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Aims: The objective was to investigate the occurrence of sublethal injury after pulsed electric field (PEF) depending on the treatment time, the electric field strength and the pH of the treatment media in two Gram‐positive (Bacillus subtilis ssp. niger, Listeria monocytogenes) and six Gram‐negative (Escherichia coli, Escherichia coli O157:H7, Pseudomonas aeruginosa, Salmonella serotype Senftenberg 775W, Salmonella serotype Typhimurium, Yersinia enterocolitica) bacterial strains.

Methods and Results: A characteristic behaviour was observed for the Gram‐positive and Gram‐negative bacteria studied. Whereas Gram‐positive bacteria showed a higher PEF resistance at pH 7·0, the Gram‐negative were more resistant at pH 4·0. In these conditions, in which bacteria showed their maximum resistance, a large proportion of sublethally injured cells were detected. In most cases, the longer …