Inactivation of E. coli O157: H7 using a pulsed nonthermal plasma system

The use of elevated temperatures to pasteurize food products leads to a loss of food quality, which stimulates research into novel nonthermal processes for food preservation. Using nonthermal plasma discharges, applied directly into the food product, proved effective in reducing the number of Escherichia coli O157:H7 cells in apple juice, by up to 7 log units. The pulsed nonthermal plasma system was developed and used to study the effects of different process parameters on the inactivation. The process parameters considered were discharge voltage, pulse number, and pulse frequency. The apple juice used had a pH of 4 and a conductivity of 2.29 mS / cm.