Comprehensive risk assessment of lead concentrations in chicken, quail, and duck egg albumen and yolk using Monte Carlo simulations.

This study conducted a comparative analysis of the concentration of the lead (Pb) in the albumen and yolk of eggs from domesticated chicken, quail, and duck, with a concurrent assessment of the potential carcinogenic and non-carcinogenic risks associated with the consumption of eggs sourced from Türkiye. A total of 78 poultry egg samples were gathered from breeding farms and farmers' markets situated in Sanliurfa province. Lead concentrations were assessed through inductively coupled plasma optical emission spectrometry (ICP-OES). Human health risk assessment adheres to the guidelines set forth by the United States Environmental Protection Agency (US EPA), which primarily emphasizes estimated daily intake (EDI), international lifetime cancer risk (ILCR), target hazard quotient (THQ), and Monte Carlo simulation (MCS) as a probabilistic approach. One-way analysis of variance (ANOVA) was employed to compare Pb concentrations within egg yolks and albumens, as well as among various types of eggs. The levels of Pb found in the albumen of chicken, quail, and duck eggs were measured to be 0.31 ± 0.11, 0.43 ± 0.11, and 0.47 ± 0.16 µg kg-1, respectively. The concentrations of Pb in the yolks of chicken, quail, and duck eggs were found to be 0.54 ± 0.19, 0.28 ± 0.11, and 0.69 ± 0.21 µg kg-1, respectively. These concentrations were below the maximum permitted levels set by the FAO/WHO. The results indicated that Pb content in all tested eggs was safe for consumption, with exposure levels significantly below Joint FAO/WHO Expert Committee on Food Additives (JECFA) risk thresholds. The THQ values were less than one, indicating no non-carcinogenic risk. In addition, this study provides accurate and reliable data for policy makers to improve food safety measures and reduce potential public health risks.

Chicken embryo cultures in the dorsal-upward orientation for the manipulation of epiblasts.

Chicken embryos have many advantages in the study of amniote embryonic development. In particular, culture techniques developed for early-stage embryos have promoted the advancement of modern developmental studies using chicken embryos. However, the standard technique involves placing chicken embryos in the ventral-upward (ventral-up) orientation, limiting manipulation of the epiblast at the dorsal surface, which is the primary source of ectodermal and mesodermal tissues. To circumvent this limitation, we developed chicken embryo cultures in the dorsal-up orientation and exploited this technique to address diverse issues. In this article, we first review the history of chicken embryo culture techniques to evaluate the advantages and limitations of the current standard technique. Then, the dorsal-up technique is discussed. These technological discussions are followed by three different examples of experimental analyses using dorsal-up cultures to illustrate their advantages: (1) EdU labeling of epiblast cells to assess potential variation in the cell proliferation rate; (2) migration behaviors of N1 enhancer-active epiblast cells revealed by tracking cells with focal fluorescent dye labeling in dorsal-up embryo culture; and (3) neural crest development of mouse neural stem cells in chicken embryos.

The change of albumen quality during the laying cycle and its potential physiological and molecular basis of laying hens.

To elucidate the regulatory mechanisms that impact variability in albumen quality of laying hens from the peak of lay to the late production phase. A 60-wk study was conducted on a cohort of 20,000 Hy-Line Brown laying hens from 20 to 80 wk old. Before commencement at 20 wk, the 10-wk-old hens were acclimatized for 10 wk. This study examined changes in albumen quality, serum, and liver antioxidant capacity, magnum morphology, and expression of albumen-protein-related genes in the magnum. To reduce sampling error, we collected eggs (n = 90) from pre-determined cages at every sampling point (5-wk intervals), and 8 hens were selected at 10-wk intervals for blood and tissue collection. Our findings revealed that age significantly affected most evaluated parameters. Albumen gel properties, including hardness, gumminess, and chewiness, increased significantly with age (P < 0.05). With the increasing of hens' age from 20 to 80 wk, the albumen proportion of eggs was decreased, but eggshell proportion, yolk proportion, thick albumen proportion, thick to thin ratio, thick albumen solid content, albumen height, Haugh units (HU), and yolk color were increased and then decreased (P < 0.05). Compared to hens aged 20 to 60 wk, the hens (70-80 wk) had significantly reduced total antioxidant capacity (TAC) and glutathione levels (GSH) in the liver and lower serum TAC and superoxide dismutase levels (SOD) (P < 0.05). The magnum mucosal folds were highest in 40 to 60 wk-old hens, and the luminal diameter increased with age (P < 0.05). In the magnum, the mRNA expression levels for OVA, CPE, and NUP205 increased significantly between 30 and 40 wk, while FBN1 expression was higher between 30 and 50 wk (P < 0.05). At 70 to 80 wk, the expression of BRCA2 was significantly downregulated (P < 0.05). Albumen height, thick albumen proportion with protein secretion-related genes, enhanced antioxidant function, and luminal diameter correlated positively. However, the thick-to-thin albumen ratio negatively correlated with BRCA2, downregulated in aged laying hens. We used principal component and cluster analysis to deduce albumen quality changes during 3 phases: 25 to 35, 40 to 55, and 60 to 80 wk. The decline in albumen quality in aging hens is linked with decreased antioxidant capacity, magnum health, and downregulation of key genes involved in protein synthesis and secretion. These findings emphasize critical albumen quality changes in laying hens and suggest molecular pathways underlying age-related albumen quality alterations.

