Because dried banana slices did not puff uniformly, the
samples were cut through the part that was not the center
to avoid the effect of dense structure at the core part. Table
4 shows the results of texture of dried banana slices in terms of the maximum force (hardness) and the number of
peaks in the force-deformation curve (crispness). In the
case of hardness it was found that banana slices dried by
VACUUM–FIR were harder than those dried by
LPSSD–FIR, as indicated by the higher value of the maximum
force. This may probably be due to the fact that
VACUUM–FIR, especially at lower drying temperature
(80 C in this case), yielded dried banana slices with more
dense structure (smaller and less pores), as can be clearly
seen in Fig. 7a and b. However, the statistical analysis
showed that the effects of drying temperature and drying
pressure as well as drying methods on the hardness were
not significant. It should be noted that, at the same drying
temperature, the hardness of dried banana slices was lower
than that of samples dried by LPSSD alone. This is probably
due to the fact that LPSSD–FIR and VACUUM–FIR
yielded dried banana slices with more porous structure
than that of samples dried by LPSSD alone