Egg White Research Articles

Egg White Diet Induces Severe Allergic Enteritis in an Animal Model Driven by Caspase-3 and Gasdermin C-Mediated Mucosal Alarmin Secretion.

Allergic enteritis is an important phenotype of food allergies. However, there is not a suitable animal model for deeply exploring the natural progression and mechanism of allergic enteritis. In our study, we successfully developed an allergic enteritis animal model by feeding mice with an egg white diet. Following the dietary challenge, allergic mice displayed typical food allergy manifestations, including decreased core temperature, aversion to the allergenic diet, and elevated levels of serum sIgE and mMCP-1. Notably, these dietary challenged mice exhibited severe gut damage, characterized by disrupted intestinal microstructure, tissue inflammation, and edema that were evident morphologically. Moreover, upon exposure to food allergens, we observed a marked increase in caspase-3 and GSDMC levels in allergic mice. These two active proteins were found to be colocalized in damaged mucosal enterocytes and were associated with the secretion of epithelial sourced alarmins, such as IL25 and TSLP. Further data on the cellular and molecular levels suggest that such severe food-induced enteritis is mediated by the caspase-3-GSDMC pathway. We believe that this established animal model provides a valuable tool for advancing research on the mechanisms of food allergies.

Characterization and Evaluation of Taihe Black-Boned Silky Fowl Eggs Based on Physical Properties, Nutritive Values, and Flavor Profiles.

Taihe black-boned silky fowl (TS) is a native chicken breed in China with more than 2000 years of history. The present study aimed to characterize and evaluate the physical, nutritional, and flavor properties of TS eggs with a comparison to two other commercial breeds. Eggs from TS (n = 60) crossbred black-boned silky fowl (CB, n = 60) and Hy-line Brown (HL, n = 60) were used for physicochemical analysis. The evaluation system was divided into four parts based on nutrient and flavor profiles: protein and amino acids, lipids and fatty acids, mineral elements, and flavor-related amino acids and volatile compounds. Results showed that TS eggs were typically associated with the lowest egg weight and the highest yolk color, as compared with CB and HL eggs. No differences were found in crude protein, crude fat, triglycerides, and cholesterol content between eggs from the different breeds, but these eggs were distinct in terms of the amino acid, fatty acid, and volatile flavor compound profiles. Moreover, the differences in amino acid and fatty acid profiles might contribute to the specific flavor of TS eggs. Evaluation results indicated that TS egg whites may be suitable as a protein source for premature infants and young children under three years old and TS egg yolks could be considered a beneficial dietary lipid source due to their potential anti-cardiovascular properties. Additionally, TS whole eggs could serve as a valuable source of selenium (Se), molybdenum (Mo), zinc (Zn), and phosphorus (P) for adults aged 18 to 65. However, TS and CB eggs showed inferior Haugh units, eggshell quality, and essential amino acid compositions for older children, adolescents, and adults. These findings provide a better insight into the health benefits of TS eggs and contribute to the breeding and nutrition regulation of TS breeds.

Determination of Plasmalogen Molecular Species in Hen Eggs

(1) Background: Plasmalogens are vinyl ether-type glycerophospholipids that are characteristically distributed in neural tissues and are significantly reduced in the brains of individuals with dementia compared to those in healthy subjects, suggesting a link between plasmalogen deficiency and cognitive decline. Hen eggs are expected to be a potential source of dietary plasmalogens, but the details remain unclear. (2) Methods: We evaluated the fresh weight, dry weight, total lipid, neutral lipids, glycolipids, and phospholipids in the egg yolk and egg white of hen egg. Then, the molecular species of plasmalogens were quantified using HPLC-ESI-MS/MS. (3) Results: In egg yolk, the total plasmalogen content was 1292.1 µg/100 g fresh weight and predominantly ethanolamine plasmalogens (PE-Pls), specifically 18:0/22:6-PE-Pls, which made up 75.6 wt% of the total plasmalogen. In egg white, the plasmalogen content was 31.4 µg/100 g fresh weight and predominantly PE-Pls, specifically 18:0/20:4-PE-Pls, which made up 49.6 wt% of the total plasmalogen. (4) Conclusions: Plasmalogens were found to be more enriched in egg yolk than in egg white. It was found that humans are likely to ingest almost 0.3 mg of total plasmalogens from one hen egg. These findings highlight the importance of plasmalogens in the daily diet, and it is recommended to explore the impact of long-term dietary plasmalogen intake to assess its effect on human health. This provides a viewpoint for the development of new food products.

