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Steamed bread has long been an important part of Chinese cuisine. This study investigated the effects of salted egg white (SEW) (5, 10, 15, and 20% w/w) on the quality of steamed breads. Findings revealed that SEW notably enhanced the bread's volume and texture, with a 20% inclusion significantly boosting water retention and rheological properties, albeit reducing bread's lightness. In addition, the H-bond absorption band intensity in the Fourier transform infrared spectroscopy (FTIR) analysis showed increased peak intensities with higher SEW levels, indicative of protein structure alterations. X-ray diffraction confirmed the presence of an amylose-lipid complex. Scanning electron microscope (SEM) and Confocal laser scanning microscope (CLSM) imaging depicted a smooth, consistent protein network with SEW addition. Consumer sensory evaluation responded favourably to the SEW15 steamed bread, suggesting its potential for food industry application. Overall, the study considers SEW an effective ingredient for improving steamed bread quality., 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 © 2024 Elsevier Ltd. All rights reserved.)

This study prepared emulsion gels by modifying ovalbumin (OVA)-flaxseed oil (FSO) emulsions with transglutaminase (TGase) and investigated their properties, structure and oxidative stability under different enzyme reaction times. Here, we found prolonged reaction times led to the transformation of α-helix and β-turn into β-sheet and random coil. The elasticity, hardness and water retention of the emulsion gels increased significantly, but the water-holding capacity decreased when the reaction time exceeded 4 h. Confocal laser scanning microscope (CLSM) indicated extended enzyme reaction time fostered oil droplet aggregation with proteins. Emulsion gel reduced FSO oxidation, especially after 4 h of the enzyme reaction, the peroxide value (PV) of the emulsion gel was reduced by 29.16% compared to the control. In summary, the enzyme reaction time of 4 h resulted in the formation of a dense gel structure and enhanced oxidative stability. This study provides the potential applications in functional foods and biomedical fields., 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 © 2024 Elsevier Ltd. All rights reserved.)

Hydrogels have emerged as a promising option for treating local scald wounds due to their unique physical and chemical properties. This study aims to evaluate the efficacy of ovalbumin/gelatin composite hydrogels in repairing deep II-degree scald wounds using a mouse dorsal skin model. Trauma tissues collected at various time points are analyzed for total protein content, hydroxyproline content, histological features, and expression of relevant markers. The results reveal that the hydrogel accelerates the healing process of scalded wounds, which is 17.27% higher than the control group. The hydrogel treatment also effectively prevents wound enlargement and redness of the edges caused by infection during the initial stage of scalding. The total protein and hydroxyproline content of the treated wounds are significantly elevated. Additionally, the hydrogel up-regulates the expression of VEGF (a crucial angiogenic factor) and down-regulates CD68 (a macrophage marker). In summary, this study provides valuable insights into the potential of multifunctional protein-based hydrogels in wound healing., (© 2024 Wiley‐VCH GmbH.)

Hydrogels could be used as wound dressings, but most protein-based hydrogels lack anti-bacterial effects. Here, we successfully prepared a silver ion cross-linked thiolated protein hydrogel (thiolated Ovalbumin and Gelatin, O3G7). The wound photographs showed that the healing rate (96.23 %) of hydrogel-treated mice was higher than the control group. Meanwhile, the hydrogel increased the granulation tissue's total protein content. Furthermore, it significantly increased the collagen content, consistent with the results of Masson's trichrome (MT) staining and immunohistochemical analysis of type I collagen (ColI). The results of hematoxylin and eosin (H&E) staining showed the growth and proliferation of inflammatory cells, granulation tissue, fibroblasts, blood vessels and hair follicles in acute wounds. O3G7 hydrogel had fewer inflammatory cells and more neovascularization, and hair follicle tissue and intact epidermis could be observed. The results of immunofluorescence and immunohistochemistry showed that the O3G7 group reduced the expression of tumor necrosis factor (TNF)-α (56.87 % of the control group) and upregulated the expression of transforming growth factor (TGF)-β (1.29 times of the control group). These results suggest that O3G7 hydrogel significantly affects the healing of acute wounds. This study demonstrates that hydrogels prepared from food-derived proteins will be promising and bio-safe candidates in bioengineering., 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 © 2023 Elsevier B.V. All rights reserved.)

