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1.
Molecules ; 29(6)2024 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-38542963

RESUMO

Pepsin, trypsin and proteinase K were used in the present study to hydrolyse the proteins from whole eggs, yolks or whites, and the resulting hydrolysates were characterised in terms of antioxidant and IgE-binding properties, using a combination of in vitro and in silico methods. Based on the degree of hydrolysis (DH) results, the egg yolk proteins are better substrates for all the tested enzymes (DH of 6.2-20.1%) compared to those from egg whites (DH of 2.0-4.4%). The SDS-PAGE analysis indicated that pepsin and proteinase K were more efficient compared to trypsin in breaking the intramolecular peptide bonds of the high molecular weight egg proteins. For all the tested substrates, enzyme-assisted hydrolysis resulted in a significant increase in antioxidant activity, suggesting that many bioactive peptides are encrypted in inactive forms in the parent proteins. The hydrolysates obtained with proteinase K exhibited the highest DPPH radical scavenging activity (124-311 µM Trolox/g protein) and the lowest residual IgE-binding capacity. The bioinformatics tools revealed that proteinase K is able to break the integrity of the main linear IgE-binding epitopes from ovalbumin and ovomucoid. It can be concluded that proteinase K is a promising tool for modulating the intrinsic properties of egg proteins.


Assuntos
Antioxidantes , Pepsina A , Antioxidantes/química , Tripsina , Endopeptidase K , Peptídeos/química , Proteínas do Ovo/química , Hidrólise , Imunoglobulina E , Hidrolisados de Proteína/química
2.
J Agric Food Chem ; 72(10): 5212-5221, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38433387

RESUMO

To investigate the alterations of yolk protein during embryonic development in Wanxi white goose, the egg yolk protein composition at days 0, 4, 7, 14, 18, and 25 of incubation (D0, D4, D7, D14, D18, and D25) was analyzed by two-dimensional gel electrophoresis combined with mass spectrometry. A total of 65 spots representing 11 proteins with significant abundance changes were detected. Apolipoprotein B-100, vitellogenin-1, vitellogenin-2-like, riboflavin-binding protein, and serotransferrin mainly participated in nutrient (lipid, riboflavin, and iron ion) transport, and vitellogenin-2-like showed a lower abundance after D14. Ovomucoid-like were involved in endopeptidase inhibitory activity and immunoglobulin binding and exhibited a higher expression after D18, suggesting a potential role in promoting the absorption of immunoglobulin and providing passive immune protection for goose embryos after D18. Furthermore, myosin-9 and actin (ACTB) were involved in the tight junction pathway, potentially contributing to barrier integrity. Serum albumin mainly participated in cytolysis and toxic substance binding. Therefore, the high expression of serum albumin, myosin-9, and ACTB throughout the incubation might protect the developing embryo. Apolipoprotein B-100, vitellogenin-1, vitellogenin-2-like, riboflavin-binding protein, and serotransferrin might play a crucial role in providing nutrition for embryonic development, and VTG-2-like was preferentially degraded/absorbed.


Assuntos
Gansos , Vitelogeninas , Animais , Vitelogeninas/análise , Gansos/metabolismo , Apolipoproteína B-100/análise , Apolipoproteína B-100/metabolismo , Proteômica , Transferrina , Proteínas do Ovo/química , Desenvolvimento Embrionário , Albumina Sérica/metabolismo , Imunoglobulinas/análise , Miosinas/análise , Miosinas/metabolismo , Gema de Ovo/química
3.
Int J Biol Macromol ; 262(Pt 2): 130053, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38360234

RESUMO

This study investigated the effects of heating temperature of egg white gels (EWGs) on the digestive characteristics by heating egg white (EW) to reach 75 °C (EWG-75) and 95 °C (EWG-95). The gel protein structure showed a decrease in the maximum tryptophan fluorescence intensity and a significant increase in the surface hydrophobicity of EWGs compared to EW (P < 0.05). The total and reactive free sulfhydryl groups were higher in the EWGs than in the EW (P < 0.05). While the proportions of α-helical and ß-sheet structures remained similar in EW and EWG-75 (P > 0.05), EWG-95 exhibited a notable decrease in α-helix content (P < 0.05) and an increase in ß-sheet content (P < 0.05). Furthermore, EWG-95 displayed higher hardness and cohesiveness than EWG-75 (P < 0.05). In the adult and elderly in vitro digestion models, EWG-95 exhibited the highest protein digestibility (50.44 % and 54.65 % in the models of elderly and adult subjects, respectively) after GI digestion (P < 0.05), followed by EWG-75 and EW. The electrophoretogram of the digesta revealed more intense protein bands in the elderly digestion model, particularly in the gastric digesta of EW, indicating slower digestion compared to the adult model. Therefore, EW should be appropriately heated before consumption, especially for elderly individuals, to facilitate efficient protein digestion and absorption.


