Application of Chemical Methods to the Determination of Egg Yolk Contamination in Commercial Productions of Egg White Compared to Enzymatic Determination

LWT ◽  
2000 ◽  
Vol 33 (2) ◽  
pp. 151-154 ◽  
Author(s):  
Henning Nielsen
Keyword(s):  
Egg Yolk ◽  
Egg White ◽  
Chemical Methods ◽  
Enzymatic Determination

Gas-Liquid Chromatographic Determination of Trace Amounts of Nitrite in Egg, Egg White, and Egg Yolk

1983 ◽  
Vol 66 (2) ◽  
pp. 260-263
Author(s):  
Akio Tanaka ◽  
Norihide Nose ◽  
Hiroyuki Masaki ◽  
Yoshinori Kikuchi ◽  
Hisao Iwasaki
Keyword(s):  
Detection Limit ◽  
Ammonium Thiocyanate ◽  
Egg Yolk ◽  
Practical Method ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Egg White ◽  
Gas Liquid Chromatography ◽  
Liquid Chromatographic

Abstract A simple, sensitive, and practical method is described for determination of nitrite in egg, egg white, and egg yolk. Egg is deproteinized by adding a mixture of ammonium thiocyanate, mercuric chloride, and zinc acetate, and centrifuged. Nitrite in the supernate is converted to tetrazolophthalazine by reaction with hydralazine in acidic solution and then determined by gas-liquid chromatography with an electroncapture detector (GLC-ECD) and a column of OV-225 on Chromosorb W(HP). Nitrite concentrations from 5 to 50 ng/mL are calculated from peak height; the detection limit is 3 ng/mL extract. Recoveries from eggs, egg whites, and egg yolks ranged from 91.7 to 98.0%. The mean nitrite concentration in 50 egg samples was 0.04 ppm (0.01-0.11 ppm) with a detection limit of 4 ng nitrite/g.

Optimal Conditions for the Enzymatic Determination of L-Lactic Acid

1962 ◽  
Vol 8 (1) ◽  
pp. 1-10 ◽  
Author(s):  
G F Olson
Keyword(s):  
Lactic Acid ◽  
Heart Muscle ◽  
Lactic Dehydrogenase ◽  
Test System ◽  
Optimal Conditions ◽  
Enzymatic Method ◽  
Chemical Methods ◽  
Enzymatic Determination ◽  
Enzymatic Procedure

Abstract A simple enzymatic method for the determination of lactic acid with muscle lactic dehydrogenase is described. L(+) Lactate in amounts from 0.04 µM to 0.4 µM can be directly measured by following the formation of reduced diphosphopyridine nucleotide at 340 mµ. The effect of varying the concentrations of reactants in the test system was studied, and the optimal concentrations for stoichiometric conversion of lactate to pyruvate were determined. When lactic acid concentrations in plasma, liver, and heart muscle were determined by both enzymatic and chemical methods, identical results were obtained. The advantages of the present enzymatic procedure over chemical methods are discussed.

scholarly journals Food and inhalation sensitization in atopic dermatitis

2021 ◽  
Vol 5 (1) ◽  
pp. 17-20
Author(s):  
E.A. Vasilyeva ◽  
◽  
Yu.E. Rusak ◽  
E.N. Efanova ◽  
L.N. Lebedeva ◽  
...  
Keyword(s):  
Atopic Dermatitis ◽  
Blood Serum ◽  
Egg Yolk ◽  
Egg White ◽  
Laboratory Research ◽  
Cow’S Milk ◽  
Food Allergens ◽  
Cow's Milk ◽  
Detection Frequency

