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1.
J Agric Food Chem ; 67(35): 9950-9957, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31403788

RESUMO

Protein glycosylation is a ubiquitous posttranslational modification that modulates protein properties, thereby influencing bioactivities within a system. Duck egg white (DEW) proteins exhibit diverse biological properties compared with their chicken egg white (CEW) counterparts, which might be related to glycosylation. N-Glycoproteome analysis of DEW was conducted, and a total of 231 N-glycosites from 68 N-glycoproteins were identified. Gene ontology analysis was used to elucidate the biofunctions of DEW N-glycoproteins and compare them with those of CEW, which showed that the differences mostly involved molecular functions and biological processes. The biological functions of DEW N-glycoproteins were illuminated through bioinformatics analysis and comparison with CEW orthologues, which showed different allergenicities and antibacterial abilities. These divergences might be initiated by specific alterations in glycosylation, which can enhance the proteolysis resistance and protein steric hindrance. These results provide new insights for discovering the effects of N-glycosylation on biofunctions during the divergence of homologous proteins.


Assuntos
Galinhas/genética , Patos/genética , Proteínas do Ovo/química , Glicoproteínas/química , Animais , Evolução Biológica , Galinhas/metabolismo , Patos/metabolismo , Proteínas do Ovo/genética , Proteínas do Ovo/metabolismo , Clara de Ovo/química , Glicoproteínas/genética , Glicoproteínas/metabolismo , Glicosilação , Proteômica
2.
Int J Nanomedicine ; 14: 3273-3282, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31190793

RESUMO

Background: Biotemplates are attractive templates for the synthesis of nanometals and inorganic compound nanostructures. Methods: In this work, for the first time, iron oxide quantum dot nanoparticles (QDNPs) were prepared using albumen as a biotemplate. Next, the prepared nanoparticles were characterized using dynamic light scattering for determination and evaluation of the hydrodynamic diameter and zeta potential of the particles. Moreover, optical and scanning electron microscopes were applied to evaluate morphology. Spherically shaped iron oxide QDNPs were obtained with appropriate particle size and distribution. Fe(NO3)3.9H2O and egg whites were used as the source of the Fe element and particle size control agent in the aqueous medium, respectively. Afterward, the effect of calcination temperature parameters on the crystallinity purity and size of Fe nanocrystals were investigated. Also, products were characterized by various detection analyses such as thermogravimetry analysis/DTA, XRD, UV-vis, Fourier transform infrared (FT-IR,) transmission electron microscopy, and SEM. In order to investigate the antibacterial effect of the synthesized Fe nanobiological samples against bacterial strains, they were dissolved in dimethyl sulfoxide and diluted using distilled water. Then, different serial dilutions of 64 µg/mL, 32 µg/mL, 16 µg/mL, 8 µg/mL, 4 3BCg/mL, 2 µg/mL, 1 µg/mL, and 0.5 µg/mL of nanobiological samples were prepared and added to the Mueller-Hinton agar medium. Results: The minimum inhibitory concentration of the synthesized iron oxide quantum dot nanobiological was determined against pathogenic microbial strains of bacteria including Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens, Micrococcus luteus, Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, and Klebsiella pneumonia on the culture medium plate. Conclusion: The present nanobiological samples can be considered as a new material candidate for antibacterial drugs.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Proteínas do Ovo/química , Compostos Férricos/química , Nanopartículas/química , Pontos Quânticos/química , Animais , Difusão Dinâmica da Luz , Camundongos , Testes de Sensibilidade Microbiana , Nanopartículas/ultraestrutura , Espectrofotometria Ultravioleta , Difração de Raios X
3.
J Agric Food Chem ; 67(26): 7428-7434, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31187991

