The effects of a pilot-scale steam decontamination system on the hygiene and sensory quality of chicken carcasses

Abstract Salmonella and Campylobacter represent the two most commonly reported zoonoses in EU and cause a significant health burden. The effects of a prototype steam treatment system (Deconizer) on reduction of aerobic bacteria, Salmonella Enteritidis and Campylobacter jejuni on chicken carcasses were investigated in the present study. In addition, the treated chicken carcasses were subjected to sensory analysis. The system tested is intended to be integrated as part of chicken production lines to give a short steam treatment to the carcasses during processing. Freshly slaughtered eviscerated chicken carcasses were transported from the slaughterhouse to a Pathogen Pilot Plant facility. The chicken carcasses were treated with steam in the Deconizer for 3 s or 5 s at 95 °C or 120 °C. For determination of reduction of aerobic bacteria, the surface of chicken carcasses was sampled at three different places: breast, outer side of leg/thigh and wing on the left side of the carcasses before steam treatment (controls) and on the right side of the carcasses after steam treatment. For investigation of the reduction of S. Enteritidis and C. jejuni, a surface area of 2 × 5 cm2 was inoculated with 20 μl mix of the bacteria strains and spread over 10 cm2 on breasts, legs and wings on the left and right sides. Bacteria were subsequently sampled before steam treatments (left side) and after treatments (right side). The Deconizer steam treatment chamber substantially reduced aerobic bacteria, Salmonella and Campylobacter on chicken carcasses within a few seconds. The reduction was 1.22–3.33 log for aerobic bacteria, 1.36–3.05 log for Salmonella Enteritidis and 0.84–4.32 log for Campylobacter jejuni. Reductions of bacteria varied strongly with sampling place and treatment time. Heat treatments for 5 s gave consistently higher reductions than 3 s at both 95 °C and 120 °C, on both breast, legs and wings, and the reduction on breast was higher than on legs and wings. The method will not impede the speed of poultry processing and gives only marginal sensory changes in the appearance of the carcasses. The method employs no chemicals and can easily be implemented in chicken facilities to enhance food safety.