Drying model for cylindrical pasta shapes using desorption isotherms

In this study, experimental desorption curves were determined based on non-linear regression analyses. Among the different sorption models tested – the Guggenheim, Anderson and de Boer (GAB) equation, the GAB-like equations (Viollaz–GAB and Timmermann–GAB), the Ferro Fontan equation and the Oswin equation – the Oswin equation was assumed as the most accurate model to represent the desorption curves of pasta. This desorption isotherm was used to predict the drying curves of pasta as the circulating air and drying pasta are in equilibrium when pasta is dried in a convection oven. Together with a description of moisture diffusion in pasta, the desorption isotherm enable to model the drying behaviour of pasta adequately. The modelled moisture concentrations of the drying curves are in good correspondence with the experimental data, obtained during drying for cylindrical and flat-shaped pasta.