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1.
Food Chem ; 369: 130828, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34488128

RESUMO

This study systematically analyzed and compared thechanges of physicochemical, functional and molecular structural characteristics between thick egg white (KEW) and thin egg white (NEW) during storage. Analysis of physicochemical properties showed that moisture content decreased significantly with the increase of pH during storage. KEW was gradually thinning, while NEW was closer to Newtonian fluid. Functional properties indicated that KEW thermal gel was gradually hard and brittle with the properties of NEW. KEW had better emulsifying property than NEW, and NEW had superior foaming ability. The α-helix and ß-sheet in the FT-IR spectrum showed a downward trend, revealing secondary structure changed from order to disorder. Enhancement of fluorescence intensity indicated the structural unfolding and exposure of tryptophan residues. SDS-PAGE proved that OVO might be related to the difference between KEW and NEW characteristics. This study provided new idea and reference value for egg storage and diversified utilization of egg white.


Assuntos
Clara de Ovo , Clara de Ovo/análise , Eletroforese em Gel de Poliacrilamida , Estrutura Molecular , Estrutura Secundária de Proteína , Espectroscopia de Infravermelho com Transformada de Fourier
2.
Poult Sci ; 100(9): 101373, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34343905

RESUMO

Though nutritional, the remaining separated duck egg white in duck egg processing plants presents challenges for its transportation and use, as it spoils easily and has a strong odor. Uses for the excess egg white are of paramount concern for agricultural resource reuse. The purpose of this study was to increase its value and use efficiency. Duck egg white was mixed with sodium hydroxide to produce translucent alkali-induced egg white jelly similar to that in preserved egg whites. To develop a heatable translucent egg white jelly, their physiochemical properties and thermal stabilities were investigated. A gel prepared with 150 mM sodium hydroxide at 25°C had optimal bloom strength and the densest microstructure. Storing the jelly at 5°C helped maintain its disulfide bonds and delayed liquefaction. Although heating decreased its bloom strength and total disulfide bond content as temperature increased (P < 0.05), scanning electron microscopy of the heated jelly revealed that the protein network structure was denser than that of unheated jelly. Heating caused parts of the structure to shrink and even dehydrate, leading to a wrinkled surface. However, no signs of liquefaction or collapse were observed, and the free alkali released during heating was lower than that from the white of existing preserved eggs. These results confirmed the thermal stability of the jelly and its potential to be served hot or used in food processing. Furthermore, in addition to disguising the odor and special flavor attributable to the alkaline treatment, adding ginger juice or turmeric to the preparation yielded higher bloom strength, resulted in lower free alkalinity, and delayed liquefaction, thus improving the jelly's thermal stability. Like preserved eggs on the market that can be served in hot congee, the proposed egg white jelly is rich in proteins and suitable for hot or instant serving. These findings may help address the problem of excessive remaining duck egg white created during food processing by diversifying duck egg processing and boosting its value.


Assuntos
Patos , Clara de Ovo , Animais , Galinhas , Clara de Ovo/análise , Manipulação de Alimentos , Óvulo
3.
Food Chem ; 360: 130054, 2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-34020367

RESUMO

A depletion study of toltrazuril and its metabolites was performed using 20 hens medicated via drinking water for two days in a dosage of 7 mg kg-1 per kg body weight. Afterward, eggs were collected for 42 days. Residues were analyzed in whole eggs and yolk and whites. Toltrazuril sulfone was found to be the most predominant in all matrices, the highest concentration was found in the yolk - 5567 µg kg-1, followed by whole eggs samples - 4767 µg kg-1 and egg whites - 532 µg kg-1. On last day toltrazuril sulfone were still detected - 22.5 µg kg-1. 70 days is required to concentration of toltrazuril sulfone reach zero. Administrating toltrazuril before the laying phase can pose a risk of residues of toltrazuril sulfone in eggs. Setting Maximum Residue Limit could reduce the risk of non-complaint samples and ensure the safety of consumers, but still requires 44 days of the withdrawal period.


