1. Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium.
2. Corresponding author. Phone: +32 (0) 16321634. Fax: +32 (0) 16321997. E-mail: benedicte.vansteertegem@biw.kuleuven.be