Induced Red Discoloration of Broiler Breast Meat: ii. Effect of Cook Temperature and Freezing

Consumers and customers typically reject fully-cooked chicken that has a red/bloody appearance even if the product is otherwise safe and wholesome. Unfortunately, chicken parts and whole bird products may exhibit this problem on a consistent basis. This study was conducted to intentionally induce a red/bloody appearance in fully-cooked chicken to create a model for studying methods to control this defect. Five trials were conducted using bony marrow (harvested from the interior of epiphyseal end caps) from either fresh femurs (three trials) or frozen femurs (two trials) that were prepared and placed in contact with chopped broiler breast meat. Meat and marrow were packed into glass tubes and heated to one of three endpoint temperatures (74, 79, or 85 C). Five replicate tubes were prepared for each endpoint temperature in each o trial (n = 75). After cooking and immediate cooling, CIE lightness (L*) and redness (a*) was determined for both the surface of the meat adjacent to the bony marrow and the surface of the marrow. The surfaces of the meat from samples prepared with fresh marrow were darker (lower L* values) and redder (higher a* values) than control meat surface samples. Each higher endpoint cook temperature resulted in a significantly (P < 0.05) lighter and less red sample. The meat exposed to frozen marrow was affected by temperature to a lesser extent as lightness increased only at 79 C and redness values did not significantly decrease from 79 o to 85 C. Lightness of the marrow surface was unaffected by freezing or endpoint cook temperature. Marrow o surface redness was decreased as cook temperature increased and freezing appeared to decrease the redness of samples cooked at either 74 or 79 C. Bony marrow was effective at inducing a red, bloody o discoloration in breast meat samples. Higher cook temperatures and freezing femurs (before harvesting marrow) improved meat lightness and redness values, although not to control values.