Assuntos
Galinhas/metabolismo , Resíduos de Drogas/análise , Ovos/análise , Triazinas/análise , Administração Oral , Animais , Clara de Ovo/análise , Gema de Ovo/química , Feminino , Sulfonas/análise , Triazinas/administração & dosagem , Triazinas/metabolismo
4.
Appl Opt ; 60(8): 2400-2411, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33690341

RESUMO

Localized hyperthermia therapy involves heating a small volume of tissue in order to kill cancerous cells selectively and with limited damage to healthy cells and surrounding tissue. However, these features are only achievable through real-time control of the tissue temperature and heated volume, both of which are difficult to obtain with current heating systems and techniques. This work introduces an optical fiber-based active heater that acts both as a miniature heat source and as a thermometer. The heat-induced damage in the tissue is caused by the conductive heat transfer from the surface of the device, while the heat is generated in an absorptive coating on the fiber by near-infrared light redirected from the fiber core to the surface by a tilted fiber Bragg grating inscribed in the fiber core. Simultaneous monitoring of the reflection spectrum of the grating provides a measure of the local temperature. Localized temperature increases between 0°C and 100°C in 10 mm-long/5 mm-diameter cylindrical volumes are obtained with continuous-wave pump power levels up to 1.8 W. Computational and experimental results further indicate that the temperature rise and dimensions of the heated volume can be maintained at a nearly stable level determined by the input optical power.


Assuntos
Tecnologia de Fibra Óptica/instrumentação , Hipertermia/diagnóstico , Animais , Morte Celular , Linhagem Celular , Simulação por Computador , Clara de Ovo/análise , Tecnologia de Fibra Óptica/métodos , Temperatura Alta , Humanos , Técnicas In Vitro , Raios Infravermelhos , Fígado/metabolismo , Modelos Químicos , Fibras Ópticas , Suínos , Temperatura
5.
Food Chem ; 345: 128022, 2021 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-33039190

RESUMO

Hen's egg white allergens, namely Gal d 1-4, cause food allergies worldwide and their intake must be strictly controlled by allergic individuals. However, an efficient method for quantifying these allergens is currently unavailable. We aimed to develop an LC-MS/MS method for simultaneous Gal d 1-4 quantification. Purified Gal d 1-4 proteins were trypsin-digested and the resulting peptides used in LC-MS/MS analysis. The limits of quantification were 9.77-39.1 ng/mL. The Gal d 1-4 recovery in fresh and processed eggs was 68.3-121.3%, and intra- and interassay coefficients of variation were 1.5-15.7% and 2.4-38.1%, respectively, indicating high sensitivity, accuracy, and reproducibility. In addition, the high specificity of this method was confirmed by testing 27 other foods. This newly developed method could provide reliable information to the industrial food and clinical fields, facilitating improved quality of life for individuals with egg allergies.


Assuntos
Alérgenos/análise , Cromatografia Líquida/métodos , Clara de Ovo/análise , Espectrometria de Massas em Tandem/métodos , Animais , Galinhas , Feminino , Humanos , Peptídeos/análise , Reprodutibilidade dos Testes
6.
Anal Chem ; 93(3): 1352-1359, 2021 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-33347273

RESUMO

Proteins are perhaps the most important yet frustratingly complicated and difficult class of compounds to analyze, manipulate, and use. One very attractive option to characterize and differentially concentrate proteins is dielectrophoresis, but according to accepted theory, the force on smaller particles the size of proteins is too low to overcome diffusive action. Here, three model proteins, immunoglobulin G, α-chymotrypsinogen A, and lysozyme, are shown to generate forces much larger than predicted by established theory are more consistent with new theoretical constructs, which include the dipole moment and interfacial polarizability. The forces exerted on the proteins are quantitatively measured against well-established electrophoretic and diffusive processes and differ for each. These forces are orders of magnitude larger than previously predicted and enable the selective isolation and concentration of proteins consistent with an extremely high-resolution separation and concentration system based on the higher-order electric properties. The separations occur over a small footprint, happen quickly, and can be made in series or parallel (and in any order) on simple devices.