RESUMO

Protein-polyphenol interactions play a very important role in wine stability assessment, especially in red varieties. Different polysaccharides can influence these interactions by protecting or disrupting charges and are even used as additives to stabilize colloidal solutions. The most common examples are mannoproteins and carboxymethyl cellulose (CMC). In some cases, the mechanisms that are involved in these reactions are not thoroughly understood and can lead to unexpected problems and delayed haze formation after CMC addition to red wines. Small-scale bench trials were conducted in model systems under different pH conditions to monitor the formation of turbidity and protection mechanisms during the interaction of proteins, polyphenols, and polysaccharides. Egg-white protein was chosen as a protein model due to its complex composition, a commercial grape tannin extract was used as polyphenol source, and pectin, glucomannan, mannoprotein, alginate, and CMC were applied as polysaccharides to model various wine conditions. Reactions were monitored in duplicate on a 50 mL scale by spectrophotometry at 860 nm over at least 30 days. Some of the polysaccharides interacted directly with proteins or polyphenols causing precipitation. Other polysaccharides delayed the reaction between proteins and other macromolecules depending on their concentration. The results of these experiments provide important insights into reaction dynamics between macromolecules that are involved in the physical stability of wine.


Assuntos
Carboximetilcelulose Sódica/química , Proteínas do Ovo/química , Extratos Vegetais/química , Polifenóis/química , Polissacarídeos/química , Vinho/análise , Animais , Galinhas , Glicoproteínas de Membrana/química , Taninos/química , Vitis/química
4.
Ecotoxicol Environ Saf ; 180: 624-631, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31132558

RESUMO

Increasing levels of estrogenic pollution in marine environments has made the development of reliable biological detection techniques urgently needed. In this study, Japanese flounder (Paralichthys olivaceus) lipovitellin (Lv) was purified and used to establish three immunological methods for the detection of vitellogenin (Vtg), a biomarker for environmental estrogens. Firstly, five different methods were employed to purify Lv, among which water-precipitation was the fastest and easiest way to purify Lv. Japanese flounder Lv was characterized as a phospholipoglycoprotein with a molecular weight of ∼369 kDa. Using purified Lv and its specific polyclonal antibody, a sandwich enzyme-linked immunosorbent assay (ELISA) was developed. This assay had a working range from 7.8 to 250 ng/mL and a detection limit of 3.1 ng/mL. Furthermore, we developed an immunohistochemistry (IHC) and an immunofluorescence (IF) assay, both of which allowed visual detection of liver Vtg. Finally, Vtg induction in plasma and liver of juvenile Japanese flounders exposed to 17ß-ethinylestradiol (EE2) was measured using these three methods. Exposure to 10 and 50 ng/L EE2 significantly increased plasma Vtg levels, and obvious positive fluorescence signals were observed near the liver sinusoidal vessels. These results confirmed that the methods developed effectively detected estrogenic activity of exogenous chemicals. Therefore, this study provides reliable methodologies for biomonitoring of estrogenic pollution in marine environments.


Assuntos
Proteínas do Ovo/isolamento & purificação , Monitoramento Ambiental/métodos , Linguado , Imunoensaio , Vitelogeninas/metabolismo , Animais , Proteínas do Ovo/química , Proteínas do Ovo/imunologia , Biomarcadores Ambientais/imunologia , Estrogênios/toxicidade , Feminino , Masculino , Vitelogeninas/imunologia , Poluentes Químicos da Água/toxicidade
5.
Prep Biochem Biotechnol ; 49(7): 639-648, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31131710

RESUMO

There are many diseases linked to oxidative stress, including cancer. Importantly, endogenous antioxidants are insufficient to protect against this process. Peptides derived from food proteins produced by hydrolysis have been investigated as exogenous antioxidants. The present study aimed to identify novel peptides with antioxidant potential produced from egg and milk proteins hydrolysis with two new fungal proteases isolated from Eupenicillium javanicum and Myceliophthora thermophila. The degree of hydrolysis at several time points was calculated and correlated to DPPH scavenging and metal chelating assays, all hydrolysates presented antioxidant activity. Casein hydrolyzed by the M. thermophila protease showed the best antioxidant activity. The identified sequences showed that the proportions of amino acids that influence antioxidant activity support the antioxidant assay. Our data reveal the conditions necessary for the successful generation of antioxidant peptides using two novel fungal proteases. This opens a potential new avenue for the design and manufacture of antioxidant molecules.


