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1.
Phys Rev Lett ; 126(9): 098001, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33750145

RESUMO

The kinetics of heat-induced gelation and the microscopic dynamics of a hen egg white gel are probed using x-ray photon correlation spectroscopy along with ultrasmall-angle x-ray scattering. The kinetics of structural growth reveals a reaction-limited aggregation process with a gel fractal dimension of ≈2 and an average network mesh size of ca. 400 nm. The dynamics probed at these length scales reveals an exponential growth of the characteristic relaxation times followed by an intriguing steady state in combination with a compressed exponential correlation function and a temporal heterogeneity. The degree of heterogeneity increases with decreasing length scale. We discuss our results in the broader context of experiments and models describing attractive colloidal gels.


Assuntos
Clara de Ovo/química , Modelos Químicos , Géis/química , Cinética , Espalhamento a Baixo Ângulo , Raios X
2.
Poult Sci ; 100(2): 452-460, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33518096

RESUMO

Ovomucoid is a major egg white protein which is considered as the most dominant allergen in chicken eggs. Owing to the difficulty of separating ovomucoid from egg whites, researchers have adopted genetic deletion for development of hypoallergenic eggs. Previously, we used CRISPR/Cas9 to establish chickens with ovomucoid gene (OVM) mutations, but it remained unknown whether such hens could produce eggs at maturity. Here, we have reported on eggs laid by OVM-targeted hens. Except for watery egg whites, the eggs had no evident abnormalities. Real-time PCR revealed alternative splicing of OVM mRNA in hens, but their expression was limited. Immunoblotting detected neither mature ovomucoid nor ovomucoid-truncated splicing variants in egg whites. Sixteen chicks hatched from 28 fertilized eggs laid by OVM-targeted hens, and fourteen of the sixteen chicks demonstrated healthy growth. Taken together, our results demonstrated that OVM knockout could almost completely eliminate ovomucoid from eggs, without abolishing fertility. Thus, the eggs developed in this study have potential as a hypoallergenic food source for most patients with egg allergies.


Assuntos
Galinhas/genética , Ovos/normas , Mutação , Ovomucina/genética , Alérgenos/genética , Animais , Galinhas/crescimento & desenvolvimento , Galinhas/fisiologia , Clara de Ovo/efeitos adversos , Clara de Ovo/química , Clara de Ovo/normas , Feminino , Deleção de Genes , Masculino , Oviposição/genética , Ovomucina/efeitos adversos , Óvulo
3.
Food Chem ; 351: 129279, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-33631615

RESUMO

The use of the antibiotic enrofloxacin (ENR) in poultry is controversial. A high-performance liquid chromatography coupled to fast-scanning fluorescence detection (HPLC-FSFD) method for the determination of ENR in egg white, egg yolk, and lyophilized samples was developed. In a first analysis, the long-term administration of ENR (100 days) to laying hens was carried out to determine its presence in egg white, yolk, or both. The predominance of ENR was observed in egg white and variations in the weight of egg white and eggshell was evidenced, showing a potential problem in the industry. Eventually, the presence of ENR was confirmed in commercial lyophilized egg white samples in concentration values around 350 µg kg-1. The consumer exposure assessment was estimated for children, adolescents, and adults. The result displayed that, in an intake of lyophilized egg white with food-producing animals, the %ADI exceeds 100%, showing toxicological levels.


Assuntos
Antibacterianos/análise , Ovos/análise , Enrofloxacina/análise , Contaminação de Alimentos/análise , Adolescente , Adulto , Animais , Galinhas , Criança , Cromatografia Líquida de Alta Pressão , Clara de Ovo/química , Gema de Ovo/química , Humanos , Espectrometria de Massas em Tandem
4.
Food Chem ; 349: 129096, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33561796

RESUMO

The mechanism between food gelation and its digestibility has attracted increasing attention over the past few decades. This study aimed to evaluate the effect of glycation degree on the gelation and digestibility of egg white gel (EWG) using an in vitro model and a multi-scale characterization of gel structure. Results showed that EWG glycated with increasing d-ribose by covalent bonds exhibited better gelling properties and lower in vitro digestibility according to the appearance of soluble proteins and peptides. Besides, glycation preference for ovotransferrin at lysine might be important for regulating gel structure and proteolysis accessibility via the ratio of fibrous and granular aggregates. Moreover, gel structure was predominant over amino acids modification for digestibility. Binding disorder and steric hindrance could ascribe to the lower digestibility of gels. These findings are enlightening for the formulation and production of food matrix with controlled digestibility through glycation in food and related pharmaceutical fields.


