Relations between glycolysis and browning of cooked scallop adductor muscle

The relation between glycolysis proceeding in scallop adductor muscle during cooking and browning of cooked muscle was studied. G6P increased rapidly at the beginning of cooking and its maximal accumulation occurred at 45 degrees C followed by F6P and FDP, but their accumulation was low compared with that of G6P. Glucose increased slowly during cooking. These substances disappeared after cooking at 110 degrees C for 90 min except for glucose. Glycogen decreased at the early stage of cooking and thereafter showed a very slow decrease. More than 80% of glycogen still remained even after cooking at 110 degrees C for 90 min. NAD began to decrease after the muscle temperature reached 60 degrees C, and disappeared after cooking at 110 degrees C for 90 min. ATP decreased rapidly at the early stage of cooking and AMP accumulated. Octopine, which is one of the end products of glycolysis in scallop adductor muscle, increased in accordance with decrease of ATP. Glycolysis proceeded very slowly in scallop adductor muscle compared with muscles of fishes. Consequently, sugar phosphates were apt to accumulate especially when scallop adductor muscles were stored at low temperatures or frozen and thawed, and thus the browning of cooked muscle occurred.