Assuntos
Albuminas/química , Antioxidantes/química , Caseínas/química , Proteínas do Ovo/química , Peptídeos/química , Proteínas do Soro do Leite/química , Albuminas/farmacologia , Animais , Antioxidantes/farmacologia , Caseínas/farmacologia , Proteínas do Ovo/farmacologia , Eupenicillium/enzimologia , Peptídeo Hidrolases/química , Peptídeos/farmacologia , Proteólise , Sordariales/enzimologia , Proteínas do Soro do Leite/farmacologia
6.
J Agric Food Chem ; 67(25): 7147-7156, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31140270

RESUMO

Egg proteins are recognized as excellent sources of bioactive peptides, such as angiotensin-converting enzyme inhibitory (ACEi) peptides. Oral administration of a thermolysin-digested egg white hydrolysate (T-EWH) caused a significant blood pressure reduction in spontaneously hypertensive rats; a further ACEi assay implied that its ACEi activity was enhanced after in vitro gastrointestinal (GI) digestion. These results indicated that T-EWH contained ACEi peptides resisting GI digestion and/or being further released during GI digestion. Therefore, the objective of this study was to identify these responsible ACEi peptides from T-EWH. The conventionally activity-guided fractionation was applied, coupled with a synchronized GI digestion throughout, during which both peptide yield and ACEi activity before and after the GI digestion were measured. Finally, six ACEi peptides (LAPYK, LKISQ, LKYAT, INKVVR, LFLIKH, and LGHWVY) with good GI resistance were identified with IC50 values <20 µM, especially LKYAT (0.09 µM). The structure-activity relationship of these peptides was discussed. The discovery of GI-resistant ACEi peptides could further support the application of egg white proteins as functional food ingredients.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/química , Proteínas do Ovo/química , Trato Gastrointestinal/metabolismo , Hipertensão/metabolismo , Peptídeos/química , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Inibidores da Enzima Conversora de Angiotensina/metabolismo , Animais , Pressão Sanguínea/efeitos dos fármacos , Galinhas , Digestão , Clara de Ovo/química , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Peptídeos/administração & dosagem , Peptídeos/metabolismo , Peptidil Dipeptidase A/química , Hidrolisados de Proteína/química , Ratos , Ratos Endogâmicos SHR
7.
Carbohydr Polym ; 213: 329-337, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30879676

RESUMO

Natural-based nanocomposites are competitive and promising materials for biomedical applications due to their biocompatibility. Herein, a novel natural-based composite was fabricated by alternately depositing lysozyme (LY) and albumin egg (AE) on electrospun cellulose nanofibrous mats via layer-by-layer self-assembly (LBL) technology. To indicate the successful deposition process and investigate the variations of the mats during LBL process, the surface morphology, physical property, chemical composition, wetting behavior and thermal stability were systematically studied. The results showed that the surface morphology and composition of the mats were significantly influenced by LBL process, which further resulted in the variation of wetting behavior. Besides, the mechanical properties were enhanced after LBL modification. In addition, the LBL structured nanofibrous mats exhibited antibacterial activity and excellent biocompatibility with L929 fibroblasts. In brief, LY and AE coated LBL structured cellulose nanofibrous mats, especially the 15 bilayers coated mats, have considerably potential applications in the biomedical field.


Assuntos
Antibacterianos/farmacologia , Materiais Biocompatíveis/farmacologia , Celulose/química , Proteínas do Ovo/química , Escherichia coli/efeitos dos fármacos , Nanofibras/química , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/síntese química , Antibacterianos/química , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Sobrevivência Celular/efeitos dos fármacos , Ovos/análise , Fibroblastos/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Propriedades de Superfície
8.
Food Chem ; 275: 600-609, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30724239

