Effects of lactic acid and lauricidin on the survival of Listeria monocytogenes, Salmonella enteritidis and Escherichia coli O157:H7 in chicken breast stored at 4°C

lauricidin and lactic acid were evaluated for their effects on growth and survival of Listeria monocytogenes (LSS). Salmonella enteritidis (S552) and Escherichia coli O157:H7 (E19) inoculated onto raw chicken breast. Fresh, raw chicken breasts were purchased immediately after slaughter and transported on ice to the laboratory within 20 min. Each chicken breast was decontaminated by briefly dipping in 70% ethonal and passed through a flame of a Bunsen burner and then allowed to cool. The decontaminated Chicken breast was dipped in TSB broth, at room temperature (25 degrees C) for 15 min, containing approximately log9CFU/ml of L. monocytogenes. S. enteritidis or E. coli O157:H7counts in chicken breast immediately after dipping in TSB broth were in the range of log7-log8 CFU/g. After inoculation, the chicken breasts were kept at room temperature for 20 min to allow attachment. Each inoculated chicken breast (25 degrees) was dipped in 0 (control - sterile water), 0.5%, 1%, 1.5% or 2% of lauricidin (w/v) or lactic acid (v/v) for 10,20 or 30 min and then individually placed in oxygen-permeable polyethylene bags. Breasts were subjected to microbiological analyses after treatment (day 0) and after storage for 2, 5, 7, 10 and 14 d at 4 degrees C. Initial counts of L. monocytogenes. S. enteritidis and E. coli O157:H7, in chicken breast treated with lauricidin decreased by 2.90, 1.31 and 2.27 log CFU/g, respectively lauricidin was more effective in reducing L. monocytogenes population than S. enteridis and E. coli O157: H7 population. Dipping chicken breast in lauricidin for 30 min caused a significant reduction of L. monocytogenes population than S. enteritidis and E.coli O157:H7 population cmpared to 10 and 20 min dipping. Initial L. monocytogenes, S. enteridis and E.coli O157:H7 counts on chicken breast treated with lactic acid decreased by 1.97, 1.71 and 2.59 log CFU/g, respectively. Lactic acid caused a higher reduction in initial S. entiritidis and E. coli O157:H7 counts compared to luaricidin. (c) 2006 Elsevier Ltd. All rights reserved.