Identification of a novel food-derived collagen peptide, hydroxyprolyl-glycine, in human peripheral blood by pre-column derivatisation with phenyl isothiocyanate

► Hydroxyprolyl-glycine (Hyp-Gly) was identified in human blood after collagen hydrolysate ingestion. ► Phenyl isothiocyanate derivatisation of peptides improved resolution of food-derived collagen peptides by RP-HPLC. ► The ratio of Hyp-Gly to Pro-Hyp depended on subjects who ingested elastin hydrolysate. ► Hyp-Gly was less susceptible to human serum peptidase than Pro-Hyp. ► Hyp-Gly extensively enhanced the growth of mouse primary fibroblasts on collagen gel in a higher extent than Pro-Hyp.