Does electroporation occur during the ohmic heating of food?

The effect of temperature on electroporation of plant tissues during the pulsed electric field (PEF) or alternative current (AC) treatment was studied. The characteristic damage time tau, which determines effectiveness of the electroporation mechanism in plant tissue damage, was estimated for potatoes tissues in the range of electric field strengths E = 40 to 500 V/cm and at temperatures T = 22 degrees C and T = 49 degrees C in PEF treatment experiments. Experimental results of the AC ohmic heating of potato and apple tissues are evidence of the importance of the electroporation mechanism of tissue damage at moderate electric fields (MEF), when the electric field strength E is under 100 V/cm, and show that effectiveness of this mechanism increases with temperature increase

Effects of Pulsed Electric Fields on Cabernet Sauvignon Grape Berries and on the Characteristics of Wines

The treatment of Cabernet Sauvignon red grapes by pulsed electric fields (PEFs) is performed prior to vinification in order to enhance the extraction of polyphenols. PEF treatments of the longest duration and of the highest energy (E = 0.7 kV/cm, t (PEF) = 200 ms, W = 31 Wh/kg) changed the structure of grape skins and produced a wine that was richer in tannins (34 %), while treatment of the highest strength (E = 4 kV/cm, t (PEF) = 1 ms, W = 4 Wh/kg) altered the visual appearance of phenolic compounds in the skins and led to greater extraction of the anthocyanins (19 %). The PEF treatments caused the depolymerization of skin tannins, improving the diffusion of these decondensed tannins which are smaller. The PEF treatment of longest duration and of the highest energy had more impact on the parietal tannins and the cell walls of the skins while treatment of the highest strength modified more the vacuolar tannins. Changes in the operating parameters of the PEF treatment (E = 0.7 to 4 kV/cm, t (PEF) = 1 to 200 ms, W = 4 to 31 Wh/kg) did not affect alcohol content, total acidity nor volatile acidity in finished wines compared to the values of the control wine, but seemed to cause a slight increase in pH (1-2 %)