed filamentous aggregations of egg white proteins. This work reveals that molecules in the polysaccharide–egg white complexes aggregate by interaction forces, which in turn have different effects on the foaming and emulsifying properties of egg white proteins.

As a natural cationic peptide, Nisin is capable of widely inhibiting the growth of Gram-positive bacteria. However, it also has drawbacks such as its antimicrobial activity being susceptible to environmental factors. Nano-encapsulation can improve the defects of nisin in food applications. In this study, nisin-loaded egg white protein nanoparticles (AH-NEn) were prepared in fixed ultrasound-mediated under pH 3.0 and 90 °C. Compared with the controls, AH-NEn exhibited smaller particle size (112.5 ± 2.85 nm), smaller PDI (0.25 ± 0.01), larger Zeta potential (24 ± 1.18 mV), and higher encapsulation efficiency (91.82%) and loading capacity (45.91%). The turbidity and Fourier transform infrared spectroscopy (FTIR) results indicated that there are other non-covalent bonding interactions between the molecules of AH-NEn besides the electrostatic forces, which accounts for the fact that it is structurally more stable than the controls. In addition, by the results of fluorescence intensity, differential scanning calorimetry (DSC), and X-ray diffraction (XRD), it was shown that thermal induction could improve the solubility, heat resistance, and encapsulation of nisin in the samples. In terms of antimicrobial function, acid-heat induction did not recede the antimicrobial activity of nisin encapsulated in egg white protein (EWP). Compared with free nisin, the loss rate of bactericidal activity of AH-NEn was reduced by 75.0% and 14.0% following treatment with trypsin or a thermal treatment at 90 °C for 30 min, respectively.

Ionizing radiation has its unique popularity as a non-thermal decontamination technique treating with protein-rich foodstuffs to ensure the microbial and sensory quality, particularly for shell eggs. However, the changes in the functional properties of egg protein fractions such as liquid egg white (LEW) with macro/microstructural information are still controversial. Hence, this study was designed to elaborate the foaming and heat-set gelation functionality of LEW following different γ-ray irradiation dose treatments (0, 1, 3 or 5 kGy). For such, the physicochemical properties (active sulfhydryl and the hydrophobicity of protein moieties), structural characteristics (through X-ray diffraction, Fourier-transform infrared spectroscopy and differential scanning calorimetry) and interfacial activities (rheological viscosity, interfacial tension, microrheological performance) were investigated. Then, the thermal gelation of LEW in relation to the texture profile and microstructure (by means of a scanning electron microscope) was evaluated followed by the swelling potency analysis of LEW gel in enzyme-free simulated gastric juice. The results indicated that irradiation significantly increased the hydrophobicity of liquid egg white proteins (LEWPs) ( p < 0.05) by exposing non-polar groups and the interfacial rearrangement from a β-sheet to linear and smaller crystal structure, leading to an enhanced foaming capacity. Microstructural analysis revealed that the higher dose irradiation (up to 5 kGy) could promote the proteins' oxidation of LEW alongside protein aggregates formed in the amorphous region, which favored heat-set gelation. As evidenced in microrheology, ≤3 kGy irradiation provided an improved viscoelastic interface film of LEW during gelatinization. Particularly, the LEW gel treated with 1 kGy irradiation had evident swelling resistance during the times of acidification at pH 1.2. These results gave new insight into the irradiation-assisted enhancement of foaming and heat-set gelation properties of LEW.

To improve the mechanical strength and oil-loading performances of egg white protein (EWP) aerogel, the effects of different grafting degrees on the modification of EWP by sodium carboxymethylcellulose (CMC-Na) were investigated. After different dry-heat treatment durations (0, 12, 24, 36, and 48 h), the EWP/CMC-Na conjugates with different grafting degrees (noted as EC0, EC12, EC24, EC36, and EC48, respectively) were obtained. Subsequently, the physicochemical properties of the conjugates, as well as the microstructure, mechanical properties, pore parameters, emulsification properties and oil-carrying properties of the conjugated aerogels, were characterized. The results showed that EC12 (with a grafting degree of 8.35%) aerogel possessed a uniform structure, the largest specific surface area, and the best emulsification performance. This facilitated a more robust aerogel (2.05 MPa) with nearly three times the mechanical strength of EWP aerogel. Moreover, this had a positive influence on the efficient loading and stable retention of oil. EC12 aerogel thus achieved an oil absorption capacity of 5.46 g/g aerogel and an oil holding capacity of 31.95%, and both values were nearly 1.7 times higher than those of EWP aerogel. In general, the EWP-based aerogel with a grafting degree of 8.35% had the best mechanical and oil-loading properties.

