1. Department of Food Science, North Carolina State University, Raleigh, North Carolina 27695-7624, Centre de recherche STELA, Departement de Sciences des Aliments et de Nutrition, Pavillon Paul-Comtois, Universite Laval, Quebec, Canada G1K 7P4, and Fonterra Research Center, Private Bag 11 029, Dairy Farm Road, Palmerston North, New Zealand