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Abstract:
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Bacteriological quality of individually quick frozen (IQF) shrimp products produced from aquacultured tiger shrimp
(Penaeus monodon) has been analysed in terms of aerobic plate count (APC), coliforms, Escherichia coli, coagulase-positive
staphylococci, Salmonella, and Listeria monocytogenes. Eight hundred forty-six samples of raw, peeled, and deveined tail-on
(RPTO), 928 samples of cooked, peeled, and deveined tail-on (CPTO), 295 samples of headless, undeveined shell-on (HLSO),
and 141 samples of raw, peeled, and deveined tail-off (RPND) shrimps were analysed for the above bacteriological parameters.
Salmonella was isolated in only one sample of raw, peeled tail-on. Serotyping of the strain revealed that it was S. typhimurium.
While none of the cooked, peeled tail-on shrimp samples exceeded the aerobic plate count (APC) of 105 colony forming units
per gram (cfu/g), 2.5% of raw, peeled, tail-on, 6.4% of raw, peeled tail-off, and 7.5% of headless shell-on shrimp samples
exceeded that level. Coliforms were detected in all the products, though at a low level. Prevalence of coliforms was higher in
headless shell-on (26%) shrimps followed by raw, peeled, and deveined tail-off (19%), raw, peeled tail-on (10%), and cooked,
peeled tail-on (3.8%) shrimps. While none of the cooked, peeled tail-on shrimp samples were positive for coagulase-positive
staphylococci and E. coli, 0.6–1.3% of the raw, peeled tail-on were positive for staphylococci and E. coli, respectively.
Prevalence of staphylococci was highest in raw, peeled tail-off (5%) shrimps and the highest prevalence of E. coli (4.8%) was
noticed in headless shell-on shrimps. L. monocytogenes was not detected in any of the cooked, peeled tail-on shrimps. Overall
results revealed that the plant under investigation had exerted good process control in order to maintain superior bacteriological
quality of their products |