Preserved egg white alleviates DSS-induced colitis in mice through the reduction of oxidative stress,modulation of inflammatory cytokines,NF-κB,MAPK and gut microbiota composition

Traditional Chinese preserved egg products have exhibited some anti-inflammatory effects,but their mechanisms of action remain unknown.This study aimed to investigate the anti-inflammatory effects of preserved egg white(PEW)treatment on dextran sulfate sodium(DSS)-induced colitis in mice and the underlying mechanisms.The results showed that treatment with PEW in mice with DSS-induced colitis for 14 days effectively improved the clinical signs,inhibited the secretion and gene expression of pro-inflammatory cytokines,and reduced myeloperoxidase(MPO)activity and oxidative stress levels.In addition,western blotting results showed that PEW significantly suppressed DSS-induced phosphorylation levels of nuclear factor-kappa B(NF-κB)p65 and p38 mitogen-activated protein kinase(MAPK)in colon tissues of mice with colitis.PEW also enhanced the production of short-chain fatty acids(SCFAs)and modulated gut microbiota composition in mice with DSS-induced colitis,including increasing the relative abundance of beneficial bacteria Lachnospiraceae,Ruminococcaceae and Muribaculaceae,and reducing the relative abundance of harmful bacteria Proteobacteria.Taken together,our study demonstrated that preserved egg white could alleviate DSS-induced colitis in mice through the reduction of oxidative stress,modulation of inflammatory cytokines,NF-κB,MAPK and gut microbiota composition.

Preliminary Study on the Separation of Lysozyme,Ovotransferrin and Ovalbumin from Egg White

[Objective] A study on separation process of lysozyme, ovotransferrin and ovalbumin from egg white. [Method] The proteins were separated by ammonium sul-fates and ion-exchange chromatography. Purity of the proteins was assayed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）. [Result] The results showed that the proteins were electrophoresis-pure. The specific activity of lysozyme was increased from 144.13 to 2 235 U/mg, and purification factor was 15-fold. Lysozyme recovery rate was estimated to be 15.76%. Bacteriostasis rate of ovotransferrin was 48.84%. [Conclusion] The procedure for separating lysozyme, ovotransferrin and ovalbumin from egg white was simple, fast, low-cost and suitable for industrilization.

A new method for determination of antithrombotic activity of egg white protein hydrolysate by microplate reader

A new method for the determination of antithrombotic activity of egg white protein hydrolysate （EWPH） was developed using a microplate reader. Reaction was carried out at 37℃and pH 7.2 with fibrinogen concentration 0.1%. Microplate reading was conducted at 405 nm. Inhibition rate of EWPH on thrombin activity showed linearity （R2 = 0.9971）, when the inhibition rate was in the range of 10-90%. The lower limit of detection （LLD, at 99.7% probability） and the biological limit of detection （BLD, at 99.7% probability） of the method were 10.643 and 40 mg/mL, respectively. The repeatability standard deviation （R.S.D.） was 1.08%. The standard deviation of the method was ±0.027 AT-U.

Dynamic High Pressure Micro-fluidization Effects on Structure and Physico-chemical Properties of Egg White Protein

The authors dealt with the effects of dynamic high pressure micro-fluidization（untreated and 20-160 MPa treated） on the structure and physico-chemical properties of egg white solutions[6%（mass fraction） or 61.2 mg protein/mL]. Micro-fluidization treatment resulted in a decrease in mean particle size, and little change in solubility. It was found that the residual denaturation enthalpy was decreased with the increase of pressure from 20 to 100 MPa and from 120 to 160 MPa, reaching into the maximum at 160 MPa. There was an increase of surface hydrophobicity with the maximum at 100 MPa observed. Simultaneously, micro-fluidization treatment also resulted in a decrease in the content of sulfhydryl groups.