Egg white protein (EWP) is susceptible to denaturation and coagulation when exposed to high temperatures, adversely affecting its flavour, thereby influencing consumers’ decisions. Here, we employ high-voltage cold plasma (HVCP) as a novel nonthermal technique to investigate its influence on the EWP’s flavour attributes using E-nose, E-tongue, and headspace gas-chromatography-ion-mobilisation spectrometry (HS-GC-IMS) due to their rapidness and high sensitivity in identifying flavour fingerprints in foods. The EWP was investigated at 0, 60, 120, 180, 240, and 300 s of HVCP treatment time. The results revealed that HVCP significantly influences the odour and taste attributes of the EWP across all treatments, with a more significant influence at 60 and 120 s of HVCP treatment. Principal component analyses of the E-nose and E-tongue clearly distinguish the odour and taste sensors’ responses. The HS-GC-IMS analysis identified 65 volatile compounds across the treatments. The volatile compounds’ concentrations increased as the HVCP treatment time was increased from 0 to 300 s. The significant compounds contributing to EWP characterisation include heptanal, ethylbenzene, ethanol, acetic acid, nonanal, heptacosane, 5-octadecanal, decanal, p-xylene, and octanal. Thus, this study shows that HVCP could be utilised to modify and improve the EWP flavour attributes.

This study aims to investigate the influence of the mixture (CGO/EWP) of carrageenan oligosaccharide (CGO) and egg white protein (EWP) (CGO/EWP, CGO: EWP = 1:1, m/m) on the functional, structural, and gelling properties of Culter alburnus myofibrillar protein (MP) during repeated freezing–thawing cycles by treating MP samples separately with EWP, CGO, or CGO/EWP based on the wet weight (1%, m/m), using samples without any cryoprotectant as the blank group. After the second repeated freezing–thawing cycle, the sulfhydryl group content was found to be significantly (p < 0.05) higher in the CGO/EWP (30.57 nmol/mg) and CGO (36.14 nmol/mg) groups than in the EWP group (23.80 nmol/mg), indicating that CGO/EWP and CGO can more effectively delay the oxidative deterioration of functional groups. Additionally, the surface hydrophobicity was shown to be significantly lower in the CGO (25.74) and CGO/EWP (27.46) groups than in the EWP (34.66) and blank (39.32) groups. Moreover, the α-helix content was higher in the CGO (35.2%) and CGO/EWP (32.3%) groups than in the EWP (29.2%) and blank (25.0%) groups. These data indicated that CGO and CGO/EWP could more effectively increase the structural stability, thereby inhibiting the exposure of hydrophobic groups and curbing the decline of α-helix content. During the heat-induced gel-forming process, EWP and CGO/EWP could enhance the gel viscoelasticity and strength. After the second freezing–thawing cycle, when compared with the blank group, the CGO/EWP group showed significantly (p < 0.05) higher water-holding capacity (66.30% versus 53.93%) and shorter T22 relaxation time (413.56 versus 474.99 ms). The integrated results indicated that CGO/EWP could more effectively delay the decrease of protein–water molecular interaction forces in the MP gel. This study shed light on the mechanism of CGO/EWP as a cryoprotective mixture in improving the deterioration of MP gelation properties during repeated freezing–thawing cycles.

