Casein content of human milk

B. Lonnerdal, E. Forsum

Research output: Contribution to journalArticle

54 Citations (Scopus)

Abstract

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 ~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.

Original languageEnglish (US)
Pages (from-to)113-120
Number of pages8
JournalAmerican Journal of Clinical Nutrition
Volume41
Issue number1
StatePublished - 1985

Fingerprint

Human Milk
breast milk
Caseins
casein
Nitrogen
ultracentrifugation
Ultracentrifugation
Trace Elements
whey protein
trace elements
nitrogen
infant nutrition
Infant Formula
Proteins
infant formulas
whey
gel electrophoresis
washing
Electrophoresis
manufacturing

ASJC Scopus subject areas

  • Food Science
  • Medicine (miscellaneous)

Cite this

Lonnerdal, B., & Forsum, E. (1985). Casein content of human milk. American Journal of Clinical Nutrition, 41(1), 113-120.

Casein content of human milk. / Lonnerdal, B.; Forsum, E.

In: American Journal of Clinical Nutrition, Vol. 41, No. 1, 1985, p. 113-120.

Research output: Contribution to journalArticle

Lonnerdal, B & Forsum, E 1985, 'Casein content of human milk', American Journal of Clinical Nutrition, vol. 41, no. 1, pp. 113-120.
Lonnerdal B, Forsum E. Casein content of human milk. American Journal of Clinical Nutrition. 1985;41(1):113-120.
Lonnerdal, B. ; Forsum, E. / Casein content of human milk. In: American Journal of Clinical Nutrition. 1985 ; Vol. 41, No. 1. pp. 113-120.
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