Isolation of Lysozyme from Chicken Egg White Using Polyacrylamide-based Cation-exchange Cryogel

An effective cation-exchange chromatographic method for lysozyme isolation from chicken egg white is presented, using supermacroporous cryogel grafted with sulfo functional groups. The chromatographic processes were carried out by one-step and sequential elution, respectively. Sodium phosphate buffer （pH 7.8） containing different concentrations of NaC1 is used as elution agent. The corresponding breakthrough characteristics and elution behaviors in the cryogel bed were investigated and analyzed. Purity of lysozyme in the elution effluent was assayed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）. The maximum purity of the obtained lysozyme was about 96%, and the cryogel is demonstrated as a potential separation medium for purification of high-purit lysozyme from chicken egg white.

Studying Some Physicochemical Characteristics of Crust Coated with White Egg and Chitosan Using a Deep-Fried Model System

In this paper, the effects of frying time, white egg (0%, 5% and 10% w/w) and chitosan (0%, 0.5% and 1.5% w/w) addition to the batter formulation on the quality of simulated crispy deep-fried Kurdish cheese nugget crusts was studied by using a deep-fried crust model. Moisture content, oil content, color and hardness of the samples were determined. Crust models were fried at 190℃ for 60, 120 and 180 s. Batter formulations and frying time significantly (p < 0.01) affected moisture, oil content, color and hardness of Crust models. Batter formulation contain 10% white egg was found to be an effective ingredient in decreasing oil content of Crust models. The mean moisture and fat content of Crust models formed with batter contained 10% white egg, fried at 190℃, for 180s were 6.207 ± 0.447 and 5.649 ± 0.394. Batters containing 5% white egg and 1.5% chitosan showed the lowest moisture content and the highest oil content among all the formulations. Crust models containing combination of white egg and chitosan were the darkest. Hardness of samples containing chitosan were the highest, specially for ch1.5 The mean hardness in 60, 120 and 180s of frying in this formulation were 21.518 ± 0.481, 36.871 ± 1.758 and 49.563 ± 1.847 respectively.

Regulation of Microstructure of Calcium Carbonate Crystals by Egg White Protein

Crystal growth of calcium carbonate in biological simulation was investigated via egg white protein with different volume fractions,during which calcium carbonate was synthesized by calcium chloride and sodium carbonate.The morphology,thermal properties and microstructure of the calcium carbonate micro-to-nanoscale crystals were characterized by scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,Fourier transform infrared spectroscopy（FTIR）,thermogravimetric analysis（TG） and X-ray diffraction（XRD） analysis.The results show that the volume fraction of egg white protein has great influence on the shape,size and morphology of calcium carbonate crystals.The calcium carbonate crystals were the mixtures of calcite-vaterite-like crystals including spherical and rough surface,which are different from that formed in pure water.With the increase of egg white protein concentration,the diameter of calcium carbonate crystals changed,the amount of formed spherical calcium carbonate particles decreased and that of vaterite increased.These results indicate that the coordination and electrostatic interaction between egg white protein and Ca2＋ significantly affect the calcium carbonate crystalization.

Interaction mechanism of egg white-derived ACE inhibitory peptide TNGIIR with ACE and its effect on the expression of ACE and AT1 receptor

The egg white-derived hexapeptide TNGIIR inhibits angiotensin-converting enzyme(ACE)activity in vitro.In this work,molecular docking revealed that TNGIIR established hydrogen bonds with the S1(Ala 354),S2(Gln 281,His 513,Tyr 520 and Lys 511)and S1(Glu 162)pockets of ACE.In addition,the potential antihypertensive effect of the oral administration of TNGIIR in spontaneously hypertensive rats(SHR)was investigated,as was the effect of this peptide on the mRNA expression of ACE and angiotensin type 1(AT1)and type 2(AT2)receptors in renal tissue.The oral administration of TNGIIR(2,10 and 50 mg/kg)for up to four weeks did not reduce the blood pressure of SHR,in contrast to captopril(10 mg/kg,orally),but attenuated the mRNA expression of ACE and AT1 receptor(as did captopril).In contrast,both TNGIIR and captopril enhanced the expression of AT2 receptor mRNA.There was no change in the circulating concentration of angiotensin I,but a slight decrease(about 10%)was seen in the concentration of circulating angiotensin II with TNGIIR and captopril.