Effect of the Addition of Egg White and Maltodextrin on the Characteristics of Dayak Onion Powder (Eleutherine palmifolia) by Foam Mat Drying Method

Dayak onion is a plant that has antioxidant content and chemical components that can be used as spices, flavor enhancers, fragrances, and food preservatives whose use is limited. Dayak onions that are easily damaged are processed into powder to make them more durable. The manufacture of powder products is carried out using the foam mat drying method with the addition of foaming agent, namely egg white, and foam stabilizer, namely maltodextrin. This study aims to determine the effect of the addition of egg whites and maltodextrin on the physicochemical and organoleptic characteristics of Dayak onion powder by the foam mat drying method. This study used a two-factor Complete Random Design (CRD) with three replicates. The observation data was processed using ANOVA at a confidence level of 5%, if there is a significant influence, a further DMRT test of 5% is carried out. The results showed that there was a significant interaction between the addition of egg white and maltodextrin in different moisture content, phenol content, and solubility. The best treatment was obtained with the addition of 8% egg white and 15% maltodextrin with 7.32% moisture content; 2.11% ash content; 51.08% antioxidant activity; 3.37 mg GAE/g phenol content; 46.65% solubility; 54.03 L; 21.00 a*; 11.43 b*; and color hedonic score 3.96 (quite red); aroma hedonic score 3.36 (slightly scented of Dayak onions); texture hedonic score 2.92 (slightly rough); 0.01% flavonoid content; and 9.35 ppm anthocyanin content.

Improving egg quality in laying hens using calcium salt of black soldier fly larvae oil

Abstract Black soldier fly larvae (BSFL) oil has gained attention as a potential substitute for vegetable oil in feed formulations designed to improve productivity and product quality. This study aimed to investigate the impact of supplementation BSFL oil calcium salt (BSFLO-SCa) on the egg quality and gene expression involved in fat metabolism in laying hens. A total of sixty 40-wk-old ISA Brown laying hens were divided into three distinct groups: a control group (T0) that received a basic diet, and two treatment groups that were supplemented with 1% (T1) and 2% (T2) BSFLO-SCa. Each group consisted of 5 replicates, with 4 laying hens per replicate. The study indicated that the inclusion of 2% of BSFLO-SCa significantly increased egg albumen weight, height, ratio, eggshell weight, and thickness (). The inclusion of 1 and 2% of BSFLO-SCa increased the yolk lightness (L*) and yellowness (b*), but redness (a*) was decreased (). Moreover, BSFLO-SCa supplementation with 1 and 2% reduced () egg fat and cholesterol. Analysis of fatty acid profiles showed significantly increased medium-chain fatty acid (MCFA) and polyunsaturated fatty acid (PUFA) (), while monosaturated fatty acid (MUFA) reduced () with 2% BSFLO-SCa. Gene expression related to lipid metabolism, such as fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC), as well as cholesterol synthesis gene expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) were downregulated (). In conclusion, the inclusion of 2% BSFLO-SCa in the diet improved quality and reduced fat and cholesterol content in eggs from laying hens. This improvement was accompanied by downregulation of key genes involved in lipid metabolism.

Enhanced gelation of sturgeon frozen surimi via egg white: Exploring the role of endogenous serine protease inhibition

AbstractThe degradation of frozen sturgeon surimi can be attributed to the endogenous serine protease. This study was first to examine the impact of egg whites on the frozen sturgeon surimi's gel properties from the perspective of inhibiting endogenous serine protease. The protease activity of egg whites group (CA + EW group, consisting of 4% egg whites and cryoprotectants) was 45.15% lower than that of cryoprotectants group (CA group, consisting of 3% sucrose, 3% sorbitol, and 0.3% sodium tripolyphosphate) at 12 weeks. From the results of inhibition kinetics, serine protease was inhibited by both anticompetitive and noncompetitive inhibition modes. Molecular docking analysis indicated that egg white achieves this inhibitory effect through ionic interactions and hydrogen bonding with serine protease. However, this inhibitory effect was absent when the freezing period was extended to 24 weeks. Compared with CA group, the CA + EW group exhibited 54.76% and 4.59% increase in gel strength and water‐holding capacity, and 32.42% reduction in cooking loss after 24 weeks of freezing. Egg whites also impeded water migration and enhanced the density and smoothness of the gel microstructure, reducing protein aggregation. These results indicated that egg whites serve a dual function: inhibiting serine protease and filling the gel network within 12 weeks, mitigating protein aggregation and ice crystal formation over 24 weeks. This study elucidated the mechanism underlying the impact of egg white on endogenous serine protease in sturgeon surimi during long‐term freezing, laying a theoretical foundation for the industrialization of sturgeon surimi.