Polysaccharide- and protein-based edible films combined with microwave technology for meat preservation.

To reduce food-borne bacterial infection caused by food spoilage, developing highly efficient food packing film is still an urgent need for food preservation. Herein, microwave-assisted antibacterial nanocomposite films CaO2@PVP/EA/CMC-Na (CP/EC) were synthesized using waste eggshell as precursor, egg albumen (EA) and sodium carboxymethylcellulose (CMCNa) as matrix by casting method. The size of CaO2@PVP (CP) nanoparticles with monodisperse spherical structures was 100-240 nm. When microwave and CP nanoparticles (0.05 mg/mL) were treated for 5 min, the mortality of E. coli and S. aureus could reach >97 %. Under microwave irradiation (6 min), the bactericidal rate of 2.5 % CP/EC film against E. coli and S. aureus reached 98.6 % and 97.2 %, respectively. After adding CP nanoparticles, the highest tensile strength (TS) and elongation at break (EB) of CP/EC film reached 19.59 MPa and 583.43 %, respectively. At 18 °C, the proliferation of bacterial colonies on meat can be significantly inhibited by 2.5 % CP/EC film. Detailed characterization showed that the excellent meat preservation activity was due to the synergistic effect of dynamic effect generated by ROS and thermal effect of microwave. This study provides a promising approach for the packaging application of polysaccharide- and protein-based biomass nanocomposite antibacterial edible films.

Studies on the Authorship of Albumen Vintage Photographs: A Combined Experimental and Chemometric Approach.

The differences in albumen photographs from vintage photographic studios were identified by energy-dispersive X-ray fluorescence spectroscopy and Fourier transform infrared spectroscopy. The results inspired the concept of finding common features characteristic of a given photographic studio. The obtained measurement data (i.e., positions of vibrational bands for characteristic groups of albumen and the mass contents of chosen elements) were analyzed chemometrically by employing the Principal Component Analysis (PCA). The PCA technique allowed us to reduce the number of relevant experimental parameters characterizing the unique features of the photographic objects. The two major components were able to distinguish the photographic objects in terms of their authorship and the time to produce a photograph. The method developed was examined for a selected group of photographs consisting of albumen prints from three Polish photographic ateliers. To validate ED-XRF measurements and, consequently, the chemometric findings, reference albumen photo samples were designed and prepared. The empirical functional relationships between the content of photochemically reduced silver particles on the photographic paper and several physicochemical factors, including time of exposure to UV light, AgNO3 concentration in a fixed bath, and concentrations of other additives, were proposed. These results can be used for the prediction of the experimental conditions under which the investigated photographs were developed.

Histological and molecular difference in albumen quality between post-adolescent hens and aged hens.

