Casein peptide release and passage to the blood in humans during digestion of milk or yogurt.

In adult humans, after milk or yogurt ingestion, many peptides derived from alpha s1-, beta- or kappa-caseins were detected in stomach, including the kappa-caseinoglycopeptide, an inhibitor of platelet aggregation. Smaller peptides derived from casein and lactoferrin were recovered from duodenum. Two long peptides, the kappa-caseinoglycopeptide and the N-terminal peptide of alpha s1-casein, were absorbed and detected in plasma. These results support the concept that food-born peptides could have physiological activities in man.