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This study systematically analyzed and compared thechanges of physicochemical, functional and molecular structural characteristics between thick egg white (KEW) and thin egg white (NEW) during storage. Analysis of physicochemical properties showed that moisture content decreased significantly with the increase of pH during storage. KEW was gradually thinning, while NEW was closer to Newtonian fluid. Functional properties indicated that KEW thermal gel was gradually hard and brittle with the properties of NEW. KEW had better emulsifying property than NEW, and NEW had superior foaming ability. The α-helix and β-sheet in the FT-IR spectrum showed a downward trend, revealing secondary structure changed from order to disorder. Enhancement of fluorescence intensity indicated the structural unfolding and exposure of tryptophan residues. SDS-PAGE proved that OVO might be related to the difference between KEW and NEW characteristics. This study provided new idea and reference value for egg storage and diversified utilization of egg white., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

A depletion study of toltrazuril and its metabolites was performed using 20 hens medicated via drinking water for two days in a dosage of 7 mg kg -1 per kg body weight. Afterward, eggs were collected for 42 days. Residues were analyzed in whole eggs and yolk and whites. Toltrazuril sulfone was found to be the most predominant in all matrices, the highest concentration was found in the yolk - 5567 µg kg -1 , followed by whole eggs samples - 4767 µg kg -1 and egg whites - 532 µg kg -1 . On last day toltrazuril sulfone were still detected - 22.5 µg kg -1 . 70 days is required to concentration of toltrazuril sulfone reach zero. Administrating toltrazuril before the laying phase can pose a risk of residues of toltrazuril sulfone in eggs. Setting Maximum Residue Limit could reduce the risk of non-complaint samples and ensure the safety of consumers, but still requires 44 days of the withdrawal period., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Though nutritional, the remaining separated duck egg white in duck egg processing plants presents challenges for its transportation and use, as it spoils easily and has a strong odor. Uses for the excess egg white are of paramount concern for agricultural resource reuse. The purpose of this study was to increase its value and use efficiency. Duck egg white was mixed with sodium hydroxide to produce translucent alkali-induced egg white jelly similar to that in preserved egg whites. To develop a heatable translucent egg white jelly, their physiochemical properties and thermal stabilities were investigated. A gel prepared with 150 mM sodium hydroxide at 25°C had optimal bloom strength and the densest microstructure. Storing the jelly at 5°C helped maintain its disulfide bonds and delayed liquefaction. Although heating decreased its bloom strength and total disulfide bond content as temperature increased (P < 0.05), scanning electron microscopy of the heated jelly revealed that the protein network structure was denser than that of unheated jelly. Heating caused parts of the structure to shrink and even dehydrate, leading to a wrinkled surface. However, no signs of liquefaction or collapse were observed, and the free alkali released during heating was lower than that from the white of existing preserved eggs. These results confirmed the thermal stability of the jelly and its potential to be served hot or used in food processing. Furthermore, in addition to disguising the odor and special flavor attributable to the alkaline treatment, adding ginger juice or turmeric to the preparation yielded higher bloom strength, resulted in lower free alkalinity, and delayed liquefaction, thus improving the jelly's thermal stability. Like preserved eggs on the market that can be served in hot congee, the proposed egg white jelly is rich in proteins and suitable for hot or instant serving. These findings may help address the problem of excessive remaining duck egg white created during food processing by diversifying duck egg processing and boosting its value., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: While eggs are a low-cost source of protein, rich in macro- and micronutrients, the association of egg intake and cardiovascular disease (CVD) remains controversial. This study investigated the effect of egg consumption on CVD parameters. Eggs were boiled, separated into four fractions (whole egg, 50% yolk-reduced whole egg, egg yolk and egg white) and then freeze-dried. The different egg fractions or distilled water (control) were orally gavaged to adult male Wistar rats at 1 g kg -1 rat body weight, each day for 8 weeks, following which basal blood pressure, heart rate, complete blood cell count, blood biochemistry, body fat and liver cell lipid accumulation were determined. The vascular functions of isolated thoracic aorta were studied using classical pharmacological techniques., Results: In comparison to the control group, none of the egg fractions affected body weight, food intake, plasma glucose or lipid profile. The yolk group experienced increased plasma alkaline phosphatase and creatinine levels, while egg white caused decreased plasma cholesterol and blood urea nitrogen. Whole egg and egg yolk increased blood pressure and mean hemoglobin concentration and the yolk increased liver lipid accumulation. Egg white decreased the white blood cell count and body fat lipids. No changes were found in basal heart rate or vascular functions in any of the groups., Conclusions: Consumption of whole egg or egg yolk at the dosage given caused hypertension, with impairment of liver and kidney functions following the intake of yolk alone. However, egg white is beneficial for the cardiovascular system as it decreased plasma cholesterol and body fat accumulation. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

Hen's egg white allergens, namely Gal d 1-4, cause food allergies worldwide and their intake must be strictly controlled by allergic individuals. However, an efficient method for quantifying these allergens is currently unavailable. We aimed to develop an LC-MS/MS method for simultaneous Gal d 1-4 quantification. Purified Gal d 1-4 proteins were trypsin-digested and the resulting peptides used in LC-MS/MS analysis. The limits of quantification were 9.77-39.1 ng/mL. The Gal d 1-4 recovery in fresh and processed eggs was 68.3-121.3%, and intra- and interassay coefficients of variation were 1.5-15.7% and 2.4-38.1%, respectively, indicating high sensitivity, accuracy, and reproducibility. In addition, the high specificity of this method was confirmed by testing 27 other foods. This newly developed method could provide reliable information to the industrial food and clinical fields, facilitating improved quality of life for individuals with egg allergies., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The presence of residues from fining agents in wines may represent a risk for allergic consumers and a source of discomfort for others, such as vegans. Even though ELISA is the official detection method for such residues, this technique may be hindered by cross-reactivity issues, or by matrix-molecule interference due to a high polyphenol content, especially in red wines. An HRMS-based method has been developed to detect pig gelatin and egg white in experimental five-year aged Nebbiolo-based red wine. Biomarker peptides were selected, after tryptic digestion, and quantified by multitarget nanoHPLC-HRMS analysis. The method resulted in an LLOQs of 5 µg/mL in the experimental wine, and between 1 and 2 µg/mL in the buffer. This method allowed both gelatin and egg white proteins to be detected and quantified in aged red wine, while whereas the commercial ELISA kit was instead unable to detect egg white in the same samples., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Localized hyperthermia therapy involves heating a small volume of tissue in order to kill cancerous cells selectively and with limited damage to healthy cells and surrounding tissue. However, these features are only achievable through real-time control of the tissue temperature and heated volume, both of which are difficult to obtain with current heating systems and techniques. This work introduces an optical fiber-based active heater that acts both as a miniature heat source and as a thermometer. The heat-induced damage in the tissue is caused by the conductive heat transfer from the surface of the device, while the heat is generated in an absorptive coating on the fiber by near-infrared light redirected from the fiber core to the surface by a tilted fiber Bragg grating inscribed in the fiber core. Simultaneous monitoring of the reflection spectrum of the grating provides a measure of the local temperature. Localized temperature increases between 0°C and 100°C in 10 mm-long/5 mm-diameter cylindrical volumes are obtained with continuous-wave pump power levels up to 1.8 W. Computational and experimental results further indicate that the temperature rise and dimensions of the heated volume can be maintained at a nearly stable level determined by the input optical power.

