Comparison of quantity and structures of hydroxyproline-containing peptides in human blood after oral ingestion of gelatin hydrolysates from different sources

J Agric Food Chem. 2007 Feb 21;55(4):1532-5. doi: 10.1021/jf062834s. Epub 2007 Jan 25.


We compared quantity and structures of food-derived gelatin hydrolysates in human blood from three sources of type I collagen in a single blind crossover study. Five healthy male volunteers ingested type I gelatin hydrolysates from fish scale, fish skin, or porcine skin after 12 h of fasting. Amounts of free form Hyp and Hyp-containing peptide were measured over a 24-h period. Hyp-containing peptides comprised approximately 30% of all detected Hyp. The total area under the concentration-time curve of the fish scale group was significantly higher than that of the porcine skin group. Pro-Hyp was a major constituent of Hyp-containing peptides. Ala-Hyp, Leu-Hyp, Ile-Hyp, Phe-Hyp, and Pro-Hyp-Gly were detected only with fish scale or fish skin gelatin hydrolysates. Ala-Hyp-Gly and Ser-Hyp-Gly were detected only with fish scale gelatin hydrolysate. The quantity and structure of Hyp-containing peptides in human blood after oral administration of gelatin hydrolysate depends on the gelatin source.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Animals
  • Collagen Type I / administration & dosage
  • Collagen Type I / chemistry
  • Cross-Over Studies
  • Fishes
  • Gelatin / administration & dosage*
  • Humans
  • Hydroxyproline / blood*
  • Male
  • Peptides / blood*
  • Protein Hydrolysates / administration & dosage*
  • Skin / chemistry
  • Swine


  • Collagen Type I
  • Peptides
  • Protein Hydrolysates
  • Gelatin
  • Hydroxyproline