Chapter 9 - Methodologies for bioavailability assessment of food-derived peptide

Abstract

Bioactive peptides identified via in vitro activity-guided fractionation in food have been quantified in the human blood after ingestion of food protein hydrolyzates. However, the in vitro active peptides were determined to be very low levels (approximately 1–2nM). On the other hand, food-derived peptides have been directly identified in human blood after the ingestion of collagen and elastin hydrolyzates. The maximum blood levels of these peptides were approximately 1–50μM. In addition, some dipeptides and tripeptides with prolyl and pyroglutamyl residues at the amino terminal, as well as α-d-asparatyl dipeptides and β-d/l-asparatyl isopeptides, were present in human and animal bloods in concentrations higher than the previously reported in vitro active peptides. Recent advances in methods and approaches for the identification of the food-derived peptides in blood and tissue extracts have been introduced in this chapter. Moreover, the possibility of the modification of food-derived peptides during the absorption process is discussed at the end of this chapter.