Proteins are perhaps the most important yet frustratingly complicated and difficult class of compounds to analyze, manipulate, and use. One very attractive option to characterize and differentially concentrate proteins is dielectrophoresis, but according to accepted theory, the force on smaller particles the size of proteins is too low to overcome diffusive action. Here, three model proteins, immunoglobulin G, α-chymotrypsinogen A, and lysozyme, are shown to generate forces much larger than predicted by established theory are more consistent with new theoretical constructs, which include the dipole moment and interfacial polarizability. The forces exerted on the proteins are quantitatively measured against well-established electrophoretic and diffusive processes and differ for each. These forces are orders of magnitude larger than previously predicted and enable the selective isolation and concentration of proteins consistent with an extremely high-resolution separation and concentration system based on the higher-order electric properties. The separations occur over a small footprint, happen quickly, and can be made in series or parallel (and in any order) on simple devices.

The reproductive tract in avian females is sensitive to hormonal regulation. Exogenous estrogen induces immature oviduct development to improve egg production after molting. In this process, regressed female reproductive tract is regenerated in response to the secretion of estrogen. However, there is limited knowledge on the physiological mechanisms underlying the regulation of the avian female reproductive system. In our previous study, results from microarray analysis revealed that the expression of genes encoding egg white proteins is affected during molting. Herein, we artificially induced the molting period in chickens through a zinc-containing diet. Subsequently, changes in the expression of genes encoding egg white proteins were confirmed in the oviduct tissue. The levels of MUC5B, ORM1, RTBDN, and TENP mRNA were significantly high in the oviduct, and the genes were repressed in the regression phase, whereas these were expressed in the recrudescence phase, particularly in the luminal epithelium and glandular epithelium of the oviduct, during molting. Moreover, we observed that gene expression was induced in the magnum, the site for the secretion of egg white components. Next, differences in expression levels of the four genes in normal and cancerous ovaries were compared. Collectively, results suggest that the four selected genes are expressed in the female chicken reproductive tract in response to hormonal regulation, and egg white protein-encoding genes may serve as modulators of the reproductive system in hens.

Nowadays, the research on the recognition and separation of proteins has attracted extensive attention in the fields of materials science, bioengineering and life science. Protein imprinted polymers are ideal recognition materials, due to its high selectivity, good stability, easy preparation, and low cost. Herein, novel surface imprinting biowaste-derived molecularly imprinted polymers (BD-MIPs) were synthesized for specific recognition and purification of lysozyme (Lyz). This is the first time that magnetic pomegranate rind-derived carbon was used as a carrier to immobilize Lyz. Then, with the self-polymerization of dopamine, a large number of biocompatible recognition sites were generated under mild conditions. The physical/chemical properties and surface morphologies of the synthetic BD-MIPs were characterized, indicating that the imprinted film was successfully synthesized, and the BD-MIPs had good thermal stability and magnetic property. To investigate the recognition performance of BD-MIPs, four adsorption experiments were performed. The results show that BD-MIPs had a high adsorption capacity of 301.87 mg g -1 , fast equilibrium time within 40 min, satisfactory selectivity and good reusability for Lyz. Furthermore, the practicability of BD-MIPs was confirmed by the isolation of Lyz from a biological sample. The good adsorption capacity and gentle one-step preparation make the BD-MIPs attractive for Lyz recognition, which shows potential values in basic biomedical research, industrial protein purification and clinical diagnostics., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Rationale: To increase the consumption of egg powder and its fractions a suitable quality control method is required to obtain more information on its nutritional composition. The proposed method enables the quantification of important elements for the functioning of the human organism, such as halogens and sulfur, in egg powder and its fractions., Methods: Up to 350 mg of egg powder or its fractions (egg white powder and egg yolk powder) were digested by microwave-induced combustion using 20 bar pressure of oxygen. The analytes were absorbed in 100 mmol L -1 of NH 4 OH solution. The determination of halogens (chlorine, bromine, fluorine, and iodine) and sulfur was performed in a single analysis using ion chromatography with conductivity detection coupled to mass spectrometry., Results: Using the proposed method, spike recoveries between 99% and 104% for all analytes were obtained, and results agreed with certified values of reference materials (agreements were between 100% and 109%). The relative standard deviations were below 8%. The variation in elemental concentration over a wide range in different fractions (whole egg powder, egg white powder, and egg yolk powder) and different brands was also observed., Conclusions: The proposed method provides reliable information about minerals in whole egg powder and its fractions, contributing to better quality control of these products. Because these food products are widely consumed, these results suggest the safe ingestion levels of these elements., (© 2020 John Wiley & Sons, Ltd.)

Electrochemical Synchronous detection of cadmium (Cd(II)) and lead (Pb(II)) was obtained by acid treated multiwalled carbon nanotube (A-MWCNT) functionalized with hyaluronic acid (Hyalu) and this mixture was separately further modified with l-cysteine (l-Cys) and l-serine (l-Ser). Under the optimized circumstance best voltammetric responses were produced by A-MWCNT/Hyalu/l-Cys and A-MWCNT/Hyalu/l-Ser modified electrodes. The peak current was linearly dependent on the Cd(II) and Pb(II) concentrations in the range from 0.4 to 4 µg L -1 . The sensitivities were calculated as 0.7 µA/nM (Cd(II)) and 3.5 µA/nM (Pb(II)) for A-MWCNT/Hyalu/l-Cys/GCE and 0.6 µA/nM (Cd(II)) and 2.6 µA/nM (Pb(II)) for A-MWCNT/Hyalu/l-Ser/GCE. From the calibration plot LODs were calculated to be 0.032 µg L -1 (Cd(II)) and 0.015 µg L -1 (Pb(II)) for A-MWCNT/Hyalu/l-Cys/GCE and 0.057 µg L -1 (Cd(II)) and 0.034 µg L -1 (Pb(II)) for A-MWCNT/Hyalu/l-Ser/GCE. Moreover, the proposed electrodes were subjected to the real sample application in honey, cocos nucifera and egg white., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Five major proteins from egg white were separated using a successive extraction/precipitation protocol. The yield and purity of the separated proteins were measured. The separated proteins were confirmed by MALDI-TOF-MS, and their structures were characterized by CD spectrum. Lysozyme was first separated using FPC 3500 resin and then ovomucin from the lysozyme-free egg white. Ammonium sulfate and citric acid were added to the resulting lysozyme- and ovomucin-free egg white solution to precipitate ovotransferrin. Ovomucoid and ovalbumin were separated from the resulting supernatant using ethanol. The separated proteins were further purified and the optimal conditions for the further purifications were suggested. The purity and yield of lysozyme, ovotransferrin, ovalbumin, and ovomucoid were higher than 90% and 77%, while those of ovomucin were about 72% and 75%, respectively. This study separated five major proteins in egg white successively using resin adsorption, pH adjustment, salt/ethanol precipitation, and ultrafiltration., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: A microgranule fertilizer was designed for localized fertilization of soil with controlled release of nutrients. The microgranule matrix was fortified with proteins, which were obtained from food industry byproducts or waste, i.e., whey protein from milk serum, soy protein from soy isolate and egg white protein from chicken egg white powder. The mechanism of the protein decomposition and migration of micro and macromolecule compounds through two different model soil systems was investigated. The potential of the protein fortified fertilizer for localized fertilization of the potted maize seeds was evaluated., Results: The study revealed that proteins slowly diffused through soil with simultaneous degradation, which was accompanied with release of ammonia ions. The highest concentration of proteins and degradation products was found in a close vicinity of the microgranule. The microgranules were used as a local fertilizer for maize seeds in the pot experiments. The experiments confirmed statistically significant improvement in root density of maize plant compared to control group., Conclusions: Byproducts or waste of food industry, such as the milk serum and soy can be used as a source of proteins that degrade in soil without a pretreatment. The degradation is accompanied with formation of ammonium ions, which can be utilized by plants as a nitrogen source. The fertilizer microgranule should be placed in a close vicinity to the plant seed, since the maximum of the protein concentration and ammonia ions is reached at a very close distance from the microgranule.