Assuntos
Calefação , Temperatura Alta , Humanos , Idoso , Temperatura , Proteínas do Ovo/química , Digestão
4.
Int J Biol Macromol ; 262(Pt 1): 129973, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38325697

RESUMO

The formation of the egg white precipitate (EWP) during dilution poses challenges in food processing. In this paper, the effects of 90 W and 360 W ultrasonic intensities on the inhibition of EWP formation were investigated. The findings revealed that 360 W sonication effectively disrupted protein aggregates, decreasing the dry matter of EWP by 5.24 %, particle size by 57.86 %, and viscosity by 82.28 %. Furthermore, the ultrasonic pretreatment unfolded protein structures and increased the content of ß-sheet structures. Combined with quantitative proteomics and intermolecular forces analysis, the mechanism by which ultrasonic pretreatment inhibited water-diluted EWP formation by altering protein interactions was proposed: ultrasonic pretreatment disrupted electrostatic interactions centered on lysozyme, as well as hydrogen-bonding interactions between ovomucin and water. In conclusion, our research provides valuable insights into the application of ultrasonic pretreatment as a means to control and improve the quality of egg white-based products.


Assuntos
Proteínas do Ovo , Clara de Ovo , Proteínas do Ovo/química , Clara de Ovo/química , Água , Ultrassom , Proteômica
5.
Mol Ecol ; 33(5): e17263, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38318732

RESUMO

The absence of robust interspecific isolation barriers among pantherines, including the iconic South American jaguar (Panthera onca), led us to study molecular evolution of typically rapidly evolving reproductive proteins within this subfamily and related groups. In this study, we delved into the evolutionary forces acting on the zona pellucida (ZP) gamete interaction protein family and the sperm-oocyte fusion protein pair IZUMO1-JUNO across the Carnivora order, distinguishing between Caniformia and Feliformia suborders and anticipating few significant diversifying changes in the Pantherinae subfamily. A chromosome-resolved jaguar genome assembly facilitated coding sequences, enabling the reconstruction of protein evolutionary histories. Examining sequence variability across more than 30 Carnivora species revealed that Feliformia exhibited significantly lower diversity compared to its sister taxa, Caniformia. Molecular evolution analyses of ZP2 and ZP3, subunits directly involved in sperm-recognition, unveiled diversifying positive selection in Feliformia, Caniformia and Pantherinae, although no significant changes were linked to sperm binding. Structural cross-linking ZP subunits, ZP4 and ZP1 exhibited lower levels or complete absence of positive selection. Notably, the fusion protein IZUMO1 displayed prominent positive selection signatures and sites in basal lineages of both Caniformia and Feliformia, extending along the Caniformia subtree but absent in Pantherinae. Conversely, JUNO did not exhibit any positive selection signatures across tested lineages and clades. Eight Caniformia-specific positive selected sites in IZUMO1 were detected within two JUNO-interaction clusters. Our findings provide for the first time insights into the evolutionary trajectories of ZP proteins and the IZUMO1-JUNO gamete interaction pair within the Carnivora order.


Assuntos
Caniformia , Carnívoros , Panthera , Animais , Masculino , Receptores de Superfície Celular/genética , Proteínas do Ovo/genética , Proteínas do Ovo/química , Proteínas do Ovo/metabolismo , Sêmen/metabolismo , Interações Espermatozoide-Óvulo/genética , Carnívoros/genética , Caniformia/metabolismo , Feliformes/metabolismo , Panthera/metabolismo , Zona Pelúcida/metabolismo
6.
Food Chem ; 442: 138448, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38245983

