Due to the high initial water content of 6.40 [kg kg−1 db] on
average a rather long drying time was observed for drying under
stationary conditions, however, a slightly different for cherries with
osmotic pretreatment. In the drying test with stable air temperature a very short period of constant drying rate (CDRP) amounting
to about 30 min can be noted on drying curves. Therefore, drying of cherries proceeded mainly in the falling drying rate period
(FDRP), as it follows from both the drying curve (DC) and the
sample temperature curve (ST). Application of osmotic dehydration caused the reduction of an initial water content to about
3.26 and 2.31 [kg kg−1 db], in cherry samples preceded by osmosis
and dewatering assisted with ultrasounds, respectively. Thus, the
power ultrasound increases the water diffusion from the biomaterial immersed in an osmotic agent solution. As it follows from Fig. 1,
the sample temperature profiles of dried cherries with preliminary
OD and UDOD were also changed with respect to that without OD.