This study focuses on the effect of the mixture (XO/EW) of xylooligosaccharides (XO) and egg white protein (EW) on the physicochemical properties, conformation, and gel-forming ability of Culter alburnus myofibrillar proteins (MP) during multiple freeze–thaw (FT) cycles. In our methodology, MP samples added with EW, XO, or XO/EW mixture (1%, v/v) are prepared, and after multiple FT cycles, the XO or XO/EW-treated samples show significant (p < 0.05) inhibition on the decrease of sulfhydryl content and the increase of carbonyl content of MP. Compared with EW, XO or XO/EW could delay the increase of surface hydrophobicity and the decline of secondary and tertiary structural properties of MP, indicating that XO or XO/EW could more effectively increase the stability of MP conformation. Meanwhile, XO/EW could more effectively reduce the decrease of gel strength and gel water holding capacity, and the increase in the T2 relaxation time of MP gel, confirming that XO/EW could substantially improve the MP gel-forming ability. Analysis of intermolecular interaction force proves that, compared with EW, XO/EW could reduce the content decrease of ionic and hydrogen bonds in MP gel. Overall, XO/EW could improve the stability of MP functional properties over multiple FT cycles. This study provides a new perspective for the potential commercial application of EW as a low-calorie cryoprotectant in aquatic products.

The effects of egg white protein and soy protein isolate addition on the nutritional and digestibility of gluten-free pasta based on banana flour were studied. The level of protein additions (soy protein or egg white protein) were 0, 5, 10 and 15% of banana flour (w/w). Pasta made from 100% durum wheat semolina was used as a control. Soy protein isolate inclusion into banana pasta increased total phenolic content (TPC) and antioxidant capacities, while egg white protein decreased the TPC and antioxidant capacities with the increasing level of addition. Starch digestibility was affected by the type of protein addition. Egg white protein lowered starch digestibility compared to soy protein isolate. Protein inclusion in banana pasta also altered protein digestibility, amino acid profiles and protein digestibility-corrected amino acid score (PDCAAS). Soy protein isolate increased protein digestibility of gluten-free pasta compared to egg white protein. Protein enrichment gave better amino acid profiles of banana pasta compared to semolina pasta with egg white protein and performed a better PDCAAS compared to soy protein isolate. These results showed that soy protein isolate and egg white protein addition enhanced nutritional qualities and digestibility properties of gluten-free banana pasta.

The 3D printing of foods is an emerging technique for producing unique and complex food items. This study presents the optimization of a new formulation for 3D printing foods on the basis of a complex system, which contains egg white protein (EWP), gelatin, cornstarch, and sucrose. The effects of different formulations on the rheological properties and the microstructure of the printing system were investigated. The formulation was optimized through response surface methodology, and a central composite design was adopted. The optimum formulation of the 3D mixture printing system was made of gelatin (14.27 g), cornstarch (19.72 g), sucrose (8.02 g), and EWP (12.98 g) in 250 mL of total deionized water with a maximum sensory evaluation score of 34.47 ± 1.02 and a viscosity of 1.374 ± 0.015 Pa·s. Results showed that the viscosity of the formulation correlated with the sensory evaluation score. The rheological properties and tribological behavior of the optimum formulation significantly differed from those of other formulations. A viscosity of 1.374 Pa·s supported the timely flow out of the printing material from the nozzle assisting 3D printability. Thus, 3D printing based on the egg white protein mixture system is a promising method for producing complex-shaped food objects.

Succinylation can improve the thermal stability of various proteins. In this study, succinylated egg white protein (SEWP) samples with different succinylation degrees were prepared by adding various succinic anhydride additives to egg white protein (EWP). The thermal stability of SEWP and the conformational structure under various succinylation degrees were investigated. With the increase in succinylation degree, the turbidity of heated SEWP solution (90 °C for 30 min) markedly declined. The heated SEWP solution with high succinylation degree (37.63%, 66.57%, and 72.37%) was transparent. Moreover, the result of differential scanning calorimetry confirmed that the thermal stability of succinylated EWP increased. The results of intrinsic fluorescence spectra and Fourier-transform infrared spectroscopy illustrate that succinylation changed the conformational structure of EWP. Succinylation increased the electrostatic repulsion and decreased the surface hydrophobicity, and it changed the aggregation morphology of EWP. Cross-linked spherical aggregates of low succinylation degree transformed to thready aggregates of a high succinylation degree. Thus, succinylation improved the thermal stability of EWP.

