studying the effect of osmosis-ultrasound compound pre-treatment on drying kiwi fruit sheets

the aim of this research was to use osmosis-ultrasound compound pre-treatment and studying the time of drying and the potentiality to rehydration in dried samples of kiwi fruit (hayvard variety). the samples were drained in three timed phases, 10, 20 and 30 minutes in room temperature in 30, 50 and 70 bx in ultrasound bath osmosis solutions. the results of drying time showed that by decreasing the concentration of kiwi fruits samples from 8 to 6 mm and increasing the concentration of osmosis solution and ultrasound time, the time of gaining 20% moisture decreased for each treatment. the studies showed that the minimum time for getting 20% moisture in 6 and 8 mm kiwi fruits in pre-treated samples with 70 bx and 30 minutes ultrasound time is 263 and 313 minutes respectively. the results of rehydration in pre-treated compound samples showed that by increasing the concentration of osmosis solution, as well as the time for ultrasound waving and increasing the kiwi fruits samples concentration from 6 to 8 mm, the rehydration decreased compared to control sample. the results of perceptive assessment in general acceptance of dried kiwi fruit showed that using pre-treated compound sample was more acceptable than the control sample.