Effect of the lactic acid bacteria on the control of listerial activity and shelf life of smoked salmon scraps

The potential protective activity of lactic acid bacteria (LAB) from cold smoked salmon scraps was evaluated towards Listeria monocytogenes. Seventy-three LAB strains were isolated and identified by biomolecular methods; Lactobacillus curvatus and Lactobacillus sakei prevailed. Three of the strains tested, identified as L. sakei, profile O, had a significant inhibitory activity against L. monocytogenes ATCC 19115 and clones DUP-1042 and DUP-18596. The evolution of microbial populations and chemical parameters were determined at time intervals to verify the shelf life. Listeria monocytogenes was isolated in half the packages also exceeding the legal limit. The shelf life of scraps was set at 30days. Clonal characterisation of L. monocytogenes was performed by ribotyping. DUP-1042, one of the human pathogen clones, was the most represented pattern. The results suggest further studies aimed at the selection of autochthonous nonspoilage LAB strains as bioprotective agents for cold smoked salmon.