Lactalbumin, also known as 'whey protein', is the albumin contained in milk and obtained from whey. Lactalbumin is found in the milk of many mammals. There are alpha and beta lactalbumins; both are contained in milk. Lactalbumin, also known as 'whey protein', is the albumin contained in milk and obtained from whey. Lactalbumin is found in the milk of many mammals. There are alpha and beta lactalbumins; both are contained in milk.