Vanadium (V) is an ultratrace metal with the insulin-tropic properties and is often researched as the diabetes drug. However, in animals, V has been reported to have toxic effects on the development, immunity, oxidation-reduction equilibrium, gastrointestinal function, and so forth. Especially in poultry, supplementation of more than 10 mg of V/kg in the layer diets has been shown to adversely affect the egg production and egg quality. In this study, we supplemented 0 mg of V/kg, 5 mg of V/kg, and 10 mg of V/kg in the layer diets for 35 D and examined the quantitative proteomics of albumen for finding the possible target signaling pathway and mechanism of V action and made the preliminary verification. In contrast to the control group, V resulted in a significant drop in the albumen height, and in oviduct ampulla, the activity of total antioxidant capacity and glutathione peroxidase significantly decreased (P = 0.01, P = 0.02), the content of malonic dialdehyde significantly increased (P = 0.01), and the apoptosis rate significantly increased in the 5-mg V/kg and 10-mg V/kg treatment groups (P ＜ 0.01). V affected 36 differentially accumulated proteins in albumen, with 23 proteins upregulated and 13 proteins downregulated. The expressions of innate protein albumen lysozyme (Q6LEL2), vitellogenin-2 (P02845), and the F1NWD0 protein in albumen belonged to the P53 family were significantly reduced, in contrast to the control (P < 0.05), and the expression of riboflavin-binding protein (P02752) was significantly improved (P < 0.05). The Hippo signaling pathway-fly, which is suitable for the key protein P53 as the most significantly affected network, might be important for discriminating V., (Copyright © 2019. Published by Elsevier Inc.)

In this study, the effects of ultrafiltration technique on the desalination efficiency, nutrient content, physicochemical properties, functional properties, texture profile, and microstructure of salted duck egg white were evaluated. The results showed that ultrafiltration can remove 92.93% salt from salted duck egg white (SDEW) and final salt% of desalted duck egg white (DDEW) was 0.65%. The analysis of nutrient content and amino acid of SDEW and desalted duck egg white powder (DDEWP) sample was significantly lower than those of fresh duck egg white (FDEW). Although emulsifying capacity of SDEW, DDEW, and DDEWP exhibited significantly lower than that of FDEW, an excellent foaming ability was found in those samples. Moreover, the texture profiles (gel strength, hardness and elasticity) of SDEW, DDEW, and DDEWP samples presented lower value than FDEW. The observation of microstructure, DDEWP possessed smooth surface of protein globules with deep hole liked donuts and distribution of a few of salt crystals. While salted duck egg white powder (SDEWP) had a raisin-like surface formation with salt formed cubic crystals. Overall, both liquid and dried material of desalted duck egg could be used as a good ingredient in baking food due to their excellent foaming capacity., (© 2020 Japanese Society of Animal Science.)

Background: Egg yolks contain large amounts of cholesterol and are suspected to be harmful after long-term consumption. In this experiment, 63 rats were used to evaluate the effect of egg white (EW) and egg yolk (EY) supplementation on serum lipids and brain cognition. The feeding time lasted 4 weeks after a 1-week acclimation., Results: Body weight was significantly higher in rats fed 132.0 g kg -1 EW and significantly lower when fed 40 g kg -1 EY (P < 0.05). Total cholesterol and low-density lipoprotein increased in rats fed 72.0 g kg -1 EW compared with rats from NC and EY groups (P < 0.05). High-density lipoprotein (HDL) was higher in rats fed 40 g kg -1 EY and decreased when fed 72.0 g kg -1 EW (P < 0.05). Rats fed a diet with EY exhibited abundant neurons in the CA1 hippocampus and complete subcellular structures. Rats fed 132 g kg -1 EW exhibited shrunken cells and swollen mitochondria. Brain-derived neurotrophic factor had constitutively low expression among groups, while tyrosine kinase B (TrkB) exhibited higher expression levels in rats fed a diet containing EY compared with other groups (P < 0.05)., Conclusion: EY consumption reduced body weight and increased HDL levels. Diet containing EY could improve cognition through enhanced trkB expression. © 2019 Society of Chemical Industry., (© 2019 Society of Chemical Industry.)

A novel, rapid and sensitive chemiluminescence (CL) method for the determination of oxytetracycline hydrochloride (OTCH) is described in this paper. The presented method was based on the fact that OTCH could immensely enhance the CL of the reaction of cerium sulfate and tris(2,2-bipyridyl) ruthenium (II) in acidic medium. Under optimal experimental conditions, CL intensity was favorably linear for OTCH in the range 5.0 × 10 -7 to 5.0 × 10 -5  g/ml, with a detection limit of 1.5 × 10 -7  g/ml (S/N = 3). The relative standard detection was 4.76% for 5.0 × 10 -6  g/ml (n = 11). This method was successfully applied to the analysis of OTCH in milk and egg white samples. According to the results of the kinetic curves for OTCH in the Ru(bipy) 3 2+ -Ce(SO 4 ) 2 CL system, together with CL and ultraviolet (UV)-visible spectra, the possible mechanism of the CL reaction is discussed briefly., (© 2019 John Wiley & Sons, Ltd.)

Ovomucin is known to be critical for keeping the high quality and freshness of thick albumen, but there is lack of understanding on the dynamics changes of this important protein during storage. This study aimed to investigate the relationship between ovomucin content and egg freshness during storage. Firstly, the viscoelasticity of albumen was shown to be much higher than that of ovomucin-depleted albumen from rheological analysis results, indicating that ovomucin is an important component in maintaining the natural viscoelasticity of albumen. Then, the ovomucin content determined by ELISA method was compared to albumen pH, Haugh unit (HU), and yolk index in terms of egg white quality and to the time of storage in terms of egg freshness at 4°C, 25°C, and 37°C, respectively. Results of the transformation kinetic showed a decrease in ovomucin content with prolonged storage time (P ≤ 0.01). Correlation analysis showed a high positive correlation between ovomucin content and HU (P ≤ 0.01) and a high negative correlation between ovomucin content and the albumen pH (P ≤ 0.01) at the test temperatures. We therefore conclude that ovomucin content in albumen can be used as an index for egg freshness. At last, predictive models of the equivalent egg age (4°C and 25°C) for evaluating the egg freshness were established by means of exponential regression model with ovomucin content as the variable. These results can provide a theoretical and technical basis for the storage and fresh evaluation of shell eggs.