Assuntos
Quimotripsinogênio/análise , Imunoglobulina G/análise , Muramidase/análise , Animais , Galinhas , Clara de Ovo/análise , Eletroforese , Muramidase/metabolismo
7.
Food Chem ; 345: 128822, 2021 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-33352406

RESUMO

The presence of residues from fining agents in wines may represent a risk for allergic consumers and a source of discomfort for others, such as vegans. Even though ELISA is the official detection method for such residues, this technique may be hindered by cross-reactivity issues, or by matrix-molecule interference due to a high polyphenol content, especially in red wines. An HRMS-based method has been developed to detect pig gelatin and egg white in experimental five-year aged Nebbiolo-based red wine. Biomarker peptides were selected, after tryptic digestion, and quantified by multitarget nanoHPLC-HRMS analysis. The method resulted in an LLOQs of 5 µg/mL in the experimental wine, and between 1 and 2 µg/mL in the buffer. This method allowed both gelatin and egg white proteins to be detected and quantified in aged red wine, while whereas the commercial ELISA kit was instead unable to detect egg white in the same samples.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Clara de Ovo/análise , Análise de Alimentos/métodos , Gelatina/análise , Espectrometria de Massas/métodos , Nanotecnologia/métodos , Vinho/análise , Animais , Suínos
8.
J Sci Food Agric ; 101(9): 3942-3951, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33348458

RESUMO

BACKGROUND: While eggs are a low-cost source of protein, rich in macro- and micronutrients, the association of egg intake and cardiovascular disease (CVD) remains controversial. This study investigated the effect of egg consumption on CVD parameters. Eggs were boiled, separated into four fractions (whole egg, 50% yolk-reduced whole egg, egg yolk and egg white) and then freeze-dried. The different egg fractions or distilled water (control) were orally gavaged to adult male Wistar rats at 1 g kg-1 rat body weight, each day for 8 weeks, following which basal blood pressure, heart rate, complete blood cell count, blood biochemistry, body fat and liver cell lipid accumulation were determined. The vascular functions of isolated thoracic aorta were studied using classical pharmacological techniques. RESULTS: In comparison to the control group, none of the egg fractions affected body weight, food intake, plasma glucose or lipid profile. The yolk group experienced increased plasma alkaline phosphatase and creatinine levels, while egg white caused decreased plasma cholesterol and blood urea nitrogen. Whole egg and egg yolk increased blood pressure and mean hemoglobin concentration and the yolk increased liver lipid accumulation. Egg white decreased the white blood cell count and body fat lipids. No changes were found in basal heart rate or vascular functions in any of the groups. CONCLUSIONS: Consumption of whole egg or egg yolk at the dosage given caused hypertension, with impairment of liver and kidney functions following the intake of yolk alone. However, egg white is beneficial for the cardiovascular system as it decreased plasma cholesterol and body fat accumulation. © 2020 Society of Chemical Industry.


Assuntos
Doenças Cardiovasculares/metabolismo , Clara de Ovo/análise , Gema de Ovo/metabolismo , Fosfatase Alcalina/sangue , Animais , Pressão Sanguínea , Peso Corporal , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/fisiopatologia , Galinhas , Colesterol/sangue , Culinária , Creatinina/sangue , Ovos/análise , Humanos , Fígado/metabolismo , Masculino , Ratos , Ratos Wistar
9.
Reproduction ; 160(5): 793-801, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32985412

RESUMO

The reproductive tract in avian females is sensitive to hormonal regulation. Exogenous estrogen induces immature oviduct development to improve egg production after molting. In this process, regressed female reproductive tract is regenerated in response to the secretion of estrogen. However, there is limited knowledge on the physiological mechanisms underlying the regulation of the avian female reproductive system. In our previous study, results from microarray analysis revealed that the expression of genes encoding egg white proteins is affected during molting. Herein, we artificially induced the molting period in chickens through a zinc-containing diet. Subsequently, changes in the expression of genes encoding egg white proteins were confirmed in the oviduct tissue. The levels of MUC5B, ORM1, RTBDN, and TENP mRNA were significantly high in the oviduct, and the genes were repressed in the regression phase, whereas these were expressed in the recrudescence phase, particularly in the luminal epithelium and glandular epithelium of the oviduct, during molting. Moreover, we observed that gene expression was induced in the magnum, the site for the secretion of egg white components. Next, differences in expression levels of the four genes in normal and cancerous ovaries were compared. Collectively, results suggest that the four selected genes are expressed in the female chicken reproductive tract in response to hormonal regulation, and egg white protein-encoding genes may serve as modulators of the reproductive system in hens.


