ASSESSMENT OF THE COLORMET(TM) FIBER OPTIC PROBE FOR THE EVALUATION OF DARK CUTTING BEEF

A study was conducted to evaluate the capability of the Colormet fiber optic probe (CFOP) to detect dark cutting (DC) beef carcasses which, in Canada, are placed in a specific B4 grade. Carcasses (n = 27) visua lly graded to have DC beef were obtained among a total population of 1 89 carcasses of different grades (B4 included). The day after slaughte r, and after grading procedures, deep muscle fiber optic color measure ments were recorded in the longissimus dorsi along with pH and objecti ve surface color measurements at the 12th rib. Based on discriminant a nalysis, the objective measurements of both color and pH had little or no discriminating power to relocate DC into the B4 category as classi fied by the grader. However, further multivariate analyses (cluster an alysis) showed CFOP measurements to be more discriminating for carcass es with dark-colored beef, compared to Minolta and pH measurements. Th ree clusters were obtained and their mean internal reflectance spectru m had similar shapes and were highly significantly different from each other at all wavelengths (p less than or equal to 0.0001). Therefore, the CFOP lightness coordinate (L value) could be used to determine a cut-off point for commercial application and would be sensitive enoug h to demarcate carcasses with intermediate DC.