Assuntos
Digestão , Clara de Ovo/química , Peptídeos/química , Peptídeos/metabolismo , Géis , Glicosilação , Lisina
5.
Food Chem ; 346: 128905, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33401085

RESUMO

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.


Assuntos
Conalbumina/metabolismo , Sonicação , Animais , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Conalbumina/isolamento & purificação , Conalbumina/farmacologia , Clara de Ovo/química , Escherichia coli/efeitos dos fármacos , Glicosilação , Interações Hidrofóbicas e Hidrofílicas , Reação de Maillard , Testes de Sensibilidade Microbiana , Estrutura Secundária de Proteína , Staphylococcus aureus/efeitos dos fármacos
6.
Biochim Biophys Acta Proteins Proteom ; 1869(1): 140556, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33075478

RESUMO

In the present work we studied the effect of 2D WS2 nanoparticles on the conformational changes in lysozyme protein at different pH values (2.0-11.5). The contributions of various structural conformations (α-helix, ß-sheets parallel and antiparallel, unordered structure and side groups) were determined by decomposition of Amid I absorbance bands. The 2D WS2 were shown to have different impact on secondary structure depending on pH of the solution and protein concentration. The amyloid fibril presence was confirmed with confocal microscopy enhanced by gold support, and fluorescent spectroscopy with amyloid-sensitive dye Thioflavin T. Our data show that WS2 can both inhibit and stimulate amyloid formation. Additionally, we have also reported an unusual spectroscopic behavior displayed by lysozyme, indicated by narrowing of Amide I and Amide II bands at pH 2.5 and 3.5 when incubated with 2D WS2 nanoparticles.


Assuntos
Amiloide/química , Nanopartículas Metálicas/química , Muramidase/química , Sulfetos/química , Compostos de Tungstênio/química , Animais , Benzotiazóis/química , Galinhas , Clara de Ovo/química , Corantes Fluorescentes/química , Concentração de Íons de Hidrogênio , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Análise Espectral/métodos
7.
Methods Mol Biol ; 2223: 49-65, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33226586

RESUMO

Egg allergy is one of the most common food allergies in children, being the most important allergenic proteins found in the egg white (EW). Allergy to EW shows a complex phenotype that involves a multifaceted reaction that can only be assessed in vivo. Although other routes of sensitization have been described, oral exposure to food antigens is one of the most suitable in humans. In mice, oral administration of allergenic proteins results in the development of tolerance, and the use of adjuvants, such as cholera toxin (CT), is required to promote Th2-biased immune responses over tolerogenic responses. In this regard, among the mouse strains that readily display Th2 responses, Balb/c has been widely used. Here, we describe a frequently used protocol of oral EW sensitization by using CT as an adjuvant and we explain in detail the methods that we have developed to analyze the sensitizing and eliciting capacity of EW proteins including evaluation of signs, measurement of serum levels of specific immunoglobulins, mast cell degranulation, cytokine secretion profile of allergen-reactive T cells, phenotyping of mesenteric lymph node- and spleen-derived dendritic and T cells by flow cytometry, and quantification of intestinal gene expression.


