Decrease In Surface Hydrophobicity Research Articles

Effect of dephenolization degree of rice bran on the structure of rice bran protein

The structure of rice bran protein obtained from defatted rice bran at various dephenolization times (0, 1, 2, 4, and 6) was examined to determine the impact of the degree of rice bran dephenolization upon rice bran protein structure. The total phenolics content in defatted rice bran and rice bran protein gradually decreased as dephenolization times increased, ranging from 390.12 to 131.16 mg GAE/100 g DW and from 30.80 to 17.85 mg/g, respectively, and the free sulfhydryl content of rice bran protein increased from 16.45 to 28.24 nmol/mg, accompanied by a decrease in surface hydrophobicity and the content of high molecular weight subunits. Furthermore, the maximum intrinsic fluorescence intensity and the flexibility of the secondary and spatial structure of rice bran protein initially increased and subsequently declined, reaching the highest level after two dephenolization cycles, while the absolute value of Zeta potential and particle size initially reduced and subsequently increased, reaching the lowest value after two dephenolization cycles. This study showed that the degree of removal of endogenous phenolics from defatted rice bran had an important effect on the structure of rice bran protein, which provided a more theoretical reference for regulating the structural characteristics of rice bran protein.

Pea protein-quercetin glycoside complexes: Interaction, foaming and emulsifying properties

Quercetin (Qu), Quercitrin (Que) and Rutin (Ru) were advisedly selected to explore the interaction of flavonoids with pea protein (PP) by spectral analysis and molecular simulation. The order of binding affinity at 298 K for the flavonoids with PP was Qu (2.26 × 105 M−1) > Ru (8.23 × 104 M−1) > Que (7.93 × 104 M−1), introducing one or two glycosides weakened the affinity. Thermodynamic analysis indicated that the dominant interaction of flavonoids with PP were hydrogen bond and Van der Waals force, which supported by the results of molecular docking simulations. Moreover, decreased surface hydrophobicity and the changed of circular dichroism showed that the conformation of PP became looser with the addition of flavonoids, then the surface tension was decreased, foaming and emulsifying properties of PP were improved. This result may be beneficial to the application of natural flavonoid nutraceuticals and improvement of protein-based food quality properties.

Characterization and Mechanism of Gel Deterioration of Egg Yolk Powder during Storage.

Egg yolk forms have several health and industrial applications, but their storage characteristics and gel mechanisms have not been thoroughly studied. In order to investigate the relationship between the changes in structure and properties of egg yolk gel and egg yolk powder during storage, in this paper, egg yolk powder was stored at 37 °C for 0, 1, 3, and 6 months in an accelerated storage experiment, and the influence of storage time on the gel properties of egg yolk powder was analyzed. The results showed that the contents of protein carbonylation and sulfhydryl in the yolk decreased gradually with the extension of storage time. Circular dichroism and fluorescence spectra showed that the ordered structure and structural stability of egg yolk proteins decreased gradually. Oxidation led to the formation of intermolecular crosslinking in the egg yolk proteins and oxidized aggregates, resulting in a decrease in surface hydrophobicity, which affected the gel properties of the egg yolk powder after rehydration, resulting in the phenomenon of lipid migration and gel degradation. The results provide a theoretical basis for improving egg yolk powder's overall quality and storage stability.

Solid‐state and submerged fermentation effects on functional properties of pea protein‐enriched flour

AbstractBackground and ObjectivesModification of plant proteins is often required to make them suitable substitutes for animal proteins in food applications. The effects of fermentation on the quality and functional properties of pea protein‐enriched flour (PPEF) were evaluated in this study. PPEF was fermented by Aspergillus oryzae, Rhizopus oryzae, Rhizopus oligosporus, Lactobacillus plantarum, and Bacillus subtilis strains using solid‐state and submerged fermentation (SSF and SmF, respectively).FindingsProtein contents significantly increased following fermentation for all samples, while lipid contents significantly decreased in SSF and increased in SmF samples. Surface properties were modified: enhanced zeta potential and decreased surface hydrophobicity were observed. At pH 7, emulsification activities and stabilities increased in A. oryzae and R. oligosporus samples, and emulsion stability increased for all fermented samples. Water and oil holding capacities increased after fermentation. SmF‐PPEF showed generally more significant changes in these properties.ConclusionsFermentation improved the functional properties of PPEF to varying degrees, depending on the mode of fermentation, pH conditions, and fermenting strains.Significance and NoveltyThis research demonstrates that fermentation can be efficient in modifying various functional properties of legume proteins, thus, helping increase their values.

