Effect of pre-treatment on viscoelastic behaviour of potato strips

The viscoelastic behaviour of french fries during deep fat frying after two different types of drying pre-treatment (air drying and osmotic dehydratio n) was examined under uniaxial compression tests. The stress-strain data of the compression test were modelled using a simple mathematical model, cont aining parameters such as the maximum stress (sigma (max)), the maximum str ain (epsilon (max)), the elasticity parameter (E) and the viscoelastic expo nent (p). The effect of air drying duration and the type of osmotic solutio n used on the compression behaviour of fried potatoes was introduced throug h the corresponding effects upon the model parameters. Pre-fry drying as we ll as osmotic pre-treatment increase the maximum stress and maximum strain of french fries during frying. Air drying pre-treatment increases the crisp ness of potato strips while osmotic pre-treatment does not affect it, with the exception of sugar solutions. (C) 2001 Elsevier Science Ltd. All rights reserved.