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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, B 1 and B 2 , with molecular weights ≥10 kDa were further obtained from preserved eggs by ultrafiltration and Superdex Peptide 10/300 GL. The potential mechanism of B 1 and B 2 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., Competing Interests: The authors declared that they have no conflicts of interest to this work. We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted., (© 2023 The Authors. Food Science & Nutrition published by Wiley Periodicals LLC.)

In this study, the duck eggs were salted with none or 2.5% and 5.0% (v/v) of liquid smoke (LS), respectively. As a control, samples salted without LS were used. The 2-thiobarbituric acid (TBA) values, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, and reducing power of the three groups were tested at 0, 7, 14, and 21 and 28 days to determine the effects of LS on the antioxidant activity of treated eggs. In addition, gas chromatography-mass spectrometry (GC-MS) and electronic nose (E-Nose) were used to analyze the volatile flavor components of fresh duck eggs, LS, control, and salted duck eggs enriched with 2.5% (v/v) LS after 28 days of salting. The TBA value considerably increased with an increase in salting period, and the treated egg's TBA value significantly associated with LS concentration. The TBA value decreased as the LS concentration increased. The amount of LS present was highly associated with their capacity to scavenge DPPH radicals. The reducing power of the samples was substantially correlated with the LS concentration, and the reducing power increased with increasing LS concentration. The GC-MS data revealed that phenols and ketones were the predominant chemicals present in the LS, and they were also found in the eggs added to the LS even though they were absent in the fresh eggs and control. The flavor of the control group and treated eggs with LS differed significantly, according to the principal component analysis and radar map of the E-nose. The texture study results revealed that the LS significantly impacted the hardness, cohesiveness, and chewiness of eggs., Competing Interests: The authors declare no potential conflicts of interest., (© Korean Society for Food Science of Animal Resources.)

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.

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.

Chitin is the most abundant natural amino polysaccharide, showing various practical applications owing to its functional properties. However, there are barriers in the development due to the difficulty of chitin extraction and purification, regarding its high crystallinity and low solubility. In recent years, some novel technologies such as microbial fermentation, ionic liquid, electrochemical extraction have emerged for the green extraction of chitin from new sources. Furthermore, nanotechnology, dissolution systems and chemical modification were applied to develop a variety of chitin-based biomaterials. Remarkably, chitin was used in delivering active ingredients and developing functional foods for weight loss, lipid reduction, gastrointestinal health, and anti-aging. Moreover, the application of chitin-based materials was expanded into medicine, energy and the environment. This review outlined the emerging extraction methods and processing routes of different chitin sources and advances in applying chitin-based materials. We aimed to provide some direction for the multi-disciplinary production and application of chitin., 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 © 2022 Elsevier Ltd. All rights reserved.)

Natural antioxidants derived from agricultural by-products have great promise and ecological advantages in the treatment of oxidative stress-related diseases. The eggshell membrane (ESM) from hatched eggs, i.e., the hatched ESM, is a globally abundant agricultural byproduct, and its high-value utilization has been rarely studied compared to the well-studied ESM from fresh eggs. In this research, we systematically characterized the hatched ESM as a novel source of antioxidant hydrolysates and explored their potential role in H2O2-induced human chondrocytes. The results showed that the hatched ESM is a protein-rich fibrous mesh material with a significantly different structure and composition from those of fresh ESM. Enzymatic hydrolysis of hatched ESM can produce antioxidant hydrolysates rich in low molecular weight (MW) peptides, which mainly derived from the Lysyl oxidase homolog by Nano-LC-MS/MS analysis. The peptide fraction with MW < 3 kDa (HEMH-I) exhibited the highest DPPH radical scavenging, Fe2+-chelating, and Fe3+-reducing abilities. In H2O2-induced human SW1353 chondrocytes, HEMH-I treatment significantly increased the cell viability and ameliorated oxidative stress, inflammatory response, and cartilage matrix degradation by reducing the level of ROS, matrix metalloprotease 3 (MMP3), MMP13, and IL-6, and by promoting the expression of SOD and type II collagen, potentially through activating the cellular Keap1/Nrf2/HO-1 pathway. This study provides a theoretical basis for the value-added application of hatched ESM waste to produce antioxidant hydrolysates and indicates their potential as functional food and pharmaceuticals.

