The EFSA (European Food Safety Authority) has recently warned of a listeriosis outbreak caused by Listeria monocytogenes in trout and cold smoked salmon that has affected 5 European countries and has caused the death of 5 people.

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.

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.

IRTA, it has been researching about bioconservation strategies to improve food safety and quality for years. It has recently studied the effectiveness of the Lactobacillus sakei CTC494 strain as a biopreservation strategy to minimize the risk associated with the potential contamination of Listeria monocytogenes in ready-to-eat smoked salmon-filled products in cooled conditions.

The team of researchers at IRTA has been able to demonstrate the efficacy of the Lactobacillus sakei CTC494 strain to 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 obtained by IRTA researchers 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 front a microorganism as dangerous as Listeria monocytogenes.

Refference: T. Aymerich, M. Rodríguez, M. Garriga, S. Bover-Cid. Assessment of the bioprotective potential of lactic acid bacteria against Listeria monocytogenes on vacuum-packed cold-smoked salmon stored at 8 °C. Food Microbiology 83 (2019), pp. 64-70  https://doi.org/10.1016/j.fm.2019.04.011

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