unpleasant odor, indicating product spoilage. After 36 h of incubation
at 27 C, total plate counts in the five tuna sample types
ranged from 8.3 to 9.6 log CFU/g.
Similar to the observation at 37 C, higher levels of S. aureus were
observed in albacore than in skipjack samples (Tables 5 and 6).
Populations of S. aureus in albacore and skipjack samples increased
by>3 log CFU/g after 10 and 12 h of incubation at 27 C, respectively.
Comparing with 7 and 9 h required for the counts of S. aureus to
increase by 3 log CFU/g in albacore and skipjack samples incubated
at 37 C, an additional 3 h were needed to allow the same increase in
both albacore and skipjack meat when incubated at 27 C.
No enterotoxin was detected in any samples incubated with
enterotoxin-producing S. aureus and incubated at 27 C for 16 h
even when the S. aureus counts were >7.0 log CFU/g in albacore
samples and 6.4 log CFU/g in skipjack samples (Tables 5 and 6).
Enterotoxin was detected in skipjack chunk after 36 h and in other
samples after 24 h of incubation at 27 C. The primary toxins
detected were SEA and SED while SEB was detected only once in
all tuna samples. However, all samples were considered spoiled
based on very unpleasant smell after 16 h of incubation at 27 C.