Phosvitin (PV) is the main phosphoprotein in egg yolk, with the highest degree of phosphorylation known in nature. The PV and resveratrol (Res) can form a complex, thus effectively improve the solubility of Res. In this work, the interaction between Res and PV was investigated by the fluorescence spectroscopy and molecular docking. The fluorescence emission intensity of PV became weak along with a red shift when it interacted with Res and the antioxidant activity was enhanced. The quenching constants of the interaction systems were 1.12×10 4  M -1 and 9.40×10 3  M -1 at 25°C and 35°C, respectively, which indicated the presence of static quenching phenomena between them. The binding constant was 1.80×10 4  M -1 , and the number of corresponding binding sites was approximately equal to one. The thermodynamic results revealed the combination was spontaneous, and the change of enthalpy and entropy was ∆H = 53.50 kJ/mol, ∆S = 261.00 J/mol·K, respectively. It indicated that the interaction forces between Res and PV were mainly hydrophobic interaction and hydrogen bonding. Molecular docking showed the binding mode, which was consistent with the experiment results. The research on the interaction between Res and PV provided theoretical guidance for the application of Res in food. PRACTICAL APPLICATION: PV is the most highly phosphorylated protein in nature and has pro-calcium absorption effects. Res is a polyphenol with strong antioxidant and anti-inflammatory activity, but its poor solubility limits its application. In this study, the solubility of Res was considerably enhanced by compounding Res and PV, and the antioxidant activity of Res was well retained. It increases the value of Res in food and other applications and opens up new possibilities for processing and utilization of PV., (© 2022 Institute of Food Technologists®.)

In this study, ovalbumin (OVA) was succinylated with the addition of different levels of succinic anhydride, and the structural and functional properties of succinylated OVA (SOVA) were investigated. SDS-PAGE and FTIR spectrum confirmed the covalent attachment of the succinyl group to OVA. Thermal stability and the absolute value of zeta potential (pH 6.0) of SOVA were enhanced by 14.90% and 76.77% higher than that of the native OVA (NOVA), respectively. Circular dichroism (CD) spectra demonstrated that the succinylation decreased the α-helix and increased β-sheet content to 21.31% and 43.28%, respectively. The content of free sulfhydryl groups increased and intrinsic fluorescence spectra suggested the SOVA became more unfolded and flexible as the degree of succinylation enhanced. Furthermore, succinylation effectively enhanced the solubility and decreased the interface tension (oil-water and air-water interface) of OVA. Compared to NOVA, the emulsifying activity and stability of SOVA were increased by 1.6 times and 1.2 times, respectively, and foaming capacity and stability were enhanced by 2.7 times and 1.5 times, respectively.

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.)

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.

Crayfish have become a heavily consumed food and its chitin-rich shell is of great value in terms of waste conversion. This study found a novel chitinase (EaChi40) from a marine bacterium Exiguobacterium antarcticum. The gene was cloned and expressed as a soluble protein of 40 kDa, having optimal activity at pH 6.0 and 30 °C. EaChi40 showed good stability and high specific activity, and kinetic studies found K m and V max were 0.86 mg/mL and 13.66 μmol/min/mg. For conversion crayfish shell into oligosaccharides, ball milling and ultrasound-assisted hydrogen peroxide decolorization were applied to pretreat crayfish shell to facilitate its hydrolysis. After the enzymatic conversion, the hydrolysis products of chitobiose and N-acetyl-D-glucosamine were 9.09 mg/mL and 9.21 mg/mL, respectively. EaChi40 efficiently degraded crayfish with a high hydrolysis rate of 76.1%. It is expected to be a good candidate for the production of chitin oligosaccharides in the food and biological fields., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The purpose of our study was to determine the impact of rosemary extract in duck eggs, as determined by in vitro antioxidant capacity, lipid oxidation, fatty acid profiles, and flavor analyses. Three groups of salted duck eggs were compared: A control group and group enriched with 0.1% and 0.5% (w/v) rosemary extracts for 28 days of salting. In a time-dependent manner, the radical scavenging activity and reduction power of eggs with 0.5% (w/v) rosemary extract were significantly higher those of the control at 28 days after salting. The fatty acid profiles of salted egg were significantly affected by rosemary extract and salting time. Palmitic acid was the most abundant fatty acid in salted egg treated with rosemary extract, followed by linoleic acid and arachidonic acid. Furthermore, the treated eggs contained more docosahexaenoic acid than the control ones. And the treated eggs also have a considerable impact on the lipid oxidation process (primary and secondary oxidation). As a result, rosemary extract can be used as a natural antioxidant spice to prevent oxidation and extend the shelf life of eggs during storage. Furthermore, flavor research using solid phase microextraction - gas chromatography - mass spectrometry and an electronic nose demonstrated that adding rosemary extract to salted eggs could give them a distinct flavor., Competing Interests: The authors declare no potential conflicts of interest., (© Korean Society for Food Science of Animal Resources.)