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.)

Ovotransferrin is the most heat-sensitive protein in egg white which alters the processing suitability. To improve thermostability, phosphorylation modification was performed under different pH values (5.0, 6.0, 7.0, 8.0, and 9.0), and the reasons for which were explored via physicochemical changes in this study. SEM and particle size results showed that phosphorylation diminished the average particle diameter and the number of attached particles. CD results revealed that the α-helix content of phosphorylated ovotransferrin increased and the random coil decreased significantly (P < 0.05). Tertiary structure, surface hydrophobicity and ζ-potential analyses showed that phosphorylation made more hydrophobic amino acids buried inside ovotransferrin. These changes might be because most of the phosphorylation occurred in α-helix and β- sheet to promote the thermal tolerance of phosphorylated ovotransferrin by improving its structure orderliness and decreasing surface hydrophobicity. The results indicated that phosphorylation was a practical method to enhance the thermal stability of heat-sensitive ovotransferrin., 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.)

Ovalbumin (OVA) is a model protein with extensive research on structure and function, however, the application of OVA in food processing is limited due to its low gelation properties. In this study, thermally-induced highly transparent and elastic hydrogels from OVA pretreated by succinylation combined with pH-shifting method were reported. Transmission electron microscope (TEM) and free sulfhydryl groups determination revealed that the pretreatment induced the stretching of the protein structure and promoted the formation of preliminary aggregates. Further heating the pretreated OVA suspension resulted in a homogeneous and macroporous gel network with thin connecting walls. Such homogeneous gel network structures may be related to the effective modulation of the thermal aggregation efficiency of proteins by succinylation and the high level of protein unfolding by pH-shifting treatments, which synergistically allowed for more active sites to be created during heating to facilitate intermolecular interactions, including hydrogen bonding and hydrophobic interactions. Notably, the method resulted in a 507.14% increase in elasticity, a 60.74% increase in water holding capacity of the OVA hydrogels compared to the native OVA hydrogels without pretreatment. Also, the hydrogels were transparent with 73.11% light transmittance. In conclusion, succinylation and pH-shifting combined treatment could be an effective method for the preparation of OVA hydrogels with superior gelation properties., 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.)

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.)

There is a huge demand to identify the sex of unhatched fertilized eggs for laying industry and to understand the differences between male and female eggs as early as possible. Then the molecular mechanisms of sex determination and sex allocation in chicken were revealed. Therefore, TMT proteomic was applied to characterize the variation of molecular matrix between unhatched male and female egg yolks. A total of 411 proteins were identified and 35 differentially expressed proteins (DEPs), including 375332005, 015809562, 763550308 (upregulated, UPs) and 1337178851, 89000557, 89000581 (downregulated, DPs), etc. were confirmed between them. Gene ontology analyses showed that DEPs were mainly involved in response to stimulus, distributed in the extracellular region and participated in binding; KEGG analyses showed that few DPs were participated in cell growth and death, transport and catabolism, signaling molecules, interaction and were enriched in ubiquitin mediated proteolysis, endocytosis, ferroptosis, etc. metabolic pathways. Moreover, most of the DEPs and related metabolic pathways were associated with sex hormones. More importantly, this study supports maternal sex-allocation theory and extends our understanding of the molecular mechanism of sex determination and differentiation in avian. Which also provides a powerful evidence for ovo sexing of unhatched fertilized domestic chicken eggs by nondestructive approach and will be of great significance to eggs processing and production., (Copyright © 2022. Published by Elsevier Inc.)

