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Background: Respiration is an important physiological activity of eggs and is closely related to their freshness. To further observe the diffusion of carbon dioxide released by egg respiration, we used a respirometer to measure the respiration parameters of eggs stored at room temperature and performed a respiration simulation using Fluent software. This paper also explores the relationship between respiratory intensity, freshness, and storage period., Results: The results demonstrate that the diffusion of carbon dioxide released from the respiration of eggs is related to the characteristics of heavy gas diffusion. By comparison, the simulated value (0.0199 m s -1 ) is close to the experimental value (0.0208 m s -1 ), which indicates that the simulation and analysis results are valid. In addition, the logarithmic model was used to assess the relationship between respiration intensity, Haugh unit, and the yolk index (R 2 values 0.89 and 0.87). The R 2 of the relationship between the real and the predicted Haugh unit value and the yolk index are 0.9 and 0.84 respectively, indicating that the model is a good fit. The equivalent egg age model was established using nonlinear regression, where the correlation coefficient R was 0.888 and P < 0.01, indicating it was both stable and reliable., Conclusion: The standard k-ε model is suitable for egg respiration simulation analysis. Respiratory intensity can be used as a potential index for nondestructive testing of egg freshness, which is a new method for nondestructive testing of egg freshness and storage period. © 2022 Society of Chemical Industry., (© 2022 Society of Chemical Industry.)

In this research, the impact of High Pressure Carbon Dioxide (HPCD) on the physicochemical, interfacial and rheological properties of liquid whole egg (LWE) was investigated. HPCD treatment increased the solubility, free sulfhydryl groups and surface hydrophobicity of LWE. The highest foaming ability (186%) and foaming stability (72%) were obtained at 60 min of HPCD treatment, which were 1.3-fold and 1.4-fold those of the control group (147% and 51%, respectively). Compared with the control group, the LWE emulsion had a minimum particle size (16.3 μm) when the treatment time was 75 min, and the highest absolute value of zeta potential reached 7.66 mV when the processing time was 60 min. HPCD treatment decreased the apparent viscosity of LWE at a low shear rate. Dynamic viscoelastic characteristics indicated that both the G' and G'' moduli of LWE under the HPCD process were lower than those of the control group at any frequency., 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.)

Sialic acids (SA) are widely found as components of oligosaccharide units in mucins, glycoproteins and other microbial polymers in nature food. The aim of this study is to create a new fluorimetric detection method applied for determinating SA in egg products by using a sensitive lectin-CdTe quantum dots (QDs) nanoprobe. Water-soluble and high luminescent CdTe QDs were conjugated with sambucus nigra bark lectin (SNA) as probe for SA detection. As a result of specific interaction between SA and SNA-CdTe QDs, the conjugations finally lead to the change of a fluorescent signal. Under optimal conditions, fluorescence intensity increase linearly with the increase of the concentration of SA ranging from 12 to 680 ng/mL. The low detection limit is 0.67 ng/mL. This quick and selective analysis method for SA detection has been used in synthetic samples and egg products with recovery between 97.92% and 110.42%, which demonstrates the application of this assay is feasible and practical., (© 2014 Institute of Food Technologists®)

The egg white protein alterations during the early phase of chicken embryonic development were recently reported by our laboratory. Nevertheless, the original albumen differences between fresh unfertilized and fertilized chicken eggs have not been investigated. By using 2-dimensional gel electrophoresis (2-DE), coupled with matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF MS/MS) method, 1 ovalbumin protein spot as well as 6 ovalbumin-related protein Y spots were identified showing more than 10-fold differences (P < 0.01) in abundance between fresh unfertilized and fertilized chicken egg whites. Six of these protein spots represented higher intensity in fertilized eggs through 2-DE analysis. It was thus concluded that ovalbumin protein family, especially ovalbumin-related protein Y, may play an important role in embryonic development, which still needs to be validated. This finding will provide insight into embryogenesis to improve our understanding of the functions of ovalbumin family proteins in regulating or supporting embryonic development.

