Hydrolyzed infant formulas serve as appropriate nutritional sources for infants afflicted with
cow's milk allergy, and
milk proteins in hydrolyzed formulas are industrially hydrolyzed extensively or partially. To investigate whether industrial hydrolysis may modulate the digestive trajectory of
milk proteins, thereby releasing different profiles of bioactive
peptides compared with standard formulas, both standard and hydrolyzed formulas were subjected to in vitro digestion and formation of bioactive
peptides were compared. One standard, one extensively hydrolyzed, and one partially hydrolyzed infant formula were digested in vitro with
pepsin and
pancreatin, taking into account the higher gastric pH of infants, and the digesta were subjected to peptidomic analysis. The standard formula released a larger variety of bioactive
peptides than from the hydrolyzed formulas, indicating that industrial hydrolysis of
milk proteins may generally attenuate their indigenous bioactivities such as antibacterial, immuno-regulatory, and anti-oxidative activities. Conversely, industrial hydrolysis may facilitate the formation of bioactive
peptides from hydrophobic
proteins/regions such as β-LG and the "strategic zone" of β-CN, which encrypt bioactive
peptides including a dipeptidyl dipeptidase-4-inhibitory, hypocholesterolemic, and
opioid peptides. Infants fed hydrolyzed infant formulas may be influenced by
milk protein-derived bioactive
peptides in a manner different from those fed standard formula.