The dose-dependent effect of egg consumption on plasma cholesterol in humans remains inconclusive. It is unknown if egg white consumed in a normal amount can reduce plasma cholesterol. We used hamsters as a model to (i) investigate the dose-dependent effect of consuming zero to five whole eggs on plasma total cholesterol (TC) and (ii) examine if egg white, equivalent to one to five eggs, possessed any reducing effects on plasma TC. In experiment 1, hamsters were divided into six groups ( n = 8 each) and fed either a control diet or one of five experimental diets supplemented with whole-egg powder equivalent to one to five eggs per 2000 kcal. Results showed that supplementation with one egg increased plasma TC by 25% compared with that of the control (226 ± 16 versus 282 ± 56 mg/dL, p < 0.05), whereas supplementation with two to five eggs did not significantly produce any additional effects on plasma cholesterol. However, supplementation with one to five eggs in diets caused a dose-dependent accumulation of cholesterol in the liver from 21.5 ± 4.4 to 71.3 ± 7.3 mg/g ( p < 0.01). In the second experiment, hamsters were divided into six groups and fed either a high-cholesterol control diet or one of five experimental diets supplemented with egg-white powder from one to five eggs. Results showed that egg-white powder affected neither plasma nor liver cholesterol levels. The egg-white powder did not affect fecal sterol excretion, suggesting it had no effect on cholesterol absorption. It was therefore concluded that consumption of two to five eggs did not significantly produce any additional effects on plasma cholesterol, whereas egg white did not possess a plasma-cholesterol-lowering activity if it was consumed at amounts similar to those in a normal human diet.

We performed the feasibility study using speckle variance optical coherence tomography (SvOCT) to monitor the thermally induced protein denaturation and coagulation process as a function of temperature and depth. SvOCT provided the depth-resolved image of protein denaturation and coagulation with microscale resolution. This study was conducted using egg white. During the heating process, as the temperature increased, increases in the speckle variance signal was observed as the egg white proteins coagulated. Additionally, by calculating the cross-correlation coefficient in specific areas, denaturized egg white conditions were successfully estimated. These results indicate that SvOCT could be used to monitor the denaturation process of various proteins.

Purified egg white is an important ingredient in a number of baked and confectionary foods because of its foaming properties. However, yolk contamination in amounts as low as 0.01% can impede the foaming ability of egg white. In this study, we used Raman spectroscopy to evaluate the hypothesis that yolk contamination in egg white could be detected based on its molecular optical properties. Yolk contaminated egg white samples (n = 115) with contamination levels ranging from 0% to 0.25% (on weight basis) were prepared. The samples were excited with a 785 nm laser and Raman spectra from 250 to 3,200 cm(-1) were recorded. The Raman spectra were baseline corrected using an optimized piecewise cubic interpolation on each spectrum and then normalized with a standard normal variate transformation. Samples were randomly divided into calibration (n = 77) and validation (n = 38) data sets. A partial least squares regression (PLSR) model was developed to predict yolk contamination levels, based on the Raman spectral fingerprint. Raman spectral peaks, in the spectral region of 1,080 and 1,666 cm(-1), had the largest influence on detecting yolk contamination in egg white. The PLSR model was able to correctly predict yolk contamination levels with an R(2) = 0.90 in the validation data set. These results demonstrate the capability of Raman spectroscopy for detection of yolk contamination at very low levels in egg white and present a strong case for development of an on-line system to be deployed in egg processing plants., (© 2016 Poultry Science Association Inc.)

Ovalbumin (OA) is the most abundant ingredient of chicken egg-white allergenic proteins. In the present study we investigated the possibility of reducing OA allergenicity by treatment with a natural protein exhibiting N-acetylglucosaminidase (NA) activity. Ascidian is cultivated as a food resource in northeast Asia. The ascidian viscera NA (AVNA) with almost no other exoglycosidases or proteolytic enzymes was isolated by applying size-exclusion chromatography to a protein precipitate of ascidian viscera. Intact OA was mixed with AVNA containing 0.2, 1.0, and 5.0 Units of NA. Anion-exchange chromatography was then used to isolate OA from AVNA-treated OA. The electrophoretic patterns and N-glycans of each isolated OA from AVNA-treated OA (iOA) were analyzed, and the terminal N-acetylglucosamines of iOA were selectively cleaved with no other degradation occurring. A competitive indirect enzyme-linked immunosorbent assay using rabbit anti-OA sera was performed to investigate the allergenicity of iOA, which was found to be significantly reduced depending on the increased NA activity compared to that of intact OA. These results indicate that OA allergenicity was reduced using a simple and mild treatment process with AVNA, and suggest that ascidian NA is an efficient natural protein for reducing the allergenicity of OA without requiring the use of harsh physical treatments or chemical conjugation., (Copyright © 2016 Elsevier Inc. All rights reserved.)

In this study, we reported iminodiacetic acid-copper ion complex (IDA-Cu) immobilized onto gold nanoparticles (GNPs)-modified glassy carbon electrode as a novel electrochemical platform for selective and sensitive determination of lysozyme (Lys). IDA-Cu complex acted as an efficient recognition element capable of capturing Lys molecules. GNPs acts as a substrate to immobilize IDA-Cu coordinative complex and its interaction with Lys leds to a great signal amplification through measuring changes in differential pulse voltammetric (DPV) peak current of [Fe(CN)6](3-/4-) redox probe. Upon the recognition of the Lys to the IDA-Cu, the peak current decreased due to the hindered electron transfer reaction on the electrode surface. Under optimum condition, it was found that the proposed method could detect Lys at wide linear concentration range (0.1 pM to 0.10 mM) with detection limit of 60 fM. Furthermore, electrochemical impedance spectroscopy (EIS) detection of Lys was demonstrated as a simple and rapid alternative analytical technique with detection limit of 80 fM at concentration range up to 0.1mM. In addition, the proposed sensor was satisfactorily applied to the determination of Lys in real samples such as hen egg white. The proposed modified electrode showing the high selectivity, good sensitivity and stability toward Lys detection may hold a great promise in developing other electrochemical sensors based on metal-chelate affinity complexes., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Due to the harmfulness of melamine to human, the quantitative detection of melamine in egg is very necessary. In the present study, the surface enhanced Raman spectra technology combined with chemometric analysis method was used to conduct melamine quantitative detection in egg white. Firstly, the melamine egg sample could be got by the method of artificial feeding hens usingdifferent feeding formulation. Then the surface enhanced Raman spectra of egg white was determined using portable Raman spectroscopy (Opto Trace RamTracer-200) and Raman enhancement reagents, and the melamine content within the white eggs was measured with gas chromatography mass spectrometry technology. The software of Raman Analyzer was used for baseline correction of Raman spectra. The correlation coefficient method was used to choose 320 spectral variables from the surface enhanced Raman spectroscopy as input variables to establish partial least squares quantitative calibration model . And the peaks-decomposition method was used to establish peaks-decomposition quantitative calibration model. Both models selected 90 and 44 samples respectively as calibration sets and validation sets during model establishment, and both models achieved good prediction effect. The determination coefficient between predicted values of partial least squares quantitative calibration model and measured values of gas chromatography mass spectrometry was 0.856, and root mean square error of prediction was 1.547. The determination coefficient was 0.947 and RMSEP was 0.893 for the peaks-decomposition quantitative calibration model. This study demonstrated that the method can effectively quantitatively detect melamine in eggs. Testing a sample only takes 15 minutes, which can provide a new way for the melamine egg detection.

