Bactericidal activity of organic acids against Salmonella typhimurium attached to broiler chicken skin

Abstract

The bactericidal activity of 0.5, 1, 2, 4, and 6% acetic, citric, lactic, malic, mandelic, propionic, or tartaric acid was determined against Salmonella typhimurium that were loosely or firmly attached to broiler chicken skin by using the skin-attachment model. Acid treatments were applied during a simulated chill (0°C/60 min), postprocess dip (23°C for 15 s), or scald (50°C for 2 min). For comparison, activity of the acid treatments when applied under these conditions were also determined against S. typhimurium in aqueous suspension. In general, bactericidal activity (mean reduction log CFU per skin) of all acids increased linearly with increasing concentration in all applications. The bactericidal activity of organic acids depended on concentration and method of application. When compared to freely suspended cells, it is clear that salmonellae both firmly and loosely attached to poultry skin have increased resistance to or are protected from organic acids. In general, concentrations of ≤4% of the acids were required to kill ≤2 log number of cells of S. typhimurium that were attached to broiler skin.