Assuntos
Células Dendríticas/efeitos dos fármacos , Modelos Animais de Doenças , Hipersensibilidade a Ovo/imunologia , Clara de Ovo/química , Imunofenotipagem/métodos , Células Th2/efeitos dos fármacos , Adjuvantes Imunológicos/administração & dosagem , Administração Oral , Animais , Biomarcadores/metabolismo , Quimiocina CCL2/genética , Quimiocina CCL2/imunologia , Galinhas , Toxina da Cólera/administração & dosagem , Células Dendríticas/citologia , Células Dendríticas/imunologia , Hipersensibilidade a Ovo/sangue , Hipersensibilidade a Ovo/genética , Hipersensibilidade a Ovo/patologia , Feminino , Citometria de Fluxo , Expressão Gênica , Humanos , Imunoglobulinas/sangue , Imunoglobulinas/classificação , Imunoglobulinas/imunologia , Interleucinas/genética , Interleucinas/imunologia , Linfonodos/citologia , Linfonodos/efeitos dos fármacos , Linfonodos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Baço/citologia , Baço/efeitos dos fármacos , Baço/imunologia , Células Th2/citologia , Células Th2/imunologia
8.
J Sci Food Agric ; 101(2): 433-440, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32648587

RESUMO

BACKGROUND: Dry heat processing remains the most promising and simple approach for achieving better gelling properties of spray-dried egg white powder (EWP). Water mobility and intermolecular interactions in gels derived from EWP were investigated after subjecting EWP to various dry heating times (0-21 days). RESULTS: The gel hardness and water-holding capacity significantly increased with an increase in dry heating time (P < 0.05), and both parameters were positively correlated with gel transparency. In contrast to the coarser structure of untreated EWP gel, the gel of EWP corresponding to 15 days of dry heating time had a fine-stranded and orderly network structure with smaller pores. An increase in the binding force between the gel and water was observed with an increase in dry heating time due to the formation of more 'protein-water' hydrogen bonds. Increasing the dry heating time resulted in an increase in the contribution of disulfide bonds, which in turn made a significant contribution to the rigidity of the EWP gels. By contrast, a decrease in the contribution of ionic bonds and hydrophobic interactions upon increasing the dry heating time promoted the formation of orderly networks. CONCLUSIONS: Overall, gel corresponding to EWP dry heating for 15 days had better gel properties, the highest transparency and water-holding capacity, as well as a fine-stranded and orderly network structure. These results provide more information on improvement of the gel properties of EWP through dry heat treatment. © 2020 Society of Chemical Industry.


Assuntos
Culinária/métodos , Clara de Ovo/química , Animais , Galinhas , Culinária/instrumentação , Ovos/análise , Ovos/parasitologia , Géis/química , Temperatura Alta , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Pós/química , Solubilidade
9.
PLoS One ; 15(12): e0244160, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33370374

RESUMO

Ischemia-reperfusion injury is an important contributor to acute kidney injury and a major factor affecting early functional recovery after kidney transplantation. We conducted this experiment to investigate the protective effect of induced multipotent stem cell transplantation on renal ischemia-reperfusion injury. Forty rabbits were divided into four groups of 10 rabbits each. Thirty rabbits were used to establish the renal ischemia-reperfusion injury model, and ten rabbits served as the model group and were not treated. Among the 30 rabbits with renal ischemia-reperfusion injury, 10 rabbits were treated with induced peripheral blood mononuclear cells (PBMCs), and 10 other rabbits were treated with noninduced PBMCs. After three weekly treatments, the serum creatinine levels, urea nitrogen levels and urine protein concentrations were quantified. The kidneys were stained with hematoxylin-eosin (HE), periodic acid-Schiff (PAS) and Masson's trichrome and then sent for commercial metabolomic testing. The kidneys of the rabbits in the model group showed different degrees of pathological changes, and the recovery of renal function was observed in the group treated with induced cells. The results indicate that PBMCs differentiate into multipotent stem cells after induction and exert a therapeutic effect on renal ischemia-reperfusion injury.


