Decontamination of Escherichia coli on the surface of soybean seeds using plasma activated water

Abstract

The objective of the study was the evaluation of the efficacy of plasma activated water (PAW) for Escherichia coli inoculated on soybean seed surface. PAW was prepared by high-power atmospheric pressure air plasma jet. The inactivation kinetics, explained by Bigelow log-linear and Weibull models, showed the significant antibacterial potential of PAW in comparison to the control (sterile distilled water). PAW treatment for 25 min let to log10 CFU/g reduction of E. coli from 6.8 to 3.6 and its antibacterial effect persisted further 44 h (2.7 log10 CFU/g). Decimal reduction time (D-value) for tested bacteria was 7 min. Furthermore, the influence on PAW on the polyphenolics content and antioxidant activity was evaluated. To identify the PAW chemistry, physical properties, including pH, redox potential, and conductivity were estimated. The levels of H2O2, nitrate (NO3−) and nitrite anions (NO2−) as long-lived species were measured and compared to SDW without plasma activation.