The decline in albumen quality resulting from aging hens poses a threat to the financial benefits of the egg industry. Exploring the underlying mechanisms from the perspective of cell molecules of albumen formation is significant for the efficient regulation of albumen quality. Two individual groups of Hy-Line Brown layers with ages of 40 (W40) and 100 (W100) wk old were used in the present study. Each group contained over 2,000 birds. This study assessed the egg quality, biochemical indicators and physiological status of hens between W40 and W100. Subsequently, a quantitative proteomic analysis was conducted to identify differences in protein abundance in magnum tissues between W40 and W100. In the W40 group, significant increases (P < 0.05) were notable for albumen quality (thick albumen solid content, albumen height, Haugh unit), serum indices (calcium, estrogen, and progesterone levels), magnum histomorphology (myosin light-chain kinase content, secretory capacity, mucosal fold, goblet cell count and proportion) as well as the total antioxidant capacity of the liver. However, the luminal diameter of the magnum, albumen gel properties and random coil of the albumen were increased (P < 0.05) in the W100 group. The activity of glutathione, superoxidase dismutase, and malondialdehyde in the liver, magnum, and serum did not vary (P > 0.05) among the groups. Proteomic analysis revealed the identification of 118 differentially expressed proteins between the groups, which comprised proteins associated with protein secretion, DNA damage and repair, cell proliferation, growth, antioxidants, and apoptosis. Furthermore, Kyoto Encyclopedia of Genes pathway analysis revealed that BRCA2 and FBN1 were significantly downregulated in Fanconi anemia (FA) and TGF-ß signaling pathways in W100, validated through quantitative real-time PCR (qRT-PCR). In conclusion, significant age-related variations in albumen quality, and magnum morphology are regulated by proteins involved in antioxidant capacity.

Albumen exosomes alleviate LPS-induced inflammation of intestinal epithelial cells via miR-22/ATM/p53/NF-κB axis.

Biological macromolecules identified in albumen were found benefit to intestinal health, whether albumen contains exosomes and function of their cargos in intestinal inflammation remain unknown. This study aimed to investigate characteristics and cargos of albumen exosomes, as well as their potential roles in alleviating inflammation in intestinal epithelial cells. Our results demonstrated that albumen contains exosomes that are cup-shaped morphology vesicles with diameter ranging from 50 to 200 nm. There were 278 miRNAs and 45 proteins with higher expression levels in albumen exosomes, and they were mainly involved in immune responses and programmed cell death pathways, including apoptosis and p53 signaling pathway. LPS induced overexpression of pro-inflammatory cytokines IL-1ß and TNF-α and excessive apoptosis, which could be reversed by albumen exosomes. The beneficial effects of exosomes could be mainly attributed to miRNA cargos and their inhibition on inflammatory response signaling pathways (p53 and NF-κB pathways). Mechanically, exosome miR-22 targeted ATM and inhibited p53/NF-κB pathway, alleviating LPS-induced overexpression of Caspase-3 and Bax, and inflammatory response. Collectively, albumen exosomes alleviate inflammation of intestinal epithelial cells via miR-22/ATM/p53/NF-κB axis and these findings may provide theoretical basis to the potential application of albumen exosomes for intestinal inflammation.

Albumen and Yolk Plasma Peptidomics for the Identification and Quantitation of Bioactive Molecules and the Quality Control of Hen Egg Products.

Hen eggs and the corresponding food products are essential components of human diet. In addition to supplying basic nutrients, they contain functional peptides that are released in vivo within the intact raw material following physiological proteolytic events affecting specific proteins or derive from technological processing of albumen and yolk fractions as a result of the dedicated use of proteases from plant and microbial sources. Besides their potential importance for functional applications, peptides released under physiological conditions in intact egg can be used as markers of product storage and deterioration. Therefore, characterization and quantitation of peptides in egg and egg-derived products can be used to implement evaluation of potential bioactivities as well as to assess food product qualitative characteristics. Here, we provide dedicated information on extraction, identification, and quantitative analysis of peptides from albumen and yolk plasma; nano-liquid chromatography-mass spectrometry combined with bioinformatic analysis of resulting raw data by different software tools allowed to assign molecules based on database searching and to evaluate their relative quantity in different samples.

The effects of nontoxic bio-based substances (egg white) on the performance and passivation of ZnO nanorods arrays-based light emitting devices.

An innovative approach is proposed to passivate the existing defects from metal oxide semiconductors by functionalizing nontoxic bio-based substances. As a demonstration, we synthesized zinc oxide nanorods (ZnO NRs) using a hydrothermal method and incorporated chicken egg white (albumen) as a passivator to the defects. X-ray diffraction analysis of ZnO NRs shows enhanced quality and crystallinity features after incorporating albumen. XPS measurements were performed not only to introduce the chemical bonding between the albumen and the bare ZnO NRs but also specifically provide evidence of successful capping and defect passivation to the surface layer of ZnO NRs. It was observed that when the albumen was annealed, it formed sulfhydryl groups and disulfide bonds (which created disulfide bridges) from the chemical reaction in irreversible thermal denaturation. Steady-state photoluminescence of ZnO NRs showed two emission bands, i.e. near band-edge emission (NBE) and deep-level emission (DL). The NBE is significantly improved as compared to DL emission after capping and annealing the albumen, while the quenching of DL emission confirmed the reduced defects arising from the surface of ZnO NRs. The advantages and enhanced characteristics of the albumen-capped ZnO NRs led to fabricating a stable and highly efficient light-emitting device. This work opens the great potential of utilizing nontoxic and low-cost biomaterials in passivating the defects of metal oxide nanomaterials for the development of bio-inspired and stable optoelectronic devices.