In this study, high-density lipoprotein (HDL) from duck egg yolk was subjected to oxidation with a system based on 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH)-derived peroxyl radicals. The effects of peroxyl radicals on the protein carbonyl, free sulfhydryl, secondary/tertiary structure, surface hydrophobicity, solubility, particle size distribution, zeta potential and fatty acid composition of HDL were investigated by using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Fourier-transform infrared spectroscopy (FTIR), circular dichroism (CD), fluorescence spectroscopy, dynamic light scattering and ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). The results indicated that the content of protein carbonyl was significantly increased, that of free sulfhydryl was obviously reduced, and the ordered secondary structure was also decreased with increasing AAPH concentration. In addition, the surface hydrophobicity and solubility of HDL showed apparent increases due to the exposure of hydrophobic groups and aggregation of protein caused by oxidation. The fatty acid composition of HDL exhibited pronounced changes due to the disrupted protein-lipid interaction and lipid oxidation by AAPH-derived peroxyl radicals. These results may help to elucidate the molecular mechanism for the effect of lipid oxidation products on the oxidation of duck yolk proteins.

Crayfish myofibril protein (CMP) gel deterioration induced by autoclaving was investigated. A series of CMP gels were obtained through treating CMP solutions at different autoclaving conditions from 100 °C/0.1 MPa to 121 °C/0.21 MPa, and then characteristics and the mechanism of gel texture deterioration along with the intensification of autoclaving were explored through determining appearance, texture, protein composition, cross-linking forces, degree of hydrolysis, water state, microstructure of the gels, and average particle size of aggregates. When autoclaving was at above 105 °C/0.103 MPa, texture of CMP gel showed a tendency to severely weaken with the intensification of autoclaving (p < 0.05), hydrophobic interaction and aggregation between proteins weakened gradually (p < 0.05), and moderately bound water in the gel decreased and T22 relaxation time significantly increased (p < 0.05). After heating for 30 min at above 105 °C/0.103 MPa, pores in the microstructure of CMP gel enlarged obviously, and myosin heavy chain (MHC) degraded. It can be concluded that CMP gel deterioration induced by autoclaving was associated with the degradation of MHC and 105 °C might be the critical temperature to ensure good texture of crayfish products.

In this paper, the effects of acylation modification on the gel behavior of ovalbumin (OVA) under heating induction have been investigated. From the obtained results, the acylated OVA hydrogels exhibited superior gelation properties than the native OVA hydrogels (NOVA-G) in terms of light transmission, gel hardness, resilience and water holding capacity. SEM revealed acylation modifications effectively promoted the formation of uniform and dense network structure of OVA hydrogels. The main intermolecular forces of the acylation-modified OVA hydrogels were hydrophobic interactions and hydrogen bonding. FTIR showed that acylation modifications caused 26.2% decrease in α-helix and 59.2% increase in β-sheet content compared to NOVA-G. Furthermore, in-vitro release experiments showed that the release rate of curcumin from acylated OVA hydrogels was significantly delayed. Moreover, the above results have shown that acylation modifications can be considered as an effective method to improve the gelation as well as drug release properties of protein hydrogels., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Using natural multi-function phytochemicals could be one of the best solutions for clean-label production. In this study, dairy ice creams were prepared containing 14% egg yolk and 0.1% of thymol (THY), trans-cinnamaldehyde (TC), menthol (MEN), or vanillin (VAN). Then, the physical, chemical, and structural characteristics were evaluated. Magnetic resonance imaging (MRI) analysis (a rapid, chemical-free, and non-invasive tool) was carried out to evaluate the water distribution. A multivariate analysis was conducted among all studied variables. According to the results, the overrun of the MEN ice cream was significantly increased as compared to the control sample. The density was also reduced in the MEN sample. Meanwhile, the spreadability (%) of VAN was significantly increased after 6 min as compared to the control treatment. MRI analysis revealed that water distribution was significantly changed in the THY group. The firmness and viscosity of THY samples were significantly increased ( p < 0.05). Multivariate analysis indicated that viscosity index and consistency were the top parameters affected by THY. The authors concluded that THY and VAN are promising stabilizers for ice-cream clean production.

