Conclusion
Hence, it can be concluded that in the case of
Pandanus (Pandanus amaryllifolius) leaves drying
time decreased considerably with increase in
microwave output power and this technique can be
successfully used to dry Pandanus leaves as compared
to shade drying, with maximum preservation of aroma.
After the initial heating period, the process attained
very high drying rates followed by the falling rate
period during which maximum drying took place and
maximum drying rates were about 282 g/100 g.min
at 720 W to 136 g/100 g.min at 180 W. Among the
three models proposed to describe the drying kinetics
of Pandanus leaves, the semi-empirical Page model
provided a good agreement between experimental
(observed) and predicted moisture ratio values with
higher coefficients of determination and lower reduced
chi-square (χ2) and RMSE values. The value of the
drying rate constant, k, increased with the increase
in microwave output power and a linear relationship
was obtained between the data of ln(MR) and drying
time (t). For constant amount of 2.5 kg/m2 fresh
sample, the effective moisture diffusivities varied
from 5.35E-08 to 1.99E-07 m2/min with the increase
in microwave output power. Comparison of aromatic
compound (2-acetyl-1-pyrroline) in Pandanus leaves
showed declining trend with increase in microwave
output power from 720 W. There was no considerable
difference in drying rate achieved at 720 W and 540
W and retention of aromatic compound was more
at the lower power level. So keeping in view both