Salmonella on Broiler Carcasses as Affected by Fresh Water Input Rate and Chlorination of Chiller Water

Abstract

Broiler carcasses, each inoculated with about 1000 cells of a marker strain of Salmonella typhimurium, and uninoculated carcasses were prechilled and chilled in a simulated commercial chilling process. For each experiment, fresh water input was either 1.90 liters (0.50 gal) or 0.95 liters (0.25 gal) per carcass, and the chlorine level was 0, 20 or 50 ppm. The rate of fresh water input had no significant effect on either cross-contamination (uninoculated carcasses showing contamination with marker organisms after chilling) or elimination of Salmonella from the inoculated carcasses. Fewer uninoculated carcasses showed marker Salmonella contamination after chilling with 50 ppm of chlorine than 0 ppm, but cross-contamination was not eliminated. Chlorine in the chilling water decreased rapidly due to the effect of organic matter. Fresh water input rate required for chilling broiler chicken carcasses has been 1.91iters I (0.50 gal) per bird since the inception of regulations applied to continuous chilling (20). The U.S. Department of Agriculture has recently published a proposed amendment to allow a reduction in that rate to 0.95 liter (0.25 gal) per carcass, provided the incoming water contains 20 ppm of available chlorine (21). Wesley (23) concluded that the reduction of chiller water input to 0.95 liter (0.25 gal) per broiler carcass had no detrimental effect on the quality of carcasses or chiller water, and would result in substantial savings to the processing industry.