ARS | Publication request: Influence of washing time on residual contamination of carcasses sprayed with lauric acid-potassium hydroxide

Submitted to: International Poultry Forum Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: October 21, 2009
Publication Date: January 24, 2010
Citation: Hinton Jr, A., Cason Jr, J.A., Buhr, R.J., Liljebjelke, K.A. 2010. Influence of washing time on residual contamination of carcasses sprayed with lauric acid-potassium hydroxide [abstract]. International Poultry Forum Proceedings.

Technical Abstract: A series of experiments were conducted to examine reductions in bacterial contamination of broiler carcasses washed for various times in a spray cabinet with a 2% lauric acid (LA)-1% potassium hydroxide (KOH) solution (w/v). Forty eviscerated carcasses and 5 ceca were obtained from the processing line of a commercial poultry processing facility. An inoculated cecal paste was prepared by mixing 5 g of cecal contents with 0.3 mL of a bacterial suspension containing 108 cfu/ml each of antibiotic resistant strains of Escherichia coli, Salmonella Typhimirum, and Campylobacter coli. A 0.1 g portion of the inoculated cecal paste was applied to the skin of each carcass and allowed to dry for 15 min. Inoculated carcasses were then placed into 4 groups of 10 carcasses, and groups were washed for 0, 5, 15, or 30 s at 100 psi (689 kPa) in a spray cabinet with the LA-KOH solution. Washed carcasses were rinsed for 15 s with sterile, deionized water to remove excess LA-KOH before whole carcass rinses were performed for 2 min in 200 mL of sterile phosphate buffered saline. Total plate count bacteria (TPC) and antibiotic resistant E. coli, Salmonella Typhimurium, and C. coli were enumerated in carcass rinsates, and the pH of rinsates was measured. Results indicated that significantly fewer bacteria, from all enumerated groups, were recovered from carcasses washed in LA-KOH for 5 s than from unwashed carcasses. Furthermore, significantly fewer TPC bacteria and Salmonella Typhimirum were recovered from carcasses washed for 15 s than for 5 s, and no C. coli were recovered from carcasses washed for 15 or 30 s. The pH of rinsates from carcasses washed for 0, 5, 15, or 30 s was 7.16, 8.12, 9.05, and 9.44, respectively. Findings indicate that increasing the time that carcasses are spray washed with LA-KOH can significantly decrease carcass contamination and that microbicidal surfactants may deserve consideration as potential sanitizers in poultry processing operations.