Plasma-treated water (PTW) possess anti-microbial potential against Pseudomonas fluorescence, which is observable for both suspended cells and cells organized in biofilms. Against that background, the chemical composition of PTW tends to focus. Various analytical techniques have been applied for analyses, which reveal various traceable reactive oxygen and nitrogen compounds (RONS). Based on these findings, it is our aim to generate a PTW analog (anPTW), which has been compared in its anti-microbial efficiency with freshly generated PTW. Additionally, a solution of every traceable compound of PTW has been mixed according to their PTW concentration. As references, we treated suspended cells and mature biofilms of P. fluorescence with PTW that originates from a microwave-driven plasma source. The anti-microbial efficiency of all solutions has been tested based on a combination of a proliferation, an XTT, and a live–dead assay. The outcomes of the test proved an anti-microbial power of PTW that suggests more active ingredients than the traceable compounds HNO₃, HNO₂, and H₂O₂ or the combined mixture of the analog.

Fourier transformation infrared (FTIR) spectroscopy was used to identify the antimicrobial chemical composition of plasma processed air (PPA) generated by a microwave plasma source—MidiPLexc. NO was found to be the first product with maximum concentration of 1030 ppm. NO ₂ was the dominant long‐living species with maximum concentration of 10 520 ppm, which was in equilibrium with its dimer—N ₂ O ₄ . Key physicochemical parameters influencing the concentrations were identified. Elevated input power mainly promoted NO ₂ generation and 1.5 SLM was determined to be the critical flow rate for the maximum NO ₂ yield. NO ₂ concentration was reduced by 40% under humid condition with 50 W power input. A prediction model of NO _x generation was made based on specific input energy (SIE).

Non-thermal plasma technology is recognized for its strong antimicrobial efficacy on food and food production environment-associated microorganisms and its ability to enhance food safety and food shelf-life