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.)

This study aims to enhance the color and microbiological qualities of a raw beef using natural ingredients. Nitroso-hemoglobin (NO-Hb) integrated with vitamin C (VC), calcium lactate, and ginger complexation were used as natural inhibitors against the growth of aerobic and pathogenic bacteria, namely (Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Salmonella. NO-Hb inhibited E. coli, S. aureus, and Salmonella, and enhanced the color stability more than nitrite in the minced beef model. After the multiexponential analysis of relaxation decays, the water component (T 2b ) was analyzed using the low-field NMR. The results indicated that, at the 7th d of cold-storage the third component (T 2 ) was detected. Significant correlations were observed between T 21 and T 22 relaxation times and water-holding capacity in minced beef, implying that the LF-NMR measurements could be an efficient method for the determination and prediction of beef freshness. NO-Hb- ginger mixture, as a novel ingredient, could be used instead of nitrite in terms of meat safety., Competing Interests: Declaration of competing interest There is no conflict of interest regarding the publication of this paper among authors., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Chitosan-based macroparticle is a common carrier for enzyme immobilization applied in food industry. Driven by the requirement of large carrier pores for the biomacromolecular substrates such as protein, the eggshell membrane powder (ESMP) was employed as multifunctional porogen to improve the physicochemical structure of chitosan-based macroparticles. The prepared macroparticles were characterized by SEM, XRD, FTIR, Raman spectroscopy, nitrogen adsorption-desorption isotherms, and thermogravimetric analysis. The results showed that an increase of ESMP percentage could improve the porosity of macro holes in macroparticles, and it also enlarged the size of mesopores. Moreover, the ESMP significantly increased (P < 0.05) the amount of papain immobilization, whereas the specific activity of immobilized papain achieved a maximum value of 871.95 U/mg at CSESM2 and then declined with the increase of ESMP. Therefore, the inclusion of 20 % ESMP in chitosan-based macroparticles gave the highest activity of its immobilized protease., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

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., Competing Interests: Declaration of Competing Interest The authors declare that ‘NO Conflict of interest’ exist in this research article., (Copyright © 2019 Elsevier B.V. All rights reserved.)

This study was focused on the differences between three concentrations of four safe bio-active volatile terpenes and natural compounds (trans-cinnamaldehyde, thymol, menthol, and vanillin) on the egg yolk volatile components. In which, Headspace Solid phase Micro Extraction (HS-SPME) followed by GC/MS were used for volatiles analysis, and electronic nose (E-Nose) with 18 sensors was used for the aroma pattern. In the results, a total of 111 different volatile compounds were identified by using GC/MS. Some ketones, amines, nitro and organic acid compounds such as hexanone were significantly reduced after using these compounds. On the other hand, first principal components (PC1) of trans-cinnamaldehyde (0.1%) was decreased significantly (p < .05) to -4.8 ± 0.8, compared to the control with 4.3 ± 2.1. And, it increased benzaldehyde and nonanal peaks area significantly to 46.56 ± 14.46 and 9.22 ± 4.81 MPA. In menthol (0.1%), the content of d-limonene was decreased to 4.65 ± 0.49 MPA, compared to the control with 14.16 ± 4.95 MPA. On the other hand, by E-Nose, vanillin (0.1%) PC1 was decreased significantly to -4.48 ± 0.43. Moreover, thymol (0.1%) decreased hydrocarbon sensation to 0.448 ± 0.005. And, vanillin (0.1%) decreased hydrogen sulfide and ketones sensation to 0.169 ± 0.01 and 0.344 ± 0.01, respectively. In conclusion, this study is providing novel information to understand the effects of bio-active molecules on the biological fatty media volatility. Also, it explains how terpenes can protect egg yolk media from the unacceptable odor formation which results from the degradation of its lipids and proteins., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

