Investigation of hygiene aspects during air chilling of poultry carcases using a model rig

1. An experimental rig, designed and built to simulate conditions found in commercial poultry chilling systems, was used to investigate the effects of varying air temperature and chilling duration, and the effect of chlorinat ed water sprays, on the microbial load present on the skin and in the body cavity of freshly eviscerated poultry carcases; deep muscle and skin temper atures were monitored during chilling at three different temperatures. 2. During dry chilling for 2 h, total viable microbe counts (TVC) and count s of coliforms and pseudomonads from the body cavity fell by between half a nd one log unit; smaller reductions were observed in samples from the breas t skin. 3. The situation changed when chlorinated water sprays (50, 100 or 250 ppm available chlorine) were applied for the first hour of chilling; spraying c arcases enhanced the reduction in numbers on the skin; the effect was most pronounced with 250 ppm chlorine; conversely, in the body cavity, the gener al effects of sprays was to increase contamination by up to one log unit. 4. There was no evidence that sprays increased the rate of chilling. 5. When carcases were held overnight in the rig at 11 degreesC after chilli ng, microbe counts on dry-chilled carcases remained stable, but increased o n carcases that had been sprayed with chlorinated water.