Better damage of chicory tissue by combined electroporation and ohmic heating for solute extraction

Damage of chicory tissue by combined electroporation and ohmic heating is studied for better solute extraction. Moderate (400-1000V/cm) and high (10,000 V/cm) PEF treatments were applied varying pause duration between the trains of individual pulses. Ohmic heating was induced with increase of the number of trains N. Temperature dependence of tissue damage degree Z is evaluated for the different PEF intensities. With higher ohmic heating, chicory tissue is faster and better damaged. Electric field strengths of 600-800V/cm combined with ohmic heating permit to enhance noticeably the solute extraction from chicory tissue. The solute diffusivity D for the different PEP treatments, is nearly the same for same values of Z. Chicory tissue treated to the same damage degree (Z.0.8-1.0) using different PEP conditions (800, 1000 and 10,000V/cm) has nearly the same diffusivity. Combined electroporation/ohmic heating pretreatment by moderate PEF (400-1000V/cm) presents an interesting alterative for the treatment of high product throughputs (e.g. in the case of inulin production from chicory). (C) 2014 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.