The application of pulsed light (PL) in combination with malic acid (MA) dips was evaluated regarding
the inactivation of Listeria innocua or Escherichia coli inoculated on different fresh-cut products (avocado,
watermelon and mushrooms) through refrigerated storage. The inoculated substrates were exposed to
individual PL (180e1100 nm, 12 J/cm2
) and MA (2% w/v) treatments or to a combination of both. The
effects on the bacterial cell structure were confirmed by Transmission Electron Microscopy (TEM). When
treatments were individually applied, inactivation of L. innocua and E. coli ranged from 0.91 to
1.1 log CFU/g and from 1.92 to 2.97 log CFU/g, respectively. Nevertheless, a much greater bactericidal
effect was observed when the treatments were sequentially applied, leading to more than 5 log reductions
of L. innocua and E. coli populations. TEM analysis revealed structural changes with modification
of cytoplasmic contents and alteration of cell membranes. The results of this study indicate that the
combination of assayed treatments may be applied to effectively control L. innocua and E. coli on the
surface of fresh-cut products for at least two weeks of storage.