This study compared mass transfer during osmotic dehydration (OD) and some
quality indices of untreated apple slices to those of apple slices pretreat
ed by either blanching, freezing, or applying high-intensity electric field
pulses (HELP) or high pressure (HP). HP, HELP, and blanching increased wat
er loss. Untreated and HELP-treated samples had comparable solids gains, wh
ich were lower (P < 0.05) than in the other samples. Apple slices turned br
own after pretreatment but the L values of these samples increased with OD.
The breaking force of dried samples increased with OD time, and pretreated
samples had firmer dried texture than the untreated. Vitamin C content dec
reased with OD time, but HP- and HELP-treated apples had better retention o
f vitamin C.