Effects of pretreatments on the diffusion kinetics and some quality parameters of osmotically dehydrated apple slices

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.