Egg White Protein Research Articles

Effects of Modified Oil Palm Kernel Expeller Fiber Enhanced via Enzymolysis Combined with Hydroxypropylation or Crosslinking on the Properties of Heat-Induced Egg White Protein Gel

Due to its poor hydration properties, oil palm kernel expeller dietary fiber (OPKEDF) is rarely used in the food industry, especially in hydrogels, despite its advantages of high availability and low cost. To address this situation, the effects of enzymolysis combined with hydroxypropylation or crosslinking on the structure and hydration properties of OPKEDF were investigated, and the impact of these modified OPKEDFs on the properties of egg white protein gel (EWPG) was studied. Enzymolysis combined with hydroxypropylation or phosphate crosslinking improved the soluble fiber content (5.25–7.79 g/100 g), water-retention and expansion abilities of OPKEDF (p < 0.05). The addition of unmodified OPKEDF or modified OPKEDF increased the random coil content of EWPG and increased the density of its microstructure. Moreover, enzymolysis combined with hydroxypropylation or crosslinking enhanced the effect of OPKEDF on the properties of EWPG, including improvements in its water-retention ability, pH, hardness (from 97.96 to 195.00 g), chewiness (from 78.65 to 147.39 g), and gumminess (from 84.63 to 152.27) and a reduction in its transparency (p < 0.05). Additionally, OPKEDF and enzymolysis and hydroxypropylated OPKEDF increased the resilience (0.297 to 0.359), but OPKEDF treated via enzymolysis and crosslinking reduced it. Therefore, OPKEDF modified by means of enzymolysis in combination with hydroxypropylation or crosslinking improved the gel properties of EWPG. However, further work is required to determine the effects of these modifications on the nutritional profile, scalability, and economic feasibility of OPKEDF and egg white gel.

Mechanism study on the improvement of egg white emulsifying characteristic by ultrasound synergized citral: Physicochemical properties, molecular flexibility, protein structure

As a natural emulsifier, egg white protein (EWP) has great interfacial characteristics and high security, and has broad development prospects. This study explored the impact of ultrasound synergized citral (CI) treatment on the microstructure, molecular flexibility and emulsifying property of EWP, and predicted the interaction between CI and ovalbumin (the main protein in EWP) through molecular docking. The decrease in free amino content and the growth in molecular weight of EWP suggested that CI and proteins were successfully grafted. The results of physicochemical properties revealed that UCEWP (ultrasound synergized citral-treated EWP) had smaller particle size and larger ζ-potential absolute value, which meant that the stability of UCEWP system was enhanced. From the perspective of interfacial characteristics, UCEWP had lower interfacial tension, which remarkably improved its emulsifying property. The emulsifying activity index (EAI) and emulsifying stability index (ESI) of UCEWP were 1.99 times and 3.19 times higher than that of natural EWP (NEWP). Analysis of Fourier transform infrared spectroscopy (FT-IR) and fluorescence spectroscopy illustrated that the secondary and tertiary structures of UCEWP were more disordered and stretched than those of EWPs. Protein microstructure demonstrated that UCEWP presented loose small particle distribution, and correlation analysis reflected that the improvement of molecular flexibility was positively correlated with the enhancement of emulsifying property. These results elucidated that ultrasound synergized CI treatment is an effective mean to improve the molecular flexibility and emulsifying property of EWP, which provides a valuable reference for further application of EWP.

Dielectric barrier discharge cold plasma alleviated the immunoreactivity of egg white proteins with improved digestibility and functional properties

With the increasing number of children allergic to egg worldwide, there is an urgent need to develop strategies for effectively utilizing egg protein. As a novel food processing that can effectively reduce allergenicity and enhance protein quality and functional properties, cold plasma (CP) is gaining attention. The study investigated the impacts of the dielectric barrier discharge CP on the immunoreactivity, in vitro digestibility, functional properties, and structural changes of egg white protein (EWP). The results showed that the EWP treated with CP for 30 min had a significant decrease in immunoglobulin (IgG)-binding capacity by approximately 20% and improved in vitro digestibility. Further studies demonstrated that the decrease in the IgG-binding capacity of EWP correlated well with the alterations in the secondary and tertiary structures. The content of α-helix was decreased by 6.5% and the surface hydrophobicity increased by 2.5 folds after the 30-min treatment, compared with the untreated samples. The oxidation of peptide amino groups induces structural changes, accompanied by the oxidation of amino acid residues. This phenomenon has been validated through surface hydrophobicity and multispectral analysis. Additionally, CP also improved the foaming and emulsifying capacity of EWP by 140% and 8.03%, respectively. These findings suggest that CP treatment could be served as a potential technology to reduce the immunoreactivity, and improve the in vitro digestibility and functionality of EWP.

