BACTERICIDAL ACTIVITY OF ORGANIC-ACIDS AGAINST SALMONELLA-TYPHIMURIUMATTACHED TO BROILER CHICKEN SKIN

The bactericidal activity of 0.5, 1, 2, 4, and 6% acetic, citric, lact ic, malic, mandelic, propionic, or tartaric acid was determined agains t Salmonella typhimurium that were loosely or firmly attached to broil er chicken skin by using the skin-attachment model. Acid treatments we re applied during a simulated chill (O degrees min), postprocess dip ( 23 degrees for 15 s), or scald (50 degrees for 2 min). For comparison, activity of the acid treatments when applied under these conditions w ere also determined against S. typhimurium in aqueous suspension. In g eneral, bactericidal activity (mean reduction log CFU per skin) of all acids increased linearly with increasing concentration in all applica tions. The bactericidal activity of organic acids depended on concentr ation and method of application. When compared to freely suspended cel ls, it is clear that salmonellae both firmly and loosely attached to p oultry skin have increased resistance to or are protected from organic acids. In general, concentrations of greater than or equal to 4% of t he acids were required to kill greater than or equal to 2 log number o f cells of S. typhimurium that were attached to broiler skin.