Controlling Listeria monocytogenes in ready-to-eat salmon products using bioprotective cultures of lactic acid bacteria: What hinders the transition from research to industrial application?

Listeria monocytogenes represents a persisting food safety challenge for ready-to-eat (RTE) salmon products, including fresh and mildly processed products such as cold smoked salmon (CSS) or gravlax, urging the need for novel preservation strategies. One promising solution is biopreservation, applying protective cultures of lactic acid bacteria (LAB) or their metabolites as a natural antilisterial agent. Carnobacterium, Leuconostoc and Latilactobacillus are among a variety of LAB naturally present in salmon products. They have been applied in food fermentation processes for decades and execute a variety of antimicrobial mechanisms. Their adaptability to the salmon raw material and the applied processing factors, have made them interesting candidates for biopreservation of such products. However, careful strain selection is required as their antilisterial efficiency and effect on sensory product quality parameters are product depended. In this review, we highlight the recent knowledge about biopreservation of RTE salmon products using bioprotective LAB cultures, focusing on the transition from research to industrial application. Criteria for biopreservation of RTE salmon products, including strain selection, application methods and process adaptations, are discussed. Finally, we discuss that upscaling to industrial applications faces several challenges that must be overcome, such as consumer acceptance, legislation, availability of commercial starter cultures, and robust strategies for handling and applying LAB in a seafood production environment.