Chlorine Spray Washing to Reduce Bacterial Contamination of Poultry Processing Equipment

About 100 cells of Salmonella/cm2 were inoculated in a thin layer of chicken fat on stainless steel plates. When plates were sprayed at 30 psi for 3.5 sec Salmonella counts were reduced about 50% with tap water alone, 90% with 20 ppm chlorine, and 96% with 40 ppm chlorine. In a commercial plant, the built-in water sprays, which rinse surfaces of the automatic eviscerating machines that come in contact with carcasses, were adjusted to different chlorine levels. When chlorine was not used for 4 hr the total plate count (TPC) of three different sample locations on each of four machines averaged 40,000 bacteria/cm2; when chlorine was not used for only 2 hr TPC averaged 4,000/cm2; when chlorine was supplied at 20 ppm, TPC averaged 400/cm2, when supplied at 40 ppm, TPC averaged 20/cm2, and when supplied at 70 ppm, TPC averaged 3/cm2. Surfaces that came in direct contact with carcasses showed higher TPC than surfaces exposed only to runoff of carcasses with wash water.