Aim: to study the association of food and inhalation sensitization with the severity of atopic dermatitis (AtD) in order to improve its treatment and prevention methods. Patients and Methods: the study included 50 patients with AtD from 2 to 44 years old. The study included clinical and laboratory research methods. The survey analyzed the history and anamnesis vitae, estimated the age at the AtD onset, determined the nature of concomitant pathology, the possible causes of cutaneous exacerbation, the allergic severity in the family history, the severity score on the SCORAD (Scoring of Atopic Dermatitis) scale and the efficacy of previous therapy. The immunological examination consisted of the quantitative determination of specific IgE and IgG antibodies in the blood serum to inhaled and food allergens by immunochemiluminescence assay on an IMMULITE 2000 XPi analyzer. Results: according to the detection frequency of IgE to food allergens in patients with AtD: the leading positions were taken by the chicken egg (egg white in 26% of cases, egg yolk in 20%); IgE to banana was detected in 17% of cases; in 12% — to cow’s milk, more common — to the β-lactoglobulin fraction. When studying the activity of inhaled allergens, respiratory sensitization to the cat epithelium was detected in 26% of cases, and to black birch — in 24%. Hypersensitivity to herbs (wormwood, herbal mixture) and house dust allergens (8%, respectively) was found much less common. In severe AtD, IgE to respiratory allergens prevailed: at n=38, the IgE concentration to cat epithelium and black birch was 12.4±1.4 IU/mL each. Besides, there was a significant sensitization to food allergens, namely, the IgE concentration to egg white — 5.4±0.9 IU/mL. Conclusion: the study revealed the sensitization of patients with AtD to food (mainly egg white, egg yolk, banana and cow’s milk) and respiratory (mainly cat epithelium, black birch) allergens. Determination of the IgE concentration in the blood serum of patients showed that there was a significant concentration increase to egg white, cat and black birch in severe AtD. Therefore, it is advisable to test for specific allergens in all patients with moderate to severe AtD. KEYWORDS: food sensitization, inhalation sensitization, atopic dermatitis, allergy, allergens, antibodies, immunochemiluminescence assay, IgE, triggers. FOR CITATION: Vasilyeva E.A., Rusak Yu.E., Efanova E.N., Lebedeva L.N. Food and inhalation sensitization in atopic dermatitis. Russian Medical Inquiry. 2021;5(1):17–20. DOI: 10.32364/2587-6821-2021-5-1-17-20.

scholarly journals Efecto del consumo de alimentos con elevado contenido lipídico sobre el perfil lipídico de ratones sanos

2019 ◽  
Vol 69 (1) ◽  
pp. 34-41
Author(s):  
Miguel A. Campuzano-Bublitz ◽  
Elena M. Araujo ◽  
Rebeca P. Peralta ◽  
Rodrigo Burgos ◽  
Carmen M. Coronel ◽  
...  
Keyword(s):  
Cardiovascular Diseases ◽  
Risk Index ◽  
Hdl Cholesterol ◽  
Egg Yolk ◽  
Egg White ◽  
Control Group ◽  
Daily Food ◽  
Healthy Female ◽  
Los Grupos

La alteración de los lípidos en sangre o dislipidemias sobre todo el colesterol y triglicéridos, son un factor de riesgo de ateroesclerosis y enfermedades cardiovasculares. En este trabajo se analizó el efecto del consumo de huevo, clara, yema de huevo, mantequilla y maní sobre el perfil lipídico de ratones sanos. Se utilizaron seis grupos de ratones hembras sanas, el grupo control (GC) recibió balanceado comercial, mientras que en los demás grupos, 15% de su alimentación diaria consistió en huevo entero (GHE), yema (GY), clara de huevo (GCH), manteca o mantequilla (GMT) o maní (GMN), durante 28 días. Al final de este periodo, se obtuvo la muestra de suero para la determinación de los niveles de colesterol total (CT), triglicéridos (TG), colesterol HDL, colesterol LDL y colesterol VLDL, y se calcularon los índices de riesgo aterogénico y de riesgo cardiaco. Se observó un aumento estadísticamente significativo en los niveles de CT y LDL en relación al GC en los grupos GHE (p<0,0001), GY (p<0,0001), GCH (p<0,005) y GMT (p<0,001), mientras que en niveles de TG presentan un aumento los grupos GHE (p<0,0001) y GY (p<0,0001). El nivel de HDL aumentó significativamente en los grupos GHE (p<0,005) y GMT (p<0,001), y en cuanto al índice de riesgo cardiaco y aterogénico el grupo GY fue el único que reveló aumento significativo (p<0,0001). En el grupo que recibió maní (GMN), no se alteraron los niveles de lípidos, y por lo tanto tampoco el riesgo cardiaco ni aterogénico, lo que se traduce en un menor riesgo de enfermedades cardiovasculares de este grupo. The alteration of blood lipids or dyslipidemias, especially cholesterol and triglycerides, are a risk factor for atherosclerosis and cardiovascular diseases. In this work, the effect of consumption of egg, egg white, egg yolk, butter and peanut on the lipid profile of healthy mice was analyzed. Six groups of healthy female mice were used, the control group (GC) received commercial pellets, while for the other groups, 15% of their daily food consisted of whole egg (GHE), egg yolk (GY), egg white (GCH) ), butter (GMT) or peanut (GMN), for 28 days. At the end of this period, a serum sample was obtained for the determination of the levels of total cholesterol (CT), triglycerides (TG), HDL cholesterol, LDL cholesterol and VLDL cholesterol, and cardiac and atherogenic risk index were calculated. A statistically significant increase in TC and LDL levels was observed in relation to GC in the GHE (p <0,0001), GY (p <0,0001), GCH (p <0,005) and GMT (p <0,001) groups; whereas TG levels showed an increase in the GHE (p <0,0001) and GY (p <0,0001) groups. The HDL level increased significantly in the groups GHE (p <0,005) and GMT (p <0,001), and in terms of the cardiac and atherogenic risk index, the GY group was the only group that revealed a significant increase (p <0,0001). In the group that received peanuts (GMN), the lipid levels were not altered, and therefore neither the cardiac nor the atherogenic risk, which indicates the risk of cardiovascular diseases in this group, were affected.