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

In this study, we evaluated potential usage of acylated ovalbumin (AOVA) nanogels fabricated via acylation modification and heat-induced self-assembly process as novel delivery systems for curcumin. Compared to native ovalbumin (NOVA) nanogels without chemical acylation, the obtained AOVA nanogels have shown smaller average hydrodynamic diameter (155.73 nm), relatively uniform size distribution (polydispersity index around 0.28), enhanced negative surface charge (-24.3 mV), and an improved stability under the conditions of high ionic strength, different pH and storage time. Moreover, AOVA nanogels exhibited a remarkable conformational change in secondary and tertiary structures, improved surface hydrophobicity, and increased free sulfhydryl content compared with NOVA nanogels. Moreover, curcumin encapsulated in AOVA nanogels displayed higher encapsulation efficiency (93.64%) and slower sustained release under simulated gastrointestinal conditions as compared with NOVA nanogels. Hence, we have suggested that AOVA nanogels successfully fabricated with improved physicochemical properties as a novel ideal carrier for hydrophobic active compounds., (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.

This study aims to evaluate the effect of ultrasonic pretreatment combined with glycation on the structural characteristics and antibacterial activity of ovotransferrin (OVT). Firstly, OVT (purity >90%) was isolated from egg white with a simple and efficient method. After the treatment of ultrasound and glycation, the browning degree of OVT increased with the rising power of ultrasound, while the number of free amino groups obviously decreased to 25.4%. Various spectrum detection showed that the structures of OVT have changed significantly, indicating the tertiary structure became more flexible and looser. The minimal inhibitory concentration of ultrasound glycated OVT were 25.0 and 32.1 μmol/L for E. coli and S. aureus, respectively. In summary, ultrasound-assisted glycation is an effective technique to improve the biological activity of OVT., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The objective of this study was to investigate the effects of repeated freeze-thaw cycles on microorganisms, amino acid composition profile, chemical composition, mineral concentrations, water mobility, and fat of beef and chicken meats. Pure cultures of specific fungi and bacteria were separately injected into the minced meat. Apart from Pseudomonas, the total count of microorganisms significantly increased (P < 0.05) during refreezing treatment with the increase of storage period in both beef and chicken meats. During freezing treatment, the total count of Staphylococcus aureus, spore forming bacteria, and lactic acid bacteria were meat-type dependent. In conclusion, freeze-thaw cycles increased the microbial counts and decreased the water holding capacity, amino acids, and mineral concentrations of beef and chicken meats., (Copyright © 2021. Published by Elsevier Ltd.)

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.)

The solvated mercuric ion (Hg 2+ ) from industrial pollutants are highly toxic to the ecological environment and human health. Driven by urgent need for the selective and sensitive detection of Hg 2+ , a magnetic relaxation switching (MRS) based on Fe 3 O 4 nanoparticles (NPs) was designed. Practically, the concentrations of Hg 2+ in industrial pollutant is usually much higher than the detection range. Thus, gold nanoparticles (AuNPs) were synthesized on the surface of Fe 3 O 4 NPs to enable the visual detection of Au@Fe 3 O 4 NPs. The presence of Hg 2+ in sample can specifically cause the aggregation of Au@Fe 3 O 4 -aptamers NPs through T-Hg 2+ -T base pairs, leading to the change in transverse relaxation time T 2 value of detection solution. The MRS sensor showed excellent response for Hg 2+ ions in the range of 10 nM-100 nM and 100 nM to 5 μM. A highly sensitive and selective measurement of Hg 2+ was obtained with a limit of detection of 2.7 nM. Noticeably, the visual detection can qualitatively analyze the Hg 2+ beyond 5 μM by naked eye without advanced instrumentation and skilled operators., Competing Interests: Declaration of Competing Interest All authors declare that they have no conflict 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., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The effects of high-intensity ultrasonic (HIU) treatment on the functional properties of egg yolk were studied in the present work. After HIU treatment, the emulsifying, foaming and gel properties of the egg yolk solution significantly increased, but the foam stability decreased. SDS-PAGE results showed that there was no obvious change in the protein bands of egg yolk, indicating that the yolk proteins did not undergo covalent crosslinking or degradation. HIU treatment enhanced the zeta potential of egg yolk components in solution and increased the free sulfhydryl content of egg yolk proteins. Moreover, the particle size distribution of egg yolk components in solution changed markedly, and these changes demonstrated that HIU treatment caused the aggregation of yolk low-density lipoprotein and the partial dissociation of yolk granules. These results revealed that HIU treatment could change the aggregation of yolk components, which in turn could influence the solution characteristics of egg yolk, finally resulting in changes to the functional properties of egg yolk., (Copyright © 2019 Elsevier B.V. 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 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 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.)

