Materials and Methods Potato peels Fresh potato or eggplant tubers were obtained from local market of Assuit in August 2011. The tubers were washed by water and peeled using kitchen vegetable peeler. The peels were dried in a hot air oven (VEBMLW Medizinische, Gerete, Berlin, Germany) at 200°C for 1 h. The dried peels were ground into a fine powder in laboratory mill (120 Perten, USA). The ground powder that passed through an 80 mesh sieve was packed into polyethylene dark bags and was stored at