Lactic acid bacteria fermentation-induced egg white protein structure deformation influencing gelling properties, with membrane concentration as a strategy to improve texture.

Egg white (EW), a rich protein source, holds promise for creating a high-protein, low-fat gel product. However, browning issues during heating and sterilization have hindered its wider application. In this study, lactic acid bacteria fermentation was employed to eliminate reducing sugar in EW, and its impact on the molecular structure and gelling properties was explored. The results revealed that fermentation would trigger protein structural unfolding and aggregation, evident from higher fluorescence intensity and enlarged protein particle diameters, resulting in the decrease in gelling hardness. In comparison, Streptococcus thermophilus-fermented EW (under 6×108CFU/mL incubation rate, fermented for 6h) exhibited the highest gel hardness, ascribed to the relatively weaker structure transformation, with high water holding capacity and stronger intermolecular hydrophobic interaction. To further enhance the gelling properties of fermented EW, membrane concentration treatment was applied, exhibiting superior characteristics in appearance, aroma, and taste. In summary, lactic acid bacteria fermentation and concentration are feasible solutions to improve appearance and texture of EW gels simultaneously. The research findings offer eco-friendly and practical strategies for enhancing the quality of EW gels, providing valuable theoretical insights for the development of innovative, texture-rich, and healthy nutritional foods.

The improvement of gel properties and volatiles for frozen egg white melted assisted with ultrasound

The variation in thawing time, deterioration behavior, secondary structure, surface hydrophobicity, and average particle size of frozen egg whites (EW) thawed with or without ultrasound were characterized to evaluate the effect of ultrasound on the gel properties and volatiles of egg white thermogel (EWG). The texture, water holding capacity, etc., gel properties and microstructure were well maintained in frozen EW thawed by ultrasound (UEW) resulted from the mitigation of deterioration behavior due to shorter melting time (reduced 91.3 %). Moreover, the deterioration of VOCs in fresh EWG due to freeze-thawing could be mitigated when thawed using ultrasound. Meanwhile, the formation of pleasant VOCs and reduction in unpleasant VOCs in EWG were also promoted by ultrasound-assisted thawing. The improvement mechanism of gel properties and volatiles for (frozen) egg white melted assisted with ultrasound were systematically elucidated and this study provided a new insight into improvement of VOCs in frozen food.

Enhanced activation of signaling pathway by recombinant human adiponectin from genome-edited chickens

Adiponectin (ADPN) exerts various cellular and metabolic functions by activating signaling pathways, including extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) pathways, the protein kinase B (Akt) pathway, and the p38 mitogen-activated protein kinase (MAPK) pathway. However, generating functional recombinant human adiponectin (hADPN) in bacterial or mammalian cells is challenging. Although ADPN agonist peptides have been developed, problems like stability, solubility, and affinity for receptors remain. Recently, a genome-edited chicken bioreactor system was established, ensuring efficient ADPN production with optimal post-transcriptional modifications. We assessed the ability of egg white (EW)-derived hADPN, commercial hADPN, various ADPN agonist peptides, and globular ADPN on activation of the ERK1/2, Akt, and p38 MAPK pathways. EW-derived hADPN, abundant in hexamers and high molecular weight multimers, significantly phosphorylated ERK1/2 in serum-starved HEK293 cells after 15 min of treatment. Comparative analysis revealed that EW-derived hADPN and commercial hADPN induced greater phosphorylation of ERK1/2, Akt, and p38 MAPK than ADPN agonist peptides and globular ADPN, with EW-derived hADPN showing the highest activation. In summary, the finding that EW-derived hADPN strongly activates the ERK1/2, Akt, p38 MAPK signaling pathways highlights that an ADPN production system based on genome-edited chickens is an advantageous alternative to existing methods.

