Synergistic antimicrobial effect of lactocin AL 705 and nisin combined with organic acid salts against Listeria innocua 7 in broth and a hard cheese

VERDI, M.C.; MELIAN, C.; CASTELLANO, P.; VIGNOLO, G.; BLANCO MASSANI, M.

INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2019

0950-5423

The effectiveness of antimicrobial mixtures against Listeria innocua 7, used as a L. monocytogenes surrogate, was investigated in broth and a food system. Synergistic effects were found for nisin (Nis), potassium sorbate (PS), calcium propionate (CP) and sodium lactate (SL), Nis + PS being the most effective binary mixture that exhibited listericidal activity in broth. To assess the effect of adding lactocin AL705 (AL705) to Nis + organic acid salt combinations, tridimensional isobolograms were generated. Sub‐MIC combinations of the antimicrobials exerted bactericidal activity against L. innocua 7 afterAL705 addition to the binary mixtures. However, when applied on Sardo cheesecontaminated with L. innocua 7 (initial inoculum 4.45 ± 0.06 CFU g ), only Nis + PS + AL705 produced count reductions respect to the control, reaching 3.04 ± 0.35 CFU g counts after 15 days at 15 °C. Ternary combinations containing AL705 showed potential to reduce antimicrobial usages for L. innocua 7 inhibition.