A chemical assessment of freshness in stored adductor muscle from scallops

The postmortem catabolism of adenosine triphosphate (ATP) in cold-stored adductor muscles from scallops (Zygochlamys patagónica) was studied. Changes in the pH of stored muscles were also studied. The ATP content increased for a short time after death and afterwards decreased up to 24 hr of storage. Thereafter, the nucleotide level remained unchanged up to the end of storage. The ADP content slightly decreased up to 48 hr and after that remained unchanged. The AMP slowly accumulated to around 15% of the total nucleotide concentration when the ATP decreased. Small amounts of IMP were detected in all samples. Conversely, adenosine (Ado) was not detected. Inosine (HxR) increased slightly after 48 hr of storage and hypoxanthine (Hx) increased significantly after 24 hr. The 260/250 absorbance ratio of muscle extracts and the pH of stored muscles fell sharply up to 24 hr and then decreased slowly up to the end of storage. The hypoxanthine concentration and the 260/250 absorbance ratio could be reliable indicators of storage age in adductor muscles from scallops