Study type: Medical/biological study (experimental study)

High voltage pulse application for the destruction of the Gram-negative bacterium Yersinia enterocolitica. med./bio.

Published in: Bioelectrochem Bioenerg 1997; 43 (1): 135-141

Aim of study (acc. to author)

The study presents a new method to inactivate microorganisms suspended in liquids using the high field pulses, where the liquid under test is not brought in dircect contact with the electrodes.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1 Hz–500 kHz
Modulation type: pulsed
-
Exposure 2: 1 Hz–500 kHz
Modulation type: pulsed
-
Exposure 3: 1 Hz–500 kHz
Modulation type: pulsed
-
Exposure 4: 1 Hz–500 kHz
Modulation type: pulsed
-

Exposure 1

Main characteristics
Frequency 1 Hz–500 kHz
Type
Waveform
Modulation
Modulation type pulsed
Pulse width 2 µs
Repetition frequency 1 Hz
Exposure setup
Exposure source
Setup Bacteria in 20 cm³ of NaCl solution having a conductivity of 0.8-1.3 S/m were placed inside a coiled glass tube which was immersed in distilled water between the concentric electrodes.
Additional info Between 1 and 250 pulses were applied.
Parameters

No parameters are specified for this exposure.

Exposure 2

Main characteristics
Frequency 1 Hz–500 kHz
Type
Waveform
Modulation
Modulation type pulsed
Pulse width 2 µs
Repetition frequency 1 Hz
Exposure setup
Exposure source
Additional info 70 pulses were applied.
Parameters

No parameters are specified for this exposure.

Exposure 3

Main characteristics
Frequency 1 Hz–500 kHz
Type
Waveform
Modulation
Modulation type pulsed
Pulse width 2 µs
Repetition frequency 1 Hz
Additional info

rise times of 500-1300 ns

Exposure setup
Exposure source
Parameters

No parameters are specified for this exposure.

Exposure 4

Main characteristics
Frequency 1 Hz–500 kHz
Type
Waveform
Modulation
Modulation type pulsed
Pulse width 2 µs
Rise time 800 ns
Repetition frequency 1 Hz
Exposure setup
Exposure source
Additional info 10 pulses were applied.
Parameters

No parameters are specified for this exposure.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The pulses applied have caused a relatively high decrease (6-7 log cycles) in the survival ratio of Y. enterocolitica. The survival ratio of Y. enterocolitica was strongly dependent on the magnitude of the voltage and on the number of pulses applied. Electron transmission micoscopy results have shown that the lethal effect was caused by rupture of the cell membrane. It can be concluded that the high voltage pulse methode provides a means to develop a non-thermal, energy efficient, sterilization technique for liquid foods.

Study character:

Study funded by

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