Due to the poor thermal stability of egg white protein (EWP), important challenges remain regarding preparation of nanoparticles for EWP above the denaturation temperature at neutral conditions. In this study, nanoparticles were fabricated from conjugates of EWP and isomalto-oligosaccharide (IMO) after heating at 90 °C for 30 min. Meanwhile, the effects of protein concentration, temperature, pH, ionic strength and degree of glycation (DG) on the formation of nanoparticles from IMO-EWP were investigated. To further reveal the formation mechanism of the nanoparticles, structures, thermal denaturation properties and surface properties were compared between EWP and IMO-EWP conjugates. Furthermore, the emulsifying activity index (EAI) and the emulsifying stability index (ESI) of nanoparticles were determined. The results indicated that glycation enhanced thermal stability and net surface charge of EWP due to changes in the EWP structure. The thermal aggregation of EWP was inhibited significantly by glycation, and enhanced with a higher degree of glycation. Meanwhile, the nanoparticles (

The partial substitution of animal protein by plant protein is a new opportunity to produce sustainable food. Hence, to control the heat treatment of a composite protein ingredient, this work investigated the thermal behavior of mixtures of raw egg white (EW) and a laboratory-prepared pea protein isolate (PPI). Ten-percentage-by-weight protein suspensions prepared with different PPI/EW weight ratios (100/0, 75/25, 50/50, 25/75, 0/100) at pH 7.5 and 9.0 were analyzed by differential scanning calorimetry (DSC) and dynamic rheology in temperature sweep mode (T < 100 °C). The DSC data revealed changes in the thermal denaturation temperatures (Td) of ovotransferrin, lysozyme, and pea legumin, supposing interactions between proteins. Denaturation enthalpy (∆H) showed a high pH dependence related to pea protein unfolding in alkaline conditions and solubility loss of some proteins in admixture. Upon temperature sweeps (25-95 °C), the elastic modulus (G') of the mixtures increased significantly with the EW content, indicating that the gel formation was governed by the EW protein. Two thermal sol-gel transitions were found in EW-containing systems. In particular, the first sol-gel transition shifted by approximately +2-3 °C at pH 9.0, probably by a steric hindering effect due to the presence of denatured and non-associated pea globulins at this pH.

In this study, oleogels were prepared by the emulsion-template method using egg-white protein microgel as a gelator and xanthan gum (XG) as thickener. The physicochemical properties of the emulsion and oleogels were investigated. The adsorption of protein on the surface of the oil droplet reached saturation when the protein microgel concentration reached 2%. The excess protein combined with XG and accumulated on the outer layer of the oleogel, which prevented the emulsion from flocculation, enhanced the oil-holding capacity of the oleogel, and had a positive effect on preventing the oxidation of oil. When the concentration of XG was less than 0.4%, the EWP microgel, combined with the XG, stabilized the emulsion. As the concentration of XG was greater than 0.4%, excessive XG in the emulsion improved the viscosity and mechanical properties of the emulsion to prevent the aggregation of oil droplets. However, the change in XG concentration had no significant effect on the oxidation of the oil.

The study investigated the effects of different microwave vacuum freeze-drying powers (100-500 W) on the emulsifying properties and structural characteristics of egg white protein, which is of great significance in enhancing the added value of EWP and promoting its application. Emulsification analysis revealed that the emulsification performance was significantly influenced by microwave power and reached its maximum at 300 W. Fourier-transform infrared spectroscopy (FT-IR) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analyses showed that microwave vacuum freeze-drying treatment altered the secondary structure of EWP without changing its peptide structure. Fluorescence measurements indicated that the maximum fluorescence emission intensity decreased, and the maximum emission wavelength shifted towards blue as the power increased. Particle size, zeta potential, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) analyses showed that the average particle size of EWP reached the minimum value of 1203.66 nm, the absolute value of zeta potential reached the maximum value of 41.35 mV, and the thermal stability was strongest, with a more uniform and loose structure observed at 300 W. Texture profile analysis (TPA) showed that appropriate power treatment significantly enhanced the chewiness and viscoelasticity of egg white protein. Therefore, appropriate power treatment could effectively improve the emulsifying properties and stability.

Egg white protein is a non-toxic and biodegradable biopolymer that forms a gel easily via simple thermal denaturation treatment. A novel aerogel on the basis of egg white protein crosslinked with graphene oxide was prepared via a facile freeze-drying method. The structure and physicochemical characteristics of the aerogels were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and Brunauer-Emmett-Teller (BET) analysis. The adsorption properties of the aerogels were investigated by studying the influencing factors such as the solution pH, dose, temperature and contact time. The adsorption capacity of methylene blue onto the aerogels was tested, whose maximum adsorption capacity, calculated by the Langmuir isotherm equation, reached 91.7 mg/g. Adsorption kinetics studies showed that the adsorption followed the pseudo-second-order kinetic model. Thermodynamic data implied that methylene blue adsorbed by the aerogels was an exothermic and spontaneous process.

