Occurrence of milk proteins in the urine of cows during an extended milking interval

1967 ◽  
Vol 34 (1) ◽  
pp. 27-30 ◽  
Author(s):  
R. L. J. Lyster ◽  
J. V. Wheelock
Keyword(s):  
Molecular Weight ◽  
Milk Proteins ◽  
Immunological Methods ◽  
Factors Affecting ◽  
Β Lactoglobulin

SummaryImmunological methods have been used to test samples of urine from 5 cows for the presence of milk proteins. None could be detected when the cows were milked twice daily at the usual intervals, but during an extended milking interval α-lactalbumin was found in the urine of all 5 cows and β-lactoglobulin in the urine of 2 cows. The urine of one cow during and after a milking interval of 39 h contained 1·63 g α-lactalbumin, 1·12 g β-lactoglobulin and a small amount of casein. One of the factors affecting the transfer of these milk constituents from the udder to the urine appears to be their molecular weight.

Factors Affecting Bioconcentration of Trace Organic Contamination in Waters

1989 ◽  
Vol 21 (2) ◽  
pp. 147-150 ◽  
Author(s):  
D. W. Hawker ◽  
D. W. Connell
Keyword(s):  
Molecular Weight ◽  
Bioconcentration Factor ◽  
Aqueous Solubility ◽  
Organic Chemicals ◽  
Organic Contamination ◽  
Hydrophobic Organic Chemicals ◽  
Factors Affecting ◽  
Water Partition Coefficient ◽  
Physicochemical Factors ◽  
Trace Organic

The influence of some important biological and physicochemical factors on the bioconcentration of hydrophobic organic chemicals is outlined. For non-ionizable, persistent compounds the bioconcentration factor can be related to a compound's octanol/water partition coefficient, aqueous solubility and molecular weight, while the lipid content of an organism also affects the bioconcentration potential of these compounds. The effect of ionization and biodegradation of organic chemicals on bioconcentration is also discussed.

Factors Affecting Molecular Weight of Enzymatically Synthesized Dextran2

1955 ◽  
Vol 77 (9) ◽  
pp. 2412-2419 ◽  
Author(s):  
H. M. Tsuchiya ◽  
N. N. Hellman ◽  
H. J. Koepsell ◽  
J. Corman ◽  
C. S. Stringer ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Factors Affecting

Attachment of Listeria innocua to Polystyrene: Effects of Ionic Strength and Conditioning Films from Culture Media and Milk Proteins

2014 ◽  
Vol 77 (3) ◽  
pp. 427-434 ◽  
Author(s):  
GILLES ROBITAILLE ◽  
SÉBASTIEN CHOINIÈRE ◽  
TIMOTHY ELLS ◽  
LOUISE DESCHÈNES ◽  
AKIER ASSANTA MAFU
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bacterial Adhesion ◽  
Bovine Serum ◽  
Biofilm Formation ◽  
Milk Protein ◽  
Milk Proteins ◽  
Listeria Innocua ◽  
Conditioning Films ◽  
Β Lactoglobulin

It is recognized that bacterial adhesion usually occurs on conditioning films made of organic macromolecules absorbed to abiotic surfaces. The objectives of this study were to determine the extent to which milk protein–coated polystyrene (PS) pegs interfere with biofilm formation and the synergistic effect of this conditioning and hypertonic growth media on the bacterial adhesion and biofilm formation of Listeria innocua, used as a nonpathogenic surrogate for Listeria monocytogenes. PS pegs were uncoated (bare PS) or individually coated with whey proteins isolate (WPI), β-lactoglobulin, bovine serum albumin, or tryptic soy broth (TSB) and were incubated in bacterial suspensions in modified Welshimer's broth. After 4 h, the number of adherent cells was dependent on the coating, as follows: TSB (107 CFU/ml) > bare PS > β-lactoglobulin > bovine serum albumin ≈ WPI (104 CFU/ml). The sessile cell counts increased up to 24 h, reaching >107 CFU per peg for all surfaces (P > 0.1), except for WPI-coated PS; this indicates that the inhibitory effects of milk protein conditioning films are transient, slowing down the adhesion process. The 4-h bacterial adhesion on milk protein–coated PS in modified Welshimer's broth supplemented with salt (0 to 10% [wt/vol]) did not vary (P > 0.1), indicating that conditioning with milk proteins was the major determinant for inhibition of bacterial adhesion and that the synergetic effect of salt and milk proteins on adhesion was minimal. Moreover, the presence of 5 to 10% salt significantly inhibited 24-h biofilm formation on the TSB-coated and bare PS, with a decrease of >3 log at 10% (wt/vol) NaCl and almost completely depleted viable sessile bacteria on the milk protein–coated PS.