Gel-Forming Ability of Rohu as Affected by Egg White Powder Addition

The gel-forming ability of rohu (Labeo rohita) mince with and without egg white powder (EW) was investigated. Gel from washed mince (washed gel) was prepared under two setting conditions: kamaboko (40°C) and modori (60°C). The gel-forming ability of kamaboko and modori gels was improved by the addition of EW at 2%. The autolytic inhibition of kamaboko gel was obtained in gel added with 2% EW, and 1% EW of modori gel. No marked change was observed in the TCA-soluble peptide content of either gel with the addition of EW above 1%. No effect on the whiteness of both gels was shown after the addition of EW. The addition of EW exhibited smaller cavities and a more compact fibrous network in microstructure.

Effects of ultra-high hydrostatic pressure on foaming and physical-chemistry properties of egg white

The influences of ultra-high hydrostatic pressure treatment on foaming and physical properties (solubility, hydrophobicity and sulfhydryl content) of egg white were investigated. A pressure range of 0-500 MPa, time range of 0-20 min and pH range of 7.5-8.5 were selected. The foaming property of egg white is improved by 350Mpa and 10min. The treatment resulted in in- crease of sulfhydryl content of egg white, while solubility and hydrophobicity were significantly decreased.

Synthesis, characterization and magnetic properties of KFeO_(2) nanoparticles prepared by a simple egg white solution route

Nanoparticles of potassium ferrite(KFeO_(2))in this work were synthesized by a simple egg white solution method upon calcination in air at 773,873,and 973 K for 2 h.The effects of calcination temperature on the structural and magnetic properties of the synthesized KFeO_(2) nanoparticles were investigated.By varying the calcination temperature,X-ray diffraction and transmission electron microscopy results indicated the changes in crystallinity and morphology including particle size,respectively.Notably,the reduction in particle size of the synthesized KFeO_(2) was found to have a remarkable influence on the magnetic properties.At room temperature,the synthesized KFeO_(2) nanoparticles prepared at 873 K exhibited the highest saturation magnetization(M_(S))of 2.07×10^(4) A·m^(−1).In addition,the coercivity(H_(C))increased from 3.51 to 16.89 kA·m^(−1) as the calcination temperature increased to 973 K.The zero-field cooled(ZFC)results showed that the blocking temperatures(T_(B))of about 125 and 85 K were observed in the samples calcined at 773 and 873 K,respectively.Therefore,this work showed that the egg white solution method is simple,cost effective,and environmentally friendly for the preparation of KFeO_(2) nanoparticles.

Phase Transformation of Amorphous Calcium Carbonate to Single-Crystalline Aragonite with Macroscopic Layered Structure in the Presence of Egg White Protein and Zinc Ion

Highly oriented calcium carbonate lamellas are exquisite structure produced by biomineralization. Strategies mimicking nature have been developed to synthesize inorganic materials with excellent structures and optimal properties. In our strategy, egg white protein and zinc ion were employed in the solution to induce the crystallization of calcium carbonate, resulting in the macroscopic aragonite laminate with an average length of 1.5 mm, which was comprised of single-crystalline tablets. During the crystallization at initial stage, it was found that the particles displayed the characteristics of amorphous calcium carbonate, which was then transformed into the sophisticated structured aragonite through a multistage assembly process. The rebuilt nacre structure in vitro was achieved owing to the synergistic effects of egg white protein and zinc ion.