Evaluation of Metal Partitioning across Humboldt Penguin (Spheniscus humboldti) Egg Components.

Humboldt Penguin (Spheniscus humboldti) population declines are attributable to several multifaceted anthropogenic impacts. At present, the exposure of Humboldt Penguins to high concentrations of heavy metals in the marine environment is a preeminent concern, due to mining along the Peruvian coast near key rookery sites. Metal and selenium concentrations were determined in eggs collected from September 2020 to April 2021 from a managed-care penguin population at the Brookfield Zoo to establish reference values for health indices conducted on wild populations. Concentrations of 16 elements, with emphasis on those found in mine efflux-arsenic, cadmium, copper, lead, mercury, selenium, and zinc-were assessed via inductively coupled plasma mass spectrometry in yolk, albumen, and eggshell. Data analyses indicate a clear delineation between egg constituents, with lipid-rich yolk displaying notably higher concentrations (µg/g) of arsenic (0.20 ± 0.064), chromium (0.086 ± 0.03), cobalt (0.01 ± 0.003), iron (238.65 ± 54.72), lead (0.32 ± 0.97), manganese (2.71 ± 0.66), molybdenum (0.57 ± 0.14), tin (3.29 ± 0.99), and zinc (64.03 ± 13.01) than other components (albumen and eggshell). These data confirm that heavy metals are partitioned differently across Humboldt Penguin egg components, which provides insight into the potential connection between embryonic nutrient source contamination and subsequent chick viability.

The effect of solution plasma treatment on the microbial safety and quality characteristics of albumen.

The aim of this study was to make eggs microbially safe and increase their durability without damaging the functional properties of the albumen and preserving the solubility of its proteins as much as possible by the solution plasma technique. The pH, Brix, density, and viscosity values of samples decreased during treatment (p < .05 except pH). Although the L* and a* values of both the albumen and egg foam decreased, the b*, hue angle, and chroma values of both increased during treatment. The L* and a* values of the albumen decreased by 7.01 and 1.89 units, and the values of the egg foam decreased by 10.93 and 1.03 units, respectively. At the end of the treatment, foaming capacity and foam stability were decreased by 25% and 21.42%, respectively. Foaming capacity values obtained as a result of this treatment were higher and foam stability values were lower compared to the values obtained in pasteurization of eggs by heat treatment. The count of the two pathogenic bacteria inoculated into the albumen decreased during the treatment (p < .05), the count of Salmonella Enteritidis decreased to 0, and the count of Staphylococcus aureus decreased by 1.09 log cfu/g at the end of the treatment. Compared to current heat treatments, solution plasma treatment caused significantly less adverse effects on albumen quality characteristics. In particular, the foaming properties of the albumen were much less affected by this method and remained at higher values compared to the values achieved by other methods. The treatment also produced a microbiologically safer product.

Enterococcus cecorum lesion strains are less sensitive to the hostile environment of albumen and more resistant to lysozyme compared to cloaca strains.

RESEARCH HIGHLIGHTS: Egg albumen inhibits Enterococcus cecorum cloaca strains more than lesion strains.Enterococcus cecorum lesion strains are resistant to high concentrations of lysozyme.Lysozyme resistance could enhance survival in albumen and body fluids.

The physicochemical features of eggshell, thick albumen, amniotic fluid, and yolk during chicken embryogenesis.