Background: Strontium is currently prescribed for patients with osteoporosis to increase bone density and reduce bone fractures but its relevance in animal nutrition is obscure. In order to investigate the effect of supplemental strontium and vitamin D3 on performance, egg quality and skeletal integrity in poultry a total of 108 laying hens, 99 weeks of age, were fed three levels of strontium (0, 500, 1000 mg kg(-1) ) and two levels of vitamin D3 (2500, 5,000 iu kg(-1)) over a 12-week period., Results: There was an improvement (P < 0.05) in egg production and feed conversion efficiency with strontium at 500 mg kg(-1) and a significant increase in egg weight in those hens fed additional vitamin D3 . Supplemental strontium increased phosphorus, sodium and strontium retention in birds fed 2500 iu D3 kg(-1) but reduced phosphorus, sodium and strontium retention in birds fed 5000 iu D3 kg(-1), resulting in an interaction (P < 0.01) between strontium and vitamin D3 . Addition of 5000 iu D3 kg(-1) increased egg weight (P < 0.05); predominantly by increased albumen content (P < 0.05), whereas strontium supplementation reduced egg weight (P < 0.001). Similarly, 5000 iu kg(-1) D3 increased apparent metabolizable energy (P < 0.05); in contrast, strontium supplementation reduced (P < 0.05) apparent metabolizable energy., Conclusion: The addition of 500 mg kg(-1) strontium significantly improved egg production and feed efficiency; however, further investigation needs to be undertaken to refine the optimum level of strontium required to maximize hen performance. The interrelationship between strontium and vitamin D3 requires further exploratory study., (© 2014 Society of Chemical Industry.)

In this study, a peptide-1 (RNRCKGTDVQAW) constructing lysozyme was conjugated with an electroactive daunomycin in order to voltammetrically detect ovalbumin (OVA). Hetero-bifunctional cross-linking agents with four kinds of ethylene chains in differing lengths were used to bind the peptide-1 and daunomycin. After a cross-linking agent had reacted with an amino group of daunomycin, the compound was introduced into the peptide to the cysteine residue in the peptide using a pendant arm. The OVA was sensed via a change in the electrode response of the daunomycin moiety, based on the binding between the peptide and the OVA. The adsorption of the peptide probe on the electrode increased with increases in the ethylene chain. The binding constants between the peptide probes and the OVA, however, did not depend on the length of the chain. This was because the ethylene chain influenced the binding. When the peptide and the daunomycin were bound using N-(6-maleimidocaproyloxy) sulfosuccinimide, the electrode response of the peptide probe was the most sensitive from among the four cross-linking agents. The calibration curve of the OVA using the peptide probe was linear and ranged from 1.5×10(-11) to 3.0×10(-10)M. Furthermore, this method could be applied to the electrochemical sensing of the OVA in egg whites and in fetal bovine serum., (Copyright © 2014 Elsevier B.V. All rights reserved.)

To alleviate the risk to allergic consumers, it is crucial to improve factors affecting the detection of food allergens in processed chocolate products. This study evaluated processing effects on (1) recovery of peanut, egg, and milk allergens using five different extraction buffers, and (2) identification of specific allergenic proteins from extracts of incurred chocolate using allergen-specific antibodies and human allergic sera. Immunochemical staining with polyclonal antibodies showed that the addition of detergent or reducing agent improved extraction efficiency of peanut proteins, but not of egg and milk proteins. Tempering decreased antibody binding regardless of extractant. Detection of IgE-reactive peanut, egg, and milk allergens was differentially affected by tempering and extractant. Detection problems associated with matrix and processing effects may be overcome by the choice of extraction buffer and detecting antibody., (Published by Elsevier Ltd.)

In this paper, the physicochemical and nutritional characteristics of preserved duck egg white were analyzed and compared with fresh egg and hard-cooked egg white (n = 3). The data obtained showed that the preserved egg white was rich in essential amino acids and minerals, such as Ca, Mg, Fe, Zn, Cu, K, and Na. After fresh duck eggs were processed into preserved eggs, contents of moisture, CP, amino acid, and water-soluble vitamin of egg white significantly decreased (P < 0.05); however, pH, free amino acid content, and most inorganic elemental contents of egg white significantly increased (P < 0.05). The preserved egg white had higher a* (redness/greenness) and b* values (yellowness/blueness; P < 0.05) and lower L* value (lightness; P < 0.05) than hard-cooked egg white. The gel hardness of preserved egg white was approximately 50% of hard-cooked egg white; however, its springiness and cohesiveness were approximately 1.5 times of hard-cooked egg white. The results indicated that pickling with alkaline and other additives can significantly change physical properties and chemical composition of duck egg white, which make preserved egg white with characteristics of rich elements, brown color, and high springiness, but low vitamin., (©2014 Poultry Science Association Inc.)

Scope: Heated foods often present low allergenicity, and have recently been used in specific oral immunotherapy for food allergies. However, the influence of heating on tolerogenicity of food allergens is not well elucidated. Here, we investigated biochemical, allergenic, and tolerogenic properties of heated egg white (EW) using a murine model of food allergy., Methods and Results: Raw EWs were treated at 80°C for 15 min (80EW, mild heating condition), 100°C for 5 min (100EW, cooking condition), or 121°C for 40 min (121EW, retort pouch condition), and freeze-dried. A transgenic OVA23-3 mice model expressing T-cell receptor specific for ovalbumin (OVA, a major EW allergen) induced Th2 cells and IgE production, and presented intestinal inflammation when fed untreated EW diet. 80EW-fed mice presented only moderate inflammation but high Th2 responses. 100EW-fed mice did not present inflammation but induced tolerance as seen in reduced T-cell responses and IgE levels. 100EW demonstrated higher digestive stability and slower absorption in intestine, compared with untreated EW and 80EW. 121EW was strongly aggregated, was not absorbed well, and developed Th1 responses without tolerance induction., Conclusion: OVA in EW treated only under a particular heat condition (e.g. 100°C for 5 min) lost allergenicity, but possessed tolerogenicity., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Chiroptical methods are widely used in structural and conformational analyses of biopolymers. The application of these methods to investigations of biofluids would provide new avenues for the molecular diagnosis of protein-misfolding diseases. In this work, samples of human blood plasma and hen egg white were analyzed using a combination of conventional and chiroptical methods: ultraviolet absorption/electronic circular dichroism (UV/ECD), Fourier transform infrared absorption/vibrational circular dichroism (FTIR/VCD), and Raman scattering/Raman optical activity (Raman/ROA). For comparison, the main components of these substances--human serum albumin (HSA) and ovalbumin (Ova)--were also analyzed by these methods. The ultraviolet region of the ECD spectrum was analyzed using the CDNN CD software package to evaluate the secondary structures of the proteins. The UV/ECD, FTIR/VCD, and Raman/ROA spectra of the substances were quite similar to those of the corresponding major proteins, while some differences were also detected and explained. The conclusions drawn from the FTIR/VCD and Raman/ROA data were in good agreement with the secondary structures calculated from ECD. The results obtained in this work demonstrate that the chiroptical methods used here can be applied to analyze not only pure protein solutions but also more complex systems, such as biological fluids.

