(Biomaster, Seward, UK) at maximum speed for 30 s. Drink samples
were homogenised by vortexing. Samples were serially diluted
with sterile saline solution and then plated in triplicate on TSA agar
plates and incubated at 45 C for 5 days. The average number of
colonies was used to calculate the viable cell concentrations. These
were expressed in log10 colony-forming units (CFU) per gram or ml
of solid or liquid food sample, respectively. The detection limit was
10 CFU.