RESUMO

Changes in physico-chemical properties, microstructure, protein structures and intermolecular force of egg yolk, plasma and granule gels during salting were investigated, using low-field nuclear magnetic resonance (LF-NMR), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and chemical analysis. The results showed that the contents of soluble protein and free sulfhydryl increased and, with D2O treatment, T21 and T22 decreased in egg yolks and plasma salted for 2 d. The particles of egg yolks, plasma and granules in the later stage of salting were disrupted and they liberated their constituents (phospholipids, neutral lipids and proteins), which randomly aggregated. The treatment with NaCl changed the spatial structure of egg yolk proteins. The results suggested that the oil exudation of salted egg yolks was mainly due to structural changes in the low-density lipoproteins. Granules were shown to contribute to the higher hardness and gelation of salted egg yolks.


Assuntos
Fenômenos Químicos , Proteínas do Ovo/química , Gema de Ovo/química , Plasma/química , Cloreto de Sódio/química , Animais , Géis , Fosfolipídeos/análise
9.
Food Chem ; 284: 180-187, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-30744844

RESUMO

Egg white lysozyme plays an important role in the processing of high value-added poultry products. Considering its applications in the food industry, lysozyme could interact with other food additives, thereby impacting their performance. The present study comparatively investigated the interaction and orientation of the mono-, dis-, and tris-azo food dyes with egg white lysozyme. Allura red AC, brilliant black PN and direct brown 1 bound to lysozyme through a static quenching mechanism with 105 magnitude binding constants. The binding affinity, mainly driven by hydrogen bonds and van der Waals forces, follows the order: direct brown 1 > brilliant black PN > allura red AC. Based on structural and computational analysis, the addition of the monoazo/disazo/trisazo dye led to differing degrees of lysozyme unfolding and numbers of azo groups. The type of substituents on the structures has momentous influence on the transportation and distribution of food dyes to egg white lysozyme.


Assuntos
Compostos Azo/química , Corantes de Alimentos/química , Muramidase/química , Compostos Azo/metabolismo , Dicroísmo Circular , Proteínas do Ovo/química , Proteínas do Ovo/metabolismo , Corantes de Alimentos/metabolismo , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Muramidase/metabolismo , Espectrometria de Fluorescência , Termodinâmica
10.
J Food Sci ; 84(2): 205-212, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30620779

RESUMO

The major driving force for the egg consumption in the United States over the past few decades was processed egg. However, the consumption of egg through the processed egg reached the plateau in recent years because of the imbalance in the demands between the egg white and yolk products. The consumer demands for egg white products are very high while those for the egg yolk, the co-product of dried egg white, are low because of the negative perceptions on egg yolk. Two key approaches that can be used to increase the value and use of egg yolk are: (1) developing new commodity products by fractionating egg yolk and apply them in various food processing, and (2) separating functional proteins and lipids from yolk and use them as is or further develop functional peptides and functional lipids and use them as pharmaceutical, nutraceutical, and cosmeceutical agents. These approaches can diversify the use of egg yolk, which eventually will help increase the consumption of egg. This review (1) discusses the current use of egg yolk products and the development of new functional commodity products from egg yolk, (2) review the important functional components in egg yolk and overview the current separation methods and their applications, (3) discuss the production of functional peptides and lipids using the separated egg proteins and lipids, and (4) suggest the future directions for the best use of egg yolk components. Development of scale-up production methods, which is vital for the practical applications, is discussed when appropriate.


Assuntos
Gema de Ovo/química , Ovos/economia , Animais , Galinhas , Proteínas do Ovo/química , Proteínas do Ovo/economia , Clara de Ovo/química , Clara de Ovo/economia , Ovos/análise , Manipulação de Alimentos/economia
11.
J Sci Food Agric ; 99(8): 3852-3859, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30680726