Construction of mixed gels of yolk granules and salted ovalbumin driven by pH: phase behavior and calcium bioaccessibility

Mixed gels of egg yolk granules (EYGs) and salted ovalbumin (SO) with different pH values were constructed to design gels of great quality and nutritional properties. However, the formation and dietary properties of mixed gels may be affected by the phase behavior of the mixed protein solution. In this study, the pH was adjusted from 3.0 to 8.0 to tune phase behavior of mixed protein solution before heating. The results demonstrated the presence of a collapsed gel and a dense phase network at pH 3.0 caused by phase separation. As the pH increased and phase separation disappeared, the EYGs-SO gel network showed a filling network structure and then changed to a loose interpenetrating network gel structure with a decreased fractal dimension (from 2.94% to 2.89%). The interpenetrating network improved gel hardness and water-holding capacity. During gelation, the phase separation reduced the gelation transition temperature. The main forces that support EYGs-SO gel were hydrogen and disulfide bonds. Moreover, EYGs-SO showed greater calcium bioaccessibility (7.85%–8.08%) at pH 3.0, 4.0, and 5.0. In summary, the phase behavior in mixed solution modulates the gelation of mixed gels. The construction of mixed gels also provides ideas and strategies for the value-added utilization of salted egg whites.

Application of Recombinant Monoclonal Antibodies from Transgenic Chicken Bioreactors in Enzyme-Linked Immunosorbent Assay.

Transgenic chicken bioreactors can efficiently produce egg whites containing large quantities of recombinant proteins. We previously developed transgenic chickens that produce recombinant monoclonal antibodies (mAbs) against epidermal growth factor receptor 2 (HER2). However, the practical applications of mAbs derived from transgenic eggs have not yet been examined. Therefore, we aimed to evaluate whether these recombinant mAbs can be used in enzyme-linked immunosorbent assay (ELISA). Recombinant HER2 mAbs from transgenic eggs were dissolved in phosphate-buffered saline and applied directly to 96-well microplates as immobilized antibodies without purification. The performance of ELISA using the unpurified recombinant HER2 mAbs from transgenic eggs was comparable to that of ELISA using commercially available purified recombinant HER2 mAbs. Moreover, ELISA using unpurified recombinant HER2 mAbs from transgenic eggs demonstrated high antigen specificity and was successfully applied to samples from cultured cell lysates derived from HER2-positive and HER2-negative cell lines. The unpurified recombinant HER2 mAbs from transgenic eggs were also efficiently used as immobilized antibodies in paper-based ELISA. In conclusion, our findings suggest that recombinant mAbs from transgenic eggs have the potential to be used to develop economic ELISA devices. To the best of our knowledge, this study is the first to use recombinant HER2 mAbs from transgenic eggs in ELISA.

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 Şanlıurfa 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.

Optimizing nitrite content in powders from plasma-activated egg whites for meat preservation using response surface methodology

The study optimized the production of powders from two types of egg whites to be used as a nitrite source for meat curing, establishing a maximum utilization limit of 2%. The necessary quantity of nitrite was established through response surface methodology to guarantee its efficacy as a preservative agent and adherence to regulatory standards. High R2 values (0.9946 for hen, 0.9962 for ostrich) validated critical factors: plasma treatment time and distance, with minimal impact from drying temperature. Under specific experimental conditions (155.93 min, 16.84 cm, 41.10 °C), obtained nitrite concentration of 4000 mg kg⁻1 was confirmed through experiments. Stability tests showed that nitrite levels remained stable over four weeks under different conditions including vacuum and air-sealed packaging, as well as different temperatures (−18 °C, 4 °C, and 26 °C). Future research should investigate long-term stability, the formation of additional compounds, and the functional properties of powders to confirm their potential for food applications.

Differentiation of Exotic Chicken Breeds based on Egg Quality Traits using Classification Tree Algorithm

This study aimed to evaluate the effect of breed on egg quality traits and to discriminate chicken breeds (i.e., Bovan Brouwn (BV), Fayoumi (FM) and Sasso (SS)) based on egg quality traits using classification tree algorithm (CTA). For this purpose, a total of 1696 eggs were utilized and the traits egg weight, albumen height, albumen weight, egg length, egg width, egg weight, shell weight, shell thickness, yolk colour, yolk height and yolk weight, were recorded. Significant differences (P<0.05) were found in egg weight, albumen height, albumen weight, and egg width, with Bovans exhibiting the highest LSM values, indicating superior egg quality

