Integration of electron beam technology into fresh produce wash water line: Effect of inoculum suspension medium and water quality parameters on the radioresistance of Salmonella Typhimurium ATCC 13311

Electron beam technology may be integrated into the fresh produce wash water line, as an advanced oxidation process (AOP). However, prior to implementation, effectiveness of the technology must be assessed. Hydroxyl radical scavengers were used to quantify the role of yield of hydroxyl radicals in inactivation of the selected pathogen in aqueous solution. The combined lethal effect of e-beam treatment with aqueous hydrogen peroxide (H2O2) solution was also investigated. The radioresistance of Salmonella Typhimurium ATCC 13311 in deionized (DI) water, that is radiation D10 values, increased (p <.05) from 0.15 ± 0.00 kGy to 0.18 ± 0.00 kGy and to 0.19 ± 0.06 kGy when peptone water (PW) and phosphate buffered saline (PBS) was dissolved into DI water, respectively. Membrane-permeable ethanol provided better protection for this pathogen than nonpermeable PEG. Results suggest that to minimize the protective effects of inoculating suspending media used for the preparation of Salmonella suspension, 1.0 mM phosphate buffer (PB) should be used in microbial studies of irradiated foods. Nitrate and dissolved organic carbon (DOC) reacting with hydrated electrons (eaq−) and hydroxyl radicals (·OH), respectively, induced more sequestering of ·OH. E-beam treatment with 0.60 kGy dose in aqueous solution with H2O2 led to a reduction of 6.44 ± 0.03 log CFU/mL f S. Typhimurium ATCC 13311.