Physicochemical properties of soybean protein isolate-based gel produced through probiotic fermentation

Soy protein isolate (SPI) was used to prepare gels through probiotic fermentation. The effects of fermentation time (0–20 h) on the physicochemical properties of resulting gel were evaluated. The effect of probiotic fermentation on physicochemical properties of gel was found to highly depend on the fermentation time. The probiotic fermentation decreased the pH value below pH 4.75 and this process also induced SPI to form a gel upon 10 h. The formation of gel was indicated by the increase of particle size, viscosity and storage modulus, and appearance of a new peak in molecular weight distribution. The formation of porous and gel-like microstructure, due to the aggregation of SPI molecules, also occurred after 10 h of fermentation. Water holding capacity of SPI-based gel reached the highest value at 15 h fermentation and decreased with further fermentation. The probiotic fermentation caused an increase of band intensity of amide-A in FTIR spectra. It also caused a decrease of surface hydrophobicity and fluorescence intensity in intrinsic tryptophan fluorescence spectra. The subunits of SPI remained intact and were not affected by probiotic fermentation.

Possible role of polypeptide-chlorogenic acid interaction in the physicochemical and sensory characteristics of quinoa-modified coffee beverage

The effect of quinoa protein hydrolysate (QPH) beverage on the physicochemical and sensory characteristics of coffee was investigated. The scores of sensory properties of coffee-quinoa beverage revealed that the unpleasant sensory characteristics, such as extreme bitterness and astringency, were covered up by the addition of quinoa beverage; while smooth mouthfeel and sweetness were enhanced. On the other hand, the introduction of coffee into quinoa beverage significantly retarded oxidation characterized by TBARS. When treated with chlorogenic acid (CGA), significant structural changes and improved functionalities of QPH were detected. CGA induced the unfolding structure of QPH and decreased surface hydrophobicity. The interaction between QPH and CGA was shown by the changes of sulfydryl content and the pattern of SDS-PAGE. Besides, neutral protease treatment increased the equilibrium oil–water interfacial pressure value of QPH, revealing improved stability of emulsions. Synergistic antioxidant effect between QPH and CGA was revealed by increased ABTS+· scavenging rate.

The impact of pH and acid-activated proteases on the decrease of immunological properties of parvalbumin from freshwater fish

Fermentation has been found as an effective method to decrease the hypersensitive reactions of consumers by freshwater fish, but the reason is not clear. Therefore, the aim of this study was to investigate the impact of pH and acid-activated proteases on the decrease of immunological properties of parvalbumin from freshwater fish, by the indicators of SDS-polyacrylamide gel electrophoresis, western blotting, enzyme-linked immunosorbent assay, surface hydrophobicity and circular dichroism. The results showed that black carp (Mylopharyngodon piceus) had the highest level of immunological properties reflected by quantitation, the content of linear epitopes and conformational epitopes of parvalbumin, and IgE-binding rate. Afterwards, purified parvalbumin from black carp was obtained with purity higher than 95%. Then, for acidification and enzyme models, it indicated that acid-activated proteases were the reason for the decrease of immunological properties. Ulteriorly, the mechanism on the level of protein structure was provided, which showed the decrease of α-helix and the increase of β-turn and random coil, as well as the decrease of surface hydrophobicity had joint contribution for the breaking of conformational epitopes. This study could provide a novel guidance for the decrease of immunological properties of fish and promote fish processing industry further.

Dose-Dependent Effect of Hyperoside on the Physicochemical and Gel Properties of Porcine Myofibrillar Proteins at Different NaCl Concentrations under Oxidative Stress.

