Plasmin Digestion of Photooxidized Milk Proteins

Chromatograms obtained by reverse phase HPLC with UV detection at 214nm of peptides after plasmin photooxidized (---) or nonoxidized (——) proteins. Peptides from A) α-casein, B) β-casein, C) κ-casein, D) α-lactalbumin, E) β-lactoglobulin, and F) lactoferrin. Photooxidized proteins (44h at 2,200 to 2,600 lx) and controls that had not been exposed to light were hydrolyzed by plasmin for 44h at 30°C in an enzyme:substrate ratio (mass ratio) of 1:150 at pH 6.8. Abs = absorption.