Bakhshiani (2008) obtained a Deff of 5.4 1010 m2 s1 for the
drying of 7 mm-thick tomato slices at 60 C. Sacilik et al. (2006)
reported Deff data for tomato halves dehydration which varied
from 1.31 109 to 1.07 109 m2 s1. The Deff values obtained in
the present work are of the same magnitude to those obtained by
Sacilik et al. (2006) and relatively high compared to the values
reported by Khazaei et al. (2008). Considering the fact that high Deff
values were obtained in studies that used salt pretreatments,
Doymaz and Ismail (2011), the salt osmotic effect may be the cause
for improved diffusive transport during drying.
The results indicate that temperature has the greatest contribution
to the Deff parameter followed by tray rotation, with air
velocity having the lowest effect on Deff. The greatest tray rotation
contribution to Deff (19.3%) was observed in the experiment performed
at 60 C and 0.6ms1 air velocity, where the maximum Deff
was obtained.