A protocol for a simple and reliable dot-blot immunoassay was developed and optimized to test work of art samples for the presence of specific proteinaceus material (i.e. ovalbumin-based). The analytical protocol has been extensively set up with respect, among the other, to protein extraction conditions, to densitometric analysis and to the colorimetric reaction conditions. Feasibility evaluation demonstrated that a commercial scanner and a free image analysis software can be used for the data acquisition and elaboration, thus facilitating the application of the proposed protocol to commonly equipped laboratories and to laboratories of museums and conservation centres. The introduction of method of standard additions in the analysis of fresh and artificially aged laboratory-prepared samples, containing egg white and various pigments, allowed us to evaluate the matrix effect and the effect of sample aging and to generate threshold density values useful for the detection of ovalbumin in samples from ancient works of art. The efficacy of the developed dot-blot immunoassay was proved testing microsamples from 13th-16th century mural paintings of Saint Francesco Church in Lodi (Italy). Despite the aging, the altered conditions of conservation, the complex matrix, and the micro-size of samples, the presence of ovalbumin was detected in all those mural painting samples where mass-spectrometry-based proteomic analysis unambiguously detected ovalbumin peptides.

Chicken eggs are recognized for their versatility as a food product and as a model for research in biology and medicine. This study investigated the egg white as a source of bioactive compounds. Egg white was fractionated using tandem ion exchange chromatography (SAX and SCX), and seven fractions were assessed for any associated bioactivity. Four fractions at various protein concentrations were shown to contain proliferative bioactivity that exceeded the FBS control. The most potent fraction (6) was used in an in vitro wound closure assay to demonstrate a positive influence on cell migration and restored scratch wounds more rapidly than the control. LC-MS/MS identified 33 proteins in fraction 6 of egg white, most of which play important roles in cell growth and development, signaling, motility, and proliferation. These candidate bioactives suggest that the egg white contains essential compounds that contribute to the growth of an embryo prior to fertilization.

Lysophosphatidic acid (lysoPtdOH), a lysophospholipid mediator, exerts diverse physiological effects, including angiogenesis, through its specific G-protein-coupled receptors. Previously, we showed that unfertilized hen egg white contains polyunsaturated fatty acid-rich lysoPtdOH and lysophospholipase D (lysoPLD). Here, we examined whether lysoPtdOH was produced by lysoPLD in the presence and absence of a hen fertilized ovum and what the physiological role of lysoPtdOH in hen egg white is. Mass spectrometry showed that fertilized hen egg white contained about 8 μM lysoPtdOH before incubation with an ovum, mainly comprised of 18:1- (12.6 %), 18:2- (37.8 %) and 20:4-molecular species (41.5 %). In an early gestation period, the lysoPtdOH was increased up to 9.6 μM, concomitant with a decrease in the level of polyunsaturated lysophosphatidylcholine (lysoPtdCho). Moreover, lysoPtdOH-degrading activities were found in egg white and the vitelline membrane, showing that these enzymes control lysoPtdOH levels in egg white. In an egg yolk angiogenesis assay, two lysoPtdOH receptor antagonists, Ki16425 and N-palmitoyl serine phosphoric acid (NASP), inhibited blood vessel formation induced by exogenously added 18:1-lysoPtdOH and its precursor lysoPtdCho on the hen yolk sac. Ki16425 and NASP also inhibited blood vessel formation in the chorioallantoic membrane (CAM). Furthermore, the relatively higher levels of LPA₁, LPA₂, LPA₄ and LPA₆ mRNA were present in the yolk sac and CAM. These results suggest that lysoPtdOH produced from lysoPtdCho by the action of lysoPLD in hen egg white is involved in the formation of blood vessel networks through several lysoPtdOH receptors on various extraembryonic membranes, including the yolk sac membrane and CAM.

This study describes the use of human serum albumin (HSA)-modified gold nanoparticles (HSA-AuNPs) for the selective extraction and enrichment of high-pI protein, lysozyme (Lyz) prior to analysis by capillary electrophoresis (CE) with UV detection. HSA-AuNPs are capable of extracting Lyz from a complex matrix because a HSA capping layer not only stabilizes gold nanoparticles in a high-salt environment but also exhibits strong electrostatic attraction with Lyz under neutral pH condition. Efficient separation of Lyz and other high-pI proteins has been successfully achieved by the filling of cationic polyelectrolyte, poly(diallydimethylammonium chloride) (PDDAC), to the background electrolyte. After capturing Lyz with HSA-AuNPs, PDDAC-filled CE can be directly used for the analysis of the extracted Lyz without the addition of the releasing agent into the extractor. The extraction efficiency relied on the pH of the solution and the concentration of HSA-AuNPs. Under optimal extraction conditions, the limit of detection at a signal-to-noise ratio of 3 for Lyz was down to 8 nM. The combination of HSA-AuNP extraction and PDDAC-filled CE has been applied the analyses of Lyz in hen egg white, human milk, and human tear. Also, this NP-based extraction can be coupled to matrix-assisted desorption/ionization time-of-flight mass spectrometry and sodium dodecyl sulfate-polyacrylamide gel electrophoresis., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Lysozyme is one of the best characterized antimicrobial proteins in egg white. Three phenotypes of egg white lysozyme in Japanese quail, Coturnix japonica, (namely fast; slow; and the combination, FS) were observed by acid polyacrylamide gel electrophoresis. The fast phenotype showed faster mobility on Acid-PAGE than the slow phenotype. Comparison of the coding sequences for lysozyme derived from the slow and fast phenotypes revealed a nonsynonymous SNP at nucleotide position 115 from the translation initiation site, which alters AA sequence of lysozyme. This nonsynonymous SNP converted glutamine (Q) in the slow phenotype to lysine (K) in the fast phenotype at AA residue 21 of mature lysozyme (Q21K). Here, we investigated the effect of these phenotypes on muramidase activity, antibacterial activity, and hatchability. Muramidase activity toward isolated cell walls of Micrococcus lysodeikticus was in the order: fast allozyme > slow allozyme > chicken (Gallus gallus), but no significant difference was found among the 3 (P > 0.05). Antibacterial activity against live Staphylococcus aureus cells was significantly greater for the fast allozyme than the slow allozyme from 20 h after incubation (P < 0.05). For the antibacterial effects against live Escherichia coli cells, the activity of fast was significantly higher than that of slow at 16 h after incubation (P < 0.05). Hatchability was estimated for reciprocal crosses of Japanese quail with the FF (fast) and SS (slow) genotypes. Hatchability was 92.5% in FF male × SS female crosses and 87.2% in SS male × FF female crosses. A Cochran-Mantel-Haenszel test revealed a significant difference between the crosses (P < 0.05) and indicated that the female-derived slow phenotype led to improved rates of hatching. Our results suggest that the nonsynonymous SNP in Japanese quail lysozyme influences the electrophoretic migration, muramidase activity, and antibacterial activity of the protein, in addition to the hatchability of the eggs. These results demonstrate, for the first time, a significant difference in antibacterial activity and hatchability between 2 lysozyme phenotypes in Japanese quail.

