Hygiene aspects of modern poultry chilling

An evaluation was made of six commercial poultry chilling systems in relati on to factors affecting microbial contamination of carcasses. These systems included water immersion chilling, air chilling and air chilling with evap orative cooling using water sprays. Samples of neck skin and body cavity we re taken from carcasses, together with samples from the chilling environmen t. These were examined for total aerobic mesophilic microbes and counts of presumptive coliform bacteria and Pseudomonas spp. at specific points in th e chilling process. Physical measurements included surface and deep-muscle temperatures of carcasses, water temperatures and chlorine concentrations i n the immersion system and air speed and temperature during air chilling. T he results obtained for water immersion chilling confirmed previous experie nce that the washing effect reduces microbial contamination of carcasses, a lthough initially the numbers of pseudomonads tended to increase. The air c hillers varied in design and mode of operation, but had little overall effe ct on microbial contamination of the skin. When a completely dry process wa s used, microbial numbers were reduced approximately ten-fold in the body c avity. However, the use of water sprays tended to increase contamination of the cavity, while relatively heavy spraying using non-chlorinated water, r esulted in a substantial increase in the numbers of pseudomonads. (C) 2000 Elsevier Science B.V. All rights reserved.