Milk protein concentrates are suitable ingredients for high-protein beverages, but are underutilized due
to poor solubility at ambient temperature and neutral pH. The other functional properties of milk protein
concentrate, such as emulsification and foaming, depend on its solubility. Milk protein concentrate with
80 g protein 100 g1 was hydrolyzed with three digestive enzymes e chymotrypsin, trypsin, and pepsin
e and one cysteine protease e papain e to improve solubility and functionality. Two hydrolysates were
produced with each enzyme at targeted levels of hydrolysis to help prevent the development of
bitterness. Reduced urea sodium dodecyl sulfate polyacrylamide gel electrophoresis showed that casein
subunits were more susceptible to hydrolysis compared with the whey proteins. Enzyme hydrolysis
improved the solubility of the milk protein concentrate in the pH range of 4.6e7.0 inclusive. All enzyme
hydrolysates had reduced surface hydrophobicity and gel strength. Hydrolysis with chymotrypsin and
trypsin improved emulsion activity and stability whereas emulsification capacity was improved with all
enzymes. Foaming properties depended on enzyme and hydrolysis time. The hydrolysis of milk protein
concentrate with food enzymes can improve solubility and alter resultant functional properties.