This experiment was conducted to explore the differences of serum steroid hormones with age and sex in hen eggs during incubation periods for identification of males and females. The concentrations of estrone (E1), estradiol (E2), estriol (E3), testosterone (T), androstenedione (A4), and dihydrotestosterone (DHT) in serum were measured by enzyme-linked immunosorbent assays in chicken embryos on 8, 10, 12, 14, and 16 D, respectively. During the development of chicken embryo, egg weight loss was closely related to age but no sex. However, it was found that both age and sex significantly affected hormones and had obviously more effect on androgens levels. Besides E2 and T, other steroids such as E1, A4, and DHT were also significantly correlated with sex (P < 0.05). Notably, the level of T and the ratio of T to E2 were significantly higher in males than females (P < 0.05). The ratio of E1 to E2 displayed different trends in different sexes, which increased in males but decreased in females. The distribution proportions of androgens and estrogens kept stable level during the late hatching periods of 12 to 16 D. The sex differences of steroids were more obvious at the late hatching stage through PCA. These suggested that the serum hormones differences in male and female embryos played a vital role in sexual differentiation. These findings not only provided the theoretical basis for sex determination of fertilized eggs in egg-laying hen strains, but also contributed to develop a non-invasive way to sex determination of fertilized eggs to meet the modern commercial application., (© 2019 Poultry Science Association Inc.)

This study mainly investigated the improvement effect of nitroso-hemoglobin (NO-Hb) and four lactic acid bacteria (LAB) ( Streptococcus thermophiles, Lactobacillus bulgaricus, Lactobacillus casei , and Montessori enterococcus ) on the color and microbiological qualities of raw beef. Three strains of Escherichia coli , Staphylococcus , Salmonella , and Pseudomonas were used as pathogenic bacteria. The results showed that both NO-Hb and LAB could enhance the color stability and scavenged the spoilage bacteria in a minced beef model. But the improvement effect of NO-Hb was more significant than LAB. This suggested that NO-Hb, as a novel ingredient, could be used as a promising substitute for nitrite in meat products to improve the color and safety of meat products. In addition, low field (LF)-NMR method has been established to be practicable to identify changes in the relaxation times of water and fat caused by different type of bacteria and the storage periods. The number of relaxation components in minced beef was affected by bacteria and increase of the storage period., Competing Interests: Conflict of Interest The authors declare no potential conflict of interest., (© Korean Society for Food Science of Animal Resources.)

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., (© 2019 Poultry Science Association Inc.)

In this study, effects of nano-TiO 2 on the microstructural, physical, mechanical and optical properties of pullulan films were investigated. The results showed that the addition of nano-TiO 2 improved the water vapor barrier properties of the film due to the tortuous path formed by nano-TiO 2 . When the concentration of nano-TiO 2 was 0.04 g/100 mL, the tensile strength of the film showed a maximum value (15.99 MPa). The elongation at break of the film continued to decrease with the increase of nano-TiO 2. The TEM analysis showed that higher concentration of nano-TiO 2 would cause greater aggregation. Meanwhile, the results of FTIR and low-field NMR indicated that the miscibility between pullulan and nano-TiO 2 was due to the formation of intermolecular hydrogen bonds during film formation. Furthermore, the addition of nano-TiO 2 significantly improved the film barrier properties to ultraviolet light., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