RESUMO

BACKGROUND: Understanding the interactions between feed additives and the functional properties of egg white protein (EWP) may offer novel insights into the effects of feed additives on laying hens and may provide an alternative for modification of the functional properties of EWP by using laying hens as bioreactors. Glycerol monolaurate (GML) is widely used in the food industry as an effective antibacterial emulsifier. In this work, the effects of three doses of dietary GML supplementation (150, 300, and 450 mg kg-1 hen) on the functional properties of EWP were investigated. RESULTS: The hardness of EWP gels was significantly improved by 300 and 450 mg kg-1 GML supplementation. Foaming capacity (FC) and foaming stability (FS) were increased after GML treatment; 450 mg kg-1 GML supplementation showed the most significant improvements, with 44.82% in FC and 23.39% in FS. Stabilization of EWP-oil emulsions was also improved, supported by a slowed creaming process and the formation of smaller oil droplets. The heat denaturation temperature and rheological properties were also modified by dietary GML supplementation, implying improved thermal stability. CONCLUSION: Our study demonstrated that GML supplementation has the potential to modify the functional properties of EWP, broadening the application of GML and providing a new perspective for evaluation of the efficacy of feed additives. © 2019 Society of Chemical Industry.


Assuntos
Ração Animal/análise , Galinhas/metabolismo , Suplementos Nutricionais/análise , Proteínas do Ovo/química , Clara de Ovo/química , Lauratos/metabolismo , Monoglicerídeos/metabolismo , Animais , Proteínas do Ovo/metabolismo , Óvulo/química , Óvulo/metabolismo , Reologia , Solubilidade , Temperatura Ambiente
12.
Food Chem ; 280: 65-72, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30642508

RESUMO

This study investigated the encapsulation of curcumin into egg white protein (EWP) nanoparticles. Processing conditions used to formulate the nanoparticles, including pH and the addition of ethanol, were used to control the unfolding and aggregation behavior of EWP. The curcumin loading capacity of the EWP nanoparticles was found to be strongly linked to the structural transitions of the protein during heat denaturation, and the microscopic properties of the particles such as particle size and zeta-potential. Fibrous particles were formed at lower pH (3.0) and were associated with a higher curcumin loading than the granular particles formed at pH 3.8. Ethanol leads to an increase in ß-sheet structure, and the formation of a coarser gel structure during heat denaturation, resulted in an increase in particle diameter. The highest curcumin loading capacities were 11.53 and 9.89 mg/g protein (with a final curcumin concentration of 312.5 µM and 268 µM respectively), at pH 3.0 and 3.8, respectively. Encapsulation in EWP nanoparticles was shown to both effectively slow the degradation ratio as well as protect the antioxidant activity of encapsulated curcumin.


Assuntos
Antioxidantes/química , Curcumina/química , Proteínas do Ovo/química , Nanopartículas/química , Dicroísmo Circular , Etanol/química , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Estrutura Secundária de Proteína
13.
Mater Sci Eng C Mater Biol Appl ; 95: 192-203, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30573242

RESUMO

Non-healing wounds are a major health problem worldwide and a significant cause of morbidity and mortality. Effective treatments for acute and chronic skin wounds are the focus of intensive research. Eggshell membrane (ESM) is a natural proteinaceous by-product of the food industry and is suitable for biomedical applications. The objective of this study was to evaluate processed eggshell membrane powder (PEP) for the promotion of skin wound healing. PEP was characterized using proteomics and bioinformatics. Proteomic analysis of PEP identified 110 proteins, including structural proteins such as collagen and cysteine-rich eggshell membrane proteins (CREMPs) that together constitute about 40% of PEP. Functional annotation clustering showed various predicted functionalities related to wound healing including response to external stimulus, defense response, inflammatory response, and cell-substrate adhesion. The impact of PEP on wound healing was determined using the mouse excisional wound splinting model with a subsequent assessment by histopathology. PEP was found to significantly accelerate wound closure at days 3, 7, and 10. Histological assessment showed significantly thicker granulation tissue in wounds treated with PEP than non-treated controls at days 10 and 17. In addition, histological scoring showed higher levels of collagen deposition at day 10 in wounds treated with PEP, with limited inflammatory reaction. Therefore, PEP is a biocompatible and non-cytotoxic biomaterial that has great potential for development into a cost-effective wound healing product.