Assuntos
Clara de Ovo/química , Rim/irrigação sanguínea , Leucócitos Mononucleares/transplante , Traumatismo por Reperfusão/terapia , Animais , Diferenciação Celular , Extratos Celulares/farmacologia , Células Cultivadas , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/efeitos dos fármacos , Células-Tronco Pluripotentes/citologia , Coelhos
10.
J Chromatogr A ; 1625: 461277, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709329

RESUMO

The influence of impregnation the chromatographic plate adsorbent layer, silica, with hen's egg white albumin (OVA) or bovine serum albumin (BSA) on the retention of some popular medicines (paracetamol, aminophenazone, theophylline, caffeine, acetanilide, ciprofloxacin, tramadol, acetylsalicylic acid, acebutolol) is investigated. The effect of composition and buffer pH of the mobile phase on solute separation selectivity is also studied. The chromatographic systems with and without above mentioned albumins and their influence on investigated drug retention are compared. In general, it has been turned out that retention of tested medicines in systems with the sorbent impregnated with albumin significantly increase relative to those with non-impregnated.


Assuntos
Cromatografia em Camada Delgada/métodos , Clara de Ovo/química , Preparações Farmacêuticas/análise , Soroalbumina Bovina/química , Sílica Gel/química , Adsorção , Animais , Bovinos , Galinhas , Feminino , Concentração de Íons de Hidrogênio , Metanol/química , Compostos Orgânicos/química , Solventes/química , Espectroscopia de Infravermelho com Transformada de Fourier , Tolueno/química
11.
Food Chem ; 330: 127319, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32569936

RESUMO

The influence of fresh egg white (EW) addition on the quality characteristics and protein aggregation in oat noodles containing wheat flour and gluten was studied. EW addition decreased cooking loss and increased cooking time of 70% oat noodles. The hardness, chewiness, tensile force and tensile distance improved significantly. A smooth surface and continuous protein network were observed by scanning electron microscopy (SEM) after adding EW. After cooking, the peak area in SE-HPLC profile of 70% oat noodles with EW decreased obviously. The extractabilities of protein in sodium dodecyl sulfate containing medium (SDSEP) of cooked wheat and oat noodles under non-reducing condition were lower than those of samples under reducing condition. The protein bands changes in SDS-PAGE profiles showed that EW could induce disulfide cross-linking of proteins in noodles. EW addition promoted proteins interaction and improved the cooking and texture properties of oat noodles.


Assuntos
Avena , Clara de Ovo/química , Farinha , Qualidade dos Alimentos , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Culinária , Dissulfetos/química , Eletroforese em Gel de Poliacrilamida , Farinha/análise , Indústria de Processamento de Alimentos , Glutens , Dureza , Microscopia Eletrônica de Varredura , Agregados Proteicos , Triticum
12.
Food Chem ; 330: 127321, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32569937

RESUMO

In this paper, changes in physicochemical properties, gel structure and in vitro digestion of marinated egg with spice or tea during braising were investigated. Results indicated that the moisture content and surface hydrophobicity of marinated egg white showed an overall decreased trend. The springiness of marinated egg white showed an increased trend, and the hardness in the late stage showed an increased trend. Microstructure showed that compact gel structures formed many holes during the braising. Intermolecular forces showed that ionic bonds and disulfide bonds played a dominant role in the marinated egg white. Secondary structure showed that the ß-turn showed a decreased trend, contrary to that of random coils and α-helices. Appropriate braising increased the digestibility of marinated egg white, but excessively long-time braising could reduce it. Both spice and tea braising could improve the gel strength of protein, and the tea braising was also slightly better than spice braising.


Assuntos
Clara de Ovo/química , Géis/química , Digestão , Proteínas Dietéticas do Ovo/química , Interações Hidrofóbicas e Hidrofílicas , Agregados Proteicos , Estrutura Secundária de Proteína , Temperatura
13.
Food Chem ; 327: 127077, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32485660

RESUMO

Compositional analyses of eggs have primarily focused on nutritional components, including large molecules, such as proteins. However, few reports have investigated the effects of heating and hen feed crops on taste components, such as free amino acids and sugars. Herein, water-soluble metabolites in raw and boiled eggs produced from chickens raised with corn- or rice-fed were analyzed. Each egg was separated into yolk and white, and freeze-dried samples were analyzed by CE-MS and LC-MS. Abundant metabolites included amino acids in yolks and sugars in whites. Compared to corn-fed, rice-fed resulted in three times higher betaine and uridine monophosphate concentrations in yolks and whites, respectively. Boiled whites contained more than four times higher concentrations of amino acids and fructose than raw whites. Metabolites in yolks exhibited minimal changes after boiling. Our findings support the use of water-soluble metabolomics to evaluate the effects of heating and feed crops on taste components.