In this study, genipin and glutaraldehyde in varied concentrations were utilized in chitosan crosslinking under alkaline condition. A UV/Vis analysis was used to investigate the molecular structure of genipin and glutaraldehyde in an aqueous alkaline solution. The results showed the formation of glutaraldehyde dimer and polymerized genipin. The FTIR-ATR, SEM, DSC, XRD, mechanical properties, crosslinking degree and swelling ratio of chitosan based films crosslinked by genipin and glutaraldehyde were determined. The results indicated that the hydrogen bonds formed between genipin and chitosan enabled the films crosslinked by genipin (1 and 5 mmol/L) to have a higher degree of crosslinking, but a lower swelling ratio than glutaraldehyde (1 and 5 mmol/L). Genipin enabled the chitosan-based film to possess better mechanical properties and crystallinity than glutaraldehyde. The polymerization of genipin had a substantial effect on the network structure and swelling behavior of chitosan-based films crosslinked by genipin., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Chitosan based organic-inorganic composite films were prepared through direct incorporation of nanosilica particles in order to enhance their performance for potential packaging material. After the addition of nanosilica, the viscosity of film-forming solutions (FFSs) decreased obviously, and the G' of FFS with 25% of nanosilica was higher than that of other FFSs with nanosilica. In low field nuclear magnetic resonance (LF-NMR) determination, the addition of 25% of nanosilica gave rise to the lowest relaxation time and peak area proportion of T 21 component. Additionally, the changes of structure characteristic of composite films with different nanosilica content were analyzed through FTIR spectroscopy, SEM and XRD analysis. The thermal stability of films improved markedly with increasing nanosilica. The optimal mechanical properties of films were yielded at 25% of nanosilica. Furthermore, the introduction of nanosilica significantly (p < 0.05) decreased the swelling ratio of chitosan based films at pH 7.6 and pH 2.6., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Antioxidant activity, lipid oxidation, fatty acid composition and volatile compounds of duck eggs supplemented with clove extract were monitored over the salting period. The results indicated that application of clove extracts significantly reduced 2-thiobarbituric acid reactive substances and anisidine values as well as the conjugated dienes levels during curing. Clove extracts along with salting time had significant effects on the fatty acid composition. The predominant fatty acid in salted duck eggs supplemented with clove extracts for 14 day of the salting process was oleic acid, followed by palmitic acid and arachidonic acid. Additionally, treated eggs exhibited a higher docosahexaenoic acid content than that of control. The results of SPME GC-MS showed the presence of 46 and 37 volatiles in the treated eggs. Eugenol, as the primary bioactive component of clove, was detected in salted eggs supplemented with clove extracts. In addition, analyzing the results obtained through electronic nose showed that clove extract brought significant changes in salted eggs flavor components., Competing Interests: Compliance with ethical standardsThe authors declared that they have no conflict of interest.

Preserved egg, a kind of alkaline-fermented food, is a traditional egg product in China. Here, we investigated the nutritional functions of preserved eggs by in vivo and in vitro experiments. The results of in vivo studies showed that the levels of triglycerides (TG), total cholesterol (TCHO) and low-density lipoprotein cholesterol/high density lipoprotein cholesterol (LDL-C/HDL-C) were significantly decreased ( p <0.05) in the liver of rats treated with preserved eggs. Meanwhile, the levels of two important cancer markers, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), were also significantly decreased ( p <0.05) in treated rats. In vitro studies were performed on Caco-2 cells, a human epithelial colorectal adenocarcinoma cell line. It demonstrated that the gastrointestinal (GI) digests of preserved eggs significantly accelerated ( p <0.05) the apoptosis by upregulating caspase-3 in the Caco-2 cells. Besides, after treated with preserved eggs, the half maximal inhibitory concentration (IC50) of preserved eggs digests to Caco-2 cells was 5.75 mg/mL, indicating the significant inhibition of cell proliferation provided by preserved eggs ( p <0.05). The results shown in this study demonstrated that preserved eggs may be a novel functional food involved with antilipemic, anti-inflammatory activity as well as the effect on accelarating the apoptosis of Caco-2 cells.