Assuntos
Proteínas do Ovo/metabolismo , Clara de Ovo/análise , Estrogênios/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Neoplasias Ovarianas/metabolismo , Oviductos/metabolismo , Animais , Galinhas , Proteínas do Ovo/genética , Feminino , Muda , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Oviductos/efeitos dos fármacos
10.
Mater Sci Eng C Mater Biol Appl ; 115: 111063, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32600689

RESUMO

Nowadays, the research on the recognition and separation of proteins has attracted extensive attention in the fields of materials science, bioengineering and life science. Protein imprinted polymers are ideal recognition materials, due to its high selectivity, good stability, easy preparation, and low cost. Herein, novel surface imprinting biowaste-derived molecularly imprinted polymers (BD-MIPs) were synthesized for specific recognition and purification of lysozyme (Lyz). This is the first time that magnetic pomegranate rind-derived carbon was used as a carrier to immobilize Lyz. Then, with the self-polymerization of dopamine, a large number of biocompatible recognition sites were generated under mild conditions. The physical/chemical properties and surface morphologies of the synthetic BD-MIPs were characterized, indicating that the imprinted film was successfully synthesized, and the BD-MIPs had good thermal stability and magnetic property. To investigate the recognition performance of BD-MIPs, four adsorption experiments were performed. The results show that BD-MIPs had a high adsorption capacity of 301.87 mg g-1, fast equilibrium time within 40 min, satisfactory selectivity and good reusability for Lyz. Furthermore, the practicability of BD-MIPs was confirmed by the isolation of Lyz from a biological sample. The good adsorption capacity and gentle one-step preparation make the BD-MIPs attractive for Lyz recognition, which shows potential values in basic biomedical research, industrial protein purification and clinical diagnostics.


Assuntos
Materiais Biocompatíveis/síntese química , Polímeros Molecularmente Impressos/síntese química , Muramidase/isolamento & purificação , Punica granatum/química , Adsorção , Animais , Materiais Biocompatíveis/química , Galinhas , Clara de Ovo/análise , Fenômenos Magnéticos , Polímeros Molecularmente Impressos/química , Resíduos
11.
Rapid Commun Mass Spectrom ; 34 Suppl 3: e8775, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32128902

RESUMO

RATIONALE: To increase the consumption of egg powder and its fractions a suitable quality control method is required to obtain more information on its nutritional composition. The proposed method enables the quantification of important elements for the functioning of the human organism, such as halogens and sulfur, in egg powder and its fractions. METHODS: Up to 350 mg of egg powder or its fractions (egg white powder and egg yolk powder) were digested by microwave-induced combustion using 20 bar pressure of oxygen. The analytes were absorbed in 100 mmol L-1 of NH4 OH solution. The determination of halogens (chlorine, bromine, fluorine, and iodine) and sulfur was performed in a single analysis using ion chromatography with conductivity detection coupled to mass spectrometry. RESULTS: Using the proposed method, spike recoveries between 99% and 104% for all analytes were obtained, and results agreed with certified values of reference materials (agreements were between 100% and 109%). The relative standard deviations were below 8%. The variation in elemental concentration over a wide range in different fractions (whole egg powder, egg white powder, and egg yolk powder) and different brands was also observed. CONCLUSIONS: The proposed method provides reliable information about minerals in whole egg powder and its fractions, contributing to better quality control of these products. Because these food products are widely consumed, these results suggest the safe ingestion levels of these elements.


Assuntos
Ovos/análise , Análise de Alimentos/métodos , Halogênios/análise , Espectrometria de Massas/métodos , Enxofre/análise , Cromatografia por Troca Iônica/métodos , Clara de Ovo/análise , Gema de Ovo/química , Limite de Detecção , Micro-Ondas , Pós/análise
12.
BMC Plant Biol ; 20(1): 126, 2020 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-32209052

RESUMO

BACKGROUND: A microgranule fertilizer was designed for localized fertilization of soil with controlled release of nutrients. The microgranule matrix was fortified with proteins, which were obtained from food industry byproducts or waste, i.e., whey protein from milk serum, soy protein from soy isolate and egg white protein from chicken egg white powder. The mechanism of the protein decomposition and migration of micro and macromolecule compounds through two different model soil systems was investigated. The potential of the protein fortified fertilizer for localized fertilization of the potted maize seeds was evaluated. RESULTS: The study revealed that proteins slowly diffused through soil with simultaneous degradation, which was accompanied with release of ammonia ions. The highest concentration of proteins and degradation products was found in a close vicinity of the microgranule. The microgranules were used as a local fertilizer for maize seeds in the pot experiments. The experiments confirmed statistically significant improvement in root density of maize plant compared to control group. CONCLUSIONS: Byproducts or waste of food industry, such as the milk serum and soy can be used as a source of proteins that degrade in soil without a pretreatment. The degradation is accompanied with formation of ammonium ions, which can be utilized by plants as a nitrogen source. The fertilizer microgranule should be placed in a close vicinity to the plant seed, since the maximum of the protein concentration and ammonia ions is reached at a very close distance from the microgranule.