RESUMO

This study was oriented towards the impacts of unique interfacial networks, formed by glycosylated and non-glycosylated egg white proteins, on the characteristics of high internal phase Pickering emulsions (HIPPEs). Glycosylated egg white protein particles (EWPG) manifested a more compact protein tertiary structure and amplified surface hydrophobicity, forming durable coral-like networks at the oil-water interface. The non-glycosylated egg white protein particles (EWP) could form spherical cluster interfacial networks. Raman spectroscopy analysis illuminated that EWPG could exhibit better interactions with aliphatic amino acids via hydrogen bonds and hydrophobic interactions. The release of free fatty acid (FFA) from both HIPPEs followed the first-order kinetic model with a combination of diffusion. EWPG-stabilized HIPPEs demonstrated superior physical stability and cellular antioxidant activity. This research shed light on the promising prospects of HIPPEs as promising amphiphilic delivery systems with capabilities to co-deliver hydrophilic and hydrophobic nutraceuticals and amplify their intracellular biological potency.


Assuntos
Antioxidantes , Ácidos Graxos não Esterificados , Emulsões/química , Antioxidantes/química , Interações Hidrofóbicas e Hidrofílicas , Proteínas do Ovo/química , Tamanho da Partícula
7.
Food Res Int ; 176: 113825, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38163687

RESUMO

This paper investigates the freeze-thaw stability of oil-in-water emulsions stabilized by high-temperature wet heating glycosylation products. Glucose (Glu), D-fructose (Fru), xylose (Xyl), maltodextrin (MD), oligofructose (FO), and oligomeric isomaltulose (IMO) were chosen as sugar sources for the glycosylation reaction with egg white proteins (EWPs) at 120 °C to prepare the GEWPs. The study reveals that the type of sugar significantly influences the Maillard reactions with EWPs. The degree of glycosylation was highest in the Xyl group with the greatest reducing capacity and lowest in the MD, FO, and IMO groups. High-temperature wet glycosylation treatment induced changes in the secondary and tertiary structures of EWP. Elevated temperature exposed hydrophobic groups within the protein, while covalent binding of hydrophilic carbohydrates via the Maillard reaction decreased the protein's H0 value. Improved foaming and emulsifying properties were attributed to the increase in α-helix content, disulfide bond formation, and reduced surface tension. Emulsions prepared from GEWPs exhibited higher apparent viscosity and G' compared to those from natural EWPs, with the GEWP/Xyl group showing the highest values. After freeze-thaw treatment, the GEWP/Fru and GEWP/FO groups demonstrated superior stability and reduced freezing point, along with minimal microstructural alterations. These findings underscore the importance of sugar type in the stability of high internal phase emulsions (HIPEs) stabilized by GEWPs, indicating that a tailored Maillard reaction can yield stabilizers with exceptional freeze-thaw stability for emulsions.


Assuntos
Carboidratos , Proteínas do Ovo , Emulsões/química , Glicosilação , Temperatura , Proteínas do Ovo/química , Açúcares , Conformação Molecular
8.
Ultrason Sonochem ; 102: 106746, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38157804

RESUMO

The dry separate curing of duck egg yolks was carried out by ultrasonic synergize NaCl (sodium chloride) and NaCl alone. The mechanism of the amelioration of salted egg yolk quality by ultrasonic synergistic NaCl dry-curing was studied. The quality variations of the salted egg yolks were analyzed for the same curing time and NaCl content achieved by ultrasonic synergistic NaCl curing and NaCl curing alone. The results showed that under the same salting time, the NaCl content, oil exudation and chewiness of U48-SEY (ultrasonic for 48 h-salted egg yolk) were higher than those in SEY (salted egg yolk). At the same NaCl content, the oil exudation and chewiness of U44-SEY (ultrasonic for 44 h-salted egg yolk) were still significantly increased. Compared to SEY, the soluble protein content and H0 of U44-SEY and U48-SEY were augmented. Scanning electron microscopy (SEM) indicated that the polyhedral particles in the salted egg yolks prepared by ultrasonic synergistic NaCl dry-curing were closely aligned and evenly distributed, and the salted egg yolks were sandier. Structural analysis revealed that the secondary and tertiary structures of egg yolk protein were changed although the ultrasonic synergistic NaCl dry-curing did not cause the fragmentation or aggregation of the peptide chain structure. The above results suggested that ultrasonic not only perfected the quality of salted egg yolk by promoting NaCl penetration, but also modified the structures of egg yolk protein by the action of ultrasonic itself, which prominently improved the quality of salted egg yolks.