Formation mechanism and stability of egg white fluid gels under ultrahigh-pressure homogenization pretreatment and synergistic heating effect

The thermal sterilization process of protein beverages inevitably leads to the formation of insoluble thermal aggregates, greatly reducing the texture and taste of protein beverages. In this study, homogenized egg white (HEW) was obtained by ultrahigh-high-pressure (UHP) homogenization pretreatment of egg white (EW), and then a special egg white fluid gel (EWFG) was prepared by water bath heating. The results showed that the optimal conditions for preparing EWFG were three cycles at 20 MPa homogenizing pressure and heating in a water bath at 72℃ for 10 min. Under these conditions, the EWFG was a milky-white homogeneous liquid with an average particle size of about 560 nm. Measurements of the physicochemical properties of HEW and EWFG showed that the UHP homogenization treatment reduced the viscosity of HEW, decreased the particle size of protein aggregates, and increased the zeta potential, which altered the interactions of proteins during the subsequent heating process and facilitated the formation of homogeneous and dispersed EWFG. EWFG showed good stability at pH 6–10 and in low-concentration saline and medium-concentration sucrose solutions. The EWFG obtained by the present treatment is more suitable for factory-scale production and has great potential for protein beverage applications.

Fermented blueberry pomace supplementation improves egg quality, liver synthesis, and ovary antioxidant capacity of laying hens

The present study aimed to investigate the effects of dietary fermented blueberry pomace (FBP) supplementation on production performance, egg quality and nutritional value, plasma biochemical parameters, follicle number, reproductive hormones, lipid metabolism, and antioxidant capacity of laying hens during the late laying period. A total of 320 (345-d-old) Yukou Jingfen No. 8 laying hens were randomly divided into 4 groups, with eight replicates per group and 10 hens per replicate. The birds were fed a basal diet (control group) and a basal diet supplemented with 0.25, 0.5, and 1.0% FBP. The trial lasted 56 d. The results showed that FBP (0.25-1.0%) supplementation increased the egg albumen height and Haugh unit compared with the control group on d 14, while 0.5 to 1.0% FBP increased the eggshell thickness compared with the 0.25% FBP group on d 28 of the trial (P < 0.05). The methionine content in egg white was higher (P < 0.05) in the 1.0% FBP group compared with the 0.25% FBP group. The CAT activity in the ovary was increased (P < 0.05) in the FBP groups compared with the control group, while plasma GSH-PX activity was higher (P < 0.05) in the 1.0% FBP group compared with the 0.25% FBP and 0.5% FBP groups. Dietary FBP supplementation up-regulated (P < 0.05) gene expressions related to lipid metabolism in the liver (ACC, FAS, SCD1, and SREBP1) and yolk precursor synthesis (ESR2 and VTG II). Moreover, CYP11A1 expression in the ovary was up-regulated (P < 0.05) in the FBP groups compared with the control group, as well as in the 0.25% FBP group compared with the 1.0% FBP group. In summary, dietary FBP supplementation improved egg quality and nutritional value, ovarian antioxidant capacity, and yolk precursor synthesis, while 1.0% FBP had better effects than 0.25 and 0.5% doses.

Impact of different housing densities combined with Environmental enrichment on the production of Japanese quail

This study evaluated the zootechnical performance, egg quality, and behavior of Japanese quails in the laying phase housed in cages of different densities and with or without environmental enrichment. A total of 224 quail were used and distributed into two groups: one with a housing density of 122.7 cm2 bird-1 and one with a housing density of 157.8 cm2 bird-1, each with and without environmental enrichment. The results showed that environmental enrichment did not influence the zootechnical performance parameters of the quail. However, housing density independently affected performance, except for egg mass and bird viability. A lower density (157.8 cm2 bird-1) resulted in greater specific egg weight, albumen percentage, and shell thickness. The interaction between density and environmental enrichment revealed that eggs from quail housed at higher density without enrichment had a greater yolk percentage, while quails housed at lower density without enrichment had a greater shell percentage. The tonic immobility time of the quails was not affected by treatment with different densities or environmental enrichment agents. It can be concluded that a lower housing density, with seven quail per cage (157.8 cm2 bird-1), regardless of environmental enrichment, provides better zootechnical performance and egg quality.

