1. Norwegian University of Life Science, Department of Chemistry, Biotechnology and Food Science, P.O. Box 5036, N-1432 Ås, Norway.
2. Corresponding author. Phone: +31 (0)30 6944431. Fax: +31 (0)30 6944295. E-mail: aamodt@voeding.tno.nl
3. Matforsk AS - Norwegian Food Research Institute, Osloveien 1, N-1430 Ås, Norway.