This study evaluated the effects of three polysaccharides, xanthan gum (XG), kappa-carrageenan (CA), and guar gum (GG), on the foaming and emulsifying properties of egg white liquid (EWL) and explored the intermolecular interactions and aggregation states in the initial polysaccharide−EWL complex. The results showed that the addition of XG and GG significantly improved the foaming stability of EWL on the one hand, from 66% to 78% and 69%, respectively (p < 0.05). On the other hand, the addition of XG and GG significantly improved the foam uniformity and density, and the average foam area decreased from 0.127 to 0.052 and 0.022 mm2, respectively (p < 0.05). The addition of XG and CA significantly improved the emulsification activity index (from 13.32 to 14.58 and 14.36 m2/mg, respectively, p < 0.05) and the emulsion stability index (from 50.89 to 53.62 and 52.18 min, respectively, p < 0.05), as well as the interfacial protein adsorption at the oil−water interface; it also reduced the creaming index. However, GG negatively affected these indicators. Furthermore, the electrostatic and hydrophobic interactions among molecules in EWL due to XG and the electrostatic, hydrogen bonding, and hydrophobic interactions among molecules in EWL due to CA ultimately led to the irregular aggregation of egg white proteins. Hydrophobic interactions and disulfide bonds between molecules in EWL−containing GG formed filamentous aggregations of egg white proteins. This work reveals that molecules in the polysaccharide−egg white complexes aggregate by interaction forces, which in turn have different effects on the foaming and emulsifying properties of egg white proteins.

This study aims to investigate the influence of the mixture (CGO/EWP) of carrageenan oligosaccharide (CGO) and egg white protein (EWP) (CGO/EWP, CGO: EWP = 1:1, m/m) on the functional, structural, and gelling properties of Culter alburnus myofibrillar protein (MP) during repeated freezing-thawing cycles by treating MP samples separately with EWP, CGO, or CGO/EWP based on the wet weight (1%, m/m), using samples without any cryoprotectant as the blank group. After the second repeated freezing-thawing cycle, the sulfhydryl group content was found to be significantly ( p < 0.05) higher in the CGO/EWP (30.57 nmol/mg) and CGO (36.14 nmol/mg) groups than in the EWP group (23.80 nmol/mg), indicating that CGO/EWP and CGO can more effectively delay the oxidative deterioration of functional groups. Additionally, the surface hydrophobicity was shown to be significantly lower in the CGO (25.74) and CGO/EWP (27.46) groups than in the EWP (34.66) and blank (39.32) groups. Moreover, the α-helix content was higher in the CGO (35.2%) and CGO/EWP (32.3%) groups than in the EWP (29.2%) and blank (25.0%) groups. These data indicated that CGO and CGO/EWP could more effectively increase the structural stability, thereby inhibiting the exposure of hydrophobic groups and curbing the decline of α-helix content. During the heat-induced gel-forming process, EWP and CGO/EWP could enhance the gel viscoelasticity and strength. After the second freezing-thawing cycle, when compared with the blank group, the CGO/EWP group showed significantly ( p < 0.05) higher water-holding capacity (66.30% versus 53.93%) and shorter T 22 relaxation time (413.56 versus 474.99 ms). The integrated results indicated that CGO/EWP could more effectively delay the decrease of protein-water molecular interaction forces in the MP gel. This study shed light on the mechanism of CGO/EWP as a cryoprotective mixture in improving the deterioration of MP gelation properties during repeated freezing-thawing cycles.

