Submitted to: Journal of Applied Poultry Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/19/2007
Publication Date: 8/24/2007
Citation: Huezo, R., Smith, D.P., Northcutt, J.K., Fletcher, D.L. 2007. Effect of Immersion or Dry Chilling on Broiler Carcass Moisture Retention and Breast Fillet Functionality. Journal of Applied Poultry Research. 16:438-447. Interpretive Summary: Poultry companies in the US are considering chilling poultry carcasses with cold air rather than with the traditional method of immersing carcasses in cold water. A study was conducted to determine if this new chilling method would affect the color of the skin or meat, or would affect how the meat behaves during further processing. Results show that the skin color and appearance was negatively affected by air chilling, so processors that sell whole birds or parts with skin may not want to convert. However, several meat attributes (color, tenderness, and initial yield) were not affected, and yield after cooking actually increased. Therefore, processors producing skinless fillets or further processed and cooked meat may want to consider switching to air chilling.
Technical Abstract: A study was conducted to investigate the effect of chilling method on broiler carcass skin color, carcass moisture retention, and breast fillet quality and functionality. One hundred fifty eviscerated broilers carcasses were removed from a commercial processing line prior to chilling, transported to the laboratory, weighed and chilled by dry air (3.5 m/s, -1.1o C, 150 min) or immersion in ice water (0.6o C, 50 min). Post-chill carcasses were weighed for moisture uptake, individually bagged and held at 4 o C for 24 h. Fillets were deboned, marinated (20% wt:wt, 20 min, 3% salt: 2% STTP) and cooked (steam cooker, 95o C, 15 min), with weights taken at each step. Carcass skin color was measured immediately after chilling and after 24 h. Fillet color was measured on the medial surface before marination and after cooking. Cooked fillets shear values were determined using an Allo-Kramer multiple blade. After 150 min of air chilling, carcasses lost 2.5% of pre-chill weight, and weight loss ranged from 3.5% to 2.2%. Water absorption during immersion averaged 9.3% of the pre-chill weight, but varied widely with a range of 3.4% to 14.7%. Immediately after chilling, Immersion chilled (IC) carcasses were significantly lighter (higher L*), less red (lower a*), and less yellow (lower b*) than air chilled (AC) carcasses. Storage time improved appearance of AC carcasses, but skin color after 24 h of storage was still significantly different for the two chilling methods (P<0.05). Raw and cooked fillet color, fillet marination pick-up, and cooked fillet tenderness were not affected by chilling method (P>0.05). Cook yield for fillets deboned from IC carcasses was significantly lower than fillets deboned from AC carcasses. Results suggest that immersion chilling is better for whole birds and skin-on parts; however, air chilling is acceptable for deboned and further processed items as fillet color, marination yield and tenderness is not affected, and cook yield is improved.