Campylobacter, Salmonella and Escherichia coli on broiler carcasses subject to a high pH scald and low pH postpick chlorine dip

Authors: Berrang, Mark; Windham, William; Meinersmann, Richard - Rick

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/1/2011
Publication Date: 3/15/2011
Citation: Berrang, M.E., Windham, W.R., Meinersmann, R.J. 2011. Campylobacter, Salmonella and Escherichia coli on broiler carcasses subject to a high pH scald and low pH postpick chlorine dip. Poultry Science. 90(4):896-900.

Interpretive Summary: Campylobacter and Salmonella are important human pathogens that can be found on poultry and contaminate poultry meat products. Broiler processors strive to develop and test new and innovative means to decontaminate carcasses. During processing, carcasses are subjected to a hot water dip called scalding to loosen the feathers prior to removal. Standard scalding was compared to a high pH scalding to determine if the high pH treatment affects presence of Salmonella and Campylobacter on carcasses. Following scalding, carcasses from both treatments were de-feathered then subjected to a chlorine dip tank. Carcasses were sampled before and after each type of scald and before and after the chlorine dip to determine presence and numbers of Campylobacter and the presence or absence of Salmonella. The high pH scalding treatment was more effective than standard scald to lessen the prevalence of Campylobacter on broiler carcasses. This improvement was maintained through the chlorine dip. In the case of Salmonella, the high pH scald was only marginally effective to lessen prevalence. Furthermore, after the chlorine dip, more carcasses from the high pH scald line had Salmonella than from the standard scald line. Each treatment shows some promise as a means to decontaminate broiler carcasses when used individually; however application would need to be optimized in order for there to be an additive affect of both treatments in series. These data are important as the industry continues to develop methods to reduce food borne pathogens.

Technical Abstract: The objective of this study was to determine the individual and combined effect of a high pH scald and a post pick chlorine dip on bacteria present on broiler carcasses. In each of three replications one flock was sampled at several sites within a commercial broiler processing plant. Carcasses were sampled by whole carcass rinse before and after treated scalding at mean pH 9.89 or control scalding at mean pH 6.88. Other carcasses from the same flock run on both the treated and control scald lines were collected and sampled before and after a chlorine dip tank operated at mean total chlorine level of 83.3 and pH 6.04. Rinses were cultured for numbers of Campylobacter and E. coli and presence or absence of Salmonella. High pH scalding was more effective than standard scald to lessen the prevalence of Campylobacter on broiler carcasses; a lower prevalence was maintained through the post pick chlorine dip tank. The pH of the scald tank made no difference in the numbers of E. coli recovered from broiler carcasses at any tested point on the processing line. High pH scald was only marginally effective to lessen Salmonella prevalence. Furthermore, the carcasses on the high pH scald line were significantly more likely to be positive for Salmonella after the post pick chlorine dip than on the control scald line. Perhaps carry over of high pH scald water rendered the chlorine in the dip tank less effective against Salmonella. Although, there is no evidence that these treatments have an additive affect when used in series, both treatments show promise individually. Perhaps further optimization and increased rinsing between treatments could result in more effective decontamination of broiler carcasses.