In this study, alcalase and neutrase were used in combination to prepare collagen peptides with high calcium binding ability. The optimal conditions for the preparation of peptide-calcium chelate (mass ratio of peptide/calcium of 4.5:1 for 40 min at 50 °C and pH 9) were determined by response surface methodology (RSM), under which a calcium chelating rate of 78.38% was obtained. The results of Ultraviolet-Visible (UV-Vis), fluorescence and Fourier transform infrared (FT-IR) spectra synthetically indicated that calcium could be chelated by carboxyl oxygen and amino nitrogen atoms of collagen peptides, thus forming peptide-calcium chelate. The chelate was stable at various temperatures and pH values, and exhibited excellent stability in the gastrointestinal environment, which could promote calcium absorption in human gastrointestinal tract. Moreover, Caco-2 cell monolayer model was used to investigate the effect of peptide-calcium chelate on promoting calcium absorption. Results showed that peptide-calcium chelate could significantly improve calcium transport in Caco-2 cell monolayer and reverse the inhibition of calcium absorption by phosphate and phytate. The findings provide a scientific basis for developing new calcium supplements and the high-value utilization of pig bone., (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.)

We investigated the effect of high density lipoprotein from egg yolk (EYHDL) on serum, hepatic and fecal lipid and fatty acids (FAs) levels and on gene expression involved in FAs metabolism. Male KM mice were fed either normal diet (ND; n=20), high fat diet (HFD; n=20), or high fat diet containing EYHDL (EYHDL; 0.6 mg/g, every day by oral gavage, n=20) for 100 days. At the end of the experiment, the effects of treatments on biochemical parameters, FAs profiles and involved gene expression were analyzed. Our results revealed that EYHDL markedly suppressed the body weight gain, accumulation of abdominal fat tissues, serum concentrations of LDL-cholesterol (LDL-C) and triglycerides, hepatic triglycerides and cholesterol accumulation, while increased serum concentration of HDL-cholesterol (HDL-C). EYHDL intake also increased total cholesterol (TC) excretions compared with HFD group. Moreover, it alleviated the severity of fatty liver and improved glucose and insulin tolerance compared with HFD. More importantly, EYHDL partially normalized FAs profiles in serum, liver and fecaces and neutralized the HFD-induced upregulation of SREBP-1c, Acaca, Fasn, GPAT and Scd1. In conclusion, our findings indicate that EYHDL may have the potential to improve metabolic disturbances that occur in HFD mice and can be considered as an appropriate dietary recommendation for the treatment of metabolic syndrome (MetS)., Competing Interests: Conflicts of Interest The authors declare no potential conflict of interest.

