analysis was conducted between 12 and 24 of incubation. However,
these results demonstrate that no enterotoxin was produced in
tuna meat inoculated with five strains of enterotoxin-producing
S. aureus and exposed to 37 C for 12 h. All the samples showed
clear sign of spoilage before enterotoxin was detected.
3.5. Growth of S. aureus and enterotoxin production in tuna
incubated at 27 C
As expected, total plate counts of tuna samples inoculated with
S. aureus and incubated at 27 C increased slower than those
observed at 37 C (Figs. 5 and 6). Total plate counts obtained from
TSA plates incubated at 37 C for 48 h were slightly though not
significantly lower than those obtained from plates incubated at
27 C for 72 h. This result indicates that certain bacteria in the tuna
samples grow better at 27 C than at 37 C. Similar to results obtained
from incubation at 37 C, microbial growth was faster in
flake than in loin and chunk samples. The total bacterial counts
increased to >7 log CFU/g in albacore samples after 16 h and in
skipjack samples after 24 h of holding at 27 C with a strong