Although the effect of storage temperature was suggested to be a more important factor than that of storage time on changes in unfertilized egg white proteins, no comprehensive analysis of the thermally induced egg white protein changes was carried out. This study presents a proteomic analysis of the changes in unfertilized egg white proteins after 15 days of storage at 4, 20, and 37 °C. Using two-dimensional electrophoresis followed by MALDI-TOF MS/MS, 32 protein spots representing 8 proteins were identified with significant differences in abundance when stored at different temperatures. An accelerated degradation of ovalbumin, possibly resulting from the reduction of antiprotease, was observed after the storage at higher temperature. In addition, an increase in the formation of ovalbumin complexes and a decrease in lipocalin family proteins were detected with increasing storage temperature, which may indicate a thermally promoted change in chicken eggs. The decrease of clusterin during the high-temperature storage was suggested to be an effective biomarker for egg quality evaluation. These findings will give insight into the effects of storage temperature on changes in unfertilized egg white proteins during storage and provide a better understanding of the thermally induced biochemical changes that may affect the egg deteriorative process.

We investigated the influence of an egg-enriched diet on plasma, hepatic and fecal lipid levels and on gene expression levels of transporters, receptors and enzymes involved in cholesterol metabolism. Sprague-Dawley rats fed an egg-enriched diet had lower plasma triglycerides, total cholesterol, low density lipoprotein (LDL)-cholesterol, hepatic triglyceride, and cholesterol concentrations, and greater plasma high-density lipoprotein cholesterol concentration, fecal neutral sterol and bile acid concentrations than those fed a plain cholesterol diet. Chicken egg yolk had no effect on sterol 12α-hydroxylase and sterol 27α-hydroxylase; but upregulated mRNA levels of hepatic LDL-receptor, cholesterol 7α-hydroxylase (CYP7A1) and lecithin cholesterol acyltransferase, and downregulated hepatic hydroxymethylglutaryl-(HMG)-CoA reductase and acyl-CoA:cholesterol acyltransferase (ACAT) after 90 days. Modification of the lipoprotein profile by an egg-enriched diet was mediated by reducing de novo cholesterol synthesis and enhancing the excretion of fecal cholesterol, via upregulation of CYP7A1 and the LDL receptor, and downregulation of HMG-CoA reductase and ACAT.

An attempt was made to develop a new protocol for preparing phosvitin that could be easy scaled up using polyethylene glycol (PEG6000). Influence of PEG6000 concentration and pH of sample solution on phosvitin isolation was investigated. Phosvitin of high purity (99%) was obtained in good yield (47%) with the optimal condition of pH 4.0 and 3% PEG6000 precipitation. In addition, through evaluating different anion-exchange chromatography methods, the DEAE procedure at pH 7.5 was finally selected as the best procedure to obtain metal-free phosvitin that lost the least protein. Furthermore, it is observed that the purity and characterizations of prepared phosvitin were similar to those of the standard phosvitin from Sigma, and the random coil of phosvitin converted into more compact structure after removing metal ion. In conclusion, the developed method was simple and suitable for scaled up preparation of phosvitin., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Preserved eggs are traditional alkali‐pickled food in China and have been enjoyed by consumers and extensively studied by researchers for their nutritional tastes and their anti‐tumor, anti‐inflammatory, antioxidant, lipid‐lowering, and blood pressure‐lowering properties. To study the anti‐tumor effects of preserved eggs, this project observed the health on rats, and anti‐tumor effects and separated anti‐tumor active components on HT‐29 cells. SD rats fed for 80 days showed that preserved eggs had no significant effect on weight, food intake, blood pH, liver tissues, or organ indices. Preserved eggs significantly increased blood levels of oxidative stress markers SOD and CAT, decreased MDA levels by 0.46, 0.23, and 0.25 times. Moreover, they also increased the level of IL‐2 from 1233 to 1340 pg/mL. Two water‐soluble bioactive peptide fractions, B1 and B2, with molecular weights ≥10 kDa were further obtained from preserved eggs by ultrafiltration and Superdex Peptide 10/300 GL. The potential mechanism of B1 and B2 is to activate the internal mitochondrial apoptotic pathway and induce apoptosis by up‐regulating the expression of the pro‐apoptotic factors cytochrome C, caspase‐3, and caspase‐9 mRNA in HT‐29 cells. [ABSTRACT FROM AUTHOR]