To improve the interfacial properties, a phosphorylation modification of OVA was performed through dry-heating at three different pH values (5.0, 7.0 and 9.0) in the presence of sodium tripolyphosphate. X-ray photoelectron and Raman spectroscopies confirmed that phosphate groups were successfully grafted onto the ovalbumin backbone through covalent interaction to form OP bond. Additionally, 23, 21 and 18 phosphorylation sites were identified in the OVA that had been phosphorylated at pH 5.0, 7.0 and 9.0 (P-OVA5, P-OVA7 and P-OVA9) respectively by MALDI-TOF mass spectroscopy. More phosphorylated peptides and possible phosphorylation sites were found here than in previous studies with the reaction time reduced to 12h. As a result, the iso-electric point (pI) of P-OVA shifted to lower pH, improving the stability of the P-OVA-included system over a wider pH range. The dynamic interfacial tension, which depends on the phosphorylation-induced conformational change, was explored by Fourier-transform Raman and circular dichroism spectroscopies, and the equilibrium interfacial tension decreased from 17.359mNm -1 for natural OVA (N-OVA) to 15.969mNm -1 for P-OVA9. Furthermore, P-OVA was applied to O/W emulsions, resulting in a narrower size distribution with a smaller particle size in P-OVA-stabilized emulsions than in N-OVA-stabilized emulsions. The increase rate of mean particle diameter after 60-min storage decreased from 72.37% for N-OVA to 7.97% for P-OVA5, implying a significant improvement of emulsion stability by preventing aggregation and coalescence. The results from this work demonstrated that the natural biopolymer can be applied to O/W emulsions by enhancing interfacial properties with phosphorylation., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A simple optimization method of immobilization of avidin on magnetic nanoparticles (MNPs)' surface was proposed in this study. The avidin-immobilized MNPs were then developed and used to immobilize a model enzyme [Horseradish peroxidase (HRP)]. The loading capacity (LC) and activity of avidin-immobilized MNPs were optimized through selecting the most appropriate nanoparticle's size and shape, glutaraldehyde concentration, cross-linking reaction time, ultrasonic processing time, and initial concentration of avidin. The LC under optimized conditions was 63.37 ± 1.29 mg avidin/g MNPs, and the immobilized protein was still able to maintain its high biological activity of 10.86 ± 0.13 U/mg (biotin-binding activity of nature avidin was 14.1 U/mg) and better thermal stability compared to free avidin. A highly reusable, stable, and easily recovered immobilized HRP was obtained using MNPs as carriers. The immobilized HRP was reused repeatedly more than 9 times and retained more than 65 % of its original activity.

The avidin-biotin interaction was evaluated systematically by fluorescence spectroscopy under different conditions of temperature, pressure, pH, metal ions, incubation time and initial avidin concentration. The binding constant was calculated according to the modified Stern-Volmer equation, which deduced the existence of static quenching mechanism. The data obtained revealed that avidin-biotin interaction exhibited temperature, pH, metal ions, incubation time and initial avidin concentration sensitivity. The binding constants decreased with increase in temperature, while the binding sites were independent of temperature. The values of thermodynamic parameter ΔH (-149.85 kJ mol(-1)) and ΔS (-284.26 J mol(-1) K(-1)) suggested hydrogen bonds and van der Waals played a major role in the reaction. The binding constants between avidin and biotin increased firstly and then decreased gradually with the increase of pH values. Metal ions can also affected the binding constants between avidin and biotin. The association kinetics firstly acquired by the combination of the change in fluorescence per unit time and the modified Stern-Volmer equation indicated that the reaction time required to reach equilibrium was 2200 s, and the average reaction rate for the binding process was very high in the first 180 s. Reaction of the avidin in the first 180 s was more than 40% of the total avidin involved in the whole process., (Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.)

Avian egg albumen participates in embryonic development by providing essential nutrients as well as antimicrobial protection. Although various biological functions of egg white proteins were suggested during embryogenesis, global changes of these proteins under incubation conditions remained uninvestigated. This study presents a proteomic analysis on the change of egg white proteins during the first week of embryonic development. By using 2-DE, together with MALDI-TOF MS/MS, thirty protein spots representing eight proteins were identified showing significant changes in abundance during incubation. An accelerating degradation of ovalbumin was observed in a wide range of molecular weight. In addition, four protein complexes were predicted according to the detected molecular weight increase. Among these speculated protein complexes, an ovalbumin spot coupled with RNA-binding protein was detected. The absence of these protein complexes before incubation, followed by the constant increase in abundance during incubation indicates conceivable pivotal roles in embryonic development. To better understand the function of the proteins identified in this study, discrepancies of egg white protein changes between fertilized and unfertilized chicken eggs were additionally demonstrated. These findings will provide insight into the embryogenesis process to improve our knowledge of egg white proteins in regulating and supporting early embryonic development., (Copyright © 2012 Elsevier B.V. All rights reserved.)

