The study, by members of Catalonia’s Institute of Agrifood Research & Technology
(IRTA), involved examining the effectiveness of the Lactobacillus sakei CTC494 strain as a biopreservation strategy to minimise the risk associated with the potential contamination of Listeria monocytogenes in ready-to-eat smoked salmon-filled products in cooled conditions.
Biopreservation strategies include the controlled and intentional use of innocuous microorganisms, specifically selected, that prevent the development of undesirable or pathogenic microorganisms. Lactic acid bacteria are present in the microbiota of many foods, including salmon and, in some cases, produce substances with an important antimicrobial activity, so that they can be used as biopreservation agents for the control of pathogens such as Listeria monocytogenes in smoked salmon. These lactic acid bacteria are not harmful to consumers.
The team at IRTA was able to demonstrate the efficacy of the Lactobacillus as a way of completely inhibit the growth of Listeria monocytogenes in vacuum-packed salmon samples kept in cooling conditions for 21 days, independently of the physico-chemical characteristics of the product.
These results, they conclude, “open up new possibilities for the application of Lactobacillus sakei CTC494 as a bioprotective agent against Listeria monocytogenes in smoked salmon and allow for progress in the levels of food safety and protection of consumer health."
The breakthrough follows a recent European Food Safety Authority (EFSA) warning of a listeriosis outbreak caused by Listeria monocytogenes in trout and cold smoked salmon that killed five people in a number of European countries.
Smoked salmon (and smoked trout) are ready-to-eat foods considered to be at risk due to the possibility of being contaminated by the Listeria monocytogenes pathogen and favoring their growth during the product's useful life.
