The Radical Water System, developed by Pershore-based firm Radical, effectively decontaminated whole cabbages that were deliberately infected with the diseases.
Salmonella traces were reduced to below the level of detection after the cabbages were sprayed with Radical for 60 seconds.
Similarly, E coli traces shrank to below or near the level of detection, while listeria levels shrank from 2.7 million - 36.2 million colony forming units (CFU)/swab to 0.3-0.11 CFU/swab after being treated.
Radical director Mark Fielding said: "This is a very encouraging set of results and demonstrates the potential of this technology in helping fresh fruit and vegetable processors protect their produce from potentially dangerous contaminants while avoiding the use of chemical-based sprays."
The system uses naturally-occurring biocides that are generated by advanced oxidation technology to reduce micro-organisms that cause illnesses such as Salmonella.