and albacore chunk (0.72 log CFU/g). When samples were incubated
at 27 C, growth of bacteria in all 5 types of samples was
slower than at 37 C, indicating 27 C was less optimal than 37 C
for growth of bacteria in these types of samples.
3.4. Growth of S. aureus and enterotoxin production in tuna
incubated at 37 C
Similar to samples without S. aureus inoculation, higher total
bacterial counts were observed in inoculated flake samples than in
inoculated chunk or loin samples (Figs. 3 and 4). All the samples
were found to contain total bacterial counts of >7 log CFU/g after
12 h of holding at 37 C with a strong unpleasant odor, indicating
product spoilage. The total bacteria counts in the samples all
increased to >9 log CFU/g with sticky mucus being observed on
surface after 36 h of incubation at 37 C.
Counts of S. aureus in albacore loin, chunk and flake samples
increased by 3.37, 3.39 and 3.50 log CFU/g, respectively, after 7 h of