Abstract: The effect of HPEF (High Power Pulsed Electric Field) on the sterilization rates of S.cerevisiae and E.coli is investigatedin this paper. The elementary mechanism of HPEF sterilization is briefly discussed. The results indicate that the survivabilities ofS.cerevisiae and E.coli remarkably decreased with electric field strength and pulse width and pulse numbers. The optimum sterilizationeffect can be reached at after being treated with 1000 pulses with 11μs Pulse width at 9kv/cm: The survivability of S.cerevisiae wasreduced by 4.5 orders and E.coli 3 orders. Concaves can be found in the cell surface , and substances in the cells can be found overflowedout, which support the theory of “electroporation” to explain the mechanism of HPEF sterilization.

Key words: high power pulsed electric field, S.cerevisiae, E.coli, survivability