Assuntos
Gema de Ovo , Cloreto de Sódio , Gema de Ovo/química , Cloreto de Sódio/química , Ultrassom , Proteínas do Ovo/análise , Proteínas do Ovo/química , Microscopia Eletrônica de Varredura
9.
Biomolecules ; 13(11)2023 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-38002318

RESUMO

Mammalian fertilization is a species-selective event that involves a series of interactions between sperm proteins and the oocyte's zona pellucida (ZP) glycoproteins. Bovine ZP consists of three glycoproteins: bZP2, bZP3, and bZP4. In our previous study, we demonstrated that bovine sperm binds to plastic wells coated with recombinant bZP4 and identified that the N-terminal domain and the middle region of bZP4 are critical for sperm-binding activity. Here, we investigated the sperm-binding site in the middle region (residues 290 to 340) of bZP4, which includes the hinge region. We showed that bovine sperm binds to bZP4's middle region in a species-selective manner. We mapped the function of bZP4's middle region to its N-glycosylation site at Asn-314 using several recombinant mutated proteins. Moreover, we showed that mutations of the N-glycosylation sites at Asn-314 close to the hinge region and Asn-146 of the hinge region of bZP4 and bZP3, respectively, reduced the sperm-binding activity of the complex of the bZP3 (from 32 to 178) and bZP4 (from 136 to 464) fragments. Together, these results suggest that ZP's middle regions of bZP3 and bZP4 form one of the sperm-binding sites of bovine ZP.


Assuntos
Glicoproteínas de Membrana , Receptores de Superfície Celular , Masculino , Bovinos , Animais , Glicoproteínas da Zona Pelúcida/genética , Glicoproteínas da Zona Pelúcida/metabolismo , Glicosilação , Glicoproteínas de Membrana/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Proteínas do Ovo/genética , Proteínas do Ovo/química , Proteínas do Ovo/metabolismo , Zona Pelúcida/metabolismo , Sêmen/metabolismo , Espermatozoides/metabolismo , Glicoproteínas/metabolismo , Mamíferos/metabolismo
10.
Food Res Int ; 173(Pt 1): 113327, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37803637

RESUMO

The pH treatment significantly enhanced the functional properties of egg white protein (EWP), but little is known about the relationship between pH treatment and in vitro digestion of EWP. In this paper, we explored the effect of pH treatment (pH 2, pH 2-7, pH 12 and pH 12-7) on the digestibility of egg white protein and peptide profiling using the digestion kinetics and peptidomics methods, separately. The results implied that all pH treatment reduced the protein digestibility in gastric phase, while alkaline pH (pH 12 and pH 12-7) showed greater digestion level and more gastric peptides, and more importantly, produced a greater amount of potentially bioactive peptides than acid treated samples. Besides, the least number of potentially bioactive peptides was obtained at pH 2, but this could be improved by adjusting pH 2 back to 7. Notably, the unique bioactive peptides induced by pH were mainly relevant to DPP IV inhibitor. These differences of digestibility and peptide profiling might be attributed to the change of protein structure and the formation of molten sphere, altering cleavage sites of digestive enzymes. This work would give an enlightening insight into the digestive and nutritional characteristics of the pH-induced EWP to expand their application in the field of food and healthcare.


Assuntos
Proteínas do Ovo , Peptídeos , Proteólise , Proteínas do Ovo/química , Peptídeos/química , Concentração de Íons de Hidrogênio
11.
Food Res Int ; 173(Pt 1): 113349, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37803654

RESUMO

Sulfated polysaccharides exhibit great potential for regulating protein-protein interactions. In the present study, three sulfated microcrystalline cellulose (MCS) with different degrees of sulfate substitution (DSS: 0.33, 0.51, 0.61) were synthesized and the effects of DSS on the regulation of egg white protein (EWP) aggregation and gelation properties were investigated. The results found that the improvement of protein mechanical properties by MCS is closely related to the level of sulfate substitution. The higher the DSS, the more ordered protein aggregates and compact gel network formed during heating as compared to that of pure EWP. Lower DSS (0.33) shows little effect on the mechanical properties of EWP. Furthermore, all the MCSs could significantly destroy the tertiary structure of protein molecules during heating, while for the secondary structure, MCS with higher DSS (0.51 and 0.61) could effectively control the decreasing tendency of α-helix and increasing tendency of ß-sheet. Hydrophobic interactions were recognized as the major intermolecular force in the compact mixed gels (EWP/MCS2 and EWP/MCS3 gels, DSS was 0.51 and 0.61, respectively). These findings provide a vital understanding of the gelling mechanism of the protein-polysaccharide system and the application of sulfated polysaccharides in protein-based food products.


