Enterobacteriaceae counts influenced by different scalding techniques in broiler processing

Abstract In the highly automated processing in broiler abattoirs, some process steps reduce the bacterial counts and inactivate or remove pathogens, while others can lead to an increase. The present study compared the reduction of Enterobacteriaceae counts (EBCs) on breast skin samples in 3 broiler abattoirs using different scalding techniques: (A) conventional immersion scalding (360 s), (B) conventional immersion scalding with thermal treatment of the water (204 s), and (C) the AeroScalder® using hot, humid, saturated air as the scalding medium (360 s in air). In 3 commercial broiler abattoirs in Germany and The Netherlands, a total of 320 breast skin samples per abattoir (before and after scalding, after plucking, before and after chilling) and water samples from the scalders were taken and examined for EBC. After scalding, a significant EBC reduction by 0.7 log was determined only for the conventional immersion scalder (Abbatoir A); the reductions of the other 2 scalders were 0.1 log (Abattoir B) and 0.2 log (Abattoir C) and not statistically significant. The EBCs after scalding differed by up to 0.5 log cfu/g when the 3 scalders were compared, and these counts can be seen as similar. For all 3 abattoirs, the largest EBC reductions (p < 0.001) of 2.8 to 3.6 logs were found after plucking. Compared to the immersion scalders, EBCs in water samples were lowest in those taken from the AeroScalder®. Hence, we conclude that the conventional immersion scalders and the AeroScalder® reduced EBCs in a comparable manner. However, the greatest reductions in EBCs were seen after the plucking steps in the studied abattoirs, not after the scalding as such.