Viability of sublethally injured bacteria of fresh and fresh-cut vegetables from the field through distribution.

ABSTRACT

Bacterial stresses can occur from the production to the distribution environments of produce, and these stresses can lead to nonlethal bacterial damage that is an injured state called sublethally injured bacteria. The damage is mainly due to the disruption of the surface structure and cytoplasmic membrane of the cells. Sublethally sanitizer-injured indicator coliform bacteria injured by chlorine, ethanol, and/or fungicide stress could exhibit on vegetables during production and harvest. Chlorine stress and cold stress could induce sublethally injured indicator and pathogenic coliform bacteria on fresh-cut vegetables during processing and subsequent storage. Enterobacter kobei and Pantoea ananatis injurd by chlorine stress, E. amnigenus, E. asburiae, and E. kobei injured by ethanol stress, and Rahnella aquatilis, Yersinia mollaretii, and Escherichia coli injured by fungicide stress could be amongst the injured cells in the coliforms detected in the produce environments. To ensure the microbiological quality and safety of fresh-cut vegetables, it is necessary to adjust the concentration of sanitizer to a level that kills bacteria and does not produce sanitizer- injured cells when sanitizer is applied to the produce, and also to consider the storage temperature to inhibit the recovery of injured bacteria due to cold injury during the chilling storage period.