1. Agricultural University of Norway, Department of Chemistry, Biotechnology and Food Science, P.O. Box 5036, N-1432 Ås, Norway.
2. Corresponding author. TNO Nutrition and Food Research. Phone: +31 (0) 30 69 44431. Fax: +31 (0) 30 69 44295. E-mail: aamodt@ voeding.tno.nl
3. Matforsk AS - Norwegian Food Research Inst., Osloveien 1, N-1430 Ås, Norway.