Assuntos
Materiais Biocompatíveis/farmacologia , Proteínas do Ovo/farmacologia , Casca de Ovo/química , Proteômica/métodos , Cicatrização/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Proteínas do Ovo/química , Masculino , Camundongos , Camundongos Endogâmicos C57BL
14.
J Agric Food Chem ; 66(44): 11854-11863, 2018 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-30296079

RESUMO

Avian egg white is essential for protecting and nourishing bird embryos during their development. Being produced in the female magnum, variability in hen oviduct gene expression may affect egg white composition in domestic chickens. Since traditional poultry breeds may represent a source of variation, in the present study we describe the egg white proteome (mass spectrometry) and corresponding magnum transcriptome (high-throughput sequencing) for 20 hens from five domestic fowl breeds (large breeds: Araucana, Czech golden pencilled, Minorca; and small breeds: Booted bantam, Rosecomb bantam). In total, we identified 189 egg white proteins and 16391 magnum-expressed genes. The majority of egg white protein content comprised proteins with an antimicrobial function. Despite general similarity, Between-class Principal Component Analysis revealed significant breed-specific variability in protein abundances, differentiating especially small and large breeds. Though we found strong association between magnum mRNA expression and egg white protein abundance across genes, coinertia analysis revealed no transcriptome/proteome costructure at the individual level. Our study is the first to show variation in protein abundances in egg white across chicken breeds with potential effects on egg quality, biosafety, and chick development. The observed interindividual variation probably results from post-transcriptional regulation creating a discrepancy between proteomic and transcriptomic data.


Assuntos
Galinhas/genética , Proteínas do Ovo/genética , Animais , Animais Domésticos/classificação , Animais Domésticos/genética , Animais Domésticos/metabolismo , Galinhas/classificação , Galinhas/metabolismo , Proteínas do Ovo/química , Proteínas do Ovo/metabolismo , Feminino , Perfilação da Expressão Gênica , Proteoma/química , Proteoma/genética , Proteoma/metabolismo , Proteômica
15.
J Food Sci ; 83(8): 2119-2126, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30035322

RESUMO

There is a growing interest in substituting animal proteins with plant protein sources in food systems. A notable example is the replacement of hen egg white (EW) protein, which is used in a wide range of food products because of its excellent foaming characteristics. Here, enzymatically hydrolyzed wheat gluten, which has greater solubility and better foaming properties than wheat gluten itself, was prepared and incorporated in a classical meringue recipe to investigate its potential as a foaming agent. Meringues based on gluten hydrolysates (GHs) had batters with lower density and greater apparent viscosity than those based solely on EW protein. Furthermore, after baking, these GH containing meringues had greater specific volume than those based on EW protein alone and no notable differences in color or texture between the different samples were noted. These outcomes were related to basic insights in the air-water interfacial behavior of GHs obtained in earlier studies. More specifically, the greater foaming capacity of GH than of EW protein solutions was related to their superior meringue batter (density and apparent viscosity) and product (specific volume) properties. While EW protein solutions had better foam stability than GH solutions (in the absence of sugar), this was apparently less relevant for meringue properties, probably due to the very high viscosity of the sugar rich batter, which could obscure differences in the intrinsic foam stabilizing ability of the samples. PRACTICAL APPLICATION: Replacing animal proteins with plant protein sources in the food industry is desirable from an economic and environmental perspective. Enzymatic hydrolysis serves as a tool to improve the foaming properties of water-insoluble wheat gluten proteins. We conclude that wheat gluten hydrolysates can be a valid functional alternative for egg white proteins in meringues, and possibly other food systems.


