PREDICTING INTRAMUSCULAR FAT IN BEEF LONGISSIMUS MUSCLE FORM SPEED OFSOUND

The ultrasonic A-mode method was investigated for intramuscular fat me asurement of beef. Cubes of meat samples that had different marbling s cores were used as specimens. Ultrasonic speed decreased with increasi ng fat concentration. The correlation coefficient was -.82 (P < .05). Conversely, the correlation coefficient between visual marbling score and fat concentration was .70 (P < .05). Quantitatively, from the firs t derivative of a nonlinear function, it was concluded that the speed decreased at a rate of 2.69 m/(s-% fat) as a function of intramuscular fat. A nonlinear regression model to predict intramuscular fat conten t in beef was developed as follows: percentage of fat concentration = 7132.1574 - 9.1222 x (speed) + 2.91803 x 10(-3) x (speed)(2) (R(2) = . 81). The nonlinear model was capable of predicting intramuscular fat c oncentration with 90% accuracy (> 8% fat) and 76.4% accuracy (< .8% fa t), respectively (P < .001).