Purpose: To study cooling rates and its impact on microbiological safety of poultry carcasses as affected by aided airflow in carcass internal cavity.
Methods: Two broilers were placed in a pilot air chiller: one used as a control, and the other one connected to a prototype device to aid airflow inside the carcass cavity. The experiment was repeated six times using 0.3, 0.5, 0.7, 1.0, 1.3, and 2.1 m/s inlet airflows to the carcass cavity. Temperatures at eight different locations within each carcass, and operating parameters of the chiller (air velocity, air relative humidity, and air temperature) were collected at 10 s intervals during air-chilling. Experimental data in addition to data obtained from a validated computer model for simulating air-chilling of poultry carcasses were used to study the effect of the aided cavity airflow on chilling rates and estimated growth of Salmonella spp.
Results: Aided airflow in carcass cavity resulted in 20-34% reduction in carcass chilling time (1.2 ± 0.3 h), and 19-72% reduction in estimated growth of Salmonella spp. (0.1 ± 0.04 log CFU/ml). Optimal inlet airflow ranged between 0.3-0.8 m/s depending on carcass size and chiller operating conditions; resulting in less than 30% increase in moisture loss. Higher inlet airflows resulted in significant moisture loss (up to 85% increase), and did not provide additional reductions in chilling times.
Significance: Increasing the airflow inside carcass cavity is a potential method to improve air-chilling rates and microbiological safety of poultry carcasses. Optimal operating parameters for air-chilling of poultry carcasses can be estimated with a computer simulation model available to use at http://foodsafety.unl.edu.