The study aimed to analyze the hatching egg and physiochemical features of eggshells, thick albumen, amniotic fluid, and yolk during the incubation of Ross 308 chicken eggs. Eggs (n = 755) were incubated for 21 d. Quality analysis of fresh eggs was performed. Eggshells, albumen, and yolk were collected from fresh eggs and incubation d 1, 7, and 14. Eggshell thickness and strength, pH, vitelline membrane strength, fatty acid (FA) in the yolk, pH, viscosity, lysozyme activity, and crude protein content in thick albumen and amniotic fluid were analyzed. Hatching parameters were calculated. Egg weight loss was constant (8.04% overall). Lower egg surface temperature was found on d 7 compared to d 4, 14, and 18. A lower thickness of posthatch eggshells was found. The strength of the vitelline membrane significantly decreased within 24 h (by over 58%). During incubation, there was a decrease in thick albumen/amniotic fluid pH; an opposite trend was found in yolk pH. The vitelline membrane strength was negatively correlated with the albumen pH. Lysozyme activity was higher in fresh thick albumen and up to 2 wk of incubation. On d 7, the lowest activity was found in the amniotic fluid. On d 14, lysozyme activity increased in amniotic fluid. The higher viscosity of the thick albumen was demonstrated on d 7 and 14 of incubation. The lowest viscosity in amniotic fluid was found on the same days. Crude protein content was higher in thick albumen (d 7 and 14) and lowest in amniotic fluid on d 7. The FA content changed between d 0 and 14. The results indicate different use of FA, where PUFA decreased. Eggshell is used in the last week of incubation. The thick albumen is reduced, while the biological value of amniotic fluid is increasing. Lysozyme activity, viscosity, and crude protein content may be interdependent. It may indicate the flow of substances and the transfer of functions from the thick albumen to the amniotic fluid during chicken embryogenesis.

The effect of theabrownins on the amino acid composition and antioxidant properties of hen eggs.

Pu-erh tea theabrownins (TBs) exert beneficial effect on egg quality and antioxidant properties of eggs, but the underlying mechanisms behind this response are unclear. In this study, we investigate the effect of TBs on egg antioxidative activity, amino acid and fatty acid profiles, and the underlying relationship between the TBs and oxidant-sensitive Nrf2 signaling pathway in laying hens. Eighty layers were fed a basal diet (control) and 400 mg/kg of TBs supplemented diet for 12 wk. TBs led to an increase in albumen height and Haugh unit (P < 0.05). The albumen lysine, valine, and tryptophan were higher in layers fed TBs, whereas yolk tryptophan, methionine, vitamin A, and α-tocopherol content were enhanced by TBs (P < 0.05). Eggs albumen and yolk showed higher total antioxidant capacity (T-AOC), reducing power (RP), and the scavenging rate of 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH), and lower MDA content than those of eggs from the control group (P < 0.05). Also, magnum Nrf2, hemeoxygenase 1 (HO-1), NAD(P)H quinone dehydrogenase 1 (NQO1), and Bcl2 expression were up-regulated by TBs, whereas magnum proapoptotic gene (Bax, caspase 3, Cyt C) were down-regulated by TBs (P < 0.05). Our findings suggest that TBs improved egg albumen quality and antioxidant activity, and the Nrf2-ARE pathway were found to be involved in this process.

Influence of non-ventilating intervals during early incubation stage on egg hatching process.

Background and Aim: The exchange of oxygen and carbon dioxide (CO2) in the incubator plays a key role in embryonic development and hatching. This study aimed to study the effect of non-ventilated (NV) intervals during the early stage of embryonic development on the hatching process. Materials and Methods: Hatching eggs (n = 7200) were equally divided into four treatment groups and incubated in four incubators. The first group was incubated in normal ventilated condition (V) during the setting phase of incubation. Ventilation holes of the three remaining incubators were closed for the first 3, 6, and 9 days and termed as NV groups (NV1, NV2, and NV3, respectively). A gradual increase in CO2 was allowed for NV groups, followed by opening the incubator holes to permit ventilation throughout the rest of the incubation periods. Results: Obtained results demonstrated that CO2 concentration gradually increased up to 0.19% for the NV1 group, 0.41% for the NV2 group, and 0.90% for the NV3 group, while CO2 concentration remained at 0.08% during the first 9 days of incubation in the V group. Albumen pH was lowered for all NV groups. The highest hatchability percentage was recorded for NV3 followed by NV2 and NV1 groups. All NV groups represented earlier and narrower spread of hatch and higher hatched chick weight. Embryos and hatched chicks in the NV groups had higher hormonal levels of thyroxin and corticosterone. Conclusion: All non-ventilation periods had positive effects on narrowing the spread of hatch, increasing hatched chick weight and hatchability percentage compared to the normal V condition. Furthermore, the non-ventilation throughout the first 9 days of incubation yielded the best hatching results.

