The Antilisterial Effect of <i>Latilactobacillus sakei</i> CTC494 in Relation to Dry Fermented Sausage Ingredients and Temperature in Meat Simulation Media

Abstract

Listeria monocytogenes, the causative agent of listeriosis, is a relevant pathogen in dry fermented sausages (DFSs), and the application of antilisterial starter cultures is an effective intervention strategy to control the pathogen during DFS production. The effect of factors in relation to DFS formulation and production, NaCl (0–40 g/L), Mn (0.08–0.32 g/L), glucose (0–40 g/L) and temperature (3–37 °C), on the behaviour of L. monocytogenes when cocultured with Latilactobacillus sakei 23K (non-bacteriocinogenic) and CTC494 (bacteriocinogenic) strains was studied through a central composite design in meat simulation media. L. sakei and L. monocytogenes counts, pH, lactic acid production and bacteriocin activity were determined in mono and coculture. The pH decrease and lactic acid production were highly influenced by glucose, while production of sakacin K by L. sakei CTC494 was observed at moderate (10 and 20 °C), but not at the lowest (3 °C) and highest (37 °C), temperatures. Coculture growth had no effect on the acidification and bacteriocin production but inhibited and inactivated L. monocytogenes when L. sakei 23K entered the early stationary phase and when L. sakei CTC494 produced sakacin K. Optimal conditions for achieving a 5-log units reduction of L. monocytogenes were at 20 °C, 20 g/L of NaCl, 0.20 g/L of Mn and 40 g/L of glucose, those highlighting the importance of considering product formulation and fermentation conditions for bioprotective starter cultures application.

Keywords

• <i>Listeria monocytogenes</i>
• starter culture
• bioprotection
• bacteriocin
• meat fermentation