Assuntos
Produtos Agrícolas , Clara de Ovo , Gema de Ovo/metabolismo , Oryza , Zea mays , Ração Animal , Animais , Galinhas , Culinária , Clara de Ovo/química , Gema de Ovo/química , Metaboloma
14.
Food Chem ; 327: 127038, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32447136

RESUMO

Polyacrylonitrile nanofiber membrane functionalized with tris(hydroxymethyl)aminomethane (P-Tris) was used in affinity membrane chromatography for lysozyme adsorption. The effects of pH and protein concentration on lysozyme adsorption were investigated. Based on Langmuir model, the adsorption capacity of P-Tris nanofiber membrane was estimated to be 345.83 mg/g. For the operation of dynamic membrane chromatography with three-layer P-Tris nanofiber membranes, the optimal operating conditions were at pH 9, 1.0 mL/min of feed flow rate, and 2 mg/mL of feed concentration. Chicken egg white (CEW) was applied as the crude feedstock of lysozyme in the optimized dynamic membrane chromatography. The percent recovery and purification factor of lysozyme obtained from the chromatography were 93.28% and 103.98 folds, respectively. Our findings demonstrated the effectiveness of P-Tris affinity nanofiber membrane for the recovery of lysozyme from complex CEW solution.


Assuntos
Cromatografia de Afinidade/métodos , Clara de Ovo/química , Muramidase/isolamento & purificação , Nanofibras/química , Trometamina/química , Adsorção , Membranas Artificiais , Muramidase/química
15.
Anim Sci J ; 91(1): e13339, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32219937

RESUMO

In this study, the effects of ultrafiltration technique on the desalination efficiency, nutrient content, physicochemical properties, functional properties, texture profile, and microstructure of salted duck egg white were evaluated. The results showed that ultrafiltration can remove 92.93% salt from salted duck egg white (SDEW) and final salt% of desalted duck egg white (DDEW) was 0.65%. The analysis of nutrient content and amino acid of SDEW and desalted duck egg white powder (DDEWP) sample was significantly lower than those of fresh duck egg white (FDEW). Although emulsifying capacity of SDEW, DDEW, and DDEWP exhibited significantly lower than that of FDEW, an excellent foaming ability was found in those samples. Moreover, the texture profiles (gel strength, hardness and elasticity) of SDEW, DDEW, and DDEWP samples presented lower value than FDEW. The observation of microstructure, DDEWP possessed smooth surface of protein globules with deep hole liked donuts and distribution of a few of salt crystals. While salted duck egg white powder (SDEWP) had a raisin-like surface formation with salt formed cubic crystals. Overall, both liquid and dried material of desalted duck egg could be used as a good ingredient in baking food due to their excellent foaming capacity.


Assuntos
Patos , Clara de Ovo/análise , Análise de Alimentos/métodos , Nutrientes/análise , Ultrafiltração/métodos , Animais , Fenômenos Químicos , Clara de Ovo/química
16.
J Food Sci ; 85(3): 834-842, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32078745