Enzymatic Determination of Cholesterol in Egg Yolk

1982 ◽  
Vol 65 (5) ◽  
pp. 1222-1224 ◽  
Author(s):  
Chih-Shang J Shen ◽  
Isabel S Chen ◽  
Alan J Sheppard
Keyword(s):  
Quantitative Determination ◽  
Methylene Chloride ◽  
Egg Yolk ◽  
Cholesterol Content ◽  
Enzymatic Determination ◽  
Test Kit ◽  
The Mean ◽  
Liquid Chromatographic ◽  
Enzymatic Test

Abstract The quantitative determination of cholesterol in egg yolk by using an enzymatic test kit is described. Cholesterol in the egg yolk is extracted with other lipid components by methylene chloride-methanol (2 + 1) and is enzymatically determined after saponification of the lipid extract. The method is relatively rapid, simple, and accurate and gives results which agree with those obtained by using a gas-liquid chromatographic (GLC) method. The mean cholesterol content of egg yolk determined by the enzymatic and GLC methods was 1237 and 1240 mg/100 g, respectively.

Rapid determination of egg yolk contamination in egg white by VIS spectroscopy

2014 ◽  
Vol 124 ◽  
pp. 117-121 ◽  
Author(s):  
Muhua Liu ◽  
Linxing Yao ◽  
Tong Wang ◽  
Jing Li ◽  
Chenxu Yu
Keyword(s):  
Rapid Determination ◽  
Egg Yolk ◽  
Egg White ◽  
Vis Spectroscopy

Determination of Egg Yolk in Egg White

1946 ◽  
Vol 18 (12) ◽  
pp. 785-788 ◽  
Author(s):  
J.H Cook ◽  
V.C. Mehlenbacher
Keyword(s):  
Egg Yolk ◽  
Egg White

Transmission Electron Microscopy of Protein Macromolecules

1971 ◽  
Vol 29 ◽  
pp. 424-425
Author(s):  
Henry S. Slayter
Keyword(s):  
Biological Systems ◽  
Metal Vapor ◽  
Resolving Power ◽  
Electron Microscopic ◽  
Chemical Methods ◽  
Molecular Weights ◽  
The Past ◽  
Physical Chemical ◽  
Transmission Electron

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.

Sem and X-Ray Analysis of Renal and Biliary Calculi

1976 ◽  
Vol 34 ◽  
pp. 306-307
Author(s):  
R. J. Narconis ◽  
G. L. Johnson
Keyword(s):  
Chemical Constituents ◽  
Natural State ◽  
X Ray Diffraction ◽  
Chemical Methods ◽  
X Ray ◽  
Additional Dimension ◽  
Biliary Calculi ◽  
Calculus Formation ◽  
Scanning Electron

Analysis of the constituents of renal and biliary calculi may be of help in the management of patients with calculous disease. Several methods of analysis are available for identifying these constituents. Most common are chemical methods, optical crystallography, x-ray diffraction, and infrared spectroscopy. The application of a SEM with x-ray analysis capabilities should be considered as an additional alternative.A scanning electron microscope equipped with an x-ray “mapping” attachment offers an additional dimension in its ability to locate elemental constituents geographically, and thus, provide a clue in determination of possible metabolic etiology in calculus formation. The ability of this method to give an undisturbed view of adjacent layers of elements in their natural state is of advantage in determining the sequence of formation of subsequent layers of chemical constituents.

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