Application of effective diffusivity approach for the moisture content prediction of tortilla chips during baking

Abstract

Fick's law of diffusion and an empirical model were used to describe moisture transport in tortilla chips during baking. An empirical model based on regression of moisture content in terms of baking time and temperature slightly over predicted the moisture content of samples. There was a good agreement ( R 2=0.93) between experimental results and predicted values with the empirical model. The model based on effective diffusivity approach also predicted the moisture content fairly good. Both liquid and vapor diffusion was effective in the transport of vapor. Liquid diffusion and vapor diffusion were dominant in the beginning and toward to end of baking, respectively. The average moisture diffusivity of samples was calculated using a nonlinear regression of moisture content data during baking. The range for the average effective diffusivity was 6.25×10 −10–10.98×10 −10 m 2/s and the diffusivity coefficient increased with increasing temperature. There was an Arrhenius type relationship between effective diffusivity coefficient and baking temperature.