This study focuses on the effect of the mixture (XO/EW) of xylooligosaccharides (XO) and egg white protein (EW) on the physicochemical properties, conformation, and gel-forming ability of Culter alburnus myofibrillar proteins (MP) during multiple freeze-thaw (FT) cycles. In our methodology, MP samples added with EW, XO, or XO/EW mixture (1%, v / v ) are prepared, and after multiple FT cycles, the XO or XO/EW-treated samples show significant ( p < 0.05) inhibition on the decrease of sulfhydryl content and the increase of carbonyl content of MP. Compared with EW, XO or XO/EW could delay the increase of surface hydrophobicity and the decline of secondary and tertiary structural properties of MP, indicating that XO or XO/EW could more effectively increase the stability of MP conformation. Meanwhile, XO/EW could more effectively reduce the decrease of gel strength and gel water holding capacity, and the increase in the T 2 relaxation time of MP gel, confirming that XO/EW could substantially improve the MP gel-forming ability. Analysis of intermolecular interaction force proves that, compared with EW, XO/EW could reduce the content decrease of ionic and hydrogen bonds in MP gel. Overall, XO/EW could improve the stability of MP functional properties over multiple FT cycles. This study provides a new perspective for the potential commercial application of EW as a low-calorie cryoprotectant in aquatic products.

The effects of egg white protein and soy protein isolate addition on the nutritional and digestibility of gluten-free pasta based on banana flour were studied. The level of protein additions (soy protein or egg white protein) were 0, 5, 10 and 15% of banana flour ( w / w ). Pasta made from 100% durum wheat semolina was used as a control. Soy protein isolate inclusion into banana pasta increased total phenolic content (TPC) and antioxidant capacities, while egg white protein decreased the TPC and antioxidant capacities with the increasing level of addition. Starch digestibility was affected by the type of protein addition. Egg white protein lowered starch digestibility compared to soy protein isolate. Protein inclusion in banana pasta also altered protein digestibility, amino acid profiles and protein digestibility-corrected amino acid score (PDCAAS). Soy protein isolate increased protein digestibility of gluten-free pasta compared to egg white protein. Protein enrichment gave better amino acid profiles of banana pasta compared to semolina pasta with egg white protein and performed a better PDCAAS compared to soy protein isolate. These results showed that soy protein isolate and egg white protein addition enhanced nutritional qualities and digestibility properties of gluten-free banana pasta.

The 3D printing of foods is an emerging technique for producing unique and complex food items. This study presents the optimization of a new formulation for 3D printing foods on the basis of a complex system, which contains egg white protein (EWP), gelatin, cornstarch, and sucrose. The effects of different formulations on the rheological properties and the microstructure of the printing system were investigated. The formulation was optimized through response surface methodology, and a central composite design was adopted. The optimum formulation of the 3D mixture printing system was made of gelatin (14.27 g), cornstarch (19.72 g), sucrose (8.02 g), and EWP (12.98 g) in 250 mL of total deionized water with a maximum sensory evaluation score of 34.47 ± 1.02 and a viscosity of 1.374 ± 0.015 Pa·s. Results showed that the viscosity of the formulation correlated with the sensory evaluation score. The rheological properties and tribological behavior of the optimum formulation significantly differed from those of other formulations. A viscosity of 1.374 Pa·s supported the timely flow out of the printing material from the nozzle assisting 3D printability. Thus, 3D printing based on the egg white protein mixture system is a promising method for producing complex-shaped food objects., Competing Interests: The authors declare no conflict of interest.

Due to the poor thermal stability of egg white protein (EWP), important challenges remain regarding preparation of nanoparticles for EWP above the denaturation temperature at neutral conditions. In this study, nanoparticles were fabricated from conjugates of EWP and isomalto-oligosaccharide (IMO) after heating at 90 °C for 30 min. Meanwhile, the effects of protein concentration, temperature, pH, ionic strength and degree of glycation (DG) on the formation of nanoparticles from IMO-EWP were investigated. To further reveal the formation mechanism of the nanoparticles, structures, thermal denaturation properties and surface properties were compared between EWP and IMO-EWP conjugates. Furthermore, the emulsifying activity index (EAI) and the emulsifying stability index (ESI) of nanoparticles were determined. The results indicated that glycation enhanced thermal stability and net surface charge of EWP due to changes in the EWP structure. The thermal aggregation of EWP was inhibited significantly by glycation, and enhanced with a higher degree of glycation. Meanwhile, the nanoparticles (<200 nm in size) were obtained at pH 3.0, 7.0 and 9.0 in the presence of NaCl. The increased thermal stability and surface net negative charge after glycation contributed to the inhibition. The EAI and ESI of nanoparticles were increased nearly 3-fold and 2-fold respectively, as compared to unheated EWP.