Effect Of Phase Change Criterion On The Prediction Of Temperature Evolution During Food Drying.

Abstract

In this work, a moisture dependent phase change criterion was considered in
Luikov´s heat and mass transfer equations and the drying process of a biological product was
investigated. Laboratory experiments were conducted to measure the temperature and the
moisture content of sweet potato samples during drying. A finite element formulation was
used to solve the coupled system of equations. The inverse problem methodology was applied
to estimate the parameters of the proposed functional relationship by minimizing the
deviation of experimental data and numerical predictions. Numerical simulation showed good
agreement with the measured temperature and moisture values. By including a variable phase
change criterion it was possible to reproduce the trends of behaviour of temperatures profiles
during drying of sweet potato, suggesting that evaporation inside the sample depends on the
local moisture content.