Effects of hot water spray and sub-zero saline chilling on bacterial decontamination of broiler carcasses

Abstract

Reduction of Salmonella on poultry carcasses is one way to prevent salmonellosis. The purpose of this research was to evaluate the effects of subzero saline chilling (SSC) with/without hot water spray (HWS) on broiler carcasses prior to chilling for bacterial reduction. Eviscerated broiler carcasses were subjected to water immersion chilling (WIC, 0% NaCl/0.5°C) or SSC (4% NaCl/−2.41°C) with/without prior HWS at 71°C for 1 min. Broiler carcasses in SSC were chilled faster than those in WIC, regardless of HWS. The combination of HWS and SSC resulted in the best reduction of mesophilic aerobic bacteria, Escherichia coli, and total coliforms on the carcasses over the WIC, SSC, and HWS/WIC. No Salmonella was detected on the carcasses in SSC and HWS/SSC while Salmonella positive was observed on the carcasses chilled in WIC and HWS/WIC. A trace of Gram-negative genus was detected on carcasses in HWS/SSC while many other microbiomes were observed on those in WIC, SSC, and HWS/WIC when quantitative microbiota profiles of 16S rRNA gene sequences were evaluated. Based on these results, chilling of broiler carcasses in 4% NaCl/−2.41°C after HWS at 71°C for 1 min significantly reduced carcass chilling time and bacterial contamination over the control chilling.