Effects of bifidocin b and lactococcin r on the growth of Listeria monocytogenes and Bacillus cereus on sterile chicken breast

In the study, the efficacies of bifidocin B and lactococcin R produced by Bifidobacterium bifidum and Lactococcus lactis subsp. cremoris R to control Listeria monocytogenes or Bacillus cereus in irradiated raw chicken breast during storage at 5-8C for 28 days or at 22-25C for 24 h were determined. Each irradiated raw chicken breast was inoculated with 10(6) cfu/g L. monocytogenes or B. cereus. It was found that both bacteriocins were more effective against L. monocytogenes or B. cereus at 5-8C than at 22-25C, and that lactococcin R was more inhibitory than bifidocin B. Challenge study analysis demonstrated that incorporation of bifidocin B or lactococcin R at a level of 1,600 or 3,200 AU/g could effectively inhibit the growth of L. monocytogenes or B. cereus for 3-4 weeks at 5-8C or 6-12 h at 22-25C.