Effects of curing additives on the control ofListeria monocytogenesby lactocin 705 in meat slurry

Abstract

Meat slurry inoculated withListeria monocytogenes(4.00 cfu g−1) was mixed with different levels of curing additives and their influence on the inhibitory effect of lactocin 705 (17,000 AU ml−1) was evaluated at 20°C. Inhibition ofL. monocytogeneswas 1.90 and 1.00 log less in meat slurry with 5 and 7% NaCl than in meat slurry without added sodium chloride. When nitrite and bacteriocin were added together, less nitrite (200 μg g−1) was required to obtain the sameListeriapopulation (3.00 log cfu g−1) as when 800 μg g−1NaNO2was used. However, when compared with lactocin 705 alone, lessListeriainhibition was observed showing also a protective effect of NaNO2. When ascorbic acid and alginate meat binder were assayed in the presence of the bacteriocin, the inhibition ofL. monocytogeneswas less effective, but when sodium lactate (2%) was added to the meat slurry, almost no protective effect was observed. These results indicated that the use of lactocin 705 to controlL. monocytogeneswas less effective in the presence of curing ingredients.