Assuntos
Proteínas do Ovo , Sulfatos , Proteínas do Ovo/química , Polissacarídeos , Géis/química , Estrutura Secundária de Proteína
12.
Int J Biol Macromol ; 253(Pt 3): 126909, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37714238

RESUMO

In this study, the properties of pigeon egg white (PEW) and chicken egg white (CEW) thermal gels were compared, with the aim of revealing the mechanisms involved in the high transparency of PEW thermal gels. Results demonstrated that PEW gels exhibited higher transparency than CEW gels. Scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis revealed that PEW gels formed a fine chain gel network structure with an average diameter of thermal aggregates (89.84 ± 7.13 nm). The molecular properties of PEW proteins, such as higher content of ß-sheet structures (32.73 %), reactive groups (free sulfhydryl groups, hydrophobic groups), and absolute zeta potential (-3.563 mV), were found to contribute to the formation of smaller thermal aggregates during thermal denaturation. The microrheology measurements showed that these features allowed PEW proteins to interact less with each other and form smaller thermal aggregates during thermal denaturation, which facilitated the formation of fine chain gel networks and thus improved the transparency of the gels. The present study initially reveals the molecular basis of the high transparency of PEW thermal gels and provides a theoretical reference for the development of new highly transparent protein materials.


Assuntos
Clara de Ovo , Temperatura Alta , Animais , Clara de Ovo/química , Columbidae , Proteínas do Ovo/química , Géis/química
13.
Sheng Wu Gong Cheng Xue Bao ; 39(7): 2684-2694, 2023 Jul 25.
Artigo em Chinês | MEDLINE | ID: mdl-37584124

RESUMO

The aim of this study was to clone the chicken zp1 gene encoding zona pellucida 1 (Zp1) and investigate its tissues expression profile and its effect on osteoblast mineralization. The expression level of zp1 was quantified in various tissues of laying hens and in the tibia of the pre- and post-sexual maturity by RT-qPCR. Zp1 overexpressed vector was transfected into chicken calvarial osteoblasts which were induced differentiation for 8 days, and the extracellular mineral and the expression of mineralization-related genes were detected. The full-length chicken zp1 gene is 3 045 bp, encoding 958 amino acids residuals, and has two N-glycosylation sites. The highest expression level of the zp1 gene was found in the liver, followed by the tibia and yolk membrane, while no expression was detected in the heart and eggshell gland. Compared with the pre-sexual maturity hens, the concentration of estrogen (E2) in plasma, the content of glycosaminoglycan (GAG) and the expression level of the zp1 gene in the tibia with post-sexual maturity were higher. The extracellular matrix and the level of osteoblast mineralization-related genes showed a significantly upregulated expression in chicken calvarial osteoblasts with Zp1 overexpressed and addition of estrogen. The expression of the zp1 gene is tissue-specific and positively regulated osteoblast mineralization under the action of estrogen, laying the foundation for elucidating the functional properties of Zp1 in chicken bones during the egg production period.


Assuntos
Galinhas , Glicoproteínas de Membrana , Feminino , Animais , Glicoproteínas da Zona Pelúcida , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Galinhas/genética , Proteínas do Ovo/química , Proteínas do Ovo/genética , Proteínas do Ovo/metabolismo , Receptores de Superfície Celular , Estrogênios
14.
Int J Biol Macromol ; 248: 125851, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37467832

RESUMO

The knowledge of fundamental rheological concepts is essential to understand the gelling process of egg white proteins (EWP), which can be used to further manipulate the gel performance with desired sensorial attributes. In this study, the rheological and gel properties of EWP as influenced by heating in the dry state were investigated. The structural changes in dry heated EWP (DEWP) were also characterized in terms of morphology, protein stability, and protein microenvironment. The results showed that moderate dry heating induced linear aggregation of DEWP and decreased the denaturation temperature (Td) and enthalpy of denaturation (ΔH). Furthermore, the cross-linking on protein surface led to nonpolar microenvironment of hydrophobic groups, which lays the foundation of improved gel properties. The specific outcomes include the increase in the G'max and the G''max values, k'/k'' values of DEWP dispersions, gel hardness and gumminess of DEWP gels and a decrease in gelation temperature of DEWP dispersions. However, few changes were found in the springiness and cohesiveness of the DEWP gels with increasing dry heating time. Notably, gels prepared with DEWP also had better digestibility. Overall, these results can provide theoretical basis for quality control and sensory evaluation of DEWP in the food industry.


