Disclosed are nutritional compositions comprising a peroxide-treated aseptic package and a nutritional liquid contained therein, wherein the nutritional liquid comprises beta-hydroxy-beta-methylbutyrate (HMB) and at least one of fat, carbohydrate, and protein. The HMB provides a buffering effect in the nutritional liquid to thus minimize an acidic pH shift that is prevalent in aseptically sterilized packages, and thus helps maintain product stability over time.