Effects of pulsed electric fields on microorganisms in orange juice using electric field strengths of 30 and 50 kV/cm

Inactivation of 4 microorganisms in orange juice was investigated in a 100 L/h flowing pulsed electric field (PEF) system. Electric field levels of 30 kV/cm and 50 kV/cm were applied, and Leuconostoc mesenteroides, E. coli, and Listeria innocua were inactivated by as much as 5 log cycles at 30 kV/cm and 50 degreesC. Saccharomyces cerevisiae ascospores were the least susceptible to PEF at all treatment levels, and a maximum of 2.5 log reduction was achieved at 50 kV/cm and 50 degreesC. Both electric field levels were effective in inactivating microorganisms at temperatures below standard thermal treatment, however, the number of pulses applied was particularly important in inactivation.