Assuntos
Proteínas do Ovo , Proteínas do Ovo/química , Géis/química , Interações Hidrofóbicas e Hidrofílicas , Reologia , Temperatura
15.
Int J Biol Macromol ; 246: 125711, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37414321

RESUMO

This study investigated the impact of varied pH treatments on the structural, emulsification, and interfacial adsorption properties of egg yolk. The solubility of egg yolk proteins decreased and then increased in response to pH changes, with a minimum value (41.95 %) observed at pH 5.0. The alkaline condition (pH 9.0) significantly impacted the secondary/tertiary structure of egg yolk, with the yolk solution displaying the lowest surface tension value (15.98 mN/m). Emulsion stability was found to be optimal when egg yolk was used as the stabilizer at pH 9.0, which corresponded to the more flexible diastolic structure, smaller emulsion droplets, increased viscoelasticity, and enhanced resistance to creaming. At pH 9.0, proteins exhibited a maximum solubility (90.79 %) due to their unfolded conformation, yet the protein adsorption content at the oil-water interface showed relatively low (54.21 %). At this time, electrostatic repulsion between the droplets and the spatial site barrier made by proteins that were unable to efficiently adsorb at the oil-water interface kept the emulsion stable. Moreover, it was found that different pH treatments could effectively regulate the relative adsorption contents of various protein subunits at the oil-water interface, and all proteins except livetin displayed good interfacial adsorption capacity at the oil-water interface.


Assuntos
Proteínas do Ovo , Água , Adsorção , Emulsões/química , Concentração de Íons de Hidrogênio , Proteínas do Ovo/química , Água/química , Gema de Ovo/química
16.
Poult Sci ; 102(7): 102711, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37167887

RESUMO

Chicken egg yolk granules (EYG) were the precipitated component of egg yolk after water dilution and centrifugation. Compared with egg yolk, EYG are rich in proteins, phospholipids, and minerals. In this study, an integrated proteomic analysis was carried out to in-depth mapping of the proteome, phosphoproteome, and N-glycoproteome of EYGs. After hydrolysis of the EYG total protein, the hydrolyzed peptides or the enriched phosphopeptides/glycopeptides were identified by liquid chromatography-tandem mass spectrometry. A total of 125 phosphorylation sites from 36 phosphoproteins and 244 N-glycosylation sites from 100 N-glycoproteins were identified in EYG. All 3 vitellogenins (precursors of egg yolk high-density lipoprotein) were heavily phosphorylated and N-glycosylated, of which 37 phosphorylation sites and 32 N-glycosylation sites were identified on vitellogenins-2. A Total of 30 N-glycosylation sites were identified on apolipoprotein-B (precursor of egg yolk low-density lipoprotein), but no phosphorylation site was identified. These phosphorylation and N-glycosylation of EYG proteins provide new insights for understanding the assembly structure and functional characteristics of EYG, thus contributing to its development and utilization.


Assuntos
Galinhas , Vitelogeninas , Animais , Galinhas/metabolismo , Vitelogeninas/análise , Vitelogeninas/metabolismo , Gema de Ovo/química , Proteômica , Proteínas do Ovo/química
17.
Molecules ; 28(6)2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36985630

RESUMO

This review article discusses advanced extraction methods to enhance the functionality of egg-derived peptides while reducing their allergenicity. While eggs are considered a nutrient-dense food, some proteins can cause allergic reactions in susceptible individuals. Therefore, various methods have been developed to reduce the allergenicity of egg-derived proteins, such as enzymatic hydrolysis, heat treatment, and glycosylation. In addition to reducing allergenicity, advanced extraction methods can enhance the functionality of egg-derived peptides. Techniques such as membrane separation, chromatography, and electrodialysis can isolate and purify specific egg-derived peptides with desired functional properties, improving their bioactivity. Further, enzymatic hydrolysis can also break down polypeptide sequences and produce bioactive peptides with various health benefits. While liquid chromatography is the most commonly used method to obtain individual proteins for developing novel food products, several challenges are associated with optimizing extraction conditions to maximize functionality and allergenicity reduction. The article also highlights the challenges and future perspectives, including optimizing extraction conditions to maximize functionality and allergenicity reduction. The review concludes by highlighting the potential for future research in this area to improve the safety and efficacy of egg-derived peptides more broadly.


