Non-protein nitrogen and true protein in infant formulas

S. M. Donovan, B. Lonnderdal

Research output: Contribution to journalArticle

58 Citations (Scopus)

Abstract

Protein and nitrogen (N) requirements of infants and the optimum protein level of infant formulas are still under debate. Human milk (HM) N is considered adequate although 25% of the N is provided as non-protein nitrogen (NPN), half in the form of urea. Soluble N, insoluble N, NPN and urea N were determined in HM and cow's milk (CM), 5 CM-based infant formulas, 4 soy protein-based formulas (SF), and manufacturers' skim milk and whey protein sources. Total, peptide and free amino acids were also determined in all samples. Levels of NPN and urea N in formulas were highly dependent on the type of whey used, with ion-exchange whey being highest, followed by electrodialyzed and ultrafiltered whey, respectively. SF contained very little NPN with the exception of Soyalac. Consequently, true protein [(Total N-NPN) x 6.38] was lower than the reported levels in several formulas. Levels of peptide and free amino acids were also affected by the method of whey prepration. While it has been recognized that 'casein-predominant' CM formulas will have different effects on metabolic indices than 'whey-predominant' formulas, this study demonstrates that there are also pronounced differences among 'whey-predominant' formulas.

Original languageEnglish (US)
Pages (from-to)497-504
Number of pages8
JournalActa Paediatrica Scandinavica
Volume78
Issue number4
StatePublished - 1989

Fingerprint

Infant Formula
Nitrogen
Urea
Milk
Proteins
Human Milk
Amino Acids
Peptides
Soybean Proteins
Milk Proteins
Ion Exchange
Caseins
Whey

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health

Cite this

Donovan, S. M., & Lonnderdal, B. (1989). Non-protein nitrogen and true protein in infant formulas. Acta Paediatrica Scandinavica, 78(4), 497-504.

Non-protein nitrogen and true protein in infant formulas. / Donovan, S. M.; Lonnderdal, B.

In: Acta Paediatrica Scandinavica, Vol. 78, No. 4, 1989, p. 497-504.

Research output: Contribution to journalArticle

Donovan, SM & Lonnderdal, B 1989, 'Non-protein nitrogen and true protein in infant formulas', Acta Paediatrica Scandinavica, vol. 78, no. 4, pp. 497-504.
Donovan, S. M. ; Lonnderdal, B. / Non-protein nitrogen and true protein in infant formulas. In: Acta Paediatrica Scandinavica. 1989 ; Vol. 78, No. 4. pp. 497-504.
@article{c2ff0ac6b81e4fe7855e8779a59f1456,
title = "Non-protein nitrogen and true protein in infant formulas",
abstract = "Protein and nitrogen (N) requirements of infants and the optimum protein level of infant formulas are still under debate. Human milk (HM) N is considered adequate although 25{\%} of the N is provided as non-protein nitrogen (NPN), half in the form of urea. Soluble N, insoluble N, NPN and urea N were determined in HM and cow's milk (CM), 5 CM-based infant formulas, 4 soy protein-based formulas (SF), and manufacturers' skim milk and whey protein sources. Total, peptide and free amino acids were also determined in all samples. Levels of NPN and urea N in formulas were highly dependent on the type of whey used, with ion-exchange whey being highest, followed by electrodialyzed and ultrafiltered whey, respectively. SF contained very little NPN with the exception of Soyalac. Consequently, true protein [(Total N-NPN) x 6.38] was lower than the reported levels in several formulas. Levels of peptide and free amino acids were also affected by the method of whey prepration. While it has been recognized that 'casein-predominant' CM formulas will have different effects on metabolic indices than 'whey-predominant' formulas, this study demonstrates that there are also pronounced differences among 'whey-predominant' formulas.",
author = "Donovan, {S. M.} and B. Lonnderdal",
year = "1989",
language = "English (US)",
volume = "78",
pages = "497--504",
journal = "Acta Paediatrica, International Journal of Paediatrics",
issn = "0803-5253",
publisher = "Wiley-Blackwell",
number = "4",

}

TY - JOUR

T1 - Non-protein nitrogen and true protein in infant formulas

AU - Donovan, S. M.

AU - Lonnderdal, B.

PY - 1989

Y1 - 1989

N2 - Protein and nitrogen (N) requirements of infants and the optimum protein level of infant formulas are still under debate. Human milk (HM) N is considered adequate although 25% of the N is provided as non-protein nitrogen (NPN), half in the form of urea. Soluble N, insoluble N, NPN and urea N were determined in HM and cow's milk (CM), 5 CM-based infant formulas, 4 soy protein-based formulas (SF), and manufacturers' skim milk and whey protein sources. Total, peptide and free amino acids were also determined in all samples. Levels of NPN and urea N in formulas were highly dependent on the type of whey used, with ion-exchange whey being highest, followed by electrodialyzed and ultrafiltered whey, respectively. SF contained very little NPN with the exception of Soyalac. Consequently, true protein [(Total N-NPN) x 6.38] was lower than the reported levels in several formulas. Levels of peptide and free amino acids were also affected by the method of whey prepration. While it has been recognized that 'casein-predominant' CM formulas will have different effects on metabolic indices than 'whey-predominant' formulas, this study demonstrates that there are also pronounced differences among 'whey-predominant' formulas.

AB - Protein and nitrogen (N) requirements of infants and the optimum protein level of infant formulas are still under debate. Human milk (HM) N is considered adequate although 25% of the N is provided as non-protein nitrogen (NPN), half in the form of urea. Soluble N, insoluble N, NPN and urea N were determined in HM and cow's milk (CM), 5 CM-based infant formulas, 4 soy protein-based formulas (SF), and manufacturers' skim milk and whey protein sources. Total, peptide and free amino acids were also determined in all samples. Levels of NPN and urea N in formulas were highly dependent on the type of whey used, with ion-exchange whey being highest, followed by electrodialyzed and ultrafiltered whey, respectively. SF contained very little NPN with the exception of Soyalac. Consequently, true protein [(Total N-NPN) x 6.38] was lower than the reported levels in several formulas. Levels of peptide and free amino acids were also affected by the method of whey prepration. While it has been recognized that 'casein-predominant' CM formulas will have different effects on metabolic indices than 'whey-predominant' formulas, this study demonstrates that there are also pronounced differences among 'whey-predominant' formulas.

UR - http://www.scopus.com/inward/record.url?scp=0024448436&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0024448436&partnerID=8YFLogxK

M3 - Article

C2 - 2782063

AN - SCOPUS:0024448436

VL - 78

SP - 497

EP - 504

JO - Acta Paediatrica, International Journal of Paediatrics

JF - Acta Paediatrica, International Journal of Paediatrics

SN - 0803-5253

IS - 4

ER -