Assuntos
Fertilizantes/análise , Indústria Alimentícia , Resíduos Industriais/análise , Nutrientes/metabolismo , Zea mays/fisiologia , Animais , Clara de Ovo/análise , Leite/química , Pós/análise , Glycine max/química
13.
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
14.
Poult Sci ; 99(3): 1705-1716, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32115038

RESUMO

Vanadium (V) is an ultratrace metal with the insulin-tropic properties and is often researched as the diabetes drug. However, in animals, V has been reported to have toxic effects on the development, immunity, oxidation-reduction equilibrium, gastrointestinal function, and so forth. Especially in poultry, supplementation of more than 10 mg of V/kg in the layer diets has been shown to adversely affect the egg production and egg quality. In this study, we supplemented 0 mg of V/kg, 5 mg of V/kg, and 10 mg of V/kg in the layer diets for 35 D and examined the quantitative proteomics of albumen for finding the possible target signaling pathway and mechanism of V action and made the preliminary verification. In contrast to the control group, V resulted in a significant drop in the albumen height, and in oviduct ampulla, the activity of total antioxidant capacity and glutathione peroxidase significantly decreased (P = 0.01, P = 0.02), the content of malonic dialdehyde significantly increased (P = 0.01), and the apoptosis rate significantly increased in the 5-mg V/kg and 10-mg V/kg treatment groups (P < 0.01). V affected 36 differentially accumulated proteins in albumen, with 23 proteins upregulated and 13 proteins downregulated. The expressions of innate protein albumen lysozyme (Q6LEL2), vitellogenin-2 (P02845), and the F1NWD0 protein in albumen belonged to the P53 family were significantly reduced, in contrast to the control (P < 0.05), and the expression of riboflavin-binding protein (P02752) was significantly improved (P < 0.05). The Hippo signaling pathway-fly, which is suitable for the key protein P53 as the most significantly affected network, might be important for discriminating V.


Assuntos
Ração Animal/análise , Clara de Ovo/análise , Proteoma , Vanádio/efeitos adversos , Animais , Galinhas , Dieta/veterinária , Proteínas do Ovo/química , Feminino , Oviductos , Transdução de Sinais
15.
Food Chem ; 317: 126430, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32092612

RESUMO

Electrochemical Synchronous detection of cadmium (Cd(II)) and lead (Pb(II)) was obtained by acid treated multiwalled carbon nanotube (A-MWCNT) functionalized with hyaluronic acid (Hyalu) and this mixture was separately further modified with l-cysteine (l-Cys) and l-serine (l-Ser). Under the optimized circumstance best voltammetric responses were produced by A-MWCNT/Hyalu/l-Cys and A-MWCNT/Hyalu/l-Ser modified electrodes. The peak current was linearly dependent on the Cd(II) and Pb(II) concentrations in the range from 0.4 to 4 µg L-1. The sensitivities were calculated as 0.7 µA/nM (Cd(II)) and 3.5 µA/nM (Pb(II)) for A-MWCNT/Hyalu/l-Cys/GCE and 0.6 µA/nM (Cd(II)) and 2.6 µA/nM (Pb(II)) for A-MWCNT/Hyalu/l-Ser/GCE. From the calibration plot LODs were calculated to be 0.032 µg L-1 (Cd(II)) and 0.015 µg L-1 (Pb(II)) for A-MWCNT/Hyalu/l-Cys/GCE and 0.057 µg L-1 (Cd(II)) and 0.034 µg L-1 (Pb(II)) for A-MWCNT/Hyalu/l-Ser/GCE. Moreover, the proposed electrodes were subjected to the real sample application in honey, cocos nucifera and egg white.


