EFFECTS OF FREEZING ADD THAWING ON POSTMORTEM BIOCHEMICAL-CHANGES IN SCALLOP ADDUCTOR MUSCLE

Effects of freezing, frozen storage, thawing, and cold storage after thawing on post-mortem biochemical changes in scallop adductor muscle were studied. Freezing and frozen storage at -70 degrees C did not affect the post-mortem biochemical changes in scallop adductor muscle. The profile of ATP and its related compounds drastically changed by the thawing procedure: ATP entirely decomposed and AMP accumulated. These changes in the scallop adductor muscle by rapid thawing were smaller than those by slow thawing. The content of octopine increased during thawing, but that of D-lactic acid was unchanged. During cold storage, the changes in the content of ATP and its related compounds, arginine, octopine, and D-lactic acid in thawed muscle were more remarkable than those in unfrozen muscle. AMP was rapidly converted into inosine (HxR) and hypoxhantine (Hx), and the amounts of HxR and Hx exceeded 65% of the total amount of ATP and its related compounds during cold storage after thawing. The degree of accumulation of octopine and D-lactic acid in thawed muscle during cold storage was much larger than in unfrozen muscle. This suggested that activation of glycolysis was induced by the thawing procedure.