Nonthermal inactivation of Saccharomyces cerevisiae in apple juice using pulsed electric fields

Abstract

High intensity pulsed electric fields were utilized in a continuous system for inactivation of Saccharomyces cerevisiae in apple juice. The applied electric energy inactivated microorganisms in apple juice and, because the pulse duration was only 2.5μs, energy remaining to heat the apple juice was minimized. The microbial inactivation was defined in terms of applied field intensity and treatment time. Less than 10% of the electrical energy for HTST was needed for achieving 6 log reduction in inactivation of S. cerevisiae in apple juice. The PEF-treated apple juice, at both 4°C and 25°C storage, had a shelf-life of more than 3 weeks.