The bacterial quality and safety of cold smoked salmon during production and subsequent chilled storage

This study aimed to investigate the bacteriology of cold smoked salmon (CSS), specifically changes in the bacterial quality (total viable count and total Enterobacteriaceae count), the concentration of spoilage bacteria (lactic acid bacteria, hydrogen sulphide producing bacteria and Pseudomonas spp.) and Listeria monocytogenes during salting, washing, smoking, maturation, packaging and chilled storage.

In-plant and laboratory based studies were undertaken. The salt concentration, pH and aw of the commercial product were 3.8% (w/w), 5.9% and 0.95%, respectively while those of the laboratory prepared CSS were 1.1%, 6.2%, and 0.94%. Although the CSS preparation process enhanced microbial quality, as determined by significant (P < 0.05) reductions in indicator and spoilage bacterial counts, L. monocytogenes was unaffected and all bacteria showed significant (P < 0.05) growth during chilled storage of the final product.

The microbial quality and safety of CSS is reliant on using uncontaminated fillets, good hygiene practices and ensuring that the shelf life does not afford L. monocytogenes sufficient time to exceed the 100 cfu g-1 maximum allowed in current EU legislation (EC 2073/2005).