Lactic acid bacteria fermentation-induced egg white protein structure deformation influencing gelling properties, with membrane concentration as a strategy to improve texture.

Egg white (EW), a rich protein source, holds promise for creating a high-protein, low-fat gel product. However, browning issues during heating and sterilization have hindered its wider application. In this study, lactic acid bacteria fermentation was employed to eliminate reducing sugar in EW, and its impact on the molecular structure and gelling properties was explored. The results revealed that fermentation would trigger protein structural unfolding and aggregation, evident from higher fluorescence intensity and enlarged protein particle diameters, resulting in the decrease in gelling hardness. In comparison, Streptococcus thermophilus-fermented EW (under 6×108CFU/mL incubation rate, fermented for 6h) exhibited the highest gel hardness, ascribed to the relatively weaker structure transformation, with high water holding capacity and stronger intermolecular hydrophobic interaction. To further enhance the gelling properties of fermented EW, membrane concentration treatment was applied, exhibiting superior characteristics in appearance, aroma, and taste. In summary, lactic acid bacteria fermentation and concentration are feasible solutions to improve appearance and texture of EW gels simultaneously. The research findings offer eco-friendly and practical strategies for enhancing the quality of EW gels, providing valuable theoretical insights for the development of innovative, texture-rich, and healthy nutritional foods.

Effect of fat replacement in high internal phase emulsions constructed by high temperature saccharification of grafted proteins on gel properties and flavor profiles of sausages

In order to mitigate the risk of cardiovascular diseases associated with excessive saturated fatty acid intake, utilizing high internal phase emulsions (HIPEs) as a substitute for animal fat in producing high-quality fat-substituted meat products is an ideal approach. This study involves the preparation of glycosylation products of egg white protein (EWP) through saccharification at high temperatures in the presence of fructooligosaccharides (FO). The resulting glycation products of EWP were employed to create colloidal particles, forming HIPEs, which were further utilized to induce the formation of HIPEs gels (HIPEs-Gs). The study investigated the effects of substituting different ratios (25%, 50%, 75%, and 100%) of animal fat with HIPEs and HIPEs-Gs on the gel properties and flavor characteristics of sausages. Results showed that, compared to the control group, substituting fat with HIPEs significantly improved the gel properties, cooking yield, and G' of sausages, while excessive HIPEs-Gs substitution yielded negative effects. Low-field nuclear magnetic resonance results also demonstrated that adding HIPEs improved water and oil distribution in the sausage batter, enhancing protein's binding capacity with water. Scanning electron microscope revealed that HIPEs substitution led to a denser gel network with smaller pores, effectively "locking in" more water. Analysis of volatile compounds indicated accelerated release of aromatic compounds, alkanes, sulfides, and lipids when fat was substituted with HIPEs and HIPEs-Gs. Electronic tongue analysis suggested that HIPEs-Gs substitution reduced response values for umami and saltiness. In conclusion, compared to HIPEs-Gs, using HIPEs as a fat substitute improves the quality of sausages.

Impact of egg white protein on mycoprotein gel: Insights into rheological properties, protein structure and Molecular interactions

The mechanisms behind Mycoprotein (MYC) formation, especially the interactions with egg white proteins (EWP), are not fully understood despite the widespread use of fungal proteins. This study investigates the formation of MYC-EWP composite gels using physicochemical and structural analyses, supported by molecular simulations. At pH 7, EWP adsorbs onto the MYC mycelium surface via hydrogen bonding and electrostatic interactions, with a binding energy of −21.97 kcal/mol. Increasing EWP concentration enlarges particle size in the suspension. Upon heating, the gel's microstructure shows irregular fibrous structures with EWP filling the spaces within the mycelium. The texture properties improve with higher EWP levels, resulting in a denser gel structure. These findings offer key insights into MYC-EWP interactions, clarifying the gelation process and providing valuable guidance for optimizing fungal protein products.