Evaluation of Quality Parameters of White and Brown Eggs in Lebanon

The quality traits of fresh marketable chicken eggs collected during winter, autumn and summer periods from different local markets in Lebanon were evaluated in order to understand the reproductive fitness of the chicken and the correlation between collection dates. A total of 2000 brown and white eggs were analyzed and compared for their external quality parameters such as egg weight, length, width, size, shell thickness, specific gravity and for their internal quality traits such as Haugh unit, yolk diameter, yolk color, and yolk height. Results show that egg weight and size varied markedly and tended to be smaller during summer period. A significant difference was found between white and brown eggs in some quality traits such as egg weight, shell thickness, egg length, and yolk diameter parameters. Egg quality parameters were significantly reduced during summer season where eggs are exposed to high temperature conditions. For grading analysis, 80% of the total eggs were classified as A with a significant difference (p < 0.05) between white and brown egg and during collection dates. Overall, brown eggs graded better than white eggs in external quality cleanliness and shape. Based on our analysis, the results of this study show that Lebanese eggs are of good quality and suggest that proper egg handling and storage conditions should be applied especially at warm environmental conditions to improve egg quality during summer season.

Physicochemical and Functional Properties of Dehydrated Japanese Quail (<i>Coturnix japonica</i>) Egg White

Physicochemical, functional and digestibility analyses were done of dehydrated quail egg white to determine its possible practical applications. Quail egg white was dehydrated by air convection using one of two temperatures and times: M1 (65℃, 3.5 h), M2 (65℃, 5.0 h), M3 (70℃, 3.5 h) and M4 (70℃, 5.0 h). Lyophilized quail egg white was used as a standard. All four air-dried treatments had good protein levels (92.56% to 93.96%), with electrophoresis showing the predominant proteins to be lysozyme, ovalbumin and ovotransferin. Denaturation temperatures ranged from 81.16℃ to 83.85℃ and denaturation enthalpy values from 5.51 to 9.08 J/g. Treatments M1-4 had lower water-holding (0.90 - 2.95 g/g) and oil-holding (0.92 - 1.01 g/g) capacities than the lyophilized treatment (4.5 g/g, 1.95 g/g, respectively). Foaming capacity was pH-dependent in all five treatments, with the lowest values at alkaline pH and the highest (153% to 222%) at acid pH (pH 2). Foam stability was lowest at acid pH and highest at alkaline pH. Emulsifying activity in the air-dried treatments was highest at pH 8 (41% - 46%). Emulsion stability was pH-dependent and highest in M3 between pH 2 and 4 (96.16% to 95.74%, respectively). In the air-dried treatments, in vitro protein digestibility was as high as 83.02% (M3).

Conditions for enzymatic hydrolysis of egg white proteins

The study on condition for enzymic hydrolysis of in egg white proteins using a dual quadratic rotary, orthogonal and regressive design shows that the optimum temperature was 68 5 ℃, and the optimum pH is 8 21 at the substrate concentration of 5 5%. Mathematic model has been established to reveal the relationship between enzyme concentration and hydrolytic time with respect to the same NR.

Desalted duck egg white nanogels as Pickering stabilizers for food-grade oil-in-water emulsion

Achieving the reuse of traditional egg by-products,salted duck egg whites(SEW),is an urgent problem to be solved.In this current work,we constructed a heat-induced gel-assisted desalination method for SEW.Subsequently,a top-down way was utilized to prepare desalted duck egg protein nanogels(DEPN)with uniformly distributed diameters and their application in the oil/water(O/W)interface system was explored.The results revealed that the increase of DEPN concentration could lower the droplet size,however,the size was negatively correlated with the oil phase fraction.Moreover,the effect of pH,ionic strength,and temperature on the emulsion stability demonstrated that the DEPN-stabilized emulsion displayed superior physical stability under different conditions.The addition of NaCl resulted in the significant decrease in droplet size of the emulsion,while further increasing the NaCl concentration,the droplet size did not decrease accordingly.Besides,heat-treatment and cold-treatment had little negative effect on the stability of the emulsion.Even if the droplet size of the emulsion increased at 80℃for 3 h,the morphology of the emulsion remained unchanged.Our study demonstrated DEPN had great potential as a stabilizer for food-grade Pickering emulsions.

