The simulation results expressed as the time evolution of
sample average temperature and average moisture content
were presented. Both temperature and moisture profiles
within the food were also shown as functions of drying time.
Figs. 2 and 3 showed a typical trend of carrot temperature
and moisture content during drying process performed
at an initial product temperature of 303 K and an initial
moisture content of 64%. Air properties were constant
and equal to 333 K and 45% for temperature and moisture
content, respectively. Based on Fig. 2, four different regions
can be defined; the initial steep temperature rise is, actually
the result of two different contributions. In fact, heat transfer
depends on the convection, due to the temperature difference
between air and solid, and, as soon as Ts is lower
than the wet bulb temperature (in the present case
320 K), on the latent heat, due to the condensation of the
vapour on food surface. Vapour condensation is also
responsible for the corresponding initial slight increase of