In addition to small amounts of minerals and carbohydrates, most of the dry matter of chicken egg white is protein, making egg white an ideal resource for obtaining food proteins. Ovalbumin (OVA), which accounts for more than 50% of the total egg white protein, is one of the most widely studied food proteins due to its multiple functional properties, and it has also been used as a model protein molecule in many research fields. The objective of this study was to develop a simple and rapid method for the purification of OVA from egg whites on large scale. First, OVA was separated from ovomucin, ovotransferrin, and ovomucoid by polyethylene glycol (PEG) concentration, using the following optimal parameters: the PEG concentration was 15%, the pH was 6.5, the salt concentration was 100 mmol/L, and the operating temperature was 10°C. The OVA-rich supernatant obtained from PEG precipitation was further purified by isoelectric precipitation at a pI of 4.5 and a temperature of 4°C, and the purified OVA was obtained with at a purity of 95.1% by HPLC, with a yield of 46.4%. After the extraction of OVA, the PEG solution was vacuum dried and then utilized cyclically in the PEG precipitation steps. The whole purification process could be finished within 2 to 3 h at a scale of several kilograms of egg white. This method has the advantages of rapidity, simplicity, low cost, and ease of scalability., (© 2018 Poultry Science Association Inc.)

A series of different eggshell membrane (ESM) and chitosan (CS) blend films (ESM/CS) were prepared for wound-care dressing. The appearance, transparency and microstructure of the films were characterized. Several wound care-related properties such as the film integrity in solution, pH, protein (BSA) and wound fluid absorption capacity as well as the antibacterial property of ESM/CS films were evaluated. The blend films were more stable than CS film after 95 h of incubation in solution. The integrity of the blend films improved significantly at the cost of a small insignificant decrease in wound fluid absorption capacity. Besides, the blend films provided an acidic environment (pH = 5.86) for wound healing. The swelling properties of ESM contributed significantly to the increase of BSA absorption capacity of the blend films (from 46.57 mg/g of CS film to 61.07 mg/g of blend film) and helped absorb more nutrients to promote the proliferation and migration of fibroblasts. Addition of CS to ESM also enhanced the antibacterial activity of the films significantly. The results indicated that the EMS/CS blend films with 0.01 g ESM/mL CS solution showed the highest high potential to be used as a wound-care dressing for humans as well as animals., (Copyright © 2018 Elsevier B.V. All rights reserved.)

As the most abundant protein in chicken eggs, ovalbumin plays an important role in the processing of high value-added poultry products. The present study investigated the effects of hydroxyl radical-induced early stage oxidation on the physicochemical and interfacial properties of chicken egg white ovalbumin. Protein carbonyl content of ovalbumin increased (from 0.78 to 1.13 nmol/mg) with the oxidation time (0-5 h), while free sulfhydryl content (from 0.43 to 0.09 nmol/mg) and free amino group content (from 0.49 to 0.43 nmol/mg) decreased. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis showed that the exposure of ovalbumin to hydroxyl radicals caused self-cross-linking and resulted in the formation of dimers and trimers. Accompanied by these changes, the surface hydrophobicity of ovalbumin was enhanced about 1.5-fold with the deepening of oxidation, and the value of zeta potential became more negative (from -7.15 to -20.51 mv). About 2 h of moderate oxidation improved the foaming and emulsifying properties of ovalbumin (1.2-fold to 1.8-fold), while excessive oxidation (3 h) decreased these interface properties. Hydroxyl radical-induced oxidation changed the surface chemical groups and structures of ovalbumin, thereby affecting the surface properties. The foaming and emulsifying properties of ovalbumin could be improved by oxidation, increasing the application possibilities of ovalbumin in the food interface system., (© 2018 Poultry Science Association Inc.)