The Sterilization Results of Dense Phase Carbon Dioxide on Liquid Egg White and the Effect on Physicochemical and Functionial Properties

[Objective]The aim was to investigate the sterilization effect of dense phase carbon dioxide（ DPCD） on liquid egg white（ LEW） and the effect on functionial properties and physicochemical properties. [Method]The prepared liquid egg white was subjected to DPCD treatment at 10 MPa,20 MPa and 30 MPa respectively at 30 ℃,the microorganism amount,pH value,dissolubility and surface sulfhydryl were detected after adjusted to 4 ℃. [Result]The results showed that the longer the sterilization time,the more obvious of the sterilization effect at 10 MPa. There was no aerobe was detected at the rest conditions. [Conclusion]The functionial properties and physicochemical properties of liquid egg white were effected by DPCD treatment.

超高压协同TG酶改性蛋清蛋白热诱导凝胶机理

为提高蛋清蛋白凝胶性,本研究以蛋清蛋白(Egg white protein,EWP)为研究对象,通过分析质构、持水率、分子作用力、傅里叶红外色谱、圆二色谱、粒径、电位、巯基含量、表面疏水力及扫描电镜的变化,探究超高压处理(Ultra-high pressure,UHP)、谷氨酰胺转胺酶处理(Transglutaminase,TG)及超高压协同TG酶处理(Ultra-high pressure synergistic Transglutaminase,UTG)的蛋清蛋白热诱导凝胶机理及结构的变化。结果表明:UHP-EWP、TG-EWP、UTG-EWP的硬度、弹性和持水性均有所提高,疏水相互作用力是维持凝胶的主要作用力;UHP-EWP、TG-EWP、UTG-EWP的α-螺旋含量均不同程度下降、β-折叠含量均上升;UHP-EWP的平均粒径值下降、电位绝对值下降,TG-EWP、UTG-EWP的变化与之相反;UHP-EWP、TG-EWP、UTG-EWP的游离巯基含量上升、总巯基含量下降、表面疏水性升高;凝胶结构更加致密光滑,平整度提高。本研究为蛋清蛋白热诱导凝胶改性提供了理论基础及研究思路。

蛋清多肽-铁螯合物的制备、表征及对Caco-2细胞的促增殖作用

为开发人体易吸收的铁补充剂,提高咸蛋清的附加值,该研究以铁螯合能力和水解度(degree of hydrolysis,DH)为指标,优化酶解条件,通过超滤和Sephadex G-15凝胶柱分离纯化铁螯合能力高的蛋清多肽。采用扫描电镜、能谱、红外光谱和X射线衍射(X-ray diffraction,XRD)对蛋清多肽-铁螯合物结构进行表征。同时探究其对Caco-2细胞活力的影响。结果表明,最佳酶解条件为底物质量分数4%、酶添加量10%、pH 8、温度50℃时酶解8 h,所得产物的铁螯合能力为95.27%。蛋清粗肽经超滤和Sephadex G-15分离纯化得到铁螯合能力最高的组分F4-4。扫描电镜、能谱、红外光谱和XRD结果表明蛋清多肽和Fe2+形成多肽-铁螯合物。细胞实验中,与蛋清多肽和硫酸亚铁相比,蛋清多肽-铁螯合物的安全性高,且有一定的促增殖作用。

蛋清蛋白微粒基低脂沙拉酱流变学特征及品质优化

本实验以蛋清蛋白微粒(egg white protein microparticles,EWPM)为代脂基质,研究EWPM/黄原胶(xanthan gum,XG)共混质量分数、pH值、氯化钠含量、糖含量、均质条件等对超低脂沙拉酱产品流变学特性的影响规律。研究发现,XG对EWPM基超低脂沙拉酱具有显著的增稠效果,然而含量过高会导致低脂沙拉酱恢复性下降。基础调味组分对超低脂沙拉酱品质的影响存在较大差异,pH值和盐对体系黏度影响较大,糖添加量对黏度的影响相对较小。适度的胶体磨均质转速和均质时间可以减小产品的粒径,增加其内部均一性,显著提高产品的整体黏度。本实验以沙拉酱流变学行为调控为重点,为低脂沙拉酱的研究提供一个更加明确的工艺优化方向。