Non-thermal atmospheric gas plasma device for surface decontamination of shell eggs

A resistive barrier discharge (RBD) prototype able to generate gas plasma at atmospheric conditions was set up. The discharge was electrically characterized and the plasma glow was analysed by optical emission spectroscopy. The decontamination power of the device was assessed on samples of shell eggs experimentally inoculated with Salmonella Enteritidis and Salmonella Typhimurium (5.5–6.5 Log CFU/eggshell) and placed in the treatment chamber. Different decontamination times (10, 20, 30, 45, 60 and 90 min) and relative humidity values (RH) of the gas mixture in the chamber (i.e. 35% and 65%, at 25 °C) were considered. All samples were treated in the plasma after-glow chamber where the measured temperature was not much higher than the room temperature, minimizing the risk of egg quality alterations.