A Retail Survey of Smoked Ready-to-eat Fish to Determine Their Microbiological Quality

A survey was conducted in the Toronto region in 1988/89 to determine the overall microbiological quality of both hot- and cold-smoked, ready-to-eat fish at the retail level. Of the samples collected, 34 were analyzed immediately after purchase (day 0) and 66 were analyzed at day 0 and after 30 d at 4°C. There was a wide variation in initial aerobic colony count (ACC) values, but most (77%) were under 10⁵ CFU/g; 39% were under 10³ CFU/g. After storage, just over half (56%) the samples had an ACC greater than 10⁷ CFU/g, but some (12%) had an ACC less than 10³ CFU/g. While coliforms were not detected in 70% of samples at day 0, or in 66% after 30 d, four samples initially had over 10³ coliforms per g, and after 30 d, 15 samples had over 10³ coliforms per g. Escherichia coli , Staphylococcus aureus , Salmonella , and Clostridium botulinum were not detected in any sample at either time. The water activity of samples varied greatly; the average water activity was 0.947, and the range was from 0.727 to 0.997 (n=98). Based on the ACC guidelines for cold-smoked fish of the International Commission on Microbiological Specifications for Foods, four samples would have been rejected at day 0, and 37 at day 30.