The effects of HYP (10, 50, and 250 μM/g protein) on the physicochemical and gel properties of myofibrillar proteins (MPs) at different NaCl concentrations under oxidative stress were explored. The incorporation of HYP significantly reduced carbonyl content and decreased the loss of free amine groups in a dose-dependent manner, regardless of NaCl concentration. In addition, HYP induced a dose-dependent decrement in total sulfhydryl content regardless of NaCl concentration, which might result from the formation of thiol-quinone adducts via Michael addition. The surface hydrophobicity was significantly increased with HYP addition. Nevertheless, compared with samples treated with 50 μM/g HYP, 250 μM/g HYP caused a significant decrease in surface hydrophobicity, which might be due to the increase in the extent of MPs unfolding and the concomitant aggregation of MPs by hydrophobic interaction. Furthermore, HYP also showed a dose-dependent increment in the water-holding capacity (WHC) and gel strength of MPs gels, which might be due to more orderly crosslinks via fibrous filaments at 0.2 M NaCl and more regular and lamellar structures with smaller and more homogeneous pores at 0.6 M NaCl. In summary, HYP reduced the oxidation-mediated changes of physicochemical characteristics, preventing the oxidative damage of MPs and reinforcing the ordered crosslinks of MPs-MPs and MPs-HYP during thermal gelation, ultimately resulting in a better gel quality. These results provide a theoretical support for the practical application of HYP as a natural antioxidant in gel-type meat products.

Impact of binding interaction modes between whey protein concentrate and quercetin on protein structural and functional characteristics

The utilization rate of proteins can be effectively improved through the interaction between proteins and polyphenols. In this study, non-covalent and covalent whey protein concentrate (WPC)-quercetin (Q) complexes were prepared. The binding principle between WPC and Q and the structural and functional properties alteration of WPC on binding with different concentrations of Q were evaluated. Fluorescence spectroscopy results demonstrated significant structural alterations of WPC characterised by fluorescence quenching and a red-shifted maximum wavelength of emission peak after the interaction between WPC and Q, and a significant decrease in β-sheet and a remarkable increase in random curl content with the increase of Q concentration in fourier transform infrared spectroscopy (FTIR). Moreover, WPC and Q were more likely to form covalent complexes rather than non-covalent ones, which was featured with higher Q binding quantity and lower sulfhydryl group content at the same Q content. The binding sites number under covalent interaction mode was about 4.75 times that of the non-covalent counterparts. Combination of Q to WPC decreased surface hydrophobicity and improved foaming capability and emulsifying activity as well as antioxidant capability both for non-covalent and covalent interaction. However, non-covalent binding increased foam stability and emulsifying stability and decreased the protein solubility characterised by protein aggregation, while opposite trends were found for covalent interaction. The interfacial stability index variations were explained by the changes of zeta-potential of complexes with the increase of Q concentration. This study provides clarifies the principle behind the binding of WPC with Q and the possible application of WPC-Q complexes in food.

Fabrication and characterization of high internal phase Pickering emulsions based on pH-mediated soy protein-epigallocatechin-3-gallate hydrophobic and hydrophilic nano-stabilizer

This study describes the feasibility of O/W High internal phase Pickering emulsions (HIPPEs) with an oil volume fraction of 0.82 stabilized by using SECNs at pH 3.0, 6.0 and 9.0. Soy protein isolate (SPI) was converted into the molten globule (MG) state at pH 3.0 and 9.0, modified by (−)-epigallocatechin-3-gallate (EGCG), and heated to obtain SPI-EGCG composite nanoparticles (SECNs). Results obtained demonstrated that with the introduction of EGCG in soy protein nanoparticles (SPNs) and increase in pH from 3.0 to 9.0, the particle distribution and tertiary structures of these nanoparticles were altered, along with decrease in surface hydrophobicity (H0), and enhancement of particle wettability and antioxidant activity. The structure of SPNs at different pH showed that there were two kinds of HIPPEs stabilizing mechanisms: nonshared multilayers (at pH 3.0 and 6.0) and mono-/shared layers (at pH 9.0). These findings provide insights into the design of protein-polyphenol nanoparticles stabilized HIPPEs suitable for the formulation of functional foods.

Whey Protein Isolate-Mesona chinensis Polysaccharide Conjugate: Characterization and Its Applications in O/W Emulsions.

Mesona chinensis polysaccharide (MCP), a common thickener, stabilizer and gelling agent in food and pharmaceuticals, also has antioxidant, immunomodulatory and hypoglycemic properties. Whey protein isolate (WPI)-MCP conjugate was prepared and used as a stabilizer for O/W emulsion in this study. FT-IR and surface hydrophobicity results showed there could exist interactions between -COO- in MCP and -NH3+ in WPI, and hydrogen bonding may be involved in the covalent binding process. The red-shifted peaks in the FT-IR spectra suggested the formation of WPI-MCP conjugate, and MCP may be bound to the hydrophobic area of WPI with decreasing surface hydrophobicity. According to chemical bond measurement, hydrophobic interaction, hydrogen bond and disulfide bond played the main role in the formation process of WPI-MCP conjugate. According to morphological analysis, the O/W emulsion formed by WPI-MCP had a larger size than the emulsion formed by WPI. The conjugation of MCP with WPI improved the apparent viscosity and gel structure of emulsions, which was concentration-dependent. The oxidative stability of the WPI-MCP emulsion was higher than that of the WPI emulsion. However, the protection effect of WPI-MCP emulsion on β-carotene still needs to be further improved.

