Effect of different concentrations of acetic, citric, and propionic acid dipping solutions on bacterial contamination of raw chicken skin.

Bacterial contamination of raw, processed poultry may include spoilage bacteria and foodborne pathogens. We evaluated different combinations of organic acid (OA) wash solutions for their ability to reduce bacterial contamination of raw chicken skin and to inhibit growth of spoilage bacteria and pathogens on skin during refrigerated storage. In experiment 1, raw chicken skin samples were dipped into a suspension of either 10(8) cfu/mL of Salmonella Typhimurium, Escherichia coli O157:H7, or Listeria monocytogenes for 30 s and then immersed in PBS or an OA wash solution mixture of 0.8% citric, 0.8% acetic, and 0.8% propionic acid (at equal wt/vol concentrations) for an additional 30 s. In experiment 2, three different concentrations of the OA wash solution (0.2, 0.4, and 0.6% at equal wt/vol concentrations) were tested against chicken skin samples contaminated with Salmonella Typhimurium. Viable pathogenic bacteria on each skin sample were enumerated after 1 and 24 h of storage at 4°C in both experiments. In experiment 3, skin samples were initially treated on d 1 with PBS or 2 concentrations of the OA mixture (0.4 and 0.8%), and total aerobic bacteria were enumerated during a 2-wk storage period. In all experiments, significant (P < 0.05) differences were observed when skin samples were treated with the OA wash solution and no spoilage organisms were recovered at any given time point, whereas increasing log10 numbers of spoilage organisms were recovered over time in PBS-treated skin samples. These results suggest that 0.2 to 0.8% concentrations of an equal-percentage mixture of this OA combination may reduce pathogens and spoilage organisms and improve food safety properties of raw poultry.