The effect of pulsed electric field (PEF) pretreatment on solid-liquid expression from potato tissue was studied on individual parenchyma tissue samples for different PEF intensities, varying relative deformations and deformation rates. The yield increased with relative deformation. The yield at any given relative deformation increased with increased PEF intensity and decreased deformation rates. The compressive force was reduced by a factor of 5 when pressing potatoes pretreated with electric field strength of 0.68 kV/cm and duration of 1 ms, at a relative deformation of 0.5 and a deformation rate of 0.1 mm/min. (c) 2004 Elsevier Ltd. All rights reserved.