Survival of listeria innocua in salmon following cold-smoke application

The ability of Listeria innocua to survive on salmon fillets during cold smoking in a commercial processing plant was investigated using a central composite rotatable response surface design to examine smoking temperatures in the range of 18 to 30 degrees C and a smoke time from 2 to 14 h. Smoke temperature did not significantly (P < 0.05) reduce counts of L. innocua on the salmon. However, the smoking time had a significant effect on L. innocua. The smoking time was directly related to the reduction in count (R2 = 0.831), and a 3-log cycle reduction in count was observed when the smoking time was 12 h. The reduction in L. innocua levels on the fish was unaffected by the pH, water activity, and salt concentration of the fillet.