Abstract
The effects of various pre-treatments Žhot water blanching, skin treatments, high pressure and high intensity electric field pulse
treatment. on the dehydration characteristics of red paprika ŽCapsicum annuum L.. were evaluated and compared with untreated
samples. Hot water blanching Ž100C, 3 min. prior to dehydration Žfluidised bed dryer at 60C, 6 h and 1 ms. resulted in the
permeabilisation of 88% of the cell membranes in paprika, which in turn resulted in a higher mass and heat transfer. Skin
treatments Žsuch as lye peeling and acid treatment., as practised conventionally, increased dehydration rates but affected only the
skin permeability. The application of high hydrostatic pressure ŽHHP, 400 MPa for 10 min at 25C. or high intensity electric field
pulses ŽHELP, 2.4 kVcm, pulse width 300 s, 10 pulses, pulse frequency 1 Hz. pre-treatments resulted in cell disintegration
indexes of 0.58 and 0.61, respectively. Cell permeabilisation of these physical treatments resulted in higher drying rates, as well as
higher mass and heat transfer coefficients, as compared to conventional pre-treatments.