Preparation of Supercapacitor Carbon Electrode Materials by Low-Temperature Carbonization of High-Nitrogen-Doped Raw Materials from Food Waste.

To address the problem of the low nitrogen (N) content of carbon materials prepared through the direct carbonization of food waste, soybean meal and egg whites with high N contents were selected to carry out carbonization experiments on food waste. At 220 °C, the effects of hydrothermal carbonization and microwave carbonization on the properties of supercapacitor electrode materials were investigated. The results show that food waste doped with soybean meal and egg whites could achieve good N doping. At a current density of 1 A·g-1, the specific capacitance of the doped carbon prepared by hydrothermal doping is as high as 220.00 F·g-1, which is much greater than that of the raw material prepared through the hydrothermal carbonization of food waste alone, indicating that the hydrothermal carbonization reactions of soybean meal, egg white, and food waste promote the electrochemical properties of the prepared carbon materials well. However, when a variety of raw materials are mixed for pyrolysis carbonization, different raw materials cannot be fully mixed in the pyrolysis process, and under the etching action of potassium hydroxide, severe local etching and local nonetching occur, resulting in a severe increase in the pore size distribution and deterioration of the electrochemical performance of the prepared carbon materials. At a current density of 1 A·g-1, the specific capacitance of these prepared carbon materials is 157.70 F·g-1, whereas it is only 62.00 F·g-1 at a high current density of 20 A·g-1. Therefore, this study suggests that the hydrothermal carbonization process is superior to the microwave pyrolysis carbonization process for preparing supercapacitor electrode materials with multiple samples doped with each other.

Separation of Lysozyme-Ovotransferrin Complexes and the Cooperative Role of Their Components in Egg White.

A complex of ovotransferrin and lysozyme was directly isolated from egg white using an anti-transferrin antibody-immobilized membrane after antiserum proteins were separated by non-denaturing two-dimensional electrophoresis and transferred onto a membrane. The complex retained lysozyme activity that catalyzes the breakdown of peptidoglycans in the bacterial cell wall at the β1-4 bond between N-acetylmuramic acid and N-acetylglucosamine residues. The activity of the purified lysozyme was suppressed to 6.4% in the presence of 1μmol Fe2+, whereas that of the mixture of the purified lysozyme and ovotransferrin was maintained at 58%. The activity of the purified lysozyme was suppressed to 35% in the presence of 10nmol Fe3+, whereas that of the mixture of the purified lysozyme and ovotransferrin was maintained at 66%. Furthermore, the bacteriolytic activity against Bacillus subtilis of egg white with reduced glycoproteins such as ovotransferrin was assessed, and the bacteriolytic activity was found to be suppressed in the presence of Fe2+ and Fe3+. This suppression was ions, thereby alleviating the inhibition of lysozyme activity by iron ions. A complex of ovotransferrin and lysozyme is efficient because ovotransferrin effectively captures iron ions near lysozyme. Thus, protein complexes containing enzymes can be applied to control their activity.

Effect of organic and nano trace minerals at reduced levels in layer diets on egg quality characteristics and its trace mineral content

An experiment was conducted to assess the effect of organic and nano trace minerals (copper, zinc, manganese and iron) at reduced levels in layer diets on various egg quality characteristics and its trace mineral content. 240 Hy- Line W80 layer birds of 29 weeks old were randomly distributed to five treatment groups with four replicates having twelve birds each. Basal diet was supplemented with inorganic trace minerals to meet 100 per cent requirement to form control diet or with organic trace minerals at 75 and 50% of requirement or with nano trace minerals at 50 and 25% of requirement to form four test diets. Each diet was offered to four replicate groups for 84 days which was conveniently divided into three phases of 28 days each. Egg quality parameters, viz. egg weight, egg shape index, albumen index, yolk index, yolk color score, Haugh unit score, egg shell weight, albumen weight and yolk weight among the treatment groups were not affected by source and level of trace minerals. However, egg shell thickness was significantly higher in 25% nano trace mineral group on 28th day. The trace minerals (Zn and Fe) in the yolk were significantly lower at reduced trace mineral levels (50% organic or nano and 25% nano form) when compared to 100% (inorganic) and 75% levels (organic form). It was concluded that the substitution of inorganic trace minerals with organic or nano trace minerals at reduced levels (50 or 25%, respectively) in layer diets does not affect the egg quality parameters, but reduces Zn and Fe content in egg yolk.