Sanitary quality and recovery of microorganisms from frozen breaded raw shrimp

Bacterial counts of 276 samples of shrimp received for processing into frozen breaded raw shrimp were high. About 30% of the samples in this study had bacterial counts of 10⁶ per g or higher. Bacterial populations can be reduced significantly by improved handling during harvesting and storage of shrimp on board of trawlers. Temperature of plate incubation had a marked effect on bacterial recovery. Counts with plate incubation at 7 or 25 C were significantly higher than at 35 C. The number of samples with bacterial counts exceeding 10⁶ per g was three times higher at the lower plate incubation temperatures. Official microbiological methods which use incubation at 35 C have low bacterial recovery and underestimate viable bacterial populations in frozen breaded shrimp. Little relationship existed between aerobic plate counts and quality indices such as coliform and enterococcal counts. Neither Salmonella nor Vibrio parahaemolyticus was isolated from plant samples of frozen breaded shrimp. ..