Influence of selected gums on the foaming properties of egg white powders: Kinetics of foam formation and baking performance

In this study, the influence of three selected gums including neutral locust bean gum (LBG), guar gum (GG), and anionic xanthan gum (XG) on the foaming and baking properties of egg white (EW) powders were investigated. Results showed that the surface tension, particle size, viscosity and interfacial adsorption modulus of reconstituted EW solutions prepared by EW powders increased with the addition of gums, along with the decrease of surface hydrophobicity, especially in the presence of the anionic XG. The kinetic analysis of foam formation showed that the addition of gums, especially for LBG and GG, were beneficial to the rapid infiltration of air in foam, thus dramatically reducing the whipping time in the preparation of cake batter. Furthermore, the angel cakes prepared by reconstituted EW solutions containing LBG or GG had higher specific volume than fresh EW. These results showed that the addition of neutral gums can improve the baking performance of EW powders by increasing the foaming rate and capacity. This study provided an insight on improving the foaming performance of EW powders by incorporating gums.

Characterization of the improved functionality in soybean protein-proanthocyanidins conjugates prepared by the alkali treatment

This study investigated the changes in functionality, structure, and protein composition in soybean protein-proanthocyanidins (SPI-PC) conjugates prepared by the alkali method with dose-ranging PC molecular grafting (0.5, 1, 2 mg/mL). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that more >180 kDa polymers were formed in SPI-PC conjugates with the increase of PC levels. The structural analysis showed that conjugation to PC altered the molecular structure of SPI, appearing the protein-unfolding with PC level-dependent. Liquid chromatography tandem MS analysis (LC/MS-MS) demonstrated that the composition of protein and peptides, as well as allergen and epitopes, were changed after SPI was conjugated with PC. The antioxidant activity of SPI-PC conjugates was increased with the increase of PC levels because high PC contents caused more hydroxyl groups in polyphenols to introduce into the SPI. Emulsifying properties were increased with the increase of PC levels, probably resulting from the unfolding of proteins, increase of random coil and decrease of surface hydrophobicity. Western-bolt and enzyme-linked immunosorbent assay (ELISA) showed a reduced IgE binding capacity in SPI-PC conjugates with PC level-dependent, which was attributed to the reduction of major soybean allergens and the masking or destruction of epitopes induced by structural changes. However, the foaming properties varied from PC levels. Overall, this study demonstrated that SPI-PC conjugates formed using the alkali method have a potential application as hypoallergenic soybean products or functional ingredients in foods. In future studies, suitable reactions (e.g., PC levels) are required to be investigated in SPI-PC conjugates for balancing various functional properties. • PC increased emulsifying, foaming and antioxidant properties in SPI. • The IgE binding capacity in SPI was reduced with the increase in PC levels. • Protein modifications and structural changes in SPI varied from PC levels. • Suitable PC levels are required to balance various functionality in conjugates.

Ultrasonic process affecting interactions between sodium caseinate and whey proteins

Ultrasound has been widely explored for several applications, such as emulsification or structural modification of food materials such as proteins. In this work, the effect of ultrasound on the control of whey proteins (WPI) aggregation was evaluated in the presence of sodium caseinate (NaCas). Solutions of NaCas, WPI and both (1:1) were treated with ultrasound under different power and time conditions and were initially evaluated in terms of particle size distribution, charge density, pH and polyacrylamide gel electrophoresis. Three pairs of conditions were adopted to provide the same energy density - A1 (450 W / 300 s, 6750 MJ/m3), A2 (150 W / 900 s, 6750 MJ/m3), A3 (600 W / 300 s, 900 MJ/m3), A4 (202.5 W / 900 s, 9112.5 MJ/m3), A5 (742.5 W / 300 s, 11137.5 MJ/m3) and A6 (247.5 W / 900 s, 11137.5 MJ/m3). Best conditions of transmitted energy - A1, A3 and A5 - were studied for surface hydrophobicity, circular dichroism and infrared spectroscopy. The decrease of surface hydrophobicity of NaCas:WPI mixtures pointed to a protective effect of NaCas against WPI denaturation, confirmed by the presence of more ordered structures by FTIR analysis that were not observed in the absence of NaCas. Finally, the effect of these structural changes on the gelation capacity of the ultrasound-treated proteins was assessed. Ultrasound was able to reduce the stress at rupture from 1988.59 Pa (control) to 1655.31 Pa (A3) and 1871.24 Pa (A5), and more markedly increase the Young modulus from 113.69 kPa (control) to 243.30 kPa (A3) and 392.44 kPa (A5). This study identified that higher power values with shorter times were able to provide greater protein changes that affected gelation properties, showing that the modulation of ultrasound conditions can produce ingredients with different techno-functional properties.

