Octopine in Postmortem Adductor Muscle of the Sea Scallop (Placopecten magellanicus)

Abstract

Study of the rate and extent of octopine formation in ice-stored sea scallop meat (Placopecten magellanicus) confirms that it, rather than lactate, is a principal end product of carbohydrate metabolism in this species. Little or no octopine is detectable in fresh muscle dissected from live scallops, but on subsequent iced storage octopine accumulates, with reciprocal decrease in arginine, to maximum levels of about 1% in 6–10 days. An active octopine dehydrogenase, catalyzing the reductive condensation of arginine and pyruvate, was present, and lactic dehydrogenase activity was absent. Octopine accumulation occurs concomitantly with nucleotide degradation (dephosphorylation of adenosine 5′-triphosphate (ATP)). Its formation is linearly related to decline in muscle pH.Octopine production had usually attained its maximum considerably before the point of inedibility was reached; hence, the use of octopine content as an index of quality in scallop meats seems limited to the early postmortem storage period, as confirmation of freshness.