Assuntos
Cádmio/análise , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Chumbo/análise , Nanocompostos/química , Cádmio/química , Calibragem , Cocos/química , Cisteína/química , Clara de Ovo/análise , Eletrodos , Análise de Alimentos/instrumentação , Mel/análise , Ácido Hialurônico/química , Chumbo/química , Limite de Detecção , Nanotubos de Carbono/química , Sensibilidade e Especificidade , Serina/química
16.
Food Chem ; 315: 126207, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31991252

RESUMO

Five major proteins from egg white were separated using a successive extraction/precipitation protocol. The yield and purity of the separated proteins were measured. The separated proteins were confirmed by MALDI-TOF-MS, and their structures were characterized by CD spectrum. Lysozyme was first separated using FPC 3500 resin and then ovomucin from the lysozyme-free egg white. Ammonium sulfate and citric acid were added to the resulting lysozyme- and ovomucin-free egg white solution to precipitate ovotransferrin. Ovomucoid and ovalbumin were separated from the resulting supernatant using ethanol. The separated proteins were further purified and the optimal conditions for the further purifications were suggested. The purity and yield of lysozyme, ovotransferrin, ovalbumin, and ovomucoid were higher than 90% and 77%, while those of ovomucin were about 72% and 75%, respectively. This study separated five major proteins in egg white successively using resin adsorption, pH adjustment, salt/ethanol precipitation, and ultrafiltration.


Assuntos
Fracionamento Químico/métodos , Proteínas do Ovo/análise , Proteínas do Ovo/isolamento & purificação , Clara de Ovo/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Sulfato de Amônio/química , Animais , Precipitação Química , Conalbumina/análise , Conalbumina/isolamento & purificação , Proteínas do Ovo/química , Clara de Ovo/análise , Etanol/química , Muramidase/análise , Muramidase/isolamento & purificação , Ovalbumina/análise , Ovalbumina/isolamento & purificação , Ovomucina/análise , Ovomucina/isolamento & purificação , Estrutura Secundária de Proteína
17.
Luminescence ; 34(3): 316-323, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30724008

RESUMO

A novel, rapid and sensitive chemiluminescence (CL) method for the determination of oxytetracycline hydrochloride (OTCH) is described in this paper. The presented method was based on the fact that OTCH could immensely enhance the CL of the reaction of cerium sulfate and tris(2,2-bipyridyl) ruthenium (II) in acidic medium. Under optimal experimental conditions, CL intensity was favorably linear for OTCH in the range 5.0 × 10-7 to 5.0 × 10-5  g/ml, with a detection limit of 1.5 × 10-7  g/ml (S/N = 3). The relative standard detection was 4.76% for 5.0 × 10-6  g/ml (n = 11). This method was successfully applied to the analysis of OTCH in milk and egg white samples. According to the results of the kinetic curves for OTCH in the Ru(bipy)3 2+ -Ce(SO4 )2 CL system, together with CL and ultraviolet (UV)-visible spectra, the possible mechanism of the CL reaction is discussed briefly.


Assuntos
Antibacterianos/análise , Clara de Ovo/análise , Medições Luminescentes/métodos , Leite/química , Oxitetraciclina/análise , Animais , Bovinos , Cério/química , Galinhas , Contaminação de Alimentos/análise , Medições Luminescentes/instrumentação , Rutênio/química , Sulfatos/química
18.
J Sci Food Agric ; 99(8): 3879-3885, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30680735

RESUMO

BACKGROUND: Egg yolks contain large amounts of cholesterol and are suspected to be harmful after long-term consumption. In this experiment, 63 rats were used to evaluate the effect of egg white (EW) and egg yolk (EY) supplementation on serum lipids and brain cognition. The feeding time lasted 4 weeks after a 1-week acclimation. RESULTS: Body weight was significantly higher in rats fed 132.0 g kg-1 EW and significantly lower when fed 40 g kg-1 EY (P < 0.05). Total cholesterol and low-density lipoprotein increased in rats fed 72.0 g kg-1 EW compared with rats from NC and EY groups (P < 0.05). High-density lipoprotein (HDL) was higher in rats fed 40 g kg-1 EY and decreased when fed 72.0 g kg-1 EW (P < 0.05). Rats fed a diet with EY exhibited abundant neurons in the CA1 hippocampus and complete subcellular structures. Rats fed 132 g kg-1 EW exhibited shrunken cells and swollen mitochondria. Brain-derived neurotrophic factor had constitutively low expression among groups, while tyrosine kinase B (TrkB) exhibited higher expression levels in rats fed a diet containing EY compared with other groups (P < 0.05). CONCLUSION: EY consumption reduced body weight and increased HDL levels. Diet containing EY could improve cognition through enhanced trkB expression. © 2019 Society of Chemical Industry.