RESUMO

Osteoporosis is a degenerative disease that threatens bone health of the elderly (especially postmenopausal women). Since osteoporosis is important to prevent, the aim of this study was to investigate the regulation of desalted duck egg white peptides (DPs) on osteoporosis. In this study, the effects of DPs on bone formation were evaluated using MC3T3-E1 cells and ovariectomized (OVX) rats. DPs significantly enhanced the preosteoblasts proliferation, differentiation, and matrix mineralization via the upregulation of wnt3a expression, low-density lipoprotein receptor-related protein-5 (LRP-5), ß-catenin, runt-related transcription factor 2 (Runx2), and osteoprotegerin (OPG) (P < 0.05). The intracellular calcium concentration was significantly elevated by DPs (P < 0.05), which is attributed to calcium influx and L-type calcium channels. Additionally, OVX rat model experiment indicated that DPs (600 mg/kg bw) had a superior effect against bone loss induced by estrogen deficiency, as it significantly declined bone turnover markers, and significantly increased biomechanical parameters (P < 0.05). Mineralized bone surfaces and bone microstructure were also obviously improved by DPs treatment. Immunohistochemical analysis showed that receptor activator of nuclear factor κ B (RANK) expression of tibia in DPs group was significantly reduced compared with the model group (P < 0.05). Our results demonstrated that DPs could enhance preosteoblasts differentiation and antiosteoporosis via wnt/ß-catenin signal pathway and several key osteogenic transcription factors such as Runx2 and OPG. PRACTICAL APPLICATION: High-value utilization of salted duck egg white, a byproduct of food industry, is worthy of in-depth study. Desalted duck egg white peptides (DPs) were proved to promote bone formation, which suggests the potentials of DPs as cofactors in osteoporosis prevention.


Assuntos
Clara de Ovo/química , Osteogênese/efeitos dos fármacos , Osteoporose Pós-Menopausa/tratamento farmacológico , Peptídeos/administração & dosagem , Animais , Osso e Ossos/metabolismo , Cálcio/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Patos , Feminino , Humanos , Proteína-5 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Proteína-5 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Camundongos , Osteoporose Pós-Menopausa/genética , Osteoporose Pós-Menopausa/metabolismo , Osteoporose Pós-Menopausa/fisiopatologia , Osteoprotegerina/genética , Osteoprotegerina/metabolismo , Peptídeos/química , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Proteína Wnt3/genética , Proteína Wnt3/metabolismo , beta Catenina/genética , beta Catenina/metabolismo
17.
Food Chem ; 315: 126201, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32007810

RESUMO

Edible films based on pullulan (Pu) and egg white (EW) were prepared in this study. As the egg white proportion increased, the mechanical properties of the blend films initially increased and then decreased. The best mechanical properties occurred at the optimal proportion of Pu:EW = 1:1. The blend films with a higher content of egg white showed a lower degradation speed of moisture and polymers. FTIR spectroscopy illustrated peak displacement, X-ray diffraction patterns showed noticeable changes, and the secondary structure of egg white was altered. These results indicated that pullulan and egg white interacted extensively. The total α-helix and ß-sheet content increased with the increment of pullulan content. The decrease of free amino content indicated that the degree of glycosylation increased with the addition of pullulan, which is associated with the Maillard reaction. The apparent color and the scanning electron microscopy images were also assessed in this study.


Assuntos
Clara de Ovo/química , Glucanos/química , Dicroísmo Circular , Cor , Proteínas do Ovo/química , Embalagem de Alimentos , Glicosilação , Reação de Maillard , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
18.
Talanta ; 211: 120727, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32070576

RESUMO

We reported a facile strategy to assemble a ratiometric nanosensor for the ovalbumin (OVA) fluorescence determination and meanwhile it can be utilized for selective visual identification by naked eyes with fluorescent test papers under 365 nm UV lamp. The nanosensor was prepared through simply mixing blue color carbon dots (CDs) and green color core-shell imprinted polymers. Blue CDs were used directly as the internal reference without participating in the imprinting process and modified molecularly imprinted polymers (MIPs) were synthesized by post-imprinting, using fluorescein isothiocyanate (FITC) as fluorescence enhanced signal. Upon the addition of different concentrations of OVA, the fluorescence intensity of FITC was enhanced, while the fluorescence intensity of CDs was almost unchanged, leading to a detection limit as low as 15.4 nM. Accordingly, the fluorescence color was gradually changed from blue to dark olive green to green with naked eyes observation. Moreover, the ratiometric nanosensor was successfully applied to detect OVA in the human urine samples with satisfactory recoveries attaining of 92.0-104.0% with relative standard deviation (RSD) of 3.3-3.9% and 93.3-101.0% with RSDs of 2.7-3.8% for the spiked chicken egg white samples. This strategy reported here opens a novel pathway for biomacromolecule detection in real applications and can realize the visual observation on fluorescent test papers.