Assuntos
Alérgenos , Hipersensibilidade a Ovo , Humanos , Peptídeos/química , Ovos/análise , Proteínas do Ovo/química
18.
J Food Sci ; 88(4): 1553-1565, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36789854

RESUMO

The study aimed to investigate the effect of high intensity ultrasonic (HIU) treatment at different times (0, 10, 20, and 30 min) on the structure and gel properties of water-soluble potato protein isolate (WPPI) and to further investigate the improvement of gel properties of ultrasonicated WPPI (UWPPI) by the addition of egg white protein (EWP). HIU reduced the particle size of WPPI, whose structure became loose and disordered, which improved gelling properties of UWPPI. Fourier transform infrared results indicated that α-helix content decreased, whereas the proportion of irregular curl increased with the increase in ultrasonication time (0-20 min), indicating that the initially ordered structure of UWPPI became disordered. After HIU treatment, the free sulfhydryl groups of UWPPI and surface hydrophobicity decreased and fluorescence intensity increased. These results demonstrated that the HIU loosened the structure of UWPPI, exposing more chromogenic groups while embedding more hydrophilic groups. After thermal induction, UWPPI gel hardness increased and exhibited excellent water holding capacity. After the addition of EWP, rheological properties stabilized, and the hardness of UWPPI-EWP gels increased significantly, forming internally structured protein gels with a tightly ordered structure and increased brightness. Thus, HIU changed the structure and gelling properties of WPPI, and the addition of EWP further enhanced the performance of hybrid protein gels. PRACTICAL APPLICATION: High intensity ultrasonic changed the structure of water-soluble potato protein isolate (WPPI) and improved the properties of WPPI gels. The addition of egg white protein significantly improved the quality of mixed protein gels which showed great potential industrial value.


Assuntos
Solanum tuberosum , Ultrassom , Proteínas do Ovo/química , Géis , Água/química
19.
Food Chem ; 409: 135263, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-36592599

RESUMO

In this study, the thermal gelation and digestion properties of hen egg white (hen EW) proteins with different salts were investigated. Results show that the addition of neutral salt - sodium chloride (NaCl) decreased the gel hardness/resilience, increased gel lightness, aggregated particle size and digestibility of hen EW proteins significantly. In contrast, alkaline salts - phosphate and carbonate addition increased the gel resilience and strain tolerance as well as reduced the aggregated particle size and gel lightness of hen EW proteins due to the increase of solution pH and negative charge. Correlation analysis shows that the digestibility of hen EW gels was affected by gel viscoelasticity, molecule forces and texture. In conclusion, thermal gelation properties of hen EW proteins could be modulated by salts with different pH/ionic strength, and thus affected the protein digestion and peptide released.


Assuntos
Clara de Ovo , Sais , Clara de Ovo/química , Cloreto de Sódio/química , Proteínas do Ovo/química , Digestão , Géis/química
20.
Food Chem ; 400: 134019, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36084589

RESUMO

Egg-white peptides (EWP, <1 kDa) have been shown to possess various bioactive properties. However, poor emulsification of EWP limits its application in functional foods. In this study, EWP aggregation induced by proanthocyanidins (PC) contributed to the improvement of emulsion properties. The two-step binding process of PC-EWP-EWP was confirmed by isothermal titration calorimetry, fluorescence spectroscopy, surface hydrophobicity, and Fourier transform infrared spectroscopy. We found that first EWP combines with PC via hydrogen bonding and hydrophobic interactions. Next, more EWPs bind to the EWP in PC-EWP via hydrogen bonding, thereby forming PC-EWP-EWP aggregates. The aggregates (PC to EWP ratio of 1:4) reduced the surface tension (6 %) and improved the contact angle (53 %). The co-adsorption of EWP and aggregates at the O/W interface improved the contact angle, protein adsorption rate, and emulsion stability. This study establishes EWP aggregates induced by PC as an effective emulsifier, thereby expanding the application fields of EWP.


Assuntos
Proteínas do Ovo , Proantocianidinas , Proteínas do Ovo/química , Clara de Ovo , Emulsões , Peptídeos
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