Methods for preserving endogenous TGF-β

A method of preparing a liquid nutritional product comprising transforming growth factor-beta (TGFβ) wherein the liquid nutritional product retains bioactivity of the TGF-β, the method comprising, in the listed order, the steps of:

• a. selecting one or more protein ingredients including at least one whey protein powder selected from the group consisting of sweet whey, demineralized whey, whey protein concentrate, whey protein isolate and combinations thereof that have been subjected to a heat load comprising medium-heat or less, wherein the one or more protein ingredients comprises TGF-β;
• b. combining the protein ingredients with one or more additional components of the liquid nutritional product to form a slurry;
• c. pasteurizing the slurry at a temperature of about 70° C. to about 75° C. for about 5 to 25 seconds;
• d. subjecting the slurry to a pressure of from about 2500 pounds per square inch (psi) to about 3500 psi at a temperature of from about 55° C. to about 65° C. for about 5 to about 20 seconds;
• e. subjecting the slurry to a temperature of from about 135° C. to about 150° C. for about 1.5 to about 15 seconds;
• and
• f. cooling the slurry to a temperature of less than about 8° C. in about 30 minutes or less.