The regulation mechanism of ultrasonic treatment on alkali-induced egg white protein gel: Structure, molecular characteristics and intermolecular forces distribution

Egg white protein can be cross-linked to form a gel under alkali induction, which is typically represented by the preserved eggs from Chinese traditional food. The effects of ultrasonic at different intensities (50 W, 100 W, 200 W, and 300 W) on alkali-induced egg white protein (EWP) gel were investigated. The gel strength rose significantly by 26.08 % upon treatment with 50 W, but it gradually declined as the intensity increased. Meanwhile, the structure unfolding and molecular aggregation of EWP were affected by ultrasonic. Compared with 300 W, 50 W could enhance surface hydrophobicity and decrease total free sulfhydryl group content more during gel formation. Selective solubility experiment confirmed that ultrasonic reduced the formation of ionic bonds, which slightly slowed down the initial gelation. Simultaneously, 50 W promoted the formation of more disulfide bonds, which helped to improve the strength of the final gel, while the same effect was not observed at 300 W. In general, moderate ultrasonic can effectively improve the alkali-induced EWP gel properties, which provides theoretical support for developing high quality preserved eggs and protein gel foods.

Effect of Hydrodynamic Cavitation and Drying Technique on Moisture Sorption Isotherm and Structural Properties of Egg White Protein Hydrolysate Powder

Effect of Hydrodynamic Cavitation and Drying Technique on Moisture Sorption Isotherm and Structural Properties of Egg White Protein Hydrolysate Powder

Effect of N-ethylmaleimide as a blocker of disulfide bonds formation on the properties of different protein-emulsion MP composite gels

Three different emulsions of myofibrillar protein (MP), soy protein isolate (SPI) and egg white protein isolate (EPI) were individually mixed with MP sol to form composite gels. N-ethylmaleimide (NEM) was used as a sulfhydryl group blocker to evaluate the effects of sulfhydryl and disulfide bonds on the properties of different protein–emulsion composite gels. The results show that the disulfide bond contents in the MP (SPI, EPI) emulsion composite gel decreased from the initial 2.4 ± 0.1, (2.3 ± 0.2, 1.8 ± 0.4) mol/kg to 0.6 ± 0.1, (0.5 ± 0.3, 0.7 ± 0.1) mol/kg with the NEM content increased. In addition, the microstructure showed that the interfacial protein membrane of the emulsion globules were broken in different degrees, indicating that the interaction between the emulsion and the gel matrix was weakened. Meanwhile, gel strength, water distribution and elastic modulus of the composite gels were reduced with NEM contents increased.

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.

Oral administration of egg white ovotransferrin prevents osteoporosis in ovariectomized rats

Ovotransferrin, an iron-binding glycoprotein, accounting for approximately 12 % of egg white protein, is a member of transferrin family. Our previous studies showed that ovotransferrin stimulates the proliferation and differentiation of osteoblasts, while inhibits osteoclastogenesis and resorption activity. The work aims to study the efficacy of orally administered ovotransferrin on the prevention of osteoporosis using ovariectomized (OVX) Sprague-Dawley rats. Oral administration of ovotransferrin showed no negative effect on body weight, food intake and organ weight. After 12-week treatment, feeding ovotransferrin at a dose of 1 % (1 g ovotransferrin/100 g diet) prevented OVX-induced bone loss and maintained relatively high bone mineral density and integrated bone microarchitecture. The serum concentration of biomarkers indicating bone formation was increased in ovotransferrin administration groups, while the bone resorption biomarkers were decreased. Ovotransferrin feeding also decreased the production of serum cytokine TNF-α and IL-6, which are two stimulators for osteoclast differentiation. In addition to its direct regulatory role on bone turnover, ovotransferrin supplementation might benefit osteoporosis prevention by inhibiting adipogenesis, and regulating immune response. Our results suggested the potential application of ovotransferrin as a functional food ingredient on the prevention of osteoporosis.

