ARS | Publication request: Effects of Broiler Carcass Immersion and Air Chilling on Bacteria Recovery, Carcass Yield and Marination Pick-up and Retention

Submitted to: U.S. Poultry and Egg
Publication Type: Other
Publication Acceptance Date: December 20, 2006
Publication Date: January 22, 2007
Citation: Northcutt, J.K., Smith, D.P., Fletcher, D.L. 2007. Effects of Broiler Carcass Immersion and Air Chilling on Bacteria Recovery, Carcass Yield and Marination Pick-up and Retention. U.S. Poultry and Egg. p. 1-3.

Interpretive Summary: In 2004, the U.S. Poultry & Egg Association funded a project designed to investigate poultry carcass microbiology and quality after traditional chilling (immersion) or chilling using cold air blast (air chilling). When broiler carcasses were immersion chilled using a high volume (16.8 L/kg), more bacteria were removed from the skin surfaces than when a low volume of water (2.1 L/kg) was used. When chiller water was analyzed on a per mL basis, equivalent counts of bacteria were recovered regardless of the volume. In a follow-up study, no difference was found in the numbers of bacteria recovered from carcasses immersion chilled in 3.33 L/kg or 6.67 L/kg. The recovery of bacteria from broiler carcasses after immersion or dry air chilling were compared and found to be similar. Both chilling methods reduced levels of coliforms and Escherichia coli in rinses of carcasses by 0.9 to 1.0 log units, while Campylobacter was reduced by 1.0 to 1.4 log units. Chilling also reduced numbers of Salmonella on carcasses (0.6 to 1.0 log reduction). Skin color for immersion chilled carcasses was lighter, less red and less yellow than air chilled carcasses. After 24 hour of storage, appearance of air chilled carcasses improved, but skin color was still different from immersion chilled carcasses. Air chilled carcasses lost approximately 2.5% of their pre-chill weight, while immersion chilled carcasses gain approximately 9.3% of their pre-chill weight. Raw and cooked fillet color, fillet marination pick-up and cooked fillet tenderness were not affected by chilling method. Results show that immersion and air chilling produce carcasses that are similar from a microbiological and quality aspect, with the exception of carcass skin color.

Technical Abstract: