1. Norwegian Food Research Institute, Osloveien 1, 1430 Ås, Norway; Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway; and Institute of Nutrition and Food Science, Department of Food Chemistry, University of Bonn, Endenicher Allee 11−13, 53115 Bonn, Germany