An evaluation of trisodium phosphate, citric acid and lactic acid cloacal wash treatments to reduce Campylobacter, total viable counts (TVC) and total enterobacteriaceae counts (TEC) on broiler carcasses during processing

Abstract

Campylobacetriosis is the most common foodborne bacterial illness in Europe and most cases are associated with the consumption of poultry. Interventions are urgently required to reduce Campylobacter counts on poultry carcasses. While trisodium phosphate (TSP), citric acid (CA) and lactic acid (LA) are effective poultry carcass decontamination treatments, their direct application on carcasses is not permitted. This study examined their effectiveness in killing Campylobacter in cloacal contents before testing their efficacy as cloacal wash treatments immediately before defeathering. In laboratory experiments, fresh broiler cloacal contents inoculated with a 5 strain cocktail of Campylobacter jejuni (3) and Campylobacter coli (2) was treated with TSP (5, 10 & 20% w/v), CA (1, 5 & 10% w/v) and LA (1, 5 & 10% v/v) and surviving cells enumerated after 0, 4 and 10 min on mCCDA. The same chemical treatments were applied as a cloacal wash in a commercial broiler plant using naturally contaminated broiler carcasses. Carcass Campylobacter, TVC (psychrophile and mesophile) and TEC were determined immediately after defeathering and evisceration. TSP (20%, w/v), CA (5 & 10%, w/v) and LA (5 & 10%, w/v) reduced Campylobacter counts in broiler cloacal contents by approximately 2.0–2.5 log10 cfu g−1 after 4 min. However, only an LA (5%, v/v) cloacal wash achieved a significant (P < 0.05) reduction in carcass Campylobacter counts (0.66 log10 cfu cm−2) and this was obtained post evisceration. In general none of the treatments affected psychrophilic or mesophilic TVC with the exception of CA (5 & 10%, w/v), where post-evisceration counts were significantly (P < 0.05) reduced by 0.88 log10 cfu cm−2 and 0.56 log10 cfu cm−2, respectively. None of the treatments significantly reduced TEC. This study provides further data supporting the application of cloacal washing but only as part of an overall package of measures designed to reduce Campylobacter contamination on broiler carcasses during processing.