CORRELATIONS OF MATURE BEEF PALATABILITY WITH OPTICAL PROBING OF RAW MEAT

Organoleptically tested samples of longissimus dorsi (LD) and semitend inosus (ST) muscles from 20 beef carcasses covering a wide chronologic al age were tested with probes for connective tissue fluorescence (365 nm excitation) and for muscle reflectance (400-800 nm). In LD, the nu mber of fluorescence peaks cm(-1) was correlated with toughness (r=0.7 3, P less than or equal to 0.005), whereas the half-width of peaks was the best single predictor for ST (r=0.66, P<0.005). Measurements on i nitial penetration of samples were more useful for predicting meat tou ghness than those made as the probe was withdrawn. With the reflectanc e probe, negative correlations of reflectance with taste intensity wer e detected (for example, r=-0.63, P less than or equal to 0.005 at 420 nm in ST), but stronger correlations of taste with the fluorescence s ignal were detected (for example, r=83, P less than or equal to 0.0005 for peaks cm(-1) measured coaxially). Correlations of the fluorescenc e signal with taste may have been fortuitous, because taste was correl ated with toughness (r=61, P less than or equal to 0.005). However, ST juiciness was correlated with the height of the largest fluorescence peak in a transect (r=0.78, P less than or equal to 0.0005 for coaxial measurements damped at 10 Hz) although no significant correlation of ST juiciness with toughness was detected (r=0.06). These results demon strate the UV probe to be a fairly robust predictor of toughness from connective tissue, working as well on a wide age range of carcasses as it does on a narrow age range. Further development may enable the emp irical prediction of taste, juiciness and hardness.