Destruction and Inhibition of Bacterial Spores by High Voltage Pulsed Electric Field

Authors

  • V.O. MARQUEZ,

    1. Authors Marquez and Mittal are with the School of Engineering, and author Griffiths is with the Dept. of Food Science, Univ. of Guelph, Guelph, Ontario, Canada, N1G 2W1. Address inquiries to Dr. G.S. Mittal.
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  • G.S. MITTAL,

    1. Authors Marquez and Mittal are with the School of Engineering, and author Griffiths is with the Dept. of Food Science, Univ. of Guelph, Guelph, Ontario, Canada, N1G 2W1. Address inquiries to Dr. G.S. Mittal.
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  • M.W. GRIFFITHS

    1. Authors Marquez and Mittal are with the School of Engineering, and author Griffiths is with the Dept. of Food Science, Univ. of Guelph, Guelph, Ontario, Canada, N1G 2W1. Address inquiries to Dr. G.S. Mittal.
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ABSTRACT

Electric field strengths (E) from 20 to 50 kV/cm with pulse numbers ranging from 15 to 50 were applied to Bacillus spore suspensions in 0.10 to 0.15% NaCl solution. The lowest count of viable spores, expressed as the logarithmic ratio of initial count before treatment to surviving spores (log(No/N) geqslant R: gt-or-equal, slanted 3.425 and 5 at 25°C) was obtained at 50 kV/cm with 30 and 50 pulses for B. subtilis and B. cereus, respectively. The log(No/N) increased with increased treatment temperature or increased time gap between pulses. Spores were unable to repair damage even after 1 mo.

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