Egg size is a crucial indicator for consumer evaluation and quality grading. The main goal of this study is to measure eggs' major and minor axes based on deep learning and single-view metrology. In this paper, we designed an egg-carrying component to obtain the actual outline of eggs. The Segformer algorithm was used to segment egg images in small batches. This study proposes a single-view measurement method suitable for eggs. Experimental results verified that the Segformer could obtain high segmentation accuracy for egg images in small batches. The mean intersection over union of the segmentation model was 96.15%, and the mean pixel accuracy was 97.17%. The R-squared was 0.969 (for the long axis) and 0.926 (for the short axis), obtained through the egg single-view measurement method proposed in this paper. [ABSTRACT FROM AUTHOR]

Preserved eggs, an alkaline-fermented food, have been widely searched for their anti-inflammatory activity. Their digestive characteristics in the human gastrointestinal tract and anti-cancer mechanism have not been well explained. In this study, we investigated the digestive characteristics and anti-tumor mechanisms of preserved eggs using an in vitro dynamic human gastrointestinal-IV (DHGI-IV) model. During digestion, the sample pH dynamically changed from 7.01 to 8.39. The samples were largely emptied in the stomach with a lag time of 45 min after 2 h. Protein and fat were significantly hydrolyzed with 90% and 87% digestibility, respectively. Moreover, preserved eggs digests (PED) significantly increased the free radical scavenging activity of ABTS, DPPH, FRAP and hydroxyl groups by 15, 14, 10 and 8 times more than the control group, respectively. PED significantly inhibited the growth, cloning and migration of HepG2 cells at concentrations of 250–1000 μg/mL. Meanwhile, it induced apoptosis by up/down-regulating the expression of the pro-apoptotic factor Bak and the anti-apoptotic gene Bcl-2 in the mitochondrial pathway. PED (1000 μg/mL) treatment resulted in 55% higher ROS production than the control, which also led to apoptosis. Furthermore, PED down-regulated the expression of the pro-angiogenic genes HIF-1α and VEGF. These findings provided a reliable scientific reference for the study of the anti-tumor activity of preserved eggs. [ABSTRACT FROM AUTHOR]

Chicken egg whites contain hundreds of proteins, and are widely used in the food, biological and pharmaceutical industries. It is highly significant to study the separation and purification of egg white proteins. This review first describes the structures and functional properties of several major active proteins in egg whites, including ovalbumin, ovotransferrin, ovomucoid, lysozyme, ovomucin, ovomacroglobulin and avidin. Then, the common techniques (including precipitation, chromatography and membrane separation) and some novel approaches (including electrophoresis, membrane chromatography, aqueous two-phase system and molecular imprinting technology) for the separation and purification of egg white proteins broadly reported in the current research are introduced. In addition, several co-purification methods for simultaneous separation of multiple proteins from egg whites have been developed to improve raw material utilization and reduce costs. In this paper, the reported techniques in the last decade for the separation and purification of chicken egg white proteins are reviewed, discussed and prospected, aiming to provide a reference for further research on egg proteins in the future. [ABSTRACT FROM AUTHOR]

