Microorganisms found protective sites in carrots and lettuce and
were able to migrate to these sites when UV radiation was applied.
In the case of tomatoes, since this fruit has a smooth surface and the
protective sites are limited, microorganisms were completely
exposed to the radiation and inactivation was achieved. Gram
negative bacteria are also more sensitive to ultraviolet light rather
than gram positive bacteria (Otto et al., 2011). The composition of
the cell wall in gram negative bacteria does not offer any protection
to the cells when they are exposed to different sanitizers, which act
directly on the cellular inner structures.