Free amino acid content in standard infant formulas: Comparison with human milk

C. Agostoni, B. Carratu, C. Boniglia, E. Riva, E. Sanzini

Research output: Contribution to journalArticle


Objective: To compare the concentration of non-protein nitrogen (NPN) and free amino acids (FAA) in powdered and liquid commercial formulas with that in human milk. Methods: The non-protein nitrogen and FAAs in pooled breast milk was compared with that in 11 protein-modified starting infant formulas (seven powdered, four liquid whey-predominant formulas) and one powdered soy-formula. Human milk was collected at the end of each feeding (hindmilk) over 24 hours in a group of 40 healthy lactating women after delivery of full-term infants at age one month. Results: In human milk glutamic acid plus glutamine and taurine were the prevalent amino acids, accounting for around 50% total FAA. In the analysed formulas the total FAA fraction was 10% or even less than in human milk, mostly represented by taurine, while methionine was high in soy formula. The sum of glutamic acid and glutamine in all the formulas was much lower than in human milk. Conclusions: Breastfed infants are supplied with FAA, mainly glutamic acid and glutamine, compared to formula-fed counterparts. The different FAA intake might be the origin of some functional differences at the enteral level between breast- and formula-fed infants.

Original languageEnglish
Pages (from-to)434-438
Number of pages5
JournalJournal of the American College of Nutrition
Issue number4
Publication statusPublished - 2000


  • Free amino acids
  • Glutamic acid
  • Glutamine
  • Human milk
  • Infant formulas

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Food Science

Fingerprint Dive into the research topics of 'Free amino acid content in standard infant formulas: Comparison with human milk'. Together they form a unique fingerprint.

  • Cite this