1. Wageningen Centre for Food Sciences (WCFS), P.O. Box 557, 6700 AN, Wageningen, The Netherlands, Wageningen University, Laboratory of Physical Chemistry and Colloid Science, P.O. Box 8038, 6700 EK Wageningen, The Netherlands, ATO Agrotechnological Research Institute, P.O. Box 17, 6700 AA, Wageningen, The Netherlands, TNO Nutrition and Food Research Institute, P.O. Box 360, 3700 AJ Zeist, The Netherlands, and Wageningen University, Laboratory of Food Physics, P.O. Box 8129, 6700 EV Wageningen, The Netherlands