EFFECTS OF DISINFECTANTS AND SPRAY WASHIN G ON SALMONELLA-ENTERITIDISCONTAMINATION ON THE SHELL SURFACE OF EGGS

The effects of disinfectants and antibacterial chemicals used in food production on Salmonella Enteritidis contamination on the shell surfac e of eggs were examined from the viewpoint of prevention of Salmonella foodborne disease due to intact eggs and egg products (whole egg, egg white, yolk, sugared yolk, salted yolk, etc.). Eggs artificially conta minated with S. Enteritidis in various ways were immersed in a solutio n of sodium hypochlorite, organic acid (fumaric acid or acetic acid) o r trisodium phosphate for 2 to 20 min. After drying, these eggs were s tored at 8 or 25 degrees C for 14 days. S. Enteritidis on the shell su rface was evaluated by direct plating on DHL agar (direct method) and by enrichment with EEM broth (enrichment method) at intervals of 0 (ex amined immediately), 1, 3, 7 and 14 days. The number of eggs contamina ted with S. Enteritidis was decreased effectively by storage for 7 to 14 days at 8 degrees C or 25 degrees C after immersion in 5 similar to 15% trisodium phosphate solution. Eighty to one hundred percent of eg gs examined were free from S. Enteritidis by the direct method, wherea s 65 similar to 87% of eggs were uncontaminated according to the enric hment method. The number of S. Enteritidis on the shell surface of egg s artificially contaminated with the organism in 2% whole eggs and 1% gelatin was decreased effectively by spray washing with fresh water af ter immersion in 1 similar to 2% trisodium phosphate solution. From th ese results, trisodium phosphate may be effective for removing Salmone lla from the shell surface of eggs during washing of eggs in grading a nd packing centers and in egg-product plants.