2.1. Model system preparation
A protocol described was followed with minor modi®cations. Gluten was prepared by extensive washing under tap water of dough obtained from durum wheat ¯our variety ``Ferro'' containing 15% proteins. Gluten (10 g) and glucose (2 g)
were added to 30 ml of deionized water. After vigorous mixing, the sample was freeze dried at 4C for 48 h. The
solid residue was ®nely ground in a Waring blender, passed through a sieve and stored desiccated at 4C. A control system was prepared by freeze-drying gluten only.