Search

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. • The effect of CP on immunoreactivity, digestibility, structure, and function of EWP was studied. • IgG binding capacity of EWP after CP treatment was decreased by 20%. • Immunoreactivity reduction in EWP was attributed to protein structural changes. • The plasma oxidation improved in vitro digestibility of EWP. • CP treatment significantly improved the foaming and emulsifying capacity of EWP. [ABSTRACT FROM AUTHOR]

Hydrophilic colloid-based edible curcumin nanoemulsion coatings was exploited to keep fried rice stabilization in the freeze-thaw cycles (FTCs), including texture, moisture loss, color and other aspects of the quality characteristics. Fried rice were coated with nanoemulsion what was obtained by flaxseed gum (FG), egg white protein (EWP), Olive oil (O), and Curcumin (Cur), namely as CFEO. The scanning electron microscopy (SEM) results showed that the CFEO nanoemulsion coating had a more homogeneous and dense surface structure. In the fried rice quality determination, the hardness of the CFEO nanoemulsion coating was significantly less than the CONTROL group in each cycle. Alternatively, for moisture loss, CONTROL group significantly accelerating the rate of loss. For the color index, the CFEO group had outstanding performance in delaying the increase of the total color difference (ΔE) and brown index (BI), additionally, significantly delayed the decline in whiteness index (WI). Retrogradation enthalpy, crystallinity and short range order analysis demonstrated the contribution of the CFEO group in the delayed starch retrogradation, and further assisted in explaining the changes in texture properties. In addition, the CFEO also played a stabilizing role in preventing the fluctuation of the T 2 water distribution. Therefore, curcumin nanoemulsion as the coating of fried rice is appropriate and can delay the decline of quality in freeze-thaw cycle. • Bullet point 1: Flaxseed gum and egg white protein were used to effectively prepare and stabilize curcumin nanoemulsion. • Bullet point 1: Curcumin nanoemulsion coating further improved the quality of freezing-thaw fried rice. • Bullet point 1: Curcumin nanoemulsion coating has a delaying effect on the retrogradation of starch in fried rice. • Bullet point 1: Curcumin nanoemulsion coating has a delaying effect on the moisture loss of fried rice. [ABSTRACT FROM AUTHOR]

The effect of cryoprotectants on the changes of physicochemical and structural properties of egg white protein (EWP) caused by repeated freeze-thaw (F-T) cycles was investigated. The cryoprotectants (4% trehalose + 0.3% carrageenan, TC; 1% xylo-oligosaccharide + 0.3% carrageenan, XC; 4% trehalose + 1% xylo-oligosaccharide, TX) were added to the egg white, and stored at F-T for 1, 3, and 5 cycles. The freezing protection effect of cryoprotectants on EWP was discussed by detecting carbonyl contents, total sulfhydryl group content, surface hydrophobicity, water-holding capacity (WHC) of heat-induced gel, SDS-PAGE and the secondary and tertiary structure of protein. The results showed that cryoprotectants could effectively inhibit the increase in surface hydrophobicity and carbonyl contents, and restrict the decrease in total sulfhydryl group content, WHC of heat-induced gel and endogenous fluorescence intensity (p < 0.05). The results can provide reference for the application of cryoprotectants in frozen EWP using in food industry. [Display omitted] • The protective effect of cryoprotectants on freeze-thaw egg white was studied. • Cryoprotectants can inhibit the structure changes of egg white protein (EWP). • Xyloologosaccharide and carrageenan (XC) have a good cryoprotective effect on EWP. • XC proved to be as a potential alternative to conventional cryoprotectants. [ABSTRACT FROM AUTHOR]

Bioactive peptides can be defined as specific protein fractions with amino acid sequence that promotes a positive impact on several biologic activities. The hydrolysis of egg white protein might result in releasing or enhancing their biological activity. The aim of this study was to evaluate the effects of the enzymatic hydrolysis of egg white proteins on their antioxidant properties. The hydrolysates were prepared with protease from Aspergillus oryzae LBA 01 (AO) produced under solid-state fermentation and two commercial proteases: protease from A. oryzae (CAO), and Bacillus licheniformis (CBL). The enzymatic hydrolysis with microbial proteases increased the antioxidant properties of egg white proteins. The egg white protein hydrolysates prepared with commercial protease CAO, presented higher antioxidant activity than the hydrolysates obtained with the other proteases. According CCRD analysis, the hydrolysates prepared with 3.0% of egg white proteins and 20.0 U of protease per mL of reaction mixture, presented high radical-scavenging effect, with an ORAC value of 1193.12±84.62 and DPPH value of 19.05±0.81 Trolox EQ µmol g −1 . In ORAC assay, the maximum antioxidant activities were observed in the hydrolysates presenting DH 50.0% obtained after 120 min of hydrolysis. In contrast, for DPPH assay the highest values of antioxidant activity were detected in the hydrolysates obtained in the first 30 min, where the degree of hydrolysis was greater than 60.0%. [ABSTRACT FROM AUTHOR]

