1. Department of Food and Nutrition, Molecular Nutrition Unit, Technical University of Munich, Am Forum 5, D-85350 Freising, Germany, Food Technology Centre, part of Wageningen University and Research Centre, Bornsesteeg 59, 6708 PD Wageningen, The Netherlands, Molecular Nutrition Research, Interdisciplinary Research Center, Justus-Liebig-University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany