Pulsed electric field (PEF) technology for microbial inactivation in low-alcohol red wine

Abstract

The decontamination of spoilage-related microbes in low-alcohol red wine was performed using a serial multiple electrode pulsed electric field (PEF) treatment system. The system consisted of seven electrodes connected in series, and it has been designed to produce square-wave high-voltage pulses of 1s duration at various electric field strengths and frequencies for decontamination. The initial counts of aerobic bacteria, yeast and lactic acid bacteria (spoilage-associated microbes) in the wine were 5.56, 5.61 and 5.22logCFU/mL, respectively. The pattern of decontamination of the spoilage microorganisms followed first-order kinetics and the decontamination effect increased as the field strength and frequency increases. D-Hz and D-PEF values were inversely related to the electric field strength of the PEF treatment. The yeast exhibited relatively low D-PEF-value than the aerobic and lactic acid bacteria. The lowest Z(PEF)-value was observed for the lactic acid bacteria (24.6kV/cm) among the spoilage microbes.