Heat and Mass Transfer during the Frying Process of Donuts

Frying is a traditional means of food preparation, and many fried food items have physical and sensory attributes that consumers consider desirable. The frying process produces physicochemical changes and presents engineering challenges due to the applied high temperatures and combined heat and mass transfer mechanisms during this type of cooking. In addition, flour transformation during cooking involves complex phenomena, in which water as an essential ingredient has an important role, since it determines the conformational state of proteins and carbohydrates, affects

the interactions between the formulation constituents, and contributes to dough structuring (Maache-Rezzoug et al., 1998).