Document Detail

Casein content of human milk.
MedLine Citation:
PMID:  3966414     Owner:  NLM     Status:  MEDLINE    
Three methods for estimating the casein content of human milk were tested; isoelectric precipitation with washing and correction for co-precipitating proteins, sedimentation by ultracentrifugation, and indirect analysis (ie analyzing for the content of the major whey proteins and subtracting these from the total protein content). Gel electrophoresis and amino acid analysis were used to confirm some of the results. The casein content (mg/ml) of mature human milk (n = 9) was 2.33 +/- 1.69 by isoelectric precipitation, 1.80 +/- 0.48 by sedimentation and 2.96 +/- 1.08 by the indirect approach. A probable partition of nitrogen in breast milk would be casein N: whey protein N: non-protein N of 20:50:30; ie the correct ratio of casein nitrogen: whey nitrogen is approximately 20:80. Analysis of trace elements and minerals demonstrates that of total Ca 10%, Mg 5%, Zn 28%, Cu 17%, and Fe 27% is bound to casein when prepared by ultracentrifugation while isoelectric precipitation causes a redistribution of some of these elements. Since the protein ratio of human milk is considered a guideline when manufacturing infant formulas, these findings should be considered with regard to infant nutrition.
B Lönnerdal; E Forsum
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The American journal of clinical nutrition     Volume:  41     ISSN:  0002-9165     ISO Abbreviation:  Am. J. Clin. Nutr.     Publication Date:  1985 Jan 
Date Detail:
Created Date:  1985-02-07     Completed Date:  1985-02-07     Revised Date:  2009-11-19    
Medline Journal Info:
Nlm Unique ID:  0376027     Medline TA:  Am J Clin Nutr     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  113-20     Citation Subset:  AIM; IM    
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MeSH Terms
Amino Acids / analysis
Caseins / analysis*
Chemical Precipitation
Electrophoresis, Polyacrylamide Gel
Isoelectric Point
Milk Proteins / analysis
Milk, Human / analysis*
Minerals / analysis
Nitrogen / analysis
Spectrophotometry, Atomic
Trace Elements / analysis
Reg. No./Substance:
0/Amino Acids; 0/Caseins; 0/Milk Proteins; 0/Minerals; 0/Trace Elements; 7727-37-9/Nitrogen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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