Effects of rosmarinic acid covalent conjugation on the allergenicity and functional properties of egg white protein

Polyphenols can form complexes with proteins, potentially enhancing the properties of egg white protein (EWP) by altering its structure. This study aimed to explore the effect of covalent conjugating with rosmarinic acid (RA), a bioactive polyphenol found in various edible Lamiaceae herbs, on the structure, allergenicity, and functional properties of EWP. The successful preparation of EWP-RA conjugates was confirmed through RA binding equivalent analysis. Fluorescence spectroscopy, Fourier transform infrared (FTIR) spectroscopy, circular dichroism (CD), and ultraviolet (UV) absorption spectroscopy collectively indicated that the covalent conjugation with RA led to significant structural alterations in EWP. Furthermore, the conjugation of RA markedly enhanced the antioxidant capacity of EWP, as evidenced by its improved ability to scavenge DPPH and ABTS+ radicals. Enzyme-linked immunosorbent assay (ELISA) results indicated a substantial reduction in the binding capacity of EWP-RA conjugates to IgG and IgE, indicating a decrease in the allergenic potential of EWP. Moreover, the incorporation of RA was associated with an increase in the absolute zeta potential, protein flexibility, and free sulfhydryl content of EWP, alongside a reduction in surface hydrophobicity. The findings also revealed that RA enhanced the emulsifying activity, emulsion stability, foaming ability and foaming stability of EWP. Furthermore, the storage performance of EWP improved after conjugation with RA. In conclusion, the covalent conjugation of EWP with RA not only diminished its allergenic potential but also improved its functional properties through structural modification. This study posits that such an approach could be an effective strategy for enhancing the functional properties of EWP while concurrently mitigating its allergenic potential, thereby offering promising applications in the formulation of future food products.

Effect of proteins and gums on rheology of rice flour, quality characteristics and estimated glycaemic index of low amylose rice gluten‐free penne

SummaryGluten‐free rice penne (GFRP) was developed from low amylose rice flour by incorporating egg white protein, soy protein isolate, guar gum and xanthan gum to produce penne with low estimated glycaemic index (eGI). The rheology of rice flour, textural properties, cooking quality, resistant starch (RS) and eGI of GFRP were investigated. Addition of proteins and hydrocolloids increased the storage modulus (G′) and loss modulus (G″). Rice gel with proteins and hydrocolloids formed a stronger and more elastic gel than the control, with highest G′ observed in rice gel with 5% egg white protein and 1% guar gum. Incorporation of proteins and hydrocolloids in GFRP significantly increased firmness, improved cooking quality and increased RS content. The eGI of GFRP added with egg white protein and guar gum reduced from seventy‐one to fifty‐three. Results suggested that the development of low eGI penne was possible by incorporating egg white proteins and guar gum.

Hydrogel foam with designed structural properties of egg white protein through building aggregates as potential dysphagia food

To address the growing demand for texture-modified foods (TMFs) among individuals with dysphagia, the structural properties of alkali-heat treated egg white protein aggregates (AHEWP) were investigated to developed hydrogel foams as suitable soft gels. The results showed that AHEWP presented partially unfolded and higher content of β-sheet structures. The alkaline shift suppressed thermally denatured molecular unfolding (exposing aromatic and hydrophobic amino acids) and blocked hydrogen bonding, leading to the generation of small-sized AHEWP. Within the pH range of 10.5–11.25, raising temperature promoted more covalent bonding to produce structurally compact aggregates. Compared to EWP, AHEWP exhibited remarkably stable foams (85.62–91.99% of FS) and could form Ca2+ crosslinked cold gels, which were contributed to the formation of hydrogel foam. The alkali-heat treatment of high intensity gave a less increase in surface tension and richer interfacial proteins. SEM and microrheology revealed that the alkaline shift transformed the hydrogel network of AHEWP into a “sheet-like” stacking structure, accompanied by a rise in the macroscopic viscosity index and a change of gelation rate. At pH 11.0 and 11.25, the higher temperature, the denser the pore and the lower the elasticity index. The self-supporting property and water loss of AHEWP hydrogel foam reduced, and their time stability enhanced with increasing pH and/or temperature. According to IDDSI, AHEWP hydrogel and hydrogel foam were attributed to level 4–7 and 4–5, respectively. Overall, AHEWP has the potential to establish hydrogel foam systems that will serve as a valuable reference for designing protein-based soft gel TMFs for dysphagia diets.

