ABSTRACT
Plantaricin BM-1, a typical IIa bacteriocin, is produced by Lactobacillus plantarum BM-1, which can be isolated from a traditionally fermented Chinese meat product. This bacteriocin exhibits perfect thermal stability and broad inhibitory activity against certain foodborne pathogens. In this study, we investigated the effect of plantaricin BM-1 combined with physicochemical treatments (sodium nitrite, heat treatment, ultrahigh pressure technology) on the control of Listeria monocytogenes populations in cooked ham. According to our results, the addition of sodium nitrite (0.075 or 0.15 mg/mL) significantly inhibited the growth of L. monocytogenes in broth, plantaricin BM-1 combined with heat treatment reduced the viable counts of L. monocytogenes more than plantaricin BM-1 alone, and plantaricin BM-1 combined with sodium nitrite and heat treatment had the greatest antibacterial effect in broth. However, the addition of sodium nitrite or heat treatment alone did not inhibit the growth of L. monocytogenes in cooked ham. The combined application of 5,120 arbitrary units per gram (AU/g) plantaricin BM-1 and 0.075 mg/g sodium nitrite reduced L. monocytogenes significantly more effectively (by 1.97 log CFU/g) than application of 5,120 AU/g plantaricin alone. Plantaricin BM-1 application combined with sodium nitrite and heat treatment led to viable counts of L. monocytogenes below the level of detection for 49 days of storage. Moreover, in cooked ham treated with 5,120 AU/g plantaricin BM-1, 0.075 mg/g sodium nitrite, and ultrahigh pressure technology (400 MPa for 5 min), viable counts of L. monocytogenes were reduced by 5.79 log CFU/g compared with control samples at the end of storage. In conclusion, the combination of plantaricin BM-1 with physicochemical treatments had a synergistic inhibitory effect on L. monocytogenes in cooked ham.
In vitro combined effect of oregano essential oil and caprylic acid against Salmonella serovars, Escherichia coli O157:H7, Staphylococcus aureus and Listeria monocytogenes