Fatty acid profiles and volatile composition in the yolks of conventional eggs from seven different species (duck, free-range chicken, silky chicken, quail, pigeon, goose, and chicken) were compared using GC-MS and electronic nose (E-nose). The results showed that there were significant differences among the fatty acid profiles of the seven avian eggs. Goose eggs contained the highest contents of saturated and monounsaturated fatty acids but the lowest content of polyunsaturated fatty acids (PUFA), and the differences were significant ( p<0.05). The PUFA proportion was the highest in the free-range chicken eggs of all the tested avian eggs. The ω-3 PUFA content and the ω-6/ω-3 ratio were significantly ( p<0.05) higher in the yolks of goose and silky chicken. The volatile compositions of egg yolks are esters, alcohols, alkenes, and nitrogenous compounds, and the major compounds that contributed to discrimination of different species of eggs were ethyl acetate, pathalic acid butyl isohexyl ester, O-methylisourea hydrogen sulfate, 1-butanol, and N-isopropylbenzamide. In addition, seven different species of eggs were distinguished from each other through principal component analysis of E-nose data, suggesting that the E-nose may be a potential technology for discriminating different species of eggs. Practical applications: The results showed that the major volatile components could be used as chemical markers to distinguish different species of eggs by the chemometric method. The results obtained from the electronic nose analysis agreed well with the GC-MS results, suggesting the potential application of the E-nose technique in the market quality control and the detection of counterfeit eggs. Twenty-two fatty acids were detected and significant differences were found in the fatty acid proportions of different poultry eggs. A total of 41 volatiles were identified by GC-MS, and E-nose can successfully discrimination different species of eggs. [ABSTRACT FROM AUTHOR]

Preserved eggs are a type of egg products made from duck eggs and have anti-inflammatory activity. The purpose of this study was to investigate the effects of preserved egg simulated gastrointestinal digests on the apoptosis of HT29 and HepG2 cells. The cells morphology, apoptosis and apoptosis associated genes (Bcl-2, Bax, COX-2) and proteins (caspase-3 and caspase-9) were evaluated. The results showed that preserved egg digests significantly up regulated the expression of genes Bax, caspase-3 and caspase-9, which are involved in cell apoptosis, and up regulated the expression of the pro-apoptotic factors Bcl-2 and COX-2 both in HT29 and HepG2 cells, leading to a reduction in the ratio of Bcl-2:Bax proteins. The results also showed that the apoptosis of HT29 and HepG2 cells was promoted by the PED in a dose-dependent manner. Thus, PED may serve as a potential functional food for cancer treatment. • The anticancer activity of preserved eggs was explored. • Preserved eggs digests promoted HT29 and HepG2 cells apoptosis in a dose dependent manner. • Preserved eggs significantly up regulated the expression of genes Bax, caspase-3 and caspase-9. [ABSTRACT FROM AUTHOR]

In this study, a proteome analysis of Tibetan chicken egg yolk as well as the comparison to that of lowland chicken were performed by label-free quantitative proteomics. A total of 135 proteins were identified and abundances of 19 of these proteins were significantly different between these two groups. These differential proteins were mainly associated with oxidative stress, defense, energy metabolism and tissue development through bioinformatics analysis. To further verify the species-specific diversity of the antioxidant capacity, the antioxidative activities of egg yolk proteins were further invested in vitro and in Caco-2 cells. It was observed that both Tibetan and lowland chicken egg yolk proteins showed antioxidant activities, but the former exerted a much stronger effect. PIT54 and glutathione peroxidase 3 were considered to be antioxidant-related candidate proteins. These results provide substantial evidence for the molecular mechanisms of enhancing physical activity levels of egg yolk proteins, especially with regard to the cross-species protective mechanisms against oxidative stress. [ABSTRACT FROM AUTHOR]

