1. Department of Food Science, University of Guelph, Guelph, ON, N1G 2W1, Canada.
2. Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN 55108, U.S.A.
3. Corresponding author. Phone: +358 (44) 0611530. Fax: (612) 625-5272.
4. Deceased; formerly Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, U.S.A.