Assuntos
Culinária/métodos , Glutens/química , Glutens/metabolismo , Triticum/química , Animais , Fenômenos Químicos , Proteínas do Ovo/química , Alimentos , Indústria Alimentícia/métodos , Hidrólise , Proteínas de Plantas , Solubilidade , Tensoativos , Viscosidade , Água
16.
Adv Food Nutr Res ; 85: 1-58, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29860972

RESUMO

The hen's egg is an important protein source of human diet. On average one large egg contains ~6g protein, which contributes to ~11% of daily protein intake. As a high-quality protein, egg proteins are well recognized as excellent sources of bioactive peptides. The objectives of this chapter are to introduce generation, bioactivities, and absorption of egg protein-derived bioactive peptides. Research on egg protein-derived bioactive peptides has been progressed during the past decades. Enzymatic hydrolysis is the major technique to prepare bioactive peptides from egg protein. Quantitative structure-activity relationships-aided in silico prediction is increasingly applied as a promising tool for efficient prediction of novel bioactive peptides. A number of bioactive peptides from egg proteins have been characterized for antioxidant, immunomodulatory, antihypertensive, antidiabetic, anticancer, and antimicrobial activities. Egg protein-derived peptides that can improve bone health have been reported as well. However, molecular mechanisms of many peptides are not fully understood. The stability and absorption routes, bioavailability, safety, and production of bioactive peptides await further investigation.


Assuntos
Proteínas do Ovo/química , Ovos/análise , Peptídeos/química , Peptídeos/farmacologia , Sequência de Aminoácidos , Animais , Simulação por Computador , Humanos , Relação Estrutura-Atividade
17.
J Food Sci ; 83(6): 1762-1768, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29745974

RESUMO

Angiotensin I converting enzyme (ACE) plays an important role in regulation of blood pressure as it converts angiotensin I into angiotensin II (a potent vasoconstrictor). Food protein-derived ACE inhibitory peptides have been considered as a safer alternative to antihypertensive drugs. In our previous study, three ACE inhibitory peptides were characterized from egg white ovotransferrin and their antihypertensive activity has been validated in spontaneously hypertensive rats. However, it is too costly to prepare these peptides from purified egg white ovotransferrin. The aims of the study were to determine the feasibility of preparing these peptides using egg white and then to optimize the conditions of preparing egg white hydrolysate. Taguchi's method was used to design experiments for optimization, which was established as follows: substrate %, pH of thermoase, time of thermoase digestion, ratio of pepsin to substrate, pH of pepsin, temperature of pepsin, and time of pepsin digestion were 7.5%, pH 8, 90 min, 1%, pH 2.5, 55 °C, and 180 min, respectively. The ACE inhibitory activity (IC50 value) and peptide yield obtained under optimal condition were 30 ± 2 µg/mL and 77.5% ± 0.3%, respectively, which were comparable to the predicted values. Hydrolysate prepared at 150 L reactor showed comparable activity but low peptide yield. Results of this study demonstrated the feasibility of using egg white protein as the starting material to prepare a functional ingredient with potent ACE inhibitory activity.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Proteínas do Ovo/farmacologia , Clara de Ovo/química , Hidrolisados de Proteína/farmacologia , Inibidores da Enzima Conversora de Angiotensina/química , Proteínas do Ovo/química , Manipulação de Alimentos , Concentração de Íons de Hidrogênio , Peptídeos/química , Peptídeos/farmacologia , Peptidil Dipeptidase A/metabolismo , Hidrolisados de Proteína/química , Reprodutibilidade dos Testes
18.
Food Chem ; 261: 36-41, 2018 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-29739603

RESUMO

Effects of NaCl concentrations and pH on the intermolecular forces and gel properties of whole chicken egg protein dispersions were studied via solubility, surface hydrophobicity, intermolecular forces, texture analysis, low-field nuclear magnetic resonance (LF-NMR) and colour analysis. Results showed that the intermolecular forces involved in the formation of egg gel were regulated by NaCl/pH. The results of gel fracture analysis suggested that the changes of fracture strength and strain were closely related with the internal balance of gel molecular forces. Moreover, a negative/positive correlation existed in the free water/bound water relaxation proportion and fracture strength. These findings provide an important theoretical basis for the innovation of heat-induced egg gel products.


