C. E. Lyon

Evaluation of animal age and muscle type on beef log juice colour and residual GOT activity when cooked to target end-point temperature of 79.4 °C†

The effectiveness of the pink-juice test to determine 79.4u2009°C end-point temperature (EPT) of cooked beef logs was appraised. Logs made from five cuts of meat from three animal age groups were fabricated in triplicate to simulate products received at ports of entry and then cooked to EPTs of 78.0–81.8u2009°C. CIELAB L*, a*, b*, C and hu2009° values of internal surfaces of freshly sliced meat and pressed juices from samples were determined. Sensory ratings were made by six trained panelists to determine intensities of residual red color of the juices. n n n nAnimal age and cut of meat had little effect on the CIELAB color values. Residual red color was apparent in all samples by both sensory and a* values analysis. Sensory ratings did not vary significantly (Pu2005<u20090.05) by animal age or cut of meat. Average values of 3.2 (intensity range, 1–9) corresponded to an EPT slightly greater than 80u2009°C; absence of red color in the juices would therefore indicate an EPT in excess of the target temp of 79.4u2009°C. Residual glutamic-oxaloacetic transaminase activity (GOT) activity, used as a collateral test for EPT, ranged from 482.5 to 1641.8 SFUu2009ml−1 of juice and differed significantly by cut of meat (Pu2005<u20090.05), but not by animal age. n n n n© 1999 Society of Chemical Industry