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 economical, effective and large-scale method for the preparation of immunoglobulin of chicken egg yolk (IgY) was developed. The method was based on an improved water dilution combining with polyethylene glycol 6000 (PEG6000) precipitation and anion-exchange chromatography. The egg yolk was diluted with 8 volumes of aseptic water, the pH of which was adjusted to 5.2 with 0.1 mol/L HCl, then the mixture was centrifuged at 5 000 x g after standing for 8 h at 4 degrees C. The crude IgY was obtained from the supernatant layer with the yield of 93.47%. The purification of IgY was achieved by 6% PEG6000 precipitation and DEAE-Toyo-pearl 650 M anion-exchange chromatographic packing. The optimum purified conditions by ion-exchange chromatography were as follows: equilibration with 0.05 mol/L phosphate buffer (pH 7.0) and elution with 0. 075 mol/L phosphate buffer (pH 7.0). The purity of the IgY fraction was consistently greater than 95% with high activity (73.77%) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This method is superior to the traditional ion-exchange chromatography that can't simultaneously obtain high purity and high recovery. Moreover, this method is suitable for a large-scale IgY preparation from chicken egg yolk.

Knowing the adsorption behavior of target proteins on biofunctional magnetic nanoparticles is of great importance for the separation and purification of proteins. Adsorption behaviors of avidin on biofunctional magnetic nanoparticles binding to iminobiotin were investigated under different conditions of temperature, pH, ionic strength, and feed avidin concentration. Biofunctionalization of the non-functional nanoparticles was performed, coupled with iminobiotin. Characterization of the particles was carried out using transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The results showed the avidin adsorption behaviors were mainly dependent on affinity interaction between avidin and iminobiotin coupled with the nanoparticles, which exhibited temperature, pH, ionic strength, and feed avidin concentration sensitivity. Maximum avidin adsorption capacity was achieved as 225 mg avidin/g biofunctional nanoparticles. Results were well fitted to the Langmuir isotherm model with the feed avidin concentration of less than 45 μg/ml. Based on the experiments above, the biofunctional magnetic nanoparticles were used to separate avidin from treated egg-white solution containing large amounts of other proteins. The avidin was isolated in 92% yield with an optical purity of more than 98.5% according to the HPSEC data. The regeneration of these nanoparticles was also studied and almost 87.3% of avidin could still be recovered by these regenerated nanoparticles., (Copyright © 2011 Elsevier B.V. All rights reserved.)

A new method for determination of lysozyme with high sensitivity based on Resonance Rayleigh scattering (RRS) by using Au nanoparticles as a probe was proposed in this experiment. The RRS spectrum, nonlinear scattering (second-order scattering (SOS), frequency doubling scattering (FDS)) spectra and absorption spectrum of the Au nanoparticles-lysozyme system have been analyzed. In addition, the effects of several factors on scattering intensities were investigated, including pH value of solution, amount of Au nanoparticles, mixing sequence of each reagent and the coexisting substances. The results showed that the coexisting substances have little influence on the RRS intensities of the systems. Moreover, the possible mechanism for the RRS enhancement of Au nanoparticles-lysozyme system was preliminary discussed. The RRS method for determination of lysozyme has good sensitivity and selectivity with the detection limits 30.1 ng/ml. The contents of lysozyme were determined with recoveries of 98.2-105.4% and relativity relative standard deviation (RSD) of 0.3-3.7%, respectively. It proved that the method established in our study is suitable for the determination of lysozyme in synthetic sample and natural chicken egg white sample., (Copyright © 2011 Elsevier B.V. All rights reserved.)

We isolated the strain MBL13 with high collagenase productivity from the soil of piled up animal bones. It was identified as Bacillus cereus. We purified and characterized Bacillus cereus collagenase (BCC). The molecular weight of BCC was 38.0 kDa and the optimum temperature and pH for the enzyme activity were 40 degrees C and 8.0 respectively. The enzyme was stable when the temperature was below 50 degrees C, but only retained 10% activity when kept at 60 degrees C for 1 h. The enzyme activity was stable between pH 7.0-8.5. Some metal ions such as Ca2+, Zn2+, Mg2+ enhanced the enzyme activity, and Cu2+ brought the obvious inhibition. In addition, EDTA and EGTA could inhibit the enzyme activity. We suggested that the purified enzyme was a member of the metalloproteases. Based on the experiment of substrate specificity, we found that the purified enzyme was bone collagenolytic protease, and had a much stronger capacity of hydrolysis for type I collagen than that for type II collagen and type III collagen. By BCC hydrolyzing bone collagen, we obtained polypeptides with different chain lengths. The comparative test indicated that the hydrolysis capacity of BBC was higher than that of standard type I collagenase. The results introduced a new strain and a novel collagenolytic protease for industrial enzyme.