Assuntos
Galinhas , Proteínas do Ovo/química , Fenômenos Mecânicos , Cloreto de Sódio/química , Animais , Géis , Temperatura Alta , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Masculino , Solubilidade , Água/química
19.
J Sci Food Agric ; 98(15): 5547-5558, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29797412

RESUMO

Eggs are an important source of macro and micronutrients within the diet, comprised of proteins, lipids, vitamins, and minerals. They are constituted by a shell, the white (containing 110 g kg-1 proteins: ovalbumin, ovotransferrin, ovomucoid, lysozyme and ovomucin), and the yolk (containing 150-170 g kg-1 proteins: lipovitellins, phosvitin, livetins, and low-density lipoproteins). Owing to their nutritional value and biological characteristics, both the egg white and yolk proteins are extensively fractionated using different techniques (e.g., liquid chromatography, ultrafiltration, electrophoresis, and chemical precipitation), in which liquid chromatography is the most commonly used technique to obtain individual proteins with high protein recovery and purity to develop novel food products. However, concerns over allergenic responses induced by certain egg proteins (e.g., ovomucoid, ovalbumin, ovotransferrin, lysozyme, α-livetin, and lipoprotein YGP42) limit their widespread use. As such, processing technologies (e.g., thermal processing, enzymatic hydrolysis, and high-pressure treatment) are investigated to reduce the allergenicity by conformational changes. In addition, biological activities (e.g., antioxidant, antimicrobial, antihypertensive, and anticancer activities) associated with egg peptides have received more attention, in which enzyme hydrolysis is demonstrated as a promising way to break polypeptides sequences and produce bioactive peptides to provide nutritional and therapeutic benefits for human health. © 2018 Society of Chemical Industry.


Assuntos
Proteínas do Ovo/química , Proteínas do Ovo/imunologia , Peptídeos/química , Peptídeos/isolamento & purificação , Animais , Anti-Infecciosos/análise , Anti-Infecciosos/química , Antioxidantes/química , Antioxidantes/isolamento & purificação , Galinhas , Proteínas do Ovo/isolamento & purificação , Manipulação de Alimentos , Humanos
20.
J Insect Sci ; 18(2)2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29718485

RESUMO

Vitellogenin (Vg) and vitellogenin receptor (VgR) play important roles in the vitellogenesis of insects. In this study, we cloned and characterized the two corresponding genes (TpVg and TpVgR) in an economically important insect, Thitarodes pui (Lepidoptera: Hepialidae), from the Tibetan plateau. The full length of TpVg is 5566 bp with a 5373 bp open reading frame (ORF) encoding 1,790 amino acids. Sequence alignment revealed that TpVg has three conserved domains: a Vitellogenin_N domain, a DUF1943 domain, and a von Willebrand factor type D domain (VWD). The full length of TpVgR is 5732 bp, with a 5397 bp ORF encoding 1798 amino acids. BLASTP showed that TpVgR belongs to the low-density lipoprotein receptor (LDLR) gene superfamily. Structural analysis revealed that TpVgR has a group of four structural domains: a ligand-binding domain (LBD), an epidermal growth factor (EGF)-precursor homology domain, a transmembrane (TM) domain, and a cytoplasmic domain. In addition, TpVgR has four cysteine-rich LDL repeats in the first ligand-binding site and seven in the second. Quantitative real-time polymerase chain reaction analysis revealed that the expression levels of TpVg and TpVgR are much higher in later pupa than in either the larval or adult stage, implying that the synthesis and uptake of Vg in T. pui occurs in the later pupal stage. These results will help us to understand the molecular mechanism of the reproductive capacity and will provide new insight into the mass rearing and utilization of T. pui.


Assuntos
Proteínas do Ovo/metabolismo , Mariposas/metabolismo , Receptores de Superfície Celular/metabolismo , Vitelogeninas/metabolismo , Animais , Proteínas do Ovo/química , Proteínas do Ovo/genética , Feminino , Mariposas/química , Mariposas/genética , Filogenia , Receptores de Superfície Celular/química , Receptores de Superfície Celular/genética , Análise de Sequência de DNA , Vitelogeninas/química , Vitelogeninas/genética
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