This study compared the long-term effects of EY consumption under two diet conditions: normal (ND + EY) and high fat diet (HFD + EY), on lipid metabolism in mice. ND + EY did not increase serum triglycerides, total cholesterol hepatic triglyceride concentrations, adipose tissue accumulation and glucose impairment, not leading to fatty liver. HFD + EY markedly decreased adipose tissue accumulation, the triglyceride and total cholesterol, and improved serum HDL-C and blood glucose impairment compared with HFD. PLS-DA analyzes showed both ND + EY and HFD + EY could decrease serum C18:1 and MUFA. HFD + EY could further decrease hepatic C18:2 and PUFA and increase C18:1 and MUFA excretion, which were associated with lower expression of Elovl6 and higher expression of Scd1 in liver. These results suggest that HFD + EY significantly improved dyslipidemia caused by HFD through modifying lipid metabolism, and ND + EY did not adversely affect the biomarkers associated with dyslipidemia risk, but showed less obvious regulation of lipid metabolism than HFD + EY., Competing Interests: Conflict of interestThe authors declare that they have no conflict of interests.

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.

In order to broaden the antimicrobial action spectrum of lysozyme against Gram-negative bacteria, different partially reduced lysozyme derivatives were obtained by reducing the R-S-S-R bonds of lysozyme using the reducing agent Na2SO3. The circular dichroism behavior analysis showed that the tertiary structure of the partially reduced lysozyme molecules became more flexible, leading to an obvious increase in the surface hydrophobicity and the tryptophan fluorescence intensity. Zeta potential analysis indicated that the introduction of SO32- led to a decrease in the surface charges of the reduced lysozyme molecules. Compared with the native lysozyme, the reduced lysozymes not only showed a 1 log increase in the antimicrobial activity against Escherichia coli ATCC 25922 and Salmonella enteritidis ATCC 13076 (P <0.05), but also maintained nearly the same antimicrobial activity against Staphylococcus aureus ATCC 29213 (P >0.05). Overall, the reductive modification with the food-friendly, compatible, and safe reducing agent Na2SO3 has broadened the antimicrobial action spectrum of the modified lysozymes against Gram-negative bacteria, with the enhancement extent depending on the reduction degree and the type of bacterial strains. The integrated results suggest that the Na2SO3-reduced lysozyme can be used as a novel safe potential bactericidal additive for food-processing industry.

Ovomucin (OVM) plays an important role in inhibiting infection of various pathogens. However, this bioactivity mechanism is not much known. Here, the role of sialic acid in OVM anti-virus activity has been studied by ELISA with lectin or ligand. Structural changes of OVM after removing sialic acid were analyzed by circular dichroism and fluorescence spectroscopy. OVM could be binding to the hemagglutinin (HA) of avian influenza viruses H 5 N 1 and H 1 N 1 , this binding was specific and required the involvement of sialic acid. When sialic acid was removed, the binding was significantly reduced 71.5% and 64.35%, respectively. Therefore, sialic acid was proved as a recognition site which avian influenza virus bound to. Meanwhile, the endogenous fluorescence and surface hydrophobicity of OVM removing sialic acid were increased and the secondary structure tended to shift to random coil. This indicated that OVM molecules were in an unfolded state and spatial conformation disorder raising weakly. Remarkably, free sialic acid strongly promoted OVM binding to HA and thereby enhanced the interaction. It may contribute to the inhibition of host cell infection, agglutinate viruses. This study can be extended to the deepening of passive immunization field., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Posttranslational N-glycosylation of food proteins plays a critical role in their structure and function. However, the N-glycoproteome of chicken egg yolk (CEY) has not been studied yet. Glycopeptides hydrolyzed from CEY proteins were enriched, with deglycosylation occurring using PNGase F, and then were identified using a shotgun glycoproteomics strategy. A total of 217 N-glycosylation sites and 86 glycoproteins were identified in CEY, and these glycoproteins are mainly involved in the binding, biological regulation, catalytic activity, and metabolic processes. Among the identified CEY glycoproteins, 22 were recognized as proteases and protease inhibitors, suggesting that a proteinase/inhibitor regulation system exists in CEY; further, 15 were members of the complement and immune systems, which provide protection against potential threats during hatching. The study provides important structural information about CEY glycoproteins and aids in the understanding of the underlying mechanism of embryo development as well as changes in CEY functional characteristics during storage and processing.