Effect of restricted feeding on hen performance, egg quality and organ characteristics of individual laying hens.

This study was to assess the impact of permanent or temporary restricted feeding on laying hen production traits, physiology, and egg quality. Two hundred and forty individually housed ISA Brown hens were monitored across 2 phases, assigned to 3 treatments: ad libitum feeding (ALF), temporary restricted feeding (TRF) and permanent restricted feeding (PRF), n = 80 hens per treatment. In Phase 1 (P1), 22 to 40 weeks, the TRF and PRF hens were offered 115 g of feed daily. In Phase 2 (P2), 41 to 46 weeks, the TRF hens were transitioned to ALF status while the ALF and PRF hens remained as in P1. From 35 to 40 weeks, eggs were collected once weekly from 15 hens per treatment and assessed for differences in albumen, yolk, and shell variables. At 45 weeks, 10 hens each from the ALF and PRF groups were euthanized and differences in organ characteristics were assessed. In P1, feed intake, feed to egg conversion ratio and body weight (BW) change were lower (P < 0.01), while albumen height and Haugh unit were higher (P < 0.01) in both PRF and TRF hen treatments compared to hens allocated the ALF treatment. In P2, TRF and ALF hens had a higher egg production and egg mass than PRF (P < 0.01) than ALF. Body weight change in P2 was higher in TRF and similar in both ALF and PRF, while feed intake and feed conversion ratio were higher in TRF followed by ALF and least in the PRF treatment group (P < 0.01). At 45 weeks ALF hens had a greater abdominal fat pad weight and fatty liver haemorrhagic syndrome lesion score compared to PRF. Restricting hens to 115 g of feed per day from point of lay restrained BW, improved feed conversion ratio and albumen quality and reduced abdominal fat pad deposition and clinical signs of fatty liver haemorrhagic syndrome in individually housed laying hens.

A Novel Approach for the Production of Mildly Salted Duck Egg Using Ozonized Brine Salting.

Salted eggs are normally produced by treating fresh duck eggs with a high salt concentration in order to acquire distinctive features and excellent preservation capabilities as a result of a series of physicochemical changes. This method, however, induces a high salt content in the product. The goal of this research was to create a new way of producing mildly salted duck eggs using ozonized brine salting. The brine was made by dissolving NaCl (26% w/v) in water or ozonized water at a concentration of 50 ng ozone/mL (ozonized brine). Compared to brine, ozonized brine resulted in salted eggs with reduced ultimate salt levels in both albumen and yolk (p < 0.05). The Haugh unit of the salted eggs generated by ozonized brine was similar to that of the brine-made salted egg group (p > 0.05), but the salted egg produced by ozonized brine matured and solidified faster because the yolk index (0.62) was higher than that of the brine (0.55) (p < 0.05). The final pH of salted eggs generated with brine and ozonized brine was not different (p > 0.05). Regardless of the salting method, both salted eggs contained low TVB-N content (<10 mg/100 g). Ozonized brine increased the protein carbonyl content in salted albumen, which may be related to albumen protein aggregation and served as a salt diffusion barrier. However, after boiling the salted egg, the protein carbonyl level was comparable to that of fresh albumen. The TBARS levels of boiled salted albumen prepared with brine and ozonized brine were comparable (p > 0.05), and the value was extremely low (~0.1 mg MDA equivalent/kg). The TBARS value of the salted yolk prepared with brine was higher than that of the salted yolk prepared with ozonized brine (p < 0.05), and both salted yolks showed increased TBARS values after cooking (p < 0.05). The albumen and yolk components appeared to be altered similarly by both brine and ozonized brine, according to the FTIR spectra. Furthermore, the appearance and color of the yolk and albumen in salted eggs prepared with brine and ozonized brine were comparable. Boiled salted albumen produced with ozonized brine had a denser structure with fewer voids. This could be attributed to the final salted egg's lower salt content and lower salt diffusion rate, which were likely caused by protein oxidation and, as a result, aggregation when ozonized brine was used.

Effects of cadmium, lead, mercury, chromium, and selenium co-treatment on egg quality and fatty acids.