In Vitro Digestion and Colonic Fermentation of UHT Treated Faba Protein Emulsions: Effects of Enzymatic Hydrolysis and Thermal Processing on Proteins and Phenolics.

Faba bean (Vicia faba L.) protein is a new plant protein alternative source with high nutrient content especially protein and phenolic compounds. The present study investigated physicochemical properties, phenolic content, antioxidant potential, and short chain fatty acids (SCFAs) production during in vitro digestion and colonic fermentation of faba bean hydrolysates and oil-in-water (O/W) emulsions. Results indicate that the enzymic hydrolysates of faba proteins exhibited higher protein solubility, increased electronegativity, and decreased surface hydrophobicity than native faba protein. O/W emulsions showed improved colloidal stability for the faba protein hydrolysates after ultra-high temperature processing (UHT). Furthermore, UHT processing preserved total phenolic content, DPPH and ABTS radical scavenging abilities while decreasing total flavonoid content and ferric reducing power. Besides, the release of phenolic compounds in faba bean hydrolysates (FBH) and emulsions (FBE) improved after intestinal digestion by 0.44 mg GAE/g and 0.55 mg GAE/g, respectively. For colonic fermentation, FBH demonstrated an approximately 10 mg TE/g higher ABTS value than FBE (106.45 mg TE/g). Total SCFAs production of both FBH and FBE was only 0.03 mM. The treatment of FBH with 30 min enzymatic hydrolysis displayed relatively higher antioxidant capacities and SCFAs production, indicating its potential to bring more benefits to gut health. Overall, this study showed that enzymic hydrolysis of faba proteins not only improved the colloidal emulsion stability, but also released antioxidant capacity during in vitro digestibility and colonic fermentation. Colonic fermentation metabolites (SCFAs) were related to the degree of hydrolysis for both FBH and FBE. Additional studies are required to further elucidate and differentiate the role of phenolics during faba protein processing and digestion stages in comparison to contributions of peptides, amino acids and microelements to digestion rates, antioxidant capacities and colonial SCFA production.

Enhancing the interfacial stability of O/W emulsion by adjusting interactions of chitosan and rice protein hydrolysate

The influences of chitosan and rice protein hydrolysate (CH/RH) ratio and oil-water ratio on the emulsification efficiency, as well as the impact of RH on the formation of CH/RH complex coacervates was investigated. Emulsions prepared by CH/RH at different concentrations (1–4%) were also evaluated. Higher proportion of CH led to an increase in turbidity, ζ-potential, and particle size and a decrease in surface hydrophobicity of CH/RH. The ζ-potential and droplet sizes of CH/RH stabilized emulsions increased with increasing CH proportion at different oil-water ratios. The formation of strong network due to electrostatic interaction between CH and RH, possessing amphiphilicity contributed by hydrophobicity of RH and hydrophilicity of CH, improve emulsion stability. The CH/RH complexes at ratio of 1:1 can form more stable emulsion as oil volume fraction from 20% to 80%. CH/RH 1:1 emulsion had greater viscosity and storage/loss modulus values than other CH/RH complexes, followed by CH/RH 1:2 at oil fraction ≥50%. Higher oil fraction (60% and 80%) enhanced the viscosity while decreased the emulsion storage stability. Increasing CH/RH concentration can help to form a thicker and stronger interfacial layer on the droplets and a more stable network structure, thus enhancing emulsion stability. Overall, CH/RH 1:1 is more effective in enhancing the interfacial adsorption and emulsification stability than CH or RH alone, especially at 50% oil volume fraction. This study may contribute to the potential of CH/RH complexes for stabilizing emulsion system at different oil contents applied in different food formulations.

