Comparison of beef color stability during display of two muscles between Japanese shorthorn steers and Japanese black steers

The beef color stability during display of two muscles, m. longissimus thoracis and m. sentitendinosus, of Japanese Shorthorn steers (n=14) was compared with that of Japanese Black steers (n=14). The beef color of each carcass was evaluated according to the Japanese Grading Standards at 24 h post mortem. Steak samples from muscles were over-wrapped with PVC film and displayed under fluorescent lights at 4degreesC for 9 days. Metmyoglobin percentages of steak samples were determined at days 0, 3, 6 and 9. The overall grade of beef color of the carcasses of Japanese Shorthorn steers was significantly (p<0.05) lower than that of Japanese Black steers. The metmyoglobin percentages during the display of two muscles of Japanese Shorthorn steers were significantly (p<0.05) lower than those of Japanese Black steers. These results suggested that though beef color evaluation of the carcasses of Japanese Shorthorn steers was lower than that of Japanese Black steers, the beef color stability during the display of the muscle of Japanese Shorthorn steers was higher than that of Japanese Black steers.