Analysis of the Bioprotective Potential of Different Lactic Acid Bacteria Against in Cold-Smoked Sea Bass, a New Product Packaged Under Vacuum and Stored at 6 ± 2°C.

The aim of the work was to monitor the presence of in cold-smoked fish products (trout, salmon, and sea bass) marketed in Italy. Cold-smoked sea bass is a new product that has not yet been commercialized and was collected from the production facility. Monitoring data have shown that cold-smoked products can be contaminated by , the presence of which has been highlighted mainly by enrichment culture (presence in 25 g). The isolated were serotyped and belonged mainly to low-virulence serotypes (1/2c), followed by serotypes 1/2a, 1/2b, and 4b. Furthermore, considering the ability of to grow in these products due to their chemical-physical characteristics (pH > 6.0, Aw > 0.97) and long shelf life at 4°C, an additional aim was to verify the activity of different bioprotective starters, including (LAK-23, Sacco srl, Alessandro Manzoni 29/A, 22071 Cadorago, CO, Italy), spp., (SAL 106), and (SAL 211), in cold-smoked sea bass. All starters were bacteriocin producers. For this experiment, smoked sea bass samples were intentionally inoculated with a mixture of three different strains of and of each starter culture. After inoculation, the smoked sea bass were vacuum-packed and stored at 6 ± 2°C for 60 days, simulating the typical abuse storage temperature of markets and home refrigerators. At 0, 15, 30, 45, and 60 days, the sea bass samples were analyzed to evaluate the effectiveness of the starters against . growth was prevented only by the addition of the LAK-23 starter. Indeed, at the end of the shelf life, the amount of observed was similar to that in the inoculum. Consequently, the use of this starter can allow the inclusion of cold-smoked sea bass or smoked fish products in category 1.3 of Regolamento CE 2073/2005, which are products that do not support the growth of this microorganism. Finally, the activity of the LAK-23 starter did not produce an off flavor or off odor in the smoked sea bass.