This study aimed to reveal the effect of selenium (Se) and heavy metals (chromium (Cr), cadmium (Cd), lead (Pb), and mercury (Hg)) on the quality, fatty acids, and 13 kinds of ions in the egg yolk and albumen. Four experimental groups were established, including a control group (control; basal diet), Se group (basal diet + Se), heavy metals group (basal diet + CdCl2 + Pb(NO3)2 + HgCl2 + CrCl3), and Se + heavy metal (HM) group (basal diet + Se + CdCl2 + Pb(NO3)2 + HgCl2 + CrCl3). Se supplementation significantly increased the experimental egg yolk percentage since Se accumulation mainly occurred in the yolks of the eggs. The Cr content in the yolks of the Se + heavy metal groups decreased at 28 days, while a significant reduction was evident in the Cd and Hg levels of the Se + heavy metal yolks compared to the heavy metal group at 84 days. The complex interactions between the elements were analyzed to determine the positive and negative correlations. Se displayed a high positive correlation with Cd and Pb in the yolk and albumen, while the heavy metals minimally affected the fatty acids in the egg yolk.

The biological value of hatching eggs of broiler chicken in the early-mid incubation period based on physicochemical and morphologic features.

The study aimed to assess various quality characteristics (physical, morphologic, mechanical) of hatching eggs during the early-mid incubation period. Hatching eggs (1,200) were bought from a broiler Ross 308 breeder flock. Before incubation, 20 eggs were analyzed for dimensions and morphologic composition. Eggs (1,176) were incubated for 21 d. Hatchability was analyzed. On d 1, 2, 4, 6, 8, 10, and 12, eggs were collected (n = 20). The eggshell surface temperature and water loss were measured. The eggshell strength and thickness and the vitelline membrane strength were analyzed. The pH of thick albumen, amniotic fluid, and yolk were determined. The viscosity and lysozyme activity were studied for the thick albumen and amniotic fluid. Water loss was proportional and significantly different between incubation days. The yolk vitelline membrane strength highly depended on incubation days, decreasing steadily within the first 2 d (R2 = 0.9643). The albumen pH decreased from d 4 till d 12 of incubation, whereas the yolk pH first increased from d 0 to d 2 before a decline on d 4. Albumen viscosity was highest on d 6. There was a strong dependence of viscosity decrease with increasing shear rate (R2 = 0.7976). On the first day of incubation, the highest lysozyme hydrolytic activity was demonstrated (33,790 U/mL) compared to the activity from the amniotic fluid (8-12 d). From d 6, lysozyme activity decreased to 70 U/mL (d 10). On d 12, amniotic fluid lysozyme activity increased by over 6,000 U/mL compared to d 10. The lysozyme hydrolytic activity was lower in the amniotic fluid (d 8-12) compared to the thick albumen (0-6 d) (P < 0.001). The embryo's protective barriers are changed, and the fractions are hydrated during incubation. It could be concluded that the lysozyme is transferred from the albumen to the amniotic fluid due to its activity.

Combined Effect of Feed and Housing System Affects Free Amino Acid Content of Egg Yolk and Albumen in Brown Layer Chickens.

In recent years, the market share for cage-free eggs has gradually increased. Because commercially available cage-free eggs are often produced not only by several housing systems but also with different feed crude protein (CP) levels, there are combined effects of feed and housing systems between cage-free and cage eggs. Therefore, using field data, this study aimed to determine the combined effects of feed and housing systems on egg traits and yolk and albumen amino acids in table eggs. Brown layers (n = 40) at the middle laying stage under two feed and housing systems (cage, CP 15.5% diet; barn, CP 17.0% diet) were used. One-way analysis of variance and Pearson's correlation analysis were used to evaluate 10 egg traits, 19 yolk amino acid traits, and 20 albumen amino acid traits. We observed significant effects of feed and housing on two egg traits (yolk weight and eggshell color redness), 16 yolk amino acids (Asp, Glu, Asn, Ser, Gln, His, Arg, Thr, Ala, Tyr, Met, Cys, Ile, Leu, Phe, and Lys), and 14 albumen amino acids (Asp, Asn, Ser, Gln, Gly, His, Arg, Thr, Ala, Val, Met, Cys, Ile, and Leu). This study revealed that eggs from the barn system (CP 17.0%) contained higher levels of free amino acids in 15 yolk and nine albumen amino acid traits. Phenotypic correlations among the 49 egg traits indicated similar correlation patterns in both systems, which implies that the balance of free amino acid content in yolk and albumen is similar in each system. Although some potential confounding factors may be present for comparing egg content between cage (CP 15.5%) and barn (CP 17.0%) systems, this study suggests that commercially available cage-free eggs may be different from cage eggs not only in external egg traits but also yolk and albumen amino acid traits.