scholarly journals Extractability, Stability, and Allergenicity of Egg White Proteins in Differently Heat-Processed Foods

2007 ◽  
Vol 90 (2) ◽  
pp. 427-436 ◽  
Author(s):  
Christiane K Fste ◽  
Kjersti E Lvberg ◽  
Helene Lindvik ◽  
Eliann Egaas
Keyword(s):  
Egg White ◽  
Food Samples ◽  
Processed Foods ◽  
Heat Treated ◽  
Extraction Buffer ◽  
Egg White Proteins ◽  
Hen’S Egg ◽  
Study Results ◽  
The Stability ◽  
Protein Extractability

Abstract Hen's egg white protein is a major cause of food allergy, and a considerable number of countries have introduced labeling directions for processed food products. To control compliance with these regulations, analytical assays for the detection of egg in manufactured foods have been developed. In this study, we have tested the performance of 3 commercially available kits for quantitative egg analysis using 6 model heat-processed foods. The 3 assays worked well under standard conditions with soluble egg white proteins, but only the kit using a denaturing-reducing extraction buffer detected egg in complex heat-treated food matrixes. The differently extracted food samples were further used to evaluate the stability and allergenicity of the egg white allergens ovalbumin, ovomucoid, ovotransferrin, and lysozyme with polyclonal anti-egg antibodies and sera of 6 patients with egg allergy. It could be shown that differences in egg protein extractability have a significant impact on the interpretation of study results.

scholarly journals ELISA Kit for Determination of Egg White Proteins: Interlaboratory Study

2010 ◽  
Vol 93 (6) ◽  
pp. 1923-1929
Author(s):  
Kvìta Tomková ◽  
Petr Cuhra ◽  
Jana Rysová ◽  
Petr Hanák ◽  
Dana Gabrovská ◽  
...  
Keyword(s):  
Statistical Tests ◽  
Egg White ◽  
Food Samples ◽  
Cross Reactivity ◽  
Interlaboratory Study ◽  
Food Matrix ◽  
Elisa Kit ◽  
Egg White Proteins ◽  
Study Results

Abstract An interlaboratory study was conducted in 11 laboratories to validate an ELISA method developed for the quantitative determination of egg white proteins (EWPs) in foods. The ELISA kit used for this study is based on sheep polyclonal antibody. It does not produce any false-positive results or cross-reactivity in a broad food matrix range with zero EWP content. All participants obtained the Egg ELISA Kit-native with standard operational procedure and the list of samples, as well as the samples and a protocol for recording test results. The study included 10 food samples. Four samples of food matrix with zero EWP content showed EWP content lower than the first standard (EWP content 0.5 mg/kg). One sample of food matrix with zero EWP content revealed EWP content higher than standard 3 (1.5 mg EWP/kg). Five food samples containing EWP as an ingredient tested positive and one negative. The statistical tests (Cochran, Dixon, and Mandel) and analysis of variance were used to evaluate the interlaboratory study results. Repeatability and reproducibility limits, as well as LOQ (1.4 mg EWP/kg) and LOD (0.43 mg EWP/kg), were calculated for the kit.

Peptic digestibility of raw and heat-coagulated hen's egg white proteins at acidic pH range

2004 ◽  
Vol 55 (8) ◽  
pp. 635-640 ◽  
Author(s):  
Kenji Yoshino ◽  
Kentaro Sakai ◽  
Yoko Mizuha ◽  
Ayako Shimizuike ◽  
Shigeru Yamamoto
Keyword(s):  
Egg White ◽  
Acidic Ph ◽  
Egg White Proteins ◽  
Hen’S Egg ◽  
Ph Range

scholarly journals Alterations in egg white-related genes expression in response to hormonal stimulation

Reproduction ◽  
2020 ◽  
Vol 160 (5) ◽  
pp. 793-801
Author(s):  
Minkyeong Lee ◽  
Changwon Yang ◽  
Gwonhwa Song ◽  
Whasun Lim
Keyword(s):  
Reproductive System ◽  
Hormonal Regulation ◽  
Egg Production ◽  
Reproductive Tract ◽  
Egg White ◽  
Female Reproductive Tract ◽  
Expression Of Genes ◽  
Egg White Proteins ◽  
Study Results ◽  
Genes Encoding

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.

Microbial Contamination of the Hen's Egg: A Review

1983 ◽  
Vol 46 (12) ◽  
pp. 1092-1098 ◽  
Author(s):  
FRANCIS J. MAYES ◽  
MUSTAFA A. TAKEBALLI
Keyword(s):  
Microbial Contamination ◽  
Egg White ◽  
Shell Membrane ◽  
Egg White Proteins ◽  
Hen’S Egg ◽  
Bactericidal Properties ◽  
Bacterial Penetration ◽  
Physical And Chemical ◽  
Microbial Attack

The hen's egg is susceptible to microbial attack in a number of ways. The yolk or the albumen may be contaminated before the egg is laid. After the egg has been laid the possibility exists of microbial penetration from the outside. In this review, both these possibilities are discussed together with the defences, both physical and chemical, that the egg has against microbial contamination. Most eggs contain no bacteria when they are laid and only become contaminated subsequently. The shell membrane offers the best protection against bacterial penetration, but once inside the egg their growth and multiplication is slowed due to the viscous nature of the egg white proteins, their pH, and the bactericidal properties of lysozyme and conalbumen.

