Spraying chicken skin with selected chemicals to reduce attached Salmonella typhimurium

Aqueous solutions of 5% and 10% trisodium phosphate (TSP), 0.1% and 0.5% cetylpyridinium chloride (CPC), 1% and 2% lactic acid (LA), and 0.1% and 0.5% grapefruit seed extract (DF-100) were evaluated in prechill spraying for reducing Salmonella typhimurium attached on chicken skins. Chicken skins were inoculated with S. typhimurium and then sprayed with the selected chemical solutions for 30 sec at 206 kPa and 20 degrees C. After chemical spraying, the skins were rinsed by spraying tap water for 30 sec. Each skin was stomached in buffered peptone water (BPW) for 1 min. The stomaching water was then diluted serially, inoculated onto both xylose lysine tergitol (XLT4) agar and Aerobic Plate Count (APC) Petrifilm, and incubated for 24 hr at 37 degrees C. The results showed that the numbers of Salmonella on the chicken skins after the chemical spraying were significantly lower than those without spray (P < 0.05). The CPC reduced Salmonella by 1.5 to 1.9 log10. TSP resulted in a 2.1 to 2.2 log10 reduction of Salmonella and DF-100 produced a 1.6 to 1.8 log10 reduction of Salmonella. The LA had a number of Salmonella with a 2.2 log10 reduction. The 0.5% CPC resulted a significantly greater reduction in Salmonella than 0.1% CPC. There were no significant differences in Salmonella reduction between different concentrations of the other three chemicals.