These investigations demonstrate that the VOC method
could potentially be used to detect L. monocytogenes contamination
in milk. The limit of detection was 1–1.5 102 CFUml1
after overnight incubation. Absence of VOCs could indicate milk
free from L. monocytogenes contamination, although this applies
only under conditions tested here. Further investigations would
be required, for example by testing longer incubation times with
smaller initial inoculum sizes, to determine whether absence of
VOCs indicates the presence of L. monocytogenes. The enrichment
broth with added selective agents cycloheximide, nalidixic acid
and acriflavine HCl was included for the suppression of
background flora and for the inhibition of species closely related
to L. monocytogenes. The method was not entirely specific for