ABSTRACT
This chapter aims to bring together some of the available methods to identify and quantify bioactive peptides in food or biological matrices, and to evaluate biological activities either in vitro or in vivo. Among others, bioactive peptides may be involved in enzyme inhibition, channel blockade, radical or metal scavenging, electrostatic or hydrophobic interaction, or receptor activation, making possible to acknowledge antihypertensive, antidiabetic, antimicrobial, cyto- and immunomodulatory, or antioxidant activities. Bioactive peptides from milk proteins are considered as food ingredients that promote human health, although in some cases they may also have detrimental effects such as the case of food peptides constituting allergenic epitopes. Although high-performance liquid chromatography-MS is a powerful technique for peptide sequencing, certain RP separations entail some difficulties, for instance, the identification of small hydrophilic peptides eluting in the first part of the chromatogram, which is usually discarded to avoid salts entering into the mass spectrometer.