Modification of structural and functional characteristics of casein treated with quercetin via two interaction modes: Covalent and non-covalent interactions

Preparation of complexes via interactions between proteins and polyphenols has become one of the methods to effectively improve utilization of proteins. In this study, the structural and functional characteristics modification of casein treated with different concentrations of quercetin (10, 20, 40, 80 and 160 μmol/g protein) via covalent and non-covalent interactions were investigated. Results revealed that covalent complexes had lower sulfhydryl group content and higher quercetin binding capacity than non-covalent ones at the same quercetin concentration. This was consistent with the results of fluorescence spectroscopy which revealed higher fluorescence quenching constant and binding sites number for the covalent complexes. Fourier transform infrared spectroscopy demonstrated similar secondary structural changing trend for covalent and non-covalent complexes. The α-helix, β-turn and random coil contents increased with increasing quercetin concentration while β-sheet content decreased. Addition of quercetin decreased surface hydrophobicity of the complexes, regardless of covalent or non-covalent interactions. Casein solubility was improved in covalent interaction, while the non-covalent interaction impaired it. Quercetin treatment improved foaming activity, emulsifying activity and antioxidant activity while decreasing foaming stability and emulsifying stability. The results could provide a theoretical foundation for potential applications of casein-quercetin complexes in the food industry.

Effects of ethanol treatment on the physicochemical properties, microstructure and protein structures of egg yolk gels

The aim of this study was to investigate the effect of ethanol treatment on the properties of egg yolk gels (EYG). The hardness of EYG showed an increasing trend, and the changes in free sulfhydryl groups manifested that ethanol treatment facilitated the formation of disulfide bonds. Environment scanning electron microscopy revealed that the degree of protein aggregation increased. Low-field nuclear magnetic resonance results indicated that ethanol treatment promoted the conversion of immobile water or lipids to free water or lipids. Moreover, the increase in the absolute of zeta potential was accompanied by the decrease in surface hydrophobicity, and the secondary structure of native egg yolk (EY) proteins underwent changes with ethanol treatment. Overall, these results demonstrated that ethanol treatment induced the structural unfolding and aggregation of EY proteins, and facilitated the better stability of the gel structures. The impact of the ethanol on the EYG increased with the concentration.

Improved thermal tolerance of ovotransferrin against pasteurization by phosphorylation

Ovotransferrin is the most heat-sensitive protein in egg white which alters the processing suitability. To improve thermostability, phosphorylation modification was performed under different pH values (5.0, 6.0, 7.0, 8.0, and 9.0), and the reasons for which were explored via physicochemical changes in this study. SEM and particle size results showed that phosphorylation diminished the average particle diameter and the number of attached particles. CD results revealed that the α-helix content of phosphorylated ovotransferrin increased and the random coil decreased significantly (P < 0.05). Tertiary structure, surface hydrophobicity and ζ-potential analyses showed that phosphorylation made more hydrophobic amino acids buried inside ovotransferrin. These changes might be because most of the phosphorylation occurred in α-helix and β- sheet to promote the thermal tolerance of phosphorylated ovotransferrin by improving its structure orderliness and decreasing surface hydrophobicity. The results indicated that phosphorylation was a practical method to enhance the thermal stability of heat-sensitive ovotransferrin.

Effect of refrigeration storage on functional properties and structure of egg white after defrosting treatments

SummaryThe changes in refrigeration storage after defrosting treatments on functional properties and structure of egg white (EW) were investigated in this study. The foaming properties and surface hydrophobicity decreased significantly (P &lt; 0.05), whereas the free thiol content of EW increased during prolonged refrigeration storage after defrosting treatments. The values of emulsifying activity index were slightly higher in EM subjected to refrigeration storage for 20–30 days after defrosting treatments (P &lt; 0.05). The texture profiles showed that the cooked EW gel subjected to refrigeration storage for 20 days after defrosting treatments, reached the minimum hardness, springiness and gumminess values vs. that of Control and Group 1. Additionally, scanning electron microscope (SEM) reflected that more and larger protein aggregates as well as irregular structure in EM during prolonged refrigeration storage after defrosting treatments. The increase in free sulfhydryl group and decrease in surface hydrophobicity tended to cause protein oxidation, aggregation and degradation, leading to deterioration of functional properties in EW following refrigeration storage after defrosting treatments. The results of this study indicate that it is important to use the EW of Control and Group 1 without any detrimental effects on functional and morphology properties in food processing industry.