Abstract
The objective was to develop a non-thermal plasma system capable of batch and continuous treatment of liquid samples. A system was designed composing of a high voltage DC power supply, a pulsing unit, and a treatment chamber. This setup was used to generate pulsed plasma pulses of 9kV and 500ns. The systems had to be designed in order to not only produce controlled pulsed plasma, but also monitor data from the sample. The voltage and current profiles can be registered and transferred into the computer for further analysis. A series of treatments in an apple juice suspension were performed varying the two most relevant process parameters: pulse number, and frequency. E. coli O157:H7 cells are counted before and after different treatments to ascertain survivability. Key process parameters responsible for cell lethality were identified for E. coli O157:H7 inactivation. Results showed that increasing pulse number (from 100 to 4000) increased lethality of cells, and that there was a range of pulse frequency that resulted in the highest lethality. Pulse frequencies between 100 and 200 Hz achieved inactivation's up to 7 log units whereas all other pulse frequencies were much less effective. The cell lethality observed was very significant since only a 5 log reduction is required for pasteurization of liquid foods.
Original language | English (US) |
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Pages | 21-29 |
Number of pages | 9 |
State | Published - 2000 |
Event | 2000 ASAE Annual International Meeting, Technical Papers: Engineering Solutions for a New Century - Milwaukee, WI., United States Duration: Jul 9 2000 → Jul 12 2000 |
Other
Other | 2000 ASAE Annual International Meeting, Technical Papers: Engineering Solutions for a New Century |
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Country/Territory | United States |
City | Milwaukee, WI. |
Period | 7/9/00 → 7/12/00 |
Keywords
- Cold pasteurization
- E. coli O157:H7 inactivation
- Food preservation
- Non-thermal plasma