The aim of this paper was to demonstrate a rapid and selective fluorescence-linked immunoassay method based on quantum dots as the fluorescent marker for the detection of Salmonella Enteritidis on eggshell. Highly-fluorescent and water-soluble CdTe quantum dots were prepared by using thioglycolic acid and 1-thioglycerol as ligands and were then conjugated with anti-Salmonella antibodies. As a result of specific interaction, Salmonella Enteritidis were specifically captured by bioconjugated CdTe quantum dots which led to the detection of a fluorescent signal. The bacterial cell images were obtained using fluorescence microscopy. Under optimal conditions, the quenched fluorescence intensity increased linearly with the log total count of Salmonella Enteritidis ranging from 3 × 102 to 3 × 107 CFU/mL within 1–2 h. The low detection limit was 1 × 102 CFU/mL without sample enrichment. This method was satisfactorily applied to the analysis of egg samples, which was demonstrated as a simple scheme for quick and selective detection of Salmonella Enteritidis on eggshell. [ABSTRACT FROM AUTHOR]

Respiration plays a crucial role in the physiological development of embryos throughout the entire incubation process and serves as a vital indicator for discerning unfertilized eggs and embryos that have stopped development. This article explores the relationship between egg respiration, fertilization status, and chicken embryo viability. First, it studied the changes in respiration of fertilized and unfertilized eggs during the early stages of incubation (Day 1–3) and found that the CO 2 production of fertilized eggs gradually increased, while those of unfertilized eggs gradually decreased. Moreover, significant differences in respiration between fertilized and unfertilized eggs were observed on the second day of incubation. Next, we employed Random Forest (RF), Logistic Regression (LR), and Support Vector Machine (SVM) models to differentiate between fertilized and unfertilized eggs. Notably, the SVM algorithm exhibited exceptional performance in discriminating between fertilized and unfertilized eggs, achieving a remarkable test set accuracy of 98.41 %. Finally, a Bayesian algorithm was applied to classify embryos as either dead, weak, or viable in middle and later stages of incubation. Bayesian discriminant analysis yielded compelling results, achieving a 100 % detection rate for deceased embryo eggs. The outcomes of this study provide a robust theoretical foundation and empirical data to advance non-destructive testing methodologies for poultry eggs. Graphic abstract. [Display omitted] • Identification of weak and dead embryo based on respiration. • Respiration analysis of fertilized and unfertilized eggs. [ABSTRACT FROM AUTHOR]

Preserved egg, a traditional Chinese egg product, is regarded as an anti-inflammatory food in traditional Chinese medicine. This study was aimed to examine anti-inflammatory effect of the simulated gastrointestinal digestive products of whole preserved egg (DWPE), preserved egg white (DPEW), and preserved egg yolk (DPEY) on lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The results demonstrated that DWPE, DPEW, or DPEY inhibited the LPS-induced secretion of Nitric oxide (NO), without marked cytotoxicity. The DWPE, DPEW, and DPEY significantly suppressed the secretion of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α and interleukin (IL)-6. Particularly, the inhibition rate of DPEW on NO, IL-6, and TNF-α could reach 25 to 27%, 31 to 42%, and 26 to 38%, respectively (P < 0.05). Furthermore, the DPEW and DPEY downregulated the gene expression of Cyclooxygenase-2 and inducible nitric oxide synthase in a dose-dependent manner. Taken together, this study indicated that DWPE, DPEW, and DPEY, especially DPEW, might serve as functional food for anti-inflammatory therapy. [ABSTRACT FROM AUTHOR]

