Chicken skins or carcasses inoculated with Salmonella typhimurium were exposed to 0.1 or 0.5% grapefruit seed extracts (DF-100) for 1 or 3 min to evaluate antibacterial activity of DF-100 and its possible application in proultry processing. The numbers of live salmonellae on chicken skins were reduced by 0.8-1.2 logs/㎠ with 0.1% and by 1.6-1.7 logs/㎠ with 0.5% DF-100. Dipping chicken carcasses into 0.5% DF-100 for 3 min reduced salmonellae by 4.3 logs/ carcass. Scanning electron microaoopy showed that DF-100 killed the cells attached but did not detach cells from the skin. No odor or changes in the color of chicken skin were detected after DF-100 treatment.