Unlabelled: A monoclonal antibody-based electrochemical luminescence method was developed for detecting and quantifying ricin in liquid egg, with a limit of detection of 0.2 ng/mL. Because this highly toxic protein, present in the seeds of Ricinus communis (castor), has been used for intentional poisoning in the past, it is important to have sensitive and reliable analytical methodology to detect ricin in food matrices such as liquid egg. The detection of this quantity of pure or crude ricin spiked into commercial samples of liquid egg provides approximately 50000-fold greater sensitivity than required to detect a toxic dose of ricin (>1 mg) in a 100 g sample., Practical Application: Because ricin has been used for intentional poisoning, there is a need for analytical methodology to detect ricin in food matrices to assure a safe food supply. Using monoclonal antibodies to ricin developed in our laboratory, we explored an assay readout system known as electrochemiluminescence. This technique afforded sensitive and specific analysis of ricin intentionally added to liquid egg and could potentially be used to monitor egg-based vaccine production., (Journal of Food Science © 2012 Institute of Food Technologists © No claim to original US government works.)

Background: Hen's egg allergy ranks among the most frequent primary food allergies in children. We aimed to investigate sensitization profiles of egg allergic patients and compare in vitro IgE reactivities of eggs from ancient chicken breeds (Araucana and Maran) with those from conventional laying hen hybrids., Methodology: Egg allergic children (n = 25) were subjected to skin prick test, double blind placebo controlled food challenge, and sensitization profiles to Gal d 1-5 were determined by allergen microarray. IgE binding and biological activity of eggs from different chicken breeds were investigated by immunoblot, ELISA, and mediator release assays., Principal Findings: We found that Gal d 1 and Gal d 2 are generally major egg allergens, whereas Gal d 3-5 displayed high sensitization prevalence only in patients reacting to both, egg white and yolk. It seems that the onset of egg allergy is mediated by egg white allergens expanding to yolk sensitization in later stages of disease. Of note, egg white/yolk weight ratios were reduced in eggs from Auraucana and Maran chicken. As determined in IgE immunoblots and mass analysis, eggs from ancient chicken breeds did not differ in their protein composition. Similar IgE-binding was observed for all egg white preparations, while an elevated allergenicity was detected in egg yolk from Araucana chicken., Conclusion/significance: Our results on allergenicity and biological activity do not confirm the common assumption that aboriginal food might be less allergenic. Comprehensive diagnosis of egg allergy should distinguish between reactivity to hen's egg white and yolk fractions to avoid unnecessary dietary restrictions to improve life quality of the allergic child and its family.

Unlabelled: This study was conducted to determine how the combination of heating rate and pH can be used to alter viscoelastic properties and microstructure of egg white protein and whey protein isolate gels. Protein solutions (1% to 7% w/v protein, pH 3.0 to 8.5) were heated using a range of heating rates (0.2 to 60 °C/min) to achieve a final temperature of 80 °C. The gelation process and viscoelastic properties of formed gels were evaluated using small strain rheology. Single phase or micro-phase separated solution conditions were determined by confocal laser scanning microscopy. In the single phase region, gels prepared by the faster heating rates had the lowest rigidity at 80 °C; however, a common G' was achieved after holding for 4 h at 80 °C . On the other hand, under micro-phase separation conditions, faster heating rates allowed phase separated particles to be frozen in the network prior to precipitation. Thus, gels produced by slower heating rates had lower rigidities than gels produced by faster heating rates. The effect of heating rate appears to depend on if the solution is under single phase or micro-phase separated conditions., Practical Application:   The effect of heating rate and/or time on protein gel firmness can be explained based on protein charge. When proteins have a high net negative charge and form soluble aggregates, there is no heating rate effect and gels with equal firmness will be formed if given enough time. In contrast, when electrostatic repulsion is low, there is a competition between protein precipitation and gel formation; thus, a faster heating rate produces a firmer gel.

Enzyme-linked immunosorbent assay (ELISA) analysis of proteins offers a particularly promising approach for investigations in cultural heritage on account of its appreciated properties of being highly specific, sensitive, relatively fast, and cost-affordable with respect to other conventional techniques. In spite of that, it has never been fully exploited for routine analyses of painting materials in consideration of several analytical issues that inhibited its diffusion in conservation science: limited sample dimensions, decrease of binder solubility and reduced availability of antibody bonding sites occurring with protein degradation. In this study, an ELISA analytical protocol suited for the identification of aged denatured proteins in ancient painting micro-samples has been developed. We focused on the detection of bovine β-casein and chicken ovalbumin as markers of bovine milk (or casein) and chicken albumen, respectively. A systematic experimentation of the ELISA protocol has been carried out on mock-ups of mural and easel painting prepared with 13 different pigments to assess limits and strengths of the method when applied for the identification of proteins in presence of a predominant inorganic matrix. The analytical procedure has been optimized with respect to protein extraction, antibodies' concentrations, incubation time and temperature; it allows the detection of the investigated proteins with sensitivity down to nanograms. The optimized protocol was then tested on artificially aged painting models. Analytical results were very encouraging and demonstrated that ELISA allows for protein analysis also in degraded painting samples. To address the feasibility of the developed ELISA methodology, we positively investigated real painting samples and results have been cross-validated by gas chromatography-mass spectrometry.

After incubation of hen egg white lysozyme (HEWL) with microbial transglutaminase (mTG) under high pressure (400-600 MPa for 30 min at 40 °C), the formation of HEWL oligomers was observed via SDS electrophoresis. At atmospheric pressure, HEWL represents no substrate for mTG. Likewise, enzymatic treatment following a pretreatment with high pressure did not lead to oligomerization. Reactive amino acid side chains were identified by peptide mapping after tryptic digestion using RP-HPLC with ESI-TOF-MS. Isopeptide-containing peptide fragments were found only in HEWL samples simultaneously treated with enzyme and pressure. It was found that mTG exclusively cross-links HEWL under high pressure by formation of an isopeptide between lysine at position 1 and glutamine at position 121 in the peptide chain. Therefore, a pressure-induced partial and reversible unfolding of the protein with exposure of lysine and glutamine side chains has to occur, resulting in a site-directed oligomerization of HEWL by mTG. The enzymatic modification of HEWL by mTG under high pressure offers interesting perspectives for further functionalization reactions.

Background: A kit, FASTKIT ELISA version II (Egg) (Nippon Meat Packers) is an enzyme-linked immunosorbent assay kit for detecting hen's egg proteins in foodstuffs. This kit is an enhanced version of FASTKIT ELISA (Egg) with a greater efficiency in terms of extraction of egg proteins from heated foodstuffs. However, the property of this kit remains to be fully elucidated., Methods: Using this new kit, we measured the amount of egg proteins in unheated or heated (140 degrees C or 180 degrees C, 20 min) homemade cookies containing whole egg, egg white or egg yolk., Results: The capability for detection of unheated or heated (140 degrees C or 180 degrees C) whole egg proteins was similar. In addition, there was no significant difference in the detectability between heated (140 degrees C) whole egg and egg white proteins. However, unheated or heated (140 degrees C or 180 degrees C) egg yolk proteins were not sufficiently measured by this kit., Conclusion: Our data suggest that this new kit is significantly improved for detection of heated egg white proteins as compared to that of old version, but not sufficient for detection of egg yolk proteins.

