VISCOELASTIC BEHAVIOR OF FRIED POTATO CRUST

A restructured potato model system was fried for 5, 10 or 15 min at 170, 180, or 190C and tested in a dynamic mechanical analyzer. Stress relaxation phenomena was described by a two-element Maxwell model with a parallel spring. The viscoelastic behavior of the crust resulted from its porous structure of open and closed foam cells embedded in oil. Relaxation of stress in the fried crust was a result of slippage of the dispersed oil through the crust and from rearrangements of the air cells. Elastic modulus of the fried crust increased for higher frying times and temperatures and were the most significant elements in distinguishing between samples. Un systeme modele a base d'amidon simulant la pomme de terre est utilise pour etudier les proprietes mecaniques de la croute de la pomme de terre frite pendant 5,10 ou 15 minutes a 170°. La viscoelasticite de la croute provient de sa structure poreuse, et de la presence de l'huile et de l'eau. Le module elastique de la croute frite augmente avec le temps de friture et la temperature.