2.2. Sample processing and analysis
For RTE foods and frozen pastries (after thawing), 20 g samples
including all constituents were taken aseptically, transferred to
sterile plastic pouches and homogenized for 60 s with 180 ml of
sterile diluent containing peptone (1 g/l), NaCl (0.85 g/l) and Tween
80 (1 ml/l) using a Stomacher Lab-Blender 400 (Seward Medical,
London, UK). Appropriate dilutions of the sample homogenates
were prepared in sterile peptone water (0.1%) and inoculated in
duplicate in growth media using standard pour- and spread-plate
techniques to estimate microbial counts, i.e. aerobic colony count,
Enterobacteriaceae, enterococci, Staphylococcus spp., S. aureus, and
B. cereus as described in Table 1. L. monocytogenes, Salmonella spp.
and presumptive E. coli O157 were detected as described in Table 1
after homogenizing 25 g of sample in 225 ml appropriate enrichment
broths.