Egg white protein (EWP) is widely used in the food industry for its technological properties, which are affected by diet- and breed-related changes in its composition. Therefore, the objective of this study was to analyse the relationship between hen variety and the protein composition, functional characteristics, and physicochemical properties of egg white (EW) obtained from Black Bone (BB), Gushi (GS), Hy-Line (HY-LINE), and Harbin White (HW) chickens. The protein composition of EW was analysed by high performance liquid chromatography (HPLC), while the secondary structure of EWP was assessed by Raman spectroscopy. BB and GS EWs had significantly higher ovalbumin content (183.38 and 168.56 μg/mL, respectfully) than HY-LINE and HW EWs (148.15 and 147.44 μg/mL, respectfully) (p < 0.05). In accordance with the higher ovalbumin content, BB and GS EWs possessed significantly better foaming and gel properties, along with greater sulfhydryl group and disulfide bond content in the EWPs, than HY-LINE and HW EWs (p < 0.05). Additionally, the ovotransferrin, ovomucin, and lysozyme contents also differed significantly among EWs from the four varieties (p < 0.05). Further, the EWPs possessed significant differences in amino acid (AA) content, including essential AAs, those contributing to egg flavour, and those associated with children's growth and preterm infant health. In conclusion, differences in protein composition likely led to dissimilar functional and physicochemical properties among EWs obtained from different hen varieties, which could provide a reference for food production and genetic breeding of laying hens. • The protein composition of EW was analysed by high performance liquid chromatography (HPLC). • The EWPs possessed significant differences in amino acid and protein content. • Differences in protein composition likely led to dissimilar functional and physicochemical properties. • Egg whites from Black Bone and Gushi chickens might be more suitable for industrial food production. [ABSTRACT FROM AUTHOR]

The article discusses a study which examines the effects of different types of ionic substances present in the food processing equipments on surface fouling of foods by investigation of adsorption of egg white proteins on the surfaces of stainless steel (SS). It mentions that the adsorption of protein depends on the combination of the type of protein and the effective charge of the coexisting ionic substance. It reports less adsorption of acidic egg white proteins in the presence of phosphate.

The article presents a study on the low cholesterol-lowering activity of egg white protein (EWP) and its potential mechanism in rats. It states that the excretion of fecal neutral sterols and bile acids was higher in rats fed with EWP than by those with casein. Results suggest that the cholesterol-lowering activity of EWP can be credited to lowering the cholesterol absorption by intervening in the micellar formation in the intestines.

An abstract of the article "Effect of an Increased Supplementation of Egg White Protein on the Post-Exercise Leukocyte Subsets and the Plasma IL-6 Levels in Male Collegiate Runners," by Yuko Mekata, Osamu Kashimura and Yukari Kawano is presented.

The present study assessed the effect of incorporation of different concentrations of tannic acid (TA) and gallic acid (GA) (0.12, 0.5 and 1%w/v) in heat-treated egg white (EW) protein and glucose (Gl) (120 °C within 20 min) at 3:3% w/w on Carboxyl methyllysine (CML) formation using RP-HPLC and fluorescence detector. TA and GA at concentrations of 0.12 %w/v led to 6-folds decrease in CML content in comparison with EW-Gl where the CML level reached nearly 50 and 42 μg/mL, respectively, after 20 min heating. The evaluation of Maillard reaction products (MRP) formation during the heating process using antioxidant activity and fluorescence intensity tests indicated that there were significant inverse relationships between fluorescence intensity and antioxidant activity in all samples especially at the first minute of the heating process. The result of FTIR and SDS-PAGE confirmed that in the presence of TA and GA, the rate of glycation of protein significantly diminished in comparison with EW-Gl. The level of intercellular reactive oxygen species in Human umbilical vein endothelial cells (HUVEC) using TA and GA-containing samples were lower than when using heat treated EW-Gl samples. Moreover heat-treated TA and GA containing samples showed high antibacterial activities. The results indicated that TA and GA have a good potential in the enhancement of safety heat-treated food products through its antioxidant and antimicrobial activities, and also preventing CML production. • High level of carboxy methyllysine was formed in heated egg white-glucose. • Tannic and gallic acid reduced the carboxy methyllysine level in heated samples. • Assayed phenolic acid reduced the AGE-induced oxidative stress in HUVE cells. • Glycation rate in the presence of phenolic acid was reduced up to 50%. • High antibacterial activity was seen in heat treated phenolic acid containing samples. [ABSTRACT FROM AUTHOR]