Selected quality and shelf life of eggs coated with mineral oil having 6 different viscosities (7, 11, 14, 18, 22, and 26 cP) were evaluated during 5 wk of storage at 25 degrees C. As the storage time increased, weight loss and albumen pH increased whereas Haugh unit and yolk index values decreased. After 5 wk of storage, eggs coated with 11, 14, 18, 22, or 26 cP oil possessed better quality than the control noncoated eggs and eggs coated with 7 cP oil. Oil coating, irrespective of viscosities, did not improve the emulsion capacity. There was an observable trend that coating with 26 cP oil was more effective in preventing weight loss and in maintaining the Haugh unit of eggs compared with coating with other viscosities of mineral oil. Based on the Haugh unit, the grade of noncoated eggs changed from "AA" at 0 wk to "C" after 3 wk whereas that of 26 cP oil-coated eggs from "AA" at 0 wk to "A" at 3 wk and "B" at 5 wk of storage. Coating with 26 cP oil reduced the weight loss of eggs by more than 10 times (0.85% compared with 8.78%) and extended the shelf life of eggs by at least 3 more weeks compared with the noncoated eggs.

The chorioallantoic membrane (CAM) assays have been intensively used to determine angiogenesis and anti-angiogenesis of medicines. In view of bioactivity, this technique should be performed with kinetic control regime in chicken embryos. Whether the dosages ever used had satisfied this requirement, we explored by mathematical analysis. A diffusion-in-egg model was established to describe several medicinal diffusions in egg white that involved the instantaneous transient kinetic behavior, the diffusion of medicines in capping volume (the volume from the air sac to the interface of egg yolk). By reviewing the diffusion of various compounds including the cited and the experimentals in this work, we conclude that all the CAM assays ever cited were performed under diffusion control regime rather than kinetic control, which may bring forth deviations caused by a diversity of constitutes in egg white through various medicine-protein interactions.

Immunofluorescence microscopy offers a highly specific analytical tool for unambiguous recognition and mapping of proteins in complex matrices. In the present work, the analytical potentials of immunofluorescence microscopy have been exploited to provide recognition of proteinaceous binders in painting cross-sections. An optimised analytical protocol is proposed for the identification of ovalbumin and of bovine serum albumin as markers of egg white and casein, respectively. The study has been carried out on laboratory model samples simulating both easel and mural paintings. The obtained results demonstrated the effectiveness of the method, suggesting the potential future use of immunofluorescence microscopy as a routine diagnostic tool in conservation science. Possible developments of the proposed methodology in order to improve the specificity of the method and its detection sensitivity are presented and discussed.

Using zymography and mass spectrometry, we identified for the first time the precursor of chicken matrix metalloprotease 2 (pro-MMP-2) as a complex with TIMP-2 (tissue inhibitor of metalloproteinases) in egg white and yolk. Real-time polymerase chain reaction confirmed that MMP-2 and its inhibitors TIMP-2 and TIMP-3 were expressed all along the oviduct and in the liver of laying hens. We also demonstrated that the processing of pro-MMP-2 into mature MMP-2 by serine proteases does not occur in vivo, although purified pro-MMP-2 undergoes proteolytic maturation by these proteases in vitro. Moreover, the relative pro-MMP-2 activity assessed by gelatin zymography was shown to decrease in egg white during the storage of unfertilized or fertilized eggs. However, the mature form of 62 kDa MMP-2 could not be detected. The fact that MMP-2 is found as a proform in fresh eggs suggests that the activity of this metalloprotease is regulated under specific conditions during embryonic development.

Both metal and flavin-dependent sulfhydryl oxidases catalyze the net generation of disulfide bonds with the reduction of oxygen to hydrogen peroxide. The first mammalian sulfhydryl oxidase to be described was an iron-dependent enzyme isolated from bovine milk whey (Janolino, V.G., and Swaisgood, H.E. (1975) J. Biol. Chem. 250, 2532-2537). This protein was reported to contain 0.5 atoms of iron per 89 kDa subunit and to be completely inhibited by ethylenediaminetetraacetate (EDTA). However the present work shows that a soluble 62 kDa FAD-linked and EDTA-insensitive sulfhydryl oxidase apparently constitutes the dominant disulfide bond-generating activity in skim milk. Unlike the metalloenzyme, the flavoprotein is not associated tightly with skim milk membranes. Sequencing of the purified bovine enzyme (>70% coverage) showed it to be a member of the Quiescin-sulfhydryl oxidase (QSOX) family. Consistent with its solubility, this bovine QSOX1 paralogue lacks the C-terminal transmembrane span of the long form of these proteins. Bovine milk QSOX1 is highly active toward reduced RNase and with the model substrate dithiothreitol. The significance of these new findings is discussed in relation to the earlier reports of metal-dependent sulfhydryl oxidases.

Eggs were collected from different areas of Faisalabad city. The quantity of sulphonamides was determined in yolk, white and whole egg and compared with the permissible limit 1 microg/ml for sulphadimethoxine available in literature. In another experiment, a group of hens were kept at a poultry farm after medicating them with darvisal liquid to see if the residues of sulphonamide pass into the eggs of poultry. The period of existence of residues was noted.

A multicompartmental electrolyzer called membrane-separated wells for isoelectric focusing and trapping (MSWIFT) has been developed and tested for micropreparative-scale isoelectric trapping separations. In the MSWIFT, the length of the heat conduction path from the center of the compartments to the wall is less than 1 mm. The compartments are made from 99.8% nonporous alumina that has a high heat conductivity and a high specific heat capacity, leading to adequate Joule heat dissipation even at power loads as high as 5 W. The length of any compartment parallel to the electric field (the intermembrane distance) can be selected to be multiples of 1.5 mm, leading to compartment volumes that are multiples of about 60 muL. A maximum of 20 (1.5 mm long) separation compartments can be readily assembled in the current version of MSWIFT. The MSWIFT has been used to desalt samples, isolate small ampholytic components (amino acids, peptides, and dyes), prefractionate complex protein mixtures and enrich minor components; these separations were achieved in 20-60 min.

Egg white ribonuclease was first found in green turtle eggs. The general properties were studied on substrate specificity, the optimum pH and temperature, and the effect of pH and temperature on the RNase activity. The enzyme studied was specific for poly (C) and degraded poly (U) at the lower rate and had the pH optimum at 7.0 and the optimum temperature at 40 degrees C. It was stable at alkaline range (pH 8.0-10.0) and up to 60 degrees C in pH 9.0 for 1 h, and unstable at acidic side for all temperatures. All of the properties studied showed similarity to RNase A. However, the optimum pH, broad range of optimum temperature and pH stability were different from RNase A. To evaluate the relationship of the structure and enzymatic properties, the 3D-structure of this enzyme was engineered by program MODELLER using two RNases (2BWL and 2BLZ) as starting models. The differences found in activity might be affected from the structure of micro environmental changing caused by amino acids deletion and substitution on the molecule.