Molecular Mechanism of Egg White Protein for Strengthening the Cross‐Linking Properties of Heat‐Induced Wheat Gluten Gel

AbstractThe chemical interaction between egg white protein (EWP) and wheat gluten (WG) is significantly influenced by the amount of EWP added. Therefore, the effects of EWP addition on the gelling properties and chemical interactions of heat‐induced WG–EWP gels are thoroughly examined. The results demonstrate that the enhancement in gel strength of WG–EWP gels is positively correlated with the amount of EWP added. EWP addition improves protein–protein interactions by reducing the freedom of water. The enhanced aggregation between WG and EWP is likely due to a decrease in surface hydrophobicity and an increase in β‐sheet content. EWP enhances cross‐linking with low molecular weight glutenin subunit (LMW‐GS), high molecular weight glutenin subunit (HMW‐GS), and gliadin (Gli). Specifically, EWP primarily cross‐links with ω‐, α‐, and γ‐Glis through S–S bonds and interacts with GS through hydrophobic interactions and S–S bonds. This study provides a theoretical foundation for improving the WG network structure in wheat‐based food production.

Formation mechanism of giant squid myofibrillar protein aggregates induced by egg white protein during heat treatment

In order to solve the problem of poor performance of giant squid gel, this study proposed a method to induce the aggregation of giant squid protein molecules by exogenous additives to improve its gel performance. The particle size, zeta potential, free sulfhydryl group, carbonyl group and hydrophobic index of protein solution were characterized by laser light scattering, fluorescence spectrum and ultraviolet spectrum, and the effect of egg white protein (EWP) on myofibrillar protein (MP) aggregation was analyzed. In the presence of EWP, the density and Rg/Rh value of protein particles decreased significantly after mixing for 600 min, indicating that the interaction between MP and EWP protein could be enhanced by embedding appropriate amount of EWP in the middle of MP protein. With the increase of the proportion of egg white protein, the blue shift of the maximum absorption wavelength of endogenous fluorescence in the mixed protein solution decreased. In the range of 25–65 °C, the change rates of surface charge, free sulfhydryl group, carbonyl group and surface hydrophobicity decreased, which proved that EWP inhibited the self-aggregation rate of MP molecules during the heating process, and induced its gel by interspersing between MP molecules to improve the formation of three-dimensional network during protein thermal gel process. Finally, the addition of EWP improved the gel properties of giant squid surimi. This study offered new direction for improving gel properties and promotes the development and application of giant squid.

Preparation of microgel particles from egg yolk components by combining phospholipase A2 with high-pressure homogenization: Physicochemical, structural properties and their effects on foaming, processing stability of egg white protein

In this study, two types of microgel particles from egg yolk components were prepared by combining enzymatic hydrolysis with high-pressure homogenization (HPH), and their differences in physicochemical properties, foaming properties, and microstructure were compared. Results showed that the particle size of both types of microgel particles had decreased from 2744.07 ± 408.26 nm (egg yolk, EY) to 144.97 ± 3.19 nm (PLA2 hydrolyzed egg yolk microgel particles, PYM) and 535.07 ± 46.07 nm (egg yolk microgel particles hydrolyzed by PLA2, YMP), from 736.24 ± 34.61 nm (EG) to 182.76 ± 4.12 nm (PLA2 hydrolyzed egg yolk granules microgel particles, PGM) and 443.98 ± 27.09 nm (egg yolk granules microgel particles hydrolyzed by PLA2, GMP). Besides, their interfacial adsorption abilities were significantly improved, reflected in the increase values in overrun, from161.90 % ± 9.84 % (EY) to 269.64 % ± 16.73 % (PMY) and 307.20 % ± 16.09 % (YMP), from 189.21 % ± 5.02 % (EG) to 280.38 % ± 36.05 % (PGM) and 261.91 % ± 34.03 % (GMP). Their structural properties showed higher stabilities after treatments. When the microgel particles are applied to cakes, the specific volume was increased from 2.05 ± 0.1 mL/g (EY) to 2.25 ± 0.13 mL/g (PYM) and 2.45 ± 0.03 mL/g (YPM), and from 2.00 ± 0.09 mL/g (EG) to 2.51 ± 0.13 mL/g (PGM) and 2.75 ± 0.21 mL/g (GMP), respectively. The hardness and chewiness were reduced with both types of microgel particles from egg yolk components, which indicated their potential value as edible foam stabilizers in the baking industry.