Effect of three cations on the stability and microstructure of protein aggregate from duck egg white under alkaline condition

2011 ◽  
Vol 17 (4) ◽  
pp. 343-349 ◽  
Author(s):  
P. Ganasen ◽  
S. Benjakul
Keyword(s):  
Negative Charge ◽  
Egg White ◽  
Alkaline Condition ◽  
Protein Aggregate ◽  
Egg White Protein ◽  
Egg White Proteins ◽  
Traditionally Prepared ◽  
Microscopic Studies ◽  
Duck Egg ◽  
The Stability

Pidan (alkaline egg) has been consumed widely in oriental countries and lead, a toxic element, has been used traditionally to yield the desirable characteristics. For safety concerns, alternative cations can be used for the production of pidan with comparable properties to traditionally prepared pidan. Turbidity measured as absorbance at 400 nm and microstructure of duck egg white proteins at pH 12 as influenced by three cations at various levels were investigated. Turbidity and particle size of egg white protein (20 g/kg) in 10 g/kg NaCl sample with CaCl2, PbO2 or ZnCl2 added at a level of 1 g/kg increased with time up to 1 h, followed by a decrease (p < 0.05). Nevertheless, the turbidity was retained more in samples added with PbO2, suggesting high stability of the aggregate formed. Zeta potential showed that the aggregates treated with PbO2 had a comparatively lower negative charge. Light microscopic studies indicated that the aggregation of egg white proteins was induced by ions but varied with the types of ions and incubation time. Therefore, PbO2 exhibited the highest stabilizing effect on egg white protein under alkaline condition. However, ZnCl2 can be used as an alternative compound even if it had lower impact on stability of aggregate of duck egg white protein.

scholarly journals Allergy to egg whites: diagnosis, symptoms (clinical features), prognosis

2018 ◽  
Vol 15 (2) ◽  
pp. 5-10
Author(s):  
A V Kudryavtseva ◽  
Y A Boguslavskaya
Keyword(s):  
Food Allergy ◽  
Skin Testing ◽  
Egg Yolk ◽  
Molecular Diagnostic ◽  
Prick Test ◽  
Heat Treated ◽  
Egg White Proteins ◽  
Hen’S Egg ◽  
Measles Vaccination ◽  
Protein Components

Allergic reactions to hen’s egg are rather a common problem, especially in infants. Hen’s eggs contain a few protein components which may serve as food allergens. They are 4 egg-white proteins: ovomucoid (Gal d 1, 11%), ovalbumin (Gal d 2, 54%), ovotransferrin (Gal d 3, 12%), lysozyme (Gal d 4, 3,4%) and one egg-yolk protein - alpha-livetin (Gal d 5). Ovomucoid (OVM) is the dominant allergen in hen’s egg. The allergenicity of egg whites depends mostly on their resistance to heat and digestive enzymes. A skin prick test size of 5 mm in children younger than 2 years old and 7 mm in children older than 2 years had a positive predicative value (PPV) of 100%. However, patient questioning and skin testing cannot be the only proof of food allergy. There exists a positive correlation between the growing levels of eggs-pecific IgE and the probability of allergic symptoms occurrence. Testing for sensitization to different hen’s egg proteins (molecular diagnostic) may assist in marking off allergy reaction to raw eggs from that one to heat-treated eggs. Questionable cases call for carrying out challenge tests which are not certified in Russia. The recent studies have demonstrated the safety of measles vaccination in children with proven eggwhite allergy. Currently, oral, sublingual and epicutaneous immunotherapy for food allergy to egg-whites has been extensively investigated in clinical trials.

Development of a Sandwich Enzyme-Linked Immunosorbent Assay for the Detection of Egg Residues in Processed Foods†

2001 ◽  
Vol 64 (11) ◽  
pp. 1812-1816 ◽  
Author(s):  
SUSAN L. HEFLE ◽  
ELIZABETH JEANNITON ◽  
STEVE L. TAYLOR
Keyword(s):  
Immunosorbent Assay ◽  
Matrix Effects ◽  
Egg White ◽  
Food Samples ◽  
Cross Reactivity ◽  
Food Hypersensitivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Processed Foods ◽  
Igg Antibody ◽  
Food Ingredients

Chicken eggs are used extensively as an excellent source of dietary proteins. These proteins have many functional properties, making them valuable food ingredients. However, eggs are a frequent cause of food hypersensitivity, especially in children. Of major concern to food processors is the inadvertent cross-contact of food products with allergenic residues, which could result in potentially life-threatening reactions in those with a food allergy. The aim of the present study was to develop an enzyme-linked immunosorbent assay (ELISA) for the detection of undeclared egg residues in foods. Commercially purified ovalbumin (OVA) and dehydrated egg white solids were used as antigens to induce antibodies in rabbits and goats. Reference pasta standards and various food samples were extracted, then clarified by centrifugation. Goat anti-egg white antibodies were used as the capture reagent, nonspecific sites were blocked with gelatin, then standard and sample extracts were added. Rabbit anti-OVA antibodies were used as detector antibodies, followed by addition of commercial goat anti-rabbit IgG antibody labeled with alkaline phosphatase and subsequent substrate addition. Twenty brands of egg-free pasta (two lots each) were analyzed using the ELISA. Fourteen common pasta ingredients were also evaluated for cross-reactivity problems in the method. The detection limit of the assay was 1 ppm spray-dried whole egg. Fifty-five percent (22 samples) of the egg-free pasta samples tested positive for the presence of undeclared egg residues, with values ranging from 1 to &gt;100,000 ppm. Minimal cross-reactivity was encountered in general, but portobello mushrooms and basil caused some minor matrix effects. This sandwich-type ELISA method can be used to detect undeclared egg residues in processed foods and to evaluate industrial clean-up operations.

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