Methods are described for treating a whey protein mixture to increase a relative concentration of α-lactalbumin protein in the mixture. The methods may include the step of adjusting a temperature of the whey protein mixture to about 10° C. or less, and adjusting the pH of the mixture to greater than 7. The may further include adding a protease enzyme to the whey protein mixture that selectively hydrolyzes β-lactoglobulin protein in the mixture. The activity of the protease enzyme in the hydrolyzed whey protein mixture may be terminated before a substantial portion of the α-lactalbumin protein has been hydrolyzed by the enzyme. In some instances, the whey protein mixture may also include glycomacropeptides that are selectively hydrolyzed with the β-lactoglobulin protein. The β-lactoglobulin and glycomacropeptide hydrolysates may be separated to produce an enhanced α-lactalbumin protein composition for infant formula, among other products.
