Heat conduction in microbes exposed to pulsed electric fields

Nonthermal pasteurization of liquid foods by intense pulsed electric fields results in advantages over conventional heat pasteurization. Thermal damag e to liquid foods can adversely affect the flavor and taste and result in l oss of nutrients, Numerical modeling of heating parameters near the microbe during exposure to these intense electric fields is described. Boundary co nditions at membrane interfaces included the continuity of temperature and continuity of heat now. Temperature, heat flow vector, and heat source were included in the one-dimensional model. Two simulations are reported here. Simulation 1 consisted of a 0.5 mu m wide microbe suspended in liquid with conductivity Of 0.01 S/m and was treated with an applied electric field of 40 kV/cm for 375 ns. Simulation 2 contained a 1.0 mu m wide microbe suspend ed in liquid with conductivity of 0.1 S/m and was treated with an applied e lectric field of 40 kV/cm for 1 mu s, Comparison is made with a uniform con ductivity model (ohmic), and it is shown that significant differences exist in the heating parameters between the two models. For the parameters used in these one-dimensional simulations, conditions for electroporation were f ound to exist without a significant temperature rise in the microbe.