UV FIBEROPTIC PROBE MEASUREMENTS OF CONNECTIVE-TISSUE IN BEEF CORRELATED WITH TASTE PANEL SCORES FOR CHEWINESS

Using Canada Grade A beef, signals from a UV fiber-optic probe for con nective tissues were correlated with panel scores for chewiness. Beef was tested at approximately 12 months (n = 59, carcass weight 293 +/- 37 kg), 17 months (n = 54, 344 +/- 43 kg), and 24 months (n = 54, 352 +/- 46 kg), using rib and round steaks. From 12 to 17 months the incid ence of fluorescence peaks (cm(-1)) increased, probably as layers of p erimysium developed and became detectable. From 17 to 24 months, the i ncidence of fluorescence peaks (cm(-1)) decreased, probably as layers of perimysium were pushed apart by muscle fiber growth. Fluorescence p eaks became wider from 17 to 24 months, probably as layers of perimysi um grew thicker. Fluorescence peaks and smooth intervals between them were converted to numerical indices. At 12, 17 and 24 months, respecti vely, absolute values for the strongest simple correlations of chewine ss with numerical indices were r = 0.32 (P less than or equal to 0.01) , 0.32 (P less than or equal to 0.01), and 0.47 (P less than or equal to 0.0005), for semitendinosus, and 0.31 (P less than or equal to 0.01 ), 0.29 (P less than or equal to 0.05), and 0.18 (NS), for Longissimus dorsi. The corresponding multiple correlations derived from stepwise repressions of indices were R = 0.64, 0.61, and 0.86 for semitendinosu s, and 0.63, 0.47 and 0.65 for Longissimus dorsi.