Bioprotective lactic acid bacteria for fresh ready‑to‑eat salmon: Antilisterial effects without compromising product...

Lactic acid bacteria (LAB) are recognised as candidates for biopreservation because of their antagonistic activities. For industrial applications, however, the performance of individual LAB strains in specific food matrices must be carefully evaluated. This study investigated the biopreservative potential of four LAB strains (Carnobacterium maltaromaticum 35, C. maltaromaticum 55, C. divergens 468, and Leuconostoc gelidum 406) in vacuum-packed fresh ready-to-eat salmon portions stored at 4 ℃ for 22 days. Strain performance was assessed based on their growth properties, effects on the microbial community, inhibition of an inoculated Listeria innocua strain (CCUG 15531), and impacts on chemical (ATP‑degradation products, biogenic amines) and physicochemical (pH, colour, water holding properties) quality of the salmon portions. LAB counts increased in the LAB-inoculated groups from 4.2-4.6 log CFU/g to 7.2-8.6 log CFU/g, and inoculated samples were associated with a lower relative abundance of Photobacterium spp., which dominated the microbial community in control samples. None of the strains adversely affected chemical or physicochemical quality. In the absence of inoculated LAB, L. innocua increased significantly from 3.4 ± 0.1 to 5.0 ± 0.3 log CFU/g, whereas in the presence of C. maltaromaticum 35, no significant proliferation was observed (p = 0.19). These findings indicate that C. maltaromaticum 35 is a promising candidate for improving the safety and microbial stability of ready-to-eat vacuum-packed salmon portions.