047 Inclusion of Bull and Cow Beef in Patty Formulation Results in Persistent Pinking in Cooked Beef

Abstract

To test the effects of bull/cow blend proportions on the color stability of precooked ground beef patties, 9.23 kg of either beef knuckles (K) and/or bull/cow blend (BC) were mixed with 2.11 kg of 50:50 beef trim in 11.34-kg batches of five treatments: 0%BC/100%K (A), 25%BC/75%K (B), 50%BC/50%K (C), 75%BC/25%K (D), and 100%BC/0%K (E) in 6 replicates. Patties (151g) were prepared using an automatic patty machine and measured for fresh color (L*, a*, and b*) after a 30-min bloom. Eighteen patties from each replicate were stored in refrigeration overnight and cooked on a gas-fired, air impingement oven to 71°C, chilled in an ice bath, and six from each replicate were external and internal cooked color were measured on 6 patties from each replicate. Twelve cooked patties were frozen and stored until reheated by either microwave oven, electric griddle, or gas-fired char grill to 71°C, then chilled in an ice bath and measured for cooked color. As the percentage of the BC increased, pH of fresh patties tended to increase (Linear, P = 0.053), and L*, a*, and b* values of fresh patties decreased (Linear P < 0.001). Both the internal and external color of cooked patties became darker (lower L*), less red (lower a*), and less yellow (lower b*) as the proportion of BC increased (Linear P < 0.001) in the ground beef. After reheating, patties with more BC beef had lighter external cooked color (Linear P < 0.001) and lighter (Linear P = 0.028), more red, and more yellow (Linear P < 0.001) internal color. When comparing cooking methods there were no differences in the external color of the patties. However, patties that were recooked in the microwave oven were lighter, more yellow, and had a greater saturation index (P < 0.001) than patties cooked on the electric griddle or gas-fired char grill. The inclusion of BC beef in ground beef formulations resulted in lighter, redder, more yellow cooked color in beef patties even after reheating. It is not clear if this persistent pinking is due to an increase in fresh pH or increased myoglobin concentration in the BC beef.