Preparation of thermally stable egg white protein microgel particles as assisted by differently charged polysaccharides: A comparatively study

Egg white proteins (EWP) were prone to thermal aggregation under heat sterilization conditions, thereby limiting their application in the field of protein beverages. In this study, EWP were microgel particleized via polysaccharide-protein phase separation to enhance their resistance to thermal aggregation during processing. Results indicated that the charge characteristics of polysaccharides were crucial factors influencing their interaction with EWP. Microstructural and physicochemical properties indicated that egg white protein microgel particles (EMGP) with the bilayer structure formation (polysaccharide shell layer and dense protein core) could only be formed in the phase separation system of EWP and anionic polysaccharides (carboxymethyl cellulose sodium salt (low viscosity), carboxymethyl cellulose sodium salt (high viscosity), High-methoxyl pectin). Additionally, the EMGP exhibited uniform size, high denaturation extent and dense structure that effectively prevented structural unfolding and exposure of active sites upon reheating of the EWP. The thermal denaturation temperatures of the EMGP were significantly higher (up to 155.8 °C, 163.5 °C, 165.7 °C), compared to natural proteins (88.8 °C). Thermal stability experiments confirmed that the suspension of 5% w/v microgel particles maintained good flow ability after heating at 100 °C for 30 min, demonstrating excellent thermal stability suitable for high-temperature pasteurization conditions. Moreover, its uniform particle size and adsorption of polysaccharides improved storage stability. In contrast, groups other than anionic polysaccharides exhibited aggregation and gelation upon heating. Overall, this study demonstrated that preparing heat-stable EMGP effectively reduces aggregation in EWP beverages during heat-pasteurization, enhanced product sensory attributes, extended shelf-life, and expanded the application scope of EWP.

Impact of plant and animal proteins with transglutaminase on the gelation properties of clam Meretrix meretrix surimi

Different sources of proteins have various ways for facilitating the gelation process of surimi matrices, leading to the diverse combined effects with transglutaminase (TG). In this study, the effects of two plant proteins, soy protein isolate (SPI) and pea protein isolate (PPI), and two animal non-muscle proteins, egg white protein (EWP) and whey protein isolate (WPI), with TG addition on the gel properties of clam Meretrix meretrix (MM) surimi gels were investigated, and the mechanisms were explored. In the presence of TG, the exogenous protein addition significantly improved (p < 0.05) the gelation process of the MM surimi. The best improvements were obtained with the combination of EWP, where the gel strength, cooking loss, and water holding capacity were enhanced by 113.08%, 67.89%, and 26.30%, respectively. The addition of SPI showed a relatively weak enhancement compared to EWP incorporation, followed by the addition of PPI and WPI. The results of optical microscopy, differential scanning calorimetry, and chemical forces demonstrated that TG preferentially promoted plant proteins to form self-aggregation in the surimi system, and SPI generated more polymers than PPI. In contrast, the interpenetration of animal proteins and MM myofibrillar proteins was improved by TG. EWP formed a double cross-linking network within the MM protein network, while WPI acted as a binder to promote protein-protein interactions. This research could provide novel insights for developing MM resources and establish a theoretical foundation for the use of composite exogenous protein additives to enhance the gel properties of MM surimi products.

Effect of exogenous protein substitution in glutinous rice cake: Batter rheology, structure, and retrogradation behavior

The investigation focused on the batter properties, baking performance, and retrogradation behavior of gluten-free sponge cakes after partial (15%, 30%, and 45%) substitution of glutinous rice flour with exogenous protein, including whey protein isolates (WPI), egg white protein (EWP), and soy protein isolate (SPI). The viscoelastic properties and apparent viscosity of batter positively correlated with substitution levels, with SPI superior to WPI and EWP. WPI could produce batter with smaller and more evenly distributed cells, contributing to an enhanced specific volume of the cake due to its stabilizing effect of gas cells to form viscoelastic films. The gelatinization of starch granules proved to be constrained by the incorporation of WPI and SPI, as evidenced by elevated gelatinization temperature and reduced enthalpy change values. The restriction could be attributed to the strengthened hydrogen bonding between the starch and protein, which subsequently alleviated the retrogradation and water redistribution of cake during storage. An unpleasant eggy or beany flavor of cake was generated at 45% substitutions of EWP and SPI. In comparison, 30% WPI contributed to an appealing aroma and mouthfeel, making it a nutritional supplement to enhance its protein content while maintaining its fine sensory attributes of gluten-free sponge cake.