Rapid, sensitive two-site ELISA for detection of cows' milk in goats' or ewes' milk using monoclonal antibodies

1994 ◽  
Vol 61 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Didier Levieux ◽  
Annie Venien
Keyword(s):  
Monoclonal Antibodies ◽  
Sandwich Elisa ◽  
High Specificity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Factors Affecting ◽  
Assay Performance ◽  
Capture Antibody ◽  
Constant Quality ◽  
Species Specific ◽  
Β Lactoglobulin

SummaryA sandwich ELISA (enzyme-linked immunosorbent assay) of the two-site type has been successfully developed for the detection of cows' milk in goats' or ewes' milk. The assay uses two monoclonal antibodies (MAb) raised in mice against cows' β-lactoglobulin (β-lg). These MAb recognize different epitopes of the β-lg, which are sufficiently distinct to allow simultaneous binding of the corresponding antibodies. One of the MAb recognizes a species-specific epitope of the bovine β-lg and was adsorbed to a plastic microtitration plate (capture antibody). The second MAb was labelled with peroxidase and used to detect the captured cows' β-lg. Factors affecting assay performance were investigated. The optimized assay is highly specific, reproducible (intra- and inter-assay CV were 8 and 13% respectively) and sensitive: as little as 5 ng β-lg/ml or 1 part cows' milk per 100000 parts goats' or ewes' milk can be detected. The technique is robust, cheap, rapid, reliable and suitable for high sample throughput, semi-automation and screening surveys. The MAb used guarantee the high specificity of the assay and indefinite reagent supply of constant quality once approved by collaborative national or international trials.

scholarly journals Development and Validation of a Method for the Quantification of Milk Proteins in Food Products Based on Liquid Chromatography with Mass Spectrometric Detection

2011 ◽  
Vol 94 (4) ◽  
pp. 1043-1059 ◽  
Author(s):  
Petra Lutter ◽  
Véronique Parisod ◽  
Hans Weymuth
Keyword(s):  
Milk Powder ◽  
Skim Milk ◽  
Internal Standard ◽  
Milk Proteins ◽  
Skim Milk Powder ◽  
Selected Reaction Monitoring ◽  
Validation Data ◽  
Development And Validation ◽  
Protein Rich ◽  
Β Lactoglobulin

Abstract The protection of allergic consumers is crucial to the food industry. Therefore, accurate methods for the detection of food allergens are required. Targeted detection of selected molecules by MS combines high selectivity with accurate quantifcation. A confrmatory method based on LC/selected reaction monitoring (SRM)-MS/MS was established and validated for the quantifcation of milk traces in food. Tryptic peptides of the major milk proteins β-lactoglobulin, β-casein, αS2-casein, and κ-casein were selected as quantitative markers. Precise quantifcation was achieved using internal standard peptides containing isotopically labeled amino acids. For each peptide, qualifer and quantifer fragments were selected according to Commission Decision 2002/657/EC. A simple sample preparation method was established without immunoaffnity or SPE enrichment steps for food matrixes containing different amounts of protein, such as baby food, breakfast cereals, infant formula, and cereals. Intermediate reproducibility, repeatability, accuracy, and measurement uncertainty were determined for each matrix. LOD values of 0.2–0.5 mg/kg, e.g., for β-lactoglobulin, were comparable to those obtained with ELISA kits. An LOQ of approximately 5 mg/kg, expressed as mass fraction skim milk powder, was validated in protein-rich infant cereals. The obtained validation data show that the described LC/SRM-MS/MS approach can serve as a confrmatory method for the determination of milk traces in selected food matrixes.

scholarly journals Variation of Detailed Protein Composition of Cow Milk Predicted from a Large Database of Mid-Infrared Spectra

Animals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 176 ◽  
Author(s):  
Marco Franzoi ◽  
Giovanni Niero ◽  
Giulio Visentin ◽  
Mauro Penasa ◽  
Martino Cassandro ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Protein Composition ◽  
Protein Fractions ◽  
Cow Milk ◽  
Fat Percentage ◽  
Dual Purpose ◽  
Factors Affecting ◽  
Dual Purpose Cattle ◽  
Milk Urea ◽  
Β Lactoglobulin

This study aimed to investigate factors affecting protein fractions, namely α-casein (α-CN), β-casein (β-CN), κ-casein (κ-CN), β-lactoglobulin (β-LG) and α-lactalbumin (α-LA) predicted from milk infrared spectra in milk of dairy and dual-purpose cattle breeds. The dataset comprised 735,328 observations from 49,049 cows in 1782 herds. Results highlighted significant differences of protein fractions in milk of the studied breeds. Significant variations of protein fractions were found also through parities and lactation, with the latter thoroughly influencing protein fractions percentage. Interesting correlations (r) were estimated between β-CN, κ-CN and β-LG, expressed as percentage of crude protein, and milk urea nitrogen (r = 0.31, −0.20 and −0.26, respectively) and between α-LA and fat percentage (r = 0.41). The present study paves the way for future studies on the associations between protein fractions and milk technological properties, and for the estimation of genetic parameters of predicted protein composition.

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