Assuntos
Técnicas Biossensoriais/métodos , Carbono/química , Clara de Ovo/química , Corantes Fluorescentes/química , Ovalbumina/análise , Polímeros/química , Pontos Quânticos , Animais , Galinhas , Humanos , Limite de Detecção , Impressão Molecular , Espectrometria de Fluorescência
19.
J Agric Food Chem ; 68(7): 2232-2239, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-31986031

RESUMO

An antioxidant peptide derived from egg white, Asp-His-Thr-Lys-Glu (DHTKE), possesses specific amino acids related to zinc delivery. This study aimed to demonstrate the molecular basis of interactions between the egg white peptide (DHTKE) and zinc ions and investigate the effect of the DHTKE-Zn complex on zinc delivery through the gastrointestinal system. Approximately one DHTKE molecule can bind one zinc ion (n = 1.048 ± 0.085) through its carboxyl, amino, and imidazole nitrogen groups on Asp, His, and Glu. The formed DHTKE-Zn complex presented uniformly distributed globular particles with a particle size of 100-500 nm and underwent dissociation and re-chelation during gastrointestinal digestion. Moreover, the DHTKE peptide mostly remained stable, with a retention rate of 98.32% under gastrointestinal digestion, although one degradation product (DHTK) was identified by nanoscale liquid chromatography-electrospray ionization-tandem mass spectrometry in the gastrointestinal digests; the effectiveness of DHTKE-Zn digests on enhancing absorption of zinc was comparable to that of the initial complex.


Assuntos
Antioxidantes/química , Portadores de Fármacos/química , Clara de Ovo/química , Trato Gastrointestinal/metabolismo , Peptídeos/química , Zinco/química , Sequência de Aminoácidos , Animais , Galinhas , Composição de Medicamentos , Sistemas de Liberação de Medicamentos , Masculino , Ratos , Ratos Wistar , Espectrometria de Massas por Ionização por Electrospray , Zinco/metabolismo
20.
Talanta ; 210: 120632, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31987190

RESUMO

An efficient and selective glycoproteins enrichment platform is essential to glycoprotein biomarkers in early clinic diagnostics. In this work, the poly (ethylene glycol) methyl ether methacrylate (PEGMA) and 4-vinylphenylboronic acid (VPBA) copolymer brushes grafted magnetic carbon nanotubes composite MCNTs@p (PEGMA-co-VPBA) was prepared by surface-initiated atom transfer polymerization and applied for the selective enrichment of glycoproteins from the complex biological samples. The as-prepared MCNTs@p (PEGMA-co-VPBA) nanocomposite was characterized by Fourier transform-infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and vibrating sample magnetometry (VSM). The MCNTs@p (PEGMA-co-VPBA) can recognize and bind specifically for glycoproteins via strong boronate affinity and excellent hydrophilicity and shows a really low non-specificity adsorption capability for non-glycoproteins. The adsorption capacity of MCNTs@p (PEGMA-co-VPBA) towards glycoproteins transferrin (Trf), horseradish peroxidase (HRP), and non-glycoproteins cytochrome c (Cyt C), lysozyme (Lyz) is 253.3 mg g-1, 51.1 mg g-1, 13.9 mg g-1 and 14.5 mg g-1, respectively. Furthermore, MCNTs@p (PEGMA-co-VPBA) can be applied to extract glycoproteins directly from egg white samples. These results demonstrated that MCNTs@p (PEGMA-co-VPBA) could be a potential affinity adsorbent in glycoprotein enrichment.


Assuntos
Ácidos Borônicos/química , Glicoproteínas/química , Metacrilatos/química , Nanotubos de Carbono/química , Polietilenoglicóis/química , Adsorção , Animais , Galinhas , Clara de Ovo/química , Interações Hidrofóbicas e Hidrofílicas , Fenômenos Magnéticos , Tamanho da Partícula , Propriedades de Superfície
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