• Respiratory changes of chicken embryos during incubation. • Classification of fertilized and unfertilized eggs based on respiration. • Nondestructive prediction of chicken embryo growth indicators based on respiration. Respiration continues throughout the incubation of eggs and is closely related to fertilization status and changes in chick embryo growth. Here, we explored the relationship between egg respiration, fertilization status, and growth indicators during incubation. First, we studied the changes in respiration of eggs during incubation and found that O 2 consumption and CO 2 emission were increased gradually during incubation and reached a maximum value when the shells were broken by the chick (21 days). Next, we established models to classify eggs according to the difference in respiration between fertilized and unfertilized eggs early during incubation using random forest (RF), logical regression, and support vector machine (SVM). The accuracy rates of RF and SVM on the third day of incubation were 99.32% and 98.63%, respectively, and reached 100% on the fifth day. Finally, a linear model was used to establish the relationship between chicken embryo respiration and yolk free body mass (YFBM) (R2 values of 0.99 and 0.98 for the early and late incubation periods, respectively), heart mass (R2 = 0.94), liver mass (R2 = 0.97), and the digestive system (DS) mass (R2 = 0.98). The R2 values for the relationships between the real and the predicted YFBM values and heart, liver, and DS masses were 0.98, 0.89, 0.87 and 0.88, respectively, indicating the good fit of the model. This study provides a theoretical basis for the detection of sterile eggs and dead-embryo eggs during incubation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Eggshell membrane (ESM) from hatched eggs is a novel source of antioxidant peptides. • The < 3 kDa hydrolysates of fresh and hatched ESM had potent antioxidant and cytoprotective effects. • Six novel peptides were identified using peptidomics and bioinformatics approaches. • P1, P4, and P6 exhibited higher chemical and cellular antioxidant effects than GSH. • ESM antioxidant peptides could activate the Keap1-Nrf2 pathway by binding to Keap1. Eggshell membranes (ESM) from fresh and hatched chicken eggs are important agricultural byproducts. In this study, we investigated the antioxidant and cytoprotective activity of hydrolysates from fresh and hatched ESM, identified the antioxidant peptides and explored their potential molecular mechanism using a combined in silico and in vitro approach. The results showed that the hydrolysates fractions (MW < 3 kDa) of both ESM exhibited excellent antioxidant effects and could protect H 2 O 2 -induced RAW264.7 cells by reducing ROS and MDA levels involving the modulation of the Keap1-Nrf2 pathway. Six novel peptides identified by integrated approaches of peptidomics and in silico bioinformatic analysis were synthesized, exhibiting significantly higher ORAC values (629.41–1823.77 µmol TE/mmol) than GSH (397.21 µmol TE/mmol). Among these, KPLCPP, MDGWPR, and LWNPR possessed stronger ABTS scavenging and cytoprotective activities than GSH. All the six peptides could dock onto the Keap1-Kelch domain. Moreover, KPLCPP and LWNPR could regulate the Keap1-Nrf2 pathway and induced the overexpression of antioxidant enzymes including HO-1, SOD and GSH-Px. With the molecular docking and western blot analysis, the underlying molecular mechanism of the ESM antioxidant peptides might be related to the activation of Keap1-Nrf2 pathway by occupying the Nrf2-binding site on Keap1. This study provides a theoretical basis for the application of fresh and hatched ESM antioxidant peptides in functional foods, as well as insights for the identification and the mechanisms research of more food-derived antioxidant peptides. [ABSTRACT FROM AUTHOR]

Abstract: A new method for the determination of lysozyme with high sensitivity based on Resonance Rayleigh scattering (RRS) by using Cd doped ZnSe quantum dots (QDs) as a probe was proposed in this experiment. Cd doped ZnSe QDs capped with glutathione were prepared in the water phase. Further, the RRS spectrum, transmission electron microscope, and absorption spectrum of the QDs–lysozyme system have been characterized. In addition, the effects of several factors on scattering intensities were investigated, including pH value of solution, amount of QDs, mixing sequence of each reagent and the coexisting substances. Moreover, the possible mechanism for the RRS enhancement of Cd doped ZnSe QDs–lysozyme system was preliminary discussed. The RRS method for the determination of lysozyme has good sensitivity with the detection limits 6.5×10−10 gmL−1. The contents of lysozyme were determined with recoveries of 97.1–101.6% and relativity standard deviation of 2.5–3.1%, respectively. It proved that the method established in our study is very sensitive, rapid, convenient and tolerant for the determination of lysozyme in synthetically and chicken egg white. [Copyright &y& Elsevier]