Use of oleic acid to reduce the population of the bacterial flora of poultry skin.

The effect of oleic acid on native bacterial flora of poultry skin was examined. Skin from commercial broiler carcasses was washed once or twice in solutions of 0, 2, 4, 6, 8, or 10% (wt/vol) oleic acid and rinsed in peptone water. Aerobic bacteria, Enterobacteriaceae, Campylobacter, and enterococci in the rinsates were enumerated. Significantly fewer aerobic bacteria, Enterobacteriaceae, Campylobacter, and enterococci were recovered from rinsates of skin washed in oleic acid than from control samples. Additionally, fewer bacteria were recovered from rinsates of skin washed in higher concentrations of oleic acid than from skin washed in lower concentrations of the fatty acid. In most cases, there was no significant difference in the number of bacteria recovered from rinsates of skin washed once or twice in solutions of oleic acid. Washing skin samples twice in 10% solutions of oleic acid significantly reduced the number of aerobic bacteria, Enterobacteriaceae, Campylobacter, and enterococci that remained attached to the skin. Campylobacter sp., Enterococcus faecalis, and Listeria monocytogenes isolates possessed the least resistance to the antibacterial activity of oleic acid in vitro, while Escherichia coli and Pseudomonas aeruginosa showed higher resistance. Enterobacter cloacae, Staphylococcus lentus, and Salmonella Typhimurium had the greatest resistance to the antibacterial activity of oleic acid. Findings indicate that oleic acid reduces the number of bacteria on the skin of processed broilers and that the fatty acid is bactericidal to several spoilage and pathogenic bacteria associated with poultry.