Influence of acid and low-temperature adaptation on pulsed electric fields resistance of Enterococcus faecium in media of different pH

Given the inability of PEF to inactivate spores, pasteurization of acid products such as fruit juices appears as one of the more feasible applications for this technology. Microbial cells present in these products would have, very likely, undergone a process of adaptation to this acid pH; however, the impact of this phenomenon on microbial PEF resistance has only been scarcely investigated. Thus, the objective of this work was to study the inactivation of Enterococcus faecium by PEF treatments after sequential exposure to sublethal acid and cold stresses. This work will provide very valuable data for process design to further develop PEF application and improve understanding of microbial inactivation.