1. Departments of Medical Genetics and Medical Biophysics, University of Toronto, Ontario, Canada M5S 1A8
2. Laboratoire de Physicochimie des Macromolécules, Institut National de la Recherche Agronomique, B.P. 527, 44072, Nantes, France
3. On postdoctoral leave from CERMAV, Grenoble, France
4. Department of Food Science, Cornell University, Ithaca, NY 14853-7201