Pulsed electric field inactivation of spoilage microorganisms in alcoholic beverages and the influence of pulse profile

In recent years, a number of new applications have emerged where pulsed power is being used in the treatment of waste and effluent, foodstuffs and beverages. One of these emerging applications is pulsed electric field (PEF) inactivation of microorganisms in liquid media. This involves the generation of electric fields of the order of 30 kV/cm across liquids contaminated with microorganisms. This induces a relatively large transmembrane potential that can lead to irreversible electroporation and consequently cell analysis. The nature of the PEF pulse profile is the subject of extensive study, and it has been reported that bipolar square waves provide superior inactivation when compared to monopolar pulses. However, results have shown that this is not the case and that monopolar PEF is at least as effective for bacterial inactivation. Results will be presented on the influence of pulse profile. Further work will show the effect of PEUF applied to alcoholic beverages containing known spoilage microorganisms, and will highlight an apparent synergistic inactivation effect of alcohol and PEF treatment.