Control of Listeria monocytogenes in fresh cheese using protective lactic acid bacteria

摘要: Abstract In the past years, there has been a particular focus on application of bacteriocins produced by lactic acid bacteria (LAB) in controlling growth pathogenic foods. The aim this study was to select LAB strains with antimicrobial activity, previously isolated from traditional Azorean artisanal cheese (Pico cheese), order identify those greatest potential reducing Listeria monocytogenes fresh cheese. Eight bacteriocin producer identified as Lactococcus lactis (1) and Enterococcus faecalis (7) were tested. general, bacteriocin-producing presented moderate at refrigeration temperatures (4 °C), increasing one log count three days. They exhibited slow acidification capacity, despite increased production displayed some after 24 h. Bacteriocin activity only detected whey inoculated two strains, but all cheeses made inhibited L. agar diffusion bioassay. No significant differences found overall sensory evaluation non-trained panel 50–52 tasters using isolates adjunct culture cheese, exception strain. To test effect situ against monocytogenes, pasteurized cows' milk artificially contaminated approximately 106 CFU/mL monocytogenes. numbers monitored during storage temperature (4 °C) for up 15 days. All controlled although more effective pathogen counts. After 7 days, reduction 4 units compared positive control. comparison, an increase 4 log CFU/mL over same period, absence LAB. combination producing sp. optimized counts 5 log units 7 days. present work demonstrates that manufacture might contribute preventing undesirable such A blend demonstrated great protective making process.