Combinations of Lyophilized Cell-adsorbed Bacteriocin of Lactobacillus curvatus CWBI-B28 with Organic Acids or Salts to Control Listeria monocytogenes on Smoked Salmon Stored at 4°C in Vacuum Packages

This study evaluated dipping solutions of lyophilized cell-adsorbed bacteriocin (LCaB) of Lactobacillus curvatus CWBI-B28 enriched with or without organic acids or salts to control Listeria monocytogenes introduced artificially on sliced smoked salmon and stored at 4°C for six weeks. Inoculated slices were immersed in a solution of LCaB (8533, 33 UA/g) or in acetic or lactic acid (1, 3, 5 g/100 ml), sodium acetate or diacetate (3, 5 g/100 ml), and potassium benzo­ate or sorbate (3 g/100 ml) for five minutes and stored at 4°C in vacuum pack­ages. Additional slices containing Listeria (10 2 cfu/g) were immersed for five minutes in LCaB solutions enriched with organic acids or salts before storage at 4°C in vacuum packages. The LCaB solution without acid or salt added reduced L. monocytogenes by 1.0 log cfu/g after two weeks. Thereafter, the pathogen multiplied in samples, with growth being faster beyond the third week. LCaB in combination with 3 or 5 g/100 ml acetic acid or sodium diacetate or 3 g/100 ml benzoate. Applied individually, it did not permit growth before five weeks. In untreated (control) smoked salmon, L. monocytogenes increased to achieve 4 log cfu/g at the end of experience.