THE KINETICS OF COOKED MEAT HEMOPROTEIN FORMATION IN MEAT AND MODEL SYSTEMS

The late of cooked meat haemoprotein formation (measured as the rate o f loss of myoglobin solubility) was found at least initially, to obey first order kinetics in meat, aqueous muscle extracts and mixtures of myoglobin and bovine serum albumin. In meat at 60 degrees C the rate w as dependent on the species, (the pigment was formed significantly fas ter in lamb m. longissimus dorsi than in beef m. longissimus dorsi) an d anatomical location (cooked meat haemoprotein was formed in beef m. 1. dorsi about twice as rapidly as in both beef shin and chuck (should er) muscle of similar pH). The rate of formation was similar in aqueou s muscle extracts to that found in meat and in these systems increased with decreasing pH. The activation energies for all beef systems stud ied were similar and typical of those associated with protein denatura tion (similar to 300 KJ mol(-1)); however, that from lamb appeared to be lower (similar to 200 KJ mol(-1)). The problems of using colour as an inner of temperature reached, either for microbial safety (E. coli 0157:H7 destruction) or quality are discussed in the light of these re sults. (C) 1998 Elsevier Science Ltd. All rights reserved.