Assuntos
Peso Corporal , Encéfalo/enzimologia , Gema de Ovo/metabolismo , Lipoproteínas HDL/sangue , Receptor trkB/metabolismo , Animais , Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Contagem de Células , Colesterol/sangue , Dieta , Clara de Ovo/análise , Hipocampo/metabolismo , Masculino , Neurônios/citologia , Neurônios/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor trkB/genética
19.
Poult Sci ; 98(1): 473-479, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30107537

RESUMO

Ovomucin is known to be critical for keeping the high quality and freshness of thick albumen, but there is lack of understanding on the dynamics changes of this important protein during storage. This study aimed to investigate the relationship between ovomucin content and egg freshness during storage. Firstly, the viscoelasticity of albumen was shown to be much higher than that of ovomucin-depleted albumen from rheological analysis results, indicating that ovomucin is an important component in maintaining the natural viscoelasticity of albumen. Then, the ovomucin content determined by ELISA method was compared to albumen pH, Haugh unit (HU), and yolk index in terms of egg white quality and to the time of storage in terms of egg freshness at 4°C, 25°C, and 37°C, respectively. Results of the transformation kinetic showed a decrease in ovomucin content with prolonged storage time (P ≤ 0.01). Correlation analysis showed a high positive correlation between ovomucin content and HU (P ≤ 0.01) and a high negative correlation between ovomucin content and the albumen pH (P ≤ 0.01) at the test temperatures. We therefore conclude that ovomucin content in albumen can be used as an index for egg freshness. At last, predictive models of the equivalent egg age (4°C and 25°C) for evaluating the egg freshness were established by means of exponential regression model with ovomucin content as the variable. These results can provide a theoretical and technical basis for the storage and fresh evaluation of shell eggs.


Assuntos
Clara de Ovo/análise , Ovos/normas , Armazenamento de Alimentos , Ovomucina/análise , Animais , Galinhas , Gema de Ovo , Ovos/análise , Concentração de Íons de Hidrogênio , Temperatura , Fatores de Tempo , Viscosidade
20.
J Agric Food Chem ; 66(48): 12805-12814, 2018 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-30415537

RESUMO

The dose-dependent effect of egg consumption on plasma cholesterol in humans remains inconclusive. It is unknown if egg white consumed in a normal amount can reduce plasma cholesterol. We used hamsters as a model to (i) investigate the dose-dependent effect of consuming zero to five whole eggs on plasma total cholesterol (TC) and (ii) examine if egg white, equivalent to one to five eggs, possessed any reducing effects on plasma TC. In experiment 1, hamsters were divided into six groups ( n = 8 each) and fed either a control diet or one of five experimental diets supplemented with whole-egg powder equivalent to one to five eggs per 2000 kcal. Results showed that supplementation with one egg increased plasma TC by 25% compared with that of the control (226 ± 16 versus 282 ± 56 mg/dL, p < 0.05), whereas supplementation with two to five eggs did not significantly produce any additional effects on plasma cholesterol. However, supplementation with one to five eggs in diets caused a dose-dependent accumulation of cholesterol in the liver from 21.5 ± 4.4 to 71.3 ± 7.3 mg/g ( p < 0.01). In the second experiment, hamsters were divided into six groups and fed either a high-cholesterol control diet or one of five experimental diets supplemented with egg-white powder from one to five eggs. Results showed that egg-white powder affected neither plasma nor liver cholesterol levels. The egg-white powder did not affect fecal sterol excretion, suggesting it had no effect on cholesterol absorption. It was therefore concluded that consumption of two to five eggs did not significantly produce any additional effects on plasma cholesterol, whereas egg white did not possess a plasma-cholesterol-lowering activity if it was consumed at amounts similar to those in a normal human diet.


Assuntos
Colesterol/metabolismo , Clara de Ovo/análise , Ovos/análise , Fígado/metabolismo , Plasma/metabolismo , Animais , Galinhas , Colesterol/sangue , Cricetinae , Dieta , Masculino , Mesocricetus
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